Re: Problem p5000etch SNF 2011-05-31 01:27:43: my wafers are stuck inside

No problem found. Unloaded all 7 wafers in auto mode with no problems.

Fwd: Spring Term EE412 Final Presentations, Tuesday, May 31, 4:30 pm

>Date: Fri, 27 May 2011 23:16:27 -0700
>From: Mary Tang <mtang@stanford.edu>
>To: labmembers@snf.stanford.edu
>Subject: Spring Term EE412 Final Presentations, Tuesday, May 31, 4:30 pm
>
>
>Dear Labmembers --
>
>Come and hear the final presentations of this
>term's EE412 projects. (And this term, there are
>projects for
>SNC!)***************************************************************
>
>
>EE412 Final Presentations: Tuesday, May 31, 2011
>
>4:30 pm in the AllenX Auditorium
>
>4:15-4:30 - Pizza (in or near the courtyard)
>
>4:30-4:50 – "AGILE: Axially Graded Index Lens." Nina Vaidya.
>
>Fabrication of thin film graded index lenses to
>concentrate light on solar cells.
>
>4:50-5:10 –"Deposition of metal and dielectric
>films in the Intlvac sputtering system." Vijay Parameshwaran .
>
>This project will describe the calibration and
>development of the Intlvac sputtering system for
>three materials: titanium, silicon dioxide, and
>tungsten. Additionally, the integration of
>these new tools within the SNF will be presented.
>
>5:10-5:30 – "Investigation of process for Metal
>Nitride films using ALD." Suhas Kumar and Adair Gerke.
>
>We investigate the process for deposition of
>metal nitride films (TiN, HfN) using the
>Savannah ALD system. We characterize the films
>to find the cause of many issues nitride films
>have had with the Savannah in the past.
>
>5:30-5:50 – "Mix-and-match: e-beam and optical
>lithography for optical waveguides and gratings." Chia-Ming Chang.
>
>The fabrication of optical waveguides and
>gratings by using JEOL e-beam and ASML.
>
>5:50-6:10 – "Corrosion-Resistant ALD
>Coatings." Joey Doll and Alexandre Haemmerli

Problem p5000etch SNF 2011-05-31 01:27:43: my wafers are stuck inside

Melody E. Grubbs: PhD Defense - Today, May 31st @ 2:30 PM in CISX-101

The Development of Amorphous Gate Metals for Threshold Voltage Variability Reduction in CMOS Devices

Melody E. Grubbs

Department of Materials Science and Engineering

Advisors: Profs. Bruce M. Clemens and Yoshio Nishi
When: Tuesday May 31st 2011 , 2:30 pm (Refreshments at 2:15 pm)
Where: Paul G. Allen Auditorium (CIS-X 101)
http://cis.stanford.edu/misc/directions.html

     Threshold voltage variability due to the polycrystalline nature of current metal gates has been identified as a problem in future generations of complementary metal oxide semiconductor (CMOS) devices. It has also been shown that the work function of these gates can vary by as much as 1 eV depending on the grain orientation. This means that as the gate dimensions become comparable to the metal grain size, the grain orientation distribution (and hence work function distribution) no longer averages out. This causes the threshold voltage to vary from device to device since the threshold voltage is directly related to the gate work function. In fact, work function differences as small as 0.2 eV have been shown to cause significant threshold voltage variation.

     In order to address this variability problem, we have developed amorphous, high temperature-stable, refractory transition metal-metalloid Ta-W-Si-B and Ta-W-Si-C metal gates. The amorphous microstructure of these materials has been shown to be stable at temperatures as high as 1100C. The work functions of these alloys have also been extracted and methods for tuning their work functions will be discussed. Additionally, since Ta-W-Si-C films have been shown to be amorphous and smooth, integrating these alloys into MOS devices may also reduce mobility degradation. Thus, Ta-W-Si-C has been integrated into long channel transistor devices in order to determine whether the effective channel mobility appears to be enhanced with respect to polycrystalline gates. Finally, we will discuss the experiments that have enabled Ta-W-Si-C to be easily integrated into deposition and processing as well as our ongoing collaboration with both Applied Materials and IMEC to integrate Ta-W-Si-C into short channel devices in order to confirm the reduction of threshold variability when compared to conventional polycrystalline metal gates.

ME PhD Oral Examination: Violet Qu (Tuesday, May 31, 10am, CISX-101)

Stanford University Ph.D. Dissertation Defense

Title: "Using a MEMS resonant strain gauge to study thin film stress relaxation"

Violet Qu

Department of Mechanical Engineering

Advisor:  Prof. Thomas W. Kenny

Date:  Tuesday, May 31st, 2011

Time: 10:00 am (Refreshments at 9:45 am)

Location: Paul G. Allen Building 101X auditorium (CISX-101)

Abstract: 

Strain gauges have a wide range of applications. Besides measuring strain, they can be used to make other sensors such as load cells, pressure gauges, accelerometers, and gyroscopes. Of the various strain sensing techniques, a MEMS resonator based approach is particularly attractive because they offer superior sensitivity and resolution. Resonant strain gauges operate on the principle that the resonant frequency of a vibrating structure is a function of the applied strain. After reviewing some state of the art microresonator strain gauges, I will introduce our device -- a double ended tuning fork (DETF) resonator packaged at the wafer level using an epitaxial sealing technology (subsequently called the eSensor). These eSensors have sensitivities of up to 1500 ppm/microstrain, and dynamic strain resolution comparable to state-of-the-art devices (9 nanostrain with 10 kHz bandwidth). However, it is the mid- to long-term measurements where the eSensor really shines, thanks to the unparalleled long-term stability offered by the epi-seal. On the time scale of about a minute, the eSensor has a 0.4 nanostrain resolution. 

With its high sensitivity and resolution, the eSensor is a good candidate for thin film stress relaxation studies. In this part of the talk, I will show how stress changes in a thin film deposited on the outside of the eSensor can be measured. This approach is validated experimentally by using a sputtered platinum (Pt) film to generate a known thermal stress by performing a temperature sweep. The minimum stress change that can be resolved using the eSensor is 0.09 MPa for a 1 micron thick film. 

The last part of the presentation consists of preliminary results from probing the mechanical properties of ALD (atomic layer deposition) alumina films. ALD is a new and fast-growing field. The ALD technique promises to produce films of superior quality than the more conventional thin film deposition methods. Though ALD is finding more and more applications in research as well as manufacturing at lightening pace,  characterization of the films' mechanical properties lags behind. The reason is, in part, because detecting stress signals from films only nanometers thick presents a real challenge to current technologies. Our experimental data show that the eSensor can clearly measure stress changes in ALD alumina films that are 65 to 80 nm thick. I will share interesting discoveries from these first experiments on the time evolution of stress in ALD alumina, and our attempts at understanding them. 

Experience with ProTEK PSB?

Hi,

Has anyone tried lithogrpahy with ProTEK PSB to make an etch mask for
a long Silicon etch? I am thinking of using this process since I need
to pattern the back (unpolished) surface of the wafer for Si etching
and my process also requires me to make a low temperature etch mask.

Thanks.
Arunanshu

Blue sticky tape as a mask during oxide etch

Hello labmembers,

I have previously used blue sticky tape as a mask for oxide etching at
the WbGen.
I now need to run a clean process and was wondering if the blue sticky
tape is compatible with clean processing.
Does anyone know if it is ok to use this tape in a clean process?

Sincerely,
Arunanshu

Comment p5000etch SNF 2011-05-30 10:53:52: All three chambers online!

Joey Doll was able to get chamber A back on line this morning. As a result, all three chambers are online as of Monday morning. He is not certain why the turbo would not fully start yesterday and will today ... but it is now on line.
John

Re: Comment p5000etch SNF 2011-05-30 10:19:58: Ch A back online

Joey Doll was able to get chamber A back on line this morning. As a result, all three chambers are online as of Monday morning. He is not certain why the turbo would not fully start yesterday and will today ... but it is now on line.
John

Re: Comment p5000etch SNF 2011-05-29 13:05:21: Chambers B and C alive ... A still down.

Joey Doll was able to get chamber A back on line this morning. As a result, all three chambers are online as of Monday morning. He is not certain why the turbo would not fully start yesterday and will today ... but it is now on line.
John

Re: Problem p5000etch SNF 2011-05-29 12:50:27: chambers B and C online

Joey Doll was able to get chamber A back on line this morning. As a result, all three chambers are online as of Monday morning. He is not certain why the turbo would not fully start yesterday and will today ... but it is now on line.
John

Re: Problem p5000etch SNF 2011-05-29 12:01:23: only chamber B is working

Joey Doll was able to get chamber A back on line this morning. As a result, all three chambers are online as of Monday morning. He is not certain why the turbo would not fully start yesterday and will today ... but it is now on line.
John

Re: Problem p5000etch SNF 2011-05-29 09:39:44: Computer reset .... but not fully tested following reset.

Joey Doll was able to get chamber A back on line this morning. As a result, all three chambers are online as of Monday morning. He is not certain why the turbo would not fully start yesterday and will today ... but it is now on line.
John

Comment p5000etch SNF 2011-05-30 10:19:58: Ch A back online

i walked by the tool this morning and saw that the Ch A turbo was on. went to vacuum service and was able to bring the chamber online. i ran two wafers w/o any trouble.
yesterday the chamber wanted to initialize the pump / pump down the chamber before coming online (which is what was giving the trouble), but looks like it got through that step overnight somehow.

Password for Computer to view microscope? (next to SVGdev)

Hi All,

Could somebody tell me the password for the computer next to SVGdev
that is used to view the camera attached to the microscope?

Thanks a lot,
Edgar

Comment p5000etch SNF 2011-05-29 13:05:21: Chambers B and C alive ... A still down.

JC Doll was able to restart the turbo and put chamber C back on line. It has not been tested, however, so please run a test wafer to be certain.
Chamber B has been run successfully this morning (Sunday) and appears to be operating properly.
Chamber A is down. If I trace the vacuum lines properly, it does not have a functional vacuum pump and, as a result, will be down until Tuesday when the experts return.
Thanks,
John

Problem p5000etch SNF 2011-05-29 12:50:27: chambers B and C online

i can't bring chamber A online, it faults while checking the ChA purge test pressure rise.

Problem p5000etch SNF 2011-05-29 12:01:23: only chamber B is working

chamber A and C is still at off-line, and I don't know how to enable them.

Problem p5000etch SNF 2011-05-29 09:39:44: Computer reset .... but not fully tested following reset.

I was able to reset the computer and it is now sitting at the login screen. I'm not sure that I know the password to get beyond this point, but I believe that this may be recovered to the point that others can use the machine. Anyone using the machine, should, of course, look very carefully to make sure that the machine is operating properly.
I'm going to clear the shutdown and write this up as a problem.
John

Re: Shutdown p5000etch SNF 2011-05-27 15:22:46: computer error message- parity error

I was able to reset the computer and it is now sitting at the login screen. I'm not sure that I know the password to get beyond this point, but I believe that this may be recovered to the point that others can use the machine. Anyone using the machine, should, of course, look very carefully to make sure that the machine is operating properly.
I'm going to clear the shutdown and write this up as a problem.
John

Spring Term EE412 Final Presentations, Tuesday, May 31, 4:30 pm

Dear Labmembers --  Come and hear the final presentations of this term's EE412 projects. (And this term, there are projects for SNC!)

***************************************************************

EE412 Final Presentations:  Tuesday, May 31, 2011

4:30 pm in the AllenX Auditorium

4:15-4:30 - Pizza (in or near the courtyard)

4:30-4:50 – “AGILE:  Axially Graded Index Lens.”  Nina Vaidya. 

Fabrication of thin film graded index lenses to concentrate light on solar cells.

4:50-5:10 –"Deposition of metal and dielectric films in the Intlvac sputtering system."  Vijay Parameshwaran . 

This project will describe the calibration and development of the Intlvac sputtering system for three materials: titanium, silicon dioxide, and tungsten.  Additionally, the integration of these new tools within the SNF will be presented.

5:10-5:30 – "Investigation of process for Metal Nitride films using ALD."  Suhas Kumar and Adair Gerke.

We investigate the process for deposition of metal nitride films (TiN, HfN) using the Savannah ALD system. We characterize the films to find the cause of many issues nitride films have had with the Savannah in the past.

5:30-5:50 – “Mix-and-match: e-beam and optical lithography for optical waveguides and gratings.”  Chia-Ming Chang.

The fabrication of optical waveguides and gratings by using JEOL e-beam and ASML.

5:50-6:10 – “Corrosion-Resistant ALD Coatings.”  Joey Doll and Alexandre Haemmerli

Shutdown p5000etch SNF 2011-05-27 15:22:46: computer error message- parity error

system need to be reset

ME PhD Oral Examination - Shingo Yoneoka, Tuesday, May 31st, 1:00 pm

University PhD Dissertation Defense

 

"ALD Metal Microbolometer Arrays"

 

Shingo Yoneoka

Department of Mechanical Engineering

 

Advisor: Prof. Thomas W. Kenny

Co-advisor: Prof. Roger T. Howe

 

Tuesday, May 31st, 2011

1:00 pm

(Refreshments served at 12:45 pm)

 

Location: Packard Building, Room 202

http://ee.stanford.edu/directions.php?bld=packard

 

Abstract

 

A bolometer is a device that measures the energy of incident electromagnetic radiation using electrical resistance change. One of the important applications of the bolometer is thermal imaging, which detects radiation in the long-wavelength infrared region (8-14 um). Conventional micromachined bolometers consist of multiple functional layers that optimize their performance. Vanadium oxide (VOx) and amorphous silicon are commonly used as thermistor. Silicon dioxide and silicon nitride are often used as the supporting and absorption layers because of their small thermal conductivity. These functional layers can be replaced by a single metal layer to further improve the thermal properties and simplify the fabrication process. However, this requires a film thickness on the order of nanometers since the impedance of the film must approach that of free space in order to absorb the wavelength of interest.

 

In this talk, we present an uncooled infrared bolometer using a few-nanometer-thick platinum (Pt) film that is formed by atomic layer deposition (ALD). ALD is used to reliably deposit Pt films with less than 10-nm thickness. While Pt has relatively low TCR, it also has low 1/f noise, good linearity, and low hysteresis, making it a good temperature sensing material over all. Incorporating the U-shaped trenches, 50x50 um bolometer pixels and 25x25 um bolometer arrays made of ~12 nm ALD Pt/Al2O3 films are successfully fabricated. The aspect ratio of the freestanding structures fabricated in this process exceeds 4,000, which is much larger than the conventional MEMS devices. The developed process can provide unusual combination of electrical, thermal, and mechanical properties that will be useful for many applications. Having the fabrication technology for ALD-grown freestanding structures, the electrical and thermal conductivities of ALD Pt films of thickness 7.3, 9.8, and 12.1 nm are measured at 50-320K. Conductivity data for the 7.3-nm bridge are reduced by 77.8% (electrical) and 66.3% (thermal) compared to bulk values due to electron scattering at material and grain boundaries. The experimental Lorenz numbers of ALD Pt films exceed bulk values due to phonon conduction. Finally, the characterization results of the fabricated bolometer pixels and arrays are described. The thermal time constant of 50x50 um and 25x25 um bolometer pixels are 1.5 ms and 0.4 ms, respectively, which are about 10 times smaller than conventional VOx bolometers. The noise equivalent temperature difference of the bolometer is 112 mK assuming negligible 1/f noise. The presented bolometer is suitable for low-cost and high-speed thermal imaging applications.

Re: Problem p5000etch SNF 2011-05-26 23:36:32: broken wafer in Ch.C

Re: Shutdown p5000etch SNF 2011-05-27 09:12:03: handling

Mike removed the broken wafer chip,. We adjusted the wafer
handoff from storage elevator to chamber wafer drop, cycled
wafer from cassette elevator to chamber C w/out problem..

Shutdown p5000etch SNF 2011-05-27 09:12:03: handling

removed broken wafers. Looking into handling issues

Problem p5000etch SNF 2011-05-26 23:36:32: broken wafer in Ch.C

Broken wafer in Ch.C. Cannot unload wafers. Wafer is stuck on the loader arm.

MSE PhD Oral Examination: Yi Wei Chen (Wednesday, June 8th @ 3:15 PM in Packard 101)

University PhD Dissertation Defense

Atomic Layer Deposited Metal Oxides for Semiconductors Used in Aqueous Solutions

(Vincent) Yi Wei Chen

Department of Materials Science and Engineering

Advisor: Prof. Paul C. McIntyre

When: Wednesday, June 8th 2011, 03:15 pm (Refreshments at 3:00 pm)
Where: Packard 101
http://campus-map.stanford.edu/index.cfm?ID=04-030

 

            In recent years, atomic layer deposition (ALD) has become a popular technique to deposit ultra-thin films with superior conformality and thickness control. Because of its unique surface adsorption-limited mechanism and the resulting capability of deposition at low temperatures and moderate pressures, ALD has found industrial applications in field effect transistor fabrication and coating of multilayer interconnection metallization.  In this work, I have explored the potential of ALD-grown metal oxide layers in applications beyond typical electronics technologies. In particular, this research has focused on using ALD-grown metal oxides to enhance the performance and stability in aqueous solutions of biomolecular sensors and semiconducting anodes for photoelectrochemical fuel synthesis.

            In the biosensing application, we have replaced the SiO₂ gate dielectric material typically used in high sensitivity bio-field-effect-transistors (bioFET) with high dielectric constant HfO₂. The SiO₂ bioFET gate dielectric suffers from poor stability and non-ideal dielectric response at the very small physical thicknesses required to achieve high sensitivity. ALD-grown HfO₂, on the other hand, is capable of providing high capacitance density with a physically thicker dielectric layer, thanks to its large dielectric constant. With the ALD-HfO₂ gate dielectric, biosensor switching behavior was demonstrated using capacitance-voltage measurements in water, while at the same time maintaining the desired high capacitance. In addition, we have verified bio-functionalization of the HfO₂ film surface with biotin molecules via photoelectron spectroscopy, and detected streptavidin and avidin binding with capacitance-voltage analysis and molecular AFM imaging methods respectively.

            For the solar fuel synthesis, we have studied the behavior of ALD-TiO₂ tunnel oxides that can protect heretofore unstable semiconductors, such as Si, used as photoanodes in water splitting. For several decades, intense research effort has been devoted to identifying an efficient photoelectrochemical cell for oxidizing water under solar illumination.   The resulting hydrogen and oxygen can be used to store energy from the intermittent terrestrial solar resource renewably, using water as a feedstock. However, photoanode materials choices have always been limited because the water oxidation half reaction at the anode surface is highly corrosive and requires large overpotentials. As a result, only oxidation-stable wide bandgap semiconductors such as TiO₂ and Fe₂O₃ have been used as the photoanode.  These photoanodes exhibit poor efficiency, however, because of their large bandgaps. Lower bandgap semiconductors, such as Si, are capable of absorbing solar light much more efficiently, but are easily corroded during water oxidation. In this work, a silicon photoanode was passivated by a thin and pinhole-free layer of ALD-TiO₂ such that efficient light absorption in the Si and the chemical stability of the TiO₂ can be exploited at the same time. This ALD-grown nanocomposite photoanode has been demonstrated to perform water oxidation with low overpotentials, while at the same time maintaining good stability with hours of continuous operation. The tunneling of electronic carriers through the thin ALD-TiO₂, required to sustain high oxidation rates, has also been investigated by varying the TiO₂ thickness.

Reminder: MSE PhD Oral Examination: Jules VanDersarl (Thursday, May 26th, 1:00 pm)

University PhD Dissertation Defense

"Interrogating, manipulating, and controlling nano-bio interfaces"

Jules J. VanDersarl

Department of Materials Science & Engineering

Advisor: Prof. Nicholas A. Melosh

Thursday, May 26th, 2011

1:00 pm 

(Refreshments at 12:45pm)

Location: Paul G. Allen Auditorium (CIS-X 101)

http://campus-map.stanford.edu/index.cfm?ID=04-055

Cells communicate through direct contact and soluble chemical signals.  Mimicking an extracellular environment requires controlling these signals at micron length scales. Integrated circuits make electronic control at these scales trivial, but fluidic control at these length scales requires very different principles. Standard microfluidic devices can finely control flowing fluids, but fluid flow affects cells in a myriad of ways. Alternatively, diffusion based chemical delivery methods tend to be crude, ill defined systems that offer very limited control.

Our lab has developed several techniques that combine the active spatial and temporal control of microfluidic systems with a delivery system that relies purely on diffusion. First, we show a silicon based array of nanoreservoirs underneath the cell culture surface which are used to store and release bioactive molecules. These reservoirs are opened and closed with electrochemical dissolution and deposition at a narrow reservoir opening. Next, we show an adaptation of traditional, elastomer based microfluidics. In these devices the cell culture area is separated from a microfluidic channel located directly underneath the chamber by a nanoporous membrane. The desirable microfluidic properties, including temporal and spatial control, are preserved, while fluidic flow over the cells is eliminated. Finally, we demonstrate a novel "nanostraw" culture surface, which is combined with the previous device to offer fluidic access directly to the cell cytosol, creating a powerful tool with implications for cell delivery and sampling.

burning/hot plate smell near chemical pass through (fiji area)

dear labmembers,
the heaters are baking out for the first time on the fiji.  thus you will smell a burning/hot plate smell around the fiji (in the vicinity of the chemical pass through doors or wbgaas).  this smell will dissipate overnight as the heaters bake out the absorbed moisture.  please contact me if you have any concerns.
j

Re: Problem p5000etch SNF 2011-05-24 13:48:02: CASSETTE A NOT IN CORRECT POSITION WHEN DOOR IS OPENED

This is not a problem. Handler will automatically Home at the start of the recipe.
If the user need cassette to go to the Home position before the starting the recipe, go to the header WAFER > Control Handler > Home all robot axis

Re: Comment p5000etch SNF 2011-05-24 13:47:27: CASSETTE A NOT IN CORRECT POSITION WHEN DOOR IS OPENED

This is not a problem. Handler will automatically Home at the start of the recipe.
If the user need cassette to go to the Home position before the starting the recipe, go to the header WAFER > Control Handler > Home all robot axis

Lost keys

Hi y'all,

Did anyone find a set of key on Tuesday afternoon around 4:00-4:30pm?
Please let me know.

Thanks,
Dinh Ton

Problem p5000etch SNF 2011-05-24 13:48:02: CASSETTE A NOT IN CORRECT POSITION WHEN DOOR IS OPENED

Comment p5000etch SNF 2011-05-24 13:47:27: CASSETTE A NOT IN CORRECT POSITION WHEN DOOR IS OPENED

Re: Query of Interest from lab members working at SNF -- whom would be interested in using BeamPROP software application if we had it here at SNF?

If the goal is to simply calculate the modes and effective indices of ridge waveguide structures, no matter how many layers, there are free alternatives available on the web. A  Matlab-based mode solver was also written by somebody in Prof. James Harris' group. I am sure that BeamProp does a lot more things than this, but maybe not all of these might be required by the majority of users. Our group maintains solvers for diffused waveguides as well as semiconductor-based slab / ridge waveguides.

Carsten

On May 24, 2011, at 10:07 AM, James W. Conway wrote:

Greetings Lab Members and Ebeam Lab Users:

A number of Users working in the Ebeam Lab are working with and fabricating optical waveguides, splitters, and resonators as well as other types of nano-optical Photonic devices.
This email is intended to solicit interest from our Users working in the lab towards acquiring BeamProp software package for our Lab.  The intention would be to split the cost of this application between SNF and another Stanford group for their users.  The application would be maintained on SNF computing equipment in the Ebeam Lab and add to our tool set of CAD and modeling software as we move into the future.

Please lend me your opinion by replying to this email if you are interested or have any comments...

Thank you,

James Conway
Ebeam Technology Group
Stanford Nanofabrication Facility



Example of the software with many thanks from Stephanie Claussen:

<moz-screenshot.png>

_____________________________________

Dipl.-Phys. Carsten Langrock, Ph.D.

Physical Sciences Research Associate

Edward L. Ginzton Laboratory, Rm. 202

Stanford University

348 Via Pueblo Mall

94305 Stanford, CA

Tel. (650) 723-0464

Fax (650) 723-2666

Ginzton Lab Shipping Address:

Astro-Physics Building, Rm. 148

452 Lomita Mall

Ginzton Lab Freight Deliveries:

 491 South Service Road

_____________________________________

Query of Interest from lab members working at SNF -- whom would be interested in using BeamPROP software application if we had it here at SNF?

Greetings Lab Members and Ebeam Lab Users:

A number of Users working in the Ebeam Lab are working with and fabricating optical waveguides, splitters, and resonators as well as other types of nano-optical Photonic devices.
This email is intended to solicit interest from our Users working in the lab towards acquiring BeamProp software package for our Lab.  The intention would be to split the cost of this application between SNF and another Stanford group for their users.  The application would be maintained on SNF computing equipment in the Ebeam Lab and add to our tool set of CAD and modeling software as we move into the future.

Please lend me your opinion by replying to this email if you are interested or have any comments...

Thank you,

James Conway
Ebeam Technology Group
Stanford Nanofabrication Facility



Example of the software with many thanks from Stephanie Claussen:

MSE PhD Oral Examination: Shu Hu (Monday, June 6th @ 10:00 AM in Clark Auditorium)

University PhD Dissertation Defense

Nanoscale Germanium Crystal Growth and Epitaxy Control for Advanced Electronics and Solar Cells

Shu Hu
Department of Materials Science and Engineering

Advisor: Prof. Paul C. McIntyre
When: Monday, June 6th 2011, 10:00 am (Refreshments at 9:45 am)
Where: James H. Clark Center Auditorium
http://campus-map.stanford.edu/index.cfm?ID=07-340

    Semiconductor crystal growth at the nanoscale and integration of different materials systems are central themes of materials research. They enable novel materials processes and device applications, and may shape the landscape of future technologies. A major challenge is growth of high-quality single crystal semiconductors (e.g. Ge) on large-mismatch (e.g. Si) and non-crystalline (e.g. glass) substrates, while managing the thermal constraints of the underlying substrates. As-grown vertical semiconductor nanowires have been demonstrated as sensors, and nanoelectronic and nanophotonic devices. However, little attention has been paid to their unique structural properties: vertical Ge nanowires can be epitaxially grown on (111)-oriented Ge and Si substrates. In my talk, I will focus on nanowire-seeded crystallization and metal-induced crystallization to realize three-dimensional integration and nanostructured solar cells. Fundamental aspects of crystal growth at the nanoscale will be discussed.

Three-dimensional (3-D) device stacking and heterogeneous materials integration can improve the performance and functionality of Si-based electronics. First, I will demonstrate liquid phase epitaxy seeded by Ge nanowires to grow micron-sized single crystal Ge islands on SiO₂. Vertical Ge nanowires can transfer the orientation and perfection of the underlying Si lattice to overlying layers several microns above. Liquid phase epitaxy was found to eliminate random nucleation that competes with epitaxial growth from nanowire seeds. The structure and electronic properties of Ge islands will be discussed. Given a low thermal budget annealing process, this technique can be repeated to build multiple active device layers, a key requirement for the fabrication of densely interconnected 3-D integrated circuits.

Vertical, tapered Ge nanowire arrays have shown enhanced light absorption properties, promising for high-efficiency solar cells. Metal-induced crystallization is a low-temperature crystal growth process for polycrystalline semiconductor deposition on large-area, non-crystalline substrates. Then, I will demonstrate Al-induced layer exchange crystallization to form polycrystalline Ge thin films with micron-sized grains and (111)-preferred orientation at 200°C. The textured thin films can serve as growth templates for aligned nanowire arrays. Imaging nucleation, growth and coalescence of Ge crystal islands allows us to characterize, model and control Ge crystallization kinetics, by tuning the knobs such as nucleation density.

--

Shu Hu, PhD Candidate

Department of Materials Science and Engineering

Stanford University

476 Lomita Mall, Stanford, CA 94305-4045

Solder reflow?

Does anyone know where I could do solder reflow on campus?

Thanks,

Edgar

photodefinable HD8820

Dear labmembers,

Does anyone have experience with HDmicrosystems photodefinable
polyimide HD8820 in SNF? This seems like a good alternative to etching
through the non-photodefinable PI2611 series.

Thanks for any advice or suggestions!

Ben

--
Benjamin Tee
Ph.D Candidate, Electrical Engineering
Stanford University
Cell: 650-704-4300
M.S (EE) Stanford University '07
B.S.E (EE) University of Michigan - Ann Arbor '06
Bao Research Group - http://baogroup.stanford.edu
Address:
381 North South Mall Rm 209
Stanford CA 94305
USA

Re: Problem p5000etch SNF 2011-05-23 08:08:52: wafer missing in Ch.C

Recovered missing wafers. Cycled 8 wafers with no problems.

Problem p5000etch SNF 2011-05-23 08:08:52: wafer missing in Ch.C

1 wafer missing (most likely in Ch.C). Another wafer was also broken, most likely in Ch.C as well.

[epi2] Reservation released from 23 May 2011 2:00pm~12:00am

Sample will not be ready by then. Sorry for using this mailing but it seems I have some trouble of sending it the right mailing list.

Thanks,

Wooshik Jung

PhD Oral Examination: Chong Xie (Tomorrow Mon May 23, 10am, CISX 101)

Nanopillars for cellular interface

Chong Xie

Department of Materials Science and Engineering
Research Advisor: Professor Yi Cui and Professor Bianxiao Cui

May 23^rd (Monday), 2011 @ 10:00 am 
(Refreshments served at 9:45 am)

Location : CISX Auditorium (101X)
http://cis.stanford.edu/misc/directions.html

The small scale of nano-materials make them one of the best man-made candidates to interact with biological systems at subcellular or even molecular level. It has been the focal point of the research interests to interfacing live cells with one dimensional nanostructures, such as nanowires and nanopillars. In this presentation, I will first introduce the general behavior of cell growth and functions in the presence of nanopillars, and then cover two topics of my PhD research: using this unique structure to interface cells both electrically and optically.
1. We achieve improved electric interface between biological cells and solid state device by using arrays of vertically aligned nanopillar electrodes.  Their tight attachment to the cell membrane allows us to acquire intracellular-like action potential signals non-destructively from cultured cardiomyocytes, which is responsible for various important cellular functions. 
2. We demonstrate below-the-diffraction-limit observation volume in vitro and inside live cells by using vertically aligned silicon dioxide nanopillars. With a diameter much smaller than the wavelength of visible light, a transparent silicon dioxide nanopillar embedded in a nontransparent substrate restricts the propagation of light and affords evanescence wave excitation along its vertical surface.  This effect creates highly-confined illumination volume that selectively excites fluorescence molecules in the vicinity of the nanopillar.  We show that this nanopillar illumination can be used for in vitro single molecule detection with high fluorescence background.  In addition, we demonstrate that vertical nanopillars interface tightly with live cells and function as highly localized light sources inside the cell.  Furthermore, chemical modification of the nanopillar surface provides a unique way to locally recruit proteins of interest and simultaneously observe their behavior within the complex, crowded environment of the cell. 

Reminder: EE PhD Oral Examination - Nahid Harjee; Monday, May 23, 2011; 8:00 a.m.

Stanford University Oral Defense – Department of Electrical Engineering

Speaker: Nahid Harjee

Advisor: Prof. Beth L. Pruitt

Co-Advisor: Prof. David Goldhaber-Gordon

Date: Monday, May 23, 2011

Time: 8:00 am (refreshments at 7:45 am)

Location: McCullough 335

http://campus-map.stanford.edu/index.cfm?ID=04-490

Title

Coaxial-Tip Piezoresistive Cantilever Probes for High-Resolution Scanning Gate Microscopy

Abstract

Scanning probe techniques provide a wealth of information about the nanoscale properties of materials and devices, ranging from surface topography to the presence of magnetic domains. In scanning gate microscopy (SGM), the current through a sample is recorded as a sharp, conductive tip that modifies the local electrostatic potential is scanned above the surface. SGM has been used to map current flow, carrier density and potential barriers. However, existing SGM probes produce broad electric fields that limit lateral resolution. In order to apply SGM effectively to nanostructures of recent interest including carbon nanotubes and quantum dots, there is a need for a probe that can produce highly-localized electric fields. This probe must also self-sense topography for tip-sample alignment, as conventional laser-based detection methods can disturb photosensitive samples.

In this talk, I will present a new probe that integrates a coaxial tip, shielding electric fields up to the tip apex, and a piezoresistor to electrically measure cantilever deflection. First, I will discuss the optimization of probe geometry and operating conditions to maximize vertical displacement resolution and investigate the effect of tip shape on lateral resolution. Next, I will describe the development of a process to batch-fabricate the probes and compare two techniques to create sub-micron tip apertures with focused ion beam milling. Finally, I will provide images of the coaxial tip potential profile, obtained using a quantum point contact at cryogenic temperatures, which demonstrate that the coaxial tip can produce significantly narrower perturbations than standard, unshielded tips.

Question about Al etch

Hi all,

 

I want to etch Al on YSZ(Y:ZrO2) substrate. Al is 30nm thick, depositied by sputtering. Does anybody have good recipe to etch Al ?

also, does Al etchant etch Platinum too? I have some Pt on the substrate, and do not want it to be etched by Al etchant...

 

Thank you all!

Jihwan

--
Jihwan An
Ph.D. Candidate
Nanoscale Prototyping Laboratory (NPL)
Department of Mechanical Engineering
Stanford University, CA

cell : 650-862-0414
e-mail: jihwanan@stanford.edu

EE PhD Oral Examination - Rebecca Schaevitz, Thursday, June 2, 2011 at 3:00pm

Stanford University Oral Defense – Department of Electrical Engineering

Speaker: Rebecca K. Schaevitz

Advisor: Prof. David A. B. Miller

Date: Thursday, June 2, 2011

Time: 3:00 pm (refreshments at 2:45 pm)

Location: Allen-X Auditorium (formerly CIS-X Auditorium) - Room 101

Title

A Simple Quantum Well Electroabsorption Calculator for the Germanium Material System

Abstract

Germanium is a unique material that is both CMOS-compatible and can be useful for optoelectronic devices. Leveraging existing CMOS technology, such as Reduced Pressure Chemical Vapor Deposition (RPCVD), Ge quantum wells are grown starting on pure Si substrates. The Ge wells exhibit strong electroabsorption behavior called the quantum-confined Stark effect (QCSE), which was unexpected in this material when it was first discovered at Stanford in 2005. With QCSE and Ge, we have the potential to develop highly CMOS-integrated optoelectronic modulators and bring optical interconnects to the short computer communication distances. However, given the novelty of the material system, we need the tools to design future devices that optimize performance.

In order to create a tool that could allow for future material and device design, we developed SQWEAC, or the Simple Quantum Well Electroabsorption Calculator. SQWEAC effectively models the Ge/SiGe quantum well electroabsorption spectra using simple physical models. The use of simple models drastically speeds up the computation time compared to more common methods like k.p and tight-binding. In this presentation, I will describe SQWEAC and show its effectiveness in modeling current Ge quantum well material. I will also present future modulator device concepts that could meet the strict criteria of power, size, extinction ratio and insertion loss, and allow us to bring optical interconnects to the chip level.

Melody E. Grubbs: PhD Defense - Tuesday, May 31st @ 2:30 PM in CISX-101

The Development of Amorphous Gate Metals for Threshold Voltage Variability Reduction in CMOS Devices

Melody E. Grubbs

Department of Materials Science and Engineering

Advisors: Profs. Bruce M. Clemens and Yoshio Nishi
When: Tuesday May 31st 2011 , 2:30 pm (Refreshments at 2:15 pm)
Where: Paul G. Allen Auditorium (CIS-X 101)
http://cis.stanford.edu/misc/directions.html

     Threshold voltage variability due to the polycrystalline nature of current metal gates has been identified as a problem in future generations of complementary metal oxide semiconductor (CMOS) devices. It has also been shown that the work function of these gates can vary by as much as 1 eV depending on the grain orientation. This means that as the gate dimensions become comparable to the metal grain size, the grain orientation distribution (and hence work function distribution) no longer averages out. This causes the threshold voltage to vary from device to device since the threshold voltage is directly related to the gate work function. In fact, work function differences as small as 0.2 eV have been shown to cause significant threshold voltage variation.

     In order to address this variability problem, we have developed amorphous, high temperature-stable, refractory transition metal-metalloid Ta-W-Si-B and Ta-W-Si-C metal gates. The amorphous microstructure of these materials has been shown to be stable at temperatures as high as 1100C. The work functions of these alloys have also been extracted and methods for tuning their work functions will be discussed. Additionally, since Ta-W-Si-C films have been shown to be amorphous and smooth, integrating these alloys into MOS devices may also reduce mobility degradation. Thus, Ta-W-Si-C has been integrated into long channel transistor devices in order to determine whether the effective channel mobility appears to be enhanced with respect to polycrystalline gates. Finally, we will discuss the experiments that have enabled Ta-W-Si-C to be easily integrated into deposition and processing as well as our ongoing collaboration with both Applied Materials and IMEC to integrate Ta-W-Si-C into short channel devices in order to confirm the reduction of threshold variability when compared to conventional polycrystalline metal gates.

Fwd: IMPORTANT! Ginzton Demo Work, Weekend 05/21 & 05/22

SNF Lab Members:

Following is the notice that there will be significant activity this weekend (5/21 and 5/22) at the Ginzton demolition site to break up much of the remaining foundation.  This activity is currently scheduled from 6 a.m. until about 5 p.m. on both Saturday and Sunday.  Folks using the Raith, AFM, and SEM inspection tools are most likely to be affected by this activity because of vibrations.

Hopefully, this will conclude the worst of the vibrations during the demolition phase.

Thanks,

John

-------- Original Message --------

Subject:	IMPORTANT! Ginzton Demo Work, Weekend 05/21 & 05/22
Date:	Thu, 19 May 2011 07:33:59 -0700
From:	Kenny Green <kennygee@stanford.edu>
To:	snflabmembers@stanford.edu, cis-building@cis.stanford.edu, ee-students@lists.stanford.edu, eefaculty@lists.stanford.edu, ee-adminlist@lists.stanford.edu, ee-academicstaff@lists.stanford.edu
CC:	Meyer, Sandy <skmeyer@stanford.edu>, Weeks, Merry <mweeks@stanford.edu>, Radovic, Svjetlana <sradovic@stanford.edu>

The below notice is from the Project Manager, Svjetlana Radovic.

Please do the needful.

Kenny

Hi All,

 

In order to complete Ginzton ” bunker conditions “(demo of building slab & foundations) we would like to work 2 full days this weekend (Saturday  05/21 & Sunday 05/22) The Contractor would start around 6 a.m. and finish at the late afternoon(around 5:00p.m. )We would still carry on with the next week May of 23^rd  morning work per initial schedule.

This weekend work would be nice to have & would help wrapping up Demo project.

 

Please let me know if you have any questions or concerns. It would be much appreciated if you can contact me ASAP

 

Many thanks on your patience & work w/ us on this project.

 

Regards,

Svjetlana

Re: Comment p5000etch SNF 2011-05-10 13:03:11: Cl2/HBr Shutdown for 5/11

Archived

Lost clean beaker near computer next to EVBond tool

Dear Labmembers,

Last friday I forgot to put away a medium size (fits 4" wafer) beaker
that was in a zipped plastic bag on the table next to the EVBond
(across from SVGcoat).
It had a couple of labels that read "EPERALTA", "DO NOT USE" on it. If
you picked it up please let me know where I can find it, I'd like to
not have to wait until tomorrow to buy a new one.

Thanks,

Edgar

EE PhD Oral Examination - Nahid Harjee, Monday, May 23, 2011; 8:00 a.m.

Stanford University Oral Defense – Department of Electrical Engineering

Speaker: Nahid Harjee

Advisor: Prof. Beth Pruitt

Co-Advisor: Prof. David Goldhaber-Gordon

Date: Monday, May 23, 2011

Time: 8:00 am (refreshments at 7:45 am)

Location: McCullough 335

http://campus-map.stanford.edu/index.cfm?ID=04-490

Title

Coaxial-Tip Piezoresistive Cantilever Probes for High-Resolution Scanning Gate Microscopy

Abstract

Scanning probe techniques provide a wealth of information about the nanoscale properties of materials and devices, ranging from surface topography to the presence of magnetic domains. In scanning gate microscopy (SGM), the current through a sample is recorded as a sharp, conductive tip that modifies the local electrostatic potential is scanned above the surface. SGM has been used to map current flow, carrier density and potential barriers. However, existing SGM probes produce broad electric fields that limit lateral resolution. In order to apply SGM effectively to nanostructures of recent interest including carbon nanotubes and quantum dots, there is a need for a probe that can produce highly-localized electric fields. This probe must also self-sense topography for tip-sample alignment, as conventional laser-based detection methods can disturb photosensitive samples.

In this talk, I will present a new probe that integrates a coaxial tip, shielding electric fields up to the tip apex, and a piezoresistor to electrically measure cantilever deflection. First, I will discuss the optimization of probe geometry and operating conditions to maximize vertical displacement resolution and investigate the effect of tip shape on lateral resolution. Next, I will describe the development of a process to batch-fabricate the probes and compare two techniques to create sub-micron tip apertures with focused ion beam milling. Finally, I will provide images of the coaxial tip potential profile, obtained using a quantum point contact at cryogenic temperatures, which demonstrate that the coaxial tip can produce significantly narrower perturbations than standard, unshielded tips.