Resolution of Alphastep.

Hi, labmembers,

I am trying to measure step heights (40~50nm) on a partly etched sample. Can
anyone tell me whether the alphastep could measure such small steps?

Thanks!

Ying

----- Original Message -----
From: "Jim McVittie" <mcvittie@cis.Stanford.EDU>
To: <mihuhou@stanford.edu>
Sent: Thursday, February 28, 2008 9:29 AM
Subject: Re: Gold substrate in Rudolph.

> Ying,
>
> 6328A is not a great place to do measurements on Au since it has a
> transition in this its optical properities in this region. The Wollam will
> give better results since you can change the wavelength. The following
> results are from http://www.luxpop.com/.

Jim
>
> First set of refs:
> At a wavelength of 6328 nm (0.196 eV), the index of refraction of gold is
> n = 5.21, k = 43.82.
>
> Note that for thin films the index can vary depending on deposition
> parameters.
>
> References:
> [1] L. G. Shulz, "The optical constants of silver, gold, copper and
> aluminum. 1) the absorption coefficient k and 2) the index of refraction
> n," J. Opt. Soc. Am. , Vol. 44, No. 5, pp. 357-362 and 362-368,
> [2] M. A. Ordal, L. L. Long, R. J. Bell, S. E. Bell, R. W. Alexander, Jr.,
> and C. A. Ward, "Optical properties of the metals Al, Co, Cu, Au, Fe, Pb,
> Ni, Pd, Pt, Ag, Ti, and W in the infrared and far infrared," Appl. Opt. ,
> Vol. 22, No. 7, 1 April 1983, pp. 1099-1119 (Molutevich et al).
>
> Second set of refs:
> At a wavelength of 6328 nm (0.196 eV), the index of refraction of gold is
> n = 5.635, k = 38.1493.
>
> Note that for thin films the index can vary greatly depending on
> deposition parameters.
> References:
> [1] E. D. Palik, "Handbook of Optical Constants of Solids, " Academic
> Press.
>
>
> On Wed, 27 Feb 2008 mihuhou@stanford.edu wrote:
>
>> Hi, Jim,
>>
>> Can you check up the gold optical information and show me how to use
>> it with Rudolph? I am available tomorrow afternoon.
>>
>> Thanks a lot!
>> Ying
>>
>
> --
> --------------------------------------------------------------
> Jim McVittie, Ph.D. Senior Research Scientist
> Allen Center for Integrated Systems Electrical Engineering
> Stanford University jmcvittie@stanford.edu
> Rm. 336, 330 Serra Mall Fax: (650) 723-4659
> Stanford, CA 94305-4075 Tel: (650) 725-3640
>
>