The Hitachi HL-700F Electron Beam Writer has been here at SNF for many years with a sorted history of up time despite significant efforts made to keep it in operational specification.
In early 2010, after a decided effort by Ted Berg, Hitachi Field Service and myself, we were able to once again bring this tool into operational service and within specifications for performance.
This 30 keV EBL system, writing in 2 mm square field size at 100 MHz speed is capable of writing isolated line features to less than 50 nm and gaps to less than 30 nm with write field and overlay stitching accuracy to within less than 150 nm (mean + 3 sigma). In the past this tool has serviced hundreds of EBL jobs and SNF projects, but with a challenging level of expertise required of the operator, due to its aged computer control interface (VAX VMS) and its general sensitivity to operator mistakes using the command line which often brought the system down for extended periods of time in the past.
In 2010 during its last period of extended up time we had a remarkably successful period of writing on this system with several projects brought in and completed on the tool, many other groups trying out the tool for evaluation for their project needs at no charge, and last but not least hundreds of Waveguides and Gratings, Nano Imprint Lithography Molds, and Process Control Monitor test patterns written to aid in EBL process development in my work here at SNF. There was also some interest from industrial and SU projects working in solar and other 2-D gratings patterns too. The system maintained sub-50 nm lines and for most writes stitching was well within its specifications. These efforts resulted in many tens of centimeters square patterned onto silicon and quartz being successfully writing by the system with good quality.
However none of the outside clients committed to using the tool in earnest for their projects, mainly due to not having their own skilled operators on that system. In one case the group ran out of funds for their project before we could get their custom samples onto the system to write last summer.
In late November 2010 we encountered the loss of several subsystems on the tool after an unusual voltage transient came through the house mains which effected the VAX emulation card functionality, latches in the switching sections in the MD and SD imaging section, and finally loss of the FE-Gun controls and ultimately the loss of emission in the FE-Gun on the system. The final event that resulted in the system being shut down all of this year thus far was the loss of the custom wired Helix cryo-compressor at the January 2011 start up phase.
Due to very limited resources available to the Ebeam Lab in 2011 I have not been able to get the resources to bring this system back up into normal operation, nor to further troubleshoot the sub-systems brought down last November.
This email is to inform you that unless you speak up now and offer us the monies and support we require to bring the system back up that we will desire to retire the HL-700F and will remove the system from the Ebeam Lab at Stanford Nanofabrication Facility by the end of the summer. This will allow Ted Berg and myself to focus our attention on other EBL and Novel Lithography methods without the significant burden that this system has placed on resources here at SNF in the past.
Your comments are invited, please reply to ebeam@snf.stanford.edu
Thank you for your support!
James Conway
Ted Berg
Ebeam Technology Group
40 nm Isolated line in HSQ at the threshold of cross link this material
Isolated 28 nm Dot shot exposure in HSQ slightly over-dosed.
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