MEMORANDUM

To: Katalin Voros, Operations Manager

From: Kim Chan, Assistant Development Engineer

Subject: 2007 Year-End Report

Date: 18 January 2008

cc: Sia Parsa, Professor Andy Neureuther

This is a summary of the activities and projects that I was involved during 2007

I. SEMICONDUCTOR PROCESSING

I have been working on special photoresist and lithography projects with the Advanced Lithography Group.

• Thinned CGR-2205 resist with PGMEA, spun coat wafers at various speed, baked, measured thickness and R. I. Chose to spin coat 1:3 CGR-2205 resist and ARC-600 anti-reflective coating on wafers, baked, test exposed a wafer on ASML stepper, and developed it for Marshal.
• Transferred the 555A etched oxide sem picture files to Marshal. After Marshal did the EBL, I inspected the cgr resist patterns under the microscope, took LEO SEM pictures on cgr and zep resist patterns and printed some cgr resist patterned pictures for Marshal. Measured oxide and zep resist thicknesses on 3” wafer, bonded oxide/zep 3” wafer on 6” silicon wafer with cool grease, baked, put under vacuum, etched oxide in centura-mxp, measured oxide and zep resist thicknesses, debonded, cleaned wafer and took sem pictures for Marshal. Found zep resist didn’t get clean in piranha bath, but needed scrubbing in acetone and then piranha clean again. Took oxide pattern sem pictures on LEO again after cleaning the zep resist and transferred sem picture files to Marshal. Checked oxide etch information and etch time, zep resist information and sent them to Marshal. Printed zep overview sem pictures, took more zep sem pictures, printed and sent them to Marshal for shotnoise experimental analysis.
• Grew 300A oxide on wafers, measured oxide thickness on nanoduv and Rudolph ellipsometer. After Marshal did the EBL, I inspected the thin oxide, pmma and cgr resist EBL patterned resist under the microscope and marked the wafers for sem work. Took sem pictures on pmma, cgr, krs and zep EBL patterned resist wafers for Marshal. Bonded 3” cgr, pmma, krs and zep resist patterned oxide wafers on 6” Si wafers with cool grease, baked, measured oxide thickness and put under vacuum. Etched oxide on cgr, pmma, krs and zep EBL patterned wafers in centura-mxp, measured oxide thickness, debonded, cleaned wafers, took sem pictures and sent them to Marshal for shotnoise experimental analysis.
• Looked for missing SPIE 04 mask.

I have been working on special projects for the Microlab process group.

• Cleaned and lubricated GCA wafer stepper 2 and 6 stage rails, cleaned and lubricated GCA pattern generator stage rails, and made masks for the Microlab while Marilyn Kushner was on vacation.
• Grew oxide, deposited PECVD oxide, ran the lithography process, etched oxide in centura-mxp and etched the silicon (pocket) wafers in TMAH and centura-dps for the RZE, Inc. in order to produce pinhole free, 482 µm to 508 µm deep and 4” circular pocket on 6” wafers. First, started process with standard I-line resist litho process on 6” oxide test and prime wafers, exposed on ksaligner, etched oxide in centura-mxp, etched silicon pocket in TMAH etchant and measured pocket depth. Found circular shape changed to octagonal shape on silicon pocket, pocket was too small to fit 4” wafers and had pinholes on pocket. Second, tried SPR-220 resist litho process on 6” oxide wafers, exposed on ksaligner and etched oxide in centura-mxp, partly etched silicon in centura-dps, finished etching the silicon pocket in TMAH etchant and measured pocket depth. Found SPR-220 resist popped off the wafer edge, sputtered onto the pocket area and prevented some oxide spots being etched. Also found SPR-220 resist produced fine hairline cracks on oxide area during centura etch. These fine hairline cracks showed up on the oxide area after TMAH etch. Third, tried 2 µm I-line resist and S1818 resist litho process on 5 µm oxide wafers, uvbake baked S1818 resist, etched oxide in centura-mxp, partly etched silicon in centura-dps, TMAH etchant and measured pocket depth. Found wafer edges were thin, ragged and fragile after TMAH etch. Fourth, tried SPR-220 resist litho process on 6.35 µm oxide 6” wafers, exposed on ksaligner, hardbake some wafers for 15 hours and more, uvbake one wafer 20 times with the “flash” recipes, etched oxide in centura-mxp and etched silicon pocket in centura-dps. Found SPR-220 resist didn’t hold up during the deep silicon etch step. Fifth, tried 100 µm negative sheet resist litho process on 6.35 µm oxide 6” wafers, used a 4” silicon wafer as a mask to expose pocket pattern on ksaligner, etched oxide in centura-mxp, partly etched silicon in centura-dps and finished the silicon pocket etch in TMAH etchant. Found silicon pocket was too small by using a 4” wafer as the mask. Sixth, tried 100 µm negative sheet resist litho process on 6.35 µm oxide 6” wafers, used a 4” silicon wafer as a mask to expose pocket pattern on ksaligner, etched oxide in centura-mxp and finished the silicon pocket etch in centura-dps. Found using 4” wafer as a mask, then the silicon pocket turned out too small to fit a 4” wafer. Seventh, asked machine shop to make 101.5 mm, 101 mm, 100.5 mm disks and 102 mm ring metal mask set for repeating the pocket wafer process with 100 µm negative sheet resist litho process on 6.35 µm PECVD oxide and 2.35 µm thermal oxide 6” wafers, used a 4” silicon wafer as a mask to expose pocket pattern on ksaligner, etched oxide in centura-mxp, finished the silicon pocket etch in centura-dps and grew oxide to strength the pocket wafers as the final step of this process. Finally, 101 mm and 100.5 mm disk masks produced the best fit for 4” wafers in the 6” pocket wafers. Greg Mullins from RZE, Inc. picked up three 100.5 mm masked pocket wafers.
• Cleaned and tested parylene system until it worked well. Cleaned S. S. L. voltage multiplier stack in p-therm, prepared parylene adhesion promoter and cleaned voltage multiplier stack in it. Deposited 52 grams parylene-c and measured the thickness for Bruce Dalen and Peter Berg from Space Sciences Laboratory.
• Collected PMMA process information, called Microchem Co. to check process information, decided on process procedure, got price quote on PMMA resist and PMMA Remover PG, calculated material and process cost. Confirmed ETR proposal, spun PMMA resist at various spin speed to get the correct thickness, designed mask layout, ran ebl exposure tests, exposed patterns on PMMA resist with jeol107 sem at 18 KV and took sem pictures on the LEO sem for Dr. Yehiel from KLA-Tencor. The following are a few sem pictures to show the comparison of the standard exposures and half dose/full dose exposures:

• Bonded Si to Si wafers with cool grease for U. C. Davis a few times.
• Ran contact angle measurement ETR on kruss.
• Assisted Rosanna Cambie to coat AR3-600 anti-reflective coating, UV210 resist, ran FEM, exposed Si and SOI wafers on ASML stepper, developed and inspected them.
• Operated the LEO SEM for Danny Xiong, took sem pictures from AMAT and sent him the sem pictures.
• Collaborated with Jimmy and Marilyn and made 65 Lam show wafers.
• Monitored the phosphoric acid bath level on sink7 after the leak was fixed. Compared phosphoric acid bath temperature reading to an external temperature thermometer. Monitored H2O drips to maintain acid level. Checked nitride etch rate before and after phosphoric acid evaporate.
• Showed Al Briggs how to install the syringe properly on the Kruss system. Searched the websites for syringe information, checked broken syringe information, related the information to Al and tested the Kruss after it was fixed.
• Assisted a lab member to swap wafer chuck parts on the Canon aligner, tried to focus his sample on the aligner and went to machine shop for proper wafer chuck screws.
• Gathered wafer chuck dimension and vacuum grooves information on spinner1 and svgcoat3, took pictures of wafer chucks and sent information to Dr. Y. Gotkis from KLA-Tencor.
• Tried out new software for matrix asher.

Processing involved many silicon equipment and analytical instruments in the Microlab. This year I learned how to use the centura-dps system, flash process on uvbake system and negative sheet resist process. Attended the wafersaw training session and watched how to deposit FOTS film on amst system.

II. EQUIPMENT & PROCESS MAINTENANCE

Equipment Maintenance

• Rinsed I-line resist line on svgcoat6 with acetone, rinsed resist bottle with acetone, re-installed the bottle with acetone, primed the line with acetone and kept the line soaking in acetone.
• Ran image quality control and illumination uniformity tests on the ASML stepper.
• Tried to solve the ASML stepper problems such as parameter out of range and lens temperature errors.
• Ran wafers to test the ASML stepper when there was a problem reported such as reticle reading problem.
• Cleared the Asyst smif pod loading and unloading problem.
• Worked with Rite Track serviceman to see if we can resolve the resist coating defect problem on svgcoat1 and svgcoat2.
• Checked nanoduv reported problem.
• Checked and cleared svgcoat6 and svgdev6 problems when needed.
• Checked and corrected program recipes to solve problems on svgcoat1, svgcoat2, svgcoat3 and svgdev.
• Replaced I-line, G-line and SPR 220-7.0 photoresists on svgcoat1/2, SPR-220-7.0 photoresist on svgcoat3, I-line and UV210 photoresists on svgcoat6 and primed the photoresist lines.
• Tried to solve I-line resist pinhole problem after dispensing on svgcoat3.
• Assisted David Lo to test svgdev6.
• Refilled water in the chiller for the svgdev6 when needed.
• Disposed resist waste and replaced new container on svgcoat6.
• Disposed resist waste from 432c sink.
• Removed stuck and broken wafers in Matrix chamber, restarted the matrix asher, loaded recipe, reset heater and tested it
• Tried to solve LEO sem focus problem and no signal input error.
• Assisted staff on Disco saw and wafersaw.
• Assisted LEO sem service representatives and checked LEO sem status when they were working on it.
• Checked and cleared gcaws6 problems such as removed stuck reticle, stage time out error, RMS, Aldn, ACS, floppy drive, air pressure, light low and auto-focus failure problems on gcaws6 when possible.
• Tested Sopra ellipsometer after the software upgrade. Checked Sopra ellipsometer log in and noise measurement problems and measured thin oxide thickness on wafer.
• Checked Quintel aligner problem and cleared it. Checked jitter problem and related the problem to Phil until it was fixed.
• Test vacuum problems on parylene system and followed through until it was fixed.
• Checked sink3, sink5, sink7 and svgcoat3 reported problems.
• Found draining problem on sink7 bath and process codes changed. Changed process codes back to the original codes. Monitored the phosphoric acid bath level after the valve was fixed.
• Assisted Changrui on gcaws6 while he was checking on how to back up the software in the system. Arranged the hard drive back up dates with Evan and Changrui. Labeled the wire connections to gcaws2 hard drive and gcaws6 Micro DFAS hard drive. Removed gcaws2 hard drive and gave it to Changrui to clone. Tested gcaws2 and gcaws6 operations after the hard drives were cloned.
• Tried to assist when jeol107 sample holder was dropped into the jeol107 chamber.
• Cleaned lab, restocked gowns and etc. for lab tour.
• Restocked aluminum foil and cool grease in Y1.
• Tested vacuum on spinner1.

Process Maintenance

I have been responsible to maintain general photolithography processes for the Advanced Photolithography Group. This involved the following:

• Recycled used 6” wafers.
• Piranha cleaned beakers, graduated cylinders and small brown bottles for mixing resists.
• Cleaned individual wafer holders and labeled them to store 3” wafers for Marshal.
• Ran focus tests on the asml stepper.
• Grew oxide, measured oxide and resist thickness on nanoduv & Rudolph elllipsometer on wafers.
• HMDS primed, coated resists, exposed wafers, PEB, developed and inspected them.
• Inspected wafers on the uvscope, took pictures on the uvscope and the LEO SEM when needed.
• Checked and informed DUV group on process data, equipment information and equipment status.
• Looked up notes on flattened mask3 C. D. sizes, thin apex-e & thin cgr-2205 resist line width results for Marshal.

I have been responsible to maintain part of the general photolithography processes for the Microlab and the process group. This involved the following:

• Monitored UV210 photoresist uniformity and thickness from svgcoat6.
• Monitored Eo and illumination uniformity of ASML stepper using UV210 photoresist.
• Recycled test, flat and ultra-flat silicon wafers to be used on the GCAWS6 and ASML stepper.
• Cleaned 6” dummy wafers for svgcoat3, svgcoat6, svgdev6 and ASML stepper.
• Prepared photoresist coated wafers for ASML stepper field servicemen and the process group.
• Refilled developers on svgdev6, EBR and HMDS on svgcoat6 when I see they are low. Restocked EBR in the lobby chemical cabinet when it was reported out
• Cleaned and dehydration baked wafers for processing.
• HMDS primed, coated resists, exposed wafers, PEB, developed and inspected them.
• Monitored the photoresist inventory on 6” wafer track, labeled DUV photoresists and stored DUV resists and AR3-600 antiflective coating in refrigerators.
• Assisted lab members in programming on the svgcoats and coating ARC-600.
• Sorted and marked 6” dummy wafers for svgcoat3, svgcoat6, svgdev6 and ASML stepper.
• Set up LEO sem accounts for qualify users.
• Restocked gloves, texwipes and printer paper in the LEO room when I see they are low.
• Informed Susan to order UV210-0.6 resist when it is low.
• Ran F/E matrix, system focus, microscope rotation, baseline tests and made corrections on gcaws6.
• Tested programs on aptchrome and asked Tom to modify them.
• Refilled developer in aptchrome.
• Tested emulsion exposure problem on gcapg. Tried the emulsion mask swapping procedure as suggested by Dick Zegra from RZE, Inc., but was unsuccessful in solving this focus problem.
• Cleaned gcaws6 FEM mask and svgcoat6 transfer stations.
• Checked SSH transfer client operation and file saving commands on kruss system.
• Checked the resist lift-off procedure and searched for usaf mask information as requested.
• Assisted Yi Du and Linjie Zhou from U. C. Davis on the cool grease bonding process.
• Assisted Marilyn on working a show wafer for a retiring professor.
• Transferred a little SPR-220 resist from svgcoat1 and svgcoat2 to a dropper bottle for a lab member. Transferred some SPR-220 resist from svgcoat1 and svgcoat2 to svgcoat3.
• Advised Anita Pongracz to filter the AR3-600 anti-reflective coating when she had granular problem.
• Assisted Anita Pongracz to mix 100:1 HF in sink7.
• Showed Antal how to set up EKC-270 resist stripper bath.
• Showed a lab member how to expose wafers on ksaligner manually.
• Showed lab members how to run FEM on gcaws6.
• Added EBR program on svgcoat3.
• Checked spin speed and spin time on srdsink8 and looked for SVC-14 resist stripper as requested.
• Checked Tystar13 and vacoven information for a lab member.
• Transferred Design CAD file to a lab member.
• Cleaned transfer boxes for sink5, brown bottles and labware.

III. INSTRUCTION & DOCUMENTATION

Instruction

• Instructed and qualified researchers on equipment operation and fabrication procedures when necessary.
• Showed staff how to use sink3, gcaws6 and LEO S.E.M.
• Gave lab tours for monthly orientation when needed.
• Assisted and showed a few lab members how to use the

- Wafer stepper 2 & 6

- Kruss Contact Angle Measurement System

- LEO S.E.M.

- Matrix asher

- Memscope

- Nanoduv Microspectrophotometer

- Svgcoat6 and svgdev6

- Sink432A, sink432C and sink3

- Sopra ellipsometer

- UVScope

- Vacoven

• Qualified lab members on the operation of the

- Canon projection aligner

- GCA wafer stepper 6

- Headway spinner

- Hummer sputter system

- Jeol107 sem

- Kruss Contact Angle Measurement System

- LEO sem

- Matrix asher

- Nanoduv

- Nanospec

- Primeoven

- Quintel aligner

- Sinkcmp spinner

- Sinks

- Sopra ellipsometer

- SVG coat and develop systems

- Technics-c asher

- UVScope

- Vacoven

- YES prime oven

Documentation

• Wrote daily reports to Professor Andy Neureuther.
• Wrote weekly reports to Sia Parsa for four months.
• Wrote cmpsink report and mask clean chapter manual.
• Revised process module 10 to 14, canon, gcaws6, heatpulse1 & 2, kruss, svgcoat1, svgcoat2, svgcoat3, svgcoat6 and svgdev chapter manuals, gcaws2 & gcaws6 written quizzes, svgcoat3, svgcoat6 and svgdev6 posted signs.
• Graded asiq, cpa, disco, gcaws2, gcaws6, jeol107 SEM, lam1-3, LEO SEM, Quintel aligner, svgcoat6, svgdev6, svgdev, sinks, wafersaw and westbond lab quizzes.
• Input the UV210-0.6 resist thickness and Eo data into the process monitor on the Microlab web page.
• Recorded gcaws6 F/E matrix test and baseline correction results on log book.
• Informed DUV researcher on the progress of the processes by sending him e-mails.

IV. SUMMARY

I had assisted Marshal Miller on his shotnoise experiments, so he could analyze the data. I had prepared thin photoresists for him to do the EBL in LBL. I grew oxide on wafers, coated with various resists, ran preliminary exposure tests, etched thin oxide patterns on wafers after Marshal did the EBL in LBL, stripped the resists and took SEM pictures before and after stripping the resists and after oxide etch for Marshal to analyze the data on his shotnoise experiments. I had assisted the Advanced Lithography Group to run the experimental process well this year.

I had completed many ETR runs, had assisted staff and lab members to make processes run smoothly in the Microlab. I had assisted the Microlab to maintain equipment when necessary to keep equipment in good running conditions and minimize equipment down time. I had graded written quizzes and qualified lab members on equipment so the lab members could use the Microlab facility. I had revised chapter manuals, process modules and written quizzes to keep them updated. I had made masks when Marilyn was away on vacation so lab members could continue their work. I had assisted the process group to maintain the general processes in the lab to run smoothly this year.