MEMORANDUM
To: Katalin Voros, Operations Manager
From: Kim Chan, Assistant Development
Engineer
Subject: 2008
Year-End Report
Date: 20
January 2009
cc: Sia Parsa, Andy Neureuther
This is a summary of the activities and
projects that I was involved during 2008
I.
SEMICONDUCTOR PROCESSING
I have been working on local
loading effect of centura-mxp project with the Advanced Lithography Group.
·
Used MASK3 FLATTENED reticle with the
aberration patterns, checked oxidation growth rate, calculated oxide deposition
time, piranha cleaned wafers in sink8, dipped them in HF bath, repeated
cleaning steps in sink6, ran oxidation run, measured oxide thickness, spun
coated 4000A of UV210-0.6 photoresist, ran exposure matrix tests on test wafers
and experimental wafers, developed wafers, inspected under microscope,
descummed, inspected, uvbaked, inspected,
etched wafers in centura-mxp, inspected, took S.E.M. pictures, ashed
resist, took S.E.M. pictures on oxide patterned wafer, diced two wafers into 4
pieces, took S.E.M. pictures on 10% over etched oxide wafer and measured the
oxide thickness on various aberration patterns with Nanospec and Nanoduv to
compare the measurement accuracy.
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.
·
Reviewed Michael Hembrecht’s mask lay out
with him, spec up a job file according to his lay out die size for gcaws6,
modified the job file, primed wafers with HMDS, coated I-line resist, exposed
first layer, developed and processed second layer, developed and inspected the
global alignment. The alignment on the global
alignment test came out good.
·
Assisted a BMLA member to process wafers
in furnaces and on wafer tracks, exposed wafers with first layer mask in
gcaws6, developed, inspected, uvbaked, ashed resist after lam etch, repeated
process to expose wafer with second layer mask to check alignment, made
alignment correction after checking CAD layout offsets, changed global
alignment marks to a different row on the file to make the microDFAS alignment
to align properly, repeated process to expose wafers with various time and
masks, descummed wafers and continued litho process after oxide/poly etch. Assisted another engineer in the same BMLA
company with his litho process and modified his job file, showed him how to run
gcaws6, copied job files, edited job files on gcaws6, run baseline correction
tests, FEM tests, how to program svgdev, how to run matrix, primeoven,
svgcoat1, svgcoat6 and svgdev6.
·
Discussed with Dr. Y. Gotkis from KLA
Tencor Corp. about recycle wafers and EBL ETR.
Checked metallization process information for potential ETR. Cleaned his wafers which were drilled with
holes in acetone, methanol, IPA, dehydration baked, set up spinner1 and spun
PMMA on them. Checked PMMA information,
Remover PG inventory and noticed Dr. Y. Gotkis.
Stripped PMMA on recycle wafers in two acetone baths, rinsed with
methanol, IPA, dehydrated baked, inspected, coated PMMA and soft baked them as
requested. Spun PMMA at various speed to
check PMMA thickness, spun UV210-0.6 resist to check resist thickness, spun ten
wafers with requested PMMA resist thickness and UV210-0.6 resist thickness and
baked them for Dr. Y. Gotkis.
·
Took pictures of the palette holder from
the Crestec EBL system, measured the screw sizes and the X & Y coordinates
of the screw positions on the palette holder, sent photos and measurements to
Matt Wasilik. After Matt Wasilik bought
the small sample holder attachment, I tested the auto-focus mode on the Crestec
EBL system with a sample on the attachment.
Decided not to use the attachment at this point, because the wafer Z
values in the Crestec software program needs to be changed every time the small
sample holder is used.
·
Prepared xetch monitor chips by checked
SiO2 etch rate on xtech, primed HMDS on wafers, spun I-line resist on xetch test
wafers and nine monitor wafers, ran exposure test on test wafers with ksaligner,
developed, exposed monitor wafers, developed, uvbaked some wafers, hard baked
some wafers, tested etch rate on lam2, etched wafers in lam2, mixed 100:1 HF,
etched wafers in 100:1 HF bath, stripped resist and recoated with I-line
resist, diced xetch monitor wafers and stripped photoresist on the xetch monitor
wafers.
·
Made 25 six-inch pocket wafers by piranha
cleaning, HF cleaning and growing wet oxide, measured oxide thickness, primed
in HMDS, coated with I-line photoresist,
cleaned pocket wafer mask, cut a black paper mask to cover some mask defects,
exposed wafers with 4” pocket, developed, cleaned developer residue on back
side of developed wafers, cleaned defects in pocket area, hardbaked resist,
touched up wafer edges with resist pen, baked them, etched wafers in
centura-mxp, stripped resist, piranha cleaned, made TMAH and 10:1 HF baths,
rinsed wafers in D. I. water, dipped in HF, rinsed in D. I. water, etched in
TMAH bath, measured pocket depth, continued to etch until the correct pocket
depth, piranha cleaned, dipped in HF, grew oxide on pocket wafers and measured
oxide thickness to complete the process.
·
Showed Haiyen Lin from Crestec Co. how to
use primeoven, spinner1, svgcoat3, HMDS prime in sink4, tystar furnaces and
uvscope. Assisted Lin how to use the
wand to send e-mails, assisted her to get Microlab card key access, set up
microscope in crestec room, get ZEP520A photoresist purchase information, get ZEP520A phtoresist MSDS, spin photoresist
on spinner1 and stored photoresist properly for her.
·
Showed Craig Tindall from LBL what the
ksaligner is capable of doing initially.
Assisted Craig to prime wafers with HMDS, prepared photoresist, cleaned
mask, calculated exposure intensity, aligned wafers to mask on ksaligner,
exposed and developed a wafer later.
Showed Craig how to use nanoduv, HMDS bubbler, spinner1, ksaligner and applied
dicing tape on back of wafer. Continued
to assist Craig on the ksaligner as he needed more wafers exposed.
·
Measured polysilicon thickness on 24
wafers on a MEMS exchange run, cleaned old KOH bath, made a new KOH bath,
checked KOH etch information and stripped amorphous Si on 14 wafers.
·
Found expired AR3-600 anti-reflective
coating turned bad after coating with it.
The film was cloudy and grainy.
Stripped it and tried a different bottle, but the result was the
same. Tried to spin AR3-600
anti-reflective coating from original bottle, filtered it and coated
again. The films still came out cloudy
and grainy. Disposed small bottles of
AR3-600 anti-reflective coating. Bought
new gallon of AR3-600 anti-reflective coating, spun coat test it at room
temperature and cold out of the refrigerator.
The film on the wafers was still cloudy and grainy. Took pictures of old and new AR3-600
anti-reflective coating films, gathered AR3-600 anti-reflective coating
information and communicated the issue with Sia Parsa to vendor. Their recommendation was to let BARC to
stabilize for a day in room temperature and it tested okay later. Wrote process Module 37 as how to apply
AR3-600 anti-reflective coating.
·
Diced a 12 inch wafer into small pieces
for Attila Szabo, touch up pieces with photoresist pen, baked and showed Attila
how to use xetch system to etch tungsten film on chips for the novellus.
·
Took pictures of tungsten boats and chrome
rods for NRC and V401 evaporators, took pictures of crucibles for EdwardsEB3
and Ultek evaporators, sorted and organized the pictures, put them on a word
file, printed, laminated and posted them on the check out drawers.
·
Stripped Cr off a mask blank and collaborated
with Jimmy and Marilyn to make show wafers for Crestec engineers, a high school
intern and Professor T. J. King.
·
After svgcoat1 was converted to six inch
wafer process, assisted in programming and testing the operation, checked all
the programs and the parameters in each program, coated wafers with each
program to verify the photoresist thickness, organized and labeled dummy wafer
boxes for svgcoat1, svgcoat2 and svgcoat3.
·
Svgcoat3 was converted to four inch wafer
process. Svgcoat3 old programs for six
inch process were not appropriate for 4 inch wafer process. Copied svgcoat2 programs and implemented in svgcoat3. Measured resist thickness, found photoresist
lines were interchanged and asked maintenance engineer to make corrections. After UTS installed a new pump for G-line
resist on svgcoat3 and solved the pump problem, assisted David Lo and the
vendor to measure the resist thickness on nanospec and I modified the programs,
coated resist on wafers with all programs, measured resist thickness to confirm
correct resist thickness, updated resist chart and posted it by svgcoat3. Assisted to put in G-line OCG DEV 934 2:1 POS
RES Developer on svgdev6 and checked the programs on it.
·
LDD-26W developer for developing patterned
UV210-0.6 resist will be eliminated by vendor.
Therefore need to compare different developers result by preparing oxide
wafers with UV21-0.6 resist, ran FEM tests with CMOS_180 job on ASML stepper, manual
developed them with LDD-26W, MF26A and MFCD26 developers. Afterward, exposed wafers with best exposure
and focus on ASML stepper, manual developed them with LDD-26W, MF26A and MFCD26
developers, inspected the resist patterns under the microscope, recorded the
result, diced, sputtered Au and took some pictures on poly iso-lines and CPG
L-bar lines on the LEO SEM. Since LEO
SEM was down for an extensive period, cross-section SEM work could not be
done. Used the Crestec EBL system as a
SEM to take some top view pictures.
After preliminary develop work was done, decided to compare LDD-26W and
MF26A developer on svgdev6 spray/puddle develop track. Grew 3000A oxide on wafers, installed MF26A
developer on svgdev6, spun UV210-0.6 resist, ran FEM test, exposed exposure matrix
with polygate and metal2 layers on Baseline170_matrix reticle, developed wafers
with LDD-26W and MF26A developers on svgdev6, inspected wafers on microscope,
diced some wafers, sputtered Au, took some top view pictures with Crestec EBL
system and will continue cross section SEM work to compare the two developers
when LEO SEM is available.
·
OiR 897-10I Positive Photoresist will be
discontinued. Therefore, need to compare
OiR 897-10I Positive Photoresist with replacement photoresist OiR 700-10
Positive Photoresist. Primed silicon
wafers, spun OiR 700 10 Positive Photoresist at various speed, spun OiR 897-10I
Positive Photoresist at spin speed as on chapter manual, measured resist
thickness, created 15.56 mm x 15.56 mm job on gcaws6, ran Eo tests with new OiR
700-10 Positive Photoresist coated wafers on gcaws6, plotted spin speed curve
and Eo swing curve. I am continuing the process characterization with a new
test mask on GCAWS6.
·
Assisted Marilyn Kushner to remove reticle
and run an exposure test with G-line photoresist on gcaws6.
·
Showed Marilyn Kushner how to solve ACS
problem on gcaws6 and how to develop wafers in manual mode on svgdev6.
·
Worked with Endré Szentkiralyi to update some
lab written quizzes.
·
Stripped photoresist and chrome on eight
recycled chrome masks, sold six to a lab member, replaced the chipped dummy
mask on the Canon aligner and kept one spare for whoever needs it.
·
Conducted lab tours for Stanford visitors
and when needed after Microlab orientation.
·
Demonstrate the Crestec EBL tool to visitors
from
Processing involved many silicon equipment and analytical
instruments in the Microlab. This year I
learned how to use the NRC evaporator to qualify a lab member and the Crestec
EBL system. After the process of
learning the Crestec EBL system, I practiced on the Crestec mask design
software, asked Laszlo Petho to design a gds file to test the Crestec software
conversion, practiced on the EBL writer, tested the new Crestec EBL system for
software bugs, coated PMMA to test the exposure and checked line resolution,
tested it as a SEM and tried the manual alignment operation. After learning the operation of the Crestec
EBL system, I have conducted ten two day training sessions, arranged with the lab
members to allow them to practice on Crestec EBL system, set up the room with
gloves, acetone, IPA, texwipes, storage box for supplies to minimize particles
transferring into the Crestec chamber, rebooted the computer to clear software
hang up problems and wrote Microlab Crestec chapter manual.
II.
EQUIPMENT & PROCESS MAINTENANCE
Equipment
Maintenance
·
Tested Crestec operation after building
power shut down and on problem reported sometime. Rebooted the computer to clear stage hang up
problems sometime. Checked Crestec EBL
system condition when the temperature was above normal in the room.
·
Ran image quality control and illumination
uniformity tests on the ASML stepper.
·
Tried to solve the ASML stepper problems
such as stuck wafer, stuck reticle inside the stepper and laser went off.
·
Ran wafers to test the ASML stepper after a
problem report was clear sometime.
·
Checked canon focus and turntable problems
and solved them.
·
Checked and cleared svgcoat2, svgcoat3, svgcoat6
and svgdev6 problems when needed.
·
Checked and corrected program recipes to
solve problems on svgcoat1 and svgcoat3.
·
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 resist pinhole problem
after svgcoat3 was converted to four-inch wafer process.
·
Assisted David Lo to solve air bubble
problem on svgcoat6.
·
Assisted Joe Donnelly on svgcoat1 and
svgdev.
·
Refilled water in the chiller for the
svgdev6 when needed.
·
Removed stuck and broken wafers in Matrix
chamber, restarted the matrix asher, loaded recipe, reset heater and tested it.
·
Assisted Phill Guillory and Winthrop
Williams on the nanospec in EE143 lab.
·
Checked the nanoduv program 7 measurement
problem with Evan Stateler.
·
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, ACS, EQ, light low, aperture,
transfer arm and auto-focus failure problems on gcaws6 when possible.
·
Assisted Greg Mullins from RZE on gcaws6
while he was working on it.
·
Tested sink7 QDRs, changed set up codes
back to original and tested them to clear QDR problems.
·
Rebooted and tested gcapg to clear
“function terminated” error.
·
Checked the LEO SEM status when it was
down.
·
Tested and tried to solve the vacuum
problems on spinner1.
Process Maintenance
I
have been responsible to maintain general photolithography processes for the
Advanced Photolithography Group. This involved the following:
·
Sorted and recycled used 6” wafers.
·
Ran focus tests on the asml stepper.
·
Grew oxide, measured oxide thickness on
nanoduv and nanospec 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.
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 & GCAWS6 stepper field servicemen and the process group.
·
Refilled developers on svgdev6, EBR and
HMDS on svgcoat6 when I see they are low.
·
Cleaned and dehydration baked wafers for
processing.
·
HMDS primed, coated resists, exposed
wafers, PEB, developed and inspected them.
·
Monitored the photoresist inventory on svgcoat6,
labeled DUV photoresists and stored DUV resists and AR3-600 anti-reflective
coating in refrigerators.
·
Assisted lab members in programming on the
svgcoats and coating AR3-600 anti-reflective coating.
·
Sorted and marked 6” dummy wafers for svgcoat1,
svgcoat3, svgcoat6, svgdev6 and ASML stepper.
·
Formatted diskettes, set up job files and
edited job files on gcaws6 for lab members.
·
Checked an ASML job file, modified and tested
it for a lab member.
·
Restocked gloves, texwipes and printer
paper in the Crestec and LEO room when I see they are low.
·
Checked photoresist inventory, informed
Susan or Adrienne to order UV210-0.6 resist when it is low.
·
Ran F/E matrix, system focus, microscope
rotation, global, insitu, MicroDFAS baseline tests and made corrections on
gcaws6.
·
Worked with a lab member to edit his job
file and fixed his MicroDFAS alignment problem on gcaws6.
·
Refilled chemicals in aptchrome.
·
Showed staff and lab members how to run
FEM on gcaws2 and gcaws6.
·
Assisted staff and lab members to program
on svgcoats.
·
Assisted a lab member to get a bottle of
chemical in the chemical storage room.
·
Rinsed empty chemical bottles left by the
lab members sometime.
·
Assisted Sia to filter AR3-600
anti-reflective coating and spun it on six inch wafers on svgcoat6.
·
Cleaned silicon reference wafers for
nanospec and nanoduv.
·
Consulted lab members on such as gcaws6
process, photoresist process, photoresist coating, litho process, sinkplate and
sink5 usage.
·
Searched OCG-825 G-line photoresist
process data on the web sites and printed it for a lab member.
·
Checked canon aligner problem log achieve
and replied e-mail to an outsider to solve his photoresist problem.
·
Transferred 495 PMMA A2 photoresist to a
small brown bottle for Crestec EBL system users.
·
Spun 495 PMMA C4 and A2 resists, baked,
measured resist thickness and added information on Crestec chapter manual.
·
Accompanied the Crestec engineers when
they did the acceptance tests.
·
Sputtered Al on wafers, spun resist,
salvaged a mask with decent patterns, exposed wafers on GCA wafer stepper 6 and
developed wafers, etched Al, diced wafers, stripped resist, measured X & Y
coordinates on Al chips, designed registration marks with Crestec software,
tested manual alignment on Crestec EBL system, but Al edges were rough. Therefore, it is not so desirable to use them
as reference for alignment demonstration.
·
Measured wafer fixture in Parylene system
and its chamber dimension to determine if it was able to fit a 4” X 8 ¾”
object for an ETR.
·
Primed wafers in HMDS, coated SPR-220
resist, ran process module 29 to test the resist cracking problem that was
reported, but found the process had no problem.
·
Showed Marilyn how to run insitu baseline
correction, MicroDFAS baseline correction, microscope rotation correction, FEM
test and how to clear ACS problem on gcaws6.
III.
INSTRUCTION & DOCUMENTATION
Instruction
·
Instructed and qualified researchers on
equipment operation and fabrication procedures when necessary.
·
Assisted and showed staff how to use
gcaws6, LEO S.E.M., nanospec, primeoven, sopra, svgcoat1, svgcoat2, svgcoat3
and svgdev.
·
Gave lab tours for monthly orientation
when needed.
·
Assisted and showed a few lab members how
to use the
-
ASIQ surface profiler
-
ASML stepper
-
Canon aligner
-
Crestec EBL system
-
GCA wafer stepper 2 & 6
-
Karl Suss aligner
-
LEO S.E.M.
-
Linewidth measurement system
-
Quintel aligner
-
Primeoven
-
Spinner1
-
Svgcoat1, Svgcoat3, Svgcoat6 and svgdev6
-
Sopra ellipsometer
-
UVScope microscope
·
Qualified lab members on the operation of
the
-
Canon projection aligner
-
Crestec EBL system
-
GCA wafer stepper 6
-
Headway spinner
-
Hummer sputter system
-
Jeol107
sem
-
Kruss Contact Angle Measurement System
-
LEO sem
-
Matrix asher
-
Memscope
-
Nanoduv
-
Nanospec
-
NRC evaporator
-
Primeoven
-
Quintel aligner
-
Sinks
-
Sopra ellipsometer
-
SVG coat and develop systems
-
Technics-c asher
-
UVScope
Documentation
·
Wrote daily reports to Professor Andy
Neureuther.
·
Wrote AR3-600 anti-reflective coating
process module 37 chapter manual.
·
Wrote Crestec EBL system chapter manual.
·
Revised crestec, svgcoat1, svgcoat2, svgcoat3
and svgcoat6 chapter manuals. Revised
svgcoat3 and svgcoat6 charts, added new signs for crestec room and posted them
up.
·
Graded asiq, cpa, gcaws6, jeol107 SEM, lab
orientation, 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.
IV. SUMMARY
I had assisted Professor A. Neureuther on the preliminary local
effect experiment. I used MASK3
FLATTENED reticle with the aberration patterns, checked oxidation growth rate,
calculated oxide deposition time, piranha cleaned wafers in sink8, dipped them
in HF bath, repeated cleaning steps in sink6, ran oxidation run, measured oxide
thickness, spun coated 4000A of UV210-0.6 photoresist, ran exposure matrix
tests on test wafers and experimental wafers, developed wafers, inspected under
microscope, descummed, inspected again, uvbaked, inspected, etched wafers in centura-mxp, inspected, took
S.E.M. pictures, ashed resist, took S.E.M. pictures on oxide patterned wafer,
diced two wafers into 4 pieces, took S.E.M. pictures on 10% over etched oxide
wafer and measured the oxide thickness on various aberration patterns with
Nanospec and Nanoduv to compare the measurement accuracy.
I had completed ETR runs and projects, 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 and process module 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.