MEMORANDUM
To: Katalin Voros, Operations Manager
From: Marilyn Kushner, Junior Development Engineer
Cc: Sia Parsa, Process Supervisor
Subject: 2007 Year-End Report
Date: 17 January 2008
The photolithography equipment used in processing that are
under my direct involvement are: the GCA Wafer Stepper(2), the GCA Pattern
Generator, and the Ultratech Mask Copier. Additional equipment in this group
includes the APT chrome and emulsion mask developers.
The online mask-making form for
mask-making requests is utilized by all lab members submitting a Mask request,
as well as other university affiliated researchers and BMLA lab members.
Mask-making requests are accepted
for both the GCA Wafer Steppers (gcaws2 and gcaws6), the Quintel contact
printer, the Karl Suss contact aligner, and the Canon 4:1 reduction printer.
Requests are also accepted for the advanced lithography ASML stepper.
The pattern generator continues to
be heavily utilized by myself and the small group of lab members who are
qualified to operate it. A total of 930 completed photomasks were logged into
the gcapg log book by the end of the calendar year, December 31st. Note: the drop in the
Mask total from last year (1230)
again was largely caused by out-sourcing to Photo Sciences, Inc. for
Mask geometries less than two microns, which are below our machine capability and/or resolution.
Former Microlab lab members who
are now faculty within the UC system continue to be tremendously loyal and
supportive of the Microlab’s mask-making facilities and refer our services to
research groups within their own university systems; this group continues to
grow as many former lab members are now faculty elsewhere throughout the United
States and continue to support the mask-making facilities in the Microlab.
New for 2007:
|
University |
Contact |
Department |
|
Duke University |
Dongning Yuan |
Gross Chemical Lab |
|
Duke University |
Tom McNicholas |
French Family Science Center |
|
Rutgers University |
Jeff Zahn |
Biomedical Engineering |
|
UC Irvine |
LiMei Yang |
N/A |
|
UC Santa Barbara |
L. K. Shen |
N/A |
|
UC Santa Cruz |
Xi Wang |
Quantum Electronics Group Baskin School of Engineering |
|
Vanderbilt University |
Dongyan Xu |
Department of Physics & Astronomy Department of Mechanical Engineering |
Ongoing:
|
University |
Contact |
Department |
|
Caltech |
Blake Axelrod |
Condensed Matter Physics |
|
Georgetown University |
Prof. Paola Barbara |
Dept. of Physics
and Pharmacology |
|
Oak Ridge National Laboratory |
Kai Xiao |
Center for Nanophase Materials Science |
|
Penn State University |
Prof. Jeff Zahn & students |
n/a |
|
Rensselaer Polytechnic Institute |
Prof. Theo Borca-Tasciuc |
Dept. of Mechanical Engineering |
|
Texas Tech University |
Prof. Shaorong Liu |
Dept. of Physics and Biochemistry |
|
n/a |
Center
for Superconductivity Material
Research Science & Engineering Center Maryland
MEMS Laboratory Dept. of
Mechanical Engg./Institute for Systems Research Nanoelectronics
Research Group |
|
|
University of Pittsburgh |
Di Gao |
N/A |
University of Texas at Austin
|
Prof. Li Shi and students Dimitriy Korobkin |
Mechanical Engineering Department Institute for Fusion Studies |
|
Vanderbilt University |
Deyuli Li |
N/A |
The GCA Pattern Generator as
scheduled monthly maintenance tasks that are performed on a routine basis. They
are: the mercury lamp change every 700 hours (followed by focus/exposure tests
for chrome and iron oxide after the lamp has burned in for 24 hrs.) Emulsion
focus/exposure tests are done on a “as
needed” basis. Other tests for the pattern generator are the angles and
alignment test, which is performed monthly on both chrome and emulsion
plates,and the stage motion tolerance test which compares two different
tolerances. By strictly adhering to a six-month major maintenance call to RZ
Associates for stage maintenance, most minor problems for the pattern generator
have been eliminated and machine uptime for this tool is excellent.
GCA Wafer Stepper (gcaws2)
The GCA
Wafer Stepper has a scheduled mercury arc lamp change every 900 hours; this is
performed by Evan Stateler, the engineer-in-charge for this equipment. After a
24-hr. lamp burn-in, new focus and exposure tests are performed to determine
the best focus and exposure times for both I-line and G-line resists. A clear
energy test follows, then a baseline correction. The baseline correction test
is also performed once and week and on request.
GCA Wafer Stepper 6-inch tool
(gcaws6)
For this
new 6” tool, I am sharing the preventive maintenance with Kim Chan. A weekly
baseline test is performed, as well as other minor preventive maintenance
chores. Under Kim’s instruction, I have learned to operate this tool and assist
lab members with it and have also set up group accounts for it. I have also
learned the micro-DFAS baseline for this as well. In addition, I correct the
written exam for this tool.
ASML Stepper (asml)
IQC tests and illumination
uniformity are performed three times a week, essentially after the laser
refill.
SVG Photoresist Coating Tracks
(svgcoat1 and svgcoat2)
Photoresist thickness tests for I-line, G-line, and the 220 thick resist are performed monthly.
The lamp intensity is measured at five points on a weekly basis using the Karl Suss UV Intensity Meter. Measurements are taken for both I-line and G-line and recorded in a logbook kept by the tool as well as online.
Every year it becomes even more of
a challenge to keep the Microlab tidy and presentable- not only for guests but
for everyday labmembers as well. Therefore, the annual Microlab CleanFest held
in late October is essesntial. This year approximately 110 active lab members
signed up and once again their efforts- appreciated by all- made a tremendous
difference in the lab’s overall appearance and boosted morale. I would like to
take this opportunity to note that many of this year’s participants were new
labmembers who had just started to use the Microlab, but they came in to clean
with a great generosity of spirit that made my task of organizing this event
much more gratifying.
The daily
“grab-bag” giveaway continues to be popular; prizes were gathered from the
Semicon West Show at the Moscone Center.
Prize-filled
tote bags were also given to the first lab member to sign up for this event, as
well as the “most cheerful, willing participant.”
Photolithography
For RZ Associates: 3” wafers are reworked and recoated with
I-line photoresist (using the Headway spinner) for their in-house projects.
ASML Mix-andMatch Photomasks: gave
top priority to the ASML photomask requests for the
ASML-GCAWS6 mix-and-match process
(ongoing.)
The “Good News” photo display case
located midway down the main hallway outside the Microlab is also maintained by
myself; it is a revolving display of life inside the Microlab.
This year
I again chaired the barbecue committee in general and was aided by several
co-chairs: Madeleine Leullier for publicity;
Warner Carlisle for grilling;
and Anita Pongracz for sports.
This year
our Microlab Operations Manager, Katalin Voros, generously sponsored this
picnic at her local neighborhood “Orinda Oaks Park” and the change in site
proved to be popular: 50 adults and 20 children attended and a good time was
had by all.
This year I am working closely with our new baseline engineer, Laszlo Szabo, to handle GDS mask files from other universities which needed to be converted into tap and tix files. I am also helping our new MEMS Exchange engineer, Attila Petho, with photolithography steps and equipment in the Microlab.
The student staff
position that was created to keep the coffee room, Microlab lobby and the
Microlab in general looking presentable
continues to work out well; this student employee, under my general supervison,
works with a high level of independence and manages this job quite well; tasks
are added as the need arises. I also supervise
the student staff that stocks chemicals and lab supplies for the Microlab and
packages up chemical waste for pickup by EH&S.
The major
photolithography equipment (the GCA Wafer Stepper and the GCA Pattern
Generator) continue to be among the most heavily used pieces of equipment in
the Microlab. For both pieces of this equipment lab members tend to train each
other, but I continue to grade the written tests and conduct the oral exams.
Following
the Microlab Orientation course and lab
tour, each new lab member is required to take the Microlab Safety Test. The
questions from this test are from the orientation, safety video, lab tour and
study handouts. This test is reviewed and updated once per year by Bob Hamilton
and myself.
There was one meeting this year, held in May, that was well attended: 20 Microlab labmembers and five staff.
The
Microlab suggestion box (located in the main Microlab hallway) is checked
periodically for new safety suggestions submitted by lab members. The items
brought up are discussed with the Microlab manager. To date, the submissions
continue to be excellent and I work with our safety manager to implement them
as soon as possible. This year the suggestions and improvements are posted
online for reference.
Equipment manuals need to be revised and/or updated frequently to reflect changes in processing and/or procedures. The following chapters have been updated or revised this year:
January - Microlab Annual Safety Review (short) Quiz - Refreshed several
of the questions (submitted to Bob Hamilton.)
March - Chapter 3.4 - APT Emulsion Process - Modified
the equipment operation and mask develop process for clarity.
Chapter 3.5 - APT Chrome Process
- Updated the chapter to describe the operation of the new switching system.
Chapter 4.33 - Photomask Cleaning
- This was a new chapter co-authored
with Kim Chan; it describes the various ways to clean photomasks in the red room.
April - Cleanroom Etiquette
Protocol Updated
May - Chapter 3.7 - Ultek Mask
Copier - Updated with Daniel Queen;
removed references to 2” plates, updated the chrome intensity settings, and
added on to Section 12.9 the way to copy a chrome mask over to iron oxide.
June - Chapter 3.6 - Iron Oxide Mask Processing - Revised/updated to describe the new operating
procedure at the aptchrome, Section 9.0, plus added Section 10.0 for
troubleshooting at the tool and Section 11.0 for figures and schematics.
July - Chapter 3.5 - APT Chrome Process - Added one line at the troubleshooting
guideline section about how to deal with a blown fuse. Specifically, if the
program recipe display screen is blank, this indicates a blown fuse and should
be reported on FAULTS promptly.
August - Chapter 3.3 - GCA3600
Pattern Generator - Updated Section 1.2: System Specifications to include all
the mask sizes and types in stock.
November - Chapter 2.1 - Cleaning
Procedures - Made corrections in section
4.3 re the RCA 1&2 cleans. Corrected the order the chemicals are added.
Corrected the hydrogen peroxide chemical formula. Noted that nitrile gloves are
now used in the Microlab rather than latex gloves.
Although I personally did not
receive any staff award this year, I nominated my student employee, Kit
Colwell, for one of the ERSO “SPOT” awards, for his excellent service, and it
was awarded to him at the ERSO holiday Christmas party.