New pryometer head installed ....
shott at stanford.edu
Tue Jun 17 12:47:42 PDT 2008
This morning AllWin has installed and calibrated a new pyrometer head on
the AG4100. The old one was producing an output of only 200-400 mV at a
thermocouple wafer reading of 1000 deg C. The new one is producing an
output in excess of 1000 mV at the same thermocouple reading.
The thermocouple calibration has been run up to a thermocouple wafer
temperature of 1195 degrees C, so you should get good temperature
performance up to process temperatures of 1150 degrees C.
Like most pyrometers, of course, it can't see anything below something
close to 400 degrees C so if you are running a low process temperature
of something on the order of 600 degrees C, you probably want to make
sure that your recipe includes a "warm up" step for a short time at 450
degrees C before moving up to the "real"process temperature so that they
system is pre-stabilized a bit.
We have not run full process qualifications with the new pyrometer, but
will try to do so at our earliest convenience. However, we are aware
that some of you are anxious to use the system, so we are releasing it
for use, pending full process qualification. If you are using it,
however, please make sure that you conduct appropriate tests with your
recipe in advance of committing any real wafers to this tool. Because
the pyrometer is at the heart of this system, you should thoroughly test
if you are planning on using the system in these early
Also, if you are running a nitridation recipe, please contact me in
advance .... I'd like to be with you so that we can monitor the status
of the ammonia flow to see if we are getting a shutdown of the excess
flow switch during high-demand ammonia flow. There were reports of
ammonia flow problems that we really haven't been able to investigate
until the pyrometer problem has been resolved .... so will now begin to
investigate that in earnest.
Happy processing on the AG4100 .... and please let us know if you
encounter any problems.
More information about the AG4100