The first book I picked up was Ghandhi, "VLSI fabrication principles",  p
468, Wiley,  ISBN 0-471-58005-8.
Your thickness of 0.075 microns looks about right.  Any number of books have
these oxidation curves in them.  Also, I'll bet there is more than one web
site that has an oxide thickness calculator.  Also, these curves can be used
as a guideline to add some oxide thickness if you under shoot. Profile your
furnace.  Check for massive gas leaks. Run some test wafers (of the same
orientation and approximately the same doping level.  You will eventually
get the thickness you want.


Roger Brennan


-----Original Message-----
From: ÇÇ´óÓÂ
Sent: Thursday, March 30, 2006 6:47 AM
To: [email protected]
Subject: [mems-talk] Question about the Deal Grove model

I am doing dry oxidation and use Deal Grove model to predict the thickness
of
thermal oxide.The oxidation temperature 1000 C and the oxidation time is 100
min.
As refered from text book, the parabolic rate constant B is 0.0117u2/h, the
linear
rate constant B/A is 0.165u and the time shift ¦Ó is 0.37h.
The Deal Grove model predicts a thickness of about 0.092u for a 100 min's
dry
oxidation on (100) wafer.

In my experiment, the O2 gas flow is 5 l/min, and the measured thickness is
about
0.075u. There is large deviation between the predicted and the measured
thickness.
I wonder if anybody can provide an explanation about this kind of deviation,
thanks in advance.