[Fwd: About epi poly process at stanford]

Mary Tang mtang at stanford.edu
Tue Aug 26 07:40:42 PDT 2008

Hi all --

What does everyone think about this request? Would a TXRF analysis of a 
wafer from this furnace be satisfactory? And is there an upper limit on 
thickness for depositing epi-poly? (By the way, I will contact him to 
inform him that TXRF may likely be required and to ask about whether 
this thickness is actually needed for his particular application and 
what kind of clean his wafers can undergo. But we should decide in 
principle whether this is OK -- basically, qualifying his SiC furnace 
for clean processing in our lab.)


-------- Original Message --------
Subject: 	About epi poly process at stanford
Date: 	Mon, 25 Aug 2008 16:27:56 -0700
From: 	Benjamin Cheng <kbcheng at berkeley.edu>
To: 	<mtang at stanford.edu>

Dear Mary,

My name is Benjamin Cheng, a graduate student working in BSAC at 

I have some questions regarding the deposition of epi-Si (ASM Epsilon II 
Single-Wafer Epitaxial Reactor) at Stanford Nanofabrication Facility.

I would like to know whether a 4” Silicon wafer with a thin layer of 
poly silicon carbide (SiC) deposited (about 500nm) using LPCVD 
(http://microlab.berkeley.edu/labmanual/chap5/5.15.html) is allowed in 
the epi tool at Stanford for a thick layer of epi-Si (~10-20 micron). 
Silicon carbide is well known to be very inert chemically and can 
withstand very harsh environment. No metal is allowed in the furnace 
tube used in depositing the SiC and so there should not be contamination 
issue. I would greatly appreciate it if you could provide me any 
information regarding the material compatibility of the epi tool at 

Thanks and look forward to hearing from you.


Benjamin Cheng


University of California, Berkeley

Department of Mechanical Engineering

Berkeley Mechanical Analysis & Design

Office: 5109 Etcheverry Hall

Phone: (510) 643 - 1099

Mary X. Tang, Ph.D.
Stanford Nanofabrication Facility
CIS Room 136, Mail Code 4070
Stanford, CA  94305
mtang at stanford.edu

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