Dear Mr. Törndahl,

the requirements for silicon fusion bonding are: wafer cleanless and wafer
surface quality. The TTV (Total Thickness Variation)of a standard prime
grade wafer (4"): 1-3 µm. The roughness RMS (root mean square) of a standard
prime grade wafer (4"): approx. 1 nm -> CMP quality. The bow or warpage
should be < 25um. These parameters should be fulfilled to achieve a
pre-bond. High quality surfaces suitable for direct bonding also have been
achieved via CMP of silicon dioxide or silicon nitride.

Best Regards,
Margarete Zoberbier

----------------------------------------------------
SUSS MicroTec
Applications Center RSC Europe
Margarete Zoberbier
Schleissheimer Str. 90
85748 Garching
Germany
Phone   +49 89 32007 - 380
Fax     +49 89 32007 - 390
email   m.zoberbier@suss.de

------------------------------

Message: 7
Date: Mon, 15 Mar 2004 15:12:22 +0100
From: Marcus T?rndahl 
Subject: [mems-talk] Bonding vs. Surface roughness
To: 
Message-ID: <000101c40a97$890fa5a0$3c35eb82@stahlmaus>
Content-Type: text/plain;       charset="iso-8859-1"

Hi,

I am searching for some information or guidelines when bonding silicon
nitride to silicon, silicon dioxide or silicon nitride. I found an article

"Spontaneous direct bonding of thick silicon nitride"
S Sanchez, C Gui and M Elwenspoek
J. Micromech. Microeng. 7 (1997) s111-113

which addresses the importance of surface smoothness with CMP before
bonding. Is there any other good references or guidelines I could use before
proceeding with my bonding experiments.

Regards,

Marcus Törndahl

Ps. Thank you for a most interesting and educating forum Ds.
_____________________________________________
Marcus Törndahl (PhD student, MScEE)
Department of Electrical Measurements/LTH
Lund University
Ole Römers väg 3
SE-221 00 Lund
Sweden