Chad,

Is this also the case when the glass is liquefied at high temperature as
suggested?

shay

-----Original Message-----
From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org]
On Behalf Of Brubaker Chad
Sent: Thursday, February 12, 2009 7:43 PM
To: General MEMS discussion
Cc: Brubaker Chad
Subject: Re: [mems-talk] Silicon_Glass Fusion Bonding

In general, the biggest difficulty with bonding of glass to silicon
(especially if we are talking Borofloat glasses rather than fused
silica) is going to be roughness.

For fusion bonding to work at all the surface roughness has to be below
2 nm RMS.  For a hermetic seal, we're talking <0.5 nm(5 A) rms.  This is
typically the polish level of prime silicon. In most cases that I have
seen, the polish level of glasses is lower than this.  We have been
successful bonding Borofloat glass to silicon (and fused silica to
silicon, for that matter), but in most cases, the glass needed to be
CMP'd first.

Best Regards,
Chad Brubaker