[mems-talk] ask for reference on gold-gold thermal compress waferbonding

[Sood, Sumant]

Hello Hu,

For Au-Au thermocompression bonding, the typical process sequence is:
pre-bond cleaning of the wafers followed by actual bonding. The quality
of the bond is greatly improved when set process temperature and
pressures are reached through gradual ramping. The bond temperature
range is between 300-350oC and pressure 2000-3500 mbar. The gold layer
tends to form clusters during bonding if the temperature ramp-up  is not
controlled. The actual bond time would be anywhere between 10 to 30
minutes depending on your gold pattern and your bonder. An inert gas (N2
or forming gas) is preferred to prevent oxidation. Au-Au thermo
compression bonding has been researched a lot and you can find some good
references by searching for appropriate keywords in Sciencedirect
/IEEEXplore. One of them to start with is 

Low-Temperature Silicon Wafer-Scale Thermocompression Bonding Using
Electroplated Gold Layers in Hermetic Packaging, Electrochem.
Solid-State Lett., Volume 8, Issue 12

The book you getting, does not discuss thermocompression bonds.


Sumant Sood
Applications Engineer
Suss Microtec

-----Original Message-----
From: mems-talk-bounces at memsnet.org
[mailto:mems-talk-bounces at memsnet.org] On Behalf Of ???
Sent: Thursday, April 26, 2007 9:50 PM
To: mems-talk
Subject: [mems-talk] ask for reference on gold-gold thermal compress
waferbonding

Hi,All,

    Would someone give some useful references on gold-gold thermal
compress wafer bonding?
    I'd like to bonding wafers by this mean. There is a book named
"semiconductor wafer bonding: science and technology". I'm buying it,
but it will takes months for us to get the book. 
    So any electronic version paper on the subject?
    Thanks!
                               Hu Xiaodong
                               Hu_xiaodong at 163.com
                               Hebei Semiconductor Research Institute