Dear,

i'm working on my thesis about solar cells on IMEC (research center in
Leuven, Belgium). But i'm stuck in a specific problem, and i'm looking
for tips and advice to solve the problem.

Problem: i can't bond a silicon wafer to a alumina-substrate(AL2O3
99.9%).

I've done some experiments without any success.
Review of experiments:
    A/ high temperature (1000°C), short bonding time (6 hours), the
bonding was          surrounded by N2-gas.
        surface conditions of the wafer and substrate:
            1. both surfaces are dry
            2. both surfaces are dry and covered by a nitride layer
            3. both surfaces are wet and covered by a nitride layer
            4. both surfaces are wet and covered by an undoped pyrox
layer

    B/  low temp (200°C) , long time (26 hours), the bonding was
surrounded by N2-gas.
        1. both surfaces are wet and covered by a nitride layer
        2. both surfaces are wet and covered by a doped pyrox (normally
the pyrox has to become viscose)

Some questions:
+Is there anybody who has some experience with the bonding topics or
somebody who's got usefull information?
+ are there logical explanations why the experiments failed and this on
the base of chemical or physical properties of the materials?
+Do you have some suggestions for other experiments (use of other values

for the parametres (temp, duration, surrounding gas, .......))?
+Can you recommand some people or specific lecture related to the
bonding problem?

All tips and advice are welcome!
Thanx a lot.
Studentical greetings.

Stijn Lenaerts
    student 'engineer in micro-electronics', KULeuven Belgium
    thesisstudent on IMEC

email:
    Stijn.lenaerts@vtk.student.kuleuven.ac.be
address:
    steengroevenlaan 5/5/0
    3001 Heverlee
    Belgium
fax:
    +32 16 20.65.29





Is there anybody who has some experience with the bonding topics or
somebody who's got usefull information? All information and tips are
welcome!

Thanx a lot.

Stijn
University KULeuven (belgium)