Hello,

Thank you for your advice.

Seems that everybody agrees with a doping process in a furnace.

BUT...

.....The thing is, that I already tried it several times and I didn't get out
the desired result. (Procedure at the end of the text)

I calculated that a Boron diffusion in (100) direction needs 48 hours
DRIVE-IN at 1100-degree-C to get a concentration of 10 to the 20 atoms per
cm cubic in 4um depth.

As the surface solubility of Boron on the Si surface is around 4 times 10 to
the 20 atoms per cm cubic I have to conduct several B2O3-predeposition and
deglaze-etch steps to get enough Boron on and in the wafer.

...Or am I mistaken here.let me know if my calculation and considerations are
wrong!!

My suggestion would have been a CVD-process at which a boron doped Si-layer
is grown on a Si(100)-Wafer surface by disintegration of Silane and Diborane
in FR-plasma or sth. like that.

But it is actually quite difficult to realize such a process within two
weeks.

Process for doping in the furnace.


Oxidation of BN-Wafer (O2-atmosphere) at 900-degree-C 1 hour

Loading Si-Wafer

Predeposition of B2O3 on Si at 900-degree-C (N2-atmosphere) 25 minutes.

DRIVE-IN at 1050-degree-C for 1hour in N2-atmosphere.

Deglaze-etch 1:10 HF:H2O---> 2 ohm-cm


Thanks,

Sebastian


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