While other possibities exist, it may be that the relatively heavily doped
substrate (1e17/ cm3) simply up-diffused and whipped out the boron layer.

Roger Brennan
110 Jeffries Cove
Rocky Mount NC 27804
(252) 442-9612
[email protected]



-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of
Dau Thanh Van
Sent: Tuesday, April 06, 2004 8:15 AM
To: 'General MEMS discussion'
Subject: [mems-talk] Light Boron diffusion in silicon


Hello everybody,

I recently tried to lighly diffused silicon by Boron. The expected
concentration is around 5e17 atoms/cm3. I reduced the temperature to 800C,
and pre-diffused in 15 minutes. For drive-in, I made at 1100C/30minutes. I
estimated the concentration should be 1e18 atoms/cm3 by Frick's law.
However, after the process, I can not measure the sheet resistance of doped
wafer.
The based concentration of the n-type wafer is 1e17 atoms/cm3, and I doped
it succesfully with the prediffusion temperature of 1000C.
Is boron solubility a problem, or the based concentration too high?
By the way, I can not dope the silicon by ion implantation method here. I
really appreciate any ideas or suggestions.
Best regards


==============
Dau Thanh Van
Ritsumeikan Uni.
==============




_______________________________________________
[email protected] mailing list: to unsubscribe or change your list
options, visit http://mail.mems-exchange.org/mailman/listinfo/mems-talk
Hosted by the MEMS Exchange, providers of MEMS processing services.
Visit us at http://www.memsnet.org/