did you etch off the boron glaze before measuring
the silicon doping?

Mark Wendman, MicroFab lab mgr
LICOS Lab for Integrated Optics
University of Alabama in Huntsville
[email protected]
office tel (256) 824-2421
fax tel    (256) 824-6618


-----Original Message-----
From: Dau Thanh Van [mailto:[email protected]]
Sent: Tuesday, April 06, 2004 6:15 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.
==============