Dear Tao.

Filmtronics has a more complete line of spin on dopants for achieving a 25
micron junction. They also have the solid planar sources of boron and
phosphorous as well as diffusion preforms .

Please contact then for a catalogue at (sales@filmtronics.com )  or call
them at 724 352 3790. they would be happy to work with you and the
diffusion can be accomplished easily without expensive boron implant which
probably does not have the energy to do what you want or the solid source
method where you need a special boat to hold the source.

The boron spin on from Filmtronics will do the job very easily and cost
effectively.

Good luck, Neal