Dear Memebers,
    I am going to use piezorisistive effect. I will dope Boron in a
n-type Si wafer to make four resistors and build a Wheatstone bridge.
The question is that:
1) The Boron resistors will be made by ion implantation. In order to get
good pn-junctions between resistor and substrate (n-type PHO wafer), how
to choose the wafer with a proper dopants (PHO) concentration? At the
same time, how to choose the ion implantation condition? (energy, source
concentration (cm^-2), the final concentration in the resistors ( cm^-3)).
2) In order to insulate the Boron-resistors, someone applies an inverse
voltage to the substrate to increase the barrier. Do you think it's
necessary? In my view, the inverse voltage is not necessary. But I am
not sure. I wonder under what condition, I don't need need to apply that
voltage?

Thanks in advance!
Happy thanksgiving!

HTao