Natural type IIa diamonds were implanted with boron at 77 K, using a m
ultiple step, low temperature boron ion implantation procedure to prod
uce an approximately uniformly doped p-type layer of about 200 nm thic
kness. This layer was used to fabricate metal insulator semiconductor
field effect transistor devices operating in the depletion mode, with
good uniformity from device to device. Two of the devices were used to
fabricate a simple demonstration circuit with a voltage gain of two.