Depends on the amount of doping. Most CMOS transistors fabricated
today have highly doped source and drains, sitting in a "well" of
lightly doped (opposite doping) material. The source and drains
transmit passibly, but the wells transmit very poorly.
In old CMOS designs (circa 1980), the gates and interconnect were
made of a single layer of metal. "Crossovers" were done using highly
doped underpasses (same doping as source and drain). Theses didn't
conduct nearly as well as the metal, but were generally sufficient
for local interconnect.
Tim
--- In Electronics_101@y..., Jim Purcell <jpurcell@w...> wrote:
d,
N-type has extra electrons that can be pushed around easily. P-
type has
"missing" electrons, but the "holes" can be pushed around.
I have often wondered whether a single slice of N or P type
material would
conduct. They don't make single slices of course,
they add impurities of each type to different parts of a single
slice to make
either diodes or transistors. And the process is a bit different
with Field
Effect transistors and MOS types.
Jim
