A semiconductor device is provided which includes a diode formed of a MISFET
and
having a current-voltage characteristic close to that of an ideal diode. Negatively
charged particles (e.g. electrons: 8a) are trapped on the drain region
(2) side of a silicon nitride film (4b) sandwiched between
films of silicon oxide (4a, 4c). When a bias voltage
is applied between the drain and source with the negatively charged particles (8a)
thus trapped and in-channel charged particles (9a) induced by them,
the MISFET exhibits different threshold values for channel formation depending
on whether it is a forward bias or a reverse bias. That is to say, when a reverse
bias is applied, the channel forms insufficiently and the source-drain current
is less likely to flow, while the channel forms sufficiently and a large source-drain
current flows when a forward bias is applied. This offers a current-voltage characteristic
close to that of the ideal diode.
