Operation of novel avalanche semiconductor detector, produced on the b
asis of heterojunctions Si - SiC and Si - SixOy is described. A unifor
m avalanche process with gain from 10(3) to 10(5) can be reached depen
ding on the conductivity of. SiC and SixOy layers. Two types of avalan
che photodetectors designed for applications in wavelength range 500 -
1000 nm with quantum efficiency 60 +/- 10 % (650nm) and 200 - 700 mn
with quantum efficiency 60 +/- 15 % (450nm) are presented.