Emission mechanism and bias-dependent emission efficiency of photons induced by drain avalanche in Si MOSFET's

Emission mechanism of photons induced by the drain avalanche in Si MOSFET's is discussed by analyzing the emission efficiency (defined by the ratio of the generated photon number to the avalanche-induced carrier number) dependences upon gate and drain voltages, which are found by both photomultiplier measurements and electrical measurements. The dependences are analyzed by using two-dimensional process-device simulator from the point of view of the bias dependences of lateral (E
L
) and vertical (E
V
) electric fields in the channel near the drain. From the analysis, it is found that the bias dependences of emission efficiency can be explained by considering two-dimensional coexistance change of the avalanche-induced electrons and holes. It is concluded that the emission mechanism is the recombination of the avalanche-induced electrons and holes.