Patent ID: 8039890

Claim:
A random number generating device comprising: a semiconductor device including a source region, a drain region, a channel region provided between the source region and the drain region, and an insulating portion provided on the channel region, the insulating portion including a trap insulating film having traps based on dangling bonds and expressed by Si U N (U=0.75), conductivity of the channel region varying randomly depending on the amount of charge caught in the traps; and a random number generating unit connected to the semiconductor device and generating random numbers based on a random variation in the conductivity of the channel region; wherein when a gate length is defined as L [μm], a channel width of the channel region is defined as W [μm], a thickness of a tunnel insulating film between the channel region and the trap insulating film is defined as T [nm] (T≧0), and a barrier height of the tunnel insulating film is defined as H [eV], the following relation is satisfied: (( U− 0.75)/(1 +U )+0.01174) 1/2 ×exp(− T{H/ 3.1 [eV]} 1/2 /0.8664[nm])/ LW 2/5 ≧0.37 [μm −7/5 ].