Orientation Effects on InGaP/GaAs HBT
晶向对InGaP/GaAs HBT性能的影响

Orientation effect on self-aligned InGaP/GaAs HBT is described.The DC current gain of the transistor with the emitter long edge parallel to orientation is greater than that of parallel to .But it shows slightly better RF performance for orientation with .f. t 69GHz compared to .f. t of 62GHz for the orientation.In previous paper,the DC current gain difference of between the two orientation transistors is attributed to the piezoelectric effect,but the difference of .f. t is not explained.It is proposed that the dependence of the characteristics is attributed to both piezoelectric effect and the difference between etched pattern in different directions.