[17p-P12-1~27] 13.7 Compound and power electron devices and process technology

[17p-P12-25] Optical AND operation in n-AlGaAs/GaAs heterojunction field effect transistor

〇Takuya Kawazu¹, Takeshi Noda¹, Yoshiki Sakuma¹ (1.NIMS)

Keywords:semiconductor, Schottky metal gate, near-infrared photoresponse

We investigated the near-infrared photoresponses of an n-AlGaAs/GaAs heterojunction field-effect transistor (FET) for the irradiation of the two lights: (A) a laser beam with the energy above the Schottky-barrier which illuminates the gate region uniformly and (B) a laser beam with the energy above the GaAs band gap which illuminates the ungate region locally. We measured a lateral photocurrent in the two dimensional electron gas (2DEG) channel at the n-AlGaAs/GaAs heterointerface and found that the FET acts as an optical AND element; the lateral photocurrent is generated only when both the light A and B illuminate the FET simultaneously. The lateral current flows from right to left when the right side of the FET is illuminated with the light B, while the left side irradiation leads to the current from left to right. The experimental results are well explained by a theory based on the current-continuity equation, where the lateral current in the 2DEG channel is driven by an asymmetric electron transfer resulting from the simultaneous irradiation of the light A and B.