A GaN-based enhancement-mode(E-Mode)metal-insulator-semiconductor(MIS)high electron mobility transistor(HEMT)with a 2 nm/5 nm/1.5nm-thin GaN/AlGaN/AlN barrier is presented.We find that the formation of a two-dimension...A GaN-based enhancement-mode(E-Mode)metal-insulator-semiconductor(MIS)high electron mobility transistor(HEMT)with a 2 nm/5 nm/1.5nm-thin GaN/AlGaN/AlN barrier is presented.We find that the formation of a two-dimensional electron gas(2DES)in the GaN/AlGaN/AlN/GaN heterostructure can be controlled by the presence of the plasma-enhanced chemical-vapor deposition(PECVD)Si_(3)N_(4) on the barrier layer,and the degree of decrease in sheet resistance R_(sh) is dependent on the Si_(3)N_(4) thickness.We choose 13 nm Si_(3)N_(4) as the gate insulator to decrease gate current and to improve the threshold voltage of devices.With selective etching of the passivation Si_(3)N_(4) under gate and over fluorine plasma treatment,the MIS-HEMT exhibits a high threshold voltage of 1.8 V.The maximum drain current Id,max and the maximum transconductance are 810 mA/mm and 190 mS/mm,respectively.The devices show a wide operation range of 4.5 V.展开更多
基金Supported by the Fundamental Research Funds for the Central Universities under Grant Nos JY10000904009 and K50510250006and the National Natural Science Foundation of China under Grant Nos 60736033 and 61106106.
文摘A GaN-based enhancement-mode(E-Mode)metal-insulator-semiconductor(MIS)high electron mobility transistor(HEMT)with a 2 nm/5 nm/1.5nm-thin GaN/AlGaN/AlN barrier is presented.We find that the formation of a two-dimensional electron gas(2DES)in the GaN/AlGaN/AlN/GaN heterostructure can be controlled by the presence of the plasma-enhanced chemical-vapor deposition(PECVD)Si_(3)N_(4) on the barrier layer,and the degree of decrease in sheet resistance R_(sh) is dependent on the Si_(3)N_(4) thickness.We choose 13 nm Si_(3)N_(4) as the gate insulator to decrease gate current and to improve the threshold voltage of devices.With selective etching of the passivation Si_(3)N_(4) under gate and over fluorine plasma treatment,the MIS-HEMT exhibits a high threshold voltage of 1.8 V.The maximum drain current Id,max and the maximum transconductance are 810 mA/mm and 190 mS/mm,respectively.The devices show a wide operation range of 4.5 V.
