Effect of gate engineering in submicron GaAs MESFET for microwave frequency applications

We present an approach of GaAs MESFET incorporating the gate engineering effect to improve immunity against the short channel effects in order to enhance the scaling capability and the device performance for microwave frequency applications. In this context, a physics-based model for I–V characteristics and various microwave characteristics such as transconductance, cut-off frequency and maximum frequency of oscillation of submicron triple material gate（TM） GaAs MESFET are developed. The reduced short channel effects have also been discussed in combined designs i.e. TM, DM and SM in order to show the impact of our approach on the GaAs MESFETs-based device design. The proposed analytical models have been verified by their good agreement with 2D numerical simulations. The models developed in this paper will be useful for submicron and microwave analysis for circuit design.

半绝缘非掺GaAs材料制备的MESFETs背栅效应

设计了一套适用于二种工艺（离子注入隔离工艺和半绝缘衬底自隔离工艺）的背栅效应测试版图，用选择离子注入形成有源层和欧姆接触区，在非掺杂的半绝缘ＧａＡｓ 衬底上制备ＧａＡｓ ＭＥＳＦＥＴｓ 器件．研究了这二种不同工艺制备的ＭＥＳＦＥＴｓ 器件的背栅效应以及不同距离背栅电极的背栅效应大小．结果表明，采用离子注入隔离工艺制备的ＭＥＳＦＥＴｓ 器件的背栅效应要比采用半绝缘衬底自隔离工艺制备ＭＥＳＦＥＴｓ器件的背栅效应小，背栅效应的大小与距离近似成反比，采用隔离注入的背栅阈值电压随距离变化的趋势比采用衬底自隔离的更大．

MESFET的源漏电压和旁栅间距对旁栅阈值电压的影响

研究了MESFET的源漏电压对旁栅阈值电压的影响和旁栅间距与旁栅阈值电压的关系。结果表明源漏电压的大小对旁栅阈值电压有一定的影响，旁栅阈值电压的大小与旁栅间距大致成正比。