TiA1和TiPtAu栅GaAs MESFET稳定性研究

在高温和大栅电流下 ,对 Ti Al栅和 Ti Pt Au栅 MESFET的稳定性进行了比较研究 ,结果表明 :( 1)两种器件的击穿电压稳定 ,栅 Schottky接触二极管理想因子 n变化不明显 ;( 2 ) Ti Al栅的 MESFET的栅特性参数 (栅电阻 Rg,势垒高度 Φb)变化明显 ,与沟道特性相关的器件参数 (如最大饱和漏电流 Idss,栅下沟道开路电阻 R0 ,夹断电压 Vp0 等 )保持相对不变 ;( 3)对 Ti Pt Au栅MESFET来说 ,栅 Schottky二极管特性 (栅电阻 Rg,势垒高度 Φb)保持相对稳定 ,与沟道特性相关的器件参数 (如最大饱和漏电流 Idss,栅下沟道开路电阻 R0 ,夹断电压 Vp0 、跨导 gm 等 )明显变化 ,适当退火后 ,有稳定的趋势。这两种器件的参数变化形成了鲜明的对比。

A Study of Stability of GaAs MESFETs with TiAl and TiPtAu Gates

A comparative study of stability of GaAs MESFETs with TiAl and TiPtAu gates at elevated temperature and high current density is presented. Results show that (1) for the two type devices, the breakdown voltage remains stable, ideality factor n changes slightly. (2) the TiAl gate Schottky diode performance parameters (gate series resistance R g, barrier height Φ b) change evidently whereas the device parameters related to channel, such as maximum drain saturation current I dss , open channel resistance R 0 below the gate, pinchoff voltage V p0 etc. remain fairly unchanged. (3) for TiPtAu gate MESFET, the Schottky diode performance remains stable whereas the devices parameters related to channel, such as maximum drain saturation current I dss , open channel resistance below the gate R 0, pinchoff voltage V p0 , the transconductance g m etc. change rapidly, after suitable annealing these parameters tend to be stable. The variations of performance parameters for the two types of MESFETs form a sharp contrast.