变In组分沟道的MM-HEMT材料电子输运特性研究

在变缓冲层高迁移率晶体管（MM_HEMT）器件中，二维电子气的输运性质对器件性能起着决定作用.通过低温下二维电子气横向电阻的量子振荡现象，结合变温度的Hall测量，系统研究了不同In组分沟道MM_HEMT器件中子带电子迁移率和浓度随温度的变化关系.结果表明，沟道中In组分为0.65的样品，材料电学性能最好，In组分高于0.65的样品，严重的晶格失配将产生位错，引起迁移率下降，大大影响材料和器件的性能. 关键词： 变缓冲层高迁移率晶体管 Shubnikov_de Hass 振荡

Electron transport properties of MM-HEMT with varied channel indium contents

Transport properties of two_dimensional electron gas (2DEG) are crucial to metamorphic high_electron_mobility transistors (MM_HEMT). We have investigated the variations of subband electron mobility and concentration versus temperature from Shubnikov_de Hass oscillations and variable temperature Hall measurements. The results indicate that the electrical performance is the best when the In content is 0.65 in the channel for MM_HEMT. When the In content exceeds 0.65, a large lattice mismatch will cause dislocations and result in the decrease of mobility and the fall of performance in materials and devices.