【摘要】 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 6 5的样品 ,材料电学性能最好 ,In组分高于 0 6 5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 .更多还原

【Abstract】 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.更多还原