Influence of temperature on strain-induced polarization Coulomb field scattering in AlN/GaN heterostructure field-effect transistors

作     者：吕元杰 冯志红 林兆军 郭红雨 顾国栋 尹甲运 王元刚 徐鹏 宋旭波 蔡树军 

作者机构：National Key Laboratory of Application Specific Integrated Circuit (ASIC)Hebei Semiconductor Research Institute School of PhysicsShandong University 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2014年第23卷第7期

页      面：645-648页

核心收录：

学科分类：07[理学] 070203[理学-原子与分子物理] 0805[工学-材料科学与工程（可授工学、理学学位）] 0704[理学-天文学] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.61306113 and 11174182) 

主　　题：AlN/GaN electron mobility polarization Coulomb field scattering polarization 

摘      要：Electron mobility scattering mechanism in AlN/GaN heterostuctures is investigated by temperature-dependent Hall measurement, and it is found that longitudinal optical phonon scattering dominates electron mobility near room temperature while the interface roughness scattering becomes the dominant carrier scattering mechanism at low temperatures （~ 100 K）. Based on measured current-voltage characteristics of prepared rectangular AlN/GaN heterostructure field-effect transistor under different temperatures, the temperature-dependent variation of electron mobility under different gate biases is inves- tigated. The polarization Coulomb field （PCF） scattering is found to become an important carrier scattering mechanism after device processing under different temperatures. Moreover, it is found that the PCF scattering is not generated from the thermal stresses, but from the piezoelectric contribution induced by the electrical field in the thin A1N barrier layer. This is attributed to the large lattice mismatch between the extreme thinner AlN barrier layer and GaN, giving rise to a stronger converse piezoelectric effect.