High temperature electron transport properties of AlGaN/GaN heterostructures with different Al-contents  

作　　者：ZHANG ZhongFen ZHANG JinCheng XU ZhiHao DUAN HuanTao HAO Yue 

机构地区：[1]Key Laboratory of Wide Band Gap Semiconductor Materials and Devices,Microelectronics Institute,Xidian University,Xi’an 710071,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2009年第12期1879-1884,共6页中国科学：物理学、力学、天文学（英文版）

摘　　要：Electron transport properties in AlGaN/GaN heterostructures with different Al-contents have been in-vestigated from room temperature up to 680 K. The temperature dependencies of electron mobility have been systematically measured for the samples. The electron mobility at 680 K were measured as 154 and 182 cm2/V.s for Al0.15Ga0.85N/GaN and Al0.40Ga0.60N/GaN heterostructures,respectively. It was found that the electron mobility of low Al-content Al0.15Ga0.85N/GaN heterostructure was less than that of high Al-content Al0.40Ga0.60N/GaN heterostructure at high temperature of 680 K,which is different from that at room temperature. Detailed analysis showed that electron occupations in the first subband were 75% and 82% at 700 K for Al0.15Ga0.85N/GaN and Al0.40Ga0.60N/GaN heterostructures,respectively,and the two dimensional gas (2DEG) ratios in the whole electron system were 30% and near 60%,respectively. That indicated the 2DEG was better confined in the well,and was still dominant in the whole electron system for higher Al-content AlGaN/GaN heterostructure at 700 K,while lower one was not. Thus it had a higher electron mobility. So a higher Al-content AlGaN/GaN heterostructure is more suitable for high-temperature applications.Electron transport properties in AlGaN/GaN heterostructures with different Al-contents have been investigated from room temperature up to 680 K. The temperature dependencies of electron mobility have been systematically measured for the samples. The electron mobility at 680 K were measured as 154 and 182 cm2/V·s for Al0.15Ga0.85N/GaN and Al0.40Ga0.60N/GaN heterostructures, respectively. It was found that the electron mobility of low Al-content Al0.15Ga0.85N/GaN heterostructure was less than that of high Al-content Al0.40Ga0.60N/GaN heterostructure at high temperature of 680 K, which is different from that at room temperature. Detailed analysis showed that electron occupations in the first subband were 75% and 82% at 700 K for Al0.15Ga0.85N/GaN and Al0.40Ga0.60N/GaN heterostructures, respectively, and the two dimensional gas (2DEG) ratios in the whole electron system were 30% and near 60%, respectively. That indicated the 2DEG was better confined in the well, and was still dominant in the whole electron system for higher Al-content AlGaN/GaN heterostructure at 700 K, while lower one was not. Thus it had a higher electron mobility. So a higher Al-content AlGaN/GaN heterostructure is more suitable for high-temperature applications.

关 键 词：ALGAN/GAN HETEROSTRUCTURE high-temperature ELECTRON-TRANSPORT 

分 类 号：O471[理学—半导体物理]