不同能量和注量电子辐照对InP HEMT材料电学特性影响

本文采用气态源分子束外延法(GSMBE)制备了匹配型InGaAs/InAlAs磷化铟基高电子迁移率器件(InP HEMT)外延结构材料。针对该外延结构材料开展了不同能量和注量电子束辐照试验，测试了InP HEMT外延结构材料二维电子气（2DEG）辐照前后的电学特性，获得了辐照前后InP HEMT外延材料二维电子气浓度和迁移率归一化退化规律，分析了不同能量和注量电子束辐照对外延材料电学特性的影响。结果发现：在相同辐照注量2×1015 cm-2条件下，电子束辐照能量越高，InP HEMT外延材料电学特性退化越严重；15 MeV电子束辐照时，当辐照注量超过4×1014 cm-2后，外延材料电学特性开始明显退化，当电子辐照注量达到3×1015 cm-2后，外延材料电学特性退化趋势减弱趋于饱和。产生上述现象原因如下：电子束与材料晶格发生能量传递，产生非电离能损(NIEL)，破坏晶格完整性，高能量电子束具有较高的非电离能损，会产生更多的位移损伤缺陷，导致InP HEMT外延材料电学特性更严重退化；InP HEMT外延材料电学特性主要受沟道InGaAs/InAlAs异质界面能带结构和各种散射过程影响，随着电子辐照注量的增加，位移损伤剂量增大，辐射损伤诱导缺陷会在沟道异质界面处集聚直至饱和。

Effects of Electron Irradiation at Different Energy and Fluences on Electrical Properties of InP HEMT Structure

The InGaAs/InAlAs InP high electron mobility transistor (HEMT) structures with lattice matched channels were grown by gas source molecular beam epitaxy (GSMBE). Effects of electron irradiation at different energy and fluence on the electrical properties of InP HEMT structures were comprehensively investigated. It was found that high energy electron beam has an obvious effect on the electrical properties of two dimensional electron gas (2DEG) at the same fluence of 2×1015 cm-2. After the fluence exceeding 4×1014 cm-2, the 2DEG mobility and density begin to decrease obviously, and did not reach saturation until the fluence was more than 3×1015 cm-2. These changes could be mainly attributed to the aggregation of irradiation induced defects at the channel heterogeneous interface with the increase of displacement damage dose.