电子辐照对InP HEMT二维电子气的影响机理研究

Indium phosphide high electron mobility transistor (InP HEMT) is suitable for deep space communication because of its high frequency, high power gain, low noise and low power consumption. This is attributed to the great electrical properties of the two-dimensional electron gas (2DEG) of the InGaAs channel due to its high saturation velocity and high electron mobility. However, the high-energy electrons in the space radiation environment, which have large electronic energy loss, will introduce micro defects in the material and the atomic mixing in the heterogeneous interface, and cause the degeneration of electron mobility and carrier density of the two-dimensional electron gas. This will lead to the degradation of key parameters (minimum noise figure, cut-off frequency, maximum oscillation frequency, ect.) of RF devices and seriously affect the stability of deep space communication. The research on the influence mechanism of electron radiation effect of two dimensional electron gas in InP HEMT material is carried out in this project. Starting from the formation mechanism of the microscopic defects of InP HEMT material by electron irradiation, the effect of radiation induced defects on the 2DEG mobility scattering mechanism is studied. Focusing on the dependence of 2DEG radiation damage on the growth structure parameters and the influence of electron irradiation on the concentration and mobility of electrons in single quantum well occupied by two subbands, and analyzes the influence mechanism of electron irradiation on 2DEG. The implementation of this project can provide data support for InP HEMT radiation hardened design.

磷化铟高电子迁移率晶体管（InP HEMT）利用InGaAs沟道具有的高迁移率二维电子气(2DEG)来工作，使其具有高速高频、高功率增益、低噪声及低功耗等特点，非常适合应用于深空通信. 然而空间辐射环境的高能电子由于具有大的电子能损，会在材料中引入微观缺陷，并可在异质界面引起原子混合，这都会造成量子阱中二维电子气迁移率μ和密度Ns发生变化，易于诱发射频器件的最小噪声系数、截止频率、最大振荡频率等关键参数退化，严重影响深空通信的稳定性。本项目开展电子辐照对InP HEMT材料2DEG的影响机理研究，从电子辐照对材料和异质界面形成的微观缺陷出发，研究辐照诱导缺陷对2DEG迁移率散射机制的影响，研究2DEG的辐射损伤与生长结构参数的依赖关系，重点研究电子辐照对量子阱中电子占据不同子带浓度、迁移率的影响，分析电子辐照对2DEG的影响机理。本项目的实施可为InP HEMT抗辐射加固设计提供科学依据。

磷化铟高电子迁移率晶体管（InP HEMT）利用InGaAs沟道具有的高迁移率二维电子气(2DEG)来工作，使其具有高速高频、高功率增益、低噪声及低功耗等特点，非常适合应用于深空通信. 但在空间辐射环境中，高能电子会在材料中引入微观缺陷，并在异质界面引起原子混合，造成量子阱中二维电子气迁移率μ和密度Ns发生变化，诱发射频器件的最小噪声系数、截止频率、最大振荡频率等关键参数退化，严重影响深空通信的稳定性。本项目开展了电子辐照对InP HEMT材料2DEG的影响机理研究。研究发现如下：（1）电子辐照导致InAlAs/InGaAs量子阱材料中形成点缺陷，增强量子阱内的缺陷散射，并在量子阱异质界面引起原子混合缺陷，增强异质界面合金无序散射，导致2DEG迁移率退化。（2）电子辐照会诱发δ掺杂Si原子向沟道迁移，增强势垒层的远程电离杂质散射，同时引起应变量子阱应力弛豫，导致异质界面势垒降低，增强界面合金散射和杂质散射，从而导致沟道二维电子气迁移率降低。（3）δ掺杂浓度越大，隔离层厚度较薄，InGaAs 沟道厚度较大，In组分较低的InP HEMT外延结构的二维电子气辐射损伤相对较低。（4）随着电子辐照剂量的增加，量子阱内的二维电子气浓度逐渐降低，导致占据第二子带的电子消失，迁移率降低。通过本项目的实施为InP HEMT抗辐射加固设计提供重要数据支撑。