Basic Mechanisms of Radiation Effects in Heterostructure Devices

随着用于军事和商业空间应用的卫星数量的迅速增长，半导体器件的辐射可靠性是一个重要的关注领域。鉴于发射和维护卫星资源的费用很高，认真考虑卫星上先进电子系统的可靠性非常重要。同样，所有的电子系统，特别是核反应堆和武器环境中使用的安全设备，即使在设备意外暴露于中子爆发的情况下，也必须可靠地运行。硅器件的辐射效应已经得到了广泛的研究。相比之下，基于III-V族化合物半导体（例如GaAs）的异质结构器件中的辐射效应的当前知识非常有限。众所周知，这些器件表现出上级性能，特别是在比常规硅器件更高的速度/频率下。因此，越来越多的砷化镓和相关的III-V族化合物半导体器件被用于卫星高速通信系统，本项目的目的是研究两种重要的异质结构器件的辐射效应：（a）高电子迁移率晶体管（HEMT）和（B）异质结双极晶体管（HBT）。这两种类型的器件被广泛地应用于GaAs射频电路和高速数字集成电路中。本研究将使用以下三种不同类型的辐射源：（1）质子（2）电子和（3）中子。我们对上述类型的辐射对感兴趣的设备的影响的知识的现状以及要进行的工作的具体细节在提案的主体中进行了讨论。该计划中涉及的研究问题的一些关键要素是：o进行实验研究，以确定器件不同层中辐射引起的缺陷的特性，以及器件性能的退化o系统地了解辐射感应缺陷的特性之间的关系，o根据辐射知识，建立一个完整的模型，预测器件在实际辐射环境中的性能退化-该研究计划的主要影响将是开发新的器件/电路设计，以提高抗辐射效应的可靠性。拟议的计划还将教育新一代设备工程师，他们在设计，制造和分析用于辐射环境应用的先进异质结构设备方面具有专业技能。预期这将导致具有改进的辐射可靠性的先进III-V族化合物半导体器件。

Radiation reliability of semiconductor devices is an important area of concern with the rapid growth in the number of satellites launched for military and commercial space-applications. Given the high cost of launching and maintaining a satellite-base resource, it is very important to give a careful consideration of the reliability of the sophisticated electronic systems on board the satellite. Similarly, all the electronic systems, especially the safety equipment used in nuclear reactor and weapon environment must operate reliably even in the case of an accidental exposure of the equipment to a burst of neutrons.Radiation effects in silicon devices have been studied extensively. In comparison, the current knowledge of radiation effects in III-V compound semiconductor (e.g. GaAs) based heterostructure devices is very limited. It is well known that these devices exhibit superior performance especially at higher speeds/frequencies than the conventional silicon devices. Hence, increasing numbers of GaAs and related III-V compound semiconductor devices are being used in satellite-based high speed communication systems.The objective of this project is to conduct research on the radiation effects in two important types of heterostructure devices: (a) High Electron Mobility Transistors (HEMTs) and (b) Heterojunction Bipolar Transistors (HBTs). Both types of devices are extensively used in a number of GaAs RF circuits and high-speed digital integrated circuits. The following three different types of radiation sources will be used in this investigation: (1) protons (2) electrons and (3) neutrons. The current status of our knowledge on the effects of the above types of radiation on the devices of interest and the specific details of the work to be conducted are discussed in the main body of the proposal.Some key elements of research issues addressed in this program are:o Conduct experimental investigations of the characterization of the radiation-induced defects in the different layers of the device and the performance degradation of the devices (HEMTs and HBTs) under different types of radiation.o Develop a systematic understanding of the relationship between the characteristics of radiation-induced defects, the basic mechanisms and degradation of the performance of the devices.o Develop a complete model for the prediction of device degradation in actual radiation environment given the knowledge of the radiation-induced defects in the constituent materials of the device structure.A major impact of this research plan will be on the development of new device/circuit designs for greater reliability against radiation effects. The proposed program will also educate a new generation of device engineers with specialized skills in the design, fabrication and analysis of advanced heterostructure devices meant for applications in radiation environment. This is expected to result in advanced III-V compound semiconductor devices with improved radiation reliability.