InP中点缺陷迁移机制的第一性原理计算

First-principles calculations of point defect migration mechanisms in InP

磷化铟作为重要的第二代半导体材料,具有禁带宽度大、电子迁移率高、光电转换效率高、抗辐照性能强等优点,是制备航天器电子器件优良材料之一.但空间辐射粒子在磷化铟电子器件中会产生点缺陷,导致其电学性能发生严重下降.本文采用第一性原理方法对磷化铟中点缺陷的稳态结构进行研究,并计算了最近邻位点的缺陷迁移能.通过构建不同电荷态点缺陷的稳态结构,发现了4种稳态结构的铟间隙和3种稳态结构磷间隙.研究空位点缺陷的迁移过程,发现磷空位比铟空位迁移能高,同时带电空位点缺陷迁移能高于中性空位.对于间隙点缺陷迁移过程的研究发现,相较于空位点缺陷,间隙点缺陷迁移能更小.在不同电荷态的铟间隙迁移过程计算中,发现了两种不同的迁移过程.计算磷间隙的迁移过程,发现了特殊的中间态结构引起多路径迁移情况.研究结果有助于深入了解磷化铟材料中缺陷的形成机制和迁移行为,对于设计和制造空间环境中长期稳定运行的磷化铟器件有重要意义.

As an important second-generation semiconductor material,indium phosphide(InP)possesses excellent advantages such as a wide bandgap,high electron mobility,high photoelectric conversion efficiency,and strong radiation resistance.It is considered an excellent material for electronic devices in aerospace applications.However,point defects generated by space radiation particles in InP electronic devices can cause their electrical performance to degrade severely.In this study,first-principles calculations are employed to investigate the stable structures of point defects in InP and calculate the migration energy values of nearest-neighbor defects.Four stable structures of In vacancies and three stable structures of P vacancies are identified by constructing the stable structures of point defects in different charge states.The migration process of vacancy defects is studied,revealing that the migration energy of P vacancies is higher than that of In vacancies.Moreover,charged vacancy defects exhibit higher migration energy values than neutral vacancies.Regarding the migration process of interstitial defects,it is found that the migration energy of interstitial defects is smaller than that of vacancy defects.In the calculation of In interstitial migration process with different charge states,two different migration processes are found.Besides,during the migration calculations of P interstitial,a special intermediate state is discovered,resulting in multiple paths migrating to the nearest-neighbor position in the migration energy barrier diagram.The research results are helpful to understand the formation mechanism and migration behavior of defects in InP materials,and are important in designing and manufacturing InP devices with longterm stable operation in space environment.