Characterization of and detection of defects in semiconductor crystals by infrared light scattering tomography

晶体中的缺陷，如位错、层错、分离的杂质和间隙原子，会根据它们的无序位置诱导出具有无序相的散射光，因为所有原子都是从由激光束照射产生的偶极子中辐射出来的。由于砷化镓晶体的电学特性强烈依赖于EL2中心，因此对于光电和高电子迁移率器件，必须控制和调整其密度和分布，其中红外光散射层析成像（IR-LST）对于这些处理非常有用，因为IR-LST可以清楚地观察到中心。由于EL2中心引起的吸收和散射的色散是由捕获在EL2中心的电子的共振引起的。由于ZnSe晶体是蓝色激光器最有前途的候选材料之一，利用LST和拉曼散射层析成像（RST）成功地检测了晶体的缺陷并对其进行了表征。在这里，LST观察到一种新的位错习惯：许多位错堆积在晶体（111）平面上的薄层内，这被称为“位错壁”。由于单晶层是外延生长在Cz-Si晶片的剥蚀带上，因此Cz-Si晶片的本征捕集中心的密度和分布以及剥蚀带的质量对晶片表面的平面器件非常重要，因此是最重要的关键因素。位于镜面抛光表面下方的缺陷对外延生长是非常有害的，即使它们非常微小和稀少。在这里，我们开发了一种内部全反射（ITR）方法，可以清晰准确地检测缺陷和间隙氧原子，因为只有被缺陷和间隙原子散射的光才能通过镜面，因为这些光以小于全反射角的角度撞击到表面，而全反射阻止了激光束的主要部分通过。少

Defects in crystals, such as dislocations, stacking faults, segregated impurities and interstitial atoms, will induce scattered light with disordered phases according to their disordered positions, because all atoms radiate from their dipoles generated by illumination of a laser beam.Since electrical characteristics of GaAs crystals is strongly dependent upon EL2 centers, their density and distribution must be controlled and adjusted for opto-electric and high electron mobility devices, where infrared light scattering tomography (IR-LST) is very useful for these processing because the centers are clearly observed by IR-LST.Dispersions of the absorption and scattering due to EL2 centers are caused by resonance of electrons trapped in the EL2 centers.Since ZnSe crystal is one of the most promising candidates for blue lasers, detection of defects in and characterization of the crystals are successfully done by LST and Raman scattering tomography (RST). Here, a new habit of dislocations wa … More s observed by LST : many dislocations were piled up within thin layrs on (111) planes of the crystals, which are called "DISLOCATION WALLS".Density and distribution of intrinsic gettering (IG) centers and quality of denuded zones in Cz-Si wafers are very important for planar devices on wafer surfaces because a sigle crystalline layr is epitaaxially grown on the denuded zone, which is, therefore, the most important key factors.The defects located just under a mirror polished surface are very harmful for the epitaxial growth, even if they were very tiny and few. Here we have developed an inside total reflection (ITR) method to clearly and accurately detect the defects and interstitial oxygen atoms there, because only the light scattered by the defects and interstitial atoms can pass through the mirror surface since this light impinges ontothe surface with angles smaller than the total reflection angle while the total reflection prevents the main part of the laser beam from passing through. Less