Atomic level characterization and property control of surface and interface in nitride semiconductor heterostructures

氮化物半导体异质结构表面和界面的原子级表征及性能控制

基本信息

批准号：
14102010
负责人：
SAKURAI Toshio
金额：
$ 78.54万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (S)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2005
项目状态：
已结题

项目摘要

In this project, atomic-level characterization was carried out in order to understand GaN heteroepitaxy1. Construction of UHVMBE-SPMIn order to characterize and control III-nitride MBE growth in atomic level, new As-free UHVMBE-STM/AFM, which is capable of atomic-resolution imaging of insulators, was constructed.2. Growth of GaN on Si(111) and its polarity controlThe effect of Ga/N flux ratio on the polarity of GaN directly grown on Si(111) was studied by the STM imaging of Ga-rich reconstructions. We found that the N-rich growth condition at nucleation stage is critical for mono N-polar GaN growth.3. Formation of metal-GaN contactMetal-Ga alloyed structures which appear upon depositing metals on GaN(0001) were studied by STM. In the case of Au, c(2x12) was formed, and in the case of Ag, ultrathin film was formed. The ultrathin Ag film was unstable at room temperature, which indicates that the possibility of forming a good ohmic contact is low.4. Halogen etching of GaNEtching process of GaN was studied by exposing GaN(0001) to Cl, and observe the surface before and after annealing using STM. In the case of Ga-terminated surface, the etching proceeds bilayer-by-bilayer, and either step-edge etching or terrace etching was observed depending on the annealing temperature.5. Growth of GaN on Si(111) via ZrB_2 buffer layerZirconium diboride is recently attracting attention as a buffer layer for GaN growth on Si. The surface structure of thin ZrB_2 film epitaxially grown on Si(111), and the growth process of GaN on it was studied using STM and AFM. We found that N-polar GaN grows regardless of the growth conditions, and that the origin of mono-polarity is the stableness of GaN(0001)-ZrB_2(0001) interface of N-polar GaN and Zr-terminated ZrB_2.

在这个项目中，为了了解gan heteroepitaxy1进行了原子级表征。构建UHVMBE-SPMIN的构建，以表征和控制原子水平的III二硝酸盐MBE生长，新的无原本的UHVMBE-STM/AFM，能够对绝缘剂进行原子分辨率成像进行构建。2。通过富含GA的重建的STM成像研究了GAN对Si（111）的生长（111）及其极性控制直接生长的Si（111）的GAN（111）的极性的影响。我们发现，成核阶段的N富生长条件对于单n极gan生长至关重要。3。通过STM研究了在GAN（0001）上沉积金属时出现的金属良好的接触式GA合金结构的形成。在AU的情况下，形成C（2x12），在Ag的情况下，形成了超薄膜。 Ultrathin Ag膜在室温下不稳定，这表明形成良好的欧姆接触的可能性很低。4。通过将GAN（0001）暴露于CL，并使用STM退火前后，研究了GAN的卤素蚀刻过程。在GA端端的表面，蚀刻会进行双层的双层，并且根据退火温度观察到逐步蚀刻或露台蚀刻。5。 GAN在SI上的生长（111）通过ZRB_2缓冲液二吡啶二氮化物的生长引起了人们的注意，作为SI上GAN生长的缓冲层。 Si（111）在SI（111）上均匀生长的薄Zrb_2薄膜的表面结构，并使用STM和AFM研究了GAN的生长过程。我们发现，无论生长条件如何，N极性GAN都会生长，而单极性的起源是n极gan和ZR终止的Zrb_2的GAN（0001）-ZRB_2（0001）界面的稳定性。