N极性GaN衬底表面超高真空清洁工艺  

Surface Cleaning Techniques on N-Polar GaN Substrates in Ultrahigh Vacuum

作　　者：王晓冉 黄增立 宋文涛[1,2] 张春玉 陈科蓓 刘争晖 徐耿钊 Wang Xiaorann;Huang Zengli;Song Wentao;Zhang Chunyu;Chen Kebei;Liu Zhenghui;Xu Gengzhao(School of Nano-Tech and Nano-Bionics,University of Science and Technology of China,Hefei 230026,China;Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Suzhou 215123,China;Nano Science and Technology Institute,University of Science and Technology of China,Suzhou 215123,China)

机构地区：[1]中国科学技术大学纳米技术与纳米仿生学院,合肥230026 [2]中国科学院苏州纳米技术与纳米仿生研究所,江苏苏州215123 [3]中国科学技术大学纳米科学技术学院,江苏苏州215123

出　　处：《半导体技术》2023年第8期683-689,712,共8页Semiconductor Technology

基　　金：苏州市基础研究试点项目(SJC2021010);中国科学院率先行动“百人计划”(宋文涛)。

摘　　要：针对经过化学腐蚀预处理并具有清晰台阶流形貌的自支撑N极性GaN衬底,研究了在超高真空中采用氩离子轰击和不同气氛保护下退火等技术进一步对其进行表面清洁的方法,并采用X射线光电子能谱和俄歇电子能谱对处理结果进行分析。实验结果表明,氩离子轰击可有效清除表面的C、O等污染,且处理后的表面能带弯曲值稳定在(1.73±0.12)eV。但是氩离子轰击也会不可避免地造成表面偏析,使表面Ga与N的原子个数比明显上升。而在氮气和氢气的混合气体通过射频等离子体源产生的原子气氛保护下以800℃退火后,既能够去除C、O等表面污染,也能抑制表面N原子的流失和表面偏析。该超高真空处理工艺对N极性GaN衬底表面具有很好的清洁效果。For the free-standing N-polar GaN substrate with clear step-flow morphology after chemical corrosion pretreatment,further surface cleaning methods such as argon ion bombardment in ultrahigh vacuum and annealing under different protective atmospheres were studied,and the treatment results were analyzed by X-ray photoelectron spectroscopy and Auger electron spectroscopy.The experimental results show that C and O contaminations can be effectively removed from the surface and the surface band bending value is stable at(1.73±0.12)eV after argon ion bombardment.However,argon ion bombardment will inevitably cause surface segregation,leading to an obvious increase of Ga to N atom ratio.While after annealing at 800℃ under the protection of mixed atomic atmosphere of N and H produced by RF plasma source,the surface contaminations such as C and O can be removed,and the escaping of N atoms from the surface and surface segregation can be suppressed.The ultrahigh vacuum treatment technology has a good cleaning effect on N-polar GaN substrate surface.

关 键 词：GAN 超高真空 氩离子轰击 退火 能带弯曲 

分 类 号：TN304.23[电子电信—物理电子学] TN305.2