单晶6H-SiC经氦离子辐照及退火后的微观组织研究  

Microstructural Investigation of Single Crystal 6H-SiC Irradiated by He^+ Ions and Annealed after Post-irradiation

作　　者：李瑞祥 周韦[2] 冉广[1] 沈强[1] 冯琦杰[2] 叶超[1] 李宁[1] 

机构地区：[1]厦门大学,福建厦门361102 [2]中国工程物理研究院,四川绵阳629000

出　　处：《稀有金属材料与工程》2018年第1期378-382,共5页Rare Metal Materials and Engineering

基　　金：中国工程物理研究院NPL;CAEP项目资助(2015AB001)

摘　　要：在400℃下对单晶6H-SiC进行了400keV氦离子辐照,辐照剂量为1×10^(16)He^+/cm^2,随后在1200和1500℃退火30min。采用透射电子显微镜和扫描电子显微镜对辐照态和退火态SiC进行微观结构观察与分析。结果表明,单晶6H-SiC在400℃经氦离子辐照后,仅观察到由辐照引起的位移损伤带,而未观察到明显尺寸的氦气泡。但经1200℃退火30min后,在辐照损伤区域形成了呈血小板状的气泡簇,其主要分布在(0001)晶面上,少量形成在(1120)晶面。辐照未在6H-SiC表面上形成明显尺寸的缺陷,而经1200℃退火30min后,SiC表面出现大尺寸的起泡和凹坑,进一步提高退火温度至1500℃时,表面起泡和形成凹坑更严重,并产生了大量裂纹。本研究同时对微观结构演化的机理进行了分析与讨论。The single crystal 6H-SiC was irradiated by 400 keV He＋ ions with 1 x 1016 He/cm2 fluence at 400 ℃ and then annealed for 30 rain at 1200 and 1500 ℃. The microstructure was observed by transmission electron microscopy and scanning electron microscopy. Results show that only the damaged layer is observed and no visible helium bubbles are formed in SiC matrix after helium ion irradiation at 400 ℃. However, after annealing at 1200 ℃ for 30 min, platelet-like planar bubbles are formed in the irradiated region, which are distributed mainly on the （0001） plane and less on the （1120） crystal plane. There is no visible size defect formed on 6H-SiC surface after helium ion irradiation. But, blisters and craters are formed after annealing at 1200 ℃ for 30 rain and become more severe with annealing temperature increasing. Some cracks are generated after annealing at 1500 ℃. The mechanism of microstructural evolution was also analyzed.

关 键 词：6H-SIC 离子辐照 氦气泡 退火 微观组织 

分 类 号：TL34[核科学技术—核技术及应用]