重掺硅片表面APCVD法生长SiO_(2)薄膜的致密性  

Compactness of SiO_(2)Films Grown by APCVD Method on Heavily-Doped Silicon Wafer Surface

作　　者：史延爽 王浩铭 田原[1] 张旭 武永超[1] Shi Yanshuang;Wang Haoming;Tian Yuan;Zhang Xu;Wu Yongchao(The 46^(th)Research Institute,CETC,Tianjin 300220,China)

机构地区：[1]中国电子科技集团公司第四十六研究所,天津300220

出　　处：《半导体技术》2024年第6期544-548,共5页Semiconductor Technology

摘　　要：在硅片加工过程中,金属杂质的存在会增大pn结器件的漏电流,甚至直接导致pn结禁带宽度变窄,为防止出现硅外延过程中造成的自掺杂现象,通常在硅片表面生长一层高致密性的SiO_(2)薄膜。基于常压化学气相沉积(APCVD)法在6英寸(1英寸≈2.54 cm)n型硅片表面生长SiO_(2)薄膜,首先研究不同沉积温度、SiH_(4)和O_(2)的体积流量比对沉积速率和SiO_(2)薄膜致密性的影响,进一步探究了不同退火温度对SiO_(2)薄膜致密性的影响,以期获得致密性较高的SiO_(2)薄膜。采用HF腐蚀速率法表征其致密性,采用扫描电子显微镜(SEM)观察SiO_(2)薄膜的表面形貌,采用F50膜厚测试仪测试SiO_(2)薄膜的厚度。结果表明,沉积温度为400℃,SiH_(4)和O_(2)的体积流量比为1∶10,退火温度为1100℃时,制备的SiO_(2)薄膜的致密性为0.096 nm/s(采用体积分数为1%的HF腐蚀)。In the process of silicon wafer processing,the presence of metal impurities will increase the leakage current of pn junction device,even directly leading to the narrowing of the pn junction band gap.To prevent self-doping caused by silicon epitaxy,a layer of SiO_(2)film with high compactness is usually grown on the surface of the silicon wafer.SiO_(2)films with high compactness were grown on the surface of 6-inch(1 inch≈2.54 cm)n-type silicon wafers by atmospheric pressure chemical vapor deposition(APCVD)method.Firstly,the effects of different deposition temperatures and volume flow ratios of SiH_(4)and O_(2)on the deposition rate and the compactness of SiO_(2)films were investigated.Then,the effect of different annealing temperatures on the compactness of SiO_(2)films was investigated,in order to obtain SiO_(2)films with high compactness.The compactness of SiO_(2)films was characterized by HF corrosion rate method,the surface morphology of SiO_(2)films was observed by scanning electron microscope(SEM),and the thickness of SiO_(2)films was measured by F50 film thickness tester.The results show that the compactness of the prepared SiO_(2)film(corroded with HF with a volume fraction of 1%)is 0.096 nm/s at a depositon temperature of 400℃,a volume flow ratio of SiH_(4)to O_(2)of 1∶10 and the annealing temperature of 1100℃.

关 键 词：常压化学气相沉积(APCVD)法 SiO_(2)薄膜 致密性 自掺杂 沉积速率 

分 类 号：TN305.5[电子电信—物理电子学]