热丝CVD法沉积超薄α-Si∶H钝化膜  

Deposition of Untra-Thin α-Si∶H Passivation Film by HWCVD Method

作　　者：田罡煜 王涛[1] 黄海宾[1] 孙喜莲[1] 高超[1] 岳之浩[1] 袁吉仁[1] 周耐根[1] 周浪[1] 

机构地区：[1]南昌大学光伏研究院,南昌330031

出　　处：《半导体技术》2017年第5期376-381,386,共7页Semiconductor Technology

基　　金：国家自然科学基金资助项目(61306084;61464007;51561022);江苏省能量转换材料与技术重点实验室开放课题基金资助项目(NJ20160032);江西省重点研发计划-技术引进与合作研究-重点项目(2016BBH80043)

摘　　要：采用热丝化学气相沉积法在n型直拉单晶硅圆片表面双面沉积厚度为10 nm的本征非晶硅(α-Si∶H)薄膜。利用光谱型椭偏测试仪和准稳态光电导法研究热丝电流、H_2体积流量和热丝与衬底之间的距离对α-Si∶H薄膜结构和钝化效果的影响。结果表明,热丝电流为21.5~23.5 A时,钝化后硅片的少子寿命随着热丝电流的增加呈现先增加后降低的趋势,热丝电流为23.0 A时,钝化效果最好;H_2体积流量为5~20 cm^3/min时,少子寿命随着H_2体积流量的增加呈现先增加后降低的规律,体积流量为15 cm^3/min时,钝化效果最好;热丝与衬底间距为4~5 cm时,随着间距的增加,薄膜的结构由晶化向非晶化转变,在间距为4.5 cm时硅片的钝化效果达到最优。Intrinsic amorphous silicon （α-Si ： H） films with the thickness of 10 nm were bifacialdeposited on the n-type czochralski silicon wafer surface by using the hot-wire chemical vapor deposition （HWCVD） method. The influences of the filament current, the H2 volume flow rate and the filament-tosubstrate distance on the α-Si ： H passivation film structure and passivation effect were studied by spec- troscopic ellipsometry and quasi-steady-state photoconductance method. The results show that after the passivation the minority carrier life time of the silicon wafer passivated with α-Si ： H films increases firstly and then decreases with the filament current increasing from 21.5 A to 23.5 A. And the passivation effect reaches the optimum state when the filament current is 23.0 A. The minority carrier life time increases firstly and then decreases with the volume flow rate of H2 increasing from 5 cm3 · min-1 to 20 cm3 · min-1 And the passivation effect reaches the optimum value when the volume flow rate of H2 is 15 cm3 · min-1 The main structure of the films transforms from crystalline state to amorphous state with the increase of the distance between the filaments and substrate from 4.0 cm to 5.0 cm. The passivation effect of the silicon wafer reaches the optimum state with a distance of 4.5 cm.

关 键 词：热丝化学气相沉积(HWCVD) 介电常数 非晶硅(α-Si:H)薄膜 钝化 带有 本征薄层的异质结(HIT) 

分 类 号：TN304.055[电子电信—物理电子学]