使用VHF PECVD探討非晶矽薄膜於N型矽基板之鈍化效果

Effects of Passivation Layer Deposited on N-type Crystalline Silicon by Using VHF 40.68 MHz Plasma Enhanced Chemical Vapor Deposition

林家豪(Jia-Hao Lin) ； 吳宏偉(Hung-Wei Wu) ； 田偉辰(Wei-Chen Tien) ； 洪政源(Cheng-Yuan Hung) ； 劉世坤(Shih-Kun Liu)

《真空科技》 31卷2期 (2018/06) Pp. 22~1-22~6

摘要

本研究提出了一種超高頻(40.68 MHz)電漿增強化學氣相沉積法(PECVD)在n型矽基板上沉積一層鈍化層，氫化非晶矽(a-Si:H)薄膜厚度為15 nm。鈍化層沉積在n型矽基板的上下兩面。在矽基板上沉積鈍化層是太陽能電池研發中的重要製程步驟，且可用於提升入射光於太陽能電池元件的效能。透過研究超高頻(VHF) PECVD的功率密度可以了解鈍化層品質與製程條件的相對關係。當以50 mW/cm^2的功率密度和800 mTorr的製程壓力進行沉積鈍化層薄膜時載子生命週期為836 μs。

關鍵字

非晶矽薄膜 ； 鈍化 ； 電漿輔助化學氣相沉積系統

並列摘要

This study presents an approach to depositing passivation layers (a-Si:H thin films with a thickness of 15 nm) on an n-type crystalline silicon wafer using very high frequency (40.68 MHz) plasma-enhanced chemical vapor deposition (PECVD). The passivation layers were deposited on the top and bottom of the n-type crystalline silicon wafer. Depositing passivation layers on a crystalline silicon wafer is a key step in the development of solar cells and is useful for improving the confinement of incident light within silicon thin films. By studying the power densities of PECVD, this study could clearly understand the relationship between thin-film quality and process conditions. The crystallinity of the a-Si:H thin films was approximately 19% (approaching a nanocrystalline structure) when PECVD was conducted at a power density of 50 mW/cm^2 and a process pressure of 800 mTorr. The silicon wafer carrier lifetime was 836 μs. The proposed approach can be applied in thin-film solar cell processes.

並列關鍵字

Amorphous Silicon Thin Film. Passivation ； Plasma Enhanced Chemical Vapor Deposition ； PECVD