以ICP-CVD製備之微晶矽薄膜與其光電特性之研究

Study of Optical and Electrical Properties for Microcrystalline Silicon Thin Films Prepared by ICP-CVD

田偉辰(Wei-chen Tian)

指導教授 ： 廖慶聰

共同指導教授 ： 翁敏航(Min-Hang Weng)

崑山科技大學/工程學院/機械工程研究所/碩士(2008年)

摘要

本研究使用感應式耦合電漿輔助化學氣相沉積系統（inductively coupled plasma chemical vapor deposition ，ICPCVD）製備一微晶矽（μc-Si）薄膜，以作為薄膜太陽能電池之半導體材料。本實驗以改變基板溫度、射頻功率及氫氣流量沈積出各種不同微晶矽薄膜，經由微拉曼光譜分析儀(micro Raman Spectrometer)、傅利葉轉換紅外線光譜儀(Fourier Transform Infrared Spectrometer, FTIR)、薄膜X光繞射儀(X-Ray Thin Film Diffractometer)、冷場發射式電子顯微鏡（Cold Field Emission Scanning Electron Microscope）、霍爾量測（Hall Measuremnet）、及紫外光/可見光吸收光譜儀(UV-visible spectroscopy)等設備的分析結果來瞭解微晶矽之微結構、電特性及光學特性。
由實驗結果可得知，提升基板溫度與射頻功率此二參數，均可改善微晶矽薄膜之微結構、電特性及光學特性。在結構上可有效改善微晶矽薄膜之結晶度，最高結晶度可達80%而晶粒大小也可達到15nm；在電性上可增加其載子移動率至80 cm2/V-s，光學特性上也可增加光譜吸收範圍達500nm至850nm。但改變氫氣與矽烷之比例，並未有顯著改變其薄膜特性。

關鍵字

微晶矽 ； 薄膜太陽能電池 ； 感應式耦合電漿輔助化學氣相沉積系統

並列摘要

To improve the efficiency of the solar cell device a microcrystalline silicon (µc-Si:H) thin film fabricated by the inductively coupled plasma chemical vapor deposition is studied. Several process parameters such as the hydrogen (H2) gas flows, the substrate temperatures and the radio frequencies (RF) power are selected to make µc-Si:H thin films and then investigate the effects of these parameters on the performance of µc-Si:H thin films. The structural, optical and electrical properties of µc-Si:H thin films are quantitatively measured by Raman spectrum, X-Ray, FTIR, Hall measuremnet, SEM and UV-visible etc.
From the results, it can be observed that the relative crystallinity, the crystal size, the mobility and the range of optical absorption spectrum of µc-Si:H thin films are increased as the increase of the substrate temperature and RF power. In this study, the optimum value of the crystal size observed by Scherrer equation can reach to 15nm. Moreover, the crystallinity factor of µc-Si:H films for each dilution ratio deposited at higher substrate temperature was about 80%. In addtition, the best value of mobility almost reach to 80 cm2/V-s. Nevertheless, results also reveal that changing the dilution ratio of hydrogen to silane won’t improve the performance of µc-Si:H thin films.

並列關鍵字

Microcrystalline Silicon ； Thin Flim Solar Cell ； Inductively Coupled Plasma Chemical Vapor Deposition ； ICPCVD

參考文獻

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