| 摘要: | 本研究利用電子迴旋共振化學氣相沉積(Electron cyclotron resonance chemical vapor deposition, ECR-CVD)於低溫製備磊晶矽薄膜， ECR-CVD屬於高密度電漿具有較快沉積速率、無電極汙染、低離子轟擊等特點。但由於ECR-CVD腔體在製程上的不穩定性，易造成實驗誤差並影響實驗結果。本實驗分析製程參數與腔體環境，找出各製程參數對薄膜結晶率與沉積速率的影響，在製程上分別改變氫稀釋比、製程壓力、微波功率、主磁場位置、基板溫度 、不同薄膜厚度、不同基板與處理方式；在腔體環境上改變腔體預鍍時間，搭配每週沉積相同參數薄膜並記錄ECR-CVD的最低壓力與清腔光譜，找出影響製程穩定性的原因與解決的方法，並藉由光放射光譜儀、橢圓儀、拉曼、X光繞射儀與穿透式電子顯微鏡來量測電漿光譜與薄膜結構特性。
如要得到穩定的製程環境，須注意腔體清潔，並藉由放射光譜儀的監控與適當時間的預鍍，使其電漿狀態穩定，且在實驗過程中注意使用的基板與處理的方式。如要沉積高結晶率的矽薄膜，必須選擇適當的氫稀釋、高的製程壓力、低的微波功率與高的基板溫度，且可以藉由放射光譜儀量測電漿中SiH*強度估算出矽薄膜的沉積速率，減少實驗所須的步驟與時間。
;In this study, the low temperature growth epitaxy silicon (epi-Si) thin films was prepared by Electron Cyclotron Resonance Chemical Vapor Deposition (ECR-CVD). ECR-CVD had many advantages, such as faster deposition rate, no electrode contamination and low ion bombardment. However, unstable process was easy to cause experimental error. We analyzed process parameters to find out how it affects the deposition and crystal rate of the thin film. We also analyzed chamber environments to find out how it affects the process stability. The process parameters effect of epi-Si thin films such as dilution ratio, process pressure, microwave power, main magnetic field position, substrate temperature, thickness of thin film, different substrates and different way to clean the substrates were investigated. The chamber environments effect of process stability such as pre-coating time, the lowest pressure of chamber and the plasma chamber cleaning were investigated. The thin films and plasma were analyzed by optical emission spectroscopy, ellipsometer, Raman spectroscopy, X-ray diffractometer and TEM.
Finally, to keep a stable process chamber, we needed to pay attention to chamber cleaning, suitable pre-coating time, substrate type and the way of substrate cleaning. We used optical emission spectroscopy to diagnose the plasma and to made sure it is stable. The experiment results showed that appropriate dilution ratio, high process pressure, low microwave power and high substrate temperature had higher crystal rate. We used optical emission spectroscopy to measure the intensity of SiH* and calculated the epi-Si thin film deposition rate. It could save the time and steps of experiment. |
