本研究利用電漿輔助化學氣相沉積(PECVD)引入矽甲烷(SiH4)、氫氣(H2)、氬氣(Ar)製備超薄氫化非晶矽本質鈍化層(< 10 nm)於矽基板上於以應用在異質接面太陽能電池。異質接面太陽能電池所需較薄之本質鈍化層，而PECVD腔體製程環境會影響本質鈍化層之品質，故如何在適當之製程環境維持本質鈍化層之優良鈍化效果是本研究專注的課題。本研究針對PECVD之製程環境變化進行探討，以期望在PECVD機台設備開發上能維持本質鈍化層之優良鈍化效果的成長。研究過程中，利用量測薄膜性質如：氫含量、結構變化…等，並搭配光放射光譜儀與四極柱質譜儀做即時性的電漿診斷分析，期望找出電漿組態對於製程環境變化之影響，並藉由此結論，在尚未成長薄膜前，就先營造出適當之製程環境。 研究結果顯示，在相同製程參數下無預鍍所沉積之本質鈍化層其載子生命週期為24us，但經預鍍後其載子生命週期可達約800us，透過光放射光譜(OES)及四極柱質譜(QMS)分析製程環境之差異性。於本PECVD系統中其SiH*放光強度需達飽和、Si*/SiH*相對強度比值達0.3~0.4之間、SiH2/SiH4之相對自由基濃度需達最低點、腔體內水氣含量降至2x106(c/s)以下、清潔腔體產生之F副產物需減少其存在以及需控制預鍍厚度約在1800nm~1900nm之間。上述研究及分析結果可獲得適當之製程環境於本PECVD系統中。 ;In this study, ultra-thin hydrogenated amorphous silicon passivation layer (< 10 nm)was prepared on silicon substrate by using silane (SiH4), hydrogen (H2) and argon (Ar) to apply silicon heterojunction (SHJ) solar cells. The chamber of PECVD processing environment will affect the quality of growing intrinsic passivation layer due to the fact that SHJ solar need a very thin passivation layer. It is our focus of this study on how to maintain processing an excellent passivation layer in a better pre-coating environment. Therefore, the changes of the pre-coating environment in PECVD were investigated. The results show that the passivation film with no pre-coating has a carrier lifetime of 24us, but after pre-coating its carrier lifetime up to 800us. The difference between pre-coating environment and without pre-coating environment can be analyzed by Optical Emission Spectroscopy (OES) and Quadrupole mass spectrometry (QMS). It is found that an appropriate environment of pre-coating established as follows：the absolute intensity of SiH* needs to be saturated, the ratio of Si*/SiH* is 0.3~0.4, the ratio of SiH2/SiH4 to reaches the lowest point, the water vapor is reduced to 2x106(c/s), by-products of F after cleaning needs to be reduced and thickness control on the pre-coating is 1800nm~1900nm. The best pre-coating environment in the PECVD system can be obtained from above experimental and analytical results.
