本論文主要目的在探討使用矽甲烷為原料的高頻電漿輔助化學氣相沉積輔以不同製程方式來製備氫化非晶矽薄膜於單晶矽晶片上形成異質接合。研究重點在利用高頻電漿並輔以脈衝調變的技術，找出缺陷最少的氫化非晶矽長膜的製程模式。膜對於單晶矽的表面鈍化，期望提升矽晶的有效少數載子生命期。
首先，以連續放電之高頻電漿輔助化學氣相沉積方式探討製程參數對非晶矽膜的影響長膜發現，我們找到最佳鍍膜條件為:在反應總壓為壓力400 mTorr、基材溫度180℃、放電之平板間距5 cm、電漿功率密度為31.85 mW/cm2、氫氣稀釋比2.5。在此條件下於矽晶雙面各沉積10 nm奈米厚的氫化非晶矽，其量得矽晶片的少數載子有效載子生命期僅有達413 µs，經過退火處理後可達1255µs，此時暗示開路電壓達為706 mV。
此外，我們將高頻電漿輔助化學氣相沉積輔以改以脈衝調變電漿模式時發現，當脈衝占空比為0.6~0.8時可成長出高品質的氫化非晶矽薄膜，此及同樣在矽晶雙面沉積10 奈米非晶矽膜之後，即可量得晶片之載子生命期達到1040 µs，(對應暗示開路電壓為698 mV)，並施加退火處理後晶片少數載子生命期更可達到1370 µs，此時暗示開路電壓達711 mV。顯示本實驗的脈衝調變電漿模式確實可以長出較低缺陷的氫化非晶矽薄膜。

Hydrogenated amorphous Si (a-Si:H) thin films were prepared on single crystal Si (c-Si) wafers to form a-Si:H/c-Si heterojuction structure using high-frequency plasma-enhanced chemical vapor deposition (HF-PECVD) technique at a reactant dilution ratio of [H2]/[SiH4] = 2.5. Emphasis was placed upon exploring the optimized pulse-modulation mode of HF-PECVD operated at around 40 MHz to obtain a-Si:H thin films with minimum defects that can passivate c-Si well.
First of all, a baseline condition to synthesize a-Si:H thin films was investigated under continuous wave mode of HF-PECVD. The films were of good quality synthesized at 400 mTorr of total pressure, 180℃ of substrate temperature, 5 cm of elelctrode working distance, 31.58 mW/cm2 of plasma power density, and 2.5 of [H2]/[SiH4] reactant dilution ratio. The as-deposited a-Si:H/c-Si heterojuction thus prepared showed a minority carrier lifetime of 413 µs, which was enhanced to 1255 µs after an annealing treatment at 200 ℃for 1 hr.
Then, pulse-modulation of HF-PECVD was adopted which showed that the as-deposited a-Si:H thin films with the least SiH2 bonding amount can be formed at a high pulsing modulation frequency of 3 × 104 Hz and pulsed duty cycles in the range of 0.6 – 0.8. The a-Si:H/c-Si heterojuction prepared under this mode showed a very high minority carrier lifetime of 1040 µs even for the as deposited state. A further heat treatment promoted minority carrier lifetime only a little bit to 1370 µs, corresponding an implied Voc of 711 mV. This results indicated that very low defect grade a-Si:H films can be formed using pulse-modulated HF-plasma mode.

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