由於光纖通訊蓬勃發展，光纖通訊系統中光檢測器的重要性與日遽增，而矽基材料相對於Ⅲ-Ⅴ族化合物半導體的製程較為簡單且成熟，因此即使本身為非直接能隙材料，仍被廣泛應用於光檢測元件的製作。故本論文首先探討非晶矽/晶質矽異質接面金屬-半導體-金屬矽基光檢測器製程與特性的改善。在論文中，首先針對非晶質矽合金薄膜對金屬-半導體-金屬矽基光檢測器暫態響應的影響做一系統性研究。接著則針對光檢測器在高溫時的漏電流機制做一詳盡的探討。再者，利用自行對準技巧簡化光檢測器的製程，只需一道光罩即可完成元件製作。最後則採用類似量子井的非晶質薄膜結構有效提昇金屬-半導體-金屬矽基光檢測器的靈敏度，此種結構元件即使在相當弱的入射光照射下(0.5微瓦)，仍可產生相當高的光電流對暗電流比值，可有效降低元件在操作時的位元錯誤率(bit error rate)。 另外，由於全彩顯示器應用市場廣大，且薄膜電晶體驅動的高分子發光二極體已成為相當重要的發光組件之一，為使薄膜電晶體與高分子發光元件的製程能進一步整合，在本論文中，我們也詳細地探討具非晶質矽基薄膜（薄膜電晶體的主要材料之一）電子與電洞注入層之高分子發光二極體的特性，成功地將有機與無機材料做一應用結合。實驗結果顯示非晶質矽基電子與電洞注入層能取代有機電子與電洞注入層，而提供有機發光層足夠的電子與電洞以利產生輻射性復合而發光。 Abstract The Si-based metal-semiconductor-metal photodetectors (MSM-PDs) had been extensively studied to improve their performances. Firstly, the effects of trap-states in a composition-graded intrinsic hydrogenated amorphous silicon-germanium (i-a-Si1-xGex:H) film on MSM-PDs’ performances were studied. The experimental results indicated that the fall time of the device transient response could be reduced significantly by employing the i-a-Si1-xGex:H layer. Secondly, the higher dark-current temperature-dependence for trench-electrode Si-based MSM-PD having an i-a-Si:H dark-current suppressing layer had been studied and improved. The poor dark-current temperature-dependence could be improved significantly by reducing the trap-states in the depletion region of the reverse-biased crystalline/amorphous Si heterojunction. Thirdly, an one-mask self-aligned technique was successfully used to fabricate trench (U-grooved)-electrode Si-based MSM-PDs. Only one photolithography mask was needed during fabrication and could drastically facilitate this device to be integrated with other devices. At last, the a-Si:H/a-SiC:H (hydrogenated amorphous silicon carbide) multi-layers were employed to enhance the sensitivity of a MSM-PD. By employing the a-Si:H/a-SiC:H multi-layers, the device dark-current could be suppressed drastically and hence when the device was illuminated under a very weak incident light power (0.5μW), the device photo to dark current ratio ( under 4 V bias voltage) could be 103 times higher than that of conventional one. Also, in order to investigate the feasibility of combining polymer and inorganic films for LED fabrication, the inorganic p-a-Si:H (or p-a-SiC:H) / n-a-SiCGe:H layers were employed as hole/electron injection layers (HILs/EILs) in the MEH-PPV polymer LEDs (PLEDs). By employing the amorphous HIL/EIL, the PLED’s threshold voltage could be reduced and brightness could be enhanced.
