穿隧式低溫多晶矽薄膜電晶體研製與應用

Fabrication and Application of Tunneling Low Temperature Poly-Silicon Thin Film Transistors

翁偲傑(Ssu-Chieh Weng)

指導教授 ： 李敏鴻

國立臺灣師範大學/理學院/光電科技研究所/碩士(2009年)

摘要

利用band to band tunneling的觀念，試著驗證可將subthreshold swing小於60 mV/dec.。側向多晶矽的p/i/n結構不只是光二極體，也可以是穿隧式薄膜電晶體在未來的應用上。而我們去驗證水平低溫多晶矽薄膜電晶體並且檢驗元件的可靠度(Reliability)。實驗中得知，穿隧電流隨溫度的變化可以加以證明，確實是band to band tunneling效應的影響；再與一般薄膜電晶體比較可靠度也是相對的好。最後，用垂直式(vertical)不同的結構去驗證是否也有穿隧效應，並且用TCAD-ISE去模擬驗證其結果。 目前為止，穿隧式薄膜電晶體仍有些需要被解決的問題。此論文目的就是透過元件製程與電性分析及元件模擬的各項參數來實踐獲得高效能的穿隧式薄膜電晶體。由於穿隧式薄膜電晶體可如傳統式薄膜電晶體用於邏輯電路上，所以穿隧式薄膜電晶體替代在低功率行動裝置上的應用是一個前瞻性的元件。

關鍵字

次臨界擺幅 ； 可靠度 ； 穿隧式 ； 薄膜電晶體

並列摘要

The concept of band to band tunneling from p+ and n+ region is researched to realize for Tunneling–TFTs with subthreshold swing < 60 mV/dec. We have demonstrated the LTPS planar Tunneling-TFTs and examined the reliability. The lateral poly-Si p/i/n structure is not only photodiode, but also tunneling-TFTs for future applications. The temperature dependence of tunneling current proves that the current is indeed due to the band to band tunneling effect. The Tunneling-pTFTs exhibits excel threshold voltage stability under constant drain current stress as compare with classical pTFTs for self-heating effect. The practical devices with the gate-controlled tunneling current and the low off-current attracts for the applications in the future. Final, the different structure of vertical is to verify whether the tunnel effect and utilize TCAD-ISE simulation results to verify.
So far, some issues of Tunneling-TFTs are still need to be resolved. In this thesis, further study of various device parameters for obtaining high-performance Tunneling-TFTs is carried out via process and electrical characteristics of device. Since there are not too many additional process steps compare with MOSFET, the Tunneling-TFTs is an advancing device for low-power mobile applications.

並列關鍵字

subthreshold swing ； Reliability ； Tunneling ； Thin Film Transistors

參考文獻

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