碳化矽雙溝槽累積型通道場效電晶體結構設計與模擬

Design and Simulation of SiC Dual Trench Accumulation Channel Field Effect Transistor (ACCUFET) Structure

李龍杰(Lung-Chieh Lee)

指導教授 ： 李坤彥

國立臺灣大學/工學院/工程科學及海洋工程學研究所/碩士(2014年)

https://doi.org/10.6342/NTU.2014.10899

摘要

為了改善電力電子系統的能量轉換效率，我們應該要設法降低半導體功率元件在導通和切換時的能量損耗，而碳化矽功率元件正是這方面的首選，因為其優異的材料性質讓它們特別適合做高電流密度和高溫的應用。在各種功率元件中，碳化矽功率金氧半電晶體的高頻切換能力使其最受矚目，然而，低通道載子遷移率、高表面態密度和劣等的氧化層穩定度一直都是該元件發展中的阻礙，我們必須克服這些難題，其中一個辦法就是提出新的元件結構。
本論文藉由Silvaco軟體設計碳化矽雙溝槽式累積型金氧半功率電晶體，針對元件結構進行製程和電性模擬，就元件內部各區塊的濃度、深度和寬度等作最佳化分析，最後預計達到元件崩潰電壓1200伏特、導通電阻5 以下 及啟動電壓(Vth)2至4伏特的規格。

關鍵字

金氧半功率電晶體 ； 4H-碳化矽 ； 累積型金氧半功率電晶體 ； 氧化層穩定度 ； 功率元件

並列摘要

To improve the energy conversion efficiency of power electronic systems, it is necessary to reduce the power losses during switching and on-state conduction of power semiconductor devices. SiC power devices are the best candidates because they have excellent material properties for high power density and high temperature applications. Among all sorts of power devices, SiC power MOSFET attracts the most attention because of its high frequency switching capability. However, low channel mobility, high interface state density as well as inferior oxide reliability still remain to be major obstacles to the development of SiC power MOSFET over the years. Therefore, it is imperative for us to overcome these issues. One way is to devise new power device structure.
In this thesis, a novel device structure called “dual trench ACCUFET” is proposed. We then simulate its electric performance and fabrication processes by using Silvaco software. After that, we analyze the simulation results and optimize the device’s performance by parameter, such as doping concentration, thickness and width, hoping to design a device exhibiting the breakdown voltage of 1200 volts, the on-resistance under 5 and the threshold voltage between 2 to 4 volts.

並列關鍵字

MOSFET ； 4H-SiC ； ACCUFET ； oxide reliability ； power device

參考文獻

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