新穎碳化矽金氧半場效電晶體結構設計與模擬

Abstract

近年來，市場對功率半導體元件追求高效率與小尺寸，且為了符合節能與降低系統功率損耗的需求趨勢，各廠商均不斷開發新型的高能源轉換效率的元件，以滿足高效率、可靠度、小型化等要求。功率電晶體在電源供應裝置中是最為受到關注的元件，由於碳化矽材料的材料特性，使得碳化矽金氧半場效電晶體(MOSFET)比傳統矽功率MOSFET有更好的效能與熱表現。 本論文利用TCAD Sentaurus進行4H-SiC碳化矽金氧半場效電晶體的設計，並針對元件結構進行電性的分析，論文一開始對一般的碳化矽MOSFET做閘極氧化層厚度、JFET寬度及混合磊晶層在順向時的表現進行優化，並帶入近年來蓬勃發展的超級接面結構，利用其電荷補償的特性增加逆向時的崩潰電壓，並以英飛凌的CoolSiC^TM產品為目標，模擬的結果成功達到崩潰電壓1200伏特以上，特徵導通電阻小於5 mΩ∙cm^2 且臨界電壓3至5伏特的規格。

In recent years, the market has pursued high efficiency and small size for power semiconductor devices to achieve the demand of energy saving and system power loss reduction. Manufacturers have continuously developed new higher energy conversion efficiency devices to attain high efficiency and reliability. Power transistors are the most attractive attention, due to the material properties of silicon carbide, SiC MOSFET has better efficiency and thermal performance than traditional silicon power MOSFET. In this paper, TCAD Sentaurus is used to design 4H-SiC metal oxide semiconductor field effect transistor and then simulate its electric performance. We analyze the simulation results and optimize the device’s performance by discussing the gate oxide thickness, JFET width and mixed epitaxial layer to optimize the forward electrical performance. We use the charge compensation characteristics of the super junction to increase the breakdown voltage and aim at Infineon's CoolSiC^TM product, the simulation results successfully reach the breakdown voltage of 1200 volts or more, the specific on-resistance is less than 5 mΩ∙cm^2 and threshold voltage is 3 to 5 volts.