4H碳化硅PNPN自支撑复合膜的HTCVD生长研究

项目名称： 4H碳化硅PNPN自支撑复合膜的HTCVD生长研究

项目编号： No.61274007

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 无线电电子学、电信技术

项目作者： 刘兴昉

作者单位： 中国科学院半导体研究所

项目金额： 82万元

中文摘要： 4H碳化硅功率器件可以极大地提高功率容量、降低能耗，目前阻碍其发展的主要是4H复杂体系外延材料的生长。本研究针对P+N-PN+和P+NP-N+结构进行生长研究，采用高温(2200℃)化学气相沉积方法（HTCVD）制备厚达200多微米的自支撑高纯N-、P-碳化硅耐压膜，以及与之匹配的基区P（或N）和发射区P+、N+薄膜，通过研究HTCVD环境下热场梯度及其对气态源物质传输作用，调节外延材料中的生长层，使各层外延材料相匹配，化学组分、载流子迁移率及其寿命可控。本研究创新点体现在分区间调制气相反应中的源蒸气压，抑制高温下气相中因预反应产生碳化硅粒子，克服碳/硅比例失衡、外延材料富碳或出现硅滴；防止气固反应前沿硅蒸气压不足导致结晶碳化硅热分解，从而可靠地制备出耐高压、大电流、低导通电阻PNPN结构材料。本研究将对超高耐压（>20KV）功率器件的4H-SiC材料实用化、为节能减排打下坚实基础。

中文关键词： 碳化硅；厚膜；流场；基平面位错；绝缘栅双极型晶体管

英文摘要： 4H silicon carbide based power devices can greatly improve the power handling capacity and reduce energy consumption. Currently the main obstacle to their development is the growth of 4H complex epitaxial materials system. Here we will investigate the growth of P+N-PN+ and P+NP-N+ structures. Using ultra-high temperature (2200 C) chemical vapor deposition (HTCVD) methods, we will prepare free-standing high-purity N-, P- silicon carbide membranes with a thickness of more than 200 microns for high reverse voltage resistance, and the matchable layer P (or N) film and the emission layers P+, N+ films as well. We will also investigate the thermal field gradient in HTCVD environment and its effect to mass transports of precursors in carrier gas, to adjust the epitaxial materials growth layers, so each layer of epitaxial materials would match one another, and the chemical ratios, carrier mobility and its lifetime would be controllable. The innovations of this work lie in: the vapor pressure of precursors will be modulated in divided partitions; silicon carbide particles in gas phases produced by pre-reaction at high temperature, the carbon/silicon ratio imbalance and epitaxial materials with carbon rich or silicon drops will be inhibited; thermal decomposition of crystalline silicon carbide due to insufficient of sili

英文关键词： SiC；Thick film；gas flow；BPD；IGBT