碳化硅MOS器件栅氧化层的钝化方法  

Passivation of silicon carbide MOS device gate oxide

作　　者：贾一凡 刘祥泰 田梦悦 陆芹 王少青 关云鹤 过立新 李立珺 郭三栋 陈海峰 JIA Yifan;LIU Xiangtai;TIAN Mengyue;LU Qin;WANG Shaoqing;GUAN Yunhe;GUO Lixin;LI Lijun;GUO Sandong;CHEN Haifeng(Key Laboratory of Advanced Semiconductor Devices and Materials,School of Electronic Engineering,Xi'an University of Posts and Telecommunications,Xi'an 710121,China)

机构地区：[1]西安邮电大学电子工程学院新型半导体器件与材料重点实验室,陕西西安710121

出　　处：《西安邮电大学学报》2020年第3期55-63,105,共10页Journal of Xi’an University of Posts and Telecommunications

基　　金：陕西省自然科学基础研究计划项目(2020JM-581);陕西省教育厅专项科学研究计划项目(20JK0909);西安邮电大学青年教师科研基金项目(102-205020025)。

摘　　要：碳化硅是一种典型的第三代半导体材料,适合用于制备高温、高压、大功率和抗辐射的电力电子器件,其金属氧化物半导体(metal-oxide-semiconductor,MOS)结构器件目前存在着沟道迁移率较低、栅氧化层可靠性较差等问题。根据陷阱的分布位置对MOS结构中的陷阱进行了分类,分别研究了NO退火钝化、氮磷同步混合钝化以及碱土金属氧化物钝化对不同类型陷阱的作用效果,并通过材料表征分析,揭示了不同钝化工艺对陷阱特性的影响机理。结果发现,NO退火能够减少界面处和近界面的电子陷阱,但也会在近界面附近引入大量的慢态空穴陷阱。氮磷同步混合钝化工艺通过在SiO2薄膜中引入适当浓度的P元素,能够有效减少氧化层中的陷阱,从而降低了栅漏电流。碱土金属钡氧化物钝化处理,在界面处会形成过氧化钡过渡层,能够降低界面处的陷阱密度。As a typical third-generation semiconductor material,silicon carbide(SiC)is suitable for the preparation of high temperature,high pressure,high power and radiation-resistant power electronic devices.However,the metal oxide semiconductor(MOS)structural devices of current SiC has low channel mobility and poor gate oxide layer reliability.Traps in MOS structures are classified based on the location of these traps.A series of experiments are carried out to study the effects of NO annealing passivation,nitrogen-phosphorus simultaneous passivation and alkali-earth metal oxide passivation on different types of traps.Then the influence mechanism of different passivation processes on trap characteristics is revealed by material characterization analysis.Results show that NO annealing can not only reduce the electron traps at the interface and near interface,but also introduce a large number of slow-state hole traps near the near interface.The nitrogen-phosphorus synchronous mixed passivation process can effectively reduce the trap in the oxide layer by introducing appropriate concentration of P elements in the SiO2 film,thus reducing the gate leakage current.The alkali-earth metal barium oxide passivation treatment can form barium peroxide transition layer at the interface,and therefore reduce the trap density at the interface.

关 键 词：碳化硅 栅氧化层 NO退火 氮磷同步混合 碱土金属氧化物 

分 类 号：TN305[电子电信—物理电子学]