4H-SiC欧姆接触研究及其应用
发布时间：2018-10-30 08:14
【摘要】：4H-SiC是性能优异的宽禁带半导体材料之一,其在高温、高频、高功率和抗辐射器件等方面具有巨大的应用潜力。但是在器件制备过程中,仍存在若干工艺难点,其中关键工艺技术之一是获得良好的欧姆接触。本文针对4H-SiC欧姆接触工艺以及相关器件制备做了如下工作：基于国内外SiC欧姆接触的调研,研究了p型和n型欧姆接触的常用金属体系和形成机理,确定了同时形成p型和n型欧姆接触的金属化方案Ni/Ti/Al,改变Ni的厚度,通过大量系统性实验研究了不同的合金退火温度和退火时间下,不同的Ni厚度对p型和n型4H-SiC欧姆接触的影响,得到同时形成p型和n型欧姆接触比接触电阻分别为4.2×10-5和7.8×10-5Ω·cm2,并采用XRD,AES和AFM等测试手段对该金属体系和4H-SiC接触表面及界面进行分析表征,探究欧姆接触形成机理。并将优化的p型欧姆接触条件应用于3300V4H-SiCPiN金属电极制备过程当中,详述了3300V4H-SiC PiN的工艺流程,并采用研究室化合物半导体工艺线进行流片并测试,器件正向特性良好。基于4H-SiC MOSFET器件的关键工艺,主要介绍了离子注入和激活退火工艺,利用TRIM软件进行离子注入仿真,得到MOSFET器件p+、p well, n+区域的注入条件,并通过SIMS验证得到仿真与实际注入分布一致的结果；基于离子注入和激活退火工艺的开发,并结合同时形成p型和n型欧姆接触的优化条件,确定了适用于4H-SiC MOSFET器件的p型和n型离子注入、激活退火和欧姆接触的工艺条件,并介绍了4H-SiC MOSFET的主要工艺步骤,用于后期器件流片。
[Abstract]:4H-SiC is one of the excellent wide band gap semiconductor materials. It has great application potential in high temperature, high frequency, high power and radiation resistant devices. However, there are still some difficulties in the fabrication of the device, one of the key technologies is to obtain good ohmic contact. Based on the investigation of SiC ohmic contact at home and abroad, the metal systems and formation mechanism of p-type and n-type ohmic contact are studied. The metallization scheme of forming p-type and n-type ohmic contact at the same time was determined. The thickness of Ni was changed by Ni/Ti/Al,. The annealing temperature and annealing time of different alloys were studied by a large number of systematic experiments. The effects of different Ni thickness on the ohmic contact of p-type and n-type 4H-SiC are obtained. The specific contact resistance of p-type and n-type 4H-SiC is 4.2 脳 10-5 and 7.8 脳 10-5 惟 cm2, respectively, and XRD, is used. The contact surface and interface of the metal system and 4H-SiC were characterized by AES and AFM, and the formation mechanism of ohmic contact was investigated. The optimized p-type ohmic contact conditions were applied to the preparation of 3300V4H-SiCPiN metal electrode. The process of 3300V4H-SiC PiN was described in detail. The flow sheet was tested by using the compound semiconductor process line in laboratory. The positive characteristics of the device were good. Based on the key technology of 4H-SiC MOSFET device, this paper mainly introduces the ion implantation and activation annealing process. The implantation conditions of p, p well, n region of MOSFET device are obtained by using TRIM software to simulate the ion implantation. The simulation results are consistent with the actual injection distribution by SIMS verification. Based on the development of ion implantation and activation annealing process and the optimal conditions for forming p-type and n-type ohmic contact at the same time, the process conditions for p-type and n-type ion implantation, activation annealing and ohmic contact for 4H-SiC MOSFET devices are determined. The main process steps of 4H-SiC MOSFET are introduced.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN304.2
本文编号：2299449
[Abstract]:4H-SiC is one of the excellent wide band gap semiconductor materials. It has great application potential in high temperature, high frequency, high power and radiation resistant devices. However, there are still some difficulties in the fabrication of the device, one of the key technologies is to obtain good ohmic contact. Based on the investigation of SiC ohmic contact at home and abroad, the metal systems and formation mechanism of p-type and n-type ohmic contact are studied. The metallization scheme of forming p-type and n-type ohmic contact at the same time was determined. The thickness of Ni was changed by Ni/Ti/Al,. The annealing temperature and annealing time of different alloys were studied by a large number of systematic experiments. The effects of different Ni thickness on the ohmic contact of p-type and n-type 4H-SiC are obtained. The specific contact resistance of p-type and n-type 4H-SiC is 4.2 脳 10-5 and 7.8 脳 10-5 惟 cm2, respectively, and XRD, is used. The contact surface and interface of the metal system and 4H-SiC were characterized by AES and AFM, and the formation mechanism of ohmic contact was investigated. The optimized p-type ohmic contact conditions were applied to the preparation of 3300V4H-SiCPiN metal electrode. The process of 3300V4H-SiC PiN was described in detail. The flow sheet was tested by using the compound semiconductor process line in laboratory. The positive characteristics of the device were good. Based on the key technology of 4H-SiC MOSFET device, this paper mainly introduces the ion implantation and activation annealing process. The implantation conditions of p, p well, n region of MOSFET device are obtained by using TRIM software to simulate the ion implantation. The simulation results are consistent with the actual injection distribution by SIMS verification. Based on the development of ion implantation and activation annealing process and the optimal conditions for forming p-type and n-type ohmic contact at the same time, the process conditions for p-type and n-type ion implantation, activation annealing and ohmic contact for 4H-SiC MOSFET devices are determined. The main process steps of 4H-SiC MOSFET are introduced.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN304.2
【参考文献】
相关博士学位论文 前1条
1 陈丰平;4H-SiC功率肖特基势垒二极管（SBD）和结型势垒肖特基（JBS）二极管的研究[D];西安电子科技大学;2012年
，本文编号：2299449
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