碳化硅宽带隙半导体材料生长技术及应用
发布时间:2008/6/5 0:00:00 访问次数:585
王强,李玉国,石礼伟,孙海波 | |||||
(山东师范大学半导体研究所,山东 济南 250014) | |||||
摘要:概括了宽带隙半导体材料碳化硅的主要特性及生长方法,介绍了其在微电子及光电子领域的应用,并对其发展动态及存在问题进行了简要评述。 关键词:宽带隙半导体;碳化硅;光电子学 1 introduction as it is well known,the traditional si and gaas devices are inapplicable at the temperature above 250 ℃,and they cannot perform well under the conditions of high frequency,high power and strong radiation. when compared with si and gaas,sic material has many advantages,such as wide bandgap,high breakdown field,high thermal conductivity,high saturated drift velocity of electrons,stable chemical properties and survival ability in strong radiation,which make it a promising candidate in the adverse circumstance where the silicon devices have been disabled. taking the advantage of its wide bandgap(23 ev~33 ev),the blue,green and ultraviolet lightemitting devices and photo detectors have been fabricated. what is more,a naturally formed thin layer of sio2 on its surface is advantageous to the devices based on sic mos,which is unique,when compared with other compounds such as gan and aln,etc. nowadays the studies of sic are mainly focused on the crystalline growth and the formation of thin films of 4hsic,6hsic,3csic,and the investigation of sic devices have also gained much concern in recent years. in this article,the progresses of sic are discussed,and the existing problems are appraised and commented. 2the basicproperties of sic 2.1the semiconductor properties of sic sic material has extraordinary thermal stability and chemical stability. there is no dopant diffusion at any rational temperature. at room temperature,it can endure any acid etching. other excellent properties of sic are showed in table 1. 2.2 poly types of sic the structure of sic is tetragonal(fig.1). the bonding of si and c atom is rather strong,but the bonding between the layers is comparatively weak,therefore sic has more than 200 polytypes. according to the crystal phases of sic,they can be sorted in
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