白丝美女被狂躁免费视频网站,500av导航大全精品,yw.193.cnc爆乳尤物未满,97se亚洲综合色区,аⅴ天堂中文在线网官网

Silicon carbide semiconductor device and a method of manufacturing the silicon carbide semiconductor device

專(zhuān)利號(hào)
US10868122B2
公開(kāi)日期
2020-12-15
申請(qǐng)人
FUJI ELECTRIC CO., LTD.（JP Kawasaki）
發(fā)明人
Takeshi Tawara; Koji Nakayama; Yoshiyuki Yonezawa; Hidekazu Tsuchida; Koichi Murata
IPC分類(lèi)
H01L29/16; H01L29/868; H01L29/66
技術(shù)領(lǐng)域
layer,type,drift,lifetime,epitaxial,carbide,silicon,vanadium,region,in
地域： Kawasaki

摘要

During epitaxial growth of an n?-type drift layer having a uniform nitrogen concentration, vanadium is doped in addition to the nitrogen, whereby an n?-type lifetime reduced layer is selectively formed in the n?-type drift layer. The n?-type lifetime reduced layer is disposed at a depth that is more than 5 μm from a pn junction surface between a p-type anode layer and the n?-type drift layer in a direction toward a cathode side, and the n?-type lifetime reduced layer is disposed separated from the pn junction surface. Further, the n?-type lifetime reduced layer is disposed in a range from the pn junction surface to a depth that is ? times a thickness of the n?-type drift layer. A vanadium concentration of the n?-type lifetime reduced layer is 1/100 to ? of a nitrogen concentration of the n?-type lifetime reduced layer.

說(shuō)明書(shū)

First, problems associated with the related arts will be discussed. With the conventional semiconductor device (refer to FIG. 14), in locally controlling the carrier lifetime of the n-type drift layer 103 and forming the n-type lifetime reduced layer 122 in the n-type drift layer 103, when the n-type lifetime reduced layer 122 has a thickness t101 that is thin, management (hereinafter, quality management) for determining whether the carrier lifetime of the n-type lifetime reduced layer 122 is set within an allowable range of the design value is difficult. For example, design values of the thickness t101, the nitrogen concentration, the vanadium concentration, and the carrier lifetime of the n-type lifetime reduced layer 122 in the n-type drift layer 103 are 10 μm, 3×1014/cm3, 1×1013/cm3, and 10 ns (nanoseconds), respectively.

In measurement of the carrier lifetime of the current state, although extinction time by recombination of carriers excited at the band edge by irradiation of excitation light such as laser or ultraviolet (UV) light is measured, since penetration length of the excitation light to the measured portion (the n-type lifetime reduced layer 122) is long, the average carrier lifetime of a portion having a thickness of several tens of μm and including the measured portion is regarded as the carrier lifetime of the measured portion. Deep ultraviolet (DUV) laser is used, whereby the penetration length of the excitation light to the measured portion may be shortened.

權(quán)利要求

1
微信群二維碼
意見(jiàn)反饋