外延层厚度对垂直结构6H-SiC光导开关特性影响的研究(英文)

Effects of the n^+-Epilayer Thickness on the Electric Characteristics of 6H-SiC Photoconductive Semiconductor Switch with a Vertical Structure

设计了新颖的具有垂直结构的6H-SiC光导开关。首先采用离子注入工艺在半绝缘6H-SiC衬底两侧生成一层p+离子注入层,然后利用外延工艺在其中的一侧生长一层n+外延层,并将此侧定义为开关的阴极。利用二维半导体器件仿真软件,研究了n+外延层厚度对6H-SiC光导开关特性的影响。结果表明,增加外延层厚度可以提高开关的击穿电压;而开关的导通电流,首先随着n+外延层厚度的增加而减小,在n+外延层厚度为5μm达到最小值,随后随着厚度的增加,导通电流增加。

6H-SiC photoconductive semiconductor switch（ PCSS） with a vertical structure is proposed. The device was characterized with p＋ion-implantation layers on the both sides of the semi-insulating（ SI） 6H-SiC bulk,and an n＋epilayer was inserted between the p＋ion-implantation layer and electrode metal at the cathode. By means of two-dimensional（ 2D） device simulator,the effects of n＋-epilayer thickness on electric characteristics of the proposed 6H-SiC PCSS had been exploited,mainly focusing on the breakdown voltage（ V B） and on-state characteristics. It is found that the breakdown voltage can be improved by increasing the thickness of n＋epilayer. The peak current of on-state just begins to decrease with the increasing of n＋-epilayer thickness,and after achieving a minimum value at the thickness of 5 μm,the peak current begins to increase.