4H-SiC金属-半导体-金属结构紫外探测器的模拟与分析

用MEDICI软件对金属-半导体-金属(MSM)结构4H-SiC紫外(UV)探测器的I-V特性以及光谱响应等特性进行了模拟与分析,并探讨了金属电极的宽度、电极间距以及外延层厚度对探测器响应度的影响.结果表明,室温下该探测器的暗电流线性密度达到10-13A/μm,且在不同电压下光电流至少比暗电流大两个数量级;探测器的光谱响应范围为200~400 nm,在347 nm处响应度达到极大值;增大指宽或者减小指间距可以提高探测器的响应度;当波长小于峰值波长时外延层厚度对探测器的响应度基本没影响,而当波长大于峰值波长时随着外延层厚度的增大探测器的响应度有所增大.

Simulation and Analysis of 4H-SiC Metal-Semiconductor-Metal Ultraviolet Photodetector

The I-V characteristics and spectral response of 4H-SiC metal-semiconductor-metal (MSM) ultraviolet (UV) photodetector have been simulated by MEDICI. The influence of the finger width and spacing of contact electrodes and epitaxial layer thickness on the spectral response has also been analyzed. The results show that the density of dark current is about 10-13 A/μm and the photo-to-dark current ratio is at least 102 at different bias voltages. The range of spectral response is 200～400 nm and the peak responsivity lies in 347 nm. We have also found that the responsivity is increases with the increase of finger width or decrease of finger spacing. The epitaxial layer thickness has almost no effect on responsivity when wavelengh is less than peak wavelength, and the responsivity increases with the increase of epitaxial layer thickness when wavelengh is greater than peak wavelength.