SiC肖特基紫外光电探测器的研制

Study on Silicon Carbide (SiC) Schottky Ultraviolet Photodetectors

采用微电子平面工艺,用宽禁带半导体n 4H SiC和金属Au(或Ni)形成肖特基接触,Ti、Ni、Ag合金在背底作欧姆接触,制备出Au/n 4H SiC和Ni/n 4H SiC肖特基紫外光电探测器。测试分析了这两种器件的光谱响应特性及其I V特性。其光谱响应范围均是200～400nm,室温无偏压下,Au/n 4H SiC的光谱响应峰值在310nm,光谱响应半宽是73nm,室温7V偏压下光谱响应峰值86.72mA/W,量子效率可达37.15%,Ni/n 4H SiC相应的参数分别为300nm、83nm、45.84mA/W及18.98%。Au/n 4H SiC室温下正向开启电压0.81V,Ni/n 4H SiC是0.52V,两者反向击穿电压均大于200V,反向漏电流小于1×10-10A。

With microelectronic flat process, Au/n-4H-SiC and Ni/n-4H-SiC Schottky ultraviolet(UV) photodetectors have been fabricated by using wide band semiconductor n-4H-SiC and metal Au(or Ni) to form Schottky contact, and Ti、Ni、Ag alloys to form ohmic contact on the back. The spectrum response characteristics and the I-V characteristics of the devices have been measured and analyzed. The response wavelength ranges from 200 nm to 400 nm. The response peak has been found at 310 nm for Au/n-4H-SiC at room temperature without any biased voltage, with the half width of response wavelength of 73 nm, the maximal spectrum responsivity of 86.72 mA/W and the maximal quantum efficiency of 37.15%. For Ni/n-4H-SiC, the corresponding parameters are 300 nm, 83 nm, 45.84 mA/W and 18.98%, respectively. The forward turn-on voltage of Au/n-4H-SiC is 0.81 V, and one of the Ni/n-4H-SiC is 0.52 V. The reverse breakdown voltages are both higher than 200 V, and the leakage currents are both smaller than 1×10^(-10) A.