In this paper, we studied the electrical and structural properties of Ni/Si/Al Ohmic contacts to p-type 4H-SiC. The p-type epilayer (N_A = 1 × 10¹⁹ cm⁻³) was grown on the N-type epilayer with Al dopants. The properties of Ni/Si/Al contacts were analyzed by changing the thickness of Si film and the annealing temperature. After annealing at 700 °C, the Ni/Si/Al contact forms ohmic contact. Compared to Ni/Al contacts, Ni/Si/Al ohmic contacts are formed at lower annealing temperature. The contact resistivity of Ni/Si/Al (80/20/100 nm) contact is 1.3 × 10⁻⁴ Ω·cm² after annealing at 800 °C. X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) are used to analyze the microstructure and observe the surface topography. The results show that Ni and Si react at low temperature to form Ni₂Si, which is the reason for the formation of Ni-based ohmic contacts. At the same time, the addition of the Si layer weakens the reaction between Ni and SiC, which reduces the generation of free C elements. The Ni/Si/Al contact shows better ohmic contact characteristics.

在本文中，我们研究了 Ni/Si/Al 欧姆接触与 p 型 4H-SiC 的电学和结构特性。p型外延层（N _A  = 1 × 10 ¹⁹  cm ^-3）在具有Al掺杂剂的N型外延层上生长。通过改变Si膜的厚度和退火温度来分析Ni/Si/Al触点的性能。在 700 °C 下退火后，Ni/Si/Al 接触形成欧姆接触。与 Ni/Al 接触相比，Ni/Si/Al 欧姆接触是在较低的退火温度下形成的。Ni/Si/Al (80/20/100 nm) 接触的接触电阻率为 1.3 × 10 ^-4  Ω·cm ²800℃退火后。X 射线衍射 (XRD) 和扫描电子显微镜 (SEM) 用于分析微观结构并观察表面形貌。结果表明，Ni和Si在低温下反应形成Ni ₂ Si，这是形成Ni基欧姆接触的原因。同时，Si层的加入减弱了Ni与SiC的反应，减少了游离C元素的产生。Ni/Si/Al 接触显示出更好的欧姆接触特性。