碳化硅表面亚微米减反射结构及其制作工艺

Antireflective Sub-Micron Structures on the Surface of Silicon Carbide and Its Fabrication Technology

创新性地提出一种经济高效的碳化硅表面亚微米减反射结构制作工艺,即＂黑碳化硅技术＂。该方法无需光刻,采用非完全后烘的光刻胶微掩膜反应离子刻蚀（RIE）工艺,克服了碳化硅材料由于高硬度和高化学稳定性而无法采用传统硅材料湿法工艺的困难。利用该技术,已在4英寸（1英寸=2.54 cm）4H-SiC单晶片表面成功制作出网格状亚微米阵列结构,其深度为200-300 nm。测试结果表明,该结构可以在390-800 nm的波长范围内使SiC表面平均反射率至少降低20%。可以应用于SiC材料制作的中间带太阳电池及紫外探测器件,提升器件的量子效率;或作为高功率GaN LED的生长衬底,增强LED的光出射效率。

An innovative and cost-effective fabrication technology of the antireflective sub-micron structures on the surface of SiC was presented, namely ＂black silicon carbide technology＂. Over- coming the difficulty of unable to use the traditional silicon materials wet etching technology due to high hardness and high chemical stability of SiC, this method used the insufficient post-baked resist as the micro-mask during reactive ion etching （RIE） process and without the photolithogra- phy. The mesh-shaped sub-micron array structures were successfully fabricated on the surface of a 4-inchs （1 inch = 2. 54 cm） 4H-SiC wafer by the technology. The depth of sub-micron structures reaches 200 - 300 nm. The test result shows that the average reflectivity of SiC in the wavelength range of 390 - 800 nm is significantly decreased by more than 20% after introducing the mesh patterning sub-micron structures. This sub-micron structures can improve the quantum efficiency of intermediate band solar cells and UV detectors made by SiC materials, or as the growth sub- strate of high power GaN LEDs, the sub-micron structures can enhance the light extraction efficiency of LEDs.