应用碳化硅表面改性技术降低全息-离子束刻蚀光栅刻槽的粗糙度

采用具有良好比刚度和热稳定性的碳化硅材料作为基底,使用全息-离子束刻蚀技术制作了光栅。碳化硅材料表面固有缺陷导致制作的光栅刻槽表面粗糙度高,槽底和槽顶粗糙度分别达到了29.6 nm和65.3 nm (R_q)。通过等离子辅助沉积技术在碳化硅表面镀制一层均匀的硅改性层,经过抛光可以获得无缺陷的超光滑表面。XRD测试表明制备的硅改性层为无定形结构。原子力显微镜的测试结果表明:经过抛光后,表面粗糙度为0.64 nm(R_q)。在此表面上制作的光栅刻槽表面粗糙度明显降低,槽底和槽顶粗糙度分别为2.96 nm和7.21 nm,相当于改性前的1/10和1/9。

Roughness Decreasing of Silicon Carbide Hologram-ion Beam Etching Grating by Using Surface Modification Technique

The gratings were fabricated by hologram-ion beam etching technique on the silicon carbide substrate that has fine stiffness and thermal stability. The intrinsic defects of the silicon carbide leads to a rough surface of the grating grooves, the roughness of the bottom and the top of the grating grooves are 29.6 nm and 65.3 nm (R_q), respectively. A uniform silicon coating were deposited by Plasma Ion Assisted Deposition (PIAD) technique on the surface of the silicon carbide substrate, then a super smooth surface was obtained after fine polishing. Characterized by XRD, we found the silicon coating is amorphous. After fine polishing, the surface roughness of the silicon carbide is 0.64 nm(R_q) measuring by AFM. The roughness of the grating grooves are significantly decreased, the roughness of the bottom and the top of the grating grooves are 2.96 nm and 7.21 nm(R_q), respectively. Comparing with the grating grooves before surface modification, the roughness of the bottom and the top are 1/10 and 1/9, respectively.