micromachines Article Laser Grinding of Single-Crystal Silicon Wafer for Surface Finishing and Electrical Properties Xinxin Li 1,†, Yimeng Wang 1,† and Yingchun Guan 1,2,3,4,* 1 School of Mechanical Engineering and Automation, Beihang University, 37 Xueyuan Road, Beijing 100083, China;
[email protected] (X.L.);
[email protected] (Y.W.) 2 National Engineering Laboratory of Additive Manufacturing for Large Metallic Components, Beihang University, 37 Xueyuan Road, Beijing 100083, China 3 International Research Institute for Multidisciplinary Science, Beihang University, 37 Xueyuan Road, Beijing 100083, China 4 Ningbo Innovation Research Institute, Beihang University, Beilun District, Ningbo 315800, China * Correspondence:
[email protected] † The two authors contributed equally to this work. Abstract: In this paper, we first report the laser grinding method for a single-crystal silicon wafer machined by diamond sawing. 3D laser scanning confocal microscope (LSCM), X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), laser micro- Raman spectroscopy were utilized to characterize the surface quality of laser-grinded Si. Results show that SiO2 layer derived from mechanical machining process has been efficiently removed after laser grinding. Surface roughness Ra has been reduced from original 400 nm to 75 nm. No obvious damages such as micro-cracks or micro-holes have been observed at the laser-grinded surface. In addition, laser grinding causes little effect on the resistivity of single-crystal silicon wafer. The insights obtained in this study provide a facile method for laser grinding silicon wafer to realize highly efficient grinding on demand. Citation: Li, X.; Wang, Y.; Guan, Y.