Through precision grinding and polishing techniques, Si (Silicon) substrates with TTV (Total Thickness Variation) <0.5 μm are fabricated, enabling high-precision machining processes and advanced fabrication nodes while reducing optical distortion and energy loss. Due to their exceptional thickness uniformity, these substrates play an indispensable role in semiconductor, photovoltaic, optical, and MEMS (Micro-Electro-Mechanical Systems) applications.