Mechanical Thinning of InP Wafer by Grinding
wafers of 2 in. diameter have been successfully ground to a thickness of 100 μm by mechanical grinding with cup‐type diamond wheels. This process can be applied, for the first time, to the mass production of optoelectronic devices, similar to the technology for devices based on the wafer‐rotating downfeed grinding method. The phenomena occurring in the grinding of were similar to those of , such as a rapid transition between mirror grinding and rough grinding, and a large wafer bow. However, the deformed layer due to the grinding of was discovered to be thicker than that of , because is a little more fragile. Still, it was thin enough, less than 1.5 μm, to be eliminated by slight chemical etching. The finished surface roughness in mirror grinding was also greater, but 0.15 μm was obtained with 3 μm diamond grains, which is small enough to be applied in device fabrications.