Ultra-precision grinding of 4H-SiC wafer by PAV/PF composite sol-gel diamond wheel

Abstract

To eliminate the deep scratches on the 4H-SiC wafer surface in the grinding process, a PVA/PF composite sol-gel diamond wheel was proposed. Diamond and fillers are sheared and dispersed in the polyvinyl alcohol-phenolic resin composite sol glue, repeatedly frozen at a low temperature of −20°C to gel, then 180°C sintering to obtain the diamond wheel. Study shows that the molecular chain of polyvinyl alcohol-phenolic resin is physically cross-linked to form gel under low-temperature conditions. Tested by mechanical property testing machines, microhardness tester, and SEM. The results show that micromorphology is more uniform, the strength of the sol-gel diamond wheel is higher, the hardness uniformity is better than that of the hot pressing diamond wheel. Grinding experiments of 4H-SiC wafer were carried out with the prepared sol-gel diamond wheel. The influence of grinding speed, feed rate, and grinding depth on the surface roughness was investigated. The results showed that by using the sol-gel diamond wheel, the surface quality of 4H-SiC wafer with an average surface roughness Ra 6.42 nm was obtained under grinding wheel speed 7000 r/min, grinding feed rate 6 µm/min, and grinding depth 15 µm, the surface quality was better than that of using hot pressing diamond wheel.

Single diamond grit scratching of unidirectional Cf/SiC composite: Mechanical responses and fracture mechanism

“…The main function of the pyrolytic carbon interface is to protect the carbon fiber from damage during chemical vapor deposition, explaining the removal mechanism of the C f /SiC composite in this experiment does not distinguish it from the SiC matrix. 39 The main mechanical properties 38,39,44 of C f /SiC composite and its main compositions at room temperature are shown in Table 1. It can be found that the axial mechanical strength is much higher than the transverse direction.…”

Approach: developing nano/sub-micron diamond slurry technology for enhanced precision polishing of optoelectronic materials

“…Achieving precise control over surface morphology and atomic-level surface roughness is crucial for determining the performance and reliability of these devices 6 – 12 However, the fabrication of SiC wafers presents challenges due to its inherent hardness and chemical stability. Conventional chemical mechanical polishing (CMP) techniques have been widely employed for achieving surface planarization and controlling atomic-level surface roughness 9 , 13 …”

The Preparation and Performance Analysis of a Cr2O3 Gel Abrasive Tool for Sapphire Substrate Polishing

“…Niu et al [15] proposed a method to process BK7 glass by a vitrified bondfixed abrasive tool formed by the combination of a precision diamond abrasive and a coarse diamond abrasive. Feng [16][17][18] proposed a Polyvinyl alcohol/phenolic resin (PVA/PF) composite sol-gel tool to process SiC wafers. The abrasive tool showed excellent processing stability during processing.…”