Combined machining method for chemistry cluster magneto-rheological of monocrystal silicon carbide wafer

Abstract

The invention provides a combined machining method for chemistry cluster magneto-rheological of a monocrystal silicon carbide wafer. The method based on the magneto-rheological effect comprises the following steps: a monocrystal silicon carbide wafer is pasted on an antimagnetic tool head through a binder; the antimagnetic tool head is mounted on a motor spindle, and swings to a certain extent relatively to a polishing disc while the antimagnetic tool head and the polishing disc rotate around respective axial lines of the antimagnetic tool head and the polishing disc; grinding material and acid-base chemical reagent both mixed into magneto-rheological fluid are used as polishing working solution; small grinding heads with the magneto-rheological effect are produced based on a magnetic substance to limit gathered free grinding material; a flexible polishing film is formed by the array combination of multipoint small grinding heads with the magneto-rheological effect based on the cluster action principle; the distance between a workpiece and an antimagnetic polishing disc and the relative rotating speed of the workpiece to the polishing disc can be controlled to reduce surface defect and layer damage of the monocrystal silicon carbide wafer; and a super smooth surface with high quality can be obtained. According to the invention, the method integrates the advantages of high mechanical efficiency of cluster magneto-rheological and chemocatalysis of chemical polishing; and the polishing efficiency is high.

Description

technical field [0001] The invention relates to a chemical cluster magneto-rheological compound processing method for a single-crystal silicon carbide wafer, which belongs to crystal material processing technology. Background technique [0002] As the core of the third-generation semiconductor material, single crystal silicon carbide (SiC) has the characteristics of large band gap, high thermal conductivity, large electron saturation drift rate, high critical breakdown electric field and low relative permittivity, so it is used It is suitable for making high-temperature, high-frequency, radiation-resistant, high-power and high-density integrated electronic devices, especially in extreme conditions and harsh environments. The characteristics of silicon carbide devices far exceed Si devices and GaAs devices. Utilizing its wide band gap, it can also produce blue, green and ultraviolet light-emitting devices and photodetection devices. In addition, silicon carbide is more and m...

AI Technical Summary

Problems solved by technology

[0005] Although the above methods can process single crystal silicon carbide wafers, the processing efficiency is relatively low.

It has been verified by the inventor's experiments that the cluster magnetorheological polishing method mentioned in the patent 200610132495.9 can be used to planarize and polish single-crystal silicon carbide wafers well, and obtain a nano-scale smooth surface. Compared with chemical mechanical polishing, This method has high processing efficiency and is an ideal planarized ultra-smooth surface processing technology, but it is still difficult to further improve the polishing efficiency, especially to obtain an atomic-level ultra-smooth surface

Because in order to obtain an ultra-smooth surface at the atomic level, the cutting depth of the abrasive grains on the surface of the workpiece must be very small and removed in a plastic state, which requires the use of ultra-fine sub-micron or even nano-scale abrasive grains and magnetic particles for magnetorheological Polishing, and the use of submicron / nano-scale magnetic particles will lead to a sharp weakening of the magnetorheological effect, reducing the polishing pressure on the processed surface, reducing the polishing efficiency, and requiring longer processing time to meet the requirements

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