uhp 600mm graphite electrodes

Research status of uhp 600mm graphite electrodes

Semiconductor devices are the core of modern industrial equipment and are widely used in core fields such as computers, consumer electronics, network communications, and automotive electronics. The semiconductor device industry is mainly composed of four basic parts: integrated circuits, optoelectronic devices, discrete devices, and sensors Among them, integrated circuits account for more than 80%, so semiconductors and integrated circuits are usually equivalent.

uhp 600mm graphite electrodes integrated circuits are mainly divided into four categories according to product types: microprocessors, memories, logic devices, and analog devices. However, with the continuous expansion of the application field of semiconductor devices, many special occasions require semiconductors to be able to be used without damage under high temperature, strong radiation, high power and other environments. The first and second generation semiconductor materials are powerless, so the third generation Semiconductor materials came into being.

At present, wide band gap semiconductor materials represented by uhp 600mm graphite electrodes (SiC), gallium nitride (GaN), zinc oxide (ZnO), diamond, and aluminum nitride (AlN) dominate the market with greater advantages, collectively referred to as Third-generation semiconductor materials. The third-generation semiconductor materials have a wider band gap, higher breakdown electric field, thermal conductivity, electron saturation rate and higher anti-radiation ability, and are more suitable for the production of high-temperature, high-frequency, anti-radiation and high-power devices , Usually called wide band gap semiconductor material (band gap greater than 2.2eV), also known as high temperature semiconductor material. From the current research on third-generation semiconductor materials and devices, uhp 600mm graphite electrodes and gallium nitride semiconductor materials are more mature, and uhp 600mm graphite electrodes are the most mature technology, while zinc oxide, diamond, aluminum nitride and other materials are more mature. The research is still in its infancy.

1. Materials and characteristics uhp 600mm graphite electrodes are commonly used in ceramic ball bearings, valves, semiconductor materials, gyroscopes, measuring instruments, aerospace and other fields, and have become an irreplaceable material in many industrial fields. SiC is a natural superlattice and a typical homogeneous polytype. The difference in stacking sequence of Si and C diatomic layers will result in different crystal structures, with more than 200 (currently known) homogeneous polytypes. Therefore, SiC is very suitable for use as a new generation of light-emitting diode (LED) substrate material and high-power power electronic material. The physical and chemical properties of uhp 600mm graphite electrodes.

2. Research on processing technology The hardness of SiC is second only to diamond, and can be used as abrasives for grinding wheels and other abrasive tools. Therefore, its mechanical processing mainly uses diamond grinding wheels for grinding, grinding and polishing, and diamond grinding wheels have the highest efficiency. It is an important means of processing SiC. However, SiC material not only has the characteristics of high hardness, but also high brittleness and low fracture toughness make it easy to cause brittle fracture of the material during the grinding process, leaving a surface fracture layer on the surface of the material, and causing serious surface and subsurface damage. , Affect processing accuracy. Therefore, in-depth study of SiC grinding mechanism and sub-surface damage is of great significance for improving the efficiency of SiC grinding processing and surface quality.

1. Grinding mechanism of hard and brittle materials Grinding hard and brittle materials, and the abrasive has a rolling effect or a micro-cutting effect on it. When the abrasive particles act on the surface with unevenness and cracks, as the grinding process progresses, part of the abrasive particles are pressed into the workpiece under the action of the grinding load, and the exposed tip is used to scratch the surface of the workpiece for micro-cutting. The other part of the abrasive particles rolls between the workpiece and the grinding disc to produce a rolling effect, which causes the surface of the workpiece to form micro-cracks, and the extension of the crack causes the surface of the workpiece to form brittle and fragmented chips, so as to achieve the purpose of surface removal. Because the tensile strength of hard and brittle materials is lower than the compressive strength, when a load is applied to abrasive grains, microcracks will occur at the maximum tensile stress on the surface of the hard and brittle materials. When the criss-crossing cracks extend and cross each other, the part surrounded by the cracks will be broken and broken into small pieces. This is the basic process of chip generation and surface formation during grinding of hard and brittle materials. Since uhp 600mm graphite electrodes are high-hardness and brittle materials, special grinding fluids are required. The main technical difficulty in grinding of uhp 600mm graphite electrodes lies in the precise measurement and control of the thinning thickness of high-hardness materials. The surface of the wafer will be damaged after grinding. Microcracks and residual stress, uhp 600mm graphite electrodes wafer thinning will produce greater warpage than uhp 600mm graphite electrodes wafer.

2. Research on polishing processing of uhp 600mm graphite electrodes At present, the polishing methods of uhp 600mm graphite electrodes mainly include: mechanical polishing, magnetorheological polishing, chemical mechanical polishing (CMP), electrochemical polishing (ECMP), catalyst assisted polishing or catalytic assisted engraving Etching (CACP/CARE), tribochemical polishing (TCP, also known as non-abrasive polishing) and plasma assisted polishing (PAP), etc. Chemical mechanical polishing (CMP) technology is currently an important method for semiconductor processing, and it is also the most effective process method that can process the surface of single crystal silicon to atomic level smoothness. It is the only practical method that can achieve both local and global planarization during processing. Technology. The processing efficiency of CMP is mainly determined by the chemical reaction rate on the surface of the workpiece. By studying the effect of process parameters on the polishing rate of SiC materials, the results show that: the rotation rate and polishing pressure have a greater impact; the temperature and the pH of the polishing solution have little effect. In order to increase the polishing rate of the material, the rotation speed should be increased as much as possible. Although increasing the polishing pressure can also increase the removal rate, it is easy to damage the polishing pad.

The current polishing method of uhp 600mm graphite electrodes has the problems of low material removal rate, high cost, and no abrasive polishing, catalytic assisted processing and other processing methods. Due to the demanding conditions and complex device operation, it is still in the laboratory. Within the scope, mass production is unlikely to be realized.