Gradient tac coating on the surface of a graphite susceptor disk

Abstract

The invention discloses a gradient TaC coating on the surface of a graphite base disc, which comprises a graphite base disc substrate, and a gradient TaC coating is provided on the surface of the graphite base disc substrate; the gradient TaC coating includes TaC components and C components, The content of TaC components gradually increases from 0% to 100% from the inside to the outside, and the gradient distribution conforms to the law of y=ax linear equation or conforms to y=ax 2 Parabolic regular distribution. The present invention utilizes CVD dynamic co-deposition technology to realize the gradient spanning of the TaC component content in the coating from 0-100%. Since the inner layer of the coating is a pyrolytic carbon layer, which is similar to the thermal expansion coefficient of the graphite matrix, and then gradually transitions, it can Effectively improve the thermal matching difference between the coating and the substrate; at the same time, the soft C component structure and nanopores in the coating can effectively relieve the thermal expansion of TaC crystals to reduce the stress peak in the coating.

Description

technical field [0001] The invention relates to the technical field of semiconductor epitaxial growth equipment, and more specifically, the invention relates to a gradient TaC coating on the surface of a graphite base disk. Background technique [0002] Graphite susceptor disks for semiconductors are key consumables for epitaxial growth of single crystal SiC, InP, GaN, and AlN semiconductors for MOCVD equipment, and play an irreplaceable role in the semiconductor chip industry chain. Graphite has excellent properties such as high temperature resistance, high thermal conductivity, and high temperature strength. It is the first choice material for epitaxial single crystal substrate susceptor disc substrate, but graphite material is easy to oxidize, corrode, and has poor wear resistance, and graphite powder is easy to produce , it is easy to release adsorbed gas under vacuum, pollute the process growth environment, and greatly reduce the quality of semiconductor films. Therefor...

AI Technical Summary

Problems solved by technology

Graphite has excellent characteristics such as high temperature resistance, high thermal conductivity, and high temperature strength. It is the first choice material for epitaxial single crystal substrate pedestal substrates, but graphite materials are easy to oxidize, corrode, and have poor wear resistance, and graphite powder is easy to produce , it is easy to release adsorbed gas under vacuum, pollute the process growth environment, and greatly reduce the quality of the semiconductor film, so it cannot be directly used to grow semiconductors, and a uniform and dense SiC ceramic coating must be coated on the surface of the graphite base plate

[0003] However, the main problems faced by traditional SiC coatings are: poor stability in high-temperature vacuum environment, slow decomposition at 1200-1400 °C, and short service life of the coating, which can no longer meet the preparation requirements of the new generation of semiconductor materials.

However, due to the large thermal expansion coefficient of TaC ceramic material (about 8.29×10-6 / K), there is a large thermal expansion difference with the graphite substrate, resulting in excessive residual stress during the preparation and use of the TaC coating. When the coating interface When the peak shear stress at the point is greater than the bonding strength of the coating, the coating will fall off

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