Silicon carbide focusing ring ceramic material
With the development of semiconductor technology, plasma etching has gradually become a technology widely used in semiconductor manufacturing processes. The plasma generated by plasma etching is highly corrosive, and it will also cause serious corrosion to the process chamber cavity and the components in the cavity during the process of etching the wafer. Therefore, the components in semiconductor processing equipment that are in contact with the plasma need It has better resistance to plasma etching.
Compared with organic and metal materials, ceramic materials generally have better physical and chemical corrosion resistance and high working temperature. Therefore, in the semiconductor industry, a variety of ceramic materials have become the manufacturing process and front-end of semiconductor single crystal silicon wafers. Manufacturing materials for the core components of the equipment in the processing process, such as SiC, AlN, Al2O3 and Y2O3, etc. The selection of ceramic materials in the plasma environment depends on the working environment of the core components and the quality requirements of the process products, such as plasma etching resistance, electrical properties, insulation, etc. The main components of the plasma etching equipment using ceramic materials are window mirrors, electrostatic chucks, focusing rings, etc.
Among them, the main purpose of the focus ring is to provide a uniform plasma, which is used to ensure the consistency and accuracy of etching. At the same time, it needs to have a conductivity similar to that of a silicon wafer. As a commonly used focus ring material, conductive silicon is almost close to the conductivity of silicon wafers, but the disadvantage is that it has poor etching resistance in fluorine-containing plasma, and the etching machine parts are often used for a period of time. The phenomenon of corrosion seriously reduces its production efficiency. In addition to having similar electrical conductivity to silicon, silicon carbide also has good resistance to ion etching, making it a more suitable focus ring material than conductive silicon.
SiC is widely used in semiconductor processing equipment components due to its excellent properties. For example, silicon carbide has excellent high temperature resistance properties and is widely used in core components of various deposition equipment. Silicon carbide has excellent thermal conductivity and electrical conductivity that matches Si wafers and is used as focus ring material, and SiC has more excellent resistance to plasma etching and is an excellent candidate material.
Some researchers have studied the etching mechanism of silicon carbide in carbon-fluorine plasma, and their conclusion shows that after silicon carbide is etched by carbon-fluorine plasma, a series of chemical reactions occur on the surface to form a thin layer of fluorocarbon polymer film, which can be The active fluorine-based plasma is prevented from further reacting with the substrate, so it has better plasma etching resistance than Si.
