Electronic specialty gases used in wafer fabrication

one The manufacturing process of silicon wafer is as follows:

1. Purification: the silicon ore plus carbon plus oxygen produces 98% metallurgical grade silicon

2. Chlorination: silicon plus hydrogen chloride gas to produce trichlorosilomethane or silicon tetrachloride

3. Reduction: high purity polysilicon crystal was produced by adding trichloromethane and hydrogen

4. Dissolve whirl: polysilicon becomes monocrystalline silicon crystal rod

5. Cutting, polishing and cleaning: monocrystalline silicon rod becomes monocrystalline silicon wafer

two Oxidation:

High temperature heating in the furnace tube: the silicon chip plus oxygen and water vapor will form a dry or wet SiO2 oxide layer on the surface of the chip.

3. Chemical vapor deposition CVD:

By chemical reactions, atoms or molecules in the gas deposit on the surface of a solid film.

Four. Etching:

The process of selectively removing unwanted material from the surface of a silicon wafer using physical and chemical methods. Etching is divided into wet method and dry method. Dry etching takes electronic gas as the medium and its advantages are obviously widely used.

Five. Ion implantation:

The desired impurity is inserted into a specific semiconductor region to alter the electrical properties of the semiconductor.

six The gas content involved in the process is not limited to:

1. HCl is used for oxidation

2. H2 is used for reduction

3. Argon gas is used to maintain the inert isolation environment and avoid the retention of gas impurities

4. Cl2, HCl, trichloroethane TCA or dichloroethylene DCE are used to control the invasion of ions into the oxide layer, to remove unnecessary metal impurities, and for cleaning purposes

5. SiH4, SiHCl2, SiHCl4, SiCl4, TEOS, NH3, N2O, WF6, H2, O2, NF3, etc., are used to form CVD membranes

6. CF4, SF4, C2F6, NF3 are used for silicon wafer etching

7. Fluoro-cl2 and bromo-br2, HBr gases are used to improve gas, anisotropy and selectivity

8. CCl4, Cl2, BCl3, etc. are used for etching aluminum and metal composite layers

9. Trivalent doped gases B2H6, BBr3, BF3, etc. are used for doping p-type semiconductors

10. Pentavalent doped gases PH3, POC13, AsH3, SbC15, etc. are used for the doping of n-type semiconductors