Special gas refers to the application in a specific field, the gas has special requirements of pure gas, high purity gas or by high purity elemental gas mixed gas mixture of binary or multiple. There are many categories of special gases, and the following are some of the main special gas categories and their representative gases:
i. Classification by chemical composition
- silicon-based gas such as silicon tetrachloride (SiCl4), etc., is widely used in the electronics industry, especially in the chemical vapor deposition (CVD) process.
- Arsenic, phosphorus and boron gases: These gases are used as doping gases in semiconductor manufacturing to adjust the conductivity type and resistivity of the material.
- Metal Hydrides, Halides and Metal Hydroxides these gases are used as reactants or catalysts in specific industrial processes.
II. Classification by field of application
- electronic gas
- use: Widely used in the processing and manufacturing process of electronic industries such as integrated circuits, display panels, photovoltaic energy, optical fiber cables, etc., mainly including cleaning, etching, lithography, epitaxy, doping, etc.
- Representative gas high Purity Ammonia, high purity hydrogen, high purity argon, high purity nitrogen, sulfur hexafluoride, nitrogen trifluoride, carbon tetrafluoride, etc.
- Medical Gases
- use: It is widely used in the medical field, such as first aid, surgery, oxygen therapy, etc.
- Representative gas oxygen, nitrogen oxygen mixture, etc.
- Standard gas: For calibrating instruments and analytical measurements.
- Environmental protection gas for environmental protection and pollution control.
- Laser Gas: Used in laser cutting and laser welding.
- Food gas: Used for food preservation and packaging.
- Electric light source gas: Used in lighting equipment, such as neon gas used in neon lights.
Other Special classifications
- doping gas: In the manufacture of semiconductor devices and integrated circuits, some or some impurities are doped into the semiconductor material to make the material have the required conductivity type and a certain resistivity. It mainly includes arsenane, phosphane, phosphorus trifluoride, phosphorus pentafluoride, etc.
- Fumigation gas: Gas with bactericidal effect, commonly used gas varieties are ethylene oxide, phosphane, methyl bromide, etc.
- Welding shielding gas: Used for gas shielded welding, improve the quality of the weld, reduce the width of the weld heating zone, and avoid material oxidation. Unit gases include argon and carbon dioxide, and binary gas mixtures include argon and oxygen, argon and carbon dioxide, etc.
In addition, there are ion implantation gas, non-liquefied gas, liquefied gas, rare gas, low pressure liquefied gas, high pressure liquefied gas and other categories. There is an intersection of these classifications, for example some gases may belong to more than one classification at the same time.