Cryo Pure

Applications

Our gases are used throughout every stage of fabrication

Gas Applications in Semiconductor Manufacturing
A reliable supply of high purity gases is critical to advanced semiconductor manufacturing. Producing an integrated circuit requires over 30 different process gases for etching, deposition, oxidation, doping, and inerting applications. The range of gases used is broader than in virtually any other industry. Trace impurities at the parts-per-million, parts-per-billion, and even parts-per-trillion levels must be measured and eliminated. Semiconductor process gases are classified as: Silicon Precursors, Dopants, Etchants, Atmospherics and Reactants

Several gases are provided as bulk gases as part of the central utilities. These include:

Nitrogen

» produced on-site by separation of air;
» used widely in many processes to provide an inert environment or to purge reactive gases after the completion of a process.

Oxygen
» produced on-site or delivered as cryogenic liquid;
» used for oxidation of silicon, one of the most critical processes in all of semiconductor manufacturing.

Argon

» delivered as cryogenic liquid;
» used to provide an inert environment for sputter deposition of metals (where even nitrogen is too reactive and leads to the formation of metal nitrides).

Hydrogen

» either produced on-site or delivered as a cryogenic liquid or compressed gas.
» delivered in bulk as a cryogenic liquid or produced on-site, is used to provide a reducing environment for annealing metal films.
Supplied from state-of-the-art production facilities located in Europe, Asia and North America,  Our  full line of semiconductor process gases ensure reliability and consistency no matter where a wafer production site is located. 

Silicon Precursor Gases
Silicon-precursor gases act as a source of silicon atoms for deposition of polycrystalline silicon, epitaxial silicon, silicon dioxide, and silicon nitride. The most common gases are silane, dichlorosilane, trichlorosilane, and silicon tetrachloride. Silicon-precursor gases such as silane and dichlorosilane are used in epitaxial and chemical vapor depositon (CVD) processes to deposit layers of silicon or silicon compounds onto silicon substrates.

Dopants
Dopant gases are a source of controllable impurities to modify local electrical properties of the semiconductor material. Specifically, a dopant contributes either an electron deficiency (p dopant) or an electron (n dopant) to the local structure of the molecule’s crystal lattice, which in turn alters the conductivity of the material. Praxair provides a full line of dopant gases.

Etchant Gases
Many gases are used in the etching process. Etchants include fluorocarbons and other fluorinated materials. The most important gases today are halocarbon 14, halocarbon 23, halocarbon 116, and nitrogen trifluoride. These etchant gases react with silicon, silicon dioxide and silicon nitride. 

Atmospherics
Atmospheric/purge gases are used for purging certain processing systems and equipment when a semiconductor manufacturer is concerned about possible back-contamination of the house purge lines. We provide a full line of atmospheric gases.

Reactants
Reactant gases include ammonia, nitrous oxide, hydrogen chloride and tungsten hexafluoride. 

Corrosive Gases
Corrosive gases, such as hydrogen bromide, hydrogen chloride, and chlorine are used for etching. The chlorine and bromine molecules are used because they form volatile products when exposed to metals. High purity is important to avoid corrosion of the gas system as well as for the best process performance. 

Chemical Mechanical Planarization 
Semiconductor chemical mechanical planarization (CMP), the process of polishing of silicon wafers, requires specialized and exacting products called slurries. The objective of this process is to produce planar films on semiconductor wafers with low non-uniformity and excellent selectivity. A wide variety of both standard and custom slurry products are used such as tungsten CMP products which offer advantages including easily dispersible suspensions, tight particle size distribution and uniform particle shapes.

Surface Coatings For Semiconductor Process Tools
By tailoring the corrosion resistance, density, hardness, coefficient of thermal expansion, and thermal and electrical conductivity properties to process requirements, surface coatings can reduce failure rates, prevent corrosion, and physical wear. Our Surface Technologies thermal spray coatings are boosting equipment performance by reducing chamber corrosion and wear as well as improving the performance of specialized chamber components such as electrostatic chucks (ESCs).