Semiconductor Applications
Crystal Growth
The Czochralski process is the typical method of crystal growth used to obtain single crystals of semiconductors (e.g., silicon, germanium). During the process, for particular crystals, inert and noble gas purging is employed to minimize nitrides, carbonyls and exogenous metal contamination.Boost your crystal growth process performance with SAES Pure Gas tailored purification solutions.
Gases Used:
Photolithography
Photolithography is a process used in semiconductor device fabrication to transfer a pattern from a photomask (also called reticle) to the surface of a substrate. Modern Optics components used in lithography and inspection/metrology equipment are constantly pushing the limits of both lense stack materials and coatings. Lenses, reticles and mirrors are all susceptible to irreversible photocontamination, even if “parts-per-trillion” (PPT) levels of Airborne Molecular Contamination (acid, base,refractory, condensable and volatile organic compounds) in the surrounding purge environment interact with the equipment’s high energy laser light.
SAES Pure Gas has developed several tailored purification solutions for photolithography optics purge gases (N2, CDA). In addition to purification of the gases, we have developed an AMC Analysis using solid state traps, called CollectTorr.
Gases Used:
Epitaxial Growth
Epitaxy is a specialized hi-tech, thin-film deposition technique. The term epitaxy describes an ordered crystalline growth on a (single-) crystalline substrate. It involves the growth of crystals of one material on the crystal face of another (heteroepitaxy), or the same (homoepitaxy) material. Epitaxy forms a thin film whose material lattice structure and orientation or lattice symmetry is identical to that of the substrate on which it is deposited. Most importantly, if the substrate is a single crystal, then the thin film will also be a single crystal. H2O, O2, CO, CO2, and CH4 are the primary impurities of concern.
The use of SAES Pure Gas purification solutions will provide tangible benefits including lower sheet resistance, fewer stacking faults and less junction leakage issues.
Gases Used:
Etching
Gas-phase etching is a fundamental step for several semiconductor processes. It can be either purely chemical (plasma etching), purely physical (ion milling), or combination of both (Reactive Ion Etching, RIE). SAES Pure Gas’s patented purification technologies for corrosive and ion milling carrier gases will improve etching gas purity to well below parts per billions levels.
Gases Used:
Metallization
Plasma-assisted deposition of thin films is extensively adopted in microelectronic circuit manufacturing. Materials deposited include conductors such as tungsten, copper, aluminum, transition-metal silicides, and refractory metals; semiconductors such as gallium arsenide, epitaxial and polycrystalline silicon; and dielectrics such as silicon oxide, silicon nitride, and silicon oxynitride. PVD process gas carriers, typically Ar or other noble gasses, have to be free of hydrocarbons (including CH4), H2O, O2, CO, CO2, and N2. Parts-per-billion levels of the aforementioned impurities can generate electromigration failures, reduce grain growth size, and generally changes the electrical film properties.
Gases Used:
