IC Knowledge - Glossary

Glossary of Integrated Circuit Terminology - H

H-Line - the output of a mercury lamp with a wavelength of 405 nanometers. H-line light sources are not widely used.
Halocarbon 14 - chemical formula CF₄, halocarbon 14 is an odorless gas. Halocarbon 14 does not have a formally established TLV but 1,000ppm is recommended. Halocarbon 14 is used as an etch gas.
Halocarbon 23 - chemical formula CHF₃, halocarbon 23 has a slightly ether like odor. Halocarbon 23 does not have a formally established TLV but 1,000ppm is recommended. Halocarbon 23 is used as an etch gas.
Halocarbon 116 - chemical formula C2F₆, halocarbon 116 has a slightly ether like odor. Halocarbon 116 does not have a formally established TLV but 1,000ppm is recommended. Halocarbon 116 is used as an etch gas.
Hard Bake - a bake performed to photoresist after develop. Hard bake is performed at a higher temperature than soft bake sense photoresist photosensitivity is no longer required (exposure and develop are already done and the pattern is formed). Hard bake stabilizes the photoresist prior to subsequent processing.
HEPA - High Efficiency Particle Air - a type of air filter that removes 99.97% of all particles greater than 0.3µm in diameter.
Hertz - frequency in cycles per second, 1 hertz equals 1 cycle per second.
Hetroepitaxy - epitaxial deposition of one type of material on a substrate of another type of material.
HMDS - Hexamethyldisalizane, a chemical primer used to remove surface moisture and improve photoresist adhesion.
High Energy Ion Implantation - ion implantation performed at an energy >750KeV. High energy ion implantation has become increasingly popular for retrograde well and buried layer formation.
High Pressure Oxidation - oxidation performed at a pressure greater than atmospheric pressure. High pressure oxidation increases oxidation rate at a given temperature.
High-k - a dielectric material with a dielectric constant greater than the dielectric constant of silicon dioxide, k>4. As minimum feature sizes have shrunk it has been necessary to shrink the thickness is gate oxides in proportion. Gate oxides are now becoming so thin that they do not display sufficiently good insulating properties. High-k materials can in theory replace silicon dioxide as a gate insulator, be used at a greater thickness, the higher the dielectric constant the thicker the film that can be used, and still adequately control the channel region.
Hillock - bumps that form in a thin film during heating and cooling.
Hole - the absence of an electron. Holes have a net negative charge equal to the charge on an electron. Holes may be mobile and can be treated exactly like they are a positive electron.
Homoepitaxy - epitaxial deposition of one type of material on a substrate of the same type of material.
Hot Carrier - carriers that have gained enough energy while transiting the channel region to be injected into the gate oxide. Hot carriers can degrade the reliability of MOS devices.
Hot Lot - a lot that is given priority and typically processed immediately upon reaching each step during fabrication.
Hydrochloric Acid - chemical formula HCl, hydrochloric acid a relatively strong acid primarily used as part of the SC2 Clean. Hydrochloric acid is commonly sold as a 47% solution and has a density of 1.19Kg/L. Hydrochloric acid burns on contact with skin or eyes and the vapors will irritate or burn eyes or lungs.
Hydrofluoric Acid - chemical formula HF, hydrofluoric acid a relatively strong acid mainly used to etch silicon dioxide. Hydrofluoric acid is commonly sold as a 49% solution and has a density of 1.17Kg/L. Fluorine is not only toxic but may be absorbed through the skin without immediate evidence of irritation and later react with the calcium in bones and or poison the person exposed to the chemical.
Hydrogen - atomic symbol, H, argon is the 1st element in the periodic table (atomic number 1) with an atomic weight of 1.008. Hydrogen is flammable and or explosive in the range of 4.0-93.9% in air and is an asphyxiant. Hydrogen is used to generate steam in furnaces by reacting with oxygen, as a pre-clean and carrier Gas during epitaxy, and as a constituent of annealing gases.
Hydrogen Bromide - chemical formula HBr, hydrogen bromide is a toxic, corrosive gas with a TLV of 3ppm. Hydrogen bromide has a strong irritating odor and is irritating to lungs, skin and eyes. Hydrogen bromide is used as an etch gas.
Hydrogen Chloride - chemical formula HCl, hydrogen chloride is a toxic, corrosive gas with a TLV of 5ppm. Hydrogen chloride has a pungent irritating odor and is irritating to lungs, skin and eyes. Hydrogen chloride is used as a cleaning gas during epitaxial deposition and as a furnace cleaning agent.
Hydrogen Fluoride - chemical formula HF, hydrogen fluoride is a toxic, corrosive gas with a TLV of 3ppm. Hydrogen fluoride has a sharp irritating odor and is irritating to lungs, skin and eyes. Hydrogen bromide is used to generate hydrofluoric acid.
Hydrogen Peroxide - chemical formula H₂O₂, hydrogen peroxide is an oxidizer used primarily as part of sulfuric acid peroxide, and SC1 cleans. hydrogen peroxide is commonly sold as a 30% solution and has a density of 1.10Kg/L. Hydrogen peroxide will burn eyes or skin on contact and may react strongly with other chemicals.