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#Glossary

##Fabrication
Fabrication (or Manufacturing)is the process of building circuits on a silicon wafer in a cleanroom environment where all aspects of production (temperature, power, chemistries, moisture, contamination, etc.) are tightly controlled. It take 40 to 150 days to complete the fabrication process. 

##Cleanroom
Cleanroom is a room that has HEPA (High Efficiency Particulate Air) filtration to remove
particles from the air. Cleanrooms are used for manufacturing where high levels of
cleanliness and sterility are required. Common applications of the cleanroom
include manufacturing of medical devices, pharmaceuticals, and semiconductors.

##Chemical mechanical planarization (CMP) 
CMP is used to smooth the surface of wafers following other manufacturing steps, such as etching and cleaning. CMP allow a new layer of features to be added.

##Cleaning
Cleaning involves removing residues left on the wafer by the etching process.

##Deposition
Deposition adds thin films of materials on a wafer to become parts of chips. Techniques include chemical vapor deposition, physical vapor deposition, electrochemical coating, spin-coating, rapid thermal processing, and tube- based diffusion and deposition.

###CVD
Chemical vapor deposition (CVD) tools create a chemical vapor that deposits films on the wafer atom-by-atom or molecule-by-molecule. 

###PVD
Physical vapor deposition (PVD) tools vaporize a solid or liquid material, which then condenses onto a substrate. The primary PVD method is called "sputtering."

###RTP
Rapid thermal processing (RTP) is critical to several steps in chip manufacturing. RTP tools include lamps, lasers, or other mechanisms to quickly increase the temperature of a wafer in order to change its properties. 

###Spin-coating
These tools spin a wafer to spread liquid material deposited on the wafer across it. Spin-coating is used extensively in photoresist coating but only for narrow applications in chip production.

###tube-based diffusion and deposition
Tube-based diffusion and deposition systems are called "tube‚"-based because substrates are loaded in cylindrical chambers for processing, either causing diffusion of dopants into a wafer (tube diffusion systems) or depositing materials for particular applications (tube deposition systems).

##Design
Design determines the layout of transistors and wiring on a chip to be manufactured.

##DRAM
Dynamic random-access memory (DRAM) is a memory chip that stores data while a computer operates, but loses it when the computer powers down.

##EDA
Electronic design automation (EDA) software is used to design chips.

##Etching
Etching tools are used to create permanent patterns on chips: after photolithography has removed certain parts of a photoresist deposited on a wafer according to a specific pattern, the etching tools etch this pattern into a permanent substrate bellow. Dry etching and wet etching use a gas and a liquid, respectively, for the etching process.

##FPGA
Field-programmable gate arrays (FPGAs) are logic chips that can be reprogrammed after deployment to suit specific calculations.

##Foundries
Foundries are semiconductor manufacturing facilities that manufacture chips for third-party customers.

##GPU
Graphics processing units (GPUs) are specialized logic chips used most commonly for graphics processing and developing artificial intelligence algorithms.

##Photolithography
In photolithography, light is used to draw patterns into semiconductor wafers, creating the tiny circuits that comprise logic chips. A photolithography tool passes light through a photomask-a transparent plate with a circuit pattern-to transfer that pattern to a wafer coated with photoresist chemical. The light dissolves parts of the photoresist according to the circuit pattern.

###ArF dry (DUV)
ArF (Argon hexa Fluoride) dry lithography scanners are advanced deep ultraviolet (DUV) photolithography tools used in high-volume semiconductor manufacturing.

###ArF immersion (DUV)
Immersion ArF is the same as dry ArF except the Scanner lens is immersed in a fluid, typically water. 

###KrF (DUV) lithography tools
KrF lithography tools are deep ultraviolet (DUV) photolithography tools that use 248 nm wavelength light from krypton fluoride lasers to pattern semiconductor features for mature node semiconductors. 

###i-line lithography tools
i-line lithography tools are ultraviolet (UV) photolithography systems used in semiconductor manufacturing for mature process nodes.

###EUV lithography tools
EUV lithography tools are the most advanced photolithography equipment currently used in mass semiconductor production. They are the only tools combining leading-edge precision (by producing light with small wavelengths) with high throughput (by using photomasks), and are necessary for mass-producing the most advanced logic chips.

##IDM
Integrated device manufacturers (IDMs) are firms that perform all three steps of production: design; fabrication; and assembly, testing, and packaging.

##Ion implanters
Ion implanters embed impurities (called dopants) into parts of wafers to change their properties.

##NAND
NAND flash is a memory chip that stores memory permanently, even when power is turned off.

##OSAT
Outsourced semiconductor assembly and test (OSAT) firms perform assembly, testing, and packaging for third-party customers.

##Packaging
Packaging involves attaching a manufactured chip to an encasing package.

##Photomasks
Photomasks are transparent plates featuring a circuit pattern through which photolithography equipment directs light in order to transfer this pattern onto the chip. Each photomask is specific to one chip design.

##Photoresist
Photoresists are chemicals deposited on a wafer that selectively dissolve to form the circuit pattern when exposed to patterned light that has passed through a photomask after being generated by a photolithography tool.

##Resist processing tools
Resist processing tools, also called "tracks," coat photoresists on wafers (typically by spin-coating, which spins the wafer to spread deposited photoresist), develop them (dissolve portions hit by light), and bake them (harden undissolved photoresist to prepare for etching).