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Wafer fabrication is a procedure composed of many repeated sequential processes to produce completeelectrical orphotoniccircuits onsemiconductorwafers in asemiconductor device fabrication process. Examples include production of radio frequency (RF) amplifiers,LEDs,optical computer components, andmicroprocessors forcomputers. Wafer fabrication is used to build components with the necessary electrical structures.
The main process begins withintegrated circuit design, whereelectrical engineers designing the circuit and defining its functions, and specifying the signals, inputs/outputs andvoltages needed. These electrical circuit specifications are entered into electrical circuit design software, such asSPICE, and then imported into circuit layout programs, which are similar to ones used forcomputer aided design. This is necessary for the layers to be defined forphotomask production. The resolution of the circuits increases rapidly with each step in design, as the scale of the circuits at the start of the design process is already being measured in fractions of micrometers. Each step thus increases circuit density for a given area.
The next part of the process ismask data preparation.
Then comes the most expensive part of the semiconductor device fabrication process, wafer fabrication.
The silicon wafers start out blank and pure. The circuits are built in layers inclean rooms. First,photoresist patterns are photo-masked in micrometer detail onto the wafers' surface. The wafers are then exposed to short-waveultraviolet light and the unexposed areas are thus etched away andcleaned. Hotchemicalvapors aredeposited on to the desired zones and baked in highheat, which permeate the vapors into the desired zones. In some cases, ions, such as O2+ or O+, are implanted in precise patterns and at a specific depth by using RF-driven ion sources.
These steps are often repeated many hundreds of times, depending on the complexity of the desired circuit and its connections.
New processes to accomplish each of these steps with better resolution and in improved ways emerge every year, with the result of constantly changing technology in the wafer fabrication industry. New technologies result in denser packing of minuscule surface features such astransistors and micro-electro-mechanical systems (MEMS). This increased density continues the trend often cited asMoore's Law.
Afab is a common term for where these processes are accomplished. Often the fab is owned by the company that sells the chips, such asIntel,Texas Instruments, orFreescale. Afoundry is a fab at which semiconductor chips or wafers are fabricated to order for third party companies that sell the chip, such as fabs owned byTaiwan Semiconductor Manufacturing Company (TSMC),United Microelectronics Corporation (UMC),GlobalFoundries andSemiconductor Manufacturing International Corporation (SMIC).
In 2013 the cost of building the next generation wafer fab was over $10 billion.[1]
After wafer fabrication and dicing, the "bare" semiconductor die leave the fab. Usually the die are packaged (seeintegrated circuit packaging) and then later those packages are assembled on a PCB; occasionally the die are used inchip on board where the bare die are placed directly on a PCB.
Referred to respectively as the wafer fab equipment[2] or wafer front end[3] (equipment) market, both using the acronym WFE, the market is that of the manufacturers of the machines which in turn manufacture semiconductors. The apexresearch link in 2020 identifiedApplied Materials,ASML,KLA-Tencor,Lam Research,TEL andDainippon Screen Manufacturing as market participants[2] while the 2019electronicsweekly.com report, citing The Information Network's president Robert Castellano, focused on the respectivemarket shares commanded by the two leaders, Applied Materials and ASML.[3]