Foundry (electronics)
Encyclopedia
In the microelectronics
industry a semiconductor fabrication plant (commonly called a fab) is a factory where devices such as integrated circuits are manufactured.
A business that operates a semiconductor fab for the purpose of fabricating the designs of other companies, such as fabless semiconductor companies
, is known as a foundry. If a foundry does not also produce its own designs, it is known as a pure-play semiconductor foundry.
Fabs require many expensive devices to function. Estimates put the cost of building a new fab over one billion
U.S. dollars with values as high as $3–4 billion not being uncommon. TSMC
will be investing 9.3 billion dollars in its Fab15 300 mm wafer manufacturing facility in Taiwan to be operational in 2012.
The central part of a fab is the clean room, an area where the environment is controlled to eliminate all dust, since even a single speck can ruin a microcircuit, which has features much smaller than dust. The clean room must also be dampened against vibration and kept within narrow bands of temperature and humidity. Controlling temperature and humidity is critical for minimizing static electricity.
The clean room contains the stepper
s for photolithography
, etching
, cleaning, doping and dicing machines. All these devices are extremely precise and thus extremely expensive. Prices for most common pieces of equipment for the processing of 300 mm wafers range from $700,000 to upwards of $4,000,000 each with a few pieces of equipment reaching as high as $50,000,000 each (e.g. steppers). A typical fab will have several hundred equipment items.
Another side effect of the cost has been the challenge to make use of older fabs. For many companies these older fabs are useful for producing designs for unique markets, such as embedded processors, flash memory
, and microcontroller
s. However, for companies with more limited product lines, it's often best to either rent out the fab, or close it entirely. This is due to the tendency of the cost of upgrading an existing fab to produce devices requiring newer technology to exceed the cost of a completely new fab.
There has been a trend to produce ever larger wafer
s, so each process step is being performed on more and more chips at once. The goal is to spread production costs (chemicals, fab time) over a larger number of saleable chips. It is impossible (or at least impracticable) to retrofit machinery to handle larger wafers. This is not to say that foundries using smaller wafers are necessarily obsolete; older foundries can be cheaper to operate, have higher yields for simple chips and still be productive.
The current state-of-the-art for wafer size is considered to be 300 mm (12 in). However, Intel is currently pushing semiconductor equipment manufacturers to move to the 450 mm wafer size. Additionally, there is a large push to completely automate the production of semiconductor chips from beginning to end. This is often referred to as the "lights-out fab
" concept.
The International Sematech Manufacturing Initiative (ISMI), an extension of the US consortium SEMATECH
, is sponsoring the "300 mm Prime" initiative. An important goal of this initiative is to enable fabs to produce smaller lots of chips; this is a response to shorter lifecycles seen in consumer electronics. The logic is that a fab that can produce smaller lots can more easily and efficiently switch its production to supply chips for a variety of electronic devices as they rapidly emerge in the marketplace. Another important goal is to reduce fabrication time by reducing the waiting time between processing steps.
Microelectronics
Microelectronics is a subfield of electronics. As the name suggests, microelectronics relates to the study and manufacture of very small electronic components. Usually, but not always, this means micrometre-scale or smaller,. These devices are made from semiconductors...
industry a semiconductor fabrication plant (commonly called a fab) is a factory where devices such as integrated circuits are manufactured.
A business that operates a semiconductor fab for the purpose of fabricating the designs of other companies, such as fabless semiconductor companies
Fabless semiconductor company
A fabless semiconductor company specializes in the design and sale of hardware devices and semiconductor chips while outsourcing the fabrication or "fab" of the devices to a specialized manufacturer called a semiconductor foundry...
, is known as a foundry. If a foundry does not also produce its own designs, it is known as a pure-play semiconductor foundry.
Fabs require many expensive devices to function. Estimates put the cost of building a new fab over one billion
1000000000 (number)
1,000,000,000 is the natural number following 999,999,999 and preceding 1,000,000,001.In scientific notation, it is written as 109....
U.S. dollars with values as high as $3–4 billion not being uncommon. TSMC
TSMC
Taiwan Semiconductor Manufacturing Company, Limited or TSMC is the world's largest dedicated independent semiconductor foundry, with its headquarters and main operations located in the Hsinchu Science Park in Hsinchu, Taiwan.-Overview:...
will be investing 9.3 billion dollars in its Fab15 300 mm wafer manufacturing facility in Taiwan to be operational in 2012.
The central part of a fab is the clean room, an area where the environment is controlled to eliminate all dust, since even a single speck can ruin a microcircuit, which has features much smaller than dust. The clean room must also be dampened against vibration and kept within narrow bands of temperature and humidity. Controlling temperature and humidity is critical for minimizing static electricity.
The clean room contains the stepper
Stepper
A stepper is a device used in the manufacture of integrated circuits that is similar in operation to a slide projector or a photographic enlarger. Steppers are an essential part of the complex process, called photolithography, that creates millions of microscopic circuit elements on the surface of...
s for photolithography
Photolithography
Photolithography is a process used in microfabrication to selectively remove parts of a thin film or the bulk of a substrate. It uses light to transfer a geometric pattern from a photomask to a light-sensitive chemical "photoresist", or simply "resist," on the substrate...
, etching
Etching (microfabrication)
Etching is used in microfabrication to chemically remove layers from the surface of a wafer during manufacturing. Etching is a critically important process module, and every wafer undergoes many etching steps before it is complete....
, cleaning, doping and dicing machines. All these devices are extremely precise and thus extremely expensive. Prices for most common pieces of equipment for the processing of 300 mm wafers range from $700,000 to upwards of $4,000,000 each with a few pieces of equipment reaching as high as $50,000,000 each (e.g. steppers). A typical fab will have several hundred equipment items.
Evolution
Typically an advance in chip-making technology requires a completely new fab to be built. In the past, the equipment to outfit a fab was not terribly expensive and there were a huge number of smaller fabs producing chips in small quantities. However, the cost of the most up-to-date equipment has since grown to the point where a new fab can cost several billion dollars.Another side effect of the cost has been the challenge to make use of older fabs. For many companies these older fabs are useful for producing designs for unique markets, such as embedded processors, flash memory
Flash memory
Flash memory is a non-volatile computer storage chip that can be electrically erased and reprogrammed. It was developed from EEPROM and must be erased in fairly large blocks before these can be rewritten with new data...
, and microcontroller
Microcontroller
A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM...
s. However, for companies with more limited product lines, it's often best to either rent out the fab, or close it entirely. This is due to the tendency of the cost of upgrading an existing fab to produce devices requiring newer technology to exceed the cost of a completely new fab.
There has been a trend to produce ever larger wafer
Wafer (electronics)
A wafer is a thin slice of semiconductor material, such as a silicon crystal, used in the fabrication of integrated circuits and other microdevices...
s, so each process step is being performed on more and more chips at once. The goal is to spread production costs (chemicals, fab time) over a larger number of saleable chips. It is impossible (or at least impracticable) to retrofit machinery to handle larger wafers. This is not to say that foundries using smaller wafers are necessarily obsolete; older foundries can be cheaper to operate, have higher yields for simple chips and still be productive.
The current state-of-the-art for wafer size is considered to be 300 mm (12 in). However, Intel is currently pushing semiconductor equipment manufacturers to move to the 450 mm wafer size. Additionally, there is a large push to completely automate the production of semiconductor chips from beginning to end. This is often referred to as the "lights-out fab
Lights out (manufacturing)
Lights out or lights-out manufacturing is a manufacturing methodology , rather than a specific process.Factories that run lights out are fully automated and require no human presence on-site. Thus, these factories can be run with the lights off. Many factories are capable of lights-out production,...
" concept.
The International Sematech Manufacturing Initiative (ISMI), an extension of the US consortium SEMATECH
SEMATECH
- Purpose :SEMATECH , a not-for-profit consortium, performs research and development to advance chip manufacturing. SEMATECH has broad engagement with various sectors of the R&D community, including chipmakers, equipment and material suppliers, universities, research institutes, and government...
, is sponsoring the "300 mm Prime" initiative. An important goal of this initiative is to enable fabs to produce smaller lots of chips; this is a response to shorter lifecycles seen in consumer electronics. The logic is that a fab that can produce smaller lots can more easily and efficiently switch its production to supply chips for a variety of electronic devices as they rapidly emerge in the marketplace. Another important goal is to reduce fabrication time by reducing the waiting time between processing steps.
See also
- Semiconductor fabricationSemiconductor fabricationSemiconductor device fabrication is the process used to create the integrated circuits that are present in everyday electrical and electronic devices. It is a multiple-step sequence of photolithographic and chemical processing steps during which electronic circuits are gradually created on a wafer...
for the process of manufacturing devices - Foundry modelFoundry modelIn microelectronics, the foundry model refers to the separation of a semiconductor fabrication plant operation from an integrated circuit design operation, into separate companies or business units.-Overview:...
for the business aspects of foundries and fabless companies - Semiconductor device fabrication
- Rock's lawRock's lawRock's law or Moore's Second Law, named for Arthur Rock, says that the cost of a semiconductor chip fabrication plant doubles every four years...
- Semiconductor consolidationSemiconductor ConsolidationSemiconductor consolidation is the recent trend of semiconductor companies collaborating in order to come to a practical synergy with the goal of being able to operate in a business model that can sustain profitability.-History:...
- Klaiber's lawKlaiber's LawSimply stated, Klaiber's law proposes that "the silicon wafer size will dictate the largest diameter of ultrapure water supply piping needed within a semiconductor wafer factory."...
- List of semiconductor fabrication plants
Further reading
- "Chip Makers Watch Their Waste", The Wall Street JournalThe Wall Street JournalThe Wall Street Journal is an American English-language international daily newspaper. It is published in New York City by Dow Jones & Company, a division of News Corporation, along with the Asian and European editions of the Journal....
, July 19, 2007, p.B3