Planar process
Encyclopedia
The planar process is a manufacturing process used in the semiconductor industry
to build individual components of a transistor
, and in turn, connect those transistors together. It is the primary process by which modern integrated circuit
s are built. The process was developed by Jean Hoerni
, one of the Traitorous Eight
, while working at Fairchild Semiconductor
.
The key concept was to view a circuit in its two-dimensional projection (a plane), thus allowing the use of photographic processing
concepts such as film negatives to mask the projection of light exposed chemicals. This allowed the use of a series of exposures on a substrate (Silicon) to create silicon oxide (insulators) or doped regions (conductors). Together with the use of metallization (to join together the integrated circuits), and the concept of p-n junction isolation (from Kurt Lehovec
), the researchers at Fairchild were able to create circuits on a single silicon crystal slice (a wafer) from a monocrystalline silicon boule.
The process involves the basic procedures of silicon dioxide
(SiO2) oxidation, SiO2 etching and heat diffusion. The final steps involves oxidizing the entire wafer with an SiO2 layer, etching contact vias to the transistors, and depositing a covering metal layer over the oxide, thus connecting the transistors without manually wiring them together.
Semiconductor industry
The semiconductor industry is the aggregate collection of companies engaged in the design and fabrication of semiconductor devices. It formed around 1960, once the fabrication of semiconductors became a viable business...
to build individual components of a transistor
Transistor
A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...
, and in turn, connect those transistors together. It is the primary process by which modern integrated circuit
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
s are built. The process was developed by Jean Hoerni
Jean Hoerni
Jean Amédée Hoerni was a silicon transistor pioneer and a member of the Traitorous Eight. He was remembered for developing the planar process....
, one of the Traitorous Eight
Traitorous Eight
The Traitorous Eight, as they became known, are eight men who left Shockley Semiconductor Laboratory to form Fairchild Semiconductor in 1957. More neutral terms include the "Fairchild Eight" and the "Shockley Eight." They have sometimes been called "Fairchildren," although this term has been also...
, while working at Fairchild Semiconductor
Fairchild Semiconductor
Fairchild Semiconductor International, Inc. is an American semiconductor company based in San Jose, California. Founded in 1957, it was a pioneer in transistor and integrated circuit manufacturing...
.
The key concept was to view a circuit in its two-dimensional projection (a plane), thus allowing the use of photographic processing
Photographic processing
Photographic processing is the chemical means by which photographic film and paper is treated after photographic exposure to produce a negative or positive image...
concepts such as film negatives to mask the projection of light exposed chemicals. This allowed the use of a series of exposures on a substrate (Silicon) to create silicon oxide (insulators) or doped regions (conductors). Together with the use of metallization (to join together the integrated circuits), and the concept of p-n junction isolation (from Kurt Lehovec
Kurt Lehovec
Kurt Lehovec is one of the pioneers of the integrated circuit, 1959. He innovated the concept of p-n junction isolation used in every circuit element with a guard ring: a reverse-biased p-n junction surrounding the planar periphery of that element. This patent was assigned to Sprague Electric...
), the researchers at Fairchild were able to create circuits on a single silicon crystal slice (a wafer) from a monocrystalline silicon boule.
The process involves the basic procedures of silicon dioxide
Silicon dioxide
The chemical compound silicon dioxide, also known as silica , is an oxide of silicon with the chemical formula '. It has been known for its hardness since antiquity...
(SiO2) oxidation, SiO2 etching and heat diffusion. The final steps involves oxidizing the entire wafer with an SiO2 layer, etching contact vias to the transistors, and depositing a covering metal layer over the oxide, thus connecting the transistors without manually wiring them together.