Very Large Scale Integration

Very Large Scale Integration (VLSI) is a process of creating an Integrated circuit by combining thousands of transistors into a single chip. VLSI began in the 1970s when complex semiconductor and communication technologies were being developed. The microprocessor is a VLSI device.

History

The history of VLSI dates back to the late 20th century. The first known published use of the term "VLSI" was in the paper "Very Large-Scale Integration" by Carver Mead, in the proceedings of the IEEE in 1975. The term VLSI was later adopted by all major semiconductor manufacturers and is now a common term in the field of electronics.

Design

VLSI design consists of several steps. The first step is the creation of an electronic schematic. This schematic is then transformed into a layout, which maps the layers of various conductor and semiconductor materials in the VLSI. This layout is then used to create a photomask, which is used in the fabrication of the VLSI.

Fabrication

The fabrication of VLSI devices involves several steps. The first step is the creation of a silicon wafer, which is then coated with a layer of silicon dioxide. This layer is then patterned with a photomask to create the layout of the VLSI. The silicon dioxide is then etched away, leaving behind the patterned silicon. This process is repeated several times to create the multiple layers of the VLSI.

Applications

VLSI devices have many applications. They are used in computers, cell phones, digital cameras, and many other electronic devices. They are also used in the medical field, for example in MRI machines and other medical imaging devices.

See also

• Integrated circuit
• Semiconductor
• Microprocessor
• Carver Mead

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