Very-large-scale integration (VLSI) is the process of building miniaturized electronic circuits, consisting mainly of semiconductor devices, called transistors, on the surface of a thin substrate of semiconductor material. These circuits, often referred as electronic chips, are used in almost all electronic equipment in use today and have revolutionized the world of electronics.
The dimension of transistors has been reduced to a fraction of a micrometer. With the aid of nanotechnology, the size of transistor may approach several nanometers. The decreasing transistor sizes make VLSI circuits faster, evidenced by the more than 1000-fold speedup of microprocessors. Large electronic chips today contain several hundreds of millions of transistors. The VLSI chips of a figure-tip size can provide functions that were delivered by thousands of print circuit-boards before.
The VLSI research has many aspects. All transistors must be properly placed and connected so that the entire circuit can operate at high frequencies. The power consumption of circuits needs to be reduced. The reliability and testability must be addressed. The VLSI design is closely related to fabrication processes and therefore research on solid-state materials is also performed.
The design of VLSI circuits is a major challenge. Consequently, it is impossible to solely rely on manual design approaches. Computer Aided Design (CAD) is widely used, which is also referred as electronic design automation (EDA). In EDA, computer programs are created to develop VLSI circuits. In CAD research, both software and hardware activities are conducted to improve design quality and reduce design time.