Semiconducting in the context of Computer processor

In organosilicon and polymer chemistry, a silicone or polysiloxane is a polymer composed of repeating units of siloxane (−O−R₂Si−O−SiR₂−, where "R" stands for an organic group). They are typically colorless oils or rubber-like substances. Silicones are used in sealants, adhesives, lubricants, medicine, cooking utensils, thermal insulation, and electrical insulation. Some common forms include silicone oil, grease, rubber, resin, and caulk.

Silicone is often confused with one of its constituent elements, silicon, but they are distinct substances. Silicon is a pure chemical element, a metalloid, which forms a dark-grey semiconducting crystalline solid. In its crystalline form it is used to make integrated circuits ("electronic chips") and solar cells. In contrast, silicone is formed by the polymerization of the siloxane molecule, which itself is made up of a variable combination of carbon, hydrogen, oxygen and silicon atoms. Depending on the chemical makeup and polymer structure of a particular silicone product, it can possess a variety of physical properties, ranging from an oily liquid to a rubbery resin.

Organic semiconductors are solids whose building blocks are pi-bonded molecules or polymers made up by carbon and hydrogen atoms and – at times – heteroatoms such as nitrogen, sulfur and oxygen. They exist in the form of molecular crystals or amorphous thin films. In general, they are electrical insulators, but become semiconducting when charges are injected from appropriate electrodes or are introduced by doping or photoexcitation.

Semiconductor device fabrication is the process used to manufacture semiconductor devices, typically integrated circuits (ICs) such as microprocessors, microcontrollers, and memories (such as RAM and flash memory). It is a multiple-step photolithographic and physico-chemical process (with steps such as thermal oxidation, thin-film deposition, ion implantation, etching) during which electronic circuits are gradually created on a wafer, typically made of pure single-crystal semiconducting material. Silicon is almost always used, but various compound semiconductors are used for specialized applications. Steps such as etching and photolithography can be used to manufacture other devices, such as LCD and OLED displays.

The fabrication process is performed in highly specialized semiconductor fabrication plants, also called foundries or "fabs", with the central part being the "clean room". In more advanced semiconductor devices, such as modern 14/10/7 nm nodes, fabrication can take up to 15 weeks, with 11–13 weeks being the industry average. Production in advanced fabrication facilities is completely automated, with automated material handling systems taking care of the transport of wafers from machine to machine.

In the context of integrated circuits, a die is a small block of semiconducting material on which a given functional circuit is fabricated. Typically, integrated circuits are produced in large batches on a single wafer of electronic-grade silicon (EGS) or other semiconductor (such as GaAs) through processes such as photolithography. The wafer is cut (diced) into many pieces, each containing one copy of the circuit. Each of these pieces is called a die.

There are three commonly used plural forms: dice, dies, and die. To simplify handling and integration onto a printed circuit board, most dies are packaged in various forms.

An electrical junction is a point or area where (a) two or more conductors or (b) different semiconducting regions of differing electrical properties make physical contact. Electrical junctions types include thermoelectricity junctions, metal–semiconductor junctions and p–n junctions. Junctions are either rectifying or non-rectifying. Non-rectifying junctions comprise ohmic contacts, which are characterised by a linear current–voltage (${\displaystyle I-V}$) relation. Electronic components employing rectifying junctions include p–n diodes, Schottky diodes and bipolar junction transistors.

The junction field-effect transistor (JFET) is one of the simplest types of field-effect transistor. JFETs are three-terminal semiconductor devices that can be used as electronically controlled switches or resistors, or to build amplifiers.

Unlike bipolar junction transistors, JFETs are exclusively voltage-controlled in that they do not need a biasing current. Electric charge flows through a semiconducting channel between source and drain terminals. By applying a reverse bias voltage to a gate terminal, the channel is pinched, so that the electric current is impeded or switched off completely. A JFET is usually conducting when there is zero voltage between its gate and source terminals. If a potential difference of the proper polarity is applied between its gate and source terminals, the JFET will be more resistive to current flow, which means less current would flow in the channel between the source and drain terminals.