Semiconductor Glossary

Capacitor: An electrical component with a dielectric material sandwiched between two metal terminals. When a voltage is applied to a capacitor, it stores electrical charge proportionate to the voltage level, and this effect (called capacitance) is used to smooth out the rectified current and suppress electrical noise. In a DRAM, capacitors are used as a memory cell device, with charged capacitors representing “1” and uncharged capacitors representing “0.” Also, capacitors block direct current while allowing alternating current to pass.

Carbon Nanotube: Carbon nanotubes refer to tubular microstructures formed by one or more layers of carbon sheet called graphene. Carbon nanotubes were discovered in 1991 by Sumio Iijima, who was a researcher at NEC’s lab in Tsukuba. Those with a single layer of graphene are called single-walled nanotubes (SWNTs), whereas those with two layers and those with more than one layer are referred to as double-walled nanotubes (DWNTs) and multi-walled nanotubes (MWNTs), respectively. Carbon nanotubes are highly promising as the next-generation semiconductor materials.

Charge-Coupled Device: An image sensing device that serves as an electronic eye. It has an array of light sensitive elements that generates electrical charges when exposed to light. The charges are consecutively transferred to adjacent elements until they reach the end of the line to be processed. CCDs are commonly used in digital cameras and scanners.

Chip: A piece of substrate made of silicon or other materials on which electronic devices or circuits are implemented. A chip is also called a pellet or a die in the manufacturing processes. Often a finished and packaged IC is referred to as a chip.

CMOS Image Sensor: A low-power image sensor based on CMOS sensor technology. A CIS consumes only about 1/10 of power needed for a CCD, operates with a single voltage supply, and can integrate peripheral circuits on the same chip.

Clean Room: A space with a controlled level of contamination for manufacturing ICs. Filtered air flows downward from the clean room ceiling toward the floor in a constant stream. An especially high level of cleanliness is required for the front-end-of-line (FEOL) processes.

Complementary Metal-Oxide Semiconductor: A device that combines a p-type MOSFET (PMOS) and an n-type MOSFET (NMOS) so they complement each other. Unlike single-type PMOS and NMOS devices, a CMOS conducts very little current except while switching between on and off states, which makes it ideal for implementing low-power logic circuits. CMOS is the mainstream of current LSI technology.

Chemical Mechanical Polishing: A technology/tool for planarizing the wafer surface by combining chemical reactions and mechanical polishing. In a typical CMP process, a wafer is pressed against a rotating table covered with a polishing pad, while a slurry containing colloidal silica abrasives is deposited between the wafer and the pad. A non-abrasive slurry may be used depending on the wafer surface material to be removed.

Chip On Board: A method for attaching a bare LSI chip directly onto the printed circuit board (PCB). The chip’s electrodes and the PCB are interconnected either by wire bonding or flip-chip bonding.

Chip On Glass: A method for mounting a bare liquid crystal display (LCD) driver chip directly onto a glass substrate. Compared to the widely used tape carrier package (TCP) method, COG requires fewer parts and process steps.

Compound Semiconductor: A compound semiconductor is a semiconductor composed of two or more elements. Examples include gallium arsenide (GaAs), gallium phosphide (GaP), indium phosphide (InP), and cadmium sulfide (CdS) semiconductors. Compound semiconductors are suitable for high-frequency, high-speed devices such as mobile phones.

Copper Interconnect: Copper interconnects were a technology which was introduced by IBM as a solution to the decrease in interconnect delay for highly scaled semiconductor devices, and have become the mainstream in interconnects for logic devices.

Central Processing Unit: A semiconductor chip that serves as the brain of a computer. It consists of a control unit, an arithmetic/logic unit, a register where the output of operations is temporarily stored, an interface with storage units, and input/output interfaces with peripherals. A CPU fulfills the first two of the five basic computer functions defined by John von Neumann (arithmetic/logic, control, memory, input, and output).

Chip Size Package, or Chip Scale Package: A tight-fitting IC package that is very close to the size of the chip. It was made possible by advancements in the wiring technology and innovations in the integration technology. CSPs help make small electronics like mobile phones even smaller and lighter.

Chemical Vapor Deposition: A chemical process for producing thin films of required materials on the surface of a substrate. Specifically, gases containing the desired materials are introduced in the reaction chamber, and chemical reactions are induced to deposit thin films on the substrate. In semiconductor production processes, CVD is used for depositing interconnect materials and dielectric films necessary to form circuits on a silicon wafer.