Glossary

Wafer

A wafer is a thin slice of semiconductor material, such as silicon, used as the substrate for the fabrication of integrated circuits. Wafers are produced by cutting a single crystal ingot into thin discs, which are then polished to create a smooth, flat surface suitable for microfabrication processes.

Doping

Doping is the process of introducing impurities into a semiconductor to modify its electrical properties. By adding specific types of atoms (dopants), the conductivity of the semiconductor can be increased, enabling the creation of p-type or n-type regions essential for the function of diodes, transistors, and other semiconductor devices.

Photolithography

Photolithography is a process used in microfabrication to pattern parts of a thin film or the bulk of a substrate. It involves using light to transfer a geometric pattern from a photomask to a light-sensitive chemical photoresist on the substrate. This process is crucial for defining the intricate patterns needed to build semiconductor devices.

Etching

Etching is a material removal process used in semiconductor fabrication. There are two main types of etching: wet etching, which uses liquid chemicals, and dry etching, which uses plasma. Etching is used to remove specific areas of material to create patterns or features on the wafer surface, often following photolithography.

Chemical Vapor Deposition (CVD)

CVD is a process used to deposit thin films on a substrate by chemical reactions of gaseous precursors. In semiconductor manufacturing, CVD is used to create high-purity, high-performance solid materials such as silicon dioxide or silicon nitride, which are essential for building various layers in semiconductor devices.

Ion Implantation

Ion implantation is a technique used to introduce impurities into a semiconductor wafer. Ions of the desired element are accelerated in an electric field and implanted into the wafer, altering its physical and electrical properties. This process is crucial for defining regions of different electrical characteristics in devices like transistors.

Dielectric

A dielectric material is an electrical insulator that can be polarized by an electric field. In semiconductor devices, dielectrics are used to separate conductive layers, provide insulation, and create capacitors. Common dielectric materials include silicon dioxide and silicon nitride.

Planarization

Planarization is the process of making a wafer surface flat and even, typically using chemical mechanical polishing (CMP). Planarization is essential in modern semiconductor manufacturing to ensure that subsequent layers are built on a uniform surface, which improves device reliability and performance.

Annealing

Annealing is a heat treatment process used in semiconductor fabrication to repair damage to the crystal structure of a wafer caused by ion implantation. It also activates dopants and helps diffuse them into the semiconductor lattice, improving the electrical properties of the wafer.

Cleanroom

A cleanroom is a controlled environment with low levels of pollutants such as dust, airborne microbes, and chemical vapors. Cleanrooms are critical in semiconductor manufacturing to prevent contamination of wafers during processing, ensuring the high yield and quality of semiconductor devices.