Semiconductor Manufacturing

Semiconductor device manufacturing is the process used to create the integrated circuits (silicon chips) that are present in everyday electrical and electronic devices. It is the process of a multiple-step sequencing of photographic and chemical processing steps during which electronic circuits are gradually created on a wafer made of pure semiconducting material. Silicon is one of the most commonly used semiconductor material today, along with various compound semiconductors.

Processing Of the Semiconductor device

In the semiconductor fabrication, the various processing steps fall into four general categories: deposition, removal, patterning, and modification of electrical properties.

• Deposition is a process that grows, coats, or otherwise transfers a material onto the wafer. Available technologies have physical vapor deposition (PVD), chemical vapor deposition (CVD), electrochemical deposition (ECD), molecular beam epitaxial (MBE) and more recently, atomic layer deposition (ALD) among others.
• Removal process may remove material from the wafer either in bulk or selectively and consist primarily of etch processes, either wet etching or dry etching. The process of Chemical-mechanical planarization (CMP) is also a removal process used between levels.
• Patterning covers all the series of processes that shape or alter the existing shape of the deposited materials and is generally referred to as lithography. For example, some conventional lithography, the wafer is coated with a chemical called a photoresist. The photoresist are exposed by a stepper, a machine that focuses, aligns, and moves the mask, exposing select portions of the wafer to short wavelength light. The unexposed layers are washed away by a developer solution. After etching and other processing, the remaining photoresist is removed by plasma ashing.
• These doping methods are followed by furnace anneal or in advanced devices, by rapid thermal anneal (RTA) which serve to activate the implanted dopants. Modification of the electrical properties now also extends to reduction of dielectric constant in low-k insulating materials via exposure to ultraviolet light in UV processing (UVP).