Semiconductor device fabrication

Semiconductor device fabrication
MOSFET scaling (process nodes)
020 µm – 1968 010 µm – 1971 006 µm – 1974 003 µm – 1977  1.5 µm – 1981 001 µm – 1984 800 nm – 1987 600 nm – 1990 350 nm – 1993 250 nm – 1996 180 nm – 1999 130 nm – 2001 090 nm – 2003 065 nm – 2005 045 nm – 2007 032 nm – 2009 028 nm – 2010 022 nm – 2012 014 nm – 2014 010 nm – 2016 007 nm – 2018 005 nm – 2020 003 nm – 2022
Future 002 nm ~ 2024
Half-nodes Density CMOS Device (multi-gate) Moore's law Transistor count Semiconductor Industry Nanoelectronics
v t e

Semiconductor device fabrication is the process used to manufacture semiconductor devices, typically integrated circuits (ICs) such as computer processors, microcontrollers, and memory chips (such as NAND flash and DRAM). It is a multiple-step photolithographic and physio-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.

The fabrication process is performed in highly specialized semiconductor fabrication plants, also called foundries or "fabs",^[1] 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.^[2] Production in advanced fabrication facilities is completely automated, with automated material handling systems taking care of the transport of wafers from machine to machine.^[3]

A wafer often has several integrated circuits which are called dies as they are pieces diced from a single wafer. Individual dies are separated from a finished wafer in a process called die singulation, also called wafer dicing. The dies can then undergo further assembly and packaging.^[4]

Within fabrication plants, the wafers are transported inside special sealed plastic boxes called FOUPs.^[3] FOUPs in many fabs contain an internal nitrogen atmosphere^[5][6] which helps prevent copper from oxidizing on the wafers. Copper is used in modern semiconductors for wiring.^[7] The insides of the processing equipment and FOUPs is kept cleaner than the surrounding air in the cleanroom. This internal atmosphere is known as a mini-environment and helps improve yield which is the amount of working devices on a wafer. This mini environment is within an EFEM (equipment front end module)^[8] which allows a machine to receive FOUPs, and introduces wafers from the FOUPs into the machine. Additionally many machines also handle wafers in clean nitrogen or vacuum environments to reduce contamination and improve process control.^[3] Fabrication plants need large amounts of liquid nitrogen to maintain the atmosphere inside production machinery and FOUPs, which are constantly purged with nitrogen.^[5][6] There can also be an air curtain or a mesh^[9] between the FOUP and the EFEM which helps reduce the amount of humidity that enters the FOUP and improves yield.^[10][11]

Companies that manufacture machines used in the industrial semiconductor fabrication process include ASML, Applied Materials, Tokyo Electron and Lam Research.