AIXTRON SE is a German-based technology company, which specialises in manufacturing metalorganic chemical vapour deposition (MOCVD) equipment, for clients in the semiconductor industry. The company's shares are listed on the Frankfurt Stock Exchange and are currently traded in the OTC market. Until December 19, 2016 AIXTRON used to be a constituent of the TecDAX index. AIXTRON returned to the German technology index as per March 20, 2017.

AIXTRON was founded as a spin-out industry from RWTH Aachen University in 1983. The company listed on the Frankfurt Stock Exchange's now-defunct Neuer Markt, in November 1997. Since going public the company has made several acquisitions, with the Scientific Equipment Division of the British company Thomas Swan & Co. and the Swedish chemical vapor deposition equipment maker Epigress AB both purchased in 1999.

The company completed a €118 million merger with American rival Genus, Inc. in March 2005 and bought British nanomaterial developer Nanoinstruments Ltd., a company spun out from the University of Cambridge, in 2007.

In December 2010 the company converted from a German Aktiengesellschaft to a Societas Europaea to reflect its European and international nature.

In October 2016 China’s Fujian Grand Chip Investment Fund LP wanted to acquire Aixtron, but Germany’s economics ministry withdrew the approval of the takeover. In November 2016 the Committee on Foreign Investment in the United States (CFIUS) recommended both sides to drop their plan, because of national security concerns.

In 2017 Aixtron sold its ALD/CVD Memory Product line produced in Sunnyvale to Eugene Technology from South Korea. The US business was the reason CFIUS had US national security conserns. Aixtron said it continues to execute restructuring measures as well as to seek the establishment of partnerships for its OLED business in order to return to profitability in 2018.

65% of AIXTRON's revenues come from clients in Asia, with around 16% coming from Europe and the remaining 19% from the United States. The company produces metalorganic chemical vapour deposition equipment, used for making a range of electronic and opto-electronic products containing compound, organic and silicon-based semiconductors as well as nanotubes and nanofibers.

Many AIXTRON systems use a "planetary reactor" process whereby gaseous semiconductor substances are deposited on revolving wafers, while others utilise a Close Coupled "shower head" method of deposition.

Manufacturing sites are located in Herzogenrath near Aachen in Germany, Cambridge in the United Kingdom, and Sunnyvale, California, United States.