Aixtron

Aixtron was founded in 1983 in Herzogenrath, outside Aachen, with roots at RWTH Aachen university. Its specialty is MOCVD — metalorganic chemical vapor deposition — in which gases break down over a hot wafer and leave behind atomic layers of compound semiconductors such as GaN and related materials.

That is how LEDs, microLED displays, lasers and silicon-carbide power electronics are born, and Aixtron shares the market mainly with America's Veeco. In 2016 US authorities blocked a Chinese takeover of the company on security grounds — an early sign of the chip war that followed. Its customers include makers of SiC transistors such as Wolfspeed.