IQE was founded by Dr Drew Nelson and Dr Michael Scott in 1988 as Epitaxial Products International. Initially, the company specialised in producing epitaxial wafers for optoelectronic devices used primarily in fiber optic telecommunications. Metal Organic Chemical Vapor Deposition technology was used to produce semiconductor lasers, light-emitting diodes and photodetectors designed to operate at wavelengths of 1300 nm and 1550 nm utilised for long distance fiber optic communications. In 1999, Epitaxial Products International merged with Pennsylvania-based Quantum Epitaxial Designs to form IQE. QED was founded by Tom Hierl. Also in 1999, the newly merged entity underwent an Initial Public Offering on the European EASDAQ stock exchange, followed a year later by a listing on the London Stock Exchange. The merger with QED brought to the group a range of new manufacturing tools based on molecular beam epitaxy technology and a range of products for the wireless telecommunications. Following the merger, IQE became the first independent outsource manufacturer of both optoelectronic and radio frequency epitaxial wafers produced using both MOCVD and MBE technologies. The Bethlehem, PA facility specialised in a number of wireless products including pseudomorphic high electron mobility transistors and metal semiconductor field-effect transistors. In 2000, the company formed a new, wholly owned subsidiary company specialising in silicon based epitaxy. IQE Silicon was established in a new facility adjacent to the group's headquarters and European manufacturing base in Cardiff, Wales, UK. The new subsidiary used chemical vapor deposition tools to produce silicon and germanium epitaxial wafers for enhanced silicon processing performance, microelectromechanical systems and nanotechnology applications. Also in 2000, the group acquired Wafer Technology based in Milton Keynes, UK. The acquisition provided the group with in-house production of gallium arsenide and indium phosphide substrates as well as adding capabilities for gallium antimonide and indium antimonide for infrared applications. In 2006, the Group acquired the Electronic Materials Division from Emcore, providing IQE with its second US operation based in Somerset, NJ. This acquisition added further Metal Organic Chemical Vapor Deposition capacity and complementary radio frequency products including heterojunction bipolar transistors and bipolar field-effect transistors. Also in 2006, the group made a further acquisition in the form of Singapore based MBET technologies which provided the group with complete multi-site, multi-technology and multi-product capabilities to form the world's largest independent contract manufacturer of epitaxial wafers. In 2009 the group added new free-standing gallium nitride substrate capability with the acquisition of NanoGaN, a spin out start-up from the University of Bath. In 2012, IQE Group acquired Galaxy Compound Semiconductors, based in Spokane, Washington, USA and MBE epitaxy manufacturing unit of RFMD, based in Greensboro, NC, USA.
The company made a stock exchange announcement on 12 November 2018 that shipments of its product would be materially reduced, also materially affecting profitability. Following this announcement, the shares fell by approximately 29%. As of December 2018, IQE was one of the most short-sold stocks on the London Stock Exchange.
