Indium phosphide

Indium phosphide
Materialscientist at en.wikipedia · CC BY-SA 3.0 · source
Name	Indium phosphide
Formula	InP
Molar mass	145.79 g·mol−1
Appearance	gray crystalline
Density	4.81 g·cm−3
Melting point	1062 °C
Solubility	insoluble in water
Crystal system	cubic (zincblende)

Indium phosphide is a III–V compound semiconductor used extensively in high-speed electronics, photonics, and optoelectronics. It is prized for its direct bandgap, high electron mobility, and thermal stability, leading to applications in lasers, photodetectors, and high-frequency transistors. Research and commercial development of indium phosphide have involved collaborations among major institutions, national laboratories, and multinational corporations.

History

The development of indium phosphide emerged alongside advances in compound semiconductor research at institutions such as Bell Labs, AT&T, IBM, RCA, and MIT. Early material characterization and device demonstrations were reported during the 1950s–1970s in journals associated with American Physical Society, IEEE, and Nature (journal), with significant contributions from researchers linked to Stanford University, University of California, Berkeley, and Cornell University. Military and aerospace interest, including programs at DARPA and collaborations with NASA, accelerated work on indium phosphide for high-frequency and radiation-hard applications. Commercialization in the 1980s–1990s involved companies like Intel, Nokia, Motorola, and specialized firms such as II-VI Incorporated and Sumitomo Electric, spurring growth of fabs in regions including Silicon Valley, Hsinchu Science Park, and Tsukuba Science City.

Crystal Structure and Properties

Indium phosphide crystallizes in the zincblende structure, similar to diamond-derived lattices and other III–V semiconductors such as Gallium arsenide, Aluminium arsenide, and Gallium phosphide. The lattice constant and cohesive energy underpin properties studied by groups at Max Planck Society, Lawrence Berkeley National Laboratory, and National Institute of Standards and Technology. Key physical parameters—direct bandgap around 1.34 eV at room temperature, high electron mobility comparable to Gallium arsenide, and strong optical absorption—make it suitable for infrared photonics and heterostructures with materials like Indium gallium arsenide and Aluminium indium arsenide. Thermal conductivity, defect formation energies, and surface reconstructions have been characterized using techniques developed at Argonne National Laboratory and computational methods from research teams at Princeton University and ETH Zurich.

Synthesis and Growth Methods

Crystal growth techniques for indium phosphide include liquid encapsulated Czochralski, vertical gradient freeze, and melt growth used historically by industrial producers such as Sumitomo Electric and Furukawa Electric. Thin-film and epitaxial methods—metalorganic chemical vapor deposition (MOCVD) pioneered by companies including MOCVD Corporation and research labs at University of California, Santa Barbara, and molecular beam epitaxy (MBE) advanced at Bell Labs and Cambridge University—enable heterostructures integrating InGaAs and AlInAs alloys. Hydride vapor phase epitaxy (HVPE) and liquid phase epitaxy (LPE) have been employed in specialty devices developed by Lucent Technologies and Samsung. Characterization methods from Oak Ridge National Laboratory and Sandia National Laboratories—transmission electron microscopy, x-ray diffraction, and secondary ion mass spectrometry—are routinely used to assess crystalline quality, impurity incorporation, and interface abruptness.

Electronic and Optical Properties

Indium phosphide’s direct bandgap yields efficient radiative recombination exploited in lasers and light-emitting devices produced by firms like Finisar and Coherent (company). High electron mobility supports heterojunction bipolar transistors and high-electron-mobility transistors explored by Texas Instruments, Broadcom, and researchers at Caltech. Optical gain, carrier lifetimes, and Auger recombination parameters have been measured in collaborative studies involving Rensselaer Polytechnic Institute, University of Cambridge, and Tokyo Institute of Technology. Band engineering using quantum wells, superlattices, and quantum dots—techniques advanced at Harvard University and EPFL—allows wavelength tuning across fiber-optic communication bands standardized by organizations such as the International Telecommunication Union.

Device Applications

Indium phosphide is central to photonic integrated circuits, distributed feedback lasers, and photodetectors used by telecommunications companies like AT&T, Verizon, and China Mobile. It underpins transceivers for optical networks developed by Cisco Systems and cloud datacenter suppliers such as Google and Amazon Web Services. High-frequency electronics for radar and satellite communications leverage InP devices in programs with Lockheed Martin, Northrop Grumman, and European Space Agency. Emerging applications include quantum photonics and single-photon sources pursued at IBM Research, Microsoft (company), and academic centers including University of Oxford and University of Cambridge.

Chemical Safety and Handling

Handling of indium phosphide in fabrication facilities follows standards from regulatory and standards bodies such as Occupational Safety and Health Administration, European Chemicals Agency, and International Organization for Standardization. Safety protocols developed at industrial fabs operated by TSMC and GlobalFoundries cover inhalation risks, chemical reactivity with acids and bases, and proper waste treatment in accordance with guidance from Environmental Protection Agency and Health and Safety Executive (UK). Material safety data sheets from manufacturers like 3M and Air Products and Chemicals outline personal protective equipment, engineering controls, and emergency procedures used in cleanrooms at research centers like Riken and Korea Advanced Institute of Science and Technology.

Market and Production Industry

The indium phosphide supply chain intersects with mining and refining sectors, involving companies such as Nyrstar and Glencore for indium sourcing, and specialized wafer suppliers like IQE plc and Rohm and Haas. Investment decisions and industry forecasts by firms like McKinsey & Company, Gartner, Inc., and IC Insights track demand from telecommunications, datacom, and defense markets. Regional manufacturing hubs include fabs in Taiwan, South Korea, Japan, United States, and Germany, with vertical integration strategies implemented by conglomerates like Sony and Samsung Electronics. Trade, export controls, and research collaborations are influenced by policies from entities such as European Commission, U.S. Department of Commerce, and Ministry of Economy, Trade and Industry (Japan).

Category:Semiconductor materials