Compound semiconductors are expected to power the next era of technological innovations, from 5G to industrial automation. How do they differ from silicon semiconductors, how are they made, and what can we expect from new research?
Image Credit: Marko Aliaksandr/Shutterstock.com
Introduction to Compound Semiconductors
Compound semiconductors (CS) have piqued the interest of researchers and engineers all over the world for more than two decades. A compound semiconductor is made up of two or more different chemical elements from two or more distinct periodic table groups, for example, elements belonging to third and fifth groups III-V.
These semiconductors are made from WBG elements and have played a critical part in the development of semiconductor devices, providing considerable quality improvements. Furthermore, CS may be classified into the III–V segment, the IV-IV segment, the II-VI section, sapphire, and others based on the various electrical properties and an expanding variety of applications.
In comparison to silicon, they feature distinctive material characteristics, such as a direct energy gap and substantial electron mobility, allowing optoelectronic, high-speed, and high-power device innovations. Charged particles in compound semiconductors travel far more rapidly than their mobility in their counterparts, allowing for more than 100 times quicker computing.
Examples of Compound Semiconductors
Gallium-arsenide (GaAs), gallium-nitride (GaN), silicon carbide (SiC), indium-phosphide (InP), and even Aluminium-gallium-indium-phosphide (AlGaInP) are among the more prevalent compound semiconductors. Gallium arsenide has received considerable attention (and funding). This semiconductor and its associated alloys are now delivering on their commitment to providing one-of-a-kind technologies to the demanding applications of the industrial, defense, and electronic goods sectors.
Current Applications and Research Focus
CS has become an essential component of many sectors, and technological institutions all around the world have invested much in research and development. They are extensively employed in photovoltaic materials and structures, with a particular emphasis on the establishment of dynamic concatenated laser technologies, semiconducting quantum dotted lasers, and shortwave infrared photodetector applications for monitoring in the oil and gas sectors.
CS is also used in the microwave epitaxial material business for technological advancements and appliances. CS is used in experiments for significant high-speed nanoelectronics such as high-speed electron mobility transistors, modular microwave ICs, heterojunction bipolar transistor components, and harmonic tunneling device material. The creation of novel dilute bismuth thermal substances on GaAs, InP, and GaSb substrates, with an emphasis on the materials' composition and optical characteristics, as well as the emergence of new dilute bismuth photonic products has also been a major application regime of compound semiconductors.
Crystal Growth Process for Compound Semiconductors
Horizontal Bndyman (HB) and Liquid Encapsulated Czochralski (LEC) are two common techniques for growing III-V compound crystals. The HB approach is advantageous for minimizing dislocation density and is thus employed in the fabrication of optoelectronic foundations.
Because the LEC approach is beneficial for expanding crystalline dimension, it is employed to provide substrates for electrical devices. The primary goals of crystallization process technology for CS are bigger crystals, fewer crystal flaws, and greater purity. Furthermore, stoichiometry management is critical in the case of compound semiconductor crystals.
The MOCVD Process for Compound Semiconductor Layer Development
For the construction of CS electrical and optoelectronic devices, exponential formation of compound semiconductor layers is required. The ability to produce high-quality multilevel CS hybrid materials with exceptional control over layer structure and composition has resulted in enormous advancements in device development.
This process has allowed access to enhanced and innovative device ideas and facilitated the large-scale assembly of CS devices. In general, MOCVD is the gas-phase development of compound semiconductor layers using metal-organic and hydride predecessors. Diachenko, Alix, and Tocaiskotter reported the first experiments in 1960 when they examined the creation of InP by trimethylindium and phosphine at temperatures ranging from 270 to 300 degrees Celsius.
Latest Research Findings and Advancements
A research article published by Kangawa et al., in the journal Crystal Growth and Design, mentions the progress made in theoretical models for CS epitaxy and reviews the doping process in Gallium Nitride MOVPE. Advances in the methodological perspective are essential to enhance the materials and system properties. As it is feasible to precisely forecast the impact of supply partial pressure and temperature on material properties, the integrated model described in the study would be the first step toward revolutionizing CS production.
More from AZoM: What is the Universal Chiplet Interconnect Express (UCIe) Standard?
Controlling the quantity of undecomposed TMG in the vapor phase was discovered to be a critical component in lowering the carbon content in GaN films using GaN MOVPE. Preheating the TMG system with NH3 to break down would be a suitable candidate for upgrading the boiler layout. Other viable alternatives include interface reconstruction management, interface band stretching, and possible obstacles to C incorporation. It was demonstrated by the researchers that growing circumstances can influence certain surface properties.
Further research published in the journal Micromachines by Lee et. al. focuses on detecting and visualizing CS knowledge bases in order to quantify CS research strategies and developing trends via a scientometric evaluation. This study not only provided an excellent method for connecting authors and research topics in the CS industry, but it also demonstrated how growth trends and research fields evolve through time, which substantially aids in realizing its knowledge domains.
Future of CS Materials
CS materials and systems are being given top priority in research studies. Material Informatics (MI), and Process Informatics (PI) models are being extensively developed for compound semiconductors. It is envisaged that a paradigm change will occur in the world of materials science as a result of ongoing collaborative efforts powered by MI and PI technical advancements.
In addition, research is being conducted to implement CS detection systems for aerospace remote monitoring systems, while processes are being researched to optimize the epitaxial materials with the purpose of rapid industrialization of the ultra-high-speed CS-based optoelectronics industry.
References and Further Reading
Science Direct, 2022. Compound Semiconductors. [Online]
Available at: https://www.sciencedirect.com/topics/engineering/compound-semiconductor
SIMIT Laboratory of Nano Materials and Nano Devices, n.d. Compound semiconductor materials, devices and applications. [Online]
Available at: http://english.sim.cas.cn/laboratory/SKLFMI/Research/csmdaa/201706/t20170609_177949.html
Lee, Qian-Yo, et al. 2022. Detecting the Knowledge Domains of Compound Semiconductors. Micromachines 13(3). 476. Available at: https://www.mdpi.com/2072-666X/13/3/476
Kangawa, Yoshihiro, et al. 2021. Progress in modeling compound semiconductor epitaxy: Unintentional doping in GaN MOVPE. Crystal Growth & Design 21(3). 1878-1890. Available at: https://pubs.acs.org/doi/10.1021/acs.cgd.0c01564
Cok, Ronald S., and David Gomez. 2021. Heterogeneous Compound Semiconductor Integration. Physica status solidi (a) 218(3). 2000394. Available at: https://inis.iaea.org/search/search.aspx?orig_q=RN:52028520
Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.