Revolutionary wide bandgap semiconductor material: diamond

In the process of searching for better broadband gap (WBG) materials, researchers are seeking to use diamond to manufacture field effect transistors (FETs) for high-power and high-frequency electronic devices. Silicon (Si) is commonly used as a material for high-power and high-frequency electronic manufacturing, and occupies a dominant position in it. Despite widespread use, researchers and companies are still studying "second best" broadband gap materials, such as silicon carbide (SiC), gallium nitride (GaN), and even diamond. More specifically, these broadband gap materials are expected to have advantages over silicon in high-power and high-frequency electronic applications.

View of diamond FET with hexagonal boron nitride gate insulator and graphite gate

In addition, alternative broadband gap materials may be more suitable for grid applications and provide reliability and higher energy conversion efficiency to achieve efficient green electronic systems. So, diamond as a potential semiconductor material for power applications? What are its significant advantages compared to silicon carbide and gallium nitride?

Diamond as a WBG material in electronic devices

As mentioned earlier, diamond is becoming increasingly popular as a wide bandgap material, as silicon may reach its theoretical limit to meet the growing demand of the most advanced high-power electronic devices.

Example diagram of PiN diode for vacuum power switching

One area where diamond is superior to other materials such as SiC is its high dielectric breakdown strength and high critical electric field. This advantage may be beneficial for reducing the on resistance of Schottky Barrier Diodes (SBDs) in high-power engineering equipment and applications. In addition, as researchers from the University of Glasgow in the UK have demonstrated in the past, engineers can also use diamond to manufacture diamond based FETs with improved radio frequency (RF) performance and a high cutoff frequency of 55 GHz.

Diamond enters high-power applications

Due to certain electrical characteristics, diamond has entered the field of high-power equipment and applications. After reviewing some research on diamond based power electronic devices, these devices can operate comfortably at high temperatures without the extensive cooling and circuit protection requirements of state-of-the-art high-power electronic devices. This type of application can be seen in the example of diamond Schottky rectifiers, which achieve high-temperature operation, low on resistance, and high breakdown voltage up to 8kV.

Schematic diagram of MESFET

 In addition, researchers have demonstrated high-frequency operation in diamond metal semiconductor field-effect transistors (MESFETs) and metal oxide semiconductor field-effect transistors (MOSFETs). Typically, these components are designed for applications in high-power radio frequency (RF) power amplifiers.

Diamond has a wide bandgap, high breakdown field strength, and high carrier mobility. In addition, it also has superior properties such as high thermal conductivity, high temperature resistance, acid and alkali resistance, corrosion resistance, and radiation resistance, making it play an important role in high-power, high-frequency, and high-temperature fields.

CSMH focuses on the production and research and development of wide bandgap semiconductor diamonds. Its core products include diamond wafers, diamond heat sinks, diamond optical windows, diamond heterojunction integrated composite substrates, etc. It is committed to promoting the application of diamonds in high-power lasers, 5G communication, new energy vehicles, new energy photovoltaics, aerospace and other fields.