Let's Go Diamond Cooling

The threat of global warming is becoming more and more critical; according to international energy proposal, about 25% of the total CO2 reduction should come from "end use efficiency". Hence, low loss power devices are an important technology for the 21st century. The fast development of diamond-based devices will contribute to the CO2 reduction plan early in this century.

Diamond is considered as a hopeful material for next generation power devices due to its favorable properties such as a high breakdown field, high thermal conductivity, high mobility and low dielectric constant. There are several big material challenges to overcome for the practical application of diamond devices. In particular, the fabrication of a single crystal wafer with large size, dislocation free, and low resistivity. However, at elevated temperatures such as from 200 to 250 °C; that is the self-heating temperature of the power devices, increased numbers of activated carriers with high mobility such as 240 cm2/Vs at 250 °C contribute to a reduction in conduction losses. This is based on a new concept of unipolar power devices that do not require "cooling systems".

According to the IEA energy proposal, about 25% (49% in total 50% reduction is expected for end use efficiency) of CO2 reduction should come from "end use efficiency", and energy savings with the use of low loss power device modules could be an important technology for achieving this goal. Following the success of replacing Si by SiC devices for low loss, high frequency operation at high voltage, the fast development of diamond devices is required to produce improved modules with lower losses.

The expected applications for diamond devices are high voltage, high output power devices with the possibility of high temperature operation. The vertical device structure is inevitable for these applications, and corresponding diamond wafer is necessary.

The market size of power device modules is expected to be 30+ trillion US dollars in 2025 and is also expected to increase every year. Diamond has the considerable advantage of consisting of carbon, hence it is free from natural resource depletion problems and are truly an important material of the 21st century.

CSMH has been conducting diamond material research for more than ten years, and has achieved breakthroughs in all three GaN& Diamond combination schemes. Existing diamond heat sinks for GaN on Diamond, Diamond on GaN and GaN&Diamond bonding, benchmarking against world-class standards. CSMH's existing diamond heat sink and diamond wafer product technical indicators have reached the world's leading level. The surface roughness of the diamond wafer growth surface is Ra<1nm, and the thermal conductivity of the diamond heat sink is 1000-2000W/m.K. Our mission is to be the most advanced compound semiconductor company in the global market, contributing to the related technology development.