On Diamond Gallium Nitride Wafer Epitaxial HEMT And Bonding

customzied size MPCVD method GaN&Diamond Heat Sink wafers for Thermal management area

According to statistics, the temperature of the working junction will drop Low 10 ° C can double the device life. The thermal conductivity of diamond is 3 to 3 higher than that of common thermal management materials (such as copper, silicon carbide and aluminum nitride)
10 times. At the same time, diamond has the advantages of light weight, electrical insulation, mechanical strength, low toxicity and low dielectric constant, which make diamond, It is an excellent choice of heat dissipation materials.

• Give full play to the inherent thermal performance of diamond, which will easily solve the "heat dissipation" problem faced by electronic power, power devices, etc.

On the volume, improve reliability and enhance power density. Once the "thermal" problem is solved, the semiconductor will also be significantly improved by effectively improving the performance of thermal management,
The service life and power of the device, at the same time, greatly reduce the operating cost.

Combination method

• 1. Diamond on GaN
• Growing diamond on GaN HEMT structure

• 2. GaN on Diamond
• Direct epitaxial growth of GaN structures on diamond substrate​

• 3. GaN/diamond bonding
• After the GaN HEMT is prepared, transfer bonding to the diamond substrate

Application area

• Microwave radio frequency- 5G communication, radar warning, satellite communication and other applications；

• Power electronics- smart grid, high-speed rail transit, new energy vehicles, consumer electronics and other applications；

Optoelectronics- LED lights, lasers, photodetectors and other applications.

GaN is widely used in radio frequency, fast charging and other fields, but its performance and reliability are related to the temperature on the channel and Joule heating efiect. The commonly used substrate materials (sapphire, silicon, silicon carbide) of GaN-based power devices have low thermal conductivity. It greatly limits the heat dissipation and high-power performance requirements of the device. Relying only on traditional substrate materials (silicon, silicon carbide) and passive cooling technology, it is difficult to meet the heat dissipation requirements under high power conditions, severely limiting the release of the potential of GaN-based power devices. Studies have shown that diamond can significantly improve the use of GaN-based power devices. Existing thermal effect problems.

Diamond has wide band gap, high thermal conductivity, high breakdown field strength, high carrier mobility, high temperature resistance, acid and alkali resistance, corrosion resistance, radiation resistance and other superior properties
High power, high frequency, high temperature fields play an important role, and are considered as one of the most promising wide band gap semiconductor materials.

Diamond on GaN

We use microwave plasma chemical vapor deposition equipment to achieve epitaxial growth of polycrystalline diamond material with a thickness of <10um on a 50.8 mm(2 inch) silicon-based gallium nitride HEMT. A scanning electron microscope and X-ray diffractometer were used to characterize the surface morphology, crystalline quality, and grain orientation of the diamond film. The results showed that the surface morphology of the sample was relatively uniform, and the diamond grains basically showed a (ill) plane growth. Higher crystal plane orientation. During the growth process, the gallium nitride (GaN) is effectively prevented from being etched by the hydrogen plasma, so that the characteristics of the GaN before and after the diamond coating do not change significantly.

GaN on Diamond

In GaN on Diamond epitaxial growth, CSMH uses a special process to grow AlN

AIN as the GaN epitaxial layer. CSMH currently has a product available-

Epi-ready-GaN on Diamond (AIN on Diamond).

The technical indicators of CSMH's diamond heat sink and wafer-level diamond products have reached the world's leading level. The surface roughness of the wafer-level diamond growth surface is Ra<lnm, and the thermal conductivity of the diamond heat sink is 1000^_2000W/m.K. By bonding with GaN, the temperature of the device can also be effectively reduced, and the stability and life of the device can be improved.