GaN material, with outstanding advantages such as wide band gap, high saturated drift velocity and high critical breakdown electric field, is known as the third generation semiconductor material and has a broad prospect in the application of optoelectronics, high-temperature high-power devices and high-frequency microwave devices. GaN power tube also has the characteristics of high-power capacity and has become a fast-developing wide band gap device. Meanwhile, due to its high breakdown voltage, high linearity performance, high efficiency and other advantages, it has been widely used and has good prospects in wireless communication base stations, broadcast television, radio stations, jammer, high-power radar, electronic countermeasures and satellite communications, etc. GaN transistor also has higher power density than traditional silicon transistor and can withstand higher operating temperatures (under 500°C).
Principle of smaller size and better heat dissipation
Studies have pointed out that thickness of GaN layer affects heat dissipation of device, and the thinner GaN layer, the lower temperature. Traditional GaN transistors are manufactured on thick substrate such as silicon or silicon carbide (SiC), which is not conducive to heat conduction of device. The lattice mismatch of epitaxial GaN on traditional substrate leads to tens or even hundreds of microns of device thickness, which is unfavorable for chip heat dissipation. Considering that heat source decreases to sub-micron level with transistor gate size, new methods such as intelligent cutting or stripping are used to separate GaN transistors from the redundant epitaxial layer, so as to get rid of the influence of thick substrate and improve thermal management capability of devices. By reducing thickness of device, the hot spot temperature of high-power GaN transistor is reduced by 50°C. GaN based power devices are characterized by low on-resistance and high-frequency operation, which effectively improve the conversion efficiency of component units and make product units more compact.