4. Conclusion

Among III-V semiconductors, the gallium nitride sector took off in the 1990s. With improvements in material growth and crystalline quality, it is ideally suited to the production of power devices requiring high operating voltages, thanks to the large breakdown field associated with the large gap. The significant conduction band discontinuity at the AlGaN/GaN, AlInN/GaN, AlN/GaN or ScAlN/GaN heterojunction, as well as the high electron saturation rate in these materials, are also assets for power, thanks to the associated high currents.

The special feature of these materials is their high spontaneous and piezoelectric polarization, making doping of the barrier zone unnecessary. The most widely used substrates are SiC, thanks to its low lattice mismatch with GaN and excellent thermal conductivity, and Si, which is highly resistive, available in larger surface areas...