Diamond power device

Advantages of diamond

Power devices play an important role in high voltage electronics. Usually, Silicon is used for the power devices. However, it is difficult to achieve further improvement in power consumption, because of its physical limit. Since diamond has superior electronic properties such as high breakdown voltage, high carrier mobility, and so on, diamond is expected as a next-generation power device semiconductor.

We succeeded in developing the world’s first diamond junction field effect transistor.

Advances of diamond

Diamond Junction Field Effect Transistor(JFET)

Diamonds are expected for using in high-voltage and low leakage current power devices. But, because of the difficulty of a selective implantation of impurities, it was not possible to produce a complex structure. In our laboratory, we fabricated diamond JFETs by utilizing the selective growth of n+-type diamond. The selective growth method uses the dependence of the diamond growth rate and amount of introduced impurities on crystal orientation. We confirmed that the fabricated JFETs have excellent high voltage and high temperature characteristics.

According to the result of evaluating the pn junction prepared in this method, this junction has extremely low reverse leakage current and large rectification ratio, compared with pn junctions reported until now.

This research is performed with AIST.

Our diamond JFET
Fig.1 Architecture and SEM image of fabricated diamond JFET
Id-Vd characteristics
Fig.2 Id-Vd characteristic of fabricated JFET