Fabrication and properties of lateral p–i–p structures using single-crystalline CVD diamond layers for high electric field applications

Abstract

Chemical-vapor-deposited diamond p–i–p structures have been fabricated on homoepitaxially grown single-crystalline layers using focused ion beam etching in order to investigate carrier transport properties of diamond in high electric fields more than 10 6 V/cm. The examined structures included a 200-nm-thick intrinsic (undoped) diamond region laterally sandwiched between two p-type (B-doped) diamond regions. At high fields above ≈3×10 7 V/cm, I– V characteristics of the lateral p–i–p structure revealed abnormal increases in current. The observed performances can be explained more reasonably in terms of impact ionization events from the valence band to the conduction band in the intrinsic diamond than in terms of direct Fowler–Nordheim tunneling events of electrons from the valence band of the negatively biased p diamond to the conduction band of the intrinsic diamond.