Thermal stability of boron nitride/silicon p-n heterojunction diodes

Heterojunctions of p-type cubic boron nitride (cBN) and n-type silicon with sp(2)-bonded BN (sp(2)BN) interlayers are fabricated under low-energy ion impact by plasma-enhanced chemical vapor deposition, and their rectification properties are studied at temperatures up to 573 K. The rectification ratio is increased up to the order of 10 5 at room temperature by optimizing the thickness of the sp(2)BN interlayer and the cBN fraction for suppressing the reverse leakage current. A highly rectifying p-type cBN/thick sp(2)BN/n-type silicon junction diode shows irreversible rectification properties mainly characterized by a marked decrease in reverse current by an order of magnitude in an initial temperature ramp/down cycle. This irreversible behavior is much more reduced by conducting the cycle twice or more. The temperature-dependent properties confirm an overall increase in effective barrier heights for carrier injection and conduction by biasing at high temperatures, which consequently increases the thermal stability of the diode performance. (C) 2015 AIP Publishing LLC.