New Phase of sp³-Bonded BN: The 5H Polytype

Abstract

A new phase of sp3-bonded BN, that is, 5H polytype, has been found. The representative lattice parameters a and c were determined to be 2.528 and 10.407 Å, respectively. The new BN phase was prepared by chemical vapor deposition assisted with 193 nm laser irradiation of the surface. Source gases were diborane and ammonia diluted in argon and hydrogen. The substrate temperature was 850 °C.