New Phases of sp~3‐bonded Boron Nitride Prepared by Photo‐Assisted Plasma Processing Methods: The Fundamentals and Applications to Electronic Devices

摘要

New sp~3‐bonded polytypic forms of BN, namely, 6H‐BN and 30H‐BN were prepared by plasma‐assisted chemical vapor deposition (CVD) with an excimer laser at 193 nm being irradiated on the growing film surface. Only the 6H‐BN was formed by post‐deposition laser irradiation (PDL) of sp~2‐bonded BN precursor films prepared by plain plasma assisted CVD. The PDL demonstrated direct photo‐induced phase transformation from sp~2‐bonded BN into denser sp~3‐bonded BN here. The growth mechanism was discussed with regard to the "bond‐strength initiative rule", according to which the local thermodynamics at very early stage of growth should favor the formation of the strongest bond available (e.g. sp2‐hybridiz ed bonds in BN). P‐type sp3‐bonded BN∕n‐type Si heterodiode solar cell was fabricated by this method and proved to work efficiently.