Open AccessLarge-roll growth of 25-inch hexagonal BN monolayer film for self-release buffer layer of free-standing GaN wafer
Author(s) -
Chenping Wu,
Abdul Majid Soomro,
Feipeng Sun,
Huachun Wang,
Youyang Huang,
Jerry J. Wu,
Chuan Liu,
Xiaodong Yang,
Na Gao,
Xiaohong Chen,
Junyong Kang,
Duanjun Cai
Publication year - 2016
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/srep34766
Subject(s) - monolayer , materials science , wafer , epitaxy , chemical vapor deposition , substrate (aquarium) , optoelectronics , layer (electronics) , foil method , buffer (optical fiber) , composite material , nanotechnology , electrical engineering , oceanography , geology , engineering
Hexagonal boron nitride (h-BN) is known as promising 2D material with a wide band-gap (~6 eV). However, the growth size of h-BN film is strongly limited by the size of reaction chamber. Here, we demonstrate the large-roll synthesis of monolayer and controllable sub-monolayer h-BN film on wound Cu foil by low pressure chemical vapor deposition (LPCVD) method. By winding the Cu foil substrate into mainspring shape supported by a multi-prong quartz fork, the reactor size limit could be overcome by extending the substrate area to a continuous 2D curl of plane inward. An extremely large-size monolayer h-BN film has been achieved over 25 inches in a 1.2” tube. The optical band gap of h-BN monolayer was determined to be 6.0 eV. The h-BN film was uniformly transferred onto 2” GaN or 4” Si wafer surfaces as a release buffer layer. By HVPE method, overgrowth of thick GaN wafer over 200 μm has been achieved free of residual strain, which could provide high quality homo-epitaxial substrate.