TY - JOUR
T1 - Growth of crack-free GaN epitaxial thin films on composite Si(111)/polycrystalline diamond substrates by MOVPE
AU - Jiang, Quanzhong
AU - Edwards, M J
AU - Shields, Philip A
AU - Allsopp, Duncan W E
AU - Bowen, Christopher R
AU - Wang, Wang N
AU - Tóth, L
AU - Pécz, B
AU - Srnanek, R
AU - Satka, A
AU - Kovac, J
PY - 2012/3
Y1 - 2012/3
N2 - This paper reports the direct growth by MOVPE of high-quality, crack-free III-nitrides (∼350 nm) on composite substrates comprising an ultra-thin Si (111) layer on which polycrystalline diamond (PD) has been deposited. The Si/PD substrates are designed to provide superior heat sinking performance for high power devices. The FWHM of rocking curves of the nitride films is measured to be ∼1100 arcsec from a GaN/Al 0.2Ga 0.8N/AlN/Si/PD multilayer structure. As expected from the low coefficient of thermal expansion of diamond, the epitaxial layers are under severe tensile stress. The Si (111) layer is shown to act as a compliant buffer layer between the III-nitride and the PD, i.e. the Si is under a compressive stress under the influence of GaN of larger thermal expansion coefficient, but the structure is mechanically stable. This technique is an obvious economic and technological advantage compared to direct growth of III-nitrides on single crystal diamond.
AB - This paper reports the direct growth by MOVPE of high-quality, crack-free III-nitrides (∼350 nm) on composite substrates comprising an ultra-thin Si (111) layer on which polycrystalline diamond (PD) has been deposited. The Si/PD substrates are designed to provide superior heat sinking performance for high power devices. The FWHM of rocking curves of the nitride films is measured to be ∼1100 arcsec from a GaN/Al 0.2Ga 0.8N/AlN/Si/PD multilayer structure. As expected from the low coefficient of thermal expansion of diamond, the epitaxial layers are under severe tensile stress. The Si (111) layer is shown to act as a compliant buffer layer between the III-nitride and the PD, i.e. the Si is under a compressive stress under the influence of GaN of larger thermal expansion coefficient, but the structure is mechanically stable. This technique is an obvious economic and technological advantage compared to direct growth of III-nitrides on single crystal diamond.
UR - http://www.scopus.com/inward/record.url?scp=84863390961&partnerID=8YFLogxK
UR - http://dx.doi.org/10.1002/pssc.201100368
U2 - 10.1002/pssc.201100368
DO - 10.1002/pssc.201100368
M3 - Article
SN - 1862-6351
VL - 9
SP - 650
EP - 653
JO - Physica Status Solidi (C) Current Topics in Solid State Physics
JF - Physica Status Solidi (C) Current Topics in Solid State Physics
IS - 3-4
ER -