Diamond-coated three-dimensional GaN micromembranes: effect of nucleation and deposition techniques

0454749 - FZÚ 2016 RIV DE eng J - Journal Article
Ižák, Tibor - Vanko, G. - Babchenko, Oleg - Potocký, Štěpán - Marton, M. - Vojs, M. - Choleva, P. - Kromka, Alexander
Diamond-coated three-dimensional GaN micromembranes: effect of nucleation and deposition techniques.
Physica Status Solidi B. Roč. 252, č. 11 (2015), s. 2585-2590. ISSN 0370-1972. E-ISSN 1521-3951
R&D Projects: GA ČR(CZ) GP14-16549P
Institutional support: RVO:68378271
Keywords : diamond film * GaN micromembranes * microwave chemical vapour deposition * polymer-based nucleation
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 1.522, year: 2015

In this work, we present technological issues on deposition of diamond films as a backside heat spreader for GaN membranes. We compared three nucleation techniques including standard ultrasonic seeding by diamond powder (DP), drop off with DP in solution and polymer based nucleation by PVA composite. The diamond growth was performed complementary by HFCVD or MWCVD. We found that standard nucleation techniques resulted in damaging of GaN membranes, or low nucleation efficiency in the Z-depth of the structures. Implementation of a novel nucleation method with PVA polymer composite led to coating of both bottom and top part of membrane including side walls. The coverage homogeneity was evaluated by scanning electron microscopy and Raman spectroscopy. The obtained results indicate that the efficiency (and/or nucleation density) of the polymer-based technique is comparable with standard ultrasonic seeding and could be used preferable for nucleation of soft and fragile substrates.
Permanent Link: http://hdl.handle.net/11104/0255399