Substrate impact on the low-temperature growth of GaN thin films by plasma-assisted atomic layer deposition
Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
AVS Science and Technology Society
041511-1 - 041511-8
Item Usage Stats
Gallium nitride (GaN) thin films were grown on Si (100), Si (111), and c-plane sapphire substrates at 200 ï¿½C via hollow-cathode plasma-assisted atomic layer deposition (HCPA-ALD) using GaEt3 and N2/H2 plasma as group-III and V precursors, respectively. The main aim of the study was to investigate the impact of substrate on the material properties of low-temperature ALD-grown GaN layers. Structural, chemical, and optical characterizations were carried out in order to evaluate and compare film quality of GaN on different substrates. X-ray reflectivity measurements showed film density values of 5.70, 5.74, and 5.54 g/cm3 for GaN grown on Si (100), Si (111), and sapphire, respectively. Grazing incidence x-ray diffraction measurements exhibited hexagonal wurtzite structure in all HCPA-ALD grown GaN samples. However, dominant diffraction peak for GaN films grown on Si and sapphire substrates were detected differently as (002) and (103), respectively. X-ray diffraction gonio scans measured from GaN grown on c-plane sapphire primarily showed (002) orientation. All samples exhibited similar refractive index values (∼2.17 at 632 nm) with 2-3 at. % of oxygen impurity existing within the bulk of the films. The grain size was calculated as ∼9-10 nm for GaN grown on Si (100) and Si (111) samples while it was ∼5 nm for GaN/sapphire sample. Root-mean-square surface roughness values found as 0.68, 0.76, and 1.83 nm for GaN deposited on Si (100), Si (111), and sapphire, respectively. Another significant difference observed between the samples was the film growth per cycle: GaN/sapphire sample showed a considerable higher thickness value when compared with GaN/Si samples, which might be attributed to a possibly more-efficient nitridation and faster nucleation of sapphire surface.
KeywordsAtomic layer deposition
Pulsed laser deposition
X ray diffraction
C-plane sapphire substrates
Gallium nitrides (GaN)
Grazing incidence X-ray diffraction
Hexagonal wurtzite structure
Low temperature growth
Plasma assisted atomic layer depositions
X-ray reflectivity measurements
Published Version (Please cite this version)http://dx.doi.org/10.1116/1.4953463
Showing items related by title, author, creator and subject.
Self-limiting low-temperature growth of crystalline AlN thin films by plasma-enhanced atomic layer deposition Ozgit, C.; Donmez I.; Alevli, M.; Bıyıklı, Necmi (2012)We report on the self-limiting growth and characterization of aluminum nitride (AlN) thin films. AlN films were deposited by plasma-enhanced atomic layer deposition on various substrates using trimethylaluminum (TMA) and ...
Optical characteristics of nanocrystalline AlxGa1-xN thin films deposited by hollow cathode plasma-assisted atomic layer deposition Goldenberg, E.; Ozgit-Akgun, C.; Bıyıklı, Necmi; Kemal Okyay, A. (AVS Science and Technology Society, 2014)Gallium nitride (GaN), aluminum nitride (AlN), and AlxGa 1-xN films have been deposited by hollow cathode plasma-assisted atomic layer deposition at 200 °C on c-plane sapphire and Si substrates. The dependence of film ...
Atomic layer deposition: an enabling technology for the growth of functional nanoscale semiconductors Bıyıklı, Necmi; Haider A. (Institute of Physics Publishing, 2017)In this paper, we present the progress in the growth of nanoscale semiconductors grown via atomic layer deposition (ALD). After the adoption by semiconductor chip industry, ALD became a widespread tool to grow functional ...