TU Darmstadt / ULB / TUbiblio

Thermal Stress and Strain in a GaN Epitaxial Layer Grown on a Sapphire Substrate by the MOCVD Method

Alaei, H. R. and Eshghi, H. and Riedel, R. and Pavlidis, D. (2010):
Thermal Stress and Strain in a GaN Epitaxial Layer Grown on a Sapphire Substrate by the MOCVD Method.
In: Chinese Journal of Physics, pp. 400-407, 48, (3), [Article]

Abstract

In this article we have studied the existence of stress and strain in a Si-doped GaN (2µm)/sapphire structure grown by the metal-organic chemical vapour deposition (MOCVD) method and tried to model the parameters. The presence of stress in our sample is supported by an E2 Raman shift mode (∆ω) of about 1.25 cm−1. To find the amount of biaxial basal plane stress we performed two techniques, XRD and film bending by a profilometer. The XRD technique confirmed that the GaN layer has a hexagonal structure with the lattice constants of c = 5.1825˚ A and a = 3.187˚ A. Our theoretical calculations show that this layer suffers a biaxial stress (σa) of about 0.175 ± 0.003 GPa. The profilometer data analysis also leads to a compatible value of 0.12 ± 0.04 GPa. These parameters altogether suggest the relation ∆ω = 7.1 ± 0.1σ cm−1/GPa for this layer.

Item Type: Article
Erschienen: 2010
Creators: Alaei, H. R. and Eshghi, H. and Riedel, R. and Pavlidis, D.
Title: Thermal Stress and Strain in a GaN Epitaxial Layer Grown on a Sapphire Substrate by the MOCVD Method
Language: English
Abstract:

In this article we have studied the existence of stress and strain in a Si-doped GaN (2µm)/sapphire structure grown by the metal-organic chemical vapour deposition (MOCVD) method and tried to model the parameters. The presence of stress in our sample is supported by an E2 Raman shift mode (∆ω) of about 1.25 cm−1. To find the amount of biaxial basal plane stress we performed two techniques, XRD and film bending by a profilometer. The XRD technique confirmed that the GaN layer has a hexagonal structure with the lattice constants of c = 5.1825˚ A and a = 3.187˚ A. Our theoretical calculations show that this layer suffers a biaxial stress (σa) of about 0.175 ± 0.003 GPa. The profilometer data analysis also leads to a compatible value of 0.12 ± 0.04 GPa. These parameters altogether suggest the relation ∆ω = 7.1 ± 0.1σ cm−1/GPa for this layer.

Journal or Publication Title: Chinese Journal of Physics
Volume: 48
Number: 3
Divisions: 11 Department of Materials and Earth Sciences
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences > Material Science > Dispersive Solids
Date Deposited: 18 Dec 2018 07:43
Export:

Optionen (nur für Redakteure)

View Item View Item