Predicted lattice-misfit stresses in a gallium-nitride (GaN) film

2017 ◽  
Author(s):  
E. Suhir ◽  
S. Yi
Keyword(s):  
Gallium Nitride ◽  
Lattice Misfit ◽  
Gan Film

Lattice-Misfit Stresses in a Circular Bi-Material Gallium-Nitride Assembly

2012 ◽  
Vol 80 (1) ◽  
Author(s):  
E. Suhir
Keyword(s):  
Gallium Nitride ◽  
Cross Sections ◽  
Circumferential Stress ◽  
Lattice Misfit ◽  
Theory Of Elasticity ◽  
Shearing Stress ◽  
Interfacial Shearing Stress ◽  
Stress Theory ◽  
Circular Configuration ◽  
Gan Film

A simple and physically meaningful analytical (“mathematical”) predictive model is developed using two-dimensional (plane-stress) theory-of-elasticity approach (TEA) for the evaluation of the effect of the circular configuration of the substrate (wafer) on the elastic lattice-misfit (mismatch) stresses (LMS) in a semiconductor and particularly in a gallium nitride (GaN) film grown on such a substrate. The addressed stresses include (1) the interfacial shearing stress supposedly responsible for the occurrence and growth of dislocations, for possible delaminations, and for the cohesive strength of the intermediate strain buffering material, if any, as well as (2) normal radial and circumferential (tangential) stresses acting in the film cross-sections and responsible for the short- and long-term strength (fracture toughness) of the film. The TEA results are compared with the formulas obtained using strength-of-materials approach (SMA). This approach considers, instead of the actual circular substrate, an elongated bi-material rectangular strip of unit width and of finite length equal to the wafer diameter. The numerical example is carried out, as an illustration, for a GaN film grown on a silicon carbide (SiC) substrate. It is concluded that the SMA model is acceptable for understanding the physics of the state of stress and for the prediction of the normal stresses in the major midportion of the assembly. The SMA model underestimates, however, the maximum interfacial shearing stress at the assembly periphery and, because of the very nature of the SMA, is unable to address the circumferential stress. The developed TEA model can be used, along with the author's earlier publications and the (traditional and routine) finite-element analyses (FEA), to assess the merits and shortcomings of a particular semiconductor crystal growth (SCG) technology, as far as the level of the expected LMS are concerned, before the actual experimentation and/or fabrication is decided upon and conducted.

FORMATION OF GaN FILM BY AMMONIATING Ga2O3 DEPOSITED ON Si SUBSTRATE WITH ELECTROPHORESIS

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4267-4270 ◽  
Author(s):  
LI YANG ◽  
CHENGSHAN XUE ◽  
HUIZHAO ZHUANG ◽  
HUAIXIANG LI ◽  
QINQIN WEI
Keyword(s):  
Fourier Transform ◽  
Gallium Nitride ◽  
Photoelectron Spectroscopy ◽  
Fourier Transform Infrared ◽  
Hexagonal Wurtzite Structure ◽  
Wurtzite Structure ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
X Ray ◽  
Gan Film

The gallium nitride (GaN) films have been successfully fabricated on silicon (111) substrates through ammoniating Ga 2 O 3 films deposited by electrophoresis. The structure and composition of the formed films were characterized by Fourier transform infrared (FTIR) transmission spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results indicate that the films formed in this study are polycrystalline GaN with hexagonal wurtzite structure.

Electroreflectance from Gallium Nitride Using Second-Harmonic Generation

1995 ◽  
Vol 395 ◽  
Author(s):  
Joseph Miragliotta ◽  
Dennis K. Wickenden
Keyword(s):  
Gallium Nitride ◽  
Electric Field ◽  
Nonlinear Response ◽  
Second Harmonic ◽  
Fundamental Absorption Edge ◽  
Third Order ◽  
Two Photon ◽  
Dc Electric Field ◽  
Gan Film ◽  
Photon Resonance

ABSTRACTThe optical second-harmonic (SH) response of a reverse biased gallium nitride (GaN) film was investigated for SH photon energies near the fundamental absorption edge. With the application of a DC electric field (∼ 100 to 220 kV/cm) along the optical axis of the sample, a strong two-photon resonance was observed in the specular reflected SH signal. This resonance was attributed to electric-field induced SH generation, EFISH, a third-order nonlinear response which arises from an induced polarization that is linearly dependent on the amplitude of the DC field. The EFISH contribution was spectrally localized at the bandedge, demonstrating the potential of SH spectroscopy for analysis of critical points in the band structure of semiconductors.

Effects of substrate quality and annealing on defect structures at GaAs/Si interfaces

1987 ◽  
Vol 45 ◽  
pp. 340-341
Author(s):  
H. L. Tsai ◽  
J. W. Lee
Keyword(s):  
Growth Process ◽  
Molecular Beam ◽  
Substrate Surface ◽  
Lattice Misfit ◽  
Device Fabrication ◽  
Silicon Substrates ◽  
Defect Structures ◽  
Gaas Film ◽  
Substrate Quality ◽  
Gaas On Si

Growth of GaAs on Si using epitaxial techniques has been receiving considerable attention for its potential application in device fabrication. However, because of the 4% lattice misfit between GaAs and Si, defect generation at the GaAs/Si interface and its propagation to the top portion of the GaAs film occur during the growth process. The performance of a device fabricated in the GaAs-on-Si film can be degraded because of the presence of these defects. This paper describes a HREM study of the effects of both the substrate surface quality and postannealing on the defect propagation and elimination.The silicon substrates used for this work were 3-4 degrees off [100] orientation. GaAs was grown on the silicon substrate by molecular beam epitaxy (MBE).

The wustite-spinel interface

1987 ◽  
Vol 45 ◽  
pp. 268-269
Author(s):  
S.R. Summerfelt ◽  
C.B. Carter
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Strain Energy ◽  
Matrix Material ◽  
Lattice Misfit ◽  
Solid State Reactions ◽  
Oxygen Sublattice ◽  
Large Particles ◽  
Small Lattice ◽  
Coherent Interfaces

The wustite-spinel interface can be viewed as a model interface because the wustite and spinel can share a common f.c.c. oxygen sublattice such that only the cations distribution changes on crossing the interface. In this study, the interface has been formed by a solid state reaction involving either external or internal oxidation. In systems with very small lattice misfit, very large particles (>lμm) with coherent interfaces have been observed. Previously, the wustite-spinel interface had been observed to facet on {111} planes for MgFe2C4 and along {100} planes for MgAl2C4 and MgCr2O4, the spinel then grows preferentially in the <001> direction. Reasons for these experimental observations have been discussed by Henriksen and Kingery by considering the strain energy. The point-defect chemistry of such solid state reactions has been examined by Schmalzried. Although MgO has been the principal matrix material examined, others such as NiO have also been studied.

Epitaxial Growth in Dislocation-Free Strained Alloy Films

2002 ◽  
Vol 715 ◽  
Author(s):  
Zhi-Feng Huang ◽  
Rashmi C. Desai
Keyword(s):  
Deposition Rate ◽  
Elastic Moduli ◽  
Composition Dependence ◽  
Critical Thickness ◽  
Lattice Misfit ◽  
Misfit Strain ◽  
Joint Stability ◽  
Alloy Films ◽  
The Stability ◽  
Stability Results

AbstractThe morphological and compositional instabilities in the heteroepitaxial strained alloy films have attracted intense interest from both experimentalists and theorists. To understand the mechanisms and properties for the generation of instabilities, we have developed a nonequilibrium, continuum model for the dislocation-free and coherent film systems. The early evolution processes of surface pro.les for both growing and postdeposition (non-growing) thin alloy films are studied through a linear stability analysis. We consider the coupling between top surface of the film and the underlying bulk, as well as the combination and interplay of different elastic effects. These e.ects are caused by filmsubstrate lattice misfit, composition dependence of film lattice constant (compositional stress), and composition dependence of both Young's and shear elastic moduli. The interplay of these factors as well as the growth temperature and deposition rate leads to rich and complicated stability results. For both the growing.lm and non-growing alloy free surface, we determine the stability conditions and diagrams for the system. These show the joint stability or instability for film morphology and compositional pro.les, as well as the asymmetry between tensile and compressive layers. The kinetic critical thickness for the onset of instability during.lm growth is also calculated, and its scaling behavior with respect to misfit strain and deposition rate determined. Our results have implications for real alloy growth systems such as SiGe and InGaAs, which agree with qualitative trends seen in recent experimental observations.

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