Inversion Domain Boundaries and Oxygen Accommodation in Aluminum Nitride

1989 ◽  
Vol 167 ◽  
Author(s):  
R. A. Youngman ◽  
J. H. Harris ◽  
P. A. Labun ◽  
R. J. Graham ◽  
J. K. Weiss
Keyword(s):  
Aluminum Nitride ◽  
Domain Boundary ◽  
Stacking Faults ◽  
Interface Energy ◽  
Optical Methods ◽  
Extended Defect ◽  
Inversion Domain ◽  
Inversion Domain Boundaries ◽  
Structural Aspects

AbstractAluminum nitride is known to have a large affinity for oxygen as an impurity. At high levels (>∼4 wt/o) the oxygen is incorporated in the form of planar stacking faults where “pure” 2H AIN is regularly interspersed with a layer of oxygen at the faults. At oxygen levels lower than ∼ 4 wt/o the structure shows an expanded c-axis. The present authors have not observed this effect, rather a random distribution of stacking faults is observed along with another, more prevalent, extended defect identified as an inversion domain boundary (IDB). The IDBs are significantly aplanar (indicating a low interface energy), and often have precipitates and other, faceted defects associated with them. The role of these defects in oxygen accommodation in AIN has been investigated both structurally and chemically by electron optical methods (SEM, TEM, STEM, HREM, CBED, EDS, EELS, and CL-TEM). The structural nature of the boundaries, in the absence of oxygen, requires Al-Al or N-N bonding to occur with some frequency across the boundary. Such bonding is unlikely due to the excess energy required. Chemical analysis (EELS) and luminescence studies (CL-TEM) reveal that oxygen is often associated with the boundaries and may mediate the bonding at the boundary. A model is proposed for the IDB which includes structural aspects combined with considerations of stoichiometry in an effort to understand the origin and energetics of this defect.

Sreels Analysis of Oxygen-Rich Inversion Domain Boundaries in Aluminum Nitride

1994 ◽  
Vol 357 ◽  
Author(s):  
J. Bruley ◽  
A.D. Westwood ◽  
R. A. Youngman ◽  
J.-C. Zhao ◽  
M.R. Notis
Keyword(s):  
Aluminum Nitride ◽  
Structural Model ◽  
Domain Boundary ◽  
Edge Structure ◽  
Spatially Resolved ◽  
Inversion Domain ◽  
Domain Boundaries ◽  
Length Data ◽  
Inversion Domain Boundaries ◽  
Electron Energy Loss

AbstractSpatially resolved electron energy loss spectroscopy analysis has been conducted on planar inversion domain boundaries in aluminum nitride. The defects were found to contain 1.5 monolayers of oxygen, in agreement with the most recent structural model of Westwood. From variations in near-edge structure, the local atomic environments of both oxygen and aluminum are compared with α-A1203, γ-A1203 and γ-AION standards. Based upon this study the stnrcture of the inversion domain boundary is found to resemble that of the cubic γ-AION spinel, and eliminates from consideration those structural models based upon ai-Al203. Furthermore, quantification of the shape resonances provided Al-O bond-length data from the inversion domain boundary interface. These distances closely agree with the Youngman Model that has recently been further refined by Westwood et al.

Oxygen incorporation in aluminum nitride via extended defects: Part III. Reevaluation of the polytypoid structure in the aluminum nitride-aluminum oxide binary system

1995 ◽  
Vol 10 (10) ◽  
pp. 2573-2585 ◽  
Author(s):  
Alistair D. Westwoord ◽  
Robert A. Youngman ◽  
Martha R. McCartney ◽  
Alasiair N. Cormack ◽  
Michael R. Notis
Keyword(s):  
Aluminum Nitride ◽  
Stacking Faults ◽  
Structural Rearrangement ◽  
Extended Defects ◽  
Structural Elements ◽  
Inversion Domain ◽  
Transmission Electron ◽  
New Variant ◽  
Domain Boundaries ◽  
Inversion Domain Boundaries

This paper extends the concepts that were developed to explain the structural rearrangement of the wurtzite AlN lattice due to incorporation of small amounts of oxygen, and to directly use them to assist in understanding the polytypoid structures. Conventional and high-resolution transmission electron microscopy, specific electron diffraction experiments, and atomistic computer simulations have been used to investigate the structural nature of the polytypoids. The experimental observations provide compelling evidence that polytypoid structures are not arrays of stacking faults, but are rather arrays of inversion domain boundaries (IDB's). A new model for the polytypoid structure is proposed with the basic repeat structural unit consisting of a planar IDB-P and a corrugated IDB. This model shares common structural elements with the model proposed by Thompson, even though in his model the polytypoids were described as consisting of stacking faults. Small additions (≃ 1000 ppm) of silicon were observed to have a dramatic effect on the polytypoid structure. First, it appears that the addition of Si causes the creation of a new variant of the planar IDB (termed IDB-P'), different from the IDB-P defect observed in the AlN-Al2O3 polytypoids; second, the addition of Si influences the structure of the corrugated IDB, such that it appears to become planar.

Interaction Between Basal Stacking Faults and Prismatic Inversion Domain Boundaries in GaN

2000 ◽  
Vol 639 ◽  
Author(s):  
Philomela Komninou ◽  
Joseph Kioseoglou ◽  
Eirini Sarigiannidou ◽  
George P. Dimitrakopulos ◽  
Thomas Kehagias ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Stacking Faults ◽  
High Resolution Electron Microscopy ◽  
High Energy ◽  
Low Energy ◽  
Inversion Domain ◽  
Resolution Electron ◽  
Domain Boundaries ◽  
Inversion Domain Boundaries

ABSTRACTThe interaction of growth intrinsic stacking faults with inversion domain boundaries in GaN epitaxial layers is studied by high resolution electron microscopy. It is observed that stacking faults may mediate a structural transformation of inversion domain boundaries, from the low energy types, known as IDB boundaries, to the high energy ones, known as Holt-type boundaries. Such interactions may be attributed to the different growth rates of adjacent domains of inverse polarity.

Junction lines of inversion domain boundaries with stacking faults in GaN

2004 ◽  
Vol 70 (11) ◽  
Author(s):  
J. Kioseoglou ◽  
G. P. Dimitrakopulos ◽  
Ph. Komninou ◽  
H. M. Polatoglou ◽  
A. Serra ◽  
...  
Keyword(s):  
Stacking Faults ◽  
Inversion Domain ◽  
Domain Boundaries ◽  
Inversion Domain Boundaries

Enhanced Light Emission at Self-assembled GaN Inversion Domain Boundary

2011 ◽  
Vol 1324 ◽  
Author(s):  
Mei-Chun Liu ◽  
Yuh-Jen Cheng ◽  
Jet-Rung Chang ◽  
Chun-Yen Chang
Keyword(s):  
Molecular Beam ◽  
Light Emission ◽  
Domain Boundary ◽  
Mbe Growth ◽  
Polarity Inversion ◽  
Circular Pattern ◽  
Inversion Domain ◽  
Domain Boundaries ◽  
Self Assembled ◽  
Inversion Domain Boundaries

ABSTRACTWe report the fabrication of GaN lateral polarity inversion heterostructure with self assembled crystalline inversion domain boundaries (IDBs). The sample was fabricated by two step molecular-beam epitaxy (MBE) with microlithography patterning in between to define IDBs. Despite the use of circular pattern, hexagonal crystalline IDBs were self assembled from the circular pattern during the second MBE growth. Both cathodoluminescent (CL) and photoluminescent (PL) measurements show a significant enhanced emission at IDBs and in particular at hexagonal corners. The ability to fabricate self assembled crystalline IDBs and its enhanced emission property can be useful in optoelectronic applications.

The Nature of Oxygen-Related Polytypoids in the Aluminum Nitride-Aluminum Oxide System

1993 ◽  
Vol 319 ◽  
Author(s):  
R.A. Youngman
Keyword(s):  
Oxygen Content ◽  
Stacking Faults ◽  
High Resolution Electron Microscopy ◽  
Oxide System ◽  
Extended Defects ◽  
Low Oxygen ◽  
Inversion Domain ◽  
Resolution Electron ◽  
Related Point ◽  
Inversion Domain Boundaries

AbstractPrevious investigations into the nature of polytypoid structures in the A1N-A12O3 and A1NSiO2 systems have concluded that these structures are comprised of ordered stacking faults which accommodate oxygen (and silicon) in the basic wurtzite (2H) AIN structure. The polytypoids are distinct chemical phases intimately related to the pure 2H AIN. More recent work in low oxygen content (<6 at.%) A1N has elucidated the evolution of oxygen-related point defects, and transformation of these defects into extended structures. These studies have shown that all oxygenrelated extended defects in the A1N-A12O3 system are inversion domain boundaries (IDBs).We present here extensions of the concepts developed from low oxygen content studies which lead to direct application in understanding the polytypoid structures. High resolution electron microscopy (HREM), specific electron diffraction experiments, and structural models are utilized to prove that the polytypoid structures are not based on stacking faults, but, in fact are based on IDBs.

Effects of defects on the morphologies of GaN nanorods grown on Si (111) substrates

2009 ◽  
Vol 24 (10) ◽  
pp. 3032-3037 ◽  
Author(s):  
Kyu Hyung Lee ◽  
Jeong Yong Lee ◽  
Y.H. Kwon ◽  
Tae Won Kang ◽  
J.H. You ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Polar Region ◽  
Domain Boundary ◽  
Hydride Vapor Phase Epitaxy ◽  
Slow Growth Rate ◽  
Selected Area Electron Diffraction ◽  
Inversion Domain ◽  
Transmission Electron ◽  
The One ◽  
Inversion Domain Boundaries

Scanning electron microscopy and transmission electron microscopy images and selected area electron diffraction pattern showed that the one-dimensional GaN nanorods with [0001]-oriented single-crystalline wurzite structures were formed on Si (111) substrates by using hydride vapor-phase epitaxy without a catalyst. Although some stacking faults and inversion domain boundaries existed in the GaN nanorods, few other defects such as threading dislocations were observed. The formation of the facet plane in the N-polar region of the GaN nanorod containing an inversion domain boundary originated from the slow growth rate, followed by the lateral adatom diffusion from the Ga-polar region to reduce the length difference.

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