CH4 Adsorption Probability on GaN(0001) and (000−1) during Metalorganic Vapor Phase Epitaxy and Its Relationship to Carbon Contamination in the Films

Abstract

Suppression of carbon contamination in GaN films grown using metalorganic vapor phase epitaxy (MOVPE) is a crucial issue in its application to high power and high frequency electronic devices. To know how to reduce the C concentration in the films, a sequential analysis based on first principles calculations is performed. Thus, surface reconstruction and the adsorption of the CH4 produced by the decomposition of the Ga source, Ga(CH3)3, and its incorporation into the GaN sub-surface layers are investigated. In this sequential analysis, the dataset of the adsorption probability of CH4 on reconstructed surfaces is indispensable, as is the energy of the C impurity in the GaN sub-surface layers. The C adsorption probability is obtained based on steepest-entropy-ascent quantum thermodynamics (SEAQT). SEAQT is a thermodynamic ensemble-based, non-phenomenological framework that can predict the behavior of non-equilibrium processes, even those far from equilibrium. This framework is suitable especially when one studies the adsorption behavior of an impurity molecule because the conventional approach, the chemical potential control method, cannot be applied to a quantitative analysis for such a system. The proposed sequential model successfully explains the influence of the growth orientation, GaN(0001) and (000−1), on the incorporation of C into the film. This model can contribute to the suppression of the C contamination in GaN MOVPE.

Special Issue “Advances in Epitaxial Materials”-Editorial Preface

“…In the Special Issue, four papers [1,3,4,10] report epitaxial growth using Metalorganic Chemical Vapor Phase Epitaxy (MOVPE). This is the most popular method used for growing most epitaxial layers in the semiconductor industry.…”

“…The popularity of nitride semiconductors is reflected in the Special Issue in papers of R. Czernecki et al [1], Y.L. Casallas-Moreno et al [2], M. Sarzynski et al [3], Akira Kusaba et al [4], and Takeshi Ohgaki et al [5].…”

A thermodynamic scaling law for electrically perturbed lipid membranes: validation with the steepest-entropy-ascent framework

“…To validate the scaling model, the non-equilibrium, ensemble-based SEAQT framework is used. It is able to model systems undergoing non-equilibrium processes, even those far from equilibrium, from the atomistic to the macroscopic level [23,34,24,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49]. This framework is not limited to any type of state (i.e.…”

DFT-Based Studies on Carbon Adsorption on the wz-GaN Surfaces and the Influence of Point Defects on the Stability of the Diamond–GaN Interfaces

“…In particular, Kempisty et al [28] studied the incorporation and interdiffusion of carbon in GaN{000 1} surfaces reconstructed during typical MOVPE growth conditions (i.e., (000 1) 3N-H, (000 1)Ga ad (H3), (0001)Ga ad (T4), and (0001)3Ga-H) and demonstrated the influence of surface states, as well as the role of the N 2 and H 2 carrier gases on carbon incorporation. Kusaba et al [29] in turn performed sequential analysis concerning the adsorption of CH 4 on GaN{000 1} reconstructed surfaces during MOVPE (surface reconstruction, CH 4 adsorption, and C incorporation) to explain the influence of the growth conditions and surface termination on the C concentration in GaN films. However, for the purpose of the present study, mainly the information about the carbon adsorption sites on clean GaN{000 1} surfaces is necessary, in order to construct a general model of the diamond-GaN interface.…”