Progress in Modeling Compound Semiconductor Epitaxy: Unintentional Doping in GaN MOVPE

Abstract

To improve the properties of semiconductors, it is necessary to construct an integrated crystal growth model that covers all elementary processes of metal–organic vapor phase epitaxy (MOVPE). Although there are several theoretical models that can reproduce any elemental growth process, they are inadequate for controlling semiconductor epitaxy: the elementary processes of (1) the vapor phase reaction, (2) the surface reaction, and (3) incorporation are entangled with each other. That is, sequential analyses of elementary growth processes from upstream (1) to downstream (3) are indispensable for an understanding of the entire process of MOVPE. In this Review, the recent progress of theoretical models based on calculations from first-principles calculations are summarized. The possibility of predicting carbon concentrations in GaN grown by MOVPE are explored as an example. The results of calculations using a model that integrates (1) → (2) → (3) reproduce the experimental tendencies of carbon incorporation. Calculations show that the contribution of each elementary growth process to a change in carbon concentration can be discussed separately, but the relationship between the input parameters and the resulting outputs can only be determined through experiment. Although this examination explores a special case, the development of a precise integrated crystal growth model would greatly contribute to innovation in semiconductor manufacturing.

DFT Modeling of Unintentional Oxygen Incorporation Enhanced by Magnesium in GaN(0001) and AlN(0001) Growth Surfaces during Metal‐Organic Vapor‐Phase Epitaxy

“…This aspect is important to reflect realistic situations during the growth process in the analysis. [ 35,36 ] A comparison of the energy gain of O incorporation in the presence of Mg defects, in the presence of Mg + H complex defects, and in the absence of such defects suggests the following. In both GaN and AlN MOVPE, Mg‐light doping can enhance unintentional O incorporation by forming stable Mg + O complex defects in subsurface layers.…”

Effects of pressure on GaN growth in a specific warm-wall MOCVD reactor

“…[13][14][15] It also benefits in the efficient cracking of trimethylgallium (TMG) over 600 °C in the atmosphere, promoting the pyrolysis path to compete with the adduct path. 16 But the long stay in a large warm region will allow the precursors to over aggregate. Due to the parasitic reactions, the nanoparticles could fall into the wafer without a thermophoretic force.…”

Optical and Structural Analysis of GaN Microneedle Crystals Obtained via GaAs Substrates Decomposition and their Possible Growth Model Using the Volmer–Weber Mechanism

“…[1] GaN was one of the materials affected by the shortage of semiconductors, which is important for the technological industry due to their optical and electrical properties, with applications in GaN-based power devices, full-color displays, Schottky barrier diodes, light-emitting diodes, highfrequency devices, laser diodes, highelectron-mobility transistors, piezoelectric microelectromechanical systems devices, and solar cells. [2][3][4][5][6][7][8] However, the global semiconductors shortage begins to decrease, and new applications of GaN for nanotechnology and microtechnology are investigated, owing to its wide bandgap of 3.4 eV (wurtzite structure) and 3.2 eV (zincblende structure). GaN nanostructures, such as nanorods, nanowires, nanotubes, GaN microneedle crystals are grown via GaAs substrates decomposition, using ultrahigh-pure anhydrous ammonia as nitrogen precursor at 900 °C for 4 min.…”