Hillock assisted p-type enhancement in N-polar GaN:Mg films grown by MOCVD

Abstract

We report on the enhanced incorporation efficiency of magnesium dopants into facets of hexagonal hillock structures in N-polar GaN, studied by comparative analysis of GaN:Mg films grown by MOCVD on high and low hillock density GaN template layers. Total magnesium concentration in planar regions surrounding a hillock structure is comparable to that within hillock sidewall facets measured at 1.3 × 1019 cm−3 by atom probe tomography, and clustering of Mg atoms is seen in all regions of the film. Within individual hillock structures a decreased Mg cluster density is observed within hillock structures as opposed to the planar regions surrounding a hillock. Additionally, the Mg cluster radius is decreased within the hillock sidewall. The favorable incorporation of Mg is attributed to Mg dopants incorporating substitutionally for Ga during growth of semi-polar facets of the hillock structures. Enhanced p-type conductivity of GaN:Mg films grown on high hillock density template layers is verified by optical and electrical measurement.

Probing structural and chemical evolution in (AlxGa1−x)2O3 using atom probe tomography: A review

“…APT combined with field ion microscopy (FIM) and time-of-flight (TOF) spectroscopy [55] is a powerful characterization technique that enables direct 3D visualization of complex structure and chemistry at the atomic level with very high sensitivity [10 atomic parts per million (appm)] [45,56] as well as near-atomic spatial and chemical resolution [57]. Over the last decade, APT has been widely used to study the atomic-level structural chemistry including local elemental segregation/clustering, layer homogeneity, interface RMS roughness, adatoms diffusions across the interfaces in wide bandgap semiconductors, and their heterostructures to explain local chemical and physical properties that directly manipulate the corresponding electrical/optical devices [18,58,59,60,61,62,63,64,65,66,67,68,69]. In addition to all these capabilities, atom collection in APT experiments provides their position coordinates, TOF, and mass-to-charge states (m/q) of each atom [57].…”

Probing structural and chemical evolution in (AlxGa1−x)2O3using atom probe tomography: A review

“…APT combined with field ion microscopy (FIM) and time-of-flight (TOF) spectroscopy [55] is a powerful characterization technique that enables direct 3D visualization of complex structure and chemistry at the atomic level with very high sensitivity [10 atomic parts per million (appm)] [45,56] as well as near-atomic spatial and chemical resolution [57]. Over the last decade, APT has been widely used to study the atomic-level structural chemistry including local elemental segregation/clustering, layer homogeneity, interface RMS roughness, adatoms diffusions across the interfaces in wide bandgap semiconductors, and their heterostructures to explain local chemical and physical properties that directly manipulate the corresponding electrical/optical devices [18,58,59,60,61,62,63,64,65,66,67,68,69]. In addition to all these capabilities, atom collection in APT experiments provides their position coordinates, TOF, and mass-to-charge states (m/q) of each atom [57].…”

Boronate probe-based hydrogen peroxide detection with AlGaN/GaN HEMT sensor

“…Over the last three decades, a tremendous amount of research has been conducted in the development of the III-nitride (III-N) material system and device technology. [1][2][3][4][5][6][7][8][9][10][11][12][13] III-N-based AlGaN/GaN high electron mobility transistors (HEMTs) have been extensively studied for biochemical sensing applications due to their high sensitivity to surface phenomena, fast response time, aqueous stability, and good biocompatibility. [14][15][16][17] In HEMT sensors, the two-dimensional electron gas (2DEG) acts as a highly conductive channel that can be modulated by changes in the surface potential.…”