Approach to high quality GaN lateral nanowires and planar cavities fabricated by focused ion beam and metal-organic vapor phase epitaxy

Abstract

We have developed a method to fabricate GaN planar nanowires and cavities by combination of Focused Ion Beam (FIB) patterning of the substrate followed by Metal Organic Vapor Phase Epitaxy (MOVPE). The method includes depositing a silicon nitride mask on a sapphire substrate, etching of the trenches in the mask by FIB with a diameter of 40 nm with subsequent MOVPE growth of GaN within trenches. It was observed that the growth rate of GaN is substantially increased due to enhanced bulk diffusion of the growth precursor therefore the model for analysis of the growth rate was developed. The GaN strips fabricated by this method demonstrate effective luminescence properties. The structures demonstrate enhancement of spontaneous emission via formation of Fabry-Perot modes.

Optical Cavity Based on GaN Planar Nanowires Grown by Selective Area Metal‐Organic Vapor Phase Epitaxy

“…CL spectra have been measured using a spot mode, when the electron beam was focused to a spot as indicated in the insert in Figure a and b, respectively. The represented CL spectra were taken at the facets of the NWs since the appearance of the Fabry–Perot modes were observed within the defect YL band . For comparison, the CL spectrum for the GaN epitaxial layer is also shown in Figure b by the black line.…”

“…There are so‐called “top‐down” and “bottom‐up” approaches to produce NWs; the first method implies growth of planar structures followed by etching while the second approach permits growth of the functional nanoobjects in their final form . We have developed a “bottom‐up” method to produce GaN planar NWs using a selective area metal‐organic vapor phase epitaxy (MOVPE) growth technique on Si 3 N 4 /GaN/Al 2 O 3 templates patterned by focused ion beam (FIB) . Recently, III‐N based ridged structures have attracted a considerable interest due to application in fin‐shaped field‐effect transistors (FinFET), which have potential advantages over conventional planar metal oxide semiconductor devices, for example, shorter switching times, high thermal performance and higher current levels .…”

Fröhlich resonance splitting in hybrid GaN nanowire-Ag nanoparticle structures

“…Previously, we have studied optical properties of hybrid structures formed by Ag NPs and GaN planar nanowires (NWs) [21], when GaN planar NWs were grown along the [10 10] in-plane crystallographic directions. In this case, the GaN NWs have demonstrated almost ideal geometric shape and high crystalline quality [22]. The effect of small Ag NPs on the emission properties reveals in the appearance of an additional narrow line at ∼3.36 eV in photoluminescence (PL) spectra in the vicinity of the Ag NPs, which was explained using a theoretical model based on the Fröhlich resonance approximation and the effective medium approach.…”

Selective area doping of GaN toward high-power applications

“…Well-defined trenches with vertical sidewalls are routinely obtained when the dry-etching technique is optimized. Dry etching has been successfully implemented with plasma techniques: magnetron reactive ion etching (RIE) [7,8], ion beam etching [9][10][11], plasma etching [12][13][14], electron cyclotron resonance etching [15][16][17], RIE [18,19], inductively coupled plasma (ICP) [20,21], and ICP-RIE [22,23]. All of these may cause plasma-induced damage (PID) [24][25][26][27][28] to and contamination of the material under treatment [29].…”