Low‐temperature hollow cathode plasma‐assisted atomic layer deposition of crystalline III‐nitride thin films and nanostructures

Abstract

Hollow cathode plasma-assisted atomic layer deposition (HCPA-ALD) is a promising technique for obtaining III-nitride thin films with low impurity concentrations at low temperatures. Here we report our previous and current efforts on the development of HCPA-ALD processes for III-nitrides together with the properties of resulting thin films and nanostructures. The content further includes nylon 6,6-GaN core-shell nanofibers, proof-of-concept thin film transistors and UV photodetectors fabricated using HCPA-ALD-grown GaN layers, as well as InN thin films deposited by HCPA-ALD using cyclopentadienyl indium and trimethylindium precursors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Low-temperature self-limiting atomic layer deposition of wurtzite InN on Si(100)

“…41 Previously, we had reported refractive index value of 2.55 at 650 nm for a ∼20 nm InN thin film grown by HCPA-ALD at the same substrate temperature but non-optimized growth conditions. 33 This shows that, with the increase in thickness of InN from 20 to 48 nm, refractive index increased from 2.55 to 2.66 at 650 nm. This improvement might be attributed to film densification with the increase in thickness of the film.…”

“…However, in the case of InN (deposited using non-optimized parameters), we had found that addition of H 2 plasma with N 2 plasma as second precursor resulted in InN films with poor crystalline quality showing high level of impurities with significant voids in the films, resulting in low-density films. 33 This profound effect of H 2 plasma was attributed to plasma-related deterioration during the growth. In that context, present results illustrate that N 2 -only plasma exposure time is critical in removing the carbon containing ligands of TMI and results indicate that higher N 2 plasma exposure time is necessary to obtain InN films with minimum amount of carbon incorporation.…”

“…Inset of Fig. 10(b) shows optical transmission spectra of InN sample grown on double 33 InN thin film exhibits 40-50% transmission in the visible regime, which approaches up to 60-70% in the NIR regime. There is a huge controversy in literature for experimental InN thin film band gap values and origin of the observed InN band gap variations between 0.6 and 2.3 eV is not very well understood.…”

Low-temperature sequential pulsed chemical vapor deposition of ternary BxGa1-xN and BxIn1-xN thin film alloys

“…% oxygen) incorporation, whereas the film deposited using N 2 plasma reveals a single phase h-InN with substantially low impurity (<2% oxygen) content. 19 In this work, we have carried out growth of InN at 450 C with N 2 /H 2 plasma as nitrogen source, and no film growth was observed. Therefore, N 2 plasma was used as nitrogen source for the growth of InN film while N 2 /H 2 plasma was used as nitrogen source for the growth of GaN film at 450 C. Metal and nitrogen precursors for growth of InN, BN, and GaN are summarized in Table I.…”

Low-temperature grown wurtzite InxGa1−xN thin films via hollow cathode plasma-assisted atomic layer deposition

“…27 However, PL measurement from InN samples did not exhibit considerable emission. In addition to defect bands at lower wavelength, broad spectral features are visible with peaks centered at 508, 618, and 671 nm for In 0.25 Ga 0.75 N, In 0.33 Ga 0.67 N, and In 0.64 Ga 0.36 N thin films, respectively.…”