Growth of poly- and single-crystal ScN on MgO(001): Role of low-energy N2+ irradiation in determining texture, microstructure evolution, and mechanical properties

Abstract

Articles you may be interested inThermoelectric properties of epitaxial ScN films deposited by reactive magnetron sputtering onto MgO(001) substrates J. Appl. Phys. 113, 153704 (2013); 10.1063/1.4801886 Growth of fullerene-like carbon nitride thin solid films by reactive magnetron sputtering; role of low-energy ion irradiation in determining microstructure and mechanical properties J. Appl. Phys. 93, 3002 (2003); 10.1063/1.1538316 Growth of single-crystal CrN on MgO(001): Effects of low-energy ion-irradiation on surface morphological evolution and physical properties Microstructure and electronic properties of the refractory semiconductor ScN grown on MgO(001) by ultra-highvacuum reactive magnetron sputter depositionScN layers, 345 nm thick, were grown on MgO͑001͒ substrates at 750°C by ultrahigh-vacuum reactive magnetron sputter deposition in pure N 2 discharges at 5 mTorr. The N 2 ϩ to Sc ratio incident at the substrate and growing film was maintained constant at 14, while the ion energy E N 2 ϩ was varied from 13 to 50 eV. All films were stoichiometric with N/Sc ratios of 1.00Ϯ0.02. However, microstructural and surface morphological evolution were found to depend strongly on E N 2 ϩ . The nucleation and initial growth stages of ScN films deposited with E N 2 ϩϭ 13 eV are dominated by the formation of 111-and 002-oriented islands, but preferred orientation rapidly evolves toward a purely 111 texture by a film thickness of Ӎ50 nm as 002 grains grow out of existence in a kinetically limited competitive growth mode. In distinct contrast, films deposited with E N 2 ϩ ϭ20 eV grow in a cube-on-cube epitaxial relationship with the substrate and exhibit no indication of 111-oriented grains, even in the earliest stages. Increasing E N 2 ϩ to 50 eV still results in epitaxial layers, but with high in-plane compressive stress and the presence of N 2 gas bubbles. All epitaxial layers contain rectangular nanopipes Ӎ1 nm wide and aligned along the growth direction. The nanopipes result from atomic shadowing near the bottom of a periodic array of surface cusps which form along orthogonal ͗100͘ directions due to kinetic roughening during growth. The hardness H and elastic modulus E of the epitaxial ScN͑001͒ layer grown with E N 2 ϩϭ 20 eV are 21.1Ϯ1.1 and 356Ϯ18 GPa, respectively. H and E increase ͑decrease͒ with increasing ͑decreasing͒ E N 2 ϩ .

First-principles modeling of localizeddstates with theGW@LDA+Uapproach

“…ScN has a NaCl structure with a͑exp͒ = 4.50 Å. 82 ZnS takes the zinc-blende structure with a͑exp͒ = 5.42 Å taken from Ref. 63.…”

A review of metal-ion-flux-controlled growth of metastable TiAlN by HIPIMS/DCMS co-sputtering

“…Adatom residence times are longer on the low-potentialenergy, low-diffusivity 111 surfaces, thus the local 111 epitaxial growth is preserved. 27,30,56 The residual defect concentration, and hence residual stress (-0.9 GPa), is lower under Al + rather than Ar + ion irradiation since Al is primarily incorporated into the lattice of the growing film, whereas Ar resides in interstitial sites.…”

“…Al + irradiation results in sufficient lattice atom displacements (through recoils and forward momentum transfer in shallow overlapping cascades) to eliminate the voids typically observed in low-temperature (Ts/Tm ≤ 0.3) TM nitride films. 17,25,28,30,31 The average column diameter, 200 Å near the substrate, increases to 600-700 Å by the middle of the film, and 700-1000 Å near the film surface.…”

“…26 The incident ion energy Ei and ion-to-metal flux ratio Ji/JMe are decisive parameters controlling nanostructural evolution during low temperature (< 500 o C; Ts/Tm < 0.3 for TiN) physical vapor deposition of transition-metal (TM) nitrides by conventional reactive DCMS. 17,25,27,28,29,30,31 The dominant ion species incident at the growth surface during DCMS with N2/Ar gas mixtures optimized to obtain stoichiometric films is typically Ar + , with N2 + and N + both contributing a few percent. 32, 33 The N2 + /N + ratio increases with increasing N2/Ar fraction, while in pure N2 discharges the dominant ion species is N2 + .…”

Atomic-scale structure of η-phase Mn3N2(010) studied by scanning tunneling microscopy and first-principles theory

“…[1][2][3][4][5][6][7][8][9][10] Manganese nitride (Mn-N) is interesting due to its magnetic properties. It is known from previous bulk studies that manganese nitride has different bulk phases, including θ (MnN), η (Mn 3 N 2 ), ε (Mn 4 N), and ζ (Mn 5 N 2 , Mn 2 N, and Mn 2 N 0.86 ).…”