Layer-by-layer growth of TiN by pulsed laser deposition onin-situannealed (100) MgO substrates

Abstract

We have grown atomically smooth heteroepitaxial TiN thin films on (100) MgO single crystals by pulsed laser deposition (PLD). To generate optimal conditions for two‐dimensional growth of TiN on MgO, the substrates were annealed in‐situ using a CO2 laser heater. The MgO surface is smooth and uniformly stepped with a terrace height of half a unit cell; a value of 0.21 nm was measured by atomic force microscopy (AFM). In‐situ RHEED oscillations during deposition of TiN indicate two‐dimensional growth mode up to a film thickness of about 43 nm. This is confirmed by AFM. The TiN films show smooth, stepped surfaces with a uniform terrace height of 0.211 nm. X‐ray diffraction measurements indicate a high film quality, as well. High resolution scans feature intensity fringes around the (200) TiN peak, indicating an abrupt interface between MgO and TiN. On asymmetric reciprocal space maps the peak broadening only in q⊥ due to finite film thickness proves a high crystalline quality. Maximum electrical conductivity of the films is 2 × 106 S/m at 300 K. AFM topography images (5 × 5 μm2) of the surface of a (100) MgO substrate with a miscut angle of γ = 0.10°, annealed at 950 °C (height scale is 0 to 3.2 nm, left) and a 43 nm thick TiN/MgO thin film grown by PLD (height scale is 0 to 2.4 nm, right). Step height is half a unit cell in both cases.

Pulsed Laser Deposition of Rocksalt Magnetic Binary Oxides

“…YAO showed an atomically smooth surface, as proven by a line scan through its surface. MgO substrate with a step-terrace surface can be obtained after vacuum annealing at 950 °C [55], but this process may cause formation of point defects, which may change the electronic structure on the substrate surface. In our treatment, the annealing environment was changed to the air, and to avoid the hindering effect of atmospheric pressure on the surface diffusion, the annealing temperature was increased; several experiments determined that 1150 °C is an optimal annealing temperature for surface treatment of MgO (001).…”

A Platform for Complementary Metal‐Oxide‐Semiconductor Compatible Plasmonics: High Plasmonic Quality Titanium Nitride Thin Films on Si (001) with a MgO Interlayer

“…However, the majority of the demonstrations of TiN's device potential in plasmonics have been on sapphire and bulk MgO substrates featured by their small lattice mismatch with TiN, enabling the best‐performing plasmonic films. [ 24,28–33 ] Even then, high deposition temperatures (not congruent with CMOS processes) were usually used to ensure the high structural quality of the TiN films. For example, using reactive sputtering and at a substrate temperature of 650 °C, a peak plasmonic figure of merit (FOM = − ε ′/ ε ″) of ≈4.5 has been demonstrated for TiN films on a bulk MgO substrate.…”

“…[15][16][17][18] In the area of plasmonics, TiN-based waveguides, [19] gyroidal metamaterials, [20] nanohole metasurfaces, [21] nanoantennas, [22][23][24] and use of TiN nanoparticles for solar energy conversion [25,26] and biomedicine [27] have been reported.However, the majority of the demonstrations of TiN's device potential in plasmonics have been on sapphire and bulk MgO substrates featured by their small lattice mismatch with TiN, enabling the best-performing plasmonic films. [24,[28][29][30][31][32][33] Even then, high deposition temperatures (not congruent with CMOS processes) were usually used to ensure the high structural quality of the TiN films. For example, using reactive sputtering and at a substrate temperature of 650 C, a peak plasmonic figure of merit (FOM ¼ Àε 0 /ε 00 ) of %4.5 has been demonstrated for TiN films on a bulk MgO substrate.…”

Raman modes and dielectric relaxation properties of epitaxial BaBiO3 thin films

“…As-received SrTiO 3 (001) and (110) substrates were treated using buffered hydrogen fluoride (NH 4 F: HF=7:1) solution with pH=4.5 for 30 s followed by heat treatment at 1000°C for two hours in order to obtain unit cell step height and terrace features [15]. MgO (100) substrates were heat treated in situ inside the PLD chamber at 850°C for 2 h in vacuum [16]. Film surfaces were scanned using an atomic force microscope (AFM) XE-100 and room temperature x-ray diffraction (XRD) were performed using the Cu kα line with RIGAKU.…”