Effect of residual H2O on epitaxial AlN film growth on 4H-SiC by alternating doses of TMA and NH3

• Published in: Applied surface science Vol. 314; pp. 1047 - 1052
• Main Authors: Perng, Ya-Chuan, Kim, Taeseung, Chang, Jane P.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 30-09-2014; Elsevier
• Subjects: Aluminum; Aluminum nitride; Atomic layer deposition; Chemical vapor deposition; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition; Deposits; Epitaxial growth; Exact sciences and technology; Moisture; Moisture effect; Molecular beam epitaxy; Physics; Preferred orientation; Reactors; Reflection high-energy electron diffraction; SiC template; Spectroscopy; X-ray photoelectron; Spectroscopy; Atomic layer deposition; Moisture effect; Reflection high-energy electron diffraction; SiC template; Epitaxial growth; X-ray photoelectron; Chemical vapor deposition; Aluminum nitride; Water; Inorganic compounds; Epitaxial layers; Semiconductor materials; Epitaxy; Aluminium nitride; Aluminium; RHEED; Film growth; CVD; Silicon carbide
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2014.06.041

•An epitaxial AlN film was synthesized on 4H-SiC using alternate doses of trimethyl aluminum (TMA) and anhydrous ammonia (a-NH3) at 540°C.•The growth per cycle (GPC) at 540°C was 1.5Å/cycle which was significantly enhanced by eliminating any present moisture in the reactor system.•The measured RMS surface roughness was comparable to that achieved by molecular beam epitaxy.•The grown AlN film showed the crystallinity and the preferred orientation along the (0001) direction on 4H-SiC templates.
An epitaxial AlN film was synthesized on 4H-SiC using alternate doses of trimethyl aluminum (TMA) and anhydrous ammonia (a-NH3) at 540°C. The growth per cycle (GPC) at the temperature was limited to 0.27Å/cycle under the minute amount of residual H2O. The formation of an inert Al–O–Al bond generated by the recombinative desorption of two Al–OH species to produce H2O has been proposed as a possible reason for the low deposition rate. By eliminating any present moisture in the reactor system, the GPC increased to 1.5Å/cycle. The suppression of the OH group generation at 540°C made it possible to deposit nearly stoichiometric AlN film which has the crystallinity with the preferred orientation along the (0001) direction on 4H-SiC templates. The measured RMS surface roughness was comparable to that achieved by molecular beam epitaxy (MBE).