Structural, Morphological, Vibrational and Optical Properties of GaN Films Grown by Reactive Sputtering: The Effect of RF Power at Low Working Pressure Limit

Author(s)

R. S. de Oliveira ^[1] ; H. A. Folli ^[2] ; C. Stegemann ^[3] ; I. M. Horta ^[4] ; B. S. Damasceno ^[5] ; W. Miyakawa ^[6] ; A. L. J. Pereira ^[7] ; M. Massi ^[8] ; A. S. da Silva Sobrinho ^[9] ; D. M. G. Leite ^[10]

Affiliation

^[1] Instituto Tecnológico de Aeronáutica. Laboratório de Plasmas e Processos - Brasil

^[2] Instituto Tecnológico de Aeronáutica. Laboratório de Plasmas e Processos - Brasil

^[3] Faculdade de Tecnologia SENAI Jaraguá do Sul - Brasil

^[4] Instituto Tecnológico de Aeronáutica. Laboratório de Plasmas e Processos - Brasil

^[5] Instituto Tecnológico de Aeronáutica. Laboratório de Plasmas e Processos - Brasil

^[6] Instituto de Estudos Avançados - Brasil

^[7] Instituto Tecnológico de Aeronáutica. Laboratório de Plasmas e Processos - Brasil

^[8] Universidade Presbiteriana Mackenzie. Escola de Engenharia - Brasil

^[9] Instituto Tecnológico de Aeronáutica. Laboratório de Plasmas e Processos - Brasil

^[10] Instituto Tecnológico de Aeronáutica. Laboratório de Plasmas e Processos - Brasil

• Document type: Journal article
• Source: MATERIALS RESEARCH-IBERO-AMERICAN JOURNAL OF MATERIALS; v. 25, 2022-01-10.

Abstract

Abstract This work reports the properties of GaN films grown onto c-Si (100) at relatively low substrate temperature (400°C) by reactive magnetron sputtering. The study depicts the effect of working pressure and RF power on the GaN film structural, vibrational and optical properties characterized by X-ray diffraction, atomic force and scanning electron microscopies, Raman spectroscopy and spectroscopic ellipsometry. Unusual low pressure deposition condition (0.40 Pa) was achieved by using a separated argon inlet directed to the Ga target surface, resulting in improved crystalline quality of the films. In this condition, the preferential crystalline orientation, the surface morphology and the optical gap of the GaN films show a strong dependence on the RF power applied to the Ga target, where low RF power (30-60 W) was responsible for increasing the c-axis orientation and the optical gap, while higher RF power (75-90 W) decreased the overall crystal quality and increased the surface roughness. (AU)

• FAPESP's process: 11/50773-0 - Center of excellence in physics and applications of plasmas
• Grantee: Ricardo Magnus Osório Galvão
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 15/06241-5 - GaN based films and heteroestructures grown by reactive sputtering for SAW devices application
• Grantee: Douglas Marcel Gonçalves Leite
• Support Opportunities: Regular Research Grants