Fabrication of GaN(1−x)Asx, Zinc‐Blende, or Wurtzite GaN Depending on GaAs Nitridation Temperature in a CVD System

• Published in: Crystal research and technology (1979) 2018-08, Vol.53 (8), p.n/a
• Main Authors: Ramírez‐González, Francisco Sebastian, García‐Salgado, Godofredo, Morales, Crisóforo, Díaz, Tomás, Rosendo, Enrique, Nieto‐Caballero, Fabiola Gabriela, Luna, José Alberto, Coyopol, Antonio, Romano, Román, Galeazzi, Reina
• Format: Article
• Language: English
• Subjects: CVD; GaN wurtzite structure; GaN zinc‐blende structure; GaN(1−x)Asx; nitridation
• ISSN: 0232-1300; 1521-4079
• DOI: 10.1002/crat.201800042

The study of GaN morphology and structure modification due to the variation of the nitridation temperature are reported. GaN is obtained by nitridation of GaAs (1 1 1) using the flow of a mixture of hydrogen and ammonia into a horizontal CVD system. The experiments are carried out at atmospheric pressures of 800, 900, and 1000 °C for 1 h. XRD results together with the pole figure indicate that GaN(1‐x)Asx is obtained at 800 °C, that zinc‐blende GaN structure is obtained at 900 °C, and that wurtzite GaN structure is obtained at 900 °C. The photoluminescence emission peak (obtained at room temperature) shifts to 420, 384, and 372 nm with the nitridation temperature change, in agreement with the XRD and pole figure results. SEM images show the morphology change, where GaN(1−x)Asx and GaN layers are obtained at 800 and 900 °C, respectively, while GaN columns are obtained at 1000 °C. The morphology and structure change due the nitridation temperature variation are also discussed based on the results. The nitridation of GaAs (1 1 1) at atmospheric pressure using a flow of NH3 and H2 is reported. The GaAs is used as the substrate and as the Ga source. The GaN(1−x)Asx ternary alloy is formed at 800 °C. The GaN zinc‐blende and wurtzite structures are formed at 900 and 1000 °C, respectively.