Parasitic masking effect in GaN SA-MOVPE using SiO2 masks deposited by the PECVD technique

• Published in: Materials science in semiconductor processing 2023-06, Vol.160, p.107394, Article 107394
• Main Authors: Stępniak, Michał, Wośko, Mateusz, Stafiniak, Andrzej, Prażmowska–Czajka, Joanna, Paszkiewicz, Regina
• Format: Article
• Language: English
• Subjects: Gallium nitride; Mask degradation; Parasitic masking; Selective area growth; Selective epitaxy; Thermal decomposition
• ISSN: 1369-8001; 1873-4081
• DOI: 10.1016/j.mssp.2023.107394

The paper reports a phenomenon of parasitic substrate masking during selective area metalorganic vapor phase epitaxy (SA-MOVPE) of gallium nitride (GaN) using silicon dioxide (SiO2) masks deposited by plasma enhanced chemical vapor deposition (PECVD) at pressures above 150 hPa. The discussion of the thermal stability and nitridation process of the SiO2 films is followed by the presentation of the experimental work results focused on the investigation of the relationship between the parasitic masking effect and pressure in the MOVPE reactor chamber. Analysis of the surface morphology is conducted using scanning electron microscopy (SEM) and atomic force microscopy (AFM). A hypothesis was proposed explaining the formation of the deposition-free region that indicates silanimine (HNSi) layer formation as a possible factor responsible for the adverse inhibition of GaN nucleation. [Display omitted] •Phenomenon of parasitic substrate masking during selective area metalorganic vapor phase epitaxy of gallium nitride using silicon dioxide masks deposited by plasma enhanced chemical vapor deposition is presented.•The relation between the width of the deposition-free region and pressure in the reactor chamber is discussed.•Analysis of the surface morphology using scanning electron microscopy is conducted.•A hypothesis explaining the formation of the deposition-free region that inhibits the gallium nitride nucleation is proposed.