Low-Interface-Trap-Density and High-Breakdown-Electric-Field SiN Films on GaN Formed by Plasma Pretreatment Using Microwave-Excited Plasma-Enhanced Chemical Vapor Deposition

• Published in: IEEE transactions on electron devices 2013-06, Vol.60 (6), p.1916-1922
• Main Authors: Watanabe, T., Teramoto, A., Nakao, Y., Sugawa, S., Ohmi, T.
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Cross-disciplinary physics: materials science; rheology; Dielectric, amorphous and glass solid devices; Electronics; Exact sciences and technology; Gallium nitride; Gallium nitride (GaN); Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Microelectronic fabrication (materials and surfaces technology); MIS capacitors; Physics; Plasma temperature; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silicon; Silicon compounds; silicon nitride; Surface treatment; Temperature measurement
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2013.2258347

We investigated the SiN/GaN interface properties formed by the microwave-excited plasma-enhanced chemical vapor deposition (PECVD) with SiH 4 /N 2 /H 2 gases. The interface and insulating properties of SiN films on GaN, formed by the microwave-excited PECVD, strongly depend on SiH 4 flow rate. Although the interface trap density is lower than 10 11 cm -2 eV -1 at the relatively high SiH 4 flow rate of 1.0 standard cm 3 /min (sccm), the breakdown electric field is very low (approximately 1 MV/cm). Using the SiH 4 plasma pretreatment before the stoichiometric SiN deposition, both low interface trap density and high breakdown voltage greater than 2 MV/cm were obtained. In this case, the clearly ordered Ga bonding near the SiN/GaN interface was estimated by electron energy loss spectroscopy. The formation of SiN film on GaN using the microwave-excited PECVD is a very useful technique for the high-quality interface properties.