Effect of lanthanum silicate interface layer on the electrical characteristics of 4H-SiC metal-oxide-semiconductor capacitors. (May 2018)

• Record Type: Journal Article
• Authors: Lei, Y.M.; Wakabayashi, H.; Tsutsui, K.; Iwai, H.; Furuhashi, M.; Tomohisa, S.; Yamakawa, S.; Kakushima, K.
• Is Part Of: Microelectronics and reliability. Volume 84(2018)
• Page Start: 248
• Page End: 252
• Publication Date: 2018-05
• Subjects: SiC -- Gate dielectrics -- Interface -- La-silicate -- MOS; Electronic apparatus and appliances -- Reliability -- Periodicals; Miniature electronic equipment -- Periodicals; Appareils électroniques -- Fiabilité -- Périodiques; Équipement électronique miniaturisé -- Périodiques; Electronic apparatus and appliances -- Reliability; Miniature electronic equipment; Periodicals; 621.3815
• DOI: 10.1016/j.microrel.2018.03.037
• Languages: English
• ISSNs: 0026-2714

Abstract

Abstract: The effect of La-silicate interface layer (IL) on the electrical characteristics of 4H-SiC metal-oxide-semiconductor (MOS) capacitors with atomic-layer-deposited SiO2 (ALD-SiO2 ) gate dielectrics was investigated. In addition to a slight reduction in the interface state density ( D it ), the surface potential fluctuation was greatly reduced due to the reduction in the fixed charges ( Q fix ) with La-silicate IL. Moreover, two orders of magnitude reduction in the oxide trap density in the ALD-SiO2 layer adjacent to the La-silicate IL was confirmed. Physical analysis revealed the reduction in carbon concentration and incorporation of La atoms adjacent to the La-silicate IL. Highlights: La-silicate interfacial layer reduces the interface state density for SiO2/SiC capacitors. Also, two orders of magnitude reduction in the oxide trap density can be achieved. Residual carbon atoms in the SiO2 adjacent to the La-silicate layer might be the origin for the improvements.