Lower ferroelectric coercive field of ScGaN with equivalent remanent polarization as ScAlN. (1st August 2022)

• Record Type: Journal Article
• Authors: Uehara, Masato; Mizutani, Ryouichi; Yasuoka, Shinnosuke; Shimizu, Takao; Yamada, Hiroshi; Akiyama, Morito; Funakubo, Hiroshi
• Is Part Of: Applied physics express. Volume 15:Number 8(2022)
• Publication Date: 2022-08-01
• Subjects: ferroelectricity -- thin film -- gallium nitride -- scandium -- sputtering; Physics -- Periodicals; Technology -- Periodicals; 621.05
• DOI: 10.35848/1882-0786/ac8048
• Languages: English
• ISSNs: 1882-0778

Abstract

Abstract: The ferroelectricity of wurtzite, Sc x Ga1− x N ( x = 0.35–0.44), was demonstrated in a metal–ferroelectric–metal capacitor. The remanent polarization ( P r ) obtained from positive-up negative-down measurements was high, exceeding 120 μ C cm −2 . The coercive field ( E c ) of Sc0.44 Ga0.56 N was approximately 3.6 MV cm −1 at 300 K, which decreased to 3 MV cm −1 at 473 K. We observed that regardless of the host material, the Sc concentration governed the E c value in Sc x Ga1− x N and Sc x Al1− x N, suggesting that the polarization switching started in the wurtzite unit cells containing Sc. Additionally, the E c of Sc x Ga1− x N was lower than that of Sc x Al1− x N when P r was equivalent.