InGaAsP n -channel inversion-mode metal-insulator-semiconductor field-effect transistor with low interface state density

• Published in: Journal of applied physics 1981, Vol.52 (10), p.6386-6394
• Main Authors: Shinoda, Yukinobu, Kobayashi, Takeshi
• Format: Article
• Language: English
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.328582

n-channel inversion-mode metal-insulator-semiconductor field-effect transistors (MISFET’s) were fabricated on In1−xGaxAsyP1−y quaternary alloy (y≃2.2x) with chemical vapor deposition (CVD) Al2O3 gate insulator. The InGaAsP MISFET exhibited compositional dependence of the effective mobility μeff. μeff monotonically increased with increasing As molar fraction y in the 0⩽y⩽0.55 experimental range. The highest mobility obtained so far was 2300 cm2/V s at room temperature, higher than that of InP MISFET devices fabricated in this laboratory (400–800 cm2/V s). Very large temperature variation in threshold voltage and zero temperature coefficient of μeff were observed on InP(y = 0) devices. Contrasting to this, small temperature variation in the threshold voltage and the clear dependence of μeff on temperature, similar to that of the bulk mobility, were seen on InGaAsP MISFET’s. These excellent characteristics of the quaternary device appeared to be brought about through reduction in the interface states near the conduction band edge. The interface state density was estimated to be 1×1012/cm2eV, as compared to 1×1013 at the InP interface. A simple analysis, including the effect of the interface state on MISFET characteristics, explained the experimental results with good consistency.