High-performance metal/SiO2/InSb capacitor fabricated by photoenhanced chemical vapor deposition

• Published in: Journal of applied physics 1990-10, Vol.68 (7), p.3701-3706
• Main Authors: Sun, Tai-Ping, Lee, Si-Chen, Liu, Kou-Chen, Pang, Yen-Ming, Yang, Sheng-Jenn
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Metals. Metallurgy; Physics; Surface and interface electron states
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.346334

The high-performance AuCr/SiO2/InSb metal-oxide-semiconductor capacitor was fabricated successfully using photoenhanced chemical vapor deposition. The 1200-Å-thick SiO2 layer was deposited on the InSb substrate at a temperature below 200 °C. Their electrical and structural properties were analyzed by capacitance-voltage and Auger electron spectroscopy, respectively. The capacitance-voltage results show that the optimal growth temperature of SiO2 is 150 °C at which the flat-band voltage of the capacitor is close to ideal and the slow interface state density is less than 5 × 1010 cm−2. For SiO2 deposited at a lower temperature, although the flat-band voltage and interface state are poorer, the subsequent thermal annealing at 150 °C for 12 h improves both quantities to the level as the optimal condition. However, for SiO2 deposited at a higher temperature (190 °C), the flat-band voltage shifts to −4 V and the slow state density increases to 1.1 × 1011 cm−2. It is found from the Auger depth profile that whatever the deposition temperature was a Si-rich region followed by an oxygen-rich region was formed at the SiO2/InSb interface. These observations are shown to be consistent with the electrical characteristics of the capacitor.