Zr_(2)/Si_(0.75)Ge_(0.25)/Si 구조의 계면 및 전기적 특성에 미치는 열처리 온도의 영향
(The) Effects of the Thermal Annealing Temperature on the Interfacial and Electrical Properties ofZr_(2)/Si_(0.75)Ge_(0.25)/Si Structures
스퍼터링 상부전극 열처리;
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The scaling down of the gate oxide thickness has led to an interest for high-permittivity (high-k) materials having low leakage current, high thermal stability, and good interface properties comparable to Si/SiO_(2) interface. In addition, during the last decade, the silicon-germanium (SiGe) technology has paved the way for a new generation of high performance devices and circuits. However, conventional thermal oxidation of Si_(x)Ge_(1-x) causes the preferential oxidation of Si that occurs Ge-rich layers at the oxide/substrate interface and causes degradation of oxide properties. Therefore, some comparative results were reported on the structural and electrical characteristics of ZrO_(2) films on Si_(0.75)Ge_(0.25)/Si substrates, performed at different annealing conditions, relative to its use in SiGe metal-oxide-semiconductor (MOS) gate dielectric applications. It was investigated that ZrO_(2) thin films had been deposited by rf-magnetron sputtering with 120 W of the loaded rf power and 1 : 1 of the gas flow rate of O_(2) : Ar. Annealing processes have been performed ranging from 550 ℃ to 650 ℃ in O2 ambient. By utilizing various characterization tools, such as XRD, SEM, AFM, RBS, XPS, TEM, C-V characteristics, and I-V characteristics, it was reported that the morphological, stoichiometric, dielectric and electrical properties of ZrO_(2) thin films on Si_(0.75)Ge_(0.25)/Si substrate were measured and analized. It was found that the transient point of annealing temperature exists to form and grow the SiO_(2) layer rapidly in vicinity to 650 ℃. Zr-silicide was formed between ZrO_(2) and Si_(0.75)Ge_(0.25)/Si substrate at the annealing temperature below 650 ℃.