Lee Kyoung-Min, Hong Wan-Shick
Department of Nano Engineering, University of Seoul, Seoul 130-743, Korea.
J Nanosci Nanotechnol. 2011 Jan;11(1):815-9. doi: 10.1166/jnn.2011.3195.
Silicon nitride (SiN(x)) films for a gate dielectric layer of thin film transistors were deposited by catalytic chemical vapor deposition at a low temperature (< or = 200 degrees C). A mixture of SiH4, NH3 and H2 was used as a source gas. Metal-insulator-semiconductor (MIS) capacitor structures were fabricated for current-voltage (I-V) and capacitance-voltage (C-V) measurements. The breakdown voltage characteristics of the SiN(x) films were improved by the increase of NH3/SiH4 and H2/SiH4 mixing ratios and substrate temperatures. H2 treatment was attempted to improve the breakdown voltage further. A breakdown voltage as high as 6.6 MV/cm was obtained after H2 annealing at 180 degrees C. The defect states inside the SiN(x) films were analyzed by photoluminescence spectra. Silicon dangling bonds (2.5 eV) and nitrogen dangling bonds (3.1 eV) were observed. These defect states inside the SiN(x) films disappeared after H2 annealing. Flat band voltage shifts were observed in C-V curves, and their magnitudes decreased as the defect states inside the SiN(x) films decreased.
通过催化化学气相沉积在低温（≤200℃）下沉积用于薄膜晶体管栅极介电层的氮化硅（SiN(x)）薄膜。使用SiH4、NH3和H2的混合物作为源气体。制备金属-绝缘体-半导体（MIS）电容器结构用于电流-电压（I-V）和电容-电压（C-V）测量。通过提高NH3/SiH4和H2/SiH4混合比以及衬底温度改善了SiN(x)薄膜的击穿电压特性。尝试进行H2处理以进一步提高击穿电压。在180℃进行H2退火后获得了高达6.6 MV/cm的击穿电压。通过光致发光光谱分析SiN(x)薄膜内部的缺陷态。观察到硅悬空键（2.5 eV）和氮悬空键（3.1 eV）。在H2退火后，SiN(x)薄膜内部的这些缺陷态消失。在C-V曲线中观察到平带电压偏移，并且随着SiN(x)薄膜内部缺陷态的减少，其幅度减小。
