Visible electroluminescence device by MOS structure with Si-implanted SiO_2

微显示器在成像、消费、娱乐和数据图形应用中变得重要，例如相机取景器、头戴式显示器。与Si LSI的上级工艺兼容性使得Si基发光器件对于便携式系统中的集成智能显示器具有吸引力。研究了50 nm Si注入SiO_2的MOS电容器直流电致发光（EL）谱。在相同电流水平下，dc-EL强度比未注入的MOS电容器大50-70倍。还观察到Si注入电容器的电容与栅极电压（C-V）特性的滞后曲线。这表明硅离子注入产生的陷阱是发光的原因。在10 Hz ~ 100 kHz的频率范围内，随着脉冲频率的增加，交流电致发光强度增强。本文报道了50 nm Si注入SiO_2的Au/SiO_2/p-Si MOS电容器直流电致发光（EL）谱。厚度为15 nm的Au膜在300 nm或更长的波长下是透明的，电阻率为3 μΩcm。透明的Au栅不仅提高了可测波长范围，而且抑制了MOS层之间的干涉效应。测量了清晰平滑的电致发光光谱，观察到蓝光发射。通过拟合五个高斯分布函数（即hv=1.2、1.6、1.9、2.4、2.8eV）来分析EL光谱。这些能级与注硅SiO_2中的陷阱有关。提出了注硅MOS EL器件的EL发射机制模型。

Microdisplays become important in imaging, consumer, entertainment and data-graphic applications, such as camera viewfinders, head-mounted displays. A superior process compatibility with Si LSI makes Si-based light emitting devices attractive for the integrated intelligent displays in portable systems. Electroluminescence (EL) spectra under direct-current (dc) operation were studied for MOS capacitors with 50 nm Si-implanted SiO_2.The dc-EL intensity became about 50-70 times larger than the unimplanted MOS capacitor at the same current levels. Hysteresis curves in capacitance vs. gate voltage (C-V) characteristics were also observed for Si implanted capacitors. It suggests that the traps generated by Si-implantation cause the light emission. The ac-EL intensity was enhanced as the pulse frequency became higher in the frequency range from 10 Hz to 100 kHz. The longer components of the spectra were dominant.EL spectra under direct-current (dc) operation are reported for Au/SiO_2/p-Si MOS capacitors with 50 nm Si-implanted SiO_2. The Au film of 15 nm thick is transparent at 300 nm or longer wavelength and has the resistivity of 3 μΩcm. The transparent Au gate not only improves measurable wavelength range but also suppresses interference effects among MOS layers. The clear and smooth EL spectra were measured and the blue light emission was observed. The EL spectrum was analyzed by fitting five Gaussian distribution functions, i.e. hv=1.2, 1.6, 1.9, 2.4, 2.8 eV. These energy levels are related to the traps in Si-implanted SiO_2 A model of EL emission mechanism is proposed for the Si-implanted MOS EL device.