Research On Silicon LEDs In Standard CMOS Process And Its Optical Interconnection System

The silicon photonics, by virtue of its high speed parallel transmission capability and low crosstalk, can not only provide a promising solution to the limitations of the current electrical paradigm such as high latency and crosstalk, but also improve the information processing speed and precision considerably. At same time it can take full advantage of the mature and cost-effective silicon technology. Although high efficiency silicon-based light emitting devices(Si-LEDs) and photodetectors are the foundation and core to the realization of silicon-based optoelectronic integrated circuits(OEICs), the light emission intensity and conversion efficiency of Si-LEDs are very low. In this paper, based on deep sub-micron VLSI technology, we explore the design and fabrication of key components in silicon-based OEICs, including Si-LEDs, silicon-based photo-detectors(PD) and their related optical interconnects strctures, at the same time make deeply research into the spectral characteristics and light-emitting mechanisms of the forward injection Si-LEDs. The highlights of this work mainly are:First of all, the basic theories of semiconductor luminescence are studied and analysed. These theories include the luminescence characteristics and mechanisms of semiconductor materials, the theories of carrier recombination, the reversible photoelectric converting theory and key indicators of luminous quality. Furthermore, the research works of Si-LEDs at home and abroad are introduced in detail, especially the Si-LEDs compatible with standard CMOS process.Then, from the angle of the adopted technology, the consideration in the design of the devices structure, and the electrical and optical properties test, this paper presents three high optical power density and low-operating-voltage Si-LEDs designed and made in a commercial standard 0.18 ?m CMOS process without any modification. Furthermore, a detailed set of light-emitting mechanisms are presented and analyzed to explain the optical spectrum obtained from the above forward-biased carrier-injection-type Si-LEDs.Finally, a feasibility study of the polysilicon PIN-LEDs which are compatible with standard CMOS processes are carried out, including the design process, the test of its optical properties and electrical characteristics. Based on the light emitting device designed above, a novel mixed optical interconnection system that consist of the monocrystalline Si-LEDs and polysilicon PIN-LEDs are studied. In this work we made an attempt for the monolithic integrated technology of silicon-based light source, optical waveguide and silicon detector which are compatible with standard CMOS process.In summary, research on the Si-based OEICs offers great opportunities as well as great challenges. Its realization is expected not only to solve the “bottleneck” of conventional electrical connection, but also has great significance in all optical system chip.