Research on Fundamentals of Opt-Electronic Integral Circuit on Silicon Substrate

本研究的目的是建立一种在硅基片上制作光波导的基本技术。基础技术确立后的最终目标是研制出新型的光电集成电路。采用硅衬底阳极氧化制备多孔硅，在多孔硅表面氧化形成的SiO_2区域作为芯层和包层材料，主要实验是硅衬底阳极氧化制备多孔硅层。为了制造波导，孔隙率必须为55%，使得孔隙在氧化期间被材料的体积膨胀完全填充。在纤芯区需要较大的孔径，以便掺杂杂质来调节折射率是有效的。另一方面，在包层区不需要掺杂杂质，孔的尺寸也不需要太大。 ...更多信息 含HF的电解液。采用高浓度HF电解液时，多孔硅的厚度不变，但孔径增大。高电流密度下的阳极氧化并不改变多孔硅的孔径大小，但可以得到较厚的多孔硅。即使在零电流密度下，多孔硅也会溶解在电解液中，并且多孔硅的孔径和厚度都随着阳极氧化时间的增加而增加。通过调节覆层区阳极氧化后电解液中HF的浓度，并参照阳极氧化法调节电流密度，可以控制孔的形状分布。由于硅基光波导易于获得大尺寸、高质量的硅片，因此，在制作工艺建立后，硅基光波导将被应用于各种光集成电路中。光电子集成电路也将通过使用硅器件技术来实现。作为光电集成电路的一个应用实例，本文提出了一种平面型多层结构光电集成神经网络电路的新结构。少

The purpose of this research is to establish a fundamental technique for the fabrication of optical waveguides on a silicon substrate. The final target after the establishment of the fundamental technique is to develop a new type of opt-electronic integrated circuit. A SiO_2 region formed by the oxiddation of porous silicon which is prepared by the anodization of the silicon substrate is assumed to be the core and cladding material.The main experiment is the preparation of porous silicon layers by the anodization of silicon substrate. In order to fabricate a waveguide, the porosity must be 55% so that the pores are completely filled by the volume expansion of material during the oxidation. The larger pore size is required in core region so that the impurity doping to adjust the refractive index is effective. On the other hand, the impurity doping is not necessary in the cladding region and the size of pore need not so large.The anodization process of silicon wafer was studied by using … More electrolyte containing HF. Using high HF cncentration electrolyte, the thickness of porous silicon does not change but the size of pore increases. The andization with high current density does not change the pore size but gives thicker porous silicon. The porous silicon dissolves into electrolyte even at zero current density, and both the pore size and the thickness of porous silicon increase as increases the anodization time.Although the final form of the optical waveguide has not yet fabricated, it will be possible to control the distribution of pore shape by adjusting the HF concentration of the electrolyte after the anodizaiton of cladding region and adjusting the current density by referring the data obtained in this research.Optical waveguides on siliocn substrate will be applied to various optical integrated circuit after the establishment of the fabrication technology because it is easy to get a large silicon wafer with high quality. Opt-electronic integrated circuits will also be realized by using silicon device technology. As an example of useful application of opt-electronic integrated circuits, a new structure of planer type multi-layer structured opt-electronic integrated neural network circuit has been proposed. Less