图案化厚膜多孔硅制备与表征

Preparation and characterization of thick patterned porous silicon layers

图案化多孔硅是微电子、微机械、光电子器件的重要组成部分。实验以含Si3N4保护层的光刻单晶硅片为基底，采用电化学阳极氧化法制备图案化厚膜多孔硅，分析阳极氧化前后Si3N4保护层表面形貌变化特征和光刻尺寸对图案化多孔硅宽度、膜层厚度的影响规律，表征图案化多孔硅的结构、组成与发光性能。结果表明，氧化前Si3N4保护层局部区域出现枝晶，阳极氧化后形成不均匀孔状结构；制备的图案化多孔硅膜厚62～83μm，其横向扩展程度和膜层厚度均随光刻尺寸增大呈减小趋势；图案化多孔硅微结构含大量不规则裂纹和硅柱，新鲜制备的表面含Si—Hx键，其光致发光峰值波长650nm。

Patterned porous silicon （PPS） is an important component of microelectronic, micromechanical, and integrated optoelectronic devices. Thick PPS layer was prepared by electrochemical anodized on pre-patterned single crystal silicon. Morphology of Si3N4 protection layer before and after anodization, the effect of lithography pattern dimension on width and thickness of PPS was studied. Microstructure, formation and photoluminescent property of PPS were characterized by SEM, FT-IR and PL spectrum. It is shown that branched crystals appear at local part of Si3N4 before anodization, and form porous structure after anodization. PPS has a thick of 62-83μm, and horizontally extending degree and thickness of PPS both decrease with the pattern dimen- sion. A large amount of crackle and silicon pole is observed in the microstructure of PPS with Si-Hx bonds on its surface, and its emission peak is at 650nm.