矽奈米薄層結構元件與量測

Abstract

奈米結構可增進元件之電、光性質，本論文透過矽奈米薄層結構及元件製作，探討矽半導體材料在奈米薄層結構下光學及電性方面之表現，以便將來能有效運用於電子、光電元件，特別是光連結。 本論文研究重點為矽奈米薄層結構製作與光電性質量測。在薄層結構方面，藉由建立蝕刻速率緩慢且表面平坦之氫氧化鉀蝕刻參數與1000℃氧化溫度下之乾氧氧化模型，能有效且準確控制矽奈米薄層之厚度，配合絕緣層上覆矽之材料，達成奈米薄層結構，並可將此結構運用於電子及光學元件中，如矽薄膜電晶體與光調變器。在量測方面，將矽奈米薄層製成穿透式元件，利用單光儀量測系統測量矽奈米薄層在光波長範圍為350 nm~500 nm下之穿透率。量測之矽奈米薄層厚度有22 nm、28 nm與42nm三種情況，不同厚度下之穿透率表現皆在光波長小於400 nm時迅速下降，推得矽奈米薄層在此波段有一劇烈變化之吸收係數，而且有不錯之光電效應，可應用於短波長之光電元件。

The nanostructure can enhance the electrical and optical properties. In this thesis, we use silicon nanoscale thin structure to study the electrical and optical performance in silicon, so we can use silicon nanostructure for electronic and opto-electrical devices applications, especially for optical interconnects. The focus of this thesis is the silicon nanoscale thin structure fabrication and measurement. In the nanostructure fabrication, we use slow and smooth etching recipe of KOH and build up the dry oxygen oxidation model at 1000℃ to control the thin film thickness of silicon accurately. We use the silicon on insulator wafer to get the Si nanoscale thin structure. This result can be used in electronic and opto-electronic devices such as the thin film transistors and modulators. In the measurement part, we fabricate the device with silicon nanoscale thin structure and use the monochromator system to measure the optical transmittance of the nanostructure between a wavelength range from 350 nm to 500 nm. The transmittance curves have a sharp reduction in each device of difference silicon thicknesses for the wavelength range less than 400 nm. Therefore, the silicon nanoscale thin structure has a strong absorption coefficient for short wavelength optical device applications.