矽晶藉由電化學蝕刻的方式形成了柱狀的多孔矽結構，而在蝕刻的過程中會出現奈米尺度的矽晶粒，這些矽奈米晶粒會引發量子侷限效應(Quantum confinement effect)，這會讓矽的光學性質表現會發生很大的不同。在此論文中，我們將探討多孔矽結構在不同蝕刻深度位置的光激發螢光光譜和拉曼散射光譜，並嘗試對光譜的結果進行更深入的探討。 在拉曼光譜上，矽晶和多孔矽的拉曼訊號有所不同，多孔矽的拉曼訊號會出現偏移、不對稱和全寬半高變寬的情況，我們認為這是源自於矽奈米晶粒的影響。在論文中透過3D phonon confinement model針對實驗結果中拉曼訊號的結果擬合出多孔矽的矽奈米晶粒大小。在量子侷限效應的影響下，光激螢光光譜也可以來判斷矽奈米晶粒的大小。本論文中，我們在同一試片中會選擇七個不同的位置，並在各個位置對不同蝕刻深度進行光譜測量，透過光譜結果，可以進一步判斷多孔矽的蝕刻深度。也可以得知多孔矽在不同蝕刻深度位置的光譜結果，並利用這些結果判斷矽奈米晶粒大小和結晶品質。此論文使用了三片以不同蝕刻電流上限製成的多孔矽試片，並依據光譜結果，來判斷蝕刻電流大小對多孔矽光性的影響。 ;Porous silicon structures are fabricated by electrochemical etching of silicon crystals. During the etching process, nanoscale silicon grains emerge, inducing the quantum confinement effect. This effect leads to significant alterations in the optical properties of silicon. In this work, we will investigate the photoluminescence and Raman scattering spectra of porous silicon structures at different etching depths. Additionally, we will attempt to provide more analysis of the spectral results. In the Raman spectra, there are discernible differences between silicon crystals and porous silicon. The Raman signal of porous silicon exhibits shifts, asymmetry, and broadening of full-width at half-maximum (FWHM), which may also arise from the influence of quantum confinement effect. In our paper, we employ a 3D phonon confinement model to fit the size of silicon nano-crystals in porous silicon based on our experimental results of the Raman signal. Photoluminescence spectra can also be utilized to determine the size of silicon nano-crystals. In this work, we select seven different positions on the same sample and conduct spectral measurements at various etching depths at each position. Through spectral results, we can further determine the etching depth of the porous silicon. Additionally, we can obtain the spectral results of porous silicon at different etching depths and use these results to determine the size and crystalline quality of silicon nanocrystals. Three samples of porous silicon were fabricated using different etching current limits, and based on the spectral results, we assess the influence of etching current magnitude on the optical properties of porous silicon.
