本論文使用拉曼光譜(Raman spectra)與光激發螢光光譜(Photoluminescence spectra)來研究碳化矽樣品的多型體結構(polytype structure)種類與螢光特性。 由於不同多型體結構的碳化矽樣品在不同的波數位置上會出現不同的聲子模態訊號，因此可藉由拉曼光譜來辨別碳化矽樣品的多型體結構種類。由實驗結果判斷，我們所使用的樣品屬於4H-SiC和6H-SiC。 利用光激發螢光光譜，可以得知碳化矽樣品中存在許多的固有缺陷，並在低溫時測得由固有缺陷產生的多條尖銳零聲子線(zero-phonon lines)訊號。由變溫光激發螢光光譜可知，螢光訊號來自多個不同的缺陷發光，且在不同溫度時有其他的缺陷亦參與發光，使擬合的峰值位置有些微的不同。將擬合後的波峰積分強度對溫度變化作圖，並利用Arrhenius的關係式對圖形做擬合可得到碳化矽樣品的活化能大小。 最後對碳化矽樣品微波加熱八次後再進行一次變溫光激發螢光光譜測量和活化能的擬合，比較微波加熱前後變溫螢光光譜的差異並討論微波加熱對樣品的影響。 ;In this work, we use Raman spectra and Photoluminescence spectra to study the polytype structure sorts and luminescence properties of silicon carbide samples, respectively. Silicon carbide samples will show different phonon mode signals at different wave number positions of Raman spectra due to the various polytype structures, therefore, the polytype structure sorts of silicon carbide samples can be distinguished by Raman spectra. From the experimental results, we can identify that the samples we used are 4H-SiC and 6H-SiC. By measuring PL spectra, we can know that there are many intrinsic defects in these silicon carbide samples, and we also measured several sharp signals of zero-phonon lines at low temperature, which are caused by the intrinsic defects. From temperature dependent PL spectra, the fluorescent signals come from multiple different defects. Besides, there are other defects also participate in the light emission at different temperature, so that the peak positions of fitting are slightly different. Plot the peak integrated intensity after fitting against the temperature, and fit the graph with Arrhenius equation, then we can get the activation energy of the silicon carbide samples. At last, we measure the temperature dependent PL spectra and fit the graph to get the activation energy again after doing microwave heating on silicon carbide samples for eight times. Then we compare the difference of temperature dependent PL spectra before and after microwave heating and discuss the influence of microwave heating on samples.
