在本論文中,我們將以電子束微影搭配雷射熱退火技術,在平面矽基板上製作出規則排列的結晶奈米鍺點,因其在空間上具有規則排列以及大小均勻等的特性,在光學及電子元件上均能有多樣的應用。首先我們使用了電子束微影系統在矽基板上的光阻層定義出規則性排列的孔洞,接著經由電子束熱蒸鍍上一層非晶鍺薄膜,經lift-off步驟後,可得到如圖形定義的整齊排列非晶鍺柱。最後再以準分子雷射進行熱退火,即可得到自我聚集的球型結晶奈米鍺點。在此,我們發現以單發低能量雷射對樣品進行多次逐步修補的方式,會得到最佳的結晶效果。 經由拉曼光譜系統對樣品分析檢測,我們可以確信所形成的量子點已具有結晶的品質,另外由FEB影像的輔佐,可看出形成的奈米鍺點大小十分的均勻,且在空間上可維持整齊的規則排列。
In our study, we fabricated the sample of ordered germanium nanocrystals by means of E-beam lithography and excimer-laser annealing on a plane silicon substrate. The technique would be useful at electron and optical applications due to its well-organized appearance and uniformity in size. E-beam lithography is firstly used to define ordered hole array on the photo resist coating on silicon substrate ,then a amorphous germanium film is deposited by E-beam thermal evaporator. After lifting-off and excimer-laser annealing, ordered self-assembled germanium nanocrystals can be obtained. We noticed that with lower laser energy and multiple shots, the crystallinity is better than high laser energy with single shot. Raman spectrum is used to analyze these nanocrystals, besides, FEB image can be a proof that the nanocrystal size is quite uniform.