三五族半導體微米捲管耦合發光特性

Abstract

在本論文中，我們製作出多種捲管結構。將因為晶格不匹配而內含內建應力的應變雙層薄膜成長於犧牲層之上，我們利用選擇性蝕刻將犧牲層去除，使得應變雙層薄膜從基板上被釋放並且捲曲成微米等級的捲管。透過光罩圖樣的設計，並結合長晶、黃光以及蝕刻的技術，我們成功地製作出內嵌有砷化銦量子點的砷化鎵/砷化銦鎵微米捲管。利用光激發量測系統，我們成功量測到單根微米捲管的共振模態，展現其環形共振腔的性質。我們也對單根微米捲管進行變溫量測，發現其共振波長隨溫度紅移，並將砷化鎵折射率對溫度變化一次項求出。另外我們也製作出耦合雙捲管，期望能夠在積體光路方面發展其應用。光激發量測顯示耦合雙捲管的確會有模分裂的產生，與Rsoft電磁場模擬軟體所得到的結果相符合。

In this thesis, several types of semiconductor microtube structures have been fabricated. We are able to form micron sized rolled-up tubes by lifting off the strained bi-layer which is composed of two lattice mismatched thin films with selective etching. With the well-designed patterns on the mask, well controlled MBE crystal growth, photolithography techniques as well as etching techniques, GaAs/InGaAs microtubes with embedded InAs quantum dots were fabricated. The light emission properties were studied using an optical pumping system, which helped us to acquire the information of the optical resonant modes of each single microtube. The microtubes showed characteristics as ring resonators with sharp peaks on the spectrum. On the other hand, we observed the thermal characteristic of each single microtube, which showed that the optical modes would red-shift as the temperature rose, and we also figured out the first order term of the effect of GaAs refractive index temperature dependence. We also fabricated coupled twin microtubes, expecting practical application as optical filters or add/drop multiplexers in optical integrated circuits. The optical spectra of the couple twin microtubes indicated the existence of mode splitting, which was predicted by the simulation results based on a FDTD software-Rsoft.