以晶元接合技術製作1.5μm波長面射型雷射之研究

Abstract

本論文的研究目的是利用晶圓接合技術製作長波長面射型雷射。我們建立了晶圓接合的系統架構與製作流程。在不同的晶圓接合溫度下，我們比較了跨異質接合接面的電阻。由掃描式電子顯微鏡與電壓-電流特性的觀察，得到了可使接面有低電阻且良好的接合介面的晶圓接合溫度。藉由分析InGaAlAs多量子井(MQW)的螢光光譜強度，得知在晶圓接合過程中對晶體結構所造成的破壞。對於布拉格反射鏡(DBR)在經過晶圓接合製程後的反射率頻譜與最大反射率也給與分析及討論。多量子井與布拉格反射鏡的光學特性不會因為經過晶圓接合製程而發生改變。在檢視經過晶圓接合製程的電性與光學特性後，我們利用晶圓接合技術接合了InGaAlAs多量子井與GaAs/AlAs布拉格反射鏡並鍍覆上SiO2/TiO2布拉格反射鏡，構成一面射型雷射之結構。此經過單次晶圓接合製程之面射型雷射，在室溫下以光激發操作的臨界激發光能量密度為4.5 kW/cm2 ，受激發光光波長為1623.5nm。此外，我們也以晶圓接合技術接合InGaAlAs多量子井與上部及底部GaAs/AlAs兩個布拉格反射鏡，構成一面射型雷射之結構。在室溫下，此經過二次晶圓接合製程之面射型雷射，之臨界激發光能量密度為5 kW/cm2 ，受激光波長為1527nm。

This thesis reports on the fabrication of long wavelength vertical surface emitting laser (LW-VCSEL) with the atomic rearrangement wafer fusion technique. We have setup a wafer fusion system and established the wafer fusion process. The resistance across fused heterojunction under different fusion temperature were compared. The proper fusion temperature for low resistance and well-fused fusion interface observed by scanning electron microscope was obtained. The peak emission wavelength and intensity of the InGaAlAs multi-quantum well (MQW) were analyzed to determine the degradation of the crystal quality during the wafer fusion process. The reflectance spectra and maximum reflectivity of GaAs/AlAs distributed Bragg reflectors (DBR) after the fusion process were also analyzed. The optical characteristics of the MQW and DBR did not alter after the wafer fusion process. After examined the electrical and optical characteristics after the fusion process, a VCSEL structure consisting of the InGaAlAs MQW, a fused bottom GaAs/AlAs DBR and a coated SiO2/TiO2 top dielectric mirror has been fabricated. This single fused VCSELs operated at room temperature by optical pumping with the threshold input power density of 4.5 kW/cm2 and the stimulated emission wavelength at 1623.5nm. We also demonstrated optically pumped VCSEL structure consisting of the InGaAlAs MQW fused with the bottom and top GaAs/AlAs DBR. The double fused VCSELs operated at room temperature with the threshold pumping power density of 5 kW/cm2 and the stimulated emission wavelength at 1527nm.