||In this thesis, we fabricate the InGaAs Quantum Dot micro-pillar electro-pumping light emitting devices by E-beam lithography, and analyze the optical and electrical properties of micro-pillar cavity devices. For the sample materials, we use S-K mode to grow 3-layer In0.65Ga0.35As QDs structures on GaAs substrate by molecular-beam epitaxy (MBE),which were capped with 10nm In0.1Ga0.9As. The N layer is consisted of 23.5 pairs N-type doped DBR structures. The thickness of the p layer is 0.5λ P-type GaAs.|
The micro-pillar with diameter of 2μm, metal coated on top (p-type) and down (n-type) facet are designed. The good confined effect of metal-pillar cavity and DBR structure provide more energy extraction inside the cavity. We expect the device lasing while the current injection.
First, we design the morphology and size of patterns by AutoCAD software. Then, we use e-beam lithography with proper exposure condition to define the patterns, and thermal evaporation to deposit metals. The superfluous metal is lifted off and the defined area metal is served as dry etching mask to transfer the pattern to the dielectric layer and epi-layer. Finally, we use SiNx layer to prevent current leakage, and the p、n contact on each facet to complete the devices. The micro-pillar cavity without/with metal coated are analyzed by micro-PL or EL system. The Whispering Gallery Mode emission wavelength at 1227nm and 1275 nm by the micro PL measurement. From the EL measurement results, the device of micro-pillar cavity with metal coated generate a main peak, 1300nm. Besides, it can efficiently improve the emission intensities. The experiment results were in good agreement with simulation`s.