Fabrication of high Q square-lattice photonic crystal microcavities

This work discusses the fabrication of two-dimensional photonic crystal microcavities (PCMs) in a thin GaAs membrane. We have developed a fabrication process for square-lattice, single-hole-defect devices, a class of PCMs that is critically sensitive to fabrication accuracy, demonstrated coupling of InAs quantum dots to the cavity modes, and shown the sensitivity of the emission to the quality of the fabrication process. Reactive ion etching conditions were optimized to produce photonic crystal holes with smooth, straight sidewalls. To achieve, uniform hole sizes throughout the device, we developed a method to correct the proximity effect introduced while defining the photonic crystal holes using electron-beam lithography. Resulting cavities have resonances with quality factors as high as 4000, which proves the quality of our fabrication. (C) 2003 American Vacuum Society