Polarity Inverted GaN for Photonic Crystal Biosensor Applications

Periodic poling of GaN (alteration of the crystallographic direction along the c-axis) has potential for applications in photonics, sensing, and non-linear optics. One approach to periodic poling of GaN, involves Molecular Beam Epitaxy (MBE) growth of heavily Mg doped GaN which results in inversion of the surface polarity from Ga-polar to N-polar GaN. Fabrication and dry etching of the inversion layer followed by re-growth, and a subsequent highly anisotropic wet etch of re-grown N-polar regions can result in periodically poled GaN with features on either the micro or nanoscale. This paper outlines the design of GaN based photonic crystal biosensors based on periodic poling. Initial results of growth, fabrication, and theoretical modeling will be discussed.