Resolution limitation in EBL optical grating fabrication on InGaAsP/InP substrate

Monte Carlo (MC) simulation and experimental point exposure energy distribution on InP substrate are used to describe the total energy response of 1st and 2nd order gratings for InP based solid state lasers. A good agreement between theoretical calculations and experimental obtained data is achieved. The triple Gaussian approximation of the energy density profiles is suggested by an analysis of computed primary electron energy spectra. Examples of both dry and wet etched gratings in InP substrate and InGaAsP epitaxial layers, which fit with calculations are given.