Patent ID: 6893500

Claim:
A process for optical filter construction, the process comprising the steps of: growing layers having a high index of refraction via a self-limiting deposition process selected from the group consisting of atomic layer epitaxy, pulsed chemical beam epitaxy, molecular layer epitaxy, and laser molecular beam epitaxy; growing layers having a low index of refraction; depositing the high and low index layers onto a substrate; monitoring, during deposition, the layer growth, the high index layer being monitored via reflection high energy electron diffraction, the low index layer being monitored via interferometric technique capable of sub-angstrom resolution; monitoring intrinsic stress using an in-situ cantilever-based intrinsic stress optical monitor; adjusting the intrinsic stress via deposition parameter modification; monitoring indices of refraction during deposition via an in-situ ellipsometer; measuring surface roughness using a reflection technique selected from the group consisting of: p-polarized reflection spectroscopy, phase modulated ellipsometry, and real-time atomic force microscopy; depositing approximately a 1-10 nanometer thick first layer of amorphous diamond-like carbon onto at least one layer; directing an oxygen ion beam onto the at least one carbon coated layer; rastering the ion beam in a sweeping fashion to allow interaction with only the carbon which protrudes above average surface height, the rastering being continued until a top layer of carbon is reduced to the level of the highest peaks in the layer; and, repeating the process as necessary, alternating the high and low index layers.