US 6,767,475 B2 · Chemical-organic planarization process for atomically smooth interfaces

Abstract

An oxygen ion process, Chemical Reactive-Ion Surface Planarization (CRISP), has been developed which enables planarization of thin film surfaces at the atomic level. Narrow/broad band filters produced with vacuum deposited multilayered thin films are designed to selectively reflect/transmit light at specific wavelengths. The optical performance is limited by the ability to control the individual layer thickness, the “roughness” of the individual layer surfaces and the stoichiometry of the layers. The process described herein will enable reduction of surface roughness at the interfaces of multilayered thin films to produce atomically smooth surfaces. The application of this process will result in the production of notch filters of less than 0.3 nm full width at half maximum (FWHM) centered at the desired wavelength. This will enable optical filters designed for telecommunication components such as next generation dense wavelength division multiplexer (DWDM) systems with significant performance improvement beyond the state-of-the-art.

Claims14

Dependent claims

A surface planarization process for planarizing vacuum-grown thin films, the process comprising the steps of:

depositing a thin layer of silicon dioxide onto a near-atomically flat fused silica substrate;
depositing approximately a 1-10 nanometer thick first layer of amorphous diamond-like carbon onto the silicon dioxide;
directing a well-focused oxygen ion beam onto the carbon coated silicon dioxide at near grazing incidence;
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 thin film;
depositing a thin layer of a titanium dioxide onto the carbon coated silicon dioxide;
depositing approximately a one-nanometer thick second layer of amorphous carbon onto the titanium dioxide;
directing a well-focused oxygen ion beam onto the carbon coated titanium dioxide at near-grazing incidence;
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 of the thin film;
and, repeating the process at least once.

6 more elements

Dependencies are inferred from the claim text.

Chemical-organic planarization process for atomically smooth interfaces

Life of this patent

Chemical-organic planarization process for atomically smooth interfaces

Life of this patent

Abstract

Claims14