Methods for preparing low scatter optical coatings
AssigneeOptical Coating Laboratory, Inc.
InventorsScott Eugene Solberg, Richard Ian Seddon, Bradley James Pond, William Thomas Beauchamp
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Abstract
The present invention is directed to a sputtering method for preparing optical coatings having low light scattering characteristics by controlling the angle of incidence of the material being sputtered without significantly reducing the coating efficiency of the sputtering process. The angle of incidence is controlled by reducing the collision scattering of the material being sputtered and by intercepting the sputtered material that would without interception arrive at the surface to be coated at high angles of incidence. The collision scattering is reduced by utilizing a sputtering gas that has a mass less than the mass of the material being sputtered.
Claims18
A sputtering process for forming at least one layer of a thick optical coating having low scattering characteristics, said process comprising the steps of:
- providing a sputtering system comprising a sputtering gas, a target comprised of material to be sputtered, and a surface upon which a layer of said material is to be formed;
- said sputtering system utilizing a sputtering gas that has a particle mass less than the particle mass of said target material to be sputtered so as to diminish deflection of target material caused by collisions of sputtered target material with the sputtering gas;
- sputtering said target material toward said surface;
- intercepting at least a major portion of any material being sputtered which without interception would arrive at said surface at incidence angles greater than about 85.degree. from normal whereby a layer of the target material having low scattering characteristics is deposited on said surface.
A magnetron sputtering process for forming at least one layer of a thick optical coating having low scattering characteristics, said process comprising the steps of:
- providing a magnetron sputtering system comprising a neon sputtering gas, a target comprised of silicon to be sputtered and a surface upon which a layer of silicon is to be formed;
- sputtering said silicon toward said surface;
- intercepting at least a major portion of any sputtered silicon which without interception would arrive at said surface at incidence angles greater than about 85.degree. from normal whereby a layer of silicon having low scattering characteristics is deposited on said surface;
- and
- reacting said deposited layer of silicon with reactive gas, so that the silicon layer becomes an optical layer.
Dependencies are inferred from the claim text.