Abstract: Fabrication of an MO disc, the formation of a master pattern of servo and track information, and the subsequent transfer of that pattern to a series of pits and grooves on a substrate. On top of that substrate, at least one sacrificial layer is provided atop a relatively hard layer. The recording stack may be provided with both silicon nitride and silicon dioxide top layers, with the silicon dioxide layer acting as a sacrificial layer to ensure that the hard layer, of silicon nitride, remains at the end of the process. A layer of aluminum or aluminum alloy may be deposited, with the aluminum plugs filling the grooves and pits (created by the embossed servo information) to a level higher than any of the adjacent layers of silicon dioxide, silicon nitride, or similar dielectric layer.

Abstract: A filter housing for retaining a roomside replaceable filter is generally provided. In one embodiment, the filter housing includes one or more sidewalls defining an interior volume. Each sidewall includes a first section and an adjacent second section sealingly coupled thereto. A sealing member is coupled to the second section and extends into the interior volume. The sealing member is adapted to provide a gas-tight seal between with a replaceable filter and the filter housing. A hole is disposed through at least one of the first or second sections. The first section is sealed to the second section around a perimeter of the hole.