Optical elements having buried layers and method of manufacture

Abstract

A buried conductive and/or reflective layer is provided in an optical element including at least one chemically vapor deposited material layer. Over a first layer of material is provided an intermediate region. The intermediate region in one embodiment includes at least one layer of a refractory-type material. In an alternate embodiment, the intermediate region is a composite intermediate region including a first passivating layer comprising a layer of a refractory-type of material such as one of the borides, carbides, nitrides, oxides and silicides, or a refractory-type of metal such as tungsten, molybdenum, tantalum, titanium and rhodium or a refractory-type of metal alloy. A conductive layer is then provided over at least a portion of the first passivating layer. Said conductive layer may comprise any one of the highly conductive/reflective metals such as copper, gold, silver, palladium, platinum and aluminum, for example. Over the conductive layer is provided a second passivating layer similarly comprising one of the aforesaid mentioned refractory-type of materials. A second layer of material is then chemically vapor deposited over the intermediate region. The single layer of refractory material provides an intermediate region having acceptable optical characteristics subsequent to chemical vapor deposition. The first and second passivating layers of the composite intermediate region isolates the conductive layer from the materials preventing interdiffusion and chemical reaction therebetween. Further, the second passivating layer protects the conductive layer from the generally corrosive and reducing or oxidizing environment provided during chemical vapor deposition of the second layer of material.