Optical interference filter
AssigneeViavi Solutions Inc.
InventorsFred VAN MILLIGEN, Georg J. OCKENFUSS
Life of this patent
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Abstract
In some implementations, an optical interference filter includes a substrate and a layer stack disposed on the substrate. The layer stack includes a first set of layers and a second set of layers. Each layer of the first set of layers comprises a first compressive material. Each layer of the second set of layers comprises a second compressive material that is different than the first compressive material. The layer stack does not include layers that fully compensate for a compressive stress of the first set of layers and the second set of layers. A net stress of the layer stack is approximately zero megapascals.
Claims20
A method comprising:
- forming, using a sputtering technique, a first set of layers and a second set of layers on a first wafer,
- wherein each layer of the first set of layers comprises a first compressive material, and
- wherein each layer of the second set of layers comprises a second compressive material that is different than the first compressive material;
- singulating the first set of layers and the second set of layers to form a plurality of layer stacks;
- forming respective patio structures for the plurality of layer stacks;
- releasing the plurality of layer stacks from the first wafer;
- and
- transferring the plurality of layer stacks to a second wafer,
- wherein a maximum thickness of the second wafer is less than a maximum thickness of the first wafer, and
- wherein a net stress of each layer stack on the second wafer is approximately zero megapascals.
An optical interference filter, comprising:
- a substrate;
- and
- a layer stack disposed on the substrate, wherein the layer stack includes:
- a first set of layers, and
- a second set of layers, wherein:
- each layer of the first set of layers comprises a first compressive material,
- each layer of the second set of layers comprises a second compressive material that is different than the first compressive material,
- the layer stack does not include layers that fully compensate for a compressive stress of the first set of layers and the second set of layers, and
- a net stress of the layer stack is approximately zero megapascals.
A wafer, comprising:
- a plurality of optical interference filters, wherein each optical interference filter includes:
- a portion of the wafer that serves as a substrate for the optical interference filter;
- and
- a layer stack disposed on the substrate, wherein the layer stack includes:
- a first set of layers, and
- a second set of layers, wherein:
- each layer of the first set of layers comprises a first compressive material,
- each layer of the second set of layers comprises a second compressive material that is different than the first compressive material,
- the layer stack does not include layers that fully compensate for a compressive stress of the first set of layers and the second set of layers, and
- a net stress of the layer stack is approximately zero megapascals.
Dependencies are inferred from the claim text.