Fabricating integrated devices using embedded masks
AssigneeLucent Technologies Inc.
InventorDennis S. Greywall
Life of this patent
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Abstract
A method of fabricating a device using a multi-layered wafer that has an embedded etch mask adapted to map a desired device structure onto an adjacent (poly)silicon layer. Due to the presence of the embedded mask, it becomes possible to delay the etching that forms the mapped structure in the (poly)silicon layer until a relatively late fabrication stage. As a result, flatness of the (poly)silicon layer is preserved for the deposition of any necessary over-layers, which substantially obviates the need for filling the voids created by the structure formation with silicon oxide.
Claims15
A method of fabricating an integrated device, comprising:
- (A) forming first and second embedded masks in a multi-layer wafer, each of said masks in contact with one or more layers of the wafer, wherein (i) the first embedded mask is in contact with a first layer of the wafer and (ii) the second embedded mask is in contact with a second different layer of the wafer;
- and
- (B) etching, using a first etchant, a portion of the first layer and a portion of the second layer from the wafer, wherein:
- the first embedded mask protects one or more other portions of the first layer from being removed by the first etchant during the etching;
- the second embedded mask protects one or more other portions of the second layer from being removed by the first etchant during the etching;
- and
- the first etchant is capable of removing material of the portions being protected by the first and second embedded masks.
Dependencies are inferred from the claim text.