Semiconductor device manufacturing: process – Coating with electrically or thermally conductive material – To form ohmic contact to semiconductive material
Reexamination Certificate
2005-06-21
2005-06-21
Quach, T. N. (Department: 2814)
Semiconductor device manufacturing: process
Coating with electrically or thermally conductive material
To form ohmic contact to semiconductive material
C438S623000, C438S624000, C438S710000, C438S717000, C438S723000, C257S758000, C257S760000
Reexamination Certificate
active
06908846
ABSTRACT:
A method for controlling a plasma etch process while etching a layer stack having a first layer disposed above an end-point generating layer is disclosed. The method includes etching through the first layer and at least partially through the end-point generating layer while monitoring an absorption rate of a light beam traversing an interior portion of the plasma processing chamber, wherein the end-point generating layer is selected from a material that produces a detectable change in the absorption rate when etched. The end-point generating layer is characterized by at least one of a first characteristic and a second characteristic. The first characteristic is an insufficient thickness to function as an etch stop layer, and the second characteristic is an insufficient selectivity to etchants employed to etch through the first layer to function as the etch stop layer. The method additionally includes generating an end-point signal upon detecting the detectable change.
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Hudson Eric
Marks Jeffrey
McMillin Brian K.
IP Strategy Group PC
Lam Research Corporation
Quach T. N.
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