Cobalt silicide etch process and apparatus
AssigneeTegal Corporation
InventorsSteven Marks, Leslie G. Jerde, Stephen P. DeOrnellas
Life of this patent
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Abstract
Method and apparatus for etching a silicide stack including etching the silicide layer at a temperature elevated from that used to etch the rest of the layers in order to accomplish anisotropic etch.
Claims38
A method of processing a silicide layer which is included in a layer stack positioned on a substrate of a wafer, the stack including a cobalt silicide layer and a polysilicon layer, the method including the steps, in any order, of:
- processing a polysilicon layer of the wafer in a reactor having an electrode, the wafer at a first temperature of approximately 80° C.;
- and
- processing the wafer using chlorine gas as an etchant with the wafer at a second temperature at or above about 150° C. in order to process the cobalt silicide layer.
A method of processing a layer stack positioned on a substrate of a wafer, the stack including a cobalt silicide layer and a polysilicon layer, the method including the steps of:
- processing a polysilicon layer of the wafer in a reactor having an electrode, the wafer at a first temperature of approximately 80° C.;
- and
- changing the temperature of the wafer to a second temperature of at or above about 150° C. in order to process the cobalt silicide layer using chlorine gas as an etchant.
A method of processing a layer stack positioned on a substrate of a wafer, the stack including a cobalt silicide layer and a polysilicon layer, the method including the steps of:
- processing a cobalt silicide layer of the wafer in a reactor having an electrode, the wafer at a first temperature of approximately 150° C.;
- and
- changing the temperature of the wafer to a second temperature of approximately 80° C. in order to process the polysilicon layer using chlorine gas as an etchant.
Dependencies are inferred from the claim text.