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US 7,396,718 B2Granted
Technique for creating different mechanical strain in different channel regions by forming an etch stop layer stack having differently modified intrinsic stress
AssigneeAdvanced Micro Devices, Inc.
InventorsKai Frohberg, Matthias Schaller, Joerg Hohage, Holger Schuehrer
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Abstract
A technique is provided that allows the formation of contact etch stop layers having different intrinsic stress for different transistors, while substantially avoiding any device degradation owing to the partial removal of the contact etch stop layer. Hereby, an additional thin etch stop layer is provided prior to the formation of the contact etch stop layers, thereby substantially maintaining the integrity of metal silicide regions, when a portion of an initially deposited contact etch stop layer is removed.
Claims9
A method, comprising:
- forming a first etch stop layer above a first transistor element and a second transistor element;
- forming a second etch stop layer above said first etch stop layer, said second etch stop layer having a first specified intrinsic stress;
- forming a third etch stop layer above said second etch stop layer,
- forming a first mask layer above said first and second transistor elements to expose said first transistor element and cover said second transistor element;
- removing a first portion of said second and third etch stop layers formed above said first transistor element by a selective etch process using said first etch stop layer as an etch stop;
- and
- forming a fourth etch stop layer above said first and second transistor elements, said fourth etch stop layer having a second intrinsic stress that differs from said first intrinsic stress.
4 more elements
Dependencies are inferred from the claim text.