Zone-based CMP target control
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChe-Liang Chung, Che-Hao Tu, Kei-Wei Chen, Chih-Wen Liu
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Abstract
The present disclosure is directed to techniques of zone-based target control in chemical mechanical polishing of wafers. Multiple zones are identified on a surface of a wafer. The CMP target is achieved on each zone in a sequence of CMP processes. Each CMP process in the sequence achieves the CMP target for only one zone, using a CMP process selective to other zones.
Claims20
A method of performing chemical mechanical polishing (CMP) on a wafer, comprising:
- identifying a first zone and a second zone on a surface of the wafer, the first zone having a structure feature different from a structure feature of the second zone;
- achieving a first CMP target thickness on the first zone by polishing the wafer using a first CMP process;
- removing a first structure feature having a first material from the second zone to generate a recess;
- filling the recess with a second material that is different from the first material;
- and
- after the filling the recess, achieving the first CMP target thickness on the second zone by polishing the wafer using a second CMP process.
A method of performing chemical mechanical polishing (CMP) on a wafer, comprising:
- identifying a first feature, a second feature, and a third feature on a surface of the wafer, the first feature being different from the second feature and the third feature;
- polishing the wafer using a first CMP process until the first feature reaches a first CMP target thickness;
- removing the third feature to form a recess;
- forming a fourth feature within the recess;
- and
- polishing the wafer using a second CMP process until the second feature reaches the first CMP target thickness.
A system for performing chemical mechanical polishing (CMP) on a wafer;
- comprising:
- a CMP platform;
- and
- a controller operable to control the CMP platform in polishing the wafer until a first target thickness is reached, the controller being configured to:
- identify a first zone and a second zone on a surface of the wafer, the first zone having a structure feature different from a structure feature of the second zone;
- control the CMP platform in polishing the wafer with a first CMP process until the first target thickness is reached on the first zone, the first CMP process being selective to the structure feature of the second zone;
- after the first target thickness is reached on the first zone, controlling the CMP platform to unload the wafer for a fabrication process different from CMP;
- and
- control the CMP platform in polishing the wafer with a second CMP process until the first target thickness is reached on the second zone, the second CMP process being selective to the structure feature of the first zone.
A method of performing chemical mechanical polishing (CMP) on a wafer, comprising:
- identifying a first zone and a second zone on a surface of the wafer, the first zone having a structure feature different from a structure feature of the second zone;
- achieving a first CMP target thickness on the first zone by polishing the wafer using a first CMP process that is selective to the structure feature of the second zone;
- and
- achieving the first CMP target thickness on the second zone by polishing the wafer using a second CMP process,
- wherein the first zone includes a long channel metal gate structure and the second zone includes a short channel metal gate structure.
Dependencies are inferred from the claim text.