Planarization method, method for polishing wafer, and CMP system
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChung-Liang Cheng, Yen-Yu Chen, Chang-Sheng Lee, Wei Zhang
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Abstract
A planarization method is provided. The planarization method includes providing a wafer, in which the wafer includes a work function layer, a surface layer formed on the work function layer and oxidized from the work function layer, and a planarization layer disposed on or above the surface layer, performing a chemical-mechanical planarization (CMP) process on the planarization layer, providing an incident light to a surface of the wafer under the CMP process, detecting absorption of the incident light by the surface layer; and stopping the CMP process in response to an increase in the detected absorption of the incident light.
Claims20
A planarization method comprising:
- providing a wafer, wherein the wafer comprises a work function layer, a surface layer formed on the work function layer and oxidized from the work function layer, and a planarization layer disposed on or above the surface layer;
- performing a chemical-mechanical planarization (CMP) process on the planarization layer;
- providing an incident light to a surface of the wafer under the CMP process;
- detecting absorption of the incident light by the surface layer;
- and
- stopping the CMP process in response to an increase in the detected absorption of the incident light.
A method for polishing a wafer, the method comprising:
- holding a wafer against a pad;
- rotating at least one of the wafer and the pad;
- providing an incident light to an end-point layer on the wafer, wherein the photon energy of the incident light is greater than the band gap energy of the end-point layer;
- detecting absorption of the incident light by the end-point layer;
- and
- stopping the rotation of at least one of the wafer and the pad in response to an increase in the detected absorption of the incident light.
Dependencies are inferred from the claim text.