Process for forming a shallow trench isolation structure
AssigneeUnited Microelectronics Corp.
InventorsChun-Lung Chen, Hsi-Mao Hsiao, Hung-Chen Yu, Tzung-Han Lee
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Abstract
A method is used to form a shallow trench isolation structure. According to the invention, prior to performing CMP on a HDPCVD oxide layer, a smoothing step is performed on the HDPCVD oxide layer to smooth the peak profile of the oxide layer to reduce the moment resulting from the CMP on the peak, and to prevent the later-formed shallow trench isolation structure from being pulled out. In addition, since the invention prevents the later-formed shallow trench isolation structure from being pulled out, the particles resulting from the oxide pulled out from the shallow trench are reduced. Thus, particle damage to the surface of the wafer is reduced.
Claims7
A method for forming a shallow trench isolation structure, comprising:
- providing a semiconductor substrate;
- forming a shallow trench in the semiconductor substrate;
- forming an oxide layer by high density plasma chemical vapor deposition to cover the semiconductor substrate and to fill the shallow trench, wherein the oxide layer has a steep peak profile;
- performing a smoothing step to smooth the steep peak profile;
- performing a chemical mechanical polishing to planarize the oxide layer;
- and
- removing the mask layer and the pad oxide layer to complete a shallow trench isolation structure.
A method for forming a shallow trench isolation structure, comprising:
- providing a semiconductor substrate;
- forming a pad oxide layer and a mask layer on the semiconductor substrate;
- patterning the mask layer, the pad oxide layer and the semiconductor substrate to form a shallow trench;
- forming a liner oxide layer in the semiconductor substrate of the shallow trench;
- forming an oxide layer by a high density plasma chemical vapor deposition to cover the semiconductor substrate and to fill the shallow trench, wherein the oxide layer has a steep peak profile;
- performing a smoothing step to smooth the steep peak profile;
- performing a chemical mechanical polishing to planarize the oxide layer;
- and
- removing the mask layer and the pad oxide layer to complete a shallow trench isolation structure.
Dependencies are inferred from the claim text.