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US 5,670,410 AGranted
Method of forming integrated CMP stopper and analog capacitor
AssigneeChartered Semiconductor Manufacturing Pte Ltd.
InventorYang Pan
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Abstract
An analog capacitor is formed as part of an integrated circuit, using normal manufacturing methods, and then the upper electrode of this capacitor is used as part of the end point detection scheme during chem.-mech. polishing (CMP). Said upper electrode is formed from polysilicon and as soon as its upper surface is exposed as a result of the CMP, the presence of silicon particles in the removed material is readily detected by one of several possible methods.
Claims13
A method for end point detection during CMP, including manufacture of an analog capacitor, comprising:
- providing an integrated circuit having active devices electrically isolated from one another by a region of field oxide;
- depositing a first layer of polysilicon on the field oxide;
- patterning and etching said first polysilicon layer to form a lower electrode and a connector thereto;
- depositing a first insulating layer over said first polysilicon layer;
- depositing a second polysilicon layer of a first thickness over said first insulating layer;
- patterning and etching said second polysilicon layer to form an upper electrode that overlies the lower electrode, thereby forming an analog capacitor;
- depositing a second insulating layer over said second polysilicon layer to a thickness greater than said first thickness;
- and
- using a polishing head, applying CMP to the second insulating layer until the presence of polysilicon in the removed material is detected.
6 more elements
Dependencies are inferred from the claim text.