Method for manufacturing alignment mark of semiconductor device using STI process
AssigneeHynix Semiconductor Inc.
InventorHyung Hwan Kim
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Abstract
The present invention discloses method for manufacturing alignment mark wherein a predetermined thickness of a device isolation film is etched prior to removing a pad nitride film during a shallow trench isolation process to increase contrast. In accordance with the method, a pad nitride film pattern and a pad oxide film pattern exposing a predetermined portion of the semiconductor substrate are formed. The semiconductor substrate is etched using the pad nitride film pattern as a mask to form an alignment mark trench. A device isolation film is formed in the trench and a predetermined thickness of the device isolation film is etched to form an alignment mark. The pad nitride film pattern is then removed.
Claims7
A method for manufacturing alignment mark of semiconductor device, the method comprising the steps of:
- sequentially forming a pad oxide film and a pad nitride film on a semiconductor substrate;
- selectively etching the pad nitride film and the pad oxide film to form a pad nitride film pattern and a pad oxide film pattern exposing a predetermined portion of the semiconductor substrate;
- etching the semiconductor substrate using the pad nitride film pattern as a mask to form an alignment mark trench having a predetermined depth;
- forming an oxide film for device isolation film filling the alignment mark trench on the entire surface;
- planarizing the oxide film for device isolation film until the pad nitride film pattern is exposed to form a device isolation film;
- and
- etching a predetermined thickness of the device isolation film to form an alignment mark prior to removing the pad nitride film pattern.
Dependencies are inferred from the claim text.