Method for forming void-free polysilicon and method for fabricating semiconductor device using the same
AssigneeSK hynix Inc.
InventorHyung-Kyun Kim
Life of this patent
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Abstract
A method for fabricating a semiconductor device includes forming a buried gate electrode in a semiconductor substrate. An insulating layer is formed over the buried gate electrode and is etched to form a contact hole exposing the semiconductor substrate. A sacrificial spacer is formed on sidewalls of the insulating layer defining the contact hole. A polysilicon layer pattern is formed in the contact hole. The sacrificial spacer is removed to form an air gap around the polysilicon layer pattern. A thermal process is performed to remove a seam existing in the polysilicon layer pattern.
Claims4
A method for fabricating a semiconductor device, the method comprising:
- forming a second layer over a first layer;
- forming an open portion by etching the second layer;
- forming a sacrificial layer on sidewalls of the second layer defining the open portion;
- forming a polysilicon layer pattern in the open portion;
- removing the sacrificial layer to form a gap between the polysilicon layer pattern and the second layer, wherein the gap exposes sidewalls and a top surface of the polysilicon layer pattern;
- and
- performing a thermal process to diffuse a seam in the polysilicon layer pattern to the exposed sidewalls and the top surface of the polysilicon layer pattern after the removing the sacrificial layer,
- wherein the thermal process is performed at a temperature range from 500° C. to 800° C. with a furnace annealing.
Dependencies are inferred from the claim text.