METHOD FOR FORMING VOID-FREE POLYSILICON AND METHOD FOR FABRICATING SEMICONDUCTOR DEVICE USING THE SAME

摘要

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.

主权项

1. A method for fabricating a semiconductor device, the method comprising:
forming a buried gate electrode in a semiconductor substrate; forming an insulating layer over the buried gate electrode; etching the insulating layer to form a contact hole exposing the semiconductor substrate; forming a sacrificial layer on sidewalls of the insulating layer defining the contact hole; forming a polysilicon layer pattern in the contact hole; removing the sacrificial spacer; and performing a thermal process to remove a seam in the polysilicon layer pattern, wherein the thermal process is performed at a temperature range from 500° C. to 800° C. with a furnace annealing.