Avoiding Field Oxide Gouging In Shallow Trench Isolation (STI) Regions
A method and device for avoiding oxide gouging in shallow trench isolation (STI) regions of a semiconductor device. A trench may be etched in an STI region and filled with insulating material. An anti-reflective coating (ARC) layer may be deposited over the STI region and extend beyond the boundaries of the STI region. A portion of the ARC layer may be etched leaving a remaining portion of the ARC layer over the STI region and extending beyond the boundaries of the STI region. A protective cap may be deposited to cover the remaining portion of the ARC layer as well as the insulating material. The protective cap may be etched back to expose the ARC layer. However, the protective cap still covers and protects the insulating material. By providing a protective cap that covers the insulating material, gouging of the insulating material in STI regions may be avoided.
1 - 5 . (canceled)
6 . A device, comprising:
a trench in an STI region;
insulating material filled in said trench;
a gate oxide layer covering a portion of said STI region and extending beyond the boundaries of said STI region;
a polysilicon layer covering said gate oxide layer, wherein said polysilicon layer covers said portion of said STI region and extends beyond the boundaries of said STI region;
an anti-reflective coating (ARC) layer covering said polysilicon layer, wherein said anti-reflective coating layer covers said portion of said STI region and extends beyond the boundaries of said STI region; and
a protective cap covering said STI region and extending beyond the boundaries of said STI region, wherein said protective cap covers said ARC anti-reflective coating layer covering said portion of said STI region, wherein said protective cap covers said insulating material filled in said trench over said STI region.
7 . The device as recited in claim 6 , wherein said protective cap comprises photoresist material.
8 . The device as recited in claim 7 , wherein said photoresist material has a thickness of about 800 Å to 1200 Å.
9 . The device as recited in claim 6 , wherein said insulating material comprises thermal oxide.
10 - 15 . (canceled)