Wafer trench article and process
AssigneeIntersil Americas Inc.
InventorsPatrick Anthony Begley, Donald Frank Hemmenway, George Bajor, Anthony Lee Rivoli, Jeanne Marie McNamara, Michael Sean Carmody, Dustin Alexander Woodbury
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Abstract
A bonded wafer 100 has a device substrate 16 with isolation trenches 30 defining device regions 18. Oxide dogbone structures are removed before filling trenches 30. Voids 36 in the trenches are spaced from the top of the trenches. The trenches are covered with an oxide layer 30 and filled with polysilicon 34. A LOCOS mask structure comprising a layer of CVD pad oxide and silicon nitride 50 cover the trenches and the adjacent device substrate regions.
Claims7
A method for fabricating trenches for integrated circuits formed on a semiconductor device substrate comprising the steps of:
- opening trenches defined by opposite sidewalls and a floor in the semiconductor device substrate to form one or more device islands between trenches;
- forming a layer of insulating material over the device substrate and over the sidewalls and the floors of the trenches and forming regions of relatively thick insulating material on the trench sidewalls near tops of the trenches;
- faceting portions of said regions of relatively thick insulating material near the tops of the trenches;
- and
- depositing fill material in the trenches.
Dependencies are inferred from the claim text.