Apparatus with overlapping deep trench and shallow trench and method of fabricating the same with low defect density
AssigneeTexas Instruments Incorporated
InventorThomas Edward Lillibridge
Life of this patent
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Abstract
An integrated circuit includes a semiconductor substrate that has a top surface. A trench is formed within the substrate, and a conductive filler structure fills the trench. An insulator is located between the semiconductor substrate and the conductive filler. The insulator has a top portion with a top surface at the top surface of the substrate, The insulator further has a bottom portion that forms a corner with the top portion and extends from the corner to a bottom of the trench.
Claims20
A method of forming an integrated circuit, comprising:
- forming a shallow trench in a semiconductor substrate;
- filling the shallow trench with an insulator;
- forming a deep trench within the shallow trench, the deep trench having a sidewall of the insulator at an upper portion, and having a sidewall of the semiconductor substrate at a lower portion;
- and
- forming a dielectric liner that touches the insulator and the semiconductor substrate within the deep trench.
A method of forming an integrated circuit, comprising:
- forming a shallow trench in a semiconductor substrate;
- forming a first dielectric layer within the shallow trench, the first dielectric layer having a surface that forms a recess having a width and a height over the shallow trench;
- and
- forming a second dielectric layer over the first dielectric layer within the recess;
- and
- forming a deep trench within the shallow trench, the deep trench having a sidewall that includes sidewalls of the first and second dielectric layers at an upper portion, and including a sidewall of the semiconductor substrate at a lower portion.
A method of forming an integrated circuit, comprising:
- forming a first trench having a first depth within a semiconductor layer, the first trench having a first sidewall and an opposing second sidewall;
- filling the first trench with an insulator;
- forming a second trench between the first and second sidewalls, the second trench having a second depth greater than the first depth, and having a third sidewall that includes a sidewall of the insulator at an upper portion of the third sidewall and a sidewall of the semiconductor layer at lower portion of the third sidewall;
- and
- forming a dielectric liner that touches the upper portion of the third sidewall and the lower portion of the third sidewall.
Dependencies are inferred from the claim text.