Multi-barrier deposition for air gap formation
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorHsiang-Wei Lin
Life of this patent
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Abstract
A method includes forming a first conductive line and a second conductive line in a dielectric layer, etching a portion of the dielectric layer to form a trench between the first conductive line and the second conductive line, and forming a first etch stop layer. The first etch stop layer extends into the trench. A second etch stop layer is formed over the first etch stop layer. The second etch stop layer extends into the trench, and the second etch stop layer is more conformal than the first etch stop layer. A dielectric material is filled into the trench and over the second etch stop layer. An air gap is formed in the dielectric material.
Claims20
An integrated circuit structure comprising:
- a dielectric layer;
- a first conductive line and a second conductive line in the dielectric layer;
- a trench in the dielectric layer, the trench extending between the first conductive line and the second conductive line;
- a first etch stop layer having a first portion with a first thickness extending over the dielectric layer, and a second portion with a second thickness, less than the first thickness, extending along sidewalls of the trench;
- a second etch stop layer contacting the first etch stop layer, the second etch stop layer having a third portion with a third thickness extending over the first portion and having a fourth portion with a fourth thickness over the second portion, wherein a first ratio of the fourth thickness to the third thickness is greater than a second ratio of the second thickness to the first thickness;
- a dielectric material in the trench and contacting the second etch stop layer;
- and
- an air gap in the dielectric material and in the trench.
An integrated circuit structure comprising:
- a substrate;
- a plurality integrated circuit devices formed on or in the substrate;
- a first connection layer over the substrate, the first connection layer including:
- a first dielectric layer, and
- a first plurality of metal lines;
- and
- a second connection layer over the first connection layer, the second connection layer including:
- a second dielectric layer,
- a second metal line,
- a trench in the second dielectric layer, the trench being adjacent the second metal line,
- a first etch stop layer extending substantially non-conformally over a first surfaced defined by the second dielectric layer, the second metal line and sidewalls and a bottom of the trench,
- a second etch stop layer contacting and extending substantially conformally over a surface defined by the first etch stop layer, and
- a dielectric material contacting and extending over the second etch stop layer into the trench, the dielectric material including an air gap within the trench.
A method comprising:
- forming a conductive line in a dielectric layer;
- etching portions of the dielectric layer to form a first trench on a first side of the conductive line and a second trench on a second side of the conductive line;
- forming a first etch stop layer, wherein the first etch stop layer extends substantially non-conformally into the first trench and the second trench;
- forming a second etch stop layer over the first etch stop layer, wherein the second etch stop layer extends substantially conformally into the first trench and the second trench;
- and
- filling a dielectric material into the first trench and the second trench.
Dependencies are inferred from the claim text.