US 9,852,984 B2 · Cut first alternative for 2D self-aligned via

Abstract

A method of lithographically cutting a Mx line before the Mx line is lithographically defined by patterning and the resulting 2DSAV device are provided. Embodiments include forming an a-Si dummy metal layer over a SiO2 layer; forming a first softmask stack over the a-Si dummy metal layer; patterning a plurality of vias through the first softmask stack down to the SiO2 layer; removing the first soft mask stack; forming first and second etch stop layers over the a-Si dummy metal layer, the first etch stop layer formed in the plurality of vias; forming a-Si mandrels on the second etch stop layer; forming oxide spacers on opposite sides of each a-Si mandrel; removing the a-Si mandrels; forming a-Si dummy metal lines in the a-Si dummy metal layer below the oxide spacers; and forming a SiOC layer between the a-Si dummy metal lines.

Claims7

Dependent claims

A device comprising:

a silicon (Si) substrate;
a silicon oxide (SiO2) layer formed over the Si substrate;
a plurality of amorphous silicon (a-Si) dummy metal lines formed over the SiO2 layer, each a-Si dummy metal line having an upper surface and one or more of the a-Si dummy metal lines having a via;
a first etch stop layer formed over the upper surface of the a-Si dummy metal lines and in the via;
a second etch stop layer formed over the first etch stop layer;
and a silicon oxycarbide (SiOC) layer between the a-Si dummy metal lines,
wherein the a-Si dummy metal lines are formed by:
etching the second etch stop layer, the first etch stop layer and an a-Si dummy metal layer down to the SiO2 layer, and
wherein the first etch stop layer formed in the via interrupts an a-Si dummy metal line including the via.

6 more elements

Dependencies are inferred from the claim text.

Cut first alternative for 2D self-aligned via

Life of this patent

Cut first alternative for 2D self-aligned via

Life of this patent

Abstract

Claims7