Method for using a CVD organic barc as a hard mask during via etch
AssigneeAdvanced Micro Devices, Inc.
InventorsRamkumar Subramanian, Fei Wang, Todd P. Lukanc, Lynne A. Okada
Life of this patent
Estimating the term…
Abstract
A method for forming a via of a metal interconnect structure in a semiconductor device employs a CVD organic BARC between a low k dielectric material and a via photoresist mask. The CVD organic BARC is deposited over the low k dielectric film and protects the film during formation and patterning of the via photoresist mask. Furthermore, the presence of the BARC permits the photoresist mask to be thinner than that used in conventional techniques thereby improving lithography resolution.
Claims10
A method of forming a via for an interconnect structure of a semiconductor device, comprising the steps of:
- forming a low k dielectric layer over a metal feature;
- depositing by chemical vapor deposition (CVD) a first bottom anti-reflective coating (BARC) to cover the low k dielectric layer, wherein the first BARC is an organic BARC;
- depositing and patterning a photoresist mask on the first BARC on the low k dielectric layer, the patterned photoresist mask containing an opening;
- forming a via hole in the low k dielectric layer and the first BARC corresponding to the opening;
- and
- removing the first BARC and the photoresist mask in a single removal step.
A method of forming an interconnect structure, comprising the steps of:
- forming a low k dielectric layer over a metal feature;
- depositing by chemical vapor deposition (CVD) a first bottom anti-reflective coating (BARC) to cover the low k dielectric layer;
- depositing and patterning a first photoresist mask on the first BARC on the low k dielectric layer, the first patterned photoresist mask containing an opening;
- forming a via hole in the low k dielectric layer and the first BARC corresponding to the opening, the via hole having a bottom and sidewalls;
- removing the first photoresist mask and the first BARC;
- depositing by chemical vapor deposition (CVD) a conformal layer of a bottom anti-reflective coating (BARC) to cover the bottom and sidewalls of the via hole and a top surface of the low k dielectric layer;
- depositing and patterning a second photoresist mask on the conformal BARC on the low k dielectric layer, the second patterned photoresist mask containing an opening at least partially over the via hole in the low k dielectric layer.
Dependencies are inferred from the claim text.