Self-Aligned Via Formation Using Spacers
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsYi-Nien Su, Jyu-Horng Shieh
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Abstract
A method includes forming a first mandrel and a second mandrel over a dielectric layer, and forming a first spacer and a second spacer on the first mandrel and the second mandrel, respectively. The first spacer and the second spacer are next to each other with a space in between. The dielectric layer is etched to form an opening in the dielectric layer, with the opening being overlapped by the space, and with the first spacer and the second spacer being used as a part of an etching mask in the etching. A conductive material is filled into the opening. A planarization process is performed on the conductive material.
Claims20
A method comprising:
- forming a first mandrel and a second mandrel over a dielectric layer;
- forming a first spacer and a second spacer on the first mandrel and the second mandrel, respectively, wherein the first spacer and the second spacer are next to each other with a first space in between;
- etching the dielectric layer to form an opening in the dielectric layer, wherein the opening is overlapped by the first space, and wherein the first spacer and the second spacer are used as a part of an etching mask in the etching;
- filling a conductive material into the opening;
- and
- performing a planarization process on the conductive material.
A method comprising:
- forming a mandrel over a dielectric layer;
- forming a first spacer on a sidewall of the mandrel, wherein the first spacer comprises a first sidewall and a second sidewall opposing to each other, wherein the second sidewall contacts the mandrel;
- etching a first portion of the dielectric layer to form a first opening in the dielectric layer, wherein the first opening has a third sidewall vertically aligned to the first sidewall;
- filling the first opening with a first conductive material;
- etching a second portion of the dielectric layer to form a second opening in the dielectric layer, wherein the second opening has a fourth sidewall vertically aligned to the second sidewall, and wherein the first opening and the second opening are on opposing sides of the mandrel;
- and
- filling the second opening with a second conductive material.
A method comprising:
- forming a hard mask over a low-k dielectric layer;
- forming a plurality of mandrels over the hard mask;
- forming a plurality of spacers on sidewalls of the plurality of mandrels, wherein a first space, a second space, and a third space separate neighboring ones of the plurality of spacers, with some portions of the hard mask exposed to the first space, the second space, and the third space;
- forming a protection layer filling into the first space;
- patterning the protection layer to remove the protection layer from the second space and the third space;
- forming a patterned etching mask over the protection layer;
- in a first etching process, etching-through a first portion of the hard mask and a first portion of the low-k dielectric layer directly underlying the second space to form a first opening in the low-k dielectric layer, wherein the protection layer and the patterned etching mask are in combination used as etching masks;
- and
- in a second etching process, etching-through a second portion of the hard mask and a second portion of the low-k dielectric layer directly underlying the third space to form a second opening in the low-k dielectric layer.
Dependencies are inferred from the claim text.