Double exposure patterning with carbonaceous hardmask
First Claim
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1. A double exposure patterning method comprising:
- providing a substrate comprising a substrate layer under a photoresist layer;
aligning, in a photolithography tool, a reticle to a feature in the substrate or substrate layer;
exposing the photoresist layer to form a first pair of photoresist lines with a first critical dimension (CD) in a first dimension and with a first space there between, the first pair of photoresist lines having a first alignment relative to the substrate layer, and wherein the exposing further prints a third photoresist line having a third CD in the first dimension;
offsetting the first alignment to have a second alignment by providing to the photolithography tool a predetermined positional offset relative to a position during the exposing, wherein the offsetting is in the first dimension, but not in a second dimension;
re-exposing the photoresist layer with the reticle to bifurcate at least one of the first pair of photoresist lines with a second space to form a pitch-reduced, critical dimension (CD) reduced double pattern comprising at least two photoresist lines and two spaces, and wherein the re-exposing trims the third photoresist line to reduce the third CD without bifurcating the third photoresist line; and
etching the substrate layer to have the pitch-reduced, CD reduced, double pattern.
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Abstract
Methods to pattern features in a substrate layer by exposing a photoresist layer more than once. In one embodiment, a single reticle may be exposed more than once with an overlay offset implemented between successive exposures to reduce the half pitch of the reticle. In particular embodiments, these methods may be employed to reduce the half pitch of the features printed with 65 nm generation lithography equipment to achieve 45 nm lithography generation CD and pitch performance.
21 Citations
8 Claims
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1. A double exposure patterning method comprising:
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providing a substrate comprising a substrate layer under a photoresist layer; aligning, in a photolithography tool, a reticle to a feature in the substrate or substrate layer; exposing the photoresist layer to form a first pair of photoresist lines with a first critical dimension (CD) in a first dimension and with a first space there between, the first pair of photoresist lines having a first alignment relative to the substrate layer, and wherein the exposing further prints a third photoresist line having a third CD in the first dimension; offsetting the first alignment to have a second alignment by providing to the photolithography tool a predetermined positional offset relative to a position during the exposing, wherein the offsetting is in the first dimension, but not in a second dimension; re-exposing the photoresist layer with the reticle to bifurcate at least one of the first pair of photoresist lines with a second space to form a pitch-reduced, critical dimension (CD) reduced double pattern comprising at least two photoresist lines and two spaces, and wherein the re-exposing trims the third photoresist line to reduce the third CD without bifurcating the third photoresist line; and etching the substrate layer to have the pitch-reduced, CD reduced, double pattern. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification