US 8,568,960 B2Granted

Multiple exposure photolithography methods

AssigneeInternational Business Machines Corporation

InventorsKuang-Jung Chen, Wu-Song Huang, Ranee Wai-Ling Kwong, Sen Liu, Pushkara R. Varanasi

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Abstract

A method that forms a film of photoresist composition on a substrate and exposes a first and second region of the film to radiation through a first and second mask having a first and second image pattern, respectively. The photoresist composition includes a polymer including labile group(s), base soluble group(s), a photosensitive acid generator, and a photosensitive base generator. The photosensitive acid generator generates first and second amounts of acid upon exposure to first and second doses of radiation, respectively. The second amount of acid exceeds the first amount of acid. The second dose of radiation exceeds the first dose of radiation. The photosensitive base generator generates a first and second amount of base upon exposure to the first and second dose of radiation, respectively. The first amount of base exceeds the first amount of acid. The second amount of acid exceeds the second amount of base.

Claims20

Dependent claims

A method comprising:

forming a film of a photoresist composition on a substrate, said photoresist composition comprising a polymer having a structure comprising at least one acid labile group or at least one base soluble group, a photosensitive acid generator, and a photosensitive base generator, said photosensitive acid generator capable of generating a first amount of acid upon exposure to a first dose of radiation, said photosensitive acid generator capable of generating a second amount of acid upon exposure to a second dose of radiation, said second amount of acid greater than said first amount of acid, said second dose of radiation greater than said first dose of radiation, said photosensitive base generator capable of generating a first amount of base upon exposure to said first dose of radiation, said photosensitive base generator capable of generating a second amount of base upon exposure to said second dose of radiation, said first amount of base greater than said first amount of acid, said second amount of base less than said second amount of acid;
exposing a first region of said film to radiation through a first mask having a first image pattern;
and
exposing a second region of said film to radiation through a second mask having a second image pattern;
wherein said photoresist composition further comprises a base proliferator, said base proliferator comprising a compound capable of generating a second base through catalytic reaction with a first base;
wherein said base proliferator is selected from the group consisting of:
wherein R4 is hydrogen or alkyl;
wherein either:
(i) each R1, R2, or R3 further comprises at least one element selected from the group consisting of oxygen, sulfur, and nitrogen;
or
(ii) each R1 or R2 is independently selected from the group consisting of a fluorinated linear alkyl, a fluorinated branched alkyl, a fluorinated cycloalkyl, an aryl, a fluorinated aryl, and combinations thereof, wherein R3 is selected from the group consisting of a fluorinated linear alkyl, a fluorinated branched alkyl, a fluorinated cycloalkyl, an aryl, a fluorinated aryl, and combinations thereof.

8 more elements

A method comprising:

forming a film of a photoresist composition on a substrate, said photoresist composition comprising a polymer having a structure comprising at least one acid labile group or at least one base soluble group, a photosensitive acid generator, and a photosensitive base generator, said photosensitive acid generator capable of generating a first amount of acid upon exposure to a first dose of radiation, said photosensitive acid generator capable of generating a second amount of acid upon exposure to a second dose of radiation, said second amount of acid greater than said first amount of acid, said second dose of radiation greater than said first dose of radiation, said photosensitive base generator capable of generating a first amount of base upon exposure to said first dose of radiation, said photosensitive base generator capable of generating a second amount of base upon exposure to said second dose of radiation, said first amount of base greater than said first amount of acid, said second amount of base less than said second amount of acid;
exposing a first region of said film to radiation through a first mask having a first image pattern;
and
exposing a second region of said film to radiation through a second mask having a second image pattern,
wherein said photosensitive base generator is a carbamate consisting of:

2 more elements

A method comprising:

forming a film of a photoresist composition on a substrate, said photoresist composition comprising a polymer having a structure comprising at least one acid labile group or at least one base soluble group, a photosensitive acid generator, and a photosensitive base generator, said photosensitive acid generator capable of generating a first amount of acid upon exposure to a first dose of radiation, said photosensitive acid generator capable of generating a second amount of acid upon exposure to a second dose of radiation, said second amount of acid greater than said first amount of acid, said second dose of radiation greater than said first dose of radiation, said photosensitive base generator capable of generating a first amount of base upon exposure to said first dose of radiation, said photosensitive base generator capable of generating a second amount of base upon exposure to said second dose of radiation, said first amount of base greater than said first amount of acid, said second amount of base less than said second amount of acid;
exposing a first region of said film to radiation through a first mask having a first image pattern;
and
exposing a second region of said film to radiation through a second mask having a second image pattern,
said photoresist composition further comprising a base proliferator, said base proliferator comprising a compound capable of generating a second base through catalytic reaction with a first base, wherein said base proliferator is selected from the group consisting of 3-nitropentane-2-yl carbamates.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/418,421Filed 13 Mar 2012 · division
Priority: 8 Jan 2008
Published: US 2012/0178027 A112 Jul 2012
Granted: 29 Oct 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification13 codes

G03F 7/038
Photosensitive materials: macromolecular compounds which are rendered insoluble or differentially wettable
G03F 7/0045
Photosensitive materials: with organic non-macromolecular light-sensitive compounds not otherwise provided for, e.g. dissolution inhibitors
G03F 7/0382
Macromolecular compounds which are rendered insoluble or differentially wettable: the macromolecular compound being present in a chemically…
G03F 7/0392
Macromolecular compounds which are photodegradable, e.g. positive electron resists: the macromolecular compound being present in a chemically…

Family

Application11/970,761Parent of this division · filed 8 Jan 2008
US 2012/0178027 A1Pre-grant publication · published 12 Jul 2012
US 8,236,476 B2Parent of this division · filed 7 Aug 2012
US 2009/0176174 A1Published application
US 8,568,960 B2This patent

From the US filing history. Foreign family members aren’t listed.

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