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US 11,112,698 B2Granted
Photoresist with gradient composition for improved uniformity
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChang Lilin, Ching-Yu Chang, Chin-Hsiang Lin
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Abstract
The present disclosure provides an embodiment of a method for lithography patterning. The method includes coating a photoresist layer over a substrate, wherein the photoresist layer includes a first polymer, and a first photo-acid generator (PAG), and a chemical additive mixed in a solvent; performing an exposing process to the photoresist layer; and performing a developing process to the photoresist layer to form a patterned photoresist layer. The chemical additive has a non-uniform distribution in the photoresist layer.
Claims20
A method for lithography patterning, comprising:
- providing a photoresist solution,
- wherein the photoresist solution includes a first polymer, a second polymer different from the first polymer in composition, a first photo-acid generator (PAG), and a second PAG different from the first PAG in composition,
- wherein the first polymer includes a chemical structure formulated as
- wherein the second polymer includes a chemical structure formulated as
- with each of parameters X, Y, and Z being a positive integer and selected such that the second polymer has a higher molecular weight than the first polymer,
- wherein the first PAG includes a chemical structure having two chemical units bonded together, the first PAG being formulated as
- and
- wherein the second PAG includes a chemical structure having two chemical units bonded together, the second PAG being formulated as
- coating the photoresist solution over a substrate to form a photoresist layer, the photoresist layer having a top surface facing away from the substrate and a bottom surface facing the substrate, wherein the coating of the photoresist solution results in the first polymer and the first PAG being distributed uniformly from the top surface to the bottom surface of the photoresist layer, the second polymer having a continuous concentration gradient decreasing from the top surface to the bottom surface of the photoresist layer, and the second PAG having a continuous concentration gradient increasing from the top surface to the bottom surface of the photoresist layer;
- performing an exposing process to the photoresist layer;
- and
- dissolving portions of the exposed photoresist layer using a solvent to form a patterned photoresist layer, wherein the continuous concentration gradients of the second polymer and the second PAG cause solubility of the exposed photoresist layer to increase from the top surface to the bottom surface.
9 more elements
A method for lithography patterning, comprising:
- forming a photoresist layer over a substrate, wherein the photoresist layer has a bottom surface facing the substrate and a top surface facing away from the substrate,
- wherein the photoresist layer includes a polymer, a first photo-acid generator (PAG), a second PAG different from the first PAG in composition, a first quencher, and a second quencher different from the first quencher in composition,
- wherein the first PAG includes a chemical structure having two chemical units bonded together, the first PAG being formulated as
- wherein the second PAG includes a chemical structure having two chemical units bonded together, the second PAG being formulated as
- the second PAG having a continuous gradient concentration increasing from a top surface to a bottom surface of the photoresist layer,
- wherein the first quencher includes a chemical structure having two chemical units bonded together, the first quencher being formulated as
- wherein the second quencher includes a chemical structure having two chemical units bonded together, the second quencher being formulated as,
- the second quencher having a continuous gradient concentration decreasing from the top surface to the bottom surface of the photoresist layer;
- performing an exposing process to the photoresist layer;
- and
- developing the photoresist layer, wherein developing the photoresist layer removes a greater portion of the photoresist layer near the bottom surface than the top surface.
8 more elements
A method for lithography patterning, comprising:
- providing a semiconductor substrate;
- forming a photoresist layer over the semiconductor substrate, wherein the photoresist layer includes a polymer, a photo-acid generator (PAG), and a dissolution additive,
- wherein the polymer is formulated as
- wherein the dissolution additive includes a first functional unit containing fluorine and a second functional unit bonded to the first functional unit, the dissolution additive being formulated as
- with X and Y each being a positive integer and selected such that a molecular weight of the dissolution additive is greater than that of the polymer, and
- wherein a concentration gradient of the dissolution additive continuously decreases from a top surface to a bottom surface of the photoresist layer;
- exposing the photoresist layer to a radiation source;
- applying a developer to the exposed photoresist layer, thereby forming a patterned photoresist layer, wherein the developer removes a greater amount of the photoresist layer near the bottom surface than the top surface;
- and
- etching the semiconductor substrate using the patterned photoresist layer as a mask.
7 more elements
Dependencies are inferred from the claim text.