CPL mask and a method and program product for generating the same
First Claim
1. A method of forming a mask for printing a pattern comprising a plurality of features, said method comprising the steps of:
- depositing a layer of transmissive material having a predefined percentage transmission on an upper surface of a mask substrate;
depositing a layer of opaque material on said transmissive material;
etching a portion of said mask substrate to achieve a partial etching depth less than a target depth, said partial etching depth being based on an etching selectivity between said transmissive layer and said mask substrate;
exposing a portion of said patterned transmissive layer by etching said opaque material; and
etching said exposed portion of said transmissive layer so as to expose a portion of said upper surface of said mask substrate from underneath the patterned transmissive layer, said etched portion of said mask substrate being further etched along with said transmissive layer, thereby achieving the target depth;
wherein said exposed portion of said upper surface of said mask substrate and said etched portion of said mask substrate further etched along with said transmissive layer exhibit a predefined phase shift relative to one another with respect to an illumination signal impinging on the mask.
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Accused Products
Abstract
A method of generating a mask for printing a pattern including a plurality of features. The method includes the steps of depositing a layer of transmissive material having a predefined percentage transmission on a substrate; depositing a layer of opaque material on the transmissive material; etching a portion of the substrate, the substrate being etched to a depth based on an etching selectivity between the transmissive layer and the substrate; exposing a portion of the transmissive layer by etching the opaque material; etching the exposed portion of the transmissive layer so as to expose an upper surface of the substrate; where the exposed portions of the substrate and the etched portions of the substrate exhibit a predefined phase shift relative to one another with respect to an illumination signal.
17 Citations
16 Claims
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1. A method of forming a mask for printing a pattern comprising a plurality of features, said method comprising the steps of:
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depositing a layer of transmissive material having a predefined percentage transmission on an upper surface of a mask substrate; depositing a layer of opaque material on said transmissive material; etching a portion of said mask substrate to achieve a partial etching depth less than a target depth, said partial etching depth being based on an etching selectivity between said transmissive layer and said mask substrate; exposing a portion of said patterned transmissive layer by etching said opaque material; and etching said exposed portion of said transmissive layer so as to expose a portion of said upper surface of said mask substrate from underneath the patterned transmissive layer, said etched portion of said mask substrate being further etched along with said transmissive layer, thereby achieving the target depth; wherein said exposed portion of said upper surface of said mask substrate and said etched portion of said mask substrate further etched along with said transmissive layer exhibit a predefined phase shift relative to one another with respect to an illumination signal impinging on the mask. - View Dependent Claims (2, 3, 4, 5, 6, 7, 16)
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8. A device manufacturing method comprising the steps of:
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(a) providing a chip substrate that is at least partially covered by a layer of radiation-sensitive material; (b) providing a projection beam of radiation using an imaging system; (c) forming a mask utilized to endow the projection beam with a pattern in its cross-section; (d) projecting the patterned beam of radiation onto a target portion of the layer of radiation-sensitive material, wherein, in step (c), said mask is formed by a method comprising the steps of; depositing a layer of transmissive material having a predefined percentage transmission on an upper surface of a mask substrate; depositing a layer of opaque material on said transmissive material; etching a portion of said mask substrate to achieve a partial etching depth less than a target depth, said partial etching depth being based on an etching selectivity between said transmissive layer and said mask substrate; exposing a portion of said patterned transmissive layer by etching said opaque material; and etching said exposed portion of said transmissive layer so as to expose a portion of said upper surface of said mask substrate from underneath the patterned transmissive layer, said etched portion of said mask substrate being further etched along with said transmissive layer, thereby achieving the target depth; wherein said exposed portion of said upper surface of said mask substrate and said etched portion of said mask substrate further etched along with said transmissive layer exhibit a predefined phase shift relative to one another with respect to the beam of radiation impinging on the mask. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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Specification