Method of manufacturing diffractive optical element
AssigneeCanon Kabushiki Kaisha
InventorsJunji Terada, Masaaki Nakabayashi, Senichi Hayashi
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Abstract
A method of manufacturing a micro-structure having a plurality of step-like elements, includes the steps of etching a first region of a substrate, corresponding to a lowest step of the step-like element, with an appropriate depth, whereby a surface of the lowest step of the step-like element is defined, and etching, subsequently, a second region of the substrate, corresponding to another step of the step-like element, with an appropriate depth, whereby a surface of that step of the step-like element is defined.
Claims12
A method of manufacturing a structure arraying a plurality of step-like elements each having at least three steps, said method comprising the steps of:
- etching, using a first resist pattern, a first region of a film comprising multiple layers having different etching rates formed on a substrate, corresponding to lowest steps of the step-like elements, to a first depth, whereby surfaces of the lowest steps of the step-like elements are defined;
- and
- etching, subsequently, using a second resist pattern different from the first resist pattern, a second region of the film, corresponding to other steps of the step-like elements, to a second depth, whereby surfaces of these said steps of the step-like elements are defined,
- wherein side walls of the step-like elements are covered with the second resist pattern during the etching of the second region.
A method of manufacturing a structure arraying a plurality of step-like elements each having at least three steps, said method comprising the steps of:
- forming, on a substrate, a film having a thickness corresponding to the height of the step-like elements;
- etching, using a first resist pattern, a first region of the film on the substrate, corresponding to lowest steps of the step-like elements, to a first depth, whereby surfaces of the lowest steps of the step-like elements are defined;
- and
- etching, subsequently, using a second resist pattern different from the first resist pattern, a second region of the film on the substrate, corresponding to other steps of the step-like elements, to a second depth, whereby surfaces of these said steps of the step-like elements are defined,
- wherein the film includes a multilayered film comprising alternate layers of two materials having different etching rates,
- wherein each layer of one of the two materials having a higher etching rate serves as a main portion of the step-like elements while each layer of the other material having a lower etching rate serves as a first stopper layer when the or each layer of the material of the higher etching rate is etched,
- wherein the film further includes a second stopper layer of a material having an etching rate lower than those of the two materials and being provided on a side of the multilayered film facing the substrate, the second stopper layer serving as a stopper when the two materials are etched, and
- wherein side walls of the step-like elements are covered with the second resist pattern during the etching of the second region.
A method of manufacturing a structure arraying a plurality of step-like elements each having at least three steps, said method comprising the steps of:
- etching, using a first resist pattern, a first region of a substrate, corresponding to lowest steps of the step-like elements, to a first depth, whereby surfaces of the lowest steps of the step-like elements are defined;
- and
- etching, subsequently, using a second resist pattern different from the first resist pattern, a second region of the substrate, corresponding to other steps of the step-like elements, to a second depth, whereby surfaces of these said steps of the step-like element are defined,
- wherein side walls of the step-like elements are covered with the second resist pattern during the etching of the second region.
Dependencies are inferred from the claim text.