Apparatus and method for aligning integrated circuit layers using multiple grating materials
First Claim
1. An apparatus for aligning layers of an integrated circuit (IC), the apparatus comprising:
- an insulator layer positioned above a semiconductor substrate;
a first diffraction grating within a first region of the insulator layer, the first diffraction grating including a first grating material within the first region of the insulator layer; and
a second diffraction grating within a second region of the insulator layer, the second diffraction grating including a second grating material within the second region of the insulator layer, wherein the second grating material is different from the first grating material, and wherein an optical contrast between the first and second grating materials is greater than an optical contrast between the second grating material and the insulator layer,wherein the first diffraction grating includes a unitary layer of the first grating material, and wherein the second diffraction grating includes a semiconductor layer over the substrate, and the second grating material over the semiconductor layer.
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Accused Products
Abstract
Embodiments of the disclosure provides an apparatus for aligning layers of an integrated circuit (IC), the apparatus including: an insulator layer positioned above a semiconductor substrate; a first diffraction grating within a first region of the insulator layer, the first diffraction grating including a first grating material within the first region of the insulator layer; and a second diffraction grating within a second region of the insulator layer, the second grating including a second grating material within the second region of the insulator layer, wherein the second grating material is different from the first grating material, and wherein an optical contrast between the first and second grating materials is greater than an optical contrast between the second grating material and the insulator layer.
12 Citations
16 Claims
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1. An apparatus for aligning layers of an integrated circuit (IC), the apparatus comprising:
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an insulator layer positioned above a semiconductor substrate; a first diffraction grating within a first region of the insulator layer, the first diffraction grating including a first grating material within the first region of the insulator layer; and a second diffraction grating within a second region of the insulator layer, the second diffraction grating including a second grating material within the second region of the insulator layer, wherein the second grating material is different from the first grating material, and wherein an optical contrast between the first and second grating materials is greater than an optical contrast between the second grating material and the insulator layer, wherein the first diffraction grating includes a unitary layer of the first grating material, and wherein the second diffraction grating includes a semiconductor layer over the substrate, and the second grating material over the semiconductor layer. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An apparatus for aligning layers of an integrated circuit (IC), the apparatus comprising:
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an insulator layer positioned above a semiconductor substrate; and a plurality of alignment marks within the insulator layer, each of the plurality of alignment marks including; a first diffraction grating within a first region of the insulator layer, the first diffraction grating including a first grating material within the first region of the insulator layer, and a second diffraction grating within a second region of the insulator layer, the second diffraction grating including a second grating material within the second region of the insulator layer, wherein the second grating material is different from the first grating material, and an optical contrast between the first and second grating materials is greater than an optical contrast between the second grating material and the insulator layer; wherein the first and second diffraction grating of each of the plurality of alignment marks are oriented horizontally within the insulator layer, the first diffraction grating of each of the plurality of alignment marks includes a unitary layer of the first grating material, the second diffraction grating of each of the plurality of alignment marks includes a semiconductor layer over the substrate, and the second grating material over the semiconductor layer, and wherein at least one of the plurality of alignment marks is oriented horizontally perpendicularly with respect to another one of the plurality of alignment marks. - View Dependent Claims (9, 10)
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11. A method to form an alignment mark for an integrated circuit (IC), the method comprising:
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forming a plurality of trenches within an insulator layer positioned above a semiconductor substrate, wherein the plurality of trenches includes at least one first trench in a first region of the insulator layer and at least one second trench in a second region of the insulator layer; forming a mask on the insulator layer to cover the second region of the insulator layer; forming a first grating material within the at least one first trench, wherein forming the first grating material includes; depositing silicon nitride (SiN) within the at least one first trench, and planarizing the deposited SiN to an upper surface of the insulator layer; removing the mask; and forming a second grating material within the at least one second trench, wherein the second grating material is different from the first grating material, and an optical contrast between the first and second grating materials is greater than an optical contrast between the second grating material and the insulator layer, and wherein forming the second grating material includes; depositing a semiconductor material within the at least one second trench, depositing titanium nitride (TiN) on the semiconductor material within the at least one second trench, and planarizing the deposited TiN to an upper surface of the insulator layer. - View Dependent Claims (12, 13, 14, 15, 16)
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Specification