Apparatuses and methods for diffraction base overlay measurements
AssigneeMicron Technology, Inc.
InventorsKazuko Tsuchiya, Toshiharu Nishiyama
Life of this patent
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Abstract
Apparatuses and methods of overlay measurement are disclosed. An example apparatus includes: a substrate comprising first material; a first layer comprising second material disposed on a surface of in the substrate; a first alignment pattern including third material disposed in the first layer; and a second layer above the first layer including a second alignment pattern. A difference between refractive indexes of the second material and the third material is greater than a difference between refractive indexes of the first material and the third material.
Claims18
An apparatus comprising:
- a substrate comprising first material;
- a first layer comprising second material embedded in a surface portion of the substrate;
- a first alignment pattern comprising third material disposed in the first layer;
- and
- a second layer above the first layer comprising a second alignment pattern,
- wherein a difference between refractive indexes of the second material and the third material is greater than a difference between refractive indexes of the first material and the third material,
- wherein the first alignment pattern comprises a plurality of first lines, wherein the plurality of first lines is in a top portion of the first layer and in a corresponding plurality of first openings in the first layer,
- wherein the second alignment pattern comprises a plurality of second lines and a plurality of second openings between adjacent second lines of the plurality of second lines, and
- wherein the plurality of second openings are are aligned with the plurality of corresponding first lines.
A method of forming a pair of alignment patterns in an alignment pattern region of a semiconductor device comprising:
- forming a substrate including first material;
- removing a portion of the substrate in the alignment pattern region to form an opening in the substrate in the alignment pattern region;
- disposing second material to form a layer in the opening;
- removing a portion of the layer to form one or more openings in the layer;
- disposing third material to fill the one or more openings in the layer to form a first alignment pattern on a top surface of the layer, wherein the first alignment pattern comprises a plurality of first lines;
- and
- disposing a second alignment pattern over the first alignment pattern, wherein the second alignment pattern comprises a plurality of second lines between a plurality of openings wherein the plurality of openings are aligned with the plurality of corresponding first lines,
- wherein a difference between refractive indexes of the second material and the third material is greater than a difference between refractive indexes of the first material and the third material.
An apparatus comprising:
- a substrate comprising first material;
- a plurality of circuit regions;
- and
- a scribe line between adjacent circuit regions of the plurality of circuit regions, comprising:
- an alignment pattern region, comprising:
- a layer comprising second material in the substrate;
- a first alignment pattern comprising third material in the layer;
- and
- a second alignment pattern above the first alignment pattern,
- wherein a difference between refractive indexes of the second material and the third material is greater than a difference between refractive indexes of the first material and the third material,
- wherein the first alignment pattern comprises a plurality of first lines, wherein the plurality of first lines is in a top portion of the layer and in a corresponding plurality of first openings in the layer,
- wherein the second alignment pattern comprises a plurality of second lines and a plurality of second openings between adjacent second lines of the plurality of second lines, and
- wherein the plurality of second openings are are aligned with the plurality of corresponding first lines.
Dependencies are inferred from the claim text.