Sensing structure, sensing chip including the same, and method for forming the same
A sensing structure, a sensing chip including the sensing structure, and method for forming the sensing structure are provided. The sensing structure includes a substrate and a metal layer. The substrate has a first recess. The metal layer is disposed on the substrate. The metal layer includes a first portion and a second portion. The first portion is disposed on a top surface of the substrate. The second portion is disposed in the first recess. The second portion includes a base portion and a protruding portion disposed on the base portion and extending away from the substrate. A gap is between the first portion and the protruding portion and surrounds the protruding portion, and the gap is in a range of 20 nm to 100 nm.
1 . A sensing structure, comprising:
a substrate having a first recess; and
a metal layer disposed on the substrate, comprising:
a first portion disposed on a top surface of the substrate; and
a second portion disposed in the first recess and comprising:
a base portion; and
a protruding portion disposed on the base portion and extending away from the substrate,
wherein a gap is between the first portion and the protruding portion and surrounds the protruding portion, and the gap is in a range of 20 nm to 100 nm,
wherein the substrate has a second recess adjacent to the first recess, and a pitch between the first recess and the second recess is in a range of 250 nm to 450 nm,
wherein the pitch is greater than a width of the base portion, and the width of the base portion is in a range of 120 nm to 250 nm, and
wherein the width of the base portion is greater than a width of the protruding portion, and the width of the protruding portion is in a range of 40 nm to 250 nm.
2 . The sensing structure as claimed in claim 1 , wherein a height of the top surface of the substrate to a bottom surface of the first recess is in a range of 20 nm to 100 nm.
3 . The sensing structure as claimed in claim 1 , wherein a height of the base portion is in a range of 20 nm to 100 nm.
4 . The sensing structure as claimed in claim 1 , wherein a height of the first portion is in a range of 20 nm to 100 nm.
5 . A sensing chip, comprising:
a filter array;
a carrier layer disposed on the filter array;
a light-blocking layer disposed on the carrier layer;
a polarizer disposed on the carrier layer; and
the sensing structure as claimed in claim 1 disposed on the light-blocking layer and the polarizer.
6 . The sensing chip as claimed in claim 5 , wherein the filter array comprises:
a first filter unit comprising a portion of a first filter and a second filter; and
a second filter unit disposed adjacent to the first filter unit and comprising a remaining portion of the first filter.
7 . The sensing chip as claimed in claim 6 , wherein the light-blocking layer is disposed directly above a boundary between the first filter unit and the second filter unit.
8 . The sensing chip as claimed in claim 6 , wherein the first filter is a band pass filter with a first wavelength range, the second filter is a band pass filter or a long pass filter with a second wavelength range, and the first wavelength range overlaps the second wavelength range.
9 . The sensing chip as claimed in claim 5 , wherein a height of the light-blocking layer is in a range of 90 nm to 250 nm.
10 . The sensing chip as claimed in claim 5 , wherein a width of the light-blocking layer is in a range of 80 nm to 150 nm.
11 . The sensing chip as claimed in claim 5 , wherein a height of the polarizer is in a range of 90 nm to 250 nm.
12 . The sensing chip as claimed in claim 5 , wherein a width of the polarizer is in a range of 80 nm to 150 nm.
13 . The sensing chip as claimed in claim 5 , wherein the polarizer comprises a first polarizer and a second polarizer, an angle between an extending direction of the first polarizer and an extending direction of the second polarizer is 45±5°, 90±5°, or 135±5°.