Semiconductor image-sensing structure having electro-optical modulator and image sensor device having the same
A semiconductor image-sensing structure includes a semiconductor substrate having a front side and a back side, a photo-sensing element disposed in the semiconductor substrate, a color filter disposed over the back side of the semiconductor substrate, and an electro-optical modulator disposed between the color filter and the photo-sensing element. The electro-optical modulator includes a first electrode, a second electrode over the first electrode, and a micro-lens between the first electrode and the second electrode.
1 . A semiconductor image-sensing structure, comprising:
a semiconductor substrate having a front side and a back side;
a first photo-sensing element and a second photo-sensing element adjacent to each other and disposed in the semiconductor substrate;
a logic device disposed on the front side of the semiconductor substrate;
a color filter disposed over the back side of the semiconductor substrate and overlapping the first photo-sensing element and the second photo-sensing element;
an electro-optical (EO) modulator disposed on the back side of the semiconductor substrate, between the first photo-sensing element and the color filter, wherein the electro-optical modulator comprises:
a first electrode;
a second electrode over the first electrode; and
a micro-lens between the first electrode and the second electrode; and
an anti-reflective coating (ARC) disposed between the electro-optical modulator and the back side of the semiconductor substrate,
wherein the first photo-sensing element is overlapped by the electro-optical modulator, and
the second photo-sensing element is free of overlapping the electro-optical modulator.
2 . The semiconductor image-sensing structure of claim 1 , further comprising a first passivation layer and a second passivation layer disposed between the color filter and the first photo-sensing element and between the color filter and the second photo-sensing element, wherein the electro-optical modulator is disposed between the first passivation layer and the second passivation layer.
3 . The semiconductor image-sensing structure of claim 1 , further comprising a second micro-lens disposed over the color filter, wherein the color filter is disposed between the second micro-lens and the electro-optical modulator.
4 . The semiconductor image-sensing structure of claim 3 , wherein a thickness of the micro-lens of the electro-optical modulator is equal to or less than a thickness of the second micro-lens.
5 . The semiconductor image-sensing structure of claim 1 , wherein the color filter has a first portion overlapping the first photo-sensing element and a second portion overlapping the second photo-sensing element.
6 . The semiconductor image-sensing structure of claim 5 , wherein the first portion of the color filter overlaps the electro-optical modulator, and the second portion of the color filter is free of overlapping the electro-optical modulator.
7 . The semiconductor image-sensing structure of claim 1 , wherein the micro-lens of the electro-optical modulator comprises various focal lengths in response to an electric field.
8 . The semiconductor image-sensing structure of claim 1 , wherein each of the first electrode and the second electrode comprises a transparent conductive material.
9 . An image sensor device, comprising:
a semiconductor substrate;
a first logic device and a second logic device disposed on a front side of the semiconductor substrate;
a first photo-sensing element and a second photo-sensing element disposed in the semiconductor substrate;
a third photo-sensing element adjacent to the first photo-sensing element and a fourth photo-sensing element adjacent to the second photo-sensing element disposed in the semiconductor substrate, wherein the first photo-sensing element and the second photo-sensing element are disposed between the third photo-sensing element and the fourth photo-sensing element;
a first color filter disposed over the first photo-sensing element and the third photo-sensing element, and a second color filter disposed over the second photo-sensing element and the fourth photo-sensing element on a back side of the semiconductor substrate, wherein the back side is opposite to the front side; and
a first electro-optical modulator disposed between the first photo-sensing element and the first color filter, and a second electro-optical modulator disposed between the second photo-sensing element and the second color filter, wherein each of the first electro-optical modulator and the second electro-optical modulator comprises:
a first electrode;
a second electrode over the first electrode; and
a micro-lens between the first electrode and the second electrode,
wherein the first electro-optical modulator and the second electro-optical modulator are separated from each other,
wherein first photo-sensing element is overlapped by the first electro-optical modulator and
the third photo-sensing element is free of overlapping the first electro-optical modulator, and
the second photo-sensing element is overlapped by the second electro-optical modulator and
the fourth photo-sensing element is free of overlapping the second electro-optical modulator.
10 . The image sensor device of claim 9 , wherein the first electro-optical modulator entirely covers the first photo-sensing element, and the second electro-optical modulator entirely covers the second photo-sensing element.
11 . The image sensor device of claim 9 , further comprising an isolation separating the first electro-optical modulator from the second electro-optical modulator.
12 . The image sensor device of claim 11 , further comprising an optical isolation grid separating the first color filter and the second color filter, wherein the optical isolation grid overlaps the isolation.
13 . The image sensor device of claim 9 , wherein the first color filter is configured to allow light beams within a first wavelength range to pass through, the second color filter is configured to allow light beams within a second wavelength range to pass through, and the first wavelength range and the second wavelength range are the same.
14 . The image sensor device of claim 9 , wherein the first color filter is configured to allow light beams within a first wavelength range to pass through, the second color filter is configured to allow light beams within a second wavelength range different from the first wavelength range to pass through.
15 . The image sensor device of claim 9 , further comprising:
a passivation layer disposed over the semiconductor substrate on the back side, wherein the first electro-optical modulator and the second electro-optical modulator are embedded in the passivation layer.
16 . The image sensor device of claim 15 , wherein the passivation layer comprises:
first portions overlapping the first photo-sensing element and the second photo-sensing element; and
second portions overlapping the third photo-sensing element and the fourth photo-sensing element,
wherein a thickness of the first portion is different from a thickness of the second portion.
17 . An image sensor device, comprising:
a color filter pattern comprising a first unit, a second unit, a third unit and a fourth unit arranged to form a square, wherein each of the first unit, the second unit, the third unit, and the fourth unit comprises four color filters arranged to form a square;
a first electro-optical modulator overlapped by a first color filter in each of the first unit, the second unit, the third unit and the fourth unit; and
a second electro-optical modulator overlapped by a second color filter in each of the first unit, the second unit, the third unit and the fourth unit,
wherein the first color filter and the second color filter are arranged left-to-right or arranged diagonally, and
wherein a third color filter and a fourth color filter in each of the first unit, the second unit, the third unit and the fourth unit are free of overlapping electro-optical modulator.
18 . The image sensor device of claim 17 , wherein the first color filter and the second color filter are configuration to allow light beams within a same wavelength range to pass through.
19 . The image sensor device of claim 17 , wherein the first color filter and the second color filter are configured to allow light beams within different wavelength ranges to pass through.
20 . The image sensor device of claim 17 , further comprising a plurality of photo-sensing elements, and wherein a number of the photo-sensing elements is equal to a number of the color filters in the color filter pattern.