U.S. patent application number 17/008797 was filed with the patent office on 2020-12-24 for image sensor for compensating for signal difference between pixels.
The applicant listed for this patent is SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to MIN JANG, TAE SUB JUNG, DONG MIN KEUM, BUM SUK KIM, JUNG SAENG KIM, JONG HOON PARK.
Application Number | 20200404203 17/008797 |
Document ID | / |
Family ID | 1000005066381 |
Filed Date | 2020-12-24 |
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United States Patent
Application |
20200404203 |
Kind Code |
A1 |
JUNG; TAE SUB ; et
al. |
December 24, 2020 |
IMAGE SENSOR FOR COMPENSATING FOR SIGNAL DIFFERENCE BETWEEN
PIXELS
Abstract
An image sensor includes two or more phase-difference detection
pixels disposed adjacent to each other, a plurality of general
pixels spaced apart from the phase-difference detection pixels,
first and second peripheral pixels, and first to third light
shields. The first and second peripheral pixels are adjacent to the
phase-difference detection pixels, and between the phase-difference
detection pixels and the general pixels. The first light shield is
disposed in one of the general pixels and has a first width. The
second light shield extends into the first peripheral pixel from a
first area between the phase-difference detection pixels and the
first peripheral pixel, and has a second width different from the
first width. The third light shield extends into the second
peripheral pixel from a second area between the phase-difference
detection pixels and the second peripheral pixel, and has a third
width different from the first width.
Inventors: |
JUNG; TAE SUB; (YONGIN-SI,
KR) ; KEUM; DONG MIN; (YONGIN-SI, KR) ; KIM;
BUM SUK; (YONGIN-SI, KR) ; KIM; JUNG SAENG;
(YONGIN-SI, KR) ; PARK; JONG HOON; (YONGIN-SI,
KR) ; JANG; MIN; (YONGIN-SI, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG ELECTRONICS CO., LTD. |
SUWON-SI |
|
KR |
|
|
Family ID: |
1000005066381 |
Appl. No.: |
17/008797 |
Filed: |
September 1, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16426445 |
May 30, 2019 |
10819929 |
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17008797 |
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15948756 |
Apr 9, 2018 |
10341595 |
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16426445 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04N 5/374 20130101;
H04N 5/3696 20130101; H01L 27/14605 20130101; H04N 5/36961
20180801; H01L 27/14645 20130101; H01L 27/1464 20130101; H01L
27/1463 20130101; H01L 27/14627 20130101; H01L 27/14621 20130101;
H01L 27/14636 20130101; H01L 27/14623 20130101 |
International
Class: |
H04N 5/369 20060101
H04N005/369; H04N 5/374 20060101 H04N005/374; H01L 27/146 20060101
H01L027/146 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 10, 2017 |
KR |
10-2017-0101639 |
Claims
1. An image sensor comprising: a first phase-difference detection
pixel and a second phase-difference detection pixel; a first
general pixel spaced apart from the first and second
phase-difference detection pixels; a first peripheral pixel
adjacent to the first phase-difference detection pixel between the
first phase-difference detection pixel and the first general pixel;
a first microlens disposed on the first and second phase-difference
detection pixels; a second microlens on the first general pixel;
and a third microlens on the first peripheral pixel, wherein a size
of the first to third microlenses are different from each
other.
2. The image sensor of claim 1, further comprising: a second
peripheral pixel disposed from the first phase-difference detection
pixel in a first direction; and a third peripheral pixel disposed
from the second phase-difference detection pixel in the first
direction, wherein the first microlens expands toward a space
between the second and third peripheral pixels.
3. The image sensor of claim 2, further comprising: a fourth
peripheral pixel disposed from the second phase-difference
detection pixel; and a fourth microlens on the fourth peripheral
pixel, wherein a size of the fourth microlens is different from the
size of the third microlens.
4. The image sensor of claim 2, wherein the second peripheral pixel
includes a red color filter, and the third peripheral pixel
includes a green color filter.
5. The image sensor of claim 4, wherein the first phase-difference
detection pixel includes a green color filter.
6. The image sensor of claim 5, further comprises a second general
pixel provide in a diagonal direction from the first
phase-difference detection pixel, and wherein the second general
pixel includes a green color filter.
7. The image sensor of claim 6, further comprises a device
separation film formed between the second peripheral pixel and the
third peripheral pixel.
8. The image sensor of claim 7, further comprises a substrate in
which the second and third peripheral pixels are formed, wherein
the substrate has a first surface and a second surface opposite to
the first surface, wherein a plurality of microlenses are formed on
the second surface, and wherein the device separation film is
formed from the first surface to the second surface.
9. The image sensor of claim 7, further comprises a substrate in
which the second and third peripheral pixels are formed, wherein
the substrate has a first surface and a second surface opposite to
the first surface, wherein the device separation film contacts with
both the first and second surfaces.
10. The image sensor of claim 7, further comprises a substrate in
which the second and third peripheral pixels are formed, wherein
the substrate has a first surface and a second surface opposite to
the first surface, wherein a plurality of microlenses are formed on
the second surface, and wherein the device separation film is
formed from the second surface to the first surface.
11. The image sensor of claim 7, further comprises a light shield
on the device separation film.
12. The image sensor of claim 10, further comprises a light shield
on the device separation film.
13. An image sensor, comprising: a first phase-difference detection
pixel and a second phase-difference detection pixel directly
adjacent to the first phase-difference detection pixel in a first
direction, the first and second phase-difference detection pixels
being formed in a first row; a first peripheral pixel disposed from
the first phase-difference detection pixel in a second direction
perpendicular to the first direction; a second peripheral pixel
disposed from the second phase-difference detection pixel in the
second direction; and a plurality of microlens formed on the first
and second phase-difference detection pixels, wherein the first and
second peripheral pixels are formed in a second row next to the
first row, wherein the microlens expands toward a space between the
first and second peripheral pixels so that a part of the microlens
is formed in the second row, wherein the first and second
phase-difference detection pixels are surrounded by a plurality of
adjacent pixels, wherein the plurality of adjacent pixels includes
the first and second peripheral pixels, and wherein the plurality
of adjacent pixels has at least three green filters, at least one
red filter, and at least one blue filter.
14. The image sensor of claim 13, wherein the plurality of adjacent
pixels further includes a third peripheral pixel and a fourth
peripheral pixel in a third row next to the second row, and wherein
the microlens expands toward a space between the third and fourth
peripheral pixels so that a part of the microlens is formed in the
third row.
15. The image sensor of claim 14, wherein the first
phase-difference detection pixel includes a green filter.
16. The image sensor of claim 15, further comprises a first general
pixel provide in a diagonal direction from the first
phase-difference detection pixel, and wherein the first general
pixel includes a green filter.
17. The image sensor of claim 16, further comprises a device
separation film formed between the first peripheral pixel and the
second peripheral pixel.
18. The image sensor of claim 13, wherein the plurality of adjacent
pixels has six pixels, at right, left, upper and lower side of the
first and second phase-difference detection pixels.
19. The image sensor of claim 18, the six pixels has three green
filters, one red filter, one blue filter, and one filter of
selected from green, blue and red.
20. The image sensor of claim 13, wherein the plurality of adjacent
pixels includes one red filter and one blue filter formed in
different rows.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This U.S. non-provisional patent application is a
continuation application of U.S. patent application Ser. No.
16/426,445 filed May 30, 2019, which is a continuation application
of U.S. patent application Ser. No. 15/948,756, filed on Apr. 9,
2018, which issued as U.S. Pat. No. 10,341,595 on Jul. 2, 2019,
which claims priority under 35 U.S.C. .sctn. 119 to Korean Patent
Application No. 10-2017-0101639, filed on Aug. 10, 2017, the
disclosures of which are incorporated by reference herein in their
entireties.
TECHNICAL FIELD
[0002] Exemplary embodiments of the present disclosure relate to an
image sensor for compensating for a signal difference between
pixels.
DISCUSSION OF THE RELATED ART
[0003] Image sensors may have a phase-difference detection
autofocus (PDAF) function which analyzes contrast of an acquired
image, and automatically adjusts a focus of an image sensor. A
method of replacing some pixels with phase-difference detection
pixels may be used in an image sensor. Phase-difference detection
pixels include phase-difference detection sensors, and as a result,
an amount of transmission of light incident on the phase-difference
detection pixels may be different from that of light incident on
imaging pixels. Thus, the amount of transmission of light incident
on peripheral pixels is affected by the amount of transmission of
light incident on the phase-difference detection pixels. The
quality of an image may be degraded by a signal difference due to
different amounts of transmission of light incident on imaging
pixels, which are adjacent to phase-difference detection pixels,
and other imaging pixels.
SUMMARY OF THE INVENTION
[0004] Exemplary embodiments of the present disclosure are directed
to providing an image sensor including a unit pixel array that
compensates for a change in signals of peripheral pixels disposed
adjacent to phase-difference detection pixels.
[0005] According to an exemplary embodiment of the present
disclosure, an image sensor includes two or more phase-difference
detection pixels disposed adjacent to each other, a plurality of
general pixels spaced apart from the phase-difference detection
pixels, first and second peripheral pixels, and first to third
light shields. The first peripheral pixel and the second peripheral
pixel are adjacent to the phase-difference detection pixels, and
between the phase-difference detection pixels and the general
pixels. The first light shield is disposed in one of the general
pixels and has a first width. The second light shield extends into
the first peripheral pixel from a first area between the
phase-difference detection pixels and the first peripheral pixel,
and has a second width different from the first width. The third
light shield extends into the second peripheral pixel from a second
area between the phase-difference detection pixels and the second
peripheral pixel, and has a third width different from the first
width.
[0006] According to an exemplary embodiment of the present
disclosure, an image sensor includes two or more phase-difference
detection pixels disposed adjacent to each other, a plurality of
general pixels spaced apart from the phase-difference detection
pixels, first and second peripheral pixels, a first light shield, a
plurality of second light shields, and a plurality of third light
shields. The first peripheral pixel and the second peripheral pixel
are adjacent to the phase-difference detection pixels, and between
the phase-difference detection pixels and the general pixels. The
first light shield is disposed in one of the general pixels and has
a first width. The plurality of second light shields extend into
the first peripheral pixel from a first area between the first
peripheral pixel and first additional pixels adjacent to the first
peripheral pixel, and have a second width different from the first
width. The plurality of third light shields extend into the second
peripheral pixel from a second area between the second peripheral
pixel and second additional pixels adjacent to the second
peripheral pixel, and have a third width different from the first
width.
[0007] According to an exemplary embodiment of the present
disclosure, an image sensor includes a unit pixel array having a
plurality of pixels. The image sensor includes two or more
phase-difference detection pixels disposed adjacent to each other,
a plurality of general pixels spaced apart from the
phase-difference detection pixels and including a first light
shield having a first width, and two or more peripheral pixels
adjacent to the phase-difference detection pixels. The two or more
peripheral pixels include a second light shield having a second
width different from the first width at one or more boundaries from
among boundaries between the two or more peripheral pixels and the
phase-difference detection pixels, the general pixels, and
additional peripheral pixels adjacent to the two or more peripheral
pixels.
[0008] According to an exemplary embodiment of the present
disclosure, an image sensor includes a first phase-difference
detection pixel including a first light shield having a first
width, a second phase-difference detection pixel disposed adjacent
to the first phase-difference detection pixel and including a
second light shield having the first width, a first peripheral
pixel disposed adjacent to the first phase-difference detection
pixel and including a third light shield having a second width
different from the first width, and a second peripheral pixel
disposed adjacent to the second phase-difference detection pixel
and including a fourth light shield having the second width. The
first and second phase-difference detection pixels include a
phase-difference detection sensor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The above and other features of the present disclosure will
become more apparent to those of ordinary skill in the art by
describing in detail exemplary embodiments thereof with reference
to the accompanying drawings, in which:
[0010] FIGS. 1, 3, 4, 5, 7, 9, 11, 13, 15, 17, 19, 20, 24 to 33,
37, and 42 are views illustrating unit pixel arrays according to
exemplary embodiments of the present disclosure.
[0011] FIGS. 2, 6, 8, 10, 12, 14, 16, 18, 21 to 23, 34 to 36, 38 to
41, and 43 to 48 are views illustrating cross-sectional structures
of the unit pixel arrays according to exemplary embodiments of the
present disclosure.
[0012] FIGS. 49 to 54 are cross-sectional views illustrating a
method of manufacturing a unit pixel array according to an
exemplary embodiment of the present disclosure.
[0013] FIG. 55 is an equivalent circuit diagram of a unit pixel
according to an exemplary embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0014] Spatially relative terms, such as "beneath", "below",
"lower", "under", "above", "upper", etc., may be used herein for
ease of description to describe one element or feature's
relationship to another element(s) or feature(s) as illustrated in
the figures. It will be understood that the spatially relative
terms are intended to encompass different orientations of the
device in use or operation in addition to the orientation depicted
in the figures. For example, if the device in the figures is turned
over, elements described as "below" or "beneath" or "under" other
elements or features would then be oriented "above" the other
elements or features. Thus, the exemplary terms "below" and "under"
can encompass both an orientation of above and below.
[0015] It will be understood that the terms "first," "second,"
"third," etc., are used herein to distinguish one element from
another, and the elements are not limited by these terms. Thus, a
"first" element in an exemplary embodiment may be described as a
"second" element in another exemplary embodiment. Further, when one
value (e.g., a thickness) is described as being about equal to or
about the same as another value, it is to be understood that the
values are equal to each other within a measurement error, or if
measurably unequal, are close enough in value to be functionally
equal to each other as would be understood by a person having
ordinary skill in the art.
[0016] A complementary metal-oxide semiconductor (CMOS) image
sensor may include a unit pixel array and a logic circuit. The unit
pixel array performs photoelectric transformation on incident light
to generate a voltage signal, and the logic circuit processes and
outputs the voltage signal. The unit pixel array may be formed by
arranging tetragonal unit pixels in a lattice form.
[0017] The unit pixel array of the CMOS image sensor may include a
color filter layer and a microlens layer disposed on a
photoelectric transformation layer that includes photodiodes.
Incident light collected through the microlens layer is filtered
through the color filter layer, and only optical signals having
frequencies in a predetermined range pass through the photoelectric
transformation layer. The photoelectric transformation layer may be
a substrate including photo detecting devices such as, for example,
photodiodes. The photo detecting device determines light intensity
in each frequency band and obtains color image data (e.g., red (R),
green (G), and blue (B) data) from the intensity.
[0018] The CMOS image sensor may have a phase-difference detection
autofocus (PDAF) function. Some of the unit pixels in the CMOS
image sensor may be phase-difference detection pixels used for
autofocusing. Imaging pixels adjacent to the phase-difference
detection pixels are referred to as peripheral pixels. Imaging
pixels not adjacent to the phase-difference detection pixels are
referred to as general pixels. The phase-difference detection pixel
may be distributed at a ratio of 1/16, 1/32, 1/64, etc. of the
total number of pixels. A phase-difference detection pixel is a
pixel that includes a phase-difference detection sensor, unlike the
peripheral pixels and general pixels. A moving direction and
distance of a lens of an imaging device may be calculated by
analyzing a phase difference of image data obtained from
photodiodes of the phase-difference detection pixels.
[0019] Hereinafter, unit pixel arrays of an image sensor according
to exemplary embodiments of the present disclosure will be
described with reference to the accompanying drawings.
[0020] FIG. 1 is a view illustrating a unit pixel array according
to an exemplary embodiment of the present disclosure. FIG. 2 is a
view taken along line I-I' of FIG. 1 and illustrating a
cross-sectional structure of the unit pixel array according to an
exemplary embodiment of the present disclosure.
[0021] The unit pixel array according to the exemplary embodiment
of the present disclosure will be described with reference to the
drawing including a unit pixel array having 5.times.5 pixels.
However, exemplary embodiments of the present disclosure are not
limited thereto. For example, exemplary embodiments may include a
unit pixel array having a different number of pixels.
[0022] Referring to FIG. 1, some pixels in the unit pixel array may
be phase-difference detection pixels AF. Two adjacent pixels may be
a pair of phase-difference detection pixels AF1 and AF2. Two
phase-difference detection pixels belonging to a pair are adjacent
to each other, have one side thereof in common, and may be disposed
to be vertically or laterally adjacent to each other in a lattice
pixel array. One pixel of the two adjacent pixels refers to a first
phase-difference detection pixel AF1 or 111, and the other pixel
thereof refers to a second phase-difference detection pixel AF2 or
112. According to exemplary embodiments, the two phase-difference
detection pixels AF1 and AF2 may be directly adjacent to each other
(e.g., they may be described as having one side thereof in common,
or as including two sides that directly contact each other), or the
two phase-difference detection pixels AF1 and AF2 may be indirectly
adjacent to each other and have intervening elements (e.g., other
pixels) disposed therebetween.
[0023] Imaging pixels, which are disposed adjacent to one of the
first phase-difference detection pixel 111 and the second
phase-difference detection pixel 112, refer to peripheral pixels.
The peripheral pixels may be disposed to be in contact with one
side of the first or second phase-difference detection pixels 111
and 112. The peripheral pixels may be pixels laterally and
vertically disposed from the first or the second phase-difference
detection pixel 111 or 112. As shown in the exemplary embodiment of
FIG. 1, the peripheral pixel disposed at a left side of the first
phase-difference detection pixel 111 is a left peripheral pixel
121, and the peripheral pixel disposed at a right side of the
second phase-difference detection pixel 112 is a right peripheral
pixel 122.
[0024] When one side is disposed to be in contact with the
phase-difference detection pixel and the peripheral pixel, the one
side in contact with both the pixels is referred to as an adjacent
side of the peripheral pixel. The peripheral pixels may be pixels
diagonally disposed from the phase-difference detection pixels 111
and 112. The peripheral pixels refer to pixels at locations at
which an amount of received light thereof is changed due to an
influence of the phase-difference detection pixels AF1 and AF2.
[0025] General pixels 130 refer to pixels at locations at which an
amount of received light thereof is not changed due to the
influence of the phase-difference detection pixels AF1 and AF2.
That is, regardless of the influence of the phase-difference
detection pixels AF1 and AF2, an amount of received light at the
general pixels 130 is not changed, unlike the peripheral pixels.
For example, imaging pixels excluding the first phase-difference
detection pixel 111, the second phase-difference detection pixel
112, the left peripheral pixel 121, and the right peripheral pixel
122 are the general pixels 130, and the amount of received light at
these pixels is not affected by the phase-difference detection
pixels AF1 and AF2.
[0026] Referring to FIG. 2, the unit pixel array may include a
color filter layer 100, a microlens layer 200, and a photoelectric
transformation layer 300. One photodiode of the photoelectric
transformation layer 300 may correspond to each pixel. The color
filter layer 100 and the microlens layer 200 may be stacked on the
photoelectric transformation layer 300.
[0027] The color filter layer 100 may be formed as a color filter
array and may include color filters 140 and light shields 150. A
Bayer arrangement including red (R), green (G), and blue (B) may be
applied as the color filter array. However, exemplary embodiments
of the present disclosure are not limited thereto, and the color
filter array may be used with a different arrangement. One filter
among R, G, and B filters arranged by the Bayer arrangement may be
included in the first phase-difference detection pixel 111 and the
second phase-difference detection pixel 112. For example, the first
phase-difference detection pixel 111 may include a B filter, and
the second phase-difference detection pixel 112 may include a G
filter. The first phase-difference detection pixel 111 and the
second phase-difference detection pixel 112 may have the same color
filter. For example, both phase-difference detection pixels 111 and
112 forming a pair may have G filters. The color filter array may
be based on a complementary color system (e.g., a system using
magenta, green, cyan, and yellow).
[0028] The pair of phase-difference detection pixels 111 and 112
disposed adjacent to each other may use the same color filters 140,
e.g., G filters. When both the first and second phase-difference
detection pixels 111 and 112 include the G filters, defective pixel
correction of the color filter layer 100 may be efficiently
performed.
[0029] The color filters 140 included in the phase-difference
detection pixels 111 and 112 may be disposed for convenience of a
process of manufacturing a color filter array in addition to having
a purpose of color implementation. For example, the
phase-difference detection pixels 111 and 112 may not include the
color filters 140 and may include white (W) filters or transparent
filters. When the phase-difference detection pixels 111 and 112 use
the W filters, an amount of received light thereof may be
increased. As the amount of received light of the phase-difference
detection pixels 111 and 112 is increased, an amount of received
light of the peripheral pixel may be affected by scattering and
dispersing subject light. Even when the G filters are disposed in
both phase-difference detection pixels 111 and 112 belonging to a
pair, since an amount of received light of the G filter is greater
than that of another color filter(s), the amount of received light
of the peripheral pixel may be affected by the pair of
phase-difference detection pixels 111 and 112. For example, the
amount of received light of the peripheral pixels 121 and 122
adjacent to the phase-difference detection pixels 111 and 112 may
be greater than that of the general pixels 130 including color
filters having the same wavelengths as the peripheral pixels 121
and 122. When the amount of received light is changed, amplitudes
of signals of the peripheral pixel and the general pixel 130 are
different, and thus, the quality of an image may be degraded.
[0030] The light shields 150 may be provided at boundaries between
the pixels to prevent light incident on each of the pixels from
being transmitted to the photoelectric transformation layer 300 of
other pixels. The light shield 150 may block subject light from
passing through the color filter 140 and being transmitted to the
photoelectric transformation layer 300. For example, the light
shield 150 may be formed of an opaque metal. The light shields 150
may be formed in a lattice shape along the boundaries between the
pixels. The light shields 150 may be formed to have the same width
in a direction toward each pixel from a boundary between adjacent
pixels. The light shield 150 may be integrally formed by a
patterning process.
[0031] The microlens layer 200 may be disposed on the color filter
layer 100, and a microlens may be disposed to correspond to each
pixel. As shown in FIG. 2, microlenses 203 including a lower
portion having the same area as an upper portion of a general pixel
may be disposed on the general pixels 130. The microlens 201 may be
disposed on each of the left peripheral pixel 121 and the right
peripheral pixel 122. One microlens 202 may be disposed on the pair
of phase-difference detection pixels 111 and 112. For example, the
one microlens 202 may be shared by the adjacent phase-difference
detection pixels 111 and 112. A size of the microlens 202 disposed
on the pair of phase-difference detection pixels 111 and 112 may be
smaller than that of an upper portion area of the pair of
phase-difference detection pixels 111 and 112. For example, as
shown in FIG. 2, the size of the portion of the microlens 202 that
contacts the upper portion area of the pair of phase-difference
detection pixels 111 and 112 may be smaller than the size of the
upper portion area of the pair of phase-difference detection pixels
111 and 112. For example, in an exemplary embodiment, the boundary
of the upper portion area of the pair of phase-difference detection
pixels 111 and 112 may expand beyond the boundary of the portion of
the microlens 202 that contacts the pair of phase-difference
detection pixels 111 and 112.
[0032] The microlens 201 disposed on each of the peripheral pixels
121 and 122 of the pair of phase-difference detection pixels 111
and 112 may have a size expanding in a direction toward the
phase-difference detection pixels 111 and 112. For example, as
shown in FIG. 2, in an exemplary embodiment, the microlens 202
disposed on the pair of phase-difference detection pixels 111 and
112 does not cover the entirety of the pair of phase-difference
detection pixels 111 and 112, and the microlens 201 disposed on
each of the peripheral pixels 121 and 122 extends onto the pair of
phase-difference detection pixels 111 and 112 in the area not
covered by the microlens 202. The microlenses 201, 202, and 203 may
be on-chip lenses. According to the exemplary embodiment of the
present disclosure shown in FIGS. 1 and 2, a phase difference may
be detected by a shared-on-chip lens method.
[0033] As denoted by arrows in FIG. 2, light passing through the
one microlens 202 may pass through each of the first and second
phase-difference detection pixels 111 and 112 and may be incident
on the photoelectric transformation layer 300 of the first and
second phase-difference detection pixels 111 and 112. An autofocus
function may be performed by detecting a phase difference of the
photoelectric transformation layer 300 of each of the
phase-difference detection pixels 111 and 112 forming a pair and
moving a location of an imaging lens of an image sensor.
[0034] In exemplary embodiments, even when the one microlens 202
having a size corresponding to two pixels is formed, the size of
the microlens 202 may not exactly correspond to the size of two
microlenses 203 in some cases. For example, as shown in the
exemplary embodiment of FIG. 2, a planar size of the microlens 202
may be smaller than a size of upper surfaces of the pair of
phase-difference detection pixels 111 and 112. For example, the
portion of the microlens 202 that contacts the upper surfaces of
the pair of phase-difference detection pixels 111 and 112 may be
smaller than the upper surfaces of the pair of phase-difference
detection pixels 111 and 112. A planar size of each of the
microlenses 201 and 201 of the peripheral pixels 121 and 122 may be
greater than a size of an upper surface of each of the peripheral
pixels 121 and 122. For example, the portion of each of the
microlenses 201 and 201 that contacts the upper surface of each of
the peripheral pixels 121 and 122 may be greater than the upper
surface of each of the peripheral pixels 121 and 122, and may
extend onto the upper surfaces of the pair of phase-difference
detection pixels 111 and 112. Since the microlenses 201 and 202
have different sizes and thus have different locations on the color
filter layer 100, an amount of received light of the peripheral
pixel may be increased. Due to a signal difference between the
peripheral pixels 121 and 122 and the general pixels 130, the
quality of an image may be degraded. For example, the microlens 201
included in the left peripheral pixel 121 of FIG. 2 is disposed to
protrude toward and onto the first phase-difference detection pixel
111. Some light incident on a left upper end of the first
phase-difference detection pixel 111 may be collected through the
microlens 201, as denoted by the dotted line arrow, and may be
incident on the left peripheral pixel 121. An amount of received
light of the left peripheral pixel 121 becomes greater than an
amount of received light of the general pixel 130, and thus, a
signal difference may occur between pixels having the same color
filter.
[0035] When the phase-difference detection pixels are located at an
edge of the pixel arrays, an incidence angle of light transmitted
from an imaging lens may be increased. In the case in which the
peripheral pixel 121 is disposed at the edge of the pixel arrays, a
size of the microlens 201 may expand toward the phase-difference
detection pixels 111 and 112. In this case, a location of the
microlens 201 on the peripheral pixel 121 may also be moved toward
the phase-difference detection pixels 111 and 112. In such a
structure, an amount of received light of the peripheral pixel 121
may be significantly increased due to the size and location of the
microlens 201 on the peripheral pixel 121 and an incidence angle of
light passing through the imaging lens. Further, since a signal of
the peripheral pixel 121 is different from a signal of the general
pixel 130, the quality of an image may be degraded.
[0036] According to an exemplary embodiment of the present
disclosure, the amount of received light of the peripheral pixel
121 may be adjusted by increasing or decreasing a width of each of
the light shields 150 disposed at the adjacent sides which are
boundaries of the phase-difference detection pixels 111 and
112.
[0037] Referring to FIG. 1, in the unit pixel array having
5.times.5 pixels, a pixel at a third row and a second column and a
pixel at the third row and a third column form the pair of
phase-difference detection pixels 111 and 112. The pixel at the
third row and the second column refers to the first
phase-difference detection pixel 111, and the pixel at the third
row and the third column refers to the second phase-difference
detection pixel 112. A pixel at the third row and a first column
disposed at a left side of the first phase-difference detection
pixel 111 refers to the left peripheral pixel 121. A pixel at the
third row and a fourth column disposed at a right side of the
second phase-difference detection pixel 112 refers to the right
peripheral pixel 122. The left peripheral pixel 121 may include a B
filter, and the right peripheral pixel 122 may include a G filter.
Each of the first phase-difference detection pixel 111 and the
second phase-difference detection pixel 112 may include G filters.
In an exemplary embodiment, the light shield 150 is not disposed
between the first phase-difference detection pixel 111 and the
second phase-difference detection pixel 112.
[0038] When an amount of received light of the phase-difference
detection pixels 111 and 112 is greater or smaller than that of the
general pixel 130, an amount of received light of the peripheral
pixels 121 and 122 affected by the phase-difference detection
pixels 111 and 112 may be compensated for by increasing or
decreasing a width of some of the light shields 150 disposed at the
peripheral pixels 121 and 122. For example, as shown in FIG. 1, an
extending width of the light shield 150 at the adjacent side of
each of the left peripheral pixel 121 and the right peripheral
pixel 122 may be adjusted. When each of the pixels is assumed to
have a square shape, the width of the light shield 150 of the
adjacent side, which is in contact with the phase-difference
detection pixels 111 and 112, from among four sides forming outer
sides of each peripheral pixel 121 and 122, may be set to be
greater than the width of the light shield 150 disposed at each of
the other pixels or sides. When the width of the light shield 150
is increased, light scattered or dispersed by the phase-difference
detection pixels 111 and 112 can be prevented from being
transmitted to the peripheral pixels 121 and 122 adjacent to the
phase-difference detection pixels 111 and 112. In addition, an
increase in the amount of light received by the peripheral pixels
121 and 122 can be suppressed by scattering or dispersing light
incident on the phase-difference detection pixels 111 and 112.
[0039] Referring to FIG. 2, which is a cross-sectional view taken
along line I-I' of FIG. 1, a width L1 of each of the light shields
150 extending in the general pixel 130 and the phase-difference
detection pixels 111 and 112 from boundaries between the general
and phase-difference detection pixels 130, 111, and 112 and pixels
adjacent thereto may be constant. The width L1 refers to a
reference width. The width of the light shield 150 of each of the
peripheral pixels 121 and 122 may be adjusted by increasing or
decreasing the reference width L1. For example, as shown in FIG. 2,
a width L2 of the light shield 150 extending in the left peripheral
pixel 121 from the adjacent side, which is a boundary between the
left peripheral pixel 121 and the first phase-difference detection
pixel 111, may be greater than the reference width L1, which is the
width of the light shield 150 of the general pixel 130. The width
L2 of the light shield 150 extending in the right peripheral pixel
122 from the adjacent side between the right peripheral pixel 122
and the second phase-difference detection pixel 112 may also be
greater than the reference width L1.
[0040] Referring to FIG. 2, in an exemplary embodiment, when the
width of the light shield 150 of the adjacent side of the left
peripheral pixel 121 is the reference width L1, light scattered or
dispersed by the first phase-difference detection pixel 111 is not
blocked by the light shield 150 of the adjacent side of the left
peripheral pixel 121. The light scattered or dispersed by the first
phase-difference detection pixel 111 may be collected in the color
filter layer 100 of the left peripheral pixel 121. When the width
L2 of the light shield 150 of the adjacent side of the left
peripheral pixel 121 is increased to be greater than the reference
width L1, the amount of light received by the left peripheral pixel
121 may be decreased because the light may be further blocked due
to an increased width L2-L1. The general pixel 130, through which
the same wavelength as a wavelength passing through the left
peripheral pixel 121 passes, is disposed at the third row and a
fifth column of the pixel array of FIG. 1. The general pixel 130 at
the third row and the fifth column is not affected by the
phase-difference detection pixels 111 and 112. The peripheral
pixels 121 and 122 may be controlled to have the same
light-receiving rate as the general pixel 130 at the third row and
the fifth column by adjusting the width of the light shield 150 of
the adjacent side of the left peripheral pixel 121. Since the
light-receiving rates of peripheral pixels 121 and 122 and the
general pixel 130 are controlled to be the same, quality
degradation of an image due to a signal difference between pixels
having the same wavelength can be prevented or reduced.
[0041] Referring to FIGS. 1 and 2, in an exemplary embodiment, two
phase-difference detection pixels 111 and 112 are disposed adjacent
to each other. In an exemplary embodiment, more than two
phase-difference detection pixels may be disposed adjacent to each
other. A plurality of general pixels 130 is spaced apart from the
phase-difference detection pixels 111 and 112. A first peripheral
pixel 121 and a second peripheral pixel 122 are disposed adjacent
to the phase-difference detection pixels 111 and 112, and between
the phase-difference detection pixels 111 and 112 and the general
pixels 130.
[0042] A first light shield 150 is disposed in one of the general
pixels 130. The first light shield 150 disposed in the one of the
general pixels 150 has a first width L1. A second light shield 150
extends into the first peripheral pixel 121 from a first area
between the phase-difference detection pixels 111 and 112 and the
first peripheral pixel 121. The second light shield 150 extending
into the first peripheral pixel 121 has a second width L2 different
from the first width L1. A third light shield 150 extends into the
second peripheral pixel 122 from a second area between the
phase-difference detection pixels 111 and 112 and the second
peripheral pixel 122. The third light shield 150 extending into the
second peripheral pixel 122 has a third width.
[0043] Since the second width of the second light shield 150
extending into the first peripheral pixel 121 and the third width
of the third light shield 150 extending into the second peripheral
pixel 122 are substantially equal to each other in the exemplary
embodiment of FIGS. 1 and 2, both the second and third widths are
represented by L2 in FIG. 2. However, exemplary embodiments are not
limited thereto. For example, as will be detailed in the exemplary
embodiments described below and shown in the accompanying figures,
in addition to the second and third widths being substantially
equal to each other, according to exemplary embodiments, each of
the second width and the third width may be greater than the first
width, each of the second width and the third width may be smaller
than the first width, the second width may be different from the
third width, each of the second width and the third width may be
greater than the first width, each of the second width and the
third width may be smaller than the first width, and the second
width may be greater than the first width and the third width may
be smaller than the first width.
[0044] FIGS. 3 and 4 are views illustrating shapes of microlenses
201, 202, and 203 of a unit pixel array according to an exemplary
embodiment of the present disclosure.
[0045] The shapes of the microlenses may be different according to
an arrangement of phase-difference detection pixels 111 and 112,
materials of the microlenses 201, 202, and 203, an annealing
temperature, etc. A light-receiving rate of a peripheral pixel may
be changed by the shape of the microlens. For example, a microlens
layer 200 may be formed on a color filter layer 100 of the unit
pixel array, as shown in FIG. 2. The microlenses 201, 202, and 203
included in the microlens layer 200 may have various shapes
including a convex portion. When the phase-difference detection
pixels 111 and 112 adjacent to each other and belonging to a pair
share one microlens 202, the microlens 202 may have a part of an
oblong elliptical shape according to a shape of the pair of
phase-difference detection pixels 111 and 112. For example, the
microlens 202 may have an elongated oval shape that spans the pair
of phase-difference detection pixels 111 and 112.
[0046] Referring to FIG. 3, the microlens 202 corresponding to the
pair of phase-difference detection pixels 111 and 112 may have an
elliptical cut surface. Sizes in direction of long and short axes
of the elliptical shape may be decreased according to, for example,
a surface tension of silicon dioxide (SiO.sub.2), which is a
material that may be used to form the microlens. Sizes of the
microlenses 201 of peripheral pixels 121 and 122 may be increased
toward adjacent sides thereof according to a change in size of the
microlens 202 disposed on the pair of phase-difference detection
pixels 111 and 112.
[0047] Referring to FIG. 4, a size of the one microlens 202 formed
on the pair of phase-difference detection pixels 111 and 112 may
expand toward a space between the one microlens 202 and a pixel
adjacent thereto, or a location thereof may be moved toward the
space.
[0048] Since a curvature of the one microlens 202 formed on the
pair of phase-difference detection pixels 111 and 112 increases as
a width in a long axis direction thereof decreases, an autofocus
characteristic thereof can be improved. The sizes of the
microlenses 201 on the peripheral pixels 121 and 122 adjacent to
the phase-difference detection pixels 111 and 112 in the long axis
direction may expand toward the adjacent sides thereof. When the
size of the microlens increases, an amount of light received
thereby increases, and thus a width of a light shield 150 of the
adjacent side may increase. The width of the light shield 150 of
the adjacent side may be set to be greater than a reference width
L1, which is a width of a light shield 150 of a general pixel
130.
[0049] Hereinafter, for convenience of explanation, a further
description of elements previously described with reference to
FIGS. 1 and 2 may be omitted.
[0050] FIG. 5 is a view illustrating a unit pixel array according
to an exemplary embodiment of the present disclosure. FIG. 6 is a
view taken along line I-I' of FIG. 5 and illustrating a
cross-sectional structure of the unit pixel array according to an
exemplary embodiment of the present disclosure.
[0051] The exemplary embodiment in FIG. 5 is the same as the
exemplary embodiment in FIG. 1 except that light shields 150 of
adjacent sides of a left peripheral pixel 121 disposed at a left
side of a first phase-difference detection pixel 111 and a right
peripheral pixel 122 disposed at a right side of a second
phase-difference detection pixel 112 have different widths.
[0052] The peripheral pixels 121 and 122 disposed at the right and
left sides of the pair of phase-difference detection pixels 111 and
112 may include color filters 140 having different wavelengths. An
amount of light received by the peripheral pixels 121 and 122 may
be different according to the wavelength of the color filter
included in the peripheral pixel. Referring to FIG. 5, the left
peripheral pixel 121 adjacent to the left side of the first
phase-difference detection pixel 111 includes a B filter. The right
peripheral pixel 122 adjacent to the right side of the second
phase-difference detection pixel 112 includes a G filter. The B
filter has a relatively shorter wavelength and a greater amount of
received light than the G filter. A width of a light shield 150 of
the left peripheral pixel 121 including the B filter may be greater
than that of the right peripheral pixel 122 having the G
filter.
[0053] Referring to FIG. 6, a width L3 of the light shield 150 of
the adjacent side of the left peripheral pixel 121 is greater than
a width L4 of the light shield 150 of the adjacent side of the
right peripheral pixel 122. Each of the widths L3 and L4 of the
light shields 150 of the adjacent sides of the peripheral pixels
121 and 122 may be greater than a reference width L1.
[0054] FIG. 7 is a view illustrating a unit pixel array according
to an exemplary embodiment of the present disclosure. FIG. 8 is a
view taken along line II-IF of FIG. 7 and illustrating a
cross-sectional structure of the unit pixel array according to an
exemplary embodiment of the present disclosure.
[0055] The exemplary embodiment of FIG. 7 is the same as the
exemplary embodiment of FIG. 1 except that peripheral pixels are
disposed above and below phase-difference detection pixels 111 and
112. A pixel at a second row and a second column above the first
phase-difference detection pixel 111 refers to a first upper
peripheral pixel 123. A pixel at a fourth row and the second column
below the first phase-difference detection pixel 111 refers to a
first lower peripheral pixel 124. A pixel at the second row and a
third column above the second phase-difference detection pixel 112
refers to a second upper peripheral pixel 125. A pixel at the
fourth row and the third column below the second phase-difference
detection pixel 112 refers to a second lower peripheral pixel 126.
The first upper peripheral pixel 123 and the second upper
peripheral pixel 125 may be collectively referred to as the upper
peripheral pixels. The first lower peripheral pixel 124 and the
second lower peripheral pixel 126 may be collectively referred to
as the lower peripheral pixels.
[0056] Referring to FIGS. 7 and 8, a width L5 of each of light
shields 150 of adjacent sides, which is in contact with the
phase-difference detection pixels 111 and 112, of the first upper
peripheral pixel 123, the second upper peripheral pixel 125, the
first lower peripheral pixel 124, and the second lower peripheral
pixel 126, is substantially the same. The width L5 of the light
shield 150 may be greater than a reference width L1.
[0057] FIG. 9 is a view illustrating a unit pixel array according
to an exemplary embodiment of the present disclosure. FIG. 10 is a
view taken along line II-IF of FIG. 9 and illustrating a
cross-sectional structure of the unit pixel array according to an
exemplary embodiment of the present disclosure.
[0058] The exemplary embodiment of FIG. 9 is the same as the
exemplary embodiment of FIG. 7 except that light shields of
adjacent sides of upper peripheral pixels 123 and 125 and lower
peripheral pixel 124 and 126 disposed above and below a pair of
phase-difference detection pixels 111 and 112 have different
widths.
[0059] Referring to FIGS. 9 and 10, a width L6 of each of light
shields 150 of adjacent sides of the upper peripheral pixels 123
and 125 is smaller than a width L7 of each of light shields 150 of
adjacent sides of the lower peripheral pixels 124 and 126. Each of
the widths L6 and L7 of the light shields 150 of the adjacent sides
of the peripheral pixels 123, 124, 125, and 126 may be greater than
a reference width L1. The width of the light shield 150 of the
adjacent side of the first upper peripheral pixel 123 may be
different from that of the light shield 150 of the adjacent side of
the second upper peripheral pixel 125. The width of the light
shield 150 of the adjacent side of the first lower peripheral pixel
124 may also be different from that of the light shield 150 of the
adjacent side of the second lower peripheral pixel 126. The widths
of the light shields 150 of the adjacent sides of the peripheral
pixels may be different for each of the peripheral pixels.
[0060] FIG. 11 is a view illustrating a unit pixel array according
to an exemplary embodiment of the present disclosure. FIG. 12 is a
view taken along line I-I' of FIG. 11 and illustrating a
cross-sectional structure of the unit pixel array according to an
exemplary embodiment of the present disclosure.
[0061] In some cases, a light-receiving rate of a peripheral pixel
is decreased by a structure of phase-difference detection pixels
111 and 112 or a shape, a location, etc. of a microlens disposed on
the phase-difference detection pixels 111 and 112. For example,
when a size of the microlens decreases and a curvature thereof
increases, a focusing function of an image sensor is improved. When
the size of the microlens decreases, an amount of light being
scattered and dispersed toward the peripheral pixel decreases, and
thus, the light-receiving rate of the peripheral pixel decreases in
some cases.
[0062] A width of a light shield 150 of an adjacent side, which is
in contact with the phase-difference detection pixels 111 and 112,
among four sides forming outer sides of the peripheral pixel may be
smaller than a reference width L1, which is a width of a light
shield 150 disposed at each of the other pixels or sides. When the
width of the light shield 150 decreases, a light-receiving rate of
the peripheral pixel may increase.
[0063] Referring to FIG. 11, the light-receiving rate of the
peripheral pixel may be increased by decreasing the width of the
light shield 150 of each of adjacent sides of a left peripheral
pixel 121 and a right peripheral pixel 122. A general pixel 130,
through which a wavelength identical to a wavelength passing
through the left peripheral pixel 121 having a B filter passes, is
disposed at a third row and a fifth column of the unit pixel array.
The general pixel 130 having the B filter is not affected by the
phase-difference detection pixels 111 and 112. A light-receiving
rate of the left peripheral pixel 121 in which the width of the
light shield is adjusted may be controlled to be the same as that
of the general pixel 130 in which the width of the light shield is
not adjusted. Since the light-receiving rate of the peripheral
pixel is controlled to be the same as that of the general pixel
130, quality degradation of an image due to a signal difference may
be prevented or reduced.
[0064] Referring to FIG. 12 which is a cross-sectional view taken
along line I-I' of FIG. 11, a width L8 of the light shield 150
extending toward the peripheral pixel from the adjacent side, which
is a boundary between the first phase-difference detection pixel
111 and the left peripheral pixel 121, may be smaller than the
reference width L1, which is the width of each of the light shields
150 of the other pixels. In the right peripheral pixel 122
including a G filter and adjacent to a right side of the second
phase-difference detection pixel 112, the width L8 of the light
shield 150 of the adjacent side which is a boundary of the second
phase-difference detection pixel 112 may also be smaller than the
reference width L1.
[0065] In FIG. 12, when the width of the light shield 150 of the
adjacent side of the left peripheral pixel 121 is the reference
width L1 indicated by a dotted line, light scattered or dispersed
by the first phase-difference detection pixel 111 may be blocked by
the light shield 150. When the width L8 of the light shield 150 is
smaller than the reference width L1, since subject light may
further pass through the left peripheral pixel 121 due to a
decreased width L1-L8, an amount of received light of the left
peripheral pixel 121 may be increased. The width L8 of the light
shield 150 may be set so that the general pixel 130 at the third
row and the fifth column and which is not affected by the
phase-difference detection pixel has the same signal size as the
left peripheral pixel 121.
[0066] FIG. 13 is a view illustrating a unit pixel array according
to an exemplary embodiment of the present disclosure. FIG. 14 is a
view taken along line I-I' of FIG. 13 and illustrating a
cross-sectional structure of the unit pixel array according to an
exemplary embodiment of the present disclosure.
[0067] The exemplary embodiment of FIG. 13 is the same as the
exemplary embodiment of FIG. 11 except that light shields 150 of
adjacent sides of a left peripheral pixel 121 and a right
peripheral pixel 122 disposed at right and left sides of a pair of
phase-difference detection pixels 111 and 112 have different
widths.
[0068] Referring to FIGS. 13 and 14, widths of the light shields
150 of the adjacent sides of the left peripheral pixel 121 and the
right peripheral pixel 122 may be adjusted to compensate for a
decrease in a light-receiving rate of the peripheral pixels 121 and
122 due to the phase-difference detection pixels 111 and 112. The
light-receiving rates of the peripheral pixels 121 and 122 may be
different for each of the peripheral pixels 121 and 122 according
to a wavelength of a color filter 140 included in each of the
peripheral pixels 121 and 122 and the phase-difference detection
pixels 111 and 112, a shape of the phase-difference detection
pixels 111 and 112, and a shape and size of the microlenses 201 and
202. For example, a light-receiving rate of the left peripheral
pixel 121 may further decrease in comparison to a light-receiving
rate of the right peripheral pixel 122. A width L9 of the light
shield 150 of the adjacent side of the left peripheral pixel 121
may be smaller than a width L10 of the light shield 150 of the
adjacent side of the right peripheral pixel 122. Each of the widths
L9 and L10 of the light shields 150 may be smaller than a reference
width L1.
[0069] FIG. 15 is a view illustrating a unit pixel array according
to an exemplary embodiment of the present disclosure. FIG. 16 is a
view taken along line II-IF of FIG. 15 and illustrating a
cross-sectional structure of the unit pixel array according to an
exemplary embodiment of the present disclosure.
[0070] The exemplary embodiment of FIG. 15 is the same as the
exemplary embodiment of FIG. 11 except that peripheral pixels 123,
124, 125 and 126 are disposed above and below phase-difference
detection pixels 111 and 112. Widths of light shields 150 of
adjacent sides of a first upper peripheral pixel 123, a second
upper peripheral pixel 125, a first lower peripheral pixel 124, and
a second lower peripheral pixel 126 may be smaller than a reference
width L1.
[0071] Referring to FIG. 16, which is a cross-sectional view taken
along line II-IF of FIG. 15, widths L11 of the light shields 150 of
the adjacent sides of the first upper peripheral pixel 123 and the
first lower peripheral pixel 124 may be substantially the same. The
width L11 of the light shield 150 may be smaller than the reference
width L1. Light scattered by the first phase-difference detection
pixel 111 and incident on the first upper peripheral pixel 123 and
the first lower peripheral pixel 124 is indicated as an arrow. When
the width of the light shield 150 of the adjacent side of the
peripheral pixel is the reference width L1, scattered light may be
blocked by the light shields 150 having the reference width L1
indicated by dotted lines. An amount of scattered light incident on
the first upper peripheral pixel 123 and the first lower peripheral
pixel 124 may be increased due to the width L11 of each of the
light shields 150 of the adjacent sides of the first upper
peripheral pixel 123 and the first lower peripheral pixel 124 being
smaller than the reference width L1. A total amount of received
light of the first upper peripheral pixel 123 and the first lower
peripheral pixel 124 may increase. The width L11 of each of the
light shields 150 of the adjacent sides of the second upper
peripheral pixel 125 and the second lower peripheral pixel 126 may
also be smaller than the reference width L1.
[0072] FIG. 17 is a view illustrating a unit pixel array according
to an exemplary embodiment of the present disclosure. FIG. 18 is a
view taken along line II-IF of FIG. 17 and illustrating a
cross-sectional structure of the unit pixel array according to an
exemplary embodiment of the present disclosure.
[0073] The exemplary embodiment of FIG. 17 is the same as the
exemplary embodiment of FIG. 15 except that light shields 150 of
adjacent sides of upper peripheral pixels 123 and 125, and lower
peripheral pixels 124 and 126, have different widths.
[0074] Referring to FIGS. 17 and 18, a width L12 of the light
shield 150 of the adjacent side of the upper peripheral pixel 123
is smaller than a width L13 of the light shield 150 of the adjacent
side of the lower peripheral pixel 124. Each of the widths L12 and
L13 of the light shields 150 of the adjacent sides of the
peripheral pixels 123 and 124 may be smaller than a reference width
L1. Since a difference exists in a change in an amount of received
light of each of the peripheral pixels 123 and 124, adjusted widths
of the light shields 150 of the adjacent sides may also be
different for each of the peripheral pixels 123 and 124.
[0075] FIG. 19 is a view illustrating a unit pixel array according
to an exemplary embodiment of the present disclosure.
[0076] Six pixels disposed at right, left, upper, and lower sides
of phase-difference detection pixels 111 and 112 may be peripheral
pixels. The peripheral pixels may also be pixels disposed in a
diagonal direction from the phase-difference detection pixels 111
and 112 in addition to the pixels disposed to have adjacent sides
at the right, left, upper, and lower sides of the phase-difference
detection pixels 111 and 112. A plurality of pixels of which an
amount of received light is changed by the phase-difference
detection pixels 111 and 112, and which are consecutively adjacent
to the phase-difference detection pixels 111 and 112 in a specific
direction, may also refer to the peripheral pixels.
[0077] The peripheral pixels disposed at the left, upper, and lower
sides of the first phase-difference detection pixel 111 refer to a
left peripheral pixel 121, a first upper peripheral pixel 123, and
a first lower peripheral pixel 124. The peripheral pixels disposed
at the right, upper, and lower sides of the second phase-difference
detection pixel 112 refer to a right peripheral pixel 122, a second
upper peripheral pixel 125, and a second lower peripheral pixel
126.
[0078] Referring to FIG. 19, widths of light shields of the
adjacent sides of the peripheral pixels may be different from each
other along the adjacent sides. For example, in the light shield
150 of the adjacent side of the first upper peripheral pixel 123
shown in FIG. 19, a width of the adjacent side may continuously
increase in one direction. The light shield 150 of the adjacent
side of the first lower peripheral pixel 124 may be continuously
changed such that the width thereof at one side of the adjacent
side is smaller than a reference width, and the width thereof at
the other side of the adjacent side is greater than the reference
width.
[0079] A change in a light-receiving rate of each of the peripheral
pixels adjacent to the pair of adjacent phase-difference detection
pixels 111 and 112 in a length direction may be greater than a
change in a light-receiving rate of each of the other peripheral
pixels. For example, when the pair of phase-difference detection
pixels 111 and 112 are laterally disposed adjacent to each other,
the change in the light-receiving rate of each of the left
peripheral pixel 121 and the right peripheral pixel 122 may be
greater than the change in the light-receiving rate of each of the
upper peripheral pixels 123 and 125 and the lower peripheral pixels
124 and 126. When the pair of phase-difference detection pixels 111
and 112 are vertically disposed to be adjacent to each other, a
change in the width of the light shield 150 of each of the adjacent
sides of the upper peripheral pixels 123 and 125 and the lower
peripheral pixels 124 and 126 may be greater than a change in the
width of the light shield 150 of each of the adjacent sides of the
left peripheral pixel 121 and the right peripheral pixel 122. The
change in the width of the light shield 150 refers to the width
relatively increasing or decreasing in comparison to a reference
width L1.
[0080] FIG. 20 is a view illustrating a unit pixel array according
to an exemplary embodiment of the present disclosure. FIG. 21 is a
view taken along line I-I' of FIG. 20 and illustrating a
cross-sectional structure of the unit pixel array according to an
exemplary embodiment of the present disclosure. FIG. 22 is a view
taken along line II-IF of FIG. 20 and illustrating a
cross-sectional structure of the unit pixel array according to an
exemplary embodiment of the present disclosure. FIG. 23 is a view
taken along line II-II' of FIG. 20 and illustrating a
cross-sectional structure of the unit pixel array according to an
exemplary embodiment of the present disclosure.
[0081] Referring to FIG. 20, a width of each of light shields 150
of adjacent sides of each of six peripheral pixels may be greater
or smaller than a width of each of light shields 150 of other
adjacent sides or peripheral pixels thereof. The width of the light
shield 150 of the adjacent side may be different from the width of
each of the light shields 150 of the other adjacent sides.
[0082] Referring to FIG. 21, which is a cross-sectional view taken
along line I-I' of FIG. 20, a width L14 of a light shield 150 of an
adjacent side of a left peripheral pixel 121 having a B filter is
smaller than a reference width L1, and a width L15 of a light
shield 150 of an adjacent side of a right peripheral pixel 122
having a G filter is greater than the reference width L1. The
widths of light shields 150 may be adjusted so that an amount of
received light of the left peripheral pixel 121 increases and an
amount of received light of the right peripheral pixel 122
decreases. By adjusting the width of the light shield 150 of the
adjacent side, the amount of received light of the left peripheral
pixel 121 may be compensated for to be the same as an amount of
received light of a general pixel 130 at a third row and a fifth
column of the unit pixel, which is shown in FIG. 20, and is not
affected by the phase-difference detection pixels 111 and 112.
[0083] Referring to FIG. 22, which is a cross-sectional view taken
along line II-IF of FIG. 20, a width of a light shield 150 of an
adjacent side of each of a first upper peripheral pixel 123 and a
first lower peripheral pixel 124, which have R filters, is greater
than the reference width L1. Even when the peripheral pixels 123
and 124 include the same R filter, widths L16 and L17 of the light
shields of the adjacent sides of the first upper peripheral pixel
123 and the first lower peripheral pixel 124 may be set to be
different according to other conditions such as, for example,
shapes or sizes of microlenses.
[0084] Referring to FIG. 23, which is a cross-sectional view taken
along line III-IIF of FIG. 20, widths L18 and L19 of light shields
150 of adjacent sides of a second upper peripheral pixel 125 and a
second lower peripheral pixel 126, which include the same G filter,
may be different. The width L18 of the light shield 150 may be
greater than the reference width L1, and the width L19 may be
smaller than the reference width L1.
[0085] FIGS. 24 to 33 are views each illustrating a unit pixel
array according to an exemplary embodiment of the present
disclosure.
[0086] Referring to FIG. 24, like the exemplary embodiment of FIG.
1, pixels disposed at right and left sides of phase-difference
detection pixels 111 and 112 may be peripheral pixels 121 and 122.
Widths of light shields 150 of all four sides of the
phase-difference detection pixels 111 and 112, which include
adjacent sides of the peripheral pixel, may be adjusted. FIG. 24
shows a case in which widths of light shields 150 of the left
peripheral pixel 121 and the right peripheral pixel 122 are the
same, and are greater than a reference width. The widths of the
light shields 150 of all of the four sides including the adjacent
sides of the peripheral pixels may also be adjusted to be the same.
When the widths of the light shields 150 of all of the four sides
are adjusted, the widths of the light shields 150 extending toward
an opening range corresponding to a center portion of the pixel may
be decreased. A dispersion characteristic of a light-receiving rate
may be improved more than that of a case in which only the width of
the light shield 150 of the adjacent side is adjusted.
[0087] Referring to FIG. 25, widths of light shields 150 at four
sides of a left peripheral pixel 121 and a right peripheral pixel
122, which are the same as those shown in the exemplary embodiment
of FIG. 24, may be different. For example, in FIG. 25, the widths
of the light shields 150 at the four sides of the left peripheral
pixel 121 having a B filter may be smaller than widths of the light
shields 150 at the four sides of the right peripheral pixel 122
having a G filter.
[0088] In FIGS. 26 and 27, widths of light shields 150 at four
sides of each of a first upper peripheral pixel 123, a first lower
peripheral pixel 124, a second upper peripheral pixel 125, and a
second lower peripheral pixel 126 are adjusted. In FIG. 26, all of
the widths of the light shields 150 of the four peripheral pixels
may be the same. In FIG. 27, the width of each of the light shields
150 at the four sides of each of the first upper peripheral pixel
123 and the second upper peripheral pixel 125 may be different from
the width of each of the light shields 150 at the four sides of
each of the first lower peripheral pixel 124 and the second lower
peripheral pixel 126. However, exemplary embodiments of the present
disclosure are not limited thereto. For example, in exemplary
embodiments, all of the widths of the light shields 150 at the four
sides of each of the four peripheral pixels, which are the upper
peripheral pixels 123 and 125 and the lower peripheral pixel 124
and 126, may be different.
[0089] The exemplary embodiments of FIGS. 28 to 31 correspond to
the exemplary embodiments of FIGS. 24 to 27, and widths of light
shields 150 at four sides of a peripheral pixel are smaller than a
reference width.
[0090] FIGS. 32 and 33 are views each illustrating a unit pixel
array according to an exemplary embodiment of the present
disclosure.
[0091] Six pixels disposed at right, left, upper, and lower sides
of phase-difference detection pixels 111 and 112 may be peripheral
pixels. In the peripheral pixels shown in FIGS. 32 and 33, the
peripheral pixels disposed at the left, upper, and lower sides of a
first phase-difference detection pixel 111 refer to a left
peripheral pixel 121, a first upper peripheral pixel 123, and a
first lower peripheral pixel 124. The peripheral pixels disposed at
the right, upper, and lower sides of a second phase-difference
detection pixel 112 refer to a right peripheral pixel 122, a second
upper peripheral pixel 125, and a second lower peripheral pixel
126.
[0092] Referring to FIG. 32, light shields 150 at four sides of
each of the six peripheral pixels may be wider or narrower than
light shields 150 of the other pixels. Widths of the light shields
150 at the four sides of the peripheral pixels may be different for
each of the peripheral pixels.
[0093] Referring to FIG. 33, widths of light shields 150 at four
sides of one peripheral pixel may be different. For example, widths
of light shields at left and upper sides of a first upper
peripheral pixel 123 in FIG. 33 may be greater than a reference
width. Widths of light shields 150 at right and lower sides of the
first upper peripheral pixel 123 may be smaller than the reference
width.
[0094] FIGS. 34 to 36 are views taken along lines IV-IV', V-V', and
VI-VI' of FIG. 32, each illustrating a cross-sectional structure of
the unit pixel array according to an exemplary embodiment of the
present disclosure.
[0095] Referring to FIG. 34, a width L20 of a light shield 150 of
each of four sides of a left peripheral pixel 121 having a B filter
is smaller than a reference width L1, and a width L21 of a light
shield 150 of each of four sides of a right peripheral pixel 122
having a G filter is greater than the reference width L1. An amount
of received light of the left peripheral pixel 121 may increase,
and an amount of received light of the right peripheral pixel 122
may decrease. By setting the widths of the light shields 150 at the
four sides of the peripheral pixels to be different from the
reference width L1, the amount of received light of the left
peripheral pixel 121 may be compensated for to be the same as an
amount of received light of a general pixel 130 at a third row and
a fifth column of the unit pixel array of FIG. 32, which is not
affected by phase-difference detection pixels 111 and 112.
[0096] Referring to FIG. 35, a width L22 of a light shield 150 of
each of four sides of a first upper peripheral pixel 123 having an
R filter is smaller than a reference width L1. A width L23 of a
light shield 150 of each of four sides of a first lower peripheral
pixel 124 having the same R filter as the first upper peripheral
pixel 123 is greater than the reference width L1. Even when the
peripheral pixels have the same R filter, the widths L22 and L23 of
the light shields 150 at the four sides of each of the first upper
peripheral pixel 123 and the first lower peripheral pixel 124 may
be set to be different according to other conditions such as, for
example, shapes or sizes of microlenses.
[0097] Referring to FIG. 36, widths L24 and L25 of light shields
150 of a second upper peripheral pixel 125 and a second lower
peripheral pixel 126, which include the same G filter, may also be
set to be different. The width L24 of the light shield 150 may be
set to be greater than a reference width L1, and the width L25 may
be set to be smaller than the reference width L1.
[0098] FIG. 37 is a view illustrating a unit pixel array according
to an exemplary embodiment of the present disclosure.
[0099] A first phase-difference detection pixel 111 and a second
phase-difference detection pixel 112 disposed adjacent to each
other may be disposed to be spaced apart from each other so that
there is no side shared therebetween. For example, unlike
previously described exemplary embodiments, in the exemplary
embodiment of FIG. 37, the first and second phase-difference
detection pixels 111 and 112 are not directly adjacent to each
other, and intervening elements are disposed therebetween. Light
shields 150 of the pair of first phase-difference detection pixel
111 and second phase-difference detection pixel 112 may extend to
be symmetrical to each other. The first and second phase-difference
detection pixels 111 and 112 may receive light at locations which
are symmetrical to each other, may be used to analyze a phase
difference between the first and second phase-difference detection
pixels 111 and 112, and may be used to perform an autofocus
function.
[0100] Referring to FIG. 37, the first phase-difference detection
pixel 111 may be disposed at a second row and a second column of
the unit array pixel, and the second phase-difference detection
pixel 112 may be disposed at a fourth row and a fourth column
thereof. The light shield 150 may extend to be formed at a right
side portion of the first phase-difference detection pixel 111,
which is located in a direction toward the second phase-difference
detection pixel 112. The light shield 150 may extend to a left side
portion of the second phase-difference detection pixel 112 to be
symmetrical to the light shield 150 of the first phase-difference
detection pixel 111. Portions on which the light shields 150 are
not disposed in the first and second phase-difference detection
pixels 111 and 112 refer to openings. By analyzing phases of light
received through the openings of the first and second
phase-difference detection pixels 111 and 112, a phase difference
in a lateral direction may be detected. The light shields 150 of
the first and second phase-difference detection pixels 111 and 112
may extend downward and upward to be symmetrical to each other. By
analyzing the phases of light received through the openings of the
pair of phase-difference detection pixels 111 and 112, a phase
difference in a vertical direction may be detected.
[0101] In an exemplary embodiment, The first phase-difference
detection pixel 111 and the second phase-difference detection pixel
112 include color filters 140. The color filter 140 may be selected
from among R, G, and B. The first and second phase-difference
detection pixels 111 and 112 may have the same color filter 140.
For example, a G filter having a relatively high light-receiving
rate may be used in each of the first and second phase-difference
detection pixels 111 and 112 so that a light-receiving rate thereof
is not limited even when a size of the opening is decreased due to
the light shield 150. In an exemplary embodiment, the first
phase-difference detection pixel 111 and the second
phase-difference detection pixel 112 do not include the color
filter 140 and include a W filter or transparent filter.
[0102] Pixels disposed at right, left, upper, and lower sides of
each of the first phase-difference detection pixel 111 and the
second phase-difference detection pixel 112 may refer to peripheral
pixels. As shown in FIG. 37, the peripheral pixels of the first
phase-difference detection pixel 111 are a left peripheral pixel
121, a right peripheral pixel 122, an upper peripheral pixel 123,
and a lower peripheral pixel 124. The peripheral pixels of the
second phase-difference detection pixel 112 are a left peripheral
pixel 127, a right peripheral pixel 128, an upper peripheral pixel
125, and a lower peripheral pixel 126. A width of a light shield
150 of an adjacent side of each of the peripheral pixels may be
adjusted to be smaller or greater than a reference width. The light
shields 150 of the adjacent sides may have different widths.
[0103] FIGS. 38 to 41 are views taken along lines VII-VII',
VIII-VIII', IX-IX', and X-X' of FIG. 37, each illustrating a
cross-sectional structure of the unit pixel array according to an
exemplary embodiment of the present disclosure.
[0104] Referring to FIGS. 38 and 39, the light shield 150 may be
formed to extend to a right side of the first phase-difference
detection pixel 111. A width of a cross-section of the light shield
150 extending in the first phase-difference detection pixel 111 may
be a width LS, and a width of a longitudinal section thereof may be
a width LL. The width LL may have a size corresponding to a length
of one side of one pixel.
[0105] Referring to FIG. 38, the width LS of the light shield 150
may be greater than a reference width L1. The first
phase-difference detection pixel 111 may receive incident light
through an opening formed at a left side thereof. The left
peripheral pixel 121 disposed at the left side of the first
phase-difference detection pixel 111 and having a G filter may be
disposed close to the opening of the first phase-difference
detection pixel 111, and thus, a light-receiving rate thereof may
be increased. A width L26 of a light shield 150 of an adjacent side
of the left peripheral pixel 121 may be greater than the reference
width L1. As a result, a light-receiving rate of the left
peripheral pixel 121 is the same as a light-receiving rate of a
general pixel 130. The right peripheral pixel 122 disposed at a
right side of the first phase-difference detection pixel 111 and
having a G filter may be disposed in a direction opposite a
direction toward the opening of the first phase-difference
detection pixel 111, and thus, a light-receiving rate thereof may
be decreased. A width L27 of a light shield of an adjacent side of
the right peripheral pixel 122 may be smaller than the reference
width L1. As a result, the light-receiving rate of the right
peripheral pixel 122 is the same as the light-receiving rate of the
general pixel 130.
[0106] Referring to FIG. 39, even when the upper peripheral pixel
123 and the lower peripheral pixel 124 of the first
phase-difference detection pixel 111 include the same color filter
140, which is a G filter, widths L28 and L29 of the light shields
150 of adjacent sides thereof may be different. For example, the
width L28 of the light shield 150 of the left peripheral pixel 121
may be smaller than the reference width L1, and the width L29 of
the light shield 150 of the right peripheral pixel 122 may be
greater than the reference width L1.
[0107] Referring to FIG. 40, the light shield 150 including a
cross-section having the width LS may be formed to extend to a left
side of the second phase-difference detection pixel 112. The second
phase-difference detection pixel 112 may receive incident light
through an opening formed at a right side thereof. Widths L30 and
L31 of light shields 150 of different adjacent sides of the left
peripheral pixel 121 and the right peripheral pixel 122 disposed at
left and right sides of the second phase-difference detection pixel
112 and having G filters may be different.
[0108] Referring to FIG. 41, widths L32 and L33 of the light
shields 150 of adjacent sides of the upper peripheral pixel 125 and
the lower peripheral pixel 126 of the second phase-difference
detection pixel 112 may also be different.
[0109] FIG. 42 is a view illustrating a unit pixel array according
to an exemplary embodiment of the present disclosure.
[0110] The exemplary embodiment of FIG. 42 has the same locations
and structures of the phase-difference detection pixels 111 and 112
as the exemplary embodiment of FIG. 37, except that widths of light
shields 150 of all four sides of a peripheral pixel (e.g., a
peripheral pixel from among peripheral pixels 121-128), which
include adjacent sides, are varied. For example, the widths of
light shields 150 of all of the four sides of a peripheral pixel
(e.g., a peripheral pixel from among peripheral pixels 121-128)
including the adjacent sides may be varied. When the widths of the
light shields 150 of all of the four sides are adjusted, the widths
of the light shields 150 extending toward an opening range
corresponding to a center portion of the peripheral pixel (e.g., a
peripheral pixel from among peripheral pixels 121-128) may be
decreased. A dispersion characteristic of a light-receiving rate
may be improved more than that of a case in which only the width of
the light shield 150 of the adjacent side is adjusted.
[0111] Referring to FIG. 42, pixels disposed at right, left, upper,
and lower sides of the first phase-difference detection pixel 111
and the second phase-difference detection pixel 112 may refer to
peripheral pixels. For example, pixels 121-128 may be peripheral
pixels. The peripheral pixels may have a light-receiving rate
different from that of a general pixel 130 according to an opening
direction or light-receiving rate of adjacent phase-difference
detection pixels 111 and 112, wavelengths of color filters 140
included in the peripheral pixels (e.g. pixels 121-128), sizes and
shapes of microlenses disposed on the pixels, etc. The width of the
light shield 150 of each of the peripheral pixels (e.g., pixels
121-128) may be adjusted to have the same light-receiving rate as
that of the general pixel 130 including a color filter 140 having
the same wavelength as a wavelength of the color filter 140 in each
of the peripheral pixels (e.g., pixels 121-128). The widths of the
light shields 150 at the four sides of each of the peripheral
pixels (e.g., pixels 121-128) may be varied together, and the
varied widths of the light shields 150 at the four sides may be
different. The widths of the light shields 150 at the four sides of
the peripheral pixel (e.g., a pixel from among peripheral pixels
121-128) may be different for each of the peripheral pixels
121-128.
[0112] According to an exemplary embodiment of the present
disclosure, the peripheral pixels may include four pixels adjacent
to the phase-difference detection pixels 111 and 112 in a diagonal
direction in addition to including the pixels at the right, left,
upper, and lower sides of the phase-difference detection pixels 111
and 112. For example, referring to FIG. 42, a pixel having a B
filter at a third row and a third column of the pixel unit array
may be a common peripheral pixel of the first phase-difference
detection pixel 111 and the second phase-difference detection pixel
112. Widths of light shields 150 of peripheral pixels having a
light-receiving rate affected by two or more phase-difference
detection pixels may also be varied from a reference width so that
the light-receiving rate of the peripheral pixels is the same as
the light-receiving rate of the general pixel 130 having the same
color filter 140.
[0113] According to an exemplary embodiment of the present
disclosure, the light-receiving rate of the peripheral pixel may be
affected by adjusting widths of light shields 150 of other
peripheral pixels other than the phase-difference detection pixel
adjacent thereto. The width of the light shield 150 of the
peripheral pixel may be adjusted according to the phase-difference
detection pixel adjacent thereto and a change in total
light-receiving rate due to the other peripheral pixels.
[0114] FIGS. 43 to 46 are views taken along lines VII-VII',
VIII-VIII', IX-IX', and X-X' of FIG. 42, each illustrating a
cross-sectional structure of the unit pixel array according to an
exemplary embodiment of the present disclosure.
[0115] Referring to FIG. 43, widths L34 of the light shields 150 at
the four sides of the left peripheral pixel 121 of the first
phase-difference detection pixel 111 may be different from widths
L35 of the light shields 150 at the four sides of the right
peripheral pixel 122. The width L34 of the light shield 150 of the
left peripheral pixel 121 may be greater than a reference width L1,
and the width L35 of the light shield 150 of the right peripheral
pixel 122 may be smaller than the reference width L1.
[0116] Referring to FIG. 44, widths L36 and L37 of the light
shields 150 at the four sides of each of the upper peripheral pixel
123 and the lower peripheral pixel 124 of the first
phase-difference detection pixel 111 may be different.
[0117] Referring to FIG. 45, widths L38 and L39 of the light
shields 150 at the four sides of each of the left peripheral pixel
127 and the right peripheral pixel 128 of the second
phase-difference detection pixel 112 may be different.
[0118] Referring to FIG. 46, widths L40 and L41 of the light
shields of the four sides of each of the upper peripheral pixel 125
and the lower peripheral pixel 126 of the second phase-difference
detection pixel 112 may be different. In addition, like the
exemplary embodiment of FIG. 33, the widths of the light shields
150 at the four sides of one peripheral pixel may also be
different.
[0119] FIGS. 47 and 48 are views each illustrating a
cross-sectional structure of a unit pixel array according to an
exemplary embodiment of the present disclosure.
[0120] The unit pixel array may sequentially include a
photoelectric transformation layer 300, a color filter layer 100
disposed on the photoelectric transformation layer 300, and a
microlens layer 200 disposed on the color filter layer 100. The
unit pixel array in FIGS. 47 and 48 has a backside illuminated
(BSI) structure in which rear surfaces of photodiodes 310 are
disposed facing the microlens layer 200.
[0121] Referring to FIG. 47, the photoelectric transformation layer
300 may include an insulating interlayer 320 in a lower portion
thereof and the photodiodes 310 in an upper portion thereof.
Interconnections 321 are included in the insulating interlayer 320,
and the photodiodes 310 are divided by device separation films 311
in units of pixels. The device separation film 311 is a front-side
deep trench isolation (FDTI) film in which a trench formed from a
front side of the photodiode to a rear side thereof is buried. A
light transmission layer 330 may be formed on the photoelectric
transformation layer 300. The color filter layer 100 including
light shields 150 and color filters 140 may be formed on the light
transmission layer 330. A planarization layer 160 may be formed on
the color filters 140. The microlens layer 200 may be formed on the
color filter layer 100 and include microlenses 201, 202, and 203 at
locations corresponding to the color filters 140.
[0122] The exemplary embodiment of FIG. 48 corresponds to the
exemplary embodiment of FIG. 47, and a device separation film 311
is a back-side deep trench isolation (BDTI) film in which a trench
formed from a rear surface of a photodiode 310 to a front surface
thereof is buried.
[0123] FIGS. 49 to 54 are cross-sectional views illustrating a
method of manufacturing a unit pixel array according to an
exemplary embodiment of the present disclosure. A method of
manufacturing a unit pixel array of an image sensor having the FDTI
structure shown in FIG. 47 will be described with reference to
FIGS. 49 to 54, but exemplary embodiments of the present disclosure
are not limited thereto.
[0124] Referring to FIG. 49, photodiodes 310 and device separation
films 311 are formed on a substrate. The device separation films
311 are formed to be adjacent to a front surface of the substrate
and spaced apart from a rear surface of the substrate.
[0125] Referring to FIG. 50, an insulating interlayer 320 is formed
on the front surface of the substrate, and transistors and
interconnections 321 are formed inside the insulating interlayer
320. A photoelectric transformation layer 300 may be formed by
forming the insulating interlayer 320 on the substrate including
the photodiode 310.
[0126] Referring to FIG. 51, a back grinding process is performed
on the rear surface of the substrate on which the insulating
interlayer 320 is formed. In this case, the device separation films
311 may be exposed.
[0127] Referring to FIG. 52, the substrate on which the insulating
interlayer 320 is formed is turned over, and a light transmission
layer 330 is formed on the rear surface thereof on which the back
grinding process is performed. The light transmission layer 330 may
be a single layer or multilayer. For example, the light
transmission layer 330 may be formed to have a three-layered
structure including an Al.sub.2O.sub.3 layer, a SiO.sub.2 layer,
and a HfO layer.
[0128] Referring to FIG. 53, a light shield 150 may be formed on
the light transmission layer 330. The light shield 150 may or may
not be formed according to a characteristic of a pixel, and a width
thereof may also be changed.
[0129] Referring to FIG. 54, each pixel is filled with a color
filter 140 such as an R filter, a G filter, a B filter, a W filter,
etc., and a planarization layer 160 is formed on the color filter.
Thus, a color filter layer 100 including the light shield 150, the
color filter 140, and the planarization layer 160 may be formed.
After the color filter layer 100 is formed, a microlens layer 200
corresponding to each pixel may be formed on the color filter layer
100.
[0130] FIG. 55 is an equivalent circuit diagram of a unit pixel
according to an exemplary embodiment of the present disclosure.
[0131] Referring to FIG. 55, each of photoelectric transformation
layers 300 of the unit pixel may include a photoelectric
transformation range PD, a transfer transistor Tx, a source follow
transistor Sx, a reset transistor Rx, and a select transistor
Ax.
[0132] The transfer transistor Tx, the source follow transistor Sx,
the reset transistor Rx, and the select transistor Ax respectively
include a transfer gate TG, a source follow gate SF, a reset gate
RG, and a select gate SEL.
[0133] The transfer gate TG of the unit pixel may be electrically
connected to a transfer gate line TGL. The reset gate RG of the
unit pixel may be electrically connected to a reset gate line RGL.
The select gate SEL of the unit pixel may be electrically connected
to a select gate line SELL.
[0134] The photoelectric transformation range PD may be a
photodiode including an N-type impurity range/region and a P-type
impurity range/region. A drain of the transfer transistor Tx may
refer to a floating diffusion range FD. The floating diffusion
range FD may be a source of the reset transistor Rx. The floating
diffusion range FD may be electrically connected to the source
follow gate SF of the source follow transistor Sx. The source
follow transistor Sx may be connected to the select transistor Ax.
The transfer transistor Tx and the source follow transistor Sx may
be connected to voltage Vdd, and the select transistor Ax may be
connected to voltage Vout.
[0135] According to exemplary embodiments of the present
disclosure, a signal difference between general pixels and
peripheral pixels adjacent to phase-difference detection pixels can
be compensated for, and thus, quality degradation of an image can
be prevented or reduced.
[0136] In addition, according to exemplary embodiments of the
present disclosure, a function of adjusting a focus of an image
sensor can be improved by adjusting sizes of microlenses without
changing a light-receiving rate of peripheral pixels.
[0137] While the present disclosure has been particularly shown and
described with reference to the exemplary embodiments thereof, it
will be understood by those of ordinary skill in the art that
various changes in form and detail may be made therein without
departing from the spirit and scope of the present disclosure as
defined by the following claims.
* * * * *