KR20150085457A - Image sensor and electronic device including the same - Google Patents

Abstract

A semiconductor substrate on which a plurality of first photo-sensing elements for sensing light in a blue wavelength region and a plurality of second photo-sensing elements for sensing light in a red wavelength region are integrated; And a second color filter for selectively absorbing light in a red wavelength range, and a pair of electrodes disposed on the color filter layer and facing each other, And a third photo sensing element located between the electrodes and including a photoactive layer that selectively absorbs light in the green wavelength region, and an electronic device including the image sensor.

Description

[0001] IMAGE SENSOR AND ELECTRONIC DEVICE INCLUDING THE SAME [0002]

An image sensor and an electronic device including the same.

A photoelectric device is a device that converts light into an electric signal using a photoelectric effect, and includes a photodiode and a phototransistor, and can be applied to an image sensor, a solar cell, and the like.

The image sensor including a photodiode is required to be miniaturized and high resolution as the edge becomes wider, and accordingly, it is necessary to reduce the pixel size. However, in the currently used silicon photodiodes, the sensitivity may be lowered because the absorption area decreases as the pixel size becomes smaller.

One embodiment provides an image sensor suitable for miniaturization and capable of reducing sensitivity degradation while having high resolution.

Another embodiment provides an electronic device comprising the image sensor.

According to an embodiment, there is provided a semiconductor light emitting device including: a semiconductor substrate on which a plurality of first light sensing elements for sensing light in a blue wavelength region and a plurality of second light sensing elements for sensing light in a red wavelength region are integrated; A color filter layer including a blue filter for selectively absorbing light in a blue wavelength region and a red filter for selectively absorbing light in a red wavelength region and a pair of electrodes facing each other, And a third photo-sensing device disposed between the electrodes and including a photoactive layer selectively absorbing light in a green wavelength region.

The blue wavelength region can exhibit a maximum absorption wavelength (λ _max) at about 400nm to less than 500nm, and the red wavelength region may represent a maximum absorption wavelength (λ _max) at about 580nm than 700nm or less, the green wavelength region Can exhibit a maximum absorption wavelength (? _Max ) at about 500 nm to 580 nm.

The pair of electrodes facing each other may be a light-transmitting electrode, and the photoactive layer may include a p-type semiconductor material selectively absorbing light in the green wavelength region and an n-type semiconductor material selectively absorbing light in the green wavelength region. . ≪ / RTI >

The image sensor may further include a condenser lens positioned on the third photosensor.

The image sensor may further include a metal wiring located below the first photo sensing device and the second photo sensing device.

The image sensor may further include a transflective layer disposed between the third photo sensing device and the color filter layer.

The transflective layer may transmit light in the blue wavelength region and the red wavelength region and selectively reflect light in the green wavelength region.

The semi-transmissive layer may include a plurality of layers in which a first layer and a second layer having different refractive indices are alternately stacked.

The thicknesses of the first layer and the second layer may be determined by the refractive index and the reflection wavelength of the first layer and the second layer.

The half width of the green wavelength region in the absorption spectrum can be determined according to the ratio of the refractive index of the first layer to the refractive index of the second layer.

The first layer may have a refractive index of about 1.2 to 1.8, and the second layer may have a refractive index of about 2.1 to 2.7.

The first layer may be a silicon oxide layer, and the second layer may be a titanium oxide layer.

Wherein the transflective layer comprises a plurality of silicon oxide layers and a plurality of titanium oxide layers alternately stacked to form a total of 5 to 10 layers, each of the silicon oxide layers having a thickness of about 10 nm to 300 nm, The titanium oxide layer may have a thickness of about 30 nm to 200 nm.

According to another embodiment, there is provided an electronic device including the image sensor.

The present invention provides an image sensor that realizes miniaturization and can reduce sensitivity degradation while having high resolution.

1 is a cross-sectional view illustrating a CMOS image sensor according to an embodiment,
2 is a cross-sectional view illustrating a CMOS image sensor according to another embodiment,
3 is a cross-sectional view illustrating a CMOS image sensor according to another embodiment,
4 is a cross-sectional view illustrating a CMOS image sensor according to another embodiment,
FIG. 5 is a cross-sectional view showing an example of a semi-transparent layer in the image sensor of FIG. 4,
6 is a cross-sectional view illustrating a CMOS image sensor according to another embodiment,
7 is a cross-sectional view illustrating a CMOS image sensor according to another embodiment.

Hereinafter, exemplary embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the drawings, the thickness is enlarged to clearly represent the layers and regions. Like parts are designated with like reference numerals throughout the specification. Whenever a portion of a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the case where it is "directly on" another portion, but also the case where there is another portion in between. Conversely, when a part is "directly over" another part, it means that there is no other part in the middle.

Hereinafter, an image sensor according to an embodiment will be described with reference to the drawings. Here, a CMOS image sensor is described as an example of an image sensor.

1 is a cross-sectional view illustrating an image sensor according to an embodiment.

The image sensor according to an embodiment includes adjacent first pixels, second pixels, and third pixels. The first pixel, the second pixel, and the third pixel have different wavelength regions mainly absorbing in the visible light region of, for example, about 380 to 780 nm. For example, the first pixel may be a blue pixel sensing light in the blue wavelength region, Two pixels may be a red pixel for sensing light in the red wavelength range and a third pixel may be a green pixel for sensing light in the green wavelength range.

The blue wavelength region can exhibit a maximum absorption wavelength (λ _max) at about 400nm to less than 500nm, and the red wavelength region may represent a maximum absorption wavelength (λ _max) at about 580nm than 700nm or less, the green wavelength region Can exhibit a maximum absorption wavelength (? _Max ) at about 500 nm to 580 nm.

The blue pixel, the red pixel, and the green pixel may be repeated in rows and / or columns in a group. However, the arrangement of the pixels can be variously modified.

1, an image sensor 300 according to an exemplary embodiment includes a blue light sensing element 50B, a red light sensing element 50R, a charge storage 50G, and a transfer transistor (not shown) integrated therein And includes a semiconductor substrate 310, a lower insulating layer 60, a color filter layer 70, an upper insulating layer 80, and a green light sensing element 100.

In FIG. 1, a component in which 'B' is included is a component included in a blue pixel, and a component in which 'R' is included in a reference pixel is a component included in a red pixel, A component containing 'G' indicates a component contained in a green pixel.

The semiconductor substrate 310 may be a silicon substrate, and a blue light sensing element 50B, a red light sensing element 50R, a charge storage 50G, and a transfer transistor (not shown) are integrated. The blue light sensing element 50B and the red light sensing element 50R may be a photodiode. The blue light sensing element 50B and the transfer transistor may be integrated per blue pixel and the red light sensing element 50R and the transfer transistor may be integrated per red pixel and the charge storage 50G and the transfer transistor may be integrated per green pixel It can be integrated.

A metal wiring (not shown) and a pad (not shown) are formed on the semiconductor substrate 310. Metal wirings and pads may be made of, but not limited to, metals having low resistivity to reduce signal delay, such as aluminum (Al), copper (Cu), silver (Ag), or alloys thereof.

A lower insulating layer 60 is formed on the metal wiring and the pad. The lower insulating layer 60 may be made of an inorganic insulating material such as silicon oxide and / or silicon nitride, or a low K material such as SiC, SiCOH, SiCO, and SiOF.

The lower insulating layer 60 may have a trench (not shown) that exposes the photo sensing elements 50B and 50R and the charge storage 50G of each pixel, respectively. The trenches may be filled with fillers.

A color filter layer 70 is formed on the lower insulating film 60. The color filter layer 70 includes a color filter 70B for a blue pixel and a color filter 70R for a red pixel. The color filter 70B of the blue pixel absorbs light in the blue wavelength region and transmits the blue light to the blue light sensing element 50B and the color filter 70R of the red pixel absorbs light in the red wavelength region, ). Green pixels do not include color filters.

An upper insulating layer 80 is formed on the color filter layer 70. The upper insulating layer 80 removes the level difference caused by the color filter layer 70 and flattenes it. The upper insulating layer 80 and the lower insulating layer 60 have a contact hole (not shown) for exposing the pad and a through hole 85 for exposing the charge storage 50G of the green pixel.

A green light sensing device 100 is formed on the upper insulating layer 80.

The green light sensing device 100 includes a lower electrode 110 and an upper electrode 120 facing each other and a photoactive layer 130G positioned between the lower electrode 110 and the upper electrode 120. [ One of the lower electrode 110 and the upper electrode 120 is an anode and the other is a cathode.

The lower electrode 110 and the upper electrode 120 may both be light emitting electrodes and the transparent electrode may be a transparent conductor such as indium tin oxide (ITO) or indium zinc oxide (IZO) Or may be a metal thin film formed to a thin thickness of several nanometers to tens of nanometers, or a single layer or a plurality of metal thin films formed of a thin thickness of several nanometers to tens of nanometers thick doped with a metal oxide.

The photoactive layer 130G selectively absorbs light in the green wavelength region and allows light in the wavelength region not the green wavelength region, that is, the blue wavelength region and the red wavelength region, to pass therethrough.

The photoactive layer 130G may include a p-type semiconductor material and an n-type semiconductor material, and the p-type semiconductor material and the n-type semiconductor material may form a pn junction. At least one of the p-type semiconductor material and the n-type semiconductor material may selectively absorb light in a green wavelength range. For example, the p-type semiconductor material and the n- . The photoactive layer 130G selectively absorbs light in the green wavelength region to generate excitons, and then separates the generated excitons into holes and electrons to generate a photoelectric effect. The photoactive layer 130G can replace the color filter of the green pixel.

The p-type semiconductor material and the n-type semiconductor material may each have an energy band gap of, for example, about 2.0 to 2.5 eV, and the p-type semiconductor material and the n-type semiconductor material may have a LUMO difference of about 0.2 to 0.7 eV Lt; / RTI >

The p-type semiconductor material may be, for example, quinacridone or a derivative thereof, and the n-type semiconductor material may be, for example, a cyanovinyl group-containing thiophene derivative, no.

The quinacridone or its derivative may be represented by, for example, the following formula (1).

[Chemical Formula 1]

In Formula 1,

R ¹ and R ² are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 heteroaryl group,

X ¹ and X ² are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C2 to C30 alkenyl group, a substituted or unsubstituted C6 to C30 aromatic group, a substituted or unsubstituted C3 to C30 aliphatic group, A C30 heterocyclic aromatic group, a cyano-containing group, a halogen-containing group, or a combination thereof.

The quinacridone or its derivative may be, for example, the following formulas (1a) to (1o), but is not limited thereto.

[Formula 1a]

[Chemical Formula 1b]

[Chemical Formula 1c]

≪ RTI ID = 0.0 &

[Formula 1e]

(1f)

[Formula 1g]

[Chemical Formula 1h]

[Formula 1i]

[Chemical Formula 1j]

[Chemical Formula 1k]

≪ EMI ID =

[Formula 1m]

[Formula 1n]

≪ EMI ID =

In the above general formulas (1a) to (1o), R ¹ and R ² are as described above.

The thiophene derivative may be represented, for example, by the following formula (2).

(2)

In Formula 2,

T ¹ , T ² and T ³ are each independently an aromatic ring having a substituted or unsubstituted thiophene moiety,

X ³ to X ⁸ each independently represent hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 heteroaryl group, a cyano group, or combinations thereof to be. X ³ to X ⁸ May be a cyano group.

T ¹ , T ^2, and T ³ may be independently selected from the groups listed in Group 1 below.

[Group 1]

In the group 1,

R ¹¹ to R ²⁶ are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 heteroaryl group, or a combination thereof.

The thiophene derivative may be, for example, selected from compounds represented by the following formulas (2a) to (2j), but is not limited thereto.

(2a)

(2b)

[Chemical Formula 2c]

(2d)

[Formula 2e]

(2f)

[Chemical Formula 2g]

[Chemical Formula 2h]

(2i)

(2j)

In the above formula (2h) or (2j)

X ₁ to X ₅ are the same or different and each independently CR ¹ R ² , SiR ³ R ⁴ , NR ⁵ , oxygen (O) or selenium (Se), wherein R ¹ to R ⁵ are the same or different and each independently hydrogen , A substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C3 to C20 hetero aryl group, or a combination thereof.

The p-type semiconductor material may be, for example, a compound represented by the following Formula 3, and the n-type semiconductor material may be a compound represented by the following Formula 4, but is not limited thereto.

(3)

In Formula 3,

R ¹ to R ⁸ is A substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 heteroaryl group, a substituted or unsubstituted C1 to C30 alkoxy group, a halogen An atom, a halogen-containing group or a combination thereof,

Wherein R ¹ to R ⁸ Lt; / RTI > are bonded to form a ring or fused ring,

R ¹ to R ⁸ Is a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 heteroaryl group, or a combination thereof,

[Chemical Formula 4]

In Formula 4,

Z ¹ to Z ⁴ are each independently oxygen (O), nitrogen (N) or sulfur (S)

X ^a1 to X ^a5 , X ^b1 to X ^b5 , X ^c1 to X ^c5 and X ^d1 to X ^d5 are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, A halogen atom, a halogen-containing group or a combination thereof,

X ⁵ and X ⁶ are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 heteroaryl group, or combinations thereof .

The compound represented by Formula 3 may be, for example, a compound represented by any one of the following Formulas 3a to 3d, and the compound represented by Formula 4 may be a compound represented by Formula 4a or 4b, no.

[Chemical Formula 3]

 (3b)

 [Chemical Formula 3c]

 (3d)

[Chemical Formula 4a]

(4b)

The p-type semiconductor material may be, for example, the above-described quinacridone or a derivative thereof, and the n-type semiconductor material may be, for example, a compound represented by the following formula (5), but is not limited thereto.

[Chemical Formula 5]

In Formula 5,

R ^a to R ¹ each independently represent hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 heteroaryl group, a halogen atom, a halogen-containing group Or a combination thereof,

X is a halogen atom or a C6 to C20 aryloxy group containing at least one halogen element.

The compound represented by Formula 5 may be at least one of compounds represented by the following Formulas 5a to 5g, but is not limited thereto.

[Chemical Formula 5a]

[Chemical Formula 5b]

[Chemical Formula 5c]

[Chemical Formula 5d]

[Chemical Formula 5e]

[Chemical Formula 5f]

[Chemical Formula 5g]

The photoactive layer 130G may be a single layer or a plurality of layers. The photoactive layer 130G may be formed of, for example, an intrinsic layer (I layer), a p-type layer / I-layer, an I-layer / n-type layer, a p-type layer / I- It can be various combinations.

The intrinsic layer (I layer) may comprise the p-type semiconductor material and the n-type semiconductor material mixed in a thickness ratio of about 1: 100 to about 100: 1. May be included in the above range in a thickness ratio of about 1:50 to 50: 1, and may be included in the range of thickness ratio of about 1:10 to 10: 1 within the range, and within the range of about 1: 1 . The p-type semiconductor material and the n-type semiconductor material have a compositional ratio in the above range, which is effective for effective exciton generation and pn junction formation.

The p-type layer may comprise the p-type semiconductor material, and the n-type layer may comprise the n-type semiconductor material.

The photoactive layer 130G may have a thickness of about 1 nm to 500 nm. And may have a thickness of about 5 nm to 300 nm within the above range. By having a thickness in the above range, the photoelectric conversion efficiency can be effectively improved by effectively absorbing light and effectively separating and transmitting holes and electrons.

When the green light sensing device 100 receives light from the upper electrode 120 side and the photoactive layer 130G absorbs light in the green wavelength region, excitons may be generated inside. The excitons are separated into holes and electrons in the photoactive layer 130G and the separated holes move to the anode side which is one of the lower electrode 110 and the upper electrode 120. The separated electrons move to the lower electrode 110 and the upper electrode The current flows to the cathode side which is the other one of the anode side and the cathode side. The separated electrons or holes may be collected in the charge storage 50G. The light in the remaining wavelength region except the green wavelength region may be sensed by the blue light sensing element 50B or the red light sensing element 50R through the lower electrode 110 and the color filters 70B and 70G.

The photoactive layer 130G may be formed on the front surface of the image sensor 300. Accordingly, the photoactive layer 130G can absorb light from the front surface of the image sensor 300, thereby increasing the area of the light.

A condenser lens (not shown) may be further formed on the green light sensing device 100. The condensing lens can control the direction of incident light and collect light into one point. The condensing lens may be, for example, cylindrical or hemispherical, but is not limited thereto.

As described above, the color filter layer including the color filter for absorbing the light in the blue wavelength region and the light in the blue wavelength region and the green light sensing element for absorbing the light in the green wavelength region among the visible light region are stacked vertically, The area can be reduced and accordingly, the miniaturization of the image sensor can be realized. In addition, the photo-sensing device which selectively absorbs light in the green wavelength range can be formed on the front surface of the image sensor, thereby increasing the area capable of absorbing light and securing the area of the color filter layer.

2 is a cross-sectional view illustrating a CMOS image sensor according to another embodiment.

2, the CMOS image sensor 300 according to the present embodiment includes a blue light sensing element 50B, a red light sensing element 50R, a charge storage 50G, and a transfer transistor A lower insulating layer 60, a color filter layer 70, an upper insulating layer 80, and a green light sensing element 100 on which a semiconductor substrate (not shown) is integrated.

The color filter layer 70 includes a blue pixel color filter 70B and a red pixel color filter 70R and the green light sensing element 100 includes a lower electrode 110, a photoactive layer 130G, (120). As described above, the photoactive layer 130G selectively absorbs light in the green wavelength region, and allows light in the wavelength regions other than the green wavelength region, that is, the blue wavelength region and the red wavelength region, to pass therethrough.

However, unlike the above-described embodiment, the metal wiring 320 is located below the blue light sensing element 50B and the red light sensing element 50R. Since the metal wiring 320 is positioned below the blue light sensing element 50B and the red light sensing element 50R, light reflection due to reflection of the metal wiring 320 made of opaque metal can be reduced, And it is possible to effectively reduce the occurrence of optical interference between pixels.

3 is a cross-sectional view illustrating a CMOS image sensor according to another embodiment.

3, the CMOS image sensor 300 according to the present embodiment includes a blue light sensing element 50B, a red light sensing element 50R, a charge storage 50G, and a transfer transistor A lower insulating layer 60, a color filter layer 70, an upper insulating layer 80, and a green light sensing element 100 on which a semiconductor substrate (not shown) is integrated.

The color filter layer 70 includes a blue pixel color filter 70B and a red pixel color filter 70R and the green light sensing element 100 includes a lower electrode 110, a photoactive layer 130G, (120). As described above, the photoactive layer 130G selectively absorbs light in the green wavelength region, and allows light in the wavelength regions other than the green wavelength region, that is, the blue wavelength region and the red wavelength region, to pass therethrough.

However, unlike the above-described embodiment, the green light sensing element 100 is provided between the lower electrode 110 and the photoactive layer 130G, and between the upper electrode 120 and the photoactive layer 130G by the charge assistant layers 140 and 150 ). Either of the charge assist layers 140 and 150 may be omitted.

The charge assistant layers 140 and 150 may include a hole injecting layer (HIL) that facilitates injection of holes, a hole transporting layer (HTL) that facilitates hole transport, The electron blocking layer (EBL), the electron injecting layer (EIL) that facilitates electron injection, the electron transporting layer (ETL) that facilitates the transport of electrons, And a hole blocking layer (HBL) blocking the hole blocking layer.

The charge-assist layer 140, 150 may comprise, for example, an organic, inorganic, or organic material. The organic material may be an organic compound having a hole or electron characteristic, and the inorganic material may be a metal oxide such as molybdenum oxide, tungsten oxide, or nickel oxide.

The hole transport layer (HTL) may include, for example, poly (3,4-ethylenedioxythiophene): poly (3,4-ethylenedioxythiophene): poly (styrenesulfonate), PEDOT: PSS, Poly (N-vinylcarbazole), polyaniline, polypyrrole, N, N, N ', N'-tetrakis (4-methoxyphenyl) N, N ', N'-tetrakis (4-methoxyphenyl) -benzidine, TPD), 4-bis [N- (1-naphthyl) NPD), m-MTDATA, 4,4 ', 4 "-tris (N-carbazolyl) -triphenylamine (4,4', 4" -tris (N-carbazolyl) -triphenylamine, TCTA), and a combination thereof. The electron blocking layer (EBL) may be formed of, for example, poly (3,4-ethylenedioxythiophene) : Poly (3,4-ethylenedioxythiophene): poly (styrenesulfonate), PEDOT: PSS), polyarylamine, poly (N-vinylcarbazole) nylcarbazole, polyaniline, polypyrrole, N, N, N ', N'-tetrakis (4-methoxyphenyl) ) -benzidine, TPD), 4-bis [N- (1-naphthyl) -N-phenyl-amino] biphenyl -NPD), m-MTDATA, 4,4 ', 4 "-tris (N-carbazolyl) -triphenylamine (4,4' But is not limited to, one selected from the combinations.

The electron transport layer (ETL) may include, for example, 1,4,5,8-naphthalene-tetracarboxylic dianhydride (NTCDA), bathocuproine (BCP _{), LiF, Alq 3, Gaq} 3, Inq 3, Znq 2, Zn (BTZ) 2, BeBq 2 and however may include one selected from a combination thereof, and the like.

The hole blocking layer (HBL) may include, for example, 1,4,5,8-naphthalene-tetracarboxylic dianhydride (NTCDA), vicocloin (BCP) _{, LiF, Alq 3, Gaq 3} , Inq 3, Znq 2, Zn (BTZ) 2, BeBq 2 and however may include one selected from a combination thereof, and the like.

4 is a cross-sectional view illustrating a CMOS image sensor according to another embodiment.

The CMOS image sensor 300 according to the present embodiment includes a blue light sensing element 50B, a red light sensing element 50R, a charge storage 50G, and a semiconductor substrate 310, a lower insulating layer 60, a color filter layer 70, an upper insulating layer 80, and a green light sensing element 100.

The color filter layer 70 includes a blue pixel color filter 70B and a red pixel color filter 70R and the green light sensing element 100 includes a lower electrode 110, a photoactive layer 130G, (120). As described above, the photoactive layer 130G selectively absorbs light in the green wavelength region, and allows light in the wavelength regions other than the green wavelength region, that is, the blue wavelength region and the red wavelength region, to pass therethrough.

However, this embodiment further includes a transflective layer 90 between the green light sensing element 100 and the color filter layer 70, unlike the above-described embodiment.

The semi-transparent layer 90 has a property of transmitting a part of light and reflecting a part of light, for example, transmitting the light in the blue wavelength region and the red wavelength region and selectively reflecting the light in the green wavelength region.

The transflective layer 90 can reflect the light in the green wavelength region which has not been absorbed by the photoactive layer 130G to the photoactive layer 130G again and increase the absorption rate of light in the green wavelength region of the photoactive layer 130G. Therefore, the efficiency of the green light sensing device 100 can be increased.

The semi-permeable layer 90 may be, for example, a distributed Bragg reflection (DBR) structure.

5 is a cross-sectional view showing an example of a transflective layer in the image sensor of FIG.

5, the semi-transmissive layer 90 may include a plurality of layers in which a first layer 90a and a second layer 90b having different refractive indices are alternately stacked, for example, five to ten Layer.

The first layer 90a may be a low refractive index layer and the second layer 90b may be a high refractive index layer. For example, the first layer 90a may have a refractive index of about 1.2 to 1.8, and the second layer 90b may have a refractive index of about 2.1 to 2.7. Within this range, the first layer 90a may have a refractive index of about 1.44 to 1.47 and the second layer 90b may have a refractive index of about 2.31 to 2.45. The first layer 90a and the second layer 90b are not particularly limited as long as the material has the refractive index. For example, the first layer may be a silicon oxide layer and the second layer may be a titanium oxide layer.

The thickness of the first layer 90a and the second layer 90b may be determined according to the refractive index and the reflection wavelength of each layer. For example, each first layer 90a may have a thickness of about 10 nm to 300 nm, The second layer 90b may have a thickness of about 30 nm to 200 nm. The total thickness of the semi-permeable layer 90 may be, for example, about 770 to 1540 nm. The thickness of each first layer 90a and each second layer 90b may be the same or different.

The refractive index of the first layer (90a), (n ₁₎ and the refractive index of the second layer (90b), (n ₂₎ is able to form a higher wavelength selectivity is high the transflective layer 90, the difference, for example, above in the absorption spectrum the full width at half maximum (full width at half maximum, FWHM ) of the third wavelength region may be determined according to the ratio of the refractive index (n ₂₎ of refraction index (n ₁₎ and the second layer (90b) of the first layer (90a). Here, the half width is a width of a wavelength corresponding to a half of the maximum absorption point, and when the half width is small, it means that the wavelength selectivity is high by selectively absorbing light in a narrow wavelength range. In other words it is possible to increase the refractive index (n ₁₎ and the ratio, that is, n is half-width narrow wavelength selectivity greater the ratio of ₂ / n ₁ of the refractive index (n ₂₎ of the second layer (90b) of the first layer (90a).

6 is a cross-sectional view illustrating a CMOS image sensor according to another embodiment.

6, the CMOS image sensor 300 according to the present embodiment includes a blue light sensing element 50B, a red light sensing element 50R, a charge storage 50G, A lower insulating layer 60, a color filter layer 70, an upper insulating layer 80, a transflective layer 90, and a green light sensing element 100 (not shown) on which transfer transistors (not shown) The color filter layer 70 includes a blue pixel color filter 70B and a red pixel color filter 70R and the green light sensing element 100 includes a lower electrode 110, 130G and an upper electrode 120. [ As described above, the photoactive layer 130G selectively absorbs light in the green wavelength region, and allows light in the wavelength regions other than the green wavelength region, that is, the blue wavelength region and the red wavelength region, to pass therethrough.

However, unlike the embodiment shown in FIG. 4, the metal wiring 320 is located under the blue light sensing element 50B and the red light sensing element 50R. Since the metal wiring 320 is positioned below the blue light sensing element 50B and the red light sensing element 50R, light reflection due to reflection of the metal wiring 320 made of opaque metal can be reduced, And it is possible to effectively reduce the occurrence of optical interference between pixels.

7 is a cross-sectional view illustrating a CMOS image sensor according to another embodiment.

Referring to FIG. 7, the CMOS image sensor 300 according to this embodiment includes a blue light sensing element 50B, a red light sensing element 50R, a charge storage 50G, A lower insulating layer 60, a color filter layer 70, an upper insulating layer 80, a transflective layer 90, and a green light sensing element 100 (not shown) on which transfer transistors (not shown) ).

The color filter layer 70 includes a blue pixel color filter 70B and a red pixel color filter 70R and the green light sensing element 100 includes a lower electrode 110, a photoactive layer 130G, (120). As described above, the photoactive layer 130G selectively absorbs light in the green wavelength region, and allows light in the wavelength regions other than the green wavelength region, that is, the blue wavelength region and the red wavelength region, to pass therethrough.

4, the green light sensing device 100 is provided between the lower electrode 110 and the photoactive layer 130G and between the upper electrode 120 and the photoactive layer 130G, 140, 150), and further includes a transflective layer (90) between the green light sensing element (100) and the color filter layer (70). The charge assist layer 140, 150 and the semi-transparent layer 90 are as described above.

The image sensor according to the above embodiments can increase the light absorbing efficiency of all the wavelength regions including the blue wavelength region, the red wavelength region and the green wavelength region, thereby increasing the sensitivity of the image sensor, Can be improved.

The electronic device may be, for example, a mobile phone or a digital camera, but is not limited thereto.

Hereinafter, embodiments of the present invention will be described in detail with reference to examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

Manufacture of image sensor

Example  One

A color filter layer including a red filter and a blue filter is formed on a semiconductor substrate on which a Si CMOS is formed, ITO is sputtered on the color filter layer to form an anode having a thickness of about 100 nm, and molybdenum oxide (MoOx) and Al Are co-deposited and laminated to a thickness of 5 nm. Subsequently, a p-type semiconductor compound (LT-E503, Lumtec) represented by the following formula (A) and an n-type semiconductor compound represented by the following formula (B) were co-deposited on the molybdenum oxide and the Al thin film (MoOx: Al) Thereby forming a thick photoactive layer. Subsequently, indium tin oxide (ITO) is deposited on the photoactive layer by a chemical vapor deposition method to form a cathode having a thickness of 80 nm, thereby fabricating a CMOS image sensor.

(A)

[Chemical Formula B]

Example  2

Except that a semi-transparent layer in which a silicon oxide layer having a refractive index of 1.4599 and a titanium oxide layer having a refractive index of 2.4236 were laminated was further formed between the color filter layer and the ITO anode in Example 1 A CMOS image sensor is manufactured.

The silicon oxide layer and the titanium oxide layer were laminated alternately 8 times, and the thicknesses of the respective layers were as shown in Table 1 below.

The first layer Silicon oxide layer 200 nm Titanium oxide layer 163 nm Second layer Silicon oxide layer 37 nm Titanium oxide layer 91nm Third Floor Silicon oxide layer 49nm Titanium oxide layer 88nm Fourth floor Silicon oxide layer 40nm Titanium oxide layer 85nm Fifth floor Silicon oxide layer 17 nm Titanium oxide layer 82nm Sixth Floor Silicon oxide layer 88nm Titanium oxide layer 91nm Seventh Floor Silicon oxide layer 25 nm Titanium oxide layer 69 nm Eighth Floor Silicon oxide layer 17 nm Titanium oxide layer 97 nm Total thickness 1239 nm

evaluation

The sensitivity and photoelectric conversion efficiency of the image sensor according to Examples 1 and 2 are evaluated.

Sensitivity was measured using Tsubosaka Electric LSBD-111/4 and Kyoritsu LB-8601, and the electron production rate of each light was measured while a specific light was irradiated for a certain time to obtain a linear graph, The sensitivity is evaluated.

The photoelectric conversion efficiency is measured using an IPCE measurement system (McScience, Korea). First, the equipment was calibrated using an Si photodiode (Hamamatsu, Japan), and a CMOS image sensor according to Examples 1 and 2 was installed in the equipment and the photoelectric conversion efficiency was measured in a wavelength range of about 350 to 750 nm do.

The results are shown in Table 2.

Sensitivity (mV / lux · s) Photoelectric conversion efficiency (%) Example 1 250 40 Example 2 343 55

Referring to Table 2, it can be seen that the image sensor according to Examples 1 and 2 has a good performance by showing sensitivity of about 250 mV / lux · s and photoelectric conversion efficiency of 40% or more, It can be confirmed that the image sensor according to the second embodiment exhibits further improved sensitivity and photoelectric conversion efficiency.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, And falls within the scope of the invention.

50B: blue light sensing element 50R: red light sensing element
60: Lower insulating layer
70: color filter 80: upper insulating layer
85: through hole 90: semi-permeable layer
100: Green light sensing element
110: lower electrode
120: upper electrode 130: photoactive layer
300: CMOS image sensor

Claims (14)

A semiconductor substrate on which a plurality of first light sensing elements for sensing light in a blue wavelength region and a plurality of second light sensing elements for sensing light in a red wavelength region are integrated,
A color filter layer disposed on the semiconductor substrate and including a blue filter selectively absorbing light in a blue wavelength range and a red filter selectively absorbing light in a red wavelength range,
A third photo-sensing device including a pair of electrodes disposed on the color filter layer and facing each other, and a photoactive layer disposed between the electrodes and selectively absorbing light in a green wavelength region,
.
The method of claim 1,
Wherein the blue wavelength region exhibits a maximum absorption wavelength (? _Max ) at a wavelength of 400 nm or more and less than 500 nm,
Wherein the red wavelength region exhibits a maximum absorption wavelength (? _Max ) of greater than 580 nm and less than 700 nm,
Wherein the green wavelength region exhibits a maximum absorption wavelength (? _Max ) at 500 nm to 580 nm.
The method of claim 1,
Wherein the pair of electrodes facing each other is a light-projecting electrode,
Wherein the photoactive layer comprises a p-type semiconductor material and an n-type semiconductor material,
Wherein at least one of the p-type semiconductor material and the n-type semiconductor material selectively absorbs light in the green wavelength region.
The method of claim 1,
And a condenser lens located on the third photo-sensing device.
The method of claim 1,
And a metal wiring located below the first photo-sensing device and the second photo-sensing device.
The method of claim 1,
And a transflective layer positioned between the third photo-sensing element and the color filter layer.
The method of claim 6,
Wherein the transflective layer transmits light in the blue wavelength region and the red wavelength region and reflects light in the green wavelength region.
8. The method of claim 7,
Wherein the transflective layer comprises a plurality of layers in which a first layer and a second layer having different refractive indices are alternately stacked.
9. The method of claim 8,
Wherein the thickness of the first layer and the second layer is determined by the refractive index and the reflection wavelength of the first layer and the second layer.
9. The method of claim 8,
Wherein the half width of the green wavelength region in the light absorption spectrum is determined by the ratio of the refractive index of the first layer to the refractive index of the second layer.
9. The method of claim 8,
The first layer has a refractive index of 1.2 to 1.8,
Wherein the second layer has a refractive index of 2.1 to 2.7
Image sensor.
9. The method of claim 8,
Wherein the first layer is a silicon oxide layer,
The second layer is a titanium oxide layer
Image sensor.
9. The method of claim 8,
Wherein the semi-transparent layer comprises a plurality of silicon oxide layers and a plurality of titanium oxide layers alternately stacked to form a total of 5 to 10 layers,
Wherein each of the silicon oxide layers has a thickness of 10 nm to 300 nm and each of the titanium oxide layers has a thickness of 30 nm to 200 nm.
An electronic device comprising an image sensor according to any one of claims 1 to 13.

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