CN109786414A - Imaging sensor and forming method thereof - Google Patents
Imaging sensor and forming method thereof Download PDFInfo
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- CN109786414A CN109786414A CN201910193328.2A CN201910193328A CN109786414A CN 109786414 A CN109786414 A CN 109786414A CN 201910193328 A CN201910193328 A CN 201910193328A CN 109786414 A CN109786414 A CN 109786414A
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- negative refraction
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Abstract
A kind of imaging sensor and forming method thereof, described image sensor may include: semiconductor substrate, have multiple photodiodes in the semiconductor substrate；Multiple reflex blocks have gap between the front of the semiconductor substrate, neighboring reflection block；Metal interlamination medium layer covers the reflex block, is formed with metal interconnection structure in the metal interlamination medium layer；Wherein, the reflecting surface of each reflex block is towards at least one photodiode, for the light for being incident to the reflecting surface to be reflected back the photodiode.The uptake of light can be improved in the present invention program, reduces optical crosstalk, increases the sensitivity of imaging sensor.
Description
Technical field
The present invention relates to technical field of manufacturing semiconductors more particularly to a kind of imaging sensor and forming method thereof.
Background technique
Imaging sensor is the core component of picture pick-up device, realizes image taking function by converting optical signals into electric signal
Energy.By taking cmos image sensor (CMOS Image Sensors, CIS) device as an example, due to its tool
There is the advantages of low-power consumption and high s/n ratio, therefore is widely applied in various fields.
By taking back-illuminated type (Back-side Illumination, BSI) CIS as an example, in existing manufacturing process, first half
Conductor substrate interior and surface form logical device, pixel device and metal interconnection structure, then using carrying wafer and institute
State the front bonding of semiconductor substrate, so the back of semiconductor substrate is carried out it is thinned, and then at the back side of semiconductor substrate
The subsequent technique of CIS is formed, such as forms latticed grid (Grid) at the semiconductor substrate back side of the pixel device,
It is formed in grid between the grid filter (Color Filter) etc..Wherein, the pixel device may include photoelectricity
Diode.
However in existing imaging sensor, since the absorption depth of light in a silicon substrate is different, a part of light
Understand reach throught photodiode and fail to be absorbed, causes quantum efficiency to decline, influence the image quality of imaging sensor.
Summary of the invention
The technical problem to be solved by the present invention is to provide a kind of imaging sensors and forming method thereof, and the suction of light can be improved
Receipts amount reduces optical crosstalk, increases the sensitivity of imaging sensor.
In order to solve the above technical problems, the embodiment of the present invention provides a kind of imaging sensor, comprising: semiconductor substrate, institute
Stating has multiple photodiodes in semiconductor substrate；Multiple reflex blocks, positioned at the front of the semiconductor substrate, neighboring reflection
There is gap between block；Metal interlamination medium layer, covers the reflex block, and it is mutual to be formed with metal in the metal interlamination medium layer
Link structure；Wherein, the reflecting surface of each reflex block is towards at least one photodiode, for that will be incident to the reflecting surface
Light is reflected back the photodiode.
Optionally, the reflex block and the photodiode correspond, and the reflecting surface direction of each reflex block is corresponding
Photodiode.
Optionally, the reflecting surface of the reflex block has a recessed portion, and the recessed portion is to far from the photodiode
Direction recess.
Optionally, the shape of the longitudinal section of the recessed portion is arc, triangle or trapezoidal；Wherein, the longitudinal section
Surface of the direction perpendicular to the semiconductor substrate.
Optionally, the imaging sensor further include: dielectric layer, positioned at the back side of the semiconductor substrate；It is latticed
Grid, positioned at the surface of the dielectric layer；Filter structure, in the opening of the grid；Wherein, under each grid opening
There is negative refraction film, the refractive index of the negative refraction film is negative value, and the negative refraction film offers in the dielectric layer of side
Optical transmission window, the optical transmission window are filled by the dielectric layer, into the light in the opening a part through described
Dielectric layer outflow in light window, the remainder of the light are spread out of through the negative refraction film.
Optionally, the shape of the cross section of the negative refraction film is hollow box；Wherein, the cross section is parallel to
The surface of the semiconductor substrate.
Optionally, the top surface of the negative refraction film is flushed with the top surface of the dielectric layer；And/or it is described
The bottom surface of negative refraction film is flushed with the bottom surface of the dielectric layer.
Optionally, the dielectric layer below the opening of the grid has groove, and the negative refraction film is located at the groove
It is interior.
Optionally, the negative refraction film below adjacent opening is connected with each other.
In order to solve the above technical problems, the embodiment of the present invention provides a kind of forming method of imaging sensor, comprising: formed
Semiconductor substrate, the semiconductor substrate is interior to have multiple photodiodes；It is formed in the front of the semiconductor substrate multiple
Independent reflex block；The metal interlamination medium layer for covering the reflex block is formed, is formed with gold in the metal interlamination medium layer
Belong to interconnection structure；Wherein, the reflecting surface of each reflex block is towards at least one photodiode, for that will be incident to the reflection
The light in face is reflected back the photodiode.
Optionally, the forming method of the imaging sensor further include: formed and be situated between at the back side of the semiconductor substrate
Matter layer；Latticed grid is formed on the surface of the dielectric layer；Filter structure is formed in the opening of the grid；Wherein,
There is negative refraction film, the refractive index of the negative refraction film is negative value, described negative in the dielectric layer of each grid opening lower section
Birefringent thin film offers optical transmission window, and the optical transmission window is filled by the dielectric layer, into one of the light in the opening
Part is spread out of through the dielectric layer outflow in the optical transmission window, the remainder of the light through the negative refraction film.
Compared with prior art, the technical solution of the embodiment of the present invention has the advantages that
In embodiments of the present invention, a kind of imaging sensor is provided, comprising: semiconductor substrate, in the semiconductor substrate
With multiple photodiodes；Multiple reflex blocks, positioned at the front of the semiconductor substrate, between having between neighboring reflection block
Gap；Metal interlamination medium layer covers the reflex block, is formed with metal interconnection structure in the metal interlamination medium layer；Wherein,
The reflecting surface of each reflex block is towards at least one photodiode, for the light for being incident to the reflecting surface to be reflected back institute
State photodiode.Using the above scheme, by the way that multiple reflex blocks are arranged, and there is gap between neighboring reflection block, it is each anti-
The reflecting surface of block is penetrated towards at least one photodiode, for the light for being incident to the reflecting surface to be reflected back two pole of photoelectricity
Pipe can make light turn again to photodiode after reflection after light passes through photodiode using reflex block
Double absorption is carried out, the uptake of light is helped to improve, reduces optical crosstalk, increases the sensitivity of imaging sensor.
Further, being arranged in the dielectric layer of each grid opening lower section has negative refraction film, so that a part of light is saturating
Cross the outflow of negative refraction film.Compared in the prior art, the incident light oblique fire angle in CIS chip edge region is larger, and light is inhaled
There is waste in receipts amount, in embodiments of the present invention, by using negative refraction film, can act on entering oblique fire by negative refraction
The reverse bounce back photodiode of light is penetrated, so that the absorbing amount consistency in CIS chip center region and fringe region
It is improved, however since absorbing amount increases, more light reach throught photodiodes are easy to cause, longitudinal leakage is generated when serious
Electric current, can be by electric two poles of the reflection of generation incident light light echo penetrated by using reflex block using the scheme of the embodiment of the present invention
Pipe to reduce longitudinal leakage current, namely by using reflex block, can be mended with using negative refraction film bring effect
Repay balance.
Further, in embodiments of the present invention, the reflecting surface of the reflex block has recessed portion, and the recessed portion is to separate
The direction of the photodiode is recessed, and helps to absorb the light reflected light electric diode of more multiple incidence direction,
To improve light absorption.
Detailed description of the invention
Fig. 1 is a kind of the schematic diagram of the section structure of imaging sensor in the prior art；
Fig. 2 is a kind of flow chart of the forming method of imaging sensor in the embodiment of the present invention；
Fig. 3 to Fig. 5 is the corresponding device of part steps in a kind of forming method of imaging sensor in the embodiment of the present invention
The schematic diagram of the section structure；
Fig. 6 is a kind of top view of the imaging sensor shown in Fig. 5 along cutting line A1-A2；
Fig. 7 is top view of another imaging sensor shown in Fig. 5 along cutting line A1-A2；
Fig. 8 is a kind of device profile structural schematic diagram of imaging sensor in the embodiment of the present invention.
Specific embodiment
In existing imaging sensor, a part of light understands reach throught photodiode and fails to be absorbed, and leads to quantum
Efficiency decline, influences the image quality of imaging sensor.
Referring to Fig.1, Fig. 1 is a kind of the schematic diagram of the section structure of imaging sensor in the prior art.
In existing imaging sensor, semiconductor substrate 100 can be provided, is formed on the surface of semiconductor substrate 100
Metallic grid 104, and then filter structure 106 is formed in the opening between metallic grid 104, and then in the filter structure
106 surface forms lens arrangement 108.
Wherein, logical device, pixel device and metal interconnecting layer are formed in the semiconductor substrate 100, it is described
Pixel device can wrap containing photodiode 102, and the metal interconnecting layer may include metal interconnection structure and metal layer
Between dielectric layer 110.
The present inventor has found after study, conventionally, as the absorption depth of light in a silicon substrate
Difference, a part of light can reach throught photodiode and fail to be absorbed, especially longer wavelengths of light (such as infrared ray,
Feux rouges) absorptivity is lower, and cause quantum efficiency to decline, influences the image quality of imaging sensor.
It should be pointed out that the light can be made of the light of different colours, and the optical wavelength of different colours is different.
The arrow direction shown referring to Fig.1, light passes through lens arrangement 108, filter structure 106 enters photodiode
102, fail absorbed light across photodiode 102, such as into or through metal interlamination medium layer 110.
It should be pointed out that when described image sensor is 3D-Stack CIS, and using logic wafer and pixel wafer
When bonding, light is also possible to across metal interlamination medium layer 110 and enters the logical device in logic wafer, influences logical device
Quality.
Specifically, 3 dimension stacking-type (3D-Stack) CIS are developed, to support the demand to higher quality image.
3D-Stack CIS can make logic wafer and pixel wafer respectively, so by the logic wafer front with
And the front bonding of the pixel wafer, since pixel portion and logic circuitry portions are mutually indepedent, high image quality can be directed to
Demand pixel portion is optimized, logic circuitry portions are optimized for high performance demand.
In embodiments of the present invention, a kind of imaging sensor is provided, comprising: semiconductor substrate, in the semiconductor substrate
With multiple photodiodes；Multiple reflex blocks, positioned at the front of the semiconductor substrate, between having between neighboring reflection block
Gap；Metal interlamination medium layer covers the reflex block, is formed with metal interconnection structure in the metal interlamination medium layer；Wherein,
The reflecting surface of each reflex block is towards at least one photodiode, for the light for being incident to the reflecting surface to be reflected back institute
State photodiode.Using the above scheme, by the way that multiple reflex blocks are arranged, and there is gap between neighboring reflection block, it is each anti-
The reflecting surface of block is penetrated towards at least one photodiode, for the light for being incident to the reflecting surface to be reflected back two pole of photoelectricity
Pipe can make light turn again to photodiode after reflection after light passes through photodiode using reflex block
Double absorption is carried out, the uptake of light is helped to improve, reduces optical crosstalk, increases the sensitivity of imaging sensor.
It is understandable to enable above-mentioned purpose of the invention, feature and beneficial effect to become apparent, with reference to the accompanying drawing to this
The specific embodiment of invention is described in detail.
Referring to Fig. 2, Fig. 2 is a kind of flow chart of the forming method of imaging sensor in the embodiment of the present invention.The formation
Method may include step S21 to step S24:
Step S21: semiconductor substrate is formed, there are multiple photodiodes in the semiconductor substrate；
Step S22: multiple independent reflex blocks are formed in the front of the semiconductor substrate；
Step S23: the metal interlamination medium layer for covering the reflex block is formed, is formed in the metal interlamination medium layer
Metal interconnection structure, wherein the reflecting surface of each reflex block is described anti-for that will be incident to towards at least one photodiode
The light for penetrating face is reflected back the photodiode.
Above-mentioned each step is illustrated below with reference to Fig. 3 to Fig. 8.
Fig. 3 to Fig. 5 is the corresponding device of each step in the forming method of the first imaging sensor in the embodiment of the present invention
The schematic diagram of the section structure.
Referring to Fig. 3, semiconductor substrate 200 is provided, there are multiple photodiodes 202 in the semiconductor substrate 200,
The front of the semiconductor substrate 200 forms multiple independent reflex blocks 220.
Wherein, in specific implementation, the semiconductor substrate 200 can be silicon substrate or the semiconductor substrate 200
Material can also be the material appropriate applied to imaging sensor such as germanium, SiGe, silicon carbide, GaAs or gallium indium,
The semiconductor substrate 200 can also be the silicon substrate of insulator surface or the germanium substrate of insulator surface, or growth
There is the substrate of epitaxial layer (Epitaxy layer, Epi layer).
The photodiode 202 can generate photo-generated carrier in the case where being excited by extraneous light intensity, i.e., electric
Son.The photodiode 202 can be formed by ion implantation technology, moreover, passing through the control energy of ion implanting and dense
Degree can control the depth and injection range of ion implanting, to control the depth and thickness of photodiode 202.
Further, the material of the reflex block 220 is needed with light reflective, can be metal material.
Further, the material of the reflex block 220 can be selected from: copper, aluminium, titanium, gold, silver, tin and other are appropriate
Metal material.
The reflecting surface of each reflex block 220 is towards at least one photodiode 202, for that will be incident to the reflecting surface
Light be reflected back the photodiode 202.It should be pointed out that the light for being incident to the reflecting surface is used to indicate
From the back side light transmission of semiconductor substrate 200 to positive light, for example including across lens arrangement, filter structure and photoelectricity two
The light of pole pipe 202.
Further, the reflex block 220 can be corresponded with the photodiode 202, each reflex block 220
Reflecting surface is towards corresponding photodiode 202.
In embodiments of the present invention, it is corresponded by the way that the reflex block 220 is arranged with the photodiode 202, it can
So that the light for passing through each photodiode 202 is pointedly reflected, and the area and photoelectricity of single reflex block 220
The sectional area of diode 202 has corresponding relationship, compared to large stretch of reflecting layer or the reflection fritter of fine particle shape, to light
Reflecting effect it is more preferable.
It should be pointed out that when described image sensor is 3D-Stack CIS, and using logic wafer and pixel wafer
When bonding, using the scheme of the embodiment of the present invention, light can also be avoided to enter the logical device in logic wafer, to improve
The quality of logical device.
Wherein, the process for forming the reflex block 220 may include: to be initially formed dielectric layer, form figure in the dielectric layer
The groove of change fills reflecting material in the trench, and then by planarization or etching technics to form the reflex block 220.
Further, the reflecting surface of the reflex block 220 can have recessed portion, and the recessed portion is to far from the photoelectricity
The direction of diode 202 is recessed.
Wherein, it is recessed by the way that the recessed portion is arranged to the direction far from the photodiode 202, can be made described anti-
The reflecting surface of block 220 is penetrated towards the photodiode 202, for the light for being incident to the reflecting surface to be reflected back photoelectricity two
Pole pipe 202.
In embodiments of the present invention, the reflecting surface of the reflex block 220 has recessed portion, and the recessed portion is to far from described
The direction of photodiode 202 is recessed, and helps to inhale the light reflected light electric diode 202 of more multiple incidence direction
It receives, to improve light absorption.It should be pointed out that the reflecting surface of the reflex block 220 can also be plane.
Further, the shape of the longitudinal section of the recessed portion is arc, triangle or trapezoidal；Wherein, the longitudinal section
Direction perpendicular to the semiconductor substrate surface.
It in embodiments of the present invention, is arc by the shape that the longitudinal section of the recessed portion is arranged, triangle or trapezoidal,
Reflecting surface compared to setting reflex block 220 is plane, is facilitated the light reflected light electric diode of more multiple incidence direction
202 are absorbed, to improve light absorption, increase the sensitivity of imaging sensor.
In specific implementation, the photoresist with radian can be formed using grayscale mask version or Photoresist reflow technique
(Photo Resist, PR), and then the groove that bottom surface has radian is formed, to form reflecting surface with the anti-of recessed portion
Penetrate block 220.In embodiments of the present invention, for specifically forming the technology mode of reflex block 220 with no restrictions.
Referring to Fig. 4, the metal interlamination medium layer 210 for covering the reflex block 220, the metal interlamination medium layer are formed
Metal interconnection structure is formed in 210.
It should be pointed out that when the reflex block 220 is arranged the position of metal interconnection structure can be avoided, not
In the case where the device function for influencing imaging sensor, realizes and the light for being incident to the reflecting surface is reflected back the photoelectricity two
Pole pipe 202.
Referring to Fig. 5, dielectric layer 221 is formed at the back side of the semiconductor substrate, there is negative refraction in the dielectric layer 221
Film 203.
Wherein, the refractive index of the negative refraction film 203 is negative value, and the negative refraction film 203 offers optical transmission window,
The optical transmission window is filled by the dielectric layer 221, and a part into the light in the opening penetrates the optical transmission window
Interior dielectric layer 221 is spread out of, and the remainder of the light is spread out of through the negative refraction film 203.
Specifically, the material of the negative refraction film 203 be properly termed as again left-handed material (Left Handed Medium,
), LHM it is used to indicate the medium that refractive index n is negative.
More specifically, the material of existing negative refraction film 203 is usually permittivity ε, magnetic permeability μ and refractive index n
The medium being negative has Quantum optics degree, negative refraction, reversed Doppler effect, reversal cerenkov radiation, ideal image etc. different
Normal physical property.Above-mentioned abnormal characteristic, make the material of the negative refraction film 203 solid-state physics, material science, optics and
Applied electromagnetics field is widely applied.
In a kind of specific embodiment of the embodiment of the present invention, the negative refraction film 203 of use, which can be, utilizes fishing net
Sample film and silver, aluminium oxide lamination are developed.
More specifically, referring to the article " theory and numerical simulation of negative index substance of " Shandong University " 2007 annual
Research " page 29 (author Song Lei), by by silver it is alternately laminated with opaque aluminium oxide together with, diameter is dug out on film
For the duck eye of 100nm, duck eye weave in.Then remove the aluminium oxide between silver layer using lithographic technique, use gain media
Filling, to form the negative refraction film 203.Above-mentioned composite construction is periodically arranged by two or more electrolyte
Artificial material made of column, arrangement period are wavelength magnitude, have luminous energy band gap, can control electromagnetic wave and propagate wherein.
It should be pointed out that in embodiments of the present invention, with no restriction to the specific implementation structure of negative refraction film 203.
Further, the dielectric layer 221 below the opening for the grid being subsequently formed can have groove, and the negative refraction is thin
Film 203 is located in the groove.
In specific implementation, first dielectric layer 221 can be performed etching to form groove, then in groove described in formation
Negative refraction film 203, so that a part of light is spread out of through negative refraction film 203, and compared to bulk zone
The negative refraction film 203 is set, it is possible to reduce the consumption of negative refraction film 203, to help to reduce production cost.
It should be pointed out that in embodiments of the present invention, for the technique side for specifically forming the negative refraction film 203
Formula is with no restrictions.
Further, the top surface of the negative refraction film 203 can be neat with the top surface of the dielectric layer 221
It is flat；And/or the bottom surface of the negative refraction film 203 can be flushed with the bottom surface of the dielectric layer 221.
In embodiments of the present invention, by the way that the top surface of negative refraction film 203 and the top of the dielectric layer 221 is arranged
Surface flushes；And/or the bottom surface of the negative refraction film 203 is set and is flushed with the bottom surface of the dielectric layer 221,
Have an opportunity to carry out negative refraction to the light for propagating to the edge of filter structure, being possible to inject adjacent photodiode 202,
The problem of to further decrease optical crosstalk.
Further, the shape of the cross section of the negative refraction film 203 can be hollow box；Wherein, the cross
Section is parallel to the surface of the semiconductor substrate 200.
Referring to Fig. 6, Fig. 6 is a kind of top view of the imaging sensor shown in Fig. 5 along cutting line A1-A2.
As shown in fig. 6, the optical transmission window of the negative refraction film 203 is filled by the dielectric layer 221, the negative refraction is thin
The shape of the cross section of film 203 can be hollow box；Wherein, the cross section is parallel to the table of the semiconductor substrate
Face.
It is understood that the width of the box should not be wide, the undersized of optical transmission window otherwise will lead to, thoroughly
Light quantity is too low and then influences image quality；The width of shown box should not be narrow, otherwise will lead to the ruler of negative refraction film 203
It is very little too small, it is difficult to achieve the effect that reduce optical crosstalk.
As a unrestricted example, the width that the box can be set is the outer of the negative refraction film 203
The 5% to 20% of the cornerwise length in edge.
It in embodiments of the present invention, is hollow box by the shape for the cross section that the negative refraction film 203 is arranged,
The regular negative refraction film 203 of shape can be formed, is irregular shape compared to the optical transmission window that negative refraction film 203 opens up
Shape can reduce process complexity, and improve the consistency of the light throughput of different angle incidence.
Further, the negative refraction film below adjacent opening is connected with each other.
In embodiments of the present invention, it is connected with each other, can be made by the way that the negative refraction film 203 below adjacent opening is arranged
The shape of negative refraction film 203 is fairly simple, facilitates the technology difficulty for reducing size Control.
Referring to Fig. 7, Fig. 7 is top view of another imaging sensor shown in Fig. 5 along cutting line A1-A2.
As shown in fig. 7, the negative refraction film 303 offers optical transmission window, and optical transmission window is filled out by the dielectric layer 321
It fills, the negative refraction film 303 is located in groove, and the shape of cross section can be hollow box；Wherein, the cross section
It is parallel to the surface of the semiconductor substrate.
It in embodiments of the present invention, is hollow box by the shape for the cross section that the negative refraction film 303 is arranged,
The regular negative refraction film 303 of shape can be formed, is irregular shape compared to the optical transmission window that negative refraction film 303 opens up
Shape can reduce process complexity, and improve the consistency of the light throughput of different angle incidence.
In embodiments of the present invention, the dielectric layer 321 below the opening by the way that the grid is arranged has groove, described negative
Birefringent thin film 303 is located in the groove, it is possible to reduce the consumption of negative refraction film 303 is produced into help to reduce
This.
Referring to Fig. 8, Fig. 8 is a kind of device profile structural schematic diagram of imaging sensor in the embodiment of the present invention.
Latticed grid 204, Jin Er is formed on the surface of the negative refraction film 203 and the dielectric layer 221
Filter structure 206 is formed in the opening of the grid 204, forms lens arrangement 208 on the surface of the filter structure 206.
Wherein, the material of the grid 204 can be metal.
Fiber line referring to shown in dotted line, the light slanted due to 203 Duis of negative refraction film can be effectively performed negative
Refraction, has an opportunity to make light via the negative refraction film 203 by reverse bounce back photodiode 202, to avoid light
The problem of injecting adjacent photodiode 202, being effectively reduced optical crosstalk.
In embodiments of the present invention, being arranged in the dielectric layer 221 of each grid opening lower section has negative refraction film 203,
So that a part of light is spread out of through negative refraction film 203.Compared in the prior art, the incidence in CIS chip edge region
Light oblique fire angle is larger, and absorbing amount has waste, in embodiments of the present invention, by using negative refraction film 203, Ke Yitong
Negative refraction effect is crossed by the reverse bounce back photodiode 202 of the incident light of oblique fire so that in CIS chip center region and
The absorbing amount consistency of fringe region is improved, however since absorbing amount increases, it is easy to cause more light to penetrate light
Electric diode 202 generates longitudinal leakage current when serious, can by using reflex block 220 using the scheme of the embodiment of the present invention
With the reflection of generation incident light light echo electric diode 202 that will be penetrated, to reduce longitudinal leakage current, namely by using reflex block 220,
Balance can be compensated with using 203 bring effect of negative refraction film.
Further, with continued reference to arrow direction shown in figure, fail to be passed through by the light that photodiode 202 absorbs
Then photodiode 202 is reflected by reflex block 220.It is understood that having an opportunity will at least by setting reflex block 220
A part of light reflected light electric diode 202, to improve light absorption.
In embodiments of the present invention, by the way that multiple reflex blocks 220 are arranged, and there is gap between neighboring reflection block 220, often
Towards at least one photodiode 202, the light for that will be incident to the reflecting surface reflects the reflecting surface of a reflex block 220
Light echo electric diode 202 can make light after reflection after light passes through photodiode 202 using reflex block 220
It turns again to photodiode 202 and carries out double absorption, help to improve the uptake of light, reduce optical crosstalk, increase figure
As the sensitivity of sensor.
In embodiments of the present invention, a kind of imaging sensor is additionally provided, may include: semiconductor substrate referring to Fig. 8
200, the semiconductor substrate is interior to have multiple photodiodes 202；Multiple reflex blocks 220 are located at the semiconductor substrate 200
Front, there is between neighboring reflection block 220 gap；Metal interlamination medium layer 210 covers the reflex block 220, the metal
Metal interconnection structure is formed in interlayer dielectric layer 210；Wherein, the reflecting surface of each reflex block 220 is towards at least one photoelectricity
Diode 202, for the light for being incident to the reflecting surface to be reflected back the photodiode 202.
Further, the reflex block 220 can be corresponded with the photodiode 202, each reflex block 220
Reflecting surface can be towards corresponding photodiode 202.
Further, the reflecting surface of the reflex block 220 has recessed portion, and the recessed portion is to far from two pole of photoelectricity
The direction of pipe 202 is recessed.
Further, the shape of the longitudinal section of the recessed portion is arc, triangle or trapezoidal；Wherein, the longitudinal section
Direction perpendicular to the semiconductor substrate 200 surface.
Further, the imaging sensor can also include: dielectric layer 221, positioned at the semiconductor substrate 200
The back side；Latticed grid 204, positioned at the surface of the dielectric layer 221；Filter structure 206, positioned at opening for the grid 204
In mouthful；Wherein, there is negative refraction film 203 in the dielectric layer 221 of each grid opening lower section, the negative refraction film 203
Refractive index is negative value, and the negative refraction film 203 offers optical transmission window, and the optical transmission window is filled by the dielectric layer 221,
A part into the light in the opening is spread out of through the dielectric layer 221 in the optical transmission window, the residue of the light
Part is spread out of through the negative refraction film 203.
In embodiments of the present invention, being arranged in the dielectric layer 221 of each grid opening lower section has negative refraction film 203,
So that a part of light is spread out of through negative refraction film 03.Compared in the prior art, the incident light in CIS chip edge region
It is larger to slant angle, absorbing amount has waste, in embodiments of the present invention, by using negative refraction film 203, can pass through
Negative refraction is acted on by the reverse bounce back photodiode 202 of the incident light of oblique fire, so that on CIS chip center region and side
The absorbing amount consistency in edge region is improved, however since absorbing amount increases, it is easy to cause more light to penetrate photoelectricity
Diode 202 generates longitudinal leakage current when serious,, can be with by using reflex block 220 using the scheme of the embodiment of the present invention
The reflection of generation incident light light echo electric diode 202 that will be penetrated, so that longitudinal leakage current is reduced, namely by using reflex block 220, it can
To compensate balance with using 203 bring effect of negative refraction film.
Further, the shape of the cross section of the negative refraction film 203 can be hollow box；Wherein, the cross
Section is parallel to the surface of the semiconductor substrate 200.
Further, the top surface of the negative refraction film 203 is flushed with the top surface of the dielectric layer 221；With/
Or, the bottom surface of the negative refraction film 203 is flushed with the bottom surface of the dielectric layer 221.
Further, the dielectric layer below the opening of the grid 204 can have groove, the negative refraction film 203
In the groove.
Further, the negative refraction film 203 below adjacent opening can be connected with each other.
In embodiments of the present invention, by the way that multiple reflex blocks 220 are arranged, and there is gap between neighboring reflection block 220, often
Towards at least one photodiode 202, the light for that will be incident to the reflecting surface reflects the reflecting surface of a reflex block 220
Light echo electric diode 202 can make light after reflection after light passes through photodiode 202 using reflex block 220
It turns again to photodiode 202 and carries out double absorption, help to improve the uptake of light, reduce optical crosstalk, increase figure
As the sensitivity of sensor.
The pass above and shown in Fig. 2 to Fig. 8 is please referred to about the principle of the imaging sensor, specific implementation and beneficial effect
In the associated description of the forming method of imaging sensor, details are not described herein again.
Although present disclosure is as above, present invention is not limited to this.Anyone skilled in the art are not departing from this
It in the spirit and scope of invention, can make various changes or modifications, therefore protection scope of the present invention should be with claim institute
Subject to the range of restriction.
Claims (11)
1. a kind of imaging sensor characterized by comprising
Semiconductor substrate, the semiconductor substrate is interior to have multiple photodiodes；
Multiple reflex blocks have gap between the front of the semiconductor substrate, neighboring reflection block；
Metal interlamination medium layer covers the reflex block, is formed with metal interconnection structure in the metal interlamination medium layer；
Wherein, the reflecting surface of each reflex block is towards at least one photodiode, for that will be incident to the light of the reflecting surface
Line reflection returns the photodiode.
2. imaging sensor according to claim 1, which is characterized in that the reflex block and the photodiode are one by one
Corresponding, the reflecting surface of each reflex block is towards corresponding photodiode.
3. imaging sensor according to claim 1, which is characterized in that the reflecting surface of the reflex block has recessed portion,
The recessed portion is recessed to the direction far from the photodiode.
4. imaging sensor according to claim 3, which is characterized in that the shape of the longitudinal section of the recessed portion is arc
Shape, triangle or trapezoidal；
Wherein, surface of the direction of the longitudinal section perpendicular to the semiconductor substrate.
5. imaging sensor according to claim 1, which is characterized in that further include:
Dielectric layer, positioned at the back side of the semiconductor substrate；
Latticed grid, positioned at the surface of the dielectric layer；
Filter structure, in the opening of the grid；
Wherein, there is negative refraction film in the dielectric layer of each grid opening lower section, the refractive index of the negative refraction film is negative
Value, the negative refraction film offer optical transmission window, and the optical transmission window is filled by the dielectric layer, into the opening
For a part of light through the dielectric layer outflow in the optical transmission window, the remainder of the light is thin through the negative refraction
Film outflow.
6. imaging sensor according to claim 5, which is characterized in that the shape of the cross section of the negative refraction film is
Hollow box；
Wherein, the cross section is parallel to the surface of the semiconductor substrate.
7. imaging sensor according to claim 5, which is characterized in that
The top surface of the negative refraction film is flushed with the top surface of the dielectric layer；
And/or
The bottom surface of the negative refraction film is flushed with the bottom surface of the dielectric layer.
8. imaging sensor according to claim 5, which is characterized in that the dielectric layer below the opening of the grid has
Groove, the negative refraction film are located in the groove.
9. imaging sensor according to claim 5, which is characterized in that the negative refraction film below adjacent opening is mutual
Connection.
10. a kind of forming method of imaging sensor characterized by comprising
Semiconductor substrate is formed, there are multiple photodiodes in the semiconductor substrate；
Multiple independent reflex blocks are formed in the front of the semiconductor substrate；
The metal interlamination medium layer for covering the reflex block is formed, metal is formed in the metal interlamination medium layer and mutually links
Structure；
Wherein, the reflecting surface of each reflex block is towards at least one photodiode, for that will be incident to the light of the reflecting surface
Line reflection returns the photodiode.
11. the forming method of imaging sensor according to claim 10, which is characterized in that further include:
Dielectric layer is formed at the back side of the semiconductor substrate；
Latticed grid is formed on the surface of the dielectric layer；
Filter structure is formed in the opening of the grid；
Wherein, there is negative refraction film in the dielectric layer of each grid opening lower section, the refractive index of the negative refraction film is negative
Value, the negative refraction film offer optical transmission window, and the optical transmission window is filled by the dielectric layer, into the opening
For a part of light through the dielectric layer outflow in the optical transmission window, the remainder of the light is thin through the negative refraction
Film outflow.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112466897A (en) * | 2019-09-06 | 2021-03-09 | 爱思开海力士有限公司 | Image sensing device |
| CN113629082A (en) * | 2021-07-19 | 2021-11-09 | 联合微电子中心有限责任公司 | Shading structure, image sensor and preparation method of image sensor |
| CN115995478A (en) * | 2023-03-24 | 2023-04-21 | 合肥新晶集成电路有限公司 | Image sensor and method for manufacturing the same |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105990384A (en) * | 2015-03-20 | 2016-10-05 | 台湾积体电路制造股份有限公司 | Composite grid structure to reduce crosstalk in back side illumination image sensors |
| CN107255885A (en) * | 2017-08-16 | 2017-10-17 | 京东方科技集团股份有限公司 | Display panel and its manufacture method |
| CN107845651A (en) * | 2017-11-02 | 2018-03-27 | 德淮半导体有限公司 | Imaging sensor and forming method thereof |
-
2019
- 2019-03-14 CN CN201910193328.2A patent/CN109786414A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105990384A (en) * | 2015-03-20 | 2016-10-05 | 台湾积体电路制造股份有限公司 | Composite grid structure to reduce crosstalk in back side illumination image sensors |
| CN107255885A (en) * | 2017-08-16 | 2017-10-17 | 京东方科技集团股份有限公司 | Display panel and its manufacture method |
| CN107845651A (en) * | 2017-11-02 | 2018-03-27 | 德淮半导体有限公司 | Imaging sensor and forming method thereof |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112466897A (en) * | 2019-09-06 | 2021-03-09 | 爱思开海力士有限公司 | Image sensing device |
| CN113629082A (en) * | 2021-07-19 | 2021-11-09 | 联合微电子中心有限责任公司 | Shading structure, image sensor and preparation method of image sensor |
| CN115995478A (en) * | 2023-03-24 | 2023-04-21 | 合肥新晶集成电路有限公司 | Image sensor and method for manufacturing the same |
| CN115995478B (en) * | 2023-03-24 | 2023-06-27 | 合肥新晶集成电路有限公司 | Image sensor and method for manufacturing the same |
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