CN109256403A - Imaging sensor front-illuminated and forming method thereof - Google Patents
Imaging sensor front-illuminated and forming method thereof Download PDFInfo
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- CN109256403A CN109256403A CN201710573378.4A CN201710573378A CN109256403A CN 109256403 A CN109256403 A CN 109256403A CN 201710573378 A CN201710573378 A CN 201710573378A CN 109256403 A CN109256403 A CN 109256403A
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Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/14636—Interconnect structures
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/14625—Optical elements or arrangements associated with the device
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14643—Photodiode arrays; MOS imagers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14683—Processes or apparatus peculiar to the manufacture or treatment of these devices or parts thereof
Abstract
The present invention relates to a kind of imaging sensors front-illuminated and forming method thereof, comprising: provides semiconductor substrate, the semiconductor substrate is formed with the photodiode area corresponding to pixel unit；In formation multiple layer metal interconnection layer in the semiconductor substrate；The forming method of at least one layer of metal interconnecting layer includes: the formation optically denser medium region above the photodiode area；Metal layer is formed around optically denser medium region；Form the optically thinner medium region covered around the metal layer and optically denser medium region.Process and current conventional cmos semiconductor process compatible, simple process of the invention, while refractive index, the pattern etc. in optically denser medium region, flexible design can be independently deployed according to design requirement again.In addition, playing the role of photoconductive tube by increasing the high optically denser medium material of refractive index on photodiode area, reduce reflection and refraction causes to obtain loss of optical signal, to improve the sensitivity of imaging sensor, reduces crosstalk.
Description
Technical field
The present invention relates to image sensor technologies field more particularly to a kind of imaging sensor front-illuminated and its formation sides
Method.
Background technique
Imaging sensor is the sensor that can be experienced optical image information and convert thereof into usable output signal, is group
At the important component of digital camera.According to the difference of element, CCD(Charge Coupled Device can be divided into, electricity
Lotus coupling element) and CMOS(Complementary Metal-OxideSemiconductor, metal-oxide semiconductor (MOS) member
Part) two major classes.With the continuous hair of CMOS integrated circuit fabrication process especially cmos image sensor design and manufacturing process
Exhibition, cmos image sensor have gradually replaced ccd image sensor as mainstream.Cmos image sensor compares with work
Industry integrated level is higher, the more low advantage of power.
CMOS image sensor product can be divided into FSI(FrontSide Illumination, front-illuminated) and BSI(Back
Side Illumination, back-illuminated type).In CMOS image sensor product front-illuminated, BEOL(Back RndOf Line, after
Segment process) there is in processing procedure the metal line for being at least two layers or more, that is, it include the metal wire and dielectric layer of multilayer.For photosensitive
Area, the distance from chip surface to photosensitive surface is bigger, this just makes incident ray have to pass through a longer distance ability
It is absorbed by photosensitive area, not only light attenuation is larger, but also makes the CRA(Chief Ray Angle of chip, chief ray and imaging surface
The angle of normal direction) cannot be too big, to affect the extensive use of imaging sensor.
In addition, reflection, refraction can occur during propagation for light due to the presence of different medium layer, so that
Light generates loss, and energy is caused to reduce, and reduces in this way from the number of electrons that chip surface reaches photodiode bottom, reduces
The sensitivity of light affects the performance of imaging sensor.
Summary of the invention
The purpose of the present invention is to provide a kind of imaging sensors front-illuminated and forming method thereof, solve the figure of the prior art
As the light loss in sensor light communication process, sensitivity is improved.
In order to solve the above technical problem, the present invention provides a kind of forming methods of imaging sensor front-illuminated, comprising:
Semiconductor substrate is provided, the semiconductor substrate is formed with the photodiode area corresponding to pixel unit；
In formation multiple layer metal interconnection layer in the semiconductor substrate；
The forming method of at least one layer of metal interconnecting layer includes: the formation optically denser medium area above the photodiode area
Domain；Metal layer is formed around optically denser medium region；It forms the light covered around the metal layer and optically denser medium region and dredges Jie
Matter region.
Optionally, the cross sectional shape in the optically denser medium region is trapezoid or triangle.
Optionally, the refractive index of the optically denser medium is at least bigger than the refractive index of the optically thinner medium by 15% or more.
Optionally, the material of the optically denser medium be one of silicon nitride, silicon oxynitride, silicon carbide, hafnium oxide or
A combination thereof.
Optionally, the material of the optically thinner medium is silica, in silicon nitride, silicon oxynitride, silicon carbide, hafnium oxide
One kind or combinations thereof.
Optionally, 2 ~ 4 layers of metal interconnecting layer are formed in the semiconductor substrate.
Optionally, the first layer to secondary top layer metal interconnecting layer forming method further include: in the optically thinner medium
The through-hole structure of connection adjacent metal interconnection layer is formed in region.
Optionally, the forming method of at least one layer of metal interconnecting layer includes:
In forming optically denser medium in the semiconductor substrate, the optically denser medium is etched, is retained on the photodiode area
The part optically denser medium of side；
The metal layer for covering remaining semiconductor substrate and optically denser medium is formed, the metal layer is etched, retains close Jie of the light
Partial metal layers around matter；
The optically thinner medium for covering the metal layer and optically denser medium is formed, optically thinner medium described in chemical mechanical grinding exposes institute
State the top of optically denser medium.
Optionally, the first layer to secondary top layer metal interconnecting layer forming method further include: etch the light dredge be situated between
Matter forms the groove for exposing the part metal layer, and metal is filled in the groove, forms through-hole structure.
Optionally, the width in the optically denser medium region is less than or equal to the width of the photodiode area.
Correspondingly, another aspect of the present invention also provides a kind of imaging sensor front-illuminated, comprising:
Semiconductor substrate, the semiconductor substrate are formed with the photodiode area corresponding to pixel unit；
The multiple layer metal interconnection layer being formed in the semiconductor substrate；
At least one layer of metal interconnecting layer includes the optically denser medium region being formed in above the photodiode area；Positioned at institute
State the metal layer around optically denser medium region；Cover the optically thinner medium region around the metal layer and optically denser medium region.
Optionally, the cross sectional shape in the optically denser medium region is trapezoid or triangle.
Optionally, refractive index of the refractive index of the optically denser medium at least than the light beam medium is big by 15% or more.
Optionally, the material of the optically denser medium be one of silicon nitride, silicon oxynitride, silicon carbide, hafnium oxide or
A combination thereof.
Optionally, the material of the optically thinner medium is silica, in silicon nitride, silicon oxynitride, silicon carbide, hafnium oxide
One kind or combinations thereof.
Optionally, 2 ~ 4 layers of metal interconnecting layer are formed in the semiconductor substrate.
Optionally, the first layer to secondary top-level metallic interconnection layer also includes to be formed in the optically thinner medium region and connect
Connect the through-hole structure of adjacent metal interconnection layer.
Optionally, the width in the optically denser medium region is less than or equal to the width of the photodiode area.
Compared with the existing technology, imaging sensor front-illuminated in the present invention and forming method thereof has below beneficial to effect
Fruit:
In the present invention, the forming method of at least one layer of metal interconnecting layer includes: the formation light above the photodiode area
Close areas of dielectric；Metal layer is formed around optically denser medium region；It is formed and is covered around the metal layer and optically denser medium region
Optically thinner medium region.Process of the invention and current conventional cmos semiconductor process compatible, simple process, while again
Refractive index, the pattern etc. in optically denser medium region, flexible design can be independently deployed according to design requirement.
In addition, playing the work of photoconductive tube by increasing the high optically denser medium material of refractive index on photodiode area
With, it reduces reflection and refraction causes to obtain loss of optical signal, so that the sensitivity of imaging sensor is improved, reduction crosstalk.
Detailed description of the invention
Fig. 1 is the flow chart of imaging sensor forming method front-illuminated in one embodiment of the invention；
Fig. 2 is the flow chart of metal interconnecting layer forming method in one embodiment of the invention；
Fig. 3 is the diagrammatic cross-section of semiconductor substrate in one embodiment of the invention；
Fig. 4 is the diagrammatic cross-section that optically denser medium is formed in one embodiment of the invention；
Fig. 5 is the diagrammatic cross-section of remaining optically denser medium in one embodiment of the invention；
Fig. 6 is the diagrammatic cross-section that metal layer is formed in one embodiment of the invention；
Fig. 7 is the diagrammatic cross-section of remaining metal layer in one embodiment of the invention；
Fig. 8 is the diagrammatic cross-section that optically thinner medium is formed in one embodiment of the invention；
Fig. 9 is the diagrammatic cross-section of remaining optically thinner medium in one embodiment of the invention；
Figure 10 is the diagrammatic cross-section that groove is formed in one embodiment of the invention；
Figure 11 is the diagrammatic cross-section that through-hole structure is formed in one embodiment of the invention；
Figure 12 is the diagrammatic cross-section that multiple layer metal interconnection line is formed in one embodiment of the invention.
Specific embodiment
In the following description, numerous specific details are set forth in order to facilitate a full understanding of the present invention.But the present invention can be with
Much it is different from other way described herein to implement, those skilled in the art can be without prejudice to intension of the present invention the case where
Under do similar popularization, therefore the present invention is not limited to the specific embodiments disclosed below.
Secondly, the present invention is described in detail using schematic diagram, when describing the embodiments of the present invention, for purposes of illustration only, institute
Stating schematic diagram is example, should not limit the scope of protection of the invention herein.
To make the above purposes, features and advantages of the invention more obvious and understandable, below in conjunction with attached drawing to the present invention
Imaging sensor front-illuminated and forming method thereof be described in detail.
With reference to shown in Figure 12, a kind of imaging sensor front-illuminated provided by the invention includes: semiconductor substrate 10, and described half
Conductor substrate 10 is formed with the photodiode area 11 corresponding to pixel unit；It is formed in more in the semiconductor substrate 10
Layer metal interconnecting layer 30,40,50；At least one layer of metal interconnecting layer 30,40 or 50, which includes, is formed in the photodiode area
The optically denser medium region 31 ', 41 or 51 of 11 tops；Metal layer 32 ' around the optically denser medium region 31 ', 41 or 51,
42 or 52；Cover the optically thinner medium region 33 ', 43 or 53 around the metal layer and optically denser medium region.
Refering to what is shown in Fig. 1, the forming method of imaging sensor front-illuminated of the invention includes the following steps:
Step S1 is executed, refering to what is shown in Fig. 3, providing semiconductor substrate 10, the semiconductor substrate 10 is formed with several correspondences
In region 11 photodiode (Photo Diode, PD) of pixel unit (Pixel).The surface of semiconductor substrate 10 has exhausted
Edge layer 20 and the through-hole structure 21 in insulating layer 20, insulating layer 20 are used to protect the device junction in semiconductor substrate 10
Structure, through-hole structure 21 are used to electrically draw the device architecture in semiconductor substrate 10.
Step S2 is executed, with reference to shown in Figure 12, in last part technology processing procedure, in forming multilayer in the semiconductor substrate 10
Metal interconnecting layer is formed in 2 ~ 4 layers of metal interconnecting layer, such as the present embodiment to serve as a contrast in semiconductor in the semiconductor substrate 10
It is formed for 3 layers of metal interconnecting layer and is illustrated on bottom 10, including the first metal interconnecting layer 30, the second metal interconnecting layer 40, the
Three metal interconnecting layers (top-level metallic interconnection layer) 50.Wherein, the forming method of at least one layer of metal interconnecting layer includes: in the light
Optically denser medium region is formed above photodiode area；Metal layer is formed around optically denser medium region；It is formed and covers the gold
Belong to the optically thinner medium region around layer and optically denser medium region.
In the present invention, the refractive index of the optically denser medium is at least bigger than the refractive index of the optically thinner medium by 15% or more, example
Such as, the refractive index of optically denser medium is greater than 20% than the refractive index of optically thinner medium, by increasing refractive index on photodiode area
High optically denser medium material, plays the role of photoconductive tube, reduces reflection and refraction in the dielectric layer of light and causes to obtain loss of optical signal,
To improve the sensitivity of imaging sensor, crosstalk is reduced.Wherein, the material of the optically denser medium is silicon nitride (SiN), nitrogen oxygen
SiClx (SiON), silicon carbide (SiC), hafnium oxide (HfO2One of) or combinations thereof.The material of the optically thinner medium is oxygen
SiClx (SiO2), silicon nitride (SiN), silicon oxynitride (SiON), silicon carbide (SiC), hafnium oxide (HfO2) one of or its group
It closes.
In addition, in order to realize the electric connection between each layer metal interconnecting layer, the first layer to secondary top layer (second layer)
Metal interconnecting layer forming method further include: in the optically thinner medium region formed connection adjacent metal interconnection layer through-hole
Metal layer in structure, through-hole structure and adjacent layer metal interconnecting layer is electrically connected.
Refering to what is shown in Fig. 2, the forming method of at least one layer of metal interconnecting layer specifically includes the following steps:
Step S21 is executed, refering to what is shown in Fig. 4, etching close Jie of the light in forming optically denser medium 31 in the semiconductor substrate 10
Matter 31 retains the part optically denser medium region 31 ' of 11 top of photodiode area, with reference to shown in Fig. 5.The present embodiment
In, optically denser medium can be performed etching using traditional photoetching technique, for example, photoresist (PH) is formed on optically denser medium 31,
Through overexposure, development, etching, removal photoresist, optically denser medium region 31 ' is formed.The optically denser medium region 31 ' is cut
Face shape is trapezoid or triangle, for example, the angle of trapezoid bottom is 80 °, so that light enters optically denser medium region 31 '
Afterwards in the close areas of dielectric 31 ' of side wall reflected light as far as possible in optically denser medium region 31 ', so that light enters light as far as possible
Photodiode area 11 improves the optical property of imaging sensor.Also, the width in the optically denser medium region 31 ' be less than etc.
In the width of the photodiode area 11.The material of the optically denser medium be silicon nitride (SiN), silicon oxynitride (SiON),
Silicon carbide (SiC), hafnium oxide (HfO2One of) or combinations thereof, in the present embodiment by taking optically denser medium 31 is silicon nitride as an example
It is illustrated, the refractive index of silicon nitride is between 1.8 ~ 2.0.
Step S22 is executed, refering to what is shown in Fig. 6, forming the metal for covering remaining semiconductor substrate 10 and optically denser medium 31 '
Layer 32, etches the metal layer 32, retains the partial metal layers 32 ' around the optically denser medium 31 ', and metal layer 32 ' is located at logical
The top of pore structure 21, and be electrically connected with through-hole structure 21, it realizes and is electrically connected with the device architecture in semiconductor substrate 10,
With reference to shown in Fig. 7.
Step S23 is executed, covers the metal layer 32 ', optically denser medium 31 ' and remaining half refering to what is shown in Fig. 8, being formed
The optically thinner medium 33 of conductor substrate 10.Then, chemical mechanical grinding (CMP) optically thinner medium 33, optically thinner medium is divided in reserve part
33 ', and etching stopping ties up optically denser medium 31 ', the top of the optically denser medium 31 ' is exposed, with reference to shown in Fig. 9.The light
The material for dredging medium is silica (SiO2), silicon nitride (SiN), silicon oxynitride (SiON), silicon carbide (SiC), hafnium oxide
(HfO2One of) or combinations thereof, it is illustrated so that optically thinner medium 33 is silica as an example in the present embodiment, the folding of silica
Penetrating rate is between 1.4 ~ 1.6.
Further, the second metal interconnecting layer 40 and are formed on the first metal interconnecting layer 30 using above-mentioned forming method
Three metal interconnecting layers (top-level metallic interconnection layer) 50, and protective layer 60 is formed on top-level metallic interconnection layer 50.Of the invention
Process and current conventional cmos semiconductor process compatible, simple process, while can also independently be adjusted according to design requirement
Refractive index, pattern etc. with the optically denser medium region 31 ', 41,51 in each layer of metal interconnecting layer 30,40,50, i.e., each layer
The material that optically denser medium can use refractive index different, and its pattern can also be different, flexible design, to meet different set
Meter demand.In the present invention, the high optically denser medium 31 ' of refractive index, 41,51, optically denser medium are formed on photodiode area 11
31 ', 41,51 refractive index is greater than the optically thinner medium 33 ' of surrounding, 43,53, plays the role of photoconductive tube, so that light is in back segment
In the dielectric layer of technique in communication process, total reflection is formed, to reduce reflection and refraction causes to obtain loss of optical signal, improves figure
As the sensitivity of sensor, crosstalk is reduced.
In addition, the electric connection in order to realize each layer metal interconnecting layer 30,40,50, the first layer to secondary top layer (second
Layer) metal interconnecting layer 30,40 forming method further include: etch the optically thinner medium, formation exposes the part metal
The groove of layer fills metal in the groove, forms through-hole structure.It is illustrated by taking the first metal interconnecting layer 30 as an example, also
It needs to form through-hole structure in optically thinner medium 33 ', specifically, firstly, the refering to what is shown in Fig. 10, etching formation of optically thinner medium 33 '
The groove 34 of partial metal layers 32 ' is exposed, then, with reference to shown in Figure 11, metal is filled in groove 34, is used to form through-hole
The first metal interconnecting layer 30 is collectively formed in structure 35, optically denser medium 31 ', metal layer 32 ', optically thinner medium 33 ' and through-hole structure 35.
Second metal interconnecting layer 40 can form through-hole structure 45 using identical technique, form the knot of the metal interconnecting layer in Figure 12
Structure, this will not be repeated here by the present invention.
In conclusion providing a kind of imaging sensor front-illuminated and forming method thereof in the present invention, comprising: provide semiconductor
Substrate, the semiconductor substrate are formed with the photodiode area corresponding to pixel unit；In shape in the semiconductor substrate
At multiple layer metal interconnection layer；The forming method of at least one layer of metal interconnecting layer includes: in rectangular on the photodiode area
At optically denser medium region；Metal layer is formed around optically denser medium region；It is formed and covers the metal layer and optically denser medium region
The optically thinner medium region of surrounding.By increasing the high optically denser medium material of refractive index on photodiode area, light guide is played
The effect of pipe, reduces reflection and refraction causes to obtain loss of optical signal, to improve the sensitivity of imaging sensor, reduces crosstalk.
Although the invention has been described by way of example and in terms of the preferred embodiments, but it is not for limiting the present invention, any this field
Technical staff without departing from the spirit and scope of the present invention, may be by the methods and technical content of the disclosure above to this hair
Bright technical solution makes possible variation and modification, therefore, anything that does not depart from the technical scheme of the invention, and according to the present invention
Technical spirit any simple modifications, equivalents, and modifications to the above embodiments, belong to technical solution of the present invention
Protection scope.
Claims (18)
1. a kind of forming method of imaging sensor front-illuminated characterized by comprising
Semiconductor substrate is provided, the semiconductor substrate is formed with the photodiode area corresponding to pixel unit；
In formation multiple layer metal interconnection layer in the semiconductor substrate；
The forming method of at least one layer of metal interconnecting layer includes: the formation optically denser medium area above the photodiode area
Domain；Metal layer is formed around optically denser medium region；It forms the light covered around the metal layer and optically denser medium region and dredges Jie
Matter region.
2. the forming method of imaging sensor front-illuminated according to claim 1, which is characterized in that the optically denser medium area
The cross sectional shape in domain is trapezoid or triangle.
3. the forming method of imaging sensor front-illuminated according to claim 1, which is characterized in that the optically denser medium
Refractive index is at least bigger than the refractive index of the optically thinner medium by 15% or more.
4. the forming method of imaging sensor front-illuminated according to claim 1, which is characterized in that the optically denser medium
Material is one of silicon nitride, silicon oxynitride, silicon carbide, hafnium oxide or combinations thereof.
5. the forming method of imaging sensor front-illuminated according to claim 1, which is characterized in that the optically thinner medium
Material is one of silica, silicon nitride, silicon oxynitride, silicon carbide, hafnium oxide or combinations thereof.
6. the forming method of imaging sensor front-illuminated according to claim 1, which is characterized in that the semiconductor substrate
On be formed with 2 ~ 4 layers of metal interconnecting layer.
7. the forming method of imaging sensor front-illuminated according to claim 1, which is characterized in that the first layer is to secondary
The forming method of the metal interconnecting layer of top layer further include: connection adjacent metal interconnection layer is formed in the optically thinner medium region
Through-hole structure.
8. the forming method of imaging sensor front-illuminated according to claim 1, which is characterized in that at least one layer of described
The forming method of metal interconnecting layer includes:
In forming optically denser medium in the semiconductor substrate, the optically denser medium is etched, is retained on the photodiode area
The part optically denser medium of side；
The metal layer for covering remaining semiconductor substrate and optically denser medium is formed, the metal layer is etched, retains close Jie of the light
Partial metal layers around matter；
The optically thinner medium for covering the metal layer and optically denser medium is formed, optically thinner medium described in chemical mechanical grinding exposes institute
State the top of optically denser medium.
9. the forming method of imaging sensor front-illuminated according to claim 8, which is characterized in that the first layer is to secondary
The forming method of the metal interconnecting layer of top layer further include: etch the optically thinner medium, formation exposes the part metal layer
Groove fills metal in the groove, forms through-hole structure.
10. the forming method of imaging sensor front-illuminated according to claim 1, which is characterized in that the optically denser medium
The width in region is less than or equal to the width of the photodiode area.
11. a kind of imaging sensor front-illuminated characterized by comprising
Semiconductor substrate, the semiconductor substrate are formed with the photodiode area corresponding to pixel unit；
The multiple layer metal interconnection layer being formed in the semiconductor substrate；
At least one layer of metal interconnecting layer includes the optically denser medium region being formed in above the photodiode area；Positioned at institute
State the metal layer around optically denser medium region；Cover the optically thinner medium region around the metal layer and optically denser medium region.
12. imaging sensor front-illuminated according to claim 11, which is characterized in that the section in the optically denser medium region
Shape is trapezoid or triangle.
13. imaging sensor front-illuminated according to claim 11, which is characterized in that the refractive index of the optically denser medium is extremely
It is few bigger by 15% or more than the refractive index of the light beam medium.
14. imaging sensor front-illuminated according to claim 11, which is characterized in that the material of the optically denser medium is nitrogen
One of SiClx, silicon oxynitride, silicon carbide, hafnium oxide or combinations thereof.
15. imaging sensor front-illuminated according to claim 11, which is characterized in that the material of the optically thinner medium is oxygen
One of SiClx, silicon nitride, silicon oxynitride, silicon carbide, hafnium oxide or combinations thereof.
16. imaging sensor front-illuminated according to claim 11, which is characterized in that be formed in the semiconductor substrate
2 ~ 4 layers of metal interconnecting layer.
17. imaging sensor front-illuminated according to claim 11, which is characterized in that the first layer to secondary top-level metallic
Interconnection layer also includes the through-hole structure for being formed in and connecting adjacent metal interconnection layer in the optically thinner medium region.
18. imaging sensor front-illuminated according to claim 11, which is characterized in that the width in the optically denser medium region
Less than or equal to the width of the photodiode area.
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