CN108899335A - Back side illumination image sensor and preparation method thereof - Google Patents
Back side illumination image sensor and preparation method thereof Download PDFInfo
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- CN108899335A CN108899335A CN201810882983.4A CN201810882983A CN108899335A CN 108899335 A CN108899335 A CN 108899335A CN 201810882983 A CN201810882983 A CN 201810882983A CN 108899335 A CN108899335 A CN 108899335A
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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
- H01L27/14683—Processes or apparatus peculiar to the manufacture or treatment of these devices or parts thereof
-
- 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
- H01L27/14609—Pixel-elements with integrated switching, control, storage or amplification elements
- H01L27/1461—Pixel-elements with integrated switching, control, storage or amplification elements characterised by the photosensitive area
-
- 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
- H01L27/14609—Pixel-elements with integrated switching, control, storage or amplification elements
- H01L27/14612—Pixel-elements with integrated switching, control, storage or amplification elements involving a transistor
- H01L27/14614—Pixel-elements with integrated switching, control, storage or amplification elements involving a transistor having a special gate structure
-
- 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
- H01L27/1464—Back illuminated imager structures
Abstract
Technical solution of the present invention discloses a kind of back side illumination image sensor and preparation method thereof, and the back side illumination image sensor includes semiconductor substrate and photodiode and photodiode isolation structure in semiconductor substrate；Epitaxial layer in semiconductor substrate and the floating diffusion region in epitaxial layer and transmission grid through the epitaxial layer.Described image sensor increases the area of photodiode, effectively raises the quantum efficiency of back side illumination image sensor.
Description
Technical field
The present invention relates to the manufacturing technology of semiconductor devices more particularly to back side illumination image sensors and preparation method thereof.
Background technique
Imaging sensor is a kind of device that optical imagery is converted into electric signal.With the hair of computer and communications industry
Exhibition, the demand to high-performance image sensors constantly increase, these high-performance image sensors are widely used in such as Digital photographic
The various necks of machine, camcorders, PCS Personal Communications System (PCS), game machine, security monitoring video camera, medical miniature camera etc
Domain.
Imaging sensor is usually two types, charge coupling device (CCD) sensor and cmos image sensor (CMOS
Image Sensors, CIS).Compared to ccd image sensor, cmos image sensor has integrated level height, small power consumption, generation
The advantages that at low cost.
In traditional cmos photosensitive element, light sensitive diode is located at circuit transistor rear, light-inletting quantity can because block by
It influences.So-called back-illuminated type CMOS exactly clubhauls it, and light is allowed to initially enter light sensitive diode, thus increase sensitive volume,
Significantly improve the shooting effect under low-light conditions.
However, using the back side illumination image sensor (BSI-CMOS Image Sensor) of global shutter capture technique,
Floating diffusion region (Floating Diffusion region, FD) is usually adjacent with photodiode.This reduce photoelectricity two
The fill factor (such as size) of pole pipe, therefore reduce the quantum efficiency (Quantum Efficiency) of photodiode.This
Outside, floating diffusion region is usually similar with photoelectric diode structure, therefore floating diffusion region is accumulated in response to incident radiation
Charge.This accumulation can pollute the charge stored in floating diffusion region, and may cause and be imaged as pseudomorphism, to prevent radiation dirty
Floating diffusion region is contaminated, metal shield is generally covered in floating diffusion region field surface.However even if lead to there are metal shield
It often also has many radiation and reaches floating diffusion region, so that global shutter efficiency (Global Shutter Efficiency,
GSE it) is deteriorated.
Summary of the invention
Technical solution of the present invention technical problems to be solved are：For existing back side illumination image sensor floating diffusion region
The quantum efficiency reduction of photodiode caused by domain is disposed adjacent with photodiode and lacking for global shutter deterioration of efficiency
It falls into, a kind of new back side illumination image sensor structure and preparation method thereof is provided, improve the quantum effect of back side illumination image sensor
Rate simultaneously improves global shutter efficiency.
In order to solve the above technical problems, the present invention provides a kind of production method of back side illumination image sensor, including：It provides
Semiconductor substrate is respectively formed photodiode and photodiode isolation structure in semiconductor substrate；In semiconductor substrate
Upper formation epitaxial layer；Floating diffusion region is formed in the epitaxial layer；The transmission grid for running through the epitaxial layer are formed in the epitaxial layer.
Optionally, the floating diffusion region position it is corresponding with the position of photodiode and not with photodiode phase
Even.
Optionally, the transmission grid include polysilicon layer and are used to be isolated between polysilicon layer and epitaxial layer described
The insulation material layer of epitaxial layer and polysilicon layer.
Optionally, the cross section structure of the transmission grid is rectangle, round, diamond shape or cross.
Optionally, the semiconductor substrate is identical as the doping type of epitaxial layer.
Optionally, when the photodiode is n-type doping, the photodiode isolation structure is p-type doping.
The floating diffusion region is n-type doping, and the transmission grid are n-type doping.
The present invention also provides a kind of back side illumination image sensors, including：
Semiconductor substrate and photodiode and photodiode isolation structure in semiconductor substrate；Positioned at half
Epitaxial layer on conductor substrate and the floating diffusion region in epitaxial layer and transmission grid through the epitaxial layer.
Optionally, the floating diffusion region position it is corresponding with the position of photodiode and not with photodiode phase
Even.
Optionally, the transmission grid include polysilicon layer and are used to be isolated between polysilicon layer and epitaxial layer described
The insulation material layer of epitaxial layer and polysilicon layer.
Optionally, the cross section structure of the transmission grid is rectangle, round, diamond shape or cross.
Optionally, the semiconductor substrate is identical as the doping type of epitaxial layer.
Optionally, when the photodiode is n-type doping, the photodiode isolation structure is p-type doping.
The floating diffusion region is n-type doping, and the transmission grid are n-type doping.
Technical solution has the advantages that：
Photodiode and photodiode isolation structure are arranged back side illumination image sensor structure of the present invention
In the semiconductor substrate, epitaxial layer is formed on a semiconductor substrate, and will transmit grid TG and floating diffusion region setting in extension
In layer, does so and increase the area of photodiode, effectively raise the quantum efficiency of back side illumination image sensor, and
It prevents incident radiation from polluting floating diffusion region in floating diffusion region stored charge, improves the global shutter of imaging sensor
Efficiency.
The production method of back side illumination image sensor of the present invention forms two pole of photoelectricity in the semiconductor substrate first
Pipe and photodiode isolation structure then again in semiconductor substrate surface grown epitaxial layer, then form run through in the epitaxial layer
The transmission grid TG and floating diffusion region of the epitaxial layer, this transmission grid, which can control 4 photodiodes simultaneously and float, to be expanded
Dissipate region.Since technique of the present invention only forms photodiode and photodiode isolation structure in the semiconductor substrate,
Transmission grid and floating diffusion region are formed in the epitaxial layer, are done so and are increased the area of photodiode, effectively mention
The high quantum efficiency of back side illumination image sensor, and prevent incident radiation from polluting in floating diffusion region stored charge and float
Diffusion zone improves the global shutter efficiency of imaging sensor.
Detailed description of the invention
Fig. 1 to Fig. 9 is that the corresponding structure of each step of production method of back side illumination image sensor in the embodiment of the present invention is shown
It is intended to；
Figure 10 is an overlooking structure figure of the back side illumination image sensor that the present invention is formed；
Figure 11 is another overlooking structure figure for the back side illumination image sensor that the present invention is formed；
Figure 12 is another overlooking structure figure for the back side illumination image sensor that the present invention is formed；
Figure 13 is another overlooking structure figure for the back side illumination image sensor that the present invention is formed.
Specific embodiment
Present inventive concept will be hereinafter described more fully with reference to attached drawing, the invention is shown in the accompanying drawings
The exemplary embodiment of design.By following referring to attached drawing exemplary embodiment described in more detail, present inventive concept it is excellent
Point and feature and the method for realizing them will be presented.It should be noted, however, that present inventive concept is not limited to following exemplary
Embodiment, but can be realized according to various forms.Therefore it provides the purpose of exemplary embodiment is used only for disclosing this hair
Bright design, and make the scope of present inventive concept as known to those skilled in the art.In the accompanying drawings, the embodiment of present inventive concept
It is not limited to particular example provided herein, and is exaggerated for purposes of clarity.
Term as used herein is used only for the purpose of describing specific embodiments rather than for limiting the present invention.As made herein
Be also intended to, singular references " one ", "one" and "the" including plural form, unless within a context in addition it is manifestly intended that.
As used herein, term "and/or" include it is associated list any of one or more of project or all combination.It should
Understand, when an element is referred to as being "connected" or "coupled" to another element, can be directly connected or be coupled to and is another
One element, or there may also be intermediary elements.
Similarly, it should be understood that when the element of such as layer, region or substrate etc is referred to as in another element "upper"
When, it can directly on the other element, or there may also be intermediary elements.In contrast, term " directly " indicates
There is no intermediary element.It is also understood that term "comprising", " including ", " comprising " and/or " including ", herein in use, referring to
Bright there are documented feature, entirety, step, operation, element and/or component, but presence or one or more additional is not precluded
Other a features, entirety, step, operation, element, component and/or their group.
In addition, detailed description in embodiment by using as the sectional view of the ideal example diagram of present inventive concept come
It is described.Therefore, the shape of exemplary diagram can be changed according to manufacturing technology and/or admissible error.Therefore,
The embodiment of present inventive concept is not limited to the specific shape shown in exemplary diagram, but may include can be according to system
Make the other shapes of technique generation.Exemplified region has general property in the accompanying drawings, and be used to show the spy of element
Shape shape.Therefore, this is not construed as limiting the range of present inventive concept.
It is also understood that although term first, second, third, etc. can be used herein to describe various elements, these
Element should not be limited by these terms.These terms are only used to distinguish an element with another element.Therefore, exist
In the case where not being detached from the teachings of the present invention, first element in some embodiments can be referred to as in other embodiments
Second element.Identical reference label or identical reference designator indicate identical element throughout the specification.
In addition, by reference to as Utopian graphical representation of exemplary cross sectional view and/or plane diagram example is described
Property embodiment.Therefore, because with the shape illustrated not being both foreseeable caused by such as manufacturing technology and/or tolerance.Cause
Exemplary embodiment, should not be interpreted as being limited to the shape in region out shown here, but should include by for example making by this
The deviation in shape caused by making.For example, the etching area for being shown as rectangle would generally have circular or curved spy
Sign.Therefore, region shown in figure is substantially schematical, and shape is not configured to show the practical shape in the region of device
Shape is also not to limit the range of exemplary embodiment.
Technical solution of the present invention is described in detail below with reference to embodiment and attached drawing.
Fig. 1 to Fig. 9 is that the corresponding structure of each step of production method of back side illumination image sensor in the embodiment of the present invention is shown
It is intended to.The production method of the back side illumination image sensor includes：Semiconductor substrate 10 is provided, in semiconductor substrate 10 respectively
Form photodiode 11 and photodiode isolation structure 12；Epitaxial layer 20 is formed over the semiconductor substrate 10；In epitaxial layer
Middle formation floating diffusion region 13；The transmission grid 14 for running through the epitaxial layer 20 are formed in epitaxial layer 20.
With reference to Fig. 1, semiconductor substrate 10 is provided, the semiconductor substrate 10 can be silicon substrate or the semiconductor
The material of substrate 10 can also be germanium, SiGe, silicon carbide, GaAs or gallium indium, and the semiconductor substrate 10 can also be
The germanium substrate on silicon substrate or insulator on insulator, or growth have the substrate of epitaxial layer.
In the present embodiment, the semiconductor substrate 10 includes P-type silicon, and the P-type silicon by carrying out p-type in a silicon substrate
Doping realizes all doping to realize, such as using ion implanting or the technique of diffusion.When executing doping process, Doped ions
Energy and doping concentration can be selected according to the prior art.The Doped ions are, for example, B, BF2Deng Doped ions are dense
Degree range is 1E14~1E16/cm3。
As shown in Figure 1, forming the first photomask pattern using deposition and etching technics in the semiconductor substrate 10
31, first photomask pattern 31 is used to define the position of the photodiode 11 (PD) in semiconductor substrate,
The optical signal that the photodiode 11 is used to receive is converted to electric signal.Each photodiode 11 is half
It can be arranged in conductor substrate 10 with Bayer (Bayer) array, also can according to need and be arranged to other any arrays.In order to meet
The requirement of the overall thickness thinning of the semiconductor substrate 10, usual each photodiode 11 is in the semiconductor substrate 10
In position lie substantially in same depth.
Later, with reference to Fig. 1 and Fig. 2, the first ion implantation technology more than once is executed, is set in semiconductor substrate 10
Positioning sets to form the photodiode 11, then removes first photomask pattern 31.
First ion implantation technology is, for example, N-type ion doping, and Doped ions concentration range is 1E11~5E12/
cm3, the Doped ions include phosphorus, ASPlasma, doping depth in the semiconductor substrate are 2~2.5 microns.
The photodiode 11 is formed by the first ion implantation technology of execution more than once, by adjusting
The concentration and injection depth of the Doped ions injected every time, form the photodiode 11.The first ion note is carried out every time
Doped ions implantation concentration used by fashionable and ion implanting depth can be adjusted according to process requirement, not done herein
It is further to limit.After executing the first ion implantation technology every time, annealing treating process can be executed, on the one hand for repairing
Multiple damage of first ion implantation technology to lattice, expands the injection ion in the first ion implantation technology further
It dissipates uniform.
In the present embodiment, first photomask pattern 31 is hard mask layer (Hard mask), for preventing rear
Continuous to carry out causing semiconductor substrate surface coarse when ion implanting, the technique for removing first photomask pattern 31 is for example, wet
Method etching technics.
As shown in Figure 3 and 4, the second light is formed using deposition and etching technics in the semiconductor substrate 10 to cover
Film figure 32, second photomask pattern 32 is for defining the photodiode isolation junction in semiconductor substrate 10
The position of structure 12 (Photodiode Isolation, PDI).
The photodiode isolation structure 12 for being isolated each photodiode, each photodiode every
Change from arrangement mode of the structure 12 in semiconductor substrate 10 according to the variation of the arrangement of photodiode 11, one
In a optional embodiment, it is arranged as groined type array.Each photodiode isolation structure 12 is in the semiconductor
Position in substrate 10 is essentially arranged at same depth.
Later, with reference to Fig. 3 and Fig. 4, the second ion implantation technology is executed, setting position is formed in semiconductor substrate 10
The photodiode isolation structure 12 then removes second photomask pattern 32.
It is second ion implanting in the case that p-type doping photodiode is n-type doping in semiconductor substrate
Technique is, for example, the doping process of P-type ion, and Doped ions concentration range is 1E12~1E13/cm3, the Doped ions packet
Include B ion, BF2Deng.Its doping depth in the semiconductor substrate is 2~2.5 microns.
Used Doped ions injection type and ion implantation concentration can be by abilities when second ion implanting
Field technique personnel are adjusted according to process requirement, and ion implanting depth can be according to the ion implanting depth of photodiode
It is adjusted, it is not further herein to be limited.After executing the second ion implantation technology, annealing treating process can be executed,
On the one hand for repairing damage of second ion implantation technology to lattice, on the other hand make the injection in the second ion implantation technology
Ion is further spread uniformly.
The technique for removing second photomask pattern 32 is, for example, wet-etching technology.
Then, semiconductor substrate 10 is cleaned, removes above-mentioned formation photodiode 11 and photodiode isolation
It is damaged caused by 10 surface of semiconductor substrate in 12 technical process of structure.The cleaning process includes：It is cleaned using RCA
Method executes cleaning to semiconductor substrate surface, executes deionized water cleaning process to semiconductor substrate surface after cleaning and dries,
And low-temperature annealing is carried out to repair surface defect to the semiconductor substrate surface.
The RCA ablution mainly uses SPM (H2SO4/H2O2)、DHF(H2O2/H2O)、APM(NH4OH/H2O2/H2O)、
HPM(HCL/H2O2/H2) etc. O chemical reagent clean semiconductor substrate.
Referring to Fig. 5, epitaxial layer 20, the doping type and semiconductor of the epitaxial layer 20 are formed over the semiconductor substrate 10
The doping type of substrate is identical, and Doped ions concentration is also identical as the doping concentration of semiconductor substrate.In the present embodiment, it is formed
Epitaxial layer 20 with p-type adulterate.
The technique for forming the epitaxial layer can be known to the skilled in the art any one epitaxial growth technology, with
P-type doping process is carried out to the epitaxial layer afterwards, the Doped ions are, for example, B, BF2Deng Doped ions concentration range is
1E14~1E16/cm3。
With reference to Fig. 6 and Fig. 7, third photomask pattern is formed using deposition and etching technics on the epitaxial layer 20
33, the third photomask pattern 33 is for defining the 13 (Floating of floating diffusion region in epitaxial layer 20
Diffusion region, FD) position, the floating diffusion region 13 is embedded in the epitaxial layer 20, position and half
The position of photodiode is corresponding in conductor substrate, is connected positioned at the top of photodiode 11, and not with photodiode.
Later, with reference to Fig. 6 and Fig. 7, third ion implantation technology is executed, setting position forms described in epitaxial layer 20
Floating diffusion region 13 then removes the third photomask pattern 33.
The floating diffusion region 13 can receive the charge of storage in the photodiode, in floating diffusion region
Middle aggregation charge.In the present embodiment, the floating diffusion region 13 has n-type doping, and Doped ions concentration range is
1E13~2E15/cm3。
The third ion implantation technology includes at least the doping process of a N-type ion, Doped ions concentration range
For 1E13~2E15/cm3, the Doped ions include P ion etc..Remove the technique of the third photomask pattern 33 for example
For wet-etching technology.
With reference to attached drawing 8, the 4th photomask pattern 34, institute are formed using deposition and etching technics on the epitaxial layer 20
The 4th photomask pattern 34 stated is used to define the position of the transmission grid 14 in epitaxial layer 20.With the 4th photomask
Pattern 34 is exposure mask, performs etching the epitaxial layer 20 to semiconductor substrate is exposed, is formed through the epitaxial layer 20
Groove.The etching technics is, for example, plasma etching.
Attached drawing 9 forms transmission grid 14 in the trench.Formed transmission grid 14 technique include：First in the extension
Then the side wall fill insulant layer 14a of layer and groove fills N-type in the insulation material layer 14a and groove and mixes
Miscellaneous polysilicon 14b removes polysilicon 14b and insulation material layer on epitaxial layers using chemical grinding technique CMP later
14a forms the transmission grid 14 for filling the groove.
Transmission grid 14 are used to improve the efficiency that the charge in photodiode is transferred in floating diffusion region 14, thus
Improve the charge transfer efficiency of imaging sensor.
Wherein, the insulation material layer may include silicon oxide or silicon nitride.The technique for forming the insulation material layer is excellent
Select chemical vapor deposition process, such as plasma activated chemical vapour deposition.
By the manufacture craft for the back side illumination image sensor that above-mentioned attached drawing 1 to attached drawing 9 describes, the back-illuminated type of formation
The top view of imaging sensor is refering to what is shown in Fig. 10, wherein Fig. 9 is the cross section structure schematic diagram in Figure 10 along the direction AA.
From fig. 10 it can be seen that the cross section structure of the transmission grid 14 is rectangle structure, according to the need of technological design
Want, the cross section structure of the transmission grid 14 can also do various modifications, such as square, except first, with reference to attached drawing 11 to
Attached drawing 13, the cross section structure of the transmission grid can also be circle, and diamond shape, cross etc. is regularly or irregularly to tie
Structure.The channel of the available different length of different cross section structures, adapts to different process requirements.
Using the production method of back side illumination image sensor described in the embodiment of the present invention, first in P-type semiconductor substrate
It is middle to form photodiode (N-type) and photodiode isolation structure PDI (p-type) using ion implanting, then again in semiconductor
The epitaxial layer of substrate surface growing P-type, then the 13 (N of transmission grid TG and floating diffusion region of vertical structure is formed in the epitaxial layer
Type), this transmission grid can control 4 photodiodes and floating diffusion region 13 simultaneously.Since technique of the present invention is half
Photodiode and photodiode isolation structure are only formed in conductor substrate, transmit grid and floating diffusion region is in epitaxial layer
Middle formation, it does so and increases the area of photodiode, effectively raise the quantum efficiency of back side illumination image sensor,
And it prevents incident radiation from polluting floating diffusion region in floating diffusion region stored charge, improves the overall situation of imaging sensor
Shutter efficiency.
Embodiment 2
The embodiment of the present invention provides a kind of back side illumination image sensor structure, refering to what is shown in Fig. 9, the back side illumination image
Sensor structure includes：
Semiconductor substrate 10 and photodiode 11 and photodiode isolation structure in semiconductor substrate 10
Array 12；Epitaxial layer 20 in semiconductor substrate 10 and the floating diffusion region 13 in epitaxial layer 20 and run through institute
State the transmission grid 14 of epitaxial layer 20.
The semiconductor substrate 10 can be that the material of silicon substrate or the semiconductor substrate 10 can also be germanium, germanium
SiClx, silicon carbide, GaAs or gallium indium, the semiconductor substrate 10 can also be the silicon substrate or insulator on insulator
On germanium substrate, or growth has the substrate of epitaxial layer.
In the present embodiment, the semiconductor substrate 10 includes P-type silicon, and the P-type silicon by carrying out p-type in a silicon substrate
Doping realizes all doping to realize, such as using ion implanting or the technique of diffusion.When executing doping process, Doped ions
Energy and doping concentration can be selected according to the prior art.The Doped ions are, for example, B, BF2Deng Doped ions are dense
Degree range is 1E14~1E16/cm3。
The optical signal that the photodiode 11 is used to receive is converted to electric signal.Two pole of each photoelectricity
Pipe 11 can be arranged in semiconductor substrate 10 with Bayer (Bayer) array, also can according to need and be arranged to other any arrays.
In order to meet the semiconductor substrate 10 overall thickness thinning requirement, usual each photodiode 11 partly leads described
Position in body substrate 10 lies substantially in same depth.
Photodiode 11 is N-type ion doping, and Doped ions concentration range is 1E11~5E12/cm3, the doping
Ion includes phosphorus, ASPlasma, doping depth in the semiconductor substrate are 2~2.5 microns.
The photodiode 11 is formed by the first ion implantation technology of execution more than once, by adjusting
The concentration and injection depth of the Doped ions injected every time, form the photodiode 11.
The photodiode isolation structure 12 is for being isolated each photodiode 11, each photodiode
Arrangement mode of the isolation structure 12 in semiconductor substrate 10 according to the arrangement of photodiode 11 variation and change,
In an optional embodiment, it is arranged as groined type array.Each photodiode isolation structure 12 is partly led described
Position in body substrate 10 is essentially arranged at same depth.
It is photodiode isolation structure in the case that p-type doping photodiode is n-type doping in semiconductor substrate
12 adulterate for p-type, and Doped ions concentration range is 1E12~1E13/cm3, the Doped ions include B ion, BF2Deng.Its
Doping depth in the semiconductor substrate is 2~2.5 microns.
The doping type of the epitaxial layer 20 is identical as the doping type of semiconductor substrate, and Doped ions concentration is also and half
The doping concentration of conductor substrate is identical.In the present embodiment, the epitaxial layer 20 of formation is adulterated with p-type.The Doped ions
For example, B, BF2It is 1E14~1E16/cm Deng, Doped ions concentration range3。
The floating diffusion region 13 is embedded in the epitaxial layer 20, and position corresponds to photoelectricity two in semiconductor substrate
The position of pole pipe is corresponding, is connected positioned at the top of photodiode 11, and not with photodiode.The floating diffusion region
Domain 13 can receive the charge of storage in the photodiode, to assemble charge in floating diffusion region.In the present embodiment,
The floating diffusion region 13 has n-type doping, and Doped ions concentration range is 1E13~2E15/cm3。
The transmission grid 14 run through the epitaxial layer 20, and the charge for improving in photodiode is transferred to floating and expands
The efficiency in region 14 is dissipated, to improve the charge transfer efficiency of imaging sensor.
The transmission grid 14 include polysilicon layer 14b and are used to be isolated between polysilicon layer and epitaxial layer described outer
Prolong the insulation material layer 14a of layer and polysilicon layer.Wherein, the insulation material layer may include silicon oxide or silicon nitride.
The top view of the back side illumination image sensor is refering to what is shown in Fig. 10, wherein Fig. 9 is in Figure 10 along the direction A ' A '
Cross section structure schematic diagram.
From fig. 10 it can be seen that the cross section structure of the transmission grid 14 is rectangle structure, according to the need of technological design
Want, the cross section structure of the transmission grid 14 can also do various modifications, such as square, in addition to this, with reference to attached drawing 11 to
Attached drawing 13, the cross section structure of the transmission grid can also be circle, and diamond shape, cross etc. is regularly or irregularly to tie
Structure.The channel of the available different length of different cross section structures, adapts to different process requirements.
Back side illumination image sensor structure described in the present embodiment, photodiode and photodiode isolation structure are set
It sets in the semiconductor substrate, forms epitaxial layer on a semiconductor substrate, and grid TG and floating diffusion region setting will be transmitted outside
Prolong in layer, do so and increase the area of photodiode, effectively raises the quantum efficiency of back side illumination image sensor, and
And preventing incident radiation from polluting floating diffusion region in floating diffusion region stored charge, the overall situation for improving imaging sensor is fast
Door efficiency.
Although the present invention discloses as above in a preferred embodiment thereof, it is not for limiting the present invention, any ability
Field technique personnel 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
Inventive technique scheme makes possible variation and modification, therefore, anything that does not depart from the technical scheme of the invention, according to this hair
Bright technical spirit belongs to the technology of the present invention to any simple modifications, equivalents, and modifications made by embodiment of above
The protection scope of scheme.
Claims (14)
1. a kind of back side illumination image sensor, which is characterized in that including：
Semiconductor substrate and photodiode and photodiode isolation structure in semiconductor substrate；
Epitaxial layer in semiconductor substrate and the floating diffusion region in epitaxial layer and through the epitaxial layer
Transmit grid.
2. back side illumination image sensor as described in claim 1, which is characterized in that the floating diffusion region position and photoelectricity two
The position of pole pipe is corresponding and is not connected with photodiode.
3. back side illumination image sensor as described in claim 1, which is characterized in that the transmission grid include polysilicon layer and position
For the insulation material layer of the epitaxial layer and polysilicon layer to be isolated between polysilicon layer and epitaxial layer.
4. back side illumination image sensor as described in claim 1, which is characterized in that the cross section structure of the transmission grid is rectangular
Shape, round, diamond shape or cross.
5. back side illumination image sensor as described in claim 1, which is characterized in that the doping of the semiconductor substrate and epitaxial layer
Type is identical.
6. back side illumination image sensor as described in claim 1, which is characterized in that when the photodiode is n-type doping,
The photodiode isolation structure is p-type doping.
7. back side illumination image sensor as claimed in claim 6, which is characterized in that the floating diffusion region is n-type doping, institute
Stating transmission grid is n-type doping.
8. a kind of production method of back side illumination image sensor, which is characterized in that including：
Semiconductor substrate is provided, photodiode and photodiode isolation structure are respectively formed in semiconductor substrate；
Epitaxial layer is formed on a semiconductor substrate；
Floating diffusion region is formed in the epitaxial layer；
The transmission grid for running through the epitaxial layer are formed in the epitaxial layer.
9. the production method of back side illumination image sensor as claimed in claim 8, which is characterized in that the floating diffusion region
Position is corresponding with the position of photodiode and is not connected with photodiode.
10. the production method of back side illumination image sensor as claimed in claim 8, which is characterized in that the transmission grid include
Polysilicon layer and the insulation material layer for being used to be isolated the epitaxial layer and polysilicon layer between polysilicon layer and epitaxial layer.
11. the production method of back side illumination image sensor as claimed in claim 8, which is characterized in that the transmission grid
Cross section structure is rectangle, round, diamond shape or cross.
12. the production method of back side illumination image sensor as claimed in claim 8, which is characterized in that the semiconductor substrate
It is identical as the doping type of epitaxial layer.
13. the production method of back side illumination image sensor as claimed in claim 8, which is characterized in that two pole of photoelectricity
When pipe is n-type doping, the photodiode isolation structure is p-type doping.
14. the production method of back side illumination image sensor as claimed in claim 13, which is characterized in that the floating diffusion region
Domain is n-type doping, and the transmission grid are n-type doping.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109950263A (en) * | 2019-03-20 | 2019-06-28 | 德淮半导体有限公司 | Imaging sensor and forming method thereof |
| CN109950268A (en) * | 2019-03-27 | 2019-06-28 | 德淮半导体有限公司 | PDAF imaging sensor and forming method thereof |
| CN113540140A (en) * | 2021-07-15 | 2021-10-22 | 上海芯物科技有限公司 | Back-illuminated complementary metal oxide semiconductor image sensor and preparation method thereof |
| CN115939159A (en) * | 2023-02-02 | 2023-04-07 | 合肥晶合集成电路股份有限公司 | Image sensor and manufacturing method thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102177585A (en) * | 2008-10-16 | 2011-09-07 | 全视科技有限公司 | Image sensor having multiple sensing layers and its method of operation and fabrication |
| US20110241145A1 (en) * | 2010-04-06 | 2011-10-06 | Victor Lenchenkov | Backside illumination image sensors with reflective light guides |
| CN103441133A (en) * | 2013-08-30 | 2013-12-11 | 格科微电子（上海）有限公司 | Back side illumination image sensor and method for reducing dark current of back side illumination image sensor |
-
2018
- 2018-08-06 CN CN201810882983.4A patent/CN108899335A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102177585A (en) * | 2008-10-16 | 2011-09-07 | 全视科技有限公司 | Image sensor having multiple sensing layers and its method of operation and fabrication |
| US20110241145A1 (en) * | 2010-04-06 | 2011-10-06 | Victor Lenchenkov | Backside illumination image sensors with reflective light guides |
| CN103441133A (en) * | 2013-08-30 | 2013-12-11 | 格科微电子（上海）有限公司 | Back side illumination image sensor and method for reducing dark current of back side illumination image sensor |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109950263A (en) * | 2019-03-20 | 2019-06-28 | 德淮半导体有限公司 | Imaging sensor and forming method thereof |
| CN109950268A (en) * | 2019-03-27 | 2019-06-28 | 德淮半导体有限公司 | PDAF imaging sensor and forming method thereof |
| CN113540140A (en) * | 2021-07-15 | 2021-10-22 | 上海芯物科技有限公司 | Back-illuminated complementary metal oxide semiconductor image sensor and preparation method thereof |
| CN115939159A (en) * | 2023-02-02 | 2023-04-07 | 合肥晶合集成电路股份有限公司 | Image sensor and manufacturing method thereof |
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