Summary of the invention
For the defects in the prior art, the embodiment of the invention provides CMOS type imaging sensors and preparation method thereof.
In a first aspect, the embodiment of the present invention provides a kind of CMOS type imaging sensor, comprising: the second oxide layer and be located at institute
State the substrate in the second oxide layer;
The substrate is located at the side of second oxide layer, and the side of the substrate, which is formed, is recessed to downwards described second
The first groove of oxide layer is successively arranged high dielectric thin film layer and first in the substrate and the first groove from the bottom to top
Oxide layer is formed in the first groove for being equipped with high dielectric thin film layer and the first oxide layer through first oxide layer, described
The connecting groove of high dielectric thin film layer and part second oxide layer, sets in first oxide layer and in the connecting groove
There is the first metal layer, aluminum wiring board is equipped on the first metal layer of the connecting groove, the aluminum wiring board passes through described
The high dielectric thin film layer electrical connection that the first metal layer and the wiring groove sidewall in connecting groove expose, in the aluminium
Voltage is provided when applying voltage on terminal plate for the high dielectric thin film layer.
Preferably, it is also formed with the second groove for being isolated between pixel unit on the substrate.
Preferably, there is pre-determined distance between the bottom of the second groove and the bottom surface of the substrate.
Preferably, including at least four second grooves, every four institutes at least four second groove
It states second groove and forms a rectangular area, each rectangular area surrounds a pixel unit wherein.
Preferably, the first metal layer is tungsten layer.
It preferably, further include the second metal layer being formed in second oxide layer;
The aluminum wiring board is electrically connected by the first metal layer and the second metal layer.
Second aspect, the present invention also provides the production methods of the CMOS type imaging sensor described in one kind, comprising:
The second oxide layer below one substrate and the substrate is provided;
Photoresist is coated in the upper surface of described substrate, the photoresist in the substrate is exposed using a mask plate aobvious
Shadow, to form the first pattern on the photoresist of the substrate;
The substrate is performed etching according to the first pattern formed on the photoresist of the substrate, is removed in the substrate
Photoresist, form first groove on the substrate, the first groove is through second oxidation of the substrate and part
Layer;
It is sequentially depositing high dielectric thin film layer and the first oxide layer from the bottom to top in the substrate and the first groove;
It is formed in the first groove for being deposited with the high dielectric thin film layer and the first oxide layer through first oxidation
The connecting groove of layer, the high dielectric thin film layer and part second oxide layer;
The first metal layer is deposited in first oxide layer and in the connecting groove, first in the connecting groove
Deposited aluminum layer on metal layer, forms aluminum wiring board, and the aluminum wiring board passes through the first metal layer in the connecting groove and described
The high dielectric thin film layer electrical connection that wiring groove sidewall exposes.
Preferably, it after the second oxide layer below a substrate and the substrate is provided, is applied in the upper surface of described substrate
Photoresist is covered, before being exposed development to the photoresist in the substrate using a mask plate, the method also includes:
Second metal layer is formed in second oxide layer;
Then, the method also includes:
The aluminum wiring board is electrically connected by the first metal layer and the second metal layer.
The third aspect, the present invention also provides the production methods of the CMOS type imaging sensor described in one kind, comprising:
The second oxide layer below one substrate and the substrate is provided;
Photoresist is coated in the upper surface of described substrate, the photoresist in the substrate is exposed using a mask plate aobvious
Shadow, to form first pattern and the second pattern on the photoresist of the substrate;The area of first pattern is greater than described the
The area of two patterns;
The substrate is performed etching according to the first pattern and the second pattern formed on the photoresist of the substrate, is removed
Photoresist in the substrate, forms first groove and second groove on the substrate, and the first groove runs through the base
Bottom and part second oxide layer have pre-determined distance between the bottom of the second groove and the bottom surface of the substrate;
It is sequentially depositing high dielectric thin film layer and the first oxidation from the bottom to top in the upper surface of the substrate and the first groove
Layer;
It is formed in the first groove for being deposited with the high dielectric thin film layer and the first oxide layer through first oxidation
The connecting groove of layer, the high dielectric thin film layer and part second oxide layer;
The first metal layer is deposited in first oxide layer and in the connecting groove, first in the connecting groove
Deposited aluminum layer on metal layer, forms aluminum wiring board, and the aluminum wiring board passes through the first metal layer in the connecting groove and described
The high dielectric thin film layer electrical connection that wiring groove sidewall exposes.
Preferably, the second groove is the second groove for being isolated between pixel unit;
Then, the method also includes:
Etch the first metal layer, first oxide layer and the high dielectric thin film between the second groove
Layer is formed between the metal grate for making light enter the entering light area of pixel unit with forming metal grate.
Preferably, the method also includes:
It is sequentially depositing high dielectric thin film layer and the first oxidation from the bottom to top in the upper surface of the substrate and the first groove
While layer, it is sequentially depositing high dielectric thin film layer and the first oxide layer from the bottom to top in the upper surface of described second groove.
Preferably, it after the second oxide layer below a substrate and the substrate is provided, is applied in the upper surface of described substrate
Photoresist is covered, before being exposed development to the photoresist in the substrate using a mask plate, the method also includes:
Second metal layer is formed in second oxide layer;
Then, the method also includes:
The aluminum wiring board is electrically connected by the first metal layer and the second metal layer.
The present invention is sequentially depositing height in the substrate and the first groove due to being initially formed first groove from the bottom to top
Dielectric film layers and the first oxide layer are formed in the first groove for being deposited with the high dielectric thin film layer and the first oxide layer and are passed through
The connecting groove for wearing first oxide layer, the high dielectric thin film layer and part second oxide layer, in first oxidation
The first metal layer is deposited on layer and in the connecting groove, the deposited aluminum layer on the first metal layer in the connecting groove is formed
Aluminum wiring board remains high dielectric thin film layer at first groove, so that aluminum wiring board be allow to pass through in the connecting groove
The high dielectric thin film layer electrical connection that the first metal layer and the wiring groove sidewall expose, and then on the aluminum wiring board
Voltage can be provided for the high dielectric thin film layer when applying voltage, make to generate between the high dielectric thin film layer and the substrate high
Potential difference when only using high dielectric thin film layer, keeps the substrate stronger to the constraint ability of electronics, thus preferably will be additional
Electronics is strapped in the surface of the substrate, can not be injected into silicon, to preferably reduce white point and dark current, light is substantially improved
Learn performance.
Specific embodiment
In order to make the object, technical scheme and advantages of the embodiment of the invention clearer, below in conjunction with the embodiment of the present invention
Attached drawing, the technical solution of the embodiment of the present invention is clearly and completely described.Obviously, described embodiment is this hair
Bright a part of the embodiment, instead of all the embodiments.Based on described the embodiment of the present invention, ordinary skill
Personnel's every other embodiment obtained under the premise of being not necessarily to creative work, shall fall within the protection scope of the present invention.
Unless otherwise defined, the technical term or scientific term that the disclosure uses should be tool in fields of the present invention
The ordinary meaning for thering is the personage of general technical ability to be understood." first ", " second " used in the disclosure and similar word are simultaneously
Any sequence, quantity or importance are not indicated, and are used only to distinguish different component parts.Equally, "one", " one " or
The similar word such as person's "the" does not indicate that quantity limits yet, but indicates that there are at least one." comprising " or "comprising" etc. are similar
Word mean to occur element or object before the word cover the element for appearing in the word presented hereinafter or object and its
It is equivalent, and it is not excluded for other elements or object.The similar word such as " connection " or " connected " be not limited to physics or
The connection of person's machinery, but may include electrical connection, it is either direct or indirect."upper", "lower", " left side ",
" right side " etc. is only used for indicating relative positional relationship, after the absolute position for being described object changes, then the relative positional relationship
May correspondingly it change.
Fig. 4 is the structural schematic diagram for the CMOS type imaging sensor that one embodiment of the invention provides.
A kind of CMOS type imaging sensor as shown in Figure 4, comprising: the second oxide layer 401 and be located at it is described second oxidation
Substrate 402 on layer 401, the substrate 402 are located at the side of second oxide layer 401, and the side of the substrate 402 is formed
It is recessed to the first groove 406 of second oxide layer 401 downwards, in the substrate 402 and the first groove 406 under
It is supreme to be successively arranged high dielectric thin film layer 403 and the first oxide layer 404, it is being equipped with high dielectric thin film layer 403 and the first oxide layer
It is formed in 404 first groove 406 and runs through first oxide layer 404, the high dielectric thin film layer 403 and part described second
The connecting groove 410 of oxide layer 401 is equipped with the first metal layer in first oxide layer 404 and in the connecting groove 410
405, aluminum wiring board 408 is equipped on the first metal layer 405 of the connecting groove 410, the aluminum wiring board 408 passes through institute
State 403 electricity of the high dielectric thin film layer that 410 side wall of the first metal layer 405 and the connecting groove in connecting groove 410 exposes
Connection provides voltage when voltage to apply on the aluminum wiring board 408 for the high dielectric thin film layer 403.
In a specific embodiment, the first metal layer 405 can be tungsten layer.The light-proofness of tungsten is good, prevent light into
Enter non-pixel areas.Certainly, the metal that the first metal layer 405 can also be good for other light-proofness, the present invention are without limitation.
The embodiment of the present invention aluminum wiring board 408 passes through the first metal layer 405 in the connecting groove 410 and the wiring
The high dielectric thin film layer 403 that 410 side wall of slot exposes is electrically connected, and can be when applying voltage on the aluminum wiring board 408
The high dielectric thin film layer 403 provides voltage, makes to generate between the high dielectric thin film layer 403 and the substrate 402 higher than only
Potential difference when with high dielectric thin film layer keeps the substrate 402 stronger to the constraint ability of electronics, thus preferably by additional electric
Beamlet is tied to the surface of the substrate 402, can not be injected into silicon, to preferably reduce white point and dark current, is substantially improved
Optical property.
As a kind of preferred embodiment, second for being isolated between pixel unit is also formed in the substrate 402
Groove 407.Further, there is pre-determined distance between the bottom of the second groove 407 and the bottom surface of the substrate 402.?
In a kind of specific embodiment, including at least four second grooves 407, at least four second groove 407
Every four second grooves 407 form a rectangular area, and a pixel unit is enclosed in it by each rectangular area
In.
The present embodiment can prevent electronics between adjacent pixel unit by being isolated between 407 pixel unit of second groove
Crosstalk, to promote the optical property and electric property of CMOS type imaging sensor.
Certainly, the quantity of the corresponding second groove 407 of each pixel unit is not limited to four, can also be more,
Such as five, six, the present embodiment is without limitation.
It is worth noting that the buffer action of second groove 407 because the substance difference filled in second groove 407 without
Together, the isolation, which can be divided into, is optically isolated and electrical isolation, and lighttight metal is filled in second groove 407 can be used for optics
Isolation, nonconducting silica is filled in second groove 407 can be used for electrical isolation.
In a specific embodiment, the width range of the second groove 407 is 70-150nm, the second groove
407 depth bounds are 1500-2500nm.The width and depth of second groove 407 can be specifically arranged as needed, the present invention couple
This is with no restrictions.
It further include the second metal layer 409 being formed in second oxide layer 401 as a kind of preferred embodiment;
The aluminum wiring board 408 is electrically connected by the first metal layer 405 and the second metal layer 409.
It is worth noting that the substrate can be silicon base.
Fig. 5 is the flow chart of the production method for the CMOS type imaging sensor that one embodiment of the invention provides.
The production method of CMOS type imaging sensor as shown in Figure 5, comprising:
The second oxide layer 401 below S501, one substrate 402 of offer and the substrate 402;
S502, photoresist is coated in the upper surface of described substrate 402, using a mask plate to the photoetching in the substrate 402
Glue is exposed development, to form the first pattern on the photoresist of the substrate 402;
It is worth noting that having the first mask pattern corresponding with the first pattern on the mask plate;
The first pattern formed on S503, the photoresist according to the substrate 402 performs etching the substrate 402, removes
The photoresist in the substrate 402 is removed, forms first groove 406 in the substrate 402, the first groove 406 runs through institute
State substrate 402 and part second oxide layer 401;
S504, it is sequentially depositing high dielectric thin film layer 403 from the bottom to top in the substrate 402 and the first groove 406
With the first oxide layer 404, formed in the first groove 406 for being deposited with the high dielectric thin film layer 403 and the first oxide layer 404
Through the connecting groove 410 of first oxide layer 404, the high dielectric thin film layer 403 and part second oxide layer 401;
The prior art can be used in the forming method of the connecting groove, is formed by exposure, development, etching, the present embodiment is not
It is described in detail again.
S505, the first metal layer 405 is deposited in first oxide layer 404 and in the connecting groove 410, described
Deposited aluminum layer on the first metal layer 405 in connecting groove 410, forms aluminum wiring board 408, and the aluminum wiring board 408 passes through described
The high dielectric thin film layer 403 that the first metal layer 405 and 410 side wall of the connecting groove in connecting groove 410 expose is electrically connected
It connects.
It is worth noting that existing method, this implementation can be used in the specific method of the step S501-S505 in the present embodiment
Example is no longer described in detail.
The production method of the CMOS type imaging sensor of the present embodiment, is initially formed first groove 406, in the substrate 402
With high dielectric thin film layer 403 and the first oxide layer 404 are sequentially depositing in the first groove 406 from the bottom to top, deposition
It states and is formed in the first groove 406 of high dielectric thin film layer 403 and the first oxide layer 404 through first oxide layer 404, described
The connecting groove 410 of high dielectric thin film layer 403 and part second oxide layer 401, in first oxide layer 404 and institute
It states and deposits the first metal layer 405, the deposited aluminum layer on the first metal layer 405 in the connecting groove 410, shape in connecting groove 410
At aluminum wiring board 408, high dielectric thin film layer 403 is remained at first groove 406, so that aluminum wiring board 408 be allow to pass through
The high dielectric thin film layer 403 that the first metal layer 405 and 410 side wall of the connecting groove in the connecting groove 410 expose
Electrical connection, and then voltage can be provided for the high dielectric thin film layer 403 when applying voltage on the aluminum wiring board 408, make institute
The potential difference generated when being higher than only with high dielectric thin film layer between high dielectric thin film layer 403 and the substrate 402 is stated, the base is made
Bottom 402 is stronger to the constraint ability of electronics, so that extra electron to be preferably strapped in the surface of the substrate 402, can not infuse
Enter into silicon, to preferably reduce white point and dark current, optical property is substantially improved.
As a kind of preferred embodiment, after the step S501, before the step S502, the method also includes:
Second metal layer 409 is formed in second oxide layer 401;
Then, the method also includes:
The aluminum wiring board 408 is electrically connected by the first metal layer 405 and the second metal layer 409.
It is worth noting that the substrate can be silicon base.
Fig. 6 be another embodiment of the present invention provides CMOS type imaging sensor production method flow chart.
The production method of CMOS type imaging sensor as shown in FIG. 6, comprising:
The second oxide layer 401 below S601, one substrate 402 of offer and the substrate 402;
S602, photoresist is coated in the upper surface of described substrate 402, using a mask plate to the photoetching in the substrate 402
Glue is exposed development, to form first pattern and the second pattern on the photoresist of the substrate 402;First pattern
Area is greater than the area of second pattern;
It is worth noting that on the mask plate have the first mask pattern corresponding with the first pattern and with the second pattern
Corresponding second mask pattern.
The first pattern and the second pattern formed on S603, the photoresist according to the substrate 402 to the substrate 402 into
Row etching, removes the photoresist in the substrate 402, and first groove 406 and second groove 407 are formed in the substrate 402,
The first groove 406 run through the substrate 402 and part second oxide layer 401, the bottom of the second groove 407 with
There is pre-determined distance between the bottom surface of the substrate 402;
S604, it is sequentially depositing high dielectric thin film layer from the bottom to top in the upper surface of the substrate 402 and the first groove 406
403 and first oxide layer 404, in the first groove 406 for being deposited with the high dielectric thin film layer 403 and the first oxide layer 404
Form the connecting groove through first oxide layer 404, the high dielectric thin film layer 403 and part second oxide layer 401
410;
In this step, one layer of high dielectric thin film layer 403, the first oxide layer can be also deposited in the second groove 407
404 enter in second groove 407, but cannot fill up, and there are gaps for meeting.
The prior art can be used in the forming method of the connecting groove, is formed by exposure, development, etching, the present embodiment is not
It is described in detail again.
S605, the first metal layer 405 is deposited in first oxide layer 404 and in the connecting groove 410, described
Deposited aluminum layer on the first metal layer 405 in connecting groove 410, forms aluminum wiring board 408, and the aluminum wiring board 408 passes through described
The high dielectric thin film layer 403 that the first metal layer 405 and 410 side wall of the connecting groove in connecting groove 410 expose is electrically connected
It connects.
In this step, the first metal layer 405 enters in the above-mentioned gap of second groove 407, and second groove 407 is filled out
It is full.
Existing method can be used in the specific method of step S601-S605 in the present embodiment, and the present embodiment is no longer described in detail.
The production method of the CMOS type imaging sensor of the present embodiment, is initially formed first groove 406, in the substrate 402
With high dielectric thin film layer 403 and the first oxide layer 404 are sequentially depositing in the first groove 406 from the bottom to top, deposition
It states and is formed in the first groove 406 of high dielectric thin film layer 403 and the first oxide layer 404 through first oxide layer 404, described
The connecting groove 410 of high dielectric thin film layer 403 and part second oxide layer 401, in first oxide layer 404 and institute
It states and deposits the first metal layer 405, the deposited aluminum layer on the first metal layer 405 in the connecting groove 410, shape in connecting groove 410
At aluminum wiring board 408, high dielectric thin film layer 403 is remained at first groove 406, so that aluminum wiring board 408 be allow to pass through
The high dielectric thin film layer 403 that the first metal layer 405 and 410 side wall of the connecting groove in the connecting groove 410 expose
Electrical connection, and then voltage can be provided for the high dielectric thin film layer 403 when applying voltage on the aluminum wiring board 408, make institute
The potential difference generated when being higher than only with high dielectric thin film layer between high dielectric thin film layer 403 and the substrate 402 is stated, the base is made
Bottom 402 is stronger to the constraint ability of electronics, so that extra electron to be preferably strapped in the surface of the substrate 402, can not infuse
Enter into silicon, to preferably reduce white point and dark current, optical property is substantially improved.And the present embodiment is according to etching
Loading effect phenomenon (load effect, because etch rate and Etching profile are related with dimension of picture and density and generate
Etching relevant to depth-to-width ratio or micro loading effect, i.e. pattern area is bigger, and the groove for etching formation is deeper, and pattern area is got over
Small, the groove for etching formation is more shallow), it is different using the first mask pattern and the second mask pattern area, on a mask plate
There is the first mask pattern and the second mask pattern simultaneously, form the different first groove of depth with single exposure, development, etching
406 and second groove 407, technique is simplified, is reduced costs.
As a kind of preferred embodiment, the second groove 407 is the second groove for being isolated between pixel unit
407;
Then, the method also includes:
Etch the first metal layer 405, first oxide layer 404 and the height between the second groove 407
Dielectric film layers 403 are formed between the metal grate for making light enter the entering light of pixel unit with forming metal grate
Area 411.
The present embodiment can make light enter pixel region by the entering light area 411 between metal grate.
It is worth noting that the buffer action of second groove 407 because the substance difference filled in second groove 407 without
Together, the isolation, which can be divided into, is optically isolated and electrical isolation, and lighttight metal is filled in second groove 407 can be used for optics
Isolation, nonconducting silica is filled in second groove 407 can be used for electrical isolation.
As a kind of preferred embodiment, the method also includes:
It is sequentially depositing 403 He of high dielectric thin film layer from the bottom to top in the upper surface of the substrate 402 and the first groove 406
While first oxide layer 404, it is sequentially depositing 403 He of high dielectric thin film layer from the bottom to top in the upper surface of described second groove 407
First oxide layer 404.
It is sequentially depositing high dielectric thin film layer 403 and the first oxide layer from the bottom to top in the upper surface of described second groove 407
404, convenient for the needs of subsequent technique.
As a kind of preferred embodiment, after the step S601, before the step S602, the method also includes:
Second metal layer 409 is formed in second oxide layer 401;
The method also includes:
The aluminum wiring board 408 is electrically connected by the first metal layer 405 and the second metal layer 409.
It is worth noting that the substrate can be silicon base.
The present invention is initially formed first groove, is sequentially depositing high dielectric from the bottom to top in the substrate and the first groove
Film layer and the first oxide layer form in the first groove for being deposited with the high dielectric thin film layer and the first oxide layer and run through institute
The connecting groove for stating the first oxide layer, the high dielectric thin film layer and part second oxide layer, in first oxide layer
And the first metal layer is deposited in the connecting groove, the deposited aluminum layer on the first metal layer in the connecting groove forms aluminium and connects
Line plate remains high dielectric thin film layer at first groove, so that aluminum wiring board be allow to pass through first in the connecting groove
The high dielectric thin film layer electrical connection that metal layer and the wiring groove sidewall expose, and then apply on the aluminum wiring board
Voltage can be provided for the high dielectric thin film layer when voltage, make to generate between the high dielectric thin film layer and the substrate higher than only
Potential difference when with high dielectric thin film layer keeps the substrate stronger to the constraint ability of electronics, thus preferably by extra electron
It is strapped in the surface of the substrate, can not be injected into silicon, to preferably reduce white point and dark current, is substantially improved optical
Energy.
The above description is merely a specific embodiment, and still, protection scope of the present invention is not limited to this, appoints
What those familiar with the art in the technical scope disclosed by the present invention, the variation or substitution that can be readily occurred in, all
It is covered by the protection scope of the present invention.Therefore, protection scope of the present invention should be with the scope of protection of the claims
Subject to.