Summary of the invention
The present invention is directed at least solve one of the technical problems existing in the prior art.For this purpose, the present invention needs to provide one
Kind.
The anti-crosstalk imaging sensor of embodiment according to the present invention comprising the pixel array comprising substrate and be formed in
Conducting wire in substrate.Pixel structure array is formed in the substrate, each dot structure includes photosensitive unit and surrounds
The photosensitive unit but the deep photodiode that setting is isolated with the photosensitive unit.The pole N of the depth photodiode and institute
State conducting wire connection, the depth photodiode is used to receive the photocarrier that the photosensitive unit overflows and clear by the conducting wire
The photocarrier overflowed except the photosensitive unit.
The photosensitive unit is isolated using the deep photodiode in the imaging sensor of better embodiment of the present invention,
Since the deep photodiode manufacture difficulty is low relative to traditional deep trench isolation structure, be easier to realize and also every
It is good from effect.
In some embodiments, imaging sensor as described in claim 1, which is characterized in that the depth photoelectricity two
The depth of pole pipe is greater than the depth of the photosensitive unit.
In some embodiments, the ratio of the depth and the depth of the photosensitive unit of the deep photodiode is greater than
Equal to 2.
In some embodiments, the ratio of the area of the area of the photosensitive unit and the dot structure is 0.44-
0.56, and the ratio of the area of the area of the photosensitive unit and the deep photodiode is 25-81.
In some embodiments, the deep photodiode of each pixel is closed hoop.
In some embodiments, the deep photodiode includes stacking gradually down along the depth direction of the substrate
The pole P, the pole N and the upper pole P, the upper pole P and the lower pole the P ground connection.
In some embodiments, the upper pole P of the deep photodiode phase of the two neighboring dot structure
It is connect with the upper pole P, the pole N is connect with the pole N, the lower pole P is connect with the lower pole P.
In some embodiments, the substrate further includes below the photosensitive unit and the deep photodiode
P type substrate.
In some embodiments, deep the distance between the photodiode and the P type substrate are less than 1 micron.
In some embodiments, the pixel array further includes the metal interconnection layer being formed in substrate, the conducting wire
It is formed in the metal interconnection layer, the metal interconnection layer is also formed with the anti-dazzle light pipe and anti-dazzle control line of array, described
Anti-dazzle light pipe is metal-oxide-semiconductor, and the pole N of the depth photodiode is connect with the drain electrode of the anti-dazzle light pipe, the anti-dazzle
The source electrode of pipe is connected to the conducting wire, and the anti-dazzle control line connect with the grid of the anti-dazzle light pipe it is described for controlling
The switch state of anti-dazzle light pipe.
Additional aspect and advantage of the invention will be set forth in part in the description, and will partially become from the following description
Obviously, or practice through the invention is recognized.
Specific embodiment
Embodiments of the present invention are described below in detail, the example of the embodiment is shown in the accompanying drawings, wherein from beginning
Same or similar element or element with the same or similar functions are indicated to same or similar label eventually.Below by ginseng
The embodiment for examining attached drawing description is exemplary, and for explaining only the invention, and is not considered as limiting the invention.
In the description of the present invention, it is to be understood that, term " first ", " second " are used for description purposes only, and cannot
It is interpreted as indication or suggestion relative importance or implicitly indicates the quantity of indicated technical characteristic.Define as a result, " the
One ", the feature of " second " can explicitly or implicitly include one or more feature.In description of the invention
In, the meaning of " plurality " is two or more, unless otherwise specifically defined.
In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, term " installation ", " phase
Even ", " connection " shall be understood in a broad sense, for example, it may be being fixedly connected, may be a detachable connection, or be integrally connected;It can
To be mechanical connection, it is also possible to be electrically connected or can be in communication with each other;It can be directly connected, it can also be by between intermediary
It connects connected, can be the connection inside two elements or the interaction relationship of two elements.For the ordinary skill of this field
For personnel, the specific meanings of the above terms in the present invention can be understood according to specific conditions.
Following disclosure provides many different embodiments or example is used to realize different structure of the invention.In order to
Simplify disclosure of the invention, hereinafter the component of specific examples and setting are described.Certainly, they are merely examples, and
And it is not intended to limit the present invention.In addition, the present invention can in different examples repeat reference numerals and/or reference letter,
This repetition is for purposes of simplicity and clarity, itself not indicate between discussed various embodiments and/or setting
Relationship.In addition, the present invention provides various specific techniques and material example, but those of ordinary skill in the art can be with
Recognize the application of other techniques and/or the use of other materials.
Referring to Fig. 1, the imaging sensor 100 of better embodiment of the present invention includes pixel array 10, column cache unit
20, row decoding unit 30, analog processing circuit unit 40, D/A converting circuit unit 50 and imaging signal processing circuit 60.
Pixel array 10 is converted to optical signal the electric signal directly proportional with light intensity for collecting optical signal.In this way, can
Object is converted to electric signal by optical image of the pick-up lens on pixel array 10.Column cache unit 20 is for adopting
Collect the electric signal that simultaneously output pixel array 10 generates.Row decoding unit 30 is used to control the exposure of pixel array 10.Simulation process
Circuit 40 is for handling and amplifying the collected electric signal of column cache unit 20.Analog to digital conversion circuit 50 is used to analog signal turn
Change digital signal into.Imaging signal processing circuit 60 is for handling digital signal to adjust the brightness of image, and exposure is white
The parameters such as balance.
Pixel array 10 may include 2,000,000 pixels, 3,000,000 pixels, 5,000,000 pixels, 10,000,000 pixels or it is more or
Less pixel.Fig. 2-3 is please referred to, in the present embodiment, to help to illustrate that specific structure, pixel array 10 include 3*3 array
Pixel 10p.
Pixel array 10 includes substrate 11.Substrate 11 is semiconductor material, for example, P is lightly doped in extension on heavily doped P-type silicon
Type silicon.Substrate 11 is in substantially rectangular patch, and including upper surface 111 and lower surface 112.
Pixel array 10 includes by carrying out the integrated circuit fabrication process such as photoetching, injection, diffusion for As in upper surface 111
Or P ion is implanted into substrate 11 and the dot structure 113 of the 3*3 array of formation and the P type substrate 114 positioned at 11 lower part of substrate.Picture
Pixel array 10 further includes metal interconnection layer 12, the colored filter being formed on upper surface 111 by integrated circuit fabrication process
13 and micro mirror array 14.
In present embodiment, each dot structure 113 includes photosensitive unit 1131 and deep photodiode 1132.Deep photoelectricity
Around photosensitive unit 1131 but setting is isolated with photosensitive unit 1131 in diode 1132.
Photosensitive unit 1131 is usually photodiode, and is used to sense the intensity for the light for entering respective pixel 10p simultaneously
It is converted into photocarrier.In this way, object can be passed through pick-up lens by pixel array 10 by setting photosensitive unit 1131
Optical imagery is converted to electric signal.
Deep photodiode 1132 is the depth photodiode deep compared with photosensitive unit 1131, in addition to that can be produced with light sensing
Outside third contact of a total solar or lunar eclipse carrier, deep photodiode 1131 can also conduct photocarrier.
In this way, leading to some pixel 10p corresponding photosensitive unit 1131 saturation and causing light current-carrying local luminance is excessively high
When son overflows, deep photodiode 1132 can receive, absorb photocarrier, adjacent without causing photocarrier to be crosstalked into
Photosensitive unit 1131 plays isolation effect between pixel 10p, so that glare phenomenon and crosstalk phenomenon be avoided to generate.
Deep photodiode 1131 includes stacking gradually the lower pole P, the pole N and the upper pole P along the depth direction of substrate 11.
Specifically, dot structure 113 is in rectangle substantially, photosensitive unit 1131 is also in rectangle substantially, the depth optical diode
1132 be the rectangular ring structure (as continuous closed hoop) around photosensitive unit 1131.
For convenience of manufacture, the deep photodiode 1132 of adjacent dot structure 113 is connected.It is specific it is two neighboring on
The pole P is connect with the upper pole P, the pole N is connect with the pole N, the lower pole P is connect with the pole lower P.In other words, adjacent dot structure 113 shares same
One photodiode 1132.
Certainly, deep photodiode 1132 is not limited to present embodiment, in other embodiments, is guaranteeing isolation effect
In the case where fruit, deep photodiode 1132 is also possible to the separated structure around photosensitive unit 1131, and discrete ring-type.
The deep photodiode 1132 of adjacent dot structure 113 can be with separately positioned to realize specific effect.
P type substrate 114 can be the epitaxial light on remaining heavily doped P-type silicon after integrated circuit fabrication process of substrate 11
Doped p-type silicon, P type substrate 114 equally can receive, absorb the photocarrier of the spilling of photosensitive unit 1131.
For the aperture opening ratio for guaranteeing pixel 10p, in present embodiment, the size of dot structure 113 is felt in 6 microns
The size of light unit 1131 is in 4-4.5 microns, and the size of deep photodiode 1132 is in 0.5-0.8 microns.Or
Person says that the ratio of the area of the area and dot structure 113 of photosensitive unit 1131 is 0.44-0.56, and photosensitive unit 1131
The ratio of the area of area and deep photodiode 1132 is 25-81.
In order to guarantee that isolation effect, the ratio of the depth and the depth of photosensitive unit 1131 of deep photodiode 1132 are greater than
Equal to 2.For example, the depth of photosensitive unit 1131 is in 1 microns, and the depth of deep photodiode 1132 is in 2 microns.
In order to increase isolation effect, deep photodiode 1132 is at a distance from P type substrate 114 less than 1 micron.In addition, p-type
The thickness of substrate 114 is in 3 microns.
Certainly, the specific size of dot structure 113 is not limited to present embodiment, can adopt depending on demand in other modes
With other sizes.
Referring to Figure 4 together, metal interconnection layer 12 could be formed with the various electric signals generated to pixel array 10 and control
Switching tube (MOSFET pipe), for example, transfer tube tx, reset transistor rst, source follower sf, selecting pipe sel and anti-dazzle light pipe tx0.
Metal interconnection layer 12 can also be formed with various control lines, for example, transmission gate control line TX, reseting controling signal line RST, row choosing
Logical control line SEL and anti-dazzle control line TX0.Metal interconnection layer 12 further includes having conducting wire Vddp and signal output line Vout.
Transmit the control of gate control line TX, reseting controling signal line RST, row gating control line SEL and anti-dazzle control line TX0
Signal processed is respectively connected to the grid of transfer tube tx, reset transistor rst, selecting pipe sel and anti-dazzle light pipe tx0, with control transfer tube tx,
The switch state of reset transistor rst, selecting pipe sel and anti-dazzle light pipe tx0.Wherein, gate control line TX, reseting controling signal line are transmitted
RST, row gating control line SEL are used to control exposure and signal acquisition of pixel array 10 etc..And anti-dazzle light pipe tx0 closure, then
The starting of anti-dazzle function, deep 1132 connecting wire Vddp of photodiode, conducting wire Vddp can be connected to power supply, and pass through power supply source
Source constantly empties deep photodiode 1132, so that deep photodiode 1132 be made to be in fixed potential.
Specifically, anti-dazzle light pipe tx0 is metal-oxide-semiconductor, the pole N of photodiode 1132 is connect with the drain electrode of anti-dazzle light pipe tx0,
The source electrode of anti-dazzle pipe tx0 is connect with conducting wire Vddp, and anti-giddy light by dominated line TX0 is connect with the grid of anti-dazzle pipe tx0 for controlling
Make the switch state of anti-dazzle light pipe tx0.
In present embodiment, optical filter that is that colored filter 13 includes array and being aligned respectively with dot structure 113
Unit 131.Filter unit 131 can be three kinds by RGB, and arrange by pattra leaves (Byer).
Micro mirror array 14 includes array and the micro mirror 141 being aligned respectively with dot structure 113, is injected pair for being refracted into
The light of dot structure 113 is answered, to improve the sensitivity of pixel array 10.
Photosensitive unit is isolated using deep photodiode 1132 in the imaging sensor 100 of better embodiment of the present invention
1131, since deep 1132 manufacture difficulty of photodiode is low relative to traditional deep trench isolation structure, be easier to realize and
And isolation effect is good, can prevent crosstalk between pixel 10p.
In the description of this specification, reference term " embodiment ", " some embodiments ", " schematically implementation
What the description of mode ", " example ", " specific example " or " some examples " etc. meant to describe in conjunction with the embodiment or example
Particular features, structures, materials, or characteristics are contained at least one embodiment or example of the invention.In this specification
In, schematic expression of the above terms are not necessarily referring to identical embodiment or example.Moreover, the specific spy of description
Sign, structure, material or feature can be combined in any suitable manner in any one or more embodiments or example.
While embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that:
These embodiments can be carried out with a variety of variations, modification, replacement in the case where not departing from the principle of the present invention and objective and become
Type, the scope of the present invention are defined by the claims and their equivalents.