Summary of the invention
The shortcoming of prior art in view of the above; The object of the present invention is to provide a kind of self energizing cmos image sensor; Be used for solving the problem that the big performance change with filter itself of image area sensor that imageing sensor that prior art detects natural daylight uses filter to cause causes poor quality images and increase imageing sensor cost; Also be used for solving the prior art needs and use the pictures different transducer to realize the problem of ultraviolet light, visible light, infrared light detection, solved the problem that can't realize self-energizing imageing sensor in the prior art simultaneously.
For realizing above-mentioned purpose and other relevant purposes, the present invention provides a kind of self energizing cmos image sensor, comprises at least:
Substrate layer; At least comprise the column bus that is positioned at wherein, amplifier, in order to current source cell that constant current is provided, in order to the graphics processing unit of image processing and be used for the energy-storage units of self-supply power source, wherein, said graphics processing unit comprises clock and control circuit at least; Row, row, layer decoder circuit; Sampling hold circuit, analog to digital converter, image processor; Said energy-storage units comprises charge storage circuit and power-switching circuit, to convert the electric charge that stores into suitable voltage through said power-switching circuit, for said cmos image sensor provides power supply; Said amplifier all links to each other with column bus with current source cell;
The sensitization lamination; The said substrate layer of range upon range of covering surface; In order to absorb the light of different-waveband simultaneously; At least comprise range upon range ofly covering being used on the said substrate layer and absorbing respectively a plurality of photosensitive layers of this different-waveband light, and respectively comprise two switch elements at least and be connected in a photo-sensitive cell between these two switch elements in this photosensitive layer;
The pixel sensing element; Be arranged in substrate layer or be arranged at least one photosensitive layer of said sensitization lamination; At least transistor is followed in the source that comprise the reset transistor that connects said photosensitive layer, connects said reset transistor and photosensitive layer, and connects said source and follow transistorized row selecting transistor.
Alternatively, said sensitization lamination comprises at least and range upon range ofly covers being used on the said substrate layer and absorb first photosensitive layer of first band of light and be layered in second photosensitive layer that being used on said first photosensitive layer absorbs second band of light.
Alternatively, said sensitization lamination also comprises the 3rd photosensitive layer that is used to absorb triband light that is layered on said second photosensitive layer.
Alternatively; Through being mixed, germanium forms in said first photosensitive layer in order to absorb the germanium material photo-sensitive cell of infrared light; Form through silicon is mixed in said second photosensitive layer in order to absorbing the silicon materials photo-sensitive cell of visible light, form carbofrax material photo-sensitive cell in said the 3rd photosensitive layer through carborundum is mixed in order to absorbing ultraviolet light.
Alternatively, respectively the material of this photosensitive layer is the photon energy of energy gap and the required absorption semi-conducting material that is complementary, and is selected from carborundum, silicon, germanium or germanium silicon respectively, or is selected from carborundum, silicon, germanium or germanium silicon through mixing respectively.
Alternatively, respectively this photosensitive layer in the said sensitization lamination is a semi-conducting material of the same race.
Alternatively, have between described substrate layer and the sensitization lamination in insulating barrier or the said sensitization lamination and have insulating barrier between each photosensitive layer.
Alternatively, the photosensitive layer in the said sensitization lamination is the compound photosensitive layer of being made up of a plurality of sensitization sublayer.
Alternatively, respectively has insulating barrier between this sensitization sublayer.
Alternatively, respectively this photo-sensitive cell of said sensitization lamination is at least a in PN junction photodiode, pinprick formula photodiode or the photogate.
Alternatively; Said pixel sensing element is arranged in a photosensitive layer of described sensitization lamination; The shared said pixel sensing element of all photo-sensitive cells of said sensitization lamination; And respectively between this photo-sensitive cell and the said pixel sensing element through a respectively corresponding switch element connection of this photo-sensitive cell, wherein, described sensitization lamination and pixel sensing element form a picture element module.
Alternatively; A plurality of said pixel sensing elements lay respectively in a plurality of photosensitive layers of described sensitization lamination; The corresponding described a plurality of pixel sensing elements of all photo-sensitive cells of said sensitization lamination; And each photo-sensitive cell of described sensitization lamination only is connected with a said pixel sensing element through its each self-corresponding switch element, and wherein, described sensitization lamination and a plurality of said pixel sensing element form a picture element module.
Alternatively, described pixel sensing element is arranged in substrate layer, the shared said pixel sensing element of all photo-sensitive cells of said sensitization lamination, and wherein, said sensitization lamination is a picture element module.
As stated, for the existing C mos image sensor, self energizing cmos image sensor of the present invention has following beneficial effect:
1) the present invention is owing to adopted the design of free of light filter, the problems such as poor quality images of also having avoided filter to cause when reducing cost;
2) the present invention makes required circuit structure can be made in (substrate layer) on independent one deck, thereby improves fill factor, curve factor greatly owing to adopt the sensitization lamination of stacked structure, further improves the quality of image;
3) the present invention is owing to adopt the sensitization lamination of stacked structure; Make a pixel have the ability that detects different-waveband light; Single exposure can obtain information such as ultraviolet light, visible light and infrared light simultaneously, on the one hand, can obtain multiple information through chip piece; Not only reduce cost and complexity, and improved the efficient and the picture quality of conversion greatly; On the other hand; When reading information needed; Can selectively the residual charge that different photosensitive layer produced be preserved, and for the entire image transducer power supply is provided, to realize self-energizing function through power-switching circuit; Make full use of the energy of light, and strengthened the adaptive capacity of imageing sensor;
4) self energizing cmos image sensor provided by the invention can be prepared in red, blue, green glow sensor devices on the different laminations that are positioned at Semiconductor substrate the same area in order to realize the accurate imaging of visible light, has further improved the integrated level of imageing sensor.
Embodiment
Below through specific instantiation execution mode of the present invention is described, those skilled in the art can understand other advantages of the present invention and effect easily by the content that this specification disclosed.The present invention can also implement or use through other different embodiment, and each item details in this specification also can be based on different viewpoints and application, carries out various modifications or change under the spirit of the present invention not deviating from.
See also Fig. 1 to Fig. 5.Need to prove; The diagram that is provided in the following specific embodiment is only explained basic conception of the present invention in a schematic way; Satisfy only show in graphic with the present invention in relevant assembly but not component count, shape and plotted when implementing according to reality; Kenel, quantity and the ratio of each assembly can be a kind of random change during its actual enforcement, and its assembly layout kenel also maybe be more complicated.
The cmos image sensor of existing detection visible light is the imageing sensor that has three kinds of color filters of red, green, blue; Because the use of filter; Cause the increase of cost; Cause that image area sensor causes poor quality images more greatly, and the performance change of filter itself also influences the quality of imaging; The existing C mos image sensor all carries out respectively for the detection of ultraviolet light, visible light, infrared light usually, does not have a kind of imageing sensor that can detect several kinds of different-waveband light simultaneously; The existing C mos image sensor can't be for self providing power supply to reach self-energizing function when detecting light.
Given this; The present invention provides a kind of self energizing cmos image sensor; At least comprise substrate layer, range upon range of sensitization lamination and the pixel sensing element that covers on the substrate layer; Wherein, column bus, amplifier, current source cell, graphics processing unit and the energy-storage units that is used for self-supply power source are positioned at substrate layer; The sensitization lamination comprises and range upon range ofly covers a plurality of photosensitive layers that being used on the said substrate layer absorbs different-waveband light, and respectively comprises two switch elements at least and be connected in a photo-sensitive cell between these two in this photosensitive layer; The pixel sensing element is arranged in substrate layer or is arranged at least one photosensitive layer of sensitization lamination.The present invention adopts the sensitization lamination of the stacked structure of free of light filter; Can realize that a pixel has ability and the self-energizing function of imageing sensor that detects different-waveband light; Cost and complexity have not only been reduced; Improve conversion efficiency, picture quality and the integrated level of imageing sensor greatly, and when making full use of the energy of light, strengthened the adaptive capacity of imageing sensor.
Embodiment one
To shown in Figure 4, the present invention provides a kind of self energizing cmos image sensor, comprises at least like Fig. 1:
Be arranged in column bus 11, amplifier 12, current source cell 13, graphics processing unit 14, and the energy-storage units 15 of substrate layer 1; The a plurality of photosensitive layers that are used to absorb different-waveband light in the range upon range of sensitization lamination 2 that covers on the said substrate layer 1; In present embodiment one; For being used to absorb three photosensitive layers of three band of light; Wherein, first photosensitive layer is that infrared light photosensitive layer 21, the second photosensitive layers are that visible light photosensitive layer 22, the 3rd photosensitive layer are ultraviolet light photosensitive layer 23; And comprise that at least reset transistor 31, source follow the pixel sensing element 3 of transistor 32 and row selecting transistor 33; In present embodiment one; Said self energizing cmos image sensor is the 4T type, and then said pixel sensing element 3 also comprises the transfering transistor 341~343 and floating diffusion region 351~353 that lays respectively at this photosensitive layer respectively.
Said substrate layer 1 material is semi-conducting material or organic film material, and wherein, said semi-conducting material is silicon, germanium or germanium silicon; Said organic film material is ZnO-TFT, and the structure of said substrate layer 1 is the semiconductor structure of homogenous material or the semiconductor structure of tape insulation buried regions, in present embodiment one; Said substrate layer 1 is a body silicon; But be not limited to this, in another embodiment, said substrate layer 1 is germanium on insulator (GOI).
As shown in Figure 1, said substrate layer 1 comprises at least and being positioned at wherein:
Said column bus 11 is connected with pixel sensing element 3 with described amplifier 12, current source cell 13.
Said amplifier 12 is in order to amplify the signal of telecommunication of reading through described pixel sensing element 3 that comprises Pixel Information; Wherein, An input links to each other with said column bus, another input end grounding, and the signal of telecommunication that comprises Pixel Information after will amplifying exports said graphics processing unit 14 to.
Said current source cell 13 comprises in order to the circuit (not shown) that constant current is provided, and makes the source in the said pixel sensing element 3 follow the grid source electric current (I of transistor 32
Ds) keep constant, for guaranteeing that source voltage and grid voltage difference are constant, thereby reach the purpose of source voltage follow grid voltage, wherein, an end of said current source cell 13 is connected other end ground connection with described column bus 11 with amplifier 12.
Said graphics processing unit 14 links to each other with the output of said amplifier 12; At least comprise clock and control circuit; Row, row, layer decoder circuit, sampling hold circuit, analog to digital converter; Image processor (not shown) will be in order to carrying out image processing through the signal of telecommunication that comprises Pixel Information that amplifier 12 amplified.
Said energy-storage units 15 comprises charge storage circuit and power-switching circuit (not shown); Be used for the electric charge that stores is converted into suitable voltage through said power-switching circuit and preserves; When the needs self energizing, the voltage of preserving is connected to the required power supply V of pixel sensing element 3
Dd, for said pixel sensing element 3 provides drain voltage V
Dd, for said cmos image sensor is realized the self-supply power source function.
Shown in Fig. 2 a; Said sensitization lamination 2 range upon range of covering on the said substrate layer 1 comprise the range upon range of a plurality of photosensitive layers that being used on the said substrate layer 1 absorbs different-waveband light that cover, at least in present embodiment one; It is range upon range of that to cover first photosensitive layer that being used on the said substrate layer absorb first band of light (infrared light) be infrared light photosensitive layer 21; Being layered in second photosensitive layer that being used on said first photosensitive layer (infrared light photosensitive layer 21) absorb second band of light (visible light) is visible light photosensitive layer 22, and to be layered in the 3rd photosensitive layer that being used on said second photosensitive layer (visible light photosensitive layer 22) absorb triband light (ultraviolet light) be ultraviolet light photosensitive layer 23, and respectively the material of this photosensitive layer is the photon energy of energy gap and the required absorption semi-conducting material that is complementary; Be selected from carborundum, silicon, germanium or germanium silicon respectively; Or be selected from carborundum, silicon, germanium or germanium silicon respectively through mixing, wherein, in present embodiment one; Said infrared light photosensitive layer 21 is germanium (Ge) material; Said visible light photosensitive layer 22 is silicon (Si) material, and said ultraviolet light photosensitive layer 23 is carborundum (SiC) material, but is not limited to this; In another embodiment, respectively the material of this photosensitive layer can be semi-conducting material of the same race.
Respectively comprise two switch elements in this photosensitive layer at least and be connected in a photo-sensitive cell between these two; Respectively this photo-sensitive cell is at least a in PN junction photodiode, pinprick formula photodiode (Pinned Diode) or the photogate; Wherein, said photo-sensitive cell is used for imageing sensor of the present invention and when exposure, carries out opto-electronic conversion, the light signal that receives is converted to the signal of telecommunication that comprises Pixel Information; In present embodiment one; Respectively the photo-sensitive cell in this photosensitive layer is the PN junction photodiode, but is not limited thereto, in another embodiment; Also there is the photo-sensitive cell type situation all inequality in this photosensitive layer respectively, promptly is respectively PN junction photodiode, pinprick formula photodiode, and a kind of (not shown) of photogate; Said switch element includes the PMOS transistor of the nmos pass transistor of a nmos pass transistor, a plurality of parallel connection or series connection, PMOS transistor or a plurality of parallel connection or series connection, and in present embodiment one, said switch element is a nmos pass transistor.
Need to prove; Photosensitive layer number described in the present embodiment one in the sensitization lamination 2 is three, and (first photosensitive layer is an infrared light photosensitive layer 21; Second photosensitive layer is that visible light photosensitive layer 22, the 3rd photosensitive layer are ultraviolet light photosensitive layer 23); But and not only be confined to this; In another embodiment, the photosensitive layer number in the said sensitization lamination 2 also can be for only being used to absorb two photosensitive layers of two kinds of different-waveband light, and it comprises and range upon range ofly covers being used on the said substrate layer and absorb first photosensitive layer of first band of light and be layered in second photosensitive layer that being used on said first photosensitive layer absorbs second band of light; Certainly, in other embodiments, the photosensitive layer number in the said sensitization lamination 2 also can be given unnecessary details at this for four photosensitive layers or more a plurality of photosensitive layer no longer one by one.
What need further specify is; Photosensitive layer in the said sensitization lamination 2 can be the compound photosensitive layer of being made up of a plurality of sensitization sublayer; In present embodiment one; Be that described first photosensitive layer (infrared light photosensitive layer 21), second photosensitive layer (visible light photosensitive layer 22) or the 3rd photosensitive layer (ultraviolet light photosensitive layer 23) can be distinguished or the compound photosensitive layer for being made up of a plurality of sensitization sublayer simultaneously; For example, be to have only said visible light photosensitive layer 22 for by a plurality of sensitization sublayer (situation of the compound photosensitive layer of 22a~22c) form shown in Fig. 2 b.
It is pointed out that for fear of crosstalking between this photosensitive layer respectively, influence picture quality, therefore adopt in insulating barrier or the said sensitization lamination 2 between each photosensitive layer the employing insulating barrier to isolate between described substrate layer 1 and the sensitization lamination 2; Need be pointed out that further that said insulating barrier 4 is single layer structure or laminated construction, said single layer structure wherein or the material of each layer in the said laminated construction are any one in silica, silicon nitride and the silicon oxynitride.Shown in Fig. 2 c; In present embodiment one; Adopt monolayer insulating layer 41 between described substrate layer 1 and the sensitization lamination 2, reach in the said sensitization lamination 2 and adopt insulating barrier (to comprise the monolayer insulating layer 421 between described infrared light photosensitive layer 21 and visible light photosensitive layer 22 between each photosensitive layer; And the monolayer insulating layer 422 between described visible light photosensitive layer 22 and the ultraviolet light photosensitive layer 23, respectively this photosensitive layer is and does not comprise sensitization sublayer situation at this moment, is single layer structure) isolate; In another embodiment; When photosensitive layer in the said sensitization lamination 2 is the compound photosensitive layer of being made up of a plurality of sensitization sublayer; Respectively has insulating barrier between this sensitization sublayer; For example, shown in Fig. 2 d have only said visible light photosensitive layer 22 for by a plurality of sensitization sublayer (situation of the compound photosensitive layer of 22a~22c) form, it respectively (has monolayer insulating layer 422a~422c between the 22a~22c) in this sensitization sublayer; Further; In other embodiments; Shown in Fig. 2 e, said infrared light photosensitive layer 21, visible light photosensitive layer 22 and ultraviolet light photosensitive layer 23 are single layer structure, but said insulating barrier 41 ", 421 " and 422 " be the insulating barrier of the laminated construction of silicon nitride and silicon oxynitride.
Particularly; In present embodiment one; Shown in Fig. 2 c, described first photosensitive layer (infrared light photosensitive layer 21), second photosensitive layer (visible light photosensitive layer 22) and the 3rd photosensitive layer (ultraviolet light photosensitive layer 23) are single layer structure, and adopt insulating barrier (to comprise the insulating barrier 421 between described infrared light photosensitive layer 21 and visible light photosensitive layer 22 between each photosensitive layer; And the insulating barrier 422 between described visible light photosensitive layer 22 and the ultraviolet light photosensitive layer 23) isolates; Simultaneously, adopt insulating barrier 41 to isolate between described substrate layer 1 and the sensitization lamination 2, and said insulating barrier 41,421 and 422 is the silicon nitride dielectric layer of single layer structure; Shown in Fig. 2 c, in present embodiment one, respectively the photo-sensitive cell in this photosensitive layer is the PN junction photodiode; As shown in Figure 1, in present embodiment one, said switch element is a nmos pass transistor, and when its grid added high voltage, said switch element closure was conducting state, and when its grounded-grid, said switch element is opened and is off-state.
Further, in present embodiment one, as shown in Figure 1; Comprise switch element 2111 and 2112 and be connected in the photo-sensitive cell (PN junction photodiode) 212 between the two in the said infrared light photosensitive layer 21, wherein, in said infrared light photosensitive layer 21; Form germanium PN junction photodiode photo-sensitive cell 212 through germanium is mixed, comprise p type island region and N type district, said p type island region ground connection; One end of said switch element 2111 is connected with said pixel sensing element 3, and an end of said switch element 2112 is connected with said energy-storage units 15, and in present embodiment one; Respectively this switch element 2111 and 2112 the other end be connected to the floating diffusion region that is arranged in infrared light photosensitive layer 21 (Floating Diffusion, FD) 351 (among the embodiment one, imageing sensor of the present invention is the 4T type; The N type district of photo-sensitive cell (PN junction photodiode) 212 is through transfering transistor (Transfer Transistor; TX) 341 be connected to floating diffusion region 351), but be not limited thereto, in another embodiment; When imageing sensor of the present invention was the 3T type, respectively this switch element 2111 and 2112 the other end were connected to the N type district of PN junction photodiode 212; In present embodiment one, as shown in Figure 1, comprise switch element 2211 and 2212 and be connected in the photo-sensitive cell (PN junction photodiode) 222 between the two in the said visible light photosensitive layer 22; Wherein, in said visible light photosensitive layer 22,, silicon forms silicon PN junction photodiode photo-sensitive cell 222 through being mixed; Comprise p type island region and N type district, said p type island region ground connection, an end of said switch element 2211 is connected with said pixel sensing element 3; One end of said switch element 2212 is connected with said energy-storage units 15, and in present embodiment one, and respectively this switch element 2211 and 2212 the other end are connected to floating diffusion region (the Floating Diffusion that is arranged in visible light photosensitive layer 22; FD) 352 (among the embodiment one; Imageing sensor of the present invention is the 4T type, and the N type district of photo-sensitive cell (PN junction photodiode) 222 is through transfering transistor (Transfer Transistor TX) 342 is connected to floating diffusion region 352); But be not limited thereto; In another embodiment, when imageing sensor of the present invention was the 3T type, respectively this switch element 2211 and 2212 the other end were connected to the N type district of PN junction photodiode 222; In present embodiment one, as shown in Figure 1, comprise switch element 2311 and 2312 and be connected in the photo-sensitive cell (PN junction photodiode) 232 between the two in the said ultraviolet light photosensitive layer 23; Wherein, in said ultraviolet light photosensitive layer 23,, carborundum (SiC) forms carborundum PN junction photodiode photo-sensitive cell (PN junction photodiode) 232 through being mixed; Comprise p type island region and N type district; Said p type island region ground connection, an end of said switch element 2311 is connected with said pixel sensing element 3, and an end of said switch element 2312 is connected with said energy-storage units 15; And in present embodiment one; Respectively this switch element 2311 and 2312 the other end be connected to the floating diffusion region that is arranged in ultraviolet light photosensitive layer 23 (Floating Diffusion, FD) 353 (among the embodiment one, imageing sensor of the present invention is the 4T type; The N type district of photo-sensitive cell (PN junction photodiode) 232 is through transfering transistor (Transfer Transistor; TX) 343 be connected to floating diffusion region 353), but be not limited thereto, in another embodiment; When imageing sensor of the present invention was the 3T type, respectively this switch element 2311 and 2312 the other end were connected to the N type district of PN junction photodiode 232.
What need particularly point out is that the light of different wave length has different response characteristics in same semi-conducting material, have only as semiconductor energy bandwidth E
GPhoton energy E less than incident light
Ph(E
Ph=h υ=hc/ λ) time, semiconductor just can absorb photon and produce electron-hole pair, and different semi-conducting materials are represented the strong and weak available absorption coefficient a of different wave length light absorption, P (x)=P
0* exp (ax), wherein, P
0Be incident intensity, P (x) is a light path x place luminous intensity in the semiconductor, when x=1, and P (d)=P
0* e, definition d is the photon penetration depth.Absorption coefficient a=a (λ) is the function of wavelength, and it depends on wavelength strongly, and absorption coefficient reduces and increases rapidly with wavelength; That is: semi-conducting material will absorb the light of different wave length; Need the different incident light path, wavelength is short more, and semi-conducting material is big more to the absorption coefficient of light; Absorb incident light fully, realize that effective light path that opto-electronic conversion needs incident light in semiconductor, to transmit is short more, on the contrary then long more.In other words, when the incident light of different wave length was absorbed in same semi-conducting material, respectively the incident light of this different wave length got into the degree of depth difference of semi-conducting material.
For the ease of absorbing the light of different-waveband simultaneously; Make imageing sensor of the present invention have the ability that detects different-waveband light; Then the present invention adopts laminated construction in order to light absorbing said sensitization lamination 2; Because respectively this photosensitive layer residing position in sensitization lamination 2 is different, therefore when respectively this photosensitive layer is semi-conducting material of the same race, also can absorb the light of different-waveband.
As shown in Figure 3, in present embodiment one, ultraviolet light, visible light and infrared light are three light that wave band is different, and its medium wavelength the shortest relative ultraviolet light is at the d nearer apart from incidence surface
1The position almost all is absorbed, and visible light is at the d placed in the middle relatively apart from incidence surface
2Position (d
2With respect to d
1And d
3, be positioned at the centre position) almost all be absorbed, and three wave band medium wavelength the longest relative infrared lights are mainly at the d far away apart from incidence surface
3The position almost all is absorbed.In view of above-mentioned theory; In present embodiment one; Described ultraviolet light photosensitive layer 23 is layered on the visible light photosensitive layer 22; Be positioned at sensitization lamination 2 part at the middle and upper levels, in order to ultraviolet light almost all is absorbed in the nearer position apart from the plane of incidence (surface of sensitization lamination 2), the bottom of ultraviolet light photosensitive layer 23 apart from the plane of incidence (surface of sensitization lamination 2) apart from r
3(or ultraviolet light photosensitive layer be compound photosensitive layer, the thickness summation of its each sublayer) is 0 and d
2Between; Described visible light photosensitive layer 22 is layered on the said infrared light photosensitive layer 21; Be arranged in the layer segment of sensitization lamination 2; In order to visible light almost all is absorbed in the position placed in the middle relatively apart from the plane of incidence (surface of sensitization lamination 2), the bottom of visible light photosensitive layer 22 apart from the plane of incidence (surface of sensitization lamination 2) apart from r
2(or visible light photosensitive layer be compound photosensitive layer, the thickness summation of its each sublayer) is at r
3And d
3Between; Described infrared light photosensitive layer 21 range upon range of covering on the substrate layer 1; Be arranged in sensitization lamination 2 underclad portion; In order to infrared light almost all is absorbed in the position far away apart from the plane of incidence (surface of sensitization lamination 2), the bottom of infrared light photosensitive layer 21 apart from the plane of incidence (surface of sensitization lamination 2) apart from r
1(or infrared light photosensitive layer be compound photosensitive layer, the thickness summation of its each sublayer) is greater than r
2
In like manner; In another embodiment; As far as visible light, because the wavelength of blue light, green glow and ruddiness is for increasing progressively situation, so blue light absorption is near the zone on the plane of incidence (surface of sensitization lamination 2); The absorption of ruddiness then concentrates on apart from the plane of incidence (surface of sensitization lamination 2) interior zone far away, and the absorption region of green glow is between between the two.
What need further specify is that when the photon energy of common semi-conductive energy gap and a certain band of light was complementary, this band of light can be by good absorption; Therefore; In the said sensitization lamination 2 respectively the material of this photosensitive layer be the photon energy of energy gap and the required absorption semi-conducting material that is complementary, wherein, in present embodiment one; For better absorbing ultraviolet light, ultraviolet light photosensitive layer 23 adopts the bigger material carborundum of energy gap; In order better to absorb visible light, visible light photosensitive layer 22 adopts the material silicon of medium energy gap; In order better to absorb infrared light, infrared light photosensitive layer 21 adopts the minimum material germanium of energy gap.
Said pixel sensing element 3 (not shown) is arranged in substrate layer 1 or is arranged at least one photosensitive layer of said sensitization lamination 2; In order to the signal of telecommunication that comprises Pixel Information that said sensitization lamination 2 is obtained (respectively this photo-sensitive cell carry out opto-electronic conversion when the exposure light signal that receives is converted to the signal of telecommunication that comprises Pixel Information); Influenced through column bus 11 and amplifier 12 by current source cell 13 and read out to graphics processing unit 14; At least comprise reset transistor 31 (the Reset Transistor that connects said photosensitive layer; RST), transistor 32 (Source Follower Transistor is followed in the source that connects said reset transistor 31 and photosensitive layer; SF); And connect row selecting transistor 33 (the Row Select that transistor 32 is followed in said source; RS), wherein, described reset transistor 31, source follow transistor 32, and row selecting transistor 33 include a kind of in the PMOS transistor of the nmos pass transistor of a nmos pass transistor, a plurality of parallel connection or series connection, PMOS transistor or a plurality of parallel connection or series connection.
It is to be noted; Said self energizing cmos image sensor is 3T type imageing sensor or 4T type imageing sensor; Wherein, The pixel sensing element 3 (not shown) of said 4T type imageing sensor also comprises and is arranged in respectively the corresponding transfering transistor of photo-sensitive cell separately of this photosensitive layer (Transfer Transistor, TX) 341~343 and floating diffusion region (Floating Diffusion, FD) 351~353; Wherein, described transfering transistor comprises a kind of in the PMOS transistor of the nmos pass transistor of a nmos pass transistor, a plurality of parallel connection or series connection, PMOS transistor or a plurality of parallel connection or series connection.
In present embodiment one, said self energizing cmos image sensor is a 4T type imageing sensor, described reset transistor 31, source follow transistor 32, row selecting transistor 33, and transfering transistor 34 be a nmos pass transistor.But do not limit to therewith, in another embodiment, the transistor in the said pixel sensing element 3 can be above-mentioned series/parallel situation or PMOS situation.
It is pointed out that said pixel sensing element 3 is arranged in substrate layer 1 or is arranged at least one photosensitive layer of said sensitization lamination 2, several kinds of situation below shown in Fig. 1,4a and 4b, existing:
As shown in Figure 1; Said pixel sensing element 3 is arranged in a photosensitive layer of described sensitization lamination 2; The shared said pixel sensing element 3 of all photo-sensitive cells of said sensitization lamination 2; And respectively connect through the switch element that respectively this photo-sensitive cell is corresponding between this photo-sensitive cell and the said pixel sensing element 3, wherein, described sensitization lamination 2 and pixel sensing element 3 formation one picture element module 5;
Shown in Fig. 4 a, described pixel sensing element 3 is arranged in substrate layer 1, the shared said pixel sensing element 3 of all photo-sensitive cells of said sensitization lamination 2, and wherein, said sensitization lamination 2 is a picture element module 5;
Shown in Fig. 4 b; A plurality of said pixel sensing elements 3 lay respectively in a plurality of photosensitive layers of described sensitization lamination 2; The signal of telecommunication that comprises Pixel Information of all photo-sensitive cells of said sensitization lamination 2 is read through described a plurality of pixel sensing elements 3; And each photo-sensitive cell of described sensitization lamination 2 only is connected with a said pixel sensing element 3 through its each self-corresponding switch element; Wherein, described sensitization lamination 2 forms a picture element module 5 with a plurality of said pixel sensing elements 3.In other words; Lay respectively in a plurality of said pixel sensing element 3 in a plurality of photosensitive layers of described sensitization lamination 2; In one embodiment; Shown in Fig. 4 b, a said pixel sensing element 3 each corresponding photo-sensitive cell, promptly the corresponding said pixel sensing element 3 with it of each self-corresponding switch element is connected each said photo-sensitive cell through it; In another embodiment; The situation that has pixel cell 3 corresponding a plurality of photo-sensitive cells, respectively this photo-sensitive cell of a promptly shared said pixel sensing element 3 shared pixel sensing element 3 that each self-corresponding switch element is corresponding with it through it is connected.
Need further be pointed out that; A plurality of described picture element modules 5 form picture element module array 6 (not shown); The signal of telecommunication that comprises Pixel Information of described picture element module array 6 transfers to graphics processing unit 14 via described pixel sensing element 3, column bus 11 and amplifier 12, so that the said signal of telecommunication that comprises Pixel Information is carried out image processing.
Particularly; In present embodiment one; As shown in Figure 1; Said pixel sensing element 3 is arranged in a photosensitive layer of described sensitization lamination 2; Wherein said photosensitive layer is visible light photosensitive layer 22 (the not concrete structure of diagram pixel sensing element 3 in semiconductor structure Fig. 2 c); The shared said pixel sensing element 3 of all photo-sensitive cells of said sensitization lamination 2 (PN junction photodiode 212~232); Said self energizing cmos image sensor is a 4T type imageing sensor, then respectively is connected through the switch element 2111,2211 and 2311 that respectively this photo-sensitive cell is corresponding between each self-corresponding floating diffusion region 351~353 of this photo-sensitive cell (PN junction photodiode 212,222 and 232) and the said pixel sensing element 3, and promptly described PN junction photodiode 212 corresponding floating diffusion regions 351 are connected with said pixel sensing element 3 through switch element 2111; Described PN junction photodiode 222 corresponding floating diffusion regions 352 are connected with said pixel sensing element 3 through switch element 2211, and described PN junction photodiode 232 corresponding floating diffusion regions 353 are connected with said pixel sensing element 3 through switch element 2311.Described sensitization lamination 2 forms a picture element module 5 with pixel sensing element 3; Further; A plurality of described picture element modules 5 form picture element module array 6 (not shown); The signal of telecommunication that comprises Pixel Information of described picture element module array 6 transfers to graphics processing unit 14 via described pixel sensing element 3, said column bus 11 and amplifier 12, so that the said signal of telecommunication that comprises Pixel Information is carried out image processing.
What need specified otherwise is; In present embodiment one; Said self energizing cmos image sensor is a 4T type imageing sensor; And respectively the shared said pixel sensing element 3 of the photo-sensitive cell of this photosensitive layer (PN junction photodiode 212,222 and 232) is as shown in Figure 1, and respectively this transistorized connected mode in the said pixel sensing element 3 is following:
Said reset transistor 31 is used for imageing sensor of the present invention and before exposure, said photo-sensitive cell (PN junction photodiode 212,222 and 232) is resetted; Wherein, Be connected through this switch element 2111,2211 and 2311 respectively respectively between each self-corresponding floating diffusion region 351~353 of each photo-sensitive cell in described respectively this photosensitive layer (PN junction photodiode 212,222 and 232) and the reset transistor 31, and reset function is controlled by reset signal Reset signal (the RST end points among Fig. 1).In Fig. 1; Said reset transistor 31 is a nmos pass transistor; Because said self energizing cmos image sensor is a 4T type imageing sensor; The source electrode of said reset transistor 31 is connected with an end of this switch element 2111,2211 respectively and 2311; And respectively this switch element 2111,2211 and 2311 the other end with lay respectively at this photosensitive layer respectively in the floating empty diffusion region (FD) 351,352 and 353 of corresponding photo-sensitive cell separately (PN junction photodiode 212,222 and 232) be connected, promptly respectively this switch element 2111,2211 and 2311 the floating empty diffusion region (FD) 351,352 and 353 of the corresponding photo-sensitive cell separately of this photosensitive layer (PN junction photodiode 212,222 and 232) is connected with being arranged in respectively with the source electrode of said reset transistor 31 respectively; The drain electrode of said reset transistor 31 meets power supply V
Dd, said power supply V
DdIt is a positive supply.
Transistor 32 is followed by means of the constant current that said current source cell 13 provides in said source, makes its grid source electric current (I
Ds) keep constant; For guaranteeing that source voltage and grid voltage difference are constant; Thereby reach the purpose of source voltage follow grid voltage, be used to read the signal of telecommunication that comprises Pixel Information that said photo-sensitive cell (PN junction photodiode 212,222 and 232) produces through opto-electronic conversion.In Fig. 1; It is a nmos pass transistor that transistor 32 is followed in said source; Because said self energizing cmos image sensor is a 4T type imageing sensor; Each self-corresponding floating diffusion region 351,352 and 353 of each photo-sensitive cell (PN junction photodiode 212,222 and 232) in the grid that transistor 32 is followed in said source and described respectively this photosensitive layer is connected through this switch element 2111,2211 and 2311 respectively respectively, and the source electrode that this moment, grid, the reset transistor 31 of transistor 32 were followed in described source all is connected with an end of this switch element 2111,2211 respectively and 2311.The drain electrode that transistor 32 is followed in said source meets said power supply V
Dd, the source electrode of transistor 32 is followed for exporting the output of the signal of telecommunication that comprises Pixel Information in said source.
Said row selecting transistor 33 is used for said source is followed the signal of telecommunication output that comprises Pixel Information of the source electrode output of transistor 32.In Fig. 1; Said row selecting transistor M3 selects NMOS pipe for use; The grid of said row selecting transistor 33 meets row selection signal RS, and the drain electrode of said row selecting transistor 33 connects the source electrode that transistor 32 is followed in said source, and the source electrode of said row selecting transistor 33 is an output.
The signal of telecommunication that comprises Pixel Information that said transfering transistor 341,342 and 343 is used for said PN junction photodiode 212,222 and 232 is produced through floating diffusion region 351,352 and 353 and switch element 2111,2211 and 2311 be input to the source electrode connection that the grid and the reset transistor 31 of transistor 32 are followed in described source.In embodiment one; As shown in Figure 1; Said transfering transistor 341,342 and 343 is selected a nmos pass transistor for use; Said transfering transistor 341,342 and 343 grid switch through shifting signal TX; Said transfering transistor 341,342 and 343 source electrode (not shown) meet the N type district of said PN junction photodiode 212,222 and 232, and said transfering transistor 341,342 and 343 drain electrode connect the source electrode connection that the grid and the reset transistor 31 of transistor 32 are followed in the source through floating diffusion region 351,352 and 353.
Before setting forth operation principle; Need to prove; Because respectively this switch element is nmos pass transistor, when the grid of switch element was high level, then switch element was in conducting state (being switch closure); When the grounded-grid of switch element, then switch element is in off-state (being switch opens).Select the reading of the signal of telecommunication that comprises Pixel Information of different photosensitive layers through switch element 2111,2211 and 2311; Select the electric charge of different photosensitive layers process opto-electronic conversion is exported to said energy-storage units 15 through switch element 2112,2212 and 2312; Convert suitable voltage into and preserve through said power-switching circuit; When the needs self energizing, the voltage of preserving is connected to the required power supply V of pixel sensing element 3
Dd, for said pixel sensing element 3 provides drain voltage V
Dd, for said cmos image sensor is realized the self-supply power source function.
With the signal of telecommunication that comprises Pixel Information that only reads ultraviolet light photosensitive layer 23, storage visible light photosensitive layer 22 and infrared light photosensitive layer 21 electric charge through its photo-sensitive cell opto-electronic conversion separately is example, describes the operation principle of said self energizing cmos image sensor:
The selection natural daylight is a light source; Before exposure; Make it be in off-state (being switch opens) grounded-grid of said switch element 2312; The then said floating empty diffusion region (FD) 353 that is arranged in said ultraviolet photosensitive layer 23 corresponding photo-sensitive cells (PN junction photodiode 232) is broken off with said energy-storage units 15, does not store the electric charge of the opto-electronic conversion of said ultraviolet light photosensitive layer 23, simultaneously; For the grid of said switch element 2311 provides high level to make it be in conducting state (being switch closure), the floating empty diffusion region (FD) 353 that then is arranged in said ultraviolet photosensitive layer 23 corresponding photo-sensitive cells (PN junction photodiode 232) is connected to the source electrode of said reset transistor 31; When the reset signal Reset of said reset transistor 31 is high level; Said reset transistor 31 conductings; (its grid switches through shifting signal TX to then said PN junction photodiode 232 through the transfering transistor corresponding with it 343; Its source electrode meets the N type district of said PN junction photodiode 232, and is not shown) and floating diffusion region 353 be connected to the drain power V of reset transistor 31
Dd, at said power supply V
DdEffect under, make said PN junction photodiode 232 partially anti-and can remove whole charges accumulated of said PN junction photodiode 232, realize resetting.
The drain electrode that transistor 32 is followed in said source meets said power supply V
DdAfter said self energizing cmos image sensor is realized resetting; Selecting natural daylight is that light source makes public; The photo-sensitive cell (PN junction photodiode 232) that is positioned at ultraviolet light photosensitive layer 23 carries out opto-electronic conversion, converts the light signal that receives to comprise Pixel Information the signal of telecommunication, because switch element 2312 is off-state (switch element grounded-grid) and switch element 2311 is conducting state (the switch element grid connects high level); Then through (its grid switches through shifting signal TX with PN junction photodiode 232 corresponding transfering transistors 343; Its source electrode meets the N type district of said PN junction photodiode 232, and is not shown) and floating diffusion region 353 be connected to the grid that transistor 32 is followed in said source, at said power supply V
DdAnd under the effect of current source cell 13, said source is followed the source electrode of transistor 32 and is exported the extremely drain electrode of said row selecting transistor 33 of the signal of telecommunication that comprises Pixel Information.
The grid of said row selecting transistor 33 meets row selection signal RS, and its drain electrode connects the source electrode that transistor 32 is followed in said source for input, and wherein, source electrode is an output.The signal of telecommunication that comprises Pixel Information that said row selecting transistor 33 is used for said source is followed the source electrode output of transistor 32 exports column bus 11 to.
Simultaneously; Selecting natural daylight is that light source is when making public; Make it be in off-state (being switch opens) grounded-grid of switch element 2211 and 2111; For the grid of switch element 2212 and 2112 provides high level to make it be in conducting state (being switch closure), make the corresponding PN junction photodiodes 222 of visible light photosensitive layer 22 and infrared light photosensitive layer 21 with 212 through opto-electronic conversion acquisition electric charge, export to said energy-storage units 15 through switch element 2212 and 2112.
Each photosensitive layer of described sensitization lamination 2 pixel sensing element 3 shared with it forms a picture element module 5, and a plurality of described picture element modules 5 form picture element module array 6 (not shown).The signal of telecommunication that comprises Pixel Information of each ultraviolet light photosensitive layer 23 of described picture element module array 6 transfers to graphics processing unit 14 via described pixel sensing element 3, said column bus 11 and amplifier 12, so that the said signal of telecommunication that comprises Pixel Information is carried out image processing; Each visible light photosensitive layer 22 of described picture element module array 6 and the electric charge of infrared light photosensitive layer 21 acquisitions; Export to said energy-storage units 15 through switch element 2212 and 2112; And the said power-switching circuit through wherein converts suitable voltage into and preserves; When the needs self energizing, the voltage of preserving is connected to the required power supply V of pixel sensing element 3
Dd, for said pixel sensing element 3 provides drain voltage V
Dd, for said cmos image sensor is realized the self-supply power source function.
In like manner; In present embodiment one; If only need read the signal of telecommunication that comprises Pixel Information of visible light photosensitive layer 22 or infrared light photosensitive layer 21; And store the electric charge of its corresponding photo-sensitive cell opto-electronic conversion in infrared light photosensitive layer 21 and ultraviolet light photosensitive layer 23 or storage visible light photosensitive layer 22 and the ultraviolet light photosensitive layer 23 simultaneously, only need adjust switch element 2211,2112 and 2312 for conducting state (being that the switch element grid adds high voltage) and simultaneously switch element 2212,2111 and 2311 for off-state (being the switch element grounded-grid) or adjustment switch element 2111,2212 and 2312 for conducting state (being that the switch element grid adds high voltage) and simultaneously switch element 2112,2211 and 2311 get final product for off-state (being the switch element grounded-grid).
The present invention provides a kind of self energizing cmos image sensor, has adopted the design of free of light filter, the problems such as poor quality images of also having avoided filter to cause when reducing cost; Adopt the sensitization lamination of stacked structure, make required circuit structure can be made in (substrate layer) on independent one deck, thereby improve fill factor, curve factor greatly; Further improve the quality of image, simultaneously, owing to adopt the sensitization lamination of stacked structure; Make a pixel have the ability that detects different-waveband light, single exposure can obtain information such as ultraviolet light, visible light and infrared light simultaneously, on the one hand; Can obtain multiple information through chip piece, not only reduce cost and complexity, and improve the efficient and the picture quality of conversion greatly; On the other hand, when reading information needed, can selectively the residual charge that different photosensitive layer produced be preserved; And for the entire image transducer power supply is provided through power-switching circuit; To realize self-energizing function, make full use of the energy of light, and strengthened the adaptive capacity of imageing sensor.
Embodiment two
Embodiment two and embodiment one adopt essentially identical technical scheme; The assembly that the self energizing cmos image sensor that to be embodiment two provide with embodiment one comprises, the relevant connection mode of inter-module and and operation principle basic identical; Difference is that the self energizing cmos image sensor among the embodiment two is the 3T type; And pixel sensing element 3 ' is arranged in substrate layer, and sensitization lamination 2 ' is used for absorbing three photosensitive layers of three band of light, and first photosensitive layer is a ruddiness photosensitive layer 21 '; Second photosensitive layer is that green glow photosensitive layer 22 ', the 3rd photosensitive layer are blue light photosensitive layer 23 ', and respectively this photosensitive layer is silicon (Si) material.
What need particularly point out is; The light of different wave length has different response characteristics in same semi-conducting material; Semi-conducting material will absorb the light of different wave length, needs the different incident light path, and wavelength is short more; Absorb incident light fully, realize that effective light path that opto-electronic conversion needs incident light in semiconductor, to transmit is short more, on the contrary then long more.For the ease of absorbing the light of different-waveband simultaneously; Make imageing sensor of the present invention have the ability that detects different-waveband light; Then the present invention adopts laminated construction in order to light absorbing said sensitization lamination; Because respectively this photosensitive layer residing position in the sensitization lamination is different, therefore when respectively this photosensitive layer is semi-conducting material of the same race, also can absorb the light of different-waveband.As far as visible light; Because the wavelength of blue light, green glow and ruddiness is for increasing progressively situation; Therefore blue light absorption is near the zone on the plane of incidence (surface of sensitization lamination); The absorption of ruddiness then concentrates on apart from the plane of incidence (surface of sensitization lamination) interior zone far away, and the absorption region of green glow is between between the two.
Therefore, in present embodiment two, be used to absorb that first photosensitive layer (ruddiness photosensitive layer 21 ') of first band of light (ruddiness) is range upon range of covers said substrate layer 1, be positioned at the orlop of sensitization lamination 2 '; Second photosensitive layer (green glow photosensitive layer 22 ') that is used to absorb second band of light (green glow) is layered in said first photosensitive layer (ruddiness photosensitive layer 21 '); The 3rd photosensitive layer (blue light photosensitive layer 23 ') that is used to absorb triband light (blue light) is layered in said second photosensitive layer (green glow photosensitive layer 22 '), is positioned at the superiors of sensitization lamination 2 '.
Equivalent circuit diagram Fig. 5 and the equivalent circuit diagram Fig. 1 among the embodiment one in the present embodiment two are basic identical.4T type self energizing cmos image sensor in the embodiment one, the pixel sensing element 3 ' of the 3T type self energizing cmos image sensor among the embodiment two has lacked transfering transistor among the embodiment one (TX) and floating diffusion region (FD); Pixel sensing element 3 in embodiment one is arranged in enforcement visible light photosensitive layer 22, and the pixel sensing element 3 ' among the embodiment two is arranged in substrate layer 1.Concrete difference is following:
See also Fig. 5; In present embodiment two; Self energizing cmos image sensor provided by the invention is the 3T type, and then pixel sensing element 3 ' comprises that reset transistor 31 ', source follow transistor 32 ' and row selecting transistor 33 ', simultaneously in present embodiment two; The pixel sensing element is arranged in substrate layer 1; The shared said pixel sensing element 3 ' of all photo-sensitive cells of said sensitization lamination 2 ' (PN junction photodiode 212 ', 222 ' and 232 '), wherein, said sensitization lamination 2 ' is a picture element module 5 '.
As shown in Figure 5, in present embodiment two, respectively this switch element 2111 ' and 2112 ' that is positioned at said ruddiness photosensitive layer 21 ' is connected to the N type district of PN junction photodiode 212 '; Respectively this switch element 2211 ' and 2212 ' that is positioned at said green glow photosensitive layer 22 ' is connected to the N type district of PN junction photodiode 222 '; Respectively this switch element 2311 ' and 2312 ' that is positioned at said blue light photosensitive layer 23 ' is connected to the N type district of PN junction photodiode 232 '.
Further; As shown in Figure 5; In present embodiment two; The source electrode of the reset transistor 31 ' of said pixel sensing element 3 ' and this switch element respectively 2111 ', an end of 2211 ' and 2311 ' are connected, and respectively this switch element 2111 ', 2211 ' and 2311 ' the other end and lay respectively at respectively in this photosensitive layer 21 ', 22 ', 23 ' separately that the N type district of photo-sensitive cell (PN junction photodiode 212 ', 222 ' and 232 ') is connected; Each photo-sensitive cell (PN junction photodiode 212 ', 222 ' and 232 ') N type district separately in the grid that transistor 32 ' is followed in the source of said pixel sensing element 3 ' and described respectively this photosensitive layer is connected through this switch element 2111 ', 2211 ' and 2311 ' respectively respectively, and the source electrode that this moment, grid, the reset transistor 31 ' of transistor 32 ' were followed in described source all is connected with this switch element respectively 2111 ', an end of 2211 ' and 2311 '.
For further illustrating the operation principle of the present invention in embodiment two; See also Fig. 5 again; With the signal of telecommunication that comprises Pixel Information that only reads blue light photosensitive layer 23 ', storage green glow photosensitive layer 22 ' and the ruddiness photosensitive layer 21 ' electric charge through its photo-sensitive cell opto-electronic conversion separately is example, describes the operation principle of said self energizing cmos image sensor in present embodiment two:
The selection natural daylight is a light source; Before exposure; When switch element 2312 ' is off-state (switch element grounded-grid) and switch element 2311 ' and is conducting state (the switch element grid connects high level); For the reset signal Reset of said reset transistor 31 ' provides high level, then said reset transistor 31 ' conducting, the N type district of said PN junction photodiode 232 ' is connected to its drain power V through reset transistor 31 '
Dd, at said power supply V
DdEffect under, make said PN junction photodiode 232 ' partially anti-and remove whole charges accumulated of said PN junction photodiode 232 ', realize resetting.
The drain electrode that transistor 32 ' is followed in said source meets said power supply V
DdAfter said self energizing cmos image sensor is realized resetting; Selecting natural daylight is that light source makes public; The photo-sensitive cell (PN junction photodiode 232 ') that is positioned at blue light photosensitive layer 23 ' carries out opto-electronic conversion, converts the light signal that receives to comprise Pixel Information the signal of telecommunication, because switch element 2312 ' is off-state (switch element grounded-grid) and switch element 2311 ' is conducting state (the switch element grid connects high level); Then the N type district with PN junction photodiode 232 ' is connected to the grid that transistor 32 ' is followed in said source, at said power supply V
DdAnd under the effect of current source cell 13, said source is followed the source electrode of transistor 32 ' and is exported the extremely drain electrode of said row selecting transistor 33 ' of the signal of telecommunication that comprises Pixel Information.
The grid of said row selecting transistor 33 ' meets row selection signal RS, and its drain electrode connects the source electrode that transistor 32 ' is followed in said source for input, and wherein, source electrode is an output.The signal of telecommunication that comprises Pixel Information that said row selecting transistor 33 ' is used for said source is followed the source electrode output of transistor 32 ' exports column bus 11 to.
Simultaneously; Selecting natural daylight is that light source is when making public; Make it be in off-state (being switch opens) grounded-grid of switch element 2211 ' and 2111 '; For the grid of switch element 2212 ' and 2112 ' provides high level to make it be in conducting state (being switch closure), make the corresponding PN junction photodiode 222 ' of green glow photosensitive layer 22 ' and ruddiness photosensitive layer 21 ' with 212 ' through opto-electronic conversion acquisition electric charge, export to said energy-storage units 15 through switch element 2212 ' and 2112 '.
The pixel sensing element that is positioned at substrate layer 13 ' that each photosensitive layer of described sensitization lamination 2 ' is shared with it forms a picture element module 5 ', and a plurality of described picture element modules 5 ' form picture element module array 6 ' (not shown).The signal of telecommunication that comprises Pixel Information of each blue light photosensitive layer 23 ' of described picture element module array 6 ' transfers to graphics processing unit 14 via described pixel sensing element 3 ', said column bus 11 and amplifier 12, so that the said signal of telecommunication that comprises Pixel Information is carried out image processing; Each green glow photosensitive layer 22 ' of described picture element module array 6 ' and the electric charge of ruddiness photosensitive layer 21 ' acquisition; Export to said energy-storage units 15 through switch element 2212 ' and 2112 '; And the said power-switching circuit through wherein converts suitable voltage into and preserves; When the needs self energizing, the voltage of preserving is connected to the required power supply V of pixel sensing element 3 '
Dd, for said pixel sensing element 3 ' provides drain voltage V
Dd, for said cmos image sensor is realized the self-supply power source function.
In like manner; In present embodiment two; If only need read the signal of telecommunication that comprises Pixel Information of green glow photosensitive layer 22 ' or ruddiness photosensitive layer 21 '; And store the electric charge of its corresponding photo-sensitive cell opto-electronic conversion in ruddiness photosensitive layer 21 ' and blue light photosensitive layer 23 ' or storage green glow photosensitive layer 22 ' and the blue light photosensitive layer 23 ' simultaneously, only need adjust switch element 2211 ', 2112 ' and 2312 ' for conducting state (being that the switch element grid adds high voltage) and simultaneously switch element 2212 ', 2111 ' and 2311 ' for off-state (being the switch element grounded-grid) or adjustment switch element 2111 ', 2212 ' and 2312 ' for conducting state (being that the switch element grid adds high voltage) and simultaneously switch element 2112 ', 2211 ' and 2311 ' get final product for off-state (being the switch element grounded-grid).
In sum, the present invention provides a kind of self energizing cmos image sensor, has adopted the design of free of light filter, the problems such as poor quality images of also having avoided filter to cause when reducing cost; Adopt the sensitization lamination of stacked structure, make required circuit structure can be made in (substrate layer) on independent one deck, thereby improve fill factor, curve factor greatly; Further improve the quality of image, simultaneously, owing to adopt the sensitization lamination of stacked structure; Make a pixel have the ability that detects different-waveband light, single exposure can obtain information such as blue light, green glow and ruddiness simultaneously, on the one hand; Can obtain multiple information through chip piece, not only reduce cost and complexity, and improve the efficient and the picture quality of conversion greatly; On the other hand, when reading information needed, can selectively the residual charge that different photosensitive layer produced be preserved; And for the entire image transducer power supply is provided through power-switching circuit; To realize self-energizing function, make full use of the energy of light, and strengthened the adaptive capacity of imageing sensor.Self energizing cmos image sensor provided by the invention can be prepared in red, blue, green glow sensor devices on the different laminations that are positioned at Semiconductor substrate the same area in order to realize the accurate imaging of visible light, has further improved the integrated level of imageing sensor.So the present invention has effectively overcome various shortcoming of the prior art and the tool high industrial utilization.
The foregoing description is illustrative principle of the present invention and effect thereof only, but not is used to limit the present invention.Any be familiar with this technological personage all can be under spirit of the present invention and category, the foregoing description is modified or is changed.Therefore, have common knowledge the knowledgeable in the affiliated such as technical field, must contain by claim of the present invention not breaking away from all equivalence modifications of being accomplished under disclosed spirit and the technological thought or changing.