CN101459757B - Cmos image sensor - Google Patents
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- CN101459757B CN101459757B CN200810187734XA CN200810187734A CN101459757B CN 101459757 B CN101459757 B CN 101459757B CN 200810187734X A CN200810187734X A CN 200810187734XA CN 200810187734 A CN200810187734 A CN 200810187734A CN 101459757 B CN101459757 B CN 101459757B
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Abstract
The invention provides a CMOS image sensor, which comprises a photorectifier converting light signals into electrical signals, a reset transistor for supplying reverse bias voltage for the photorectifier, a transfer transistor for converting electric charges on the photorectifier into voltage signals and further comprises a capacitor and a photoelectric element which are connected in series between the photorectifier and the transfer transistor from the direction of the photorectifier to the direction of the transfer transistor, when the photoelectric element is illuminated by light, photoproduction voltage signals are generated, and the CMOS image sensor can select collected light, thereby improving the sensibility of the image sensor.
Description
Technical field
The present invention relates to the image sensor technologies field, particularly a kind of cmos image sensor.
Background technology
Imageing sensor is the semiconductor device that optical imagery is converted to the signal of telecommunication.At present, traditional imageing sensor comprises charge-coupled device (CCD) imageing sensor and metal-oxide semiconductor (MOS) (MOS) imageing sensor, because cmos image sensor has the advantage of low-power consumption and high s/n ratio, therefore use more extensive in field of image sensors.In cmos image sensor, extensively adopt semiconductor photo diode as photo-electric conversion element, light signal is converted to the signal of telecommunication.
Cmos image sensor is divided into three usually and manages imageing sensors and four pipe imageing sensors, because the basic principle of three pipe imageing sensors and four pipe imageing sensors is identical, is that example is introduced with three circuit diagrams of managing imageing sensors shown in Figure 1 below therefore.Three pipe imageing sensors comprise be used for light signal be converted to the signal of telecommunication photodiode 110, be used for to described photodiode 110 provide reverse bias voltage reset transistor 120, be used for the change in electrical charge on the described photodiode 110 shifted and be the transfering transistor 130 of voltage signal, because imageing sensor can comprise many group said structures, therefore export one by one for the light intensity signal that a plurality of photodiodes 110 are gathered, also comprise the switching transistor 140 of control output.Usually reset transistor 120, transfering transistor 130 and switching transistor 140 all are nmos pass transistors.The positive pole of photodiode 110 meets low level VSS, negative pole connects the source electrode of reset transistor 120, the drain electrode of reset transistor 120 meets high level VDD, the grid of reset transistor 120 meets the reset signal Reset of input, the source electrode of reset transistor 120 switches through the grid of shifting transistor 130, the drain electrode of transfering transistor 130 meets high level VDD, the source electrode of transfering transistor 130 connects the drain electrode of switching transistor 140, signal Select in the grid selecting of switching transistor 140, the source electrode of switching transistor 140 are output out.
Before illumination, input high level reset signal Reset at first, thereby reset transistor 120 conductings, and photodiode 110 is because of not having illumination so reverse current very little, thereby reset transistor 120 source voltages approach high level VDD, thus transfering transistor 130 conductings, and the source electrode output of transfering transistor 130 approaches high level VDD, signal Select is a high level in the grid selecting of switching transistor 140, thereby the output of the source electrode of switching transistor 140 just approaches high level VDD.After illumination, the reverse current of photodiode 110 increases, and the strong more reverse current of illumination is big more, strong more reset transistor 120 source voltages of illumination just are low more, thereby the source electrode output voltage of the source electrode output voltage of transfering transistor 130 and switching transistor 140 can obtain intensity variations by the source electrode output voltage of switching transistor 140 is just measured like this along with reduction.
Above-mentioned imageing sensor is normally gathered light intensity signal by the photodiode 110 that forms on the Semiconductor substrate, and the light intensity that photodiode 110 is gathered is by the area decision of the PN junction of accepting illumination, so just limited the ability of photodiode 110 collection light intensity, make above-mentioned imageing sensor can only gather the light in its corresponding wavelength scope, and can not collection light be selected, for example can only gather visible light, thereby make that the range limited system sensitivity of image sensor application is low.
Summary of the invention
The invention provides a kind of imageing sensor, solved the low problem of sensitivity of imageing sensor.
In order to address the above problem, the invention provides a kind of cmos image sensor, comprise be used for light signal be converted to the signal of telecommunication photodiode, be used for to described photodiode provide reverse bias voltage reset transistor, be used for the change in electrical charge on the described photodiode shifted and be the transfering transistor of voltage signal, also comprise from described photodiode and be connected on capacitor and photoelectric cell between described photodiode and the described transfering transistor to described transfering transistor direction, described photoelectric cell produces the photovoltage signal during by illumination.
Optionally, described photodiode comprises the p type impurity diffusion region of stacked monocrystalline silicon and the N type impurity diffusion zone of monocrystalline silicon, has floating diffusion region on the p type impurity diffusion region of described monocrystalline silicon, and described capacitor is arranged on the described floating diffusion region.
Optionally, described photoelectric cell is arranged on the described capacitor, described photoelectric cell is a diode, comprise the p type impurity diffusion region of stacked polysilicon and the N type impurity diffusion zone of polysilicon, described p type impurity diffusion region is arranged on the pole plate of capacitor away from described photodiode one side, and the N type impurity diffusion zone of described polysilicon layer is electrically connected with the grid of transfering transistor.
Optionally, described photoelectric cell is arranged on the described capacitor, described photoelectric cell is a diode, comprise the p type impurity diffusion region of stacked polysilicon and the N type impurity diffusion zone of polysilicon, described N type impurity diffusion zone is arranged on the grid of transfering transistor, and the p type impurity diffusion region of described polysilicon layer is electrically connected with the pole plate of capacitor away from described photodiode one side.
Optionally, described photoelectric cell is a diode, the p type impurity diffusion region that comprises the N type impurity diffusion zone and the polysilicon of stacked polysilicon, described N type impurity diffusion zone is arranged on the pole plate of capacitor away from described photodiode one side, and the p type impurity diffusion region of described polysilicon layer is electrically connected with the grid of transfering transistor.
Optionally, described photoelectric cell is arranged on the described capacitor, described photoelectric cell is a diode, the p type impurity diffusion region that comprises the N type impurity diffusion zone and the polysilicon of stacked polysilicon, described p type impurity diffusion region is arranged on the grid of transfering transistor, and the N type impurity diffusion zone of described polysilicon layer is electrically connected with the pole plate of capacitor away from described photodiode one side.
Optionally, described photoelectric cell is a semi-conducting material, and energy gap is less than the energy gap of monocrystalline silicon.
Optionally, described photoelectric cell is a Schottky diode.
Optionally, described photoelectric cell is a piezoelectric.
Optionally, described photoelectric cell is during by illumination, produces from described transfering transistor to the electric current of described photodiode direction or from the electric current of described photodiode to described transfering transistor direction, and described electric current makes described photoelectric cell produce the photovoltage signal.
In the technique scheme, cmos image sensor, comprise the photodiode that is used for light signal is converted to the signal of telecommunication, be used for providing the reset transistor of reverse bias voltage to described photodiode, be used for the transfer of the change in electrical charge on the described photodiode is the transfering transistor of voltage signal, also comprise from described photodiode and be connected on capacitor and photoelectric cell between described photodiode and the described transfering transistor to described transfering transistor direction, described photoelectric cell is during by illumination, produce the photovoltage signal, so this cmos image sensor utilizes and the photoelectric cell of photodiode series connection, can select the light of gathering, for example can select to gather infrared light and visible light or only gather visible light, thereby improved the sensitivity of imageing sensor, and isolation by capacitor, make the leakage current of photoelectric cell not flow out, thereby reduced the noise that leakage current brings, improved signal to noise ratio.
Description of drawings
By the more specifically explanation of the preferred embodiments of the present invention shown in the accompanying drawing, above-mentioned and other purpose, feature and advantage of the present invention will be more clear.Reference numeral identical in whole accompanying drawings is indicated identical part.Painstakingly do not draw accompanying drawing, focus on illustrating purport of the present invention by actual size equal proportion convergent-divergent.
Fig. 1 is the circuit diagram of a kind of cmos image sensor in the prior art;
Fig. 2 is the structural representation of cmos image sensor shown in Figure 1;
Fig. 3 is the circuit diagram of cmos image sensor first embodiment of the present invention;
Fig. 4 is the structural representation of cmos image sensor first embodiment of the present invention;
Fig. 5 is the circuit diagram of cmos image sensor second embodiment of the present invention;
Fig. 6 is the structural representation of cmos image sensor second embodiment of the present invention.
Embodiment
For above-mentioned purpose of the present invention, feature and advantage can be become apparent more, the specific embodiment of the present invention is described in detail below in conjunction with accompanying drawing.
A lot of details have been set forth in the following description so that fully understand the present invention.But the present invention can implement much to be different from alternate manner described here, and those skilled in the art can do similar popularization under the situation of intension of the present invention, so the present invention is not subjected to the restriction of following public specific embodiment.
Secondly, the present invention utilizes schematic diagram to be described in detail, when the embodiment of the invention is described in detail in detail; for ease of explanation; the profile of expression device architecture can be disobeyed general ratio and be done local the amplification, and described schematic diagram is example, and it should not limit the scope of protection of the invention at this.The three dimensions size that in actual fabrication, should comprise in addition, length, width and the degree of depth.
Fig. 2 is the structural representation of cmos image sensor shown in Figure 1.As shown in Figure 2, traditional cmos image sensor is to gather light intensity signal by the photodiode 110 that forms on the Semiconductor substrate, is transferred to transfering transistor 130 then.Photodiode 110 is by reverse voltage effect work, and when not having illumination, reverse current extremely faint (being generally less than 0.1fA) is dark current; When illumination was arranged, luminous energy made charge carrier generation energy level transition, thereby produced reverse current, and reverse current increases to several microamperes rapidly, is called photoelectric current.Light intensity is big more, and reverse current is also big more.The variation of light causes that photodiode 110 electric currents change, and this just can convert light signal to the signal of telecommunication.If connect load on circuit, for example transfering transistor has just obtained the signal of telecommunication in the load, and this signal of telecommunication along with the variation of light respective change.Wherein, the core of photodiode 110 is PN junctions, compares with general-purpose diode, structurally different is that for the ease of accepting incident illumination, it is bigger that the PN junction area is done as far as possible, electrode area is tried one's best littler, and the junction depth of PN junction is very shallow, is generally less than 1 micron.
Think after inventor's research, though do the PN junction area of photodiode 110 big as far as possible in the prior art, but, the PN junction area make the area of imageing sensor also increase because increasing, make cost increase, therefore in order to reduce cost, the PN junction area can not unrestrictedly increase, make the light intensity of photodiode collection be restricted like this, and because this photodiode makes in the monocrystalline silicon layer of Semiconductor substrate and forms, therefore can only gather the light of wavelength usually, therefore adopt the sensitivity of imageing sensor of prior art illustrated in figures 1 and 2 lower less than 1100nm.
The inventor further finds, if the photoelectric cell of connecting again on the basis of original photodiode just can increase the collecting efficiency to light intensity.But, realize that the series connection of photoelectric cell exists some that technical problem to be solved is arranged.For example, normal light electric diode 110 mixes to monocrystalline silicon layer and makes, if the photoelectric cell that increases newly is also made in the monocrystalline silicon layer of Semiconductor substrate, will increase the area of imageing sensor so equally.If utilize other method to make, also can have some defectives.For example the deposit spathic silicon layer forms polysilicon diode on monocrystalline silicon layer, perhaps utilize other piezoelectric to form photoelectric cell, because the energy gap of polysilicon and other piezoelectric is littler than monocrystalline silicon, therefore all can produce leakage current, will bring noise like this, make that the sensitivity of cmos image sensor is relatively poor.
Based on above-mentioned research and discovery, the inventor is through creative work, a kind of cmos image sensor is provided, comprise the photodiode that is used for light signal is converted to the signal of telecommunication, be used for providing the reset transistor of reverse bias voltage to described photodiode, be used for the transfer of the change in electrical charge on the described photodiode is the transfering transistor of voltage signal, also comprise from described photodiode and be connected on capacitor and photoelectric cell between described photodiode and the described transfering transistor to described transfering transistor direction, described photoelectric cell produces the photovoltage signal during by illumination.
Utilize capacitor that the photoelectric cell and the photodiode that increase newly are isolated in this invention, thereby improve collecting efficiency to light intensity, increase the sensitivity of imageing sensor, and, therefore do not increase noise because capacitor is isolated the leakage current that photoelectric cell produces.
Below in conjunction with accompanying drawing following embodiment is described in detail.
Embodiment one
Fig. 3 is the circuit diagram of cmos image sensor first embodiment of the present invention, and Fig. 4 is the structural representation of cmos image sensor first embodiment of the present invention.
Imageing sensor as shown in Figure 3, comprise the photodiode 210 that is used for light signal is converted to the signal of telecommunication, be used for providing the reset transistor 220 of reverse bias voltage to described photodiode 210, be used for the transfer of the change in electrical charge on the described photodiode 210 is the transfering transistor 230 of voltage signal, also comprise from described photodiode 210 and be connected on capacitor 215 and photoelectric cell 216 between described photodiode 210 and the described transfering transistor 230 to described transfering transistor 230 directions, described photoelectric cell 216 is during by illumination, produce the photovoltage signal, concrete generation is from the electric current of described transfering transistor 230 to described photodiode 210 directions, and described electric current makes described photoelectric cell 216 produce the photovoltage signal.Described photovoltage signal is the voltage signal that light signal changes into through photoelectric cell
Concrete, reset transistor 220 is the NMOS pipe, and the grid of reset transistor 220 meets reset signal Reset, and the drain electrode of reset transistor 220 meets high level VDD, the source electrode of reset transistor 220 connects the negative pole of photodiode 210, and the positive pole of photodiode 210 meets low level VSS.The negative pole of photodiode 210 connects the positive plate of capacitor 215, the negative plate of capacitor 215 connects the positive pole of photoelectric cell 216, and is concrete, and transfering transistor 230 is the NMOS pipe, the grid of transfering transistor 230 connects the negative pole of photoelectric cell 216, and the drain electrode of transfering transistor 230 meets high level VDD.
In addition, cmos image sensor can also comprise switching transistor 240, and switching transistor 240 is used to control described transfering transistor 230 and carries out the output of voltage.For example switching transistor 240 can be for NMOS manages, signal Select in the grid selecting, and the source electrode of shifting transistor 230 is switched through in drain electrode, and the source electrode of switching transistor 240 is output out.When the selected signal Select that connects when the grid of this switching transistor 240 was high level, these switching transistor 240 conductings were exported.
Concrete, as shown in Figure 4, the structure of concrete in the present embodiment imageing sensor is: have described photodiode 210 and floating diffusion region FD in Semiconductor substrate, described photodiode 210 is included in the p type impurity diffusion region 211 of monocrystalline silicon stacked in the thickness direction and the N type impurity diffusion zone 212 of monocrystalline silicon, described N type impurity diffusion zone 212 is positioned at p type impurity diffusion region 211 lower floors, and described floating diffusion region FD is positioned on the N type impurity diffusion zone 212.Have capacitor 215 and photoelectric cell 216 in the middle dielectric layer 200 on Semiconductor substrate, described capacitor 215 is arranged on the floating diffusion region FD.Described photoelectric cell 216 is positioned on the capacitor 215, and particularly, photoelectric cell described in the present embodiment 216 is a diode.The positive electrical of described photoelectric cell 216 connects the pole plate away from described photodiode 210 of described capacitor 215, and the negative pole of described photoelectric cell 216 switches through shifting transistor 230.
Wherein, described photoelectric cell 216 is a semi-conducting material, and the energy gap of this semi-conducting material is less than the energy gap of monocrystalline silicon.Concrete, described photoelectric cell 216 is included in the p type impurity diffusion region 218 of polysilicon stacked in the thickness direction and the N type impurity diffusion zone 219 of polysilicon, described p type impurity diffusion region 218 is arranged on the pole plate of capacitor 215 away from described photodiode 210 1 sides, and the N type impurity diffusion zone 219 of described polysilicon is electrically connected by plain conductor 250 with the grid of transfering transistor 230.
In other embodiments, photoelectric cell 216 also can be positioned on the grid that shifts metal-oxide-semiconductor 230, is electrically connected by plain conductor with the side pole plate of capacitor 215 away from photodiode 210 then.
Wherein, described photoelectric cell 216 is a semi-conducting material, and the energy gap of this semi-conducting material is less than the energy gap of monocrystalline silicon.Because the energy gap of monocrystalline silicon makes the light of wavelength less than 1100nm, when for example radiation of visible light is to photodiode 210, energy level transition can take place in charge carrier, therefore make photodiode 210 produce bigger reverse current, therefore yet along with the increase of light wavelength, the energy of light is also more little, if when optical wavelength is greater than 1100nm, light energy makes single crystal silicon material that energy level transition be difficult for take place, so the photodiode of single crystal silicon material can not be excited and produces bigger reverse current.Like this when irradiates light optical wavelength during greater than 1100nm, infrared light for example, then not induction of photodiode 210 can not be gathered, and therefore makes that the sensitivity of imageing sensor is relatively poor.And in the present embodiment, photoelectric cell 216 utilizes the semi-conducting material manufacturing of energy gap less than the energy gap of monocrystalline silicon, for example polysilicon or germanium.Like this when irradiates light optical wavelength during greater than 1100nm, infrared light for example, then photoelectric cell 216 can be excited and produce bigger reverse current, thus output voltage signal therefore make this imageing sensor can receive infrared light, and sensitivity is higher.
Because along with reducing of energy gap, the possibility of the charge carrier generation energy level transition of semi-conducting material increases, therefore leakage current increases, but utilize 215 pairs of photoelectric cells 216 of capacitor to isolate in the embodiments of the invention, thereby make leakage current not have path, can not flow out, thereby can not influence signal to noise ratio.Therefore when increasing image sensor sensitivity, do not increase noise.
The operation principle of above-mentioned cmos image sensor is as follows:
Before illumination, reset transistor 220 conductings, be used for providing reverse bias voltage to photodiode 210, because the reverse current of photodiode 210 is extremely faint, the voltage of negative pole that therefore makes photodiode 210 after resetting is near high level VDD, for example 3.3V, after the dividing potential drop through capacitor 215 and photoelectric cell 216, the grid voltage of transfering transistor 230 for example equals 3v, makes transfering transistor 230 conductings, so the source electrode of transfering transistor 230 output high level.Wherein, photoelectric cell 216 can select Schottky diode because have capacitor 215 between Schottky diode and the photodiode 210, therefore makes leakage current be isolated by capacitor, therefore can not influence signal to noise ratio.
After illumination, luminous energy makes the charge carrier generation energy level transition of photodiode 210, thereby produces reverse current, and reverse current increases to tens microamperes rapidly, also becomes photoelectric current, and light intensity is big more, and reverse current is also big more.Therefore the current potential of photodiode 210 negative poles reduces, and light intensity is strong more, and the current potential of photodiode 210 negative poles is low more.Along with the current potential of photodiode 210 negative poles is low more, the negative pole current potential of capacitor 215 also reduces.Concrete photoelectric cell 216 can be for contacting the Schottky diode that forms by metal line with polysilicon layer, the photovoltage of Schottky diode increases in illumination, make the very fast reduction of negative pole current potential of capacitor 215, along with the negative electricity potential drop of capacitor 215 is low, the grid voltage of transfering transistor 230 also reduces, therefore the source electrode output voltage of transfering transistor 230 also reduces, and the source electrode output voltage of the strong more transfering transistor of light intensity is low more, thus the voltage signal that transfering transistor 230 outputs change with light intensity.Therefore photoelectric cell 216 has increased the variation of transfering transistor 230 output voltages, and photoelectric cell 216 can also gather the infrared light of wavelength greater than 1100nm, has therefore increased the sensitivity of imageing sensor.
In other embodiments, described photoelectric cell also can be piezoelectric, perhaps other organic photoelectric material.
Embodiment two
Fig. 5 is the circuit diagram of cmos image sensor second embodiment of the present invention, and Fig. 6 is the structural representation of cmos image sensor second embodiment of the present invention.
Imageing sensor as shown in Figure 5, comprise the photodiode 310 that is used for light signal is converted to the signal of telecommunication, be used for providing the reset transistor 320 of reverse bias voltage to described photodiode 310, be used for the transfer of the change in electrical charge on the described photodiode 310 is the transfering transistor 330 of voltage signal, also comprise from described photodiode 310 and be connected on capacitor 315 and photoelectric cell 316 between described photodiode 310 and the described transfering transistor 330 to described transfering transistor 330 directions, described photoelectric cell 316 is during by illumination, generation is from the electric current of described photodiode 310 to described transfering transistor 330 directions, and described electric current makes described photoelectric cell 316 produce the photovoltage signal.
Concrete, reset transistor 320 is the NMOS pipe, and the grid of reset transistor 320 meets reset signal Reset, and the drain electrode of reset transistor 320 meets high level VDD, the source electrode of reset transistor 320 connects the negative pole of photodiode 310, and the positive pole of photodiode 310 meets low level VSS.The negative pole of photodiode 310 connects the positive plate of capacitor 315, the negative plate of capacitor 315 connects the negative pole of photoelectric cell 316, and is concrete, and transfering transistor 330 is the NMOS pipe, the grid of transfering transistor 330 connects the positive pole of photoelectric cell 316, and the drain electrode of transfering transistor 330 meets high level VDD.
Concrete, as shown in Figure 6, the structure of concrete in the present embodiment imageing sensor is: have described photodiode 310 and floating diffusion region FD in Semiconductor substrate, described photodiode 310 is included in the p type impurity diffusion region 311 of monocrystalline silicon stacked in the thickness direction and the N type impurity diffusion zone 312 of monocrystalline silicon, described N type impurity diffusion zone 312 is positioned at p type impurity diffusion region 311 lower floors, and described floating diffusion region FD is positioned on the N type impurity diffusion zone 312.Have capacitor 315 and photoelectric cell 316 in the middle dielectric layer 300 on Semiconductor substrate, described capacitor 315 is arranged on the floating diffusion region FD.Described photoelectric cell 316 is positioned on the capacitor 315, and particularly, photoelectric cell described in the present embodiment 316 is a diode.The negative electricity of described photoelectric cell 316 connects the pole plate away from described photodiode 310 of described capacitor 315, and the positive pole of described photoelectric cell 316 switches through shifting transistor 330.
Wherein, described photoelectric cell 316 is a semi-conducting material, and the energy gap of this semi-conducting material is less than the energy gap of monocrystalline silicon.Concrete, described photoelectric cell 316 is included in the p type impurity diffusion region 318 of polysilicon stacked in the thickness direction and the N type impurity diffusion zone 319 of polysilicon, described N type impurity diffusion zone 318 is arranged on the pole plate of capacitor 315 away from described photodiode 310 1 sides, and described p type impurity diffusion region 319 at polysilicon layer is electrically connected by plain conductor 350 with the grid of transfering transistor 330.
In other embodiments, photoelectric cell 316 also can be positioned on the grid that shifts metal-oxide-semiconductor 330, is electrically connected by plain conductor with the side pole plate of capacitor 315 away from photodiode 310 then.
Embodiment two repeats no more with embodiment one identical part in addition.
The operation principle of the cmos image sensor of embodiment two is as follows:
Before illumination, the photovoltage of this photoelectric cell 316 is zero, after illumination, the photovoltage of this photoelectric cell 316 changes with light intensity, because it oppositely is connected between capacitor 315 and the transfering transistor 330, therefore this photoelectric cell 316 can reduce the grid voltage reduction amount of transfering transistor 330 after illumination, so can reduce the voltage signal of the corresponding output of light intensity, is applied to the strong excessively cmos image sensor of illumination.
Except that the foregoing description, cmos image sensor of the present invention also can be other structures.For example four manage image sensor architectures.
In the above-described embodiments, high level VDD is a power supply signal, and low level VSS is an earth signal.
The above only is preferred embodiment of the present invention, is not the present invention is done any pro forma restriction.
Though the present invention discloses as above with preferred embodiment, yet be not in order to limit the present invention.Any those of ordinary skill in the art, do not breaking away under the technical solution of the present invention scope situation, all can utilize the method and the technology contents of above-mentioned announcement that technical solution of the present invention is made many possible changes and modification, or be revised as the equivalent embodiment of equivalent variations.Therefore, every content that does not break away from technical solution of the present invention, all still belongs in the scope of technical solution of the present invention protection any simple modification, equivalent variations and modification that above embodiment did according to technical spirit of the present invention.
Claims (9)
1. cmos image sensor, comprise the photodiode that is used for light signal is converted to the signal of telecommunication, be used for providing the reset transistor of reverse bias voltage to described photodiode, be used for the transfer of the change in electrical charge on the described photodiode is the transfering transistor of voltage signal, it is characterized in that, also comprise from described photodiode and be connected on capacitor and photoelectric cell between described photodiode and the described transfering transistor to described transfering transistor direction, described photoelectric cell is during by illumination, produce the photovoltage signal, described photoelectric cell is a semi-conducting material, and energy gap is less than the energy gap of monocrystalline silicon.
2. cmos image sensor according to claim 1, it is characterized in that, described photodiode comprises the p type impurity diffusion region of stacked monocrystalline silicon and the N type impurity diffusion zone of monocrystalline silicon, described N type impurity diffusion zone is positioned at p type impurity diffusion region lower floor, and also have floating diffusion region on described N type impurity diffusion zone, described capacitor is arranged on the described floating diffusion region.
3. cmos image sensor according to claim 2, it is characterized in that, described photoelectric cell is arranged on the described capacitor, described photoelectric cell is a diode, comprise the p type impurity diffusion region of stacked polysilicon and the N type impurity diffusion zone of polysilicon, described p type impurity diffusion region is arranged on the pole plate of capacitor away from described photodiode one side, and the N type impurity diffusion zone of described polysilicon is electrically connected with the grid of transfering transistor.
4. cmos image sensor according to claim 2, it is characterized in that, described photoelectric cell is arranged on the described capacitor, described photoelectric cell is a diode, comprise the p type impurity diffusion region of stacked polysilicon and the N type impurity diffusion zone of polysilicon, described N type impurity diffusion zone is arranged on the grid of transfering transistor, and the p type impurity diffusion region of described polysilicon is electrically connected with the pole plate of capacitor away from described photodiode one side.
5. cmos image sensor according to claim 2, it is characterized in that, described photoelectric cell is a diode, the p type impurity diffusion region that comprises the N type impurity diffusion zone and the polysilicon of stacked polysilicon, described N type impurity diffusion zone is arranged on the pole plate of capacitor away from described photodiode one side, and the p type impurity diffusion region of described polysilicon is electrically connected with the grid of transfering transistor.
6. cmos image sensor according to claim 2, it is characterized in that, described photoelectric cell is arranged on the described capacitor, described photoelectric cell is a diode, the p type impurity diffusion region that comprises the N type impurity diffusion zone and the polysilicon of stacked polysilicon, described p type impurity diffusion region is arranged on the grid of transfering transistor, and the N type impurity diffusion zone of described polysilicon is electrically connected with the pole plate of capacitor away from described photodiode one side.
7. cmos image sensor according to claim 1 is characterized in that, described photoelectric cell is a Schottky diode.
8. cmos image sensor according to claim 2 is characterized in that, described photoelectric cell is a piezoelectric.
9. cmos image sensor according to claim 1, it is characterized in that, described photoelectric cell is during by illumination, to the electric current of described photodiode direction or from the electric current of described photodiode to described transfering transistor direction, described electric current makes described photoelectric cell produce the photovoltage signal from described transfering transistor in generation.
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| CN102044548B (en) * | 2009-10-20 | 2013-01-23 | 中芯国际集成电路制造(上海)有限公司 | CMOS (Complementary Metal-Oxide-Semiconductor Transistor) image sensor |
| JP5495864B2 (en) * | 2010-03-08 | 2014-05-21 | キヤノン株式会社 | Photoelectric conversion device |
| CN102299163B (en) * | 2011-09-13 | 2014-01-08 | 中国科学院上海高等研究院 | Image sensor |
| CN108732609B (en) * | 2017-04-24 | 2022-01-25 | 睿生光电股份有限公司 | Sensing device |
| CN109427827A (en) * | 2017-08-23 | 2019-03-05 | 上海瑞艾立光电技术有限公司 | Imaging sensor and image detector |
| CN109212400B (en) * | 2018-08-23 | 2021-04-23 | 宁波飞芯电子科技有限公司 | Method for testing photo-generated charge transfer efficiency in photodiode |
| CN111312693B (en) * | 2020-02-21 | 2023-11-03 | 上海集成电路研发中心有限公司 | Image sensor structure |
| CN114363542B (en) * | 2021-12-24 | 2023-11-24 | 合肥维信诺科技有限公司 | Photosensitive circuit structure and optical device |
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