CN107193010B - Photosensitive element and range-measurement system - Google Patents

Photosensitive element and range-measurement system Download PDF

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Publication number
CN107193010B
CN107193010B CN201710497978.7A CN201710497978A CN107193010B CN 107193010 B CN107193010 B CN 107193010B CN 201710497978 A CN201710497978 A CN 201710497978A CN 107193010 B CN107193010 B CN 107193010B
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photosensitive
door
transmission gate
signal
potential well
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CN107193010A (en
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东尚清
李碧洲
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EPCO Microelectronics (Jiangsu) Co., Ltd
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Ai Puke Microelectronics (shanghai) Co Ltd
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
    • G01S17/06—Systems determining position data of a target
    • G01S17/08—Systems determining position data of a target for measuring distance only

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Solid State Image Pick-Up Elements (AREA)
  • Optical Radar Systems And Details Thereof (AREA)

Abstract

The application provides a kind of photosensitive element and range-measurement system.In the application, the photosensitive element includes: substrate, grid, signal reading point and the anti-dazzling screen that p-type is lightly doped；Grid includes: photosensitive door and transmission gate；There are gaps between photosensitive door and transmission gate；Substrate includes photosensitive area and non-photo-sensing area, and photosensitive door is located at photosensitive area, and signal reads point and is located at non-photo-sensing area with transmission gate, and anti-dazzling screen is located on non-photo-sensing area；Photosensitive door includes at least successively adjacent the first photosensitive door, the second photosensitive door and the photosensitive door of third；First photosensitive door, the photosensitive door of third are p-type heavy doping, and the second photosensitive door is N-type heavy doping；Adjacent photosensitive door is in contact；Transmission gate includes first transmission gate adjacent with the first photosensitive door and second transmission gate adjacent with the photosensitive door of third；Transmission gate is p-type heavy doping, and it is adjacent with transmission gate that signal reads point.The technical solution of the application can make range-measurement system work under low pressure, while the ranging speed of range-measurement system can be improved.

Description

Photosensitive element and range-measurement system
Technical field
This application involves apart from detection technique field, in particular to a kind of photosensitive element and range-measurement system.
Background technique
In the related technology, the TOF based on phase-detection (Time of Flight, flight time) ranging technology can pass through To the transmitting signal of testee transmitting and by the phase difference between the reflected reflection signal of testee, to calculate ranging The distance between device and testee.
Single-point distance can be measured using TOF measurement technology.When obtaining the 3D information of object, two two dimensions can be passed through Camera obtains two width two dimensional images of object, and by the available 3-D image of algorithm process, wherein the 3-D image is carried The depth information of object.
Summary of the invention
The embodiment of the present application provides a kind of photosensitive element and range-measurement system, and range-measurement system can be made to carry out ranging under low pressure Work, while the ranging speed of range-measurement system can be improved.
The application section Example provides a kind of photosensitive element, comprising: substrate that p-type is lightly doped is located at the substrate The grid of top, the signal on the substrate read point and anti-dazzling screen；The grid includes: photosensitive door and transmission gate； There are gaps between the photosensitive door and the transmission gate；The substrate includes photosensitive area and non-photo-sensing area, the photosensitive door position In the photosensitive area, the signal reads point and is located at the non-photo-sensing area with the transmission gate, and the anti-dazzling screen is located at described non- On photosensitive area；Wherein,
The photosensitive door includes at least successively adjacent the first photosensitive door, the second photosensitive door and the photosensitive door of third；Described One photosensitive door, the photosensitive door of the third are p-type heavy doping, and the second photosensitive door is N-type heavy doping；The first photosensitive door It is in contact with the described second photosensitive door, the second photosensitive door is in contact with the photosensitive door of the third；The transmission gate include with The first adjacent transmission gate of first photosensitive door and second transmission gate adjacent with the photosensitive door of the third；Described first passes Defeated door and second transmission gate are p-type heavy doping；It includes adjacent with first transmission gate that the signal, which reads point, One signal reads point and the second signal adjacent with second transmission gate reads point；
The first photosensitive door, the second photosensitive door, the photosensitive door of the third, first transmission gate, described second Apply corresponding predeterminated voltage signal on transmission gate, reads so as to read point in first signal from first transmission When the photogenerated signals charge that door passes through, the potential well of potential well depth, the first photosensitive door formation that the second photosensitive door is formed The potential well depth that depth, first transmission gate are formed is sequentially increased, and is read point in the second signal and is read from described second When the photogenerated signals charge that transmission gate passes through, potential well depth, the photosensitive door of the third of the second photosensitive door formation are formed The potential well depth that potential well depth, second transmission gate are formed is sequentially increased.
The embodiment of the present application major technique effect achieved is: by arranging successively phase on the substrate that p-type is lightly doped Adjacent the first photosensitive door, the second photosensitive door and the photosensitive door of third, and the first photosensitive door, that the photosensitive door of third is all made of p-type is heavily doped Miscellaneous, the second photosensitive door uses N-type heavy doping, and (first is photosensitive for the photosensitive door of the substrate being lightly doped due to p-type and p-type heavy doping Door, the photosensitive door of third) between work function difference be 0.3V, between the substrate that p-type is lightly doped and the second photosensitive door of N-type heavy doping Work function difference be -0.8V, that is, the threshold value electricity of photosensitive door using the photosensitive door of p-type heavy doping than using N-type heavy doping Pressure wants small 1.1V.In this way, even if applying identical effective electricity on the photosensitive door of p-type heavy doping and the photosensitive door of N-type heavy doping Pressure, the potential well depth that the photosensitive door of p-type heavy doping is formed is deeper than the potential well depth that the photosensitive door of N-type heavy doping is formed, that is, exists Under identical effective voltage, the photosensitive door of p-type heavy doping and the potential well depth difference that the photosensitive door of N-type heavy doping is formed are larger.One Aspect, above-mentioned effective voltage can be smaller, in this way, the operating voltage of photosensitive element can be reduced, so that above-mentioned is photosensitive Element and range-measurement system can carry out ranging work under low pressure；On the other hand, even if under lower effective voltage, due to The potential well depth difference that the photosensitive door of p-type heavy doping and the photosensitive door of N-type heavy doping are formed is larger, the speed that electronics drifts about in potential well Degree will increase, so that signal, which reads point, can quickly read photogenerated signals charge, and then improve the ranging speed of system.Institute With the technical solution of the application can reduce the operating voltage of photosensitive element, improve the movement velocity of photogenerated charge, and then make Range-measurement system can carry out ranging work under low pressure, while the ranging speed of range-measurement system can be improved.
In one embodiment of the application, the first photosensitive door may include adjacent with first transmission gate first Photosensitive area and second photosensitive area adjacent with first photosensitive area；Point is read in first signal to read from described first When the photogenerated signals charge that transmission gate passes through, potential well depth, second photosensitive area that the second photosensitive door is formed are formed First potential well depth of potential well depth, first transmission gate formation that potential well depth, first photosensitive area are formed successively increases Greatly.In this way, the drift path of photogenerated charge can be made smoother, helps to reduce noise, improve ranging accuracy.
In one embodiment of the application, the second photosensitive door may include the third adjacent with the described first photosensitive door Photosensitive area and fourth photosensitive area adjacent with the third photosensitive area；Point is read in first signal to read from described first When the photogenerated signals charge that transmission gate passes through, potential well depth, the third photosensitive area of the 4th photosensitive area formation are formed The potential well depth that potential well depth, first transmission gate that potential well depth, the first photosensitive door are formed are formed is sequentially increased；? When the second signal reads point and reads from the photogenerated signals charge that second transmission gate passes through, the third photosensitive area is formed Potential well depth, the 4th photosensitive area potential well depth, the photosensitive door of the third that are formed formed potential well depth, described second The potential well depth that transmission gate is formed is sequentially increased.In this way, the drift path of photogenerated charge can be made smoother, help to subtract Few noise, improves ranging accuracy.
In one embodiment of the application, the photosensitive door of third may include the adjacent with the described second photosensitive door the 5th Photosensitive area and the 6th sense light area adjacent with the 5th photosensitive area；Point is read in the second signal to read from described second When the photogenerated signals charge that transmission gate passes through, potential well depth, the 5th photosensitive area that the second photosensitive door is formed are formed The potential well depth of potential well depth, second transmission gate formation that potential well depth, 6th sense light area are formed is sequentially increased.This Sample can make the drift path of photogenerated charge smoother, help to reduce noise, improve range accuracy.
In one embodiment of the application, the first photosensitive door, the second photosensitive door, on the photosensitive door of the third The first predeterminated voltage signal can be applied；The second predeterminated voltage signal, second transmission can be applied on first transmission gate Apply third predeterminated voltage signal on door；The second predeterminated voltage signal and the third predeterminated voltage signal are reversed each other Square-wave signal, the duty ratio of the second predeterminated voltage signal and the third predeterminated voltage signal is 1:1, described second The high level of predeterminated voltage signal is identical as the high level of the third predeterminated voltage signal, the second predeterminated voltage signal Low level is identical as the low level of the third predeterminated voltage signal；The high level is higher than the first predeterminated voltage signal Voltage value, the low level are lower than the voltage value of the first predeterminated voltage signal.
In one embodiment of the application, above-mentioned photosensitive element may also include positioned at the substrate and the grid it Between the epitaxial layer that is lightly doped of p-type；The doping concentration of the epitaxial layer is lower than the doping concentration of the substrate；The signal is read Point is located on the epitaxial layer.This way it is possible to avoid mutual crosstalk between signal, improves range accuracy.
In one embodiment of the application, above-mentioned photosensitive element may also include to be allowed in advance above the photosensitive door If the filtering film that the light of frequency passes through.In this way, invalid filtered optical signal can be fallen, avoid generating interference to ranging.
In one embodiment of the application, above-mentioned photosensitive element may also include above the anti-dazzling screen, cover The photosensitive area and the non-photo-sensing area and the micro- poly- mirror for being used to converge in received light the photosensitive area.In this way, can mention High light receiving efficiency further increases ranging speed.
In one embodiment of the application, the photosensitive Men Shangke offers loophole.In this way, photosensitive effect can be improved Rate further increases ranging speed.
In one embodiment of the application, above-mentioned photosensitive element may also include positioned at first transmission gate and first Signal reads the first collection door between point and reads second between point positioned at second transmission gate and second signal and receives Ji Men；The first collection door and the second collection door are p-type heavy doping；Described first collects door, second collection Apply corresponding predeterminated voltage signal on door, is collected so as to read point reading the first collection door in first signal Photogenerated signals charge when, potential well depth that potential well depth that the second photosensitive door is formed, the first photosensitive door are formed, institute The potential well depth of the potential well depth, the first collection door of stating the formation of the first transmission gate is sequentially increased, and is read in the second signal It is potential well depth that the second photosensitive door is formed, described when point reads described second and collects the photogenerated signals charge that door is collected out The potential well depth of potential well depth, second transmission gate formation that the photosensitive door of third is formed, described second collect the gesture that door is formed Well depth is sequentially increased.
In one embodiment of the application, above-mentioned photosensitive element, which may also include, is connected to the first signal reading point The reading circuit between point is read with the second signal；The reading circuit reads the voltage letter of point based on first signal First voltage signal number is obtained, the reading circuit obtains second voltage letter based on the voltage signal that the second signal reads point Number；The first voltage signal carries the information of the photogenerated signals charge passed through from first transmission gate；The second voltage Signal carries the information of the photogenerated signals charge passed through from second transmission gate.
The application section Example additionally provides a kind of photosensitive element, comprising: substrate that p-type is lightly doped is located at the lining Grid above bottom, the signal on the substrate read point and anti-dazzling screen；The grid includes: photosensitive door and transmission Door；There are gaps between the photosensitive door and the transmission gate；The substrate includes photosensitive area and non-photo-sensing area, the photosensitive door Positioned at the photosensitive area, the signal reads point and is located at the non-photo-sensing area with the transmission gate, and the anti-dazzling screen is located at described On non-photo-sensing area；Wherein,
The photosensitive door includes the photosensitive door of N-type heavy doping and positioned at the more of the photosensitive door two sides of the N-type heavy doping The photosensitive door of a p-type heavy doping；It is adjacent with the photosensitive door of the multiple p-type heavy doping in the photosensitive door of the N-type heavy doping Two photosensitive doors are in contact；The transmission gate includes the first transmission gate and the second transmission gate positioned at the photosensitive area two sides, And first transmission gate and second transmission gate are p-type heavy doping；It includes passing with described first that the signal, which reads point, The first adjacent signal of defeated door reads point and the second signal adjacent with second transmission gate reads point；
The photosensitive door of the N-type heavy doping, the photosensitive door of the multiple p-type heavy doping, first transmission gate, described Apply corresponding predeterminated voltage signal on two transmission gates, to form photogenerated signals charge from the photosensitive of the N-type heavy doping Door reads the drift path of point, second signal reading point to the first signal respectively.
The embodiment of the present application major technique effect achieved is: by arranging that N-type is heavily doped on the substrate that p-type is lightly doped The photosensitive door of miscellaneous photosensitive door and multiple p-type heavy doping positioned at the photosensitive door two sides of N-type heavy doping, and since p-type is gently mixed Work function difference between the photosensitive door of miscellaneous substrate and p-type heavy doping is 0.3V, the substrate that p-type is lightly doped and N-type heavy doping Work function difference between photosensitive door is -0.8V, that is, using p-type heavy doping photosensitive door than using the photosensitive of N-type heavy doping The threshold voltage of door wants small 1.1V.In this way, even if applying phase on the photosensitive door of p-type heavy doping and the photosensitive door of N-type heavy doping Same effective voltage, the potential well depth that the photosensitive door of p-type heavy doping is formed is than the potential well depth that the photosensitive door of N-type heavy doping is formed It is deeper, i.e., under identical effective voltage, the potential well depth of the photosensitive door formation of the photosensitive door and N-type heavy doping of p-type heavy doping Difference is larger.On the one hand, above-mentioned effective voltage can be smaller, in this way, the operating voltage of photosensitive element can be reduced, so that on The photosensitive element and range-measurement system stated can carry out ranging work under low pressure；On the other hand, even if in lower effective electricity Pressure, since the potential well depth difference of the photosensitive door formation of the photosensitive door and N-type heavy doping of p-type heavy doping is larger, electronics is in potential well The speed of middle drift will increase, so that signal, which reads point, can quickly read photogenerated signals charge, and then improve system Ranging speed.So the technical solution of the application, can reduce the operating voltage of photosensitive element, the movement of photogenerated charge is improved Speed, and then so that range-measurement system is carried out ranging work under low pressure, while the ranging speed of range-measurement system can be improved.
The application section Example additionally provides a kind of range-measurement system, comprising: modulated for emitting to object under test The transmitting terminal of incident light and receiving end for receiving reflected light；The incident light is reflected to form described by the object under test Reflected light；
The receiving end includes camera lens and range finding chip；Wherein the range finding chip includes processing module and above-mentioned sense The light-sensing element array that optical element is constituted；The reflected light is via the camera lens by the photosensitive element in the light-sensing element array It receives；
The photosensitive element receives the photogenerated signals charge generated after the reflected light and carries the reflected light and institute State the phase information between incident light；The phase information carries the range information of the object under test；
The photogenerated signals charge that the processing module is generated based on photosensitive elements multiple in the light-sensing element array It is handled to obtain the three-dimensional distance information of the object under test.
Detailed description of the invention
Fig. 1 is the structural schematic diagram according to a kind of range-measurement system shown in the relevant technologies.
Fig. 2 is a kind of structural schematic diagram of range-measurement system shown in one exemplary embodiment of the application.
Fig. 3 is the TOF modulation system schematic diagram shown in one exemplary embodiment of the application.
Fig. 4 is a kind of diagrammatic cross-section of photosensitive element shown in one exemplary embodiment of the application.
Fig. 5 is that a kind of substrate shown in one exemplary embodiment of the application and the work function relationship between photosensitive door are illustrated Figure.
Fig. 6 is a kind of photogenerated signals charge-trapping schematic diagram shown in one exemplary embodiment of the application.
Fig. 7 is the voltage relationship schematic diagram applied on photosensitive door shown in one exemplary embodiment of the application and transmission gate.
Fig. 8 is a kind of structural schematic diagram of reading circuit shown in one exemplary embodiment of the application.
Fig. 9 is a kind of structural schematic diagram of processing module shown in one exemplary embodiment of the application.
Figure 10 is a kind of top view of photosensitive element shown in the application another exemplary embodiment.
Figure 11 is a kind of diagrammatic cross-section of photosensitive element shown in the application another exemplary embodiment.
Figure 12 is a kind of top view of photosensitive element shown in the application another exemplary embodiment.
Figure 13 is a kind of diagrammatic cross-section of photosensitive element shown in the application another exemplary embodiment.
Figure 14 is a kind of diagrammatic cross-section of photosensitive element shown in the application another exemplary embodiment.
Specific embodiment
Example embodiments are described in detail here, and the example is illustrated in the accompanying drawings.Following description is related to When attached drawing, unless otherwise indicated, the same numbers in different drawings indicate the same or similar elements.Following exemplary embodiment party Embodiment described in formula does not represent all embodiments consistent with the application.On the contrary, they be only with it is such as appended The example of the consistent device and method of some aspects be described in detail in claims, the application.
It is only to be not intended to be limiting the application merely for for the purpose of describing particular embodiments in term used in this application. It is also intended in the application and the "an" of singular used in the attached claims, " described " and "the" including majority Form, unless the context clearly indicates other meaning.It is also understood that term "and/or" used herein refers to and wraps It may be combined containing one or more associated any or all of project listed.
It will be appreciated that though various information, but this may be described using term first, second, third, etc. in the application A little information should not necessarily be limited by these terms.These terms are only used to for same type of information being distinguished from each other out.For example, not departing from In the case where the application range, the first information can also be referred to as the second information, and similarly, the second information can also be referred to as One information.Depending on context, word as used in this " if " can be construed to " ... when " or " when ... When " or " in response to determination ".
With reference to the accompanying drawing, it elaborates to some embodiments of the present application.In the absence of conflict, following reality The feature applied in example and embodiment can be combined with each other.
Referring to Figure 1, in the related technology, the TOF based on phase-detection (Time of Flight, flight time) ranging system System 1 includes transmitting terminal 2 and receiving end 3, and transmitting terminal 1 is used to emit modulated incident light O1 to object under test 4, and incident light O1 is Square wave, incident light O1 reflects to form the reflected light O2 by the object under test 4, after the receiving end reflected light O2 3 receives, ranging System 1 can obtain the distance between object under test 4 and range-measurement system 1 based on the phase difference between incident light O1 and reflected light O2 D。
However, in the related technology, obtaining object when obtaining the 3D information of object or through two two-dimentional cameras Two width two dimensional images, by the available 3-D image of algorithm process, wherein the 3-D image carries the depth information of object, consumption When realize long or by the splicing of single-point distance measuring sensor, but bulky, operating voltage is high, can not be applied to intelligent end It holds in (such as mobile phone).
Based on this, this application provides a kind of photosensitive element and range-measurement systems, can solve above-mentioned technical problem, the survey It is small away from system bulk, can to carry out ranging work, ranging speed under low pressure fast.
Referring to Fig. 2, the range-measurement system 1 that the exemplary embodiment of the application provides includes: transmitting terminal 2 and receiving end 3.Its In, transmitting terminal 2 is used to emit to object under test 4 modulated incident light O1, and receiving end 3 is reflected for receiving by object under test 4 Reflected light O2 back；The incident light O1 reflects to form the reflected light O2 by the object under test 4.In an exemplary reality It applies in example, the light source of transmitting terminal 2 can be LED light source or laser tube light source, laser light source etc., and the wavelength of incident light O1 can be The infrared light of 800nm-1200nm or so.The transmission power of transmitting terminal 2 can be different according to application scenarios.Transmitting terminal 2 Emission current may range from 10mA~10A.
In the present embodiment, the receiving end 3 includes for the camera lens 6 of focusing and for based on reflected light O2 and reflection Light O2 obtains the range finding chip 7 of the three-dimensional distance information of object under test 4.Wherein, the range finding chip 7 include processing module 8 with And light-sensing element array 5, light-sensing element array 5 can be made of multiple photosensitive elements 9 as shown in Figure 4；The reflected light O2 It is received via the camera lens 6 by the photosensitive element 9 in the light-sensing element array 5,6 center of camera lens is directed at light-sensing element array 5 Center.In one exemplary embodiment, light-sensing element array 5 can be the photosensitive of 160*120,320*240,640*480 Element arrays.
One photosensitive element 9 receives the photogenerated signals charge generated after the reflected light O2 and carries the reflected light O2 With the phase information between the incident light O1, wherein the phase information carries the range information of the object under test 4. Processing module 8 carries out handling the available object under test 4 based on the photogenerated signals charge that a photosensitive element 9 generates Single-point range information.
It refers to Fig. 3, the method that range-measurement system 1 detects the single-point range information of object under test 4 is as follows: is measured respectively from entering Penetrate 0 degree of light, 90 degree, 180 degree, the amplitude of 270 degree of corresponding reflected lights, according to arctangent cp cp operation calculate reflected light and incident light it Between phase difference.The method of specific detection amplitude is: receiving end 3 (light-sensing element array 5) carries out while emitting incident light O1 It receives, wherein tranmitting frequency is consistent with integral door frequency is received.Phase difference between incident light O1 and reflected light O2It is 0 degree When, the voltage amplitude value integrated is S0；Phase difference between incident light O1 and reflected light O2When being 90 degree, integral is obtained Voltage amplitude value be S90；Work as phase differenceWhen for 180 degree, the voltage amplitude value integrated is S180；Work as phase differenceIt is 270 When, the voltage amplitude value integrated is S270.Wherein, phase difference OrIf phase difference is less than a cycle, i.e. phase differenceIt, then can root when between 0 to 2 π According to phase differenceCalculate to obtain distance Wherein c is the light velocity, and f is incident light frequency.
When needing to detect the three-dimensional distance information of object under test 4, triggering transmitting terminal 2 emits incident light O1, when photosensitive member After part array 5 exposes, the photogenerated signals charge that multiple photosensitive elements 9 generate in light-sensing element array 5 is read, and by handling The processing of module 8 obtains the three-dimensional distance information of the object under test 4.
The structure of single photosensitive element 9 in the present embodiment is described below.
Referring to Fig. 4, photosensitive element 9 includes: substrate S, the grid G above the substrate S, position that p-type is lightly doped Point, anti-dazzling screen and reading circuit 10 are read in the signal in the substrate S.The grid G includes: photosensitive door and transmission gate, There are gaps between the photosensitive door and the transmission gate.The substrate S includes photosensitive area and non-photo-sensing area, the photosensitive door position In the photosensitive area, the signal reads point and is located at the non-photo-sensing area with the transmission gate, and the anti-dazzling screen is located at described non- On photosensitive area.Silica (SiO is filled between anti-dazzling screen and substrate, grid2).In one exemplary embodiment, it serves as a contrast The thickness of bottom S can be several hundred microns.
The photosensitive door includes first photosensitive successively adjacent Dga, second photosensitive Dg and the photosensitive door Dgb of third；Institute Stating the photosensitive door Dgb of first photosensitive Dga, the third is p-type heavy doping, and second photosensitive Dg is N-type heavy doping；Institute It states first photosensitive Dga to be in contact with second photosensitive Dg, second photosensitive Dg and the photosensitive door Dgb phase of the third Contact.The transmission gate include the first transmission gate Gma adjacent with first photosensitive Dga and with the photosensitive door of the third The second Dgb adjacent transmission gate Gmb；The first transmission gate Gma and the second transmission gate Gmb is p-type heavy doping；It is described Signal read point include first signal adjacent with the first transmission gate Gma read point Outa and with second transmission gate Gmb adjacent second signal reads point Outb.Anti-dazzling screen includes being located at the first transmission gate Gma and first signal reading The first anti-dazzling screen S1 above point Outa and it is located at the second transmission gate Gmb and the second signal reads the top point Outb The second anti-dazzling screen S2.In one embodiment, the shading gold that the first anti-dazzling screen S1, the second anti-dazzling screen S2 can be made of metal Belong to layer.
If reflected light O2 is irradiated to first photosensitive Dga, second photosensitive Dg and the photosensitive door of third when needing ranging When on Dgb, energy is greater than the photon of material band gap by semiconductor absorber.Electron hole is generated in the semiconductor body under grid G Right, more sons (hole) are repelled by grid G voltage, are flowed away by substrate S, and few son (electronics), which is collected in potential well, forms signal electricity Lotus.Since these signal charges are generated because of illumination, photogenerated signals charge can be described as.Photogenerated signals charge passes through transmission Door arriving signal reads point and can be read, and specifically can read point Outa in the first signal, second signal reads point Outb and read It takes.
Photogenerated signals charge determines that signal reads the reading speed of point from the speed that photosensitive area floats to signal reading point. Specifically, the speed that photogenerated signals charge floats to signal reading point from photosensitive area is faster, and the reading speed that signal reads point is got over Fastly, range-measurement system hair ranging speed is faster.The present embodiment is designed using doping type of the work function to each photosensitive door, It not only increases photogenerated signals charge and floats to the speed that signal reads point from photosensitive area, also reduce the work of photosensitive element 9 Voltage, specific as follows:
Since work function difference is bigger, threshold voltage is higher.Fig. 5 is referred to, wherein the unit of work function is electron-volt (eV).Between the substrate S being lightly doped due to p-type and the photosensitive door of p-type heavy doping (the photosensitive door Dgb of first photosensitive Dga, third) Work function difference be 0.3V, work function difference between the substrate S that p-type is lightly doped and second photosensitive Dg of N-type heavy doping is- 0.8V, that is, the threshold voltage of the photosensitive door using the photosensitive door of p-type heavy doping than using N-type heavy doping are 1.1V small.This Sample, even if applying identical effective voltage on the photosensitive door of p-type heavy doping and the photosensitive door of N-type heavy doping, p-type heavy doping The potential well depth that photosensitive door is formed is deeper than the potential well depth that the photosensitive door of N-type heavy doping is formed, i.e., in identical effective voltage Under, the photosensitive door of p-type heavy doping and the potential well depth difference that the photosensitive door of N-type heavy doping is formed are larger.So the doping of photosensitive door Type is different, and obtained work function is different, and then the contact potential difference between neighboring photosensitive door is different, eventually leads to threshold voltage Different, potential well depth difference.After applying corresponding voltage on each photosensitive door, it is deep that required different potential wells can be formed Degree, if potential well depth gradually deepens, it is deeper local that a shallower place of routing potential well is flowed to potential well by electronics e, specifically may be used Referring to Fig. 6.Fig. 6 is that the first signal reads the case where point Outa reads photogenerated signals charge, the potential well that second photosensitive Dg is formed The potential well depth of potential well depth, the first transmission gate Gma formation that depth, first photosensitive Dga are formed is sequentially increased.
It is important that, on the one hand, above-mentioned effective voltage can be smaller, in this way, the work of photosensitive element 9 can be reduced Voltage allows above-mentioned photosensitive element 9 and range-measurement system to carry out ranging work, such as above-mentioned ranging system under low pressure System can integrate in mobile phone for detecting three-dimensional distance information；On the other hand, even if under lower effective voltage, due to P The potential well depth difference that the photosensitive door of type heavy doping and the photosensitive door of N-type heavy doping are formed is larger, the speed that electronics drifts about in potential well Degree will increase, so that signal, which reads point, can quickly read photogenerated signals charge, and then help to improve the ranging of system Speed.
When carrying out distance detection, first photosensitive Dga, second photosensitive Dg, the photosensitive door of the third Dgb, the first transmission gate Gma, corresponding predeterminated voltage can be applied according to actual needs on the second transmission gate Gmb Signal.Referring to Fig. 7, in one exemplary embodiment, first photosensitive Dga, second photosensitive Dg, described Apply the first predeterminated voltage signal V1 on three photosensitive Dgb；Apply the second predeterminated voltage signal on the first transmission gate Gma Apply third predeterminated voltage signal Vb on Va, the second transmission gate Gmb；The second predeterminated voltage signal Va and the third Predeterminated voltage signal Vb is square-wave signal reversed each other, and the second predeterminated voltage signal Va and the third predeterminated voltage are believed The duty ratio of number Vb is 1:1, the high level of the second predeterminated voltage signal Va and the third predeterminated voltage signal Vb's High level is identical, the low level phase of the low level of the second predeterminated voltage signal Va and the third predeterminated voltage signal Vb Together；The high level is higher than the voltage value of the first predeterminated voltage signal V1, and the low level is lower than the described first default electricity Press the voltage value of signal V1.Wherein the frequency of square-wave signal can be between 1KHz to 1GHz.Wherein, each square-wave cycle into The primary photosensitive integral of row.General single exposure needs photosensitive integral many times, such as 1,000 times.Repeatedly ranging spirit can be improved in integral Sensitivity reduces error.
Referring to Fig. 6, reading point Outa in first signal reads the photoproduction letter passed through from the first transmission gate Gma In the case where number charge, the potential well that potential well depth that second photosensitive Dg is formed, first photosensitive Dga are formed is deep The potential well depth that degree, the first transmission gate Gma are formed is sequentially increased, and photogenerated signals charge can be from second photosensitive Dg via the One photosensitive Dga rapid drift is to the first transmission gate Gma；And point Outb is read in the second signal and is read from second biography In the case where the photogenerated signals charge that defeated door Gmb passes through, the potential well depth of second photosensitive Dg formation, the third are photosensitive The potential well depth that potential well depth that door Dgb is formed, the second transmission gate Gmb are formed is sequentially increased, and photogenerated signals charge can be from Second photosensitive Dg is via the photosensitive door Dgb rapid drift of third to the second transmission gate Gmb.
Fig. 3, Fig. 4 and Fig. 8 are please referred to, reading circuit 10 is connected to first signal and reads point Outa and second letter It number reads between point Outb, point Outa and second signal reading point Outb can be read by the first signal and replace reading photogenerated signals Charge.The first voltage of output end Oa can be obtained based on the voltage signal that first signal reads point Outa for the reading circuit Signal, and subsequent processing module 8 is exported, the reading circuit is obtained based on the voltage signal that the second signal reads point Outb To the second voltage signal of output end Ob, and the logical subsequent processing module 8 of output.Wherein, the first voltage signal carry from The information for the photogenerated signals charge that the first transmission gate Gma passes through；The second voltage signal is carried from second transmission The information for the photogenerated signals charge that door Gmb passes through.
Referring to Fig. 8, reading circuit 10 may include power supply E, the first reset terminal R1, the second reset terminal R2, metal-oxide-semiconductor M1, M2, M3, M4, M5, M6, M7, M8, wherein metal-oxide-semiconductor M1, M5 are PMOS tube, and metal-oxide-semiconductor M2, M3, M4, M6, M7, M8 are NMOS tube, and L1 is Row selects signal line, L2 are column selection signal line, when the equal input high level of row selects signal line L1 and column selection signal line L2, photosensitive element 9 is selected, and reading circuit 10 reads the voltage signal of output end Oa and output end Ob, and output processing module 8.In order to obtain The three-dimensional distance information of object under test 4 and when reading data, can select to read photosensitive member in light-sensing element array 5 one by one through ranks The voltage signal of the output end Oa and output end Ob of part 9.
Referring to Fig. 9, in one exemplary embodiment, processing module 8 may include driving/filter circuit 11, bias light Eliminate circuit 12, signal amplification/sample circuit 13.Voltage signal of the driving/filter circuit 11 to output end Oa and output end Ob Output to bias light eliminates circuit 12 after the voltage signal of input is filtered, and bias light eliminates circuit 12 to received letter Number carry out background subtraction light processing and export to signal amplification/sample circuit 13, signal amplification/sample circuit 13 is to received signal It amplifies, digital quantization processing, the initial range information of available object under test 4.Then processing module 8 can be to be measured The initial range information of object 4 compensates, such as temperature-compensating, technological compensa tion, compensation of ageing, the compensation of mould group foozle Deng available final range information.
Referring to Fig. 10, preferably, in one exemplary embodiment, first photosensitive Dga may include with it is described The the first first transmission gate Gma adjacent photosensitive area A1 and second photosensitive area A2 adjacent with first photosensitive area.In ranging When, the voltage applied on the first photosensitive area A1 can be greater than the voltage that the second photosensitive area A2 applies, in this way, in first signal In the case where reading the photogenerated signals charge that point Outa reading passes through from the first transmission gate Gma, the first photosensitive area A1 The potential well depth of formation is greater than the potential well depth that the second photosensitive area A2 is formed, in turn, so that second photosensitive Dg shape At potential well depth, the second photosensitive area A2 formed potential well depth, the first photosensitive area A1 formed potential well depth, institute The first potential well depth for stating the first transmission gate Gma formation is sequentially increased.In this way, the drift path of photogenerated charge can be made more Smoothly, facilitate to reduce noise, improve ranging accuracy.
Please continue to refer to Figure 10, it is preferable that in another exemplary embodiment, second photosensitive Dg includes and institute State first photosensitive Dga adjacent third photosensitive area A3 and the fourth photosensitive area A4 adjacent with the third photosensitive area；Institute In the case where stating the photogenerated signals charge that the reading point Outa reading of the first signal passes through from the first transmission gate Gma, third sense The voltage applied on light area A3 is greater than the voltage applied on the 4th photosensitive area A4, in this way, the gesture that the 4th photosensitive area A4 is formed Potential well depth that potential well depth that well depth, the third photosensitive area A3 are formed, first photosensitive Dga are formed, described the The potential well depth that one transmission gate Gma is formed is sequentially increased.Point Outb is read in the second signal to read from second transmission In the case where the photogenerated signals charge that door Gmb passes through, the voltage applied on the 4th photosensitive area A4, which is greater than on third photosensitive area A3, to be applied The voltage added, in this way, the third photosensitive area A3 formed potential well depth, the 4th photosensitive area A4 formed potential well depth, The potential well depth that potential well depth, the second transmission gate Gmb that the photosensitive door Dgb of third is formed are formed can be sequentially increased. In this way, the drift path of photogenerated charge can be made more smooth, helps to reduce noise, improve ranging accuracy.
Please continue to refer to Figure 10, it is preferable that in another exemplary embodiment, the photosensitive door Dgb of third include with The 5th adjacent photosensitive area A5 of the second photosensitive Dg and 6th sense light area A6 adjacent with the 5th photosensitive area；Institute In the case where stating the photogenerated signals charge that second signal reading point Outb reading passes through from the second transmission gate Gmb, 6th sense The voltage applied on light area A6 is greater than the voltage applied on the 5th photosensitive area A5, in this way, the gesture that second photosensitive Dg is formed The potential well depth of potential well depth, 6th sense light area A6 formation that well depth, the 5th photosensitive area A5 are formed, described second The potential well depth that transmission gate Gmb is formed can be sequentially increased.In this way, the drift path of photogenerated charge can be made more smooth, Help to reduce noise, improves ranging accuracy.
Please refer to Figure 11, it is preferable that in one exemplary embodiment, photosensitive element 9 further include be located at the substrate S with The epitaxial layer EL that p-type between the grid G is lightly doped；The doping concentration of the epitaxial layer EL is lower than the doping of the substrate S Concentration；The signal reads point and is located on the epitaxial layer.Wherein, the thickness of epitaxial layer EL can be 10 microns.Due to extension Layer EL has high resistivity, can be conducive to the range accuracy of raising system to avoid signal cross-talk.
Please refer to Fig. 4 and Figure 11, it is preferable that in one exemplary embodiment, photosensitive element 9 may also include positioned at described The filtering film F for allowing the light of predeterminated frequency to pass through above photosensitive door.The light of the predeterminated frequency is the light of working frequency, that is, sends out Penetrate the incident light O1 of 2 transmitting of end.For example, filtering film F can only allow the infrared light of 850nm.This way it is possible to avoid work frequency The interference generated when light other than rate is to range-measurement system ranging, improves the range accuracy of system.
Please continue to refer to Fig. 4 and Figure 11, it is preferable that photosensitive element 9 may also include above described anti-dazzling screen S1, S2, Cover the photosensitive area and the non-photo-sensing area and micro- poly- mirror PM for received light to be converged in the photosensitive area.In this way, Received light can be converged in photosensitive area, light receiving efficiency is improved, further increase the ranging speed of system.
Please refer to Figure 12, it is preferable that in one exemplary embodiment, described photosensitive door Dga, Dg, Dgb are upper to be offered Loophole H.In this way, light transmission capacity can be increased, light receiving efficiency is improved, the ranging speed of system is further increased.
Figure 13 is please referred to, in one exemplary embodiment, photosensitive element 9 may also include positioned at first transmission gate Gma and the first signal read the first collection door IGma between point Outa and are located at the letter of the second transmission gate Gmb and second Number read point Outb between second collection door IGmb；It is P that the first collection door IGma and described second, which collects door IGmb, Type heavy doping.Apply corresponding predeterminated voltage signal on the first collection door IGma, the second collection door IGmb, with Make when first signal reads point Outa and reads the photogenerated signals charge that described first collects door IGma collection, described second Potential well depth, the first transmission gate Gma of potential well depth, first photosensitive Dga formation that photosensitive door Dg is formed are formed Potential well depth, it is described first collection door IGma potential well depth be sequentially increased, the second signal read point Outb reading Described second when collecting the photogenerated signals charge that door IGmb is collected, potential well depth that second photosensitive Dg is formed, described the The potential well depth of potential well depth, the second transmission gate Gmb formation that three photosensitive Dgb are formed, described second collect door IGmb The potential well depth of formation is sequentially increased.
Figure 14 is please referred to, in one exemplary embodiment, the photosensitive Men Keyi photosensitive doors including N-type heavy doping Dg and the photosensitive door of multiple p-type heavy doping positioned at the two sides photosensitive door Dg of the N-type heavy doping.Specifically it can be, it is photosensitive Door includes first photosensitive Dga, second photosensitive Dg, the photosensitive door Dgb of third, the four photosensitive Dgc, the five photosensitive Dgd, the Two photosensitive Dg are N-type heavy doping, the photosensitive door Dgb of first photosensitive Dga, third, the four photosensitive Dgc, the five photosensitive Dgd For p-type heavy doping.First photosensitive Dga, the four photosensitive Dgc are located at the side of the photosensitive door Dg of N-type heavy doping, and third is photosensitive Door Dgb, the five photosensitive Dgd are located at the other side of the photosensitive door Dg of N-type heavy doping.The photosensitive door of four photosensitive Dgc and first Dga is in contact, and first photosensitive Dga is also in contact with second photosensitive Dg, second photosensitive Dg also with the photosensitive door Dgb phase of third Contact, the photosensitive door Dgb of third are also in contact with the five photosensitive Dgd.First photosensitive Dga, second photosensitive Dg, third are photosensitive Door Dgb, the four photosensitive Dgc, the five photosensitive Dgd, the first transmission gate Gma, apply on the second transmission gate Gmb it is each Self-corresponding predeterminated voltage signal reads point to the first signal respectively to form photogenerated signals charge from second photosensitive Dg Outa, second signal read the drift path of point Outb.It reads for example, reading point Outa in first signal from described first In the case where the photogenerated signals charge that transmission gate Gma passes through, the potential well depth of second photosensitive Dg formation, first sense The potential well that potential well depth, the first transmission gate Gma of potential well depth, the four photosensitive Dgc formation that optical gate Dga is formed are formed Depth is sequentially increased, and photogenerated signals charge can be with via first photosensitive Dga, the four photosensitive Dgc from second photosensitive Dg Rapid drift is to the first transmission gate Gma；And it reads point Outb in the second signal and reads from the second transmission gate Gmb and pass through Photogenerated signals charge in the case where, potential well depth that second photosensitive Dg is formed, the photosensitive door Dgb of the third are formed The potential well depth that potential well depth, the second transmission gate Gmb that potential well depth, the five photosensitive Dgd are formed are formed is sequentially increased, Photogenerated signals charge can be with rapid drift to second via the photosensitive door Dgb of third, the five photosensitive Dgd from second photosensitive Dg Transmission gate Gmb.
The embodiment of the present application major technique effect achieved is: by arranging that N-type is heavily doped on the substrate that p-type is lightly doped The photosensitive door of miscellaneous photosensitive door and the p-type heavy doping positioned at the photosensitive door two sides of N-type heavy doping, and be lightly doped due to p-type Work function difference between substrate and the photosensitive door of p-type heavy doping is 0.3V, and the substrate that p-type is lightly doped is photosensitive with N-type heavy doping Work function difference between door is -0.8V, that is, the photosensitive door using the photosensitive door of p-type heavy doping than using N-type heavy doping Threshold voltage wants small 1.1V.In this way, even if applying on the photosensitive door of p-type heavy doping and the photosensitive door of N-type heavy doping identical Effective voltage, the potential well depth that the potential well depth that the photosensitive door of p-type heavy doping is formed is formed than the photosensitive door of N-type heavy doping is more Deep, i.e., under identical effective voltage, the photosensitive door of p-type heavy doping and the potential well depth that the photosensitive door of N-type heavy doping is formed are poor It is larger.On the one hand, above-mentioned effective voltage can be smaller, in this way, the operating voltage of photosensitive element can be reduced, so that above-mentioned Photosensitive element and range-measurement system can carry out ranging work under low pressure；On the other hand, even if in lower effective voltage Under, since the potential well depth difference of the photosensitive door formation of the photosensitive door and N-type heavy doping of p-type heavy doping is larger, electronics is in potential well The speed of drift will increase, so that signal, which reads point, can quickly read photogenerated signals charge, and then improve the survey of system Away from speed.So the technical solution of the application, can reduce the operating voltage of photosensitive element, the movement speed of photogenerated charge is improved Degree, and then so that range-measurement system is carried out ranging work under low pressure, while the ranging speed of range-measurement system can be improved.
Fig. 4, Figure 11 and Figure 13 are please referred to, the exemplary embodiment of the application additionally provides a kind of photosensitive element 9.The sense Optical element 9, comprising: substrate S that p-type is lightly doped, the grid G above the substrate S, the signal in the substrate S Read point and anti-dazzling screen；The grid G includes: photosensitive door and transmission gate；Exist between the photosensitive door and the transmission gate Gap；The substrate S includes photosensitive area and non-photo-sensing area, and the photosensitive door is located at the photosensitive area, the signal read point with The transmission gate is located at the non-photo-sensing area, and the anti-dazzling screen is located on the non-photo-sensing area；Wherein,
The photosensitive door includes at least successively adjacent first photosensitive Dga, second photosensitive Dg and the photosensitive door of third Dgb；The photosensitive door Dgb of first photosensitive Dga, the third is p-type heavy doping, and second photosensitive Dg is N-type weight Doping；First photosensitive Dga is in contact with second photosensitive Dg, and second photosensitive Dg and the third are photosensitive Door Dgb is in contact；The transmission gate includes the first transmission gate Gma adjacent with first photosensitive Dga and with described The second three photosensitive Dgb adjacent transmission gate Gmb；The first transmission gate Gma and the second transmission gate Gmb is p-type weight Doping；The signal read point include first signal adjacent with the first transmission gate Gma read point Outa and with it is described Second transmission gate Gmb adjacent second signal reads point Outb；
First photosensitive Dga, second photosensitive Dg, the photosensitive door Dgb of the third, first transmission gate Apply corresponding predeterminated voltage signal on Gma, the second transmission gate Gmb, so as to read point in first signal When Outa is read from the photogenerated signals charge that the first transmission gate Gma passes through, the potential well that second photosensitive Dg is formed is deep The potential well depth of potential well depth, the first transmission gate Gma formation that degree, first photosensitive Dga are formed is sequentially increased, When the second signal reads point Outb and reads from the photogenerated signals charge that the second transmission gate Gmb passes through, described second feels Potential well depth, the second transmission gate Gmb of potential well depth, the photosensitive door Dgb formation of the third that optical gate Dg is formed are formed Potential well depth is sequentially increased.
The embodiment of the present application major technique effect achieved is: by arranging successively phase in the substrate S that p-type is lightly doped Adjacent first photosensitive Dga, second photosensitive Dg and the photosensitive door Dgb of third, and the photosensitive door Dgb of first photosensitive Dga, third It is all made of p-type heavy doping, second photosensitive Dg uses N-type heavy doping, and the substrate S that is lightly doped due to p-type and p-type heavy doping Work function difference between photosensitive door (the photosensitive door Dgb of first photosensitive Dga, third) is 0.3V, the substrate S and N-type that p-type is lightly doped Work function difference between second photosensitive Dg of heavy doping is -0.8V, that is, uses the photosensitive door of p-type heavy doping to compare and use N The threshold voltage of the photosensitive door of type heavy doping wants small 1.1V.In this way, even if photosensitive door and N-type heavy doping in p-type heavy doping Apply identical effective voltage, photosensitive door of the potential well depth that the photosensitive door of p-type heavy doping is formed than N-type heavy doping on photosensitive door The potential well depth of formation is deeper, i.e., under identical effective voltage, the photosensitive door of p-type heavy doping and the photosensitive door of N-type heavy doping The potential well depth difference of formation is larger.On the one hand, above-mentioned effective voltage can be smaller, in this way, photosensitive element 9 can be reduced Operating voltage allows above-mentioned photosensitive element 9 and range-measurement system to carry out ranging work under low pressure；On the other hand, i.e., Make under lower effective voltage, since the potential well depth of the photosensitive door formation of the photosensitive door and N-type heavy doping of p-type heavy doping is poor Larger, the speed that electronics drifts about in potential well will increase, so that signal, which reads point, can quickly read photogenerated signals charge, And then improve the ranging speed of system.So the technical solution of the application, can reduce the operating voltage of photosensitive element 9, improve The movement velocity of photogenerated charge, and then so that range-measurement system is carried out ranging work under low pressure, while ranging system can be improved The ranging speed of system.
Figure 14 is please referred to, the exemplary embodiment of the application additionally provides a kind of photosensitive element 9.The photosensitive element 9, packet It includes: substrate S, the grid above the substrate, the signal reading point in the substrate S and the screening that p-type is lightly doped Mating plate；The grid includes: photosensitive door and transmission gate；There are gaps between the photosensitive door and the transmission gate；The substrate S Including photosensitive area and non-photo-sensing area, the photosensitive door is located at the photosensitive area, and the signal reads point and is located at the transmission gate The non-photo-sensing area, the anti-dazzling screen are located on the non-photo-sensing area.
The photosensitive door includes the photosensitive door of N-type heavy doping and positioned at the more of the photosensitive door two sides of the N-type heavy doping The photosensitive door of a p-type heavy doping；It is adjacent with the photosensitive door of the multiple p-type heavy doping in the photosensitive door of the N-type heavy doping Two photosensitive doors are in contact；The transmission gate includes the first transmission gate and the second transmission gate positioned at the photosensitive area two sides, And first transmission gate and second transmission gate are p-type heavy doping；It includes passing with described first that the signal, which reads point, The first adjacent signal of defeated door reads point and the second signal adjacent with second transmission gate reads point.
The photosensitive door of the N-type heavy doping, the photosensitive door of the multiple p-type heavy doping, first transmission gate, described Apply corresponding predeterminated voltage signal on two transmission gates, to form photogenerated signals charge from the photosensitive of the N-type heavy doping Door reads the drift path of point, second signal reading point to the first signal respectively.
The embodiment of the present application major technique effect achieved is: by arranging that N-type is heavily doped on the substrate that p-type is lightly doped The photosensitive door of miscellaneous photosensitive door and multiple p-type heavy doping positioned at the photosensitive door two sides of N-type heavy doping, and since p-type is gently mixed Work function difference between the photosensitive door of miscellaneous substrate and p-type heavy doping is 0.3V, the substrate that p-type is lightly doped and N-type heavy doping Work function difference between photosensitive door is -0.8V, that is, using p-type heavy doping photosensitive door than using the photosensitive of N-type heavy doping The threshold voltage of door wants small 1.1V.In this way, even if applying phase on the photosensitive door of p-type heavy doping and the photosensitive door of N-type heavy doping Same effective voltage, the potential well depth that the photosensitive door of p-type heavy doping is formed is than the potential well depth that the photosensitive door of N-type heavy doping is formed It is deeper, i.e., under identical effective voltage, the potential well depth of the photosensitive door formation of the photosensitive door and N-type heavy doping of p-type heavy doping Difference is larger.On the one hand, above-mentioned effective voltage can be smaller, in this way, the operating voltage of photosensitive element can be reduced, so that on The photosensitive element and range-measurement system stated can carry out ranging work under low pressure；On the other hand, even if in lower effective electricity Pressure, since the potential well depth difference of the photosensitive door formation of the photosensitive door and N-type heavy doping of p-type heavy doping is larger, electronics is in potential well The speed of middle drift will increase, so that signal, which reads point, can quickly read photogenerated signals charge, and then improve system Ranging speed.So the technical solution of the application, can reduce the operating voltage of photosensitive element, the movement of photogenerated charge is improved Speed, and then so that range-measurement system is carried out ranging work under low pressure, while the ranging speed of range-measurement system can be improved.
It should be noted that the incident light being mentioned above is alternatively referred to as transmitted wave, reflected light is alternatively referred to as received wave.On The different appellations to same thing are stated, do not limit the protection scope of the application.
The apparatus embodiments described above are merely exemplary, wherein described, unit can as illustrated by the separation member It is physically separated with being or may not be, component shown as a unit may or may not be physics list Member, it can it is in one place, or may be distributed over multiple network units.It can be selected according to the actual needs In some or all of the modules realize the purpose of application scheme.Those of ordinary skill in the art are not paying creative labor In the case where dynamic, it can understand and implement.
The foregoing is merely the preferred embodiments of the application, not to limit the application, all essences in the application Within mind and principle, any modification, equivalent substitution, improvement and etc. done be should be included within the scope of the application protection.

Claims (13)

1. a kind of photosensitive element characterized by comprising substrate that p-type is lightly doped, the grid above the substrate, position Point and anti-dazzling screen are read in the signal on the substrate；The grid includes: photosensitive door and transmission gate；The photosensitive door and institute State between transmission gate that there are gaps；The substrate includes photosensitive area and non-photo-sensing area, and the photosensitive door is located at the photosensitive area, institute It states signal reading point and is located at the non-photo-sensing area with the transmission gate, the anti-dazzling screen is located on the non-photo-sensing area；Wherein,
The photosensitive door includes at least successively adjacent the first photosensitive door, the second photosensitive door and the photosensitive door of third；First sense Optical gate, the photosensitive door of the third are p-type heavy doping, and the second photosensitive door is N-type heavy doping；The first photosensitive door and institute It states the second photosensitive door to be in contact, the second photosensitive door is in contact with the photosensitive door of the third；The transmission gate include with it is described The first adjacent transmission gate of first photosensitive door and second transmission gate adjacent with the photosensitive door of the third；First transmission gate It is p-type heavy doping with second transmission gate；It includes first letter adjacent with first transmission gate that the signal, which reads point, It number reads point and the second signal adjacent with second transmission gate reads point；
The first photosensitive door, the second photosensitive door, the photosensitive door of the third, first transmission gate, second transmission Apply corresponding predeterminated voltage signal on door, leads to so as to read point in first signal and read from first transmission gate When the photogenerated signals charge crossed, the potential well depth of potential well depth, the first photosensitive door formation that the second photosensitive door is formed, The potential well depth that first transmission gate is formed is sequentially increased, and is read point in the second signal and is read from second transmission gate By photogenerated signals charge when, the potential well that potential well depth that the second photosensitive door is formed, the photosensitive door of the third are formed is deep The potential well depth that degree, second transmission gate are formed is sequentially increased.
2. photosensitive element according to claim 1, which is characterized in that the first photosensitive door includes and described first transmits The first adjacent photosensitive area of door and second photosensitive area adjacent with first photosensitive area；
When first signal reads point and reads from the photogenerated signals charge that first transmission gate passes through, described second is photosensitive The potential well depth of door formation, the potential well depth of second photosensitive area formation, the potential well depth of first photosensitive area formation, institute The first potential well depth for stating the formation of the first transmission gate is sequentially increased.
3. photosensitive element according to claim 1, which is characterized in that the second photosensitive door include with it is described first photosensitive The adjacent third photosensitive area of door and fourth photosensitive area adjacent with the third photosensitive area；
When first signal reads point and reads from the photogenerated signals charge that first transmission gate passes through, the described 4th is photosensitive The potential well depth of potential well depth, third photosensitive area formation that area is formed, the potential well depth of the first photosensitive door formation, institute The potential well depth for stating the formation of the first transmission gate is sequentially increased；
When the second signal reads point and reads from the photogenerated signals charge that second transmission gate passes through, the third is photosensitive The potential well depth of the photosensitive door formation of the potential well depth of area's formation, the potential well depth of the 4th photosensitive area formation, the third, institute The potential well depth for stating the formation of the second transmission gate is sequentially increased.
4. photosensitive element according to claim 1, which is characterized in that the photosensitive door of third include with it is described second photosensitive The 5th adjacent photosensitive area of door and the 6th sense light area adjacent with the 5th photosensitive area；
When the second signal reads point and reads from the photogenerated signals charge that second transmission gate passes through, described second is photosensitive The potential well depth of door formation, the potential well depth of the 5th photosensitive area formation, the potential well depth of 6th sense light area formation, institute The potential well depth for stating the formation of the second transmission gate is sequentially increased.
5. photosensitive element according to claim 1, which is characterized in that the first photosensitive door, the second photosensitive door, institute It states and applies the first predeterminated voltage signal on the photosensitive door of third；
Apply the second predeterminated voltage signal on first transmission gate, applies third predeterminated voltage letter on second transmission gate Number；The second predeterminated voltage signal and the third predeterminated voltage signal are square-wave signal reversed each other, and described second is pre- If the duty ratio of voltage signal and the third predeterminated voltage signal is 1:1, the high level of the second predeterminated voltage signal Identical as the high level of the third predeterminated voltage signal, the low level and the third of the second predeterminated voltage signal are default The low level of voltage signal is identical；
The high level is higher than the voltage value of the first predeterminated voltage signal, and the low level is lower than first predeterminated voltage The voltage value of signal.
6. photosensitive element according to claim 1, which is characterized in that further include between the substrate and the grid The epitaxial layer that is lightly doped of p-type；The doping concentration of the epitaxial layer is lower than the doping concentration of the substrate；
The signal reads point and is located on the epitaxial layer.
7. photosensitive element according to claim 1, which is characterized in that further include being located above the photosensitive door to allow to preset The filtering film that the light of frequency passes through.
8. photosensitive element according to claim 1, which is characterized in that further include being located above the anti-dazzling screen, covering institute State photosensitive area and the non-photo-sensing area and micro- poly- mirror for received light to be converged in the photosensitive area.
9. photosensitive element according to claim 1, which is characterized in that offer loophole on the photosensitive door.
10. photosensitive element according to claim 1, which is characterized in that further include being located at first transmission gate and first Signal reads the first collection door between point and reads second between point positioned at second transmission gate and second signal and receives Ji Men；The first collection door and the second collection door are p-type heavy doping；
Apply corresponding predeterminated voltage signal on the first collection door, the second collection door, so that described first When signal reads the photogenerated signals charge that point reading the first collection door is collected, the potential well that the second photosensitive door is formed is deep Degree, the potential well depth that the first photosensitive door is formed, the potential well depth of first transmission gate formation, described first collect door Potential well depth is sequentially increased, when the second signal reads point and reads the photogenerated signals charge that described second collects door collection, Potential well depth, second transmission gate of potential well depth, the photosensitive door formation of the third that the second photosensitive door is formed are formed Potential well depth, it is described second collection door formed potential well depth be sequentially increased.
11. photosensitive element according to claim 1, which is characterized in that further include being connected to first signal to read point The reading circuit between point is read with the second signal；
The reading circuit obtains first voltage signal, the reading circuit based on the voltage signal that first signal reads point The voltage signal for reading point based on the second signal obtains second voltage signal；
The first voltage signal carries the information of the photogenerated signals charge passed through from first transmission gate；
The second voltage signal carries the information of the photogenerated signals charge passed through from second transmission gate.
12. a kind of photosensitive element characterized by comprising substrate that p-type is lightly doped, the grid above the substrate, position Point and anti-dazzling screen are read in the signal on the substrate；The grid includes: photosensitive door and transmission gate；The photosensitive door and institute State between transmission gate that there are gaps；The substrate includes photosensitive area and non-photo-sensing area, and the photosensitive door is located at the photosensitive area, institute It states signal reading point and is located at the non-photo-sensing area with the transmission gate, the anti-dazzling screen is located on the non-photo-sensing area；Wherein,
The photosensitive door includes the photosensitive door of N-type heavy doping and multiple p-types positioned at the photosensitive door two sides of the N-type heavy doping The photosensitive door of heavy doping；The two neighboring sense in the photosensitive door of the N-type heavy doping and the photosensitive door of the multiple p-type heavy doping Optical gate is in contact；The transmission gate includes the first transmission gate and the second transmission gate positioned at the photosensitive area two sides, and described First transmission gate and second transmission gate are p-type heavy doping；The signal reads point The first adjacent signal reads point and the second signal adjacent with second transmission gate reads point；
The photosensitive door of the N-type heavy doping, the photosensitive door of the multiple p-type heavy doping, first transmission gate, described second pass Apply corresponding predeterminated voltage signal on defeated door, to form photogenerated signals charge from the photosensitive door of the N-type heavy doping point It is clipped to the drift path that the first signal reads point, second signal reading point.
13. a kind of range-measurement system characterized by comprising for emitting the transmitting terminal of modulated incident light to object under test And the receiving end for receiving reflected light；The incident light reflects to form the reflected light by the object under test；
The receiving end includes camera lens and range finding chip；Wherein the range finding chip includes processing module and such as claim 1 The light-sensing element array constituted to 12 described in any item photosensitive elements；The reflected light is via the camera lens by the photosensitive member Photosensitive element in part array receives；
The photosensitive element receive the photogenerated signals charge that is generated after the reflected light carry the reflected light with it is described enter Penetrate the phase information between light；The phase information carries the range information of the object under test；
The processing module is carried out based on the photogenerated signals charge that photosensitive elements multiple in the light-sensing element array generate Processing obtains the three-dimensional distance information of the object under test.
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CN102235860A (en) * 2010-04-20 2011-11-09 原相科技股份有限公司 Distance measuring device, stereo image sensing device and optical touch control system
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