CN105336751A

CN105336751A - Photoelectric sensor and manufacturing method thereof

Info

Publication number: CN105336751A
Application number: CN201410284240.9A
Authority: CN
Inventors: 林崴平
Original assignee: Shanghai Luoji Technology Co Ltd
Current assignee: Shanghai Luoji Technology Co Ltd
Priority date: 2014-06-23
Filing date: 2014-06-23
Publication date: 2016-02-17
Anticipated expiration: 2034-06-23
Also published as: CN105336751B

Abstract

The invention provides a photoelectric sensor and a manufacturing method thereof. The photoelectric sensor comprises a pixel unit arranged on the substrate; and the pixel unit includes a photodiode and a thin-film transistor. A drain structure of the thin-film transistor servers as a cathode structure of the photodiode, so that the area occupied by the pixel can be reduced and the resolution ratio of the photoelectric sensor can be improved. Moreover, the anode structure and the cathode structure of the photodiode are arranged in a transverse mode, so that the thickness of the photoelectric sensor can be effectively reduced and thus the photoelectric sensor has advantages of small size and high resolution ration. Besides, the manufacturing method of the photoelectric sensor can be combined with the traditional LCD manufacturing method, thereby simplifying the production process of the photoelectric sensor, reducing the production cycle, and effectively reducing the production cost.

Description

Photoelectric sensor and manufacture method thereof

Technical field

The present invention relates to semiconductor applications, be specifically related to a kind of photoelectric sensor and manufacture method thereof.

Background technology

Fingerprint recognition causes recently as very ancient bio-identification mode and pays close attention to widely, and more it brings wide prospect to the prospect especially in mobile payment.People have also been invented the method for a variety of fingerprint recognition, such as optics, condenser type, microwave, a variety of mode such as temperature and ultrasonic wave.But various mode has its merits and demerits.Such as traditional optical pickocff mode cannot realize frivolous, and especially under high-resolution requirement, legacy equipment is bulky cannot be portable, is therefore difficult to be integrated in the such equipment of mobile phone.Although other mode solves frivolous problem, large area array cannot be realized, maybe cannot in conjunction with other functions, and complex process, cost is high.

Namely medical Amorphous silicon flat-panel detectors of the prior art is a kind of traditional optical pickocff, comprise amorphous silicon photodiodes and thin-film transistor, its operation principle is: at the anode of amorphous silicon photodiodes, namely P-type layer adds a negative voltage between-3--9V, when light signal is irradiated in amorphous silicon photodiodes, in amorphous silicon photodiodes, produce electron hole pair.Under the effect of electric field, hole converges in anode P-type layer, and electronics converges to negative electrode N-type layer.When thin-film transistor turns off, signal constantly accumulates, and when thin-film transistor is opened, electric charge outputs to data wire.The size of the charge signal amount that foundation detects is to judge the power of light signal.

Fig. 1 shows the generalized section of a kind of Amorphous silicon flat-panel detectors pixel cell of prior art, transparency carrier 01 is formed multiple flat panel detector pixel cell, each flat panel detector pixel cell comprises thin-film transistor 03 and amorphous silicon photodiodes, wherein amorphous silicon photodiodes comprises the first light shield layer 02 formed successively being formed at transparency carrier 01 surface, first insulating barrier 04, drain electrode layer 05, N-type layer 06, intermediate layer 07, P-type layer 08 and contact electrode 09, thin-film transistor 03 and amorphous silicon photodiodes insulate by dielectric layer 10, the second light shield layer 12 is formed with without the need to dielectric layer 10 surface in the region of illumination at thin-film transistor 03 and part, contact electrode 09 is formed connecting electrode 11, passivation layer 11 is formed above the second light shield layer 12 and connecting electrode 11.Wherein the first light shield layer 02 and the grid of thin-film transistor 03 are at same metal level, the drain electrode of drain electrode layer 05 and thin-film transistor 03 is at same metal level, as can be seen from the figure, the major part of this amorphous silicon photodiodes is P-type layer 08, the lamination of intermediate layer 07 and N-type layer 06, wherein intermediate layer 07 is through light dope process, therefore, the thickness of Amorphous silicon flat-panel detectors is similar to and has superposed again the laminated thickness of amorphous silicon photodiodes above in the drain electrode of thin-film transistor 03, and the thickness in intermediate layer 07 in amorphous silicon photodiodes is at 1 microns, make the thickness of Amorphous silicon flat-panel detectors larger, the light path of incident light in the pixel cell of flat panel detector is longer, adjacent pixel cell may be entered and produce interference.And flat panel detector pixel comprises discrete thin-film transistor 03 and amorphous silicon photodiodes, also at regular intervals between thin-film transistor 03 and amorphous silicon photodiodes, flat panel detector pixel cell area occupied is comparatively large, makes resolution lower.In addition, the needs of amorphous silicon photodiodes make separately after formation thin-film transistor 03, need multistep film forming and photoetching process, make production cost higher.If the Amorphous silicon flat-panel detectors of this structure is used for the fields such as fingerprint recognition, the problem that production cost is high, resolution is low will limit its application on the portable equipments such as mobile phone.

Therefore, propose a kind of photoelectric sensor and manufacture method thereof, manufacture the photoelectric sensor that a kind of production cost is lower, resolution is high, become those skilled in the art's problem demanding prompt solution.

Summary of the invention

The problem that the present invention solves is to provide a kind of photoelectric sensor and manufacture method thereof, and described photoelectric sensor has the advantage that production cost is lower, resolution is high, can preferably for fingerprint recognition.

For solving the problem, the invention provides a kind of photoelectric sensor, for realizing fingerprint recognition, comprising:

Substrate, described substrate comprises the first area for the formation of thin-film transistor, the second area for the formation of photodiode;

Be positioned at the grid of first area substrate surface;

Be positioned at the intrinsic semiconductor layer on grid;

Be positioned at discrete the first conductive structure, second conductive structure on described intrinsic semiconductor layer surface on the substrate of first area, compared with described first conductive structure, described second conductive structure is closer to the second area of described substrate, described first conductive structure and described second conductive structure include and are positioned at the first doping semiconductor layer in intrinsic semiconductor layer and the first electrode layer, described first conductive structure is used as the source configuration of described thin-film transistor, and described second conductive structure is used as the drain electrode structure of described thin-film transistor;

Be covered in the dielectric layer in described first conductive structure, the second conductive structure and intrinsic semiconductor layer, the described dielectric layer be arranged on second area substrate has the opening running through described dielectric layer, and described opening exposes described intrinsic semiconductor layer;

Be arranged in the second doping semiconductor layer, the second electrode lay of described opening successively, be arranged in the second doping semiconductor layer of described opening, the second electrode lay forms the 3rd conductive structure;

Described second conductive structure is also used as the cathode construction of photodiode, described 3rd conductive structure being arranged in opening is used as the anode construction of photodiode, and the intrinsic semiconductor between described 3rd conductive structure and described second conductive structure is used as the light absorbing zone of photodiode;

The light signal that fingerprint reflects can be converted into the signal of telecommunication by described photodiode, and is exported by thin-film transistor, and described photodiode and described thin-film transistor form a pixel cell.

Optionally, described second doping semiconductor layer, the second electrode lay are also formed on dielectric layer corresponding to first area, and for forming the 4th conductive structure, described 4th conductive structure and described second conductive structure are for forming storage capacitance.

Optionally, the first insulating barrier is provided with between described substrate and described intrinsic semiconductor layer.

Optionally, the material of described substrate, the first insulating barrier and dielectric layer is light transmissive material.

Optionally, described photoelectric sensor also comprises: the second insulating barrier being covered in described dielectric layer and the second electrode lay surface, and the material of described second insulating barrier is light transmissive material.

Optionally, the material of described first insulating barrier, dielectric layer, the second insulating barrier is silicon nitride, silica or spin-on material.

Optionally, be positioned at the contact electrode on described the second electrode lay surface, the material of described contact electrode is tin indium oxide or zinc oxide.

Optionally, described open bottom edge and the second conductive structure near the spacing of edge of opening in the scope of 1 to 5 microns.

Optionally, described second conductive structure is in the pectination with comb part, the 3rd conductive structure in described opening is in the pectination with comb part, and the 3rd conductive structure in described opening and described first conductive structure, the second conductive structure are oppositely arranged and comb part is alternately arranged.

Optionally, described photoelectric sensor comprises multiple described pixel cell, and multiple pixel cell is array-like arrangement;

Described photoelectric sensor also comprises: many grid leads arranged in the row direction, described in every bar, one end of grid lead is electrically connected with external drive circuit, often the thin-film transistor gate of row pixel cell is electrically connected, for thin-film transistor gate provides scanning voltage with a grid lead of going together;

Many the first lead-in wires along column direction arrangement, described in every bar, one end of the first lead-in wire is electrically connected with external drive circuit, one first of the first electrode layer in first conductive structure of every row pixel cell and same column goes between and is electrically connected, for the first electrode layer in described first conductive structure provides basic voltage;

Many the second lead-in wires along column direction arrangement, described in every bar, one end of the second lead-in wire is electrically connected with external drive circuit, and often the second electrode lay of row pixel cell goes between with second of same column and is electrically connected, for described the second electrode lay provides signal voltage.

Optionally, described photoelectric sensor also comprises:

At turn-on grid electrode lead-in wire, the first lead-in wire, second grid via hole, the first via hole, second via hole gone between of the array external that described pixel cell forms.

Optionally, in described grid via hole, the first via hole, the second via hole, there is conductive layer, grid lead, the first lead-in wire, the second lead-in wire to be electrically connected with external drive circuit.

Optionally, photoelectric sensor also comprises: be positioned at the protective layer above described multiple pixel cell.

Optionally, photoelectric sensor also comprises: be arranged at the backlight below substrate, and the light that described backlight sends is projected to above pixel cell by the logical photo structure that is arranged in pixel cell;

Described photodiode is pointed the light of reflection, to carry out fingerprint recognition for detecting described light.

Optionally, described photoelectric sensor also comprises: the light shield layer being positioned at second area substrate surface, at described light shield layer zone line or have the first light hole exposing described substrate at light shield layer edge;

Described intrinsic semiconductor layer zone line or intrinsic semiconductor layer edge have the second light hole be positioned at directly over described first light hole;

Described first light hole and described second light hole are for forming described logical photo structure.

Optionally, the 3rd conductive structure in described opening is closed rectangle, the 3rd light hole is formed bottom the 3rd conductive structure in said opening, described 3rd light hole exposes the second light hole, described second conductive structure surrounds closed frame-type centered by described opening, make the 3rd conductive structure in the second conductive structure and described opening be back-shaped structure, described logical photo structure also comprises described 3rd light hole.

Optionally, the aperture of described first light hole, the second light hole, the 3rd light hole is in the scope of 0 to 10 microns.

Optionally, the intrinsic semiconductor layer in described opening and between the second conductive structure is blocked by described light shield layer completely.

Optionally, described light shield layer and described second conductive structure are for forming storage capacitance.

Optionally, described photoelectric sensor comprises multiple described pixel cell, and multiple pixel cell is array-like arrangement; Described photoelectric sensor also comprises:

Many bars of the 3rd lead-in wires along column direction arrangement, described in every article, one end of the 3rd lead-in wire is electrically connected with an external drive circuit, and often the light shield layer of row pixel cell goes between with an article the 3rd of same column and is electrically connected, for light shield layer provides external voltage.

Optionally, described external voltage is in 0 scope to-10V.

Optionally, described scanning voltage is in-10 scopes to 15V, and described basic voltage is in 0 scope to 3V, and described signal voltage is in 0 scope to-10V.

The present invention also provides a kind of manufacture method of photoelectric sensor, it is characterized in that, comprising:

There is provided substrate, form multiple pixel cell over the substrate, wherein each pixel cell comprises thin-film transistor and photodiode;

The step forming pixel cell comprises:

There is provided substrate, described substrate comprises the first area for the formation of thin-film transistor, the second area for the formation of photodiode;

Grid is formed at described first area substrate surface;

Described grid forms intrinsic semiconductor layer;

Described intrinsic semiconductor layer surface on the substrate of first area forms discrete the first conductive structure, the second conductive structure, compared with described first conductive structure, described second conductive structure is closer to the second area of described substrate, described first conductive structure and described second conductive structure include and are positioned at the first doping semiconductor layer in intrinsic semiconductor layer and the first electrode layer, described first conductive structure is used as the source configuration of described thin-film transistor, and described second conductive structure is used as the drain electrode structure of described thin-film transistor;

Blanket dielectric layer in described first conductive structure, the second conductive structure and intrinsic semiconductor layer;

Form the opening running through described dielectric layer being arranged in the described dielectric layer on second area substrate, described opening exposes described intrinsic semiconductor layer;

Form the second doping semiconductor layer, the second electrode lay successively in said opening, the second doping semiconductor layer in described opening, the second electrode lay form the 3rd conductive structure;

Described second conductive structure is also used as photodiode cathode structure; Described 3rd conductive structure being arranged in opening is used as the anode construction of photodiode, and the intrinsic semiconductor between described 3rd conductive structure and described second conductive structure is used as the light absorbing zone of photodiode;

The light signal that fingerprint reflects can be converted into the signal of telecommunication by described photodiode, and is exported by thin-film transistor, thus makes described pixel cell can be used in fingerprint recognition.

Optionally, in the step forming described second doping semiconductor layer, the second electrode lay, described second doping semiconductor layer, the second electrode lay are also formed on dielectric layer corresponding to first area, for forming the 4th conductive structure, described 4th conductive structure and described second conductive structure are for forming storage capacitance.

Optionally, after formation grid, before forming intrinsic semiconductor layer, also on described grid, form the first insulating barrier, described intrinsic semiconductor layer is formed with on described first insulating barrier.

Optionally, described manufacture method also comprises: at described dielectric layer and the second electrode lay surface coverage second insulating barrier, and the material of described second insulating barrier is light transmissive material.

Optionally, described manufacture method also comprises: the second electrode lay surface in said opening forms contact electrode, and the material of described contact electrode is tin indium oxide or zinc oxide.

Optionally, make the spacing of the close edge of opening of described open bottom edge and the second conductive structure in the scope of 1 to 5 microns.

Optionally, make described first conductive structure, the second conductive structure in the pectination with comb part, the 3rd conductive structure in described opening is in the pectination with comb part, and the comb part of the 3rd conductive structure in described opening and described first conductive structure, the second conductive structure are oppositely arranged and comb part is alternately arranged.

Optionally, described manufacture method also comprises: below substrate, arrange backlight, and the light that described backlight sends is projected to above pixel cell by the logical photo structure that is formed in pixel cell.

Optionally, in the process forming grid, synchronously form light shield layer at second area substrate surface, at described light shield layer zone line or the first light hole exposing described substrate in the formation of light shield layer edge;

The second light hole be positioned at directly over described first light hole is formed at described intrinsic semiconductor layer zone line or intrinsic semiconductor layer edge;

Optionally, the 3rd conductive structure in described opening is made to be closed rectangle, the 3rd light hole is formed bottom the 3rd conductive structure in said opening, described 3rd light hole exposes the second light hole, described second conductive structure is made to surround closed frame-type centered by described opening, make the 3rd conductive structure in the second conductive structure and described opening be back-shaped structure, described logical photo structure also comprises described 3rd light hole.

Optionally, make described first light hole, the second light hole, the 3rd light hole aperture in the scope of 0 to 10 microns.

Optionally, the process forming grid and light shield layer at described substrate surface comprises: adopt magnetron sputtering method to form the first metal layer at described substrate surface, removing part the first metal layer to exposing substrate surface by photoetching, forming the first light hole in thin-film transistor gate, light shield layer and light shield layer.

Optionally, the process forming intrinsic semiconductor layer at described first surface of insulating layer comprises: using plasma strengthens chemical vapour deposition technique, at described first surface of insulating layer deposition intrinsic amorphous silicon, remove part intrinsic amorphous silicon to exposing the first surface of insulating layer by photoetching, the intrinsic amorphous silicon of reservation forms intrinsic semiconductor layer.

Optionally, comprise in the process of described intrinsic semiconductor layer surface formation the first conductive structure, the second conductive structure: using plasma strengthens chemical vapour deposition technique at described intrinsic semiconductor layer surface deposition N-type amorphous silicon, the second metal level is covered in described N-type amorphous silicon surfaces, photoetching is carried out to described second metal level, N-type amorphous silicon, remove most second metal level, N-type amorphous silicon to exposing intrinsic semiconductor layer, remaining N-type amorphous silicon forms the first doping semiconductor layer, and remaining second metal level forms the first electrode layer.

Optionally, the material of described the second electrode lay is metal or light transmitting electro-conductive material.

Optionally, on the first electrode side dielectric layer surface and described opening in formed formed successively the second doping semiconductor layer, the second electrode lay process comprise: in described dielectric layer surface and described opening, cover the P-type non-crystalline silicon, the 3rd metal level that are formed successively, remove part P-type non-crystalline silicon, the 3rd metal level to exposing dielectric layer surface by photoetching, the P-type non-crystalline silicon being arranged in above the first electrode, described opening and open circumferential, the 3rd metal level of reservation form the second doping semiconductor layer, the second electrode lay.

Optionally, described manufacture method also comprises:

Described multiple pixel cell is made to be array-like arrangement;

When forming grid, synchronous formation many grid leads arranged in the row direction, described in every bar, one end of grid lead is electrically connected with external drive circuit, and often the grid of row pixel cell is electrically connected with a grid lead of going together;

When formation the first electrode layer, the first lead-in wire that synchronous formation many arranges along column direction, described in every bar, one end of the first lead-in wire is electrically connected with external drive circuit, and one first of the first electrode layer in the first conductive structure of every row pixel cell and same column goes between and is electrically connected;

When forming the second electrode lay, synchronous formation many is along the second lead-in wire of column direction arrangement, and described in every bar, one end of the second lead-in wire is electrically connected with external drive circuit, and often the second electrode lay of row pixel cell goes between with second of same column and is electrically connected.

Optionally, described manufacture method also comprises:

At the array external that described pixel cell forms, form grid via hole, the first via hole, second via hole of turn-on grid electrode lead-in wire, the first lead-in wire, the second lead-in wire respectively.

Optionally, form conductive layer at described grid via hole, the first via hole, the second via hole, grid lead, the first lead-in wire, the second lead-in wire to be electrically connected with external drive circuit.

Optionally, described manufacture method also comprises: above described multiple pixel cell, form protective layer.

Compared with prior art, technical scheme of the present invention has the following advantages:

Photoelectric sensor of the present invention comprises the pixel cell be positioned on described substrate, pixel cell is made up of photodiode and thin-film transistor, substrate has the grid being positioned at substrate first area, be positioned at the raceway groove of the intrinsic semiconductor layer above substrate first area as thin-film transistor, be positioned at the light absorbing zone of the intrinsic semiconductor layer on substrate second area as the photodiode of transverse direction, be positioned at the first conductive structure in the intrinsic semiconductor layer of substrate first area, source configuration, drain electrode structure that the second conductive structure is used separately as described thin-film transistor.

First conductive structure, second conductive structure and intrinsic semiconductor layer are coated with dielectric layer, there is the opening running through described dielectric layer being arranged in the described dielectric layer on second area substrate, described opening exposes described intrinsic semiconductor layer, described opening comprises the second doping semiconductor layer formed successively, 3rd conductive structure of the second electrode lay, described 3rd conductive structure is used as the anode construction of photodiode, and described second conductive structure is also used as the cathode construction of horizontal photodiode, described the second electrode lay connects negative potential, when light injects the intrinsic semiconductor layer between the second conductive structure and described opening, horizontal photodiode is opened, accumulate in first doping semiconductor layer of negative electrical charge constantly in the second conductive structure, hole is constantly accumulated in the second doping semiconductor layer of the 3rd conductive structure, because the second conductive structure is also used as the drain electrode structure of thin-film transistor, when thin-film transistor is opened, the source configuration of thin-film transistor is communicated with drain electrode structure, the electric charge accumulated in second conductive structure enters source configuration by raceway groove, and then exported by source configuration, the quantity of electric charge accumulated in first doping semiconductor layer that can affect in the second conductive structure because intensity of illumination is different, thus when affecting thin-film transistor unlatching, the output current of the source configuration of thin-film transistor, therefore photoelectric sensor of the present invention can be used for fingerprint recognition, when finger is placed on the upper surface of photoelectric sensor of the present invention, be irradiated to finger surface from the light of substrate direction injection and form reflection.The light of reflection is absorbed by photodiode and converts the signal of telecommunication to.Uneven due to fingerprint, the signal of protruding position reflection is strong, and the signal of the regional reflex of depression is weak, thus the signal strength signal intensity that optical pickocff is exported is different.The vertical stratification of photodiode in device is surveyed relative to prior art amorphous silicon flat panel, photodiode in photoelectric sensor of the present invention adopts transversary, the cathode construction of horizontal photodiode, anode construction lays respectively at the diverse location in intrinsic semiconductor layer, cathode construction, intrinsic semiconductor layer between anode construction serves as light absorbing zone, make the thickness of horizontal photodiode less, under the incident light of same angle, the light path of incident light in pixel cell is shorter, make the binding character of pixel cell to light high, be not easy between adjacent pixel cell to produce interference.And the upper surface of the light absorbing zone of intrinsic semiconductor layer directly can be subject to the irradiation of light, is of value to the charge accumulation of horizontal photodiode.In addition, second conductive structure is used as the drain electrode structure of described thin-film transistor, also be used as the cathode construction of horizontal photodiode, namely horizontal photodiode directly stored charge on the drain electrode structure of thin-film transistor, and along with thin-film transistor is opened, signal is exported, which save the area shared by pixel cell, what pixel cell can be made is less, and then the finger region of more small size is independently identified, improve the resolution of photoelectric sensor.

In addition, in photoelectric sensor of the present invention pixel cell manufacture method in, while formation thin-film transistor, also form negative electrode and the light absorbing zone of horizontal photoelectric sensor, the manufacture method of hinge structure thin-film transistor has only had more the steps such as the second doping semiconductor layer of being formed and being used as horizontal photodiode anode and the second electrode lay, compared with the Amorphous silicon flat-panel detectors of prior art, without the need to carrying out the step forming independently photodiode again after formation thin-film transistor, effectively reduce production cost.

Further, photoelectric sensor of the present invention can comprise: be formed at the 4th conductive structure on dielectric layer corresponding to first area, described 4th conductive structure and described second conductive structure for forming storage capacitance, to improve the ability of the second conductive structure stored charge.Photoelectric sensor of the present invention can comprise: the light shield layer being positioned at second area substrate surface, for blocking light incident below substrate, avoids the interference to light absorbing zone.

Further, photoelectric sensor of the present invention can comprise: be arranged at the backlight below substrate, the light that described backlight sends is projected to above pixel cell by a logical photo structure, and described photodiode is pointed the light of reflection, to carry out fingerprint recognition for detecting described light.Adopt backlight as light source, make above photoelectric sensor without the need to adding lens, make photoelectric sensor entirety more frivolous, and enter the light of photoelectric sensor substantially linearly, the area ratio of the body surface that the area of each pixel cell and pixel cell detect is 1:1, light uniformity is better, and external environmental light can be avoided better on the impact of photoelectric sensor.

Further, the pixel cell of photoelectric sensor of the present invention can be back-shaped structure: the 3rd conductive structure in described opening is closed rectangle, bottom the 3rd conductive structure in said opening, there is the 3rd light hole, described 3rd light hole exposes logical photo structure, described electromigration layer and the first electrode layer surround closed frame-type centered by described opening, make the second conductive structure, the 3rd conductive structure is back-shaped structure.Only can be incident from the central area of back-shaped structure from the light of substrate direction incidence, the light of other position can by the first electrode layer, the second electrode lay stops and can not be irradiated on body surface and horizontal photoelectric diode, due to the first light hole, second light hole, 3rd light hole is positioned at the center of back-shaped structure, relative to other structures, incident ray through back-shaped structure is more concentrated, when pixel cell area occupied is constant, the angle of incident ray is less, incident ray is when the surface reflection of object, its reflection angle is subject to the constraint of thickness and incidence angle, can only reflex in its corresponding pixel, be not easy to scatter to other pixels, thus improve the precision of photoelectric sensor.

Accompanying drawing explanation

Fig. 1 is the cutaway view of a kind of Amorphous silicon flat-panel detectors pixel cell of prior art;

Fig. 2 is the cutaway view of photoelectric sensor pixel cell one embodiment of the present invention;

Fig. 3 is the circuit diagram of photoelectric sensor one embodiment of the present invention;

Fig. 4 is the cutaway view of photoelectric sensor one embodiment outside lead of the present invention;

Fig. 5 is the vertical view of the embodiment of a kind of back-shaped structure of photoelectric sensor pixel cell of the present invention;

Fig. 6 is the cutaway view along AA` line in Fig. 5;

Fig. 7 is the vertical view of the embodiment of a kind of pectinate texture of photoelectric sensor pixel cell of the present invention;

Fig. 8 to Figure 16 is the cutaway view of pixel cell in each step of manufacture method one embodiment of photoelectric sensor of the present invention;

Figure 17 is the vertical view of the embodiment of a kind of back-shaped structure of manufacture method pixel cell of photoelectric sensor of the present invention;

Figure 18 is the cutaway view along BB` line in Figure 17;

Figure 19 is the vertical view of the embodiment of a kind of pectinate texture of manufacture method pixel cell of photoelectric sensor of the present invention.

Embodiment

The general volume of existing optical pickocff is comparatively large, and resolution is lower, is difficult to the fingerprint recognition field of portable set.

In order to solve the problems of the technologies described above, the invention provides a kind of photoelectric sensor and manufacture method thereof, described photoelectric sensor production cost is lower, and resolution is higher, thus can be applied to fingerprint recognition better.

First the present invention provides a kind of photoelectric sensor, and described photoelectric sensor comprises substrate and is positioned at the pixel cell on described substrate.

Elaborate below in conjunction with the technical scheme of accompanying drawing to photoelectric sensor of the present invention.

In the present embodiment, described photoelectric sensor is integrated on the array base palte of LCD, that is, described photoelectric sensor is identical with the part manufacture craft of the array base palte of LCD, the photoelectric sensor and LCD that are used for fingerprint recognition can be integrated like this, be of value to and reduce the volume that mobile phone etc. uses the portable set of photoelectric sensor, but the present invention not limit this, in other embodiments, described photoelectric sensor can also be independent making.

With reference to figure 2, show the cross-sectional schematic of photoelectric sensor one embodiment pixel cell of the present invention.Photoelectric sensor of the present invention comprises:

Substrate 100, the material of described substrate 100 is light transmissive material, in the present embodiment, identical with LCD array base palte, and described substrate 100 is glass substrate.But the present invention does not limit this, in other embodiments, described substrate 100 can also be made for its light transmissive materials such as light-passing plastics.

In the present embodiment, the incident ray of photoelectric sensor is injected and penetrates above photoelectric sensor below substrate 100, on the photosensor side object 110 surface occur reflection and reflected light electric transducer in, so substrate need adopt light transmissive material make to ensure that light can pass through.

Wherein substrate 100 comprises multiple first area for the formation of thin-film transistor, the second area for the formation of photodiode.

Photoelectric sensor comprises the multiple pixel cells be formed on described substrate, and each pixel cell includes thin-film transistor and horizontal photodiode, and particularly, each pixel cell comprises:

Be positioned at the grid 101A on first area substrate 100 surface, be positioned at the light shield layer 101B on second area substrate 100 surface, the edge of described light shield layer 101B has the first light hole 201 exposing described substrate.

In the present embodiment, wherein grid 101A and light shield layer 101B is for etching same rete and being formed, so the material of grid 101A and light shield layer 101B, thickness are all identical.Described grid 101A and light shield layer 101B is metal, optionally, identical with existing LCD array technique, that the material of described grid and light shield layer 101B can be the metals such as molybdenum, aluminium, niobium or wherein several alloys, the grid 101A in such photoelectric sensor and light shield layer 101B can make with the thin-film transistor gate in LCD array base palte simultaneously.

The effect of described grid 101A is the grid for thin-film transistor in photoelectric sensor of the present invention, the effect of light shield layer 101B blocks light incident below substrate to enter photodiode, there is the first light hole 201 exposing described substrate 100 in light shield layer 101B, make light can enter pixel cell by the first light hole 201.

It should be noted that, in the present embodiment, the incident ray of photoelectric sensor is injected and penetrates above photoelectric sensor below substrate 100, therefore light shield layer 101B is needed to block light incident below substrate, in other embodiments, the incident ray of photoelectric sensor can also be incident above pixel cell, under such circumstances, also can not arrange light shield layer 101B.

It should be noted that, in order to ensure that, in the occlusion effect of light shield layer 101B to light below substrate 100, as shown in Figure 2, light shield layer 101B can slightly above the second area of substrate 100.

It should be noted that, in the present embodiment, the multiple pixel cells be positioned on substrate 100 are array arrangement, as shown in Figure 2, first light hole 201 is positioned at the substrate frontside edge of second area, in fact the first light hole 201 is between the light shield layer 101B of the pixel cell shown in Fig. 2 and the grid of adjacent pixel unit or light shield layer, but the present invention does not limit the particular location of the first light hole 201 in light shield layer 101B, and the first light hole 201 can also be positioned at the zone line of light shield layer 101B.

Aperture due to the first light hole 201 can affect the maximum incident angle degree of incident ray, and optionally, the aperture of described first light hole 201 is in the scope of 0 to 10 microns.

Be covered in described first light hole 201 and first insulating barrier on the surface of grid 101A and light shield layer 101B.Described first insulating barrier is for making other structure electric insulations above grid 101A, light shield layer 101B and the first insulating barrier 102.

In the present embodiment, the material of described first insulating barrier 102 is silicon nitride, silicon nitride is the material usually adopted with gate insulator in the thin-film transistor in LCD array base palte, the first insulating barrier 102 in photoelectric sensor of the present invention and gate insulator in the thin-film transistor in LCD array base palte can synchronously be formed, in other embodiments, the material of described first insulating barrier 102 can also be silica or spin-on material.It should be noted that, because the first light hole 201 has the effect of logical light, and the first light hole 201 is filled by the first insulating barrier, and for ensureing the logical light of the first light hole 201, the material of the first insulating barrier 102 is required to be light transmissive material.

Be positioned at the intrinsic semiconductor layer 103 on described first insulating barrier 102 surface, described intrinsic semiconductor layer 103 edge has the second light hole 202 be positioned at directly over described first light hole 201.

Described first light hole 201 and the second light hole 202 form logical photo structure, the light sent below substrate is projected to above pixel cell by logical photo structure, described light can be detected to make described photodiode and be pointed the light of reflection, to carry out fingerprint recognition.

In other embodiments, when the incident ray of photoelectric sensor is incident above pixel cell, described logical photo structure can not be set.

In pixel cell of the present invention, part intrinsic semiconductor layer 103 is used as the raceway groove of thin-film transistor, and part intrinsic semiconductor layer 103 is used as the light absorbing zone of horizontal photodiode.

In the present embodiment, the material of described intrinsic semiconductor layer 103 is intrinsic amorphous silicon, identical with the material of the channel layer of the thin-film transistor in LCD array base palte, the intrinsic semiconductor layer 103 in photoelectric sensor of the present invention and channel layer in the thin-film transistor in LCD array base palte can synchronously be formed.Intrinsic amorphous silicon is a kind of semi-conducting material being usually used in depositing on a glass substrate, but the material of the present invention to intrinsic semiconductor layer 103 does not limit.

Because intrinsic semiconductor layer 103 also will as the light absorbing zone of the photodiode of transverse direction, so in the present embodiment, intrinsic semiconductor layer 103 edge has the second light hole 202 be positioned at directly over described first light hole 201, pass through to make light incident below substrate 100, second light hole 202 is positioned at intrinsic semiconductor layer 103 edge, namely between the intrinsic semiconductor layer 103 and the intrinsic semiconductor layer 103 of adjacent pixel unit of the pixel cell shown in Fig. 2, but the present invention does not limit at the particular location of intrinsic semiconductor layer 103 the second light hole 202, for ensureing that the second light hole 202 is positioned at above the first light hole 201, in other embodiments, described second light hole 202 can also be positioned at the zone line of intrinsic semiconductor layer 103.Optionally, the second light hole 202 is identical with the aperture of the first light hole 201, in the scope of 0 to 10 microns.

Be positioned at the first discrete conductive structure 301 on described intrinsic semiconductor layer 103 surface on first area substrate 100, second conductive structure 302, compared with described first conductive structure 301, described second conductive structure 302 is closer to the second area of described substrate 100, described first conductive structure 301 comprises and is positioned at the first doping semiconductor layer 104A in intrinsic semiconductor layer 103 and the first electrode layer 105A, described second conductive structure 302 comprises and is positioned at the first doping semiconductor layer 104B in intrinsic semiconductor layer and the first electrode layer 105B, first conductive structure 301, second conductive structure 302 is synchronous formation.Described first conductive structure 301 is used as the source configuration of described thin-film transistor, and described second conductive structure 302 is used as the drain electrode structure of described thin-film transistor.

It should be noted that, have spacing between the first conductive structure 301, second conductive structure 302 in the present embodiment, the intrinsic semiconductor layer 103 between the first conductive structure 301, second conductive structure 302 is as the raceway groove of thin-film transistor.

It should be noted that, identical with the source class structure of the thin-film transistor in LCD array base palte, drain electrode structure, the material of the first electrode layer 105A, the first electrode layer 105B is metal, optionally, identical with existing LCD array technique, described, the material of the first electrode layer 105A, the first electrode layer 105B can be metal or wherein several alloys such as molybdenum, aluminium, niobium, and the first electrode layer 105A in such photoelectric sensor, the first electrode layer 105B can make with the thin-film transistor source-drain electrode in LCD array base palte simultaneously.The effect of the first electrode layer 105A in the first conductive structure 301 and the first electrode layer 105 in the second conductive structure 302 is used separately as the leakage level structure of thin-film transistor, the electrode of source configuration, for inputing or outputing voltage.The material of described first doping semiconductor layer 104 is N-type amorphous silicon, and the effect of the first doping semiconductor layer 104 is contact performances of raising first electrode layer 105A, the first electrode layer 105B and intrinsic semiconductor layer 103.Intrinsic semiconductor layer 103 between such first conductive structure 301, second conductive structure 302, first conductive structure 301 and the second conductive structure 302 and grid 101A constitute the primary structure of pixel cell thin-film transistor of the present invention.

Be covered in the dielectric layer 106 in described first conductive structure 301, second conductive structure 302 and intrinsic semiconductor layer 103, have the opening 203 running through described dielectric layer being arranged in the described dielectric layer 106 on second area substrate 100, described opening 203 exposes described intrinsic semiconductor layer 103.In the present embodiment, relative to the first light hole 201, second light hole 202, described opening 203 is closer to described second conductive structure 302.

Particularly, in the present embodiment, the material of described dielectric layer 106 is silicon nitride, silicon nitride is the material usually adopted with source and drain insulating barrier in the thin-film transistor in LCD array base palte, the first insulating barrier 102 in photoelectric sensor of the present invention and source and drain insulating barrier in the thin-film transistor in LCD array base palte can synchronously be formed, in other embodiments, the material of described dielectric layer 106 can also be silica or spin-on material.

It should be noted that, because the second light hole 202 has the effect of logical light, and in the present embodiment, dielectric layer 106 is while covering intrinsic semiconductor layer 103, filled by second light hole 202, for ensureing the logical light of the second light hole 202, the material of dielectric layer 106 is required to be light transmissive material.

Be arranged in the second doping semiconductor layer 107A, the second electrode lay 108A on dielectric layer 106 surface on first area substrate 100 and the second doping semiconductor layer 107B, the second electrode lay 108B that are formed successively of described opening 203, described the second electrode lay 108 exposes described second light hole 202, and described the second electrode lay 108A is electrically connected with the second electrode lay 108B in described opening 203.Described second doping semiconductor layer 107A, the second doping semiconductor layer 107B are synchronous formation, and described the second electrode lay 108A and the second electrode lay 108B is synchronous formation.

Due to the restriction of exposure technology in actual fabrication, the the second doping semiconductor layer 107B, the second electrode lay 108B that are formed successively in described opening 203 can extend to the edge of described opening 203 upper end, but the length of extending is very little, lead-in wire can be set between the second electrode lay 108B at the edge of described opening 203 upper end and the second electrode lay 108A on dielectric layer 106 surface on first area substrate 100, be electrically connected to make the second electrode lay 108A and the second electrode lay 108B.

In the present embodiment, pixel cell also comprises: the second insulating barrier 109 being covered in described dielectric layer 106, the second electrode lay 108A and the second electrode lay 108B surface, the material of described second insulating barrier 109 is light transmissive material, particularly, the material of described second insulating barrier 109 can be silicon nitride, silica or spin-on material.The effect of described second insulating barrier 109 is primary structures of protection photodiode and thin-film transistor, and makes photodiode and thin-film transistor and other structural insulations.

In the present embodiment, pixel cell also comprises: the contact electrode (not shown) being arranged in the second electrode lay 108B surface of described opening 203, the material of described contact electrode is tin indium oxide or zinc oxide, the benefit arranging contact electrode is, the reliability of the second electrode lay 108B can be strengthened, the corrosion resistance of the oxidation such as tin indium oxide or zinc oxide electric conducting material is stronger, described the second electrode lay 108 upper surface covers by contact electrode, the second electrode lay 108B can be made to be not easy oxidation and to affect performance, but the present invention does not limit whether arranging contact electrode.

In the present embodiment, the material of described second doping semiconductor layer 107A, the second doping semiconductor layer 107B is P-type non-crystalline silicon.The material of described the second electrode lay 108A, the second electrode lay 108B is metal material, and optionally, metal material can be metal or wherein several alloys such as molybdenum, aluminium, niobium.

Described the second doping semiconductor layer 107B, the second electrode lay 108B that are formed successively being arranged in opening 203 forms the 3rd conductive structure 303,3rd conductive structure 303 is used as the anode construction of photodiode in photoelectric sensor pixel cell of the present invention, wherein, in 3rd conductive structure 303, the second doping semiconductor layer 107B of P-type non-crystalline silicon contacts with intrinsic semiconductor layer 103, for the anode of photodiode, the second electrode lay 108B in 3rd conductive structure 303 accesses signal voltage, for anode provides fixing negative potential by lead-in wire.

Described second conductive structure 302, except being used as the drain electrode structure of thin-film transistor, is also used as the cathode construction of horizontal photodiode; Intrinsic semiconductor 103 between described 3rd conductive structure 303 and described second conductive structure 302 is used as the light absorbing zone of photodiode.The cathode construction of such photodiode, anode construction, light absorbing zone constitute the photodiode of a transverse direction.The second electrode lay 108 in described 3rd conductive structure 303 connects fixing negative potential.

The the second doping semiconductor layer 107A and the second electrode lay 108A that are positioned at dielectric layer 106 surface on first area substrate 100 form the 4th conductive structure 304, described 4th conductive structure 304 can play interception, prevent the light above other pixel cells from entering this pixel cell and bringing interference, and prevent the light above his pixel cell to be irradiated to intrinsic semiconductor layer 103 between the first conductive structure 301, second conductive structure 302, the i.e. raceway groove of thin-film transistor.In the present embodiment, the second electrode lay 108A being arranged in the 4th conductive structure 304 is electrically connected with the second electrode lay 108B of described 3rd conductive structure 303, the current potential being arranged in the second electrode lay 108A of the 4th conductive structure 304 is like this identical with the current potential of the second electrode lay 108B of described 3rd conductive structure 303, be fixing negative potential, such 4th conductive structure 304 and the second conductive structure 302 form storage capacitance, are conducive to the maintenance of the negative electrical charge of the accumulation of horizontal photodiode cathode.In addition, in the present embodiment, light shield layer 101B also accesses external voltage, and the external voltage of light shield layer 101B is in the scope of 0V to-10V, thus form another storage capacitance with the second conductive structure 302, improve the maintenance effect of the stored charge of horizontal photodiode cathode further.In other embodiments, light shield layer 101B can also be connected with grid, namely the external voltage of light shield layer 101B is identical with grid, also the effect forming storage capacitance with the second conductive structure 302 can be played, and light shield layer 101B is also connected with grid and can makes to be blocked completely below intrinsic semiconductor layer 103, at utmost avoids the light below substrate to enter intrinsic semiconductor layer 103.

It should be noted that, in other embodiments, can not also arrange the 4th conductive structure 304, but arrange other and can form the structure of storage capacitance by the second conductive structure 302, the present invention is not restricted this.

It should be noted that, signal for simplicity in Fig. 2, the adjoining dimensions of the second conductive structure 302 and the first conductive structure 301, in fact because the second conductive structure 302 is also used as the negative electrode of photodiode, storage capacitance is formed to store negative electrical charge with the second electrode lay 108, light shield layer 101B, for making storage capacitance larger to improve magnitude of the stored charge, optionally, the area of the second conductive structure 302 is greater than the area of the first conductive structure 301.

With reference to figure 2, the operation principle of the pixel cell of photoelectric sensor of the present invention is as follows: the second electrode lay 108 in described 3rd conductive structure 303 accesses fixing negative voltage, the first electrode layer 105 in described first conductive structure 301 accesses positive voltage or no-voltage, when the grid 101A access of thin-film transistor is greater than the scanning voltage of threshold voltage, thin-film transistor is opened, the transferring charge of the second electrode lay 105A in the first conductive structure 301 is in the second electrode lay 105B in the second conductive structure 302, described basic voltage is greater than described signal voltage, negative bias is loaded with like this in the photodiode of transverse direction.From the light (as shown in phantom in Figure 2) below substrate by the first light hole 201, second light hole 202 to the second insulating barrier 109 upper surface, object 110 (such as pointing) surface above pixel cell is reflected, the light of reflection is injected in the intrinsic semiconductor 103 between described opening 203 and described second conductive structure 302, accumulate in the first doping semiconductor layer 104B of negative electrical charge constantly in the second conductive structure 302, accumulate in the second doping semiconductor layer 107B of hole constantly in described opening 203.

Because the second conductive structure 302 is also used as the drain electrode structure of thin-film transistor, when thin-film transistor is opened (grid 101A accesses scanning voltage), the source configuration (the first conductive structure 301) of thin-film transistor is communicated with drain electrode structure (the second conductive structure 302), in second conductive structure 302, the negative electrical charge of accumulation enters the first conductive structure 301 by raceway groove, and then exported by the first conductive structure 301, due to the quantity of electric charge accumulated in the first doping semiconductor layer 104B that light intensity can affect in the second conductive structure 302, thus affect the output current of the source configuration of thin-film transistor when thin-film transistor is opened, when thin-film transistor is opened, the electric charge of drain electrode structure accumulation empties, the basic voltage of the first electrode layer 105A in the first conductive structure 301 is transferred to the second electrode lay 105B in the second conductive structure 302 simultaneously, the second electrode lay 105B in the second conductive structure 302 is made to recover zero potential or positive potential, when thin-film transistor cuts out, negative electrical charge is accumulated in continuous the first doping semiconductor layer 104B in the second conductive structure 302 again.The light intensity that transverse diode receives can be reflected by the output current of the source configuration of thin-film transistor, so namely, complete the conversion of light signal to the signal of telecommunication, and exported by thin-film transistor, and the rough surface of finger print is different to the reflected intensity of light, make the light intensity of horizontal photodiode detection different, correspondingly, the signal of telecommunication that thin-film transistor exports is also different, and then realizes fingerprint recognition.

It should be noted that, intrinsic semiconductor layer 102 between described opening 203 and the second conductive structure 302 is blocked by described light shield layer 101B completely, intrinsic semiconductor layer 102 below opening 203 is also blocked completely, to ensure that the light injected below substrate can not enter intrinsic semiconductor layer 103.Due in the present embodiment, do not arrange other retes that can shut out the light below intrinsic semiconductor layer 102 except light shield layer 101B, therefore, light shield layer 101B needs to block below intrinsic semiconductor layer 103 completely, to improve detection accuracy as far as possible.In other embodiments, other light-shielding structure can also be set, to strengthen shaded effect further below light shield layer 101B or between light shield layer 101B and intrinsic semiconductor layer 103.Photoelectric sensor of the present invention comprises multiple above-mentioned pixel cell, and described multiple pixel cell is array-like arrangement.

Photoelectric sensor of the present invention also comprises: be positioned at the protective layer (not shown) above described multiple pixel cell, and described protective layer is that light transmissive material is made.The benefit arranging protective layer is, can reduce the damage of outer bound pair photodiode.

The present embodiment photoelectric sensor also comprises and is arranged at backlight (not shown) below substrate, and the light that described backlight sends is projected to above pixel cell by the logical photo structure in pixel cell.Namely the present embodiment photoelectric sensor has the light source carried, and light source is positioned at the below of photoelectric sensor.The light source that prior art major part is used for the transducer of fingerprint recognition comes above sensor, for ensureing that the light that light source sends can enter in the pixel cell under finger covering, lens or prism is typically provided with above pixel cell, but the thickness of lens or prism is larger, and lens can make incident ray bend, the area of the body surface that area and the pixel cell of each pixel cell detect is different, and the light uniformity entering transducer is poor, is also easily subject to the impact of external surround lighting.And light source is positioned at the below of photoelectric sensor in the present embodiment, side is without the need to lens so on the photosensor, make photoelectric sensor entirety more frivolous, and enter the light of photoelectric sensor substantially linearly, the area ratio of the body surface that the area of each pixel cell and pixel cell detect is 1:1, light uniformity is better, and external environmental light can be avoided better on the impact of photoelectric sensor.

It should be noted that, for same substrate simultaneously for the formation of the embodiment of photoelectric sensor and LCD, because current LCD adopts transmissive display substantially, backlight is provided with below array base palte, backlight generally adopts LED formula or cold-cathode fluorescent tubular type, and therefore optical pickocff of the present invention also can adopt the backlight of backlight as photoelectric sensor of LCD.Thus improve the integrated level of photoelectric sensor of the present invention.

To sum up, photoelectric sensor of the present invention can be used for fingerprint recognition, when finger is placed on the upper surface of photoelectric sensor of the present invention, is irradiated to finger surface forms reflection from the light of substrate 100 direction injection.The light of reflection is absorbed by the photodiode of transverse direction and converts the signal of telecommunication to.Uneven due to fingerprint, the signal of protruding position reflection is strong, and the signal of the regional reflex of depression is weak, thus the signal strength signal intensity that optical pickocff is exported is different.

The vertical stratification of photodiode in device is surveyed relative to prior art amorphous silicon flat panel, photodiode in photoelectric sensor of the present invention adopts transversary, the cathode construction of horizontal photodiode, anode construction lays respectively at the diverse location in intrinsic semiconductor layer, cathode construction, intrinsic semiconductor layer between anode construction serves as light absorbing zone, make the thickness of horizontal photodiode less, and the vertical stratification of the photodiode in existing Amorphous silicon flat-panel detectors is arranged in the top of thin-film transistor source-drain electrode place rete, and in the photodiode of the transverse direction of photoelectric sensor of the present invention, anode construction due to described horizontal photodiode is arranged in described opening 203, all be positioned in intrinsic semiconductor layer 103 with cathode construction, so the anode construction of described horizontal photodiode and cathode construction adopt horizontally set, only be equivalent to above the source-drain electrode of thin-film transistor, superposed the second doping semiconductor layer 107, the thickness of the second electrode lay 108 and dielectric layer 106, this thickness of three layers is about 200 nanometers, be far smaller than the height (about 1 micron) of the vertical stratification of the photodiode in flat panel detector, make the thickness of horizontal photodiode less, under the incident light of same angle, the light path of incident light in pixel cell is shorter, make the binding character of pixel cell to light high, be not easy between adjacent pixel cell to produce interference, be of value to the resolution improving photoelectric sensor.And the upper surface of the light absorbing zone of intrinsic semiconductor layer directly can be subject to the irradiation of light, is of value to the charge accumulation of horizontal photodiode.

In addition, second conductive structure 302 is used as the drain electrode structure of described thin-film transistor, also be used as the cathode construction of horizontal photodiode, namely horizontal photodiode directly stored charge on the drain electrode structure of thin-film transistor, and along with thin-film transistor is opened, signal is exported, in the present embodiment, the interval S at close opening 203 edge of described opening 203 bottom margin and the second conductive structure 302 is in the scope of 1 to 5 microns, relative to prior art thin-film transistor and the mutual independently structure of photodiode, thin-film transistor of the present invention is nearer with horizontal photodiode distance, which save the area shared by pixel cell, what pixel cell can be made is less, and then the finger areas of more small size is independently identified, improve the resolution of photoelectric sensor.

Further, the photodiode of photoelectric sensor of the present invention is transversary, the lug boss that height and the width as longitudinal diode are larger can not be formed, make photoelectric sensor pixel cell of the present invention comparatively smooth, therefore the thickness of dielectric layer 106 can be thinner, further increase the anti-interference between pixel cell, and the storage capacitance that the thickness reduction of dielectric layer 106 can make the 4th conductive structure 304 above substrate 100 first area and the second conductive structure 302 form increases, the magnitude of the stored charge of the first doping semiconductor layer 105B in the second conductive structure 302 can be improved.

It should be noted that, photoelectric sensor of the present invention also comprises a plurality of leads, for the electrical connection by multiple pixel cell, with reference to figure 3, shows the circuit diagram of photoelectric sensor pixel unit array of the present invention.

Described a plurality of leads comprises:

Many the grid leads arranged in the row direction 401, described in every bar, one end of grid lead 401 is electrically connected with external drive circuit, often the grid 101A of the thin-film transistor 001 of row pixel cell is electrically connected with a grid lead 401 of going together, for grid 101A provides scanning voltage, described scanning voltage is in-10 scopes to 15V.It should be noted that, the scanning voltage that many grid leads 401 provide is progressive scan mode, and namely from the first row, often the grid of row pixel cell enters sweep time successively.In order to ensure that the quantity of electric charge of the accumulation of each pixel cell is only by the impact of light intensity, often the scanning voltage of row pixel cell is all identical with sweep time.

Many the first lead-in wires 402 along column direction arrangement, described in every bar, one end of the first lead-in wire 402 is electrically connected with external drive circuit, often the source electrode (the first electrode layer 105 in the first conductive structure 301) of the thin-film transistor 001 of row pixel cell goes between with first of same column and is electrically connected, for the first electrode layer 105 in described first conductive structure 301 provides basic voltage, described basic voltage is in 0 scope to 3V.In the present embodiment, described basic voltage is fixed value.

Many the second lead-in wires 403 along column direction arrangement, described in every bar, one end of the second lead-in wire 403 is electrically connected with external drive circuit, often horizontal in the row pixel cell anode electrode (the second electrode lay 108B of the 3rd conductive structure 303) of photodiode 002 and an article second of same column go between and 402 to be electrically connected, for described the second electrode lay 108B provides signal voltage, described signal voltage is in 0 scope to-10V.In the present embodiment, described signal voltage is fixed value.Because in the array that whole pixel cell forms, the signal voltage of the second electrode lay 108B is all identical, therefore many second lead-in wires 403 can be gathered outside pel array is a lead-in wire also input voltage.It should be noted that, due to all pixel cells signal voltage all in 0 scope to-10V and the value of signal voltage immobilize, so can by second of each row lead-in wire 403 accumulate outside pixel unit array one lead-in wire and be connected with external power supply.

It should be noted that, due in the present embodiment, the second electrode lay 108A also forms contact electrode, therefore contact electrode can be adopted to be electrically connected by the second electrode lay 108B of all pixel cells, thus only need the second lead-in wire 403 to be electrically connected with the contact electrode in any position in photoelectric sensor, just can provide signal voltage to the second electrode lay 108B of all pixel cells.

Many articles of the 3rd lead-in wire (not shown) along column direction arrangement, described in every article, one end of the 3rd lead-in wire is electrically connected with external drive circuit, or go between 402 to be electrically connected with second, often the described light shield layer 101B of row pixel cell photodiode 002 goes between with an article the 3rd of same column and is electrically connected, for light shield layer 101B provides external voltage, to make light shield layer 101B and to be formed another storage capacitance with the second conductive structure 302.Described external voltage is in 0 scope to-10V, and in the present embodiment, described external voltage is fixed value.It should be noted that, in other embodiments, described 3rd lead-in wire can not also be set, but light shield layer 101B is electrically connected with grid 101A, for light shield layer 101B provides scanning voltage, also can make light shield layer 101B and form another storage capacitance with the second conductive structure 302.

Fig. 4 shows the cutaway view schematic diagram of grid lead 401, first lead-in wire 402, second lead-in wire 403 at the array external of described pixel cell.

With reference to figure 4, in photoelectric sensor of the present invention, at the array external of pixel cell composition, be respectively equipped with grid via hole 501, first via hole 502, second via hole 503 of turn-on grid electrode lead-in wire 401, first lead-in wire 402, second lead-in wire 403.

In the present embodiment, be coated with grid conducting layer 601, first conductive layer 602, second conductive layer 603 respectively in described grid via hole 501, first via hole 502, second via hole 503, be electrically connected with external drive circuit with the 402, second lead-in wire 403 that grid lead 401, first is gone between.Particularly, in the present embodiment, the material of described grid conducting layer 601, first conductive layer 602, second conductive layer 603 is tin indium oxide.The terminal of extraneous drive circuit can cohere at grid conducting layer 601, first conductive layer 602, second conductive layer 603, for grid lead 401, first lead-in wire 402, second lead-in wire 403 provides voltage.The benefit arranging grid conducting layer 601, first conductive layer 602, second conductive layer 603 of tin indium oxide is, the non-oxidizability of tin indium oxide is strong, under the covering of tin indium oxide, oxidation is less likely to occur grid lead 401, first lead-in wire 402, second lead-in wire 403, thus improves the reliability of grid lead 401, first lead-in wire 402, second lead-in wire 403.But the present invention does not limit whether arranging grid conducting layer 601, first conductive layer 602, second conductive layer 603, in other embodiments, can not also arrange grid conducting layer 601, first conductive layer 602, second conductive layer 603, the terminal of extraneous drive circuit directly can cohere the grid lead 401, first exposed at grid via hole 501, first via hole 502, second via hole 503 and go between on the 402, second lead-in wire 403.

It should be noted that, in other embodiments, driving chip can also be adopted and read the photodiode of chip to transverse direction and drive and read, particularly, bind driving chip on the substrate 100 and read chip, make grid lead 401, first lead-in wire 402, second lead-in wire 403 and dynamic chip and read chip electrical to connect, driving chip is connected with external power supply by flexible PCB with reading chip.The present invention does not limit the driving of the photodiode of transverse direction and playback mode.

With reference to the operation principle of above-mentioned photoelectric sensor pixel cell, the area of pixel cell is the key element determining resolution of photoelectric sensor, and the interference between adjacent pixel unit also can affect the resolution of photoelectric sensor.The resolution of photoelectric sensor can be improved by the interference reduced between pixel cell area or reduction adjacent pixel unit.

Therefore, for improving resolution further, in another embodiment, in photoelectric sensor pixel cell of the present invention, the anode construction of photodiode and cathode construction surround hollow structure, can reduce the interference between adjacent pixel unit.Below in conjunction with Fig. 5, Fig. 6, another embodiment is described.Please refer to Fig. 5, Fig. 6, Fig. 5 is the birds-eye perspective of pixel cell in another embodiment, Fig. 6 is the cutaway view of Fig. 5 along AA` line, it should be noted that, in order to the anode construction of the photodiode by transverse direction and the position relationship of cathode construction are illustrated clear, eliminate the 4th semiconductor structure 304 in Figure 5.

As shown in Figure 5, Figure 6, in the present embodiment, the first area of substrate 100 surrounds second area, and light shield layer 101B is closed rectangle, and described first light hole 201 is positioned at light shield layer 101B center.

Described opening 203 is positioned at the center of light shield layer 101B, described opening 203 is rectangle, the second doping semiconductor layer 107 in described opening 203, the second electrode lay 108 is the rectangle closed, namely the 3rd conductive structure 303 is the rectangle closed, the second doping semiconductor layer 107B in described opening 203, the second electrode lay 108B bottom centre forms the 3rd light hole 204, described 3rd light hole 204 is as a part for logical photo structure, expose the second light hole 204, described second conductive structure 302 surrounds closed frame-type centered by described opening 203, make the second conductive structure 302, 3rd conductive structure 303 is in back-shaped structure.It should be noted that, 4th conductive structure 304 (not showing in Fig. 5) is positioned at above the second conductive structure 302, closed frame-type is surrounded equally centered by described opening 203, with make the 4th conductive structure 304 and the second conductive structure 302 larger in the projection overlapping area of substrate 100 plane, the storage capacitance that 4th conductive structure 304 and the second conductive structure 302 are formed is comparatively large, improves the quantity of electric charge stored in the second doping semiconductor layer 105B in the second conductive structure 302.

It should be noted that, as shown in Figure 5, described first conductive structure 301 is only as the source configuration of thin-film transistor, therefore the first conductive structure 301 is positioned at the second conductive structure 302 side, and relative second conductive structure 302 area is less, same, described grid 101A is for being positioned at below the first conductive structure 301, second conductive structure 302, and relative second conductive structure 302 area is less.

In the present embodiment, back-shaped structure can be better to light binding effect.In back-shaped structure, the light (dotted line with arrow Fig. 6) sent from substrate 100 direction can only from the first light hole 201, second light hole 202 of the middle section of back-shaped structure, the 3rd light hole 204 incidence, and the light of other position can be blocked a layer 101B and blocks and can not be irradiated on the light absorbing zone of body surface and horizontal photoelectric diode.Because the first light hole 201, second light hole 202, the 3rd light hole 204 are positioned at the center of back-shaped structure, relative to other structures, incident ray through back-shaped structure is more concentrated, and when pixel cell area occupied is constant, the angle of incident ray is less, incident ray is when the surface reflection of object, its reflection angle is subject to the constraint of thickness and incidence angle, can only reflex in its corresponding pixel, be not easy to scatter to other pixels, thus improve the precision of photoelectric sensor.Described first light hole 201, second light hole 202, the aperture D2 of the 3rd light hole 204 is identical, in the scope of 0 to 10 microns, first light hole 201, second light hole 202, the aperture D2 of the 3rd light hole 204 is identical, can be stronger to the binding character of the light of incidence, when the first light hole 201, second light hole 202, when the aperture D2 of the 3rd light hole 204 is 10 microns, according to the difference in height D1 of the second electrode lay 108A bottom described opening 203 and substrate 100, can show that incident angle θ can not be greater than 4 degree, the thickness of usual protective layer 111 far can be thicker than the second insulating barrier 109, therefore incidence angle θ is less, incident ray is when the surface reflection of object, the angle of reflection ray is also less, reflection ray above this pixel cell is more easily constrained in this pixel cell.When photoelectric sensor of the present invention is used for fingerprint recognition, because finger surface is uneven, be easy to make light produce diffuse reflection, reduce incident angle θ, and then the angle reducing reflection ray be particularly important.In addition, as shown in Figure 6, under the condition that the incident angle θ of light is certain, because the pixel cell of photoelectric sensor of the present invention is thinner, the light path of incident ray in pixel cell is shorter, the incident ray of this pixel cell is more difficult to be injected in adjacent pixel unit, and then improves the resolution of photoelectric sensor.

In other embodiments, the anode construction of described horizontal photodiode can also in relative pectinate texture with cathode construction.With reference to figure 7, show the birds-eye perspective of a photoelectric sensor pixel cell of the present invention embodiment again, the cutaway view of Fig. 7 can reference diagram 2.It should be noted that, in order to the anode construction of the photodiode by transverse direction and the position relationship of cathode construction are illustrated clear, eliminate the second electrode lay 108A of the 4th semiconductor structure 304 in the figure 7.

Described second conductive structure 302 is in the pectination with comb part 701, the second doping semiconductor layer 107 in described opening 203, the second electrode lay 108 (i.e. the 3rd conductive structure 303) are in the pectination with comb part 702, and the comb part 701 of the comb part 702 of the 3rd conductive structure 303 and the second conductive structure 302 is oppositely arranged and is alternately arranged.4th conductive structure 304 is positioned at above the second conductive structure 302, and equally in the pectination with comb part, the anode construction of so namely horizontal photodiode is relative pectinate texture with cathode construction pipe.The anode construction of horizontal photodiode and cathode construction are that the benefit of relative pectinate texture is, the 4th conductive structure 304 and the overlapping area of the second conductive structure 302 in the projection of parallel substrate 100 surface direction can be increased, and then increase the storage capacitance that the 4th conductive structure 304 and the second conductive structure 302 formed, and then the quantity of electric charge stored in the first doping semiconductor layer 105B in raising the second conductive structure 302.

The present invention also provides a kind of manufacture method of photoelectric sensor, utilize the manufacture method of photoelectric sensor of the present invention, can produce but be not limited to the present invention propose photoelectric sensor, equally, the photoelectric sensor that the present invention proposes is not limited to use the manufacture method of photoelectric sensor provided by the invention to make and draws.

Fig. 8 to Figure 16 shows the cutaway view of each step of manufacture method one embodiment of photoelectric sensor of the present invention, elaborates to the technical scheme of the manufacture method of photoelectric sensor of the present invention below in conjunction with Fig. 8 to Figure 16.It should be noted that, the manufacture method of photoelectric sensor of the present invention roughly comprises: provide substrate, form multiple pixel cell over the substrate, wherein each pixel cell comprises thin-film transistor and photodiode, in the following description, for a pixel cell, the manufacture method of photoelectric sensor of the present invention is described.

With reference to figure 8, provide substrate 100`, described substrate 100` is light-transmissive substrates.Described substrate 100` comprises the first area for the formation of thin-film transistor, the second area for the formation of photodiode.

Particularly, in the present embodiment, the material of described substrate 100` is light transmissive material, in the present embodiment, identical with LCD array base palte, and described substrate 100` is glass substrate.But the present invention does not limit this, in other embodiments, described substrate 100` can also make for its light transmissive materials such as light-passing plastics.The incident ray of photoelectric sensor of the present invention is injected and penetrates above photoelectric sensor below substrate 100`, on the photosensor side body surface occur reflection and reflected light electric transducer in, so substrate need adopt light transmissive material make to ensure that light can pass through.

Continue with reference to figure 8, on described substrate 100, formation is positioned at the grid 101A` on substrate 100` surface, first area, is positioned at the light shield layer 101B` on second area substrate 100` surface, and exposes the first light hole 201` of described substrate 100` in light shield layer 101B`.

Particularly, first on described substrate 100`, the first metal layer (not shown) is covered.

In the present embodiment, magnetron sputtering method is adopted to be form grid, light shield layer in the effect of described substrate 100` surface deposition the first metal layer 101`, described the first metal layer 101`.Identical with existing LCD array technique, that the material of the first metal layer 101` can be the metals such as molybdenum, aluminium, niobium or wherein several alloys, the first metal layer 101` in such photoelectric sensor can deposit with the thin-film transistor gate material layer in LCD array base palte simultaneously form.

Particularly, described the first metal layer 101` forms photoresist layer (not shown), photoresist layer arranges the first mask plate, described first mask plate has the pattern of corresponding grid 101A`, light shield layer 101B`, make photoresist layer graphical, again with patterned photoresist layer for mask, the first metal layer 101` is etched to the surface of exposing described substrate 100`, forms grid 101A`, light shield layer 101B`.

In the present embodiment, wherein grid 101A` and light shield layer 101B` is for etching the first metal layer 101` and being formed, so the material of grid 101A` and light shield layer 101B`, thickness are all identical.In addition, described first mask plate can also be arranged the pattern of the thin-film transistor gate in corresponding LCD array base palte, thus the grid 101A` in photoelectric sensor and light shield layer 101B` is made with the thin-film transistor gate in LCD array base palte simultaneously.

It should be noted that, in the present embodiment, the incident ray of photoelectric sensor is injected and penetrates above photoelectric sensor below substrate 100`, therefore light shield layer 101B` is needed to block light incident below substrate, in other embodiments, the incident ray of photoelectric sensor can also be incident above pixel cell, under such circumstances, also can not form light shield layer 101B`.

The effect of described grid 101A` is the grid for thin-film transistor in photoelectric sensor of the present invention, light incident below substrate is blocked in the effect of light shield layer 101B`, form the first light hole 201` exposing described substrate 100` at light shield layer 101B` edge, make light can enter pixel cell by the first light hole 201`.

It should be noted that, in the present embodiment, the multiple pixel cells be positioned on substrate 100` are array arrangement, as shown in Figure 8, first light hole 201` is positioned at the substrate 100` edge of second area, in fact the first light hole 201` is between the light shield layer 101B` of the pixel cell shown in Fig. 2 and the grid of adjacent pixel unit or light shield layer, but the present invention does not limit the particular location of the first light hole 201` in light shield layer 101B`, and the first light hole 201` can also be positioned at the centre position of light shield layer 101B`.

The aperture of the first light hole 201` can affect the maximum incident angle degree of incident ray, and optionally, the aperture of described first light hole 201` is in the scope of 0 to 10 microns.

With reference to figure 9, in described first light hole 201` and on the surface of grid 101A` and light shield layer 101B`, cover the first insulating barrier 102`.

Particularly, in the present embodiment, using plasma strengthens chemical vapour deposition technique, in described first light hole 201`, and the deposited on silicon first insulating barrier 102` of thin-film transistor gate 101A` and light shield layer 101B`, the material of described first insulating barrier 102` is silicon nitride, silicon nitride is the material usually adopted with gate insulator in the thin-film transistor in LCD array base palte, the first insulating barrier 102` in photoelectric sensor of the present invention and gate insulator in the thin-film transistor in LCD array base palte can synchronously be formed, in other embodiments, the material of described first insulating barrier 102` can also be silica or spin-on material.It should be noted that, because the first light hole 201` has the effect of logical light, and the first light hole 201` fills by the first insulating barrier 102`, and for ensureing the logical light of the first light hole 201`, the material of the first insulating barrier 102` is required to be light transmissive material.

Continue with reference to figure 9, form intrinsic semiconductor layer 103`. on the surface at described first insulating barrier 102`

Particularly, the material of described intrinsic semiconductor layer 103` is amorphous silicon, can strengthen chemical vapour deposition technique, at described first insulating barrier 102` surface deposition intrinsic amorphous silicon by using plasma.

In pixel cell of the present invention, part intrinsic semiconductor layer 103` is used as the raceway groove of thin-film transistor, and part intrinsic semiconductor layer 103` is used as the light absorbing zone of photodiode.In the present embodiment, the material of described intrinsic semiconductor layer 103` is intrinsic amorphous silicon, identical with the material of the channel layer of the thin-film transistor in LCD array base palte, the intrinsic semiconductor layer 103` in photoelectric sensor of the present invention and channel layer in the thin-film transistor in LCD array base palte can synchronously be formed.Intrinsic amorphous silicon is a kind of semi-conducting material being usually used in depositing on a glass substrate, but the material of the present invention to intrinsic semiconductor layer 103` does not limit.Because intrinsic semiconductor layer 103` also will as the light absorbing zone of photodiode.

Please continue to refer to Fig. 9, in described half intrinsic conductor layer 103`, be formed with the second light hole 202` be positioned at directly over described first light hole 201`.Particularly, in the present embodiment, by photoetching, the intrinsic semiconductor layer 103` above described first light hole 201` is removed, to form the second light hole 202`.

The the second light hole 202` be positioned at directly over described first light hole 201` formed in intrinsic semiconductor layer, passes through for making light incident below substrate.Optionally, the second light hole 202` is identical with the aperture of the first light hole 201`, in the scope of 0 to 10 microns.

Described first light hole 201 and the second light hole 202 form logical photo structure, the light that described backlight sends is projected to above pixel cell by logical photo structure, described light can be detected to make described photodiode and be pointed the light of reflection, to carry out fingerprint recognition.

In other embodiments, when the incident ray of photoelectric sensor is incident above pixel cell, described logical photo structure can not be formed.

With reference to Figure 10, at described intrinsic semiconductor layer 103` surface deposition N-type amorphous silicon 104C`, cover the second metal level 105C` in described N-type amorphous silicon surfaces.

Particularly, using plasma strengthens chemical vapour deposition technique at described semiconductor layer surface deposited n-type amorphous silicon 104C`, adopt magnetron sputtering method to cover the second metal level 105C`, but the concrete grammar of the present invention to formation N-type amorphous silicon 104C`, the second metal level 105C` does not limit.

With reference to Figure 11, the described intrinsic semiconductor layer 103` surface on the substrate 100` of first area forms discrete the first conductive structure 301`, the second conductive structure 302`.

Particularly, described N-type amorphous silicon 104C`, the first metal layer 105C` form patterned photoresist layer, described N-type amorphous silicon 104C`, the second metal level 105C` are etched, remove part N-type amorphous silicon 104C`, the first metal layer 105C` to exposing intrinsic semiconductor layer 103`, the N-type amorphous silicon 104C` of reservation, the first metal layer 105C` form the first conductive structure 301`, the second conductive structure 302`.

Compared with described first conductive structure 301`, described second conductive structure 302` is closer to the second area of described substrate 100`, described first conductive structure 301` comprises and is positioned at the first doping semiconductor layer 104A` on intrinsic semiconductor layer 103` and the first electrode layer 105A`, described second conductive structure 302` comprises and is positioned at the first doping semiconductor layer 104B` in intrinsic semiconductor layer and the first electrode layer 105B`, described first doping semiconductor layer 104`A and the first doping semiconductor layer 104B` is that N-type amorphous silicon 104C` is formed, described first electrode layer 105` and the first electrode layer 105B` is that the second metal level 105C` is formed, i.e. the first conductive structure 301`, second conductive structure 302` is synchronous formation.Described first conductive structure 301` is used as the source configuration of described thin-film transistor, and described second conductive structure 302` is used as the drain electrode structure of described thin-film transistor.

It should be noted that to have spacing between the first conductive structure 301` in the present embodiment, the second conductive structure 302`, the intrinsic semiconductor layer 103` between the first conductive structure 301`, the second conductive structure 302` is as the raceway groove of thin-film transistor.

It should be noted that, identical with the source class structure of the thin-film transistor in LCD array base palte, drain electrode structure, the material of the first electrode layer 105A` and the first electrode layer 105B` is metal, optionally, identical with existing LCD array technique, described, the material of the first electrode layer 105A` and the first electrode layer 105B` can be metal or wherein several alloys such as molybdenum, aluminium, niobium, and the first electrode layer 105A` in such photoelectric sensor and the first electrode layer 105B` can make with the thin-film transistor source-drain electrode in LCD array base palte simultaneously.The first electrode layer 105A` of the first conductive structure 301`, the second conductive structure 302`, the effect of the first electrode layer 105B` are used separately as the source class structure of thin-film transistor, the electrode of drain electrode structure.The material of described first doping semiconductor layer 104A` and the first doping semiconductor layer 104B` is N-type amorphous silicon, and the effect of the first doping semiconductor layer 104A` and the first doping semiconductor layer 104B` is the contact performance of raising first electrode layer 105A`, the first electrode layer 105B` intrinsic semiconductor layer 103`.Intrinsic semiconductor layer 103` between such first conductive structure 301`, the second conductive structure 302`, the first conductive structure 301`, the second conductive structure 302` and grid 101A` constitutes the primary structure of pixel cell thin-film transistor of the present invention, substantially identical with the primary structure of the thin-film transistor in LCD array base palte.

With reference to Figure 12, blanket dielectric layer 106` on described first conductive structure 301`, the second conductive structure 302` and intrinsic semiconductor layer 103`.

Particularly, in the present embodiment, the material of described dielectric layer 106` is silicon nitride, silicon nitride is the material usually adopted with source and drain insulating barrier in the thin-film transistor in LCD array base palte, the first insulating barrier 102` in photoelectric sensor of the present invention and source and drain insulating barrier in the thin-film transistor in LCD array base palte can synchronously be formed, in other embodiments, the material of described dielectric layer 106` can also be silica or spin-on material.It should be noted that, because the second light hole 202` has the effect of logical light, and in the present embodiment, dielectric layer is while covering intrinsic semiconductor layer 103`, filled by second light hole 202`, for ensureing the logical light of the second light hole 202`, the material of dielectric layer 106` is required to be light transmissive material.

With reference to Figure 13, form the opening 203` running through described dielectric layer being arranged in the described dielectric layer 106` on second area substrate 100`, described opening 203` exposes described intrinsic semiconductor layer 103`.

Particularly, in the present embodiment, the method for photoetching is adopted to form described opening 203`.Relative to the first light hole 201`, the second light hole 202`, described opening 203` is closer to described second conductive structure 302`.

With reference to Figure 14, in described dielectric layer 106` surface and described opening 203`, cover the P-type non-crystalline silicon 107C`, the 3rd metal level 108C` that are formed successively.

Particularly, using plasma strengthens chemical vapour deposition technique and deposit P-type non-crystalline silicon 107C` in described dielectric layer 106` surface and described opening 203`, adopt magnetron sputtering method to cover the 3rd metal level 108C`, but the concrete grammar of the present invention to formation P-type non-crystalline silicon 107C`, the 3rd metal level 108A` does not limit.

With reference to Figure 15, part P-type non-crystalline silicon 107C` is removed by photoetching, 3rd metal level 108A` is to exposing dielectric layer 106` surface, the P-type non-crystalline silicon 107C` be positioned at above the first conductive structure 301` retained, 3rd metal level 108C`, form the second doping semiconductor layer 107A`, the second electrode lay 108A`, and the P-type non-crystalline silicon 107C` in described opening 203`, 3rd metal level 108C` forms the second doping semiconductor layer 107B`, the second electrode lay 108B`, the second doping semiconductor layer 107A` above first conductive structure 301`, the second electrode lay 108`A forms the 4th conductive structure 304`, P-type non-crystalline silicon 107B` in described opening 203`, the 3rd metal level 108B` form the 3rd conductive structure 303`.

It should be noted that, described the second electrode lay 108B` exposes described second light hole 202`, in the present embodiment, in the process of the second electrode lay 108B` of formation the 3rd conductive structure 303` and the second electrode lay 108A` of the 4th conductive structure 304`, between the second electrode lay 108B` and the second electrode lay 108A` of the 4th conductive structure 304` of the 3rd conductive structure 303`, form one article go between, be electrically connected with the second electrode lay 108A` of the 4th conductive structure 304` to make the second electrode lay 108B` of the 3rd conductive structure 303`.

In the present embodiment, the material of described second doping semiconductor layer 107A` and the second doping semiconductor layer 107B` is P-type non-crystalline silicon, the material of described the second electrode lay 108A` and the second electrode lay 108B` is metal, optionally, can be metal or wherein several alloys such as molybdenum, aluminium, niobium, in other embodiments, the material of described the second electrode lay 108` can also be the light transmitting electro-conductive such as tin indium oxide, zinc oxide material.

Described 3rd conductive structure 303` is used as the anode construction of photodiode horizontal in photoelectric sensor pixel cell of the present invention, wherein, second doping semiconductor layer 107B` of P-type non-crystalline silicon is the anode of horizontal photodiode, the second electrode lay 108B` is anode electrode, by access signal voltage for anode provides fixing negative potential.

Described second conductive structure 302`, except being used as the drain electrode structure of thin-film transistor, is also used as the cathode construction of horizontal photodiode; Intrinsic semiconductor 103` between described second conductive structure 302` and described 3rd conductive structure 303` is used as the light absorbing zone of photodiode.The cathode construction of such photodiode, anode construction, light absorbing zone constitute the photodiode of a transverse direction.

The second doping semiconductor layer 107` of the 4th conductive structure 304` and the second electrode lay 108` plays interception, prevent the light above other pixel cells from entering this pixel cell and bringing interference, and the second electrode lay 108A` of the 4th conductive structure 304` is electrically connected with the second electrode lay 108B` of described 3rd conductive structure 303`, the current potential of the second electrode lay 108A` of described like this 4th conductive structure 304` is identical with the current potential of the second electrode lay 108` of described 3rd conductive structure 303`, be fixing negative potential, 4th conductive structure 304` and the second conductive structure 302` constitutes storage capacitance, be conducive to the maintenance of the stored charge of horizontal photodiode cathode.In addition, in the present embodiment, light shield layer 101B` also accesses external voltage, and the external voltage of light shield layer 101B` is in the scope of 0V to 10V, thus form another storage capacitance with the second conductive structure 302`, improve the maintenance effect of the stored charge of horizontal photodiode cathode further.In other embodiments, light shield layer 101B` can also be connected with grid, namely the external voltage of light shield layer 101B` is identical with grid, also the effect forming storage capacitance with the second conductive structure 302` can be played, and light shield layer 101B is also connected with grid and can makes to be blocked completely below intrinsic semiconductor layer 103`, at utmost avoids the light below substrate to enter intrinsic semiconductor layer 103`.

It should be noted that, in other embodiments, can not also form the 4th conductive structure 304`, but form other and can form the structure of storage capacitance by the second conductive structure 302, the present invention is not restricted this.

Described light signal can be converted into the signal of telecommunication by described horizontal photodiode, and is exported by thin-film transistor, thus makes described pixel cell can be used in fingerprint recognition.

With reference to Figure 16, in the present embodiment, after formation the 4th conductive structure 304`, the second conductive structure 302`, at described dielectric layer 106`, the second electrode lay 108A` and the second electrode lay 108B` surface coverage second insulating barrier 109`, the material of described second insulating barrier 109` is light transmissive material, particularly, the material of described second insulating barrier 109` can be silicon nitride, silica or spin-on material.The effect of described second insulating barrier 109` is the primary structure of protection photodiode and thin-film transistor, and makes photodiode and thin-film transistor and other structural insulations.

In the present embodiment, contact electrode (not shown) is also formed on the second electrode lay 108B` surface of described 3rd conductive structure 303`, the material of described contact electrode is tin indium oxide or zinc oxide, the benefit forming contact electrode is, can strengthen the reliability of the second electrode lay 108B`, but the present invention does not limit to whether forming contact electrode.

The manufacture method of photoelectric sensor of the present invention forms multiple above-mentioned pixel cell simultaneously, and described multiple pixel cell is array-like arrangement.

The manufacture method of photoelectric sensor of the present invention also comprises: above described multiple pixel cell, form protective layer (not shown).The benefit forming protective layer is, can reduce the damage of outer bound pair photodiode.

Below substrate, arrange backlight, the light that described backlight sends is projected to above pixel cell by the logical photo structure in pixel cell.Namely photoelectric sensor of the present invention has the light source carried, and light source is positioned at the below of photoelectric sensor, and external environmental light can be avoided so better on the impact of photoelectric sensor.Because current LCD adopts transmissive display substantially, backlight is provided with below array base palte, backlight generally adopts LED formula or cold-cathode fluorescent tubular type, therefore optical pickocff of the present invention can be integrated on same glass with the thin film transistor (TFT) array of liquid crystal panel, adopts the backlight of backlight as photoelectric sensor of LCD.

The manufacture method of photoelectric sensor of the present invention also comprises: formed connect between pixel cell, a plurality of leads of pixel cell and external drive circuit.Can continue with reference to figure 3, and combine with reference to figure 8 to Figure 16:

Particularly, when forming thin-film transistor gate 101A`, light shield layer 101B`, the grid lead 401 that synchronous formation many arranges in the row direction, described in every bar, one end of grid lead 401 is electrically connected with external drive circuit, often the grid 101A` of the thin-film transistor 001 of row pixel cell is electrically connected with a grid lead 401 of going together, for grid 101A` provides scanning voltage;

When forming thin-film transistor gate 101A`, light shield layer 101B`, also synchronous formation many articles is along the 3rd lead-in wire (not shown) of column direction arrangement, described in every article, one end of the 3rd lead-in wire is electrically connected with external drive circuit, or go between 402 to be electrically connected with second, often in row pixel cell, the described light shield layer 101B` of photodiode 002 goes between with an article the 3rd of same column and is electrically connected, for light shield layer 101B` provides external voltage, to make light shield layer 101B` and to be formed another storage capacitance with the second conductive structure 302.It should be noted that, in other embodiments, described 3rd lead-in wire can not also be set, but light shield layer 101B` is electrically connected with grid 101A`, for light shield layer 101B` provides scanning voltage, also can make light shield layer 101B` and form another storage capacitance with the second conductive structure 302.

When formation first electrode layer 105`, the first lead-in wire 402 that synchronous formation many arranges along column direction, described in every bar, one end of the first lead-in wire 402 is electrically connected with external drive circuit, often the source electrode (the first electrode layer 105A` in the first conductive structure 301`) of the thin-film transistor 001 of row pixel cell goes between with first of same column and is electrically connected, for the first electrode layer 105A` in described first conductive structure 301` provides basic voltage;

When forming the second electrode lay 108B`, the second lead-in wire 403 that synchronous formation many arranges along column direction, described in every bar, one end of the second lead-in wire 403 is electrically connected with external drive circuit, often in row pixel cell, the anode electrode (the second electrode lay 108B` of the 3rd conductive structure 303`) of photodiode 002 and an article second of same column go between and 402 to be electrically connected, for described the second electrode lay 108B` provides signal voltage;

It should be noted that, due to all pixel cells signal voltage all in 0 scope to-10V and the value of signal voltage immobilize, so can by second of each row lead-in wire 403 accumulate outside pixel unit array one lead-in wire and be connected with external power supply.

Can continue with reference to figure 4, in the outside of described pixel unit array, form grid via hole 501, first via hole 502, second via hole 503 of turn-on grid electrode lead-in wire 401, first lead-in wire 402, second lead-in wire 403 respectively.

In described grid via hole 501, first via hole 502, second via hole 503, form conductive layer 603, be electrically connected with external drive circuit with the 402, second lead-in wire 403 that grid lead 401, first is gone between.

It should be noted that, in other embodiments, driving chip can also be adopted and read the photodiode of chip to transverse direction and drive and read, particularly, bind driving chip on the substrate 100 and read chip, make grid lead 401, first lead-in wire 402, second lead-in wire 403 and driving chip and read chip electrical to connect, driving chip is connected with external power supply by flexible PCB with reading chip.The present invention does not limit the driving of the photodiode of transverse direction and playback mode.

As as described in above-described embodiment, form step before dielectric layer in the manufacture method of photoelectric sensor of the present invention synchronously to make with the thin-film transistor on LCD array base palte, namely in photoelectric sensor of the present invention pixel cell manufacture method in, while formation thin-film transistor, also form negative electrode and the light absorbing zone of lateral light electric transducer, the manufacture method of hinge structure thin-film transistor has only had more the steps such as the second doping semiconductor layer of being formed and being used as transverse diode anode and the second electrode lay, compared with the Amorphous silicon flat-panel detectors of prior art, without the need to carrying out the step forming independently photodiode again after formation thin-film transistor, reduce production cost, and the later step of the formation dielectric layer of photoelectric sensor of the present invention also can adopt the process equipment of LCD to complete, the backlight of LCD can also be used as the backlight of photoelectric sensor of the present invention, therefore, the manufacture method of photoelectric sensor of the present invention can combine with traditional LC D manufacture method, simplify the production technology of photoelectric sensor, shorten the production cycle, effectively reduce production cost.

For improving resolution further, in another embodiment, anode construction and the thin-film transistor of the photodiode of the transverse direction in the pixel cell of photoelectric sensor manufacture method of the present invention surround hollow structure.

Particularly, with reference to Figure 17,18, Figure 17 shows the vertical view of the embodiment of a kind of back-shaped structure of pixel cell that photoelectric sensor manufacture method of the present invention makes, Figure 18 is the cutaway view of Figure 17 along BB` line, it should be noted that, in order to the anode construction of the photodiode by transverse direction and the position relationship of cathode construction are illustrated clear, eliminate the second electrode lay 108A` of the 4th semiconductor structure 304` in fig. 17.

In the present embodiment, the step of formation light shield layer 101B`, the first light hole 201`, opening 203`, the first conductive structure 301`, the second conductive structure 302`, the 3rd conductive structure 303`, the second conductive structure 304` is different from above-described embodiment, other steps are roughly the same with above-described embodiment, do not repeat them here.

The first area of substrate 100` surrounds second area, and in the process forming light shield layer 101B`, make light shield layer 101B` be closed rectangle, described first light hole 201` is positioned at light shield layer 101B` central core.

In the process of formation first conductive structure 301`, the second conductive structure 302`, make described first conductive structure 301`, the second conductive structure 302` surround closed frame-type,

In the process forming opening 203`, make described opening 203` be positioned at the center of light shield layer 101B`, be positioned at the first conductive structure 301` simultaneously, center that the second conductive structure 302` surrounds closed frame-type, described opening 203` is rectangle.

In the process of formation second doping semiconductor layer 107A`, the second doping semiconductor layer 107B`, the second electrode lay 108A`, the second electrode lay 108B`, the second doping semiconductor layer 107B`, the second electrode lay 108B` in described opening 203` is made to be closed rectangle, then the second doping semiconductor layer 107B` in described opening 203`, the second electrode lay 108B` bottom centre form the 3rd light hole 204`, described 3rd light hole 204` is as a part for logical photo structure, and described 3rd light hole 204 exposes the second light hole 202`.Make described second conductive structure 302` surround closed frame-type centered by described opening 203`, make the second conductive structure 302`, the 3rd conductive structure 303` is back-shaped structure.It should be noted that, 4th conductive structure 304` (not showing in Figure 17) is positioned at above the second conductive structure 302`, closed frame-type is surrounded equally centered by described opening 203`, to make the 4th conductive structure 304` and the second conductive structure 302` larger in the projection overlapping area of substrate 100 plane, the storage capacitance that 4th conductive structure 304` and the second conductive structure 302 are formed is comparatively large, improves the quantity of electric charge stored in the second doping semiconductor layer 105A` in the second conductive structure 302`.

In other embodiments, the pixel cell that can also make in relative pectinate texture of photoelectric sensor manufacture method of the present invention.With reference to Figure 19, the birds-eye perspective of the pixel cell showing a photoelectric sensor manufacture method of the present invention embodiment again, the cutaway view of Figure 19 can with reference to Figure 16.In the present embodiment, the step of formation opening 203`, the first conductive structure 301`, the second conductive structure 302`, the 3rd conductive structure 303`, the 4th conductive structure 304` is different from the embodiment that first photoelectric sensor manufacture method of the present invention provides, other steps are roughly the same with the embodiment first provided, and do not repeat them here.

In the process of formation second conductive structure 302`, make described second conductive structure 302` in the pectination with comb part 701`, in the process forming opening 203`, make opening 203` in the pectination with comb part, the second doping semiconductor layer 107B`, the second electrode lay 108B` (i.e. the 3rd conductive structure 303`) in described opening 203` are in the pectination with comb part 702`, and the comb part 701` of the comb part 702` of the 3rd conductive structure 303` and the second conductive structure 302` is oppositely arranged and is alternately arranged.In the step of formation the 4th conductive structure 304`, the 4th conductive structure 304` is made to be positioned at above the second conductive structure 302`, same in the pectination with comb part, the anode construction of so namely horizontal photodiode is relative pectinate texture with cathode construction pipe.The anode construction of horizontal photodiode and cathode construction are that the benefit of relative pectinate texture is, the 4th conductive structure 304` and the overlapping area of the second conductive structure 302` in the projection of parallel substrate 100` surface direction can be increased, and then the storage capacitance that increase the 4th conductive structure 304` and the second conductive structure 302` is formed, and then improve the quantity of electric charge stored in the second doping semiconductor layer 105A` in the second conductive structure 302`.

Although the present invention discloses as above, the present invention is not defined in this.Any those skilled in the art, without departing from the spirit and scope of the present invention, all can make various changes or modifications, and therefore protection scope of the present invention should be as the criterion with claim limited range.

Claims

1. a photoelectric sensor, for realizing fingerprint recognition, is characterized in that, comprising:

Be positioned at the grid of first area substrate surface;

Be positioned at the intrinsic semiconductor layer on grid;

2. photoelectric sensor according to claim 1, it is characterized in that, described second doping semiconductor layer, the second electrode lay are also formed on dielectric layer corresponding to first area, and for forming the 4th conductive structure, described 4th conductive structure and described second conductive structure are for forming storage capacitance.

3. photoelectric sensor according to claim 1, is characterized in that, is provided with the first insulating barrier between described substrate and described intrinsic semiconductor layer.

4. photoelectric sensor according to claim 3, is characterized in that, the material of described substrate, the first insulating barrier and dielectric layer is light transmissive material.

5. photoelectric sensor according to claim 1, is characterized in that, described photoelectric sensor also comprises: the second insulating barrier being covered in described dielectric layer and the second electrode lay surface, and the material of described second insulating barrier is light transmissive material.

6. photoelectric sensor according to claim 5, is characterized in that, the material of described first insulating barrier, dielectric layer, the second insulating barrier is silicon nitride, silica or spin-on material.

7. photoelectric sensor according to claim 1, is characterized in that, is positioned at the contact electrode on described the second electrode lay surface, and the material of described contact electrode is tin indium oxide or zinc oxide.

8. photoelectric sensor according to claim 1, is characterized in that, described open bottom edge and the second conductive structure near the spacing of edge of opening in the scope of 1 to 5 microns.

9. photoelectric sensor according to claim 1, it is characterized in that, described second conductive structure is in the pectination with comb part, the 3rd conductive structure in described opening is in the pectination with comb part, and the 3rd conductive structure in described opening and described first conductive structure, the second conductive structure are oppositely arranged and comb part is alternately arranged.

10. photoelectric sensor according to claim 1, is characterized in that, described photoelectric sensor comprises multiple described pixel cell, and multiple pixel cell is array-like arrangement;

11. photoelectric sensors according to claim 10, is characterized in that, described photoelectric sensor also comprises:

12. photoelectric sensors according to claim 11, is characterized in that, have conductive layer in described grid via hole, the first via hole, the second via hole, grid lead, the first lead-in wire, the second lead-in wire to be electrically connected with external drive circuit.

13. photoelectric sensors according to claim 1, it is characterized in that, photoelectric sensor also comprises: be positioned at the protective layer above described multiple pixel cell.

14. photoelectric sensors according to claim 1, it is characterized in that, photoelectric sensor also comprises: be arranged at the backlight below substrate, and the light that described backlight sends is projected to above pixel cell by the logical photo structure that is arranged in pixel cell;

15. photoelectric sensors according to claim 14, it is characterized in that, described photoelectric sensor also comprises: the light shield layer being positioned at second area substrate surface, at described light shield layer zone line or have the first light hole exposing described substrate at light shield layer edge;

16. photoelectric sensors according to claim 15, it is characterized in that, the 3rd conductive structure in described opening is closed rectangle, the 3rd light hole is formed bottom the 3rd conductive structure in said opening, described 3rd light hole exposes the second light hole, described second conductive structure surrounds closed frame-type centered by described opening, makes the 3rd conductive structure in the second conductive structure and described opening be back-shaped structure, and described logical photo structure also comprises described 3rd light hole.

17. photoelectric sensors according to claim 16, is characterized in that, the aperture of described first light hole, the second light hole, the 3rd light hole is in the scope of 0 to 10 microns.

18. photoelectric sensors according to claim 15, is characterized in that, the intrinsic semiconductor layer in described opening and between the second conductive structure is blocked by described light shield layer completely.

19. photoelectric sensors according to claim 18, is characterized in that, described light shield layer and described second conductive structure are for forming storage capacitance.

20. photoelectric sensors according to claim 19, is characterized in that, described photoelectric sensor comprises multiple described pixel cell, and multiple pixel cell is array-like arrangement; Described photoelectric sensor also comprises:

21. photoelectric sensors according to claim 20, is characterized in that, described external voltage is in 0 scope to-10V.

22. photoelectric sensors according to claim 12, is characterized in that, described scanning voltage is in-10 scopes to 15V, and described basic voltage is in 0 scope to 3V, and described signal voltage is in 0 scope to-10V.

The manufacture method of 23. 1 kinds of photoelectric sensors, is characterized in that, comprising:

The step forming pixel cell comprises:

Grid is formed at described first area substrate surface;

Described grid forms intrinsic semiconductor layer;

24. manufacture methods according to claim 23, it is characterized in that, in the step forming described second doping semiconductor layer, the second electrode lay, described second doping semiconductor layer, the second electrode lay are also formed on dielectric layer corresponding to first area, for forming the 4th conductive structure, described 4th conductive structure and described second conductive structure are for forming storage capacitance.

25. manufacture methods according to claim 23, is characterized in that, after formation grid, before forming intrinsic semiconductor layer, also on described grid, form the first insulating barrier, and described intrinsic semiconductor layer is formed with on described first insulating barrier.

26. manufacture methods according to claim 25, is characterized in that, the material of described substrate, the first insulating barrier and dielectric layer is light transmissive material.

27. manufacture methods according to claim 23, is characterized in that, also comprise: at described dielectric layer and the second electrode lay surface coverage second insulating barrier, and the material of described second insulating barrier is light transmissive material.

28. manufacture methods according to claim 27, is characterized in that, the material of described first insulating barrier, dielectric layer, the second insulating barrier is silicon nitride, silica or spin-on material.

29. manufacture methods according to claim 23, is characterized in that, also comprise: the second electrode lay surface in said opening forms contact electrode, and the material of described contact electrode is tin indium oxide or zinc oxide.

30. manufacture methods according to claim 23, is characterized in that, make the spacing of the close edge of opening of described open bottom edge and the second conductive structure in the scope of 1 to 5 microns.

31. manufacture methods according to claim 23, it is characterized in that, make described first conductive structure, the second conductive structure in the pectination with comb part, the 3rd conductive structure in described opening is in the pectination with comb part, and the comb part of the 3rd conductive structure in described opening and described first conductive structure, the second conductive structure are oppositely arranged and comb part is alternately arranged.

32. manufacture methods according to claim 23, is characterized in that, also comprise: below substrate, arrange backlight, and the light that described backlight sends is projected to above pixel cell by the logical photo structure that is formed in pixel cell.

33. manufacture methods according to claim 32, is characterized in that,

In the process forming grid, synchronously form light shield layer at second area substrate surface, at described light shield layer zone line or the first light hole exposing described substrate in the formation of light shield layer edge;

34. manufacture methods according to claim 33, it is characterized in that, the 3rd conductive structure in described opening is made to be closed rectangle, the 3rd light hole is formed bottom the 3rd conductive structure in said opening, described 3rd light hole exposes the second light hole, make described second conductive structure surround closed frame-type centered by described opening, make the 3rd conductive structure in the second conductive structure and described opening be back-shaped structure, described logical photo structure also comprises described 3rd light hole.

35. manufacture methods according to claim 34, is characterized in that, make described first light hole, the second light hole, the 3rd light hole aperture in the scope of 0 to 10 microns.

36. manufacture methods according to claim 33, is characterized in that, the intrinsic semiconductor layer in described opening and between the second conductive structure is blocked by described light shield layer completely.

37. manufacture methods according to claim 33, it is characterized in that, the process forming grid and light shield layer at described substrate surface comprises: adopt magnetron sputtering method to form the first metal layer at described substrate surface, removing part the first metal layer to exposing substrate surface by photoetching, forming the first light hole in thin-film transistor gate, light shield layer and light shield layer.

38. manufacture methods according to claim 25, it is characterized in that, the process forming intrinsic semiconductor layer at described first surface of insulating layer comprises: using plasma strengthens chemical vapour deposition technique, at described first surface of insulating layer deposition intrinsic amorphous silicon, remove part intrinsic amorphous silicon to exposing the first surface of insulating layer by photoetching, the intrinsic amorphous silicon of reservation forms intrinsic semiconductor layer.

39. manufacture methods according to claim 23, it is characterized in that, the first conductive structure is formed on described intrinsic semiconductor layer surface, the process of the second conductive structure comprises: using plasma strengthens chemical vapour deposition technique at described intrinsic semiconductor layer surface deposition N-type amorphous silicon, the second metal level is covered in described N-type amorphous silicon surfaces, to described second metal level, N-type amorphous silicon carries out photoetching, remove most second metal level, N-type amorphous silicon is to exposing intrinsic semiconductor layer, remaining N-type amorphous silicon forms the first doping semiconductor layer, remaining second metal level forms the first electrode layer.

40. manufacture methods according to claim 23, is characterized in that, the material of described the second electrode lay is metal or light transmitting electro-conductive material.

41. manufacture methods according to claim 23, it is characterized in that, the second doping semiconductor layer formed successively is formed in dielectric layer surface square on the first electrode and described opening, the process of the second electrode lay comprises: in described dielectric layer surface and described opening, cover the P-type non-crystalline silicon formed successively, 3rd metal level, part P-type non-crystalline silicon is removed by photoetching, 3rd metal level is to exposing dielectric layer surface, what retain is positioned at above the first electrode, in described opening and the P-type non-crystalline silicon of open circumferential, 3rd metal level forms the second doping semiconductor layer, the second electrode lay.

42. manufacture methods according to claim 23, is characterized in that, also comprise:

Described multiple pixel cell is made to be array-like arrangement;

43. manufacture methods according to claim 42, is characterized in that, also comprise:

44. manufacture methods according to claim 42, is characterized in that, form conductive layer at described grid via hole, the first via hole, the second via hole, grid lead, the first lead-in wire, the second lead-in wire to be electrically connected with external drive circuit.

45. manufacture methods according to claim 42, is characterized in that, also comprise: above described multiple pixel cell, form protective layer.