CN102544031A - Cavity type super deep light emitting diode of image sensor and process method thereof - Google Patents
Cavity type super deep light emitting diode of image sensor and process method thereof Download PDFInfo
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- CN102544031A CN102544031A CN2010106215121A CN201010621512A CN102544031A CN 102544031 A CN102544031 A CN 102544031A CN 2010106215121 A CN2010106215121 A CN 2010106215121A CN 201010621512 A CN201010621512 A CN 201010621512A CN 102544031 A CN102544031 A CN 102544031A
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Abstract
The invention discloses a cavity type super deep light emitting diode of a complementary metal-oxide-semiconductor (CMOS) image sensor and a process method thereof. A P type substrate is grounded or connected to a negative power supply; an N type epitaxial layer grows on the P type substrate, and is connected to a positive power supply; and a super deep P type light-emitting diode injection region is formed in the N type epitaxial layer. Heating treatment is performed, so that a smooth and deep doping profile is obtained.
Description
Technical field
The present invention relates to a kind of CMOS (CMOS) imageing sensor, particularly relate to a kind of ultra dark optical diode of cavity type that is applied to the cmos image sensor of automobile.
Background technology
CMOS (CMOS) imageing sensor is widely used in camera, network camera, monitoring camera, toy or the Medical Devices of mobile phone.Cmos image sensor also can be applicable to severe environment, and for example automotive applications owing to its severe operating environment, is very overcritical for imageing sensor therefore.In order to be applied to automobile, must solve some problems of cmos image sensor.
The first, in order to let automobile can obtain more details information to judge night, imageing sensor must have higher sensitivity or signal noise ratio (SNR).
Second; Because the operating temperature of automobile can be higher than general application; For example therefore the camera of mobile phone needs lower dark current, in order to keep HDR; Reduce the dark signal heterogeneity (dark signal non-uniformity, DSNU) and reduce dark signal impulsive noise (shot noise).
The 3rd, because the road surface scene at night belongs to the HDR pattern, so cmos image sensor needs good excessive (blooming) control in superbright zone, receives the regional excessive electric charge of superbright than dark areas around it and waters down preventing.For some HDR mechanism of tradition, because (integration) asynchronism(-nization) that adds up of its optical diode, the therefore long optical diode that adds up can destroy the information of the short optical diode that adds up.
The 4th, because automobile tail light and traffic sign have stronger ruddiness composition, so ruddiness information is very important for automotive applications.Moreover in order to make better judgement, imageing sensor need be collected infrared light and the near infrared light information outside the visible spectrum.
Each pixel of traditional cmos imageing sensor is come expression signal with electronics, and the transistor in the pixel is all N type metal oxide semiconductor (NMOS) transistor.In pixel, hole that photon produced and electronics are stored in the P side and the N side of optical diode respectively.After exposure, the NMOS transmission gate only transmits the unsteady diffusion of electronics to N type, and (floating diffusion, FD) node are voltage signal by the FD junction capacitance with electronic switch again.This voltage signal then is passed to the output of pixel by subsequent conditioning circuit.
In order to improve above-mentioned dark current and excessive problem; Thereby disclose cavity type optical diode as shown in Figure 1; Can be with reference to " Low-Crosstalk and Low-Dark-Current CMOS Image-Sensor technology Using a Hole-Based Detector " that the people delivered such as Eric Stevens; IEEE International Solid-State Circuits Conference in 2008,60-61.
Cavity type optical diode shown in Figure 1 more can suppress dark current than traditional electrical subtype cmos image sensor.Wherein, P type substrate 10 can be used as the discharge region in excessive hole, to migrate out substrate (bulk) dark current.In addition, assemble by the alloy (dopant) of Si/SiO2 interface, for example between shallow channel isolation area (STI) 12 and the N+ well 14, dark current can significantly reduce, and this differs from the electron type cmos image sensor can produce the alloy separation in this place.In addition, because the mobility (mobility) in hole is less than electronics, therefore under identical electric field and CHARGE DISTRIBUTION situation, the drift of cavity type cmos image sensor (drift) electric current and dissufion current are much smaller than the electron type cmos image sensor.Moreover, because the P type substrate 10 of ground connection provides electronegative potential with the excessive hole of discharging cavity type optical diode, thereby can provide good excessive control, urgently be applicable to automotive applications.
Yet,, make the degree of depth of P type optical diode 16 of cavity type cmos image sensor be subject to the injection degree of depth of N type well 18 because N type alloy overweights P type alloy.For example, the atomic weight of N type phosphorus be 30.97 or arsenic be 74.92, and the atomic weight of P type boron is 10.81.Therefore, shallow P type optical diode 16 can't absorb enough electron-hole pairs to contain the absorption region of ruddiness/near infrared light.On the other hand, for the P type optical diode 16 of given depth, the degree of depth of N type well 18 will be subject to interference (crosstalk) and excessive control.If too dark, then diffusion charge can get into neighborhood pixels, and can't be absorbed by P type optical diode 16.
Therefore, need badly and propose a kind of Novel CMOS imageing sensor, with ruddiness/near infrared light reaction of improving structure shown in Figure 1 and keep its excessive and Interference Control.
Summary of the invention
In view of above-mentioned; One of purpose of the embodiment of the invention is to propose the structure and the technology of the ultra dark optical diode of cavity type of a kind of CMOS (CMOS) imageing sensor, and it has ruddiness/near infrared light reaction of improvement, the interference that reduces, excessive and less dark current.
According to the embodiment of the invention, the ultra dark optical diode of the cavity type of cmos image sensor comprises the substrate of P type, N type epitaxial loayer and ultra dark P type optical diode injection zone.P type substrate ground connection or be connected to negative supply.N type outer layer growth and is connected to positive supply in the substrate of P type.Ultra dark P type optical diode injection zone is formed in the N type epitaxial loayer.
Description of drawings
Fig. 1 shows the profile of the cavity type optical diode of traditional cmos imageing sensor;
Fig. 2 shows electronics moldeed depth optical diode;
Fig. 3 shows the profile of the ultra dark optical diode of cavity type of the cmos image sensor of the embodiment of the invention;
The technology of the ultra dark optical diode of cavity type of the cmos image sensor of Fig. 4 A to Fig. 4 C demonstration embodiment of the invention.
Embodiment
Disturb for the longer wavelength reaction and the reduction diffusion that strengthen ruddiness/near infrared light, the electron type optical diode that Fig. 2 proposes has dark N type optical diode 20, and it can absorb electron-hole pair to contain ruddiness/near infrared light absorption region and the more signals of absorption.In addition, the diffusion charge that is positioned at the P type epitaxial loayer 22 under the dark N type optical diode 20 can be reduced in a large number, therefore, the diffusion charge that gets into neighborhood pixels can be reduced.In Fig. 1, because of the interference that excessive discharge reduced but can cause bad ruddiness/near infrared light reaction.Yet Fig. 2 does not have the excessive discharge situation of Fig. 1.
In order to take into account the advantage of Fig. 1 and Fig. 2, Fig. 3 shows the profile of the ultra dark optical diode of cavity type of CMOS (CMOS) imageing sensor of the embodiment of the invention.Accompanying drawing only demonstrates main element, sees also Fig. 4 C than detailed structure.In the present embodiment, " deeply " or " ultra dark (ultra-deep) " refers to that greater than 0.5 micron for example the 0.5-2 micron then refers to greater than 2 microns in a preferred embodiment.The optical diode that is disclosed is applicable to severe environment, automotive applications for example, but not as limit.Of Fig. 1, the cavity type optical diode can reach than low-dark current, so the optical diode of present embodiment can meet the harsh temperature requirement of automotive applications.
In the present embodiment, as Fig. 1, P type substrate 30 ground connection or be connected to negative supply.P type substrate 30 is in order to discharge excessive hole, and this helps the HDR scene at night.Under general operation, P type substrate 30 can reduce the interference of ruddiness/near infrared light signal.Further details about excessive control can be with reference to " Interline CCD Image Sensor with an Antiblooming Structure " that the people delivered such as Yasuo Ishihara; IEEE Transactions on Electron Devices; Vo1.ED-31; No.1, in January, 1984; Or G.Agranov etc. " Super Small, Sub 2 μ m Pixels For Novel CMOS Image Sensors " that the people delivered, International Image Sensor Workshop, 7-10 day in June, 2007, Ogunquit, Maine USA.
N type epitaxial loayer 31 is formed in the P type substrate 30, and is connected to positive supply AVDD.Dark P type optical diode 32 injection regions are formed in the N type epitaxial loayer 31.Because using N type epitaxial loayer 31, present embodiment, therefore can not receive the injection degree of depth restriction of heavier N type alloy like the N type well of Fig. 1.Because P type alloy is lighter, therefore, compared to traditional electrical subtype optical diode, dark P type optical diode 32 injection regions of present embodiment can be darker, thereby can improve signal noise ruddiness/near infrared light reaction when.
In N type epitaxial loayer 31, form isolated area, for example shallow channel isolation area (STI) 33.N+ structure cell (cell) separator 34 is formed on side and bottom in shallow channel isolation area 33.Compared to the P type separator 24 of Fig. 2, because N type alloy is heavier, the thermal diffusion of the N type separator 34 of present embodiment can reduce greatly.Therefore, the Miniaturizable separator, and stay more spaces to give optical diode 32.By this, can improve signal absorption and interference problem.
The technology of the ultra dark optical diode of cavity type of the cmos image sensor of Fig. 4 A to Fig. 4 C demonstration embodiment of the invention.The element identical with Fig. 3 indicates with the similar elements symbol.Each step can be used conventional semiconductor processing techniques, and its details is omitted.
In Fig. 4 A, P type substrate (or being called for short substrate) 30 is provided, the N type of growing on it again epitaxial loayer (or abbreviating epitaxial loayer as) 31.In the present embodiment, the thickness of epitaxial loayer 31 is 6 microns or greater than 6 microns, but not as limit.
Then, still consult Fig. 4 A, carry out repeatedly dark P type optical diode and inject, to form dark P type optical diode (or abbreviating optical diode as) 32 injection regions.This injection is executed in the defined zone of shielding (not being shown in graphic).Injecting each time to use different-energy to reach required profile.In addition, after each injection, can use heat treatment to make its contour smoothing.Its profile also can determine according to the heat treatment of subsequent process steps.Then, form shallow channel isolation area 33 in epitaxial loayer 31.
In Fig. 4 B, inject structure cell separator (or structure cell N type well) 34 in the side and the bottom of shallow channel isolation area 33, and inject dark separator (or deep N-well) 37 for 34 times in the structure cell separator.In addition, inject N type raceway groove 38 injection zones in epitaxial loayer 31 upper epidermis zone, it is positioned at top, dark optical diode 32 injection regions.Above-mentioned structure cell separator 34, dark separator 37 and raceway groove 38 injection zones can be carried out according to suitable order.Then, form transmission gate 35 on epitaxial loayer 31.
In Fig. 4 C, inject the tip (pinning) 39 injection zones in epitaxial loayer 31 upper epidermis zone.In the present embodiment, the N type tip 39 injection zones are positioned at raceway groove 38 injection zones.Between raceway groove 38 injection zones and dark optical diode 32 injection regions, inject P type surface light diode 40 injection zones, as main cavity type optical diode.In the present embodiment, the tip 39 injection zones and raceway groove 38 injection zones are mainly in order to suppress dark current and optimization transmission gate 35.The tip 39 injection zones and surface light diode 40 injection zones can be carried out according to suitable order.Then, inject the unsteady diffusion of P+ 36 injection zones.
The above is merely the preferred embodiments of the present invention, is not in order to limit interest field of the present invention; All other do not break away from the equivalence of being accomplished under the spirit that invention discloses and changes or modify, and all should be included in the following claim scope.
Claims (18)
1. the ultra dark optical diode of cavity type of a CMOS (CMOS) imageing sensor comprises:
The substrate of P type, ground connection or be connected to negative supply;
N type epitaxial loayer grows in the substrate of said P type, and said N type epitaxial loayer is connected to positive supply; And
Ultra dark P type optical diode injection zone is formed in the said N type epitaxial loayer.
2. the ultra dark optical diode of the cavity type of cmos image sensor as claimed in claim 1, the thickness of wherein said ultra dark P type optical diode injection zone is greater than 0.5 micron.
3. the ultra dark optical diode of the cavity type of cmos image sensor as claimed in claim 2, the thickness of wherein said ultra dark P type optical diode injection zone is the 0.5-2 micron.
4. the ultra dark optical diode of the cavity type of cmos image sensor as claimed in claim 2, the thickness of wherein said ultra dark P type optical diode injection zone is greater than 2 microns.
5. the ultra dark optical diode of the cavity type of cmos image sensor as claimed in claim 1 also comprises:
Isolated area is formed in the said N type epitaxial loayer.
6. the ultra dark optical diode of the cavity type of cmos image sensor as claimed in claim 5, wherein said isolated area is a shallow channel isolation area.
7. the ultra dark optical diode of the cavity type of cmos image sensor as claimed in claim 5 also comprises:
N type structure cell separator is formed at the side and the bottom of said isolated area.
8. the process of the ultra dark optical diode of cavity type of a CMOS (CMOS) imageing sensor comprises:
The substrate of P type is provided;
Growth N type epitaxial loayer is in the substrate of said P type; And
Form ultra dark P type optical diode injection zone in said N type epitaxial loayer.
9. the process of the ultra dark optical diode of cavity type of cmos image sensor as claimed in claim 8, the formation of wherein said ultra dark P type optical diode injection zone comprise uses different-energy to inject to carry out repeatedly.
10. the process of the ultra dark optical diode of cavity type of cmos image sensor as claimed in claim 9 also comprises:
After said injection each time, perhaps impose heat treatment by subsequent process steps.
11. the process of the ultra dark optical diode of cavity type of cmos image sensor as claimed in claim 8 also comprises:
Form isolated area in said N type epitaxial loayer.
12. the process of the ultra dark optical diode of cavity type of cmos image sensor as claimed in claim 11 also comprises:
Form N type structure cell separator in the side and the bottom of said isolated area; And
Inject N moldeed depth separator under said structure cell separator.
13. the process of the ultra dark optical diode of cavity type of cmos image sensor as claimed in claim 8 also comprises:
Inject the upper epidermis zone of raceway groove injection zone in said N type epitaxial loayer, wherein said raceway groove injection zone is positioned at said ultra dark P type optical diode injection zone top.
14. the process of the ultra dark optical diode of cavity type of cmos image sensor as claimed in claim 13 also comprises:
Inject the upper epidermis zone of N type tip injection zone in said N type epitaxial loayer; And
Inject P type surface light diode injection zone in said N type epitaxial loayer; As the Charge Storage of a main cavity type optical diode, wherein said surface light diode injection zone is between said raceway groove injection zone and said ultra dark P type optical diode injection zone.
15. the process of the ultra dark optical diode of cavity type of cmos image sensor as claimed in claim 8 also comprises:
Form transmission gate on said N type epitaxial loayer; And
Form the P type and float the diffusion injection zone in said N type epitaxial loayer, wherein said transmission gate floats between the diffusion injection zone at said ultra dark P type optical diode injection zone and said P type.
16. the process of the ultra dark optical diode of cavity type of cmos image sensor as claimed in claim 8, the thickness of wherein said ultra dark P type optical diode injection zone is greater than 0.5 micron.
17. the process of the ultra dark optical diode of cavity type of cmos image sensor as claimed in claim 16, the thickness of wherein said ultra dark P type optical diode injection zone is the 0.5-2 micron.
18. the process of the ultra dark optical diode of cavity type of cmos image sensor as claimed in claim 16, the thickness of wherein said ultra dark P type optical diode injection zone is greater than 2 microns.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6514785B1 (en) * | 2000-06-09 | 2003-02-04 | Taiwan Semiconductor Manufacturing Company | CMOS image sensor n-type pin-diode structure |
| CN101159282A (en) * | 2006-10-04 | 2008-04-09 | 株式会社东芝 | Amplifying type solid cameraing element |
| CN101202246A (en) * | 2006-12-15 | 2008-06-18 | 中芯国际集成电路制造(上海)有限公司 | Forming method of pixel unit of CMOS image sensor |
| CN101473441A (en) * | 2006-06-20 | 2009-07-01 | 伊斯曼柯达公司 | PMOS pixel structure with low cross talk |
| US20100084692A1 (en) * | 2008-10-08 | 2010-04-08 | Omnivision Technologies, Inc. | Image sensor with low crosstalk and high red sensitivity |
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2010
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6514785B1 (en) * | 2000-06-09 | 2003-02-04 | Taiwan Semiconductor Manufacturing Company | CMOS image sensor n-type pin-diode structure |
| CN101473441A (en) * | 2006-06-20 | 2009-07-01 | 伊斯曼柯达公司 | PMOS pixel structure with low cross talk |
| CN101159282A (en) * | 2006-10-04 | 2008-04-09 | 株式会社东芝 | Amplifying type solid cameraing element |
| CN101202246A (en) * | 2006-12-15 | 2008-06-18 | 中芯国际集成电路制造(上海)有限公司 | Forming method of pixel unit of CMOS image sensor |
| US20100084692A1 (en) * | 2008-10-08 | 2010-04-08 | Omnivision Technologies, Inc. | Image sensor with low crosstalk and high red sensitivity |
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