KR20130006168A - Sensor and data processing system having the same - Google Patents

Abstract

PURPOSE: A sensor and a data processing system are provided to increase a generation range of an electric field in a side, thereby increasing photoelectron resolution. CONSTITUTION: A sensor(10) includes a depth pixel(16) of 1-tab pixel structure. A photoelectric transformation area generates a photo charge. An insulating layer is implemented on a semiconductor substrate. The semiconductor substrate includes the photoelectric transformation area. A first photo gate and a second photo gate are implemented on the insulating layer.

Description

Sensor and data processing system including same {SENSOR AND DATA PROCESSING SYSTEM HAVING THE SAME}

An embodiment according to the concept of the present invention relates to a sensor, and more particularly, to a sensor having a photogate structure capable of increasing a generation range of a lateral field and a data processing system including the same.

The distance sensor measures the time until the optical signal in the form of pulses emitted from a source is reflected back by the target object (or the measurement object), and between the distance sensor and the target object based on the measured time. The distance (or depth) of can be calculated.

Microwaves, light waves, or ultrasonic waves are mainly used as signals output from the source. The distance sensor may measure the distance using a time of flight (TOF) measurement method.

A depth sensor including a depth pixel of a 1-tap pixel structure applies each of the gate signals having a phase difference of 0 degrees, 90 degrees, 180 degrees, and 270 degrees with time difference to the depth pixel, and is measured with a time difference. The distance to the target object may be calculated using each of the frame signals.

At this time, in order to increase the accuracy of the calculated distance, it is necessary to effectively move the generated photocharge toward the sensing node corresponding to the voltage level of each of the gate signals.

Therefore, the technical problem to be achieved by the present invention is to provide a sensor and a data processing system including the same that can increase the photoelectric resolution by increasing the generation range of the lateral electric field.

According to an embodiment of the present disclosure, a sensor includes a depth pixel of a 1-tab pixel structure, and the depth pixel includes a photoelectric conversion region for generating photocharges and a semiconductor substrate including the photoelectric conversion region. An insulating layer formed on the insulating layer, and a first photo gate and a second photo gate each of which is formed on the insulating layer, wherein the first photo gate has a protruding pattern protruding toward the second photo gate in a central region thereof. The second photo gate has a structure spaced apart from the protruding pattern and encloses the protruding pattern, and the size of the cross-sectional area of the first photo gate is different from that of the second photo gate.

The sensor may generate a depth signal based on the photocharge transferred to a floating diffusion region adjacent to the first photo gate.

In addition, the sensor may measure the depth to the target object based on the time of flight (TOF).

In addition, gate signals having a phase difference of 0 degrees, 90 degrees, 180 degrees, and 270 degrees may be applied to the first photo gate with a time difference.

In addition, the size of the cross-sectional area of the first photo gate may be greater than the size of the cross-sectional area of the second photo gate.

Data processing system according to an embodiment of the present invention includes the sensor and a processor for controlling the operation of the sensor.

The sensor is moved to a floating diffusion region adjacent to the first photo gate.

A depth signal may be generated based on the transferred photocharges.

In addition, gate signals having a phase difference of 0 degrees, 90 degrees, 180 degrees, and 270 degrees may be applied to the first photo gate with a time difference.

In addition, the sensor may measure the depth to the target object based on the time of flight (TOF).

The data processing system may be implemented as a 3D range finder, a game controller, a distance camera, or a gesture sensing device.

The sensor according to the embodiment of the present invention has an effect of increasing the separation or resolution of the photoelectrons generated by enlarging the range in which the lateral field occurs, including the photo gate structure having the protruding pattern.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to more fully understand the drawings recited in the detailed description of the present invention, a detailed description of each drawing is provided.
1 is a block diagram of a sensor including a depth pixel according to an exemplary embodiment of the present invention.
FIG. 2 illustrates a cross-sectional view of the depth pixel shown in FIG. 1, a plan view of a plurality of gates included in the depth pixel, and a potential distribution of a semiconductor surface for explaining the operation of the depth pixel.
3 is a circuit diagram including a plurality of photo gates and a plurality of transistors implemented in a depth pixel illustrated in FIG. 1.
FIG. 4 is a graph illustrating gate signals applied to the first photo gate and the second photo gate shown in FIG. 2.
5 is a block diagram of an image sensor including a depth pixel according to another exemplary embodiment.
FIG. 6 is a block diagram of a data processing system including the image sensor shown in FIG. 5.
FIG. 7 is a block diagram of a data processing system including the sensor shown in FIG. 1.
FIG. 8 is another embodiment of a data processing system including the sensor shown in FIG. 1.

Specific structural to functional descriptions of the embodiments according to the inventive concept disclosed herein are merely illustrated for the purpose of describing the embodiments according to the inventive concept. It may be embodied in various forms and should not be construed as limited to the embodiments set forth herein or in the application.

Embodiments in accordance with the concepts of the present invention can make various changes and have various forms, so that specific embodiments are illustrated in the drawings and described in detail in this specification or application. It is to be understood, however, that it is not intended to limit the embodiments according to the concepts of the present invention to the particular forms of disclosure, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Terms such as first and / or second may be used to describe various components, but the components should not be limited by the terms. The terms are intended to distinguish one element from another, for example, without departing from the scope of the invention in accordance with the concepts of the present invention, the first element may be termed the second element, The second component may also be referred to as a first component.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Other expressions describing the relationship between components, such as "between" and "immediately between," or "neighboring to," and "directly neighboring to" should be interpreted as well.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, the terms "comprises ", or" having ", or the like, specify that there is a stated feature, number, step, operation, , Steps, operations, components, parts, or combinations thereof, as a matter of principle.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined herein. Do not.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings.

1 is a block diagram of a sensor including a depth pixel according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the sensor 10 emits an infrared light signal EL, for example, a modulated infrared photon signal, to the outside using the infrared light source 12, and the infrared light signal EL. The time when the light is emitted from the infrared light source 12 and the infrared light signal EL are reflected by the subject 11 or the target object and then the infrared light signal incident on the sensor 10 (this is referred to as a “reflected light signal”). The distance or depth d to the subject 11 may be measured by using Equation 1 representing the time difference td of the incident time of RL 'or RL.

Here, d represents the distance or depth between the sensor 10 and the subject 11, and c represents the luminous flux.

The sensor 10 includes an infrared light source 12, a depth sensor array 14, an infrared pass filter 17, a CDS / ADC circuit 18, a timing controller 20, a row decoder 22, and a memory. (24). In addition, the sensor 10 may further include an image signal processor 150.

According to an embodiment, the sensor 10 and the image signal processor 150 may be implemented as one semiconductor chip, for example, a system on chip (SoC), and the sensor 10 and the image signal processor 150 may be different from each other. It may be implemented as a semiconductor chip. In some embodiments, the sensor 10 may be used together with a color image sensor chip to simultaneously measure 3D image information and depth information.

In addition, the sensor 10 may further include a column decoder (not shown) for transmitting data output from the memory 24 to the image signal processor 150 under the control of the timing controller 20.

In addition, the sensor 10 may further include a lens (not shown) for condensing the reflected light signal RL ′ with the infrared light passing filter 17. The operation of the infrared filter 17 and the lens module (not shown) including the lens may be controlled by the timing controller 20.

Depth sensor array 14 may include a number of depth pixels 16. Each of the plurality of depth pixels 16 may generate a plurality of frame signals based on a reflected light signal RL or RL 'reflected from the target object and a plurality of gate signals. The plurality of gate signals are periodically applied to each of the plurality of depth pixels 16 with a constant phase difference.

The timing controller 20 may control the operation of the infrared light source 12 and the operation of each of the plurality of depth pixels 16. Under the control of the timing controller 20, the infrared light source 12 may emit an infrared light signal EL to the outside.

In detail, the timing controller 20 may generate a plurality of gate signals for controlling the operation of each of the plurality of photogates implemented in each of the plurality of distance pixels 16.

The infrared light source 12 may be implemented as a light emitting diode (LED), a laser diode (LD), or an organic light emitting diode (OLED). The sensor 10 may include a plurality of infrared light sources disposed around the depth sensor array 14, but only one infrared light source 12 is shown in FIG. 1 for convenience of description.

The CDS / ADC circuit 18 performs correlated double sampling (CDS) on each of the signals output from the depth pixel array 14 in response to the control signals output from the timing controller 20. In addition, the CSD / ADC circuit 18 outputs each of the digital signals by analog-to-digital converting each of the CDS signals.

The memory 24 may receive and store each digital signal output from the CDS / ADC circuit 18. Each digital signal stored in the memory 24 may be output to the image signal processor 150 by a column decoder (not shown).

FIG. 2 illustrates a cross-sectional view of the depth pixel shown in FIG. 1, a plan view of a plurality of gates included in the depth pixel, and a potential distribution of a semiconductor surface for explaining the operation of the depth pixel. In FIG. 2, only one depth pixel is shown for convenience of description.

1 and 2, depth pixel 16 has a one-tap pixel structure. That is, the sensor 10 may generate a depth signal based on the photocharges transferred to the floating diffusion region adjacent to one gate electrode of the plurality of gate electrodes. That is, since the plurality of gate electrodes do not have a symmetrical structure, the depth pixel 16 has a one-tap pixel structure.

The depth pixel 16 includes a first photo gate PG1, a second photo gate PG2, a first transfer circuit TX1, a second transfer circuit TX2, a first bridging region BD1, and a second bridging region. (BD2), a first floating diffusion region FD1, and a second floating diffusion region FD2.

According to an embodiment, the first bridging area BD1 and the second bridging area BD2 may not be implemented. The bridging regions BD1 and BD2 are regions in which photoelectrons generated in the photoelectric conversion region are accumulated. The bridging regions BD1 and BD2 and the floating diffusion regions FD1 and FD2 may be formed inside the semiconductor substrate (eg, a P ^- type epitaxial region 16-1).

Inside the semiconductor substrate 16-1 positioned below each of the first and second photo gates PG1 and PG2, each of the first and second photo gates PG1 and PG2 passes through the first and second photo gates PG1 and PG2. Photoelectrons (or photocharges) are generated by the reflected light signal RL or RL '. That is, the photoelectric conversion region means a region where the photoelectron is generated.

The photo gates PG1 and PG2 and the semiconductor substrate 16-1 and between the transfer circuits TX1 and TX2 and the semiconductor substrate 16-1 are insulated with an insulating layer. If the semiconductor substrate 16-1 may be a silicon substrate, the insulating layer may be silicon oxide (SiO ₂ ). In addition, the photo gates PG1 and PG2 may be implemented with polysilicon or metal.

Each of the first photo gate PG1 and the second photo gate PG2 has a collection operation and a transfer in response to each of the two gate signals having a 180 degree phase difference output from the timing controller 20. You can control the operation.

Here, the collecting operation refers to an operation in which photoelectrons generated by the reflected light signal RL or RL 'are collected on the surface of the semiconductor substrate 16-1, and the transmission operation refers to the collected photoelectrons. It means an operation of transmitting to each of the floating diffusion regions FD2 and FD2 by using each of the transmission circuits TX1 and TX2.

The first photo gate PG1 includes a protruding pattern 16-3 protruding toward the second photo gate PG2 in the central region. The second photo gate PG2 has a structure spaced apart from the protruding pattern 16-3 and surrounding the protruding pattern 16-3. At this time, the size of the cross-sectional area of the first photo gate PG1 and the size of the cross-sectional area of the second photo gate PG2 are different. In some embodiments, the size of the cross-sectional area of the first photo gate PG1 may be greater than the size of the cross-sectional area of the second photo gate PG2.

The potential distribution shown in FIG. 2 is a potential distribution when a low level voltage, for example, 0 V is applied to the first photo gate PG1, and a high level voltage, for example, 3.3 V is applied to the second photo gate PG2. Shows. In this case, the optoelectronics 1 generated in the photoelectric conversion region move to the second bridging region BD2. This is because the lateral field 3 is formed by the difference between the voltage applied to the first photo gate PG1 and the voltage applied to the second photo gate PG2. Therefore, in order to increase the photoelectron resolution of the sensor 10, it is necessary to increase the range in which the side electric field 3 is generated. As a result, the sensor 10 according to the embodiment of the present invention includes the structures of the first photo gate PG1 and the second photo gate PG2 as described above, thereby increasing the range in which the side electric field 3 is formed. Can be.

Here, the photoelectron resolution means the ability of the sensor 10 to move the generated optoelectronics 1 to a bridging region or floating diffusion region to be moved. In addition, the lateral electric field means a potential distribution having a slope so that the generated optoelectronics 1 can move.

3 is a circuit diagram including a plurality of photo gates and a plurality of transistors implemented in a depth pixel illustrated in FIG. 1.

1 to 3, the first transfer circuit TX1, which may be implemented as a MOSFET, is inside the semiconductor substrate 16-1 in response to the first transfer signal TG1 output from the timing controller 20. The optoelectronic generated in the transfer to the first floating diffusion region (FD1).

In addition, the second transmission circuit TX2, which may be implemented as a MOSFET, transmits the generated photoelectrons to the second floating diffusion region FD2 in response to the second transmission signal TG2 output from the timing controller 20. do. According to an embodiment, the first transmission signal TG1 and the second transmission signal TG2 may be the same signal.

Each reset transistor RX1 and RX2 may reset each floating diffusion region FD1 and FD2 in response to a reset signal RS output from the timing controller 20.

Each drive transistor DX1 and DX2, which can serve as a source follower buffer amplifier, responds to the voltage generated by the photoelectrons charged in the respective floating diffusion regions FD1 and FD2. An operation of buffering the supply voltage VDD may be performed.

Each of the select transistors SX1 and SX2 may output a signal buffered by each of the drive transistors DX1 and DX2 to each column line in response to the select signal SEL output from the timing controller 20. Can be.

FIG. 4 is a graph illustrating gate signals applied to the first photo gate and the second photo gate shown in FIG. 2.

1 to 4, the depth pixel 16 measures frame signals in response to gate signals G1a and G2a having a phase difference of 180 degrees, and then gate signals G1b having a phase difference of 180 degrees. And frame signals in response to G2b). Similarly, the depth pixel 16 measures frame signals in response to gate signals G1c and G2c having a phase difference of 180 degrees, and then frame signals in response to gate signals G1d and G2d having a phase difference of 180 degrees. Can be measured. That is, gate signals G1a to G1d having a phase difference of 90 degrees are periodically applied to the first photo gate PG1 and gate signals G2a to 90 degree having a phase difference of 90 degrees to the second photo gate PG2. G2d) is applied periodically. In this case, gate signals having a phase difference of 180 degrees with each of the gate signals applied to the first photo gate PG1 are periodically applied to the second photo gate PG2.

In this case, the sensor 10 may generate a depth signal based on the photoelectrons transferred to the floating diffusion region FD1 adjacent to the first photo gate PG1. According to an embodiment, the sensor 10 may generate a depth signal based on the photoelectrons transferred to the floating diffusion region FD2 adjacent to the second photo gate PG2. That is, the depth pixel 16 included in the sensor 10 has a one-tap pixel structure.

5 is a block diagram of an image sensor including a depth pixel according to another exemplary embodiment.

The image sensor 100 illustrated in FIG. 5 has a function of measuring depth information using distance pixels, and each color information (eg, a red color pixel, a green color pixel, and a blue color pixel). For example, a three-dimensional image sensor capable of combining the functions of measuring red color information, green color information, and blue color information) to obtain each color information together with the depth information.

The image sensor 100 includes an infrared light source 12, a timing controller 20, a pixel array 110, a row decoder 22, a column decoder 124, a CDS / ADC circuit 130, and an image signal processor 150. ). In some embodiments, the column decoder 124 may be disposed between the CDS / ADC circuit 130 and the image signal processor 150.

The infrared light source 12 may generate an infrared light signal, that is, a modulated infrared light signal under the control of the timing controller 20.

The pixel array 110 includes a plurality of pixels. Each of the plurality of pixels may be arranged by mixing at least two pixels among red pixels, green pixels, blue pixels, depth pixels, magenta pixels, cyan pixels, or yellow pixels. Each of the plurality of pixels is arranged in a matrix form at the intersection of the plurality of row lines and the plurality of column lines.

The red pixel generates a red pixel signal corresponding to wavelengths belonging to the red region of the visible light region, the green pixel generates a green pixel signal corresponding to wavelengths belonging to the green region of the visible light region, and the blue pixel Generates a blue pixel signal corresponding to wavelengths belonging to a blue region of the visible region. The depth pixel may generate a depth pixel signal corresponding to wavelengths belonging to an infrared region.

The structure and operation of the depth pixel implemented in the pixel array 110 are substantially the same as the structure and operation of the depth pixel described with reference to FIGS. 2 to 4.

The row decoder 22 may select any one of a plurality of rows implemented in the pixel array 110 in response to control signals output from the timing controller 20. A plurality of pixels may be arranged in each of the plurality of rows.

The column decoder 124 may select at least one column line among a plurality of column lines implemented in the pixel array 110 in response to control signals output from the timing controller 20.

Any one of the plurality of pixels implemented in the pixel array 110 may be selected by the row decoder 22 and the column decoder. Accordingly, a signal (eg, depth information or color information) generated by one selected pixel may be transmitted to the CDS / ADC circuit 130.

The CDS / ADC circuit 130 converts a signal (eg, depth information or color information) output from the pixel array 110 or the column decoder 124 into a digital signal. For example, the CDS / ADC circuit 130 generates a CDS signal by performing a CDS operation on a signal (eg, depth information or color information) output from the pixel array 110, and performs an ADC operation on the generated CDS signal. Digital signals can be generated.

The image signal processor 150 may detect a digital pixel signal (eg, depth information or color information) from the digital signal output from the CDS / ADC circuit 130 or the column decoder 124.

FIG. 6 is a block diagram of a data processing system including the image sensor shown in FIG. 5.

Referring to FIG. 6, the data processing system 200 may include an image sensor 100 and a processor 210.

The processor 210 may control an operation of the image sensor 100, for example, an operation of the timing controller 20. The processor 210 may store a program for controlling the operation of the image sensor 100. According to an embodiment, the processor 210 may access a memory (not shown) in which a program for controlling the operation of the image sensor 100 is stored and execute the program stored in the memory.

The image sensor 100 may generate 3D image information based on each digital pixel signal (eg, color information or depth information) under the control of the processor 210. The generated 3D image information may be displayed through a display (not shown) connected to the interface 230.

The 3D image information generated by the image sensor 100 may be stored in the memory device 220 through the bus 201 under the control of the processor 210. The memory device 220 may be implemented as a nonvolatile memory device.

The interface 230 may be implemented as an interface for inputting and outputting 3D image information. According to an embodiment, the interface 230 may be implemented as an input device such as a keyboard, a mouse, or a touch pad, or may be implemented as an output device such as a display or a printer.

FIG. 7 is a block diagram of a data processing system including the sensor shown in FIG. 1.

Referring to FIG. 7, the data processing system 300 includes a depth sensor 10, a color image sensor 310 including a plurality of color pixels, and a processor 210.

In FIG. 7, for convenience of description, the depth sensor 10 and the color image sensor 310 are physically separated from each other, but the depth sensor 10 and the color image sensor 310 are physically overlapped with each other. Circuits may be included.

Here, the color image sensor 310 may refer to an image sensor including a pixel array including red pixels, green pixels, and blue pixels, without including depth pixels. Accordingly, the processor 210 may determine the depth information detected by the depth sensor 10 and each color information detected by the color image sensor 310 (eg, red information, green information, blue information, magenta information, cyan information, Alternatively, the 3D image information may be generated based on at least one of the yellow information, and the generated 3D image information may be displayed on the display.

3D image information generated by the processor 210 may be stored in the memory device 220 through the bus 301.

The data processing system 200 or 300 shown in FIG. 6 or 7 may be used in a three-dimensional range finder, game controller, depth camera, or gesture sensing apparatus.

FIG. 8 is another embodiment of a data processing system including the sensor shown in FIG. 1.

Referring to FIG. 8, a data processing system 400 that can only operate as a simple depth (or distance) measurement sensor includes a distance sensor 10 and a processor 210 for controlling the operation of the distance sensor 10. do.

The processor 210 may calculate distance information or depth information between the data processing system 400 and the projectile (or target object) based on the depth information output from the depth sensor 10. Distance information or depth information measured by the processor 210 may be stored in the memory device 220 through the bus 401.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

10: Sensor
12: infrared light source
14: depth sensor array
16: depth pixel
17: Infrared pass filter
18: CDS / ADC circuit
20: timing controller
22: low decoder
24: memory
100: image sensor
110: pixel array
124: column decoder
130: CDS / ADC circuit
150: image signal processor
200: data processing system

Claims (10)

Includes depth pixels of a 1-tab pixel structure,
The depth pixel is,
Photoelectric conversion regions for generating photocharges;
An insulating layer formed on the semiconductor substrate including the photoelectric conversion region; And
Each comprising a first photo gate and a second photo gate implemented on the insulating layer,
A protruding pattern protruding from the central region toward the second photo gate is formed in the first photo gate.
The second photo gate has a structure spaced apart from the protruding pattern and surrounding the protruding pattern,
The size of the cross-sectional area of the first photo gate and the size of the cross-sectional area of the second photo gate are different. The method of claim 1,
And the sensor generates a depth signal based on the photocharge transferred to a floating diffusion region adjacent to the first photo gate. The method of claim 1,
The sensor measures the depth to the object based on the time of flight (TOF). The method of claim 2,
And a gate signal having a phase difference of 0 degrees, 90 degrees, 180 degrees, and 270 degrees is applied to the first photo gate with a time difference. The method of claim 2,
The size of the cross-sectional area of the first photo gate is greater than the size of the cross-sectional area of the second photo gate. The sensor of claim 1; And
And a processor for controlling the operation of the sensor. The method of claim 6, wherein the sensor,
And a depth signal based on the photocharges transferred to the floating diffusion region adjacent to the first photo gate. The method of claim 7, wherein
And a gate signal having a phase difference of 0 degrees, 90 degrees, 180 degrees, and 270 degrees is applied to the first photo gate with a time difference. The method according to claim 6,
The sensor measures a depth to a target object based on a time of flight (TOF). The method according to claim 6,
The data processing system is a three-dimensional range finder, a game controller, a distance camera, or a gesture sensing device.

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