3DIMENSION IMAGE SENSOR AND SYSTEM INCLUDING THE SAME

A 3D image sensor includes a first color filter configured to pass wavelengths of a first region of visible light and wavelengths of infrared light; a second color filter configured to pass wavelengths of a second region of visible light and the wavelengths of infrared light; and an infrared sensor configured to detect the wavelengths of infrared light passed through the first color filter.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1is a side view of a camera module according to at least one example embodiment of the inventive concepts. Referring toFIG. 1, the camera module10includes a board11, a dual band pass filter13, a lens holder15, a lens17, and a 3D image sensor20.

The dual band pass filter13passes wavelengths of visible region and wavelengths of infrared region. The 3D image sensor20generates color information and depth information by using the wavelengths of visible region and the wavelengths of infrared region. The 3D image sensor20is mounted on the board11.

FIG. 2is a block diagram of the camera module shown inFIG. 1. Referring toFIGS. 1 and 2, the 3D image sensor20capable of generating color information and depth information by using a time of flight (TOF) principle includes a pixel array22, a row decoder24, a timing controller26, a photogate controller28, and a logic circuit30.

The row decoder24selects any one of rows in response to a row address output from the timing controller26. Here, the row denotes assembly of pixels arranged in the X-direction in the pixel array22. The photogate controller28generates photogate control signals and provides the photogate control signals to the pixel array22under the control of the timing controller26.

The logic circuit30processes signals detected by the pixels embodied in the pixel array22to generate color information and depth information under the control of the timing controller26and outputs the processed signals into an image signal processor (ISP). The logic circuit30is embodied into two divisions, a circuit for processing detected signals for generating color information and a circuit for processing detected signals for generating depth information.

The image signal processor may calculate color information and depth information based on the processed signals. The 3D image sensor20and the image signal processor may be embodied into one chip or separated chips.

According to an exemplary embodiment, the logic circuit30may include an analog-digital conversion block (not shown) capable of converting detection signals output from the pixel array22into digital signals. According to another exemplary embodiment, the logic circuit30may include a correlated double sampling (CDS) block (not shown) for performing CDS with respect to the detection signals output from the pixel array22and an analog-digital conversion block (not shown) for converting the signals output from the CDS block into digital signals. Also, the logic circuit30may further include a column decoder (not shown) for outputting output signals of the analog-digital conversion block into the image signal processor under the control of the timing controller26.

A light source driver32may generate a clock signal (MLS) capable of driving a light source34under the control of the timing controller26. The light source34radiates a modulated optical signal EL into an object40. Examples of the light source34include, for example, one or more of a Light Emitting Diode (LED), Organic Light-Emitting Diode (OLED), infrared diode, and a laser diode. The modulated optical signal EL may be a sinusoidal wave or a square wave. The light source34is used for generating depth information. The light source34may be embodied as one or more light sources.

The light source driver32provides a clock signal MLS or information about the clock signal MLS to a photogate controller28.

Optical signal RL may be, for example, light reflected from the modulated optical signal EL. When the modulated signal EL output from the light source34is reflected from the object40, and the object40has different distances Z1, Z2, and Z3, a distance Z may be calculated as followings. For example, when the modulated optical signal EL is cos ωt, and the optical signal RL incident to an infrared sensor (not shown) or an optical signal RL detected by the infrared sensor is cos (ωt+φ), a phase shift φ by TOF is as followings;

wherein C is the speed of light. Accordingly, the distance Z from the light source34or the pixel array22to the object40may be obtained by followings;

The light source driver32and the light source34may be embodied into one chip along with the image sensor20.

The reflected light signal RL is input to the pixel array22through the lens17. The light AL is light reflected by the surrounding light36and is also input to the pixel array22through the lens17. The reflected light AL is used for generating color information. The light signal RL incident to the pixel array22through the lens may be detected by the infrared sensor.

FIG. 3is a cross-sectional view of the pixel array shown inFIG. 2according to at least one example embodiment of the inventive concepts. Referring toFIGS. 1 and 3, the pixel array22-1may be divided into a color pixel region21-1and a depth pixel region23-1.

The color pixel region21-1includes micro lenses51-1,53-1, and55-1, color filters57-1and61-1, an anti-reflective layer63-1, a first epitaxial layer65-1, a first inter-metal dielectric layer73-1, and a first pad91-1.

Each of the micro lenses51-1,53-1, and55-1concentrates light incident from the outside. The color pixel region21-1may be embodied without the micro lenses51-1,53-1, and55-1in some embodiments. The light incident from the outside includes the light AL reflected by the surrounding light36and the light signal RL reflected by the light source34. The light signal RL is used for generating depth information. The light incident from the outside includes wavelengths of visible region and wavelengths of infrared region passed through the dual band pass filter13.

Each of the color filters57-1and61-1transmits wavelengths of the visible region and wavelengths of the infrared region. For example, each of the color filters57-1and61-1may be include at least one of a blue filter and a red filter. The blue filter passes wavelengths of blue region within the visible region and wavelengths of infrared region. The red filter passes wavelengths of red region within visible region and wavelengths of infrared region. The wavelengths become longer from a blue region toward a red region of visible region. For example, when the color filters57-1and61-1are a blue filter and a red filter, respectively, almost all of the wavelengths passed through the blue filter may be transmitted to an optical detector67-1, and the wavelengths passed through the red filter may be transmitted further than the wavelengths passed through the blue filter.

According to at least one example embodiment of the example embodiments, the color filter57-1or61-1may be a cyan filter, magenta filter, or yellow filter. The cyan filter transmits wavelengths of 450˜550 nm range within the visible region and wavelengths of infrared region. The magenta filter transmits wavelengths of 400˜480 nm range within the visible region and wavelengths of infrared region. The yellow filter transmits wavelengths of 500˜600 nm range within the visible region and wavelengths of infrared region.

The color pixel region21-1includes an infrared filter59-1. The wavelengths of infrared region are longer than the wavelengths of visible region. Thus, when the infrared filter59-1is used, the wavelengths of the infrared region are transmitted to the infrared sensor85-1. A color filter (for example, a green filter) may be used instead of the infrared filter. The green filter transmits wavelengths of green region in within the visible region and wavelengths of infrared region.

The anti-reflective layer63-1is used for reducing reflection. The anti-reflective layer63-1increases contrast of image. The first epitaxial layer65-1includes optical detectors67-1,69-1, and71-1.

Each of the optical detectors67-1,69-1, and71-1generates a photoelectron in response to the light input from the outside. That is, each of the optical detectors67-1,69-1, and71-1generates photoelectrons in response to the light including wavelengths of visible region and wavelengths of infrared region. The optical detectors67-1and71-1are used for generating color information. The light passed through the infrared filter59-1is converted into photoelectrons by the optical detector69-1. The converted photoelectrons may be used for compensating the color information.

Each of the optical detectors67-1,69-1and71-1is formed on the first epitaxial layer65-1. Each of the optical detectors67-1,69-1and71-1is a photosensitive element and may be embodied as, for example, one or more of a photodiode, phototransistor, photogate, or pinned photodiode (PPD).

The inter-metal dielectric layer73-1may be formed in an oxide layer or a composite layer of oxide layer and nitride layer. The oxide layer may be, for example, a silicon oxide layer. The inter-metal dielectric layer73-1may include metals75-1. An electric wiring required for the sensing operation of the color pixel region21-1may be formed by metals75-1. The metals75-1may include, for example, one or more of copper, titanium, and titanium nitride.

The color pixel region21-1may be embodied in the form of a back side illuminated (BSI) structure. The depth pixel region23-1includes a second inter-metal dielectric layer79-1, a second epitaxial layer (83-1), and a second pad93-1. The depth pixel23-1may further include a near-infrared pass filter77-1. The near-infrared pass filter77-1may be required to prevent long wavelengths (for example, wavelengths of red region) of visible region from being transmitted to the infrared sensor85-1. According to at least one example embodiment of the inventive concepts, the wavelengths of light passed by the near-infrared pass filter77-1may include wavelengths smaller than those passed by the infrared filter59-1. For example, the near-infrared pass filter77-1may pass wavelengths of light above 820 mm while the infrared filter59-1may pass wavelengths of light above 850 mm.

The second inter-metal dielectric layer79-1may be formed in an oxide layer or a composite layer of oxide layer and nitride layer. The oxide layer may be, for example, a silicon oxide layer. The second inter-metal dielectric layer79-1may include metals81-1. An electric wiring required for the sensing operation of the color pixel region23-1may be formed by metal81-1.

The infrared sensor85-1is formed on the second epitaxial layer83-1. The infrared sensor85-1detects wavelengths of infrared region. That is, the infrared sensor85-1generates photoelectrons in response to the light including wavelengths of infrared region. The light is incident by the light source34. The infrared sensor85-1is used for generating depth information. The infrared sensor85-1may be embodied by using a photo gate (not shown).

According to at least one example embodiment of the inventive concepts, the size of the infrared sensor85-1may be larger than the size of the color filter57-1or61-1. The depth pixel region23-1may be embodied in the form of a front side illuminated (FSI) structure. According to at least one example embodiment of the inventive concepts, bonding may be required once to manufacture the pixel array22-1. The first pad91-1is located on the second pad93-1. That is, according to at least one example embodiment of the inventive concepts, the color pixel region21-1is stacked on the depth pixel region23-1.

FIG. 4is a cross-sectional view of the pixel array shown inFIG. 2according to another exemplary embodiment. Referring toFIGS. 2 and 4, the pixel array22-2may be divided into a color pixel region21-2and a depth pixel region23-2.

The color pixel region21-2includes micro lenses51-2,53-2, and55-2, color filters57-2,61-2, an infrared filter59-2, an anti-reflective layer63-2, a first epitaxial layer65-2, a first inter-metal dielectric layer73-2, and a first pad91-1. According to at least one example embodiment of the inventive concepts, the color pixel region21-2may have the same structure and function as the color pixel region21-1ofFIG. 3. Accordingly, detailed descriptions of components51-2,53-2,55-2,57-2,59-2,61-2,63-2,65-2,73-2, and91-2ofFIG. 4are omitted.

The depth pixel region23-2includes a second epitaxial layer83-2, a second inter-metal dielectric layer79-2, a carrier substrate87-2, and a second pad93-2. An infrared filter85-2is formed on the second epitaxial layer83-2. According to at least one example embodiment of the inventive concepts, the infrared sensor85-2may have the same structure and function as the infrared sensor85-1ofFIG. 3. Accordingly, detailed descriptions of the infrared sensor85-2are omitted.

The second inter-metal dielectric layer79-2may be formed in an oxide layer or a composite layer of oxide layer and nitride layer. The oxide layer may be, for example a silicon oxide layer. The second inter-metal dielectric layer79-2may include metals81-2,82-2. Electric wiring used for the sensing operation of the depth pixel region23-2may be formed by metals81-2. Further, the metals82-2may be used to reflect the light incident through the infrared sensor85-1back to the infrared sensor85-1.

The carrier substrate87-2may be a silicon substrate. The depth pixel region23-2may further include a near-infrared pass filter77-2. The near-infrared pass filter77-2passes wavelengths of near-infrared pass filter region to transmit wavelengths of infrared region to the infrared sensor85-2. The depth pixel region23-2may be embodied in the form. of a back side illuminated (BSI) structure. According to at least one example embodiment of the inventive concepts, bonding may be required twice to manufacture the pixel array22-2. The first pad91-2is located on the second pad93-2.

FIG. 5is a cross-sectional view of the pixel array shown inFIG. 2according to yet another exemplary embodiment of the inventive concepts. Referring toFIGS. 2 and 5, the pixel array22-3may be divided into a color pixel region21-3and a depth pixel region23-3.

The color pixel region21-3includes micro lenses51-3,53-3, and55-3, color filters57-3,61-3, an anti-reflective layer63-3, a first epitaxial layer65-3, a first inter-metal dielectric layer73-3, and a first pad93-3.

According to at least one example embodiment of the inventive concepts, the micro lenses51-3,53-3, and55-3, color filters57-3,61-3, the anti-reflective layer63-3, and the infrared filter59-3may have the same structure and functions as the micro lenses51-1,53-1, and55-1, color filters57-1,61-1, the anti-reflective layer63-1, and the infrared filter59-1ofFIG. 3. Accordingly, detailed descriptions of the above-referenced components of pixel region21-3are omitted.

The first epitaxial layer65-3includes optical detectors67-3,69-3, and71-3. The first inter-metal dielectric layer73-3includes metals75-3. According to at least one example embodiment of the inventive concepts, the optical detectors67-3,69-3,71-3and the metals75-3may have the same structure and functions as the optical detectors67-1,69-1,71-1and the metal75-1ofFIG. 3. Accordingly, detailed descriptions of the above-referenced components of pixel region21-3are omitted.

The color pixel region21-3may be embodied in the form of a front side illuminated (FSI) structure. According to at least one example embodiment of the inventive concepts, the depth pixel region23-3may be the same as the depth pixel region23-1ofFIG. 3, Accordingly, detailed descriptions of the pixel region23-3are omitted. The first pad91-3is located on a second pad93-3.

FIG. 6is a cross-sectional view of the pixel array shown inFIG. 2according to still yet another exemplary embodiment of the inventive concepts. Referring toFIGS. 2 and 6, the pixel array22-4may be divided into a color pixel region21-4and a depth pixel region23-4. According to at least one example embodiment of the inventive concepts, the color pixel region21-4may be the same as the color pixel region21-3ofFIG. 5. Accordingly, detailed descriptions of the above-referenced components of pixel region21-4are omitted. Also, the depth pixel region23-4is identical to the depth pixel region23-2, thereby omitting detailed descriptions thereof.

FIG. 7is a top view of the pixel array22shown inFIG. 2. Referring toFIGS. 2 and 7, the pixel array22may be embodied as an M×N matrix (where M and N are natural numbers). However, for convenience of explanation,FIG. 7will be explained with reference to an example where matrix22-5is a 4×4 matrix.

The 4×4 matrix22-5includes red filters R, green filters G, and blue filters B. According to at least one example embodiment of the inventive concepts, each filter R, G, and B may have the same size. Further, according to at least one example embodiment of the inventive concepts, the 4×4 matrix may include cyan filters, magenta filters, or yellow filters instead of one or all of the red filters R, green filters G, and blue filters B.

FIG. 8is a top view of the pixel array22shown inFIG. 2according to another exemplary embodiment. Referring toFIGS. 2 and 8, as is discussed above, the pixel array22may be embodied as an M×N matrix. However, 4×4 matrix22-6is shown as an example for convenience of explanation. The 4×4 matrix22-6includes red filters R, green filters G, blue filters B, and infrared filters IR. According to at least one example embodiment of the inventive concepts, each filter R, G, B, and IR may have the same size. Further, according to at least one example embodiment of the inventive concepts, the 4×4 matrix may include cyan filters, magenta filters, and yellow filters instead of one or all of the red filters R, green filters G, and blue filters B.

FIG. 9is a block diagram of a 3D image sensing system including the camera module ofFIG. 1. Referring toFIG. 9, the 3D image sensing system900is a device for providing a user with 3D images. The 3D images denote images including depth information and color information.

For example, the 3D image sensing system900may be included in a 3D digital camera or any electronic device including the 3D digital camera, including, for example, portable electronic devices. The 3D image sensing system900may process three dimensional image information. The 3D image sensing system900may include a camera module930and a processor910for controlling the operation of the camera module930. The camera module930may be, for example, the camera module10shown inFIG. 1.

The 3D image sensing system900may further include an interface940. The interface940may be an image display device such as 3D display device.

The 3D image sensing system900may further include a memory device920storing a movie or a still image captured by the camera module930. The memory device920may be embodied into a non-volatile memory device. The non-volatile memory device may be embodied into Electrically Erasable Programmable Read-Only Memory (EEPROM), flash memory, Magnetic RAM (MRAM), Spin-Transfer Torque MRAM, Conductive bridging RAM (CBRAM), Ferroelectric RAM (FeRAM), Phase change RAM (PRAM) also referred to as Ovonic Unified Memory (OUM), Resistive RAM (RRAM or ReRAM), Nanotube RRAM, Polymer RAM (PoRAM), Nano Floating Gate Memory (NFGM), holographic memory, Molecular Electronics Memory Device, or Insulator Resistance Change Memory.

FIG. 10is a block diagram of another 3D image sensing system including the camera module shown inFIG. 1. Referring toFIG. 10, the 3D image sensing system1200may be embodied into a data processing apparatus capable of using or supporting an MIPI interface, for example, mobile phone, personal digital assistant (PDA), portable multi-media player (PMP), or smart phone. The 3D image sensing system1200includes an application processor1210, a camera module1240, and a 3D display1250.

A CSI host1212embodied in the application processor1210may perform serial communication with a CSI device1241of the camera module1240through a camera serial interface (CSI). At this time, for example, the CSI host1212may include an optical deserializer DES, and the CSI device1241may include an optical serializer SER. The camera module1240may be, for example, the camera module10ofFIG. 1.

A DSI host1211included in the application processor1210may perform serial communication with a DSI device1251of a 3D display1250through a display serial interface (DSI). At this time, for example, the DSI host1211may include an optical serializer SER and the DSI device1251may include an optical deserializer DES.

The 3D image sensing system1200may further include an RF chip1260communicating with the application processor1210. A PHY1213of the 3D image system1200and a PHY1261of the RF chip1260may exchange data according to MIPI DigRF. The 3D image sensing system1200may further include a GPS1220, a storage1270, a mike1280, a DRAM1285and a speaker1290, and may perform communication by using a Wimax1230module, WLAN1300module, and a UWB1310module.

The 3D image sensor and the system including the same according to at least one example embodiment of the inventive concepts may generate depth information and color information at the same time by allowing the color filter to pass wavelengths of visible region and wavelengths of infrared region.