Image Sensor

Abstract

An image sensor is disclosed. The image sensor includes: first pixels of a first color, which are arranged alternately with pixels of a second color along a first direction of a pixel array; second pixels of the first color, which are arranged alternately with pixels of a third color along a first direction in a row different from the row of the first pixels of the first color; an isolation layer formed to surround the first pixel in the pixel array and configured to have a first depth; and an isolation layer formed to surround the second pixel in the pixel array and configured to have a second depth different from the first depth. One of the first pixel of the first color and the second pixel of the first color and each of the pixel of the second color and the pixel of the third color are configured to selectively receive light of different colors, respectively.

Description

Technical Field

[0001] The techniques and implementations disclosed in this patent document generally relate to an image sensor having an isolation layer configured to optically isolate a plurality of consecutive or adjacent pixels from each other. Background Art

[0002] Image sensors are semiconductor devices used to capture optical images and convert them into electrical signals. With the recent development of computer, automobile, medical and communication technologies, efforts to develop high-quality, high-performance image sensors continue to meet the needs of various devices such as smart phones, digital cameras, game consoles, Internet of Things (IoT), robots, surveillance cameras, medical micro cameras, etc.

[0003] A very common type of image sensing device is a charge coupled device (CCD), which has long dominated the field of image sensors. Another common type of image sensing device is a complementary metal oxide semiconductor (CMOS) image sensing device. CCD image sensors have advantages over CMOS image sensors in terms of noise characteristics and image quality. However, due to certain advantages over their CCD counterparts (including, for example, higher frame rates and shutter speeds), CMOS image sensors are now widely used. In addition, CMOS image sensors and signal processing circuits can be integrated into a single chip, thereby enabling electronic devices to be miniaturized while achieving lower power consumption. In addition, the use of CMOS manufacturing technology can reduce production costs. These characteristics of CMOS image sensors make these sensors better suited for implementation in mobile devices. Summary of the invention

[0004] Among other features and benefits, embodiments of the disclosed technology relate to an image sensor that is capable of effectively reducing noise in an image.

[0005] Some embodiments of the disclosed technology relate to an image sensor capable of reducing noise in an image by minimizing incidence angle variations associated with green pixels.

[0006] In one embodiment of the disclosed technology, an image sensor may include: first pixels of a first color, which are arranged alternately with pixels of a second color along a first direction of a pixel array; second pixels of the first color, which are arranged alternately with pixels of a third color along a first direction in a row different from the row of the first pixels of the first color; an isolation layer formed to surround the first pixel in the pixel array and configured to have a first depth; and an isolation layer formed to surround the second pixel in the pixel array and configured to have a second depth different from the first depth. One of the first pixel of the first color and the second pixel of the first color and each of the pixel of the second color and the pixel of the third color are configured to selectively receive light of different colors, respectively.

[0007] In another embodiment of the disclosed technology, an image sensor may include: a color filter array including a red filter, a blue filter, and a green filter arranged in a Bayer pattern; and a substrate in which an isolation layer is formed to surround each of the red filter, the blue filter, and the green filter. The isolation layer surrounding the green filter adjacent to the red filter included in the color filter array along a first direction has a first depth. The isolation layer surrounding the green filter adjacent to the blue filter included in the color filter array along the first direction has a second depth different from the first depth. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a block diagram illustrating an example of an image sensor based on some implementations of the disclosed technology.

[0009] Figure 2 Some implementations based on the disclosed technology are shown Figure 1 A schematic diagram of an example of a pixel array is shown.

[0010] Figure 3 Some implementations based on the disclosed technology are shown Figure 2 Schematic diagram of an example of the right region (RT) is shown.

[0011] Figure 4 is a diagram showing some implementations based on the disclosed technology. Figure 3 A cross-sectional view of the comparative example of the right region (RT) cut along the first cutting line shown.

[0012] Figure 5 is a diagram showing some implementations based on the disclosed technology. Figure 3 A cross-sectional view of an example of the right side region (RT) taken along the first cutting line shown.

[0013] Figure 6 is a diagram showing some implementations based on the disclosed technology. Figure 3 A cross-sectional view of the comparative example of the right region (RT) cut along the second cutting line shown.

[0014] Figure 7 is a diagram showing some implementations based on the disclosed technology. Figure 3 An example cross-sectional view of the right region (RT) taken along the second cutting line is shown.

[0015] Figure 8 Some implementations based on the disclosed technology are shown Figure 2 Schematic diagram of an example of a top region (TP) is shown.

[0016] Fig. 9 is a diagram showing some implementations based on the disclosed technology. Figure 8 A cross-sectional view of a comparative example of a top region (TP) taken along a third cutting line is shown.

[0017] Fig.10 is a diagram showing some implementations based on the disclosed technology. Figure 8 A cross-sectional view of an example of a top region (TP) taken along a third cutting line is shown.

[0018] Fig.11 is a diagram showing some implementations based on the disclosed technology. Figure 8 A cross-sectional view of a comparative example of a top region (TP) taken along a fourth cutting line is shown.

[0019] Fig.12 is a diagram showing some implementations based on the disclosed technology. Figure 8 A cross-sectional view of an example of a top region (TP) taken along a fourth cutting line is shown.

[0020] Fig.13 is a conceptual diagram illustrating a method of improving the GG ratio based on some implementations of the disclosed technology. DETAILED DESCRIPTION

[0021] The present patent document provides an implementation and example of an image sensor that substantially solves one or more problems caused by limitations and disadvantages of the related art. Some implementations of the disclosed technology are directed to minimizing the amount of noise associated with a signal generated from a green pixel. Some embodiments of the disclosed technology provide an image sensor that is capable of reducing noise generated due to changes in the angle of incidence of light at a green pixel arranged in an area close to an edge area of ​​a pixel array.

[0022] Figure 1 is a block diagram illustrating an example of an image sensor 100 based on some implementations of the disclosed technology.

[0023] In some implementations, image sensor 100 may include pixel array 110 , row decoder 120 , correlated double sampling (CDS) circuit 130 , analog-to-digital converter (ADC) 140 , output buffer 150 , column decoder 160 , and timing controller 170 .

[0024] The pixel array 110 may include a plurality of unit pixels arranged in a two-dimensional (2D) shape. The plurality of unit pixels may be implemented so that at least two unit pixels share at least one element, so that a plurality of unit pixels designed as a unit of a shared pixel structure sharing at least one element can convert an optical signal or incident light into an electrical signal on a shared pixel basis. The pixel array 110 may receive a drive signal including (among other signals) a row selection signal, a reset control signal, a transmission (Tx) control signal, etc. from the row decoder 120, and may operate based on the drive signal received from the row decoder 120.

[0025] For example, a 4-transistor (Tr) based unit pixel may include a photodiode, a transfer transistor, a reset transistor, a driving transistor, and a selection transistor.

[0026] The photodiode can accumulate therein a photocharge corresponding to the amount of incident light. One end of the photodiode can be connected to receive a source voltage, and the other end of the photodiode can be connected to a transfer transistor. In some implementations, the source voltage can be a ground voltage. In the context of this patent document, the photodiode can include any type of photoelectric conversion element. For example, the photodiode can be a phototransistor, a photogate, a pinned photodiode, or a combination thereof.

[0027] The transfer transistor may be connected in series between the photodiode and the floating diffusion (FD) region. The transfer transistor may be turned on or off in response to a transmission (Tx) control signal. The turned-on transfer transistor may transmit the photocharge accumulated in the photodiode to the floating diffusion (FD) region.

[0028] The floating diffusion (FD) region may receive photocharges of the photodiode through the transfer transistor and may accumulate the received photocharges therein. The floating diffusion (FD) region may be modeled as a junction capacitor.

[0029] The reset transistor may be coupled between the drain voltage and the floating diffusion (FD) region and may reset the voltage at the floating diffusion (FD) region to the drain voltage in response to a reset control signal. In some implementations, the drain voltage may be a supply voltage (or power supply voltage).

[0030] The drive transistor may amplify a voltage level of a floating diffusion (FD) region to which photocharges accumulated in the photodiode have been transmitted, and may transmit the amplified voltage to the selection transistor. In some implementations, the drive transistor may operate as a source follower transistor.

[0031] When a read operation is performed on a row basis, the selection transistor can be used to select at least one pixel. The selection transistor can be turned on by a selection control signal so that a signal corresponding to a voltage at a floating diffusion (FD) region supplied to the drain of the selection transistor (i.e., the source of the source follower transistor) can be output as an output voltage.

[0032] The output voltage of the selection transistor may correspond to a reference signal (ie, a signal corresponding to a reset floating diffusion (FD) region) and an image signal (ie, a signal corresponding to a floating diffusion (FD) region accumulating photocharges received from the photodiode PD).

[0033] The row decoder 120 may drive the pixel array 110 under the control of the timing controller 170. In some implementations, the row decoder may select at least one row from the pixel array 110. The row decoder 120 may generate a row selection signal to select at least one row among the plurality of rows. The row decoder 120 may sequentially enable a pixel reset signal for a pixel corresponding to at least one selected row and a transmit (Tx) signal for the pixel. As a result, an analog reference signal and an image signal generated from each pixel of the selected row may be sequentially sent to the CDS circuit 130. In this case, the reference signal and the image signal may be collectively referred to as a pixel signal as needed.

[0034] The CDS circuit 130 may sequentially sample and hold a reference signal and an image signal transmitted from the pixel array 110 to each of the plurality of column lines. That is, the CDS circuit 130 may sample and hold the levels of the reference signal and the image signal corresponding to each column of the pixel array 110.

[0035] Upon receiving a control signal from the timing controller 170 , the CDS circuit 130 may transmit a correlated double sampling (CDS) signal corresponding to a reference signal and an image signal for each column to the ADC 140 .

[0036] In some implementations, the CDS circuit 130 may be used to remove an undesired offset value of a pixel by sampling the pixel signal twice to remove the difference between the two samples. For example, correlated double sampling (CDS) may remove an undesired offset value of a pixel by comparing the pixel output voltage obtained before and after light is incident on the pixel so that only the pixel output voltage based on the incident light can be measured.

[0037] ADC 140 may be used to convert an analog CDS signal into a digital signal. ADC 140 may receive a CDS signal for each column from CDS circuit 130, may convert the received CDS signal into a digital signal, and may thus output a digital signal. ADC 140 may generate digital image data based on the CDS signal for each column and a ramp signal received from timing controller 170.

[0038] The ADC 140 may include a plurality of column counters corresponding to the respective columns of the pixel array 110, and may convert the CDS signal of each column into a digital signal as image data using the column counters. In another embodiment, the ADC 140 may include a single global counter, and may convert the CDS signal corresponding to each column into a digital signal using a global code received from the global counter.

[0039] The output buffer 150 may receive image data of each column from the ADC 140, may capture the received image data, and may output the captured image data. The output buffer 150 may temporarily store the image data output from the ADC 140 upon receiving a control signal from the timing controller 170. The output buffer 150 may operate as an interface configured to compensate for a difference in a transmission (Tx) speed (or a processing speed) between the image sensor 100 and another device coupled to the image sensor 100.

[0040] The column decoder 160 may select a column of the output buffer 150 upon receiving a control signal from the timing controller 170, and may sequentially output the image data temporarily stored in the output buffer 150. In some implementations, when receiving an address signal from the timing controller 170, the column decoder 160 may generate a column selection signal based on the received address signal, and select a column of the output buffer 150, so that the column decoder 160 may control the image data to be output from the selected column of the output buffer 150 as the output signal S0.

[0041] The timing controller 170 may control the row decoder 120 , the ADC 140 , the output buffer 150 , and the column decoder 160 .

[0042] The timing controller 170 may provide a clock signal to the internal circuit of the image sensor 100. The timing controller 170 may also provide a control signal required for timing control and an address signal required for selecting a row or column to the row decoder 120, the column decoder 160, the ADC 140, and the output buffer 150. In one embodiment, the timing controller 170 may include a logic control circuit, a phase-locked loop (PLL) circuit, a timing control circuit, a communication interface circuit, etc.

[0043] Figure 2Some implementations based on the disclosed technology are shown Figure 1 Schematic diagram of an example of a pixel array shown.

[0044] In some implementations, pixel array 110 can include a plurality of pixels arranged in a matrix including a plurality of rows and a plurality of columns.

[0045] A plurality of pixels may be arranged in a Bayer pattern, and any (2×2) pixel array may include a single red pixel (R), a single blue pixel (B), and two green pixels Gr and Gb. A green pixel (Gr) may represent a green pixel adjacent to a red pixel (R) in a row direction (or a first direction), and a green pixel (Gb) may represent a green pixel adjacent to a blue pixel (B) in a row direction (or a first direction). In other words, in a single row of the pixel array 110, red pixels (R) and green pixels (Gr) may be arranged alternately along the row direction. In another row adjacent to the above-mentioned single row, blue pixels (B) and green pixels (Gb) may be arranged alternately along the row direction. In an embodiment of the disclosed technology, a green pixel (Gr) may be defined as a first green pixel, and a green pixel (Gb) may be defined as a second green pixel. In addition, a red pixel (R) may be defined as a first pixel, and a blue pixel (B) may be defined as a second pixel. As will be described later, any one of the first green pixel and the second green pixel may receive light of different colors, and the first pixel and the second pixel may receive light of different colors.

[0046] In the context of this patent document, a red pixel refers to an imaging pixel including a red color filter, a blue pixel refers to an imaging pixel including a blue color filter, and a green pixel refers to an imaging pixel including a green color filter.

[0047] The red pixel (R), the blue pixel (B), and the green pixels Gr and Gb can be classified according to the type of color filter contained in each pixel. Each imaging pixel includes a filter located above each photoelectric conversion element to filter the light to be detected by the photoelectric conversion element. That is, the color filter contained in the red pixel (R) can be used to filter the wavelength band corresponding to red light, and can pass the filtered light therethrough, so that the intensity of the light corresponding to red can be sensed. The color filter contained in the blue pixel (B) can pass the wavelength band corresponding to blue therethrough, so that the intensity of the light corresponding to blue light can be sensed by the corresponding photoelectric conversion element. The color filter contained in each of the green pixels Gr and Gb can pass the wavelength band corresponding to green therethrough, so that the intensity of the light corresponding to green light can be sensed by the corresponding photoelectric conversion element. The imaging pixels in the pixel array 110 are classified according to the type of color filter contained in each pixel, and therefore each photoelectric conversion element has a color filter thereon. Therefore, it can be said that the pixel arrangement in the pixel array 110 matches the color filter arrangement in the color filter array (CFA).

[0048] In some implementations, the pixel array 110 may be divided into different regions, including a central region (CT), a left region (LF) located on a first side of the central region (CT) (which will be referred to as the “left side” or the “left region” for convenience), a right region (RT) located on a second side of the central region (CT) (the opposite side to the first side; which will be referred to as the “right side” or the “right region” for convenience), a top region (TP) located on a third side (e.g., located above the central region (CT)), and a bottom region (BT) located on a fourth side (e.g., located below the central region (CT)). In other words, the left region (LF), the right region (RT), the top region (TP), and the bottom region (BT) may be classified according to their relative positions relative to the central region (CT).

[0049] The number of rows and columns included in each of the central region (CT), the left region (LF), the right region (RT), the top region (TP), and the bottom region (BT) may vary according to the specifications required for the image sensor device, and a plurality of regions adjacent to each other may be arranged continuously or spaced a predetermined distance apart from each other as required. In one example, each of the left region (LF), the right region (RT), the top region (TP), and the bottom region (BT) may be divided into a plurality of sub-regions.

[0050] When operating an image sensor including a pixel array 110, light incident on an imaging pixel passes through a lens module (not shown) including at least one lens arranged with an optical axis as the center, and then the light reaches the pixel array 110 to convert the intensity of the incident light into an electrical signal. In this case, since the central region (CT), the left region (LF), the right region (RT), the top region (TP), and the bottom region (BT) are located at different positions, the incident angle of the chief ray (also referred to as the key ray) directed to different regions (CT, LF, RT, TP, BT) may vary. Assuming that the optical axis can be located at the center point of the pixel array 110, the pixel array 110 is spaced a predetermined distance from the lens module (not shown), and the chief ray can propagate from the point where the lens module (not shown) and the optical axis intersect toward each region of the pixel array 110. Therefore, the main light of the left region (LF) can enter the left region (LF) from the center point of the pixel array 110 along the left direction, the main light of the right region (RT) can enter the right region (RT) from the center point of the pixel array 110 along the right direction, the main light of the top region (TP) can enter the top region (TP) from the center point of the pixel array 110 along the upward direction, and the main light of the bottom region (BT) can enter the bottom region (BT) from the center point of the pixel array 110 along the downward direction.

[0051] Figure 3 Some implementations based on the disclosed technology are shown Figure 2 Schematic diagram of an example of the right region (RT) is shown.

[0052] In some implementations, the right region (RT) may include pixels arranged in a (4×4) matrix, and the pixels may be arranged in a Bayer pattern. Figure 3 Pixels arranged in a (4×4) matrix are disclosed, and the arrangement of pixels in the matrix may vary according to various embodiments.

[0053] As described above, the main light of the right region (RT) may be arranged in a direction from the center point of the pixel array 110 to the right side of the pixel array 110. In this case, the isolation layer (e.g., Figure 5 The depth of the green pixel (Gb) may be set to a first depth greater than the reference depth. Figure 7 The depth of 234) can be set to a second depth that is less than the reference depth.

[0054] although Figures 3 to 7 The following examples shown will focus on the right region (RT) for disclosure, but in some implementations, the same or similar structure may also be applied to the left region (LF).

[0055] exist Figure 3 In FIG. 1 , an isolation layer corresponding to a first depth is represented by a solid line, and another isolation layer corresponding to a second depth is represented by a dotted line.

[0056] Figure 4 is a diagram showing some implementations based on the disclosed technology. Figure 3 The cross-sectional view of the comparative example of the right region (RT) cut along the first cutting line AA′ is shown.

[0057] Assuming that the depth of the isolation layer included in the right region (RT) is set as the reference depth (DTr), Figure 4 A cross-sectional view 200 taken along a first cutting line AA′ is shown in FIG.

[0058] Reference Figure 4 , the cross-sectional view 200 may include a substrate 210 , at least one photodiode 220 , at least one isolation layer 230 , at least one grid 250 , at least one over-coating layer 260 , and at least one microlens 270 .

[0059] The substrate 210 may be a silicon substrate and may include at least one photodiode 220 and at least one isolation layer 230. The substrate 210 may be a P-type substrate doped with P-type ions. The bottom surface of the substrate 210 may be defined as the front surface, and the top surface of the substrate 210 may be defined as the back surface. Therefore, each pixel may include a back side illumination (BSI) structure designed to receive incident light through the back surface of the substrate 210.

[0060] The photodiode 220 can be formed as an N-type doped region by ion implantation of N-type ions. In one embodiment, the photodiode 220 can be formed by stacking a plurality of doped regions. In this case, the lower doped region can be formed by implanting N+ ions, and the upper doped region can be formed by implanting N- ions. The photodiode 220 can be arranged on as large an area as possible to increase the fill factor indicating the light receiving (Rx) efficiency.

[0061] When viewed in a plane, the isolation layer 230 may be formed to surround the peripheral area of ​​each pixel. In one example, the isolation layer 230 may be formed by etching a predetermined depth in a vertical direction from the back side of the substrate 210, and the process may be performed using a deep trench isolation (DTI) process. The isolation layer 230 may be used to electrically isolate or optically isolate each of the continuous pixels that are adjacent to each other. Because the isolation layer 230 is formed by a DTI process on the back side of the substrate 210, the isolation layer 230 may be defined as a backside DTI (BDTI).

[0062] In some implementations, the isolation layer 230 may include a sidewall 230a and an inner layer 230b. In some implementations, the sidewall 230a may be formed outside the inner layer 230b, or may surround the inner layer 230b. In some implementations, the inner layer 230b may include an electrode connected to an interconnect structure in the image sensor.

[0063] The sidewall 230a may be formed of an insulating material having a different refractive index from the substrate 210. That is, the sidewall 230a may be formed of an insulating material having a high reflectivity in a different manner from the substrate 210. In some implementations, the sidewall 230a may be formed of at least one selected from the group consisting of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film. The sidewall 230a may be used to avoid possible optical crosstalk that may result in a reduction in a signal-to-noise ratio (SNR) due to light that enters a pixel and accidentally propagates to another pixel near the pixel.

[0064] The inner layer 230b may be formed of a conductive material that fills the trench region of the isolation layer 230 in the inner region of the sidewall 230a. In some implementations, the inner layer 230b may be formed of polysilicon or doped polysilicon doped with impurities. In one embodiment of the disclosed technology, the inner layer 230b may receive a negative (-) bias from an external circuit (e.g., a row decoder 120). When a negative bias is applied to the inner layer 230b, the electrons in the inner layer 230b may move to a position closer to the sidewall 230a. As a result, the holes in the substrate 210 may flow to the interface between the sidewall 230a and the substrate 210, so that the resulting holes may be accumulated and fixed. As described above, the holes in the substrate 210 that are accumulated and fixed at the interface between the sidewall 230a and the substrate 210 can suppress the undesired electron flow (i.e., dark current) generated on the surface of the substrate 210 due to the DTI process.

[0065] The depth of the isolation layer 230 may be set to Figure 4The reference depth (DTr) shown. The reference depth (DTr) may indicate the depth of the isolation layer 230 formed in the central region (CT) where the incident light is vertically guided and not tilted. That is, the reference depth (DTr) may indicate a predetermined depth by which the anti-noise characteristics associated with crosstalk, dark current, or any other unwanted noise of the pixel signal in the central region (CT) where the main light is incident in the same or similar direction as the optical axis direction may be optimized.

[0066] The color filter 240 may be formed over the substrate 210 and may selectively pass light having a specific wavelength (eg, red light, green light, blue light, etc.) therethrough. In one implementation, an anti-reflection layer (not shown) may be formed under the color filter 240 .

[0067] The grid 250 may be formed between color filters 240 that are continuous (or adjacent) to each other to prevent optical crosstalk between the continuous color filters 240. In some implementations, the grid 250 may be formed of a metal material (eg, tungsten) having a high light absorption rate.

[0068] The cover layer 260 may be disposed above the color filter 240 and the grid 250 and may prevent diffuse reflection of incident light received from the outside, thereby suppressing flare characteristics. In addition, the cover layer 260 may compensate for the step difference between the color filter 240 and the grid 250, so that the cover layer 260 may allow the microlens 270 to have a constant height.

[0069] The microlens 270 may be formed on the cover layer 260 and may increase light-condensing capability of incident light, thereby improving light receiving (Rx) efficiency.

[0070] Reference Figure 4 , since the isolation layer 230 having the reference depth (DTr) is spaced a certain distance from the front surface of the substrate 210, optical crosstalk may occur in a lower region of the isolation layer 230 between consecutive pixels.

[0071] Light leakage to adjacent pixels may cause unwanted noise. For example, the leakage light (A1) represents a light beam that has passed through the red color filter 240 of the red pixel (R) but has not been absorbed into the photodiode 220 of the red pixel (R). The leakage light (A1) may pass through the lower portion of the isolation layer 230 and be absorbed into the photodiode 220 of the green pixel (Gr).

[0072] In addition, leakage light (B1) indicates a light beam that has passed through green color filter 240 of green pixel (Gr) but is not absorbed into photodiode 220 of green pixel (Gr). Leakage light (B1) may pass through the lower portion of isolation layer 230 and be absorbed into photodiode 220 of red pixel (R).

[0073] The leakage light (A1) may be light having a wavelength corresponding to red, and the leakage light (B1) may be light having a wavelength corresponding to green. Figure 4 As shown, the light leakage (A1) can reach deeper than the light leakage (B1).

[0074] Since the main light is inclined in the right direction, each of the leakage lights A1 and B1 affecting the green pixel (Gr) can be considered to be an optical component or a light component propagating from or to the red pixel (R).

[0075] Figure 5 is a diagram showing some implementations based on the disclosed technology. Figure 3 FIG. 1 is a cross-sectional view of an example of the right side region (RT) taken along the first cutting line AA′ shown in FIG.

[0076] Reference Figure 4 and Figure 5 , assuming that the area around Figure 3 The depth of the isolation layer of the green pixel (Gr) in the right region (RT) is set to a first depth (DT1). Figure 5 A cross-sectional view 300 taken along a first cutting line AA′ is shown.

[0077] The cross-sectional view 300 may include a substrate 210 , at least one photodiode 220 , at least one isolation layer 232 , at least one color filter 240 , at least one grid 250 , at least one capping layer 260 , and at least one microlens 270 .

[0078] In addition to the depth of the isolation layer 232, Figure 5 The remaining components shown can be Figure 4 The cross-sectional views 200 shown are the same or similar.

[0079] Figure 5 The first depth (DT1) of the isolation layer 232 shown may be greater than Figure 4 The reference depth (DTr) of the isolation layer 230 is shown.

[0080] As the depth of the isolation layer 232 designed to prevent optical crosstalk gradually increases, Figure 5 The light leakage (A2) and light leakage (B2) shown can be made smaller than Figure 4Leakage light (A1) and leakage light (B1) shown. In addition, the reduction of leakage light (A1) having a wavelength corresponding to red light and capable of reaching deeper than leakage light (B1) may be greater than the reduction of leakage light (B1) having a wavelength corresponding to green light.

[0081] Therefore, if Figure 4 The cross-sectional view shown is compared to Figure 5 As can be seen from the cross-sectional view shown, the change (or variation) of the leakage light affecting the pixel signal of the green pixel (Gr) can be expressed as follows:

[0082] Light leakage variation about green pixel (Gr) = (A2-A1)-(B2-B1) (Equation 1)

[0083] Since the pixel signal of the green pixel (Gr) is proportional to the intensity of light absorbed into the photodiode 220 , the pixel signal of the green pixel (Gr) may have a signal variation component corresponding to a leakage light variation component with respect to the green pixel (Gr).

[0084] Because the reduction (A1-A2) of the leakage light (A1) is greater than the reduction (B1-B2) of the leakage light (B1), each of the leakage light variation with respect to the green pixel (Gr) and the signal variation component with respect to the green pixel (Gr) can be represented by a negative (-) number.

[0085] Figure 6 is a diagram showing some implementations based on the disclosed technology. Figure 3 The cross-sectional view of the comparative example of the right region (RT) cut along the second cutting line BB' is shown.

[0086] Reference Figure 4 and Figure 6 , assuming it is included in Figure 3 The depth of the isolation layer in the right region (RT) shown is set as the reference depth (DTr). Figure 6 A cross-sectional view 400 taken along a second cutting line BB′ is shown in FIG.

[0087] The cross-sectional view 400 may include a substrate 210 , at least one photodiode 220 , at least one isolation layer 230 , at least one color filter 240 , at least one grid 250 , at least one capping layer 260 , and at least one microlens 270 .

[0088] In addition to the type of color filter 240, Figure 6 The remaining components shown are similar in structure and material to Figure 4 The cross-sectional views 200 shown are substantially the same, and thus redundant content will be omitted for the sake of brevity.

[0089] Reference Figure 6, since the isolation layer 230 having the reference depth (DTr) is spaced apart from the front surface of the substrate 210 by a predetermined distance, optical crosstalk may occur in a lower region of the isolation layer 230 between consecutive pixels.

[0090] Leakage light (C1) indicates a light beam that has passed through the blue color filter 240 of the blue pixel (B) but has not been absorbed into the photodiode 220 of the blue pixel (B). The leakage light (C1) may pass through the lower portion of the isolation layer 230 and be absorbed into the photodiode 220 of the green pixel (Gb).

[0091] In addition, leakage light (D1) indicates a light beam that has passed through green color filter 240 of green pixel (Gb) but is not absorbed into photodiode 220 of green pixel (Gb). Leakage light (D1) may pass through a lower portion of isolation layer 230 and be absorbed into photodiode 220 of blue pixel (B).

[0092] The leakage light (C1) may be light having a wavelength corresponding to blue light, and the leakage light (D1) may be light having a wavelength corresponding to green light. Figure 6 As shown, the leakage light (D1) may reach deeper than the leakage light (C1) having the same incident angle.

[0093] Since the main light is inclined to the right, each of the leakage lights C1 and D1 affecting the green pixel (Gb) can be considered to be an optical component or a light component propagating from or to the blue pixel (B).

[0094] Figure 7 is a diagram showing some implementations based on the disclosed technology. Figure 3 FIG. 1 is a cross-sectional view of an example of the right side region (RT) taken by the second cutting line BB′ shown in FIG.

[0095] Reference Figure 4 , Figure 6 and Figure 7 , assuming that the area around Figure 3 The depth of the isolation layer of the green pixel (Gb) in the right region (RT) is set to the second depth (DT2). Figure 7 A cross-sectional view 500 taken along a second cutting line BB′ is shown in FIG.

[0096] The cross-sectional view 500 may include a substrate 210 , at least one photodiode 220 , at least one isolation layer 234 , at least one color filter 240 , at least one grid 250 , at least one capping layer 260 , and at least one microlens 270 .

[0097] In addition to the depth of the isolation layer 234 and the type of the color filter 240, Figure 7 The remaining components shown can be Figure 4 The cross-sectional views 200 shown are the same or similar.

[0098] Figure 7 The second depth (DT2) of the isolation layer 234 shown may be less than Figure 6 The reference depth (DTr) of the isolation layer 230 is shown.

[0099] As the depth of the isolation layer 234 designed to prevent optical crosstalk gradually decreases, Figure 7 The light leakage (C2) and light leakage (D2) shown may become larger than Figure 6 Leakage light (C1) and leakage light (D1) are shown. In addition, the increase of leakage light (D2) having a wavelength corresponding to green light and capable of reaching deeper than leakage light (C2) may be greater than the increase of leakage light (C2) having a wavelength corresponding to blue light.

[0100] Therefore, if Figure 6 The cross-sectional view shown is compared to Figure 7 As can be seen from the cross-sectional view shown, the light leakage variation (or change) affecting the pixel signal of the green pixel (Gb) can be expressed as follows:

[0101] Leakage variation of green pixel (Gb) = (C2-C1)-(D2-D1) (Equation 2)

[0102] Since the pixel signal of the green pixel (Gb) is proportional to the intensity of light absorbed into the photodiode 220, the pixel signal of the green pixel (Gb) may have a signal variation component corresponding to a leakage light variation component with respect to the green pixel (Gb).

[0103] Because the increase (D2-D1) of the leakage light (D1) is greater than the increase (C2-C1) of the leakage light (C1), each of the leakage light variation with respect to the green pixel (Gb) and the signal variation component with respect to the green pixel (Gb) may be represented by a negative (-) number.

[0104] Reference Figure 5 and Figure 7 In the right region (RT) of the pixel array 110, the depth of the isolation layer 232 surrounding the green pixel (Gr) increases, so that the signal change component of the green pixel (Gr) can be adjusted to a negative (-) number. In addition, the depth of the isolation layer 234 surrounding the green pixel (Gb) decreases, so that the signal change component of the green pixel (Gb) can be adjusted to a negative (-) number.

[0105] A GG ratio (or a GG difference) used as one of indicators representing the performance or throughput of the image sensor 100 may be expressed by Equation 3 below.

[0106] GG ratio = (Grsig -Gb sig ) / ((Gr sig +Gb sig ) / 2) (Equation 3)

[0107] In Equation 3, G rsig can represent the pixel signal of a green pixel (Gr) (which is a green pixel adjacent to a red pixel), and Gb sig The pixel signal of the green pixel (Gb) which is a green pixel adjacent to the blue pixel and adjacent to the green pixel (Gr) can be represented. sig As the value of Gb increases, the amount of noise from green pixels (Gr) is expected to increase. sig As the value of gradually increases, the amount of noise from the green pixel (Gb) is expected to increase. In the right region (RT) and the left region (LF) of the pixel array 110, the light transmitted from the red pixel (R) to the green pixel (Gr) may have a higher intensity (or a higher priority), so that the GG ratio is generally represented by a positive (+) number.

[0108] If the deviation (or difference) between the GG ratio and the ideal value is considered large, the depth of the isolation layer 232 surrounding the green pixel (Gr) is increased so that the signal change component (ΔGr) of the green pixel (Gr) is sig ) is adjusted to a negative (-) number. In addition, the depth of the isolation layer 234 surrounding the green pixel (Gb) is reduced so that the signal change component (ΔGb) of the green pixel (Gb) sig ) is adjusted to a negative (-) number. Here, the signal change component (△Gr sig ) can be adjusted to be higher than the signal change component (△Gb) of the green pixel (Gb) sig ). For example, the signal change component (△Gr sig ) can be associated with the difference between the first depth (DT1) and the reference depth (DTr), and the signal change component (△Gb) of the green pixel (Gb) sig ) can be associated with the difference between the second depth (DT2) and the reference depth (DTr), so that the signal change component (△Gr) of the green pixel (Gr) can be sig ) is higher than the signal change component (△Gb) of the green pixel (Gb) sig ) are determined by experiments using the absolute value of .

[0109] When only the GG ratio is considered, it is more preferable to reduce the signal variation component (ΔGb) of the green pixel (Gb) by increasing the depth of the isolation layer 234 surrounding the green pixel (Gb).sig ) is adjusted to a positive (+) number, but the light receiving (Rx) efficiency of the green pixel is reduced, so that the pixel signal characteristics (e.g., sensitivity) of the green pixel may be unexpectedly deteriorated. Therefore, it can be considered that reducing the depth of the isolation layer 234 surrounding the green pixel (Gb) is more beneficial in terms of the overall pixel signal characteristics.

[0110] Figure 8 Some implementations based on the disclosed technology are shown Figure 2 Schematic diagram of an example of a top region (TP) is shown.

[0111] In some implementations, the top region (TP) may include a plurality of pixels arranged in a (4×4) matrix structure, and the pixels may be arranged in a Bayer pattern. That is, any (2×2) pixel array may include a single red pixel (R), a single blue pixel (B), and two green pixels Gr and Gb. The green pixel (Gr) may be a green pixel adjacent to the red pixel (R) along the row direction, and the green pixel (Gb) may be a green pixel adjacent to the blue pixel (B) along the row direction.

[0112] As described above, the main light at the top region (TP) propagates in an upward direction from the center point of the pixel array 110. In this case, the isolation layer (e.g., Fig.10 The depth of 236) may be a third depth greater than the reference depth. In addition, the isolation layer (eg, Fig.12 The depth of 238) may be a fourth depth that is smaller than the reference depth.

[0113] Although for ease of description, we focus on the top region (TP) Figures 8 to 12 The structure shown in is described, but in some implementations, Figures 8 to 12 The same or similar structure as in can also be applied to the bottom region (BT).

[0114] exist Figure 8 In FIG. 1 , the isolation layer having the third depth is represented by a solid line, and the isolation layer having the fourth depth is represented by a dotted line.

[0115] Fig. 9 is a diagram showing some implementations based on the disclosed technology. Figure 8 A cross-sectional view of a comparative example of a top region (TP) taken along a third cutting line CC′ is shown.

[0116] In some implementations, the assumption is included in Figure 8 The depth of the isolation layer in the top region (TP) shown is set as the reference depth (DTr). Fig. 9A cross-sectional view 600 taken along a third cutting line CC′ is shown in FIG.

[0117] The cross-sectional view 600 may include a substrate 210 , at least one photodiode 220 , at least one isolation layer 230 , at least one color filter 240 , at least one grid 250 , at least one capping layer 260 , and at least one microlens 270 .

[0118] In addition to the type of color filter 240, Fig. 9 The remaining components shown can be Figure 4 The cross-sectional views 200 shown are the same or similar.

[0119] The depth of the isolation layer 230 may be set to Fig. 9 The reference depth (DTr) shown. The reference depth (DTr) may indicate the depth of the isolation layer 230 formed in the central region (CT) where the incident light is vertically guided and not tilted. That is, the reference depth (DTr) may indicate a predetermined depth by which the anti-noise characteristics associated with crosstalk, dark current, or any other unwanted noise of the pixel signal in the central region (CT) where the main light is incident in the same or similar direction as the optical axis direction may be optimized.

[0120] Reference Fig. 9 Since the isolation layer 230 having the reference depth (DTr) is spaced a predetermined distance from the front surface of the substrate 210, optical crosstalk may occur in the lower region of the isolation layer 230 between consecutive pixels.

[0121] Leakage light (E1) indicates a light beam that has passed through the blue color filter 240 of the blue pixel (B) but is not absorbed into the photodiode 220 of the blue pixel (B). The leakage light (E1) may pass through the lower portion of the isolation layer 230 and be absorbed into the photodiode 220 of the green pixel (Gr).

[0122] In addition, leakage light (F1) indicates a light beam that has passed through green color filter 240 of green pixel (Gr) but is not absorbed into photodiode 220 of green pixel (Gr). Leakage light (F1) may pass through a lower portion of isolation layer 230 and be absorbed into photodiode 220 of blue pixel (B).

[0123] The leakage light (E1) may be light having a wavelength corresponding to blue light, and the leakage light (F1) may be light having a wavelength corresponding to green light. Fig. 9 As shown, the leakage light (F1) can reach deeper than the leakage light (E1) with the same incident angle.

[0124] Since the main light is inclined in the upward direction, each of the leakage lights E1 and F1 affecting the green pixel (Gr) may be considered to be an optical component or a light component propagating from or to the blue pixel (B).

[0125] Fig.10 is a diagram showing some implementations based on the disclosed technology. Figure 8 FIG. 1 is a cross-sectional view of one example of a top region (TP) taken along a third cutting line CC′ shown in FIG.

[0126] Reference Figure 8 and Fig.10 , assuming that the area around Figure 8 The depth of the isolation layer of the green pixel (Gr) in the top region (TP) is set to a third depth (DT3). Fig.10 A cross-sectional view 700 taken along a third cutting line CC′ is shown in FIG.

[0127] The cross-sectional view 700 may include a substrate 210 , at least one photodiode 220 , at least one isolation layer 236 , at least one color filter 240 , at least one grid 250 , at least one capping layer 260 , and at least one microlens 270 .

[0128] In addition to the depth of isolation layer 236, Fig.10 The remaining components shown can be Fig. 9 The cross-sectional views 600 shown are the same or similar.

[0129] Fig.10 The third depth (DT3) of the isolation layer 236 shown may be greater than Fig. 9 The reference depth (DTr) of the isolation layer 230 is shown.

[0130] As the depth of the isolation layer 236 designed to prevent optical crosstalk gradually increases, Fig.10 The light leakage (E2) and light leakage (F2) shown can be made smaller than Fig. 9 Leakage light (E1) and leakage light (F1) shown. In addition, the reduction of leakage light (F1) having a wavelength corresponding to green light and capable of reaching deeper than leakage light (E1) may be greater than the reduction of leakage light (E1) having a wavelength corresponding to blue light.

[0131] Therefore, if Fig. 9 The cross-sectional view shown is compared to Fig.10 As can be seen from the cross-sectional view shown, the light leakage variation (or change) affecting the pixel signal of the green pixel (Gr) can be expressed as follows:

[0132] Leakage variation of green pixel (Gr) = (E2-E1)-(F2-F1) (Equation 4)

[0133] Since the pixel signal of the green pixel (Gr) is proportional to the intensity of light absorbed into the photodiode 220 , the pixel signal of the green pixel (Gr) may have a signal variation component corresponding to a leakage light variation component with respect to the green pixel (Gr).

[0134] Because the reduction (F1-F2) of the leakage light (F1) is greater than the reduction (E1-E2) of the leakage light (E1), each of the leakage light variation with respect to the green pixel (Gr) and the signal variation component with respect to the green pixel (Gr) can be represented by a positive (+) number.

[0135] Fig.11 is a diagram showing some implementations based on the disclosed technology. Figure 8 A cross-sectional view of a comparative example of a top region (TP) taken along a fourth cutting line DD′ is shown.

[0136] Reference Figure 8 and Fig.11 , assuming it is included in Figure 8 The depth of the isolation layer in the top region (TP) shown is set as the reference depth (DTr). Fig.11 A cross-sectional view 800 taken along a fourth cutting line DD′ is shown in FIG.

[0137] The cross-sectional view 800 may include a substrate 210 , at least one photodiode 220 , at least one isolation layer 230 , at least one color filter 240 , at least one grid 250 , at least one capping layer 260 , and at least one microlens 270 .

[0138] In addition to the type of color filter 240, Fig.11 The remaining components shown are similar in structure and material to Figure 4 The cross-sectional views 200 shown are substantially the same, and thus redundant content will be omitted herein for the sake of brevity.

[0139] Reference Fig.11 Since the isolation layer 230 having the reference depth (DTr) is spaced apart from the front surface of the substrate 210 by a predetermined distance, optical crosstalk may occur in a lower region of the isolation layer 230 between consecutive pixels.

[0140] That is, the leakage light (G1) represents a light beam that has passed through the red color filter 240 of the red pixel (R) but has not been absorbed into the photodiode 220 of the red pixel (R). The leakage light (G1) may pass through the lower portion of the isolation layer 230 and be absorbed into the photodiode 220 of the green pixel (Gb).

[0141] In addition, leakage light (H1) indicates a light beam that has passed through green color filter 240 of green pixel (Gb) but is not absorbed into photodiode 220 of green pixel (Gb). Leakage light (H1) may pass through a lower portion of isolation layer 230 and be absorbed into photodiode 220 of red pixel (R).

[0142] The leakage light (G1) may be light having a wavelength corresponding to red light, and the leakage light (H1) may be light having a wavelength corresponding to green light. Fig.11 As shown, the leakage light (G1) can reach deeper than the leakage light (H1) having the same incident angle.

[0143] Since the main light is inclined in the upward direction, it can be considered that each of the leakage lights G1 and H1 affecting the green pixel (Gb) is an optical component or a light component propagating from or to the red pixel (R).

[0144] Fig.12 is a diagram showing some implementations based on the disclosed technology. Figure 8 FIG. 1 is a cross-sectional view of one example of a top region (TP) taken along a fourth cutting line DD′ shown in FIG.

[0145] Reference Fig. 9 , Fig.11 and Fig.12 , assuming that the area around Figure 8 The depth of the isolation layer of the green pixel (Gb) in the top region (TP) is set to a fourth depth (DT4). Fig.12 A cross-sectional view 900 taken along a fourth cutting line DD′ is shown in FIG.

[0146] The cross-sectional view 900 may include a substrate 210 , at least one photodiode 220 , at least one isolation layer 238 , at least one color filter 240 , at least one grid 250 , at least one capping layer 260 , and at least one microlens 270 .

[0147] In addition to the depth of isolation layer 238 and the type of color filter 240, Fig.12 The remaining components shown can be Figure 4 The cross-sectional views 200 shown are the same or similar.

[0148] Fig.12 The fourth depth (DT4) of the isolation layer 238 shown may be less than Fig.11 The reference depth (DTr) of the isolation layer 230 is shown.

[0149] As the depth of the isolation layer 238 designed to prevent optical crosstalk gradually decreases, Fig.12 The light leakage (G2) and light leakage (H2) shown can become larger than Fig.11 Leakage light (G1) and leakage light (H1) are shown. In addition, the increase of leakage light (G2) having a wavelength corresponding to red light and capable of reaching deeper than leakage light (H2) may be greater than the increase of leakage light (H2) having a wavelength corresponding to green light.

[0150] Therefore, if Fig.11 The cross-sectional view shown is compared to Fig.12 As can be seen from the cross-sectional view shown, the light leakage variation (or change) affecting the pixel signal of the green pixel (Gb) can be expressed as follows:

[0151] Leakage variation of green pixel (Gb) = (G2-G1)-(H2-H1) (Equation 5)

[0152] Since the pixel signal of the green pixel (Gb) is proportional to the intensity of light absorbed into the photodiode 220, the pixel signal of the green pixel (Gb) may have a signal variation component corresponding to a leakage light variation component with respect to the green pixel (Gb).

[0153] Because the increase (G2-G1) of the leakage light (G1) is greater than the increase (H2-F1) of the leakage light (H1), each of the leakage light variation with respect to the green pixel (Gb) and the signal variation component with respect to the green pixel (Gb) can be represented by a positive (+) number.

[0154] Reference Fig.10 and Fig.12 In the top area (TP) of the pixel array 110, the signal change component of the green pixel (Gr) can be adjusted to a positive (+) number by increasing the depth of the isolation layer 236 surrounding the green pixel (Gr), and the signal change component of the green pixel (Gb) can also be adjusted to a positive (+) number by reducing the depth of the isolation layer 238 surrounding the green pixel (Gb).

[0155] In each of the top region (TP) and the bottom region (BT) of the pixel array 110, light transmitted from the red pixel (R) to the green pixel (Gb) may have a higher intensity (or higher priority) such that the GG ratio is generally represented by a negative (-) number.

[0156] If the deviation (or difference) between the GG ratio and the ideal value is considered large, the depth of the isolation layer 236 surrounding the green pixel (Gr) is increased so that the signal change component (ΔGr) of the green pixel (Gr) is sig ) is adjusted to a positive (+) number. In addition, the depth of the isolation layer 238 surrounding the green pixel (Gb) is reduced so that the signal change component (ΔGb) of the green pixel (Gb) sig ) is adjusted to a positive (+) number. Here, the signal change component (△Gr) of the green pixel (Gr)sig ) can be adjusted to be higher than the signal change component (△Gb) of the green pixel (Gb) sig ). For example, the signal change component (△Gr sig ) can be associated with the difference between the third depth (DT3) and the reference depth (DTr), and the signal change component (△Gb) of the green pixel (Gb) sig ) can be associated with the difference between the fourth depth (DT4) and the reference depth (DTr), so that the signal change component (△Gr) of the green pixel (Gr) can be sig ) is higher than the signal change component (△Gb) of the green pixel (Gb) sig ) are determined by experiment in the form of absolute values ​​of .

[0157] When only the GG ratio is considered, it is more preferable to reduce the signal variation component (ΔGb) of the green pixel (Gb) by increasing the depth of the isolation layer 238 surrounding the green pixel (Gb). sig ) is adjusted to a negative (-) number, but the light receiving (Rx) efficiency of the green pixel is reduced, so that the pixel signal characteristics (e.g., sensitivity) of the green pixel may be unexpectedly deteriorated. Therefore, it can be considered that reducing the depth of the isolation layer 238 surrounding the green pixel (Gb) is more beneficial in terms of the overall pixel signal characteristics.

[0158] Fig.13 is a conceptual diagram illustrating a method for improving the GG ratio based on some implementations of the disclosed technology.

[0159] Fig.13 The left graph of may illustrate GG ratios of respective regions in a case where isolation layers included in the pixel array 110 have the same reference depth (DTr).

[0160] Reference Fig.13 , if the number of columns included in the pixel array 110 is greater than the number of rows included in the pixel array 110, the left region (LF) can be divided into a first left region (LF1) and a second left region (LF2), and the right region (RT) can be divided into a first right region (RT1) and a second right region (RT2).

[0161] As described above, according to the arrangement characteristics of the Bayer pattern and the main light direction, each of the GG ratio of the top area (TP) and the GG ratio of the bottom area (BT) can be represented by "-6" corresponding to a negative (-) number. In addition, the GG ratio of the first left area (LF1) and the GG ratio of the second left area (LF2) can be represented by "+10" and "+6", respectively, and the GG ratio of the first right area (RT1) and the GG ratio of the second right area (RT2) can be represented by "+6" and "+10", respectively. The absolute value of the GG ratio can gradually increase in the order from +6 to +10 in inverse proportion to the distance to the edge area of ​​the pixel array 110.

[0162] Fig.13 The right graph of FIG. 1 may illustrate GG ratios of respective regions in a case where the depth of each isolation layer included in the pixel array 110 has been adjusted.

[0163] In each of the left and right regions (LF1, LF2, RT1, RT2), the depth of the isolation layer 232 surrounding the green pixel (Gr) may be increased to reduce the signal variation component (ΔGr) of the green pixel (Gr). sig ) is adjusted to a negative (-) number, and the depth of the isolation layer 234 surrounding the green pixel (Gb) can be reduced to reduce the signal change component (ΔGb) of the green pixel (Gb) sig ) is adjusted to a negative (-) number, so that the signal change component (△Gr sig ) can be adjusted to be higher than the signal change component (△Gb) of the green pixel (Gb) sig ). In this case, the depth of the isolation layer surrounding the green pixel (Gr) and the depth of the isolation layer surrounding the green pixel (Gb) in each of the left region LF1 and the right region RT2 relatively close to the edge of the pixel array 110 may be different from the depth of the isolation layer surrounding the green pixel (Gr) and the depth of the isolation layer surrounding the green pixel (Gb) in each of the left region LF2 and the right region RT1 relatively far from the edge of the pixel array 110. This is because the absolute value of the GG ratio in each of the left region LF1 and the right region RT2 relatively close to the edge of the pixel array 110 is higher than the absolute value of the GG ratio in each of the remaining left region LF2 and the right region RT1, so that the change of the GG ratio in each of the left region LF1 and the right region RT2 should be adjusted to a higher value. For example, the depth of each isolation layer in the peripheral area of ​​the green pixel (Gr) and the green pixel (Gb) in each of the left region LF1 and the right region RT2 may be greater than the depth of each isolation layer in the peripheral area of ​​the green pixel (Gr) and the green pixel (Gb) in each of the left region LF2 and the right region RT1.

[0164] Although for ease of description, Fig.13 It has been disclosed exemplarily that each of the left and right regions is divided into two regions in a manner that can improve the GG ratio, but it should be noted that each of the left and right regions can also be divided into three or more regions in a manner that can improve the GG ratio as needed. In addition, each of the top and bottom regions can also be divided into a plurality of regions so that the GG ratio can also be gradually improved.

[0165] As from Fig.13 It can be seen that it can be recognized that the GG ratio of the first left region (LF1) is reduced by "3", and the GG ratio of the second right region (RT2) is reduced by "3", and it can also be recognized that the GG ratio of the second left region (LF2) is reduced by "2", and the GG ratio of the first right region (RT1) is reduced by "2".

[0166] Likewise, in each of the top region (TP) and the bottom region (BT), the signal variation component (ΔGr) of the green pixel (Gr) may be reduced by increasing the depth of the isolation layer 236 surrounding the green pixel (Gr). sig ) is adjusted to a positive (+) number, and the signal change component (ΔGb) of the green pixel (Gb) can also be reduced by reducing the depth of the isolation layer 238 surrounding the green pixel (Gb). sig ) is adjusted to a positive (+) number. In this case, the signal change component (△Gr sig ) can be adjusted to be higher than the signal change component (△Gb) of the green pixel (Gb) sig )’s absolute value.

[0167] As from Fig.13 As can be seen in FIG. 1 , it can be recognized that the GG ratio of the top region (TP) increases by “2”, and the GG ratio of the bottom region (BT) increases by “2”.

[0168] According to the above description, an image sensor according to an embodiment of the disclosed technology can be implemented in a manner that reduces the amount of noise that can be generated by green pixels arranged in an area close to an edge area of ​​a pixel array, thereby achieving improved imaging performance. Embodiments of the disclosed technology can provide a variety of effects.

[0169] Although this patent document contains many details, these details should not be interpreted as limitations on the scope of any invention or what may be claimed, but rather should be interpreted as descriptions of features specific to a particular embodiment of a particular invention. Certain features described in this patent document in the context of discrete embodiments may also be implemented in combination in a single embodiment. Conversely, the various features described in the context of a single embodiment may also be implemented separately in multiple embodiments or in any suitable sub-combination. In addition, although features may be described above as operating in certain combinations, and even initially claimed as such, in some cases, one or more features from a claimed combination may be deleted from the combination, and a claimed combination may involve a sub-combination or a variation of a sub-combination.

[0170] Similarly, although operations are described in a particular order in the drawings, this should not be understood as requiring that the operations be performed in the particular order shown or in chronological order, or that all of the operations shown be performed to obtain the desired results. In addition, the separation of various system components in the embodiments described in this patent document should not be understood as requiring such separation in all embodiments.

[0171] Only a few implementations and examples are described, and other implementations, enhancements, and variations may be made based on what is described and illustrated in this patent document.

[0172] CROSS-REFERENCE TO RELATED APPLICATIONS

[0173] This patent document claims priority to and the benefit of Korean Patent Application No. 10-2019-0145197, filed on November 13, 2019, the disclosure of which is incorporated herein by reference in its entirety as a part of the disclosure of this patent document.

Claims

1. An image sensor, the image sensor include: substrate; first pixels of a first color, the first pixels being arranged alternately with pixels of a second color in the substrate along a first direction of a pixel array; as well as second pixels of the first color, the second pixels being arranged in the substrate in a row different from the row of the first pixels of the first color in the first direction in alternation with pixels of a third color; an isolation layer formed in the substrate to surround the first pixel in the pixel array and configured to have a first depth; as well as an isolation layer formed in the substrate to surround the second pixel in the pixel array and configured to have a second depth different from the first depth, Among them, one of the first pixel of the first color and the second pixel of the first color and each of the pixel of the second color and the pixel of the third color are configured to selectively receive light of different colors, respectively.

2. The image sensor according to claim 1, in, The first depth is greater than the second depth.

3. The image sensor according to claim 1, in, The first color is green, and the second color and the third color are red and blue, respectively.

4. The image sensor according to claim 3, in, The first pixel of the first color, the second pixel of the first color, the pixel of the second color, and the pixel of the third color constitute a Bayer pattern.

5. The image sensor according to claim 1, in, The pixel array includes a top region, a bottom region, a left region, and a right region which are respectively arranged at a top side, a bottom side, a left side, and a right side with respect to a central region of the pixel array.

6. The image sensor according to claim 5, in: The isolation layer surrounding the first pixel of the first color in the central area and the isolation layer surrounding the second pixel of the first color in the central area are configured to have a reference depth.

7. The image sensor according to claim 6, in, The first depth is greater than the reference depth.

8. The image sensor according to claim 6, in, The second depth is smaller than the reference depth.

9. The image sensor according to claim 5, in: At least one of the top area, the bottom area, the left area, and the right area is divided into a plurality of areas; and The isolation layer surrounding the first pixel of the first color in one area selected from the plurality of areas and the isolation layer surrounding the first pixel of the first color in another area are configured to have different depths.

10. The image sensor according to claim 5, in: At least one of the top area, the bottom area, the left area, and the right area is divided into a plurality of areas; and The isolation layer surrounding the second pixel of the first color in one area selected from the plurality of areas and the isolation layer surrounding the second pixel of the first color in another area are configured to have different depths.

11. The image sensor according to claim 1, in, Each of the first pixel of the first color and the second pixel of the first color, the pixel of the second color, and the pixel of the third color includes: a color filter disposed over the substrate and configured to allow light corresponding to one of red, blue, and green to selectively pass therethrough; and A photodiode is disposed below the color filter and in the substrate.

12. The image sensor according to claim 11, in, The isolation layer is a backside deep trench isolation layer, and the backside deep trench isolation layer is etched to a predetermined depth from the backside of the substrate in a vertical direction.

13. The image sensor according to claim 11, in, The isolation layer comprises: an inner layer comprising a conductive material configured to receive a bias voltage; and A side wall is configured to surround the inner layer.

14. The image sensor according to claim 1, in, The first direction is a row direction.

15. An image sensor, the image sensor include: a color filter array including red, blue, and green filters arranged in a Bayer pattern; as well as a substrate in which an isolation layer is formed to surround a pixel corresponding to each of the red color filter, the blue color filter, and the green color filter, in: an isolation layer surrounding a pixel corresponding to a green color filter adjacent to a red color filter included in the color filter array in a first direction has a first depth; and The isolation layer surrounding a pixel corresponding to a green color filter adjacent to a blue color filter included in the color filter array along the first direction has a second depth different from the first depth.

16. The image sensor according to claim 15, in, The first depth is greater than the second depth.

17. The image sensor according to claim 15, in, The color filter array includes a top region, a bottom region, a left region, and a right region which are respectively arranged at a top side, a bottom side, a left side, and a right side with respect to a central region of the color filter array.

18. The image sensor according to claim 17, in: An isolation layer surrounding pixels corresponding to a green filter adjacent to a red filter included in the central area along the first direction and an isolation layer surrounding pixels corresponding to a green filter adjacent to a blue filter included in the central area along the first direction are configured to have a reference depth.

19. The image sensor according to claim 18, in, The first depth is greater than the reference depth.

20. The image sensor according to claim 18, in, The second depth is smaller than the reference depth.

Images