KR102318195B1 - Method for fabricating image sensor - Google Patents

Abstract

A method of manufacturing an image sensor is provided. A method of manufacturing an image sensor includes providing a substrate including an active pixel sensor region, an optical black sensor region and a pad region, forming a pad on the pad region, and the active pixel A passivation layer is formed to cover the sensor area, the optical black sensor area, and the pad area, and the passivation layer is etched to cover the pad area and expose the active pixel sensor area, wherein the passivation layer is formed from the top to the bottom and forming a color filter layer conformally on the active pixel sensor region having a slope profile that gradually increases in width.

Description

Method for fabricating image sensor

The present invention relates to a method of manufacturing an image sensor.

An image sensor is a device that converts an optical image into an electrical signal. Recently, with the development of the computer industry and the communication industry, the demand for image sensors with improved performance in various fields such as digital cameras, camcorders, PCS (Personal Communication System), game devices, security cameras, medical micro cameras, and robots is increasing. have.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing an image sensor that prevents a phenomenon in which the thickness of a color filter becomes non-uniform by minimizing a step difference between a substrate and a passivation film by using a passivation film having an inclined profile.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

An embodiment of a method of manufacturing an image sensor according to the technical idea of the present invention for solving the above problems is a substrate including an active pixel sensor area, an optical black sensor area, and a pad area and forming a pad on the pad area, forming a passivation layer covering the active pixel sensor area, the optical black sensor area, and the pad area, etching the passivation layer to cover the pad area, and the active pixel and forming a passivation layer exposing the sensor area, wherein the passivation layer has a slope profile that increases from the top to the bottom, and forms a color filter layer conformally on the active pixel sensor area.

Another embodiment of the method for manufacturing an image sensor according to the technical idea of the present invention for solving the above problems is a substrate including an active pixel sensor area, an optical black sensor area, and a pad area a mask pattern for forming a pad on the pad region, forming a protective layer covering the active pixel sensor region, the optical black sensor region, and the pad region, and exposing the active pixel sensor region on the protective layer forming a, wherein the mask pattern has a slope profile that becomes wider from the top to the bottom, and etching the passivation layer using the slope profile of the mask pattern, wherein etching the passivation layer includes: and transferring the inclination profile of the mask pattern to the passivation layer by using an etching material having substantially the same etch ratio to the pattern and the passivation layer.

Other specific details of the invention are included in the detailed description and drawings.

1 is a diagram for explaining a schematic planar arrangement of an image sensor according to some embodiments according to the technical spirit of the present invention.
2 is a block diagram of an image sensor according to some embodiments according to the inventive concept.
3 is a diagram illustrating an equivalent circuit diagram of a sensor array according to some embodiments according to the spirit of the present invention.
4 is a diagram illustrating an image sensor according to an embodiment according to the technical spirit of the present invention.
5 to 15 are intermediate steps for explaining a method of manufacturing an image sensor according to an embodiment according to the spirit of the present invention.
16 is an intermediate step view for explaining a method of manufacturing an image sensor according to another embodiment according to the technical spirit of the present invention.
17 to 19 are intermediate steps for explaining a method of manufacturing an image sensor according to still another embodiment according to the spirit of the present invention.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly defined in particular.

Hereinafter, a schematic planar arrangement of an image sensor according to some embodiments according to the inventive concept will be described with reference to FIG. 1 .

1 is a view for explaining a schematic planar arrangement of an image sensor according to some embodiments according to the technical spirit of the present invention.

Referring to FIG. 1 , the image sensor 1 includes a sensor array region, a circuit region including a plurality of circuits formed around the sensor array region, and a plurality of pads 117 disposed around the circuit region. It may include a pad region III.

The sensor array region includes an active pixel sensor region (I) including an active pixel for generating an active signal corresponding to wavelengths of light from the outside, and optical black (optical black) by blocking light from the outside. an optical black sensor region II for generating a black) signal.

A dummy pixel area may be disposed at an edge portion of the active pixel sensor area I adjacent to the optical black sensor area II. However, the technical spirit of the present invention is not limited thereto. That is, in some other embodiments, the dummy pixel region may be omitted.

In some embodiments, the plurality of pads 117 formed in the pad region III may transmit and receive electrical signals to and from an external device. In some other embodiments, the plurality of pads 117 may perform a function of transferring driving power such as a power voltage or a ground voltage supplied from the outside to circuits disposed in the circuit area.

The active pixel sensor array region includes an active pixel sensor array including a plurality of unit pixels. Each of the plurality of unit pixels may include a photoelectric conversion element.

The circuit region includes a plurality of CMOS transistors, and may provide a constant signal to each unit pixel of the active pixel sensor array region or control an output signal in each unit pixel.

Hereinafter, an image sensor according to some embodiments according to the inventive concept will be described with reference to FIG. 2 .

2 is a block diagram of an image sensor according to some embodiments according to the inventive concept.

Referring to FIG. 2 , an image sensor 1 according to some embodiments according to the inventive concept includes an active pixel sensor array 10 in which pixels including photoelectric conversion elements are two-dimensionally arranged, and a timing generator (timing). generator 20, row decoder 30, row driver 40, Correlated Double Sampler (CDS) 50, Analog to Digital Converter (ADC) ) 60 , a latch 70 , and a column decoder 80 .

The active pixel sensor array 10 includes a plurality of two-dimensionally arranged unit pixels. The plurality of unit pixels may perform a function of converting an optical image into an electrical output signal.

The active pixel sensor array 10 may be driven by receiving a plurality of driving signals, such as a row selection signal, a reset signal, and a charge transfer signal, from the row driver 40 . In addition, the converted electrical output signal may be provided to the correlated double sampler 50 through a vertical signal line.

The timing generator 20 may provide a timing signal and a control signal to the row decoder 30 and the column decoder 80 .

The row driver 40 may provide a plurality of driving signals for driving a plurality of unit pixels to the active pixel sensor array 10 according to a result decoded by the row decoder 30 . In general, when unit pixels are arranged in a matrix form, a driving signal may be provided for each row.

The correlated double sampler 50 may receive and hold and sample the output signal formed in the active pixel sensor array 10 through a vertical signal line. That is, by double sampling a specific noise level and a signal level by the output signal, a difference level corresponding to the difference between the noise level and the signal level may be output.

The analog-to-digital converter 60 may convert an analog signal corresponding to the difference level into a digital signal and output the converted analog signal.

The latch unit 70 latches the digital signal, and the latched signal may be sequentially output to the image signal processing unit according to a decoding result of the column decoder 80 .

Hereinafter, an equivalent circuit diagram of a sensor array according to some embodiments according to the spirit of the present invention will be described with reference to FIG. 3 .

3 is a diagram illustrating an equivalent circuit diagram of a sensor array according to some embodiments according to the spirit of the present invention.

Referring to FIG. 3 , pixels P are arranged in a matrix form to constitute the active pixel sensor array 10 . Each pixel P includes a photoelectric conversion element 11 , a floating diffusion region 13 , a charge transfer element 15 , a drive element 17 , a reset element 18 , and a selection element 19 . These functions will be described using the i-row pixels (P(i, j), P(i, j+1), P(i, j+2), P(i, j+3), ... ) as an example. do.

The photoelectric conversion element 11 may absorb incident light and accumulate charges corresponding to the amount of light. A photodiode, a phototransistor, a photogate, a pinned photodiode, or a combination thereof may be applied as the photoelectric conversion element 11 , and a photodiode is exemplified in the drawing.

Each photoelectric conversion element 11 may be coupled with a respective charge transfer element 15 that transfers the accumulated charge to the floating diffusion region 13 .

The floating diffusion region (FD) 13 is a region that converts electric charges into voltages and has parasitic capacitance, so that electric charges may be accumulated.

The drive element 17 exemplified as a source-follower amplifier amplifies a change in the electrical potential of the floating diffusion region 13 that has received the charge accumulated in each photoelectric conversion element 11 and outputs it to the output line Vout. can do.

The reset element 18 may periodically reset the floating diffusion region 13 . The reset element 18 may consist of one MOS transistor driven by a bias provided by a reset line RX(i) for applying a predetermined bias (ie, a reset signal).

When the reset element 18 is turned on by the bias provided by the reset line RX(i), a predetermined electrical potential provided to the drain of the reset element 18, for example, the power supply voltage VDD, floats. may be transferred to the diffusion region 13 .

The selection element 19 may perform a function of selecting a pixel P to be read in row units. The selection element 19 may be composed of one MOS transistor driven by a bias (ie, a row selection signal) provided by the row selection line SEL(i).

When the selection element 19 is turned on by the bias provided by the row selection line SEL(i), a predetermined electrical potential provided to the drain of the selection element 19, for example, the power supply voltage VDD, is driven may be transferred to the drain region of the device 17 .

A transfer line TX(i) for applying a bias to the charge transfer element 15, a reset line RX(i) for applying a bias to the reset element 18, and a row for applying a bias to the selection element 19 The selection lines SEL(i) may be arranged to extend substantially parallel to each other in the row direction.

Hereinafter, an image sensor according to an embodiment according to the spirit of the present invention will be described with reference to FIG. 4 .

4 is a diagram illustrating an image sensor according to an embodiment according to the technical spirit of the present invention.

Referring to FIG. 4 , the image sensor includes an active pixel sensor region (I), an optical black sensor region (II), and a pad region (III).

The active pixel sensor region I is a region in which the active pixel sensor array 10 of FIG. 2 is formed.

The optical black sensor area (II) blocks the inflow of light and provides a reference of the black signal to the active pixel sensor area (I). formed to be

Accordingly, the dark current of the active pixel sensor array 10 of the active pixel sensor region I may be corrected based on the dark current of the optical black sensor region II.

The pad region III is a region in which a plurality of pads 117 are formed.

The image sensor includes a substrate 100 , a photoelectric conversion device (PD), an insulating structure 110 , a gate 113 , a second metal wiring 114 , a through via 115 , an insulating layer 116 , a pad 117 , It includes a passivation layer 160 , a color filter 180 , and a microlens 190 .

The substrate 100 is, for example, using a P-type or N-type bulk substrate, or by growing a P-type or N-type epitaxial layer on a P-type bulk substrate, or a P-type or N-type epitaxial layer on an N-type bulk substrate. It can also be used to grow. In addition, the substrate 100 may use a substrate such as an organic plastic substrate in addition to the semiconductor substrate.

A photoelectric conversion element, for example, a photodiode PD, is formed in the substrate 100 of the active pixel sensor region I and the optical black sensor region II. The photoelectric conversion device PD may be formed close to the lower surface of the substrate 100 , but the technical spirit of the present invention is not limited thereto.

A plurality of gates 113 may be disposed on the lower surface of the substrate 100 . 4 illustrates that the gate 113 is formed in the active pixel sensor region (I) and the optical black sensor region (II), the technical spirit of the present invention is not limited thereto. That is, in some other embodiments, the gate 113 may also be formed in the pad region III.

The gate 113 may be, for example, a gate of a charge transfer device, a gate of a reset device, or a gate of a drive device. In FIG. 4 , the gate 113 is shown to be formed on the lower surface of the substrate 100 , but the technical spirit of the present invention is not limited thereto. That is, in some other embodiments, the gate 113 may be recessed into the substrate 100 .

The insulating structure 110 may be disposed on the lower surface of the substrate 100 . The insulating structure 110 may include an interlayer insulating layer 111 , a first metal wiring 112 , and a second metal wiring 114 . The second metal wiring 114 may include a plurality of wirings formed at the same level as the plurality of wirings included in the first metal wiring 112 .

The interlayer insulating film 111 may include, for example, at least one of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, and a combination thereof, but the technical spirit of the present invention is not limited thereto.

The first metal wiring 112 may include, for example, at least one of aluminum (Al), copper (Cu), and tungsten (W), but the inventive concept is not limited thereto.

The first metal wiring 112 is formed in the active pixel sensor region I and the optical black sensor region II, and may include a plurality of interconnections sequentially stacked.

In FIG. 4 , three layers of the first metal wiring 112 are sequentially stacked. However, this is only for convenience of description, and the technical spirit of the present invention is not limited thereto.

The insulating layer 116 may be disposed on the upper surface of the substrate 100 . The insulating layer 116 may include an oxide insulating layer or a nitride insulating layer.

When the insulating layer 116 includes hafnium oxide (HfOx), the insulating layer 116 may serve to reduce a dark current of the image sensor.

The pad 117 may be disposed on the insulating layer 116 of the pad region III to protrude from the substrate 100 . Driving power may be supplied from the outside through the pad 117 .

The pad 117 may include, for example, at least one of tungsten (W) or aluminum (Al), but the inventive concept is not limited thereto.

In the pad region III, the through via 115 may be formed to pass through a portion of the insulating layer 116 , the substrate 100 , and the interlayer insulating layer 110 . The through via 115 may electrically connect the pad 117 and the second metal wire 114 .

A voltage may be applied to the image sensor through the second metal wire 114 , the through via 115 , and the pad 117 .

The passivation layer 160 may be disposed to cover the pad 117 on the optical black sensor region II and the pad region III.

Specifically, the passivation layer 160 may be formed on the pad region III to completely cover the pad 117 . In this case, as shown in FIG. 4 , the passivation layer 160 may have an inclined profile that increases in width from the top to the bottom.

In some other embodiments, the optical black sensor region II may be formed to cover a portion of the insulating layer 116 adjacent to the pad region III.

Although it is illustrated in FIG. 4 that the passivation layer 160 is not formed on the active pixel sensor region I, the technical spirit of the present invention is not limited thereto. That is, in some other embodiments, the passivation layer 160 may be partially formed on the active pixel sensor region (I).

The passivation layer 160 may include at least one of silicon oxide, silicon nitride, silicon oxynitride, and a combination thereof, but the technical spirit of the present invention is not limited thereto.

Since the passivation layer 160 has an inclined profile, a step difference between the pad 117 formed to protrude from the substrate 100 and the substrate 100 may be reduced. In the method of manufacturing an image sensor according to the technical concept of the present invention, the pigment may be conformally formed in the pigment application process for forming the color filter 180 by using the slope profile formed on the passivation film 160 .

Also, the passivation layer 160 may function to protect the pad 117 from an external environment.

The color filter 180 may be disposed on the insulating layer 116 on the active pixel sensor region I. The color filter 130 may include a red color filter, a green color filter, and a blue color filter.

The microlens 190 may be disposed on the color filter 180 on the active pixel sensor region I. The microlens 190 may be made of an organic material such as a photosensitive resin or an inorganic material.

Although not shown in FIG. 4 , various films including a light blocking film for blocking light flowing into the optical black sensor region II may be further formed on the insulating film 116 formed in the optical black sensor region II. of course there is

Hereinafter, a method of manufacturing an image sensor according to an exemplary embodiment according to the inventive concept will be described with reference to FIGS. 5 to 15 .

5 to 15 are intermediate steps for explaining a method of manufacturing an image sensor according to an embodiment according to the spirit of the present invention.

First, referring to FIG. 5 , an active pixel sensor region (I), an optical black sensor region (II), and a pad region (III) are defined on a substrate 100 .

A plurality of unit pixels are formed on the substrate 100 of the active pixel sensor region (I) and the optical black sensor region (II). In order to form a plurality of unit pixels, a photoelectric conversion element PD such as a photodiode and a plurality of impurity diffusion regions are formed in the substrate 100 of the active pixel sensor region I and the optical black sensor region II. . In addition, a plurality of gates 113 are formed on the lower surface of the substrate 100 .

Next, on the lower surface of the substrate 100 in the active pixel sensor region (I) and the optical black sensor region (II), at least a part is formed by an interlayer insulating film 111 covering the substrate 100 and an interlayer insulating film 111 . An insulating structure 110 including a plurality of insulated first metal wirings 112 is formed.

While the insulating structure 110 is formed in the active pixel sensor region (I) and the optical black sensor region (II), at least a portion is insulated by the interlayer insulating film 111 and the interlayer insulating film 111 in the pad region (III). A plurality of second metal wirings 114 are formed.

In some embodiments, each of the interlayer insulating layers 111 may include a plurality of layers. In the active pixel sensor region (I), the optical black sensor region (II), and the pad region (III), the layers formed at the same level among the plurality of first metal wires 112 and the plurality of second metal wires 114 are It can be formed in the same process step.

In some embodiments, the interlayer insulating layer 111 is at least one selected from Flowable OXide (FOX), High Density Plasma (HDP) oxide, Tonen Silazene (TOSZ), Spin On Glass (SOG), or Undoped Silica Glass (USG). may be made of a material of

Next, referring to FIG. 6 , an insulating layer 116 including an oxide insulating layer or a nitride insulating layer is formed on the upper surface of the substrate 100 .

Then, referring to FIG. 7 , a portion of the insulating layer 116 , the substrate 100 , and the interlayer insulating layer 110 is etched to form a trench C in the pad region III. The trench C may be formed by, for example, a dry etching process, a wet etching process, or a combination thereof.

Specifically, the insulating layer 116 and the substrate 100 are removed from the pad region III using an etch mask pattern, and a trench C penetrating the substrate 102 to expose the second metal wiring 114 is formed. formed, and the etch mask pattern is removed.

Next, referring to FIG. 8 , a through-via 115 is formed in the trench C, and a pad 117 is formed on the through-via 115 . Accordingly, the second metal wire 114 and the pad 117 may be electrically connected.

Next, referring to FIG. 9 , a protective layer 120 covering the pad 117 is formed on the active pixel sensor region I, the optical black sensor region II, and the pad region III. The passivation layer 120 may include at least one of silicon oxide, silicon nitride, silicon oxynitride, and a combination thereof.

The passivation layer 120 may be formed using chemical vapor deposition, spin coating, plasma enhanced CVD (PECVD), high density plasma CVD (HDP-CVD), or the like.

Next, referring to FIG. 10 , a mask layer 130 is formed on the passivation layer 120 . In this case, the mask layer 130 may be conformally formed on the passivation layer 120 such that the thickness h1 of the mask layer 130 and the thickness h2 of the passivation layer 120 are substantially the same.

Next, referring to FIG. 11 , the mask layer 130 may be exposed using the photomask 140 formed on the partial region of the optical black sensor region II and the pad region III. However, the technical spirit of the present invention is not limited thereto. That is, in some other embodiments, the photomask 140 may be formed only on the pad region III.

Specifically, as shown in FIG. 11 , light L is irradiated to the photomask 140 obliquely from the pad region III to the active pixel sensor region I, and the active pixel sensor region I and the optical The mask layer 130 formed on a partial region of the black sensor region II may be exposed.

Accordingly, the exposure region R1 having an inclination profile that is narrower in width from the top to the bottom may be formed on some regions of the active pixel sensor region I and the optical black sensor region II.

In addition, the non-exposed region R2 having an inclination profile that becomes wider from the top to the bottom may be formed on the partial region of the optical black sensor region II and the pad region III.

Subsequently, referring to FIG. 12 , the mask pattern 150 may be formed through a positive process. However, the technical spirit of the present invention is not limited thereto. That is, in some other embodiments, the mask pattern 150 may be formed through a negative process.

Specifically, the exposure region R1 may be removed using a chemical reaction using a developer. As a result, a mask pattern 150 having a slanted profile P1 that becomes wider from the top to the bottom may be formed on a partial region of the optical black sensor region II and the pad region III.

In this case, the mask pattern 150 may be formed so that the thickness h1 of the mask pattern 150 and the thickness h2 of the passivation layer 120 are substantially the same.

11 and 12 , the mask pattern 150 is illustrated as being formed on a partial region of the optical black sensor region II and on the pad region III, but the technical spirit of the present invention is not limited thereto. That is, in some other embodiments, the mask pattern 150 may be formed on a partial region of the active pixel sensor region (I), the optical black sensor region (II), and the pad region (III).

Next, referring to FIGS. 12 and 13 , the passivation layer 160 covering the pad 117 may be formed on a partial region of the optical black sensor region II and the pad region III by etching the passivation layer 120 . can In this case, the passivation layer 160 has an inclined profile P2 whose width increases from the top to the bottom.

Specifically, the passivation layer 160 uses an etching material having substantially the same etch ratio as that of the mask pattern 150 and the passivation layer 120 to form the inclination profile P1 of the mask pattern 150 into the passivation layer 120 . It can be formed by transferring (transfer) to.

More specifically, the passivation layer 160 is formed using an etching material having substantially the same etch ratio as that of the mask pattern 150 and the passivation layer 120 to form the mask pattern 150 and the active pixel sensor region (I). The inclination profile P1 of the mask pattern 150 may be transferred to the passivation layer 160 by sequentially etching the passivation layer 120 exposed thereon simultaneously from the top.

Since the thickness h1 of the mask pattern 150 and the thickness h2 of the passivation layer 120 have substantially the same thickness, the shape of the mask pattern 150 is transferred to the passivation layer 120 to form the mask pattern 150 and The passivation layer 160 having the same shape may be formed.

Accordingly, the slope profile P1 of the mask pattern 150 may be formed to be substantially the same as the slope profile P2 of the passivation layer 160 . Also, the lower width W1 of the mask pattern 150 and the lower width W2 of the passivation layer 160 may be formed to be substantially the same.

Next, referring to FIG. 14 , a color filter layer 170 is conformally formed on the exposed insulating layer 116 and the passivation layer 160 .

The color filter layer 170 may be formed through a spin coating process. In this case, the color filter film 170 is formed relatively conformally by using the passivation film 160 having an inclined profile that becomes wider from the upper part to the lower part compared to the conventional passivation film having a step difference. can be

Next, referring to FIG. 15 , the remaining color filter layer 170 excluding the color filter layer 170 formed on the active pixel sensor region (I) is etched.

Subsequently, as shown in FIG. 4 , the color filter 180 and the microlens 190 may be sequentially formed on the active pixel sensor region I through a subsequent process.

In the method of manufacturing an image sensor according to an embodiment according to the technical concept of the present invention, the passivation layer 160 having a slope profile that is wider from the top to the bottom is used on the active pixel sensor region (I). A step difference between the insulating film 116 formed on the ? and the passivation film 160 formed on the optical black sensor region (II) and the pad region (III) can be minimized.

Accordingly, it is possible to prevent a phenomenon in which the thickness of the color filter 180 positioned adjacent to the optical black sensor region II becomes non-uniform.

Hereinafter, a method of manufacturing an image sensor according to another embodiment according to the spirit of the present invention will be described with reference to FIG. 16 . Differences from the method of manufacturing the image sensor shown in FIG. 11 will be mainly described.

16 is an intermediate step view for explaining a method of manufacturing an image sensor according to another embodiment according to the technical spirit of the present invention.

Referring to FIG. 16 , the mask layer 130 ( 130 of FIG. 10 ) may be exposed using the photomask 240 formed on a partial region of the active pixel sensor region I and the optical black sensor region II. However, the technical spirit of the present invention is not limited thereto. That is, in some other embodiments, the photomask 240 may be formed on a portion of the active pixel sensor region (I), the optical black sensor region (II), and the pad region (III).

Specifically, as shown in FIG. 16 , light L is irradiated to the photomask 240 obliquely from the pad region III to the active pixel sensor region I, and a portion of the optical black sensor region II is irradiated. The mask layer ( 130 in FIG. 10 ) formed on the region and the pad region III may be exposed.

Accordingly, it is possible to form the exposure region R3 having an inclination profile that becomes wider from the top to the bottom on the partial region of the optical black sensor region II and the pad region III.

In addition, the non-exposed region R4 having an inclination profile that becomes narrower from the top to the bottom may be formed on a portion of the active pixel sensor region I and the optical black sensor region II.

Subsequently, the mask pattern 150 shown in FIG. 12 may be formed through a negative process.

Specifically, the non-exposed region R4 may be removed using a chemical reaction using a developer. For this reason, as shown in FIG. 12 , a mask pattern 150 having an inclined profile P1 that becomes wider from the top to the bottom is formed on a partial region of the optical black sensor region II and the pad region III. can be formed.

Hereinafter, a method of manufacturing an image sensor according to another exemplary embodiment according to the inventive concept will be described with reference to FIGS. 17 to 19 . Differences from the method of manufacturing the image sensor shown in FIGS. 10 to 12 will be mainly described.

17 to 19 are intermediate steps for explaining a method of manufacturing an image sensor according to still another embodiment according to the spirit of the present invention.

Referring to FIG. 17 , a mask layer 330 is formed on the passivation layer 120 . In this case, the mask layer 330 may be conformally formed on the passivation layer 120 so that the thickness h3 of the mask layer 330 and the thickness h2 of the passivation layer 120 are different from each other.

For example, as shown in FIG. 17 , the mask layer 330 is conformally formed on the passivation layer 120 so that the thickness h3 of the mask layer 330 is smaller than the thickness h2 of the passivation layer 120 . can be However, the technical spirit of the present invention is not limited thereto, that is, in some other embodiments, in the mask layer 330 , the thickness of the mask layer 330 is greater than the thickness h2 of the passivation layer 120 . ) may be conformally formed on the

Referring to FIG. 18 , light L is irradiated to the photomask 340 obliquely from the pad region III to the active pixel sensor region I, and the active pixel sensor region I and the optical black sensor region II are irradiated. ), the mask layer 330 formed on a partial region may be exposed.

Referring to FIG. 19 , the mask pattern 350 may be formed through a positive process.

The exposed region R5 of the mask layer 330 is removed using a chemical reaction using a developer, and only the non-exposed region R6 may exist. As a result, a mask pattern 350 having an inclined profile P3 that is wider from an upper portion to a lower portion may be formed on a partial region of the optical black sensor region II and the pad region III.

In this case, the mask pattern 350 and the passivation layer 120 may have different etching ratios with respect to the etching material. For example, as shown in FIG. 19 , when the thickness h3 of the mask pattern 350 is smaller than the thickness h2 of the passivation layer 120 , the etching ratio of the mask pattern 350 to the etching material is the etching material. It may be smaller than the etch ratio of the passivation layer 120 to .

That is, the passivation layer 120 may be etched relatively more than the mask pattern 350 with respect to the etching material. Accordingly, the inclination profile P3 of the mask pattern 350 and the inclination profile (P2 in FIG. 13 ) of the passivation layer ( 160 of FIG. 13 ) formed by the transfer of the mask pattern 350 may be different.

On the other hand, when the thickness of the mask pattern 350 is greater than the thickness h2 of the passivation layer 120 , the etching ratio of the mask pattern 350 to the etching material may be greater than the etching ratio of the protective layer 120 to the etching material. have.

That is, the mask pattern 350 may be etched relatively more than the passivation layer 120 with respect to the etching material. Accordingly, the inclination profile of the mask pattern 350 and the inclination profile (P2 in FIG. 13 ) of the passivation layer ( 160 of FIG. 13 ) formed by the transfer of the mask pattern 350 may be different.

Although embodiments according to the technical idea of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments, but may be manufactured in various different forms, and is commonly used in the technical field to which the present invention pertains. Those skilled in the art will understand that the present invention may be implemented in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

I: Active pixel sensor area Ⅱ: Optical black sensor area
III: pad area 100: substrate
117: pad 120: shield
130: mask layer 140: photo mask
150: mask pattern 160: passivation film
170: color filter film 180: color filter
190: micro lens

Claims (10)

To provide a substrate comprising an active pixel sensor region, a light blocking region, and a pad region,
forming a pad on the pad area;
forming a protective layer covering the active pixel sensor area, the light blocking area, and the pad area;
The passivation layer is etched to cover the pad area and to form a passivation layer exposing the active pixel sensor area, wherein the passivation layer is formed from an upper portion toward a lower portion adjacent to the substrate based on a cross-section perpendicular to the substrate. has an inclined profile that is widened in the horizontal direction parallel to
and forming a color filter film conformally on the active pixel sensor region. The method of claim 1,
Forming the passivation film,
A mask pattern exposing the active pixel sensor region is formed on the passivation layer, wherein the mask pattern has an inclined profile in which a width in the horizontal direction is widened from an upper portion to a lower portion;
and transferring the inclination profile of the mask pattern to the passivation layer by using etching materials having different etch ratios with respect to the mask pattern and the passivation layer. 3. The method of claim 2,
Forming the mask pattern,
A method of manufacturing an image sensor, comprising: irradiating light to a mask layer obliquely to form a mask pattern having an inclined profile in which the width in the horizontal direction increases from an upper portion to a lower portion. 3. The method of claim 2,
Forming the mask pattern,
exposing the mask layer formed on the protective film using a photomask,
and removing the exposed area of the mask layer. 3. The method of claim 2,
Forming the mask pattern,
exposing the mask layer formed on the protective film using a photomask,
and removing an unexposed region of the mask layer. The method of claim 1,
Forming the passivation film,
A mask pattern exposing the active pixel sensor region is formed on the passivation layer, wherein the mask pattern has an inclined profile in which a width in the horizontal direction is widened from an upper portion to a lower portion;
etching the passivation layer using the mask pattern to form the passivation layer;
The method of manufacturing an image sensor, wherein the inclination profile of the mask pattern and the inclination profile of the passivation layer are different from each other. To provide a substrate comprising an active pixel sensor region, a light blocking region, and a pad region,
forming a pad on the pad area;
forming a protective layer covering the active pixel sensor area, the light blocking area, and the pad area;
A mask pattern exposing the active pixel sensor region is formed on the passivation layer, and based on a cross-section perpendicular to the substrate, the mask pattern extends from an upper portion to a lower portion adjacent to the substrate in a horizontal direction parallel to the upper surface of the substrate. has an inclined profile that widens the width of
Including etching the protective layer using the slope profile of the mask pattern,
The etching of the passivation layer may include transferring an inclination profile of the mask pattern to the passivation layer using an etching material having substantially the same etch ratio to the mask pattern and the passivation layer. Way. 8. The method of claim 7,
After transferring the slope profile of the mask pattern to the passivation layer to form a passivation layer,
forming a color filter film conformally on the passivation film and the exposed active pixel sensor region;
and removing the color filter film formed on the passivation film to form a color filter on the active pixel sensor region. 8. The method of claim 7,
Transferring the slope profile of the mask pattern to the protective film,
and sequentially etching the mask pattern and the passivation layer exposed on the active pixel sensor region using the etching material simultaneously from an upper portion. 8. The method of claim 7,
A thickness of the mask pattern and a thickness of the passivation layer are substantially the same.

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