TWI622166B - Image sensor - Google Patents

Abstract

An image sensor includes a visible light receiving portion and an infrared light receiving portion. The visible light receiving portion is configured to receive visible light, and the infrared light receiving portion is configured to receive infrared light. The visible light receiving portion includes a color filter ball layer for collecting visible light. In some embodiments of the invention, the infrared light receiving portion includes infrared light penetrating the filter sphere layer for collecting infrared light. In some other embodiments of the invention, the infrared light receiving portion includes a white filter sphere layer for collecting infrared light.

Description

Image sensor

The present invention relates to an image sensor, and more particularly to an image sensor having an infrared light sensing function.

With the development of access control systems and security systems, biometric techniques that use human features to confirm personal identity are gaining popularity. The highly reliable iris recognition technology is one of the popular biometric technologies. When the iris recognition technology is applied to an electronic device, such as a smart phone, the smart phone needs an image sensor capable of receiving visible light and infrared light, respectively, to realize the iris recognition function. Conventional image sensors have two distinct parts to receive visible and infrared light, respectively.

The invention provides an image sensor comprising a visible light receiving portion and an infrared light receiving portion. The visible light receiving portion is configured to receive visible light, and the infrared light receiving portion is configured to receive infrared light. The visible light receiving portion includes a color filter ball layer for collecting visible light. The infrared light receiving portion includes an infrared light penetrating filter sphere layer for collecting infrared light.

According to an embodiment of the present invention, the visible light receiving unit further It includes a visible light diode and an infrared light blocking filter layer. The infrared light cut filter layer is disposed on the visible light photodiode, and the color filter ball layer is disposed on the infrared light cut filter layer. The visible light passes through the color filter sphere layer and the infrared light cut filter layer and is received by the visible light photodiode.

According to an embodiment of the invention, the infrared light receiving unit further includes an infrared light diode and a white filter layer. The white filter layer is disposed on the infrared light photodiode, and the infrared light penetrating filter sphere layer is disposed on the white filter layer. The infrared light passes through the infrared light penetrating filter sphere layer and the white filter layer and is received by the infrared light photodiode.

According to an embodiment of the invention, the image sensor further includes a wafer layer, and the wafer layer is located on the visible light diode and the infrared light diode. The first portion of the wafer layer is located in the visible light receiving portion, and the second portion of the wafer layer is located in the infrared light receiving portion.

According to an embodiment of the invention, the first portion of the wafer layer is between the infrared light-cutting filter layer and the visible light diode, and the second portion of the wafer layer is located between the white filter layer and the infrared light-emitting layer. Between the polar bodies.

According to an embodiment of the invention, the color filter sphere layer comprises a red filter unit, a green filter unit, and a blue filter unit.

According to an embodiment of the invention, the image sensor further includes a flat layer, and the flat layer is used to provide a flat surface. The color filter sphere layer is disposed on a flat surface.

According to an embodiment of the invention, the flat layer is located in the visible light receiving portion and the infrared light receiving portion.

The invention further provides an image sensor comprising visible light The receiving part and the infrared light receiving part. The visible light receiving portion is configured to receive visible light, and the infrared light receiving portion is configured to receive infrared light. The visible light receiving portion includes a color filter ball layer for collecting visible light. The infrared light receiving portion includes a white filter ball layer for collecting infrared light.

According to still another embodiment of the present invention, the visible light receiving portion further includes a visible light photodiode and an infrared light blocking filter layer. The infrared light cut filter layer is disposed on the visible light photodiode, and the color filter ball layer is disposed on the infrared light cut filter layer. The visible light passes through the color filter sphere layer and the infrared light cut filter layer and is received by the visible light photodiode.

According to still another embodiment of the present invention, the infrared light receiving portion further includes an infrared light photodiode and an infrared light penetrating filter layer. The infrared light penetrating filter layer is disposed on the infrared light photodiode, and the white filter ball layer is disposed on the infrared light penetrating filter layer. The infrared light passes through the white filter sphere layer and the infrared light penetrates the filter layer and is received by the infrared light photodiode.

According to still another embodiment of the present invention, the image sensor further includes a wafer layer, and the wafer layer is located on the visible light diode and the infrared light diode. The first portion of the wafer layer is located in the visible light receiving portion, and the second portion of the wafer layer is located in the infrared light receiving portion.

According to still another embodiment of the present invention, the first portion of the wafer layer is between the infrared light cut filter layer and the visible light diode, and the second portion of the wafer layer is located at the infrared light penetrating filter layer. Between the infrared light and the diode.

According to still another embodiment of the present invention, the color filter ball layer includes a red filter unit, a green filter unit, and a blue filter unit.

According to still another embodiment of the present invention, the image sensor further includes a flat layer for providing a flat surface. The color filter sphere layer is disposed on a flat surface.

According to still another embodiment of the present invention, the flat layer is located in the visible light receiving portion and the infrared light receiving portion.

100, 200‧‧‧ image sensor

100E‧‧‧ components

1000‧‧‧ method

110‧‧‧ Visible light receiving department

1100, 1200‧‧‧ steps

112‧‧‧ Visible light sensing layer

114‧‧‧Infrared light transmission filter

116‧‧‧Color filter sphere

116a‧‧‧Red Filter Unit

116b‧‧‧Blue filter unit

116c‧‧‧Green Filter Unit

116E‧‧‧Color filter layer

120, 220‧‧‧Infrared light receiving department

122‧‧‧Infrared light sensing layer

124‧‧‧White filter layer

126‧‧‧Infrared light penetrating filter sphere

126E, 226‧‧ ‧ infrared light transmission filter

224‧‧‧White filter sphere

ML‧‧‧microlens layer

PL‧‧‧flat layer

WA‧‧‧ wafer layer

A better understanding of the aspects of the present disclosure can be obtained from the following detailed description taken in conjunction with the drawings. It should be noted that, according to industry standard practices, the features are not drawn to scale. In fact, in order to make the discussion clearer, the dimensions of each feature can be arbitrarily increased or decreased.

1 is a cross-sectional view showing an image sensor according to a first embodiment of the present invention.

Fig. 2 is a cross-sectional view showing an image sensor according to a second embodiment of the present invention.

FIG. 3 is a flow chart showing a method of forming an image sensor according to a first embodiment of the present invention.

[Fig. 4a] to [Fig. 4b] are cross-sectional views showing an image sensor corresponding to the steps of the method of forming an image sensor according to the first embodiment of the present invention.

The disclosure provides many different embodiments or examples for implementing the various features disclosed herein. In order to simplify the disclosure, specific examples of components and layouts are described below. Of course, these are just examples and not To limit the disclosure. For example, if it is mentioned in the following description that the first feature is formed on the second feature, this may include an embodiment in which the first feature is in direct contact with the second feature; this may also include between the first feature and the second feature. Embodiments of other features are formed that make the first feature not in direct contact with the second feature. Moreover, the disclosure may repeat the symbols and/or text in various examples. This repetition is for the purpose of brevity and clarity, but does not in itself determine the relationship between the various embodiments and/or arrangements discussed.

Furthermore, spatially relative terms such as "lower", "lower", """"""""""" These spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. These devices can also be rotated (e.g., rotated 90 degrees or rotated to other directions), and the spatially relative descriptions used herein can also be interpreted accordingly.

1 is a cross-sectional view of an image sensor 100 in accordance with a first embodiment of the present invention. As shown in FIG. 1 , the image sensor 100 includes a visible light receiving unit 110 and an infrared light receiving unit 120 . The visible light receiving unit 110 is configured to receive visible light, and the infrared light receiving unit 120 is configured to receive infrared light.

As shown in FIG. 1 , the visible light receiving unit 110 includes a visible light sensing layer 112 , an infrared light cutoff (IR Cut) filter layer 114 , and a color filter ball layer 116 . The color filter ball layer 116 is disposed on the infrared light cut filter layer 114, and the infrared light cut filter layer 114 is disposed on the visible light sensing layer 112 to provide colored light to the visible light sensing layer 112. The visible light sensing layer 112 is configured to receive visible light to generate a main image signal accordingly. In this embodiment, the sense of visible light The measurement layer 112 includes at least one photodiode to sense colored light. The photodiode can be a complementary metal oxide semiconductor (CMOS) diode. However, embodiments of the invention are not limited thereto.

The infrared light cut filter layer 114 is used to cut off infrared light. In other words, when light passes through the infrared light cut filter layer 114, the infrared light cut filter layer 114 blocks the transmission of infrared light. In the present embodiment, the infrared light cut filter layer 114 blocks light having a wavelength of more than 850 nm, but embodiments of the present invention are not limited thereto.

The color filter sphere layer 116 is used to collect visible light and provide colored light. In the present embodiment, the color filter ball layer 116 includes a red filter unit 116a, a blue filter unit 116b, and a green filter unit 116c, but embodiments of the present invention are not limited thereto.

As shown in FIG. 1, the infrared light receiving portion 120 includes an infrared light sensing layer 122, a white filter layer 124, and an infrared light penetrating (IR Pass) filter ball layer 126. The infrared light penetrating filter layer 126 is disposed on the white filter layer 124, and the white filter layer 124 is disposed on the infrared light sensing layer 122 to provide infrared light to the infrared light sensing layer 122. The infrared light sensing layer 122 is configured to receive infrared light to generate an auxiliary image signal accordingly. In this embodiment, the infrared light sensing layer 122 includes at least one photodiode to sense infrared light. The photodiode can be a complementary MOS diode. However, embodiments of the invention are not limited thereto.

Infrared light penetrates the filter sphere layer 126 for collecting infrared light and intercepting visible light. In other words, when light passes through the infrared light through the filter sphere layer 126 Infrared light penetrates the filter sphere layer 126 to block the transmission of visible light. In the present embodiment, the infrared light penetrating filter sphere layer 126 blocks light having a wavelength of less than 850 nm, but embodiments of the present invention are not limited thereto.

The white filter layer 124 is used to pass infrared light. In the present embodiment, the white filter layer 124 is a white photoresist, but embodiments of the present invention are not limited thereto.

Specifically, when the image sensor 100 is used to sense an object such as an iris, the object is focused through the color filter ball layer 116 and the infrared light penetrating the filter ball layer 126. Moreover, the focus of the image sensor 100 can be adjusted by changing the thickness of the color filter sphere layer 116 and the thickness of the infrared light penetrating the filter sphere layer 126. It should be noted that in the present embodiment, the thickness of the color filter ball layer 116 is substantially equal to the thickness of the infrared light penetrating filter ball layer 126, but embodiments of the present invention are not limited thereto.

As shown in FIG. 1, the visible light receiving unit 110 and the infrared light receiving unit 120 further include a wafer layer WA and a flat layer PL. The wafer layer WA is formed on the visible light sensing layer 112 and the infrared light sensing layer 122 to provide a substrate on which the infrared light cut filter layer 114 and the white filter layer 124 are formed. In the present embodiment, the wafer layer WA is a glass wafer, but embodiments of the present invention are not limited thereto. It should be noted that in the present embodiment, the thickness of the infrared light cut filter layer 114 is substantially equal to the thickness of the white filter layer 124, but embodiments of the present invention are not limited thereto.

A flat layer PL is formed on the infrared light cut filter layer 114 and the white filter layer 124 to provide a flat surface on which the color filter ball layer 116 and the infrared light penetrating filter sphere layer 126 are disposed. The flat layer PL also provides a good interface The color filter sphere layer 116 and the infrared light penetrating filter sphere layer 126 are attached to the flat layer PL.

The light path of the infrared light received by the infrared light sensing layer 122 extends from the infrared light penetrating filter sphere layer 126 through the flat layer PL and the white filter layer 124. Compared with the conventional image sensor, the image sensor 100 has a small light intensity loss due to the reduction of the light path of the infrared light. Therefore, the infrared light received by the image sensor 100 has a better light intensity to meet the needs of the user.

2 is a cross-sectional view of an image sensor 200 in accordance with a second embodiment of the present invention. As shown in FIG. 2 , the image sensor 200 includes a visible light receiving portion 110 and an infrared light receiving portion 220 , wherein the infrared light receiving portion 220 includes an infrared light penetrating filter layer 226 and a white filter ball layer 224 . The structure of the image sensor 200 is similar to that of the image sensor 100, except that the white filter layer 124 and the infrared light penetrating filter layer 126 are respectively penetrated by the infrared light filter layer 226 and the white filter. The ball layer 224 is replaced.

The infrared light penetrates the filter layer 226 for intercepting visible light. In other words, when light passes through the infrared light through the filter layer 226, the infrared light penetrates the filter layer 226 to block the transmission of visible light. In the present embodiment, the infrared light penetrating filter layer 226 blocks light having a wavelength of less than 850 nm, but embodiments of the present invention are not limited thereto.

The white filter sphere layer 224 is used to collect light and pass the light therethrough. In the present embodiment, the white filter ball layer 224 is a white photoresist, but embodiments of the present invention are not limited thereto.

Specifically, when the image sensor 200 is used to sense an object (such as In the case of the iris, the object is focused through the color filter sphere layer 116 and the white filter sphere layer 224. Furthermore, the focus of the image sensor 200 can be adjusted by changing the thickness of the color filter sphere layer 116 and the thickness of the white filter sphere layer 224. It should be noted that in the present embodiment, the thickness of the color filter ball layer 116 is substantially equal to the thickness of the white filter ball layer 224, but embodiments of the present invention are not limited thereto.

The light path of the infrared light received by the infrared light sensing layer 122 extends from the white filter ball layer 224 through the flat layer PL and the infrared light penetrating filter layer 226. Similar to the image sensor 100, the infrared light received by the image sensor 200 has a better light intensity to meet the needs of the user.

Referring to FIG. 3 and FIG. 4a to FIG. 4b, FIG. 3 is a flow chart showing a method 1000 of forming an image sensor 100 according to a first embodiment of the present invention. 4a-4b are cross-sectional views of image sensor 100 corresponding to steps 1100-1200 of method 1000 of forming image sensor 100 in accordance with a first embodiment of the present invention. Method 1000 begins at step 1100. In step 1100, the component 100E as shown in FIG. 4a includes a visible light sensing layer 112, an infrared light sensing layer 122, a wafer layer WA, an infrared light blocking filter layer 114, a white filter layer 124, a flat layer PL, The color filter layer 116E, the infrared light penetrating filter layer 126E, and the microlens layer ML, wherein the microlens layer ML is formed on the color filter layer 116E and the infrared light transmission filter layer 126E as the color filter layer 116E and The infrared light penetrates the mask of the filter layer 126E. It should be noted that the material of the microlens layer ML may be epoxy resin, optical glue, polymethylmethacrylates (PMMAs), polyurethane plastics (PUs), polydimethylsiloxane (PDMS) or other thermosetting. Light hardening The light transmissive material, but embodiments of the invention are not limited thereto.

As shown in FIG. 4b, in step 1200 of method 1000, element 100E is etched through an etch process. Specifically, the microlens layer ML is etched such that the remaining color filter layer 116E and the remaining infrared light transmission filter layer 126E have substantially the same upper surface as the upper surface of the microlens layer ML, thereby forming The color filter sphere layer 116 and infrared light as shown in FIG. 1 penetrate the filter sphere layer 126. As such, the image sensor 100 is formed.

It should be noted that the method of forming the image sensor 200 is similar to the method of forming the image sensor 100. Therefore, the description of the method of forming the image sensor 200 will not be described herein.

It can be seen from the above that the structure of the image sensor of the present invention can effectively improve the light intensity of the infrared light received by the image sensor to meet the needs of the user, thereby reducing the subsequent analysis of optical signals on other instruments (eg, Difficulty in video signal).

The features of several embodiments are summarized above, and those skilled in the art will be able to understand the aspects of the disclosure. Those skilled in the art will appreciate that the present disclosure can be readily utilized as a basis for designing or modifying other processes and structures, thereby achieving the same objectives and/or achieving the same advantages as the embodiments described herein. . It should be understood by those skilled in the art that the invention may be made without departing from the spirit and scope of the disclosure.

Claims (16)

An image sensor includes: a visible light receiving portion for receiving a visible light, wherein the visible light receiving portion includes a color filter ball layer for collecting the visible light; and an infrared light receiving portion for receiving an infrared light The infrared light receiving portion includes an infrared light penetrating filter sphere layer for collecting the infrared light and cutting off the visible light. The image sensor of claim 1, wherein the visible light receiving portion further comprises: a visible light photodiode; and an infrared light blocking filter layer disposed on the visible light diode; wherein the color The filter ball layer is disposed on the infrared light cut filter layer, and the visible light passes through the color filter ball layer and the infrared light cut filter layer to be received by the visible light diode. The image sensor of claim 2, wherein the infrared light receiving portion further comprises: an infrared light photodiode; and a white filter layer disposed on the infrared light photodiode; The infrared light penetrating filter sphere layer is disposed on the white filter layer, and the infrared light passes through the infrared light penetrating filter sphere layer and the white filter layer to be received by the infrared light photodiode. The image sensor of claim 3, further comprising a wafer layer on the visible light diode and the infrared light diode, wherein a first portion of the wafer layer is located The visible light receiving portion has a second portion of the wafer layer located in the infrared light receiving portion. The image sensor of claim 4, wherein the first portion of the wafer layer is between the infrared light-cut filter layer and the visible light diode, and the wafer layer The second portion is located between the white filter layer and the infrared light diode. The image sensor of claim 1, wherein the color filter sphere layer comprises a red filter unit, a green filter unit, and a blue filter unit. The image sensor of claim 1, further comprising a flat layer for providing a flat surface, wherein the color filter ball layer is disposed on the flat surface. The image sensor of claim 7, wherein the flat layer is located in the visible light receiving portion and the infrared light receiving portion. An image sensor includes: a visible light receiving portion for receiving a visible light, wherein the visible light The receiving portion includes a color filter ball layer for collecting the visible light, and an infrared light receiving portion for receiving an infrared light, wherein the infrared light receiving portion includes a white filter ball layer for collecting the infrared light. The image sensor of claim 9, wherein the visible light receiving portion further comprises: a visible light photodiode; and an infrared light blocking filter layer disposed on the visible light diode; wherein the color The filter ball layer is disposed on the infrared light cut filter layer, and the visible light passes through the color filter ball layer and the infrared light cut filter layer to be received by the visible light diode. The image sensor of claim 9, wherein the infrared light receiving portion further comprises: an infrared light photodiode; and an infrared light penetrating filter layer disposed on the infrared light photodiode Wherein the white filter ball layer is disposed on the infrared light penetrating filter layer, the infrared light passes through the white filter ball layer and the infrared light penetrates the filter layer and is received by the infrared light photodiode . The image sensor of claim 11, further comprising a wafer layer on the visible light diode and the infrared light diode, wherein a first portion of the wafer layer is located The visible light receiving portion has a second portion of the wafer layer located in the infrared light receiving portion. The image sensor of claim 12, wherein the first portion of the wafer layer is between the infrared light-cut filter layer and the visible light diode, and the wafer layer The second portion is located between the infrared light penetrating filter layer and the infrared light photodiode. The image sensor of claim 9, wherein the color filter sphere layer comprises a red filter unit, a green filter unit, and a blue filter unit. The image sensor of claim 9, further comprising a flat layer for providing a flat surface, wherein the color filter ball layer is disposed on the flat surface. The image sensor of claim 15, wherein the flat layer is located in the visible light receiving portion and the infrared light receiving portion.