Sensor device and method of manufacturing a sensor device

Abstract

A sensor device (1) comprises a first group of receiving elements (2), a second group of receiving elements (3), a third group of receiving elements (4) and a fourth group of receiving elements (5) for detecting light in the red, green, blue and infrared wavelength ranges. At least one first sub-device (6) is formed by arranging one receiving element (2) of the first group, two receiving elements (3) of the second group and one receiving element (4) of the third group in a first-type Bayer pattern. At least one second sub-device (7, 7') is formed by arranging two receiving elements of the second group (3), one receiving element of the fourth group (5) and one receiving element (2) of the first group or one receiving element (4) of the third group in a second-type Bayer pattern. At least one first sub-device (6) and at least one second sub-device (7, 7') are arranged adjacent to each other in a main extension plane of the sensor device (1).

Description

Technical Field

[0001] The present disclosure relates to a sensor device, an image sensor, and a method for manufacturing a sensor device. Background Art

[0002] CMOS image sensors are used in a wide range of applications, for example in camera modules and smartphones, tablets, laptops, etc. Some of these applications, such as photography, rely on sensitivity in the visible light domain, while others, such as 3D imaging and recognition, require the image sensor to be sensitive in the infrared (IR) domain. For example, the infrared domain is used in dark environments or at least in conditions of limited brightness. But the infrared domain can also be used to enhance ordinary RGB images: it brings "texture" (because infrared radiation can "see through" certain conditions (such as haze), while light in the visible wavelength domain cannot). Due to space limitations in prior art devices, it is desirable to provide an image sensor that is sensitive in both the visible light domain and the infrared domain. To this end, each sensor device of the image sensor includes a color receiving element and an IR receiving element for the infrared spectrum, each color receiving element being sensitive to a specific part of the visible light spectrum.

[0003] Sensor devices with only visible color receiving elements usually arrange these elements in a specific pattern, the so-called Bayer pattern, where the sensor device comprises four receiving elements arranged in a 2×2 array, two of the four receiving elements being arranged opposite each other and being sensitive to the green part of the visible spectrum, while the other two receiving elements are sensitive to the blue domain and the red domain, respectively. The reason for having two receiving elements for the green domain is that the human eye is more sensitive to green than to red or blue. An image signal processor (ISP) maps monochrome picture elements (each element contains only the monochrome information of its receiving element) to an array of multicolor picture elements (each element stores all received colors), which is achieved by evaluating the color information from neighboring receiving elements. Furthermore, the ISP may use algorithms, for example for edge preservation of the image. The image conversion performed by the ISP is sometimes called demosaicing.

[0004] The implementation of an additional IR receiving element in these image sensors is usually achieved by sacrificing one of the green receiving elements of the Bayer filter array pattern. However, this results in the fact that standard demosaicing (or debayering) causes a degradation of the image quality and / or complex and / or dedicated computationally intensive algorithms. Furthermore, since the human eye is most sensitive to the color green, the loss of a green receiving element results in a degradation of the image perception.

[0005] An object to be achieved is therefore to provide an improved concept for a sensor device which is able to sense light in the visible and infrared wavelength range and which overcomes the above-mentioned disadvantages of prior art sensor devices.

[0006] This object is achieved by the subject matter of the independent claims. Embodiments and developments of improved concepts are defined in the dependent claims.

[0007] The improved concept is based on the idea of ​​quadrupling the Bayer pattern so that a 4×4 receiving element array is formed by 8 green receiving elements, 4 red receiving elements, and 4 blue receiving elements. However, some of the blue (or red) receiving elements can be replaced by near-infrared (NIR) receiving elements. In such an array, it is relatively easy to fill the NIR receiving elements with blue (or red) color information from adjacent receiving elements, thereby producing a standard RGGB Bayer pattern, enabling existing ISP chips to be used for demosaicing.

[0008] Here and below, a green receiving element refers to a receiving element capable of sensing light within a green wavelength range. Therefore, a blue receiving element and a red receiving element refer to receiving elements capable of sensing light within a blue or red wavelength range, respectively. An IR receiving element refers to a receiving element capable of sensing light in an infrared domain, particularly in an NIR domain. The term "light" may generally refer to electromagnetic radiation, including infrared radiation, near infrared radiation, and visible light. Therefore, green light, blue light, red light, and NIR light will refer to light within the corresponding wavelength ranges. In addition, below, the term "color information" refers to the intensity value of light within a specific wavelength range. For example, a wavelength range can correspond to blue light, green light, or red light. However, it may also correspond to IR or NIR light. Therefore, the term "color" refers to various wavelength domains of light, including the IR wavelength domain.

[0009] The sensor device according to the improved concept includes a first group of receiving elements configured to detect light in the red wavelength range. In addition, the sensor device according to the improved concept includes a second group of receiving elements configured to detect light in the green wavelength range, a third group of receiving elements configured to detect light in the blue wavelength range, and a fourth group of receiving elements configured to detect light in the infrared wavelength range.

[0010] In the sensor device according to the improved concept, at least one first sub-device is formed by arranging one receiving element of the first group, two receiving elements of the second group, and one receiving element of the third group in a first-type Bayer pattern.

[0011] At least one second sub-device is formed by arranging two receiving elements of the second group, one receiving element of the fourth group, and one receiving element of the first group or the third group in a second-type Bayer pattern.

[0012] Here and hereinafter, the term "Bayer-like pattern" refers to a pattern in which four receiving elements are arranged in a 2×2 array, one of which is sensitive to a first wavelength range, two of which are arranged opposite to each other and are sensitive to a second wavelength range, and the remaining receiving elements show sensitivity in a third wavelength range or a fourth wavelength range, respectively. This means that if two receiving elements are sensitive to green light and the other two are sensitive to red light and blue light, respectively, the Bayer-like pattern can be the original Bayer pattern. However, the Bayer-like pattern can also include receiving elements that are sensitive to light of different colors. For example, one receiving element of the Bayer-like pattern can be sensitive to IR light, so that one receiving element of the original Bayer-like pattern is replaced by the IR receiving element.

[0013] In the first type Bayer pattern and the second type Bayer pattern, the same group of receiving elements can be arranged in the same position. For example, if the receiving elements of the second group are placed in the lower left corner and the upper right corner of the first type Bayer pattern, the second type Bayer pattern can also have those receiving elements in these corners. The same applies to the receiving elements of other groups.

[0014] In a preferred embodiment, the first type of Bayer pattern refers to an original Bayer pattern formed by one red receiving element, two green receiving elements and one blue receiving element. In this preferred embodiment, the second type of Bayer pattern refers to a pattern in which the blue or red receiving element of the original Bayer pattern is replaced by an IR receiving element.

[0015] In a sensor device according to a further development, the at least one first subdevice and the at least one second subdevice are arranged adjacent to one another in a main extension plane of the sensor device.

[0016] This means that the first sub-device and the second sub-device are arranged adjacent to each other in a transverse direction parallel to the main extension plane of the sensor device. This can also mean that the first sub-device and the second sub-device have a common boundary. However, in the case of forming a further first sub-device, they can also have a common boundary with each other. The same applies to the further second sub-device.

[0017] Image sensors with sensitivity in both the visible and infrared wavelength ranges can be conveniently used for visible light imaging, for example for photography, and infrared imaging, for example for 3D imaging and / or recognition applications using active illumination with an infrared light source. Image quality can be improved by using the infrared domain. Different wavelengths have different absorption characteristics in, for example, humid air (such as haze or fog). In these environments, infrared light has better absorption characteristics than visible light. Therefore, adding IR / NIR sensitivity to an image sensor allows adding "texture" to the image, thereby improving image quality. Furthermore, image sensors with sensitivity in the IR / NIR domain allow use in dark environments.

[0018] Each receiving element of the sensor device according to the improved concept is configured to capture optical information incident on the corresponding receiving element and generate electrical information representing the optical information. In particular, for image sensors manufactured according to standard CMOS technology, the working principle of the receiving element is to convert light intensity into photocurrent using a photodiode. In this regard, silicon-based photodiodes are a common choice, because these diodes are sensitive in a wide wavelength range of 190nm to 1100nm, thus covering the relevant parts of the electromagnetic spectrum in the visible and infrared domains. In addition, due to the large band gap of silicon, silicon-based photodiodes show excellent noise performance compared to other photodiodes (such as germanium-based photodiodes).

[0019] For readout purposes, i.e., for transferring charge from the photodiode to a storage capacitor, a storage element, an analog-to-digital converter, etc., the first group of receiving elements, the second group of receiving elements, the third group of receiving elements, and / or the fourth group of receiving elements can be connected to a shared floating diffusion. Alternatively, each group of receiving elements can be connected to a respective floating diffusion, or all receiving elements can be connected to a single floating diffusion.

[0020] To adjust the sensitivity to a specific part of the incident electromagnetic radiation spectrum, each receiving element can include, in addition to the photodiode, a filter arranged between the top surface of the receiving element (ie the photodiode) and the incident electromagnetic radiation source. For example, each receiving element includes a wavelength filter.

[0021] The wavelength filter of each receiving element of the first, second and third groups of receiving elements can be one of the complementary color filters, for example according to the RGB additive color model. For example, a red color filter is transmissive or translucent for red light, but is opaque for other light, in particular for green light, blue light and / or infrared light. Thus, for each of the complementary colors red, green and blue, at least one receiving element of the first, second or third groups of receiving elements is sensitive to the corresponding complementary color. Here and below, "transmissive" or "translucent" refers to a transparency of at least 60% or at least 80%.

[0022] Similarly, each receiving element in the fourth group of receiving elements can include an infrared filter, such as a near infrared filter. In order to provide a receiving element that is primarily or solely sensitive to infrared light of a specific wavelength range, the receiving elements of the fourth group of receiving elements can include an infrared filter. The wavelength range transmitted by the infrared filter can depend on the spectrum of the illumination source, such as an infrared LED. For example, the transmission wavelength range of the infrared filter includes light of 940nm or 850nm.

[0023] By arranging the receiving elements of the sensor device into a Bayer-like pattern, an existing ISP chip can be used for demosaicing. This reduces the cost of image sensors using the sensor device because a separate ISP chip does not need to be developed. By demosaicing, a digital image containing image information in the visible wavelength domain can be generated. There may be another image processing path that outputs image information in the IR wavelength domain.

[0024] According to the improved concept, the second sub-device is different from the first sub-device in that the receiving elements of the first group or the receiving elements of the third group are replaced by the receiving elements of the fourth group. The image quality loss that can be expressed by the peak signal-to-noise ratio (PSNR) is relatively low. This is because in the second sub-device, the missing color information of the receiving elements from the first group or the receiving elements of the third group can be inferred from the adjacent first sub-device. Correspondingly, in the first sub-device, the missing IR color information can be inferred from the adjacent second sub-device.

[0025] In the embodiment where the second sub-assembly is formed of one red receiving element, two green receiving elements and one IR receiving element, the resulting sensor assembly includes more red receiving elements than blue receiving elements. This is advantageous because the human eye is least sensitive to the blue color but has a higher sensitivity to the red domain.

[0026] In some embodiments, the sensor device includes a plurality of first sub-devices and a plurality of second sub-devices, and the plurality of first sub-devices and the plurality of second sub-devices are arranged in a matrix.

[0027] This means that the sensor device may comprise at least two first sub-devices and at least two second sub-devices.In a preferred embodiment, the first sub-devices and the second sub-devices may be arranged in a checkerboard pattern.

[0028] In order to obtain sufficient image resolution, the sensor device can be formed to a desired size. Furthermore, the receiving elements are arranged such that the receiving elements of each group are effectively distributed on a matrix.

[0029] In some embodiments of the sensor device, two of the first sub-devices and two of the second sub-devices are arranged in a 2×2 matrix, such that each of the first sub-devices and the second sub-devices is arranged at a diagonal of the 2×2 matrix.

[0030] Since each sub-assembly is formed by four receiving elements, the sensor assembly comprises a 4×4 array of receiving elements. Such an array comprises 8 (50%) receiving elements of the second group and 2 (12.5%) receiving elements of the fourth group. Furthermore, the array comprises 4 (25%) receiving elements of the first group and 2 (12.5%) receiving elements of the third group, or vice versa. This means that there is a surplus of receiving elements of the second group.

[0031] It should be noted that further sub-devices may extend the sensor device in each lateral direction. Hence, a 2x2 matrix may be understood as a unit cell of a larger sensor device comprising a plurality of such 2x2 matrices arranged next to each other.

[0032] The receiving elements of each group are distributed on the sensor device in an efficient manner. In addition, the sensor device includes a sufficiently large number of receiving elements of each group per unit area. For example, since the human eye is most sensitive to green, there are excess green receiving elements. Each sub-device is formed into a Bayer-like pattern, which allows the use of conventional ISP chips.

[0033] In some embodiments, at least one second sub-device is formed by arranging one receiving element of the first group, two receiving elements of the second group, and one receiving element of the fourth group in a second type of Bayer pattern. At least one third sub-device is formed by arranging two receiving elements of the second group, one receiving element of the third group, and one receiving element of the fourth group in a third type of Bayer pattern.

[0034] The first part device, the second part device and the third part device are arranged adjacent to one another in a main extension plane of the sensor device.

[0035] As described above, the first type of Bayer pattern refers to an original Bayer pattern formed by one red receiving element, two green receiving elements, and one blue receiving element. In this embodiment, the second type of Bayer pattern is defined as a pattern in which the blue receiving element of the original Bayer pattern is replaced by an IR receiving element. The third type of Bayer pattern refers to a pattern in which the red receiving element is replaced by an IR receiving element.

[0036] In the first type of Bayer pattern, the second type of Bayer pattern, and the third type of Bayer pattern, the first group of receiving elements, the second group of receiving elements, and the third group of receiving elements can be arranged in the same position. For example, if the second group of receiving elements are placed in the lower left corner and the upper right corner of the first type of Bayer pattern, the third type of Bayer pattern can also have those receiving elements in these corners. The same applies to the first group of receiving elements and the third group of receiving elements.

[0037] The first sub-device, the second sub-device and the third sub-device may be arranged so that one of the sub-devices has a common boundary with the corresponding other two sub-devices. However, in the case of forming an additional first sub-device, they may also have a common boundary with each other. This applies to the additional second sub-device and the additional third sub-device.

[0038] Since the missing color information of each sub-device can be inferred from the adjacent sub-device having a receiving element for detecting the missing color, the loss of image quality is low. For example, in the third sub-device, the missing color information of red can be inferred from the adjacent first sub-device or second sub-device.

[0039] In some embodiments, the sensor device includes a plurality of first sub-devices, a plurality of second sub-devices, and / or a plurality of third sub-devices, and the plurality of first sub-devices, second sub-devices, and third sub-devices are arranged in a matrix.

[0040] The matrix enables different sub-devices to be adjacent to each other and share a common border. However, sub-devices of the same kind may also be adjacent to each other so that they share a common border.

[0041] In order to obtain sufficient image resolution, the sensor device can be formed to a desired size. Furthermore, the receiving elements can be arranged such that the receiving elements of each group are effectively distributed on a matrix.

[0042] In some embodiments of the sensor device, two of the first sub-devices, one of the second sub-devices and one of the third sub-devices are arranged in a 2×2 matrix such that the first sub-devices are arranged at opposite corners of the 2×2 matrix.

[0043] Since each sub-assembly is formed by four receiving elements, the receiving element assembly includes a 4×4 receiving element array, which includes 8 green receiving elements (50% of the total number of receiving elements), 3 red receiving elements (18.75%), 3 blue receiving elements (18.75%), and 2 IR receiving elements (12.5%).

[0044] It should be noted that the sensor device may comprise further first sub-devices, second sub-devices and third sub-devices which may extend the sensor element device in each lateral direction. In this sense, a 2×2 matrix may be understood as a cell of a sensor device comprising a plurality of such 2×2 matrices arranged adjacent to each other.

[0045] The receiving elements of each group are distributed on the sensor device in an efficient manner. In addition, the sensor device includes a sufficiently large number of receiving elements of each group per unit area. For example, since the human eye is most sensitive to green, there are excess green receiving elements. Each sub-device is formed into a Bayer-like pattern, which allows the use of a conventional ISP chip.

[0046] In some embodiments of the sensor device, three of the first subdevices, three of the second subdevices and three of the third subdevices are arranged in a 3×3 matrix such that in a main plane in which the sensor device extends, different subdevices are adjacent to each other.

[0047] Different sub-devices are adjacent to each other in the lateral direction. This means that the first sub-device, the second sub-device and the third sub-device are arranged adjacent to each other, so that the first sub-device has a common border with the second sub-device and another common border with the third sub-device. In addition, the second sub-device has a common border with the third sub-device. Sub-devices of the same type do not have common borders with each other.

[0048] Since each sub-assembly is formed by four receiving elements, the receiving element assembly includes a 6×6 receiving element array, which includes 18 green receiving elements (50% of the total number of receiving elements), 6 red receiving elements (16.67%), 6 blue receiving elements (16.67%), and 6 IR receiving elements (16.7%).

[0049] It should be noted that the receiving element arrangement may include further first sub-arrangements, second sub-arrangements and third sub-arrangements which may extend the sensor arrangement in each lateral direction. In this sense, a 3×3 matrix may be understood as a unit cell of a larger sensor arrangement comprising a plurality of such 3×3 matrices arranged adjacent to each other.

[0050] The receiving elements of each group are distributed over the sensor device in an efficient manner. Furthermore, the sensor device comprises a sufficiently large number of receiving elements of each group per unit area. For example, there is an excess of green receiving elements. Each sub-device forms a Bayer-like pattern, which allows the use of conventional ISP chips. Furthermore, the loss of image quality is low, since color information missing in one of the sub-devices can be inferred from the adjacent sub-devices.

[0051] In some embodiments of the sensor device, the receiving element has a rectangular top surface, in particular a square top surface. Rectangular or square receiving elements can be combined into an array. Four receiving elements can be arranged in a Bayer-like pattern.

[0052] In some embodiments of the sensor device, the receiving element comprises a sensor element, such as a photodiode.

[0053] As described above, the sensor elements are configured to capture optical information from electromagnetic radiation incident on the respective sensor elements. The sensor elements generate electrical signals representing the optical information. In particular, for image sensors manufactured according to standard CMOS technology, the working principle of the sensor elements is to convert light intensity into photocurrent using a photodiode. In some embodiments, the sensor elements (e.g., photodiodes) are tuned to a portion of the wavelength spectrum. This means that the sensor elements can be implemented differently depending on the wavelength range they are to detect. Therefore, at least some of the sensor elements may have different characteristics, such as being more sensitive to NIR light.

[0054] The sensor element, for example a photodiode, efficiently converts the optical information into an electrical signal which can be further evaluated by a readout circuit.

[0055] In some embodiments of the sensor device, the receiving element further comprises a wavelength filter.

[0056] For example, the first group of receiving elements, the second group of receiving elements, and the third group of receiving elements are sensitive to a specific portion of the visible gamut (e.g., the red portion, the green portion, or the blue portion). For example, the sensitivity is achieved by using appropriate color filters as described above. In this way, these groups of four receiving elements can be arranged in an array to achieve the above-mentioned Bayer pattern or Bayer-like pattern.

[0057] The receiving element of the fourth group includes an infrared filter. For example, the infrared filter can be a near infrared filter. With the help of the infrared filter as described above, a receiving element is provided that is mainly or exclusively sensitive to infrared light of a specific wavelength range. The wavelength range transmitted by the infrared filter can depend on the spectrum of the illumination source, such as an infrared LED. For example, the transmission wavelength range of the infrared filter includes light of 940nm or 850nm.

[0058] In some embodiments, sensitivity to a particular wavelength domain is achieved by a combination of more than one filter. For example, a bandpass filter is combined with a cutoff filter. The bandpass filter can transmit light of a particular color, while the cutoff filter can additionally block light in a different wavelength domain, such as ultraviolet (UV) light.

[0059] Furthermore, an image sensor comprising the sensor device is provided. This means that all features disclosed for the sensor device are also disclosed for and applicable to the image sensor, and vice versa. The image sensor further comprises a circuit for reading out an electrical signal from the receiving element.

[0060] For example, for readout purposes, an image sensor includes a storage capacitor, a memory element, an analog-to-digital converter (ADC), etc.

[0061] Such image sensors can be conveniently applied to electronic devices such as smartphones, tablets, laptops or camera modules. For example, the camera module is configured to operate in the visible domain for photography and / or video capture, and in the infrared domain for 3D imaging and / or recognition purposes. In addition, image sensors with infrared sensitivity can be used in dark environments where video feeds are required. Such applications range from mobile phone face unlocking to automotive driver monitoring systems. Both deploy illuminators in the near infrared spectrum so that the phone user / driver is not dazzled by the light illuminating him / her. This means that an illuminator that can use a flash will not interfere with the person being photographed because the flash is in the invisible wavelength range, such as NIR light.

[0062] In some embodiments, the image sensor further includes an image signal processor configured to generate a digital image based on the electrical signal from the receiving element.

[0063] The circuit can be implemented so that the electrical signal from the receiving element is pre-processed for the ISP. For example, the pre-processing can include simulating missing color information. For image information in the IR wavelength domain, the circuit can provide another image processing path to the ISP. As described above, the ISP maps monochrome image elements to an array of multi-color image elements, which is achieved by evaluating color information from adjacent receiving elements. In addition, the ISP can also be responsible for tasks such as edge preservation of the image. The image conversion performed by the ISP is called demosaicing. Since the receiving elements are arranged according to a Bayer-like pattern, conventional ISP chips can be used for image sensors.

[0064] The object is also achieved by a method for producing a sensor device. All features disclosed for the sensor device are also disclosed and apply to the method for producing the sensor device and vice versa.

[0065] The method includes providing a first group of receiving elements configured to detect light in a red wavelength range, providing a second group of receiving elements configured to detect light in a green wavelength range, providing a third group of receiving elements configured to detect light in a blue wavelength range, and providing a fourth group of receiving elements configured to detect light in an infrared wavelength range.

[0066] The method also includes forming at least one first sub-device by arranging one receiving element of a first group, two receiving elements of a second group, and one receiving element of a third group in a first-type Bayer pattern.

[0067] The method also includes forming at least one second sub-device by arranging two receiving elements of the second group, one receiving element of the fourth group, and one receiving element of the first group or the third group in a second-type Bayer pattern.

[0068] The method further comprises arranging the at least one first sub-device and the at least one second sub-device adjacent to each other in a main extension plane of the sensor device.

[0069] By arranging the receiving elements in a Bayer-like pattern, existing ISP chips can be used for demosaicing. This reduces the cost of image sensors using the sensor device because there is no need to develop a separate ISP chip. Since color information missing in one corresponding sub-device can be inferred from adjacent sub-devices, the loss of image quality is low.

[0070] In a variation of the method, it further comprises forming a plurality of first sub-devices and a plurality of second sub-devices and arranging the plurality of first sub-devices and the plurality of second sub-devices in a matrix.

[0071] In order to obtain sufficient image resolution, the sensor device can be formed to a desired size. Furthermore, the receiving elements can be arranged such that the receiving elements of each group are effectively distributed on a matrix.

[0072] In a variation of the method, two of the first sub-devices and two of the second sub-devices are arranged in a 2×2 matrix such that each of the first sub-devices and the second sub-devices is arranged in a diagonal of the 2×2 matrix.

[0073] The receiving elements of each group are distributed over the receiving element arrangement in an efficient manner. Furthermore, the sensor arrangement comprises a sufficiently large number of receiving elements of each group per unit area.

[0074] According to the above-mentioned embodiments of the receiving element device, other embodiments of the method are obvious to those skilled in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] The following description of the drawings may further illustrate and explain various aspects of the improved concept. Components and parts of the sensor device that have the same function or have the same effect are denoted by the same reference numerals. Identical or effectively identical components and parts may be described only for the first drawing in which they appear. Their description need not be repeated in consecutive drawings.

[0076] Figure 1 An exemplary embodiment of a sensor device according to an improved concept is shown.

[0077] Figure 2 Another exemplary embodiment of a sensor device according to an improved concept is shown.

[0078] Figure 3 Another exemplary embodiment of a sensor device according to an improved concept is shown.

[0079] Figure 4 Another exemplary embodiment of a sensor device according to an improved concept is shown.

[0080] Figure 5 Another exemplary embodiment of a sensor device according to an improved concept is shown.

[0081] Figure 6 Another exemplary embodiment of a sensor device according to an improved concept is shown.

[0082] Figure 7 Another exemplary embodiment of a sensor device according to an improved concept is shown.

[0083] Figure 8 An example of a sensor arrangement is shown.

[0084] Fig. 9 A perspective view of a sub-assembly is shown.

[0085] Fig.10 A schematic diagram of an image sensor comprising a sensor arrangement is shown. DETAILED DESCRIPTION

[0086] Figure 1 FIG. 1 shows a top view of an exemplary embodiment of a sensor device 1 . Figure 1 The sensor device 1 comprises eight receiving elements 2, 3, 4, 5 arranged in a 2×4 array. In particular, the sensor device 1 comprises one receiving element 2 of a first group, four receiving elements 3 of a second group, one receiving element 4 of a third group, and one receiving element 5 of a fourth group.

[0087] The first group of receiving elements 2 is configured to detect light in the red wavelength range. Therefore, hereinafter, the first group of receiving elements 2 will be referred to as red receiving elements 2.

[0088] The receiving elements 3 of the second group are configured to detect light in the green wavelength range, and thus the receiving elements 3 of the second group will be referred to as green receiving elements 3 .

[0089] The receiving elements 4 of the third group are configured to detect light in the blue wavelength range, and thus the receiving elements 4 of the third group will be referred to as blue receiving elements 4 .

[0090] The receiving elements 5 of the fourth group are configured to detect light in the infrared (IR) or near infrared (NIR) wavelength range, and thus the receiving elements 5 of the fourth group will be referred to as IR receiving elements 5 .

[0091] according to Figure 1 The sensor device 1 can be regarded as being formed by a first sub-device 6 forming a first-type Bayer pattern and a second sub-device 7 forming a second-type Bayer pattern. The corresponding Bayer-like pattern is formed by a 2×2 array of receiving elements, two of which are arranged opposite to each other and are sensitive to the first wavelength range, while the other two receiving elements show sensitivity in the second wavelength range and the third wavelength range, respectively. Therefore, the Bayer-like pattern includes the upper right corner, the upper left corner, the lower right corner and the lower left corner of the pattern.

[0092] exist Figure 1In the first sub-device 6 of the embodiment, the first type of Bayer pattern is formed by one red receiving element 2, two green receiving elements 3 and one blue receiving element 4. The two green receiving elements 3 are arranged opposite to each other at the lower left corner and the upper right corner of the first type of Bayer pattern. The red receiving element 2 is arranged at the upper left corner of the first type of Bayer pattern, and the blue receiving element 4 is arranged at the lower right corner. However, the positions of the corresponding receiving elements 2, 3, and 4 in the first type of Bayer pattern can also be interchanged, as long as the two green receiving elements 3 are arranged opposite to each other.

[0093] exist Figure 1 In the second sub-device 7, the second type of Bayer pattern is formed by one red receiving element 2, two green receiving elements 3 and one IR receiving element 5. The two green receiving elements 3 are arranged opposite to each other at the lower left corner and the upper right corner of the second type of Bayer pattern. The red receiving element 2 is arranged at the upper left corner of the second type of Bayer pattern, and the IR receiving element 5 is arranged at the lower right corner of the second type of Bayer pattern. The positions of the corresponding receiving elements 2, 3, 5 within the second type of Bayer pattern can also be interchanged, as long as the two green receiving elements 3 are arranged opposite to each other. However, in the first type of Bayer pattern and the second type of Bayer pattern, the positions of the receiving elements of the same group can be equal. This means that the receiving elements common to the first sub-device 6 and the second sub-device 7 can be located at the same position.

[0094] The first sub-device 6 and the second sub-device 7 are adjacent to each other in a transverse direction x. The transverse directions x, y extend parallel to a main extension plane of the sensor device 1. This means that the first sub-device shares a common border with the second sub-device 7. The common border is indicated by a dashed line.

[0095] It should be noted that the sensor device 1 may include further first sub-devices 6 and second sub-devices 7 which are arranged in a similar manner. Figure 1 This means that further sub-devices can extend the sensor device 1 in each lateral direction x, y, which is indicated by an ellipse. In this sense, Figure 1 A unit cell of the sensor device 1 may be shown.

[0096] Figure 2 A further exemplary embodiment of a sensor device 1 is shown in a top view. Figure 2 The sensor device 1 and Figure 1The sensor device of is similar to that of , but the difference is that the second sub-device 7' is formed by one IR receiving element 5, two green receiving elements 3 and one blue receiving element 4 forming the second type Bayer pattern. Similarly, the two green receiving elements 3 are arranged opposite to each other at the lower left corner and the upper right corner of the first type Bayer pattern. The IR receiving element 5 is arranged at the upper left corner of the second type Bayer pattern, and the blue receiving element 4 is arranged at the lower right corner of the second type Bayer pattern. Therefore, in the first type Bayer pattern and the second type Bayer pattern, the positions of the receiving elements of the same group are equal.

[0097] Figure 1 All other features already described in also apply to Figure 2 It should be noted that the two embodiments can also be combined with each other, so that by combining Figure 1 and Figure 2 to form an overall sensor device 1.

[0098] Figure 3 A further exemplary embodiment of a sensor device 1 is shown in a top view. Figure 3 The sensor device 1 comprises Figure 1 Described are three first sub-devices 6 and one second sub-device 7. The first sub-devices 6 and the second sub-devices 7 are arranged in a 2×2 matrix such that they are adjacent to each other in the lateral directions x, y.

[0099] In this embodiment, three first sub-devices 6 are arranged in three quadrants of the sensor device 1, and second sub-devices 7 are arranged in the remaining quadrants. Figure 3 The assignment of sub-devices to specific quadrants of the sensor device 1 is arbitrary.

[0100] It is obvious to readers skilled in the art that by exchanging the first sub-device 6 and the second sub-device 7, a Figure 3 A similar sensor array is formed, thereby combining three second sub-devices 7 and one first sub-device 6. In addition, the second sub-device 7' can also be Figure 2 As shown, the green receiving element 5 is formed by providing two green receiving elements, one blue receiving element and one IR receiving element.

[0101] Figure 1 All other features already described in also apply to Figure 3 It should be noted that these embodiments can also be combined with each other, so that by combining Figures 1 to 3 to form an overall sensor device 1.

[0102] Figure 4 A preferred embodiment of the sensor device 1 is shown in a top view. Figure 4The sensor device 1 comprises Figure 1 Described are two first sub-devices 6 and two second sub-devices 7. The first sub-devices 6 and the second sub-devices 7 are arranged in a 2×2 matrix such that they are adjacent to each other in the lateral directions x, y.

[0103] In this embodiment, two first sub-devices 6 are arranged in opposite quadrants of the sensor device 1, and two second sub-devices 7 are arranged in the remaining two opposite quadrants. Figure 4 The assignment of sub-devices to specific quadrants of the sensor device 1 is arbitrary as long as equal sub-devices (ie sub-devices with equal Bayer-like patterns) are arranged in opposite quadrants. Thus, the sub-devices are arranged in a checkerboard pattern.

[0104] The sensor device 1 according to this embodiment includes sixteen receiving elements arranged in a 4×4 array. In particular, the sensor device 1 includes eight green receiving elements 3, four red receiving elements 2, two blue receiving elements 4, and two IR receiving elements 5. Compared to the conventional Bayer pattern array, the two blue receiving elements 4 are replaced by IR receiving elements 5. The image sensor 14 including the sensor device 1 is capable of detecting IR radiation. The loss of color information in the blue domain can be compensated by the effective distribution of the blue receiving elements 4. In addition, the human eye is least sensitive to blue, so the missing color information is less important.

[0105] It should be noted that the sensor device 1 may include further first sub-devices 6 and second sub-devices 7 which are arranged in a similar manner. Figure 4 This means that further sub-devices can extend the sensor device 1 in each lateral direction x, y, which are indicated by ellipses. In this sense, Figure 4 1 shows a unit cell of the sensor device 1. Figure 4 The embodiments can be combined with Figures 1 to 3 The previously discussed embodiments are combined.

[0106] Figure 5 A top view of another preferred embodiment of the sensor device 1 is shown, which is Figure 4 The embodiments of Figure 5 The difference of the embodiment is that the second sub-device 7' is composed of Figure 2 The described second type of Bayer pattern is formed by one IR receiving element 5, two green receiving elements 3 and one blue receiving element 4.

[0107] Therefore, the sensor device 1 includes eight green receiving elements 3, four blue receiving elements 4, two red receiving elements 2 and two IR receiving elements 5. Figure 4Compared with the embodiment of , this embodiment is less sensitive to the red domain but more sensitive to blue.

[0108] Figure 4 All other features already described in also apply to Figure 5 The embodiment shown in .

[0109] Figure 6 FIG. 1 shows a top view of another preferred embodiment of the sensor device 1. In this embodiment, the second sub-device 7 is formed by forming a second type of Bayer pattern (see Figure 1 The third sub-device 8 is formed by one IR receiving element 5, two green receiving elements 3 and one blue receiving element 4 forming a third type of Bayer pattern. The third type of Bayer pattern corresponds to Figure 2 This means that in this embodiment, two variations of the second type of Bayer pattern are combined.

[0110] The first sub-device 6, the second sub-device 7 and the third sub-device 8 are arranged in a 2×2 matrix so that they are adjacent to each other in the lateral directions x, y. In this embodiment, the two first sub-devices 6 are arranged in opposite quadrants of the sensor device 1, while the second sub-device 7 and the third sub-device 8 are arranged in the remaining two opposite quadrants. Figure 6 The assignment of sub-devices to specific quadrants of the sensor device 1 is arbitrary.

[0111] Likewise, the sensor device 1 according to this embodiment includes sixteen receiving elements arranged in a 4×4 array. However, in this case, the sensor device 1 includes eight green receiving elements 3, three red receiving elements 2, three blue receiving elements 4, and two IR receiving elements 5. Therefore, there are an equal number of red receiving elements and blue receiving elements 4.

[0112] As mentioned above, according to Figure 6 The sensor device 1 can be extended in each lateral direction x, y.

[0113] Figure 7 A top view of another embodiment of the sensor device 1 is shown. The sensor device 1 according to this embodiment comprises three first sub-devices 6, three second sub-devices 7 and three third sub-devices 8 arranged in a 3×3 matrix.

[0114] The sub-devices are arranged in a 3×3 matrix so that in the lateral directions x, y, different sub-devices are adjacent to each other. In other words, equal sub-devices do not share common borders with each other. This means that the first sub-device 6 shares a common border with the second sub-device 7 and the third sub-device 8, but not with other first sub-devices 6. Therefore, this also applies to the second sub-device 7 and the third sub-device 8.

[0115] Figure 7 One exemplary layout of the sub-devices in a 3 x 3 matrix is ​​shown. However, the exact location of each sub-device within the sensor device 1 is arbitrary. Other arrangements are also possible.

[0116] according to Figure 7 The embodiment includes receiving elements arranged in a 6×6 array. For example, the sensor device 1 includes 18 green receiving elements 3 (50%), 6 red receiving elements 2 (16.67%), 6 blue receiving elements 4 (16.67%), and 6 IR receiving elements 5 (16.67%). Therefore, the number of red receiving elements, blue receiving elements, and infrared receiving elements 5 is equal, and these receiving elements are evenly distributed on the sensor array. There is an excess of green receiving elements 3, which is proved by the fact that the human eye is most sensitive to the green wavelength domain.

[0117] As mentioned above, the sensor device 1 can be expanded by further sub-devices in order to form a sufficiently large array of receiving elements.

[0118] Figure 8 A top view of an exemplary sensor device 1 is shown. The example comprises two first sub-devices 6 and two further sub-devices 17, 17', which are formed by one red receiving element 2, one green receiving element, one blue receiving element 4 and one IR receiving element 5. This means that compared to a conventional Bayer pattern, one of the green receiving elements 3 is replaced. In one of the two further sub-devices 17, 17', the green receiving element in the upper right corner of the 2×2 array is replaced by the IR receiving element 5, and in the other of the two further sub-devices 17, 17', the green receiving element in the lower left corner of the 2×2 array is replaced by the IR receiving element 5.

[0119] The first sub-devices and the further sub-devices 6, 17, 17' are arranged in a 2×2 matrix so that they are adjacent to each other in the lateral directions x, y. In this embodiment, two first sub-devices 6 are arranged in opposite quadrants of the sensor device 1, while the further sub-devices 17, 17' are arranged in the remaining two opposite quadrants. Figure 8 The assignment of sub-devices to specific quadrants of the sensor device 1 is arbitrary.

[0120] Fig. 9A perspective view of an exemplary first sub-device 6 of the sensor device 1 is shown. The dashed line indicates that further sub-devices can be arranged next to it in the lateral directions x, y, so that a complete sensor device 1 is formed. The first sub-device 6 comprises a substrate 9 in which sensor elements 10 are arranged. The sensor elements 10 can each be formed in the same substrate 9, for example a semiconductor substrate 9. Each sensor element 10 comprises a top surface 11.

[0121] In a vertical direction z, perpendicular to the main extension plane of the sensor device 1, a filter layer 12 is arranged on the top surface 11 of the sensor element 10. The filter layer 12 comprises wavelength filters 13 such that they form a first kind of Bayer pattern. This means that two opposite wavelength filters 13 are transparent for green light, while the remaining wavelength filters 13 are transparent for red light and blue light, respectively. Wavelength filters 13 for IR light can similarly be arranged on top of the sensor element 10. The wavelength filters 13 are arranged between the top surface 11 of the sensor element 10 and a source (not shown) of incident electromagnetic radiation. In this way, the underlying sensor element 10 detects light in a specific wavelength domain for which the corresponding wavelength filter 13 is transparent.

[0122] Fig.10 A schematic diagram of an exemplary embodiment of an image sensor 14 including the above-mentioned sensor device 1 is shown. The image sensor 14 also includes a circuit 15 for reading out electrical signals from receiving elements. For example, the circuit 15 may include a storage capacitor, a storage element, an analog-to-digital converter (ADC), etc. The circuit 15 is electrically connected to the receiving elements 2, 3, 4, 5 of the sensor device 1. It should be noted that the sensor device may include a plurality of receiving elements 2, 3, 4, 5. The circuit 15 and the sensor device 1 may be integrated on a sensor chip 18. The image sensor 14 also includes an image signal processor ISP 16, which is configured to generate a digital image based on the electrical signals from the receiving elements. Therefore, the ISP 16 is electrically connected to the circuit 15 for reading out electrical signals from the receiving elements. The ISP 16 may form a chip separate from the sensor chip 18. The circuit 15 can be implemented so that the electrical signals from the receiving elements 2, 3, 4, 5 are pre-processed for the ISP 16. In this way, the standard ISP 16 can be used for demosaicing. The circuit 15 can provide another image processing path for image information in the IR wavelength domain to the ISP 16.

[0123] In order to familiarize the reader with the novel aspects of the present concept, embodiments of the sensor device 1 and method of manufacturing the sensor device 1 disclosed herein have been discussed. Although preferred embodiments have been shown and described, numerous changes, modifications, equivalents, and substitutions may be made to the disclosed concept by those skilled in the art without necessarily departing from the scope of the claims.

[0124] It should be understood that the present disclosure is not limited to the disclosed embodiments and the contents that have been particularly shown and described above. On the contrary, the features described in the separate dependent claims or the specification may be advantageously combined. In addition, the scope of the present disclosure includes those variations and modifications that are obvious to those skilled in the art and fall within the scope of the appended claims.

[0125] The term "comprising" used in the claims or in the description does not exclude other elements or steps of the corresponding features or procedures. If the terms "a" or "an" are used in combination with a feature, it does not exclude a plurality of such features. Furthermore, any reference signs in the claims should not be construed as limiting the scope.

[0126] This patent application claims priority from European patent application No. 20196692.6, the disclosure of which is incorporated herein by reference.

[0127] Reference numerals

[0128] 1 Sensor device

[0129] 2 Red receiving element

[0130] 3 Green receiving element

[0131] 4 Blue receiving element

[0132] 5 IR receiving element

[0133] 6 First sub-device

[0134] 7, 7' Second sub-device

[0135] 8 The third sub-device

[0136] 9 Substrate

[0137] 10 Sensor element

[0138] 11 Top surface of sensor element

[0139] 12 Filter Layers

[0140] 13 wavelength filter

[0141] 14 Image Sensor

[0142] 15 Circuit

[0143] 16 Image Signal Processor

[0144] 17, 17' Other sub-devices

[0145] 18 Sensor chip

[0146] x, y horizontal direction

[0147] z vertical direction

Claims

1. A sensor device (1), comprising: - a first set of receiving elements (2) configured to detect light in the red wavelength range, - a second set of receiving elements (3) configured to detect light in the green wavelength range, - a third group of receiving elements (4) configured to detect light in the blue wavelength range, - a fourth set of receiving elements (5) configured to detect light in the infrared wavelength range, such that - a plurality of first sub-devices (6) are formed by arranging one receiving element (2) of a first group, two receiving elements (3) of a second group and one receiving element (4) of a third group in a first type Bayer pattern, respectively; - a plurality of second sub-devices (7) are formed by arranging two receiving elements (3) of the second group, one receiving element (5) of the fourth group and one receiving element (2) of the first group in a second type of Bayer pattern, respectively; and - a plurality of third sub-devices are formed by arranging two receiving elements (3) of the second group, one receiving element (4) of the third group and one receiving element (5) of the fourth group in a third type of Bayer pattern, respectively, wherein - three of the first sub-devices (6), three of the second sub-devices (7) and three of the third sub-devices (8) are arranged in a 3×3 matrix so that in a main extension plane of the sensor device (1), different sub-devices (6, 7, 8) are adjacent to each other.

2. The sensor device (1) according to claim 1, wherein: The receiving element (2, 3, 4, 5) has a top surface with a rectangular shape.

3. The sensor device (1) according to claim 1, wherein: The receiving element (2, 3, 4, 5) comprises a sensor element (10).

4. The sensor device (1) according to claim 1, wherein: The receiving element (2, 3, 4, 5) further comprises a wavelength filter (13).

5. The sensor device (1) according to claim 1, wherein: The receiving element (2, 3, 4, 5) has a top surface with a square shape.

6. The sensor device (1) according to claim 1, wherein: The receiving elements (2, 3, 4, 5) include photodiodes.

7. An image sensor (14) comprising the sensor device (1) according to claim 1, the image sensor (14) further comprising a circuit (15) for reading out the electrical signal from the receiving element (2, 3, 4, 5).

8. The image sensor (14) according to claim 7, further comprising an image signal processor (16), the image signal processor (16) being configured to generate a digital image based on the electrical signals from the receiving elements (2, 3, 4, 5).

9. A method for manufacturing a sensor device (1), the method comprising: - providing a first set of receiving elements (2) configured to detect light in the red wavelength range, - a second set of receiving elements (3) configured to detect light in the green wavelength range, - a third group of receiving elements (4) configured to detect light in the blue wavelength range, - a fourth group of receiving elements (5) configured to detect light in the infrared wavelength range, - forming a plurality of first sub-devices (6) by arranging one receiving element (2) of a first group, two receiving elements (3) of a second group and one receiving element (4) of a third group in a first type Bayer pattern, respectively; - forming a plurality of second sub-devices (7) by arranging two receiving elements (3) of the second group, one receiving element (5) of the fourth group and one receiving element (2) of the first group in a second type of Bayer pattern, respectively; and - forming a plurality of third sub-devices (8) by arranging two receiving elements (3) of the second group, one receiving element (4) of the third group and one receiving element (5) of the fourth group in a third type of Bayer pattern, respectively, wherein - three of the first sub-devices (6), three of the second sub-devices (7) and three of the third sub-devices (8) are arranged in a 3×3 matrix so that in a main extension plane of the sensor device (1), different sub-devices (6, 7, 8) are adjacent to each other.

Images