Composite device

Abstract

To provide an electronic appliance having reduced power consumption and provide a multifunctional electronic appliance that can easily be reduced in weight and size.SOLUTION: A composite device includes a sensor device and a display device. The sensor device includes a first communication unit and a sensor unit and is wearable on a human body. The display device includes a display unit, a second communication unit, and a control unit. The first communication unit has a function for transmitting a signal including information acquired by the sensor unit. The second communication unit has a function for receiving the above-mentioned signal. The control unit has a function for returning from a suspended state in response to the above-mentioned signal. The control unit has a function for generating first image data on the basis of the above-mentioned information and outputting the first image data to the display unit. The display unit has a function for displaying an image on the basis of the first image data.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] 1. Field of the Invention An aspect of the present invention relates to a display device, a sensor device, and an imaging device.

[0002] Note that one embodiment of the present invention is not limited to the above technical field. Examples of the technical field of one embodiment of the present invention disclosed in this specification and the like include a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, an electronic device, a lighting device, an input device, an input / output device, a driving method thereof, or a manufacturing method thereof. A semiconductor device refers to any device that can function by utilizing semiconductor characteristics. [Background technology]

[0003] In recent years, devices for virtual reality (VR) and augmented reality (AR) have been actively developed.

[0004] Representative examples of display devices that can be applied to display panels include liquid crystal display devices, light-emitting devices equipped with light-emitting elements such as organic EL (Electro Luminescence) elements and light-emitting diodes (LEDs: Light Emitting Diodes), and electronic paper that displays images using an electrophoretic method.

[0005] For example, the basic structure of an organic EL element is a layer containing a light-emitting organic compound sandwiched between a pair of electrodes. By applying a voltage to this element, light can be emitted from the light-emitting organic compound. A display device to which such an organic EL element is applied does not require a backlight, which is necessary in liquid crystal display devices and the like, and therefore a thin, lightweight, high-contrast, and low-power display device can be realized. For example, an example of a display device using an organic EL element is described in Patent Document 1. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2002-324673 A Summary of the Invention [Problem to be solved by the invention]

[0007] Since VR and AR devices are worn on the human body, they are preferably small and lightweight. However, in order to realize long-term use in an environment without a power supply, it is necessary to install a large-capacity battery, which makes it difficult to reduce the size and weight of the device. In addition, as the power consumption increases due to the multi-function of the device, a larger capacity battery is required.

[0008] In recent years, with the rise in health awareness, there is a demand for devices that can grasp and manage health conditions in daily life. For example, medical devices such as blood pressure monitors and electrocardiograms are becoming smaller and cheaper for personal use. In addition, information terminals such as smartphones and tablet terminals are becoming more multifunctional, with the addition of functions to manage acquired data. On the other hand, for those who are not so health conscious, such daily measurements are often a hassle, and so there is a tendency for people to be polarized into those who manage their health and those who do not.

[0009] An object of one embodiment of the present invention is to provide an electronic device with reduced power consumption. Another object is to provide an electronic device that can be easily reduced in weight and size and has multiple functions. Another object is to provide an electronic device that allows easy management of a health state. Another object is to provide an electronic device that can display images with enhanced realism. Another object is to provide a novel display device, sensor device, electronic device, composite device, or the like.

[0010] Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these can be extracted from the description of the specification, drawings, claims, etc. [Means for solving the problem]

[0011] One aspect of the present invention is a composite device having a sensor device and a display device. The sensor device has a first communication unit and a sensor unit, and is wearable on a human body. The display device has a display unit, a second communication unit, and a control unit. The first communication unit has a function of transmitting a signal including information acquired by the sensor unit. The second communication unit has a function of receiving the signal. The control unit has a function of returning from a sleep state in response to the signal. The control unit has a function of generating first image data based on the information and outputting it to the display unit, and the display unit has a function of displaying an image based on the first image data.

[0012] In the above, the sensor device is preferably configured to be attached (wearable) to the eyeball. Alternatively, the sensor device is preferably configured to be attached (wearable) to the skin. Alternatively, the sensor device is preferably configured to be attached (wearable) to the wrist, finger, or arm. Alternatively, the sensor device is preferably fixed to clothing.

[0013] In the above, the sensor unit preferably has a function of detecting one or more of blood glucose level, heart rate, blood pressure, body temperature, oxygen saturation, and neutral fat concentration.

[0014] In the above, it is preferable that the display section has a pixel density of 1000 ppi or more and 10000 ppi or less, and the number of pixels in the scanning line direction or the signal line direction is 2000 or more and 10000 or less.

[0015] In the above, the display device preferably includes an imaging unit, and the control unit preferably has a function of generating first image data based on information included in the signal and second image data input from the imaging unit, and outputting the first image data to the display unit. Effect of the Invention

[0016] According to one embodiment of the present invention, an electronic device with reduced power consumption can be provided. Alternatively, an electronic device that is easily made lighter and smaller and has multiple functions can be provided. Alternatively, an electronic device that allows easy management of health conditions can be provided. Alternatively, an electronic device that can display images with enhanced realism can be provided. Alternatively, a novel electronic device, a composite device, or the like can be provided.

[0017] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these can be extracted from the description in the specification, drawings, claims, etc. [Brief description of the drawings]

[0018] [Figure 1] 1A and 1B are diagrams showing an example of the configuration of a composite device. [Diagram 2] FIG. 2 is a diagram illustrating an example of the operation of the display device. [Diagram 3] 3A to 3E are diagrams illustrating an example of the configuration of the sensor device. [Figure 4] 4A to 4C are diagrams for explaining examples of images. [Diagram 5] 5A and 5B are diagrams showing an example of the configuration of a composite device. [Figure 6] 6A and 6B are diagrams illustrating an example of the configuration of an electronic device. [Figure 7] 7A and 7B are diagrams illustrating configuration examples of electronic devices. [Figure 8] 8A and 8B are diagrams showing configuration examples of a display panel. [Figure 9] 9A and 9B are diagrams showing a configuration example of a display module. [Figure 10] FIG. 10 is a diagram illustrating a configuration example of a semiconductor device. [Figure 11] FIG. 11 is a diagram illustrating a configuration example of a semiconductor device. [Figure 12] FIG. 12 is a diagram illustrating a configuration example of a semiconductor device. [Figure 13] FIG. 13 is a diagram illustrating a configuration example of a semiconductor device. [Figure 14] 14A to 14C are diagrams showing configuration examples of a semiconductor device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, the embodiments will be described with reference to the drawings. However, it will be easily understood by those skilled in the art that the embodiments can be implemented in many different ways, and that the modes and details can be changed in various ways without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the following embodiments.

[0020] In the configuration of the invention described below, the same parts or parts having similar functions are denoted by the same reference numerals in different drawings, and the repeated explanations are omitted. In addition, when referring to similar functions, the same hatch pattern may be used and no particular reference numeral may be used.

[0021] In addition, in each figure described in this specification, the size of each component, the thickness of a layer, or an area may be exaggerated for clarity, and therefore, the drawings are not necessarily limited to the scale.

[0022] In addition, ordinal numbers such as "first" and "second" in this specification are used to avoid confusion of components and do not limit the numbers.

[0023] (Embodiment 1) In this embodiment, a display device, a sensor device, and a composite device including the display device and the sensor device according to one embodiment of the present invention will be described with reference to drawings.

[0024] [Example of a composite device configuration] 1A shows a schematic diagram of a composite device 10. The composite device 10 includes a display device 11 and a sensor device 12.

[0025] The display device 11 includes a control unit 21, a display unit 22, an imaging unit 23, and a lens 24. The sensor device 12 includes a sensor unit 31 and a communication unit 32.

[0026] The display device 11 is preferably configured to be (wearable) mounted on the head of the human body. For example, it can be used as a glasses-type display device or a goggle-type display device. It may also be configured to view an image with one eye.

[0027] The sensor device 12 is configured to be attached (wearable) to the human body. FIG. 1A shows an example in which the sensor device 12 is configured to be attached to the eyeball of the human body. The sensor device 12 shown in FIG. 1A can also be used as a contact lens. Note that the configuration of the sensor device 12 is not limited to this, and can take various forms.

[0028] The display unit 22 of the display device 11 has a plurality of pixels and has a function of displaying an image. Each pixel has one or more display elements. As the display element, various display elements such as a light-emitting element, a liquid crystal element, a microcapsule, an electrophoretic element, an electrowetting element, an electrofluidic element, an electrochromic element, and a MEMS element can be used.

[0029] In particular, by using light-emitting elements for the display elements of the display unit 22, high contrast can be obtained, and therefore a more realistic image can be displayed. As the light-emitting elements, organic EL elements, LED elements, inorganic EL elements, etc. can be used. In particular, it is preferable to use organic EL elements.

[0030] LED elements come in a variety of sizes, from large to small, including macro LEDs (also called giant LEDs), mini LEDs, and micro LEDs. Here, LED chips with a side dimension of over 1 mm are called macro LEDs, those with a side dimension of over 100 μm and less than 1 mm are called mini LEDs, and those with a side dimension of 100 μm or less are called micro LEDs. It is particularly preferable to use micro LEDs as the LED element to be applied to pixels. By using micro LEDs, extremely high-definition display devices can be realized.

[0031] The higher the resolution of the display unit 22, the more preferable. The pixel density of the display unit 22 can be set to 1000 ppi or more and 50000 ppi or less, preferably 2000 ppi or more and 20000 ppi or less, more preferably 3000 ppi or more and 10000 ppi or less, and even more preferably 5000 ppi or more and 10000 ppi or less. Typically, the pixel density can be set to 4500 ppi or more and 5500 ppi or less, 5500 ppi or more and 6500 ppi or less, or 6500 ppi or more and 7500 ppi or less.

[0032] Moreover, it is preferable that the display unit 22 has a higher resolution. The number of pixels of the display unit 22 in the scanning line direction or the signal line direction can be, for example, 1000 to 20000, preferably 2000 to 10000, more preferably 3000 to 10000. When two display units 22 are provided for the left eye and the right eye, the shape of the display area can be close to a square (the ratio of the length to the width is 0.8 to 1.2). On the other hand, when one display area is used separately for the right eye and the left eye, it is preferable that the shape of the display area is a horizontally long rectangle (for example, the ratio of the length to the width is 1.5 to 5.0). Moreover, the display unit 22 may be adapted to a television standard with an aspect ratio of 16:9, in which case the resolution can be the FHD standard, the 4K2K standard, or the 8K4K standard.

[0033] Furthermore, a so-called see-through panel that transmits external light may be used as the display unit 22. This allows the display device 11 to be used as a device for AR. In this case, the display device 11 may not be provided with the imaging unit 23.

[0034] The imaging unit 23 is provided at a position where it can capture an image of the front when the display device 11 is worn. The image captured by the imaging unit 23 can be displayed on the display unit 22 via the control unit 21.

[0035] A camera can be suitably used as the imaging unit 23. The higher the resolution of the imaging element of the imaging unit 23, the more preferable it is. In particular, it is preferable for the imaging element to have the same number of pixels as the display unit 22 or more.

[0036] The control unit 21 has a function of generating and outputting an image signal S1 to be supplied to the display unit 22. The control unit 21 has a function of controlling the operation of the imaging unit 23, and a function of acquiring an image signal S2 input from the imaging unit 23. The control unit 21 has a function of receiving a signal 33 supplied from the sensor device 12, and a function of generating an image signal S1 to be output to the display unit 22 based on information included in the signal 33.

[0037] For example, the control unit 21 can display an image captured by the imaging unit 23 on the display unit 22 with almost no delay based on image data captured by the imaging unit 23 and included in the image signal S2. The control unit 21 can also generate a composite image by combining an image generated based on information acquired by the sensor device 12 with an image included in the image signal S2, and display the composite image on the display unit 22. This enables so-called AR display or MR (Mixed Reality) display.

[0038] The sensor device 12 includes a sensor unit 31 and a communication unit 32. The sensor device 12 can transmit information acquired by the sensor unit 31 to the control unit 21 of the display device 11 via the communication unit 32.

[0039] The sensor unit 31 can have a sensor capable of acquiring various biological information. For example, the sensor unit can be a contact sensor that touches the human body, an optical sensor that uses light, an electrical sensor that uses an electronic signal from the human body, a sensor that can acquire the components and properties of bodily fluids (such as tears and sweat), or the like.

[0040] 1A can measure the concentrations of salt, glucose, and the like from tears using the sensor unit 31. For example, the blood glucose level of the user can be estimated from the glucose concentration measured by the sensor unit 31.

[0041] The communication unit 32 has a function of transmitting a signal 33 including information acquired by the sensor unit 31 to the display device 11. The communication unit 32 can have a configuration including an antenna, a signal generating circuit, a modulation circuit, and the like.

[0042] 1A clearly shows the user's eyeball 41. For ease of understanding, a gap is shown between the eyeball 41 and the sensor device 12. However, in reality, the sensor device 12 can be worn so as to be in contact with the eyeball 41.

[0043] The lens 24 is provided between the display unit 22 and the sensor device 12, and has a function of adjusting focus. Note that in cases where the distance between the display unit 22 and the eyeball 41 is sufficient and focus adjustment is not required, or in cases where the sensor device 12 has a focus adjustment function, the lens 24 may not be provided.

[0044] A user can view the image displayed on the display unit 22 through the sensor device 12 and the lens 24 .

[0045] By attaching the display device 11 to the head and the sensor device 12 to the eyeball 41, the communication distance between the communication unit 25 and the communication unit 32 becomes extremely short. Therefore, the power required for communication can be made extremely small, and the power consumption of the composite device 10 can be reduced. In addition, because the power required for communication is small, the impact of communication radio waves on health can be made negligibly small.

[0046] FIG. 1B shows a block diagram of composite device 10.

[0047] The control unit 21 has a communication unit 25 and an image generation unit 26. To the control unit 21, an image signal S2 is input from the imaging unit 23, and a signal 33 is input from the sensor device 12. An image signal S0 may also be input from the outside. Moreover, the control unit 21 outputs an image signal S1 to the display unit 22.

[0048] The communication unit 25 has a function of receiving a signal 33 transmitted from the sensor device 12 and outputting data contained in the signal to the image generation unit 26. The communication unit 25 can be configured to include, for example, an antenna, a demodulation circuit, and the like.

[0049] When the communication unit 25 and the communication unit 32 are configured to be capable of communicating with each other, each of them may have a demodulation circuit and a modulation circuit.

[0050] It is preferable that the communication unit 25 has a function of switching to a stopped state (also called a dormant state) during a period when there is no input of the signal 33. At this time, the control unit 21 has a function of returning the communication unit 25 from the dormant state based on the input of the signal 33. By putting the communication unit 25, which includes an analog circuit, into a dormant state during a period when operation is not required, it is possible to significantly reduce the power consumption of the control unit 21. Furthermore, it is possible to realize a smaller and lighter display device 11.

[0051] 2 is a schematic timing chart showing the signal 33 and the operation of the communication unit 25. One of the signals 33 has a pulse signal 33a and a signal 33b including data. As shown in FIG. 2, the signal 33 transmitted from the communication unit 32 is a signal in which a pair of the pulse signal 33a and the signal 33b is output intermittently.

[0052] The operations of the communication unit 25 are roughly divided into three groups: a return operation 25a, a processing operation 25b, and a pause operation 25c. When the control unit 21 receives a pulse signal 33a, it controls the communication unit 25 to execute the return operation 25a. In the return operation 25a, the communication unit 25 returns from the pause state. After the return operation 25a, in the processing operation 25b, the communication unit 25 demodulates the received signal 33b to generate data and outputs the data to the image generation unit 26. After completing the output, the communication unit 25 transitions to the pause state via the pause operation 25c.

[0053] Here, in FIG. 2, the operation period T act and the break period T off The rest period T off However, during the operation period T act The longer the operating period T is, the more power consumption can be reduced. For example, the sampling frequency required to monitor changes in a person's biological information can be 10 Hz or less, 5 Hz or less, 1 Hz or less, or 0.1 Hz or less, so the reception frequency of the signal 33 can be about the same. act Since the period can be set to an extremely short period (eg, about several tens of microseconds to several tens of milliseconds), the communication unit 25 can be in a dormant state for most of the period.

[0054] 1B has a function of generating image data based on the data contained in the signal 33 input from the communication unit 25, and generating composite image data by combining the image data with image data contained in the image signal S2 input from the imaging unit 23. The control unit 21 generates an image signal S1 including the composite image data, and outputs it to the display unit 22.

[0055] In addition, in the case where the image signal S0 is input from the outside, the image generation unit 26 may have a function of generating composite image data by combining the image data contained in the image signal S0 and image data generated based on the data contained in the signal 33.

[0056] In addition, the image generation unit 26 may have a function of generating composite image data by combining image data contained in the image signal S1, image data contained in the image signal S0, and image data generated based on the data contained in the signal 33.

[0057] [About the sensor device] Although the sensor device 12 has been described above as being configured to be attached to the eyeball of the human body, the sensor device 12 may take various forms. Other examples of the sensor device 12 will be described below.

[0058] Fig. 3A shows sensor device 12 configured to be attached to the skin. Fig. 3A shows sensor device 12 attached to arm 42. Sensor device 12 has chip-like sensor unit 31 and communication unit 32. The exterior body of sensor device 12 is preferably a thin sheet-like member, and is preferably flexible or stretchable. Sensor device 12 may have an adhesive on the surface that comes into contact with the skin.

[0059] Fig. 3B shows sensor device 12 configured to be worn by wrapping it around arm 42 (wrist). Sensor device 12 has at least a sensor unit 31 and a communication unit 32. Sensor device 12 shown in Fig. 3B may also have an information display unit, and for example, sensor device 12 may function as a wristwatch-type information terminal device.

[0060] Fig. 3C shows a sensor device 12 configured to be worn on a finger 43. The sensor device 12 shown in Fig. 3C has at least a sensor unit 31 and a communication unit 32. The sensor device 12 may have an information display unit, and may function as a finger-shaped information terminal device, for example. Furthermore, the sensor device 12 may be configured to have a gyro sensor or the like, and may be used as an input device using gestures.

[0061] 3D shows sensor device 12 configured to be worn on upper arm 44 of user 40. Sensor device 12 has at least a sensor unit 31 and a communication unit 32. Sensor device 12 preferably has a cylindrical exterior body made of a stretchable material, or a cylindrical exterior body with a part of the cylinder missing (i.e., a cross-sectional shape that is roughly C-shaped).

[0062] FIG. 3E shows the sensor device 12 attached to the inside of the clothing 45 of the user 40. The sensor device 12 has at least a sensor unit 31 and a communication unit 32. When the user 40 wears the clothing 45 on the innermost side, it is preferable that a part of the sensor device 12 contacts the skin. In addition, even when the user 40 wears other clothing on the inner side of the clothing 45, it is preferable that the sensor device 12 can acquire the user's biometric information through the other clothing. Note that the sensor device 12 may be attached to the outside of the clothing 45 or to the inside of the clothing 45.

[0063] Here, the sensor device 12 preferably has a function of detecting one or more of blood glucose level, heart rate, pulse rate, blood pressure, body temperature, oxygen saturation, and neutral fat concentration. As described above, the blood glucose level can be estimated by measuring the glucose concentration in body fluids.

[0064] In addition, arteries (arterioles) can be optically measured because their reflectance to infrared or visible light changes according to fluctuations in blood oxygen saturation. By acquiring this change over time, i.e., acquiring the time modulation of blood oxygen saturation, pulse wave information can be acquired. This makes it possible to measure the user's heart rate. In addition, infrared or visible light can be used to detect blood triglyceride concentrations, blood glucose concentrations in the blood or in the dermis, and the like.

[0065] Furthermore, by configuring the sensor unit 31 to include electrodes that come into contact with the skin, it is possible to measure an electrocardiogram.

[0066] Blood pressure can also be calculated from the electrocardiogram and the difference in timing between the two beats of the pulse wave (length of pulse wave propagation time). High blood pressure results in a short pulse wave propagation time, and conversely, low blood pressure results in a long pulse wave propagation time. The relationship between heart rate and blood pressure calculated from the electrocardiogram and pulse wave can also be used to estimate the user's physical condition. For example, if both the heart rate and blood pressure are high, it can be estimated that the user is in a state of tension or excitement, and conversely, if both the heart rate and blood pressure are low, it can be estimated that the user is in a relaxed state. Furthermore, if the user continues to have low blood pressure and a high heart rate, this may be a sign of heart disease.

[0067] It is preferable to provide the sensor device 12 or the display device 11 with a means for acquiring other biological information. For example, in addition to internal biological information such as electrocardiogram, blood pressure, and body temperature, there is superficial biological information such as facial expression, complexion, and pupils. Information on the number of steps, exercise intensity, elevation change, and diet (calories ingested, nutrients, etc.) are also important information for health care. Using multiple biological information enables comprehensive health management, which leads not only to daily health management but also to early detection of injuries and illnesses.

[0068] The sensor device 12 may also have a GPS (Global Positioning System) and may be configured to be able to acquire location information. The sensor device 12 may also have a function of electronic payment.

[0069] [Example image] An example of an image that can be presented to the user by the multifunction device 10 will be described below.

[0070] FIG. 4A shows an example of an image 50a that appears in the user's field of vision while eating. In the image 50a, image information 51a is shown superimposed on an actual image captured by the imaging unit 23. The image information 51a shown in FIG. 4A presents an icon image (image resembling a sugar cube) representing the blood glucose level, a comment to warn the user that the blood glucose level is high, and an estimated blood glucose level (CAUTION!! 140 mg / dL). The user can recognize that his or her blood glucose level is high through the image information 51a, and can take actions such as reducing the amount of food eaten, canceling an order for dessert, or ordering a drink that suppresses the rise in blood glucose level.

[0071] FIG. 4B shows an example of an image 50b that appears in the field of view of a user who is hiking. Image information 51b is shown in image 50b. The image information 51b presents an icon image (image resembling a heart) intended to indicate a heart rate, a comment to warn the user that the heart rate is high, and the measured heart rate value (CAUTION!! 130 bpm). The user can check his or her own heart rate through image information 51b, and can take action such as taking a break or slowing down his or her walking speed.

[0072] FIG. 4C shows an example of an image 50c that appears in the field of view of a user who is calling and scolding a subordinate. Image information 51c is shown in image 50c. Image information 51c shows an icon image (image imitating a heart and an electrocardiogram) representing blood pressure, a comment to warn the user that the blood pressure is high, and an estimated blood pressure value (CAUTION!! 160 mmHg). Image information 51c allows the user to recognize that he or she is in a highly excited state, and can take action such as taking a deep breath to suppress his or her anger or reconsidering how he or she treats his or her subordinate.

[0073] In the above example, a comment is displayed to warn the user, but a specific action may be encouraged. For example, in the situation shown in FIG. 4C, a comment encouraging the user to take a deep breath or an animated image may be displayed.

[0074] [Variations] Below, a modification of the above configuration example will be described.

[0075] FIG. 5A shows a schematic diagram of the composite device 10a, and FIG. 5B shows a block diagram of the composite device 10a.

[0076] The multifunction device 10a includes a sensor device 12a having an image display function, and an information processing device 13.

[0077] The sensor device 12a includes a display unit 34 in addition to the sensor unit 31 and the communication unit 32. The display unit 34 has a function of displaying an image. As the display unit 34, a see-through display can be suitably used.

[0078] The communication unit 32 has a function of transmitting a signal 33 including information acquired by the sensor unit 31 to the information processing device 13. The communication unit 32 also has a function of demodulating the signal 27 received from the information processing device 13 and outputting an image signal included in the signal 27 to the display unit 34.

[0079] The display unit 34 can display an image based on an image signal input from the communication unit 32 .

[0080] The information processing device 13 includes a control unit 21. The control unit 21 includes a communication unit 25 and an image generation unit .

[0081] The communication unit 25 has a function of receiving a signal 33 transmitted from the sensor device 12a and outputting data included in the signal to the image generation unit 26. The communication unit 25 also has a function of transmitting a signal 27 including the image signal S1 input from the image generation unit 26 to the sensor device 12a.

[0082] The image generating section 26 has a function of generating an image signal S1 based on the data contained in the signal 33 from the communication section 25 and outputting the image signal S1 to the communication section 25 when the data is input.

[0083] The user can see the image displayed on the display unit 34 superimposed on the transmitted image through the sensor device 12a. The composite device 10a can present an AR display to the user. Also, the display unit 34 may be configured not to transmit light, and a VR display may be presented to the user.

[0084] By adopting such a configuration, the configuration of the composite device 10a can be extremely simplified. In addition, since the information processing device 13 can be easily made small and lightweight, it can be put in a pocket or a bag. In this case, since a device to be worn on the head is not required, it can be a device that does not cause bother to the user.

[0085] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification.

[0086] (Embodiment 2) In this embodiment, a configuration example of an electronic device including a display device that can be used in a composite device of one embodiment of the present invention will be described.

[0087] 6A shows a perspective view of a glasses-type electronic device 900. The electronic device 900 includes a pair of display panels 901, a pair of housings (a housing 902a and a housing 902b), a pair of optical members 903, a pair of mounting units 904, and the like.

[0088] The electronic device 900 can project an image displayed on the display panel 901 onto a display area 906 of the optical member 903. In addition, since the optical member 903 is translucent, the user can see the image displayed in the display area 906 superimposed on a transmitted image visually recognized through the optical member 903. Therefore, the electronic device 900 is an electronic device capable of AR display.

[0089] One of the housings 902a is provided with a camera 905 capable of capturing an image of the front. The housing 902a has a wireless communication device 907, which can supply a video signal or the like to the housings 902a and 902b. Note that instead of or in addition to the wireless communication device 907, a connector to which a cable to which a video signal or a power supply potential can be connected may be provided. The housing 902a or the housing 902b may be provided with an acceleration sensor such as a gyro sensor, which can detect the direction of the user's head and display an image corresponding to the direction in the display region 906. The housing 902a or the housing 902b is preferably provided with a battery, which can be charged wirelessly or by wire.

[0090] The housing 902b is also provided with a processor 908. The processor 908 has a function of controlling various components of the electronic device 900, such as the camera 905, the wireless communication device 907, and the pair of display panels 901, a function of generating an image, etc. The processor 908 may have a function of generating a composite image for AR display.

[0091] Data communication with an external device can be performed by the wireless communication device 907. For example, data transmitted from the outside can be output to the processor 908, and the processor 908 can generate image data for AR display based on the data. Examples of data transmitted from the outside include image data and data including bioinformation transmitted from a biosensor device or the like.

[0092] 6B, a method of projecting an image onto the display area 906 of the electronic device 900 will be described. A display panel 901, a lens 911, and a reflector 912 are provided inside the housing 902 (housing 902a and housing 902b). In addition, a portion of the optical member 903 that corresponds to the display area 906 has a reflecting surface 913 that functions as a half mirror.

[0093] Light 915 emitted from the display panel 901 passes through the lens 911 and is reflected by the reflector 912 towards the optical member 903. Inside the optical member 903, the light 915 is repeatedly totally reflected at the end face of the optical member 903 and reaches the reflecting surface 913, whereby an image is projected onto the reflecting surface 913. This allows the user to visually recognize both the light 915 reflected by the reflecting surface 913 and the transmitted light 916 that has passed through the optical member 903 (including the reflecting surface 913).

[0094] 6B shows an example in which the surface of the reflector 912 and the reflecting surface 913 each have a curved surface. This allows for greater freedom in optical design and allows for a thinner optical member 903 than when these are flat. Note that the surface of the reflector 912 and the reflecting surface 913 may also be flat.

[0095] A member having a mirror surface can be used as the reflector 912, and it is preferable that the reflector has a high reflectance. Also, a half mirror utilizing the reflection of a metal film may be used as the reflector surface 913, but the transmittance of the transmitted light 916 can be increased by using a prism utilizing total reflection or the like.

[0096] Here, the housing 902 preferably has a mechanism for adjusting the distance between the lens 911 and the display panel 901 and the angle between them. This makes it possible to adjust the focus and enlarge or reduce the image. For example, the lens 911 or the display panel 901 or both may be configured to be movable in the direction of the optical axis.

[0097] Furthermore, it is preferable that the housing 902 has a mechanism capable of adjusting the angle of the reflector 912. It is possible to change the position of the display area 906 where an image is displayed by changing the angle of the reflector 912. This makes it possible to position the display area 906 at an optimal position according to the position of the user's eyes.

[0098] A display device or a display module according to one embodiment of the present invention can be applied to the display panel 901. Thus, the electronic device 900 can provide an extremely high-definition display.

[0099] 7A and 7B show perspective views of a goggle-type electronic device 950. Fig. 7A is a perspective view showing the front, top, and left side of the electronic device 950, and Fig. 7B is a perspective view showing the back, bottom, and right side of the electronic device 950.

[0100] The electronic device 950 includes a pair of display panels 951, a housing 952, a pair of mounting portions 954, a cushioning member 955, and a pair of lenses 956. The pair of display panels 951 are provided inside the housing 952 at positions viewable through the lenses 956.

[0101] The electronic device 950 is an electronic device for VR. A user wearing the electronic device 950 can view an image displayed on the display panel 951 through the lens 956. Also, by displaying different images on the pair of display panels 951, a three-dimensional display using parallax can be performed. Also, the housing 952 of the electronic device 950 may be provided with a waterproof function so that the electronic device 950 can be used in water. In this case, it is preferable to make the shape of the housing 952 streamlined, since this can reduce water resistance and enable faster swimming.

[0102] Furthermore, an input terminal 957 and an output terminal 958 are provided on the rear side of the housing 952. A cable for supplying a video signal from a video output device or the like, or power for charging a battery provided within the housing 952, can be connected to the input terminal 957. The output terminal 958 functions as, for example, an audio output terminal, and earphones, headphones, or the like can be connected. Note that, in the case of a configuration capable of outputting audio data via wireless communication or in the case of outputting audio from an external video output device, the audio output terminal does not need to be provided.

[0103] The housing 952 is provided with a camera 959 capable of capturing an image of the front. The electronic device 950 can display an image captured by the camera 959 or a composite image using the image. The electronic device 950 can perform AR display and MR display in addition to VR display.

[0104] The housing 952 is provided with a processor 961 and a wireless communication device 962. The processor 961 can control various components of the electronic device 950, such as the pair of display panels 951, the camera 959, and the wireless communication device 962. The processor 961 can generate an image to be displayed on the display panel 951.

[0105] Also, data communication with external devices can be performed by the wireless communication device 962. For example, data transmitted from the outside can be output to the processor 961, and the processor 961 can generate image data for VR display, AR display, or MR display based on the data. Examples of data transmitted from the outside include image data, as well as data including biological information transmitted from a biological sensor device or the like.

[0106] In addition, the housing 952 preferably has a mechanism for adjusting the left-right positions of the lens 956 and the display panel 951 so that the lens 956 and the display panel 951 are positioned optimally according to the position of the user's eyes. In addition, the housing 952 preferably has a mechanism for adjusting the focus by changing the distance between the lens 956 and the display panel 951.

[0107] The display device or display module of one embodiment of the present invention can be applied to the display panel 951. Therefore, the electronic device 950 can display images with extremely high definition. This can provide a user with a high sense of immersion.

[0108] The cushioning member 955 is a portion that comes into contact with the user's face (forehead, cheeks, etc.). The cushioning member 955 comes into close contact with the user's face, thereby preventing light leakage and enhancing the sense of immersion. It is preferable that the cushioning member 955 is made of a soft material so that it comes into close contact with the user's face when the user wears the electronic device 950. For example, materials such as rubber, silicone rubber, urethane, and sponge can be used. In addition, if a sponge or the like having a surface covered with cloth or leather (natural leather or synthetic leather) is used, a gap is unlikely to occur between the user's face and the cushioning member 955, and light leakage can be suitably prevented. In addition, using such a material is preferable because it is pleasant to the touch and does not make the user feel cold when worn in cold seasons. It is preferable that the members that come into contact with the user's skin, such as the cushioning member 955 and the wearing part 954, are configured to be removable, which makes cleaning and replacement easy.

[0109] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification.

[0110] (Embodiment 3) In this embodiment, a configuration example of a display panel that can be applied to a composite device of one embodiment of the present invention will be described. The display panel described below can achieve extremely high resolution and can therefore be suitably used for a display portion of a display device or a sensor device.

[0111] [Pixel configuration example] An example of a pixel arrangement method suitable for a high-definition display panel will be described below.

[0112] For example, in the configuration shown below, a display device can be realized in which pixels including light-emitting elements are arranged in a display region with a resolution (pixel density) of 1000 ppi or more and 50000 ppi or less, preferably 2000 ppi or more and 20000 ppi or less, more preferably 3000 ppi or more and 10000 ppi or less, and even more preferably 5000 ppi or more and 10000 ppi or less. Typically, the pixel density can be 4500 ppi or more and 5500 ppi or less, 5500 ppi or more and 6500 ppi or less, or 6500 ppi or more and 7500 ppi or less.

[0113] [Example of pixel circuit configuration] 8A shows an example of a circuit diagram of the pixel unit 70. The pixel unit 70 is composed of two pixels (pixel 70a and pixel 70b). In addition, the pixel unit 70 is connected to wiring 91a, wiring 91b, wiring 92a, wiring 92b, wiring 92c, wiring 92d, wiring 93a, wiring 93b, wiring 93c, etc.

[0114] The pixel 70a has subpixels 71a, 72a, and 73a. The pixel 70b has subpixels 71b, 72b, and 73b. The subpixels 71a, 72a, and 73a have pixel circuits 81a, 82a, and 83a, respectively. The subpixels 71b, 72b, and 73b have pixel circuits 81b, 82b, and 83b, respectively.

[0115] Each sub-pixel has a pixel circuit and a display element 60. For example, the sub-pixel 71a has a pixel circuit 81a and a display element 60. Here, a case is shown in which a light-emitting element such as an organic EL element is used as the display element 60.

[0116] The wirings 91a and 91b each function as a scan line (also referred to as a gate line). The wirings 92a, 92b, 92c, and 92d each function as a signal line (also referred to as a source line or a data line). The wirings 93a, 93b, and 93c each supply a potential to the display element 60.

[0117] The pixel circuit 81a is electrically connected to the wirings 91a, 92a, and 93a. The pixel circuit 82a is electrically connected to the wirings 91b, 92d, and 93a. The pixel circuit 83a is electrically connected to the wirings 91a, 92b, and 93b. The pixel circuit 81b is electrically connected to the wirings 91b, 92a, and 93b. The pixel circuit 82b is electrically connected to the wirings 91a, 92c, and 93c. The pixel circuit 83b is electrically connected to the wirings 91b, 92b, and 93c.

[0118] As shown in Figure 8A, by connecting two gate lines to one pixel, the number of source lines can be halved compared to the stripe arrangement, which makes it possible to halve the number of ICs used as source driver circuits and reduce the number of parts.

[0119] In addition, it is preferable to configure a wiring that functions as a signal line to connect pixel circuits corresponding to the same color. For example, when a signal with an adjusted potential is supplied to the wiring in order to correct the luminance variation between pixels, the correction value may be significantly different for each color. Therefore, by making all pixel circuits connected to one signal line pixel circuits corresponding to the same color, the correction can be made easier.

[0120] Each pixel circuit includes a transistor 61, a transistor 62, and a capacitor 63. For example, in the pixel circuit 81a, the gate of the transistor 61 is electrically connected to a wiring 91a, one of the source or drain is electrically connected to a wiring 92a, and the other of the source or drain is electrically connected to the gate of the transistor 62 and one electrode of the capacitor 63. One of the source or drain of the transistor 62 is electrically connected to one electrode of the display element 60, and the other of the source or drain is electrically connected to the other electrode of the capacitor 63 and a wiring 93a. The other electrode of the display element 60 is electrically connected to a wiring to which a potential V1 is applied.

[0121] As shown in FIG. 8A, the other pixel circuits have the same configuration as the pixel circuit 81a, except that the wiring to which the gate of the transistor 61 is connected, the wiring to which one of the source or drain of the transistor 61 is connected, and the wiring to which the other electrode of the capacitor 63 is connected are different.

[0122] 8A, the transistor 61 functions as a selection transistor. The transistor 62 is connected in series to the display element 60 and has a function of controlling a current flowing through the display element 60. The capacitor 63 has a function of holding a potential of a node to which the gate of the transistor 62 is connected. Note that when a leakage current in an off state of the transistor 61 or a leakage current through the gate of the transistor 62 is extremely small, the capacitor 63 does not necessarily have to be provided.

[0123] 8A, the transistor 62 preferably has a first gate and a second gate that are electrically connected to each other. By having two gates in this way, the current that can flow through the transistor 62 can be increased. In particular, in a high-definition display device, this is preferable because the current can be increased without increasing the size of the transistor 62, particularly the channel width.

[0124] Note that the transistor 62 may have one gate. With such a configuration, the process of forming the second gate is not necessary, and therefore the process can be simplified compared to the above. The transistor 61 may have two gates. With such a configuration, the size of each transistor can be reduced. Furthermore, the first gate and the second gate of each transistor may be electrically connected to each other. Alternatively, one of the gates may be electrically connected to a different wiring. In this case, the threshold voltage of the transistor can be controlled by changing the potential applied to the wiring.

[0125] Of the pair of electrodes of the display element 60, the electrode electrically connected to the transistor 62 corresponds to a pixel electrode. Here, FIG. 8A shows a configuration in which the electrode electrically connected to the transistor 62 of the display element 60 is a cathode, and the opposite electrode is an anode. Such a configuration is particularly effective when the transistor 62 is an n-channel transistor. That is, when the transistor 62 is on, the potential provided by the wiring 93a becomes the source potential, so that the current flowing through the transistor 62 can be made constant regardless of variations or fluctuations in the resistance of the display element 60. In addition, a p-channel transistor may be used as the transistor included in the pixel circuit.

[0126] [Example of the display element configuration] Fig. 8B is a schematic top view showing an example of a method for arranging display elements, Fig. 8B shows a schematic top view of two pixel units.

[0127] The pixel 70a has a display element R1, a display element G1, and a display element B1. The pixel 70b has a display element R2, a display element G2, and a display element B2. The display elements R1 and R2 are red display elements, the display elements G1 and G2 are green display elements, and the display elements B1 and B2 are blue display elements.

[0128] Focusing on the display elements R1 and R2, they are arranged in a zigzag pattern in the vertical direction. Similarly, the display elements G1 and G2, and the display elements B1 and B2 are also arranged in a zigzag pattern. This configuration improves viewing angle dependency, and reduces the occurrence of deviations in chromaticity and luminance when viewed from an oblique direction relative to the display surface.

[0129] The above is a description of an example of the pixel configuration.

[0130] [Example of display module configuration] A configuration example of a display module of one embodiment of the present invention will be described below.

[0131] 9A is a perspective schematic diagram of a display module 280. The display module 280 includes a display device 200 and an FPC 290.

[0132] The display module 280 has a substrate 201 and a substrate 202. Also, a display unit 281 is provided on the substrate 202 side. The display unit 281 is a region for displaying an image in the display module 280, and is a region where light from each pixel provided in a pixel unit 284 described later can be viewed.

[0133] 9B is a perspective view showing a schematic configuration of the substrate 201 side. The substrate 201 has a configuration in which a circuit portion 282, a pixel circuit portion 283 on the circuit portion 282, and a pixel portion 284 on the pixel circuit portion 283 are laminated. The substrate 201 also has a terminal portion 285 for connecting to an FPC 290 in a portion of the substrate 201 that does not overlap with the pixel portion 284. The terminal portion 285 and the circuit portion 282 are electrically connected by a wiring portion 286 consisting of a plurality of wirings.

[0134] The pixel section 284 has a plurality of pixels 284a arranged in a matrix. An enlarged view of one pixel 284a is shown on the right side of Fig. 9B. The pixel 284a has a display element R1, a display element G1, a display element B1, a display element R2, a display element G2, and a display element B2. The pixel 284a corresponds to the pixel unit 70 illustrated in Figs. 8A and 8B above.

[0135] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged in a matrix. One pixel circuit 283a is a circuit that controls the emission of six display elements of one pixel 284a. One pixel circuit 283a may be configured to have six circuits that control the emission of one display element. For example, the pixel circuit 283a may have at least one selection transistor, one current control transistor (drive transistor), and a capacitance element for each display element. At this time, a gate signal is input to the gate of the selection transistor, and a source signal is input to either the source or the drain. This realizes an active matrix display device.

[0136] The circuit portion 282 has a circuit for driving each pixel circuit 283a of the pixel circuit portion 283. For example, it is preferable that the circuit portion 282 has a gate line driver circuit, a source line driver circuit, etc. In addition, the circuit portion 282 may have an arithmetic circuit, a memory circuit, a power supply circuit, etc.

[0137] The FPC 290 functions as wiring for supplying a video signal and a power supply potential from the outside to the circuit portion 282. In addition, an IC may be mounted on the FPC 290.

[0138] The display module 280 can be configured such that the pixel circuit section 283, the circuit section 282, etc. are stacked below the pixel section 284, so that the aperture ratio (effective display area ratio) of the display section 281 can be extremely high. For example, the aperture ratio of the display section 281 can be set to 40% or more and less than 100%, preferably 50% or more and 95% or less, and more preferably 60% or more and 95% or less. In addition, the pixels 284a can be arranged at an extremely high density, so that the resolution of the display section 281 can be extremely high. For example, it is preferable that the pixels 284a are arranged in the display section 281 with a resolution (pixel density) of 1000 ppi or more and 50000 ppi or less, preferably 2000 ppi or more and 20000 ppi or less, more preferably 3000 ppi or more and 10000 ppi or less, and even more preferably 5000 ppi or more and 10000 ppi or less. Typically, the pixel density can be 4500 ppi or more and 5500 ppi or less, 5500 ppi or more and 6500 ppi or less, or 6500 ppi or more and 7500 ppi or less.

[0139] Such a display module 280 is extremely high-definition and can be suitably used in VR devices such as head-mounted displays or glasses-type AR devices. For example, even in a configuration in which the display unit of the display module 280 is viewed through a lens, the display module 280 has an extremely high-definition display unit 281, so that even if the display unit is enlarged with a lens, pixels are not visible, and a highly immersive display can be performed. In addition, the display module 280 is not limited to this, and can be suitably used in electronic devices having a relatively small display unit. For example, it can be suitably used in the display unit of a wearable electronic device such as a wristwatch-type electronic device.

[0140] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification.

[0141] (Embodiment 4) In this embodiment, an example of a CPU applicable to a composite system according to an aspect of the present invention will be described. The CPU exemplified below can be suitably used particularly for a control unit included in a display device.

[0142] <Configuration of CPU> The semiconductor device 5400 shown in FIG. 10 includes a CPU core 5401, a power management unit 5421, and a peripheral circuit 5422. The power management unit 5421 includes a power controller 5402 and a power switch 5403. The peripheral circuit 5422 includes a cache 5404 having a cache memory, a bus interface (BUS I / F) 5405, and a debug interface (Debug I / F) 5406. The CPU core 5401 includes a data bus 5423, a control unit 5407, a PC (program counter) 5408, a pipeline register 5409, a pipeline register 5410, an ALU (arithmetic logic unit) 5411, and a register file 5412. Data exchange between the CPU core 5401 and the peripheral circuit 5422 such as the cache 5404 is performed via the data bus 5423.

[0143] The semiconductor device (cell) can be applied to many logic circuits including the power controller 5402 and the control unit 5407. In particular, it can be applied to all logic circuits that can be configured using standard cells. As a result, a small semiconductor device 5400 can be provided. Also, a semiconductor device 5400 capable of reducing power consumption can be provided. Also, a semiconductor device 5400 capable of improving the operating speed can be provided. Also, a semiconductor device 5400 capable of reducing fluctuations in the power supply voltage can be provided.

[0144] By using a p-channel Si transistor and a transistor including an oxide semiconductor (preferably an oxide including In, Ga, and Zn) in a channel formation region in a semiconductor device (cell) and applying the semiconductor device (cell) to a semiconductor device 5400, a small-sized semiconductor device 5400 can be provided. Also, a semiconductor device 5400 capable of reducing power consumption can be provided. Also, a semiconductor device 5400 capable of improving operation speed can be provided. In particular, by using only p-channel Si transistors, manufacturing costs can be kept low.

[0145] The control device 5407 has the function of decoding and executing instructions contained in a program such as an input application by comprehensively controlling the operation of the PC 5408, pipeline register 5409, pipeline register 5410, ALU 5411, register file 5412, cache 5404, bus interface 5405, debug interface 5406, and power controller 5402.

[0146] The ALU 5411 has a function of performing various arithmetic operations such as arithmetic operations and logical operations.

[0147] The cache 5404 has a function of temporarily storing frequently used data. The PC 5408 is a register having a function of storing the address of the next instruction to be executed. Although not shown in FIG. 10, the cache 5404 is provided with a cache controller that controls the operation of the cache memory.

[0148] The pipeline register 5409 is a register that has the function of temporarily storing instruction data.

[0149] The register file 5412 has a plurality of registers including general-purpose registers, and can store data read from the main memory, data obtained as a result of arithmetic processing by the ALU 5411, and the like.

[0150] The pipeline register 5410 is a register having a function of temporarily storing data used in the arithmetic processing of the ALU 5411, or data obtained as a result of the arithmetic processing of the ALU 5411, and the like.

[0151] The bus interface 5405 functions as a data path between the semiconductor device 5400 and various devices external to the semiconductor device 5400. The debug interface 5406 functions as a signal path for inputting commands for controlling debugging to the semiconductor device 5400.

[0152] The power switch 5403 has a function of controlling the supply of power supply voltage to various circuits other than the power controller 5402 included in the semiconductor device 5400. The various circuits described above belong to several power domains, and the supply of power supply voltage to various circuits belonging to the same power domain is controlled by the power switch 5403. In addition, the power controller 5402 has a function of controlling the operation of the power switch 5403.

[0153] The semiconductor device 5400 having the above configuration is capable of performing power gating. An example of the flow of power gating operations will be described below.

[0154] First, the CPU core 5401 sets the timing to stop the supply of the power supply voltage in a register of the power controller 5402. Next, the CPU core 5401 sends a command to start power gating to the power controller 5402. Next, various registers and a cache 5404 included in the semiconductor device 5400 start saving data. Next, the supply of the power supply voltage to various circuits other than the power controller 5402 of the semiconductor device 5400 is stopped by the power switch 5403. Next, an interrupt signal is input to the power controller 5402, and the supply of the power supply voltage to various circuits of the semiconductor device 5400 is started. Note that a counter may be provided in the power controller 5402, and the timing to start the supply of the power supply voltage may be determined using the counter, regardless of the input of the interrupt signal. Next, various registers and a cache 5404 start restoring data. Next, the execution of instructions in the control device 5407 is resumed.

[0155] This type of power gating can be performed on the entire processor, or on one or more logic circuits that make up the processor. Also, the supply of power can be stopped even for a short period of time. This allows power consumption to be reduced at a fine spatial or temporal granularity.

[0156] When performing power gating, it is preferable to be able to quickly evacuate information held by the CPU core 5401 and the peripheral circuit 5422. This makes it possible to turn the power on and off in a short period of time, resulting in a greater power saving effect.

[0157] In order to save information held by the CPU core 5401 and the peripheral circuit 5422 in a short time, it is preferable that the flip-flop circuit can save data within the circuit (called a backup-capable flip-flop circuit). It is also preferable that the SRAM cell can save data within the cell (called a backup-capable SRAM cell). It is preferable that the backup-capable flip-flop circuit or SRAM cell has a transistor including an oxide semiconductor (preferably an oxide containing In, Ga, and Zn) in a channel formation region. As a result, since the transistor has a low off-current, the backup-capable flip-flop circuit or SRAM cell can hold information for a long period of time without power supply. Furthermore, since the transistor has a high switching speed, the backup-capable flip-flop circuit or SRAM cell may be able to save and restore data in a short period of time.

[0158] An example of a flip-flop circuit capable of backing up will be described with reference to FIG.

[0159] 11 is an example of a flip-flop circuit capable of backing up. The semiconductor device 5500 includes a first memory circuit 5501, a second memory circuit 5502, a third memory circuit 5503, and a read circuit 5504. A potential difference between a potential V1 and a potential V2 is supplied to the semiconductor device 5500 as a power supply voltage. One of the potentials V1 and V2 is at a high level, and the other is at a low level. Hereinafter, a configuration example of the semiconductor device 5500 will be described taking as an example a case where the potential V1 is at a low level and the potential V2 is at a high level.

[0160] The first memory circuit 5501 has a function of holding data when a signal D including data is input during a period when a power supply voltage is supplied to the semiconductor device 5500. During a period when a power supply voltage is supplied to the semiconductor device 5500, a signal Q including the held data is output from the first memory circuit 5501. On the other hand, the first memory circuit 5501 cannot hold data during a period when a power supply voltage is not supplied to the semiconductor device 5500. That is, the first memory circuit 5501 can be called a volatile memory circuit.

[0161] The second memory circuit 5502 has a function of reading and storing (or saving) data held in the first memory circuit 5501. The third memory circuit 5503 has a function of reading and storing (or saving) data held in the second memory circuit 5502. The reading circuit 5504 has a function of reading data held in the second memory circuit 5502 or the third memory circuit 5503 and storing (or restoring) the data to the first memory circuit 5501.

[0162] In particular, the third memory circuit 5503 has a function of reading and storing (or saving) data held in the second memory circuit 5502 even during a period when power supply voltage is not supplied to the semiconductor device 5500.

[0163] 11, the second memory circuit 5502 includes a transistor 5512 and a capacitor 5519. The third memory circuit 5503 includes a transistor 5513, a transistor 5515, and a capacitor 5520. The reading circuit 5504 includes a transistor 5510, a transistor 5518, a transistor 5509, and a transistor 5517.

[0164] The transistor 5512 has a function of charging and discharging charge to and from a capacitor 5519 according to data held in the first memory circuit 5501. It is preferable that the transistor 5512 can quickly charge and discharge charge to and from the capacitor 5519 according to data held in the first memory circuit 5501. Specifically, it is preferable that the transistor 5512 contains crystalline silicon (preferably polycrystalline silicon, more preferably single crystal silicon) in a channel formation region.

[0165] The transistor 5513 is turned on or off depending on the charge held in the capacitor 5519. The transistor 5515 has a function of charging and discharging charge to and from the capacitor 5520 depending on the potential of the wiring 5544 when the transistor 5513 is turned on. It is preferable that the off-state current of the transistor 5515 is extremely small. Specifically, it is preferable that the transistor 5515 includes an oxide semiconductor (preferably an oxide containing In, Ga, and Zn) in a channel formation region.

[0166] To specifically describe the connection relationship of each element, one of the source and drain of the transistor 5512 is connected to the first memory circuit 5501. The other of the source and drain of the transistor 5512 is connected to one electrode of a capacitor 5519, a gate of a transistor 5513, and a gate of a transistor 5518. The other electrode of the capacitor 5519 is connected to a wiring 5542. One of the source and drain of the transistor 5513 is connected to a wiring 5544. The other of the source and drain of the transistor 5513 is connected to one of the source and drain of a transistor 5515. The other of the source and drain of the transistor 5515 is connected to one electrode of a capacitor 5520 and a gate of a transistor 5510. The other electrode of the capacitor 5520 is connected to a wiring 5543. One of the source and drain of the transistor 5510 is connected to a wiring 5541. The other of the source and drain of the transistor 5510 is connected to one of the source and drain of the transistor 5518. The other of the source and drain of the transistor 5518 is connected to one of the source and drain of the transistor 5509. The other of the source and drain of the transistor 5509 is connected to one of the source and drain of the transistor 5517 and the first memory circuit 5501. The other of the source and drain of the transistor 5517 is connected to a wiring 5540. Although the gate of the transistor 5509 is connected to the gate of the transistor 5517 in FIG. 11, the gate of the transistor 5509 is not necessarily connected to the gate of the transistor 5517.

[0167] A transistor including an oxide semiconductor can be used as the transistor 5515. Because the off-state current of the transistor 5515 is small, the semiconductor device 5500 can retain data for a long period of time without power supply. Because the transistor 5515 has favorable switching characteristics, the semiconductor device 5500 can perform high-speed backup and recovery.

[0168] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification.

[0169] (Embodiment 5) In this embodiment, a configuration example of a semiconductor device that can be applied to a display device or a sensor device included in a composite device of one embodiment of the present invention will be described. The semiconductor device exemplified below can be applied particularly to a control unit included in a display device. In addition, the semiconductor device can also be applied to an imaging unit, a sensor unit, a communication unit, or the like included in a sensor device.

[0170] 12 includes a transistor 300, a transistor 500, and a capacitor 800. Fig. 14A is a cross-sectional view of the transistor 500 in the channel length direction, Fig. 14B is a cross-sectional view of the transistor 500 in the channel width direction, and Fig. 14C is a cross-sectional view of the transistor 300 in the channel width direction.

[0171] The transistor 500 is a transistor including a metal oxide in a channel formation region (OS transistor). Since the off-state current of the transistor 500 is small, when the transistor 500 is used as an OS transistor in a semiconductor device, written data can be held for a long period of time.

[0172] 12, the semiconductor device described in this embodiment includes a transistor 300, a transistor 500, and a capacitor 800. The transistor 500 is provided above the transistor 300, and the capacitor 800 is provided above the transistors 300 and 500.

[0173] The transistor 300 is provided over a substrate 311 and includes a conductor 316, an insulator 315, a semiconductor region 313 formed of a part of the substrate 311, and a low-resistance region 314a and a low-resistance region 314b functioning as a source region or a drain region. Note that the transistor 300 can be applied to a transistor included in a memory, or the like.

[0174] 14C , the upper surface and the side surface in the channel width direction of the semiconductor region 313 of the transistor 300 are covered with a conductor 316 via an insulator 315. By forming the transistor 300 as a fin type in this manner, the effective channel width is increased, thereby improving the on-characteristics of the transistor 300. In addition, the contribution of the electric field of the gate electrode can be increased, thereby improving the off-characteristics of the transistor 300.

[0175] The transistor 300 may be either a p-channel type or an n-channel type.

[0176] The region where the channel of the semiconductor region 313 is formed, the region nearby, the low resistance region 314a which becomes the source region or the drain region, and the low resistance region 314b preferably contain a semiconductor such as a silicon-based semiconductor, and preferably contain single crystal silicon. Alternatively, they may be formed of a material containing Ge (germanium), SiGe (silicon germanium), GaAs (gallium arsenide), GaAlAs (gallium aluminum arsenide), or the like. A configuration using silicon in which the effective mass is controlled by applying stress to the crystal lattice and changing the lattice spacing may be used. Alternatively, the transistor 300 may be a HEMT (High Electron Mobility Transistor) by using GaAs and GaAlAs, or the like.

[0177] The low resistance region 314a and the low resistance region 314b contain, in addition to the semiconductor material applied to the semiconductor region 313, an element that imparts n-type conductivity, such as arsenic or phosphorus, or an element that imparts p-type conductivity, such as boron.

[0178] The conductor 316 functioning as the gate electrode can be made of a conductive material such as a semiconductor material, such as silicon, containing an element that imparts n-type conductivity, such as arsenic or phosphorus, or an element that imparts p-type conductivity, such as boron, a metal material, an alloy material, or a metal oxide material.

[0179] Since the work function is determined by the material of the conductor, the threshold voltage of the transistor can be adjusted by selecting the material of the conductor. Specifically, it is preferable to use a material such as titanium nitride or tantalum nitride for the conductor. Furthermore, in order to achieve both electrical conductivity and embeddability, it is preferable to use a metal material such as tungsten or aluminum as the conductor in a laminated state, and in particular, it is preferable to use tungsten in terms of heat resistance.

[0180] 12 is just an example and is not limited to the structure, and an appropriate transistor may be used depending on the circuit configuration and driving method. For example, when a semiconductor device is formed using only OS transistors, the transistor 300 may have a similar structure to a transistor 500 including an oxide semiconductor as shown in FIG 13. The details of the transistor 500 will be described later.

[0181] An insulator 320, an insulator 322, an insulator 324, and an insulator 326 are stacked in this order over the transistor 300.

[0182] As the insulators 320, 322, 324, and 326, for example, silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, aluminum oxide, aluminum oxynitride, aluminum nitride oxide, aluminum nitride, or the like can be used.

[0183] In this specification, silicon oxynitride refers to a material having a higher oxygen content than nitrogen, silicon nitride oxide refers to a material having a higher nitrogen content than oxygen, aluminum oxynitride refers to a material having a higher oxygen content than nitrogen, and aluminum nitride oxide refers to a material having a higher nitrogen content than oxygen.

[0184] The insulator 322 may function as a planarizing film that planarizes steps caused by the transistor 300 provided thereunder. For example, the top surface of the insulator 322 may be planarized by a planarization process using a chemical mechanical polishing (CMP) method or the like to improve the planarity.

[0185] The insulator 324 is preferably a film having a barrier property that prevents hydrogen or impurities from diffusing from the substrate 311 or the transistor 300 to a region where the transistor 500 is provided.

[0186] As an example of a film having a barrier property against hydrogen, for example, silicon nitride formed by a CVD method can be used. Here, when hydrogen diffuses into a semiconductor element having an oxide semiconductor such as the transistor 500, the characteristics of the semiconductor element may deteriorate. Therefore, it is preferable to use a film that suppresses the diffusion of hydrogen between the transistor 500 and the transistor 300. Specifically, the film that suppresses the diffusion of hydrogen is a film that releases a small amount of hydrogen.

[0187] The amount of desorption of hydrogen can be analyzed, for example, by using thermal desorption spectrometry (TDS). For example, the amount of desorption of hydrogen from the insulator 324 is calculated as 10×10 per area of ​​the insulator 324 when the surface temperature of the film is in the range of 50° C. to 500° C. in the TDS analysis. 15 atoms / cm 2 Less than or equal to 5×10 15 atoms / cm 2 The following is acceptable.

[0188] The insulator 326 preferably has a lower dielectric constant than the insulator 324. For example, the relative dielectric constant of the insulator 326 is preferably less than 4, and more preferably less than 3. For example, the relative dielectric constant of the insulator 326 is preferably 0.7 times or less, and more preferably 0.6 times or less, the relative dielectric constant of the insulator 324. By using a material with a low dielectric constant as the interlayer film, the parasitic capacitance generated between wirings can be reduced.

[0189] A conductor 328, a conductor 330, and the like that connect to the capacitor 800 or the transistor 500 are embedded in the insulator 320, the insulator 322, the insulator 324, and the insulator 326. The conductor 328 and the conductor 330 function as a plug or a wiring. In addition, a plurality of conductors that function as a plug or a wiring may be collectively given the same reference symbol. In this specification and the like, a wiring and a plug connected to the wiring may be integrated. That is, there are cases where a part of a conductor functions as a wiring and a case where a part of a conductor functions as a plug.

[0190] As the material for each plug and wiring (conductor 328, conductor 330, etc.), a conductive material such as a metal material, an alloy material, a metal nitride material, or a metal oxide material can be used in a single layer or a laminated layer. It is preferable to use a high melting point material such as tungsten or molybdenum that has both heat resistance and conductivity, and it is preferable to use tungsten. Alternatively, it is preferable to form the wiring from a low resistance conductive material such as aluminum or copper. By using a low resistance conductive material, it is possible to reduce the wiring resistance.

[0191] A wiring layer may be provided over the insulator 326 and the conductor 330. For example, in FIG. 12 , an insulator 350, an insulator 352, and an insulator 354 are stacked in this order. A conductor 356 is formed in the insulator 350, the insulator 352, and the insulator 354. The conductor 356 functions as a plug or a wiring connected to the transistor 300. Note that the conductor 356 can be provided using a material similar to that of the conductor 328 and the conductor 330.

[0192] Note that, for example, the insulator 350 is preferably an insulator having a barrier property against hydrogen, similar to the insulator 324. The conductor 356 preferably includes a conductor having a barrier property against hydrogen. In particular, a conductor having a barrier property against hydrogen is formed in an opening of the insulator 350 having a barrier property against hydrogen. With this structure, the transistor 300 and the transistor 500 can be separated by a barrier layer, and diffusion of hydrogen from the transistor 300 to the transistor 500 can be suppressed.

[0193] Note that, for example, tantalum nitride or the like may be used as the conductor having a barrier property against hydrogen. By stacking tantalum nitride and tungsten having high conductivity, it is possible to suppress diffusion of hydrogen from the transistor 300 while maintaining the conductivity of the wiring. In this case, a structure in which the tantalum nitride layer having a barrier property against hydrogen is in contact with the insulator 350 having a barrier property against hydrogen is preferable.

[0194] A wiring layer may be provided over the insulator 354 and the conductor 356. For example, in FIG. 12, an insulator 360, an insulator 362, and an insulator 364 are stacked in this order. A conductor 366 is formed in the insulator 360, the insulator 362, and the insulator 364. The conductor 366 functions as a plug or a wiring. The conductor 366 can be provided using a material similar to that of the conductor 328 and the conductor 330.

[0195] Note that, for example, the insulator 360 is preferably an insulator having a barrier property against hydrogen, similar to the insulator 324. The conductor 366 preferably includes a conductor having a barrier property against hydrogen. In particular, a conductor having a barrier property against hydrogen is formed in an opening of the insulator 360 having a barrier property against hydrogen. With this structure, the transistor 300 and the transistor 500 can be separated by a barrier layer, and diffusion of hydrogen from the transistor 300 to the transistor 500 can be suppressed.

[0196] A wiring layer may be provided over the insulator 364 and the conductor 366. For example, in FIG. 12, an insulator 370, an insulator 372, and an insulator 374 are stacked in this order. A conductor 376 is formed in the insulator 370, the insulator 372, and the insulator 374. The conductor 376 functions as a plug or a wiring. Note that the conductor 376 can be provided using a material similar to that of the conductor 328 and the conductor 330.

[0197] Note that, for example, the insulator 370 is preferably an insulator having a barrier property against hydrogen, similar to the insulator 324. The conductor 376 preferably includes a conductor having a barrier property against hydrogen. In particular, a conductor having a barrier property against hydrogen is formed in an opening of the insulator 370 having a barrier property against hydrogen. With this structure, the transistor 300 and the transistor 500 can be separated by a barrier layer, and diffusion of hydrogen from the transistor 300 to the transistor 500 can be suppressed.

[0198] A wiring layer may be provided over the insulator 374 and the conductor 376. For example, in FIG. 12, an insulator 380, an insulator 382, ​​and an insulator 384 are stacked in this order. A conductor 386 is formed in the insulator 380, the insulator 382, ​​and the insulator 384. The conductor 386 functions as a plug or a wiring. Note that the conductor 386 can be provided using a material similar to that of the conductor 328 and the conductor 330.

[0199] Note that, for example, the insulator 380 is preferably an insulator having a barrier property against hydrogen, similar to the insulator 324. The conductor 386 preferably includes a conductor having a barrier property against hydrogen. In particular, a conductor having a barrier property against hydrogen is formed in an opening of the insulator 380 having a barrier property against hydrogen. With this structure, the transistor 300 and the transistor 500 can be separated by a barrier layer, and diffusion of hydrogen from the transistor 300 to the transistor 500 can be suppressed.

[0200] In the above, a wiring layer including the conductor 356, a wiring layer including the conductor 366, a wiring layer including the conductor 376, and a wiring layer including the conductor 386 have been described, but the semiconductor device of this embodiment is not limited to this. There may be three or fewer wiring layers similar to the wiring layer including the conductor 356, or there may be five or more wiring layers similar to the wiring layer including the conductor 356.

[0201] An insulator 510, an insulator 512, an insulator 514, and an insulator 516 are stacked in this order over the insulator 384. Any of the insulator 510, the insulator 512, the insulator 514, and the insulator 516 is preferably made of a substance that has a barrier property against oxygen or hydrogen.

[0202] For example, the insulator 510 and the insulator 514 are preferably formed using a film having a barrier property that prevents hydrogen or impurities from diffusing from the substrate 311 or a region where the transistor 300 is provided to a region where the transistor 500 is provided. Therefore, a material similar to that of the insulator 324 can be used.

[0203] As an example of a film having a barrier property against hydrogen, silicon nitride formed by a CVD method can be used. Here, when hydrogen diffuses into a semiconductor element having an oxide semiconductor such as the transistor 500, the characteristics of the semiconductor element may deteriorate. Therefore, it is preferable to use a film that suppresses the diffusion of hydrogen between the transistor 500 and the transistor 300. Specifically, the film that suppresses the diffusion of hydrogen is a film that releases a small amount of hydrogen.

[0204] As a film having a barrier property against hydrogen, for example, the insulator 510 and the insulator 514 are preferably made of a metal oxide such as aluminum oxide, hafnium oxide, or tantalum oxide.

[0205] In particular, aluminum oxide has a high blocking effect of preventing the film from permeating both oxygen and impurities such as hydrogen and moisture, which are factors that cause fluctuations in the electrical characteristics of a transistor. Therefore, aluminum oxide can prevent impurities such as hydrogen and moisture from entering the transistor 500 during and after the transistor manufacturing process. In addition, aluminum oxide can suppress the release of oxygen from the oxide that constitutes the transistor 500. Therefore, aluminum oxide is suitable for use as a protective film for the transistor 500.

[0206] For example, the insulator 512 and the insulator 516 can be formed using a material similar to that of the insulator 320. By using a material with a relatively low dielectric constant for these insulators, parasitic capacitance between wirings can be reduced. For example, the insulator 512 and the insulator 516 can be formed using a silicon oxide film, a silicon oxynitride film, or the like.

[0207] A conductor 518, a conductor constituting the transistor 500 (for example, the conductor 503), and the like are embedded in the insulator 510, the insulator 512, the insulator 514, and the insulator 516. Note that the conductor 518 functions as a plug or a wiring connected to the capacitor 800 or the transistor 300. The conductor 518 can be formed using a material similar to that of the conductor 328 and the conductor 330.

[0208] In particular, the insulator 510 and the conductor 518 in the region in contact with the insulator 514 are preferably conductors having barrier properties against oxygen, hydrogen, and water. With this structure, the transistors 300 and 500 can be separated by a layer having barrier properties against oxygen, hydrogen, and water, and diffusion of hydrogen from the transistor 300 to the transistor 500 can be suppressed.

[0209] Above the insulator 516 is a transistor 500 .

[0210] As shown in Figures 14A and 14B, transistor 500 has a conductor 503 arranged so as to be embedded in insulator 514 and insulator 516, an insulator 522 arranged on insulator 516 and conductor 503, an insulator 524 arranged on insulator 522, an oxide 530a arranged on insulator 524, an oxide 530b arranged on oxide 530a, an oxide 530c arranged on oxide 530b, conductors 542a and 542b arranged apart from each other on oxide 530c, an insulator 580 arranged on conductor 542a and conductor 542b and having an opening formed therein overlapping with conductor 542a and conductor 542b, an insulator 550 arranged on the bottom and side surfaces of the opening, and a conductor 560 arranged on the formation surface of insulator 550.

[0211] 14A and 14B, it is preferable that an insulator 544 is disposed between the oxide 530a, the oxide 530b, the conductor 542a, and the conductor 542b and the insulator 580. It is preferable that the conductor 560 has a conductor 560a provided inside the insulator 550 and a conductor 560b provided so as to be embedded inside the conductor 560a, as shown in FIGS. 14A and 14B. It is preferable that an insulator 574 is disposed on the insulator 580, the conductor 560, and the insulator 550, as shown in FIGS. 14A and 14B.

[0212] In the following, oxide 530a, oxide 530b, and oxide 530c may be collectively referred to as oxide 530.

[0213] In the transistor 500, a three-layer structure of oxides 530a, 530b, and 530c is shown in the region where a channel is formed and in the vicinity thereof, but the present invention is not limited thereto. For example, a single layer of oxide 530b, a two-layer structure of oxides 530b and 530a, a two-layer structure of oxides 530b and 530c, or a stacked structure of four or more layers may be provided. In addition, in the transistor 500, the conductor 560 is shown as having a two-layer stacked structure, but the present invention is not limited thereto. For example, the conductor 560 may have a single-layer structure or a stacked structure of three or more layers. In addition, the transistor 500 shown in FIG. 12 and FIG. 14A is an example, and the present invention is not limited thereto, and an appropriate transistor may be used depending on the circuit configuration and the driving method.

[0214] Here, the conductor 560 functions as a gate electrode of the transistor, and the conductors 542a and 542b function as a source electrode and a drain electrode, respectively. As described above, the conductor 560 is formed so as to be embedded in the opening of the insulator 580 and in the region sandwiched between the conductors 542a and 542b. The arrangement of the conductors 560, 542a, and 542b is selected in a self-aligned manner with respect to the opening of the insulator 580. That is, in the transistor 500, the gate electrode can be arranged in a self-aligned manner between the source electrode and the drain electrode. Therefore, the conductor 560 can be formed without providing a margin for alignment, so that the area occupied by the transistor 500 can be reduced. This allows the semiconductor device to be miniaturized and highly integrated.

[0215] Furthermore, since the conductor 560 is formed in a self-aligned manner in the region between the conductor 542a and the conductor 542b, the conductor 560 does not have a region overlapping with the conductor 542a or the conductor 542b. This makes it possible to reduce the parasitic capacitance formed between the conductor 560 and the conductor 542a and between the conductor 560 and the conductor 542b. As a result, the switching speed of the transistor 500 can be improved, and high frequency characteristics can be achieved.

[0216] The conductor 560 may function as a first gate (also referred to as a top gate) electrode. The conductor 503 may function as a second gate (also referred to as a bottom gate) electrode. In this case, the threshold voltage of the transistor 500 can be controlled by changing the potential applied to the conductor 503 independently of the potential applied to the conductor 560. In particular, by applying a negative potential to the conductor 503, the threshold voltage of the transistor 500 can be made higher than 0 V, and the off-current can be reduced. Therefore, applying a negative potential to the conductor 503 can reduce the drain current when the potential applied to the conductor 560 is 0 V, compared to when a negative potential is not applied.

[0217] The conductor 503 is disposed so as to overlap the oxide 530 and the conductor 560. In this manner, when a potential is applied to the conductor 560 and the conductor 503, an electric field generated from the conductor 560 and an electric field generated from the conductor 503 are connected, and a channel formation region formed in the oxide 530 can be covered. In this specification and the like, a transistor structure in which a channel formation region is electrically surrounded by the electric fields of the first gate electrode and the second gate electrode is referred to as a surrounded channel (S-channel) structure.

[0218] The conductor 503 has a structure similar to that of the conductor 518, and the conductor 503a is formed in contact with the inner walls of the openings of the insulator 514 and the insulator 516, and the conductor 503b is formed further inside. Note that, although the transistor 500 has a structure in which the conductor 503a and the conductor 503b are stacked, the present invention is not limited to this. For example, the conductor 503 may have a single layer or a stacked structure of three or more layers.

[0219] Here, the conductor 503a is preferably made of a conductive material having a function of suppressing the diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, and copper atoms (the impurities are less likely to permeate through). Alternatively, it is preferable to use a conductive material having a function of suppressing the diffusion of oxygen (e.g., at least one of oxygen atoms, oxygen molecules, etc.) (the oxygen is less likely to permeate through). Note that in this specification, the function of suppressing the diffusion of impurities or oxygen refers to the function of suppressing the diffusion of any one or all of the impurities or the oxygen.

[0220] For example, the conductor 503a has a function of suppressing the diffusion of oxygen, so that the conductor 503b can be prevented from being oxidized and the conductivity from decreasing.

[0221] In addition, when the conductor 503 also functions as a wiring, it is preferable that the conductor 503b is made of a highly conductive material containing tungsten, copper, or aluminum as a main component. Although the conductor 503b is illustrated as a single layer, it may have a laminated structure, for example, a laminate of titanium or titanium nitride and the above-mentioned conductive material.

[0222] The insulators 522, 524, and 550 function as gate insulating films.

[0223] Here, the insulator 524 and the insulator 550 in contact with the oxide 530 preferably contain more oxygen than the oxygen required for the stoichiometric composition. That is, an excess oxygen region is preferably formed in the insulator 524 and the insulator 550. By providing such an insulator containing excess oxygen in contact with the oxide 530, oxygen vacancies in the oxide 530 can be reduced and the reliability of the transistor 500 can be improved.

[0224] Specifically, it is preferable to use an oxide material from which some oxygen is released by heating as an insulator having an excess oxygen region. An oxide material from which oxygen is released by heating is an oxide material from which the amount of released oxygen converted into oxygen atoms is 1.0×1018 atoms / cm 3 More than 1.0×10 19 atoms / cm 3 More preferably, 2.0×10 19 atoms / cm 3 or more than 3.0 x 10 20 atoms / cm 3 The oxide film is one having the above-mentioned properties. The surface temperature of the film during the TDS analysis is preferably in the range of 100° C. or higher and 700° C. or lower, or 100° C. or higher and 400° C. or lower.

[0225] When the insulator 524 has an excess oxygen region, it is preferable that the insulator 522 has a function of suppressing the diffusion of oxygen (eg, oxygen atoms, oxygen molecules, etc.) (the oxygen is less likely to permeate).

[0226] The insulator 522 preferably has a function of suppressing diffusion of oxygen and impurities, so that oxygen contained in the oxide 530 does not diffuse toward the insulator 516. Furthermore, reaction of the conductor 503 with the insulator 524 or oxygen contained in the oxide 530 can be suppressed.

[0227] The insulator 522 is preferably a single layer or a multilayer insulator containing a so-called high-k material, such as aluminum oxide, hafnium oxide, oxide containing aluminum and hafnium (hafnium aluminate), tantalum oxide, zirconium oxide, lead zirconate titanate (PZT), strontium titanate (SrTiO3), or (Ba,Sr)TiO3 (BST). As transistors become smaller and more highly integrated, problems such as leakage current may occur due to the thinning of the gate insulating film. By using a high-k material for the insulator that functions as the gate insulating film, it is possible to reduce the gate potential during transistor operation while maintaining the physical film thickness.

[0228] In particular, it is preferable to use an insulator containing an oxide of one or both of aluminum and hafnium, which are insulating materials having a function of suppressing the diffusion of impurities and oxygen (the oxygen is unlikely to permeate through them). As an insulator containing an oxide of one or both of aluminum and hafnium, it is preferable to use aluminum oxide, hafnium oxide, an oxide containing aluminum and hafnium (hafnium aluminate), or the like. When the insulator 522 is formed using such a material, the insulator 522 functions as a layer that suppresses release of oxygen from the oxide 530 and the intrusion of impurities such as hydrogen into the oxide 530 from the periphery of the transistor 500.

[0229] Alternatively, for example, aluminum oxide, bismuth oxide, germanium oxide, niobium oxide, silicon oxide, titanium oxide, tungsten oxide, yttrium oxide, or zirconium oxide may be added to these insulators. Alternatively, these insulators may be nitrided. Silicon oxide, silicon oxynitride, or silicon nitride may be stacked on the above insulators.

[0230] 14A and 14B, the second gate insulating film has a two-layer stack structure including the insulators 522 and 524. However, the second gate insulating film may have a single layer or a stack structure of three or more layers. In this case, the second gate insulating film is not limited to a stack structure made of the same material, and may have a stack structure made of different materials.

[0231] In the transistor 500, it is preferable to use a metal oxide functioning as an oxide semiconductor for the oxide 530 including the channel formation region. For example, a metal oxide such as In-M-Zn oxide (wherein the element M is one or more selected from aluminum, gallium, yttrium, copper, vanadium, beryllium, boron, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, etc.) may be used as the oxide 530. In particular, it is preferable that the In-M-Zn oxide applicable to the oxide 530 is CAAC-OS or CAC-OS, which will be described later. Alternatively, In-Ga oxide or In-Zn oxide may be used as the oxide 530.

[0232] The metal oxide that functions as a channel formation region in the oxide 530 preferably has a band gap of 2 eV or more, preferably 2.5 eV or more. In this manner, by using a metal oxide with a wide band gap, the off-state current of the transistor can be reduced.

[0233] The oxide 530 has the oxide 530a below the oxide 530b, so that the diffusion of impurities from structures formed below the oxide 530a to the oxide 530b can be suppressed. Also, the oxide 530 has the oxide 530c on the oxide 530b, so that the diffusion of impurities from structures formed above the oxide 530c to the oxide 530b can be suppressed.

[0234] The oxide 530 preferably has a laminated structure of a plurality of oxide layers having different atomic ratios of metal atoms. Specifically, in the metal oxide used for the oxide 530a, the atomic ratio of element M among the constituent elements is preferably larger than the atomic ratio of element M among the constituent elements in the metal oxide used for the oxide 530b. In addition, in the metal oxide used for the oxide 530a, the atomic ratio of element M to In is preferably larger than the atomic ratio of element M to In in the metal oxide used for the oxide 530b. In addition, in the metal oxide used for the oxide 530b, the atomic ratio of In to element M is preferably larger than the atomic ratio of In to element M in the metal oxide used for the oxide 530a. In addition, the oxide 530c can use a metal oxide that can be used for the oxide 530a or the oxide 530b.

[0235] In addition, the energy of the conduction band minimum of the oxide 530a and the oxide 530c is preferably higher than that of the oxide 530b. In other words, the electron affinity of the oxide 530a and the oxide 530c is preferably smaller than that of the oxide 530b.

[0236] Here, the energy level of the conduction band minimum changes gradually at the junction of the oxide 530a, the oxide 530b, and the oxide 530c. In other words, it can be said that the energy level of the conduction band minimum at the junction of the oxide 530a, the oxide 530b, and the oxide 530c changes continuously or is a continuous junction. To achieve this, it is preferable to reduce the defect level density of the mixed layer formed at the interface between the oxide 530a and the oxide 530b and the interface between the oxide 530b and the oxide 530c.

[0237] Specifically, the oxides 530a and 530b, and the oxides 530b and 530c have a common element other than oxygen (as a main component), so that a mixed layer with a low density of defect states can be formed. For example, when the oxide 530b is an In-Ga-Zn oxide, the oxides 530a and 530c may be made of an In-Ga-Zn oxide, a Ga-Zn oxide, or a gallium oxide.

[0238] At this time, the main carrier path is the oxide 530b. By configuring the oxide 530a and the oxide 530c as described above, the defect state density at the interface between the oxide 530a and the oxide 530b and at the interface between the oxide 530b and the oxide 530c can be reduced. Therefore, the effect of interface scattering on carrier conduction is reduced, and the transistor 500 can obtain a high on-state current.

[0239] Conductors 542a and 542b functioning as a source electrode and a drain electrode are provided on the oxide 530c. As the conductors 542a and 542b, it is preferable to use a metal element selected from aluminum, chromium, copper, silver, gold, platinum, tantalum, nickel, titanium, molybdenum, tungsten, hafnium, vanadium, niobium, manganese, magnesium, zirconium, beryllium, indium, ruthenium, iridium, strontium, and lanthanum, an alloy containing the above-mentioned metal elements, or an alloy combining the above-mentioned metal elements. For example, it is preferable to use tantalum nitride, titanium nitride, tungsten, a nitride containing titanium and aluminum, a nitride containing tantalum and aluminum, ruthenium oxide, ruthenium nitride, an oxide containing strontium and ruthenium, an oxide containing lanthanum and nickel, or the like. In addition, tantalum nitride, titanium nitride, nitrides containing titanium and aluminum, nitrides containing tantalum and aluminum, ruthenium oxide, ruthenium nitride, oxides containing strontium and ruthenium, and oxides containing lanthanum and nickel are conductive materials that are difficult to oxidize, or materials that maintain conductivity even when oxygen is absorbed, and are therefore preferable.Furthermore, metal nitride films such as tantalum nitride are preferable because they have barrier properties against hydrogen or oxygen.

[0240] 14A and 14B, the conductor 542a and the conductor 542b are shown as a single-layer structure, but may be a laminated structure of two or more layers. For example, a tantalum nitride film and a tungsten film may be laminated. A titanium film and an aluminum film may be laminated. Alternatively, a two-layer structure in which an aluminum film is laminated on a tungsten film, a two-layer structure in which a copper film is laminated on a copper-magnesium-aluminum alloy film, a two-layer structure in which a copper film is laminated on a titanium film, or a two-layer structure in which a copper film is laminated on a tungsten film may be used.

[0241] In addition, there are three-layer structures in which a titanium film or titanium nitride film is laminated on the titanium film or titanium nitride film, an aluminum film or copper film is laminated on the titanium film or titanium nitride film, and a titanium film or titanium nitride film is further formed thereon, and a three-layer structure in which a molybdenum film or molybdenum nitride film is laminated on the molybdenum film or molybdenum nitride film, an aluminum film or copper film is laminated on the molybdenum film or molybdenum nitride film, and a molybdenum film or molybdenum nitride film is further formed thereon, etc. Note that a transparent conductive material containing indium oxide, tin oxide, or zinc oxide may be used.

[0242] 14A, regions 543a and 543b may be formed as low-resistance regions at and near the interface of the oxide 530 with the conductor 542a (conductor 542b). In this case, the region 543a functions as one of the source region and the drain region, and the region 543b functions as the other of the source region and the drain region. A channel formation region is formed in a region sandwiched between the regions 543a and 543b.

[0243] By providing the conductor 542a (conductor 542b) so as to be in contact with the oxide 530, the oxygen concentration in the region 543a (region 543b) may be reduced. Also, a metal compound layer containing a metal contained in the conductor 542a (conductor 542b) and a component of the oxide 530 may be formed in the region 543a (region 543b). In such a case, the carrier concentration in the region 543a (region 543b) increases, and the region 543a (region 543b) becomes a low-resistance region.

[0244] The insulator 544 is provided to cover the conductor 542a and the conductor 542b and suppresses oxidation of the conductor 542a and the conductor 542b. In this case, the insulator 544 may be provided to cover the side surface of the oxide 530 and to be in contact with the insulator 524.

[0245] The insulator 544 can be a metal oxide containing one or more elements selected from hafnium, aluminum, gallium, yttrium, zirconium, tungsten, titanium, tantalum, nickel, germanium, neodymium, lanthanum, magnesium, etc. Alternatively, the insulator 544 can be silicon nitride oxide, silicon nitride, or the like.

[0246] In particular, it is preferable to use, as the insulator 544, an insulator containing an oxide of either or both of aluminum and hafnium, such as aluminum oxide, hafnium oxide, or an oxide containing aluminum and hafnium (hafnium aluminate). In particular, hafnium aluminate has higher heat resistance than a hafnium oxide film. Therefore, it is preferable because it is less likely to crystallize in a heat treatment in a later step. Note that the insulator 544 is not an essential component when the conductor 542a and the conductor 542b are made of a material having oxidation resistance or when the conductivity does not decrease significantly even when oxygen is absorbed. It may be designed appropriately depending on the desired transistor characteristics.

[0247] The insulator 544 can prevent impurities such as water and hydrogen contained in the insulator 580 from diffusing to the oxide 530b through the oxide 530c and the insulator 550. The insulator 580 can also prevent the conductor 560 from being oxidized by excess oxygen contained in the insulator 580.

[0248] The insulator 550 functions as a first gate insulating film. Like the insulator 524 described above, the insulator 550 is preferably formed using an insulator that contains excess oxygen and releases oxygen by heating.

[0249] Specifically, silicon oxide having excess oxygen, silicon oxynitride, silicon nitride oxide, silicon nitride, silicon oxide to which fluorine is added, silicon oxide to which carbon is added, silicon oxide to which carbon and nitrogen are added, and silicon oxide having vacancies can be used. In particular, silicon oxide and silicon oxynitride are preferable because they are stable against heat.

[0250] Furthermore, in order to efficiently supply excess oxygen contained in the insulator 550 to the oxide 530, a metal oxide may be provided between the insulator 550 and the conductor 560. The metal oxide preferably suppresses oxygen diffusion from the insulator 550 to the conductor 560. By providing a metal oxide that suppresses oxygen diffusion, the diffusion of excess oxygen from the insulator 550 to the conductor 560 is suppressed. That is, a decrease in the amount of excess oxygen supplied to the oxide 530 can be suppressed. Furthermore, oxidation of the conductor 560 due to the excess oxygen can be suppressed. As the metal oxide, a material that can be used for the insulator 544 may be used.

[0251] The insulator 550 may have a laminated structure, similar to the second gate insulating film. As transistors become smaller and more highly integrated, problems such as leakage current may occur due to the thinning of the gate insulating film. Therefore, by making the insulator that functions as the gate insulating film a laminated structure of a high-k material and a thermally stable material, it is possible to reduce the gate potential during transistor operation while maintaining the physical film thickness. In addition, a laminated structure that is thermally stable and has a high relative dielectric constant can be obtained.

[0252] Although the conductor 560 functioning as the first gate electrode is shown as having a two-layer structure in FIGS. 14A and 14B, it may have a single-layer structure or a laminated structure of three or more layers.

[0253] The conductor 560a is preferably made of a conductive material having a function of suppressing the diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, nitrogen oxide molecules (N2O, NO, NO2, etc.), and copper atoms. Alternatively, it is preferably made of a conductive material having a function of suppressing the diffusion of oxygen (for example, at least one of oxygen atoms, oxygen molecules, etc.). When the conductor 560a has a function of suppressing the diffusion of oxygen, it is possible to suppress the conductor 560b from being oxidized by the oxygen contained in the insulator 550 and the conductivity from decreasing. As a conductive material having a function of suppressing the diffusion of oxygen, for example, tantalum, tantalum nitride, ruthenium, or ruthenium oxide is preferably used. In addition, an oxide semiconductor applicable to the oxide 530 can be used as the conductor 560a. In that case, the conductor 560b can be formed by a sputtering method to reduce the electrical resistance value of the conductor 560a and make it a conductor. This can be called an OC (Oxide Conductor) electrode.

[0254] The conductor 560b is preferably made of a conductive material containing tungsten, copper, or aluminum as a main component. Since the conductor 560b also functions as wiring, it is preferable to use a conductor having high conductivity. For example, a conductive material containing tungsten, copper, or aluminum as a main component can be used. The conductor 560b may have a layered structure, for example, a layered structure of titanium or titanium nitride and the above conductive material.

[0255] The insulator 580 is provided on the conductor 542a and the conductor 542b via the insulator 544. The insulator 580 preferably has an excess oxygen region. For example, the insulator 580 preferably has silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, silicon oxide to which fluorine has been added, silicon oxide to which carbon has been added, silicon oxide to which carbon and nitrogen have been added, silicon oxide having voids, or a resin. In particular, silicon oxide and silicon oxynitride are preferable because they are thermally stable. In particular, silicon oxide and silicon oxide having voids are preferable because they allow for easy formation of an excess oxygen region in a later step.

[0256] The insulator 580 preferably has an excess oxygen region. By providing the insulator 580, which releases oxygen when heated, in contact with the insulator 550, oxygen in the insulator 580 can be efficiently supplied to the oxide 530 through the insulator 550. Note that the concentration of impurities such as water or hydrogen in the insulator 580 is preferably reduced.

[0257] The opening of the insulator 580 is formed to overlap the region between the conductor 542a and the conductor 542b. As a result, the conductor 560 is formed so as to be embedded in the opening of the insulator 580 and the region sandwiched between the conductor 542a and the conductor 542b.

[0258] In miniaturizing a semiconductor device, it is necessary to shorten the gate length, but it is also necessary to prevent the conductivity of the conductor 560 from decreasing. If the film thickness of the conductor 560 is increased for that purpose, the conductor 560 may have a shape with a high aspect ratio. In this embodiment, the conductor 560 is provided so as to be embedded in the opening of the insulator 580, so that even if the conductor 560 has a shape with a high aspect ratio, the conductor 560 can be formed without collapsing during the process.

[0259] The insulator 574 is preferably provided in contact with a top surface of the insulator 580, a top surface of the conductor 560, and a top surface of the insulator 550. By forming the insulator 574 by a sputtering method, excess oxygen regions can be provided in the insulator 550 and the insulator 580. This allows oxygen to be supplied from the excess oxygen regions into the oxide 530.

[0260] For example, the insulator 574 can be a metal oxide containing one or more elements selected from hafnium, aluminum, gallium, yttrium, zirconium, tungsten, titanium, tantalum, nickel, germanium, magnesium, and the like.

[0261] In particular, aluminum oxide has high barrier properties and can suppress the diffusion of hydrogen and nitrogen even in a thin film of 0.5 nm to 3.0 nm. Therefore, aluminum oxide formed by sputtering can function as a barrier film against impurities such as hydrogen as well as an oxygen source.

[0262] An insulator 581 functioning as an interlayer film is preferably provided over the insulator 574. Like the insulator 524, the insulator 581 preferably has a reduced concentration of impurities such as water or hydrogen.

[0263] Furthermore, conductor 540a and conductor 540b are arranged in openings formed in insulator 581, insulator 574, insulator 580, and insulator 544. Conductor 540a and conductor 540b are provided facing each other with conductor 560 interposed therebetween. Conductor 540a and conductor 540b have the same configuration as conductor 546 and conductor 548 described later. Furthermore, as shown in FIG. 14A , an insulator functioning as a barrier film against impurities such as hydrogen may be provided between a sidewall of the opening and conductor 540a or conductor 540b.

[0264] An insulator 582 is provided over the insulator 581. The insulator 582 is preferably made of a substance that has a barrier property against oxygen and hydrogen. Therefore, the insulator 582 can be made of a material similar to that of the insulator 514. For example, the insulator 582 is preferably made of a metal oxide such as aluminum oxide, hafnium oxide, or tantalum oxide.

[0265] In particular, aluminum oxide has a high blocking effect of preventing the film from permeating both oxygen and impurities such as hydrogen and moisture, which are factors that cause fluctuations in the electrical characteristics of a transistor. Therefore, aluminum oxide can prevent impurities such as hydrogen and moisture from entering the transistor 500 during and after the transistor manufacturing process. In addition, aluminum oxide can suppress the release of oxygen from the oxide that constitutes the transistor 500. Therefore, aluminum oxide is suitable for use as a protective film for the transistor 500.

[0266] An insulator 586 is provided over the insulator 582. The insulator 586 can be formed using a material similar to that of the insulator 320. By using a material with a relatively low dielectric constant for these insulators, parasitic capacitance between wirings can be reduced. For example, a silicon oxide film, a silicon oxynitride film, or the like can be used as the insulator 586.

[0267] Furthermore, conductors 546, 548, etc. are embedded in insulators 522, 524, 544, 580, 574, 581, 582, and 586.

[0268] The conductor 546 and the conductor 548 function as a plug or a wiring connected to the capacitor 800, the transistor 500, or the transistor 300. The conductor 546 and the conductor 548 can be formed using a material similar to that of the conductor 328 and the conductor 330.

[0269] Next, a capacitor 800 is provided above the transistor 500. The capacitor 800 includes a conductor 810, a conductor 820, and an insulator 830.

[0270] A conductor 812 may be provided over the conductor 546 and the conductor 548. The conductor 812 functions as a plug or a wiring connected to the transistor 500. The conductor 810 functions as an electrode of the capacitor 800. Note that the conductor 812 and the conductor 810 can be formed at the same time.

[0271] A metal film containing an element selected from molybdenum, titanium, tantalum, tungsten, aluminum, copper, chromium, neodymium, and scandium, or a metal nitride film containing the above-mentioned element (tantalum nitride film, titanium nitride film, molybdenum nitride film, tungsten nitride film), etc. can be used for the conductor 812 and the conductor 810. Alternatively, a conductive material such as indium tin oxide, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium zinc oxide, or indium tin oxide with silicon oxide added can also be used.

[0272] 12, the conductor 812 and the conductor 810 have a single-layer structure, but are not limited to this structure and may have a stacked structure of two or more layers. For example, a conductor having barrier properties and a conductor having high adhesion to the conductor having high conductivity may be formed between a conductor having barrier properties and a conductor having high conductivity.

[0273] The conductor 820 is provided so as to overlap with the conductor 810 with the insulator 830 interposed therebetween. Note that the conductor 820 can be made of a conductive material such as a metal material, an alloy material, or a metal oxide material. It is preferable to use a high melting point material such as tungsten or molybdenum that has both heat resistance and conductivity, and it is particularly preferable to use tungsten. Furthermore, when the conductor 820 is formed simultaneously with other structures such as a conductor, a low resistance metal material such as Cu (copper) or Al (aluminum) may be used.

[0274] An insulator 840 is provided over the conductor 820 and the insulator 830. The insulator 840 can be provided using a material similar to that of the insulator 320. The insulator 840 may also function as a planarizing film that covers the uneven shape underneath.

[0275] By using this structure, in a semiconductor device including a transistor having an oxide semiconductor, a change in electrical characteristics can be suppressed and reliability can be improved. Also, miniaturization or high integration can be achieved in a memory device, an arithmetic device, or the like including a transistor having an oxide semiconductor.

[0276] [Metal oxides] Hereinafter, a metal oxide that can be used for a semiconductor layer (oxide 530) in which a channel of a transistor is formed will be described.

[0277] In this specification and the like, metal oxides containing nitrogen may also be collectively referred to as metal oxides. Metal oxides containing nitrogen may also be referred to as metal oxynitrides. For example, metal oxides containing nitrogen, such as zinc oxynitride (ZnON), may be used for the semiconductor layer.

[0278] In this specification, etc., the term CAAC (c-axis aligned crystal) and CAC (Cloud-Aligned Composite) may be used. CAAC represents an example of a crystal structure, and CAC represents an example of a function or material configuration.

[0279] For example, the semiconductor layer can be made of a cloud-aligned composite (CAC)-oxide semiconductor (OS).

[0280] CAC-OS or CAC-metal oxide has a conductive function in a part of the material and an insulating function in a part of the material, and has a function as a semiconductor as a whole. When CAC-OS or CAC-metal oxide is used in a semiconductor layer of a transistor, the conductive function is a function of flowing electrons (or holes) that become carriers, and the insulating function is a function of not flowing electrons that become carriers. By making the conductive function and the insulating function act complementarily, it is possible to impart a switching function (on / off function) to CAC-OS or CAC-metal oxide. By separating the respective functions in CAC-OS or CAC-metal oxide, it is possible to maximize both functions.

[0281] Moreover, the CAC-OS or CAC-metal oxide has a conductive region and an insulating region. The conductive region has the above-mentioned conductive function, and the insulating region has the above-mentioned insulating function. In addition, in the material, the conductive region and the insulating region may be separated at the nanoparticle level. In addition, the conductive region and the insulating region may be unevenly distributed in the material. In addition, the conductive region may be observed to be connected in a cloud shape with a blurred periphery.

[0282] In addition, in the CAC-OS or CAC-metal oxide, the conductive regions and the insulating regions may each be dispersed in the material with a size of 0.5 nm to 10 nm, preferably 0.5 nm to 3 nm.

[0283] In addition, the CAC-OS or CAC-metal oxide is composed of components having different band gaps. For example, the CAC-OS or CAC-metal oxide is composed of a component having a wide gap due to an insulating region and a component having a narrow gap due to a conductive region. In this configuration, when carriers are caused to flow, the carriers mainly flow in the component having the narrow gap. In addition, the component having the narrow gap acts complementarily on the component having the wide gap, and carriers also flow in the component having the wide gap in conjunction with the component having the narrow gap. Therefore, when the above CAC-OS or CAC-metal oxide is used in the channel formation region of a transistor, a high current driving force in the on state of the transistor, that is, a large on-current and a high field effect mobility can be obtained.

[0284] That is, CAC-OS or CAC-metal oxide can also be called a matrix composite or a metal matrix composite.

[0285] Oxide semiconductors (metal oxides) are classified into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors, such as c-axis aligned crystalline oxide semiconductors (CAAC-OS), polycrystalline oxide semiconductors, nanocrystalline oxide semiconductors (nc-OS), amorphous-like oxide semiconductors (a-like OS), and amorphous oxide semiconductors.

[0286] CAAC-OS has a c-axis orientation and a distorted crystal structure in which multiple nanocrystals are connected in the ab-plane direction. The distortion refers to a portion where the lattice orientation changes between a region with a uniform lattice arrangement and a region with a different uniform lattice arrangement in the region where multiple nanocrystals are connected.

[0287] Nanocrystals are basically hexagonal, but may be non-regular hexagonal. In addition, the lattice arrangement may be pentagonal or heptagonal due to the distortion. In CAAC-OS, it is difficult to confirm clear grain boundaries even in the vicinity of the distortion. In other words, it is found that the formation of grain boundaries is suppressed by the distortion of the lattice arrangement. This is because CAAC-OS can tolerate distortion due to the fact that the arrangement of oxygen atoms in the ab-plane direction is not dense and the bond distance between atoms changes due to the substitution of metal elements.

[0288] CAAC-OS also tends to have a layered crystal structure (also referred to as a layered structure) in which a layer containing indium and oxygen (hereinafter, In layer) and a layer containing element M, zinc, and oxygen (hereinafter, (M, Zn) layer) are stacked. Note that indium and element M can be substituted for each other, and when element M in an (M, Zn) layer is substituted for indium, it can also be represented as an (In, M, Zn) layer. When indium in an In layer is substituted for element M, it can also be represented as an (In, M) layer.

[0289] CAAC-OS is a metal oxide with high crystallinity. On the other hand, it is difficult to confirm clear crystal boundaries in CAAC-OS, so it is said that the decrease in electron mobility caused by crystal boundaries is unlikely to occur. In addition, since the crystallinity of metal oxides can be decreased by the inclusion of impurities or the generation of defects, CAAC-OS is unlikely to have impurities or defects (oxygen vacancies (V O : It is also called oxygen vacancy. ) Therefore, metal oxides with CAAC-OS have stable physical properties. Therefore, metal oxides with CAAC-OS are resistant to heat and highly reliable.

[0290] The nc-OS has periodic atomic arrangement in a microscopic region (for example, a region of 1 nm to 10 nm, particularly a region of 1 nm to 3 nm). In addition, the nc-OS does not show regularity in the crystal orientation between different nanocrystals. Therefore, no orientation is seen throughout the film. Therefore, depending on the analysis method, the nc-OS may be indistinguishable from an a-like OS or an amorphous oxide semiconductor.

[0291] Indium-gallium-zinc oxide (hereinafter referred to as IGZO), a type of metal oxide containing indium, gallium, and zinc, may have a stable structure when made into the above-mentioned nanocrystals. In particular, since IGZO tends to have difficulty in crystal growth in the atmosphere, it may be structurally more stable when made into small crystals (for example, the above-mentioned nanocrystals) rather than large crystals (here, crystals of several mm or several cm).

[0292] The a-like OS is a metal oxide having a structure between the nc-OS and an amorphous oxide semiconductor. The a-like OS has a pore or low-density region. That is, the a-like OS has lower crystallinity than the nc-OS and CAAC-OS.

[0293] Oxide semiconductors (metal oxides) have a variety of structures and each structure has different characteristics. The oxide semiconductor of one embodiment of the present invention may include two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, an a-like OS, an nc-OS, and a CAAC-OS.

[0294] The metal oxide film functioning as the semiconductor layer can be formed using either one or both of an inert gas and an oxygen gas. The flow rate ratio of oxygen (oxygen partial pressure) during the formation of the metal oxide film is not particularly limited. However, in order to obtain a transistor with high field effect mobility, the flow rate ratio of oxygen (oxygen partial pressure) during the formation of the metal oxide film is preferably 0% or more and 30% or less, more preferably 5% or more and 30% or less, and even more preferably 7% or more and 15% or less.

[0295] The energy gap of the metal oxide is preferably 2 eV or more, more preferably 2.5 eV or more, and further preferably 3 eV or more. By using a metal oxide having such a wide energy gap, the off-state current of the transistor can be reduced.

[0296] The substrate temperature during deposition of the metal oxide film is preferably 350° C. or lower, more preferably room temperature or higher and 200° C. or lower, and further preferably room temperature or higher and 130° C. or lower. When the substrate temperature during deposition of the metal oxide film is room temperature, productivity can be increased, which is preferable.

[0297] The metal oxide film can be formed by a sputtering method, or by other methods such as PLD, PECVD, thermal CVD, ALD, and vacuum deposition.

[0298] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification. [Explanation of symbols]

[0299] R1, R2, G1, G2, B1, B2: display elements, S0, S1, S2: image signals, 10, 10a: composite device, 11: display device, 12, 12a: sensor device, 13: information processing device, 21: control unit, 22: display unit, 23: imaging unit, 24: lens, 25: communication unit, 25a: recovery operation, 25b: processing operation, 25c: pause operation, 26: image generation unit, 27: signal, 31: sensor unit, 32: communication unit, 33: signal, 33a: pulse signal, 33b: signal, 34: display unit, 40: user, 41: eyeball, 42: arm, 43: finger, 44: upper arm, 45: clothing, 50a, 50b, 50c: image, 51a, 51b, 51c: image information

Claims

[Claim 1] A sensor device and a display device, The sensor device has a first communication unit and a sensor unit, and is attachable to an eyeball of a human body; The display device includes a display unit, a control unit, and an imaging unit. The control unit has a second communication unit, the first communication unit has a function of transmitting a signal including information acquired by the sensor unit; the second communication unit has a function of receiving the signal, The control unit has a function of returning from a sleep state in response to the signal, the control unit has a function of generating first image data based on the information and outputting the first image data to the display unit; the control unit has a function of generating the first image data based on the information included in the signal and second image data input from the imaging unit, and outputting the first image data to the display unit; the display unit includes a first transistor, a second transistor, a capacitor, and a light-emitting element; one of a source and a drain of the first transistor is electrically connected to a gate of the second transistor; one of a source and a drain of the first transistor is electrically connected to one electrode of the capacitance element; one of a source and a drain of the second transistor is electrically connected to one electrode of the light-emitting element; the other of the source and drain of the second transistor is electrically connected to the other electrode of the capacitive element.

Images