Display device

Abstract

To provide a display element in which the capacitance generated between transistors does not affect the burning phenomenon of a display image.SOLUTION: A display element includes a light emission unit of a current driving type and a driving unit for driving a light emission unit. The driving unit includes a capacitance unit, a driving transistor for flowing a current according to a voltage held by the capacitance unit into the light emission unit, and a writing transistor for writing a signal voltage into the capacitance unit. The driving transistor and the writing transistor are formed in a semiconductor substrate while being separated by an element separation region. The capacitance generated in a part where the driving transistor and the writing transistor face each other across the element separation region functions at least a part of the capacitance unit.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a display element, a display device, and an electronic device, and more specifically, to a display element used in an ultra-small display that requires a pixel pitch on the order of micrometers, a display device including such a display element, and an electronic device including such a display device. [Background technology]

[0002] Display elements having a current-driven light-emitting portion and display devices having such display elements are well known. For example, display elements having a light-emitting portion made of an organic electroluminescence element have attracted attention as display elements capable of emitting high-luminance light by low-voltage direct current driving. Display devices having organic electroluminescence elements are used not only in direct-view displays but also in ultra-compact displays that require pixel pitches in the order of micrometers.

[0003] In order to realize a pixel pitch in the order of micrometers, a driving section for driving a current-driven light-emitting section is formed on a semiconductor substrate (see, for example, Patent Document 1). The driving section is composed of a plurality of transistors and the like. Therefore, in order to isolate adjacent transistors, an element isolation region is required between the transistors. For such applications, the so-called STI (Shallow Trench Isolation) method is suitable, since it can form element isolation regions finer than the LOCOS (Local Oxidation of Silicon) method. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-98779 A Summary of the Invention [Problem to be solved by the invention]

[0005] As pixel pitch becomes finer, the distance between transistors facing each other across the element isolation region becomes narrower. As a result, the capacitance between the transistors facing each other across the element isolation region increases. It is thought that the effect of this capacitance accentuates the burn-in phenomenon of the displayed image caused by the deterioration of the light-emitting area over time.

[0006] Therefore, an object of the present disclosure is to provide a display element in which capacitance generated between transistors does not accentuate the burn-in phenomenon of a displayed image, a display device including such a display element, and an electronic device including such a display device. [Means for solving the problem]

[0007] In order to achieve the above object, a display element according to a first aspect of the present disclosure comprises: The device includes a current-driven light-emitting unit and a drive unit for driving the light-emitting unit, the drive unit includes a capacitance unit, a drive transistor that causes a current corresponding to a voltage held by the capacitance unit to flow to the light-emitting unit, and a write transistor that writes a signal voltage to the capacitance unit; the drive transistor and the write transistor are formed on a semiconductor substrate and are separated by an element isolation region; a capacitance generated in a portion where the drive transistor and the write transistor face each other via an element isolation region functions as at least a part of a capacitance section; It is a display element.

[0008] In order to achieve the above object, a display device according to a first aspect of the present disclosure includes: A display device having display elements arranged in a two-dimensional matrix, The display element includes a current-driven light-emitting unit and a drive unit for driving the light-emitting unit. the drive unit includes a capacitance unit, a drive transistor that causes a current corresponding to a voltage held by the capacitance unit to flow to the light-emitting unit, and a write transistor that writes a signal voltage to the capacitance unit; the drive transistor and the write transistor are formed on a semiconductor substrate and are separated by an element isolation region; a capacitance generated in a portion where the drive transistor and the write transistor face each other via an element isolation region functions as at least a part of a capacitance section; It is a display device.

[0009] In order to achieve the above object, an electronic device according to a first aspect of the present disclosure includes: An electronic device equipped with a display device having display elements arranged in a two-dimensional matrix, The display element includes a current-driven light-emitting unit and a drive unit for driving the light-emitting unit. the drive unit includes a capacitance unit, a drive transistor that causes a current corresponding to a voltage held by the capacitance unit to flow to the light-emitting unit, and a write transistor that writes a signal voltage to the capacitance unit; the drive transistor and the write transistor are formed on a semiconductor substrate and are separated by an element isolation region; a capacitance generated in a portion where the drive transistor and the write transistor face each other via an element isolation region functions as at least a part of a capacitance section; It is an electronic device. Effect of the Invention

[0010] In the display element of the present disclosure, the driving section includes a driving transistor that passes a current corresponding to the voltage held by the capacitance section to the light-emitting section, and a writing transistor that writes a signal voltage to the capacitance section. The capacitance generated at the portion where the driving transistor and the writing transistor face each other via the element isolation region functions as at least a part of the capacitance section. This makes it possible to prevent the burn-in phenomenon caused by the effect of the change over time in the voltage-current characteristic (VI) of the current-driven light-emitting section from being accentuated by the effect of the capacitance. The effects described in the present disclosure are merely examples and are not limited thereto, and additional effects may also be present. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a conceptual diagram of a display device according to a first embodiment. [Diagram 2] FIG. 2 is an equivalent circuit diagram of a display element including a light-emitting section and a driver for driving the light-emitting section. [Diagram 3] FIG. 3 is a schematic partial cross-sectional view of a portion including a display element in the display region. [Figure 4] FIG. 4 is a schematic plan view for explaining the arrangement of transistors in a driving section according to the first embodiment. [Diagram 5] FIG. 5 is a schematic cross-sectional view for explaining a cross-sectional structure of a transistor in a driving section according to the first embodiment. [Figure 6] FIG. 6 is a schematic plan view for explaining the arrangement of transistors in a driving section of a reference example. [Figure 7] FIG. 7 is a schematic cross-sectional view for explaining a cross-sectional structure of a transistor in a driving portion of a reference example. [Figure 8] FIG. 8 is a conceptual diagram of a display device provided with a display element including a drive section of a reference example. [Figure 9] Fig. 9A is a schematic diagram for explaining the relationship between the current flowing through a light-emitting section made of an organic electroluminescence element and the voltage between the anode electrode and the cathode electrode of the light-emitting section, and Fig. 9B is a schematic graph for explaining the change over time in the voltage-current characteristic (VI) of the light-emitting section. [Figure 10] Fig. 10A is a schematic circuit diagram for explaining a drain current that flows when a display element including a drive unit of a reference example emits light, and Fig. 10B is a schematic graph for explaining the operation of a display element including a drive unit of a reference example. [Figure 11] FIG. 11 is an equivalent circuit diagram of the display element in the first embodiment. [Figure 12] FIG. 12 is a schematic plan view for explaining shield wiring in a driving section of a reference example. [Figure 13] FIG. 13 is a schematic plan view for explaining shield wiring in the driving section according to the first embodiment. [Figure 14] FIG. 14 is a schematic cross-sectional view for explaining a cross-sectional structure of a transistor according to a first modification of the first embodiment. As shown in FIG. [Figure 15] FIG. 15 is a conceptual diagram of a display device according to the second embodiment. [Figure 16] FIG. 16 is a schematic plan view for explaining the arrangement of transistors in a driving section according to the second embodiment. [Figure 17] FIG. 17 is a conceptual diagram of a display device according to the third embodiment. [Figure 18] FIG. 18 is a schematic plan view for explaining the arrangement of transistors in a driving section according to the third embodiment. [Figure 19] FIG. 19 is a diagram showing the appearance of a lens-interchangeable single-lens reflex type digital still camera, with FIG. 19A showing a front view and FIG. 19B showing a rear view. [Figure 20] FIG. 20 is an external view of the head mounted display. [Figure 21] FIG. 21 is an external view of a see-through head mounted display. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the present disclosure will be described based on the embodiments with reference to the drawings. The present disclosure is not limited to the embodiments, and various numerical values ​​and materials in the embodiments are examples. In the following description, the same elements or elements having the same functions will be designated by the same reference numerals, and duplicated descriptions will be omitted. The description will be given in the following order. 1. General Description of Display Element, Display Device, and Electronic Device According to the Present Disclosure 2. First embodiment 3. Second embodiment 4. Third embodiment 5. Description of electronic devices, etc.

[0013] [General Description of Display Element, Display Device, and Electronic Device According to the Present Disclosure] As described above, the display element according to the first embodiment of the present disclosure, and the display element used in the display device according to the first embodiment of the present disclosure and the electronic device according to the first embodiment of the present disclosure (hereinafter, these may be simply referred to as the "display element of the present disclosure"), The device includes a current-driven light-emitting unit and a drive unit for driving the light-emitting unit, the drive unit includes a capacitance unit, a drive transistor that causes a current corresponding to a voltage held by the capacitance unit to flow to the light-emitting unit, and a write transistor that writes a signal voltage to the capacitance unit; the drive transistor and the write transistor are formed on a semiconductor substrate and are separated by an element isolation region; A capacitance generated in a portion where the drive transistor and the write transistor face each other via an element isolation region functions as at least a part of a capacitance section.

[0014] In the display element of the present disclosure, The drive transistor and the write transistor are provided in a well formed in a semiconductor substrate, the driving transistor has one source / drain region connected to a power supply line and the other source / drain region connected to one of the light emitting sections; the write transistor has one source / drain region to which a signal voltage is externally supplied and the other source / drain region connected to a gate electrode of the drive transistor; the other source / drain region of the write transistor and one source / drain region of the drive transistor are formed to face each other via an element isolation region; It can be configured as follows.

[0015] In the display element of the present disclosure, which includes the various preferred configurations described above, the element isolation region can be formed by an STI (Shallow Trench Isolation) structure in which an insulator is embedded in a trench dug in the surface of a semiconductor substrate.

[0016] In this case, the impurity diffusion layer forming the source / drain region of the drive transistor and the impurity diffusion layer forming the source / drain region of the write transistor are set to have a junction depth of 1 micrometer or more; It can be configured as follows.

[0017] In the display element of the present disclosure including the various preferred configurations described above, the driving transistor may be a p-channel type field effect transistor. In this case, the writing transistor may be an n-channel type or a p-channel type. From the viewpoint of commonality of the manufacturing process, it is preferable that the conductivity type of the writing transistor is the same as that of the driving transistor, that is, a p-channel type field effect transistor.

[0018] In the display element of the present disclosure including the various preferred configurations described above, a shield wiring may be provided around the gate wiring for connecting the other source / drain region of the writing transistor to the gate electrode of the driving transistor. In this case, the shield wiring may be connected to a power supply line.

[0019] In the display element of the present disclosure including the various preferred configurations described above, the driving section may further include another transistor. The driving section may further include a switching transistor connected between a power supply line and one of the source / drain regions of the driving transistor, or the driving section may further include a switching transistor connected between one end of the light-emitting section and the other of the source / drain regions of the driving transistor. As the current-driven light-emitting portion constituting the display element of the present disclosure including the various preferred configurations described above, an organic electroluminescence element, an LED element, a semiconductor laser element, etc. can be used. These elements can be constructed using well-known materials and methods. From the viewpoint of constructing a flat display device, it is particularly preferable that the light-emitting portion is constructed from an organic electroluminescence element.

[0020] Hereinafter, the display element, the display device, and the electronic device according to the present disclosure may be simply referred to as the present disclosure.

[0021] The source driver and the like that drive the display device may be integrated and configured as one unit on the semiconductor substrate on which the display elements are arranged, or may be configured as separate units as appropriate. These may be configured using well-known circuit elements. For example, the source driver, power supply unit, and vertical scanner shown in FIG. 1 may also be configured using well-known circuit elements. In applications requiring miniaturization, such as display devices for head-mounted displays and viewfinders, it is preferable to configure the display elements and the driver on the same semiconductor substrate.

[0022] The display device may have a so-called monochrome display configuration, or may have a color display configuration. In the case of a color display configuration, one pixel may be configured to be composed of a plurality of sub-pixels, specifically, one pixel may be configured to be composed of a set of a red display element, a green display element, and a blue display element. Furthermore, one or more types of display elements may be added to these three types of display elements to form a set.

[0023] Examples of pixel values ​​of the display device include U-XGA (1600, 1200), HD-TV (1920, 1080), Q-XGA (2048, 1536), as well as (3840, 2160) and (7680, 4320), and other image display resolutions, but are not limited to these values.

[0024] The various conditions in this specification are satisfied not only when they are strictly mathematically satisfied, but also when they are substantially satisfied. The existence of various variations occurring in design or manufacturing is permitted. In addition, the drawings used in the following description are schematic and do not show actual dimensions or their ratios. For example, FIG. 3 described later shows a cross-sectional structure of a display device, but does not show the ratios of width, height, thickness, etc. In addition, the waveform shapes in the timing chart shown in FIG. 10 are also schematic.

[0025] [First embodiment] The first embodiment relates to a display element, a display device, and an electronic device according to a first aspect of the present disclosure.

[0026] FIG. 1 is a conceptual diagram of a display device according to a first embodiment.

[0027] First, an overview of the display device will be described with reference to Fig. 1. The display device 1 has display elements 70 arranged in a two-dimensional matrix. More specifically, each display element 70 is arranged in a two-dimensional matrix of N elements in the row direction and M elements in the column direction, totaling N x M elements, in a state where each display element 70 is connected to a scanning line WS1 and a power supply line (current supply line) PS1 extending in the row direction (X direction in Fig. 1) and a data line DTL extending in the column direction (Y direction in Fig. 1).

[0028] A display area 80 for displaying an image is formed by the display elements 70 arranged in a two-dimensional matrix. The number of rows of the display elements 70 in the display area 80 is M, and the number of display elements 70 constituting each row is N.

[0029] The number of scanning lines WS1 and the number of power supply lines PS1 are each M. The display element 70 in the m-th row (where m=1, 2, . . . , M) has the m-th scanning line WS1 m and the m-th power supply line PS1 m and form one display element row.

[0030] The number of control lines DS1 shown in FIG. 15 and the number of control lines EM1 shown in FIG. 17 are also M, and the mth control line DS1 is connected to the display element in the mth row. m and control line EM1 m is connected.

[0031] The number of data lines DTL is N. The display element 70 in the nth column (where n=1, 2, . . . , N) has the nth data line DTL n is connected to

[0032] 1, the display device 1 includes a common power supply line PS2 commonly connected to all of the display elements 70. A common voltage, for example, a ground potential, is constantly supplied to the common power supply line PS2.

[0033] The display device 1 includes a source driver 110 for driving a display area 80, a power supply unit 120, and a vertical scanner .

[0034] The display region 80 is formed on a semiconductor substrate made of silicon. The source driver 110, the power supply unit 120, and the vertical scanner 130 are also formed on the semiconductor substrate 100. In other words, the display device 1 is a display device integrated with a driver circuit.

[0035] The source driver 110 receives a signal LD ​​representing a gray scale corresponding to an image to be displayed from, for example, a device not shown. Sig The signal LD ​​is input. Sig is, for example, a low-voltage digital signal. Sig The analog signal generated corresponds to the gray scale value of the pixel and is supplied to the data line DTL as a video signal. The analog signal generated has a peak value of, for example, about 10 volts.

[0036] The vertical scanner 130 supplies a scanning signal to the scanning line WS1. The scanning signal causes line-sequential scanning on a row-by-row basis of the display element 70. In response to the scanning of the scanning line WS1, the power supply unit 120 supplies a predetermined driving voltage to the power supply line PS1.

[0037] The display device 1 is, for example, a color display device, and a group of three display elements 70 arranged in a row direction constitutes one pixel. Therefore, if N'=N / 3, then the display area 80 has N' pixels arranged in the row direction and M pixels arranged in the column direction, for a total of N'×M pixels.

[0038] As described above, the display elements 70 are line-sequentially scanned row by row by the scanning signal of the vertical scanner 130. The display element 70 located in the m-th row and n-th column will be referred to as the (n, m)-th display element 70 hereinafter.

[0039] In the display device 1, N display elements 70 arranged in the m-th row are driven simultaneously. In other words, the timing of emission / non-emission of the N display elements 70 arranged along the row direction is controlled for each row to which they belong. If the display frame rate of the display device 1 is represented as FR (times / second), the scanning period per row (so-called horizontal scanning period) when the display device 1 is line-sequentially scanned row by row is less than (1 / FR)×(1 / M) seconds.

[0040] The above has described the outline of the display device 1. Next, the display element 70 will be described in detail.

[0041] Fig. 2 is an equivalent circuit diagram of a display element including a light-emitting section and a drive section for driving the light-emitting section. For convenience of illustration, Fig. 2 shows the wiring relationship for one display element 70, more specifically, the (n, m)th display element 70.

[0042] The display element 70 includes a current-driven light-emitting unit ELP and a driving unit 71 for driving the light-emitting unit ELP. S , capacitance part C SA driving transistor TR that passes a current to the light-emitting section ELP according to the voltage held by D , and the signal voltage is applied to the capacitance section C S A write transistor TR for writing to W It is equipped with:

[0043] The light-emitting unit ELP is a current-driven light-emitting unit whose light-emitting luminance changes according to the value of the current flowing through it, and is specifically composed of an organic electroluminescence element. The light-emitting unit ELP has a well-known configuration and structure consisting of an anode electrode, a hole transport layer, a light-emitting layer, an electron transport layer, a cathode electrode, etc.

[0044] Drive transistor TR D The write transistor TR W The write transistor TR W may be an n-channel field effect transistor.

[0045] Capacity part C S is the driving transistor TR D The gate electrode of the driving transistor TR is used to hold a voltage (so-called gate-source voltage) relative to the source region of the driving transistor TR. D One of the source / drain regions (the side connected to the power supply line PS1 in FIG. 2) serves as a source region, and the other source / drain region serves as a drain region. S The first and second electrodes constituting the driving transistor TR D The driving transistor TR is connected to one of the source / drain regions and the gate electrode. D The other source / drain region is connected to the anode electrode of the light emitting portion ELP.

[0046] Write transistor TR W The gate electrode is connected to the scanning line WS1, one of the source / drain regions is connected to the data line DTL, and the driving transistor TR DThe other source / drain region is connected to the gate electrode of the first gate electrode.

[0047] The other end of the light emitting portion ELP (specifically, the cathode electrode) is connected to a common power supply line PS2. A predetermined voltage V Cath The capacitance of the light-emitting unit ELP is represented by the symbol C EL The capacitance of the light emitting part ELP is C EL In cases where the capacitance is too small to drive the display element 70, an auxiliary capacitance may be provided that is connected in parallel to the light emitting section ELP as necessary.

[0048] In a state where a voltage corresponding to the luminance of an image to be displayed is supplied from the source driver 110 to the data line DTL, the write transistor TR W When the capacitor C S A voltage corresponding to the grayscale value of the image to be displayed is written to the write transistor TR W is put into a non-conducting state, and the capacitive section C S The drive transistor TR D A current flows through the light emitting portion ELP, causing the light emitting portion ELP to emit light.

[0049] Here, the driving transistor TR D In the light-emitting state of the light-emitting section ELP, the drain current I ds In the light-emitting state of the light-emitting section ELP, the driving transistor TR D One of the source / drain regions serves as a source region, and the other serves as a drain region. μ : Effective mobility L: Channel length W: Channel width V CC : Drive voltage supplied to the source region V Sig : Signal voltage applied to the gate electrode V th : Threshold voltage C ox: (dielectric constant of gate insulating layer) × (dielectric constant of vacuum) / (thickness of gate insulating layer) k ≡ (1 / 2) (W / L) C ox Let us assume that.

[0050] I ds =k μ ((V CC -V Sig )-|V th |) 2 (1)

[0051] Here, a description will be given of the three-dimensional arrangement of the light emitting portion ELP, the transistors, etc. Fig. 3 is a schematic partial cross-sectional view of a portion including a display element in the display region.

[0052] Each transistor constituting the display element 70 is formed on a semiconductor substrate (indicated by reference numeral 100 in FIG. 1) that is formed by forming a semiconductor layer 20 made of silicon on a base material 10. More specifically, the driving transistor TR D and the write transistor TR W The driving transistor TR is provided in an n-type well 21 formed in the semiconductor layer 20. For convenience of illustration, the driving transistor TR D Only the driving transistors TR D 1 shows a pair of source / drain regions of the MOSFET.

[0053] Each transistor is surrounded by an element isolation region 22. Reference numeral 32 denotes a transistor TR D The gate electrode of the driving transistor TR is denoted by reference numeral 31, and the gate insulating layer is denoted by reference numeral 32. As will be described later with reference to FIG. D and the write transistor TR W is formed on a semiconductor substrate in a state of being isolated by an element isolation region 22. For convenience of illustration, the gate electrode is represented by the reference symbol 31 in Figures 4, 5, 6, 7, 12, 13, 14, 16, and 18 described below, regardless of the type of transistor.

[0054] Capacity part C SThe other electrode 32' constituting the driving transistor TR is made of the same material layer as the gate electrode 32, and is formed on an insulating layer 31' made of the same material layer as the gate insulating layer 31. D An interlayer insulating layer 33 is formed on the entire surface of the semiconductor layer 20 including the gate electrode 32 and the electrode 32'. The electrode 32' and an electrode 34 described below are disposed to face each other with the interlayer insulating layer 33 interposed therebetween.

[0055] Drive transistor TR D One of the source / drain regions 23A is connected to the power supply line PS1 and the electrode 34 through a contact hole 35 provided in the interlayer insulating layer 33. The connection portion is hidden and cannot be seen in Fig. 3. An interlayer insulating layer 40 is further formed on the interlayer insulating layer 33.

[0056] On the interlayer insulating layer 40, a light emitting section ELP is provided, which is composed of an anode electrode 51, a hole transport layer, a light emitting layer, an electron transport layer, and a cathode electrode 53. In the drawing, the hole transport layer, the light emitting layer, and the electron transport layer are represented as one layer 52. On a portion of the interlayer insulating layer 40 on which the light emitting section ELP is not provided, a second interlayer insulating layer 54 is provided, and a transparent substrate 60 is disposed on the second interlayer insulating layer 54 and the cathode electrode 53. Light emitted from the light emitting layer passes through the substrate 60 and is emitted to the outside.

[0057] Anode electrode 51 and driving transistor TR D The other source / drain region 23B is connected via a contact hole 36 or the like provided in the interlayer insulating layer 33. Note that in FIG.

[0058] The cathode electrode 53 is connected to the wiring 37 (voltage V Cath The common power supply line PS2 is connected to the power supply line PS1.

[0059] Above, we have explained the three-dimensional arrangement of the light emitting unit ELP, the transistors, etc. Next, we will explain the arrangement of the transistors in the driving unit according to the first embodiment.

[0060] Fig. 4 is a schematic plan view for explaining the arrangement of transistors in the driving section according to the first embodiment. Fig. 5 is a schematic cross-sectional view for explaining the cross-sectional structure of the transistors in the driving section according to the first embodiment.

[0061] As shown in FIG. 4 and FIG. 5, a driving transistor TR D and the write transistor TR W The write transistor TR is formed on a semiconductor substrate in a state where it is isolated by an element isolation region 22. W The other source / drain region 23D and the driving transistor TR D One of the source / drain regions 23A is formed to face the other via an element isolation region 22. The element isolation region 22 is formed by an STI (Shallow Trench Isolation) structure in which an insulator is buried in a trench dug in the surface of a semiconductor substrate.

[0062] As explained earlier, the drive transistor TR D The write transistor TR has one source / drain region 23A to which the power supply line PS1 is connected and the other source / drain region 23B to which one of the light emitting parts ELP is connected. W The source / drain region 23C is connected to a driving transistor TR. D and the other source / drain region 23D connected to the gate electrode of the first source / drain region 23B.

[0063] As pixel pitches become finer, the write transistor TR W The other source / drain region 23D and the driving transistor TR D The distance between the terminals of the other source / drain region 23A is narrowed. As a result, the capacitance (parasitic capacitance) (symbol CS1 ) increases.

[0064] However, in the driving section 71 of the present disclosure, the driving transistor TR D and the write transistor TR W The capacitance generated in the portion where the transistors face each other via the element isolation region 22 functions as at least a part of the capacitance portion. As will be described in detail later with reference to Fig. 11, in this configuration, the capacitance generated between the transistors does not accentuate the burn-in phenomenon of the displayed image.

[0065] Next, in order to facilitate understanding of the present disclosure, a description will be given of the arrangement of transistors in a driving section of a reference example in which the burn-in phenomenon is accentuated by capacitance occurring between transistors, and the problems associated with this arrangement.

[0066] Fig. 6 is a schematic plan view for explaining the arrangement of transistors in a driving section of a reference example, and Fig. 7 is a schematic cross-sectional view for explaining a cross-sectional structure of a transistor in a driving section of a reference example.

[0067] As is clear from a comparison between FIG. 4 and FIG. 6, in the driving section of the reference example (indicated by reference numeral 971 in FIG. 8 described later), a driving transistor TR D The connection relationship between the pair of source / drain regions 23A, 23B, the power supply line PS1, and the light emitting section ELP is the opposite to that in the driving section 71 of the first embodiment.

[0068] In this connection, the driving transistor TR D and the write transistor TR W A capacitance is generated in the portion where the elements face each other via the element isolation region 22. This capacitance is denoted by the symbol C GA It is expressed as:

[0069] Fig. 8 is a conceptual diagram of a display device including a display element including a drive unit of a reference example. For convenience of illustration, Fig. 8 shows the wiring relationship of one display element 970 in the display device 9, more specifically, the (n, m)th display element 970.

[0070] As shown in FIG. 8, in a display element 970 including a driving unit 971 of the reference example, a capacitance C GA is the driving transistor TR D The gate electrode of the light emitting portion ELP is connected to the anode electrode of the light emitting portion ELP, and the gate electrode of the light emitting portion ELP functions as a capacitance connected between the gate electrode of the light emitting portion ELP and the anode electrode of the light emitting portion ELP. As will be described below, in this case, the change in luminance due to the change over time in the voltage-current characteristic (VI) of the light emitting portion ELP is more emphasized.

[0071] Fig. 9A is a schematic diagram for explaining the relationship between the current flowing through a light-emitting section made of an organic electroluminescence element and the voltage between the anode electrode and the cathode electrode of the light-emitting section, and Fig. 9B is a schematic graph for explaining the change over time in the voltage-current characteristic (VI) of the light-emitting section.

[0072] In general, the luminance of the light-emitting section ELP made of an organic electroluminescence element is proportional to the current flowing therethrough. Therefore, basically, the current I OLED If the voltage V between the terminals (anode electrode and cathode electrode) of the light-emitting part ELP is the same, the brightness of the light-emitting part ELP is also the same. OLED shows a tendency to gradually increase with time. Therefore, as shown in Fig. 9B, the voltage-current characteristic (VI) of the light emitting part ELP changes from the initial state with time.

[0073] As explained above, the current I OLED If the voltage V between the terminals of the light-emitting part ELP is the same, the brightness of the light-emitting part ELP will basically be the same. However, due to changes over time, OLED Therefore, the current I OLED The voltage between the terminals of the light-emitting part ELP in the initial state corresponding to V OLED_INI Then, the voltage between the terminals of the light-emitting part ELP after aging is V OLED_INI +V CWT It can be expressed as:

[0074] In the driving unit 971 of the reference example, the above-mentioned voltage V CWTDue to the influence of D The gate voltage of the display changes, and the burn-in phenomenon is emphasized. This will be described below with reference to FIG.

[0075] Fig. 10A is a schematic circuit diagram for explaining a drain current that flows when a display element including a drive unit of a reference example emits light, and Fig. 10B is a schematic graph for explaining the operation of a display element including a drive unit of a reference example.

[0076] As shown in FIG. 10B, the write transistor TR W becomes conductive and then becomes non-conductive.

[0077] Write transistor TR W When the data line DTL is in a conductive state, the driving transistor TR D A signal voltage V Sig is written. The driving transistor TR D The gate-source voltage of (V CC -V Sig After the write operation is completed, the write transistor TR W This causes the driving transistor TR D The gate electrode is in a floating state.

[0078] By writing a signal voltage, the drain current I ds flows to the light-emitting section ELP, and the anode voltage V of the light-emitting section ELP ANODE The voltage V when the light emitting part ELP is in the initial state also rises. ANODE The increase in A_INI If we express it as such, the increase in the light-emitting part ELP after aging is (V A_INI +V CWT ) can be expressed as

[0079] As described above, after the writing is completed, the driving transistor TR D The gate electrode of the capacitor CGA The change in the anode voltage is transmitted to the driving transistor TR D The gate electrode of the semiconductor device is extended.

[0080] When the light-emitting section ELP is in the initial state, the driving transistor TR D The change in the gate electrode is V A_INI C GA / (C S +C GA ) This is expressed as: Moreover, the drain current after the gate voltage change is I ds =k μ ((V CC -(V Sig +V A_INI C GA / (C S +C GA ))-|V th |) 2 This is expressed as:

[0081] On the other hand, when the light emitting section ELP has changed over time, the driving transistor TR D The change in the gate electrode is (V A_INI +V CWT )·C GA / (C S +C GA ) This is expressed as: Moreover, the drain current after the gate voltage change is I ds =k μ ((V CC -(V Sig +(V A_INI +V CWT )·C GA / (C S +C GA ))-|V th |) 2 This is expressed as:

[0082] Therefore, when comparing the initial state and the change over time, the change in the gate voltage due to capacitive coupling is V CWT CGA / (C S +C GA ) As a result, a difference also occurs in the drain current. Qualitatively, a change occurs in which the drain current decreases due to the change over time. This causes a further decrease in the current flowing through the light-emitting part ELP after the change over time, giving rise to a problem in which the burn-in phenomenon of the displayed image due to the change over time in the light-emitting part ELP is emphasized.

[0083] This phenomenon also occurs when the capacitance C GA The larger it is, the more pronounced it becomes.

[0084] The arrangement of transistors in the driving section 971 of the reference example and the problems associated with it have been described above.

[0085] In the driving section 71 according to the first embodiment, the driving transistor TR D and the write transistor TR W The capacitance generated at the portion where the gate electrode and the gate insulating film face each other via the element isolation region 22 functions as at least a part of the capacitance portion. This makes it difficult for the gate voltage to change due to capacitive coupling to occur.

[0086] In the driving section 71 having the transistor structure shown in FIG. 4 and FIG. 5, the driving transistor TR D and the write transistor TR W The capacitance C S1 is the driving transistor TR D One of the source / drain regions 23A and the driving transistor TR D The capacitance C S1 functions as a part of the capacitance section. S1 If the capacitance C is sufficient to hold the video signal, S It is also possible to adopt a configuration in which is omitted.

[0087] In the first embodiment, the anode voltage V ANODE Even if the voltage-current characteristic (VI) of a current-driven light-emitting unit changes, the problem of capacitive coupling described above does not occur. Therefore, it is possible to prevent the burn-in phenomenon caused by the change over time of the voltage-current characteristic (VI) of the current-driven light-emitting unit from being accentuated by the effect of capacitance.

[0088] Depending on the arrangement of the transistors constituting the driving unit 71, shielding wiring may be provided to prevent signal coupling occurring between wirings, etc. To facilitate understanding, first, the arrangement of the shielding wiring in the driving unit 971 of the reference example described above will be described.

[0089] 12 is a schematic plan view for explaining shield wiring in a driving section of a reference example, in which the layout relationship of transistors is the same as that in FIG.

[0090] In the transistor arrangement shown in FIG. W The other source / drain region 23D and the driving transistor TR D The wiring path connecting the gate electrode of the light emitting portion ELP and the portion to which the anode electrode of the light emitting portion ELP is connected crosses. Therefore, in order to prevent coupling, it was necessary to insert a separate shield wiring 38 as shown in FIG.

[0091] In the first embodiment, the write transistor TR W The other source / drain region 23D and the driving transistor TR D The wiring path connecting the gate electrodes of the gate electrodes intersects with the portion to which the power supply line PS1 is connected. Therefore, basically, even if there is no shield wiring, coupling can be prevented to some extent.

[0092] In order to prevent the coupling more effectively, as shown in FIG. W The other source / drain region 23D and the driving transistor TR DA configuration may also be adopted in which a shield wiring 38 is provided around the gate wiring for connecting the gate electrode of the gate electrode 31. By configuring the shield wiring to be connected to the power supply line PS1, it is possible to simplify the wiring. In order to prevent capacitance from occurring between the gate and anode wiring, it is preferable to route the shield wiring 38 so as to surround the gate wiring, as shown in FIG.

[0093] The first embodiment has been described above. In the present disclosure, it is preferable that the capacitance between transistors is large. In order to increase the capacitance, it is effective to increase the junction depth of the impurity diffusion layer that constitutes the transistor. FIG. 14 shows an example in which the junction depth of the impurity diffusion layer is deeper than that in FIG. 5. Driving transistor TR D impurity diffusion layers forming the source / drain regions of the write transistor TR W The impurity diffusion layers forming the source / drain regions are preferably set to have a junction depth of 1 micrometer or more.

[0094] In a configuration in which capacitance is secured by the area of ​​the planar layout, the capacitance decreases as the resolution increases. On the other hand, in the configuration of the present disclosure in which capacitance is secured in the vertical direction by the junction depth of the transistor, it is possible to achieve high resolution while securing capacitance.

[0095] [Second embodiment] The second embodiment relates to a display element, a display device, and an electronic device according to a second aspect of the present disclosure.

[0096] In the second embodiment, the drive section further includes a switching transistor connected between a power supply line and one of the source / drain regions of the drive transistor. The above points are the main difference from the first embodiment.

[0097] Fig. 15 is a conceptual diagram of a display device according to the second embodiment. For convenience of illustration, Fig. 15 shows the wiring relationship of one display element 270 in the display device 2, more specifically, the (n, m)th display element 270.

[0098] In the second embodiment, the driving unit 271 includes a power supply line PS1 and a driving transistor TR D A switching transistor TR S The conductive type of the switching transistor is not particularly limited, but from the viewpoint of standardization of the semiconductor manufacturing process, the switching transistor TR S The switching transistor TR is preferably a p-channel type field effect transistor. S The conductive / non-conductive state of is controlled by a signal supplied to the gate electrode from the light emission control scanner 240 via a control line DS1, and for example, an operation such as reducing the characteristic variation for each driving unit can be performed.

[0099] 16 is a schematic plan view for explaining the arrangement of transistors in the driving section according to the second embodiment. Reference numerals 23E and 23F denote switching transistors TR S In this arrangement, the capacitance between the transistors functions as part of the capacitance section.

[0100] [Third embodiment] The third embodiment relates to a display element, a display device, and an electronic device according to a third aspect of the present disclosure.

[0101] In the third embodiment, the driving section further includes a switching transistor connected between one end of the light emitting section and the other source / drain region of the driving transistor. The above points are the main difference from the first embodiment.

[0102] Fig. 17 is a conceptual diagram of a display device according to the third embodiment. For convenience of illustration, Fig. 17 shows the wiring relationship of one display element 370 in the display device 3, more specifically, the (n, m)th display element 370.

[0103] In the third embodiment, the driving section 371 has one end of the light emitting section ELP and a driving transistor TR D A switching transistor TR connected between the other source / drain region 23D of M The conductive type of the switching transistor is not particularly limited, but from the viewpoint of standardization of the semiconductor manufacturing process, the switching transistor TR M The switching transistor TR is preferably a p-channel type field effect transistor. M The conductive / non-conductive state of is controlled by a signal supplied to the gate electrode from the light emission control scanner 340 via a control line EM1, and it is possible to perform an operation such as reducing the characteristic variation for each driving unit.

[0104] 18 is a schematic plan view for explaining the arrangement of transistors in the driving section according to the third embodiment. Reference numerals 23G and 23H denote switching transistors TR M In this arrangement, the capacitance between the transistors functions as part of the capacitance section.

[0105] [Electronic equipment] The display device of the present disclosure described above can be used as a display unit (display unit) of electronic devices in various fields that displays a video signal input to the electronic device or a video signal generated within the electronic device as an image or video. For example, it can be used as a display unit of a television set, a digital still camera, a notebook personal computer, a portable terminal device such as a mobile phone, a video camera, a head-mounted display, etc.

[0106] The display device of the present disclosure also includes a sealed module. An example of the display device is a display module formed by attaching a counter part such as transparent glass to a pixel array part. The display module may be provided with a circuit part or a flexible printed circuit (FPC) for inputting and outputting signals from the outside to the pixel array part. Below, a digital still camera and a head mounted display are given as specific examples of electronic devices using the display device of the present disclosure. However, the specific examples given here are merely examples and are not limited thereto.

[0107] (Example 1) Fig. 19 is an external view of a lens-interchangeable single-lens reflex type digital still camera, with Fig. 19A showing a front view and Fig. 19B showing a rear view. A lens-interchangeable single-lens reflex type digital still camera has, for example, an interchangeable taking lens unit (interchangeable lens) 412 on the right side of the front of a camera main body (camera body) 411, and a grip part 413 for the photographer to hold on the left side of the front.

[0108] A monitor 414 is provided at approximately the center of the back surface of the camera body 411. A viewfinder (eyepiece window) 415 is provided above the monitor 414. By looking through the viewfinder 415, the photographer can visually confirm the optical image of the subject guided by the photographing lens unit 412 and determine the composition.

[0109] In the lens-interchangeable single-lens reflex type digital still camera having the above configuration, the display device of the present disclosure can be used as the viewfinder 415. That is, the lens-interchangeable single-lens reflex type digital still camera according to this example is produced by using the display device of the present disclosure as the viewfinder 415.

[0110] (Example 2) 20 is an external view of a head mounted display. The head mounted display has, for example, ear hooks 512 on both sides of a glasses-shaped display unit 511 for wearing on the user's head. In this head mounted display, the display device of the present disclosure can be used as the display unit 511. That is, the head mounted display according to this example is produced by using the display device of the present disclosure as the display unit 511.

[0111] (Example 3) 21 is an external view of the see-through head mounted display 611. The see-through head mounted display 611 is composed of a main body 612, an arm 613, and a lens barrel 614.

[0112] The main body 612 is connected to the arm 613 and the glasses 600. Specifically, an end of the long side of the main body 612 is coupled to the arm 613, and one side of the main body 612 is connected to the glasses 600 via a connecting member. The main body 612 may be directly attached to the head of the human body.

[0113] The main body 612 incorporates a control board for controlling the operation of the see-through head mounted display 611 and a display unit. The arm 613 connects the main body 612 and the lens barrel 614 and supports the lens barrel 614. Specifically, the arm 613 is coupled to an end of the main body 612 and an end of the lens barrel 614, respectively, and fixes the lens barrel 614. The arm 613 also incorporates a signal line for communicating data related to an image provided from the main body 612 to the lens barrel 614.

[0114] The lens barrel 614 projects image light provided from the main body 612 via the arm 613 through an eyepiece lens toward the eyes of a user wearing the see-through head mounted display 611. In this see-through head mounted display 611, the display unit of the main body 612 can use the display device of the present disclosure.

[0115] [others] The technology of the present disclosure can also be configured as follows. [A1] The device includes a current-driven light-emitting unit and a drive unit for driving the light-emitting unit, the drive unit includes a capacitance unit, a drive transistor that causes a current corresponding to a voltage held by the capacitance unit to flow to the light-emitting unit, and a write transistor that writes a signal voltage to the capacitance unit; the drive transistor and the write transistor are formed on a semiconductor substrate and are separated by an element isolation region; a capacitance generated in a portion where the drive transistor and the write transistor face each other via an element isolation region functions as at least a part of a capacitance section; Display element. [A2] The drive transistor and the write transistor are provided in a well formed in a semiconductor substrate, the driving transistor has one source / drain region connected to a power supply line and the other source / drain region connected to one of the light emitting sections; the write transistor has one source / drain region to which a signal voltage is externally supplied and the other source / drain region connected to a gate electrode of the drive transistor; the other source / drain region of the write transistor and one source / drain region of the drive transistor are formed to face each other via an element isolation region; The display element according to the above [A1]. [A3] The element isolation region is formed by an STI (Shallow Trench Isolation) structure in which an insulator is embedded in a trench dug in the surface of a semiconductor substrate. The display element according to the above [A1] or [A2]. [A4] the impurity diffusion layer forming the source / drain region of the drive transistor and the impurity diffusion layer forming the source / drain region of the write transistor are set to have a junction depth of 1 micrometer or more; A display element according to any one of the above [A1] to [A3]. [A5] The drive transistor is a p-channel field effect transistor. A display element according to any one of the above [A1] to [A4]. [A6] The write transistor is a p-channel field effect transistor. A display element according to any one of the above [A1] to [A5]. [A7] a shield wiring is provided around the gate wiring for connecting the other source / drain region of the write transistor and the gate electrode of the drive transistor; A display element according to any one of the above [A2] to [A6]. [A8] The shield wiring is connected to the power supply line. A display element according to any one of the above [A7]. [A9] The driving section further includes a switching transistor connected between the power supply line and one of the source / drain regions of the driving transistor. A display element according to any one of the above [A2] to [A8]. [A10] The driving section further includes a switching transistor connected between one end of the light emitting section and the other source / drain region of the driving transistor. A display element according to any one of the above [A2] to [A8]. [A11] The light-emitting part is made of an organic electroluminescence element. A display element according to any one of the above [A1] to [A10].

[0116] [B1] A display device having display elements arranged in a two-dimensional matrix, The display element includes a current-driven light-emitting unit and a drive unit for driving the light-emitting unit. the drive unit includes a capacitance unit, a drive transistor that causes a current corresponding to a voltage held by the capacitance unit to flow to the light-emitting unit, and a write transistor that writes a signal voltage to the capacitance unit; the drive transistor and the write transistor are formed on a semiconductor substrate and are separated by an element isolation region; a capacitance generated in a portion where the drive transistor and the write transistor face each other via an element isolation region functions as at least a part of a capacitance section; Display device. [B2] The drive transistor and the write transistor are provided in a well formed in a semiconductor substrate, the driving transistor has one source / drain region connected to a power supply line and the other source / drain region connected to one of the light emitting sections; the write transistor has one source / drain region to which a signal voltage is externally supplied and the other source / drain region connected to a gate electrode of the drive transistor; the other source / drain region of the write transistor and one source / drain region of the drive transistor are formed to face each other via an element isolation region; The display device according to the above [B1]. [B3] The element isolation region is formed by an STI (Shallow Trench Isolation) structure in which an insulator is embedded in a trench dug in the surface of a semiconductor substrate. The display device according to the above [B1] or [B2]. [B4] the impurity diffusion layer forming the source / drain region of the drive transistor and the impurity diffusion layer forming the source / drain region of the write transistor are set to have a junction depth of 1 micrometer or more; The display device according to any one of [B1] to [B3] above. [B5] The drive transistor is a p-channel field effect transistor. The display device according to any one of [B1] to [B4] above. [B6] The write transistor is a p-channel field effect transistor. The display device according to any one of [B1] to [B5] above. [B7] a shield wiring is provided around the gate wiring for connecting the other source / drain region of the write transistor and the gate electrode of the drive transistor; The display device according to any one of [B2] to [B6] above. [B8] The shield wiring is connected to the power supply line. The display device according to any one of the above [B7]. [B9] The driving section further includes a switching transistor connected between the power supply line and one of the source / drain regions of the driving transistor. The display device according to any one of [B2] to [B8] above. [B10] The driving section further includes a switching transistor connected between one end of the light emitting section and the other source / drain region of the driving transistor. The display device according to any one of [B2] to [B8] above. [B11] The light-emitting part is made of an organic electroluminescence element. The display device according to any one of the above [B1] to [B10].

[0117] [C1] An electronic device equipped with a display device having display elements arranged in a two-dimensional matrix, The display element includes a current-driven light-emitting unit and a drive unit for driving the light-emitting unit. the drive unit includes a capacitance unit, a drive transistor that causes a current corresponding to a voltage held by the capacitance unit to flow to the light-emitting unit, and a write transistor that writes a signal voltage to the capacitance unit; the drive transistor and the write transistor are formed on a semiconductor substrate and are separated by an element isolation region; a capacitance generated in a portion where the drive transistor and the write transistor face each other via an element isolation region functions as at least a part of a capacitance section; electronic equipment. [C2] The drive transistor and the write transistor are provided in a well formed in a semiconductor substrate, the driving transistor has one source / drain region connected to a power supply line and the other source / drain region connected to one of the light emitting sections; the write transistor has one source / drain region to which a signal voltage is externally supplied and the other source / drain region connected to a gate electrode of the drive transistor; the other source / drain region of the write transistor and one source / drain region of the drive transistor are formed to face each other via an element isolation region; The electronic device according to [C1] above. [C3] The element isolation region is formed by an STI (Shallow Trench Isolation) structure in which an insulator is embedded in a trench dug in the surface of a semiconductor substrate. The electronic device according to [C1] or [C2] above. [C4] the impurity diffusion layer forming the source / drain region of the drive transistor and the impurity diffusion layer forming the source / drain region of the write transistor are set to have a junction depth of 1 micrometer or more; An electronic device according to any one of [C1] to [C3] above. [C5] The drive transistor is a p-channel field effect transistor. An electronic device according to any one of [C1] to [C4] above. [C6] The write transistor is a p-channel field effect transistor. An electronic device according to any one of [C1] to [C5] above. [C7] a shield wiring is provided around the gate wiring for connecting the other source / drain region of the write transistor and the gate electrode of the drive transistor; An electronic device according to any one of [C2] to [C6] above. [C8] The shield wiring is connected to the power supply line. The electronic device according to any one of the above [C7]. [C9] The driving section further includes a switching transistor connected between the power supply line and one of the source / drain regions of the driving transistor. An electronic device according to any one of [C2] to [C8] above. [C10] The driving section further includes a switching transistor connected between one end of the light emitting section and the other source / drain region of the driving transistor. An electronic device according to any one of [C2] to [C8] above. [C11] The light-emitting part is made of an organic electroluminescence element. The electronic device according to any one of [C1] to [C10] above. [Explanation of symbols]

[0118] 1, 2, 3, 9... display device, 10... substrate, 20... semiconductor layer, 21... n-type well, 22... element isolation region, 23A, 23B, 23C, 23D, 23E, 23F, 23G, 23H... source / drain region, 31... gate insulating layer, 31'... insulating layer, 32... gate electrode, 32'... other electrode, 33... interlayer insulating layer, 34... one electrode, 35, 36... contact hole, 37... wiring, 38... shield wiring, 40... interlayer insulating layer , 51...anode electrode, 52...hole transport layer, light emitting layer, and electron transport layer, 53...cathode electrode, 54...second interlayer insulating layer, 55, 56...contact holes, 60...transparent substrate, 70, 270, 370, 970...display element, 71, 271, 371, 971...driver section, 80...display area, 100...semiconductor substrate, 110...source driver, 120...power supply section, 130...vertical scanner, 240, 340...light emission control scanner, TR W Write transistor, TR D Drive transistor, C S Capacitor section, ELP Organic electroluminescence light-emitting section, C EL The capacitance of the light-emitting part ELP, C GA ...Capacity of reference example, C S1 ...Capacity, TR S ,TR M ···Switching transistor, WS1···Scanning line, DTL···Data line, PS1···Power supply line, PS2···Common power supply line, DS1, ME1···Control line, 411···Camera main body, 412···Photographing lens unit, 413···Grip section, 414···Monitor, 415···Viewfinder, 511···Glasses-shaped display section, 512···Ear hook section, 600···Glasses, 611···See-through head mounted display, 612···Main body, 613···Arm, 614···Lens barrel

Claims

1. A plurality of data lines extending along a first direction; A plurality of control lines extending along a second direction perpendicular to the first direction; A plurality of pixel circuits arranged in a matrix; Equipped with Each of the plurality of pixel circuits A light-emitting element; a capacitance for storing a data voltage supplied from a corresponding one of the plurality of data lines; a first transistor having one of a source and a drain electrically connected to an anode of the light-emitting element; a second transistor having one of a source and a drain electrically connected to an anode of the light-emitting element; a third transistor that controls writing of the data voltage to the capacitance; Equipped with a channel length direction of each of the first transistor, the second transistor, and the third transistor extends along the first direction; a part of an element isolation region of a semiconductor substrate is interposed between the other of the source and drain of the first transistor and one of the source and drain of the third transistor; One of the source and the drain of the first transistor is electrically connected directly to the anode of the light-emitting element. Display device.

2. the other of the source and the drain of the first transistor is electrically connected directly to the other of the source and the drain of the second transistor; The display device according to claim 1 .

3. a control line of the second transistor among the plurality of control lines is arranged to intersect with a channel region of the third transistor in a plan view; The display device according to claim 1 or 2.

4. one electrode of the capacitor is electrically connected directly to the other of the source and the drain of the first transistor; The display device according to any one of claims 1 to 3.

5. the other electrode of the capacitor is connected to the gate of the first transistor; The display device according to claim 4.

6. the first transistor and the second transistor are connected in series; The display device according to any one of claims 1 to 5.

7. the light-emitting element, the first transistor, and the second transistor are connected in series; The display device according to any one of claims 1 to 5.

8. a channel region of the third transistor being a part of an island-shaped semiconductor layer structurally separated from the semiconductor layer of the first transistor and the semiconductor layer of the second transistor; The display device according to any one of claims 1 to 7.

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