JP2008185868A - Electro-optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electro-optical device capable of preventing ambient light reflected between layers of insulating films on a light-transmitting substrate from being incident on an optical sensor. <P>SOLUTION: In an element substrate 10 of the electro-optical device 100, the optical sensor 310 is formed on a region outside a pixel region 10b, and the optical sensor 310 is formed between an underlayer protective film 12 and a gate insulating film 2 formed on the light-transmitting substrate 10d. From among the light emitted from a backlight device 600, although the light emitted in an oblique direction may possibly be reflected between layers of interlayer insulating films 7, 8 and a light shielding film 11a and travel toward the optical sensor 310, such ambient light is shielded by a light shielding film 6k formed inside a through-hole 7k. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electro-optical device including an optical sensor.

  Electronic devices such as personal computers and mobile phones equipped with an electro-optical device as a display device are used in various environments with different ambient light intensities. Accordingly, if the driving conditions in the electro-optical device are changed in accordance with changes in the ambient light, it is possible to improve image quality and reduce power consumption.

  For example, in a transmissive or anti-transmissive liquid crystal device which is a typical electro-optical device, a backlight device is provided on the back surface of the liquid crystal panel, and light emitted from the backlight device is modulated by the liquid crystal panel. . In such a liquid crystal device, the power consumption of the backlight device is large. Therefore, an optical sensor composed of discrete components is mounted on the liquid crystal device, and external light (environmental light) is measured by this optical sensor, and the intensity of the backlight device is adjusted according to the measurement result to reduce power consumption. It has been proposed to plan (see, for example, Patent Document 1).

  However, the technique described in Patent Document 1 has a problem that man-hours and costs increase because an optical sensor made of discrete components is mounted on a flexible substrate.

In view of this, it is conceivable to form a photosensor on an element substrate by using a process of forming a thin film transistor (TFT / Thin Film Transistor) on the element substrate of the liquid crystal panel. Even without using an optical sensor, it is possible to detect external light incident from the side of the light-transmitting counter substrate.
JP 2003-78838 A

  However, when a photosensor is formed on a translucent substrate using a process of forming a thin film transistor (TFT / Thin Film Transistor), the photosensor is interposed between a plurality of insulating films formed on the translucent substrate. As a result, light may leak through the insulating film to the optical sensor. For example, out of the light emitted from the backlight device toward the liquid crystal panel, the light emitted in an oblique direction may be reflected between the layers of the insulating film and enter the optical sensor as disturbance light. The sensitivity of the optical sensor is reduced. In addition, when light emitted from the backlight device toward the liquid crystal panel is emitted in an oblique direction, it is reflected by the case, etc., then reflected between the layers of the insulating film, and enters the optical sensor as disturbance light There is also.

  In addition, when a light shielding film that blocks light from the light transmitting substrate side is formed on the lower layer side of the light sensor in the light transmitting substrate, the light sensor is repeatedly reflected between the insulating film and the light shielding film. Disturbance light may travel toward the light and may easily enter the optical sensor.

  In view of the above problems, an object of the present invention is to provide an electro-optical device capable of preventing ambient light from entering a photosensor while being reflected on an interlayer of an insulating film on a translucent substrate. There is.

  In order to solve the above problems, according to the present invention, in an electro-optical device in which a pixel region and an optical sensor are formed on a light-transmitting substrate, a plurality of insulating films are stacked on the light-transmitting substrate. In addition, the photosensor is formed between any one of the plurality of insulating films, and a first light-shielding film is formed on a lower layer side of the photosensor in a region overlapping with the photosensor. At least one of a first region adjacent to the sensor on the pixel region side and a second region adjacent to the photosensor on the side opposite to the pixel region side is provided with the plurality of layers. In the insulating film, a through hole is formed to reach the first light shielding film from any insulating film positioned above the semiconductor layer that receives light in the photosensor. That two light-shielding films are formed. And butterflies.

  In the present invention, an optical sensor is formed in the outer region of the pixel region on the translucent substrate, and this optical sensor detects target light incident from a direction opposite to the side where the translucent substrate is located. . Here, since the first light shielding film is formed on the lower layer side from the optical sensor, disturbance light is prevented from directly entering the optical sensor from the translucent substrate side. Further, in the optical sensor, since the semiconductor layer that receives light is formed between the plurality of insulating films formed on the light-transmitting substrate, light leaks to the optical sensor through the insulating film. However, in the present invention, a through hole is formed at a position adjacent to the optical sensor, and a second light shielding film is formed inside the through hole. It is possible to prevent disturbance light from entering from the direction. For example, in the case where the through hole and the second light shielding film are formed in the first region, the light emitted from the backlight device in the oblique direction is the interlayer between the insulating films. Or being reflected by the first light shielding film and entering the optical sensor as disturbance light. On the other hand, in the case where the through hole and the second light shielding film are formed in the second region, of the light emitted from the backlight device toward the liquid crystal panel, It is possible to prevent the light reflected from the inner surface of the case from being reflected by the interlayer of the insulating film or the first light shielding film and entering the optical sensor as disturbance light. Therefore, according to the present invention, the sensitivity of the optical sensor can be increased.

  In the present invention, it is preferable that the through hole and the second light shielding film are formed at least in the first region. In the case where the through hole and the second light shielding film are formed in the first region, out of the light emitted from the backlight device, the light emitted in the oblique direction is the interlayer between the insulating films and the second one. It is possible to prevent the light from being reflected by one light shielding film and entering the optical sensor as strong disturbance light.

  In the present invention, the first light-shielding film and the second light-shielding film are conductive films, and at least one of the plurality of insulating films is provided between the first light-shielding film and the photosensor. It is preferable that the first light-shielding film is held at a constant potential via the second light-shielding film. When the first light-shielding film is a conductive film, the first light-shielding film and the optical sensor are in a capacitively coupled state, and fluctuations in the potential of the first light-shielding film affect the light detection by the optical sensor. However, if the first light-shielding film is held at a constant potential by utilizing the fact that the second light-shielding film is connected to the first light-shielding film, fluctuations in the potential of the first light-shielding film are prevented. can do.

  In the present invention, a wiring electrically connected to the photosensor through a contact hole is formed on any of the multi-layered insulation films located above the photosensor. The second light shielding film preferably includes a conductive film formed between the same layers as the wiring. If comprised in this way, it is not necessary to add the process of forming the 2nd light shielding film separately.

  In the present invention, the through hole includes a pilot hole part and an upper hole part communicating with the pilot hole part, and the second light shielding film includes the first light shielding film via the pilot hole part. It is preferable to include a lower-layer conductive film electrically connected to the upper-layer conductive film and the upper-layer conductive film made of the conductive film formed in the same layer as the wiring. With this configuration, it is not necessary to electrically connect the second light shielding film to the first light shielding film through the through hole having a large aspect ratio. An electrical connection can be made reliably.

  In the present invention, a plurality of the through holes are arranged in a first direction along the end facing the photosensor in the pixel region to form a hole row, and the hole row is arranged in the first direction. A plurality of rows are arranged in a second direction orthogonal to each other, and two hole rows adjacent in the second direction in the plurality of through-row rows are included in one hole row when viewed from the second direction. A configuration in which the space between the through holes is closed by the second light shielding film formed in the through hole included in the other hole row may be employed.

  In the present invention, it is possible to adopt a configuration in which the through hole extends in a slit shape in a direction along an end facing the optical sensor in the pixel region.

  In the electro-optical device according to the aspect of the invention, it is preferable that a driving condition in the pixel region is adjusted based on a light detection result by the optical sensor.

  In addition, when the pixel region includes a light source device that emits light, it is preferable to control the amount of light emitted from the light source device based on a light detection result by the optical sensor.

  The electro-optical device to which the present invention is applied can be used in electronic devices such as personal computers, mobile phones, and portable information terminals.

  The present invention will be described below with reference to the drawings. In the following embodiments, a light detection device according to the present invention is configured in a TFT active matrix driving type liquid crystal device which is a typical electro-optical device. In the drawings to be referred to in the following description, the scales are different for each layer and each member so that each layer and each member have a size that can be recognized on the drawing.

[Embodiment 1]
(overall structure)
FIG. 1 is a block diagram showing an electrical configuration of an electro-optical device to which the present invention is applied. An electro-optical device 100 shown in FIG. 1 is a totally transmissive liquid crystal device, and includes a liquid crystal panel 100p, an image processing circuit 202, a timing generation circuit 203, a power supply circuit 201, a dimming circuit 500, and a backlight device 600 (light source device). Etc. The image processing circuit 202, the timing generation circuit 203, and the power supply circuit 201 are configured by an IC or the like mounted on the flexible substrate 108 (see FIGS. 2A and 2B) connected to the liquid crystal panel 100p. The light control circuit 500 and the backlight device 600 are configured outside the liquid crystal panel 100p.

  In the timing generation circuit 203, a dot clock for driving each pixel 100a of the liquid crystal panel 100p is generated, and based on this dot clock, clock signals VCK, HCK, inverted clock signals VCKB, HCKB, transfer start pulses HSP, VSP. Is generated. When input image data is input from the outside, the image processing circuit 202 generates an image signal based on the input image data and supplies it to the liquid crystal panel 100p. The power supply circuit 201 generates a plurality of power supplies VDD, VSS, VHH, and VLL and supplies them to the liquid crystal panel 100p.

  The liquid crystal panel 100p includes a pixel region 10b (pixel array region) in which a plurality of pixels 100a are arranged in a matrix in the central region. In the liquid crystal panel 100p, on the element substrate 10 described later, a plurality of data lines 6a and a plurality of scanning lines 3a extend vertically and horizontally inside the pixel region 10b, and the pixel 100a is located at a position corresponding to the intersection. Is configured. In each of the plurality of pixels 100a, a thin film transistor 30 as a pixel switching element and a pixel electrode 9a are formed. The data line 6 a is electrically connected to the source of the thin film transistor 30, the scanning line 3 a is electrically connected to the gate of the thin film transistor 30, and the pixel electrode 9 a is electrically connected to the drain of the thin film transistor 30.

  In the element substrate 10, a scanning line driving circuit 104 and a data line driving circuit 101 are configured outside the pixel region 10 b. The data line driving circuit 101 is electrically connected to the data line 6a and sequentially supplies image signals to the data lines 6a. The scanning line driving circuit 104 is electrically connected to the scanning line 3a, and sequentially supplies the scanning signal to each scanning line 3a.

  In each pixel 100a, the pixel electrode 9a is opposed to a common electrode formed on a counter substrate, which will be described later, via liquid crystal, and constitutes a liquid crystal capacitor 50a. Each pixel 100a is provided with a holding capacitor 60 in parallel with the liquid crystal capacitor 50a in order to prevent the image signal held in the liquid crystal capacitor 50a from leaking. In this embodiment, in order to form the storage capacitor 60, the capacitor line 3b is formed in parallel with the scanning line 3a, and the capacitor line 3b is connected to a common potential line (not shown) and has a predetermined potential. Is held in. The storage capacitor 60 may be formed between the preceding scanning line 3a.

  In the electro-optical device 100, the visibility of the display image depends on the brightness of the environment. For example, under natural daylight, it is necessary to set the light emission luminance of the backlight device 600 high and display a bright screen. On the other hand, in a dark environment at night, a clear image can be displayed even if the light emission luminance of the backlight device 600 is not as high as during the daytime. Therefore, it is desirable to adjust the light emission luminance of the backlight device 600 according to the illuminance of the ambient light. Therefore, the electro-optical device 100 according to the present embodiment includes a light detection device 300 including a light sensor 310 and a detection circuit 340. The light detection device 300 measures the illuminance of ambient light. In addition, the dimming circuit 500 controls the backlight device 600 to emit light with a luminance corresponding to the illuminance data obtained by the light detection device 300. A specific configuration of the light detection apparatus 300 will be described later. Note that the detection circuit 340 may be configured on the element substrate 10.

(Specific configuration of the liquid crystal panel 100p)
FIGS. 2A and 2B are a plan view of the liquid crystal panel 100p of the electro-optical device 100 to which the present invention is applied as viewed from the side of the counter substrate together with each component, and a cross-sectional view thereof taken along line HH ′. . As shown in FIGS. 2A and 2B, in the liquid crystal panel 100p of the electro-optical device 100, the element substrate 10 and the translucent counter substrate 20 made of glass or the like through a predetermined gap are provided. Is bonded by a sealing material 107 (a region with a slanting line in the lower right in FIG. 2A), and the sealing material 107 is disposed along the outer peripheral edge of the counter substrate 20. The sealing material 107 is an adhesive made of a photo-curing resin, a thermosetting resin, or the like, and is mixed with a gap material such as glass fiber or glass beads for setting the distance between both substrates to a predetermined value. In a corner portion of the counter substrate 20 and the like, a vertical conductive material (not shown) is formed for electrical conduction between the element substrate 10 and the counter substrate 20.

  In the element substrate 10, a data line driving circuit 101 and a plurality of terminals 102 are formed along one side of the element substrate 10 in a region outside the inner peripheral edge of the sealing material 107, and along the side adjacent to this one side. A scanning line driving circuit 104 is formed. In addition, a flexible substrate 108 is connected to the element substrate 10 by a terminal 102. The element substrate 10 may include a protection circuit and an inspection circuit for protecting the pixel region 10b, the data line driving circuit 101, and the scanning line driving circuit 104 from static electricity, but the description thereof is omitted. .

  As will be described in detail later, pixel electrodes 9 a are formed in a matrix on the element substrate 10. On the other hand, the counter substrate 20 is formed with a frame-shaped light-shielding film 23b (a region with a diagonal line rising to the right in FIG. 2A) in the inner region of the sealant 107, and the inner side is the image display region. 10a. In the counter substrate 20, a light shielding film 23 a called a black matrix or black stripe is formed in a region facing the vertical and horizontal boundary regions of the pixel electrode 9 a of the element substrate 10, and ITO (Indium) is formed on the upper layer side. A counter electrode 21 made of a (tin oxide) film is formed. In the pixel area 10b, a dummy pixel may be formed in an area overlapping the light shielding film 23b. In this case, an area excluding the dummy pixel in the pixel area 10b is used as the image display area 10a. It will be. In this embodiment, since a photocurable adhesive is used as the sealing material 107, the light shielding film 23b and the sealing material 107 are formed at positions shifted so that light irradiation from the counter substrate 20 side is possible. When the sealing material 107 is photocured by light irradiation from the 10 side, or when a thermosetting adhesive is used for the sealing material 107, the light shielding film 23 b and the sealing material 107 are formed at overlapping positions. A configuration can also be adopted.

  A liquid crystal 50 as an electro-optical material is sealed in a space surrounded by the sealing material 107. The liquid crystal 50 takes a predetermined alignment state by the alignment films 16 and 22 (see FIG. 3B) formed on the element substrate 10 and the counter substrate in a state where an electric field from the pixel electrode 9a is not applied. The liquid crystal 50 is made of, for example, one or a mixture of several types of nematic liquid crystals.

  In the electro-optical device 100, a backlight device 600 is disposed on the back side of the element substrate 10, and light emitted from the backlight device 600 is incident on the liquid crystal panel 100p from the element substrate 10 side to face the counter substrate. The light is modulated while being emitted from the side 20, and is emitted as display light from the side of the counter substrate 20. As the backlight device 600, a surface light source device can be adopted, and a light source device using an LED element and a light guide plate can also be adopted.

  In the liquid crystal panel 100p, an optical sensor 310 is disposed at a position facing the data line driving circuit 101 with the image display region 10a interposed therebetween. In the present embodiment, the optical sensor 310 includes a light receiving element formed on the element substrate 10. A part of the light shielding film 23b formed on the counter substrate 20 is notched, and the optical sensor 310 is formed in a region of the element substrate 10 that overlaps the notch 23c of the light shielding film 23b.

  The electro-optical device 100 formed in this way is mounted on an electronic device in a state of being housed in, for example, the case 40 shown in FIG. Here, when the electro-optical device 100 is used as a color display device of an electronic device such as a mobile computer, a cellular phone, or a liquid crystal television described later, a color filter (not shown) and a protective film are formed on the counter substrate 20. Is done. Further, on the light incident side surface or the light emitting side of the counter substrate 20 and the element substrate 10, the type of the liquid crystal 50 to be used, that is, an operation mode such as a TN (twisted nematic) mode, an STN (super TN) mode, Depending on the normally white mode / normally black mode, a polarizing film, a retardation film, a polarizing plate, and the like are arranged in a predetermined direction. The electro-optical device 100 is not limited to a transmissive type, and may be configured as a transflective type.

(Configuration of each pixel)
3A and 3B are plan views of adjacent pixels in the element substrate 10 used in the electro-optical device 100 to which the present invention is applied, and electro-optics at positions corresponding to the AA ′ line. It is sectional drawing when the apparatus 100 is cut | disconnected.

  As shown in FIGS. 3A and 3B, the element substrate 10 is provided with a base protective film 12 made of a silicon oxide film or the like on the surface of a light-transmitting substrate 10d made of glass or the like. On the surface side, an N-channel thin film transistor 30 is formed at a position adjacent to the pixel electrode 9a. The thin film transistor 30 has a twin gate structure. The island-shaped semiconductor film 1a includes a high concentration source region 1d, a channel formation region 1b, a high concentration N type region 1g, a channel from the source side to the drain side. The formation region 1c and the high concentration drain region 1e are arranged in this order. A gate insulating film 2 made of a silicon oxide film or the like is formed above the semiconductor film 1a, and a scanning line 3a is formed above the gate insulating film 2. A part of the scanning line 3a is opposed to the channel formation regions 1b and 1c through the gate insulating film 2 as a gate electrode.

The semiconductor film 1a is a polysilicon film that is polycrystallized by laser annealing, lamp annealing, or the like after an amorphous silicon film is formed on the translucent substrate 10d. The high-concentration source region 1d, the high-concentration N-type region 1g, and the high-concentration drain region 1e are about 0.1 × 10 ¹⁵ / cm ² to about 10 × 10 ¹⁵ / cm ^{2 using the} scanning line 3a (gate electrode) as a mask. This is a semiconductor region formed by introducing high-concentration N-type impurities (such as phosphorus ions) at a dose of.

  On the upper layer side of the thin film transistor 30, interlayer insulating films 7 and 8 are formed. A data line 6a and a drain electrode 6b are formed on the surface of the interlayer insulating film 7. The data line 6a is electrically connected to the high concentration source region 1d through a contact hole 7a formed in the interlayer insulating film 7. Yes. A pixel electrode 9 a made of an ITO film is formed on the surface of the interlayer insulating film 8. The pixel electrode 9 a is electrically connected to the drain electrode 6 b through the contact hole 8 a formed in the interlayer insulating film 8, and the drain electrode 6 b is connected to the contact hole formed in the interlayer insulating film 7 and the gate insulating film 2. 7b is electrically connected to the high concentration drain region 1e. An alignment film 16 made of a polyimide film is formed on the surface side of the pixel electrode 9a. For the extended portion 1f (lower electrode) from the high-concentration drain region 1e, the capacitive line 3b in the same layer as the scanning line 3a is provided via an insulating film (dielectric film) formed simultaneously with the gate insulating film 2. Are opposed to each other as an upper electrode, thereby forming a storage capacitor 60. In this embodiment, the scanning line 3a and the capacitor line 3b are formed of a single layer film or a laminated film such as a molybdenum film, an aluminum film, a titanium film, a tungsten film, a tantalum film, or a chromium film. The data line 6a and the drain electrode 6b are also formed of a single layer film or a laminated film such as a molybdenum film, an aluminum film, a titanium film, a tungsten film, a tantalum film, or a chromium film.

(Configuration of drive circuit)
Referring again to FIG. 2A, in the electro-optical device 100 of the present embodiment, the data line driving circuit 101, the scanning line driving circuit 104, and the like inside the surface side of the element substrate 10 using the peripheral region of the pixel region 10b. A circuit is formed. In configuring such a shift register of the data line driving circuit 101 and the scanning line driving circuit 104, a complementary thin film transistor including an N-channel thin film transistor and a P-channel thin film transistor is used, although illustration is omitted. It is done.

(Configuration of optical sensor and its peripheral parts)
FIGS. 4A and 4B are a plan view of the optical sensor used in the electro-optical device to which the present invention is applied and its vicinity, and a BB ′ sectional view thereof, and FIG. A thin film transistor 30 for pixel switching is also shown.

  As shown in FIGS. 4A and 4B, in the element substrate 10 of the present embodiment, a photosensor 310 is formed in the outer region of the pixel region 10b, and the photosensor 310 connects a plurality of light receiving elements to the wiring 6h. , 6i are electrically connected in parallel. In this embodiment, the optical sensor 310 is formed between the base protective film 12 and the gate insulating film 2 among the base protective film 12, the gate insulating film 2, the interlayer insulating film 7, and the interlayer insulating film 8. A high-concentration N-type region 1x, an intrinsic region 1y, and a high-concentration P-type region 1z are arranged in this order in the semiconductor film 1w. For the optical sensor 310, wirings 6h and 6i formed on the upper layer of the interlayer insulating film 7 are electrically connected to the high-concentration N-type region 1x and the high-concentration P-type region 1z through the contact holes 7h and 7i, respectively. Connected.

The semiconductor film 1w is a polysilicon film formed simultaneously with the semiconductor film 1a constituting the thin film transistor 30. The high-concentration N-type region 1x is formed from about 0.1 × 10 ¹⁵ / cm ² to about 10 × 10 ¹⁵ / cm ² using a resist mask when forming the high-concentration N-type regions of the thin film transistor 30 and the complementary thin film transistor. This is a semiconductor region formed by introducing high-concentration N-type impurities (such as phosphorus ions) at a dose of. The high-concentration P-type region 1z uses a resist mask to form a dose amount of about 0.1 × 10 ¹⁵ / cm ² to about 10 × 10 ¹⁵ / cm ² when forming the high-concentration P-type region of the complementary thin film transistor. The semiconductor region is formed by introducing a high concentration P-type impurity (boron ions or the like). The wirings 6h and 6i are metal films formed simultaneously with the data lines 6a and the drain electrodes 6b, and are made of a single layer film or a laminated film such as a molybdenum film, an aluminum film, a titanium film, a tungsten film, a tantalum film, or a chromium film. .

  The optical sensor 310 configured as described above overlaps the notch 23c of the light shielding film 23b formed on the counter substrate 20, and external light (target light / environment light / arrow P) entering from the counter substrate 20 side. Can be detected. The light shielding film 23b is a molybdenum film, an aluminum film, a titanium film, a tungsten film, a tantalum film, a chromium film, or the like formed simultaneously with the light shielding film 23a (see FIGS. 2B and 3B) constituting the black matrix. It consists of a single layer film or a laminated film. Here, the light shielding film 23b is also formed in a region overlapping between the pixel region 10b and the optical sensor 310.

  On the side where the translucent substrate 10d is positioned with respect to the semiconductor film 1w, in this embodiment, between the translucent substrate 10d and the base protective film 12, a molybdenum film, A light shielding film 11a (first light shielding film) made of a single layer film or a laminated film such as an aluminum film, a titanium film, a tungsten film, a tantalum film, or a chromium film is formed. For this reason, the light from the backlight device 600 does not directly enter the intrinsic region 1y. In this embodiment, the light shielding film 11a is formed over a wide area, and a part of the light shielding film 11a is formed up to an area between the pixel area 10b and the photosensor 310.

  In the present embodiment, the first region 10e adjacent to the photosensor 310 on the pixel region 10b side, and the second region 10f adjacent to the photosensor 310 on the side opposite to the pixel region 10b side, 1 region 10e includes a plurality of insulating films (underlying protective film 12, gate insulating film 2, interlayer insulating film 7, and interlayer insulating film 8) in an interlayer located above the semiconductor film 1w of the optical sensor 310. A through hole 7k reaching from the insulating film 7 to the light shielding film 11a is formed, and the through hole 7k passes through the interlayer insulating film 7, the gate insulating film 2, and the base protective film 12.

  A light shielding film 6k (second light shielding film) is formed inside the through hole 7k, and the light shielding film 6k covers the bottom and side walls of the through hole 7k. The light shielding film 6k is a metal film formed simultaneously with the wirings 6h and 6i, the data line 6a, and the drain electrode 6b, and is a single layer film such as a molybdenum film, an aluminum film, a titanium film, a tungsten film, a tantalum film, or a chromium film. It consists of a laminated film. Therefore, the light shielding film 6k and the light shielding film 11a are electrically connected. The light shielding film 6k is electrically connected to the capacitor line 3b and other constant potential lines shown in FIG. 3B, and the light shielding film 11a is held at a constant potential via the light shielding film 6k.

  In the present embodiment, a plurality of through holes 7k are arranged in the first direction X along the end facing the optical sensor 310 in the pixel region 10b to form the hole rows 41, 42. Are arranged in parallel in a second direction Y (a direction from the pixel region 10b toward the optical sensor 310) orthogonal to the first direction X.

  Further, when the hole rows 41 and 42 are viewed from the second direction Y, the light shielding film 6k formed between the through holes 7k included in one hole row 41 in the through holes 7k included in the other hole row 42. The space between the through holes 7k included in the hole row 42 is closed by the light shielding film 6k formed in the through hole 7k included in the hole row 41. Specifically, in the hole row 41, the through holes 7k are arranged with a predetermined interval, but the interval is narrower than the dimension Lx in the first direction X of the through hole 7k, and the hole row 42 The included through holes 7k are arranged between the through holes 7k included in the hole row 41. On the contrary, in the hole row 42, the through holes 7k are arranged at a predetermined interval, but the interval is narrower than the dimension Lx in the first direction X of the through hole 7k and The included through holes 7k are arranged between the through holes 7k included in the hole row 42.

(Manufacturing method of electro-optical device and photodetector)
In addition to FIGS. 3 and 4, a method for manufacturing the electro-optical device 100 and the light detection device 300 will be described with reference to FIG. 5. 5A to 5H show a method of manufacturing the thin film transistor 30 for pixel switching and the optical sensor 310 on the element substrate 10 in the manufacturing process of the electro-optical device 100 and the light detection device 300 to which the present invention is applied. It is process sectional drawing shown. 5A to 5H each correspond to FIG. 4B.

  First, as shown in FIG. 5A, a molybdenum film, an aluminum film, a titanium film, a surface of a transparent substrate 10d made of glass or the like cleaned by ultrasonic cleaning or the like in the first light shielding film forming step, After a metal film such as a tungsten film, a tantalum film, or a chromium film is formed, the metal film is patterned using a photolithography technique to form a light shielding film 11a (first light shielding film).

  Next, in the base protective film forming step, as shown in FIG. 5B, silicon is formed on the entire surface of the translucent substrate 10d by a plasma CVD method or the like under a temperature condition of 150 to 450 ° C. A base protective film 12 made of an oxide film is formed.

  Next, in the semiconductor film formation step, the semiconductor film 1 made of an amorphous silicon film is formed on the entire surface of the translucent substrate 10d under the temperature condition of the substrate temperature of 150 to 450 ° C. by plasma CVD, for example, 40 to 50 nm. Then, the semiconductor film 1 is polycrystallized by a laser annealing method or the like. Next, the semiconductor film 1 is patterned using a photolithography technique to form the semiconductor films 1a and 1w in an island shape as shown in FIG.

  Next, in the gate insulating film formation step, as shown in FIG. 5D, the gate insulating film 2 made of a silicon oxide film or the like is formed on the semiconductor films 1a and 1w by using a CVD method or the like. Although not shown in the drawing, after this process, an N-type impurity (phosphorus ion or the like) is implanted into the extended portion 1f of the semiconductor film 1a to form the storage capacitor 60 between the capacitor line 3b. An electrode is formed.

  Next, in the gate electrode forming step, a metal film such as a molybdenum film, an aluminum film, a titanium film, a tungsten film, a tantalum film, or a chromium film is formed on the entire surface of the light-transmitting substrate 10d, and then a photolithography technique is used. The metal film is patterned to form the scanning line 3a, the capacitor line 3b, and the gate electrode 3e as shown in FIG. As a result, the storage capacitor 60 is formed.

  Next, as shown in FIG. 5F, an impurity introduction step is performed on the semiconductor films 1a, 1w, and the like. In this impurity introducing step, a resist mask (not shown) partially covering the surface of the semiconductor film 1w and the semiconductor film on the driver circuit side is formed on the gate insulating film 2 in the high concentration N-type impurity introducing step. Then, high-concentration N-type impurities (such as phosphorus ions) are introduced into the semiconductor films 1a and 1w and the semiconductor film on the driver circuit side, so that the high-concentration source region 1d, high-concentration N-type region 1g and high-concentration drain of the semiconductor film 1a are introduced. A region 1e and the like are formed, and a high concentration N-type region 1x is formed in the semiconductor film 1w. Further, in the high-concentration P-type impurity introduction step, a resist mask (not shown) that partially covers the entire surface of the semiconductor film 1a and the surface of the semiconductor film 1w and the semiconductor film on the driver circuit side above the gate insulating film 2. In the state in which the high-concentration P-type region 1z of the semiconductor film 1w is formed by introducing a high-concentration P-type impurity (such as boron ions) into the semiconductor film 1w or the semiconductor film on the driver circuit side. At that time, regions where impurities are not introduced become channel forming regions 1b and 1c and intrinsic region 1y.

  Next, in the first interlayer insulating film forming step, as shown in FIG. 5G, an interlayer insulating film 7 made of a silicon oxide film or the like is formed using a CVD method or the like, and then a photolithography technique is used. Contact holes 7a, 7b, 7h, 7i and through holes 7k are formed. Here, since the depths of the contact holes 7a, 7b, 7h, 7i and the through holes 7k are greatly different, after forming the upper hole portions of the contact holes 7a, 7b, 7h, 7i and the through holes 7k, the resist A mask is formed, and a pilot hole portion of the through hole 7k is formed.

  Next, in the wiring formation step, as shown in FIG. 5H, a metal such as a molybdenum film, an aluminum film, a titanium film, a tungsten film, a tantalum film, or a laminated film thereof is formed on the entire surface of the translucent substrate 10d. After the film is formed, the metal film is patterned using a photolithography technique to form the data line 6a, the drain electrode 6b, the wirings 6h and 6i, and the light shielding film 6k (second light shielding film).

  Although the illustration of the subsequent steps is omitted, in the second interlayer insulating film forming step, as shown in FIGS. 3B and 4B, the interlayer insulating film 8 having the contact hole 8a is formed. To do. Next, in the pixel electrode forming step, an ITO film is formed on the entire surface of the translucent substrate 10d, and then patterned using a photolithography technique to form the pixel electrode 9a. Thereafter, the alignment film 16 shown in FIG. 3B is formed. As a result, the element substrate 10 is completed.

(Main effects of this form)
As described above, in the electro-optical device 100 according to this embodiment, the optical sensor 310 is formed in the element substrate 10 in the outer region of the pixel region 10b, and the optical sensor 310 is external light incident from the counter substrate 20 side. Is detected. Therefore, the detection circuit 340 outputs the illuminance data to the dimming device 500, and the dimming device 500 can control the backlight device 600 to emit light under conditions according to the external light.

  Further, in this embodiment, since the light shielding film 11a (first light shielding film) is formed on the lower layer side from the optical sensor 310, the backlight device 600 directly from the light transmitting substrate 10d side to the optical sensor 310. The emitted light does not enter as disturbance light. Further, the optical sensor 310 is formed between the base protective film 12 and the gate insulating film 2 formed on the translucent substrate 10d, and the interlayer insulating films 7 and 8 are formed on the upper layer. When the display is performed in the image display region 10a, as indicated by an arrow Q in FIG. 4B, among the light emitted from the backlight device 600, the light emitted in an oblique direction is the interlayer insulating films 7 and 8. However, the disturbance light is blocked by the light blocking film 6k (second light blocking film) formed inside the through hole 7k. Therefore, since disturbance light does not enter the optical sensor 310, the sensitivity of the optical sensor 310 can be increased.

  The through hole 7k is formed using a process of forming contact holes 7h and 7i, and the light shielding film 6k is formed using a process of forming wirings 6h and 6i. Therefore, it is possible to prevent the ambient light from entering the optical sensor 310 with a minimum increase in the number of processes.

  Further, the base protective film 12 is interposed between the light shielding film 11a and the optical sensor 310, and the light shielding film 11a is capacitively coupled to the optical sensor 310, but the light shielding film 11a is interposed via the light shielding film 6k. It is held at a constant potential. For this reason, since the potential fluctuation of the light shielding film 11a does not affect the light detection in the light sensor 310, the sensitivity of the light sensor 310 can also be increased in this respect.

[Embodiment 2]
FIGS. 6A and 6B are a plan view of the optical sensor used in the electro-optical device according to the second embodiment of the present invention and its vicinity, and a CC ′ cross-sectional view thereof, and FIG. ) Also shows a thin film transistor 30 for pixel switching. Since the basic configuration of the present embodiment and later-described third and fourth embodiments is the same as that of the first embodiment, common portions are denoted by the same reference numerals and illustrated. Is omitted.

  As shown in FIGS. 6A and 6B, in the element substrate 10 of the present embodiment, as in the first embodiment, the photosensor 310 is formed in the outer region of the pixel region 10b. Is a PIN junction diode formed between the base protective film 12 and the gate insulating film 2 among the base protective film 12, the gate insulating film 2, the interlayer insulating film 7, and the interlayer insulating film 8. . The optical sensor 310 overlaps the notch 23c of the light shielding film 23b formed on the counter substrate 20, and detects external light (target light / environment light / indicated by arrow P) incident from the counter substrate 20 side. Is possible. A single-layer film such as a molybdenum film, an aluminum film, a titanium film, a tungsten film, a tantalum film, or a chromium film is formed between the light-transmitting substrate 10d and the base protective film 12 so as to overlap with a region including the optical sensor 310. A light shielding film 11a (first light shielding film) made of a laminated film or the like is formed.

  In the present embodiment, the first region 10e adjacent to the photosensor 310 on the pixel region 10b side, and the second region 10f adjacent to the photosensor 310 on the side opposite to the pixel region 10b side, In the first region 10e, an interlayer insulation located on the upper layer side of the semiconductor film 1w of the optical sensor 310 in the multiple layers of insulating films (the base protective film 12, the gate insulating film 2, the interlayer insulating film 7, and the interlayer insulating film 8). A through hole 7s that reaches the light shielding film 11a from the film 7 is formed. In this embodiment, the through hole 7s includes a pilot hole portion 12t that penetrates the base protective film 12, and an upper hole portion 7t that penetrates the gate insulating film 2 and the interlayer insulating film 7 and communicates with the pilot hole portion 12t.

  A light shielding film 6s (second light shielding film) is formed in the through hole 7s. In this embodiment, the light shielding film 6s includes a lower layer side light shielding film 4t (lower layer side conductive film) electrically connected to the light shielding film 11a inside the pilot hole portion 12t, and a lower layer side light shielding film inside the upper hole portion 7t. The upper layer side light-shielding film 6t (upper layer side conductive film) electrically connected to 4t. The lower layer side light-shielding film 4t is made of a single layer film or a laminated film such as a molybdenum film, an aluminum film, a titanium film, a tungsten film, a tantalum film, or a chromium film, and covers the bottom and side walls of the pilot hole portion 12t. The upper-layer side light-shielding film 6t is formed of a single layer film or a laminated film such as a molybdenum film, an aluminum film, a titanium film, a tungsten film, a tantalum film, or a chromium film formed simultaneously with the wirings 6h and 6i, the data line 6a, and the drain electrode 6b. And covers the side wall of the upper hole portion 7t.

  In this way, the light shielding film 6s is formed inside the through hole 7s, and the light shielding film 6s and the light shielding film 11a are electrically connected. At least one of the lower layer side light shielding film 4t and the upper layer side light shielding film 6t is electrically connected to the capacitor line 3b and other constant potential lines shown in FIG. 3B, and the light shielding film 11a is composed of the light shielding film 6k. Is held at a constant potential.

  In the present embodiment, a plurality of through holes 7 s are arranged in the first direction X along the end facing the optical sensor 310 in the pixel region 10 b to form the hole rows 41 and 42. Are arranged in parallel in a second direction Y (a direction from the pixel region 10b toward the optical sensor 310) orthogonal to the first direction X. Further, when the hole rows 41 and 42 are viewed from the second direction Y, the light shielding film 6s formed between the through holes 7s included in one hole row 41 in the through holes 7s included in the other hole row 42. And the space between the through holes 7 s included in the hole row 42 is closed by a light shielding film 6 s formed in the through holes 7 s included in the hole row 41. Specifically, in the hole row 41, the through holes 7s are arranged at a predetermined interval, but the interval is narrower than the dimension Lx in the first direction X of the through holes 7s, and the hole row 42 The included through holes 7 s are arranged between the through holes 7 s included in the hole row 41. On the contrary, in the hole row 42, the through holes 7s are arranged at a predetermined interval. However, the interval is narrower than the dimension Lx in the first direction X of the through hole 7s, and The included through holes 7 s are arranged between the through holes 7 s included in the hole row 42.

  In such a configuration, after the base protective film 12 is formed, a pilot hole portion 12t is formed in the base protective film 12 using a photolithography technique. Further, after forming the pilot hole portion 12t, a metal film such as a molybdenum film, an aluminum film, a titanium film, a tungsten film, a tantalum film, or a chromium film is formed, and then the metal film is patterned using a photolithography technique. Thus, the lower-layer side light-shielding film 4t is formed. Other steps are the same as those in the first embodiment, and thus the description thereof is omitted.

  As described above, also in this embodiment, the external light incident from the counter substrate 20 side can be detected by the optical sensor 310, and the backlight device 600 is controlled to emit light under conditions according to the external light. Can do. Further, since the light shielding film 11a (first light shielding film) is formed on the lower layer side from the optical sensor 310, the light emitted from the backlight device 600 directly to the optical sensor 310 from the translucent substrate 10d side. Does not enter as disturbance light. Further, as indicated by an arrow Q in FIG. 6B, among the light emitted from the backlight device 600, the light emitted in an oblique direction is reflected by the interlayer insulating films 7 and 8 and the light shielding film 11a. The ambient light may travel toward the optical sensor 310, but the disturbance light may be transmitted through the light shielding film 6s (second light shielding film / lower layer) formed inside the through hole 7s (the lower hole portion 12t and the upper hole portion 7t). The side light shielding film 4t and the upper layer side light shielding film 6t) are blocked. Therefore, since disturbance light does not enter the optical sensor 310, the sensitivity of the optical sensor 310 can be increased.

[Embodiment 3]
FIG. 7 is a plan view of an optical sensor used in the electro-optical device according to Embodiment 3 of the present invention and the vicinity thereof. 7 is represented as shown in FIG. 4B, this embodiment will be described with reference to FIG. 4B and FIG.

  In the first and second embodiments, the hole array is formed by the plurality of through holes 7k and 7s in the first region 10e adjacent to the photosensor 310 on the pixel region 10b side. As shown in FIG. 4B and FIG. 7, a slit-like through hole 7k extending along the end facing the optical sensor 310 is formed in the pixel region 10b, and the light shielding film 6k is formed inside the through hole 7k. Is formed. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  Even in this embodiment configured as described above, the light emitted from the backlight device 600 in the oblique direction is reflected by the interlayer insulating films 7 and 8 and the light shielding film 11a, so that the light sensor 310 can emit light. However, the disturbing light has the same effect as the first embodiment, such as being blocked by the light shielding film 6k formed inside the through hole 7k. The structure in which the through hole extends in a slit shape may be applied to the through hole 7s (the lower hole portion 12t and the upper hole portion 7t) employed in the second embodiment.

[Embodiment 4]
8A and 8B are an optical sensor used in the electro-optical device according to Embodiment 4 of the present invention, a plan view of the vicinity thereof, and a cross-sectional view taken along line EE ′ thereof.

  In the first to third embodiments, the through holes 7k and 7s in which the light shielding films 6k and 6s are formed are formed in the first region 10e adjacent to the optical sensor 310 on the pixel region 10b side. In this embodiment, as shown in FIGS. 8A and 8B, the first region 10e adjacent to the optical sensor 310 on the pixel region 10b side, and the pixel region 10b side on the optical sensor 310, A through hole 7k having a light shielding film 6k formed therein is formed in both of the second regions 10f adjacent on the opposite side. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  Even in this embodiment configured as described above, the light emitted from the backlight device 600 in the oblique direction is reflected by the interlayer insulating films 7 and 8 and the light shielding film 11a, so that the light sensor 310 can emit light. However, the disturbance light has the same effect as that of the first embodiment, such as being blocked by the light shielding film 6k formed inside the through hole 7k of the first region 10e.

  Further, among the light emitted from the backlight device 600, the light emitted in the oblique direction is reflected by the inner surface of the case 40 shown in FIG. 2B, and then shown by the arrow R in FIG. In addition, even when the light is reflected by the interlayer insulating films 7 and 8 or the light shielding film 11a and proceeds toward the optical sensor 310, the disturbance light is formed inside the through hole 7k of the second region 10f. The light shielding film 6k blocks the light. Therefore, since disturbance light does not enter the optical sensor 310, the sensitivity of the optical sensor 310 can be increased. For forming a through hole in which a light shielding film is formed inside both the first region 10e and the second region 10f adjacent to the optical sensor 310, refer to the second embodiment. You may employ | adopt the structure demonstrated and the structure demonstrated with reference to Embodiment 3. FIG.

[Application examples to other electro-optical devices]
In the above embodiment, the first region 10e adjacent to the optical sensor 310 on the pixel region 10b side is always provided with a through hole having a light shielding film formed therein, but the disturbance light from the pixel region 10b side is provided. When the countermeasure is applied in another configuration, a through hole having a light shielding film formed therein is formed only in the second region 10f adjacent to the photosensor 310 on the side opposite to the pixel region 10b side. You may arrange.

  In the above embodiment, the case where the optical sensor 310 is a PIN junction type diode has been described. However, a MOS type diode in which an N-type thin film transistor is diode-connected or a MOS type diode in which a P-type thin film transistor is diode-connected is used as the optical sensor 310. In some cases, the present invention may be suitable. Further, when performing light detection using the optical sensor 310, the optical sensor 310 constituting the main sensor is disposed in the region overlapping the notch 23c of the light shielding film 23b, while the sub sensor is configured in the region overlapping the light shielding film 23b. The light sensor 310 may be arranged, and the intensity of external light may be obtained from the difference between the detection results. For example, a sensor circuit is configured by electrically connecting a main sensor and a sub sensor in series via a node, and external light is generated based on a current or voltage extracted from the node when a voltage is applied to both ends of the sensor circuit. May be detected.

  In the above embodiment, in the above embodiment, the amount of light emitted from the backlight device is controlled based on the detection result of the light detection device 300 in the liquid crystal device, but based on the detection result of the light detection device 300. The signal supplied to each pixel 100a may be controlled. In the above embodiment, a liquid crystal device is described as an example of the electro-optical device 100. However, in the organic electroluminescence device, a signal supplied to each pixel is controlled based on a detection result in the light detection device 300. Also good.

[Example of mounting on electronic devices]
Next, an electronic apparatus to which the electro-optical device 100 according to the above-described embodiment is applied will be described. FIG. 9A shows a configuration of a mobile personal computer including the electro-optical device 100. The personal computer 2000 includes an electro-optical device 100 as a display unit and a main body 2010. The main body 2010 is provided with a power switch 2001 and a keyboard 2002. FIG. 9B shows a configuration of a mobile phone provided with the electro-optical device 100. A cellular phone 3000 includes a plurality of operation buttons 3001, scroll buttons 3002, and the electro-optical device 100 as a display unit. By operating the scroll button 3002, the screen displayed on the electro-optical device 100 is scrolled. FIG. 9C shows the configuration of a personal digital assistant (PDA) to which the electro-optical device 100 is applied. The information portable terminal 4000 includes a plurality of operation buttons 4001, a power switch 4002, and the electro-optical device 100 as a display unit. When the power switch 4002 is operated, various types of information such as an address book and a schedule book are displayed on the electro-optical device 100.

  As an electronic apparatus to which the electro-optical device 100 is applied, in addition to those shown in FIG. 9, a digital still camera, a liquid crystal television, a viewfinder type, a monitor direct view type video tape recorder, a car navigation device, a pager, an electronic notebook, Examples include calculators, word processors, workstations, videophones, POS terminals, devices with touch panels, and the like. The electro-optical device 100 described above can be applied as a display unit of these various electronic devices.

1 is a block diagram illustrating an electrical configuration of an electro-optical device to which the present invention is applied. (A), (b) is the top view which looked at the liquid crystal panel of the electro-optical apparatus to which this invention was applied from the opposing board | substrate side with each component, and its HH 'sectional drawing. (A), (b) is a plan view of adjacent pixels in the element substrate 10 used in the electro-optical device to which the present invention is applied, and the electro-optical device is cut at a position corresponding to the line AA ′. It is sectional drawing when doing. (A), (b) is the top view of the optical sensor used for the electro-optical apparatus based on Embodiment 1 of this invention, its vicinity, and its BB 'sectional drawing, respectively. It is process sectional drawing which shows the thin film transistor for pixel switching shown in FIG. 4, and the manufacturing method of an optical sensor. (A), (b) is the top view of the optical sensor used for the electro-optical apparatus based on Embodiment 2 of this invention, its vicinity, and its CC 'sectional drawing, respectively. FIG. 6 is a plan view of an optical sensor used in an electro-optical device according to Embodiment 3 of the invention and the vicinity thereof. (A), (b) is the top view of the optical sensor used for the electro-optical apparatus based on Embodiment 4 of this invention, its vicinity, and its EE 'sectional drawing, respectively. It is explanatory drawing of the electronic device provided with the electro-optical apparatus to which this invention is applied.

Explanation of symbols

1w..Semiconductor film of optical sensor, 1x..High-concentration N-type region of optical sensor, 1y..Intrinsic region of optical sensor, 1z..High-concentration P-type region of optical sensor. ..Lower side light shielding film (lower layer side conductive film), 6k, 6s ..Light shielding film inside through hole (second light shielding film), 6t ..Upper layer side light shielding film (upper layer side conductive film), 7, 8 Interlayer insulating film, 7k, 7s, through hole, 7t, upper hole portion of through hole, 10. element substrate, 10a, image display area, 10b, pixel area, 10d, translucent substrate, 10e ··· a first region adjacent to the optical sensor, 10f ·· a second region adjacent to the optical sensor, 11a · · a light shielding film (first light shielding film) on the element substrate side, 12 · · a base protective film, 12t..Prepared hole portion of through hole, 20..Counter substrate, 23a, 23b..Light shielding film on counter substrate side, 30..Pixel TFT for switching, 40 ... case, 100 ... electro-optical device, 100p ... liquid crystal panel, 300 ... photodetector, 310 ... photosensor, 600 ... backlight device

Claims (9)

In an electro-optical device in which a pixel region and an optical sensor are formed on a translucent substrate,
A plurality of insulating films are stacked on the translucent substrate, and the photosensor is formed between any of the plurality of insulating films,
On the lower layer side of the photosensor, a first light shielding film is formed in a region overlapping the photosensor,
At least one of a first region adjacent to the photosensor on the pixel region side and a second region adjacent to the photosensor on the side opposite to the pixel region side includes the plurality of regions. A through-hole that reaches the first light-shielding film from any one of the insulating films positioned above the semiconductor layer that receives light in the photosensor is formed in the insulating film of the layer,
An electro-optical device, wherein a second light-shielding film is formed inside the through hole.   The electro-optical device according to claim 1, wherein the through hole and the second light shielding film are formed at least in the first region. The first light shielding film and the second light shielding film are conductive films, and at least one of the plurality of insulating films is interposed between the first light shielding film and the photosensor,
The electro-optical device according to claim 1, wherein the first light shielding film is held at a constant potential via the second light shielding film. A wiring electrically connected to the photosensor through a contact hole is formed on any one of the multi-layered insulation films located above the photosensor.
4. The electro-optical device according to claim 1, wherein the second light-shielding film includes a conductive film formed between the same layers as the wirings. 5. The through hole includes a pilot hole part and an upper hole part communicating with the pilot hole part,
The second light-shielding film includes a lower-layer-side conductive film electrically connected to the first light-shielding film through the pilot hole portion, and an upper-layer side composed of the conductive film formed in the same layer as the wiring The electro-optical device according to claim 4, further comprising a conductive film. A plurality of the through holes are arranged in a first direction along the end facing the photosensor in the pixel region to form a hole row,
The hole rows are arranged in a plurality of rows in a second direction orthogonal to the first direction,
When two hole rows adjacent in the second direction in the plurality of through rows are viewed from the second direction, a space between the through holes included in one hole row is included in the other hole row. The electro-optical device according to claim 1, wherein the electro-optical device is closed by the second light shielding film formed in the through hole.   6. The electro-optical device according to claim 1, wherein the through hole extends in a slit shape in a direction along an end portion facing the optical sensor in the pixel region.   The electro-optical device according to claim 1, wherein a driving condition in the pixel region is adjusted based on a light detection result by the optical sensor. A light source device for emitting light to the pixel region;
The electro-optical device according to claim 1, wherein an emitted light amount in the device is controlled based on a light detection result by the optical sensor.

Images