JP4532418B2 - Optical sensor and manufacturing method thereof - Google Patents

Description

  The present invention relates to a photoelectric conversion device, and more particularly to a photoelectric conversion device including a thin film semiconductor element and a manufacturing method thereof. In addition, the present invention relates to an electronic device using a photoelectric conversion device.

  Many photoelectric conversion devices generally used for electromagnetic wave detection are known. For example, devices having sensitivity from ultraviolet rays to infrared rays are collectively called optical sensors. Among them, those having sensitivity in the visible light region with a wavelength of 400 nm to 700 nm are particularly called visible light sensors, and are used in many devices that require illuminance adjustment and on / off control according to the human living environment. .

  Particularly in a display device, the brightness around the display device is detected and the display luminance is adjusted. This is because it is possible to reduce wasteful power by detecting ambient brightness and obtaining appropriate display brightness. For example, such an optical sensor for adjusting luminance is used in a mobile phone or a personal computer (see, for example, Patent Document 1).

  Further, not only the brightness of the surroundings but also the brightness of the backlight of a display device, particularly a liquid crystal display device, is detected by an optical sensor to adjust the brightness of the display screen (for example, Patent Document 2 and Patent Document 3). reference).

  In a display device using a projector, the convergence is adjusted using an optical sensor. Convergence adjustment is adjustment of an image so that the image of each color of RGB does not shift. The position of the image of each color is detected using an optical sensor, and the image is arranged at the correct position (see, for example, Patent Document 4).

  The structure of a conventionally used optical sensor is shown in FIG. In FIG. 6, a first transparent electrode 1002 is formed over a substrate 1001, and a p-type semiconductor layer 1003, an intrinsic semiconductor layer 1004, and an n-type semiconductor layer 1005 that serve as photoelectric conversion layers are formed over the first transparent electrode 1002. Has been. Further, a second transparent electrode 1006 is formed on the n-type semiconductor layer 1005. Next, an insulating separation layer 1007 is formed to cover the transparent electrodes 1002 and 1006, and a contact hole is formed in the insulating separation layer 1007. Further, a first extraction electrode 1008 connected to the first transparent electrode 1002 and a second extraction electrode 1009 connected to the second transparent electrode 1006 are formed.

  The optical sensor shown in FIG. 6 has a problem that electrostatic breakdown is likely to occur because the transparent electrodes 1002 and 1006 are formed, and the resistance decreases and the speed of electrostatic discharge increases. Further, the electric field concentrates on the ends of the p-type semiconductor layer 1003, the intrinsic semiconductor layer 1004, and the n-type semiconductor layer 1005 which are photoelectric conversion layers, and electrostatic breakdown may easily occur.

Further, the transparent electrode 1006 is formed on the entire surface of the n-type semiconductor layer 1005 that is the upper layer of the photoelectric conversion layer, and the transparent electrode 1002 is formed on the entire surface of the p-type semiconductor layer 1003 that is the lower layer of the photoelectric conversion layer. The intensity of incident light may be reduced.
JP 2003-60744 A Japanese Patent No. 3171808 Japanese Patent No. 3193315 JP 2003-47017 A

  In view of the above, an object of the present invention is to produce an optical sensor having a structure capable of suppressing electrostatic breakdown.

  In the present invention, in order to solve the above-described problem, a transparent electrode that overlaps the entire surface of the light receiving region is not formed. In the present invention, the p-type semiconductor layer of the photoelectric conversion layer is used as one electrode, and the n-type semiconductor layer is used as the other electrode. When a p-type semiconductor layer and an n-type semiconductor layer are used as electrodes, resistance increases and electrostatic breakdown can be suppressed.

  Further, by separating the positions of the p-type semiconductor layer and the n-type semiconductor layer serving as electrodes, the resistance is increased, so that the breakdown voltage can be improved.

  The present invention provides, on a substrate, a photoelectric conversion layer having a first semiconductor layer of one conductivity type, a second semiconductor layer, and a third semiconductor layer of a conductivity type opposite to the one conductivity type; A first electrode that contacts the first semiconductor layer by a groove formed in the photoelectric conversion layer, and a groove that is formed in contact with the third semiconductor layer in the photoelectric conversion layer and exposes the third semiconductor layer And a second electrode in contact with the third semiconductor layer through a groove formed in the insulating layer, the first electrode of the photoelectric conversion layer, the insulation The region not covered with the layer and the second electrode relates to a photoelectric conversion device in which the third semiconductor layer is removed.

  According to the present invention, there is provided a photoelectric conversion layer having a first semiconductor layer of one conductivity type, a second semiconductor layer, and a third semiconductor layer of a conductivity type opposite to the one conductivity type on a substrate. Forming a first insulating layer having a first groove on the photoelectric conversion layer, forming a second groove in the photoelectric conversion layer, and passing the first groove through the second groove; Forming a first electrode layer in contact with the semiconductor layer, forming a second electrode layer in contact with the third semiconductor layer of the photoelectric conversion layer through the first groove, the first electrode, The present invention relates to a method for manufacturing a photoelectric conversion device, wherein the third semiconductor layer is removed in a region not covered with an insulating layer and the second electrode.

  The present invention includes, on a substrate, a photoelectric conversion element and a circuit that performs signal processing on an output value of the photoelectric conversion element. The photoelectric conversion element includes a first semiconductor layer of one conductivity type and a second semiconductor. A photoelectric conversion layer having a layer and a third semiconductor layer having a conductivity type opposite to the one conductivity type, a first electrode in contact with the first semiconductor layer by a groove formed in the photoelectric conversion layer, An insulating layer formed in contact with the third semiconductor layer in the photoelectric conversion layer and formed with a groove exposing the third semiconductor layer, and the third layer via the groove formed in the insulating layer A region having a second electrode in contact with the semiconductor layer and not covered with the first electrode, the insulating layer, and the second electrode of the photoelectric conversion layer; The circuit includes a plurality of thin film transistors, and the plurality of thin film transistors Each of which includes an island-shaped semiconductor region including a source region, a drain region, and a channel formation region, a gate insulating film, a gate electrode, a source electrode electrically connected to the source region, and an electrical connection to the drain region. And a drain electrode connected to the semiconductor device.

  The circuit is an amplifier circuit that amplifies the output value of the photoelectric conversion element.

  The present invention has a first electrode, a first semiconductor film of one conductivity type, a second semiconductor film, and a third semiconductor film of a conductivity type opposite to the one conductivity type on a substrate. A photoelectric conversion layer, an insulating film covering the first electrode and the photoelectric conversion layer, a second electrode formed on the insulating film and in contact with a part of the first electrode, and the insulating film And a third electrode in contact with part of the third semiconductor film, wherein the photoelectric conversion layer is in contact with part of the first electrode. It relates to the device.

  In the present invention, the first electrode is a transparent electrode.

  In the present invention, the transparent electrode is formed by using an indium oxide tin oxide alloy containing silicon, zinc oxide, tin oxide, indium oxide, indium oxide, and a target obtained by mixing 2 wt% or more and 20 wt% or less of zinc oxide. Any one of indium zinc oxide alloys is included.

  In the present invention, the first electrode is a light-shielding conductive film.

  In the present invention, the light-shielding conductive film is selected from titanium, tungsten, tantalum, molybdenum, neodymium, cobalt, zirconium, zinc, ruthenium, rhodium, palladium, osmium, iridium, platinum, aluminum, gold, silver, and copper. Either a single layer film made of an element or an alloy material or a compound material containing the element as a main component, or a single layer film made of these nitrides, for example, titanium nitride, tungsten nitride, tantalum nitride, or molybdenum nitride Is included.

  In the present invention, after the third semiconductor layer is removed, a second insulating film having a groove is formed, and the first electrode layer and the groove are formed through the groove formed in the second insulating film. A first lead electrode and a second lead electrode connected to each of the second electrode layers are formed.

  In the present invention, a conductive film is formed between the substrate and the first semiconductor layer.

  In the present invention, the conductive film is a transparent conductive film.

  In the present invention, a color filter is formed between the substrate and the first semiconductor layer.

  In the present invention, each of the source electrode and the drain electrode is a laminated film.

  In the present invention, the laminated film is a film in which a titanium (Ti) film, an aluminum (Al) film containing a small amount of silicon (Si), and a titanium (Ti) film are laminated.

  In the present invention, each of the source electrode and the drain electrode is a single layer film.

  In the present invention, the single layer film includes titanium (Ti), tungsten (W), tantalum (Ta), molybdenum (Mo), neodymium (Nd), cobalt (Co), zirconium (Zr), zinc (Zn), An element selected from ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), or an alloy material or a compound material containing the element as a main component A single-layer film or a single-layer film made of these nitrides, for example, titanium nitride, tungsten nitride, tantalum nitride, or molybdenum nitride.

  The present invention has a first electrode, a first semiconductor film of one conductivity type, a second semiconductor film, and a third semiconductor film of a conductivity type opposite to the one conductivity type on a substrate. A photoelectric conversion layer, an insulating film covering the first electrode and the photoelectric conversion layer, a second electrode formed on the insulating film and in contact with a part of the first electrode, and the insulating film And a third electrode in contact with part of the third semiconductor film, wherein the photoelectric conversion layer is in contact with part of the first electrode. It relates to the device.

  In the present invention, the first electrode is a transparent electrode.

  In the present invention, the transparent electrode is formed by using an indium oxide tin oxide alloy containing silicon, zinc oxide, tin oxide, indium oxide, indium oxide, and a target obtained by mixing 2 wt% or more and 20 wt% or less of zinc oxide. Any one of indium zinc oxide alloys is included.

  In the present invention, the first electrode is a light-shielding conductive film.

  In the present invention, the light-shielding conductive film is selected from titanium, tungsten, tantalum, molybdenum, neodymium, cobalt, zirconium, zinc, ruthenium, rhodium, palladium, osmium, iridium, platinum, aluminum, gold, silver, and copper. Either a single layer film made of an element or an alloy material or a compound material containing the element as a main component, or a single layer film made of these nitrides, for example, titanium nitride, tungsten nitride, tantalum nitride, or molybdenum nitride Is included.

  In the present invention, the substrate is a flexible substrate.

  In the present invention, the substrate is a glass substrate.

  In the present invention, the flexible substrate is any one of a polyethylene naphthalate (PEN) film, a polyethylene terephthalate (PET) film, and a polybutylene naphthalate (PBN) film.

  According to the present invention, an optical sensor in which electrostatic breakdown is suppressed can be manufactured. In addition, an electric device incorporating such an optical sensor can have high reliability.

  Furthermore, the optical sensor manufactured according to the present invention can bring the wavelength of light to be absorbed closer to the sensitivity of the human eye.

  This embodiment will be described with reference to FIGS. 1A to 1C, FIGS. 2A to 2C, and FIGS. 3A to 3C.

  First, for example, a p-type semi-amorphous semiconductor film is formed on the substrate 101 as the p-type semiconductor film 102. In this embodiment, a flexible substrate is used as the substrate 101, and specifically, a polyethylene naphthalate (PEN) film is used. Besides polyethylene naphthalate, a film of polyethylene terephthalate (PET), polybutylene naphthalate (PBN), or the like may be used. A glass substrate may also be used.

  Further, as the p-type semiconductor film 102, a semi-amorphous silicon film containing an impurity element belonging to Group 13 such as boron (B) is formed by a plasma CVD method.

Note that the semi-amorphous semiconductor film is a film including a semiconductor having a structure intermediate between an amorphous semiconductor and a semiconductor (including single crystal and polycrystal) films having a crystal structure. This semi-amorphous semiconductor film is a semiconductor film having a third state that is stable in terms of free energy, and is a crystalline film having short-range order and lattice distortion, and has a grain size of 0.5 to 20 nm. And can be dispersed in the non-single-crystal semiconductor film. The semi-amorphous semiconductor film has its Raman spectrum shifted to a lower wavenumber than 520 cm ⁻¹ , and diffraction peaks of (111) and (220) that are derived from the Si crystal lattice are observed in X-ray diffraction. The Further, in order to terminate dangling bonds (dangling bonds), at least 1 atomic% or more of hydrogen or halogen is contained. In this specification, for convenience, such a semiconductor film is referred to as a semi-amorphous semiconductor (SAS) film. Further, by adding a rare gas element such as helium, argon, krypton, or neon to further promote lattice distortion, stability is improved and a good semi-amorphous semiconductor film can be obtained. Note that a microcrystalline semiconductor film is also included in the semi-amorphous semiconductor film.

The SAS film can be obtained by glow discharge decomposition of a gas containing silicon. A typical gas containing silicon is SiH ₄ , and Si ₂ H ₆ , SiH ₂ Cl ₂ , SiHCl ₃ , SiCl ₄ , SiF _{4, and the} like can also be used. In addition, it is easy to form a SAS film by diluting a gas containing silicon with hydrogen or a gas obtained by adding one or more kinds of rare gas elements selected from helium, argon, krypton, and neon to hydrogen. Can be. It is preferable to dilute the gas containing silicon within a range of a dilution rate of 2 to 1000 times. Furthermore, a gas containing silicon, a carbide gas such as CH ₄ or C ₂ H ₆ , a germanium gas such as GeH ₄ or GeF ₄ , F _2, or the like is mixed, so that the energy bandwidth is 1.5-2. It may be adjusted to .4 eV, or 0.9 to 1.1 eV.

  After the p-type semiconductor film 102 is formed, a semiconductor film (intrinsic semiconductor film) 103 and an n-type semiconductor film 104 that do not contain an impurity imparting conductivity type and an n-type semiconductor film 104 are sequentially formed (FIG. 1A). Thus, a photoelectric conversion layer including the p-type semiconductor film 102, the intrinsic semiconductor film (also referred to as i-type semiconductor film) 103, and the n-type semiconductor film 104 is formed.

  As the intrinsic semiconductor film 103, a semi-amorphous silicon film may be formed by a plasma CVD method, for example. Further, as the n-type semiconductor film 104, a semi-amorphous silicon film containing an impurity element of 15 group, for example, phosphorus (P) may be formed, or an impurity element of 15 group is introduced after the semi-amorphous silicon film is formed. May be. However, the amount of impurities is adjusted so that the electric conductivity of the p-type semi-amorphous semiconductor film 102 and the n-type semi-amorphous semiconductor film 104 is 1 S / cm.

  Further, as the p-type semiconductor film 102, the intrinsic semiconductor film 103, and the n-type semiconductor film 104, not only a semi-amorphous semiconductor film but also an amorphous semiconductor film may be used.

  Note that although the p-type semiconductor film, the intrinsic semiconductor film, and the n-type semiconductor film are stacked in this order in this embodiment mode, the p-type semiconductor film and the n-type semiconductor film may be stacked in the reverse order. That is, an n-type semiconductor film, an intrinsic semiconductor film, and a p-type semiconductor film may be stacked in this order.

  Next, an insulating film 106 having a groove-like opening (hereinafter referred to as “groove”, also referred to as “open hole”) 108 is formed over the n-type semiconductor film 104 by a screen printing method or the like (FIG. 1B). . The trench 108 is in contact with the n-type semiconductor film 104. Next, a groove 107 is formed in the insulating film 106, the n-type semiconductor film 104, the intrinsic semiconductor film 103, and the p-type semiconductor film 102 by laser scribing (FIG. 2A). The trench 107 is formed in the p-type semiconductor film 102, the intrinsic semiconductor film 103, and the n-type semiconductor film 104, and is in contact with the p-type semiconductor film 102. The width of the groove 107 is 50 μm to 300 μm.

  After the groove 107 is formed, the electrode layers 110 and 111 are formed by an inkjet method using a conductive paste (FIG. 2B). As the conductive paste, a conductive paste containing a metal material such as silver (Ag), gold (Au), copper (Cu), nickel (Ni), or a conductive carbon paste can be used. The electrode layers 110 and 111 may be formed by a screen printing method.

  Next, etching is performed using the electrode layers 110 and 111 and the insulating film 106 as a mask (FIG. 2C). By this etching, a part of the n-type semiconductor film 104, the intrinsic semiconductor film 103, and the insulating film 106 is etched to form the opening 120. By this step, the n-type semiconductor film 104 is removed, and a part of the intrinsic semiconductor film 103 is exposed. As a result, the n-type semiconductor film 104 is electrically disconnected from the electrode layer 110, and the electrode layers 110 and 111 are not short-circuited.

  Next, an insulating film 112 is formed so as to cover the electrode layers 110 and 111, the insulating film 106, the n-type semiconductor film 104, and the intrinsic semiconductor film 103 and the p-type semiconductor film 102 exposed by etching (FIG. 3A). . Further, grooves 121 and 122 are formed in the insulating film 112 again by laser scribing (FIG. 3B), and lead electrodes 113 and 114 are formed using a conductive paste (FIG. 3C). As the conductive paste, the material used when the electrode layers 110 and 111 are formed may be used.

  As described above, one cell of the optical sensor is created. In the photosensor manufactured in this embodiment, the p-type semiconductor film 102 and the n-type semiconductor film 104 among the p-type semiconductor film 102, the intrinsic semiconductor film 103, and the n-type semiconductor film 104 which are photoelectric conversion layers are substantially formed. Since it functions as an electrode, it is not necessary to form a transparent electrode.

  In the optical sensor of the present invention, the region 116 where the electrode layer 110 and the p-type semiconductor film 102 are in contact and the region 117 where the electrode layer 111 and the n-type semiconductor film 104 are in contact can be separated from each other by distance. The current flows through the extraction electrode 113, the electrode layer 110, the p-type semiconductor film 102, the intrinsic semiconductor film 103, the n-type semiconductor film 104, the electrode layer 111, and the extraction electrode 114. As described above, the region where the electrode layer 110 and the p-type semiconductor film 102 are in contact with each other and the region where the electrode layer 111 and the n-type semiconductor film 104 are in contact are separated from each other. It is possible to improve the withstand voltage against electrostatic breakdown.

A top view of the photosensor of FIG. 3C is shown in FIG. However, the insulating film 112 is not shown. When the distance X ₁ (μm) between the electrode layers 110 and 111 is increased, the resistance increases when X ₁ is large. Therefore it is necessary to determine the X ₁ in view of the breakdown voltage for the entire device resistance value and the electrostatic breakdown. That breakdown voltage becomes small against electrostatic breakdown decreases the resistance and X ₁ is too small. Meanwhile X ₁ is too high is too large element overall resistance, because no longer function as a device.

  Since an optical sensor in which electrostatic breakdown is suppressed according to the present invention can be manufactured, a highly reliable product incorporating such an optical sensor can be obtained.

  In addition, since the semiconductor film used for the photoelectric conversion layer can be used instead of the electrode, the thickness of the photosensor can be reduced as compared with the conventional case.

  Furthermore, the wavelength of light absorbed by the optical sensor of the present invention is made closer to the sensitivity of the human eye by using a semiconductor film used for the photoelectric conversion layer instead of the electrode without forming the transparent electrode that has been conventionally formed. Will be able to.

  In this embodiment, examples in which the optical sensor obtained by the present invention is incorporated into various electronic devices will be described. Examples of electronic devices to which the present invention is applied include computers, displays, mobile phones, and televisions. Specific examples of these electronic devices are shown in FIGS. 8, 9 </ b> A to 9 </ b> B, 10 </ b> A to 10 </ b> B, 11, and 19.

  FIG. 8 illustrates a mobile phone, which includes a main body (A) 601, a main body (B) 602, a housing 603, operation keys 604, an audio input unit 605, an audio output unit 606, a circuit board 607, a display panel (A) 608, and a display. A panel (B) 609, a hinge 610, a light-transmitting material portion 611, and an optical sensor 612 are provided. The present invention can be applied to the optical sensor 612.

  The optical sensor 612 detects light transmitted through the translucent material portion 611 and controls the luminance of the display panel (A) 608 and the display panel (B) 609 in accordance with the detected illuminance of external light, or the optical sensor 612. Illumination control of the operation key 604 is performed based on the illuminance obtained in the above. Thereby, current consumption of the mobile phone can be suppressed.

  9A and 9B illustrate another example of a mobile phone. 9A and 9B, 621 is a main body, 622 is a housing, 623 is a display panel, 624 is an operation key, 625 is an audio output unit, 626 is an audio input unit, and 627 and 628 are optical sensors. Part.

  In the cellular phone illustrated in FIG. 9A, the luminance of the display panel 623 and the operation keys 624 can be controlled by detecting external light using the optical sensor portion 628 provided in the main body 621.

  In addition, in the mobile phone illustrated in FIG. 9B, an optical sensor portion 628 is provided inside the main body 621 in addition to the structure in FIG. The light sensor portion 628 can also detect the luminance of the backlight provided in the display panel 623.

  FIG. 10A illustrates a computer, which includes a main body 631, a housing 632, a display portion 633, a keyboard 634, an external connection port 635, a pointing mouse 636, and the like.

  FIG. 10B shows a display device, which corresponds to a television receiver or the like. This display device includes a housing 641, a support base 642, a display portion 643, and the like.

  FIG. 11 shows a detailed structure in the case where a liquid crystal panel is used as the display portion 633 provided in the computer in FIG. 10A and the display portion 643 of the display device in FIG.

  A liquid crystal panel 662 illustrated in FIG. 11 is incorporated in a housing 661 and includes substrates 651a and 651b, a liquid crystal layer 652 sandwiched between the substrates 651a and 651b, polarizing filters 653a and 653b, a backlight 654, and the like. Yes. An optical sensor portion 655 is formed in the housing 661.

  The light sensor unit 655 manufactured using the present invention senses the amount of light from the backlight 654, and the information is fed back to adjust the luminance of the liquid crystal panel 662.

  FIG. 19A and FIG. 19B are diagrams showing an example in which the photosensor of the present invention is incorporated in a camera, for example, a digital camera. FIG. 19A is a perspective view seen from the front side of the digital camera, and FIG. 19B is a perspective view seen from the rear side. In FIG. 19A, the digital camera includes a release button 1301, a main switch 1302, a finder window 1303, a flash 1304, a lens 1305, a lens barrel 1306, and a housing 1307.

  In FIG. 19B, a finder eyepiece window 1311, a monitor 1312, and operation buttons 1313 are provided.

  When the release button 1301 is pressed down to a half position, the focus adjustment mechanism and the exposure adjustment mechanism are operated, and when the release button 1301 is pressed down to the lowest position, the shutter is opened.

  A main switch 1302 is turned on / off by pressing or rotating the digital camera.

  The finder window 1303 is disposed on the front of the lens 1305 on the front surface of the digital camera, and is a device for confirming the shooting range and focus position from the finder eyepiece window 1311 shown in FIG.

  The flash 1304 is arranged at the upper front of the digital camera, and emits auxiliary light simultaneously with the release button being pressed to open the shutter when the subject brightness is low.

  The lens 1305 is disposed in front of the digital camera. The lens is composed of a focusing lens, a zoom lens, and the like, and constitutes a photographing optical system together with a shutter and a diaphragm (not shown). In addition, an imaging element such as a CCD (Charge Coupled Device) is provided behind the lens.

  The lens barrel 1306 moves the lens position in order to focus the focusing lens, the zoom lens, and the like. During photographing, the lens 1305 is moved forward to move the lens 1305 forward. In addition, when carrying, the lens 1305 is moved down to be compact. In this embodiment, the structure is such that the subject can be zoomed by extending the lens barrel. However, the structure is not limited to this structure, and the structure of the imaging optical system in the housing 1307 is not limited. It may be a digital camera capable of zooming without extending the cylinder.

  The viewfinder eyepiece window 1311 is provided on the upper rear surface of the digital camera, and is a window provided for eye contact when confirming a shooting range and a focus position.

  The operation buttons 1313 are various function buttons provided on the rear surface of the digital camera, and include a setup button, a menu button, a display button, a function button, a selection button, and the like.

  When the optical sensor of the present invention is incorporated in the camera shown in FIGS. 19A and 19B, the optical sensor can detect the presence and intensity of light, thereby adjusting the exposure of the camera. Can do.

  The optical sensor of the present invention can be applied to other electronic devices such as a projection television and a navigation system. In other words, it can be used for any object that needs to detect light.

  In this embodiment, an example in which an auxiliary electrode is provided will be described with reference to FIGS. 4A to 4B and FIG.

  In FIG. 4A, 201 is a substrate, 203 is a p-type semiconductor film, 205 is an intrinsic semiconductor film, and 206 is an n-type semiconductor film. 207 and 208 are electrode layers, 209 and 210 are insulating films, and 211 and 212 are lead electrodes.

In this example, an auxiliary electrode 204 is added to the structure of the embodiment. The auxiliary electrode 204 may be formed using a conductive film. In this embodiment, a transparent conductive film is used as the conductive film, and an indium tin oxide alloy containing silicon (Si) (also referred to as indium tin oxide containing Si) is used as the transparent conductive film material. In addition to an indium tin oxide alloy containing Si, a target in which zinc oxide (ZnO), tin oxide (SnO ₂ ), indium oxide and indium oxide are further mixed with 2 to ₂₀ wt% zinc oxide (ZnO) is used. The formed conductive film material may be used.

  In addition, the auxiliary electrode 204 may be formed using a conductive film that is not a transparent conductive film as long as the area of the light receiving region can be secured sufficiently. As such a conductive film, titanium (Ti), tungsten (W), tantalum (Ta), molybdenum (Mo), neodymium (Nd), cobalt (Co), zirconium (Zr), zinc (Zn), ruthenium (Ru). ), Rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), aluminum (Al), gold (Au), silver (Ag), copper (Cu) A single layer film made of an element, or an alloy material or a compound material containing the element as a main component, or a single layer film made of a nitride thereof, for example, titanium nitride, tungsten nitride, tantalum nitride, or molybdenum nitride is used. it can.

  When the auxiliary electrode 204 is formed, the resistance of the entire element is lowered, while the auxiliary electrode 204 is formed in contact with the p-type semiconductor film 203 so that the electric resistances of the p-type semiconductor film 203 and the n-type semiconductor film 206 are made uniform. There is an advantage that can be.

  When the auxiliary electrode 204 is used, as shown in FIG. 4B, the auxiliary electrode 204 is etched as an etching stopper when the intrinsic semiconductor film 205 for separating the electrode layers 207 and 208 is etched. Can do. Therefore, the intrinsic semiconductor film 205 and the p-type semiconductor film 203 can be etched until the auxiliary electrode 204 is exposed.

  A top view of the photosensor of FIG. 4B is shown in FIG. However, in order to make the drawing easy to see, the insulating film 209 is represented by a region surrounded by a dotted line, and the insulating film 210 is not shown. The grooves 221 and 222 correspond to the grooves 107 and 108 in FIG.

When the distance X ₂ (μm) between the auxiliary electrode 204 and the electrode layer 208 is set, the resistance increases when X ₂ is large. Therefore it is necessary to determine the X ₂ in view of the breakdown voltage for the entire device resistance value and the electrostatic breakdown. That breakdown voltage becomes small against electrostatic breakdown decreases the resistance and X ₂ is too small. Whereas X ₂ is too high is too large element overall resistance, because no longer function as a device.

  In addition, this embodiment can be applied to any description in Embodiment Mode and Embodiment 1.

  In this embodiment, an example in which a color filter is formed in the optical sensor of the present invention will be described with reference to FIGS.

  FIG. 7A shows an optical sensor in which a color filter is formed in FIG. 7A includes a substrate 301, a p-type semiconductor film 302, an intrinsic semiconductor film 303, an n-type semiconductor film 304, an insulating film 305, electrode layers 306 and 307, an insulating film 308, and extraction electrodes 309 and 310. In addition, a color filter 311 is formed.

  By providing the color filter 311, light of red (R), green (G), and blue (B) can be selectively absorbed.

  FIG. 7B illustrates an example in which a color filter is formed between the substrate and the photoelectric conversion layer.

  In FIG. 7B, 321 is a substrate, 322 is a p-type semiconductor film, 323 is an intrinsic semiconductor film, 324 is an n-type semiconductor film, 325 and 328 are insulating films, 326 and 327 are electrode layers, and 329 and 330 are lead-out films. Electrodes, 331 are color filters, and 332 are passivation films. The passivation film 332 may be formed using the same material as the insulating film 325.

  In the structure as shown in FIG. 7B, even if light entering from the substrate side passes through the color filter even if it is oblique, incident light can be used effectively.

  In addition, this embodiment can be applied to any description of the embodiment mode and Embodiments 1 and 2.

  In this embodiment, a semiconductor device using the photoelectric conversion device of the present invention is illustrated in FIGS. 13A to 13B, FIGS. 14A to 14B, and FIGS. This will be described with reference to (C), FIGS. 16, 17, and 20A to 20D.

  FIG. 13A shows an example of a two-terminal visible light sensor chip (2.0 mm × 1.5 mm) as an example of a semiconductor device using the photoelectric conversion device of the present invention. In FIG. 13A, reference numeral 710 denotes a substrate, 712 denotes a base insulating film, and 713 denotes a gate insulating film. Since the light to be received passes through the substrate 710, the base insulating film 712, and the gate insulating film 713, it is desirable to use materials having high light-transmitting properties for all of these materials.

  The PIN photoelectric conversion element 725 may be formed based on the description of the embodiment mode, and its structure is shown in this example. A photoelectric conversion element 725 in this example includes a wiring 719, a protective electrode 718, a p-type semiconductor layer 721 p that is a photoelectric conversion layer 721, an n-type semiconductor layer 721 n, and between the p-type semiconductor layer 721 p and the n-type semiconductor layer 721 n. An intrinsic (i-type) semiconductor layer 721i and a terminal electrode 726.

  The wiring 719 has a stacked structure of a refractory metal film and a low resistance metal film (such as an aluminum alloy or pure aluminum). Here, the wiring 719 has a three-layer structure in which a titanium film (Ti film), an aluminum film (Al film), and a Ti film are sequentially stacked. A protective electrode 718 is formed so as to cover the wiring 719.

  When the photoelectric conversion layer 721 is etched, the wiring 719 is protected by the protective electrode 718 that covers the wiring 719. The material of the protective electrode 718 is preferably a conductive material whose etching rate is lower than that of the photoelectric conversion layer with respect to a gas (or etchant) for etching the photoelectric conversion layer 721. In addition, the material of the protective electrode 718 is preferably a conductive material that does not react with the photoelectric conversion layer 721 to form an alloy.

  Further, a circuit for signal processing the output value of the PIN photoelectric conversion element 725 is provided. In this embodiment, an amplifier circuit is provided as a circuit for processing an output value of the photoelectric conversion element 725. An amplifier circuit provided on the same substrate for amplifying the output value of the photoelectric conversion element 725 includes a current mirror circuit 732 including n-channel thin film transistors (TFTs) 730 and 731 (FIG. 13 (A)).

  FIG. 13B shows an equivalent circuit diagram of a two-terminal visible light sensor. FIG. 13B is an equivalent circuit diagram using n-channel TFTs, but only p-channel TFTs may be used instead of n-channel TFTs.

  Although two TFTs are shown in FIG. 13A, in order to actually increase the output value by a factor of 5, for example, an n-channel TFT 730 (channel length (L) and channel width (W) are each 8 μm). , 50 μm) and ten n-channel TFTs 731 (channel length (L) and channel width (W) are 8 μm and 50 μm, respectively).

  Further, in order to increase the output value by m, one n-channel TFT 730 and m n-channel TFT 731 may be provided. For example, FIG. 16 shows an example in which one n-channel TFT 730 and 100 n-channel TFT 731 are provided to increase the output value by 100 times. In FIG. 16, the same components as those in FIGS. 13A to 13B and FIGS. 14A to 14C are denoted by the same reference numerals. In FIG. 16, an n-channel TFT 731 is composed of 100 n-channel TFTs 731a, 731b, 731c, 731d. As a result, the photocurrent generated in the photoelectric conversion element 725 is amplified 100 times and output.

  Note that when the amplifier circuit is formed of a p-channel TFT, an equivalent circuit diagram shown in FIG. 17 is obtained. In FIG. 17, terminal electrodes 726 and 753 are the same as FIG. 13B, but a photoelectric conversion element 825 and p-channel TFTs 830 and 831 may be connected as shown in FIG. The p-channel TFT 830 is electrically connected to the anode electrode of the photoelectric conversion element 825. The photoelectric conversion element 825 is formed by sequentially stacking an n-type semiconductor layer, an intrinsic semiconductor layer (i-type semiconductor layer), and a p-type semiconductor layer on a second electrode (anode side electrode) connected to the p-channel TFT 830. The first electrode (cathode side electrode) may be formed. Alternatively, a photoelectric conversion element in which the stacking order is reversed may be used. A p-type semiconductor layer, an intrinsic semiconductor layer (i-type semiconductor layer), and an n-type semiconductor layer are sequentially stacked on the first electrode (cathode side electrode). Thereafter, a second electrode (anode electrode) connected to the p-channel TFT 830 may be formed, and a cathode terminal electrode connected to the first electrode may be formed.

  Further, an amplifier circuit for amplifying the output value may be constituted by an operational amplifier (op-amp) in which n-channel TFTs or p-channel TFTs are appropriately combined, but has five terminals. In addition, an operational amplifier can be configured by an operational amplifier and a level shifter can be used to reduce the number of power supplies to four terminals.

  However, in this embodiment, an amplifier circuit for amplifying the output value is formed. However, if necessary, a circuit for converting the output value into another output format may be produced instead of the amplifier circuit.

  In FIG. 13A, n-channel TFTs 730 and 731 each show an example of a top gate TFT having a structure including one channel formation region (referred to as a “single gate structure” in this specification). Variation in on-state current value may be reduced by using a structure having a plurality of formation regions. In order to reduce the off-current value, lightly doped drain (LDD) regions may be provided in the n-channel TFTs 730 and 731. An LDD region is a region in which an impurity element is added at a low concentration between a channel formation region and a source region or a drain region formed by adding an impurity element at a high concentration. When the LDD region is provided, This has the effect of relaxing the electric field in the vicinity of the drain region and preventing deterioration due to hot carrier injection. In order to prevent deterioration of the on-current value due to hot carriers, a structure in which n-channel TFTs 730 and 731 are arranged with an LDD region overlapped with a gate electrode with a gate insulating film interposed therebetween (in this specification, “GOLD (Gate− (Drain Overlapped LDD) structure ”).

  When the GOLD structure is used, the electric field in the vicinity of the drain region is further relaxed and the deterioration due to hot carrier injection is prevented as compared with the case where the GOLD structure is not overlapped with the LDD region gate electrode. By adopting such a GOLD structure, the electric field strength in the vicinity of the drain region is relaxed and hot carrier injection is prevented, which is effective in preventing a deterioration phenomenon.

  A wiring 714 is a wiring connected to the wiring 719 and extends above the channel formation region of the TFT 730 of the amplifier circuit and serves as a gate electrode.

  A wiring 715 is a wiring connected to the n-type semiconductor layer 721n and is connected to a drain wiring (also referred to as a drain electrode) or a source wiring (also referred to as a source electrode) of the TFT 731. Reference numerals 716 and 717 denote insulating films, and 720 denotes a connection electrode. Since the light to be received passes through the insulating films 716 and 717, it is preferable to use materials having high light-transmitting properties for these materials. Note that the insulating film 717 is preferably a silicon oxide (SiOx) film formed by a CVD method. When the insulating film 717 is a silicon oxide film formed by a CVD method, the fixing strength is improved.

  The terminal electrode 750 is formed in the same process as the wirings 714 and 715, and the terminal electrode 751 is formed in the same process as the wirings 719 and 720.

  The terminal electrode 726 is connected to the n-type semiconductor layer 721n, and is mounted on the electrode 761 of the printed wiring board 760 with solder 764. The terminal electrode 753 is formed in the same process as the terminal electrode 726, and is mounted on the electrode 762 of the printed wiring board 760 with solder 763.

  In addition, a manufacturing process for obtaining the above structure is described below with reference to FIGS. 14A to 14C and FIGS. 20A to 20D.

  First, an element is formed over a substrate (first substrate 710). Here, AN100 which is one of glass substrates is used as the substrate 710.

  Next, a silicon oxide film containing nitrogen (film thickness: 100 nm) is formed as a base insulating film 712 by plasma CVD, and further a semiconductor film such as an amorphous silicon film containing hydrogen (film thickness: 54 nm) is exposed to the atmosphere. Are stacked. The base insulating film 712 may be stacked using a silicon oxide film, a silicon nitride film, or a silicon oxide film containing nitrogen. For example, a film in which a silicon nitride film containing oxygen is stacked with a thickness of 50 nm and a silicon oxide film containing nitrogen is stacked with a thickness of 100 nm may be formed as the base insulating film 712. Note that the silicon oxide film or silicon nitride film containing nitrogen functions as a blocking layer for preventing diffusion of impurities such as alkali metal from the glass substrate.

  Next, the amorphous silicon film is crystallized by a known technique (solid phase growth method, laser crystallization method, crystallization method using a catalytic metal, etc.), and a semiconductor film having a crystal structure (crystalline semiconductor film) For example, a polycrystalline silicon film is formed. Here, a polycrystalline silicon film is obtained by a crystallization method using a catalytic element. A nickel acetate solution containing 10 ppm nickel by weight is added with a spinner. In addition, it may replace with spinner addition and may use the method of spraying nickel element on the whole surface by a sputtering method. Next, heat treatment is performed for crystallization to form a semiconductor film having a crystal structure (here, a polycrystalline silicon film). Here, after heat treatment (500 ° C., 1 hour), heat treatment for crystallization (550 ° C., 4 hours) is performed to obtain a polycrystalline silicon film.

  Next, the oxide film on the surface of the polycrystalline silicon film is removed with dilute hydrofluoric acid or the like. After that, irradiation with laser light (XeCl: wavelength 308 nm) for increasing the crystallization rate and repairing defects left in the crystal grains is performed in the air or an oxygen atmosphere.

As the laser light, excimer laser light having a wavelength of 400 nm or less, or the second harmonic or the third harmonic of a YAG laser is used. Here, a pulsed laser beam having a repetition frequency of about 10 to 1000 Hz is used, the laser beam is condensed to 100 to 500 mJ / cm ² by an optical system, and irradiated with an overlap rate of 90 to 95%. May be scanned. In this embodiment, laser light irradiation is performed in the atmosphere at a repetition frequency of 30 Hz and an energy density of 470 mJ / cm ² .

Note that an oxide film is formed on the surface by irradiation with a laser beam because it is performed in the air or in an oxygen atmosphere. Although an example using a pulse laser is shown in this embodiment, a continuous wave laser may be used. In order to obtain a crystal with a large grain size when crystallizing a semiconductor film, continuous oscillation is possible. It is preferable to apply a second to fourth harmonic of the fundamental wave using a solid-state laser. Typically, a second harmonic (532 nm) or a third harmonic (355 nm) of an Nd: YVO ₄ laser (fundamental wave 1064 nm) may be applied.

In the case of using a continuous wave laser, laser light emitted from a continuous wave YVO ₄ laser having an output of 10 W is converted into a harmonic by a non-linear optical element. There is also a method of emitting harmonics by putting a YVO ₄ crystal and a nonlinear optical element in a resonator. Preferably, the laser beam is shaped into a rectangular or elliptical shape on the irradiation surface by an optical system, and the object to be processed is irradiated. At this time, the energy density of approximately 0.01 to 100 MW / cm ² (preferably 0.1 to 10 MW / cm ²⁾ is required. Then, irradiation may be performed by moving the semiconductor film relative to the laser light at a speed of about 10 to 2000 cm / s.

  Next, in addition to the oxide film formed by the laser light irradiation, the surface is treated with ozone water for 120 seconds to form a barrier layer made of an oxide film having a total thickness of 1 to 5 nm. This barrier layer is formed to remove a catalyst element added for crystallization, for example, nickel (Ni) from the film. Here, the barrier layer is formed using ozone water, but the surface of the semiconductor film having a crystal structure is oxidized by a method of oxidizing the surface of the semiconductor film having a crystal structure by irradiation with ultraviolet light in an oxygen atmosphere or the oxygen plasma treatment. The barrier layer may be formed by depositing an oxide film of about 1 to 10 nm by a method, plasma CVD method, sputtering method or vapor deposition method. Further, the oxide film formed by laser light irradiation may be removed before forming the barrier layer.

Next, an amorphous silicon film containing an argon element serving as a gettering site is formed with a thickness of 10 to 400 nm, here 100 nm, over the barrier layer by a sputtering method. Here, the amorphous silicon film containing an argon element is formed using a silicon target in an atmosphere containing argon. In the case where an amorphous silicon film containing an argon element is formed using a plasma CVD method, the film formation conditions are a monosilane / argon flow rate ratio (SiH ₄ : Ar) of 1:99 and a film formation pressure of 6.665 Pa. The RF power density is 0.087 W / cm ² and the film formation temperature is 350 ° C.

  Thereafter, the catalyst element is removed (gettering) by performing a heat treatment for 3 minutes in a furnace heated to 650 ° C. As a result, the concentration of the catalytic element in the semiconductor film having a crystal structure is reduced. A lamp annealing apparatus may be used instead of the furnace.

  Next, the amorphous silicon film containing an argon element which is a gettering site is selectively removed using the barrier layer as an etching stopper, and then the barrier layer is selectively removed with dilute hydrofluoric acid. Note that during gettering, nickel tends to move to a region with a high oxygen concentration, and thus it is desirable to remove the barrier layer made of an oxide film after gettering.

  Note that in the case where the semiconductor film is not crystallized using a catalytic element, the above-described barrier layer formation, gettering site formation, heat treatment for gettering, gettering site removal, barrier layer removal, etc. This step is unnecessary.

  Next, after forming a thin oxide film with ozone water on the surface of the obtained semiconductor film having a crystalline structure (for example, a crystalline silicon film), a mask made of resist is formed using a first photomask, and a desired film is formed. Semiconductor films (referred to as “island semiconductor regions” in this specification) 741 and 742 that are separated into island shapes by etching treatment are formed (see FIG. 20A). After the island-shaped semiconductor regions 741 and 742 are formed, the resist mask is removed.

Next, if necessary, a small amount of impurity element (boron or phosphorus) is doped in order to control the threshold value of the TFT. Here, an ion doping method in which diborane (B ₂ H ₆ ) is plasma-excited without mass separation is used.

  Next, the oxide film is removed with an etchant containing hydrofluoric acid, and at the same time, the surface of the island-shaped semiconductor region is washed, and then an insulating film containing silicon as a main component and serving as the gate insulating film 713 is formed. Here, a silicon oxide film containing nitrogen (composition ratio: Si = 32%, O = 59%, N = 7%, H = 2%) with a thickness of 115 nm is formed by a plasma CVD method.

  Next, after a metal film is formed over the gate insulating film 713, gate electrodes 744 and 745, wirings 714 and 715, and a terminal electrode 750 are formed using a second photomask (see FIG. 20B). As this metal film, for example, a film in which tantalum nitride (TaN) and tungsten (W) are stacked in a thickness of 30 nm and 370 nm, respectively, is used.

  In addition to the above, the gate electrodes 744 and 745, the wirings 714 and 715, and the terminal electrode 750 include titanium (Ti), tungsten (W), tantalum (Ta), molybdenum (Mo), neodymium (Nd), cobalt (Co ), Zirconium (Zr), zinc (Zn), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), aluminum (Al), gold (Au) ), Silver (Ag), copper (Cu), or a single layer film made of an alloy material or a compound material containing the element as a main component, or a nitride thereof, for example, titanium nitride, tungsten nitride A single layer film made of tantalum nitride or molybdenum nitride can be used.

  Next, the island-shaped semiconductor regions 741 and 742 are doped to form a source region or a drain region 747 of the TFT 730 and a source region or a drain region 748 of the TFT 731 (see FIG. 20C). A channel formation region is formed between the source region and the drain region in the island-shaped semiconductor region 741 of the TFT 730, and a channel formation region is formed between the source region and the drain region in the island-shaped semiconductor region 742 of the TFT 731. The

  Next, after forming a first interlayer insulating film (not shown) including a silicon oxide film by CVD with a thickness of 50 nm, a step of activating the impurity element added to each island-like semiconductor region is performed. This activation process is performed by a rapid thermal annealing method (RTA method) using a lamp light source, a method of irradiating a YAG laser or an excimer laser from the back surface, a heat treatment using a furnace, or a combination thereof. By different methods.

  Next, a second interlayer insulating film 716 including a silicon nitride film containing hydrogen and oxygen is formed with a thickness of 10 nm, for example.

  Next, a third interlayer insulating film 717 made of an insulating material is formed over the second interlayer insulating film 716 (see FIG. 20D). As the third interlayer insulating film 717, an insulating film obtained by a CVD method can be used. In this embodiment, in order to improve adhesion, a silicon oxide film containing nitrogen formed with a thickness of 900 nm is formed as the third interlayer insulating film 717.

  Next, heat treatment (300 to 550 ° C. for 1 to 12 hours, for example, in a nitrogen atmosphere at 410 ° C. for 1 hour) is performed to hydrogenate the island-shaped semiconductor film. This step is performed in order to terminate dangling bonds of the island-shaped semiconductor film with hydrogen contained in the second interlayer insulating film 716. The island-shaped semiconductor film can be hydrogenated regardless of the presence of the gate insulating film 713.

  Further, as the third interlayer insulating film 717, an insulating film using siloxane and a stacked structure thereof can be used. Siloxane has a skeleton structure with a bond of silicon (Si) and oxygen (O). As a substituent, a compound containing at least hydrogen (for example, an alkyl group or aromatic hydrocarbon) is used. Fluorine may be used as a substituent. Alternatively, as a substituent, a compound containing at least hydrogen and fluorine may be used.

  In the case where an insulating film using siloxane and a stacked structure thereof are used as the third interlayer insulating film 717, a heat treatment for hydrogenating the island-shaped semiconductor film is performed after forming the second interlayer insulating film 716. Next, a third interlayer insulating film 717 can be formed.

  Next, a resist mask is formed using a third photomask, and the first interlayer insulating film, the second interlayer insulating film 716, the third interlayer insulating film 717, and the gate insulating film 713 are selectively etched. A contact hole is formed. Then, the resist mask is removed.

  Note that the third interlayer insulating film 717 may be formed as necessary. When the third interlayer insulating film 717 is not formed, the first interlayer insulating film and the second interlayer insulating film 716 are formed after the second interlayer insulating film 716 is formed. The second interlayer insulating film 716 and the gate insulating film 713 are selectively etched to form contact holes.

  Next, after a metal laminated film is formed by a sputtering method, a mask made of a resist is formed using a fourth photomask, and the metal film is selectively etched to form a wiring 719, a connection electrode 720, and a terminal electrode 751. The source or drain electrode 771 of the TFT 730 and the source or drain electrode 772 of the TFT 731 are formed. Then, the resist mask is removed. Note that the metal laminated film of this example is formed by laminating three layers of a Ti film with a thickness of 100 nm, an Al film containing a trace amount of Si with a thickness of 350 nm, and a Ti film with a thickness of 100 nm.

  Through the above steps, top-gate TFTs 730 and 731 using a polycrystalline silicon film can be manufactured.

  Next, after forming a conductive metal film (such as titanium (Ti) or molybdenum (Mo)) that hardly reacts with a photoelectric conversion layer (typically amorphous silicon) to be formed later, A mask made of a resist is formed using this photomask, and a conductive metal film is selectively etched to form a protective electrode 718 covering the wiring 719 (FIG. 14A). Here, a 200-nm-thick Ti film obtained by sputtering is used. Similarly, the connection electrode 720, the terminal electrode 751, and the source or drain electrode of the TFT are also covered with a conductive metal film. Accordingly, the conductive metal film also covers the side surface of the electrode where the second Al film is exposed, and the conductive metal film can prevent diffusion of aluminum atoms into the photoelectric conversion layer.

  Next, the photoelectric conversion layer 721 is formed. The photoelectric conversion layer 721 may be formed based on the description of Embodiment Mode and Examples 1 to 3.

  Next, a sealing layer 724 made of an insulating material (for example, an inorganic insulating film containing silicon) is formed over the entire surface with a thickness (1 μm to 30 μm) to obtain the state shown in FIG. Here, a silicon oxide film containing nitrogen having a thickness of 1 μm is formed as the insulating material film by a CVD method. Adhesion is improved by using an insulating film formed by CVD.

  Next, after the sealing layer 724 is etched to provide an opening, terminal electrodes 726 and 753 are formed by a sputtering method. The terminal electrodes 726 and 753 are laminated films of a titanium film (Ti film) (100 nm), a nickel film (Ni) film (300 nm), and a gold film (Au film) (50 nm). The fixing strength of the terminal electrode 726 and the terminal electrode 753 thus obtained exceeds 5N, and has a sufficient fixing strength as a terminal electrode.

  Through the above steps, the terminal electrode 726 and the terminal electrode 753 that can be soldered are formed, and the structure illustrated in FIG. 14C is obtained.

  Next, a plurality of optical sensor chips are cut out individually. A large amount of optical sensor chips (2 mm × 1.5 mm) can be manufactured from one large-area substrate (for example, 600 cm × 720 cm).

  A sectional view (side view) of one cut out optical sensor chip (2 mm × 1.5 mm) is shown in FIG. 15A, a bottom view thereof is shown in FIG. 15B, and a top view thereof is shown in FIG. . In FIG. 15, the same reference numerals are used for portions that are the same as those in FIGS. 13 and 14. 15A, the total film thickness including the substrate 710, the element formation region 800, the terminal electrode 726, and the terminal electrode 753 is 0.8 ± 0.05 mm.

  In addition, in order to reduce the total film thickness of the optical sensor chip, the substrate 710 may be thinned by CMP processing or the like and then individually cut with a dicer to cut out a plurality of optical sensor chips.

In FIG. 15B, one electrode size of the terminal electrodes 726 and 753 is 0.6 mm × 1.1 mm, and the electrode interval is 0.4 mm. In FIG. 15C, the area of the light receiving portion 801 is approximately equal to the area of the second electrode and is 1.57 mm ² . The amplifier circuit portion 802 is provided with about 100 TFTs.

  Finally, the obtained optical sensor chip is mounted on the mounting surface of the printed wiring board 760. The terminal electrodes 726 and 761 and the terminal electrodes 753 and 762 are connected by using solders 764 and 763, respectively, which are previously formed on the electrodes 761 and 762 of the printed wiring board 760 by a screen printing method or the like. Then, after the solder and the terminal electrode are in contact with each other, the solder reflow process is performed for mounting. The solder reflow process is performed, for example, in an inert gas atmosphere at a temperature of about 255 ° C. to 265 ° C. for about 10 seconds. In addition to solder, bumps formed of metal (gold, silver, etc.) or bumps formed of conductive resin can be used. Moreover, you may mount using lead-free solder in consideration of an environmental problem.

  FIG. 14A shows an optical sensor chip mounted through the above steps. The photosensor of the present invention (a circuit-integrated photosensor having an amplifier circuit that increases the output value by 100) can obtain a photocurrent of about 10 μA at an illuminance of 100 lux. The sensitivity wavelength range of the optical sensor of the present invention is 350 to 750 nm, and the peak sensitivity wavelength is 580 nm. The dark current (Vr = 5V) is 1000 pA.

  Note that this embodiment can be combined with any description in Embodiment Mode and Embodiments 1 to 3.

  In this embodiment, an example different from that of Embodiment 2 is shown for an optical sensor provided with an auxiliary electrode, with reference to FIGS.

  18A includes an auxiliary electrode 902, a p-type semiconductor film 903, an intrinsic semiconductor film 904, an n-type semiconductor film 905, a first insulating film 906, a second insulating film 907, An electrode layer 911, an electrode layer 912, an extraction electrode 913, and an extraction electrode 914 are provided.

A manufacturing process of the optical sensor of this example is described below. First, the auxiliary electrode 902 is formed over the substrate 901 with a transparent conductive film. In this embodiment, an indium tin oxide alloy containing silicon (Si) (also referred to as indium tin oxide containing Si) is used as the transparent conductive film material. In addition to the indium tin oxide alloy containing Si, it is formed using a target in which zinc oxide (ZnO), tin oxide (SnO ₂ ), indium oxide, and indium oxide are mixed with ₂ to 20 wt% zinc oxide (ZnO). Alternatively, an indium zinc oxide alloy may be used.

  In addition, the auxiliary electrode 902 may be formed using a conductive film that is not a transparent conductive film, for example, a light-shielding conductive film, as long as the area of the light receiving region can be secured sufficiently. As such a conductive film, titanium (Ti), tungsten (W), tantalum (Ta), molybdenum (Mo), neodymium (Nd), cobalt (Co), zirconium (Zr), zinc (Zn), ruthenium (Ru). ), Rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), aluminum (Al), gold (Au), silver (Ag), copper (Cu) A single layer film made of an element, or an alloy material or a compound material containing the element as a main component, or a single layer film made of a nitride thereof, for example, titanium nitride, tungsten nitride, tantalum nitride, or molybdenum nitride is used. it can.

  When the auxiliary electrode 902 is formed, a photoelectric conversion layer including a p-type semiconductor film 903, an intrinsic semiconductor film 904, and an n-type semiconductor film 905 is formed. Note that the photoelectric conversion layer including the p-type semiconductor film 903, the intrinsic semiconductor film 904, and the n-type semiconductor film 905 may be stacked in the reverse order, that is, the n-type semiconductor film, the intrinsic semiconductor film, and the p-type semiconductor film. A photoelectric conversion layer may be formed by stacking in order.

  In this embodiment, for example, a p-type semi-amorphous semiconductor film is formed as the p-type semiconductor film 903. As the p-type semi-amorphous semiconductor film, a semi-amorphous silicon film containing an impurity element belonging to Group 13 such as boron (B) is formed by a plasma CVD method.

  After the p-type semiconductor film 903 is formed, a semiconductor film (intrinsic semiconductor film) 904 and an n-type semiconductor film 905 that do not contain an impurity imparting conductivity type are formed in order.

  As the intrinsic semiconductor film 904, a semi-amorphous silicon film may be formed by a plasma CVD method, for example. Further, as the n-type semiconductor film 905, a semi-amorphous silicon film containing an impurity element of 15 group, for example, phosphorus (P) may be formed, or an impurity element of 15 group is introduced after the semi-amorphous silicon film is formed. May be. However, the amount of impurities is adjusted so that the electric conductivity of the p-type semi-amorphous semiconductor film 903 and the n-type semi-amorphous semiconductor film 905 is 1 S / cm.

  Further, as the p-type semiconductor film 903, the intrinsic semiconductor film 904, and the n-type semiconductor film 905, not only a semi-amorphous semiconductor film but also an amorphous semiconductor film may be used.

  Next, a first insulating film 906 is formed over the n-type semiconductor film 905 by screen printing or the like.

  Next, the p-type semiconductor film 903, the intrinsic semiconductor film 904, the n-type semiconductor film 905, and the first insulating film 906 are etched to expose part of the auxiliary electrode 902. That is, the p-type semiconductor film 903, the intrinsic semiconductor film 904, the n-type semiconductor film 905, and the first insulating film 906 overlap with another part of the auxiliary electrode 902, and the p-type semiconductor film 903 and the intrinsic semiconductor film A photoelectric conversion layer formed of 904 and the n-type semiconductor film 905 overlaps and is in contact with another part of the auxiliary electrode 902. Thereafter, a second insulating film 907 is formed to cover the auxiliary electrode 902, the p-type semiconductor film 903, the intrinsic semiconductor film 904, the n-type semiconductor film 905, and the first insulating film 906.

  Next, contact holes (grooves) are formed in the first insulating film 906 and the second insulating film 907, and electrode layers 911 and 912 are formed by a screen printing method using a conductive paste. As the conductive paste, a conductive paste containing a metal material such as silver (Ag), gold (Au), copper (Cu), nickel (Ni), or a conductive carbon paste can be used. The electrode layers 911 and 912 may be formed by an ink jet method. That is, the electrode layer 911 is connected to a part of the auxiliary electrode 902 instead of the entire surface instead of the entire surface of the auxiliary electrode 902, and the electrode layer 912 is connected to a part of the n-type semiconductor film 905, not the entire surface. Connected.

  Further, if necessary, lead electrodes 913 and 914 are formed in contact with the electrode layers 911 and 912 (FIG. 18A). The extraction electrodes 913 and 914 may be formed in the same manner as the electrode layers 911 and 912.

  FIG. 18B shows an example in which an electrode is formed on the photoelectric conversion layer of the photosensor in FIG. 18B, an auxiliary electrode 932 is formed over a substrate 931, and a photoelectric conversion layer including a p-type semiconductor film 933, an intrinsic semiconductor film 934, and an n-type semiconductor film 935 overlaps with and is in contact with part of the auxiliary electrode 932. ing.

  Next, an upper electrode 936 is formed over the n-type semiconductor film 935 so as to overlap with part of the n-type semiconductor film 935. The upper electrode 936 may be formed using a material similar to that of the auxiliary electrode 932.

  Further, a first insulating film 937 and a second insulating film 938 are formed, contact holes (grooves) are formed, and then electrode layers 941 and 942 are formed. Further, lead electrodes 943 and 944 are formed as necessary. The first insulating film 937, the second insulating film 938, the electrode layers 941 and 942, and the extraction electrodes 943 and 944 may be formed using the same materials and manufacturing steps as those in FIG.

  When the upper electrode 936 is formed, the resistance of the entire photosensor is reduced, but the resistance value of the photosensor can be adjusted by the distance between the auxiliary electrode 932 and the upper electrode 936.

When the length of the region where the auxiliary electrode 932 and the p-type semiconductor film 933 overlap is X ₃ (= 100 μm) and the distance between the end of the auxiliary electrode 932 and the end of the upper electrode 936 is X ₄ , X ₄ Table 1 shows the withstand voltage (V) and the series resistance (Ω) when O is 0 μm, 100 μm, and 200 μm, respectively.

  As can be seen from Table 1, even when the upper electrode 936 is formed and the resistance value of the photosensor is lowered, the resistance value of the entire element can be increased by changing the distance between the upper electrode 936 and the auxiliary electrode 932. Thereby, it is possible to produce an optical sensor that can suppress electrostatic breakdown.

  Note that this embodiment can be combined with any description of the embodiment mode and Embodiments 1 to 4 if necessary.

  In this example, an example different from Example 4 is shown with respect to a visible light sensor in which wirings and electrodes are single-layer conductive films, with reference to FIG. In addition, the same thing as Example 4 is shown with the same code | symbol.

  FIG. 21 includes FIGS. 13 (A) to 13 (B), FIGS. 14 (A) to 14 (B), FIGS. 15 (A) to 15 (C), and FIG. 20 (A) according to the fourth embodiment. A protective electrode 718, 773, 776, 774 and 775 is provided over the wiring 719, the connection electrode 720, the terminal electrode 751, the source or drain electrode 771 of the TFT 730, and the source or drain electrode 772 of the TFT 731 in FIG. The visible light sensor made into the structure which is not provided is shown.

  In FIG. 21, a wiring 1404, a connection electrode 1405, a terminal electrode 1401, a source or drain electrode 1402 of the TFT 731 and a source or drain electrode 1403 of the TFT 730 are formed of a single-layer conductive film. A titanium film (Ti film) is preferable. Further, in place of the titanium film, tungsten (W), tantalum (Ta), molybdenum (Mo), neodymium (Nd), cobalt (Co), zirconium (Zr), zinc (Zn), ruthenium (Ru), rhodium (Rh) ), Palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), or a single layer film made of an alloy material or a compound material containing the element as a main component, or these A single layer film made of a nitride such as titanium nitride, tungsten nitride, tantalum nitride, or molybdenum nitride can be used. By forming the wiring 1404, the connection electrode 1405, the terminal electrode 1401, the source or drain electrode 1402 of the TFT 731 and the source or drain electrode 1403 of the TFT 730 as a single layer film, the number of depositions can be reduced in the manufacturing process. It becomes.

  Note that this embodiment can be combined with any description of the embodiment modes and embodiments 1 to 5 if necessary.

  According to the present invention, a photoelectric conversion device with improved breakdown voltage against electrostatic breakdown can be manufactured. In addition, by incorporating the photoelectric conversion device of the present invention, a highly reliable electric device can be obtained.

4A and 4B show a manufacturing process of an optical sensor of the present invention. 4A and 4B show a manufacturing process of an optical sensor of the present invention. 4A and 4B show a manufacturing process of an optical sensor of the present invention. 4A and 4B show a manufacturing process of an optical sensor of the present invention. The top view of the photosensor of the present invention. Sectional drawing of the conventional optical sensor. 4A and 4B show a manufacturing process of an optical sensor of the present invention. The figure which shows the example of the electric equipment incorporating the optical sensor of this invention. The figure which shows the example of the electric equipment incorporating the optical sensor of this invention. The figure which shows the example of the electric equipment incorporating the optical sensor of this invention. The figure which shows the example of the electric equipment incorporating the optical sensor of this invention. The top view of the photosensor of the present invention. The figure which shows the manufacturing process of the apparatus which mounted the optical sensor of this invention. The figure which shows the manufacturing process of the apparatus which mounted the optical sensor of this invention. The figure which shows the manufacturing process of the apparatus which mounted the optical sensor of this invention. The equivalent circuit diagram of the visible light sensor incorporating the optical sensor of this invention. The equivalent circuit diagram of the visible light sensor incorporating the optical sensor of this invention. 4A and 4B show a manufacturing process of an optical sensor of the present invention. The figure which shows the example of the electric equipment incorporating the optical sensor of this invention. The figure which shows the manufacturing process of the apparatus which mounted the optical sensor of this invention. The figure which shows the manufacturing process of the apparatus which mounted the optical sensor of this invention.

Explanation of symbols

101 substrate 102 p-type semiconductor film 103 intrinsic semiconductor film 104 n-type semiconductor film 106 insulating film 107 groove 108 groove 110 electrode layer 111 electrode layer 112 insulating film 113 extraction electrode 114 extraction electrode 116 region 117 region 120 opening 121 groove 122 groove

Claims (14)

A substrate,
A first semiconductor film provided with one conductivity type on the substrate;
A second semiconductor film in contact with the first semiconductor film;
A third semiconductor film having a conductivity type opposite to that of the first semiconductor film in contact with the second semiconductor film;
An opening provided in the second semiconductor film and the third semiconductor film and electrically separating a part of the third semiconductor film from another area of the third semiconductor film;
An insulating film selectively provided so as to cover the partial region of the third semiconductor film;
A first groove provided in the insulating film;
A first electrode provided on the insulating film and in contact with the partial region of the third semiconductor film via the first groove;
A second groove provided in the first semiconductor film, the second semiconductor film, and the third semiconductor film;
A second electrode provided on the other region of the third semiconductor film and in contact with a side surface of the first semiconductor film, the second semiconductor film, and the third semiconductor film in the second groove; And an optical sensor. A substrate,
A first semiconductor film provided with one conductivity type on the substrate;
A second semiconductor film in contact with the first semiconductor film;
A third semiconductor film having a conductivity type opposite to that of the first semiconductor film in contact with the second semiconductor film;
An opening provided in the second semiconductor film and the third semiconductor film and electrically separating a part of the third semiconductor film from another area of the third semiconductor film;
An insulating film selectively provided so as to cover the partial region of the third semiconductor film;
A first groove provided in the insulating film;
A first electrode provided on the insulating film and in contact with the partial region of the third semiconductor film via the first groove;
A second groove provided in the first semiconductor film, the second semiconductor film, and the third semiconductor film;
  A second electrode provided on the other region of the third semiconductor film and in contact with a side surface of the first semiconductor film, the second semiconductor film, and the third semiconductor film in the second groove; When,
  An optical sensor comprising: a third electrode that is selectively provided between the substrate and the first semiconductor film and is electrically connected to the second electrode. A substrate,
A first semiconductor film provided with one conductivity type on the substrate;
A second semiconductor film in contact with the first semiconductor film;
A third semiconductor film having a conductivity type opposite to that of the first semiconductor film in contact with the second semiconductor film;
A part of the first semiconductor film, the second semiconductor film, and the third semiconductor film is provided in the first semiconductor film, the second semiconductor film, and the third semiconductor film. An opening electrically separated from other regions of the first semiconductor film, the second semiconductor film, and the third semiconductor film;
An insulating film selectively provided so as to cover the partial region of the third semiconductor film;
A first groove provided in the insulating film;
A first electrode provided on the insulating film and in contact with the partial region of the third semiconductor film via the first groove;
A second groove provided in the other region of the first semiconductor film, the second semiconductor film, and the third semiconductor film;
A second electrode provided on the other region of the third semiconductor film and in contact with a side surface of the first semiconductor film, the second semiconductor film, and the third semiconductor film in the second groove; When,
An optical sensor comprising: a third electrode that is selectively provided between the substrate and the first semiconductor film and is electrically connected to the second electrode. In claim 2 or claim 3,
The third electrode is an indium oxide oxide formed using a target in which indium tin oxide alloy containing silicon, zinc oxide, tin oxide, indium oxide, indium oxide and zinc oxide of 2 wt% or more and 20 wt% or less are mixed. An optical sensor comprising any one of zinc alloys. In claim 2 or claim 3,
It said third electrode, titanium, tungsten, tantalum, molybdenum, neodymium, cobalt, zirconium, zinc, ruthenium, rhodium, palladium, osmium, iridium, platinum, aluminum, gold, silver, should be selected from copper shift one of An optical sensor comprising at least an element. In any one of Claims 1 thru | or 5,
The optical sensor according to claim 1, wherein the substrate is a flexible substrate. In claim 6,
The optical sensor is characterized in that the flexible substrate is any one of a polyethylene naphthalate (PEN) film, a polyethylene terephthalate (PET) film, and a polybutylene naphthalate (PBN) film. In any one of Claims 1 thru | or 5,
The optical sensor , wherein the substrate is a glass substrate. Light sensor according to any one of claims 1 to 8, an optical sensor, characterized in that to absorb the light selected by the color filter. Forming a first semiconductor film having one conductivity type on a substrate;
Forming a second semiconductor film in contact with the first semiconductor film;
Forming a third semiconductor film having a conductivity type opposite to that of the first semiconductor film in contact with the second semiconductor film;
An insulating film having a first groove is selectively formed on the third semiconductor film so that a part of the third semiconductor film is exposed;
Forming a second groove in the first semiconductor film, the second semiconductor film, and the third semiconductor film by laser scribing;
Forming a first electrode in contact with the third semiconductor film via the first groove on the insulating film, and forming the first semiconductor film in the second groove on the third semiconductor film; Forming a second electrode in contact with a side surface of the second semiconductor film and the third semiconductor film,
Etching is performed using the first electrode, the second electrode, and the insulating film as a mask to form an opening in the second semiconductor film and the third semiconductor film, whereby the third semiconductor film is formed. A method for manufacturing an optical sensor, wherein a part of a semiconductor film is electrically separated from another area. Forming a first semiconductor film having one conductivity type on a substrate;
Forming a second semiconductor film in contact with the first semiconductor film;
Forming a third semiconductor film having a conductivity type opposite to that of the first semiconductor film in contact with the second semiconductor film;
An insulating film having a first groove is selectively formed on the third semiconductor film so that a part of the third semiconductor film is exposed;
Forming a second groove in the first semiconductor film, the second semiconductor film, and the third semiconductor film by laser scribing;
Forming a first electrode in contact with the third semiconductor film via the first groove on the insulating film, and forming the first semiconductor film in the second groove on the third semiconductor film; Forming a second electrode in contact with a side surface of the second semiconductor film and the third semiconductor film,
Etching is performed using the first electrode, the second electrode, and the insulating film as a mask to form an opening in the second semiconductor film and the third semiconductor film, whereby the third semiconductor film is formed. Electrically separating a part of the semiconductor film from other regions,
Before forming the first semiconductor film, a third electrode for electrically connecting to the second electrode is formed over the substrate, and a method for manufacturing an optical sensor is provided. Forming a first semiconductor film having one conductivity type on a substrate;
Forming a second semiconductor film in contact with the first semiconductor film;
Forming a third semiconductor film having a conductivity type opposite to that of the first semiconductor film in contact with the second semiconductor film;
An insulating film having a first groove is selectively formed on the third semiconductor film so that a part of the third semiconductor film is exposed;
Forming a second groove in the first semiconductor film, the second semiconductor film, and the third semiconductor film by laser scribing;
Forming a first electrode in contact with the third semiconductor film via the first groove on the insulating film, and forming the first semiconductor film in the second groove on the third semiconductor film; Forming a second electrode in contact with a side surface of the second semiconductor film and the third semiconductor film,
Etching is performed to form openings in the first semiconductor film, the second semiconductor film, and the third semiconductor film, so that the first semiconductor film, the second semiconductor film, and the second semiconductor film are formed. Part of the semiconductor film 3 is electrically separated from other regions of the first semiconductor film, the second semiconductor film, and the third semiconductor film;
Before forming the first semiconductor film, a third electrode for electrically connecting to the second electrode is formed on the substrate,
The method for manufacturing a semiconductor device, wherein the etching is performed using the third electrode as an etching stopper. In any one of Claims 10 to 12,
An optical sensor, wherein the insulating film is formed by a screen printing method. In any one of Claims 10 to 13,
The optical sensor, wherein the first electrode and the second electrode are formed by an inkjet method.

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