JP2004071538A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for preventing a transistor from being irradiated by radiation when forming a metal film by an electron beam evaporation method. <P>SOLUTION: The display device comprises a transistor and a light-emitting element electrically connected to the transistor, and a thin film having a radiation-absorbing ability is provided with a part of a configuration part of the transistor. The display device with the above described configuration prevents the transistor from being irradiated with the radiation, when forming the metal film by the electron beam evaporation method from above the thin film having the radiation-absorbing ability. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a display device using a semiconductor element (typically, a transistor) as a device, that is, a technical field related to an electroluminescence display device, a liquid crystal display device, a field emission display device, and other display devices, and the display device. It belongs to the technical field related to the electronic device provided in the video display unit.
[0002]
[Prior art]
2. Description of the Related Art In recent years, development of a liquid crystal display device or an electroluminescence (Electro Luminescence) display device in which a transistor, that is, a thin film transistor or a MOS transistor is integrated on a substrate, has been advanced. Each of these display devices is characterized in that a transistor is formed on a glass substrate by using a thin film formation technique, and the transistor is arranged in each pixel arranged in a matrix to function as a display device that performs image display. .
[0003]
FIG. 11 shows the structure of a typical active matrix type electroluminescent display device. In FIG. 11, reference numeral 1101 denotes a base, over which a thin film transistor 1102 is provided, and a pixel electrode 1103 functioning as an anode of a light-emitting element is connected to the thin film transistor 1102. An insulating film having an opening is provided over the pixel electrode 1103 at a position corresponding to the pixel electrode 1103, and a light-emitting body 1105 and a metal film 1106 functioning as a cathode of a light-emitting element are provided so as to cover them. . The electroluminescence display device emits light by injecting current into the light emitting body 1105 to display an image.
[0004]
At this time, the pixel electrode 1103 and the insulating film 1104 can be formed by a normal process. However, when an organic compound is used as the light-emitting body 1105, a deposition method, a coating method, an inkjet method, or a printing method can be used. Is used. Further, in forming the metal film 1106 thereon, since the heat resistance of the light emitting body 1105 is as low as 100 ° C. or less, an evaporation method or a sputtering method is used.
[0005]
[Problems to be solved by the invention]
The present inventors have found that an abnormality is found in the threshold voltage of the thin film transistor in the electroluminescent display device having the structure shown in FIG. 11 manufactured in the course of research and development. As a result of investigating the cause, when a metal film serving as a cathode was formed by an electron beam evaporation method, a threshold voltage (V _G ) Found a significant shift. FIG. 12 shows the result. The data shown in FIG. 12 shows the drain voltage-gate voltage characteristics (hereinafter referred to as I _D -V _G It is called a characteristic. ). As is clear from FIG. 12, it was found that the threshold voltage after the formation was shifted by about 4 V to the minus side as compared with the threshold voltage before the formation of the cathode. Further, it was confirmed that the S value (subthreshold coefficient) indicating the steepness of the switching characteristics was also increased (deteriorated).
[0006]
This is probably because some damage was given to the thin film transistor when the cathode was formed, and as a result, the threshold voltage and the S value changed significantly. The present invention has been made in view of these problems, and it is an object of the present invention to provide a technique for forming a metal film without causing abnormal characteristics of a thin film transistor.
[0007]
[Means for Solving the Problems]
The cause of the abnormal characteristics of the thin film transistor was considered to be an operation failure of the thin film transistor due to radiation damage, and deterioration due to generation of charges or levels in the gate insulating film. It is well known that a transistor malfunctions due to radiation damage. In general, the generation of positive charges in an oxide film caused by irradiation with radiation (gamma rays, neutrons, X-rays, etc.), Si-SiO ₂ There are three categories: generation of interface states at the interface and generation of neutral electron traps in the oxide film. The operation failure of the transistor due to radiation damage is described in detail in "Realize Co., Ltd., issued on July 31, 1991, edited by Kenji Taniguchi et al.," Silicon Thermal Oxide Film and Its Interface ", pp. 167-182." I have.
[0008]
In addition, in film formation by electron beam evaporation, it is known that radiation (typically, X-rays) is generated from a metal melted by electron beam irradiation. It is speculated that the radiation generated at this time caused the generation of positive charges and the generation of interface states in the gate insulating film and the like of the thin-film transistor, resulting in the observation of characteristic anomalies such as a shift of the threshold voltage to the negative side. did.
[0009]
The gist of the present invention is characterized in that a metal film is formed by an electron beam evaporation method in a state where the above-mentioned radiation shielding means is provided on a substrate on which a transistor is formed, thereby preventing radiation damage of the transistor. It is. In order to achieve the object, a first aspect of the present invention is to provide an insulating film containing lead, iron, or another element having a radiation absorbing ability (hereinafter, referred to as an insulating film having a radiation absorbing ability) on a transistor. The method is characterized in that a metal film is formed by an electron beam evaporation method in a state in which the metal film is in an inclined state. More preferably, at this time, the radiation absorbing film is covered with an inorganic insulating film.
[0010]
Further, instead of using a radiation absorbing film, a metal film containing lead or iron can be used as a source electrode and a drain electrode of the transistor or a black mask (light-shielding film) to protect the transistor from irradiation.
[0011]
In a second aspect of the present invention, an insulating film containing lead, iron, or another element having a radiation absorbing ability (hereinafter, referred to as an insulating film having a radiation absorbing ability) is used as a part of an interlayer insulating film of a transistor. A metal film is formed by an electron beam evaporation method in a state where a channel formation region is protected by an insulating film having a radiation absorbing ability.
[0012]
A third aspect of the present invention is that lead, iron, or another element having a radiation absorbing ability is used as part or all of a source wiring, a drain wiring, a gate wiring, or a light-shielding film (generally called a black matrix) of a transistor. Forming a metal film by an electron beam evaporation method while using a conductive film made of (hereinafter referred to as a conductive film having a radiation absorbing ability; the same applies hereinafter) while protecting a channel formation region with the conductive film having the radiation absorbing ability. It is characterized by.
[0013]
A fourth aspect of the present invention is that a conductive film containing lead, iron, or another element having a radiation absorbing ability (having a radiation absorbing ability) is used as part or all of a source wiring, a drain wiring, a gate wiring, or a light-shielding film of a transistor. A metal film is formed by an electron beam evaporation method in a state where a channel formation region is protected by the conductive film containing an element having a radiation absorbing ability. .
[0014]
By including lead, iron, or another element having a radiation absorbing ability in the insulating film or the conductive film, the insulating film or the conductive film can have a radiation shielding function. Then, an electron beam evaporation method is performed from above with the insulating film or the conductive film protecting the channel formation region of the transistor (meaning that the insulating film or the conductive film is provided between the channel formation region and the evaporation source). Accordingly, the radiation can be suppressed from reaching the transistor (particularly, a channel formation region and a gate insulating film in contact with the channel formation region).
[0015]
Note that the insulating film or the conductive film having the radiation shielding function can be used as a part of the structure of the display device as it is. In the case of an insulating film, the resistivity is reduced by including a metal element such as lead or iron. However, the insulating film having the radiation absorbing ability is covered or sandwiched with another insulating film to form an interlayer insulating film. Insulation can be sufficiently ensured.
[0016]
Further, when an insulating film having a radiation absorbing ability is used, the higher the amount (concentration) of lead or iron contained therein, the higher the radiation absorbing ability, but on the other hand, the lower the resistance, the lower the resistance. . Therefore, the concentration of lead or iron to be contained depends on the resistivity of the insulating film having a radiation absorbing ability being 1.0 × 10 ¹² Ωcm or more, preferably 1.0 × 10 ¹⁴ It is preferable to adjust so as to be Ωcm or more. It is also possible to disperse particles in which lead or iron particles are wrapped with an insulator to suppress a decrease in resistivity.
[0017]
Note that, instead of the insulating film having the radiation absorbing ability, it is also possible to use a silicon carbide film, a gallium nitride film, a diamond film, a diamond-like carbon film, or another thin film having high resistance to radiation.
[0018]
When a conductive film having a radiation-absorbing ability is used, a conductive film made of lead, iron, or another element having a radiation-absorbing ability can be used as it is. It is also possible to use a conductive film in which an element having a radiation absorbing ability is added to a conductive film other than a film. The content concentration at this time may be 1 to 30 atomic% (typically 1 to 10 atomic%).
[0019]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
[Embodiment 1]
An embodiment of the present invention will be described with reference to FIG. The pixel configuration illustrated in FIG. 13A is a known configuration, in which 1301 is a data signal line, 1302 is a gate signal line, 1303 is a power supply line, and 1304 is a switching thin film transistor (hereinafter, referred to as a switching TFT). Reference numeral 1305 denotes a charge holding capacitor, 1306 denotes a driving thin film transistor (hereinafter referred to as driving TFT) for supplying current to the light emitting element, and 1307 denotes a pixel electrode connected to the drain of the driving TFT. The electrode 1307 functions as an anode of the light-emitting element. Note that a light-emitting element here is a layer of a light-emitting body (light-emitting layer, carrier injection layer, carrier transport layer, carrier blocking layer, and other organic or inorganic compounds necessary for light emission) between a pair of electrodes (anode and cathode). Refers to an element provided with a laminated body. For example, in this embodiment, an electroluminescence element is provided as a light-emitting element.
[0021]
The most characteristic point of the present invention is that the above-mentioned radiation absorbing film 1308 is provided in a portion other than the pixel electrode 1307 (excluding the end of the pixel electrode). In this embodiment mode, an organic resin film containing lead is used as the radiation absorption film 1308. At this time, fine particles of lead may be dispersed, or fine particles of lead wrapped with an insulator may be dispersed.
[0022]
FIG. 13B shows a drawing corresponding to the cut surface along AA ′ at this time. In FIG. 13B, reference numeral 1310 denotes a base, which can be a glass base, a quartz base, a plastic base, or another light-transmitting base. The driving TFT 1306 is formed on the base 1310 using a known semiconductor process. In addition, a radiation absorbing film 1308 patterned in a lattice pattern is provided so as to cover an end of the pixel electrode 1307 formed to be connected to the driving TFT 1306 and at least the driving TFT and the switching TFT.
[0023]
A luminous body 1311, a metal film 1312 functioning as a cathode, and a passivation film 1313 are provided over the pixel electrode 1307 and the radiation absorption film 1308. The light-emitting body 1311 refers to a carrier injection layer, a carrier transport layer, a carrier blocking layer, a light-emitting layer, an organic compound or an inorganic compound which contributes to recombination of carriers, or a stacked body thereof. As the configuration of the light emitting body 1311, a known configuration can be used. As the metal film 1312, an aluminum film or a silver thin film containing an element belonging to Group 1 or 2 of the periodic table can be used. In addition, as the passivation film 1313, a silicon nitride film, an aluminum nitride film, a diamond-like carbon film, or another insulating film having a high blocking property against moisture and oxygen can be used.
[0024]
In the display device having the pixel structure of this embodiment, even when an electron beam evaporation method is used to form the metal film 1312 serving as a cathode, radiation such as gamma rays, electron beams, or X-rays is blocked by the radiation absorbing film 1308. It does not directly reach a thin film transistor (especially a silicon oxide film serving as a gate insulating film), so that an operation failure due to a so-called radiation error such as generation of a positive charge and an increase in an interface state can be avoided.
[0025]
As described above, with the pixel structure described in this embodiment, a metal film can be formed without being affected by radiation when a metal film is formed using an electron beam evaporation method. It is possible to suppress the occurrence of defects such as abnormal threshold voltage and abnormal S value.
[0026]
[Embodiment 2]
This embodiment is an example in which a driver circuit for controlling a video signal and a gate signal transmitted to a signal line in a pixel portion is provided over the same base as the pixel portion. FIG. 14 is a top view showing a state in which a radiation absorbing film is provided on portions other than the pixel electrodes in an electroluminescence display device in which a drive circuit is integrally formed.
[0027]
14, a base 1401 includes a data signal line driver circuit 1402, gate signal line driver circuits 1403a and 1403b, and a signal processing circuit (a correction circuit, a memory circuit, an arithmetic circuit, and other signal processing circuits; the same applies hereinafter). 1404 a and 1404 b and a pixel portion 1405 are provided. A pixel electrode 1406 is provided for each of a plurality of pixels included in the pixel portion 1405.
[0028]
In the case of this embodiment mode, by providing the radiation absorbing film 1407 for all parts other than the pixel electrode 1406 (excluding the end of the pixel electrode), the data signal line driver circuit 1402, the gate signal line driver circuit 1403a, Irradiation to the transistors included in the signal processing circuit 1403b and the signal processing circuits 1404a and 1404b can be prevented. As a result, it is possible to suppress occurrence of a defect such as a threshold voltage abnormality or an S value abnormality of the transistor due to the irradiation, and it is possible to secure the stability of the operation of the drive circuit and the signal processing circuit.
[0029]
[Embodiment 3]
In this embodiment, an example in which the surface of a radiation absorbing film is covered with an insulating film will be described with reference to FIGS. FIG. 15 is a cross-sectional view corresponding to FIG. 13B, and is all the same as the structure in FIG. 13B except that the radiation absorbing film 1308 is covered with the insulating film 1501. Therefore, the same reference numerals as in FIG.
[0030]
As the insulating film 1501, a silicon nitride film, a silicon oxide film, a silicon oxynitride film, or another insulating film can be used; however, an insulating film with good adhesion to the radiation absorption film 1308 is preferable. Further, since it is necessary to remove a portion corresponding to the pixel electrode 1307 by etching later, the insulating film must be able to secure a selectivity with the material of the pixel electrode 1307. As the pixel electrode 1307, an oxide conductive film (typically, an ITO film) or a metal film (typically, a titanium film or a titanium nitride film) is used, and an insulating film having a high selectivity with these materials is used. The combination may be determined experimentally.
[0031]
With the above structure, in forming a metal film by an electron beam evaporation method, a malfunction due to irradiation of a transistor with radiation can be prevented. Note that the configuration of the present embodiment may be combined with Embodiments 1 and 2.
[0032]
[Embodiment 4]
In this embodiment, an example in which a pixel electrode functioning as an anode is formed using a metal film will be described with reference to FIGS. FIG. 16 is a cross-sectional view corresponding to FIG. 13B, and is all the same as the configuration in FIG. 13B except that the materials of the pixel electrode 1601 and the cathode 1602 are changed. Therefore, the same reference numerals as in FIG.
[0033]
When the pixel electrode 1601 is used as an anode, a metal film such as a titanium film, a titanium nitride film, a platinum thin film or a gold thin film or a stack of an oxide conductive film and a metal film stacked so that the outermost surface is an oxide conductive film. A membrane can be used. In these cases, since light is emitted upward in the drawing, the cathode 1602 needs to have a light-transmitting property. Therefore, as the cathode 1602, an aluminum film or a silver thin film containing an element belonging to Group 1 or 2 of the periodic table is provided on the side in contact with the light-emitting body 1311 to a thickness of about 20 to 70 nm, and an oxide conductive film is formed thereon. May be laminated to form a light-transmitting metal film as a whole.
[0034]
If the pixel electrode 1601 is used as a cathode, a metal film having an outermost surface of an aluminum film or a silver thin film containing an element belonging to Group 1 or 2 of the periodic table can be used. In this case as well, light is emitted upward in the drawing, so that the cathode 1602 needs to have translucency. Therefore, an oxide conductive film may be used as the cathode 1602.
[0035]
With the above structure, in forming a metal film by an electron beam evaporation method, a malfunction due to irradiation of a transistor with radiation can be prevented. Note that the configuration of this embodiment may be combined with Embodiments 1 to 3.
[Embodiment 5]
An embodiment of the present invention will be described with reference to FIG. In the pixel configuration shown in FIG. 1A, 101 is a data signal line, 102 is a gate signal line, 103 is a power supply line, 104 is a switching thin film transistor (hereinafter referred to as a switching TFT, the same applies hereinafter), and 105 is a charge holding transistor. , A driving thin film transistor (driving TFT, hereinafter the same) for supplying a current to the light emitting element, a pixel electrode 107 connected to the drain of the driving TFT, and a pixel electrode 107 of the light emitting element. Functions as an anode. Reference numeral 112 denotes a counter electrode, and the counter electrode 112 functions as a cathode of the light emitting element. Note that a light-emitting element here is a layer of a light-emitting body (light-emitting layer, carrier injection layer, carrier transport layer, carrier blocking layer, and other organic or inorganic compounds necessary for light emission) between a pair of electrodes (anode and cathode). Refers to an element provided with a laminated body. For example, in this embodiment, an electroluminescence element is provided as a light-emitting element.
[0036]
FIG. 1B shows a drawing corresponding to a cut surface taken along the line AA ′ at this time. In FIG. 1B, reference numeral 110 denotes a substrate, and a glass substrate, a quartz substrate, a plastic substrate, or another light-transmitting substrate can be used. The driving TFT 106 is formed on the base 110 using a semiconductor process. Further, an insulating film 108 patterned in a lattice pattern is provided so as to cover an end portion of the pixel electrode 107 formed to be connected to the driving TFT 106 and at least the driving TFT and the switching TFT.
[0037]
On the pixel electrode 107 and the insulating film 108, a light emitting body 111, a counter electrode 112 functioning as a cathode, and a passivation film 113 are provided. The light-emitting body 111 refers to a carrier injection layer, a carrier transport layer, a carrier blocking layer, a light-emitting layer, an organic compound or an inorganic compound that contributes to recombination of carriers, or a stacked body thereof. As the configuration of the light emitting body 111, a known configuration can be used. Further, as the counter electrode 112, an aluminum film or a silver thin film containing an element belonging to Group 1 or 2 of the periodic table can be used. In this embodiment, light emitted from the light-emitting body 111 is transmitted. Therefore, it is desirable that the film thickness be 50 nm or less. Further, as the passivation film 113, a silicon nitride film, an aluminum nitride film, a diamond-like carbon film, or an insulating film having a high blocking property against moisture and oxygen can be used.
[0038]
Here, an enlarged view of a portion corresponding to the driving TFT 106 is shown in FIG. In FIG. 1C, reference numeral 121 denotes a source region, 122 denotes a drain region, and 123 denotes a channel formation region. These semiconductor regions constitute an active layer. Of course, another semiconductor region such as an LDD region may be provided. Reference numeral 124 denotes a gate insulating film, 125 denotes a gate electrode, and 126 denotes a silicon compound film.
[0039]
The most characteristic point of this embodiment mode is that an insulating film 127 having a radiation absorbing ability is provided over the silicon compound film 126. In this embodiment mode, a silicon compound film containing lead at a concentration of 1 to 10 at% is used as the insulating film 127 having a radiation absorbing ability. As for the film thickness, the larger the film thickness, the higher the absorption ability is preferable, but it is sufficient if the film thickness is at least the wavelength of radiation.
[0040]
Further, an organic resin film 128 is provided as a planarizing film on the insulating film 127 having a radiation absorbing ability. That is, the interlayer insulating film is constituted by the insulating film 127 having the radiation absorbing ability and the organic resin film 128. In other words, it can be said that the insulating film having the radiation absorbing ability is included as a part of the interlayer insulating film. The interlayer insulating film may have a laminated structure of two or more layers, and an insulating film having a radiation absorbing ability may be used for any of the layers. In addition, since the insulating film having a radiation absorbing ability contains a metal such as lead or iron in the film, it is used sandwiched between silicon compound films (particularly a silicon compound film containing nitrogen is preferable) in order to minimize diffusion. It is also effective.
[0041]
The organic resin film 128 is preferably formed using a photosensitive resin film because a film without plasma damage can be formed. Further, since the organic resin film 128 may generate gas due to heating or a change with time, a silicon compound film such as a silicon nitride film having a high barrier property is provided on the organic resin film so that a degassing component is applied to the light emitting element. Preventing the effects is also effective. Of course, if a flattening effect is required, it is also possible to use a silicon compound film formed by solution coating called spin-on-glass.
[0042]
Then, on the organic resin film 128, an aluminum film (including not only pure aluminum but also an aluminum film to which an aluminum alloy or another element is added; the same applies hereinafter) or a laminated structure of an aluminum film and another metal film A source line 129 and a pixel electrode (also serving as a drain line) 107 are provided.
[0043]
Note that when the organic resin film 128 is formed, a first opening is provided in advance in the gate insulating film 124, the silicon compound film 126, and the insulating film 127 having a radiation absorbing ability, and thereafter, the organic resin film 128 is provided. desirable. Then, a second opening having a smaller diameter than the above-described first opening is provided in the organic resin film 128, and the source wiring 129 and the pixel electrode 107 are connected to the source region 121 and the drain region 122 through the second opening, respectively. Is done. In this manner, the source wiring 129 and the pixel electrode 107 do not come into contact with the insulating film 127 having a radiation absorbing ability, and the leakage current through the insulating film 127 having the radiation absorbing ability can be suppressed.
[0044]
In the display device having the pixel structure of this embodiment mode, even when an electron beam evaporation method is used to form the counter electrode 112 serving as a cathode, an insulating film 127 having a radiation absorbing ability for radiation such as gamma rays, electron beams, or X rays. Thus, the semiconductor device does not directly reach the channel formation region and the gate insulating film in contact with the channel formation region, so that an operation failure due to a so-called radiation error such as generation of a positive charge and an increase in an interface state can be avoided.
[0045]
As described above, with the pixel structure described in this embodiment, a metal film can be formed without being affected by radiation when a metal film is formed using an electron beam evaporation method. It is possible to suppress the occurrence of defects such as abnormal threshold voltage and abnormal S value.
[0046]
[Embodiment 6]
In this embodiment, an example in which a conductive film having a radiation absorbing ability is used as part or all of a source wiring and a drain wiring (also serving as a pixel electrode) will be described. Basically, the structure of the entire display device and the structure of the light-emitting element are the same as those in Embodiment Mode 5, and therefore, this embodiment mode will be described using an enlarged portion corresponding to FIG.
[0047]
In FIG. 2, for the description of the portions denoted by the same reference numerals as in FIG. 1C, Embodiment 5 may be referred to. The present embodiment is characterized in that the source wiring 201 includes the first conductive film 201a, the second conductive film 201b, the third conductive film 201c, and the fourth conductive film 201d, and the second conductive film The point that a conductive film having a radiation absorbing ability is used as 201b. Similarly, the pixel electrode 202 includes a first conductive film 202a, a second conductive film 202b, a third conductive film 202c, and a fourth conductive film 202d, and has a radiation absorbing ability as the second conductive film 202b. A conductive film is used. Further, the source wiring 201 is provided so as to cover above the channel formation region 123.
[0048]
In this embodiment, a titanium film is used as the first conductive films 201a and 202a in order to improve ohmic contact with the source region 121 and the drain region 122. Further, a thin film of lead or iron is used as the second conductive films 201b and 202b. Further, an aluminum film is used as the third conductive films 201c and 202c in order to reduce wiring resistance. Further, a titanium nitride film is used as the fourth conductive films 201d and 202d because a material having a large work function is used to function as an anode of the light emitting element. Of course, other conductive films are not limited to these as long as a conductive film having a radiation absorbing ability is used as the second conductive films 201b and 202b.
[0049]
In the display device having the pixel structure of this embodiment, even when an electron beam evaporation method is used to form the counter electrode 112 serving as a cathode, a conductive film 201b in which radiation such as gamma rays, electron beams, or X-rays has a radiation absorbing ability is used. Thus, the semiconductor device does not directly reach the channel formation region and the gate insulating film in contact with the channel formation region, so that an operation failure due to a so-called radiation error such as generation of a positive charge and an increase in an interface state can be avoided.
[0050]
As described above, with the pixel structure described in this embodiment, a metal film can be formed without being affected by radiation when a metal film is formed using an electron beam evaporation method. It is possible to suppress the occurrence of defects such as abnormal threshold voltage and abnormal S value.
[0051]
Note that in this embodiment mode, the insulating film having the radiation absorbing ability described in Embodiment Mode 5 is used as a part of the interlayer insulating film, and the radiation shielding effect is further increased in combination with this embodiment mode. It is possible to increase.
[0052]
[Embodiment 7]
In this embodiment, an example in which a conductive film containing an element having a radiation absorbing ability is used as part or all of a source wiring and a drain wiring (also serving as a pixel electrode) will be described. Basically, the structure of the entire display device and the structure of the light-emitting element are the same as those in Embodiment Mode 5, and therefore, this embodiment mode will be described using an enlarged portion corresponding to FIG.
[0053]
In FIG. 3, for the description of the portions denoted by the same reference numerals as in FIG. 1C, Embodiment 5 may be referred to. A feature of this embodiment is that the source wiring 301 includes the first conductive film 301a, the second conductive film 301b, and the third conductive film 301c, and the second conductive film 301b has a radiation absorbing ability. The point is that a conductive film containing an element is used. Similarly, the pixel electrode 302 includes a first conductive film 302a, a second conductive film 302b, and a third conductive film 302c, and the second conductive film 302b includes a conductive film containing an element having a radiation absorbing ability. Used. Further, a source wiring 301 is provided so as to cover above the channel formation region 123.
[0054]
In this embodiment mode, a titanium film is used as the first conductive films 301a and 302a in order to improve ohmic contact with the source region 121 and the drain region 122. In addition, an aluminum film containing lead or iron is used as the second conductive films 301b and 302b in order to have a function of shielding radiation and to reduce wiring resistance. Further, a titanium nitride film is used as the third conductive films 301c and 302c in order to function as an anode of the light emitting element. Of course, other conductive films are not limited to these as long as a conductive film having a radiation absorbing ability is used as the second conductive films 301b and 302b.
[0055]
In the display device having the pixel structure of this embodiment, even when an electron beam evaporation method is used to form the counter electrode 112 serving as a cathode, radiation such as gamma rays, electron beams, or X-rays contains an element having a radiation absorbing ability. The channel formation region and the gate insulating film in contact with the channel formation region are not directly blocked by the conductive film 301b, so that a malfunction due to a so-called radiation error such as generation of a positive charge and an increase in an interface state can be avoided.
[0056]
As described above, with the pixel structure described in this embodiment, a metal film can be formed without being affected by radiation when a metal film is formed using an electron beam evaporation method. It is possible to suppress the occurrence of defects such as abnormal threshold voltage and abnormal S value.
[0057]
Note that in this embodiment mode, the insulating film having the radiation absorbing ability described in Embodiment Mode 5 is used as a part of the interlayer insulating film, and the radiation shielding effect is further increased in combination with this embodiment mode. It is possible to increase.
[0058]
Embodiment 8
FIGS. 4A to 4C show an example in which the structure of the pixel electrode in this embodiment is different from that of the fifth embodiment. Basically, the configuration of the entire display device and the configuration of the light-emitting element are the same as those in Embodiment 5, and the description of the parts denoted by the same reference numerals as those in FIGS. 5 should be referred to.
[0059]
A feature of this embodiment is that a pixel electrode 402 electrically connected to a drain wiring 401 is provided, and the pixel electrode 402 is formed using an oxide conductive film. Needless to say, the pixel electrode 402 formed using an oxide conductive film functions as an anode of the light-emitting element. Therefore, the structure of the light-emitting body 403 is different from that in Embodiment 5, but a known structure may be used as in Embodiment 5. In addition, the same material as the counter electrode 112 described in Embodiment 5 may be used for the counter electrode 404; however, in this embodiment, light emitted from the light-emitting body 403 is emitted to the base 110 side. You do not need to worry about the thickness. Note that the base 110 must be made of a material that transmits visible light.
[0060]
Further, it is desirable that the insulating film 127 having a radiation absorbing ability be removed in the light emitting region. This is because the transmittance is reduced because the insulating film contains an element having a radiation absorbing ability. However, if sufficient transmittance can be ensured by lowering the concentration of an element having a radiation absorbing ability in the insulating film, it is possible to leave such a case.
[0061]
In the display device having the pixel structure of this embodiment mode, even when an electron beam evaporation method is used to form the counter electrode 404 serving as a cathode, the insulating film 127 has a radiation absorbing ability such as gamma rays, electron beams, or X-rays. Thus, the semiconductor device does not directly reach the channel formation region and the gate insulating film in contact with the channel formation region, so that an operation failure due to a so-called radiation error such as generation of a positive charge and an increase in an interface state can be avoided.
[0062]
As described above, with the pixel structure described in this embodiment, a metal film can be formed without being affected by radiation when a metal film is formed using an electron beam evaporation method. It is possible to suppress the occurrence of defects such as abnormal threshold voltage and abnormal S value.
[0063]
Embodiment 9
In this embodiment, an example is described in which a conductive film having a radiation absorbing ability is used as part or all of a source wiring and a drain wiring (also serving as a pixel electrode) in Embodiment 8. Except that the configuration of the pixel electrode is the same as that of Embodiment 8, the configuration of the entire display device and the configuration of the light emitting element are basically the same as those of Embodiment 5.
[0064]
In FIG. 5, for the description of the portions denoted by the same reference numerals as in FIG. 1C or FIG. 4C, Embodiment 5 or Embodiment 8 may be referred to. The present embodiment is characterized in that the source wiring 501 includes the first conductive film 501a, the second conductive film 501b, the third conductive film 501c, and the fourth conductive film 501d, and the second conductive film The point is that a conductive film having a radiation absorbing ability is used as 501b. Similarly, the pixel electrode 502 includes a first conductive film 502a, a second conductive film 502b, a third conductive film 502c, and a fourth conductive film 502d, and has a radiation absorbing ability as the second conductive film 502b. A conductive film is used. Further, a source wiring 501 is provided so as to cover above the channel formation region 123.
[0065]
In this embodiment mode, titanium films are used as the first conductive films 501a and 502a in order to improve ohmic contact with the source region 121 and the drain region 122. Further, a thin film of lead or iron is used as the second conductive films 501b and 502b. An aluminum film is used as the third conductive films 501c and 502c in order to reduce wiring resistance. Further, a titanium nitride film is used as the fourth conductive films 501d and 502d because a material having a high work function is used to function as an anode of the light-emitting element. Of course, other conductive films are not limited to these as long as a conductive film having a radiation absorbing ability is used as the second conductive films 501b and 502b.
[0066]
In the display device having the pixel structure of this embodiment, even when an electron beam evaporation method is used to form the counter electrode 404 serving as a cathode, a conductive film 501b in which radiation such as gamma rays, electron beams, or X-rays has a radiation absorbing ability is used. Thus, the semiconductor device does not directly reach the channel formation region and the gate insulating film in contact with the channel formation region, so that an operation failure due to a so-called radiation error such as generation of a positive charge and an increase in an interface state can be avoided.
[0067]
As described above, with the pixel structure described in this embodiment, a metal film can be formed without being affected by radiation when a metal film is formed using an electron beam evaporation method. It is possible to suppress the occurrence of defects such as abnormal threshold voltage and abnormal S value.
[0068]
Note that in this embodiment, the radiation shielding effect is further increased by using the insulating film having a radiation absorbing ability described in Embodiment 8 as part of the interlayer insulating film in combination with this embodiment. It is possible to increase.
[0069]
[Embodiment 10]
In this embodiment mode, an example is described in which a conductive film containing an element having a radiation absorbing ability is used for part or all of a source wiring and a drain wiring (also serving as a pixel electrode) in Embodiment 8. Except that the configuration of the pixel electrode is the same as that of Embodiment 8, the configuration of the entire display device and the configuration of the light emitting element are basically the same as those of Embodiment 5.
[0070]
In FIG. 6, for the description of the portions denoted by the same reference numerals as those in FIG. 1C or FIG. 4C, Embodiment 5 or Embodiment 8 may be referred to. A feature of this embodiment is that the source wiring 601 is formed of the first conductive film 601a, the second conductive film 601b, and the third conductive film 601c, and the second conductive film 601b has a radiation absorbing ability. The point is that a conductive film containing an element is used. Similarly, the pixel electrode 602 includes a first conductive film 602a, a second conductive film 602b, and a third conductive film 602c, and the second conductive film 602b includes a conductive film containing an element having a radiation absorbing ability. Used. Further, a source wiring 601 is provided so as to cover above the channel formation region 123.
[0071]
In this embodiment mode, a titanium film is used as the first conductive films 601a and 602a in order to improve ohmic contact with the source region 121 and the drain region 122. Further, an aluminum film containing lead or iron is used as the second conductive films 601b and 602b in order to provide a function of shielding radiation and also reduce wiring resistance. Further, a titanium nitride film is used as the third conductive films 601c and 602c in order to function as an anode of the light emitting element. Of course, other conductive films are not limited to these as long as a conductive film having a radiation absorbing ability is used as the second conductive films 601b and 602b.
[0072]
In the display device having the pixel structure of this embodiment, even when an electron beam evaporation method is used to form the counter electrode 404 serving as a cathode, radiation such as gamma rays, electron beams, or X-rays includes an element having a radiation absorbing ability. Since the channel formation region and the gate insulating film in contact with the channel formation region are not directly blocked by the conductive film 601b, an operation failure due to a so-called radiation error such as generation of a positive charge and an increase in interface states can be avoided.
[0073]
As described above, with the pixel structure described in this embodiment, a metal film can be formed without being affected by radiation when a metal film is formed using an electron beam evaporation method. It is possible to suppress the occurrence of defects such as abnormal threshold voltage and abnormal S value.
[0074]
Note that in this embodiment, the radiation shielding effect is further increased by using the insulating film having a radiation absorbing ability described in Embodiment 8 as part of the interlayer insulating film in combination with this embodiment. It is possible to increase.
[0075]
[Embodiment 11]
In this embodiment mode, an example in which a conductive film having a radiation absorbing ability is used as part or all of a light-blocking film is shown in FIGS. Note that the entire structure of the display device and the structure of the light-emitting element are basically the same as those in Embodiment Mode 5 or Embodiment Mode 8. Therefore, an enlarged view corresponding to FIG. 1C or FIG. explain.
[0076]
In FIG. 7A, for the portions denoted by the same reference numerals as those in FIG. 1C, Embodiment 5 may be referred to. A feature of this embodiment mode is that an inorganic insulating film 701 is provided over a silicon compound film 126 and a conductive film having a radiation absorbing ability is provided thereon as a light-blocking film 702. In this embodiment mode, the organic resin film 128 is provided as a flattening film on the light shielding film 702.
[0077]
Here, as the light-blocking film 702, a conductive film containing an element having a radiation absorbing ability can be used, or a conductive film having a radiation absorbing ability or a conductive film containing an element having a radiation absorbing ability and another conductive film can be used. Can be used. At this time, it is preferable that the potential of the light-blocking film 702 be fixed. This is because the effect of reducing the variation in the threshold voltage (Vth) of the driving TFT 106 can be obtained by setting the fixed potential.
[0078]
In the case of FIG. 7A, light emitted from the light-emitting body 111 is emitted to the counter electrode 112 side. In particular, the provision of the light-blocking film 702 reduces the aperture ratio (effective display area). There is no trouble. In addition, a heat radiation effect can be expected by the light shielding film 702, and uniform heat generation due to the operation of the driving TFT can be expected. Further, an effect of blocking light leaked from a gap between the source wiring 129 and the pixel electrode 107 can be obtained.
[0079]
In FIG. 7B, the description of the portions denoted by the same reference numerals as in FIG. 1C or FIG. 4C can be referred to Embodiment 5 or 8. Here also, a feature is that an inorganic insulating film 701 is provided over the silicon compound film 126, and a conductive film having a radiation absorbing ability is provided thereon as a light-shielding film 702. In this case as well, as the light-blocking film 702, a conductive film containing an element having a radiation absorbing ability can be used, or a conductive film having a radiation absorbing ability, a conductive film containing an element having a radiation absorbing ability, and another conductive film can be used. Can also be used. Further, by fixing the potential of the light-shielding film 702, variation in the threshold voltage (Vth) of the driving TFT 106 can be reduced.
[0080]
However, in the case of FIG. 7B, since light emitted from the light-emitting body 403 is emitted to the pixel electrode 402 side, the light-shielding film 702 needs to be removed in a light-emitting region. Also in this case, an effect of blocking light leaked from a gap between the source wiring 129 and the pixel electrode 401 can be obtained.
[0081]
In the display device having the pixel structure of this embodiment, even when an electron beam evaporation method is used to form the counter electrode 112 or 404 serving as a cathode, radiation such as gamma rays, electron beams, or X-rays is blocked by the light-blocking film 702. As a result, the semiconductor device does not directly reach the channel formation region and the gate insulating film in contact with the channel formation region, so that an operation failure due to a so-called radiation error such as generation of a positive charge and increase in an interface state can be avoided.
[0082]
As described above, with the pixel structure described in this embodiment, a metal film can be formed without being affected by radiation when a metal film is formed using an electron beam evaporation method. It is possible to suppress the occurrence of defects such as abnormal threshold voltage and abnormal S value.
[0083]
Note that in this embodiment mode, radiation is obtained by using the insulating film having a radiation absorbing ability described in Embodiment Mode 5 or 8 as a part of the interlayer insulating film in combination with this embodiment mode. Can further enhance the shielding effect.
[0084]
[Embodiment 12]
In this embodiment mode, an example in which a conductive film having a radiation absorbing ability is used as part or all of a gate electrode (or a gate wiring) of a transistor is illustrated in FIGS. Note that the structure of the entire display device and the structure of the light-emitting element are basically the same as those in Embodiment Mode 5, and thus the description will be made with reference to an enlarged view corresponding to FIG.
[0085]
In this embodiment mode, the active layer includes a source region 801, a drain region 802, LDD (lightly doped drain) regions 803a and 803b, and a channel formation region 804. Further, the gate electrode 805 is provided with the gate insulating film 124 interposed therebetween, and the gate electrode 805 includes a first conductive film 805a and a second conductive film 805b. Here, the first conductive film 805a is a conductive film having a radiation absorbing ability, and the second conductive film 805b is an aluminum film, a tungsten film, a tantalum film, or another metal film. Note that it is preferable to use a conductive film containing an element having a radiation absorbing ability as the second conductive film 805b because a radiation shielding effect is further improved.
[0086]
Further, in this embodiment, the two-layer structure of the first conductive film 805a and the second conductive film 805b is described as an example; however, a gate electrode having a three-layer structure or more may be used. It is not limited to the shape of the present embodiment. However, as shown in this embodiment mode, deterioration due to hot carrier injection is suppressed by making a part of the gate electrode 805 overlap (overlap) the LDD regions 803a and 803b with the gate insulating film 124 interposed therebetween. be able to. Further, since the width of the first conductive film 805a having a radiation absorbing ability is longer than the channel length of the channel formation region, the channel formation region can be more effectively protected from radiation.
[0087]
In the display device having the pixel structure of this embodiment, even when an electron beam evaporation method is used to form the counter electrode 112 or 404 serving as a cathode, radiation such as gamma rays, electron beams, or X-rays is blocked by the gate electrode 805. As a result, the semiconductor device does not directly reach the channel formation region and the gate insulating film in contact with the channel formation region, so that an operation failure due to a so-called radiation error such as generation of a positive charge and increase in an interface state can be avoided.
[0088]
As described above, with the pixel structure described in this embodiment, a metal film can be formed without being affected by radiation when a metal film is formed using an electron beam evaporation method. It is possible to suppress the occurrence of defects such as abnormal threshold voltage and abnormal S value.
[0089]
Note that in this embodiment, the insulating film having the radiation absorbing ability described in Embodiment 5 is used as a part of the interlayer insulating film, or the radiation shown in Embodiment 6 is used as part or all of the source wiring and the like. By using the conductive film having the absorbing ability or the conductive film containing the element having the radiation absorbing ability described in Embodiment Mode 7 in combination with this embodiment mode, the radiation shielding effect can be further enhanced. It is possible. Of course, it is also possible to adopt the configuration of the pixel electrode as described in Embodiments 8 to 10.
[0090]
Embodiment 13
In this embodiment, an overall structure of an electroluminescent display device to which the present invention can be applied will be described with reference to FIGS. FIG. 9 is a top view of an electroluminescent display device formed by sealing an element substrate on which a thin film transistor is formed with a sealing material, and FIG. 9B is a BB view of FIG. 9C is a cross-sectional view taken along line AA ′ of FIG. 9A.
[0091]
On the substrate 21, a pixel portion (display portion) 22, a data line driving circuit 23 provided so as to surround the pixel portion 22, gate line driving circuits 24a and 24b, and a protection circuit 25 are arranged. A sealing material 26 is provided. Regarding the structure of the pixel portion 22, any of the structures described in Embodiments 8 to 12 may be used. As the sealing material 26, an ultraviolet curable resin, an epoxy resin, or another resin can be used, but it is desirable to use a material having as low hygroscopicity as possible. Note that the sealant 26 may be provided so as to overlap a part of the data line drive circuit 23, the gate line drive circuits 24a and 24b, and the protection circuit 25, or may be provided avoiding these circuits.
[0092]
Then, the sealing material 27 is adhered using the sealing material 26, and a closed space 28 is formed by the substrate 21, the sealing material 26, and the sealing material 27. As the sealing material 27, a glass material, a metal material (typically, a stainless steel material), a ceramic material, and a plastic material (including a plastic film) can be used. In addition, as described in Embodiments 8 to 12, sealing with an insulating film alone is possible.
[0093]
When a material different from that of the substrate 21 is used as the sealing material 27, the adhesion of the sealing material 26 may be impaired due to a difference in thermal expansion coefficient. Therefore, it is desirable that the sealing material 27 be made of the same material as the substrate 21 on which the transistor is formed. In other words, it is desirable to use a substrate having the same coefficient of thermal expansion as the substrate 21. In this embodiment, glass is used as the material of the substrate 21 and the sealing material 27, and the sealing material 27 has a uniform thermal expansion coefficient by allowing the substrate 21 to pass through the same thermal history as the thermal history in the process of manufacturing the thin film transistor.
[0094]
A moisture absorbing agent (barium oxide, calcium oxide, or the like) 29 is provided in advance in the concave portion of the sealing material 27, and adsorbs moisture, oxygen, or the like in the closed space 28 to maintain a clean atmosphere, and maintain the EL layer. It plays a role in suppressing deterioration. The concave portion is covered with a fine mesh-shaped cover member 30, which allows air and moisture to pass through but does not allow the moisture absorbent 29 to pass through. The closed space 28 may be filled with a rare gas such as nitrogen or argon, and may be filled with a resin or liquid if it is inert.
[0095]
Further, a terminal portion 31 for transmitting a signal to the data line driving circuit 23 and the gate line driving circuits 24a and 24b is provided on the substrate 21, and the terminal portion 31 is connected to the terminal portion 31 via an FPC (flexible print circuit) 32. A data signal such as a video signal is transmitted. The cross section of the terminal portion 31 is as shown in FIG. 9B, and is provided on the FPC 32 side with a wiring having a structure in which an oxide conductive film 34 is stacked over a wiring 33 formed simultaneously with a gate wiring or a data wiring. The wiring 35 is electrically connected using a resin 37 in which a conductor 36 is dispersed. The conductor 36 may be a spherical polymer compound which is plated with gold or silver.
[0096]
In the present embodiment, the protection circuit 25 is provided between the terminal unit 31 and the data line driving circuit 23, and when static electricity such as a sudden pulse signal enters between the two, the protection circuit 25 sends the pulse signal to the outside. Play the role of letting go. At that time, first, a high-voltage signal that is instantaneously input is dulled by a capacitor, and other high voltages can be released to the outside by a circuit configured using a thin film transistor or a thin film diode. Of course, the protection circuit may be provided in another place, for example, between the pixel portion 22 and the data line driving circuit 23 or between the pixel portion 22 and the gate line driving circuits 24a and 24b.
[0097]
Note that the electroluminescent display device described in this embodiment mode may use the pixel structures of Embodiment Modes 5 to 7. In that case, the oxide conductive film 34 cannot be provided in the terminal portion 31, but there is no particular problem in operation.
[0098]
[Embodiment 14]
Each of the structures of the thin film transistors described in Embodiments 1 to 11 has a top gate structure (specifically, a planar structure); however, in each embodiment, a thin film transistor has a bottom gate structure (specifically, an inverted staggered structure). It is also possible. In this case, the positions of the semiconductor layer such as the active layer and the first metal layer such as the gate electrode are merely reversed. Of course, the present invention is not limited to a thin film transistor, but may be applied to a transistor having a MOS structure formed using a silicon well.
[0099]
[Embodiment 15]
Each of the display devices described in Embodiment Modes 1 to 13 exemplifies an electroluminescence display device. However, the present invention is applicable to all semiconductor processes using an electron beam evaporation method. The present invention may be applied to a liquid crystal display device, a field emission display device, and other display devices to be used.
[0100]
[Embodiment 16]
Electronic devices using the display device of the present invention as a display unit include a video camera, a digital camera, a goggle-type display (head-mounted display), a navigation system, a sound reproducing device (car audio, an audio component, etc.), a notebook personal computer, A game device, a portable information terminal (a mobile computer, a mobile phone, a portable game machine, an electronic book, or the like), and an image reproducing device provided with a recording medium (specifically, a recording medium such as a Digital Versatile Disc (DVD)). Device having a display capable of displaying the image). FIG. 10 shows specific examples of these electronic devices.
[0101]
FIG. 10A illustrates a television, which includes a housing 2001, a support base 2002, a display portion 2003, a speaker portion 2004, a video input terminal 2005, and the like. The present invention can be applied to the display portion 2003. It should be noted that all information display televisions for personal computers, TV broadcast reception, advertisement display, and the like are included.
[0102]
FIG. 10B illustrates a digital camera, which includes a main body 2101, a display portion 2102, an image receiving portion 2103, operation keys 2104, an external connection port 2105, a shutter 2106, and the like. The present invention can be applied to the display portion 2102.
[0103]
FIG. 10C illustrates a laptop personal computer, which includes a main body 2201, a housing 2202, a display portion 2203, a keyboard 2204, an external connection port 2205, a pointing mouse 2206, and the like. The present invention can be applied to the display portion 2203.
[0104]
FIG. 10D illustrates a mobile computer, which includes a main body 2301, a display portion 2302, a switch 2303, operation keys 2304, an infrared port 2305, and the like. The present invention can be applied to the display portion 2302.
[0105]
FIG. 10E illustrates a portable image reproducing device (specifically, a DVD reproducing device) including a recording medium, which includes a main body 2401, a housing 2402, a display portion A 2403, a display portion B 2404, and a recording medium (such as a DVD). A reading unit 2405, operation keys 2406, a speaker unit 2407, and the like are included. The display portion A 2403 mainly displays image information, and the display portion B 2404 mainly displays character information. The present invention can be applied to the display portions A, B 2403, and 2404. Note that the image reproducing device provided with the recording medium includes a home game machine and the like.
[0106]
FIG. 10F illustrates a goggle-type display (head-mounted display), which includes a main body 2501, a display portion 2502, and an arm portion 2503. The present invention can be applied to the display portion 2502.
[0107]
FIG. 10G illustrates a video camera, which includes a main body 2601, a display portion 2602, a housing 2603, an external connection port 2604, a remote control receiving portion 2605, an image receiving portion 2606, a battery 2607, a voice input portion 2608, operation keys 2609, and the like. . The present invention can be applied to the display portion 2602.
[0108]
FIG. 10H illustrates a mobile phone, which includes a main body 2701, a housing 2702, a display portion 2703, a sound input portion 2704, a sound output portion 2705, operation keys 2706, an external connection port 2707, an antenna 2708, and the like. The present invention can be applied to the display portion 2703. Note that the display portion 2703 displays white characters on a black background, so that current consumption of the mobile phone can be suppressed.
[0109]
As described above, the display device obtained by implementing the present invention may be used as a display unit of any electronic device. Note that a display device having any of the structures described in Embodiments 1 to 15 may be used for the electronic device of this embodiment.
[0110]
【The invention's effect】
According to the present invention, when forming a metal film, particularly by an electron beam evaporation method, a problem that a transistor formed on a substrate to be processed is irradiated with gamma rays, neutrons, X-rays, and other radiations is solved, and an oxide film generated by the radiation is solved. Generation of internal positive charge, Si-SiO ₂ It is possible to prevent a malfunction of the transistor due to the generation of interface states at the interface and the generation of neutral electron traps in the oxide film. Further, a highly reliable display device can be obtained by preventing abnormalities in the threshold voltage and the S value.
[Brief description of the drawings]
1A and 1B are a top view and a cross-sectional view illustrating a pixel structure of a display device.
FIG. 2 is a cross-sectional view illustrating a structure of a display device.
FIG. 3 is a cross-sectional view illustrating a structure of a display device.
4A and 4B are a top view and a cross-sectional view illustrating a pixel structure of a display device.
FIG. 5 is a cross-sectional view illustrating a structure of a display device.
FIG. 6 is a cross-sectional view illustrating a structure of a display device.
FIG. 7 is a cross-sectional view illustrating a structure of a display device.
FIG. 8 is a cross-sectional view illustrating a structure of a display device.
FIG. 9 illustrates an appearance of a display device.
FIG. 10 illustrates an example of an electronic device.
FIG. 11 is a cross-sectional view illustrating a pixel configuration of a conventional display device.
FIG. 12 shows a thin film transistor I _D -V _G Graph showing characteristics.
13A and 13B are a top view and a cross-sectional view illustrating a pixel structure of a display device.
FIG. 14 is a top view illustrating a structure of a display device.
FIG. 15 is a cross-sectional view illustrating a pixel structure of a display device.
FIG. 16 is a cross-sectional view illustrating a pixel structure of a display device.

Claims (27)

A display device having a transistor on a base and a light emitting element electrically connected to the transistor, wherein a radiation absorbing film is provided above the transistor and below a cathode of the light emitting element. . A display device including a transistor on a base and a light emitting element electrically connected to the transistor, wherein a radiation absorbing film is provided above the transistor and below a cathode of the light emitting element, and the radiation absorbing film is insulated. A display device, which is covered with a film. 3. The display device according to claim 1, wherein the radiation absorbing film is provided in a lattice pattern. A display device including a transistor on a base and a light emitting element electrically connected to the transistor, wherein an insulating film containing lead or iron is provided above the transistor and below a cathode of the light emitting element. Characteristic display device. A display device including a transistor on a base and a light-emitting element electrically connected to the transistor, wherein an insulating film containing lead or iron is provided above the transistor and below a cathode of the light-emitting element, A display device, wherein an insulating film containing lead or iron is covered with the insulating film. The display device according to claim 4, wherein the lead or iron-containing insulating film is provided in a lattice pattern. 7. The display device according to claim 1, wherein the light emitting element is an electroluminescence element. A display device including a transistor and a light-emitting element electrically connected to the transistor, wherein the transistor includes an insulating film having a radiation absorbing ability as part of an interlayer insulating film. A display device including a transistor and a light-emitting element electrically connected to the transistor, wherein the transistor includes an interlayer insulating film including a structure in which an insulating film having a radiation absorbing ability is stacked over a silicon compound film. A display device characterized by the above-mentioned. A display device including a transistor and a light-emitting element electrically connected to the transistor, wherein the transistor includes an interlayer insulating film including a structure in which an insulating film having a radiation absorbing ability is sandwiched between silicon compound films. Display device. The display device according to any one of claims 8 to 10, wherein the silicon compound film is a silicon compound film containing nitrogen. The display device according to claim 8, wherein an organic resin film is provided above the insulating film having a radiation absorbing ability. 13. The display device according to claim 8, wherein the insulating film having a radiation absorbing ability is an insulating film containing lead or iron. A display device including a transistor and a light-emitting element electrically connected to the transistor, wherein a conductive film having a radiation absorbing ability is provided over a channel formation region of the transistor. A display device including a transistor and a light-emitting element electrically connected to the transistor, wherein a conductive film having a radiation absorbing ability is provided over a channel formation region of the transistor, and the conductive material having the radiation absorbing ability is provided. A display device, wherein the potential of the film is fixed. A display device including a transistor and a light-emitting element electrically connected to the transistor, wherein the transistor includes a conductive film having a radiation absorbing ability as part or all of a source wiring or a drain wiring. Display device. A display device including a transistor and a light-emitting element electrically connected to the transistor, wherein the transistor includes a conductive film having a radiation absorbing function as part or all of a gate wiring. The display device according to any one of claims 14 to 17, wherein the conductive film having a radiation absorbing ability is stacked with another conductive film. The display device according to any one of claims 14 to 18, wherein the conductive film having a radiation absorbing ability is a conductive film made of lead or iron. A display device including a transistor and a light-emitting element electrically connected to the transistor, wherein a conductive film containing an element having a radiation absorbing ability is provided over a channel formation region of the transistor. Display device. A display device including a transistor and a light-emitting element electrically connected to the transistor, wherein a conductive film containing an element having a radiation absorbing ability is provided above a channel formation region of the transistor, and A potential of a conductive film containing an element having a fixed electric potential. A display device including a transistor and a light-emitting element electrically connected to the transistor, wherein the transistor includes a conductive film containing an element having a radiation absorbing ability as part or all of a source wiring or a drain wiring. Characteristic display device. A display device including a transistor and a light-emitting element electrically connected to the transistor, wherein the transistor includes a conductive film containing an element having a radiation absorbing ability as part or all of a gate wiring. Display device. The display device according to any one of claims 20 to 23, wherein the element having a radiation absorbing ability is lead or iron. The display device according to any one of claims 20 to 23, wherein the conductive film containing the element having a radiation absorbing ability is an aluminum film containing lead or iron. 26. The display device according to claim 8, wherein the light emitting element is an electroluminescence element. An electronic apparatus comprising the display device according to any one of claims 1 to 26 provided in a display unit.

Images