ACTIVE MATRIX SUBSTRATE, AND X-RAY IMAGING PANEL INCLUDING SAME

An active matrix substrate 1 has a plurality of pixels, which each of pixels has a switching element. Each of the pixels includes a pair of electrodes 14a, 14b connected with the switching element; a photoelectric conversion element including a semiconductor layer 15 provided between the pair of electrodes; an inorganic film covering a surface of the photoelectric conversion element; and an organic resin film 106b covering the inorganic film. The inorganic film includes a first inorganic film 105a, and a second inorganic film 105b provided in a layer different from that of the first inorganic film 105a. The first inorganic film 105a is provided in contact with at least a side surface of the photoelectric conversion element, and the second inorganic film 105b is in contact with at least a part of the first inorganic film 105a and covers the side surface of the photoelectric conversion element.

TECHNICAL FIELD

The present invention relates to an active matrix substrate, and an X-ray imaging panel including the same.

BACKGROUND ART

Conventionally, a photoelectric conversion device has been known that includes an active matrix substrate provided with photoelectric conversion elements each of which is connected with a switching element in each pixel. Patent Document 1 discloses such a photoelectric conversion device. This photoelectric conversion device includes thin film transistors as switching elements, and includes photodiodes as photoelectric conversion elements. In the photodiode, a p-type semiconductor layer, an i-type semiconductor layer, and an n-type semiconductor layer are used as semiconductor layers, and electrodes are connected to the p-type semiconductor layer and the n-type semiconductor layer, respectively. The photodiode is covered with a resin film made of an epoxy resin.

PRIOR ART DOCUMENT

Patent Document

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

Incidentally, after an imaging panel is produced, a surface of the imaging panel is scarred in some cases. If moisture in the atmosphere gets in the inside through scars of the imaging panel surface, leakage current in semiconductor layers of photodiodes tends to flow in between electrodes. More specifically, for example, in the imaging panel illustrated inFIG. 27A, moisture gets in the inside through a scar J of the imaging panel surface, moisture permeates the resin film22on the photodiode12.FIG. 27Bis an enlarged view illustrating a part of a broken line frame210illustrated inFIG. 27A. As illustrated inFIG. 27B, the photodiode12is covered with an inorganic film21, but in step-like parts of end portions of a semiconductor layer122and an electrode121ain the photodiode12, the inorganic film21tends to be discontinuous. If moisture permeates the resin film22, and moisture gets in the inside through a part2101where the inorganic film21is discontinuous, the inorganic film21becomes a leakage path through which leakage current of the semiconductor layer122flows, and leakage current flows between the electrodes121aand121b(seeFIG. 27A). When leakage current flows between the electrodes121aand121b, X-ray detection accuracy decreases.

The present invention provides a technique that enables to prevent decreases in the detection accuracy caused by leakage current of photoelectric conversion elements.

Means to Solve the Problem

An active matrix substrate of the present invention that solves the above-described problem is an active matrix substrate having a plurality of pixels, wherein each of the pixels includes: a switching element; a photoelectric conversion element including a pair of electrodes connected with the switching element, and a semiconductor layer provided between the pair of electrodes; an inorganic film covering a surface of the photoelectric conversion element; and an organic resin film covering the inorganic film, wherein the inorganic film includes a first inorganic film, and a second inorganic film provided in a layer different from that of the first inorganic film, the first inorganic film is provided in contact with at least a side surface of the photoelectric conversion element, and the second inorganic film is provided so as to be in contact with at least a part of the first inorganic film and cover the side surface of the photoelectric conversion element.

Effect of the Invention

The present invention makes it possible to prevent decreases in the detection accuracy caused by leakage current of photoelectric conversion elements.

MODE FOR CARRYING OUT THE INVENTION

An active matrix substrate according to one embodiment of the present invention is an active matrix substrate having a plurality of pixels, wherein each of the pixels includes: a switching element; a photoelectric conversion element including a pair of electrodes connected with the switching element, and a semiconductor layer provided between the pair of electrodes; an inorganic film covering a surface of the photoelectric conversion element; and an organic resin film covering the inorganic film, wherein the inorganic film includes a first inorganic film, and a second inorganic film provided in a layer different from that of the first inorganic film, the first inorganic film is provided in contact with at least a side surface of the photoelectric conversion element, and the second inorganic film is provided so as to be in contact with at least a part of the first inorganic film and cover the side surface of the photoelectric conversion element (the first configuration).

According to the first configuration, the first inorganic film is provided in contact with the side surface of the photoelectric conversion element, and further, the side surface of the photoelectric conversion element is covered with the second inorganic film provided in contact with the first inorganic film. Therefore, in a case where the first inorganic film covering the side surface of the photoelectric conversion element has a discontinuous part, even if moisture permeates the organic resin film, the second inorganic film makes it unlikely that moisture would get in the inside the first inorganic film. As a result, it is unlikely that the first inorganic film would serves as a leakage path for leakage current of the photoelectric conversion element, whereby light detection accuracy hardly decreases.

The first configuration may be further characterized in that either the first inorganic film or the second inorganic film is arranged so as to be in contact with one of the pair of electrodes (the second configuration).

With the second configuration, one of the electrodes of the photoelectric conversion element can be protected by either the first inorganic film or the second inorganic film.

The first configuration may be further characterized in that the first inorganic film is arranged so as to be in contact with one of the pair of electrodes, and the second inorganic film is arranged so as to overlap with the one of the electrodes with the first inorganic film being interposed therebetween (the third configuration).

According to the third configuration, one of the electrodes of the photoelectric conversion element is covered with the first inorganic film and the second inorganic film. Accordingly, as compared with a case of being covered with either one of the inorganic films, the electrode can be protected more surely.

Any one of the first to third configurations may be further characterized in that the organic resin film includes a first organic resin film, and a second organic resin film provided in a layer different from that of the first organic resin film; the first organic resin film is provided between the first inorganic film and the second inorganic film, so as to overlap with the side surface of the photoelectric conversion element when viewed in a plan view; and the second organic resin film is provided so as to cover the second inorganic film (the fourth configuration).

According to the fourth configuration, the side surface of the photoelectric conversion element is covered with the first inorganic film, the second organic resin film, and the second inorganic film. Therefore, as compared with a case where the second organic resin film is not provided, the permeation of moisture into the second inorganic film can be prevented further.

The fourth configuration may be further characterized in that the first inorganic film and the first organic resin film of each pixel is positioned apart from the first inorganic film and the first organic resin film of another adjacent pixel, respectively (the fifth configuration).

According to the fifth configuration, the first inorganic film and the first organic resin film are arranged so as to be divided and separated between adjacent pixels. In a case where moisture gets in the inside of the first inorganic film and the second organic resin film at a certain pixel, if there is a discontinuous part in the first inorganic film covering the side surface of the photoelectric conversion element of the pixel, moisture gets into the discontinuous part, thereby causing the first inorganic film to become a leakage path. The first inorganic film and the first organic resin film, however, are divided and separated between the pixels, whereby the leakage path does not extend to another adjacent pixel.

The first or second configuration may be further characterized in that the first inorganic film and the second inorganic film overlap with each other at the side surface of the photoelectric conversion element, and the organic resin film is arranged so as to cover the first inorganic film and the second inorganic film (the sixth configuration).

According to the sixth configuration, the side surface of the photoelectric conversion element is covered with the first inorganic film and the second inorganic film. Even though the first inorganic film covering the side surface of the photoelectric conversion element has a discontinuous part, when moisture permeates the organic resin film, it is therefore unlikely that moisture would get in the discontinuous part and a leakage path would be formed in the first inorganic film.

Any one of the first to sixth configurations may be further characterized in that each of the first inorganic film and the second inorganic film has a thickness of an integer multiple of 150 nm (the seventh configuration).

With the seventh configuration, the photoelectric conversion efficiency in the photoelectric conversion element can be improved.

An X-ray imaging panel according to one embodiment of the present invention includes: the active matrix substrate according to any one of the first to seventh configurations; and a scintillator that converts irradiated X-rays into scintillation light (the eighth configuration).

According to the eighth configuration, the first inorganic film is provided in contact with the side surface of the photoelectric conversion element, and further, the side surface of the photoelectric conversion element is covered with the second inorganic film provided in contact with the first inorganic film. Therefore, in a case where the first inorganic film covering the side surface of the photoelectric conversion element has a discontinuous part, even if moisture penetrates through the organic resin film covering the first inorganic film and the second inorganic film, the second inorganic film makes it unlikely that moisture would get in the inside the first inorganic film. As a result, it is unlikely that the first inorganic film would serves as a leakage path for leakage current of the photoelectric conversion element, whereby X-ray detection accuracy hardly decreases.

The following description describes embodiments of the present invention in detail, while referring to the drawings. Identical or equivalent parts in the drawings are denoted by the same reference numerals, and the descriptions of the same are not repeated.

FIG. 1schematically illustrates an X-ray imaging device to which an active matrix substrate of the present embodiment is applied. The X-ray imaging device100includes an active matrix substrate1and a control unit2. The control unit2includes a gate control unit2A and a signal reading unit2B. X-rays are emitted from an X-ray source3to an object S. X-rays transmitted through the object S are converted into fluorescence (hereinafter referred to as scintillation light) by a scintillator4provided on the active matrix substrate1. The X-ray imaging device100obtains an X-ray image by picking up scintillation light with use of the active matrix substrate1and the control unit2.

FIG. 2schematically illustrates a schematic configuration of the active matrix substrate1. As illustrated inFIG. 2, a plurality of source lines10, and a plurality of gate lines11that intersect with the source lines10, are formed on the active matrix substrate1. The gate lines11are connected with the gate control unit2A, and the source lines10are connected with the signal reading unit2B.

The active matrix substrate1includes TFTs13connected to the source lines10and the gate lines11, at positions where the source lines10and the gate lines11intersect. Further, in areas surrounded by the source lines10and the gate lines11(hereinafter referred to as pixels), photodiodes12are provided, respectively. In each pixel, the photodiode12converts scintillation light obtained by converting X-rays transmitted through the object S, into charges in accordance with the amount of the light.

The gate lines11on the active matrix substrate1are sequentially switched by the gate control unit2A into a selected state, and the TFT13connected to the gate line11in the selected state is turned ON. When the TFT13is turned ON, a signal according to the charges obtained by conversion in the photodiode12is output to the signal reading unit2B through the source line10.

FIG. 3is an enlarged plan view illustrating a part of a pixel part of the active matrix substrate1illustrated inFIG. 2in which pixels are provided.

As illustrated inFIG. 3, the pixel surrounded by the gate lines11and the source lines10has the photodiode12and the TFT13.

The photodiode12includes a lower electrode14a, a photoelectric conversion layer15, and an upper electrode14b. The TFT13includes a gate electrode13aintegrated with the gate line11, a semiconductor activity layer13b, a source electrode13cintegrated with the source line10, and a drain electrode13d. The drain electrode13dand the lower electrode14aare connected with each other via a contact hole CH1.

Further, a bias line16is arranged so as to overlap with the gate line11and the source line10when viewed in a plan view. The bias line16is connected with a transparent conductive film17. The transparent conductive film17supplies a bias voltage to the photodiode12via a contact holes CH2.

Here,FIG. 4illustrates a cross-sectional view taken along line A-A in the pixel part P1ofFIG. 3. As illustrated inFIG. 4, the gate electrode13aintegrated with the gate line11(seeFIG. 3), and the gate insulating film102, are formed on the substrate101. The substrate101is has insulating property, and is formed with, for example, a glass substrate or the like.

The gate electrode13aand the gate line11are formed by laminating, for example, a metal film made of titanium (Ti) in the lower layer, and a metal film made of copper (Cu) in the upper layer. The gate electrode13aand the gate line11may have a structure obtained by laminating a metal film made of aluminum (Al) in the lower layer, and a metal film made of molybdenum nitride (MoN) in the upper layer. In this example, the metal films in the lower layer and the upper layer have thicknesses of about 300 nm and 100 nm, respectively. The material and thickness of the gate electrode13aand the gate line11, however, are not limited to these.

The gate insulating film102covers the gate electrode13a. To form the gate insulating film102, the following may be used, for example: silicon oxide (SiOx); silicon nitride (SiNx); silicon oxide nitride (SiOxNy)(x>y); silicon nitride oxide (SiNxOy)(x>y); or the like. In the present embodiment, the gate insulating film102is formed by laminating an insulating film made of silicon oxide (SiOx) in the upper layer, and an insulating film made of silicon nitride (SiNx) in the lower layer. In this example, the insulating film made of silicon oxide (SiOx) has a thickness of about 50 nm, and the insulating film made of silicon nitride (SiNx) has a thickness of about 400 nm. The material and the thickness of the gate insulating film102, however, are not limited to these.

A semiconductor activity layer13b, and a source electrode13cand a drain electrode13dconnected with the semiconductor activity layer13b, are provided on the gate electrode13awith the gate insulating film102being interposed therebetween.

The semiconductor activity layer13bis in contact with the gate insulating film102. The semiconductor activity layer13bis made of an oxide semiconductor. As the oxide semiconductor, for example, the following may be used: InGaO3(ZnO)5; magnesium zinc oxide (MgxZn1-xO); cadmium zinc oxide (CdxZn1-xO); cadmium oxide (CdO); or an amorphous oxide semiconductor containing indium (In), gallium (Ga), and zinc (Zn) at a predetermined ratio. In this example, the semiconductor activity layer13bis made of an amorphous oxide semiconductor containing indium (In), gallium (Ga), and zinc (Zn) at a predetermined ratio. In this example, the semiconductor activity layer13bhas a thickness of about 70 nm. The material and the thickness of the semiconductor activity layer13b, however, are not limited to these.

The source electrode13cand the drain electrode13dare arranged so as to be in contact with a part of the semiconductor activity layer13bon the gate insulating film102. In this example, the source electrode13cis integrally formed with the source line10(seeFIG. 3). The drain electrode13dis connected with the lower electrode14avia the contact hole CH1.

The source electrode13cand the drain electrode13dare provided on the same layer. The source electrode13cand drain electrode13dhave a three-layer structure obtained by laminating, for example, a metal film made of molybdenum nitride (MoN), a metal film made of aluminum (Al), and a metal film made of titanium (Ti). In this example, these three layers have thicknesses of about 100 nm, 500 nm, and 50 nm, respectively, in the order from the upper layer. The material and the thickness of the source electrode13cand drain electrode13d, however, are not limited to these.

On the gate insulating film102, a first insulating film103is provided so as to overlap with the source electrode13cand drain electrode13d. The first insulating film103has an opening on the drain electrode13d. The first insulating film103has a structure laminated silicon nitride (SiN) and silicon oxide (SiO2) in the stated order.

On the first insulating film103, a second insulating film104is provided. The second insulating film104has an opening on the drain electrode13d, and the contact hole CH1is formed with the opening of the first insulating film103and the opening of the second insulating film104form.

The second insulating film104is made of, for example, an organic transparent resin such as an acrylic resin or a siloxane-based resin, and has a thickness of about 2.5 μm. The material and the thickness of the second insulating film104, however, are not limited to these.

On the second insulating film104, the lower electrode14ais provided. The lower electrode14ais connected with the drain electrode13dvia the contact hole CH1. The lower electrode14ais formed with, for example, a metal film containing molybdenum nitride (MoN). In this example, the lower electrode14bhas a thickness of about 200 nm, but the thickness thereof is not limited to this.

On the lower electrode14a, the photoelectric conversion layer15is provided. The photoelectric conversion layer15has such a configuration that an n-type amorphous semiconductor layer151, an intrinsic amorphous semiconductor layer152, and a p-type amorphous semiconductor layer153are laminated in the stated order. In this example, the photoelectric conversion layer15has a length in the X axis direction which is smaller than the length of the lower electrode14ain the X axis direction.

The n-type amorphous semiconductor layer151is made of amorphous silicon doped with an n-type impurity (for example, phosphorus).

The intrinsic amorphous semiconductor layer152is made of intrinsic amorphous silicon. The intrinsic amorphous semiconductor layer152is in contact with the n-type amorphous semiconductor layer151.

The p-type amorphous semiconductor layer153is made of amorphous silicon doped with a p-type impurity (for example, boron). The p-type amorphous semiconductor layer153is in contact with the intrinsic amorphous semiconductor layer152.

In this example, the n-type amorphous semiconductor layer151has a thickness of about 30 nm, the intrinsic amorphous semiconductor layer has a thickness of about 1000 nm, and the p-type amorphous semiconductor layer153has a thickness of about 5 nm; the thicknesses thereof, however, are not limited to these.

On the photoelectric conversion layer15, the upper electrode14bis provided. The upper electrode14bis made of, for example, indium tin oxide (ITO), and has a thickness of about 70 nm. The material and the thickness of the upper electrode14b, however, are not limited to these.

A 3a-th insulating film105aand a 3b-th insulating film105bas inorganic films are provided so as to be in contact with the surface of the photodiode12. The 3a-th insulating film105aand the 3b-th insulating film105bare provided so as to be positioned apart from each other in the direction vertical to the substrate101outside the photodiode12. Between the 3a-th insulating film105aand the 3b-th insulating film105b, a 4a-th insulating film106aas an organic resin film is provided. Further, on the 3b-th insulating film105b, a 4b-th insulating film106bas an organic resin film is provided.

More specifically, the 3a-th insulating film105ais provided so as to extend from vicinities of ends on both sides of the upper electrode14b, to be in contact with side surface portions of the photodiode12, and to cover the second insulating film104. In other words, the 3a-th insulating film105ais arranged so as to be divided and separated above the upper electrode14b, and so as to cover the side surfaces of the photodiode12and the second insulating film104.

The 3b-th insulating film105bis in contact with the 3a-th insulating film105aon the upper electrode14b, and has an opening in a part of the surface of the upper electrode14bwhere the 3a-th insulating film105ais not provided. The 3b-th insulating film105bis formed extending to outside the photodiode12, covering side surfaces of the photodiode12with the 4a-th insulating film106abeing interposed therebetween.

In other words, in the present embodiment, the 3a-th insulating film105a, the 4a-th insulating film106a, and the 3b-th insulating film105barranged outside the photodiode12are extended to the photodiode12of the adjacent pixel.

The 4b-th insulating film106bis provided on the 3b-th insulating film105bso that the 4b-th insulating film106bhas an opening above the opening of the 3b-th insulating film105b. The contact hole CH2is formed with the openings of the 3b-th insulating film105band the 4b-th insulating film106bform.

In this example, the 3a-th insulating film105aand the 3b-th insulating film105bare made of, for example, silicon nitride (SiN), and each of the same has a thickness of about 300 nm; the materials and the thicknesses of these, however, are not limited to these.

The 4a-th insulating film106aand the 4b-th insulating film106bare made of an organic transparent resin composed of, for example, an acrylic resin or a siloxane-based resin, and these have thicknesses of, for example, about 1.5 μm and 1.0 μm, respectively; the materials and the thicknesses of the 4a-th insulating film106aand the 4b-th insulating film106b, however, are not limited to these.

On the 4b-th insulating film106b, the bias line16, as well as the transparent conductive film17connected with the bias line16, are provided. The transparent conductive film17is in contact with the upper electrode14bat the contact hole CH2.

The bias line16is connected to the control unit2(seeFIG. 1). The bias line16applies a bias voltage input from the control unit2, to the upper electrode14bvia the contact hole CH2.

The bias line16has a three-layer structure. More specifically, the bias line16has a structure obtained by laminating, in the order from the upper layer, a metal film made of molybdenum nitride (MoN), a metal film made of aluminum (Al), and a metal film made of titanium (Ti). In this example, the metal films of these three layers have thicknesses of, in the order from the upper layer, about 100 nm, 300 nm, and 50 nm, respectively. The materials and the thicknesses of the bias line16, however, are not limited to these.

The transparent conductive film17is made of, for example, ITO, and has a thickness of about 70 nm: the material and the thickness of the transparent conductive film17, however, are not limited to these.

Further, on the 4b-th insulating film106b, a fifth insulating film107as an inorganic insulating film is provided so as to cover the transparent conductive film17. The fifth insulating film107is made of, for example, silicon nitride (SiN), and has a thickness of, for example, about 200 nm; the material and the thickness of the fifth insulating film107, however, are not limited to these.

A sixth insulating film108made of a resin film is provided so as to cover the fifth insulating film107. The sixth insulating film108is formed with an organic transparent resin made of, for example, an acrylic resin or a siloxane-based resin, and has a thickness of, for example, about 2.0 μm; the material and the thickness of the sixth insulating film108, however, are not limited to these.

(Method for Producing the Active Matrix Substrate1)

Next, the following description describes a method for producing the active matrix substrate1while referring toFIGS. 5A to 5U.FIGS. 5A to 5Uillustrate cross-sectional views of the active matrix substrate1in steps of the producing process, respectively (cross sections taken along line A-A inFIG. 3).

As illustrated inFIG. 5A, the gate insulating film102and the TFT13are formed on the substrate101by using a known method.

Subsequently, the first insulating film103is formed by laminating silicon nitride (SiN) and silicon oxide (SiO2), by using, for example, plasma CVD (seeFIG. 5B).

Thereafter, a heat treatment at about 350° C. is applied to an entire surface of the substrate101, and then, photolithography, and dry etching using fluorine-containing gas are performed, whereby the first insulating film103is patterned (seeFIG. 5C). Through these steps, the opening103aof the first insulating film103is formed above the drain electrode13d.

Next, the second insulating film104made of an acrylic resin or a siloxane-based resin is formed on the first insulating film103by, for example, slit-coating (seeFIG. 5D). Thereafter, by using photolithography, the second insulating film104is patterned (seeFIG. 5E). Through this step, the opening104aof the second insulating film104is formed on the opening103a, whereby the contact hole CH1composed of the opening103aand the104ais formed.

Subsequently, a metal film made of molybdenum nitride (MoN) is formed by, for example, sputtering, and photolithography and wet etching are carried out so that the metal film is patterned. Through these steps, the lower electrode14ais formed on the second insulating film104so that the lower electrode14ais connected with the drain electrode13dvia the contact hole CH1(seeFIG. 5F).

Next, the n-type amorphous semiconductor layer151, the intrinsic amorphous semiconductor layer152, and the p-type amorphous semiconductor layer153are formed in the stated order by using, for example, plasma CVD. Thereafter, for example, a transparent conductive film made of ITO is formed by using sputtering, and photolithography and dry etching are carried out so that the transparent conductive film is patterned. Through this step, the upper electrode14bis formed on the p-type amorphous semiconductor layer153(seeFIG. 5G).

Next, photolithography and dry etching are performed, whereby the n-type amorphous semiconductor layer151, the intrinsic amorphous semiconductor layer152, and the p-type amorphous semiconductor layer153are patterned (seeFIG. 5H). Through this step, the photoelectric conversion layer15is formed.

Next, the 3a-th insulating film105amade of silicon nitride (SiN) is formed by, for example, plasma CVD (seeFIG. 5I). Thereafter, photolithography and dry etching are carried out so that the 3a-th insulating film105ais patterned (seeFIG. 5J). Through these steps, an opening H1of the 3a-th insulating film105ais formed on the upper electrode14b.

In some cases, however, the etching with respect to the 3a-th insulating film105afor forming the opening H1causes film thinning of the upper electrode14b, i.e., a decrease in the thickness of the top surface portion of the upper electrode14b. In the present embodiment, therefore, it is desirable that the thickness of the upper electrode14bwhen it is formed should be set with influences of the etching of the 3a-th insulating film105abeing taken into consideration.

Subsequently, the 4a-th insulating film106amade of, for example, an acrylic resin or a siloxane-based resin is formed by slit-coating (seeFIG. 5K). Thereafter, by using photolithography, the 4a-th insulating film106ais patterned (seeFIG. 5L). Through these steps, an opening H2of the 4a-th insulating film106a, which has an opening width greater than that of the opening H1, is formed on the opening H1of the 3a-th insulating film105a.

Subsequently, the 3b-th insulating film105bmade of silicon nitride (SiN) is formed by, for example, plasma CVD, so as to cover the 4a-th insulating film106a(seeFIG. 5M). Thereafter, photolithography and dry etching are carried out so that the 3b-th insulating film105bis patterned (seeFIG. 5N). Through these steps, an opening H3of the 3b-th insulating film105bis formed on the upper electrode14b.

Next, for example, the 4b-th insulating film106bmade of an acrylic resin or a siloxane-based resin is formed by slit-coating so as to cover the 3b-th insulating film105b(seeFIG. 5O), and the 4b-th insulating film106bis patterned by using photolithography (seeFIG. 5P). Through these steps, an opening H4of the 4b-th insulating film106bis formed on the opening H3of the 3b-th insulating film105b, whereby the contact hole CH2, composed of the openings H3and H4, is formed.

Subsequently, a metal film160is formed by laminating molybdenum nitride (MoN), aluminum (Al), and titanium (Ti) in the stated order, by, for example, sputtering (seeFIG. 5Q). Thereafter, photolithography and wet etching are carried out so that the metal film160is patterned (seeFIG. 5R). For wet etching of the metal film160, for example, an etchant containing acetic acid, nitric acid, and phosphoric acid is used. Through these steps, the bias line16is formed on the fourth insulating film106.

Next, a transparent conductive film made of ITO is formed by, for example, sputtering, and then, photolithography and dry etching are carried out so that the transparent conductive film is patterned. Through these steps, the transparent conductive film17is formed that is connected with the bias line16and is connected with the photoelectric conversion layer15via the contact hole CH2(seeFIG. 5S).

Subsequently, the fifth insulating film107made of silicon nitride (SiN) is formed on the 4b-th insulating film106bso as to cover the transparent conductive film17, by, for example, plasma CVD (seeFIG. 5T).

Next, the sixth insulating film108made of an acrylic resin or a siloxane-based resin is formed so as to cover the fifth insulating film107by, for example, slit-coating (seeFIG. 5U). Through this process, the active matrix substrate1of the present embodiment is produced.

In the active matrix substrate1of the present embodiment, side surfaces of the photodiode12are covered with the 3a-th insulating film105a, the top surface of the upper electrode14bis covered with the 3b-th insulating film105b, and further, the 3a-th insulating film105aand the 3b-th insulating film105bare in contact with each other on the upper electrode14b. Besides, outside the photodiode12, the 3a-th insulating film105ais covered with the 4a-th insulating film106aand the 3b-th insulating film105b. In other words, the side surfaces of the photodiode12are covered with the 3a-th insulating film105a, the 4a-th insulating film106a, and the 3b-th insulating film105b.

The 3a-th insulating film105aand the 3b-th insulating film105b, which are inorganic insulating films, have higher waterproofness than that of the 4a-th insulating film106aand the 4b-th insulating film106b, which are resin films. Accordingly, in a case where moisture permeates the 4b-th insulating film106bthrough a scar occurring to the surface of the active matrix substrate1, even with any discontinuous part being present in the 3a-th insulating film105acovering the side surfaces of the photodiode12, moisture can be prevented by the 3b-th insulating film105bfrom penetrating through the discontinuous part in the 3a-th insulating film105a. As a result, the discontinuous part of the 3a-th insulating film105adoes not serve as a leakage path for leakage current of the photodiode12, and hence, this makes it possible to reduce deterioration of the X-ray detection accuracy caused by leakage current.

In the above-described step inFIG. 5J, the 3a-th insulating film105ais patterned by using photolithography so that the opening H1of the 3a-th insulating film105ais formed, but this step may be carried out as follows. For example, after the 4a-th insulating film106ais formed on the 3a-th insulating film105a, the 3a-th insulating film105ais patterned by using the 4a-th insulating film106aas a mask so that the opening H1of the 3a-th insulating film105ais formed. Further, in the above-described step inFIG. 5N, the 3b-th insulating film105bis patterned by using photolithography so that the opening H3of the 3b-th insulating film105bis formed, but this step may be as follows instead. For example, after the 3b-th insulating film105bis formed in the step inFIG. 5M, the 4b-th insulating film106bis formed on the 3b-th insulating film105b. Thereafter, patterning is carried out by using the 4b-th insulating film106bas a mask so that the opening H3of the 3b-th insulating film105bis formed.

Here, operations of the X-ray imaging device100illustrated inFIG. 1are described. First, X-rays are emitted from the X-ray source3. Here, the control unit2applies a predetermined voltage (bias voltage) to the bias line16(seeFIG. 3and the like). X-rays emitted from the X-ray source3transmit an object S, and are incident on the scintillator4. The X-rays incident on the scintillator4are converted into fluorescence (scintillation light), and the scintillation light is incident on the active matrix substrate1. When the scintillation light is incident on the photodiode12provided in each pixel in the active matrix substrate1, the scintillation light is changed to charges by the photodiode12in accordance with the amount of the scintillation light. A signal according to the charges obtained by conversion by the photodiode12is read out through the source line10to the signal reading unit2B (seeFIG. 2and the like) when the TFT13(seeFIG. 3and the like) is in the ON state according to a gate voltage (positive voltage) that is output from the gate control unit2A through the gate line11. Then, an X-ray image in accordance with the signal thus read out is generated in the control unit2.

Embodiment 1 is described above with reference to an example in which, outside the photodiode12, the 3a-th insulating film105a, the 4a-th insulating film106a, and the 3b-th insulating film105bare extended to the photodiode12of the adjacent pixel. In this case, if not only the surface of the active matrix substrate1has scars, but also the 3b-th insulating film105bhas a discontinuous part, a scar, or the like, there is a possibility that moisture would penetrate from the scar or the like of the 3b-th insulating film105bto the 4a-th insulating film106a. If moisture permeates the 4a-th insulating film106a, moisture gets in the discontinuous part of not only the 3a-th insulating film105acovering side surfaces of the photodiode12of a certain one of the pixels, but also in the 3a-th insulating film105acovering side surfaces of the photodiode12of another pixel adjacent thereto. In other words, a leakage path is formed in side surfaces of the photodiodes12of a plurality of the pixels, whereby a range in which leakage current flows is extended.

The following description describes the present embodiment in which the extension of a leakage path is reduced even if moisture penetrates from the 3b-th insulating film105b.

FIG. 6is a cross-sectional view of the pixel part of the active matrix substrate in the present embodiment. InFIG. 68, members identical to those in Embodiment 1 are denoted by the same reference symbols as those in Embodiment 1. The following description principally describes configurations different from those in Embodiment 1.

As illustrated inFIG. 6, in the active matrix substrate1A, a part of the 3a-th insulating film105athat is in contact with the second insulating film104has a length smaller than that in Embodiment 1. The 4a-th insulating film106ais provided exclusively on the 3a-th insulating film105a.

Outside the photodiode12, the 3b-th insulating film105bis provided on the second insulating film104so as to cover the 4a-th insulating film106aand the 3a-th insulating film105a. The 3b-th insulating film105bis in contact with the 3a-th insulating film105anot only on the upper electrode14b, but also on the second insulating film104.

In other words, in the present embodiment, the 3b-th insulating film105boutside the photodiode12is extended to an adjacent pixel, but the 3a-th insulating films105acorresponding to adjacent ones of the pixels are divided and separated from each other, and so are the 4a-th insulating films106acorresponding to adjacent ones of the pixels.

In this way, in the present embodiment, the 3a-th insulating film105aand the 4a-th insulating film106aare not extended to an adjacent pixel. Even if moisture permeates the 4a-th insulating film106aof a certain pixel, the moisture therefore does not penetrate to the 4a-th insulating film106aof a pixel adjacent to the foregoing pixel, whereby the extension of leakage path can be prevented.

Incidentally, in this case, it is likely that moisture would penetrate through a discontinuous part of the 3a-th insulating film105acovering side surfaces of the photodiode12of the pixel in which moisture has permeated the 4a-th insulating film106a, and this 3a-th insulating film105aserves as a leakage path through which leakage current flows. But if there is no scar or the like in the 3b-th insulating film105b, the 3b-th insulating film105bprevents moisture from getting into the discontinuous part of the 3a-th insulating film105a, and no leakage path is formed, as is the case with Embodiment 1.

The active matrix substrate1A in the present embodiment is produced through the following process. More specifically, after the above-described steps illustrated inFIGS. 5A to 5Iare performed, photolithography and dry etching are carried out in the state illustrated inFIG. 5Iso that the 3a-th insulating film105ais patterned. Here, the 3a-th insulating film105ain contact with the second insulating film104is etched so that the opening H1of the 3a-th insulating film105ais formed, and at the same time, the 3a-th insulating films105aof adjacent ones of the pixels are separated from each other (seeFIG. 7A).

Subsequently, in the same manner as that in the step illustrated inFIG. 5K, the 4a-th insulating film106ais formed so as to cover the 3a-th insulating film105(seeFIG. 7B), and thereafter, the 4a-th insulating film106ais patterned by using photolithography (seeFIG. 7C). Through these steps, the 4a-th insulating film106ais formed exclusively on the 3a-th insulating film105a, and the opening H2of the 4a-th insulating film106a, having a width greater than that of the opening H1, is formed.

Subsequently, in the same manner as that in the step illustrated inFIG. 5M, the 3b-th insulating film105bis formed so as to cover the 4a-th insulating film106a(seeFIG. 7D), and photolithography and dry etching are carried out so that the 3b-th insulating film105bis patterned (seeFIG. 7E). Through these steps, the 3a-th insulating film105aand the 3b-th insulating film105bare connected inside and outside the photodiode12, and the opening H3of the 3b-th insulating film105bis formed on the upper electrode14b. Thereafter, steps identical to the above-described steps illustrated inFIGS. 5O to 5Uare carried out, whereby the active matrix substrate1A is produced.

Embodiment 1 is described above with reference to an exemplary configuration in which the side surface portions of the photodiode12are covered with the 3a-th insulating film105a, and the top surface of the upper electrode14bexcept for the portion thereof where the contact hole CH2is formed is covered with the 3b-th insulating film105b. In this case, when the 3a-th insulating film105ais pattered, the top surface of the upper electrode14bis affected by etching, film thinning occurs to the top surface portion of the upper electrode14b, i.e., the thickness of the top surface portion of the upper electrode14bdecreases. As the present embodiment, an exemplary configuration is described in which the formation of a leakage path at the side surfaces of the photodiode12is prevented, without film thinning occurring to the upper electrode14b.

FIG. 8is a cross-sectional view illustrating a pixel part of an active matrix substrate in the present embodiment. InFIG. 8, members identical to those in Embodiment 1 are denoted by the same reference symbols as those in Embodiment 1. The following description principally describes configurations different from those in Embodiment 1.

As illustrated inFIG. 8, in an active matrix substrate1B, the 3a-th insulating film105acovers the surfaces of the photodiode12except for a part of the top surface of the photodiode12. In other words, the 3a-th insulating film105ais divided and separated on the top surface of the upper electrode14b, and cover the side surfaces of the photodiode12. The 3a-th insulating film105aon the second insulating film104is extended to the adjacent pixel.

The 4a-th insulating film106ais provided so as to cover the 3a-th insulating film105aoutside the photodiode12, and is extended to the adjacent pixel.

The 3b-th insulating film105bis provided so as to be in contact with the 3a-th insulating film105ainside the photodiode12, and to cover the 4a-th insulating film106ainside the photodiode12. In other words, the 3b-th insulating film105bcovers the side surfaces of the photodiode12with the 3a-th insulating film105aand the 4a-th insulating film106abeing interposed therebetween.

The production of the active matrix substrate B in the present embodiment is performed as follows. In the present embodiment, after steps identical to those described above with reference toFIGS. 5A to 5Iare carried out, photolithography and dry etching are carried out so that the 3a-th insulating film105ais patterned (seeFIG. 9A). Through these steps, an opening H11of the 3a-th insulating film105ais formed on the upper electrode14b. The opening H11has a width smaller than that of the opening H1of the 3a-th insulating film105ain Embodiment 1 described above, and therefore, the area of the top surface of the upper electrode14bcovered with the 3a-th insulating film105ais larger than that in Embodiment 1. It is therefore less likely that film thinning would be caused to the top surface of the upper electrode14bby the etching of the 3a-th insulating film105a.

After the step illustrated inFIG. 9A, the 4a-th insulating film106ais formed in the same manner as that of the step illustrated inFIG. 5Kso as to cover the 3a-th insulating film105a(seeFIG. 9B), and thereafter, by using photolithography, 4a-th insulating film106ais patterned (seeFIG. 9C). Through these steps, the 4a-th insulating film106acovering the 3a-th insulating film105ais formed outside the photodiode12, and the opening H2of the 4a-th insulating film106a, having a width greater than that of the opening H11, is formed.

Subsequently, in the same manner as that in the step illustrated inFIG. 5M, the 3b-th insulating film105bis formed so as to cover the 4a-th insulating film106a(seeFIG. 9D), and photolithography and dry etching are carried out so that the 3b-th insulating film105bis patterned (seeFIG. 9E). Through these steps, on the 3a-th insulating film105a, an opening H3of the 3b-th insulating film105bis formed, outside the opening H11.

Thereafter, in the same manner as that in the above-described step illustrated inFIG. 5O, the 4b-th insulating film106bcovering the 3a-th insulating film105aand the 3b-th insulating film105bis formed, a contact hole CH21composed of the opening H11and the opening H4of the 4b-th insulating film106b(seeFIG. 8) is formed using the same manner as that inFIG. 5Pdescribed above. Subsequently, steps identical to the above-described steps illustrated inFIGS. 5O to 5Uare carried out, whereby the active matrix substrate1B is produced.

Embodiment 3 is described above with reference to an exemplary configuration in which the 4a-th insulating film106ais extended to the photodiode12of the adjacent pixel outside the photodiode12. In this case, if the 3b-th insulating film105bhas a discontinuous part, a scar, or like as described above in conjunction with Embodiment 2, moisture penetrates through this part to the 4a-th insulating film106a, and a leakage path is formed in the 3a-th insulating film105athat covers side surfaces of the photodiodes12of a plurality of pixels. As the present embodiment, an exemplary configuration is described in which the extension of a leakage path is prevented even if moisture penetrates from the 3b-th insulating film105bin the structure of Embodiment 3.

FIG. 10is a cross-sectional view illustrating a pixel part of an active matrix substrate in the present embodiment. InFIG. 10, members identical to those in Embodiment 3 are denoted by the same reference symbols as those in Embodiment 3. The following description principally describes configurations different from those in Embodiment 3.

As illustrated inFIG. 10, in an active matrix substrate1C, the 3a-th insulating film105aand the 3b-th insulating film105bare in contact with each other in a part area of the top surface on the photodiode12and an area outside the photodiode12, and the 4a-th insulating film106ais provided in an area outside the photodiode12, interposed between the 3a-th insulating film105aand the 3b-th insulating film105b. In other words, the 4a-th insulating film106ais not extended to the adjacent pixel outside the photodiode12, and is separated between adjacent ones of the pixels. Accordingly, even if moisture penetrating from a discontinuous part, a scar, or the like occurring to the 3b-th insulating film105bpermeates the 4a-th insulating film106a, the permeation of the moisture into the 4a-th insulating film106aof the adjacent pixel is prevented, and the leakage path is not extended to the 3a-th insulating film105aof the foregoing pixel.

The production of the active matrix substrate1C in the present embodiment is performed as follows. After the above-described step illustrated inFIG. 9B, the 4a-th insulating film106ais patterned by using photolithography (seeFIG. 11). Through this step, the 4a-th insulating film106ais formed that has the opening H2on an outer side with respect to the opening H11of the 3a-th insulating film105a, overlaps with a part of the 3a-th insulating film105athat covers side surfaces of the photodiode12, and is divided and separated between adjacent ones of the pixels. Thereafter, steps identical to the above-described steps illustrated inFIG. 9Dand the subsequent drawings are carried out, whereby the active matrix substrate1C is produced.

Embodiment 3 is described above with reference to an exemplary configuration in which the 3b-th insulating film105bis not provided on the top surface of the upper electrode14b, but the 3a-th insulating film105aand the 3b-th insulating film105bmay be provided on the top surface of the upper electrode14bin an overlapping state. The following description describes the configuration in this case more specifically.

FIG. 12is a cross-sectional view illustrating a pixel part of an active matrix substrate in the present embodiment. InFIG. 12, members identical to those in Embodiment 3 are denoted by the same reference symbols as those in Embodiment 3. The following description principally describes configurations different from those in Embodiment 3.

As illustrated inFIG. 12, in the active matrix substrate1D, the 3b-th insulating film105boverlaps with the 3a-th insulating film105aprovided on the top surface of the upper electrode14b, and outside the photodiode12, the 3b-th insulating film105bis provided on the 4a-th insulating film106a. In other words, outside the photodiode12, the 3a-th insulating film105aand the 3b-th insulating film105boverlap with each other with the 4a-th insulating film106abeing interposed therebetween.

The production of the active matrix substrate1D is performed as follows. Steps identical to those described above with reference toFIGS. 5A to 5Iare carried out, and thereafter, the 4a-th insulating film106amade of an acrylic resin or a siloxane-based resin is formed by, for example, slit-coating (seeFIG. 13A). Subsequently, by using photolithography, the 4a-th insulating film106ais patterned (seeFIG. 13B). Through these steps, the opening H21of the 4a-th insulating film106ais formed on the 3a-th insulating film105a, on a part area of the top surface on the photodiode12.

Next, by a step identical to that illustrated inFIG. 5M, the 3b-th insulating film105bis formed so as to cover the 4a-th insulating film106a(seeFIG. 13C), and then, photolithography and dry etching are carried out so that the 3a-th insulating film105aand the 3b-th insulating film105bare patterned (seeFIG. 13D). Through these steps, an opening H22passing through the 3a-th insulating film105aand the 3b-th insulating film105bis formed on the upper electrode14b.

Subsequently, by a method identical to the above-described method illustrated inFIG. 5O, the 4b-th insulating film106bcovering the 3b-th insulating film105bis formed (seeFIG. 13E), and then, by using a method identical to the above-described method illustrated inFIG. 5P, the opening H4of the 4b-th insulating film106bis formed on the opening H22, whereby a contact hole CH22composed of the opening H22and the opening H4is formed (seeFIG. 13F). Thereafter, steps identical to the above-described steps illustrated inFIGS. 5Q to 5Uare carried out, whereby the active matrix substrate1D is produced.

Incidentally, in this example, inFIG. 13D, the 3a-th insulating film105aand the 3b-th insulating film105bare patterned by using photolithography, but the process may be as follows instead: after the 3b-th insulating film105bis formed, the 4b-th insulating film106bis formed, and the 3a-th insulating film105aand the 3b-th insulating film105bare patterned by using the 4b-th insulating film106bas a mask, whereby the opening H22is formed.

In the present embodiment, the 3b-th insulating film105bis formed so as to overlap with the 3a-th insulating film105aon the top surface of the upper electrode14b. Further, both of the 3a-th insulating film105aand the 3b-th insulating film105bare simultaneously patterned so that the opening H22passing through the 3a-th insulating film105aand the 3b-th insulating film105bis formed. It is therefore unlikely that film thinning would occur to the 3a-th insulating film105adue to the patterning, as compared with Embodiments 3 and 4 mentioned above, and it is unlikely that film thinning would occur to the top surface of the upper electrode14bdue to the patterning, as compared with Embodiments 1 and 2 mentioned above.

Further, in the present embodiment, when moisture permeates the 4b-th insulating film106bthrough a scar or the like on the surface of the active matrix substrate1D, even with any discontinuous part being present in the 3a-th insulating film105acovering the side surfaces of the photodiode12, permeation of moisture into the 3a-th insulating film105acan be prevented by the 3b-th insulating film105b. As a result, a discontinuous part of the 3a-th insulating film105adoes not serve as a leakage path, it is unlikely that the X-ray detection accuracy would degrade due to leakage current.

In Embodiment 5 described above, outside the photodiode12, the 4a-th insulating film106ais extended to the photodiode12of the adjacent pixel, but for preventing the extension of a leakage path, the 4a-th insulating film106amay be divided and separated between the photodiodes12of adjacent ones of the pixels. The following description describes a configuration of an active matrix substrate in this case.

FIG. 14is a cross-sectional view of a pixel part of an active matrix substrate in the present embodiment. InFIG. 14, members identical to those in Embodiment 5 are denoted by the same reference symbols as those in Embodiment 5. The following description principally describes configurations different from those in Embodiment 5.

As illustrated inFIG. 14, in an active matrix substrate1E in the present embodiment, the 3a-th insulating film105aand the 3b-th insulating film105bare in contact with each other outside the photodiode12, and the 4a-th insulating film106ais provided between the 3a-th insulating film105aand the 3b-th insulating film105b, outside the photodiode12. In other words, the 4a-th insulating film106ais not extended to the adjacent pixel, and is separated between adjacent ones of the pixels.

The production of the active matrix substrate1E in the present embodiment is performed as follows. In other words, after the above-described step illustrated inFIG. 13A, the 4a-th insulating film106ais patterned by using photolithography (seeFIG. 15). Through this step, the 4a-th insulating film106aother than portions thereof covering the side surfaces of the photodiode12, on the 3a-th insulating film105a, is removed. As a result, the 4a-th insulating film106aoverlaps with the 3a-th insulating film105aprovided on the side surfaces of the photodiode12, and is positioned apart from another 4a-th insulating film106aof the adjacent pixel. Thereafter, steps identical to the above-described steps illustrated inFIG. 13Cand the subsequent drawings are carried out, whereby the active matrix substrate1E is produced.

With such a configuration, even if moisture penetrating from a discontinuous part, a scar, or the like occurring to the 3b-th insulating film105bpermeates the 4a-th insulating film106a, the permeation of the moisture into the 4a-th insulating film106aof the adjacent pixel is prevented, and the leakage path is not extended to the 3a-th insulating film105aof the foregoing pixel.

Embodiments 1 and 3 are described above with reference to an exemplary configuration in which the 4a-th insulating film106ais provided between the 3a-th insulating film105aand the 3b-th insulating film105boutside the photodiode12, but the structure may be such that the 4a-th insulating film106ais not provided. The following description describes modification examples of Embodiment 1 and Embodiment 3 having a structure in which the 4a-th insulating film106ais not provided.

(7-1) Modification Example of Embodiment 1

FIG. 16is a cross-sectional view of a pixel part in Embodiment 1 having a structure in which the 4a-th insulating film106ais not provided. InFIG. 16, members identical to those in Embodiment 1 are denoted by the same reference symbols as those in Embodiment 1. The following description principally describes configurations different from those in Embodiment 1.

As illustrated inFIG. 16, in an active matrix substrate1F, the 3b-th insulating film105bis arranged so as to overlap with the 3a-th insulating film105acovering the side surfaces of the photodiode12. In other words, outside the photodiode12, the 3b-th insulating film105boverlaps with the 3a-th insulating film105a.

The production of the active matrix substrate1F is performed as follows. First, steps identical to the above-described steps illustrated inFIGS. 5A to 5Jare carried out, and thereafter, the 3b-th insulating film105bis formed on the 3a-th insulating film105aby a step identical to the above-described step illustrated inFIG. 5M(seeFIG. 17A). Thereafter, above the upper electrode14b, and inside the opening H1of the 3a-th insulating film105a, the opening H3of the 3b-th insulating film105bis formed by a step identical to the above-described step illustrated inFIG. 5N(seeFIG. 17B). Subsequently, steps identical to the above-described steps illustrated inFIGS. 5O to 5Uare carried out, whereby the active matrix substrate1F is produced.

(7-2) Modification Example of Embodiment 3

FIG. 18is a cross-sectional view of a pixel part of an active matrix substrate, which is a cross-sectional view illustrating a structure of Embodiment 3 having a structure in which the 4a-th insulating film106ais not provided. InFIG. 18, members identical to those in Embodiment 3 are denoted by the same reference symbols as those in Embodiment 3.

As illustrated inFIG. 18, in an active matrix substrate1G, the 3b-th insulating film105bis arranged so as to overlap with the 3a-th insulating film105acovering side surfaces of the photodiode12. In other words, outside the photodiode12, the 3b-th insulating film105boverlaps with the 3a-th insulating film105a.

The production of the active matrix substrate1G is performed as follows. First, a step identical to the above-described step illustrated inFIG. 9Ais carried out, and thereafter, the 3b-th insulating film105bis formed on the 3a-th insulating film105aby a step identical to the above-described step illustrated inFIG. 9D(seeFIG. 19A). Thereafter, the opening H3of the 3b-th insulating film105b, which is greater than the opening H1, is formed on the 3a-th insulating film105aby a step identical to the above-described step illustrated inFIG. 5N(seeFIG. 19B). Subsequently, steps identical to the above-described steps illustrated inFIGS. 5O to 5Uare carried out, whereby the active matrix substrate1G is produced.

If moisture penetrates through a scar or the like of the surface of the above-described active matrix substrate1F,1G and permeates the 4b-th insulating film106b, the surface of the 3b-th insulating film105bis exposed to moisture. Since the 3a-th insulating film105ais covered with the 3b-th insulating film105b, however, it is unlikely that moisture would permeate the 3a-th insulating film105a, even with a discontinuous part being present in the 3a-th insulating film105acovering the side surfaces of the photodiode12. This therefore makes it unlikely that leakage current would flow. Besides, since the step of forming the 4a-th insulating film106a(seeFIGS. 5K, 5L) is unnecessary in the case of the above-described configuration, the number of steps for producing the active matrix substrate can be reduced, as compared with Embodiments 1 and 3.

In (7-1) and (7-2) described above, the 3a-th insulating film105aprovided outside the photodiode12is extended to the photodiode12of the adjacent pixel, but the configuration may be such that, as illustrated inFIG. 20orFIG. 21, the 3a-th insulating film105ais not extended to the adjacent pixel, and is positioned apart from the 3a-th insulating film105acorresponding to the adjacent pixel.

Incidentally,FIG. 20is a cross-sectional view illustrating the above-described case ofFIG. 16modified so that the 3a-th insulating film105ais not extended to the adjacent pixel. Further,FIG. 21is a cross-sectional view illustrating the above-described case ofFIG. 18modified so that the 3a-th insulating film105ais not extended to the adjacent pixel.

When the active matrix substrate illustrated inFIG. 20orFIG. 21is produced, not only the top surface of the upper electrode14b, but also the 3a-th insulating film105aon the second insulating film104may be etched so as to have a predetermined length in the step illustrated inFIG. 5J.

In the case of the structures illustrated inFIG. 20andFIG. 21as well, as is the case with the structures of (7-1) and (7-2) described above, since the 3a-th insulating film105ais covered with the 3b-th insulating film105b, it is unlikely that moisture would permeate the 3a-th insulating film105a, even with a discontinuous part being present in the 3a-th insulating film105acovering the side surfaces of the photodiode12. This therefore makes it unlikely that a leakage path would be formed. Besides, since the step of forming the 4a-th insulating film106a(seeFIGS. 5K, 5L) is unnecessary, the number of steps for producing the active matrix substrate can be reduced.

In Embodiments 1 to 7, the 3a-th insulating film105aand the 3b-th insulating film105bpreferably have a thickness of an integer multiple of 150 nm.

FIG. 22illustrates a graph of the transmittance of an inorganic insulating film containing SiN when the thickness of the contain inorganic insulating film is varied and is irradiated with light having a wavelength of 550 nm. As illustrated inFIG. 22, in the cases where the thickness is 150 nm, 300 nm, 450 nm, and 600 nm, the transmittance is approximately 100%, but when the thickness is other than these, the transmittance varies in a range of greater than 90% and smaller than 100%.

Accordingly, when the thickness of the inorganic insulating film provided on the photodiode12(seeFIG. 3and the like) is set to an integer multiple of 150 nm, the photoelectric conversion efficiency in the photodiode12can be enhanced, whereby the X-ray detection accuracy can be improved.

Embodiments of the present invention are thus described above, but the above-described embodiments are merely examples for implementing the present invention. The present invention is not limited to the above-described embodiments, and can be appropriately modified and implemented without departing from the scope of the invention.

Modification Example 1

In Embodiments 5 and 6 described above, the 4a-th insulating film106amay be provided not only on the side surface parts of the photodiode12, but also on the 3a-th insulating film105acovering the upper electrode14b. The following description describes such a configuration.

(1) Modification Example of Embodiment 5

FIG. 23is a cross-sectional view of a pixel part according to Modification Example of Embodiment 5. InFIG. 23, members identical to those in Embodiment 5 are denoted by the same reference symbols as those in Embodiment 5. The following description principally describes configurations different from those in Embodiment 5.

As illustrated inFIG. 23, in an active matrix substrate1H according to the present modification example, the 4a-th insulating film106ais provided not only on side surface parts of the photodiode12, but also on the 3a-th insulating film105acovering the upper electrode14b.

The active matrix substrate1H of the present modification example can be formed as follows. First, the above-described steps illustrated inFIGS. 5A to 5IandFIG. 13Aare carried out, and thereafter, the 4a-th insulating film106ais patterned by using photolithography (seeFIG. 24A). Through these steps, an opening H13of the 4a-th insulating film106ais formed on a part of the 3a-th insulating film105acovering the upper electrode14b.

Next, the 3b-th insulating film105bis formed so as to cover the 4a-th insulating film106aby a step identical to the above-described step illustrated inFIG. 5M(seeFIG. 24B). Subsequently, photolithography and dry etching are carried out so that the 3a-th insulating film105aand the 3b-th insulating film105bare patterned (seeFIG. 240). Through these steps, on the upper electrode14b, and on an inner side with respect to the opening H13of the 4a-th insulating film106a, an opening H23that passes through the 3a-th insulating film105aand the 3b-th insulating film105bis formed.

Incidentally, in the step illustrated inFIG. 240, the same photomask may be used for patterning the 3a-th insulating film105aand for patterning the 3b-th insulating film105b, and these insulating films may be simultaneously etched. In the case of doing so, there is no need to prepare respective photomasks for the 3a-th insulating film105aand the 3b-th insulating film105b, and the number of the steps can be reduced.

Subsequently, the 4b-th insulating film106bis form so as to cover the 3b-th insulating film105b, by the same method as the above-described method illustrated inFIG. 5O(seeFIG. 24D), and thereafter, on the opening H23, an opening H33of the 4b-th insulating film106b, which is greater than the opening H23, is formed by the same method as the above-described method illustrated inFIG. 5P, whereby a contact hole CH23composed of the opening H23and the opening H33is formed (seeFIG. 24E). In the patterning of the 4b-th insulating film106b, the photomask used for patterning the 4a-th insulating film106amay be applied. By doing so, the number of photomasks used in patterning the 4b-th insulating film106bcan be reduced.

Thereafter, steps identical to the above-described steps illustrated inFIGS. 5Q to 5Uare carried out, whereby the active matrix substrate1H illustrated inFIG. 23is produced.

(2) Modification Example of Embodiment 6

FIG. 25is a cross-sectional view of a pixel part according to Modification Example of Embodiment 6. InFIG. 25, members identical to those in Embodiment 6 are denoted by the same reference symbols as those in Embodiment 6. The following description principally describes configurations different from those in Embodiment 6.

As illustrated inFIG. 25, in an active matrix substrate1I according to the present modification example, the 4a-th insulating film106ais provided not only on side surface parts of the photodiode12, but also on the 3a-th insulating film105acovering the upper electrode14b.

The active matrix substrate1I of the present modification example can be formed as follows. First, the above-described steps illustrated inFIGS. 5A to 5Eare carried out. Subsequently, a metal film140made of molybdenum nitride (MoN) is formed by sputtering on the second insulating film104, and a resist300for forming a lower electrode of the photodiode12is formed by using photolithography on the metal film140(seeFIG. 26A).

Then, the metal film140is wet-etched (seeFIG. 26B). Here, the metal film140is etched so that an end of the metal film140is arranged on an inner side with respect to the resist300by Δd (for example, 2 μm). Thereafter, the resist is removed, whereby the lower electrode14ais formed (seeFIG. 26C).

Incidentally, the photomask used in forming the resist300in the step illustrated inFIG. 26Acan be also used in a step described below of forming the 4a-th insulating film106a. By performing the etching in the step illustrated inFIG. 26Bin such a manner that an end of the metal film140is located on an inner side with respect to the resist300, the lower electrode14bis completely covered with the 4a-th insulating film106a.

Subsequently, after steps identical to those illustrated inFIGS. 5G to 5I, andFIG. 13Aare carried out, the 4a-th insulating film106aon the 3a-th insulating film105ais patterned by using photolithography (seeFIG. 26D). Through this step, an opening H14of the 4a-th insulating film106ais formed on a part of the 3a-th insulating film105acovering the upper electrode14b.

Subsequently, after the 3b-th insulating film105bis formed on the 4a-th insulating film106aby carrying out a step identical to the above-described step illustrated inFIG. 5M, photolithography and dry etching are carried out so that the 3a-th insulating film105aand the 3b-th insulating film105bare patterned (seeFIG. 26E). Through this step, an opening H24passing through the 3a-th insulating film105aand the 3b-th insulating film105bis formed on the upper electrode14b, on an inner side with respect to the opening H14of the 4a-th insulating film106a.

The respective photomasks when used in forming the lower electrode14aand forming the 3b-th insulating film105bcan be used as a photomask used for patterning the 4a-th insulating film106ain the step illustrated inFIG. 26D. With this configuration, there is no need to prepare a photomask exclusively for the 4a-th insulating film106a, and the number of steps can be reduced. Further, in the step illustrated inFIG. 26E, the same photomask is used for patterning the 3a-th insulating film105aand the 3b-th insulating film105band these insulating films are simultaneously etched. By doing so, there is no need to prepare respective photomasks for the 3a-th insulating film105aand the 3b-th insulating film105b, and the number of steps can be reduced.

Subsequently, by a method identical to the above-described method illustrated inFIG. 5O, the 4b-th insulating film106bis formed so as to cover the 3b-th insulating film105b, and thereafter, by using a method identical to the above-described method illustrated inFIG. 5P, an opening H34of the 4b-th insulating film106b, which is greater than the opening H24, is formed on the opening H24so that a contact hole CH24composed of the opening H24and the opening H34is formed (seeFIG. 26F). For patterning the 4b-th insulating film106b, the photomask used for patterning the 4a-th insulating film106amay be used. By doing so, the photomask for patterning the 4b-th insulating film106bcan be omitted.

Thereafter, by carried out steps identical to the above-described steps illustrated inFIGS. 5Q to 5U, the active matrix substrate1I illustrated inFIG. 25is produced.

In Modification Examples of Embodiments 5 and 6, the top part of the upper electrode14bis covered with the 3a-th insulating film105aand the 4a-th insulating film106a. Even if moisture penetrates through the 4b-th insulating film106b, the two insulating films, i.e., the 4a-th insulating film106aand the 3a-th insulating film105a, makes it unlikely that moisture would get in, not only the side surface parts of the photodiode12, but also the top part of the photodiode12, and a leakage path would be formed.

DESCRIPTION OF REFERENCE NUMERALS