JP4848675B2 - Transistor array panel and method of manufacturing transistor array panel - Google Patents

Description

  The present invention relates to a transistor array panel in which a transistor and a capacitor are provided for each pixel, and a method for manufacturing the same.

  An organic electroluminescence element (hereinafter, the term electroluminescence is abbreviated as EL) is a self-luminous element in which an anode, an organic EL layer, and a cathode are laminated in this order. Research and development of an EL display panel using an organic EL element as a pixel is progressing.

  As described in Patent Document 1, an active matrix driving type EL display panel is provided with a plurality of thin film transistors per pixel, and the organic EL elements are caused to emit light by the thin film transistors. In addition, a capacitor, that is, a capacitor, is provided in each pixel so that the thin film transistor of each pixel keeps a current flowing through the organic EL element.

  When manufacturing an active matrix drive type display panel, it is preferable to pattern a thin film transistor for each pixel to produce a transistor array panel, and then pattern an organic EL element on the surface of the transistor array panel for each pixel. The reason why the organic EL element is patterned after the thin film transistor is that the temperature at which the thin film transistor is formed exceeds the heat resistance temperature of the organic EL element.

  In such a transistor array panel, wiring lines such as signal lines and scanning lines are provided in addition to thin film transistors and capacitors. The scanning lines are formed by patterning a gate metal serving as a gate of a thin film transistor, for example. It is formed by patterning a source / drain metal that becomes a source / drain of a thin film transistor. The pair of electrodes of the capacitor are formed by patterning the gate metal and source / drain metal of the thin film transistor, respectively.

  A protective film is formed on the entire surface of the transistor array panel, and the thin film transistors, capacitors, signal lines, and scanning lines are covered with the protective film.

When patterning the organic EL element, one of the anode and the cathode is used as a pixel electrode and patterned on the surface of the transistor array panel for each pixel, an organic EL layer is laminated on each pixel electrode, and the other of the anode and the cathode is used as the other. A film is formed on one surface as a common counter electrode.
JP-A-8-330600

  By the way, the signal line and the scanning line have a structure that hardly overlaps except for the intersection region in order to minimize the overlapping parasitic capacitance. For this reason, the thickness of one of the gate metal and the source / drain metal is deposited outside the intersecting region of these wirings, but the other thickness is not deposited. On the other hand, since both the gate metal and the source / drain metal are deposited in the capacitor, a step is generated between the wiring region and the capacitor region. Such a step is not easily relieved even if an insulating film is coated thereon, and the step affects the region where the pixel electrode is formed. If the pixel electrode is uneven due to a level difference, the film thickness of the organic EL layer may not be uniform, or the organic EL layer may be partially interrupted and the pixel electrode and the common electrode may be short-circuited.

  Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to suppress a step between the capacitor portion and the wiring portion on the surface of the transistor array panel.

In order to solve the above-described problems, a transistor array panel according to the present invention includes a transistor composed of a plurality of layers, a first electrode formed of a layer serving as a gate of the transistor, and a layer serving as a drain of the transistor. A pixel circuit having a second electrode formed, and a capacitor having an insulating film sandwiched between the first electrode and the second electrode, and the capacitor, and one of a layer serving as a gate and a drain of the transistor. the wiring connected to the pixel circuits, the gate of the transistor in the region where the other is not formed of a layer to be a drain, provided along the extending direction of the wiring so as to overlap with the wiring, the transistor the plurality of layers to become a layer of the layer to be a gate of the transistor, the drain to become the layer and the said transistor And film for step suppress formed of at least one layer except the Enmaku, characterized in that it comprises a.

According to the method for manufacturing a transistor array panel of the present invention, a wiring connected to a pixel circuit having a transistor composed of a plurality of layers is formed by one of the gate and drain layers of the transistor, A capacitor of the pixel circuit, comprising: a first electrode formed of a layer comprising: a second electrode formed of a layer serving as a drain of the transistor; and an insulating film sandwiched between the first electrode and the second electrode. Formed in a region where the other of the layers serving as the gate and drain of the transistor is not formed , and among the layers serving as the plurality of layers of the transistor along the extending direction of the wiring so as to overlap the wiring . a layer serving as gates of said transistors, stepped suppressed at least one layer except the drain to become the layer and the insulating layer of the transistor And forming a membrane.

  The transistor array panel of the present invention includes a transistor, a first electrode formed by a layer that becomes a gate of the transistor, a second electrode formed by a layer that becomes a drain of the transistor, and the first electrode and the second electrode. A pixel circuit having an insulating film sandwiched between electrodes; a wiring formed by one of layers serving as a gate and a drain of the transistor and connected to the pixel circuit; a gate and a drain of the transistor; A step-suppressing film provided along the extending direction of the wiring so as not to overlap the capacitor and to overlap the wiring in a region where the other layer is not formed. And

  As a preferred example of such a manufacturing method, a transistor gate, one electrode of a capacitor, and a wiring are simultaneously patterned on an insulating substrate, and the gate, the one electrode, and the wiring are covered with a gate insulating film. Then, a step suppressing film is patterned on the gate insulating film so as to overlap the wiring, and the source / drain of the transistor and the other electrode of the capacitor are patterned.

  In the manufacturing method, the step-suppressing film is patterned at the same time as the semiconductor film of the transistor is patterned on the gate insulating film, or the ohmic film of the transistor is patterned on the gate insulating film. At the same time, the step suppressing film is patterned, or the channel protecting film for protecting the semiconductor film of the transistor is patterned on the gate insulating film, and at the same time, the step suppressing film is patterned. It is preferable.

  As described above, the step suppressing film is patterned at the same time as the patterning of the transistor semiconductor film on the gate insulating film. Therefore, the step suppressing film can be obtained only by changing the patterning mask of the transistor semiconductor film. Can be formed. Similarly, a step-suppressing film can be formed simply by changing the patterning mask for the channel protective film of the transistor or by changing the patterning mask for the ohmic film of the thin film transistor. Therefore, it is not necessary to increase the number of steps for the film for suppressing the step.

  In the manufacturing method, it is preferable to pattern the step-suppressing film by applying a resin so as to overlap the wiring.

  As described above, since the step suppressing film is patterned separately from the transistor, the step suppressing film thickness can be adjusted regardless of the film thickness of each film of the transistor.

  According to the present invention, a step can be suppressed between the capacitor portion and the wiring portion.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, although various technically preferable limitations for implementing the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

FIG. 1 is an equivalent circuit diagram of the EL display panel 1.
When the EL display panel 1 is viewed in plan, the plurality of scanning lines X and the plurality of supply lines Z are parallel to each other and extend in the row direction, and the signal line group Y is parallel to each other and extends in the column direction. Yes. The scanning line X and the signal line group Y are insulated from each other, and the scanning line X and the signal line group Y are orthogonal to each other in plan view. Similarly, the supply line Z and the signal line group Y are insulated from each other, and the supply line Z and the signal line group Y are orthogonal to each other in plan view. The pixel groups arranged in parallel in the direction (row direction) orthogonal to the signal line group Y emit light in the same color. Then, the three pixels continuously arranged along the extending direction (column direction) of the signal line group Y emit light in different colors, specifically red, green, and blue, respectively. Therefore, the signal line group Y is connected to the signal line Y _R which is connected to a pixel group that emits red light, and the signal line Y _G which is connected to a group of pixels emitting green light, a pixel group that emits blue light and the signal line Y _B that, in being configured. Therefore, the signal line Y _R , the signal line Y _G , and the signal line Y _B are arranged along the column direction while being spaced apart from each other between two adjacent pixels in the row direction. . Each pixel is provided with a pixel circuit P, and the pixel circuits P are arranged in a matrix like the pixels. The red pixel is connected to the scanning line X, the signal lines Y _R and the supply line Z pixel circuit P is at the intersection of the scanning lines X and the signal lines Y _R, the pixel circuit P is the scanning line X is the green pixels and at the intersection of the signal lines Y _G is connected to the scanning line X, the signal lines Y _G and the supply lines Z, the scan line pixel circuits P for blue pixels at the intersection of the scanning lines X and the signal lines Y _B X, is connected to the signal line Y _B and the supply lines Z. That is, each pixel circuit P is connected to any one of the signal line Y _R , the signal line Y _G , and the signal line Y _B. In addition, one electroluminescence (EL) element L is provided for each pixel, one end of each electroluminescence element L is connected to the pixel circuit P, and the other end is connected to a common potential _VCOM (for example, ground). Has been.

The pixel circuit P is connected to the electroluminescence element L from the supply line Z based on the gradation signal (voltage signal or current signal) of the signal line Y _R (or signal line Y _G , signal line Y _B ) and the scanning signal of the scanning line X. The electroluminescence element L emits light at a timing corresponding to the scanning signal and with an intensity corresponding to the gradation signal. The pixel circuit P includes a plurality of thin film transistors and a capacitor.

  FIG. 2 is a cross-sectional view of one pixel of the EL display panel 1. In FIG. 2, the transistor 21 which is one thin film transistor in the pixel circuit P of one pixel is shown in a state where the transistor 21 is broken in a cross section parallel to the channel length direction. Other transistors also have the same stacked structure as the transistor 21, and the transistor 21 and the other transistors in the pixel circuit P are all vapor phase growth methods (sputtering, CVD method, PVD method, etc.), photolithography methods, etching methods. Therefore, the transistor 21 will be described in particular, and description of the other transistors will be omitted.

  The transistor 21 is an inverted staggered transistor provided on the insulating substrate 2. Specifically, the transistor 21 includes a gate 21g formed on the insulating substrate 2, a semiconductor film 21c facing the gate 21g with the gate insulating film 31 interposed therebetween, and a channel formed on the central portion of the semiconductor film 21c. Ohmic films 21a and 21b that are formed to be separated from each other on both ends of the protective film 21p and the semiconductor film 21c and partially overlap the channel protective film 21p, a drain 21d that is formed on the ohmic film 21a, and an ohmic film 21s formed on 21b. Note that the transistor 21 may be formed by meandering the channel in a U shape or a Z shape in plan view in order to increase the channel width.

The gate insulating film 31 and the channel protective film 21p are made of SiO ₂ or SiN. The semiconductor film 21c has intrinsic amorphous silicon or intrinsic polysilicon. The ohmic films 21a and 21b have amorphous silicon or polysilicon (n + Si) containing a conductive impurity (for example, phosphorus).

  A capacitor 24 is provided in the vicinity of the transistor 21. The capacitor 24 includes an electrode 24a formed integrally with the gate 21g of the transistor 21, and an electrode 24b formed integrally with the drain 21d of the transistor 21 and facing the electrode 24a with the gate insulating film 31 interposed therebetween.

  For the gate 21g of the transistor 21 and the electrode 24a of the capacitor 24, a conductive gate layer (for example, a conductive film made of Al and Ti) formed on the insulating substrate 2 by vapor deposition is used for photolithography and etching. It is formed by patterning using.

  A signal line group Y is formed on the insulating substrate 2. The signal line group Y is formed simultaneously with the gate 21g of the transistor 21 and the electrode 24a of the capacitor 24 by patterning the gate layer. The gate 21g, the electrode 24a, and the signal line group Y are covered with a common gate insulating film 31.

  On the gate insulating film 31, a semiconductor film 71 for suppressing a step is formed along the signal line group Y so as to overlap the signal line group Y without overlapping the capacitor 24. The semiconductor film 71 is formed by patterning a solid semiconductor film formed on the gate insulating film 31 by a vapor deposition method using a photolithography method and an etching method. It is formed simultaneously with the film 21c.

  An insulating film 72 for suppressing a step is laminated on the semiconductor film 71 without overlapping the capacitor 24. The insulating film 72 is formed by patterning the whole surface of the insulating film formed by vapor deposition using a photolithography method and an etching method, and becomes an insulating film that becomes the channel protective film 21p of the transistor 21. The film is patterned and formed at the same time as the channel protective film 21p.

The drain 21d and source 21s of the transistor 21 and the electrode 24b of the capacitor 24 are conductive drain layers formed on the entire surface by vapor deposition (for example, a film made of Al and Ti stacked on a Cr film). Is formed by patterning using a photolithography method and an etching method. The scanning line X and the supply line Z are formed simultaneously with the source 21s, the drain 21d, and the electrode 24b by patterning the drain layer. The source 21s, the drain 21d, the electrode 24b, the scanning line X, and the supply line Z are covered with a common protective insulating film 32 made of SiO ₂ or SiN.

  Although the drain layer is not deposited on the upper layer of the signal line group Y, the semiconductor film 71 and the insulating film 72 are formed, so that the surface of the protective insulating film 32 has a portion above the signal line group Y and a capacitor. The level difference between the upper part of 24 is suppressed, and the level difference becomes very small.

  A planarizing film 33 obtained by curing a photosensitive resin is laminated on the protective insulating film 32. The surface of the planarization film 33 is flattened, and unevenness due to the transistor 21, the capacitor 24, the scanning line X, the signal line group Y, and the supply line Z is eliminated by the planarization film 33.

  The stacked structure from the insulating substrate 2 to the planarizing film 33 is the transistor array panel 50.

On the planarizing film 33, pixel electrodes 20a that are anodes of the organic EL elements L are formed for each pixel, and a plurality of pixel electrodes 20a are arranged in a matrix. The pixel electrode 20a may overlap the signal line group Y and may overlap the capacitor 24, or may be provided in the vicinity of the capacitor 24 without overlapping. Since the step between the portion above the signal line group Y and the portion above the capacitor 24 is suppressed by the semiconductor film 71 and the insulating film 72, the planarizing film 33 can be obtained without making the planarizing film 33 extremely thick. Since the surface 33 is in a substantially flat state, the pixel electrode 20a formed thereon is not uneven.
In each pixel circuit P, a transistor whose gate is to be connected to the scanning line X is connected to the scanning line X through a contact hole 51 provided in the gate insulating film 31.
In each pixel circuit P, a transistor whose source or drain is to be connected to any of the signal line Y _R , signal line Y _G , and signal line Y _B is connected via a contact hole 52 provided in the gate insulating film 31. The source or drain is connected to one of the signal line Y _R , the signal line Y _G , and the signal line Y _B.

The pixel electrode 20a is a conductive film (for example, tin-doped indium oxide (ITO), zinc-doped indium oxide, indium oxide (In ₂ O ₃ ), tin oxide) formed on the planarizing film 33 by a vapor deposition method. It is formed by patterning (SnO ₂ ), zinc oxide (ZnO) or cadmium-tin oxide (CTO) using a photolithography method and an etching method. In each pixel, a contact hole 91 is formed so as to penetrate the planarization film 33 and the protective insulating film 32, and the pixel electrode 20 a and the electrode 24 b of the capacitor 24 are connected by a conductive pad 92 buried in the contact hole 91. .

  On the planarizing film 33, a partition wall 41 is provided in addition to the pixel electrode 20a. The partition wall 41 is formed in a mesh shape so as to sew between the pixel electrodes 20a. The transistor 21 is provided below the partition wall 41, and a part of the partition wall 41 overlaps the transistor 21. At least the surface of the partition is electrically insulated.

  An organic EL layer 20b of the organic EL element L is stacked on the pixel electrode 20a. The organic EL layer 20b is formed by stacking two or more organic compound-containing layers. Here, the organic EL layer 20b includes a hole transport layer made of PEDOT (polythiophene) which is a conductive polymer and PSS (polystyrene sulfonic acid) which is a dopant, and a light emitting layer made of a polyphenylene vinylene or polyfluorene light emitting material. Are stacked in this order. Note that the organic EL layer 20b may have a three-layer structure in which the hole transport layer, the light emitting layer, and the electron transport layer are sequentially formed from the pixel electrode 20a, or the light emitting layer and the electron transport layer are sequentially formed from the pixel electrode 20a. It may be a layered structure or another laminated structure.

  The organic EL layer 20b is formed by a wet coating method (for example, an ink jet method). In this case, an organic compound-containing liquid containing PEDOT and PSS serving as a hole transport layer is applied to the pixel electrode 20a, and then an organic compound-containing liquid containing a polyfluorene-based luminescent material serving as a light-emitting layer is applied. Since the partition walls 41 are provided, it is possible to prevent the organic compound-containing liquid applied to the adjacent pixel electrodes 20a from mixing over the partition walls 41.

  An organic EL layer 20b that emits red light is formed on the red pixel, an organic EL layer 20b that emits green light is formed on the green pixel, and an organic EL layer 20b that emits blue light is formed on the blue pixel. Films are formed and are not mixed by the partition walls 41 interposed between them.

  On the organic EL layer 20b, a counter electrode 20c which is a cathode of the organic EL element L is formed. The counter electrode 20c is a common electrode formed in common for all the pixels, and is formed on the entire surface.

  The counter electrode 20c is formed of a material having a work function lower than that of the pixel electrode 20a. Specifically, the counter electrode 20c is formed of a simple substance or an alloy containing at least one of indium, magnesium, calcium, lithium, barium, and a rare earth metal. Yes. The counter electrode 20c may have a stacked structure in which layers of the various materials are stacked, or may have a stacked structure in which a metal layer is deposited in addition to the layers of the various materials described above. In the case of the bottom emission type, for example, the counter electrode 20c is a laminated structure including a high-purity barium layer having a low work function provided on the organic EL layer 20b side and an aluminum layer provided so as to cover the barium layer. Or a laminated structure composed of a lithium layer provided on the organic EL layer 20b side and an aluminum layer provided so as to cover the barium layer.

  When the EL display panel 1 is a top emission type, the counter electrode 20c is a transparent electrode and the pixel electrode 20a is a light reflective electrode. In this case, the pixel electrode 20a may be composed of a lower reflective conductive layer and an upper transparent conductive layer laminated on the reflective conductive layer and made of a metal oxide.

  Next, a method for manufacturing the EL display panel 1 will be described.

  First, the transistor array panel 50 is manufactured as shown in the process diagrams of FIGS. The manufacturing process of the transistor array panel 50 is as follows.

As shown in FIG. 3, the signal layer Y _R , the signal line Y _G, and the signal line Y _B are formed by covering a gate layer on the upper surface of the transistor array panel 50 and sequentially performing a vapor deposition method, a photolithography method, and an etching method. At the same time, the gate 21g of the transistor 21 and the electrode 24a of the capacitor 24 are patterned. Next, the gate insulating film 31 is formed by vapor deposition.

Next, a semiconductor film 81 is formed on the gate insulating film 31 by vapor deposition. Next, an insulating film to be the channel protective film 21p is coated on the entire surface by vapor deposition, and then the photolithography method and the etching method are sequentially performed to pattern the channel protective film 21p for each transistor 21 and at the same time. The insulating film 72 is patterned from this insulating film so as to overlap the signal line Y _R , the signal line Y _G and the signal line Y _B. If the insulating film 72 is formed simultaneously with the channel protective film 21p, it is not necessary to increase the number of processes for patterning the insulating film 72.

  Next, as shown in FIG. 4, ohmic films 21 a and 21 b are patterned for each transistor 21 by sequentially performing a vapor deposition method, a photolithography method, and an etching method.

  Next, as shown in FIG. 5, the semiconductor film 81 is etched with an etchant. The photoresist mask, the ohmic films 21a and 21b, the channel protective film 21p, and the insulating film 72 at the time of etching protect the semiconductor film 81 from the etchant. It functions as an etching block for this purpose. By processing the shape of the semiconductor film 81, the semiconductor film 71 and the semiconductor film 21c are obtained. If the semiconductor film 71 is formed simultaneously with the semiconductor film 21c, it is not necessary to increase the number of processes for patterning the semiconductor film 71.

Next, after forming the contact hole 51 and the contact hole 52 in the gate insulating film 31, the drain layer is covered on the upper surface of the transistor array panel 50, and the vapor phase growth method, the photolithography method, and the etching method are sequentially performed. The scanning line X and the supply line Z are patterned, and at the same time, the source 21s and drain 21d of the transistor 21 and the electrode 24b of the capacitor 24 are patterned. At this time, the transistor of the pixel circuit P is appropriately connected to the scanning line X or the signal line Y _R (or the signal line Y _G , the signal line Y _B ).

  Next, as shown in FIG. 6, a protective insulating film 32 is formed on the entire surface by vapor deposition.

  Next, a planarizing film 33 is formed by applying a resin to the protective insulating film 32 by dip coating, spin coating, or the like and curing the resin. Thus, the transistor array panel 50 is manufactured.

  After manufacturing the transistor array panel 50, a contact hole 91 is formed for each pixel, a conductive pad 92 is embedded, and the pixel electrode 20a is patterned in the order of vapor deposition, photolithography, and etching. Next, a photosensitive resin is applied to the planarizing film 33 by a spin coating method, a dip coating method, or the like, and the partition wall 41 is formed by exposing and developing the photosensitive resin.

  Next, an organic compound-containing liquid containing a hole injection material is applied to the pixel electrode 20a, and after the organic compound-containing liquid is cured, an organic compound-containing liquid containing a polyphenylene vinylene-based or polyfluorene-based luminescent material is applied. When the organic compound-containing liquid is dried and coated, the light emitting layer 20b is formed by patterning for each pixel. As an application method, an ink-jet method (droplet discharge method) or other printing method is used, and coating is performed for each color. When the light emitting layer 20b is patterned, the pixel electrode 20a is substantially flat without unevenness due to the planarizing film 33, the semiconductor film 71, and the insulating film 72. Therefore, the light emitting layer 20b is not interrupted, and the entire pixel electrode 20a is not interrupted. Can be covered with the light emitting layer 20b.

  Next, the counter electrode 20c is formed on the entire surface by vapor deposition. Specifically, a thin film of Ca or Ba is formed on the entire surface by vacuum deposition, and an opaque conductive layer such as Al in the case of bottom emission, and a transparent conductive layer such as ITO in the case of top emission A film is formed on the entire surface. As described above, since the entire pixel electrode 20a is covered with the light emitting layer 20b without the light emitting layer 20b being interrupted, a short circuit between the pixel electrode 20a and the counter electrode 20c can be prevented.

[Modification 1]
In the above embodiment, the semiconductor film 71 and the insulating film 72 are stacked on the gate insulating film 31 on the signal line group Y. However, as shown in FIG. 7, the semiconductor film 71 and the step-suppressing ohmic film 73 are sequentially stacked. Alternatively, as shown in FIG. 8, the semiconductor film 71, the step suppressing ohmic film 73, and the insulating film 72 may be stacked in this order. Here, the step-suppressing ohmic film 73 is formed together with the ohmic films 21a and 21b by patterning the ohmic layer on the entire surface, which is the source of the ohmic films 21a and 21b of the transistor 21, using a photolithography method and an etching method. It has been done.

A method for manufacturing the EL display panel in the case of FIG. 7 will be described. As in the case of the manufacturing method described above, the signal line Y _R , the signal line Y _G , the signal line Y _B , the gate 21 g of the transistor 21 and the electrode 24 a of the capacitor 24 are patterned, and then the gate insulating film 31 is formed. . Next, the semiconductor film 81 is formed on the entire surface, and the channel protective film 21 p is patterned for each transistor 21. Next, the ohmic films 21a and 21b and the ohmic film 73 for suppressing the step are formed by vapor deposition, and a photolithography method and an etching method are sequentially performed, so that the ohmic films 21a and 21b are provided for each transistor 21. At the same time, the ohmic film 73 is patterned so as to overlap the signal line Y _R , the signal line Y _G and the signal line Y _B. Next, the semiconductor film 81 is etched with an etchant. An etching block for protecting the semiconductor film 81 from the etchant by the photoresist mask, the ohmic films 21a and 21b, the channel protective film 21p, and the ohmic film 73 at the time of etching is etched. Function as. By processing the shape of the semiconductor film 81, the semiconductor film 71 and the semiconductor film 21c are obtained. Next, the scanning line X and the supply line Z are patterned, and at the same time, the source 21s and drain 21d of the transistor 21 and the electrode 24b of the capacitor 24 are patterned. Next, as in the case described above, the protective insulating film 32 is formed on the entire surface, the planarizing film 33 is formed, the pixel electrode 20a is patterned, the partition wall 41 is patterned, and the light emitting layer 20b is patterned. Then, the counter electrode 20c is formed.

A method for manufacturing the EL display panel in the case of FIG. 8 will be described. As in the case of the manufacturing method described above, the signal line Y _R , the signal line Y _G , the signal line Y _B , the gate 21 g of the transistor 21 and the electrode 24 a of the capacitor 24 are patterned, and then the gate insulating film 31 is formed. . Next, the semiconductor film 81 is formed on the entire surface, the channel protective film 21p is patterned for each transistor 21, and at the same time, the insulating film 72 is overlaid on the signal line Y _R , the signal line Y _G and the signal line Y _B. Pattern. Next, the ohmic films 21a and 21b and the ohmic film 73 for suppressing the step are formed by vapor deposition, and a photolithography method and an etching method are sequentially performed, so that the ohmic films 21a and 21b are provided for each transistor 21. At the same time, the ohmic film 73 is patterned so as to overlap the signal line Y _R , the signal line Y _G and the signal line Y _B. Subsequently, the semiconductor film 81 located under the ohmic films 21a and 21b and the step suppressing ohmic film 73 is etched with an etchant. The photoresist mask, ohmic films 21a and 21b, the channel protective film 21p, and the ohmic film 73 are etched. Functions as an etching block for protecting the semiconductor film 81 from the etchant. In this way, the semiconductor film 71 and the semiconductor film 21c are obtained by processing the shape of the semiconductor film 81. Next, the scanning line X and the supply line Z are patterned, and at the same time, the source 21s and drain 21d of the transistor 21 and the electrode 24b of the capacitor 24 are patterned. Next, as in the case described above, the protective insulating film 32 is formed on the entire surface, the planarizing film 33 is formed, the pixel electrode 20a is patterned, the partition wall 41 is patterned, and the light emitting layer 20b is patterned. Then, the counter electrode 20c is formed.

Note that the semiconductor film 71 may be patterned on the signal line Y _R , the signal line Y _G and the signal line Y _B without forming the ohmic film 73 and the insulating film 72, or the ohmic film 73 and the semiconductor film 71 may be patterned. The insulating film 72 may be patterned without forming the semiconductor film 71, the ohmic film 73 may be patterned without patterning the semiconductor film 71 and the insulating film 72, or the insulating film 72 may be formed without forming the semiconductor film 71. And the ohmic film 73 may be laminated in order.

[Modification 2]
In the above embodiment, the semiconductor film 71 and the insulating film 72 are patterned simultaneously with the patterning of the transistor 21. However, as shown in FIG. 9, the organic film 74 for suppressing a step is formed without patterning the semiconductor film 71 and the insulating film 72. May be patterned so as to overlap the signal line Y _R , the signal line Y _G and the signal line Y _B. The organic film 74 is patterned by applying a thermosetting or ultraviolet curable resin to the protective insulating film 32 so as to overlap the signal line Y _R , the signal line Y _G and the signal line Y _B. . The organic film 74 is patterned after the protective insulating film 32 is formed and before the planarization film 33 is formed. The organic film 74 is patterned on the signal line Y _R , the signal line Y _G, and the signal line Y _B , so that the surface of the protective insulating film 32 is the signal line Y _R , the signal line Y _{G, the} signal line Y _B, and the capacitor. The step between 24 is eliminated and the step becomes very small. The manufacturing method of the EL display panel of FIG. 9 is the same as that of the above embodiment except that the organic film 74 is patterned without patterning the semiconductor film 71 and the insulating film 72.

Since the organic film 74 for suppressing the step is patterned separately from the transistor 21, the film thickness of the organic film 74 can be adjusted regardless of the film thickness of each film of the transistor 21. Therefore, the step between the part above the capacitor 24 and the part above the signal line Y _R , signal line Y _G and signal line Y _B can be eliminated with higher accuracy.

[Modification 3]
The above-described embodiment, in the modification, the scan line X and supply line Z is formed from the drain layer, the signal line Y _R, the signal lines Y _G and the signal lines Y _B was formed from the gate layer, the signal line Y _R The signal line Y _G and the signal line Y _B may be formed from the drain layer, and the scanning line X and the supply line Z may be formed from the gate layer. In this case, the semiconductor film 71, the insulating film 72, the ohmic film 73, or the organic film 74 is stacked so as to overlap the scanning line X and the supply line Z as in the above-described embodiment and modification.

[Modification 4]
In the above embodiment and the modification, the layers used for the transistors in the pixel circuit P in order to suppress the step are stacked along the signal line Y _R , the signal line Y _G, and the signal line Y _B. However, the present invention is not limited to this. Layers used for the transistors in the pixel circuit P may be stacked along the scanning line X as in the above-described embodiment or modification, and the step between the scanning line X and the capacitor 24 may be suppressed.

[Modification 5]
In the embodiment and the modification, except for Modification 2, a plurality of films for suppressing a step are laminated, but a single layer may be used. That is, only the step suppressing semiconductor film 71, the step suppressing insulating film 72, or the step suppressing ohmic film 73 may be used.
A plurality of the above embodiments and modifications may be combined as long as there is consistency.

2 is an equivalent circuit diagram of the EL display panel 1. FIG. 2 is a cross-sectional view of one pixel of the EL display panel 1. FIG. FIG. 4 is a diagram showing one step in a method for manufacturing an EL display panel 1. It is the figure which showed the next process of FIG. It is the figure which showed the next process of FIG. It is the figure which showed the next process of FIG. 6 is a cross-sectional view of one pixel in a modification of the EL display panel 1. FIG. 6 is a cross-sectional view of one pixel in a modification of the EL display panel 1. FIG. 6 is a cross-sectional view of one pixel in a modification of the EL display panel 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 EL display panel 21 Transistor 21g Gate 21s Source 21d Drain 24 Capacitor 24a Electrode 24b Electrode 50 Transistor array panel 71 Semiconductor film for level | step difference suppression 72 Insulating film for level | step difference suppression 73 Ohmic film for level | step difference suppression 74 Organic film for level | step difference suppression

Claims (4)

A transistor composed of a plurality of layers, a first electrode formed of a layer serving as a gate of the transistor, a second electrode formed of a layer serving as a drain of the transistor, and the first electrode and the second electrode; A capacitor having a sandwiched insulating film, and a pixel circuit,
A wiring formed by one of layers serving as a gate and a drain of the transistor and connected to the pixel circuit;
In a region where the other of the layers serving as the gate and drain of the transistor is not formed , the transistor is provided along the extending direction of the wiring so as to overlap the wiring, and among the layers serving as the plurality of layers of the transistor , A step-suppressing film formed of at least one layer excluding a layer serving as a gate of a transistor, a layer serving as a drain of the transistor, and the insulating film ;
A transistor array panel comprising: A transistor ; a first electrode formed by a layer serving as a gate of the transistor; a second electrode formed by a layer serving as a drain of the transistor; and an insulating film sandwiched between the first electrode and the second electrode. A pixel circuit having a capacitor ;
A wiring formed by one of layers serving as a gate and a drain of the transistor and connected to the pixel circuit;
A step-suppressing film provided along the extending direction of the wiring so as not to overlap the capacitor and to overlap the wiring in the region where the other of the gate and drain layers of the transistor is not formed When,
A transistor array panel comprising:   The transistor array panel according to claim 1, further comprising a pixel electrode formed above the step suppressing film. A wiring connected to a pixel circuit having a transistor composed of a plurality of layers is formed by one of the gate and drain layers of the transistor ,
A first electrode formed in a layer serving as a gate of the transistor; a second electrode formed in a layer serving as a drain of the transistor; and an insulating film sandwiched between the first electrode and the second electrode. Forming a capacitor of the pixel circuit ,
In a region where the other of the gate and drain layers of the transistor is not formed , the transistor includes a plurality of layers of the transistor along the extending direction of the wiring so as to overlap the wiring . Forming a step-reducing film with at least one layer excluding the gate layer, the drain layer of the transistor, and the insulating film ;
A method of manufacturing a transistor array panel.

Images