JP2011061098A - Organic light-emitting display device and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic light-emitting display device for satisfactorily fulfilling characteristics required for a drive transistor and a switching transistor of an organic light-emitting display device, and to provide a method for manufacturing the same. <P>SOLUTION: The organic light-emitting display device includes a reverse stagger-type switching transistor and the drive transistor formed on an identical substrate. The switching transistor has a first channel layer comprising a first semiconductor layer, and the drive transistor has a second channel layer comprising a crystalline second semiconductor layer different from the first semiconductor layer and the first semiconductor layer laminated on the second semiconductor layer. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an organic light emitting display device and a method for manufacturing the same.

  For example, there is an electronic device using an organic electroluminescence display device (hereinafter referred to as an organic light emitting display device) or a liquid crystal display device. In such an electronic apparatus, that is, an organic light emitting display device or a liquid crystal display device, display elements arranged in a matrix are configured, and the display elements are driven by a plurality of thin film transistors.

  An organic light emitting display device in which a display element is configured includes two electrodes and a light emitting layer between the two electrodes. In such an organic light emitting display device, electrons or holes are injected from each electrode and recombined to emit light while releasing energy when returning to the ground state.

  In addition, in such an organic light emitting display device, there are driving methods of an active matrix method and a passive matrix method. In the active matrix system, the organic light emitting display device includes a thin film transistor including a switching element (switching transistor) and a current driving drive element (current driving transistor) and a capacitance for each pixel. When the switching element for selecting the target pixel is turned on, the data voltage from the data line is stored in the capacitance. Furthermore, the current is supplied to the light emitting element by applying them to the gate voltage of the current driving transistor and flowing the current from the current supply line to the source or drain electrode of the current driving transistor (for example, Patent Document 1 and Patent Document 2). ).

  In Patent Document 1, a display is provided with a current driving transistor whose channel layer has a laminated structure of amorphous silicon films and a switching transistor whose channel layer has a three-layer structure of polycrystalline silicon, microcrystalline silicon, and amorphous silicon. An apparatus is disclosed. Patent Document 2 discloses a display device including a current driving transistor whose channel layer is a single microcrystalline silicon film or a single amorphous silicon film layer and a switching transistor whose channel layer is amorphous silicon. ing.

JP-A-5-226656 JP 2007-219517 A

  However, the organic light emitting display device including the driving transistor and the switching transistor disclosed in Patent Document 1 and Patent Document 2 cannot sufficiently satisfy the characteristics required for the driving transistor and the switching transistor.

  The reason is as follows. In an organic light emitting display device, required characteristics are different between a switching transistor and a driving transistor. That is, the channel layer of the driving transistor is required to have a characteristic of flowing a large current through the organic light emitting element, and the channel layer of the switching transistor is required to have a characteristic of reducing the off current. Therefore, in order to flow a large current to the driving transistor, a channel layer made of a polycrystalline or microcrystalline semiconductor film is necessary, and the amorphous silicon film laminated structure disclosed in Patent Document 1 and Patent Document 2 or The channel layer formed of a single amorphous silicon film cannot sufficiently satisfy the required characteristics. In addition, when the polycrystalline or microcrystalline semiconductor film disclosed in Patent Document 1 is used for the channel layer of the switching transistor, the off-current flowing through the interface on the back channel side of the channel layer increases. As a result, the gate voltage supplied to the drive transistor decreases, and the display quality may deteriorate. That is, the characteristics required for the channel layer of the switching transistor cannot be sufficiently satisfied.

  Therefore, the present invention focuses on the above-described problems, and provides an organic light emitting display device that sufficiently satisfies the characteristics required for the drive transistor and switching transistor of the organic light emitting display device, and a method for manufacturing the same. Objective.

  In order to achieve the above object, an organic light emitting display device according to the present invention is an organic light emitting display device including an inverted staggered switching transistor and a driving transistor formed on the same substrate, and the switching transistor includes: A first channel layer made of one semiconductor layer, wherein the driving transistor has a second semiconductor layer that is different in crystallinity from the first semiconductor layer, and the first semiconductor layered on the second semiconductor layer. And a second channel layer made up of layers.

  According to the present invention, it is possible to realize an organic light emitting display device that sufficiently satisfies the characteristics required for the driving transistor and the switching transistor of the organic light emitting display device, and a method for manufacturing the same. Thereby, there is also an effect that the display quality characteristic of the organic light emitting display device can be improved.

1 is a cross-sectional view illustrating a structure of a thin film transistor that constitutes an organic light emitting display device according to an embodiment of the present invention. It is a figure which shows the equivalent circuit of the organic light emitting display apparatus which concerns on embodiment of this invention. 3 is a flowchart illustrating a manufacturing process of a thin film transistor of the organic light emitting display device according to the embodiment of the invention. FIG. 6 is a cross-sectional view for explaining a method for manufacturing a thin film transistor of an organic light emitting display device according to an embodiment of the present invention. FIG. 6 is a cross-sectional view for explaining a method for manufacturing a thin film transistor of an organic light emitting display device according to an embodiment of the present invention. FIG. 6 is a cross-sectional view for explaining a method for manufacturing a thin film transistor of an organic light emitting display device according to an embodiment of the present invention. FIG. 6 is a cross-sectional view for explaining a method for manufacturing a thin film transistor of an organic light emitting display device according to an embodiment of the present invention. FIG. 6 is a cross-sectional view for explaining a method for manufacturing a thin film transistor of an organic light emitting display device according to an embodiment of the present invention. FIG. 6 is a cross-sectional view for explaining a method for manufacturing a thin film transistor of an organic light emitting display device according to an embodiment of the present invention. FIG. 6 is a cross-sectional view for explaining a method for manufacturing a thin film transistor of an organic light emitting display device according to an embodiment of the present invention. FIG. 6 is a cross-sectional view for explaining a method for manufacturing a thin film transistor of an organic light emitting display device according to an embodiment of the present invention. FIG. 6 is a cross-sectional view for explaining a method for manufacturing a thin film transistor of an organic light emitting display device according to an embodiment of the present invention. FIG. 6 is a cross-sectional view for explaining a method for manufacturing a thin film transistor of an organic light emitting display device according to an embodiment of the present invention. FIG. 6 is a cross-sectional view for explaining a method for manufacturing a thin film transistor of an organic light emitting display device according to an embodiment of the present invention. It is a figure which shows the current-voltage characteristic of the thin-film transistor of the organic light emitting display which concerns on embodiment of this invention.

  An organic light emitting display device according to an aspect of the present invention includes an inverted staggered switching transistor and a driving transistor formed over the same substrate, the switching transistor including a first semiconductor layer. The driving transistor includes a second semiconductor layer that is different in crystallinity from the first semiconductor layer, and the first semiconductor layer stacked on the second semiconductor layer. And a second channel layer.

  Here, the organic light emitting display device further includes a data line, a scanning line, and a current supply line, the switching transistor further includes a first gate electrode electrically connected to the scanning line, and the substrate. And a first gate insulating film formed to cover the gate electrode, and a first gate insulating film formed on both ends of the first channel layer on the first gate insulating film and electrically connected to the data line. A first or second drain electrode; and the first channel layer is formed on the first gate insulating film corresponding to the gate electrode; A second gate electrode connected to one of the one source and the first drain electrode, and a second gate formed on the substrate so as to cover the gate electrode An edge film, and a second source or drain electrode formed on both ends of the second channel layer on the second gate insulating film and electrically connected to the current supply line. The channel layer may be formed on the second gate insulating film corresponding to the second gate electrode.

  According to this aspect, the channel layer of the driving transistor has a stacked structure in which the second semiconductor layer and the first semiconductor layer are stacked from the lower layer, and the channel layer of the switching transistor has a structure including only the first semiconductor layer. . That is, the crystallinity of the semiconductor layer constituting the channel layer on the gate electrode side of the driving transistor and the switching transistor is different, and the current transmission characteristics of the driving transistor and the switching transistor are different. Accordingly, it is possible to realize an organic light emitting display device that sufficiently satisfies the characteristics required for the drive transistor and the switching transistor of the organic light emitting display device.

  The first semiconductor layer may be made of an amorphous semiconductor, and the second semiconductor layer may be made of a polycrystalline semiconductor.

  According to this aspect, since the second semiconductor layer is made of a crystalline (including microcrystalline) semiconductor, the driving transistor can have high mobility and on-current. Therefore, a large current can be supplied to the organic EL element. Further, since the first semiconductor layer is an amorphous semiconductor, the switching transistor has an off-state current as compared with the case where a polycrystalline (including microcrystalline) semiconductor of the second semiconductor layer is used as a channel layer. Can be reduced. Therefore, it is possible to suppress a data voltage drop due to the switching transistor. This is because when the polycrystalline or microcrystalline semiconductor of the first semiconductor layer is used, the off-current flowing to the back channel interface side increases.

  At this time, the second semiconductor layer is formed as a polycrystalline semiconductor having crystallinity by heat treatment or laser of an amorphous semiconductor.

  In the organic light emitting display device which is one embodiment of the present invention, in the second channel layer of the driving transistor, the first semiconductor layer and the second semiconductor layer may have a stacked structure.

  According to this aspect, in the driving transistor, the first semiconductor layer is stacked on the second semiconductor layer, whereby the resistance between the source electrode and the drain electrode can be increased, and the off-current is suppressed. An effect is obtained.

  The organic light-emitting display device which is one embodiment of the present invention includes a first semiconductor layer in the second channel layer of the driving transistor and a first semiconductor layer in the first channel layer of the switching transistor in the film. The hydrogen contents may be the same, and the film thicknesses of the first semiconductor layer in the second channel layer of the switching transistor and the first semiconductor layer in the first channel layer of the driving transistor are the same. There may be.

  According to this aspect, the specifications of the dry etching process in the channel etch process can be made the same by using the same film thickness of the first semiconductor layer and the hydrogen content in each film used in the drive transistor and the switching transistor. There is an effect.

  The present invention can be realized not only as an organic light emitting display device having such characteristic means, but also as a method for manufacturing an organic light emitting display device including the characteristic means included in the organic light emitting display device as a step. Can be realized.

  A method of manufacturing an organic light emitting display device according to an aspect of the present invention is a method of manufacturing an organic light emitting display device including an inverted staggered switching transistor and a driving transistor formed over the same substrate. A first step of forming a second semiconductor layer constituting a channel layer, and a second step of forming a first semiconductor layer having a different crystallinity from the second semiconductor layer, wherein in the second step, The first semiconductor layer constituting the channel layer of the switching transistor and the first semiconductor layer constituting the channel layer of the driving transistor and stacked on the second semiconductor layer are formed.

  Here, in the first step, the second semiconductor layer may be formed of a polycrystalline semiconductor, and in the second step, the first semiconductor layer may be formed of an amorphous semiconductor.

  In the first step, after the second semiconductor layer is formed of an amorphous semiconductor, the formed amorphous semiconductor is subjected to heat treatment or laser treatment to form a polycrystalline semiconductor having crystallinity. It is good.

(Embodiment)
Hereinafter, an exemplary embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view illustrating a structure of a thin film transistor that constitutes an organic light emitting display device according to an embodiment of the present invention. FIG. 1 shows a cross-sectional view of a thin film transistor constituting the switching transistor 1 and a thin film transistor constituting the drive transistor 2, which are formed on a common insulating substrate 10.

  As shown in FIG. 1, the drive transistor 2 is an inverted staggered and channel-etched thin film transistor, and includes an insulating substrate 10, a gate electrode 12, a gate insulating film 13, a crystalline silicon film 15, and an amorphous film. A silicon film 16, an n + silicon film 17, and source / drain electrodes 18 are provided.

The insulating substrate 10 is a substrate made of transparent glass or quartz.
The gate electrode 12 is formed on the insulating substrate 10 and is made of, for example, a metal such as molybdenum (Mo) or Mo alloy, a metal such as titanium (Ti), aluminum (Al) or Al alloy, copper (Cu) or Cu alloy. It is made of metal or metal such as silver (Ag), chromium (Cr), tantalum (Ta), or tungsten (W).

The gate insulating film 13 is formed so as to cover the gate electrode 12 and is made of silicon oxide (SiO _x ) or silicon nitride (SiN _x ). Note that the gate insulating film 13 may have a stacked structure of silicon oxide (SiO _x ) and silicon nitride (SiN _x ).

  The crystalline silicon film 15 is formed on the gate insulating film 13. In the crystalline silicon film 15, an amorphous silicon film 14 (not shown) is formed on the gate insulating film 13, and the amorphous silicon film 14 is polycrystallized (including microcrystallization) by heat treatment or laser. Is formed.

  The term “polycrystal” as used herein has a broad meaning including not only a polycrystal in a narrow sense consisting of crystals of 50 nm or more but also a microcrystal in a narrow sense consisting of crystals of 50 nm or less. Hereinafter, polycrystal is described in a broad sense.

  The amorphous silicon film 16 is formed on the crystalline silicon film 15 left by patterning. Thus, the driving transistor 2 has a channel layer having a structure in which the amorphous silicon film 16 is stacked on the crystalline silicon film 15.

  The n + silicon film 17 is formed so as to cover the amorphous silicon film 16, the side surfaces of the crystalline silicon film 15, and the gate insulating film 13.

  The source / drain electrode 18 is formed on the n + silicon film 17, and is made of, for example, a metal such as molybdenum (Mo) or Mo alloy, a metal such as titanium (Ti), aluminum (Al) or Al alloy, copper (Cu) or Cu. It is made of a metal material such as an alloy or a metal such as silver (Ag), chromium (Cr), tantalum (Ta), or tungsten (W).

As described above, the drive transistor 2 is configured.
On the other hand, the switching transistor 1 is an inverted staggered channel etch type thin film transistor, and includes an insulating substrate 10, a gate electrode 11, a gate insulating film 13, an amorphous silicon film 16, an n + silicon film 17, and a source. A drain electrode 18 is provided. Elements similar to those of the drive transistor 2 are denoted by the same reference numerals.

The insulating substrate 10 is a substrate made of transparent glass or quartz.
The gate electrode 11 is formed on the insulating substrate 10, and similarly to the gate electrode 12, for example, a metal such as molybdenum (Mo) or an Mo alloy, a metal such as titanium (Ti), aluminum (Al), or an Al alloy, copper (Cu), and the like. Or it consists of metals, such as Cu alloy, or metals, such as silver (Ag), chromium (Cr), tantalum (Ta), or tungsten (W).

The gate insulating film 13 is formed so as to cover the gate electrode 11. Here, the gate insulating film 13 is made of silicon oxide (SiO _x ) or silicon nitride (SiN _x ) as described above. Further, the gate insulating film 13 may have a laminated structure of silicon oxide (SiO _x ) and silicon nitride (SiN _x ).

  The amorphous silicon film 16 is formed on the gate insulating film 13. Here, the crystalline silicon film 15 is not present because it has been removed by patterning. That is, the amorphous silicon film 16 is formed on the gate insulating film 13 from which the crystalline silicon film 15 has been removed by patterning. As described above, the switching transistor 1 has a channel layer having a structure including only the amorphous silicon film 16.

  Note that the amorphous silicon film 16 in the switching transistor 1 and the amorphous silicon film 16 in the drive transistor 2 are preferably substantially equal in thickness. The amorphous silicon film 16 in the switching transistor 1 and the amorphous silicon film 16 in the drive transistor 2 each contain hydrogen, and the hydrogen contents are preferably the same.

  The n + silicon film 17 is formed so as to cover the amorphous silicon film 16 and the gate insulating film 13.

  The source / drain electrodes 18 are formed on the n + silicon film 17. Further, as described above, the source / drain electrode 18 is made of, for example, a metal such as molybdenum (Mo) or Mo alloy, a metal such as titanium (Ti), aluminum (Al) or Al alloy, copper (Cu) or Cu alloy. It is made of a metal or a metal material such as silver (Ag), chromium (Cr), tantalum (Ta), or tungsten (W).

As described above, the switching transistor 1 is configured.
As described above, the switching transistor 1 and the driving transistor 2 which are thin film transistors of the organic light emitting display device according to the embodiment of the present invention are configured.

  FIG. 2 is a diagram showing an equivalent circuit of the organic light emitting display device according to the embodiment of the present invention. The organic light emitting display device shown in FIG. 2 includes a switching transistor 1, a driving transistor 2, a data line 3, a scanning line 4, a current supply line 5, a capacitance 6, and an organic EL element 7.

  The switching transistor 1 is connected to the data line 3, the scanning line 4, and the capacitance 6.

  The driving transistor 2 is connected to the current supply line 5, the capacitance 6, and the organic EL element 7.

  The data line 3 is a wiring through which data (the magnitude of the voltage value) that determines the brightness of the pixel of the organic EL element 7 is transmitted to the pixel of the organic EL element 7.

  The scanning line 4 is a wiring through which data for determining the switch (ON / OFF) of the pixel of the organic EL element 7 is transmitted to the pixel of the organic EL element 7.

The current supply line 5 is a wiring for supplying a large current to the drive transistor 2.
The capacitance 6 holds a voltage value (charge) for a certain time.

As described above, the organic light emitting display device according to the present embodiment is configured.
Next, a manufacturing method of the thin film transistor, that is, the switching transistor 1 and the driving transistor 2 of the organic light emitting display device configured as described above will be described.

  FIG. 3 is a flowchart showing a manufacturing process of a thin film transistor of the organic light emitting display device according to the embodiment of the present invention. 4A to 4K are views for explaining a method of manufacturing a thin film transistor of the organic light emitting display device according to the embodiment of the present invention.

  First, the gate electrodes (gate electrode 11 and gate electrode 12) are formed and patterned (S101).

  Specifically, a metal to be a gate electrode (gate electrode 11 and gate electrode 12) is deposited on the insulating substrate 10 by sputtering, and the gate electrode 11 in the switching transistor 1 and the gate electrode 12 in the driving transistor are formed by photo and etching. (FIG. 4A). Here, the gate electrode 11 and the gate electrode 12 are made of metal such as molybdenum (Mo) or Mo alloy, metal such as titanium (Ti), aluminum (Al) or Al alloy, metal such as copper (Cu) or Cu alloy, Alternatively, a metal material such as silver (Ag), chromium (Cr), tantalum (Ta), or tungsten (W) is used.

  Subsequently, a gate insulating film 13 is formed on the gate electrodes (gate electrode 11 and gate electrode 12) (S102), and an amorphous silicon film is formed on the gate insulating film 13 (S103).

Specifically, a gate insulating film 13 is formed on the gate electrode 11 and the gate electrode 12 by plasma CVD, that is, to cover the insulating substrate 10, the gate electrode 11, and the gate electrode 12 (FIG. 4B). An amorphous silicon film 14 is continuously formed on the formed gate insulating film 13 (FIG. 4C). Here, the gate insulating film 13 is made of silicon oxide (SiO _x ) or silicon nitride (SiN _x ). Note that the gate insulating film 13 may have a stacked structure of silicon oxide (SiO _x ) and silicon nitride (SiN _x ).

  Subsequently, the amorphous silicon film 14 is changed to a crystalline silicon film 15 by, eg, laser annealing (S104). Specifically, dehydrogenation treatment is performed on the formed amorphous silicon film 14. Thereafter, the amorphous silicon film 14 is made polycrystalline (including microcrystals) by laser or thermal annealing to form a crystalline silicon film 15 (FIG. 4D).

  Subsequently, patterning is performed so as to leave a crystalline silicon film in a drive transistor region which is a region to be the drive transistor 2 (S105).

  Specifically, the crystalline silicon film 15 is patterned by photo and etching so as to leave the crystalline silicon film 15 in the drive transistor region. Here, the crystalline silicon film 15 is patterned so as to remain above the channel region of the driving transistor 2 and not to remain in the region which becomes the channel of the switching transistor 1 (FIG. 4E).

  Subsequently, a second amorphous silicon film 16 is formed (S106), and the silicon film layers in the channel region of the driving transistor 2 and the channel region of the switching transistor 1 are patterned (S107).

  Specifically, first, a hydrogen termination process is performed on the crystalline silicon film 15 left by patterning by a hydrogen plasma process or the like. Next, a second amorphous silicon film 16 is formed on the crystalline silicon film 15 left by patterning by plasma CVD and on the gate insulating film 13 from which the crystalline silicon film 15 has been removed by patterning. A film is formed (FIG. 4F). Then, the silicon film layer (the layer of the amorphous silicon film 16 and the crystalline silicon film 15 and the amorphous silicon film 16) is patterned so that the channel region of the driving transistor 2 and the channel region of the switching transistor 1 remain. The amorphous silicon film 16 and the crystalline silicon film 15 to be removed are removed by etching (FIG. 4G). Thereby, a desired channel layer is formed in the switching transistor 1 and the driving transistor 2.

  Here, the film thickness of the amorphous silicon film 16 and the hydrogen content in the film in the drive transistor 2 and the switching transistor 1 are made the same. Thereby, the specifications of the dry etching process of the channel etching process to be performed later can be made the same.

Subsequently, an n + silicon film 17 and a source / drain electrode 18 are formed (S108).
Specifically, the amorphous silicon film 16 and the crystalline material are formed in the region to be the driving transistor 2 so as to cover the amorphous silicon film 16 and the gate insulating film 13 in the region to be the switching transistor 1 by plasma CVD. An n + silicon film 17 is formed so as to cover the side surface of the silicon film 15 and the gate insulating film 13 (FIG. 4H).

  Then, a metal to be the source / drain electrode 18 is deposited on the formed n + silicon film 17 by sputtering (FIG. 4I). Here, the source / drain electrodes are made of metal such as molybdenum (Mo) or Mo alloy, metal such as titanium (Ti), aluminum (Al) or Al alloy, metal such as copper (Cu) or Cu alloy, or silver. It is made of a metal material such as (Ag), chromium (Cr), tantalum (Ta), or tungsten (W).

  Subsequently, the source / drain electrode 18 is patterned (S109). Then, the n + silicon film 17 is etched (S109), and the second amorphous silicon film 16 is partially etched (S110).

  Specifically, the source / drain electrodes 18 are formed by photo and etching (FIG. 4J). Further, the n + silicon film 17 is etched, and the amorphous silicon film 16 in the channel regions of the switching transistor 1 and the drive transistor 2 is partially etched (FIG. 4K). In other words, the amorphous silicon film 16 is channel etched so as to leave a part of the amorphous silicon film 16 in the channel region of the switching transistor 1 and the driving transistor 2.

  In this way, the channel etch type thin film transistor, that is, the switching transistor 1 and the driving transistor 2 are collectively formed.

  As described above, the thin film transistor, that is, the switching transistor 1 and the driving transistor 2 of the organic light emitting display device are manufactured.

  FIG. 5 is a diagram illustrating current-voltage characteristics of the thin film transistor of the organic light emitting display device according to the embodiment of the present invention.

  FIG. 5 shows TFT (Thin Film Transistor) characteristics of the switching transistor 1 and the driving transistor 2 of the organic light emitting display device configured as described above. Specifically, the TFT characteristics of the switching transistor 1 are indicated by solid lines, and the TFT characteristics of the drive transistor 2 are indicated by dotted lines.

  As shown in FIG. 5, in the switching transistor 1, an on current = 7.0 μA and an off current = 1.9 pA are obtained, and in the driving transistor 2, an on current = 110 μA and an off current = 11.2 pA are obtained. ing. Here, the on-current is the drain current when Vg = 5.0V, and the off-current is the drain current value when Vg = −10V.

  As described above, the off-state current of the switching transistor 1 has a reduction effect of about 1/10 compared with the driving transistor 2. On the other hand, the on-state current of the drive transistor 2 is about 15 times that of the switching transistor 1.

  As described above, in the thin film transistor of the organic light emitting display device according to the embodiment of the present invention, the channel layer of the driving transistor 2 has a stacked structure of the crystalline silicon film 15 and the amorphous silicon film 16, and the channel of the switching transistor 1. The layer is only the amorphous silicon film 16. That is, the driving transistor 2 and the switching transistor 1 have different crystalline semiconductor layers in the channel layer on the gate insulating film 13 side. Thereby, the drive transistor 2 and the switching transistor 1 can have different current transmission characteristics.

  Specifically, the drive transistor 2 can have high mobility and on-current by including the crystalline silicon film 15 made of a polycrystalline semiconductor. Therefore, a large current can be supplied to the organic EL element 7.

  On the other hand, since the switching transistor 1 has only the amorphous silicon film 16 made of an amorphous semiconductor, the switching transistor 1 has a crystalline silicon film 15 made of a polycrystalline semiconductor as a channel layer in the switching transistor 1. Thus, the off current can be reduced. Therefore, a data voltage drop due to the switching transistor 1 can be suppressed. Here, when the switching transistor 1 is formed of the polycrystalline silicon film 15 made of a polycrystalline semiconductor as a channel layer, the off-current flowing to the back channel interface side increases.

  In addition, since the driving transistor 2 includes a channel layer having a structure in which the amorphous silicon film 16 is stacked on the crystalline silicon film 15, the resistance between the source electrode and the drain electrode can be increased, and the driving transistor 2 is turned off. An effect of suppressing current is obtained.

  Further, by making the film thickness of the amorphous silicon film 16 and the hydrogen content in the film in the drive transistor 2 and the switching transistor 1 the same, it is possible to make the specifications of the dry etching process of the channel etch process the same. is there.

  As described above, according to the present invention, it is possible to realize an organic light emitting display device that sufficiently satisfies characteristics required for a drive transistor and a switching transistor of the organic light emitting display device, and a method for manufacturing the same.

  As described above, the organic light emitting display device and the manufacturing method thereof according to the present invention have been described based on the embodiment. However, the present invention is not limited to this embodiment. Unless it deviates from the meaning of this invention, the form which carried out the various deformation | transformation which those skilled in the art can think to this embodiment, and the structure constructed | assembled combining the component in different embodiment is also contained in the scope of the present invention. .

  INDUSTRIAL APPLICABILITY The present invention can be used for an organic light emitting display device and a manufacturing method thereof, and more particularly, to an organic light emitting display device that constitutes an electronic device using a technique for forming a plurality of thin film transistors having different element structures on a shared substrate and a manufacturing method thereof. Can be used.

DESCRIPTION OF SYMBOLS 1 Switching transistor 2 Drive transistor 3 Data line 4 Scan line 5 Current supply line 6 Capacitance 7 Organic EL element 10 Insulating substrate 11, 12 Gate electrode 13 Gate insulating film 14, 16 Amorphous silicon film 15 Crystalline silicon film 17 n + silicon Film 18 Source / drain electrode

Claims (10)

An organic light emitting display device comprising an inverted stagger type switching transistor and a driving transistor formed on the same substrate,
The switching transistor is
A first channel layer comprising a first semiconductor layer;
The drive transistor is
An organic light emitting display device comprising: a second semiconductor layer having a different crystallinity from the first semiconductor layer; and a second channel layer including the first semiconductor layer stacked on the second semiconductor layer. The organic light emitting display device further includes a data line, a scanning line, and a current supply line,
The switching transistor further includes:
A first gate electrode electrically connected to the scan line;
A first gate insulating film formed on the substrate so as to cover the gate electrode;
A first source or drain electrode formed on both ends of the first channel layer on the first gate insulating film and electrically connected to the data line;
The first channel layer is formed on the first gate insulating film corresponding to the gate electrode,
The driving transistor further includes:
A second gate electrode connected to one of the first source or first drain electrode of the switching transistor;
A second gate insulating film formed on the substrate so as to cover the gate electrode;
A second source electrode or a second drain electrode formed on both ends of the second channel layer on the second gate insulating film and electrically connected to the current supply line;
The organic light emitting display device according to claim 1, wherein the second channel layer is formed on the second gate insulating film corresponding to the second gate electrode. The organic light emitting display device according to claim 1, wherein the first semiconductor layer is made of an amorphous semiconductor, and the second semiconductor layer is made of a polycrystalline semiconductor. The organic light emitting display device according to claim 1, wherein the second semiconductor layer is formed as a polycrystalline semiconductor having crystallinity by heat treatment or laser processing of an amorphous semiconductor. The organic light emitting display device according to claim 1, wherein in the second channel layer of the driving transistor, the first semiconductor layer and the second semiconductor layer have a stacked structure. The hydrogen content of the first semiconductor layer in the second channel layer of the driving transistor and the first semiconductor layer in the first channel layer of the switching transistor in the film are the same. The organic light-emitting display device described. 3. The organic light emitting display device according to claim 1, wherein the film thicknesses of the first semiconductor layer in the second channel layer of the switching transistor and the first semiconductor layer in the first channel layer of the driving transistor are the same. . A method of manufacturing an organic light emitting display device comprising an inverted stagger type switching transistor and a driving transistor formed on the same substrate,
A first step of forming a second semiconductor layer constituting a channel layer of the driving transistor;
A second step of forming a first semiconductor layer that is crystalline different from the second semiconductor layer,
In the second step,
An organic light emitting display device comprising: a first semiconductor layer that forms a channel layer of the switching transistor; and a first semiconductor layer that forms a channel layer of the driving transistor and is stacked on the second semiconductor layer. Production method. In the first step, the second semiconductor layer is formed of a polycrystalline semiconductor,
The method of manufacturing an organic light emitting display device according to claim 8, wherein in the second step, the first semiconductor layer is formed of an amorphous semiconductor. The first semiconductor step includes forming the second semiconductor layer from an amorphous semiconductor, and then performing heat treatment or laser treatment on the formed amorphous semiconductor to form a polycrystalline semiconductor having crystallinity. 10. A method for producing an organic light emitting display device according to item 9.

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