KR20110126038A - Method for manufacturing electronic device, thin film transistor, electro optic apparatus and sensor - Google Patents

Abstract

PURPOSE: The manufacturing method of an electronic device, a thin film transistor, an electro-optical device, and a sensor are provided to control the generation of excess carrier by enhancing oxygen partial pressure within a vacuum film deposition room. CONSTITUTION: A first layer which contains oxide layered in the top of a substrate. The first layer contains at least one element among In, Ga, Zn, and Sn. The deposition of the first layer is executed in a vacuum film deposition room which is blocked with atmosphere. The vacuum film deposition room comprises a first vacuum film deposition room and a second vacuum film deposition room which is connected with the first vacuum film deposition room through a transfer room. A second layer consisting of same material or different material with the first layer is layered.

Description

METHOD FOR MANUFACTURING ELECTRONIC DEVICE, THIN FILM TRANSISTOR, ELECTRO OPTIC APPARATUS AND SENSOR}

The present invention relates to a method for manufacturing an electronic device, a thin film transistor, an electro-optical device, and a sensor.

In recent years, as an electronic device, research into a thin film transistor using an oxide semiconductor film having an oxygen indefiniteness ratio including an In—Ga—Zn—O system (IGZO) as a channel layer (active layer) has been actively conducted. The oxide semiconductor film can be formed on a flexible transparent thin film transistor on a substrate such as a plastic plate or a film because the oxide semiconductor film can be formed at a low temperature and a low temperature process and exhibits higher mobility than amorphous silicon and is transparent to visible light. .

In manufacturing a thin film transistor using such an oxide semiconductor film, it is important to perform defect control at an interface from the viewpoint of stability and controllability of the device. In particular, defects at the interface between the active layer using the oxide semiconductor film and the gate insulating layer are considered to be one of device deterioration factors, such as causing a threshold shift in transistor characteristics (Non-Patent Document 1).

In addition, as an electronic device, a tunnel junction element in which a ferromagnetic material or a magnetic semiconductor are bonded to an insulating film including an oxide has recently attracted attention. It is known that this tunnel junction element exhibits a magnetoresistance larger than the GMR effect which has already been put to practical use, and is highly expected to be applied to a new high performance magnetic head or a new nonvolatile memory (MRAM, etc.). In an electronic device including a tunnel barrier (insulating film) and an electrode layer including this tunnel junction element, it is known that the interface state between the insulating film and the electrode layer has a great influence on its transport characteristics (Non-Patent Document 2). This leads to a reduction in the magnetoresistance ratio and an increase in the leakage current, which greatly hinders the value as an electronic device.

As described above, in electronic devices including thin film transistors and tunnel junction elements, reducing defects at interfaces such as an active layer / gate insulating layer and an insulating film / electrode layer greatly contributes to the improvement of the device performance and stability.

For this reason, various measures to reduce the defect of the said interface are also reported. As a representative example, the report example in a thin film transistor is given to the following.

Patent Document 1 discloses that in a thin film transistor, annealing in an oxidizing atmosphere of 300 ° C. or higher after the formation of an active layer reduces oxygen deficiency that may become a defect between the active layer and the gate insulating layer interface.

Further, Patent Documents 2 and 3 disclose a thin film transistor in which an active layer is formed, followed by a so-called plasma irradiation treatment in which oxygen or ozone plasma is irradiated to the active layer, thereby eliminating oxygen vacancies in the active layer and the gate insulating layer interface. Reducing is disclosed.

Japanese Patent Publication No. 2006-502597 Japanese Laid-Open Patent Publication 2008-42088 Japanese Laid-Open Patent Publication 2006-165531

 J. M. Lee, et al., Appl. Phys. Lett, 93 (2008) 093 504  S. Yuasa et al., Surface Science Vol. 28, No. 1, pp. 15-21, (2007)  R. R. Oleson, et al., Jour. of Appl. Phys., 50 (1979) 3677  Y. Park, et al., Proceedings of the IDW'07 Digest, 2007 (unpublished), Vol. AMD 9-1, p. 1775.

However, as in the method of Patent Document 1, in order to anneal the active layer on the substrate at a high temperature, a substrate having high heat resistance must be used, thereby narrowing the selectivity of the substrate, and particularly limiting the use of a flexible substrate made of organic or the like. .

Next, in the method of Patent Literature 2, the oxygen vacancies can be reduced without annealing the thin film transistor. However, in order to perform the plasma irradiation treatment, it is necessary to use a plasma generating mechanism separately from the film forming mechanism. It is not preferable from a viewpoint.

In addition, it has been reported that plasma irradiation causes damage to the object rather than damage depending on the usage or use conditions, thereby increasing the defects in the object, and thus, switch characteristics are lost due to unexpected changes in the resistance value or lowering of the active layer. (Non Patent Literature 3, Non Patent Literature 4). Therefore, the defect control by the plasma irradiation process requires high expertise and know-how, and is not preferable from the viewpoint of widening the process margin as a film forming method.

As described above, in the prior art, a defect control method by annealing treatment or plasma irradiation treatment has been used, but at a low temperature (for example, a process temperature of 200 ° C. or lower), no special mechanism and high knowledge are required. There was no method of simply reducing the defect of an interface.

An object of the present invention is to provide a method for manufacturing an electronic device, a thin film transistor, an electro-optical device, and a sensor that can easily reduce an interface defect.

The said subject of this invention was solved by the following means.

<1> A first film forming step of forming a first layer containing an oxygen irregularity oxide on a substrate in a vacuum film forming chamber cut off from the atmosphere, and the same material as the first layer on the first layer. Or an interior in which the first layer is blocked from the atmosphere including the vacuum film forming chamber between the second film forming step of forming the second layer made of different materials and the second film forming step after the first film forming step and before the second film forming step. The manufacturing method of the electronic device which has a partial pressure control process which keeps it under oxygen partial pressure higher than the oxygen partial pressure in the said vacuum film-forming chamber in a said 1st film-forming process.

In the <2> partial pressure control step, the oxygen partial pressure after the first film forming step and before the second film forming step is set to be at least 2.1 × 10 ⁻³ Pa or more as compared with the oxygen partial pressure in the first film forming step. . The manufacturing method of the electronic device as described in <1>.

<3> The said vacuum film forming chamber includes a 1st vacuum film forming chamber, and the 2nd vacuum film forming chamber connected with the said 1st vacuum film forming chamber and a conveyance chamber. In the said 1st film forming process, it is the said 1st vacuum film forming chamber in the said The first layer is formed, and in the second film forming step, the second layer is formed in the second vacuum film forming chamber, and in the partial pressure control step, in the first vacuum film forming chamber, in the conveying chamber, and the The manufacturing method of the electronic device as described in <1> or <2> which makes oxygen partial pressure in a 2nd vacuum film-forming chamber higher than oxygen partial pressure in the said 1st vacuum film-forming chamber in a said 1st film-forming process.

In the <4> said 1st film-forming process and the said 2nd film-forming process, the said vacuum film-forming chamber, the target holder arrange | positioned in the said vacuum film-forming chamber, and hold | maintains a target, and is arrange | positioned facing the said target holder, and hold | maintains the said board | substrate And a first film forming process and a second film forming process are performed in the same vacuum film forming chamber by a sputtering device having a substrate holder, and a plasma generating unit for generating a plasma space between the target holder and the substrate. In this case, the partial pressure control step is performed after the first film forming step and before the second film forming step, and a shutter is disposed between the target holder and the substrate in the same vacuum film forming chamber. The manufacturing method of the electronic device as described in 1> or <2>.

The manufacturing method of the electronic device as described in <1> or <2> whose <5> said 1st layer is a conductor, a semiconductor, or an insulator.

<6> The said 1st layer is a manufacturing method of the electronic device as described in <5> which is a semiconductor layer containing at least 1 type of element among In, Ga, Zn, and Sn.

<7> The first layer is a method of manufacturing an electronic device according to the In _x Ga _y Zn _z O _δ of the semiconductor layer containing the (x, y, z, δ > 0), <6>.

The manufacturing method of the electronic device as described in <7> whose <8> said board | substrate has flexibility, and the said 1st layer and the said 2nd layer are amorphous.

The electronic device as described in <1> or <2> which forms the said 1st layer which consists of a semiconductor in a <9> said 1st film-forming process, and forms the said 2nd layer which consists of an insulator in a said 2nd film-forming process. Method of preparation.

<10> The film-forming process of forming the 3rd layer containing an oxygen nonamorphous oxide on the said board | substrate in the said vacuum film-forming chamber before the said 1st film-forming process, In the said 1st film-forming process, it is the said board | substrate. In the film-forming process of a said 3rd layer, the said 1st layer is formed into a film through the said 3rd layer, and the said 3rd layer is formed in the said 3rd layer in the film formation process of the said 3rd layer and before the said 1st film formation process. The manufacturing method of the electronic device as described in <1> or <2> hold | maintained under oxygen partial pressure higher than the oxygen partial pressure in the said vacuum film forming chamber of the said.

The thin film transistor produced by forming an active layer as said 1st layer using the manufacturing method of the electronic device in any one of <11> <1> or <2>.

The electro-optical device provided with the thin film transistor as described in <12> <11>.

The sensor provided with the thin film transistor as described in <13> <11>.

According to the present invention, it is possible to provide a method for manufacturing an electronic device, a thin film transistor, an electro-optical device, and a sensor that can easily reduce oxygen vacancies at an interface.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows the manufacturing procedure of the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention.
The figure which showed the oxygen partial pressure state around the board | substrate in each process in the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention.
The schematic diagram of the electronic device obtained by the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention.
4 is a diagram illustrating a partial schematic cross-sectional view of a sputter apparatus.
Fig. 5 is a schematic diagram showing an example of a thin film transistor according to a second embodiment of the present invention, having a top gate structure and a bottom contact type.
Fig. 6 is a schematic diagram showing an example of a thin film transistor according to a second embodiment of the present invention, having a top gate structure and a top contact type.
Fig. 7 is a schematic diagram showing an example of a thin film transistor according to an embodiment of the present invention, which is a bottom gate structure and has a top contact type.
8 is a schematic diagram showing a Hall element as an example of an electronic device according to an embodiment of the present invention.
9 is a diagram showing an oxygen partial pressure state around a substrate during each step in the method of manufacturing an electronic device according to an embodiment of the present invention.
Fig. 10 is a plot of the specific resistance value of the IGZO laminated film formed by varying the oxygen partial pressure in the vacuum film forming chamber during the non-film formation, and plotting the abscissa with the oxygen partial pressure.
Fig. 11 is a plot of the carrier concentration of the IGZO laminated film formed by changing the oxygen partial pressure in the vacuum deposition chamber during non-film formation, and plotting the abscissa with oxygen partial pressure.
Fig. 12 shows the oxygen in the vacuum film forming chamber during the film formation with respect to the specific resistance of the IGZO laminated film 2 element formed by forming the oxygen partial pressure during the film formation at an oxygen partial pressure of 8.6 × 10 ⁻³ Pa or 2.8 × 10 ⁻² Pa. Drawing plotting partial pressure on the horizontal axis.
FIG. 13 shows the carrier concentration of the IGZO laminated film 2 element formed by forming the oxygen partial pressure at the time of non-forming at an oxygen partial pressure of 8.6 × 10 ^-3 Pa or 2.8 × 10 ^-2 Pa. Plot oxygen partial pressure on the abscissa.
14 is a diagram plotting the specific resistance of the laminated films of Comparative Example 4 and Example 6. FIG.
FIG. 15 is a plot of the carrier concentrations of the laminated films of Comparative Example 4 and Example 6. FIG.

EMBODIMENT OF THE INVENTION Hereinafter, one Embodiment of the manufacturing method of a electronic device of this invention, a thin film transistor, an electro-optical device, and a sensor is demonstrated using drawing. In addition, what has substantially the same function is demonstrated with the same code | symbol throughout the whole figure, and the description may be abbreviate | omitted in some cases.

(1st embodiment)

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the manufacturing procedure of the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention.

Board Preparation

As for the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention, as shown to FIG. 1 (A), the board | substrate 10 is prepared first. Since the board | substrate 10 can perform all the processes mentioned later at low temperature (for example, 200 degrees C or less), the board | substrate with low heat resistance, such as a flexible resin substrate, can also be used, It can select suitably according to a use.

First film formation process

Next, as shown to FIG. 1 (B), the 1st film-forming film which forms the 1st layer 12 containing the oxygen indefinite oxide on the board | substrate 10 in the vacuum film-forming chamber cut | disconnected with air | atmosphere. Carry out the process.

Furthermore, the "vacuum" in the chamber is a vacuum, the vacuum reached inside the deposition chamber is also refers to more than 10 ^-8 ㎩ 10 ^-1 ㎩ or less. In addition, "containing an oxide" means both when all or one part of the structural components which comprise the 1st layer 12 are oxides.

In this 1st film-forming process, it is not limited to forming the 1st layer 12 directly on the board | substrate 10, and also includes the case of forming the 1st layer 12 indirectly on the board | substrate 10. In the case of indirectly forming the first layer 12, for example, a film is formed on the conductor layer, the semiconductor layer, or the insulator layer formed on the substrate 10, or on the laminated structure thereof. have.

The first layer 12 to be formed on the substrate 10 may be any of a conductor, a semiconductor, or an insulator as long as it has oxygen irregularity. In the embodiment, "conductor" refers to the specific resistance value, point to less than 10 ^-2 Ω㎝ material, "semiconductor" is a specific resistance value of 10 ^-2 or more Ω㎝ 10 ⁷ refers to Ω㎝ less material, the insulator is Points to a material whose resistivity is greater than 10 ⁷ Ωcm.

When the first layer 12 is a conductor, Al, Sc, Ti, Mn, Fe, Ga, Y, In, Sn, Ho, Er, Tm, Yb, Lu, Mg, Ca, Ni, Zn, Sr and It is preferable to contain at least 1 type of element chosen from the group which consists of Ba.

When the first layer 12 is a semiconductor, the first layer 12 is Al, Sc, Ti, Mn, Fe, Ga, Y, In, Sn, Ho, Er, Tm, Yb, Lu, Mg, Ca , At least one element selected from the group consisting of Ni, Zn, Sr, and Ba, more preferably at least one element selected from In, Ga, Zn, and Sn, and more preferably, In _x Ga _y More preferably, it contains Zn _z O _δ (x, y, z, δ> 0).

In the case where the first layer 12 is an insulator, InGaZnO _{4 -δ} (δ ≥ 0), SiON, SiO ₂ , Al ₂ O ₃ , Y ₂ O ₃ , MgO, TiO ₂ , GeO ₂ , Ta ₂ O It is preferable to contain ₅ , HfO ₂ , Sc ₂ O ₃ , Ga ₂ O ₃ , ZrO ₂ , Ln ₂ O ₃ (an oxide of lanthanoid), or at least two or more of these compounds. In addition, in these enumerations, materials other than InGaZnO _{4 -δ} (δ> 0) do not have an oxygen deficiency amount (δ), but are completely determined by conventional oxygen content determination methods such as iodine and coulometry. Even if it cannot measure, if it has some oxygen irregularities, it shall be used as an insulator of this embodiment.

In addition, although the 1st layer 12 is effective in the film containing a crystalline phase, an amorphous phase, or a microcrystal, it is preferable that it is amorphous from a film uniformity viewpoint. This is because an amorphous film is easy to form a uniform film over a large area, and it is easy to suppress variations in device characteristics because no grain boundaries such as polycrystals exist. For example, if it is an amorphous film, such as an amorphous IGZO film | membrane, it can form into a film at low temperature (substrate temperature 200 degrees C or less), and it is easy to form as a board | substrate 10 on the flexible resin substrate like a plastic substrate. Therefore, application to a flexible display etc. provided with the resin substrate in which electronic devices, such as a thin film transistor which has the 1st layer 12, were mounted becomes easier.

In addition, whether or not the first layer 12 is amorphous can be confirmed by X-ray diffraction measurement. That is, when the clear peak which shows a crystal structure is not detected by X-ray diffraction measurement, it can be judged that the 1st layer 12 is amorphous.

The film formation of the first layer 12 is used in, for example, a wet method such as a printing method or a coating method, a physical method such as a vacuum deposition method, a sputtering method or an ion plating method, or a chemical method such as CVD or plasma CVD method. The film is formed according to a method selected appropriately considering the aptitude for the material.

Here, the oxygen partial pressure in the vacuum film forming chamber during the first film forming step is not particularly limited, but is, for example, 1.0 × 10 ⁻¹ Pa or less and 1.0 × 10 ⁻⁴ Pa or more.

Second film formation process

Next, as shown to FIG. 1 (C), the 2nd layer which consists of the same material or different material from the said 1st layer 12 on the 1st layer 12 in the vacuum film forming chamber cut | disconnected with air | atmosphere ( 14) A second film forming step of forming a film is carried out.

Similar to the first layer 12, the second layer 14 may be either a conductor, a semiconductor, or an insulator, and may contain a crystalline phase, an amorphous phase, or a microcrystal. However, compared with the 1st layer 12, the 2nd layer 14 does not need to contain the oxide which has oxygen indefiniteness especially.

Although the method similar to the 1st layer 12 is mentioned about the film-forming method of the 2nd layer 14, the oxygen partial pressure in the vacuum film forming chamber in the various conditions in a 2nd film forming process, for example, a 2nd film forming process, It may be the same as or different from the oxygen partial pressure in the vacuum film forming chamber during the first film forming step. Moreover, you may be higher than the oxygen partial pressure used at the partial pressure control process mentioned later.

Here, in the "vacuum film forming chamber" used in the first film forming step and the second film forming step, not only a single vacuum film forming chamber but also a second vacuum film forming chamber connected to the first vacuum film forming chamber and the first vacuum film forming chamber and the transfer chamber. It includes the case which consists of several vacuum film-forming chambers, such as a chamber. Therefore, the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention may perform a 1st film forming process and a 2nd film forming process in a single vacuum film forming chamber, and performs a 1st film forming process and a 2nd film forming process, The separation may be performed in two or more vacuum film forming chambers connected by the transport chamber, which is cut off from the atmosphere.

In the case of forming a film in two or more vacuum film forming chambers connected by a transport chamber blocked from the atmosphere, for example, in the first film forming step, the first layer 12 is formed in the first vacuum film forming chamber. It forms into a film and conveys the board | substrate 10 in which the 1st layer 12 was laminated | stacked to a 2nd vacuum film-forming chamber via a conveyance chamber, and in a 2nd film-forming process, it is on the 1st layer 12 in a 2nd vacuum film-forming chamber. The case where the 2nd layer 14 is formed into a film is mentioned.

When all the film-forming processes are performed in a single vacuum film-forming chamber, the cost accompanying the conveyance process of the board | substrate 10 and the time shortening of a film-forming process can be expected. On the other hand, when film-forming is performed in two or more vacuum film-forming chambers connected by the transfer chamber cut | disconnected with air | atmosphere, mixing of an impurity is carried out only by forming a specific material only in one vacuum film-forming chamber, for example. It can be expected to improve the film properties.

Partial Pressure Control Process

FIG. 2 is a diagram showing an oxygen partial pressure state around the substrate 10 during each step in the method for manufacturing an electronic device according to the first embodiment of the present invention.

As shown in FIG. 2, between the process shown to FIG. 1 (B) and the process shown to FIG. 1 (C), ie, after a 1st film forming process and before a 2nd film forming process, it is the atmosphere containing a vacuum film forming chamber. In a room blocked with, the partial pressure control step of maintaining the first layer 12 under an oxygen partial pressure higher than the oxygen partial pressure in the vacuum deposition chamber in the first film forming step is performed.

In this partial pressure control process, the oxygen in the first layer 12 is 2.1 × 10 ⁻³ Pa or more higher than the oxygen partial pressure in the vacuum film forming chamber in the first film forming step from the first film forming step to the second film forming step. It is preferable to keep it under partial pressure. Moreover, it is preferable that it is 5.9x10 <^-3> Pa or more as an absolute value. This is because the oxygen deficiency at the interface between the first layer 12 and the second layer 14 described later can be reliably reduced.

The term "between the first film forming step and the second film forming step" is preferably between just after the first film forming step and just before the second film forming step, from the viewpoint of reliably reducing oxygen deficiency. At least a part of it before the second film forming step may be performed.

In fact, depending on the type of film forming apparatus used in the first film forming step and the second film forming step, a time for switching to the oxygen partial pressure used in the second film forming step is required immediately before the second film forming step, Even after the film forming step and before the second film forming step, there may be a time (for example, 2 to 5 seconds) at which the oxygen partial pressure equal to the oxygen partial pressure used in the second film forming step is set. In such a case, if the oxygen partial pressure used in the second film forming step is equal to or less than the oxygen partial pressure used in the first film forming step, the value immediately before the second film forming step during the first film forming step and before the second film forming step is used. The period of time is not such that the first layer 12 is kept at an oxygen partial pressure higher than the oxygen partial pressure in the vacuum deposition chamber in the first film forming step, but at least during the second film forming step after the first film forming step. In other periods, the first layer 12 can be maintained under an oxygen partial pressure higher than the oxygen partial pressure in the vacuum film forming chamber in the first film forming step. Of course, when using the film-forming apparatus which does not need the said switching time, as mentioned above, the 1st layer 12 is vacuumed in a 1st film-forming process, just after a 1st film-forming process and just before a 2nd film-forming process. It can also be maintained under oxygen partial pressure higher than the oxygen partial pressure in the deposition chamber.

In FIG. 2, the oxygen partial pressure around the substrate 10 is controlled to increase rapidly from the oxygen partial pressure in the first film forming step to a predetermined oxygen partial pressure immediately after the first film forming step, but may be controlled to increase gradually. . Similarly, although it controls so that the oxygen partial pressure around the board | substrate 10 may raise it rapidly from the predetermined | prescribed oxygen partial pressure which raised said oxygen partial pressure in a 2nd film-forming process, you may control so that it may become low gradually.

Moreover, between the 1st film forming process and the 2nd film forming process, the 1st layer 12 is cut off from the oxygen partial pressure in the vacuum film forming chamber in a 1st film forming process in the room | bed cut off from the atmosphere containing a vacuum film forming chamber. In order to maintain under high oxygen partial pressure, when performing a 1st film forming process and a 2nd film forming process in a single vacuum film forming chamber, the oxygen partial pressure in the vacuum film forming chamber in a 1st film forming process only in the said single vacuum film forming chamber. Controlled by higher oxygen partial pressure. In addition, when performing the 1st film-forming process and the 2nd film-forming process as mentioned above in the 2 or more vacuum film forming chambers connected by the conveyance chamber cut | disconnected with air | atmosphere, it carries out in a 1st vacuum film forming chamber, and conveys. All rooms in the chamber and the second vacuum film forming chamber are controlled to an oxygen partial pressure higher than the oxygen partial pressure in the first vacuum film forming chamber in the first film forming step.

End of film formation

After the second film forming step, the substrate 10 on which the first layer 12 and the second layer 14 are laminated is taken out from the vacuum film forming chamber into the atmosphere. As a result, the electronic device 20 as shown in FIG. 3 can be obtained.

The obtained electronic device 20 includes, for example, a thin film transistor, a tunnel junction element, an electro-optical device, a memory device, and the like.

Of these electronic devices, the electro-optical device refers to a general device equipped with an electro-optical element which emits light by an electrical action or changes the light state from the outside, and emits light by itself and controls passage of light from the outside. It includes. For example, as an electro-optical element, a liquid crystal element, an electrophoretic element having a dispersion medium in which electrophoretic particles are dispersed, an EL (electroluminescence) element, and electrons generated by application of an electric field touch the light emitting plate to emit light The active matrix display device etc. provided with the electron emission element to make it mean.

-effect-

Here, when the substrate 10 is maintained under the same oxygen partial pressure as the first film forming process, for example, after the first film forming process and before the second film forming process, a part of oxygen is removed from the surface of the first layer 12. When it exits and performs a 2nd film-forming process as it is, in and out of oxygen is suppressed from the surface of the 1st layer 12 (interface of the 1st layer 12 and the 2nd layer 14), and a 1st layer ( The oxygen content of the surface of the first layer 12 is almost fixed in a state in which some oxygen is released from the surface of 12), that is, in a state where the amount of oxygen deficiency is large.

On the other hand, according to the manufacturing method of the electronic device 20 of 1st Embodiment of this invention, between the 1st film forming process and the 2nd film forming process, it is made in the room | bed cut off from the atmosphere containing a vacuum film forming chamber, By performing a partial pressure control step of holding the first layer 12 under an oxygen partial pressure higher than the oxygen partial pressure in the vacuum film forming chamber in the first film forming step, the first layer after the first film forming step and before the second film forming step. The escape of a part of oxygen from the surface of (12) is suppressed. After that, since the second layer 14 is formed on the first layer 12 by the second film forming process, the surface of the first layer 12 (the first layer 12 and the second layer 14). Oxygen is hard to escape from the interface), and the oxygen content of the surface of the first layer 12 is almost fixed in a state where the amount of oxygen deficiency is zero or small.

Therefore, the electronic device 20 which reduced the oxygen deficiency as a defect of the interface of the 1st layer 12 and the 2nd layer 14 can be obtained.

And in the case of such a manufacturing method, since the special mechanism and the advanced knowledge are not needed compared with a plasma irradiation process, the electron which reduced the defect of the interface of the 1st layer 12 and the 2nd layer 14 simply The device 20 can be obtained. In addition, since plasma is not directly irradiated to the surface of the first layer 12 as compared with the plasma irradiation treatment, it is possible to suppress the plasma damage on the surface of the first layer 12, and thus the first layer due to plasma damage. The defect of the interface of (12) and the 2nd layer 14 can be reduced.

In addition, compared with the case of annealing the first layer 12, although depending on the material of the first layer or the second layer, for example, amorphous IGZO or the like is used for the first layer 12 and the second layer 14. In the case of a material of, the whole process of the manufacturing method can be performed at a low temperature (for example, a process temperature of 200 ° C or less). Therefore, as the board | substrate 10, the board | substrate with low heat resistance, such as a flexible resin substrate, can also be used, and a wide range of board | substrates can be selected suitably according to a use.

Other processes

In the manufacturing method of the electronic device 20 which concerns on 1st Embodiment of this invention, various processes other than the above process can be added suitably.

For example, before the first film forming step, a film forming step of forming a third layer (not shown) containing an oxygen non-oxidizing oxide on the substrate 10 in the vacuum film forming chamber may be added, in which case In the first film forming step, the first layer 12 is formed on the substrate 10 via the third layer, and the third layer is formed after the film forming step of the third layer and before the first film forming step. It maintains under oxygen partial pressure higher than the oxygen partial pressure in the vacuum film-forming chamber in the film-forming process of a 3rd layer.

Similarly, after the second film forming step, a film forming step of forming a fourth layer (not shown) on the second layer 14 in the vacuum film forming chamber can be added. And when the 2nd layer 14 contains the oxygen non-amorphous oxide, the 2nd layer 14 is made into the film after the film forming process of the 2nd layer 14, and until the film forming process of a 4th layer. It maintains under oxygen partial pressure higher than the oxygen partial pressure in the vacuum film-forming chamber in the film-forming process of the two-layer 14.

Thus, in the electronic device which consists of a several layer structure of three or more layers, when laminating | stacking a predetermined | prescribed layer on the layer of the oxide having an oxygen irregularity, the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention. Can be applied.

Here, in the electronic device which consists of several layer structure including the electronic device 20 shown in FIG. 3, when the uppermost layer of a layer structure contains oxide with oxygen indefiniteness, when an electronic device is taken out in air | atmosphere, The oxygen partial pressure in the atmosphere is very high compared to the oxygen partial pressure in the vacuum deposition chamber at about 2.0 × 10 ⁴ ,, and since the uppermost layer is exposed to the atmosphere, oxygen enters the uppermost layer and the oxygen deficiency of the uppermost layer can be compensated. The partial pressure control process as described above is not necessary.

However, even if the board | substrate 10 is once taken out in air | atmosphere between the 1st film-forming process and the 2nd film-forming process, the partial pressure control process as mentioned above is required. Because, even if the surface of the first layer 12 formed on the substrate 10 is taken out in the atmosphere to compensate for the oxygen deficiency, when the substrate 10 is placed in the vacuum deposition chamber again, the oxygen partial pressure is lowered. This is because oxygen is released from the surface of the first layer 12. Thus, the term "between the first film forming step and the second film forming step" in the above-described partial pressure control step includes the case where the substrate 10 is once taken out of the atmosphere between the first film forming step and the second film forming step. I shall do it.

In addition, although the case where it is effective about the oxide which has an oxygen deficiency was demonstrated in this 1st Embodiment, it is also effective also about the oxide which has excess oxygen.

In addition, a 1st film forming process and a 2nd film forming process can be formed into a film by the following sputter apparatuses.

4 is a diagram illustrating a partial schematic cross-sectional view of a sputter apparatus.

As shown in FIG. 4, the sputtering apparatus 100 includes a substrate holder such as an electrostatic chuck having a heater 102A therein which can hold the substrate 10 and heat the substrate 10 to a predetermined temperature. 102, the shutter 106 which allows free entry and exit between the plasma electrode (cathode electrode) 104 which generates a plasma, the plasma electrode 104 which is a substrate holder 102 and a target holder, and the vacuum film containing them The chamber 108 is schematically configured. In addition, this plasma electrode 104 is corresponded to the target holder holding target T. FIG.

The power supply 110 for controlling the electric potential of the board | substrate 10 is connected to the board | substrate 10. FIG.

In addition, the substrate holder 102 and the plasma electrode 104 are disposed to face each other, and the target T having a composition corresponding to the composition of the film to be formed on the plasma electrode 104 is mounted. The plasma electrode 104 is connected to the high frequency power supply 112.

In addition, the plasma electrode 104 and the high frequency power supply 112 are called a plasma generation part. In FIG. 4, the substrate holder 102 and the plasma electrode 104 face each other, that is, the surface of the substrate holder 102 and the surface of the plasma electrode 104 face each other in parallel, but the surface of the substrate holder 102. The surfaces of the plasma electrode 104 may not face each other and may face each other at a predetermined angle.

In the vacuum film forming chamber 108, a gas introduction pipe 114 for introducing a gas (film forming gas) G necessary for film formation into the vacuum film forming chamber 108, and the exhaust V of the gas in the vacuum film forming chamber 108. The gas discharge pipe 116 which performs the process is attached. As the gas G, an Ar / O ₂ mixed gas or the like is used. In addition, the vacuum film forming chamber 108 is grounded.

On the bottom surface 108A of the vacuum deposition chamber 108, an earth shield, that is, a ground member 118, which is formed so as to surround the plasma electrode 104 is formed. This grounding member 118 is for preventing the vacuum deposition chamber 108 from discharging from the plasma electrode 104 toward the side or the lower side.

At the time of film formation, in a state where the shutter 106 is retracted from the target, a high frequency AC voltage is applied to the plasma electrode 104 by the high frequency power supply 112, and the vacuum deposition chamber 108 and the plasma electrode 104 are applied. Each of these acts as an anode and a cathode to generate a discharge therebetween, and the gas G introduced into the vacuum deposition chamber 108 is converted into plasma to generate positive ions Ip such as Ar ions. The generated positive ions Ip sputter the target T. The constituent elements Tp of the target T sputtered on the positive ions Ip are released from the target and deposited on the substrate 10 in a neutral or ionized state. By carrying out this deposition for a predetermined time, a film of a predetermined thickness is formed. In the figure, reference numeral P denotes a plasma space (the space above the shutter 106 is also a plasma space because the shutter 106 is retracted during film formation).

And when using the above-mentioned sputtering apparatus 100 and performing the above-mentioned 1st film forming process and 2nd film forming process in the same vacuum film forming chamber 108, before a 2nd film forming process after a 1st film forming process. In addition to performing the partial pressure control step, the shutter 106 is moved and the shutter 106 is disposed between the target holder and the substrate 10 in the vacuum film forming chamber 108.

By adding such a process to the manufacturing method of the electronic device 20 which concerns on 1st Embodiment of this invention, plasma P generate | occur | produces in the space on a target holder after a 1st film formation process and before a 2nd film formation process. Even if it is, the plasma P toward the substrate 10 side is blocked by the shutter 106, so that plasma damage is caused to the surface of the first layer 12 laminated on the substrate 10 above the shutter 106. Can prevent coating. In addition, the sputtering apparatus 100 used for film-forming can set the electric potential of a plasma to 0V by inserting the shutter 106, and plasma damage is prevented also from an acceleration potential viewpoint.

As a result, the defect of the interface of the 1st layer 12 and the 2nd layer 14 by plasma damage can be reduced more.

In addition, although the case where one shutter 106 was arrange | positioned between the target holder and the board | substrate 10 was demonstrated, when there exists a shutter for cathode and the board | substrate 10 separately, it is possible to reliably prevent plasma damage. From the viewpoint, it is preferable to arrange both of them between the target holder and the substrate 10.

(2nd embodiment)

Next, in 2nd Embodiment, the thin film transistor is taken as an example as the electronic device 20 shown in FIG. 3, and the electronic device 20 is demonstrated more concretely.

The thin film transistor according to the second embodiment of the present invention has at least a gate electrode, a gate insulating layer, an active layer, a source electrode and a drain electrode, applies a voltage to the gate electrode to control a current flowing in the active layer, and the source electrode An active element having a function of switching a current between a drain electrode and a drain electrode.

The device structure of the thin film transistor may be any of so-called reverse stagger structure (also called bottom gate type) and stagger structure (also called top gate type) based on the position of the gate electrode. Moreover, any aspect of what is called a top contact type and a bottom contact type may be sufficient, based on the contact part of an active layer, a source electrode, and a drain electrode (it is called "a source drain electrode" suitably).

In addition, the top gate type is a form in which a gate electrode is disposed above the gate insulating layer, and an active layer is formed below the gate insulating layer. In the bottom gate type, a gate electrode is disposed below the gate insulating layer, and the gate insulation is formed. The active layer is formed on the upper side of the layer. The bottom contact type is a form in which a source / drain electrode is formed before the active layer and the lower surface of the active layer is in contact with the source / drain electrode. The top contact type is an active layer is formed before the source / drain electrode. It is the form which contacts source / drain electrode.

5 is a schematic diagram showing an example of a thin film transistor according to the second embodiment of the present invention, which has a top gate structure and a bottom contact type. The thin film transistor 200 is provided with a source electrode 204 and a drain electrode 206 spaced apart from each other on a substrate 10, and furthermore, an active layer 208 is stacked thereon, and a gate is formed on the active layer 208. It is the structure which laminated | stacked the insulating layer 210 and the gate electrode 212 in order.

6 is a schematic diagram showing an example of a thin film transistor having a top gate structure and a top contact type as the thin film transistor according to the second embodiment of the present invention. In the thin film transistor 300, the active layer 302 is laminated on the surface of the substrate 10, and the source electrode 304 and the drain electrode 306 are provided on the active layer 302 so as to be spaced apart from each other. The gate insulating layer 308 and the gate electrode 310 are laminated | stacked in order.

7 is a schematic diagram showing an example of a thin film transistor having a bottom gate structure and a top contact type as the thin film transistor according to the embodiment of the present invention. The thin film transistor 400 has the gate electrode 402, the gate insulating layer 404, and the active layer 406 stacked on the substrate 10 in order, and has a source electrode (on the surface of the active layer 406). The configuration 408 and the drain electrode 410 are spaced apart from each other.

The thin film transistor according to the second embodiment of the present invention may have various configurations in addition to the above, and may be configured to include a protective layer on an active layer, an insulating layer on a substrate, or the like as appropriate.

Next, the thin film transistor 200 which is a top gate structure and a bottom contact type as shown in FIG. 5 is demonstrated about the thin film transistor which concerns on embodiment of this invention as an example.

Board Preparation

First, the substrate 10 for forming the thin film transistor 200 is prepared.

There is no restriction | limiting in particular about the shape, structure, size, etc. of the board | substrate 10, According to the objective, it can select suitably. The structure of the board | substrate 10 may be a single layer structure, or a laminated structure may be sufficient as it.

The material of the board | substrate 10 does not have a restriction | limiting in particular, For example, Inorganic substrates, such as YSZ (yttrium stabilized zirconium), glass, and a board | substrate which has flexibility, A saturated polyester / polyethylene terephthalate (PET) type resin substrate, Polyethylene naphthalate (PEN) resin substrate, crosslinked fumaric acid diester resin substrate, polycarbonate (PC) resin substrate, polyether sulfone (PES) resin substrate, polysulfone (PSF, PSU) resin substrate, polyarylate (PAR ) Resin substrate, cyclic polyolefin (COP, COC) resin substrate, cellulose resin substrate, polyimide (PI) resin substrate, polyamideimide (PAI) resin substrate, maleimide-olefin resin substrate, polyamide (PA) resin Substrate, acrylic resin substrate, fluorine resin substrate, epoxy resin substrate, silicone resin film substrate, polybenzazole resin substrate, substrate by episulfide compound, liquid crystal pole Composite with nanoparticles such as a mercury (LCP) substrate, a cyanate resin substrate, an aromatic ether resin substrate, a substrate made of a composite plastic material with silicon oxide particles, metal nanoparticles, inorganic oxide nanoparticles, and inorganic nitride nanoparticles With a substrate made of a plastic material, a substrate made of a composite plastic material with metal- and non-machined nanofibers and a microfiber, a substrate made of a composite plastic material with carbon fibers and carbon nanotubes, with glass ferlake, glass fiber, and glass beads A substrate made of a composite plastic material, a substrate made of a composite plastic material with clay minerals or particles having a mica derived crystal structure, a substrate made of a laminated plastic material having at least one bonding interface between thin glass and the single organic material, Inorganic layers (eg SiO ₂ , Al ₂ O ₃ , SiO _x N _y ) and an organic layer are laminated alternately to form a substrate made of a composite material having a barrier performance having at least one bonding interface, a stainless steel substrate, a metal multilayer substrate laminated with stainless steel and dissimilar metals, and an aluminum substrate. By performing an oxidation treatment (for example, an anodic oxidation treatment) on the surface, an aluminum substrate having a predetermined oxide coating and the like having improved surface insulation can be mentioned.

Moreover, it is preferable that the thickness of the board | substrate in this invention is 50 micrometers or more and 500 micrometers or less. If the thickness of the substrate is 50 µm or more, the flatness of the substrate itself is further improved. Moreover, if the thickness of a board | substrate is 500 micrometers or less, the flexibility of the board | substrate itself will improve more, and it will become easier to use as a board | substrate for flexible displays.

Formation of Source and Drain Electrodes

Next, source and drain electrodes 204 and 206 are formed on the substrate 10.

Specifically, the conductive film serving as the source / drain electrodes 204 and 206 may be, for example, a wet method such as a printing method or a coating method, a physical method such as a vacuum deposition method, a sputtering method, an ion plating method, or a CVD or plasma CVD method. It forms in accordance with the method selected suitably in consideration of aptitude with the material used in chemical methods, such as these. The film thickness of the conductive film is preferably 10 nm or more and 1000 nm or less, more preferably 50 nm or more and 100 nm or less, in consideration of film forming properties, patterning property by etching or lift-off method, and conductivity. Subsequently, the conductive film is patterned into a predetermined shape by an etching or lift-off method to form source electrodes and drain electrodes 204 and 206. At this time, it is preferable to simultaneously pattern the source and drain electrodes 204 and 206 and the wirings connected to these electrodes 204 and 206.

As the source and drain electrodes 204 and 206, those having high conductivity are used. For example, metals such as Al, Mo, Cr, Ta, Ti, Au, Au, Al-Nd, APC (Ag alloy manufactured by Furuya Metal Co., Ltd.), tin oxide, zinc oxide, indium oxide, indium tin oxide ( Metal oxide conductive films such as ITO) and zinc indium oxide (IZO). As the source and drain electrodes 204 and 206, these conductive films can be used as a single layer structure or a laminated structure of two or more layers.

Formation of Active Layer (First Film Formation Process)

Next, the active layer 208 as the first layer 12 containing an oxide having an oxygen indefinite ratio on the substrate 10 and on the source / drain electrodes 204 and 206 in a vacuum deposition chamber blocked from the atmosphere. ).

Specifically, first, a first film forming step of forming an oxide semiconductor film to be the active layer 208 is performed. In the first film forming step, for example, a wet method such as a printing method or a coating method, a physical method such as a vacuum deposition method, a sputtering method or an ion plating method, or a chemical method such as CVD or plasma CVD method, etc. The film is formed according to the method selected appropriately considering the aptitude. Subsequently, the oxide semiconductor film is patterned into a predetermined shape by an etching or lift-off method to form an active layer 208.

As for the thickness of the active layer 208, about 5 nm or more and about 200 nm or less are preferable. This is because a good film of uniformity may not be obtained at 5 nm or less.

As the constituent material of the active layer 208, the material in the case where the above-described first layer 12 is a semiconductor can be appropriately selected.

Partial Pressure Control Process

Next, after the first film forming step and before the second film forming step of forming the gate insulating layer 210 as the second layer 14 to be described later, the room is separated from the atmosphere including the vacuum film forming chamber. The partial pressure control step of holding the active layer 208 as the first layer 12 under an oxygen partial pressure higher than the oxygen partial pressure in the vacuum deposition chamber in the first film forming step is performed.

In addition, it is preferable that this partial pressure control process is performed also during the patterning of the oxide semiconductor film mentioned above.

Formation of the gate insulating layer (second film forming step)

Next, on the active layer 208, the gate insulating layer 210 as the second layer 14 is formed.

Specifically, first, a second film forming step of forming an insulating film to be the gate insulating layer 210 is performed. In this second film forming step, the aptitude with the material used in a wet method such as a printing method, a coating method, a physical method such as a vacuum deposition method, a sputtering method, an ion plating method, or a chemical method such as CVD or plasma CVD method is considered. The film formation is carried out according to the appropriately selected method. The insulating film thus formed is patterned into a predetermined shape by photolithography and etching to form a gate insulating layer 210.

In addition, the gate insulating layer 210 needs to have a thickness for lowering the leakage current and improving the voltage resistance, while an excessively large thickness of the gate insulating layer 210 causes an increase in the driving voltage. Although the thickness of the gate insulating layer 210 may differ depending on a material, 10 nm or more and 10 micrometers or less are preferable, 50 nm or more and 1000 nm or less are more preferable, 100 nm or more and 400 nm or less are especially preferable. In addition, as the gate insulating layer 210, the film formed into a film can be used as a single layer structure or a laminated structure of two or more layers.

It is preferable that the gate insulating layer 210 has high insulation. For example SiN _x , InGaZnO _{4 -δ} (δ ≥ 0), SiON, SiO ₂ , Al ₂ O ₃ , Y ₂ O ₃ , MgO, TiO ₂ , GeO ₂ , Ta ₂ O ₅ , HfO ₂ , Sc ₂ O _{3, Ga 2 O 3, ZrO} 2, may be an insulating film or a compound thereof, such as Ln ₂ O ₃ (the oxide of a lanthanoid), at least an insulating film containing two or more.

Formation of Gate Electrode

Next, the gate electrode 212 is formed on the gate insulating layer 210.

 Specifically, the conductive film serving as the gate electrode 212 may be, for example, a wet method such as a printing method or a coating method, a physical method such as a vacuum deposition method, a sputtering method, an ion plating method, or a chemical method such as CVD or plasma CVD method. It forms in accordance with the method selected suitably in consideration of aptitude with the material used in etc. The film thickness of the conductive film is preferably 10 nm or more and 1000 nm or less, more preferably 50 nm or more and 200 nm or less, in consideration of film formability, patterning property by etching or lift-off method, and conductivity. After the film formation, the gate electrode 212 is formed by patterning a predetermined shape by etching or lift-off method. At this time, it is preferable to simultaneously pattern the gate electrode 212 and the gate wiring.

It is preferable that the gate electrode 212 has high conductivity. For example, metals such as Al, Mo, Cr, Ta, Ti, Au, Al-Nd, APC (Ag alloy manufactured by Furuya Metal Co., Ltd.), tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO) And metal oxide conductive films such as indium zinc oxide (IZO). As the gate electrode 212, these conductive films can also be used as a single layer structure or a laminated structure of two or more layers.

-effect-

Here, in the case where the first layer 12 is an active layer 208 made of an oxide semiconductor, in addition to those shown in the above [Background Art] column (the occurrence of a threshold shift), oxygen vacancies in the first layer 12 are caused by the oxygen deficiency of the first layer 12. It is known that the specific resistance, carrier concentration, and carrier mobility are greatly changed (A. Takagi, et al., Thin Solid Films, 486 (2005) 38, H. Hosono, J. Non-cryst Solid, 352 (2006) 851 Reference). This is because the carriers generated by the oxygen defect dominate the conduction mechanism of the oxide.

Therefore, when forming the oxide semiconductor film which becomes the active layer 208 generally, the method of controlling the electrical conduction characteristic of an oxide semiconductor film is controlled by controlling the oxygen partial pressure at the time of film-forming, and controlling the oxygen deficiency in a film | membrane. However, the method of controlling the oxygen partial pressure in the vacuum film formation chamber after oxide semiconductor film film-forming has not been examined until now.

In the method for manufacturing an electronic device according to the second embodiment of the present invention, an oxide semiconductor film is formed in a vacuum film formation chamber, and then oxygen deficiency on the surface of the oxide semiconductor film is controlled by controlling the oxygen partial pressure in the vacuum film formation chamber. As a technique for controlling, the resistivity and carrier concentration of the oxide semiconductor film can be controlled accordingly.

Specifically, the active layer 208 as the first layer 12 in the room separated from the atmosphere including the vacuum film forming chamber after the first film forming step and the second film forming step is subjected to the first film forming step. By performing the partial pressure control step of maintaining the oxygen partial pressure higher than the oxygen partial pressure in the vacuum film formation chamber, the increase in oxygen vacancies on the surface of the active layer 208 can be suppressed. In addition, it is possible to suppress generation of excess carriers generated on the surface of the active layer 208. After the partial pressure control process, when an insulating film serving as the gate insulating layer 210 is formed, a laminated film in which the increase in oxygen vacancies on the surface of the active layer 208 is reduced (oxygen content is fixed) is obtained. Since the increase in the defect level of the interface of the active layer 208 and the gate insulating layer 210 is suppressed in the thin film transistor 200 provided with the laminated film produced in this way, device deterioration, such as a threshold value shift, is very small. Moreover, since generation | occurrence | production of the excess carrier from the surface of the active layer 208 is suppressed, it becomes easy to manufacture a normally off thin film transistor. The normally off thin film transistor refers to a switching element that is turned off when the gate voltage applied to the sample is 0 V, and has a lower power consumption than the normally on transistor, and the demand is higher.

Modification Example of Thin Film Transistor

The manufacturing method of the electronic device which concerns on 2nd Embodiment of this invention is a thin film transistor (refer Japanese Unexamined-Japanese-Patent No. 2007-73701) which has an active layer which consists of lamination of several oxide semiconductor film which has a different electrical characteristic. It is also effective in forming a laminated film. In this case, both the first layer 12 and the second layer 14 become oxide semiconductor films.

Specifically, a first film forming step of forming an oxide semiconductor film on a substrate in a vacuum film forming chamber is performed, and the oxygen partial pressure in the vacuum film forming chamber after the first film forming step is higher than that of the oxide semiconductor film. After that (the active layer 208 as the first layer 12 is kept under an oxygen partial pressure higher than the oxygen partial pressure in the vacuum film forming chamber in the first film forming step), and an oxide semiconductor film showing different electrical properties is formed again. Oxygen deficiency at the interface of an oxide semiconductor film and an oxide semiconductor film can be reduced. The thin film transistor having the laminated film of the oxide semiconductor film in the active layer is critical compared with the thin film transistor having the laminated film of the oxide semiconductor film formed in the active layer sequentially without using the electronic device manufacturing method according to the second embodiment of the present invention. The generation of device deterioration factors such as value shift and excess carriers is reduced, and stability is increased.

Moreover, the manufacturing method of the electronic device which concerns on 2nd Embodiment of this invention is effective also about film-forming of an oxide insulator film. For example, in the thin film transistor 400 of the bottom gate structure as shown in FIG. 7, the gate insulating layer 404 and the active layer which consist of an oxide insulator film on the structure which has the gate electrode 402 on the board | substrate 10 are shown. 406 may be formed sequentially. In such a configuration, it is known that the oxygen characteristic of the oxide insulator film constituting the gate insulating layer 404 is increased, so that the insulating characteristic is changed by the oxygen deficiency, such as an increase in the gate leakage current (K. Shiraishi). , et al., Thin Solid Films 508 (2006) 305-310).

Therefore, after performing the 1st film-forming process which forms the oxide insulator film used as the gate insulating layer 404 as the 1st layer 12 on the structure which is the manufacturing method of the electronic device which concerns on 2nd Embodiment of this invention. 1st film-forming in the room | bed cut off the gate insulating layer 404 from the atmosphere containing a vacuum film-forming chamber, until the 2nd film-forming process of forming the semiconductor film used as the active layer 406 as the 2nd layer 14. By performing the partial pressure control step of maintaining the oxygen partial pressure higher than the oxygen partial pressure in the vacuum film forming chamber in the step, oxygen vacancies on the surface of the gate insulating layer 404 can be reduced, and the semiconductor constituting the active layer 406 thereafter. By forming a film, the defect level at the interface between the gate insulating layer 404 and the active layer 406 can be reduced, whereby a thin film transistor having high insulation resistance and showing good stability can be provided. It is possible.

Further, the gate insulating layer 404 formed of such an oxide insulator film may be formed of InGaZnO _4-δ (δ ≥ 0), SiON, SiO ₂ , Al ₂ O ₃ , Y ₂ O ₃ , MgO, TiO ₂ , GeO ₂ , An insulating film such as Ta ₂ O ₅ , HfO ₂ , Sc ₂ O ₃ , Ga ₂ O ₃ , ZrO ₂ , Ln ₂ O ₃ (an oxide of lanthanoid), or an insulating film containing at least two of these compounds may be used. In this case, the active layer 406 need not be an oxide, for example, a group IV semiconductor such as amorphous silicon, low temperature polycrystalline silicon, a compound semiconductor such as GaAs, GaN, InP, SiC, or carbon such as diamond. Semiconductor materials, such as an organic semiconductor, such as a type | system | group semiconductor, a metal oxide semiconductor, or pentacene, can be used.

Moreover, the electronic device which concerns on 2nd Embodiment of this invention is a top contact type thin film transistor 300 as shown in FIG. 6, and makes the active layer 302 the 1st layer 12, and uses the gate insulating layer ( In the case where the source / drain electrodes 304 and 306 are formed on the active layer 302 before the formation of the 308, the period between the formation of the active layer 302 and the formation of the source / drain electrodes 304 and 306 is performed. In addition, a part of the active layer 302 is exposed even after the source / drain electrodes 304 and 306 are formed and before the gate insulating layer 308 is formed. Therefore, in such a case, it is preferable to perform the above-mentioned partial pressure control process in each non-film formation (time of film formation interruption). The same applies to the case of the top contact thin film transistor 300 of FIG. However, even in the case of the top contact thin film transistor, the gate insulating layer 308 is first formed on the active layer 302, and then the source and drain electrodes 304 and 306 are formed through the contact holes. This is not the case (only one partial pressure control process may be required).

In addition, although the case where the electronic device which concerns on the 2nd Embodiment of this invention was demonstrated with a thin film transistor, the manufacturing method of the electronic device which concerns on 2nd Embodiment of this invention consists of an oxide insulator layer and an electrode layer including a tunnel junction element. It is also effective for electronic devices. This is because by using the manufacturing method of the electronic device according to the second embodiment of the present invention, an improvement in the magnetoresistance ratio, a decrease in the leakage current, and a reduction of the noise accompanying it can be expected.

Example

EMBODIMENT OF THE INVENTION Below, although the Example demonstrates the manufacturing method of a electronic device, a thin film transistor, an electro-optical device, and a sensor concerning this invention, this invention is not limited at all by these Examples.

Fig. 8A is a schematic diagram showing a hall element as an example of the electronic device according to the embodiment of the present invention. FIG. 8B is a schematic diagram illustrating a comparative example of the hall elements of FIG. 8A.

As shown in FIG. 8 (A), in the present embodiment, on the substrate 502 in a single vacuum deposition chamber using the above-described manufacturing method of the electronic device, under the film forming conditions as shown in Table 1 below. The first layer 504, the second layer 506, and the third layer 508 (the laminated film 510 of the composite oxide semiconductor (IGZO)) composed of In, Ga, Zn, and O are sequentially formed, and these laminated layers are formed. Six Hall elements 500 were fabricated in which a four-terminal electrode was bonded to the film 510 by evaporation for the evaluation of electrical characteristics. As the substrate 502, a synthetic quartz glass substrate (manufactured by Cobalt Material, Inc., part number T-4040) was used.

9 is a diagram showing an oxygen partial pressure around the substrate 502 during each step in the method of manufacturing an electronic device according to the embodiment of the present invention.

As shown in FIG. 9, in forming these IGZO laminated films 510, these six Hall elements 500 are formed from the film forming process of the first layer 504 to the film forming process of the second layer 506. The oxygen partial pressure in the vacuum film forming chamber for 1 minute between the film forming process of the second layer 506 and the film forming process of the second layer 506 is set to the following 1.0 × 10 ⁻⁷ Pa to 2.8 × 10 ^−2. It controls by the predetermined | prescribed oxygen partial pressure between kPa, and is producing as an element of Examples 1-3 or Comparative Examples 1-3, respectively.

In Table 2, in the non-film formation in the element of each Example and a comparative example (during the film forming process of the 1st layer 504 after the film forming process of the 2nd layer 506, and of the 2nd layer 506), The value of the controlled oxygen partial pressure of the 3rd layer 508 to the film forming process after the film forming process is shown. Moreover, in Table 2, the contrast column of the oxygen partial pressure at the time of this film-forming and the oxygen partial pressure at the time of film-forming of the 1st layer 504 and the 2nd layer 506 was also created.

In addition, as a comparison, as shown in FIG. 8 (B), the first layer 504, the second layer 506, and the third layer 508 without using partial pressure control at the time of non-film formation as described above. The IGZO single layer 602 was formed into a film 70 nm on the board | substrate 502 on the conditions exactly the same as that of the, and the hall element 600 was produced. What is different is that film formation was performed continuously without stopping film formation.

And the specific resistance, carrier concentration, and hole mobility were evaluated about each hall element 500 and 600 by the van der Pauw method using the hall measuring apparatus (made by Toyo Technica).

FIG. 10 is a plot of the specific resistance value of the IGZO laminated film 510 formed by varying the oxygen partial pressure in the vacuum deposition chamber during non-film formation, taking the horizontal axis as the oxygen partial pressure. In addition, the specific resistance value of the IGZO single layer 602 was about 1.3 × 10 Ω · cm.

In Comparative Examples 1, 2, and 3 in which the partial pressure of oxygen was 4.4 × 10 ⁻³ Pa or less, it can be seen that the specific resistance is reduced by one or more orders of magnitude compared with the IGZO single membrane 602. From this result, it became clear that oxygen vacancies at the interface of the IGZO film were changed by the partial pressure of oxygen at the time of film formation interruption (non-film formation) when film formation was performed by introducing film formation interruption. In particular, even when the partial pressure of oxygen at the time of film formation is the same as the partial pressure of oxygen at the time of film formation, low resistance occurs, and when the oxygen partial pressure at the time of film formation is not controlled at all (when the oxygen partial pressure at the time of film formation is maintained as it is). ) Means that the resistance of the film is reduced and the desired electrical characteristics cannot be obtained.

On the other hand, Examples 1, 2, and 3 in which the partial pressure of oxygen in the vacuum film formation chamber at the time of stopping film formation were more than 4.4 × 10 ⁻³ Pa, showed a specific resistance equivalent to that of the IGZO single layer 602. From this, it became clear that the increase in the oxygen deficiency on the surface of the IGZO film occurring at the time of stopping film formation can be suppressed by raising the oxygen partial pressure at the time of stopping the film formation than at the time of film formation.

In addition, since the specific resistance value of the IGZO single layer 602 is about 1.3 × 10 Ω · cm, the specific resistance value of the IGZO laminated film 510 is closer to the specific resistance value of the IGZO single layer 602. For example, it is preferable to exist in the range of 1.3 ohm * cm or more and 1.3 * 10 <^3> ohm * cm or less (error bars in drawing), and the oxygen partial pressure corresponding to the lower limit of this specific resistance value is somewhat more than 4.4 * 10 <^-3> Pa. High 4.7 × 10 ^{-3 3} (○ in the figure). From the standpoint of certainty, the oxygen partial pressure at the time of film formation is lower than 2.1 × 10 ⁻³ Pa or more by subtracting the oxygen partial pressure 4.4 × 10 ⁻³ Pa at the time of film formation from the oxygen partial pressure at the time of film formation, and the oxygen partial pressure at the time of non-film formation is made higher than that at the time of film formation. It is preferable.

11 plots the horizontal axis as the oxygen partial pressure with respect to the carrier concentration of the IGZO laminated film 510 formed by changing the oxygen partial pressure in the vacuum film formation chamber during non-film formation. The carrier concentration of IGZO alone film 602 is about 4.2 × 10 ¹⁶ ㎝ ^- and ^3.

By setting the oxygen partial pressure in the vacuum film formation chamber at the time of non-film formation to be more than 4.4 x 10 &lt; ^-3 &gt; Pa, it is understood that the carrier concentration is almost constant (Examples 1, 2 and 3). The carrier concentration in this oxygen partial pressure area | region exceeding 4.4x10 <^-3> Pa is almost the same value as the carrier concentration of the IGZO single film 602 obtained by continuous film-forming. Therefore, this is because the oxygen partial pressure at the time of non-film formation is higher than that at the time of film formation, so that the oxygen deficiency at the interface of the IGZO film is about the same as that in the film of the IGZO monolayer 602, thereby suppressing the occurrence of excess carriers due to the increase in oxygen deficiency. It means.

Next, as Examples 4 and 5, only the oxygen partial pressure at the time of film formation was changed from 4.4x10 <^-3> Pa to 2.2x10 <^-3> Pa, and the oxygen partial pressure in the vacuum film forming chamber at the time of non-film formation was 8.6x. ㎩ 10 ^-3 or 2.8 × 10 ^-2 ㎩ the IGZO film laminated to a oxygen partial pressure (the first layer, second layer, third layer) was produced in the two Hall elements with the substrate. For comparison, 70 nm of an IGZO single film was formed on the same substrate with the same composition and film formation conditions as those of the first, second and third layers. Example 4, alone IGZO film resistivity to be compared with approximately 5 2.9 × 10 ^-2 Ω · ㎝, the carrier concentration is from about 1.2 × 10 ¹⁹ ㎝ ^- and ^3.

Fig. 12 shows the oxygen in the vacuum film forming chamber during the film formation with respect to the specific resistance of the IGZO laminated film 2 element formed by forming the oxygen partial pressure during the film formation at an oxygen partial pressure of 8.6 × 10 ⁻³ Pa or 2.8 × 10 ⁻² Pa. The partial pressure is plotted on the horizontal axis. FIG. 13 shows the carrier concentration of two IGZO laminated film elements formed by forming an oxygen partial pressure at the time of non-forming at an oxygen partial pressure of 8.6 × 10 ^-3 Pa or 2.8 × 10 ^-2 Pa. Oxygen partial pressure is plotted on the abscissa.

According to FIG. 12, it turns out that the specific resistance value of a laminated film is substantially the same as the specific resistance value of a single film by making oxygen partial pressure in the vacuum film forming chamber at the time of a non-film formation higher than at the time of film-forming. 13, it turns out that the carrier concentration of a laminated film is substantially equal to the carrier concentration of a single film | membrane by making oxygen partial pressure in the vacuum film forming chamber at the time of non-film formation higher than the film formation time. This fact means that by increasing the oxygen partial pressure in the vacuum deposition chamber during non-forming, the oxygen vacancies at the interface of the IGZO film become about the same as those in the IGZO single film, thereby suppressing the occurrence of excess carriers. In addition, it has shown that the oxygen deficiency control method by controlling the oxygen partial pressure at the time of non-forming film is a universal control technique also possible in the laminated film of the oxide semiconductor formed into a film by different film forming conditions.

Next, using the manufacturing method of the above-mentioned electronic device, two Hall elements with the IGZO laminated film which modulated the composition of each layer and the oxygen partial pressure at the time of film-forming as shown in Table 3 below were produced. Of the two, one is the Hall element of Comparative Example 4 in which the oxygen partial pressure in each layer film formation and the oxygen partial pressure after each layer film forming step (non-film formation) are the same with respect to the laminated film subjected to such composition and oxygen modulation, The other is the hall element of Example 6 which raised the oxygen partial pressure after each layer film-forming process to 2.8x10 <^-2> Pa rather than the oxygen partial pressure in each layer film-forming. In addition, a board | substrate and an evaluation method are the same as that of the Example and the comparative example mentioned above. The film composition and the oxygen partial pressure in the film formation are completely the same in both Comparative Examples 4 and 6. In Table 4, oxygen partial pressures at the time of film-forming and non-film-forming of Comparative Example 4 and Example 6 are shown.

14 is a diagram plotting the specific resistance of the laminated films of Comparative Example 4 and Example 6. FIG. 15 is a figure which plotted the carrier density | concentration of the laminated | multilayer film of Comparative Example 4 and Example 6. FIG.

As shown in FIG. 14, with respect to the comparative example 4, it turns out that the specific resistance value of Example 6 is a little higher by 1 digit. Moreover, as shown in FIG. 15, with respect to the comparative example 4, it turns out that the carrier density | concentration of Example 6 is a little lower by 1 digit. These results show that even in a laminated film that modulates the film composition and the oxygen partial pressure at the time of film formation by increasing the oxygen partial pressure at the time of non-film formation, the reduction in resistance due to the increase in oxygen deficiency at each IGZO film interface is suppressed, and the excess carrier It means to suppress the occurrence of.

Moreover, when the specific resistance value of only the 3rd layer of Example 6 was measured, it confirmed that it was 1.4 * 10 <^7> ohm * cm. As a result, in consideration of the specific resistance value of FIG. 14, the IGZO laminated film according to Example 6 has a layer of insulator on the layer of the semiconductor. It turned out that the excess carrier generation of a layer can be suppressed.

10: substrate
12: first layer
14: second layer
20: electronic device
100: sputter device
102: Board Holder
104: plasma electrode (target holder)
106: shutter
108: vacuum deposition chamber
200: thin film transistor
208: active layer (first layer)
210: gate insulating layer (second layer)
300: thin film transistor
302: active layer (first layer)
308: gate insulating layer (second layer)
400: thin film transistor
404: gate insulating layer (second layer or first layer)
406: active layer (first layer)
500: Hall element (electronic device)
502: substrate
504: first layer (third layer)
506: second layer (first layer)
508: third layer (second layer)
600: Hall element (electronic device)

Claims (13)

A first film forming step of forming a first layer containing an oxide of oxygen indefinite on a substrate in a vacuum film forming chamber that is blocked from the atmosphere;
A second film forming step of forming a second layer comprising the same material or a different material as the first layer on the first layer;
Oxygen partial pressure in the vacuum film forming chamber in the first film forming step in the room in which the first layer is blocked from the atmosphere including the vacuum film forming chamber after the first film forming step and before the second film forming step. The manufacturing method of an electronic device which has a partial pressure control process maintained under higher oxygen partial pressure. The method of claim 1,
The said partial pressure control process WHEREIN: The electronic device which made oxygen partial pressure between the said 1st film formation process and the said 2nd film formation process until 2.1x10 <^-3> Pa or more higher than the oxygen partial pressure in a said 1st film formation process. Method of preparation. The method according to claim 1 or 2,
The vacuum deposition chamber includes a first vacuum deposition chamber and a second vacuum deposition chamber connected through the first vacuum deposition chamber and the transfer chamber,
In the first film forming step, the first layer is formed in the first vacuum film forming chamber,
In the second film forming step, the second layer is formed in the second vacuum film forming chamber,
In the partial pressure control step, the oxygen partial pressure in the first vacuum deposition chamber, the transfer chamber, and the second vacuum deposition chamber is higher than the oxygen partial pressure in the first vacuum deposition chamber in the first deposition process. The manufacturing method of an electronic device. The method according to claim 1 or 2,
In the first film forming process and the second film forming process, a target holder disposed in the vacuum film forming chamber, the vacuum film forming chamber, holding a target, and facing the target holder, and a substrate holder holding the substrate. And a sputtering device including a plasma generating unit for generating a plasma space between the target holder and the substrate,
In the case where the first film forming step and the second film forming step are performed in the same vacuum film forming chamber, the partial pressure control step is performed after the first film forming step and before the second film forming step. And a shutter disposed between the target holder and the substrate in the same vacuum deposition chamber. The method according to claim 1 or 2,
The said 1st layer is a manufacturing method of an electronic device which is a conductor, a semiconductor, or an insulator. The method of claim 5, wherein
The said 1st layer is a manufacturing method of an electronic device which is a semiconductor layer containing at least 1 type of element among In, Ga, Zn, and Sn. The method according to claim 6,
The first layer is a method for manufacturing an electronic device, which is a semiconductor layer containing In _x Ga _y Zn _z O _δ (x, y, z, δ> 0). The method of claim 7, wherein
The substrate is flexible, and the first layer and the second layer are amorphous. The method according to claim 1 or 2,
In the first film forming step, the first layer made of a semiconductor is formed.
In the second film forming step, a method for manufacturing an electronic device is formed by forming the second layer made of an insulator. The method according to claim 1 or 2,
Before the first film forming step, a film forming step of forming a third layer containing an oxygen irregularity oxide on the substrate in the vacuum film forming chamber,
In the first film forming process, the third layer is formed on the substrate via the third layer, and the third layer is formed after the film forming process of the third layer and before the first film forming process. The manufacturing method of an electronic device maintained under oxygen partial pressure higher than the oxygen partial pressure in the said vacuum film-forming chamber in the film-forming process of a said 3rd layer. The thin film transistor produced by forming an active layer as said 1st layer using the manufacturing method of the electronic device of Claim 1 or 2. The electro-optical device provided with the thin film transistor of Claim 11. The sensor provided with the thin film transistor of Claim 11.

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