TW201515106A - Forming method of multi-layer protective film and forming device of multi-layer protective film - Google Patents

Abstract

The invention provides a forming method of a multi-layer protective film and a forming device of a multi-layer protective film. The forming method of a multi-layer protective film can be free of a dehydrogenation process. In a process of forming a grid protective film (31) and a passivation layer (35) provided with silicon nitride films (31a, 35b) and silicon oxide films (31b, 35a) and contacting with a channel (32) formed by IGZO, silicon oxide films (31b, 35a) are formed by using silicon chloride gas and oxygen free of hydrogen atoms; silicon nitride films (31a, 35b) are formed by using silicon chloride gas and nitrogen gas free of hydrogen atom to continuously perform film formation of the silicon oxide films (31b, 35a) and the silicon nitride films (31a, 35b).

Description

Method for forming multilayer protective film and device for forming multilayer protective film

The present invention relates to a method for forming a multilayer protective film for protecting an oxide semiconductor and a device for forming a multilayer protective film.

Conventionally, a FPD (Flat Panel Display) uses a liquid crystal element as a light-emitting element. However, in order to realize a thin FPD, a thin-film transistor (TFT: Thin Film Transistor) is used for the liquid crystal element.

Moreover, in recent years, in order to realize a sheet display or a next generation thin television, the use of an organic EL (Electrouminescence) element has been developed. Since the organic EL element is a self-luminous type of light-emitting element, unlike the liquid crystal element, and no backlight is required, a thinner display can be realized.

Although the organic EL element is a current-driven type element and a high-speed switching operation is required in a TFT applied to an organic EL element, the electron mobility of an amorphous germanium which is currently mainly used as a constituent material of a channel is not so It is high, and therefore, the amorphous germanium is not suitable for the constituent material of the channel of the organic EL.

Thus, a TFT using a channel formed by an oxide semiconductor which can attain a high electron mobility has been proposed. For example, IGZO composed of an oxide of indium (In), gallium (Ga), and zinc (Zn) is known as an oxide semiconductor for use in such a TFT (see, for example, Non-Patent Document 1). Although IGZO is in an amorphous state but has a relatively high electron mobility (for example, 10 cm ² /(V.s) or more), high-speed switching can be realized when a channel of a TFT is formed using an oxide semiconductor such as IGZO. action.

Further, in the TFT, in order to reliably protect the channel from ions or moisture from the outside, a protective film of the channel is formed by a plurality of films such as a tantalum nitride (SiN) film and a yttrium oxide (SiO ₂ ) film (for example, See Patent Document 1). However, for example, when a tantalum nitride film is formed by plasma CVD (Chemical Vapor Deposition), cesane (SiH ₄ ) is mostly used as a germanium source, and ammonia (NH ₃ ) is used as a nitrogen source, but plasma is used from decane. When ammonia forms a tantalum nitride film, there is a case where a hydrogen radical or a hydrogen ion enters a defect of a tantalum nitride film as a hydrogen atom. That is, there is a case where the protective film contains a hydrogen atom.

Since the hydrogen atom contained in the protective film is an oxide semiconductor For example, when the oxygen atom is detached from the IGZO as time passes, the characteristics of the IGZO are changed. Therefore, after the protective film of the channel is formed, it is necessary to perform a dehydrogenation process in which heat treatment is applied to the protective film to positively detach the hydrogen atom from the protective film. .

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent No. 3148183

[Non-patent literature]

[Non-Patent Document 1] "Oxide Semiconductor TFT for Realizing a Light and Thin Sheet Display", Miura Kentaro and others, Toshiba REVIEW Vol. 67 No. 1 (2012)

However, since the dehydrogenation process requires time, there is a problem that productivity is lowered. Further, as described above, in the dehydrogenation process, although the heat treatment is applied to the protective film, when the organic EL device is applied to the sheet display, since the substrate of the sheet display is formed of a resin, the substrate is also present. The problem of deformation and deterioration due to heat.

It is an object of the present invention to provide a method for forming a multilayer protective film which does not require dehydrogenation engineering and a device for forming a multilayer protective film.

The method for forming a multilayer protective film according to claim 1, wherein the method for forming a multilayer protective film that contacts an oxide semiconductor and contains at least a tantalum nitride film and a hafnium oxide film is characterized in that a step of forming a ruthenium oxide film, using a ruthenium tetrachloride (SiCl ₄ ) gas or a silicon germanium tetrafluoride (SiF ₄ ) gas and an oxygen-containing gas containing no hydrogen atoms to form the ruthenium oxide film; and nitriding In the ruthenium film forming step, the ruthenium nitride film is formed using the ruthenium tetrachloride gas or the ruthenium tetrafluoride gas and a nitrogen gas containing no hydrogen atom, and the ruthenium oxide film formation step and the nitrogen are continuously performed. Film formation step of ruthenium film.

The method for forming a multilayer protective film according to claim 2, wherein the method for forming a multilayer protective film according to claim 1, wherein the ruthenium oxide film formation is performed before the step of forming the tantalum nitride film step.

The method for forming a multilayer protective film according to claim 2 is the method for forming a multilayer protective film according to claim 2, wherein the step of forming the ruthenium oxide film is switched to the film formation of the tantalum nitride film. In the step, the supply of the oxygen-containing gas is stopped while the supply of the antimony tetrachloride gas or the antimony tetrafluoride gas is continued, and then the supply of the nitrogen-containing gas is started.

The method for forming a multilayer protective film according to the invention of claim 4, wherein the step of forming the ruthenium oxide film is switched to the film formation of the tantalum nitride film. In the step, the temperature of the substrate on which the oxide semiconductor is formed is temporarily lowered.

The method for forming a multilayer protective film according to claim 5, wherein the method for forming a multilayer protective film according to claim 1, wherein the film formation by the tantalum nitride film is performed before the step of forming the ruthenium oxide film step.

The method for forming a multilayer protective film according to claim 6 is the shape of the multilayer protective film described in claim 5 In the method of switching the film formation step of the tantalum nitride film to the film formation step of the hafnium oxide film, the supply of the nitrogen-containing gas is stopped while the supply of the hafnium tetrachloride gas or the hafnium tetrafluoride gas is continued. Then, the supply of the aforementioned oxygen-containing gas is started.

The method for forming a multilayer protective film according to claim 7 is the method for forming a multilayer protective film according to claim 6, wherein the step of forming the tantalum nitride film is switched to the film formation of the ruthenium oxide film. In the step, the temperature of the substrate on which the oxide semiconductor is formed is temporarily lowered.

The method for forming a multilayer protective film according to any one of claims 1 to 7, wherein the nitrogen-containing nitrogen gas system does not contain a hydrogen atom.

The method for forming a multilayer protective film according to any one of claims 1 to 8, wherein the oxygen-containing oxygen-containing system does not contain a hydrogen atom.

The method for forming a multilayer protective film according to any one of claims 1 to 9, wherein the oxide semiconductor contains oxidation of indium, gallium, and zinc. Things.

The method for forming a multilayer protective film according to any one of claims 1 to 10, wherein the multilayer protective film is a primer layer in a crystal structure. At least one of a gate protective film, a barrier layer and a passivation layer.

In order to achieve the above object, a method for forming a multilayer protective film according to claim 12 is a method of forming a multilayer protective film comprising a film comprising at least an oxide and a semiconductor and a film containing at least nitrogen and cerium and a film containing oxygen and cerium. Characterized by the use of at least one of a ruthenium tetrachloride (SiCl ₄ ) gas or a silicon germanium tetrafluoride (SiF ₄ ) gas and an oxygen-containing gas containing no hydrogen atoms and a nitrogen-containing gas containing no hydrogen atoms. A multilayer protective film comprising at least two of a ruthenium film, a tantalum nitride film, and a tantalum nitride film, and the at least two films constituting the multilayer protective film are formed by performing a continuous film formation process.

In order to achieve the above object, the apparatus for forming a multilayer protective film according to claim 13 is a device for forming a multilayer protective film which is in contact with an oxide semiconductor and includes at least a tantalum nitride film and a hafnium oxide film. a helium-containing gas supply unit that supplies helium tetrachloride gas or a hafnium tetrafluoride gas; an oxygen-containing gas supply unit that supplies an oxygen-containing gas that does not contain hydrogen atoms; and a nitrogen-containing gas supply unit that supplies a hydrogen-free gas containing unit The nitrogen gas is supplied to the ruthenium tetrachloride gas or the ruthenium tetrafluoride gas and the oxygen-containing gas to form the ruthenium oxide film, and the ruthenium tetrachloride gas or the ruthenium tetrafluoride gas and the nitrogen gas-containing gas are supplied. The tantalum nitride film is formed, and the formation of the tantalum oxide film and the formation of the tantalum nitride film are continuously performed.

The apparatus for forming a multilayer protective film according to claim 13 is the apparatus for forming a multilayer protective film according to claim 13, comprising an ICP (Inductively Coupling Plasma) antenna, and the ICP antenna is used The resulting inductively coupled plasma forms the foregoing hafnium oxide film and the tantalum nitride film.

According to the present invention, a hafnium tetrachloride gas or a hafnium tetrafluoride gas and an oxygen-containing gas containing no hydrogen atoms are used in the film formation of the hafnium oxide film, and hafnium tetrachloride gas or a film is formed in the film formation of the tantalum nitride film. The antimony tetrafluoride gas and the nitrogen-containing gas containing no hydrogen atom do not enter the defects of the hafnium oxide film or the tantalum nitride film, and the multilayer protective film does not contain hydrogen atoms. As a result, it is not necessary to perform a dehydrogenation process. Further, since the film formation of the ruthenium oxide film and the film formation of the tantalum nitride film are continuously performed, it is possible to prevent the unnecessary components from being mixed into the multilayer protective film.

S‧‧‧Substrate

10‧‧‧Micro plasma CVD film forming device

13‧‧‧ICP antenna

18‧‧‧矽 Gas supply department

19‧‧‧Oxygen gas supply department

20‧‧‧Nitrogen supply unit

28,36,38,46‧‧‧TFT

31,43‧‧‧ gate protective film

31a, 35b, 37b, 39a, 43b‧‧‧ nitride film

31b, 35a, 37a, 39b, 43a‧‧‧ oxide film

31c‧‧‧Nitride film

32,40‧‧‧ channel

35‧‧‧ Passivation layer

37‧‧‧etching layer

39‧‧‧Undercoat

Fig. 1 is a cross-sectional view schematically showing a configuration of a plasma CVD film forming apparatus as a forming apparatus of a multilayer protective film according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view showing a configuration of a gate-type TFT formed by a method of forming a multilayer protective film according to the embodiment.

Fig. 3 is a flow chart showing a method of forming a multilayer protective film of the present embodiment.

Fig. 4 is an enlarged cross-sectional view showing a laminated structure of the gate protective film of Fig. 2;

Fig. 5 is a cross-sectional view showing a configuration of a modified example of a gate-type TFT formed by a method of forming a multilayer protective film according to the embodiment.

Fig. 6 shows a method of forming a multilayer protective film according to the embodiment A cross-sectional view showing the structure of the upper gate type TFT.

Fig. 7 is a cross-sectional view showing a configuration of a modified example of a gate-type TFT formed by a method of forming a multilayer protective film according to the embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, a device for forming a multilayer protective film according to an embodiment of the present invention will be described.

Fig. 1 is a cross-sectional view schematically showing the configuration of a plasma CVD film forming apparatus as a forming apparatus for a multilayer protective film of the present embodiment.

In FIG. 1, the plasma CVD film forming apparatus 10 includes, for example, a chamber 11 having a substantially casing shape, and a substrate for housing an FPD or a sheet display (hereinafter simply referred to as "substrate") S; 12, disposed at the bottom of the chamber 11 and placed on the substrate S; the ICP antenna 13 is disposed outside the chamber 11 to face the mounting table 12 inside the chamber 11; and the window member 14 is configured The top of the chamber 11 is interposed between the mounting table 12 and the ICP antenna 13.

The chamber 11 has an exhaust device (not shown) that evacuates the chamber 11 to decompress the inside of the chamber 11. The window member 14 of the chamber 11 is composed of a dielectric material that partitions the inside and the outside of the chamber 11.

The window member 14 is supported by the side wall of the chamber 11 via an insulating member (not shown), and the window member 14 is not in direct contact with the chamber 11, and is electrically non-conductive. Moreover, the window member 14 has at least a cover load The substrate S placed on the mounting table 12 has a full size. Further, the window member 14 may be composed of a plurality of divided pieces.

Three gas introduction ports 15, 16, and 17 are provided in the side wall of the chamber 11, and the gas introduction port 15 is connected to the helium-containing gas supply portion 18 disposed outside the chamber 11 via the gas introduction pipe 22, and the gas is introduced. The port 16 is connected to the oxygen-containing gas supply unit 19 and the nitrogen-containing gas supply unit 20 disposed outside the chamber 11 via the gas introduction pipe 23, and the gas introduction port 17 is connected to the gas introduction pipe 24 via the gas introduction pipe 24 A rare gas supply portion 21 outside the chamber 11.

The helium-containing gas supply unit 18 supplies a helium-containing gas such as hafnium tetrachloride (SiCl ₄ ) gas to the inside of the chamber 11 via the gas introduction port 15, and the oxygen-containing gas supply unit 19 passes through the gas introduction port 16 to the chamber. An oxygen-containing gas containing no hydrogen atom, for example, oxygen, and a nitrogen-containing gas supply unit 20 are supplied to the inside of the chamber 11 through a gas introduction port 16 to supply a nitrogen-containing gas containing no hydrogen atom, for example, nitrogen gas, and a rare gas supply unit. 21, a rare gas such as argon is supplied to the inside of the chamber 11 via the gas introduction port 17.

Each of the gas introduction pipes 22, 23, and 24 has a mass flow controller or a valve (all not shown), and adjusts the flow rates of the respective gases supplied from the gas introduction ports 15, 16, and 17. In particular, the gas introduction pipe 23 has a three-way valve (not shown), and switches the gas supplied from the gas introduction port 16 to any of oxygen gas and nitrogen gas.

The ICP antenna 13 is constituted by an annular wire disposed along the upper surface of the window member 14, and is connected to the high frequency power supply via the matching unit 25. 26. The high-frequency current from the high-frequency power source 26 flows through the ICP antenna 13, and the high-frequency current is generated in the ICP antenna 13 via the window member 14 to generate a magnetic field inside the chamber 11. Although the magnetic field changes with time due to the generation of a high-frequency current, a magnetic field that changes with time generates an induced electric field, and electrons accelerated by the induced electric field are generated with molecules or atoms of a gas introduced into the chamber 11. Collision and inductively coupled plasma.

In the plasma CVD film forming apparatus 10, cations or radicals are generated from indium tetrachloride gas, oxygen gas, and argon gas supplied to the inside of the chamber 11 by inductively coupled plasma, and oxidation is formed on the substrate S by CVD. The ruthenium film is formed, and a ruthenium or a radical is generated from ruthenium tetrachloride gas, nitrogen gas, and argon gas supplied to the inside of the chamber 11, and a tantalum nitride film is formed on the substrate S by CVD, whereby a ruthenium oxide film is formed. And a multilayer protective film composed of a tantalum nitride film. Further, although the argon gas is not a material gas which directly constitutes a ruthenium oxide film or a tantalum nitride film, the ruthenium tetrachloride gas, oxygen gas, and nitrogen gas which are material gases directly constituting the ruthenium oxide film or the tantalum nitride film are appropriately adjusted. The concentration can further facilitate the discharge or the like for generating the inductively coupled plasma, and can play an auxiliary role in the film formation process.

Further, the plasma CVD film forming apparatus 10 further includes a controller 27 for controlling the operation of each component of the plasma CVD film forming apparatus 10.

Fig. 2 is a cross-sectional view showing the structure of a gate-type TFT formed by a method of forming a multilayer protective film according to the embodiment.

In FIG. 2, the TFT 28 is provided with an undercoat layer 29 formed on the substrate S, and a gate electrode 30 partially formed on the undercoat layer 29. The gate protective film 31 is formed of a multilayer protective film formed to cover the undercoat layer 29 and the gate electrode 30. The channel 32 is formed on the gate protective film 31 so as to be disposed on the gate electrode 30. The source electrode 33 and the drain electrode 34 are respectively formed on the gate protection film 31 on both sides of the channel 32; and the passivation layer 35 is formed to cover the channel 32, the source electrode 33 and the drain electrode 34. It is composed of a multilayer protective film.

In the TFT 28, the channel 32 is composed of IGZO, and the gate protective film 31 has a tantalum nitride film 31a and a tantalum oxide film 31b laminated from the lower side in the drawing, and the passivation layer 35 has a laminate from the lower side in the drawing. The hafnium oxide film 35a and the tantalum nitride film 35b. In the gate protective film 31, the ruthenium oxide film 31b is in contact with the channel 32, and in the passivation layer 35, the ruthenium oxide film 35a is in contact with the channel 32.

Here, since the yttrium oxide film 31b, the yttrium oxide film 35a, and the channel 32 are both made of an oxide and are easily connected to each other, the gate protection can be suppressed by causing the yttrium oxide film 31b or the yttrium oxide film 35a to contact the channel 32. The film 31, the channel 32, and the passivation layer 35 are mutually peeled off.

In addition, the laminated form in the gate protective film 31 or the passivation layer 35 is not limited to those shown in FIG. 2. For example, in the gate protective film 31, the hafnium oxide film 31b and nitrogen may be sequentially arranged from the lower side in the drawing. The ruthenium film 31a is laminated and the tantalum nitride film 31a is in contact with the channel 32. In the passivation layer 35, the tantalum nitride film 35b and the yttrium oxide film 35a may be sequentially laminated and nitrided from the lower side in the drawing. The diaphragm 35b contacts the channel 32.

Fig. 3 is a flow chart showing a method of forming the multilayer protective film of the embodiment.

The flowchart of Fig. 3 is executed by controlling the operation of each component of the plasma CVD film forming apparatus 10 by the controller 27 in accordance with a predetermined program.

First, the undercoat layer 29 is formed, and the substrate S on which the gate electrode 30 is formed is carried into the chamber 11 of the plasma CVD film forming apparatus 10 and placed on the mounting table 12.

Next, after decompressing the inside of the chamber 11 and the internal vacuum degree reaches a predetermined value, helium tetrachloride gas, nitrogen gas, and argon are supplied from the respective gas introduction ports 15, 16, 17 to the inside of the chamber 11. By using the ICP antenna 13, an induced electric field is formed inside the chamber 11 and an inductively coupled plasma is generated, and cations or radicals are generated from ruthenium tetrachloride gas, nitrogen gas, and argon gas, whereby by CVD The tantalum nitride film 31a is formed in such a manner as to cover the undercoat layer 29 or the gate electrode 30 (step S31) (a hafnium nitride film forming step).

Next, while supplying the supply of helium tetrachloride gas and argon gas and the generation of the induced electric field, the supply of nitrogen gas is stopped, and then the supply of oxygen is started, and oxidation is formed by CVD covering the tantalum nitride film 31a. The ruthenium film 31b (step S32) (the ruthenium oxide film formation step).

Thereby, the gate protective film 31 having the tantalum nitride film 31a and the tantalum oxide film 31b is formed. When the film formation of the tantalum nitride film 31a is switched to the film formation of the tantalum oxide film 31b and oxygen is supplied, since an induced electric field is continuously generated and nitrogen gas is also present in a small amount, there is a presence of oxygen and nitrogen in the CVD. The period during which both the cation or free radical is produced. As a result, as shown in FIG. 4, in the gate protective film 31, although the tantalum nitride film An extremely thin tantalum nitride film 31c is formed between 31a and the tantalum oxide film 31b. However, since the tantalum nitride film 31c connects the tantalum oxide film 31b and the tantalum nitride film 31a to each other, the gate can be suppressed. The layers of the tantalum nitride film 31a and the tantalum oxide film 31b in the pole protective film 31 are separated.

Next, the substrate S is carried out from the plasma CVD film forming apparatus 10, and the channel 32, the source electrode 33, and the drain electrode 34 are formed in another film forming apparatus (not shown) (step S33).

Next, the substrate S is again carried into the chamber 11 of the plasma CVD film forming apparatus 10 and placed on the mounting table 12, and the inside of the chamber 11 is decompressed to bring the internal vacuum to a predetermined value. Thereafter, helium tetrachloride gas, oxygen gas, and argon gas are supplied from the respective gas introduction ports 15, 16, and 17 to the inside of the chamber 11, and inductively coupled plasma is generated inside the chamber 11, and the gas is filtered from hafnium tetrachloride. Oxygen and argon generate cations or radicals, whereby the ruthenium oxide film 35a is formed by CVD covering the channel 32, the source electrode 33, and the drain electrode 34 (step S34) (the ruthenium oxide film formation step) .

Next, while continuing the supply of the helium tetrachloride gas and the argon gas and the generation of the induced electric field, the supply of oxygen is stopped, and then the supply of nitrogen gas is started, and nitridation is formed by CVD covering the tantalum oxide film 35a. The ruthenium film 35b (step S35) (the ruthenium nitride film formation step).

Thereby, the passivation layer 35 having the hafnium oxide film 35a and the tantalum nitride film 35b is formed. When the film formation from the film formation of the hafnium oxide film 35a is switched to the film formation of the tantalum nitride film 35b and nitrogen gas is supplied, since an induced electric field is continuously generated and nitrogen gas is also present in a small amount, it is also present in the CVD. There are periods of both cations or free radicals generated from oxygen and nitrogen. As a result, in the passivation layer 35, since an extremely thin tantalum nitride film (not shown) is formed between the tantalum oxide film 35a and the tantalum nitride film 35b, the passivation layer 35 can also suppress ruthenium oxide. The layers of the film 35a and the tantalum nitride film 35b are separated.

Next, after the passivation layer 35 is formed, the method is ended.

According to the method for forming a multilayer protective film of the present embodiment, the hafnium tetrachloride gas and the oxygen gas containing no hydrogen atoms are used for the formation of the tantalum oxide films 31b and 35a, and the tantalum nitride films 31a and 35b are formed. By using a hafnium tetrachloride gas containing no hydrogen atom and nitrogen gas, hydrogen atoms do not enter the defects of the hafnium oxide film 31b, 35a or the tantalum nitride films 31a, 35b, and are in contact with the channel 32 composed of IGZO. The gate protective film 31 or the passivation layer 35 does not contain hydrogen atoms. As a result, in the film formation of the gate protective film 31 or the passivation layer 35, it is not necessary to perform a dehydrogenation process.

Further, in the above-described method of forming a multilayer protective film, the tantalum nitride film 31a and the tantalum oxide film 31b are continuously performed by switching the substrate S into oxygen without switching from the chamber 11 to oxygen or by switching the oxygen gas to nitrogen gas. Since the film formation and the formation of the hafnium oxide film 35a and the tantalum nitride film 35b prevent the unnecessary components from being mixed into the gate protection film 31 or the passivation layer 35, the productivity can be shortened.

Further, in the above-described method of forming a multilayer protective film, when the film is formed by switching from the film formation of the tantalum nitride film 31a to the film formation of the tantalum oxide film 31b, and when the film is transferred from the film of the tantalum oxide film 35a to nitrogen, Phlegm film When the film formation of 35b is continued, the supply of helium tetrachloride gas and argon gas is not performed, and the switching of the helium-containing gas or the rare gas is not performed, so that the productivity can be further shortened.

In the method for forming a multilayer protective film described above, since an induced electric field is continuously generated, generation of fine particles due to destruction or regeneration of the plasma can be suppressed without performing the elimination or regeneration of the inductively coupled plasma.

Further, in the above method for forming a multilayer protective film, cations or radicals are generated from ruthenium tetrachloride gas, oxygen gas, and nitrogen by inductively coupled plasma, and ruthenium oxide films 31b, 35a and tantalum nitride are formed by CVD. Membranes 31a, 35b. Since the density of the inductively coupled plasma is high, cationization or radicalization of ruthenium tetrachloride gas, oxygen gas, and nitrogen gas is promoted, and therefore, oxidation can be performed at a relatively low temperature, for example, 200 ° C or lower (more preferably, 150 ° C or lower). Film formation is performed on the ruthenium films 31b and 35a and the tantalum nitride films 31a and 35b. As a result, when the TFT 28 is applied to the organic EL, the substrate S of the sheet display can be suppressed from being deformed and deteriorated by heat.

In the method for forming a multilayer protective film described above, although hafnium tetrachloride gas is used as the helium-containing gas, the helium-containing gas is not limited thereto, and for example, germanium tetrafluoride (SiF ₄ ) gas or germanium tetrabromide may be used. (SiBr ₄ ) gas or cesium tetraiodide (SiI4) gas. Further, although oxygen gas is used as the oxygen-containing gas, the oxygen-containing gas is not limited thereto, and for example, ozone gas may be used.

Further, although nitrogen gas is used as the nitrogen-containing gas, the nitrogen-containing gas is not limited thereto, and for example, nitric oxide gas, nitrous oxide (N ₂ O) gas, nitrogen trifluoride (NF ₃ ) gas, or nitrogen tribromide may be used. (NBr ₃ ) gas, nitrogen trichloride (NCl ₃ ) gas. Further, although argon gas is used as the rare gas, the rare gas is not limited thereto, and for example, helium, neon or xenon may be used.

Further, even if a plasma CVD apparatus 31b, 35a or a tantalum nitride film 31a, 35b is formed by using a plasma CVD apparatus other than the inductively coupled plasma, it is formed by ruthenium tetrachloride. When a gas, a germanium tetrafluoride gas, a helium tetrabromide gas, a helium tetraiodide gas, or a nitrogen gas is used for the film formation treatment, it is possible to perform an excellent use by using an inductively coupled plasma capable of generating a high-density plasma. Film formation treatment. Further, in the present embodiment, the dielectric member CVD film forming apparatus using dielectric is used for the window member 14. However, a metal window composed of a plurality of divided divided pieces may be used as the window member. In the state of the inductively coupled plasma CVD film forming apparatus, the form of the ICP antenna 13 is not limited to a ring shape, and may be another form such as a straight line as long as it straddles each divided piece.

In the above-described method of forming a multilayer protective film, the channel 32 is formed of IGZO, but the channel 32 may be formed of another oxide semiconductor. For example, as long as the oxygen atom is removed by the mixed hydrogen atoms and the characteristics are changed, the same effect as in the case where the channel 32 is formed by IGZO can be obtained by applying the present invention. Further, in the above-described method of forming a multilayer protective film, the gate protective film 31 or the passivation layer 35 has a two-layer structure composed of a tantalum nitride film and a hafnium oxide film, but the gate protective film 31 or the passivation layer. The structure of the multilayer protective film of 35 or the like is not limited to the two-layer structure, and may be a three-layer structure or more composed of a layer containing no hydrogen atoms.

Further, the gate protective film 31 or the passivation layer 35 which is in contact with the channel 32 does not contain hydrogen atoms, but is in the gate protective film 31 and the passivation layer. In the film formation process of 35, it is difficult to prevent the film of both of them from containing hydrogen atoms, and at least one of the gate protective film 31 and the passivation layer 35 may not contain a hydrogen atom. Even in this case, it is possible to suppress the detachment of oxygen atoms from IGZO to some extent.

Further, in the present embodiment, when the gate protective film 31 or the passivation layer 35 is formed, a tantalum nitride film may be formed instead of the hafnium oxide films 31b and 35a, and a tantalum nitride film may be formed instead of nitrogen. The ruthenium film 31a, 35b.

Further, in the above-described method of forming a multilayer protective film, when the film formation from the film formation of the tantalum nitride film 31a is switched to the film formation of the tantalum oxide film 31b, or when the film is transferred from the film of the tantalum oxide film 35a to nitrogen, When the film of the ruthenium film 35b is formed, the temperature of the substrate S may be temporarily lowered, or the supply of the ruthenium tetrachloride gas may be stopped. Further, in the case where the particles are rarely generated in the generation and erasure of the plasma, the inductively coupled plasma can be temporarily destroyed when the above-described processing is switched. Thereby, the film formation reaction after the film formation of the tantalum nitride film 31a can be suppressed until the film formation of the ruthenium oxide film 31b is performed, or the film formation reaction after the film formation of the ruthenium oxide film 35a can be suppressed until the ruthenium nitride is formed. The film 35b is formed into a film, and a film other than the ruthenium oxide film or the tantalum nitride film can be formed between the yttrium oxide films 31b and 35a and the tantalum nitride films 31a and 35b.

The present invention has been described above using the embodiments, but the present invention is not limited to the embodiments described above.

For example, the above-described method of forming a multilayer protective film is applied not only to the TFT 28 of Fig. 2 but also to the formation of a multilayer protective film of a TFT having another configuration.

Fig. 5 is a cross-sectional view showing a configuration of a modification of the gate-type TFT formed by the method of forming the multilayer protective film of the embodiment.

In FIG. 5, the TFT 36 is provided with: an undercoat layer 29; a gate electrode 30; a gate protective film 31; a channel 32; a source electrode 33 and a drain electrode 34; and an etching resist layer 37 formed to cover the channel A multilayer protective film of 32 is formed; and a passivation layer 38 is formed to cover the etching resist layer 37, the source electrode 33, and the drain electrode 34.

In the TFT 36, the etching resist layer 37 has a hafnium oxide film 37a and a tantalum nitride film 37b laminated from the lower side in the drawing. In the etching resist layer 37, the hafnium oxide film 37a is in contact with the channel 32. Thereby, mutual peeling of the channel 32 and the etching resist layer 37 can be suppressed.

Further, in the etching resist layer 37, the tantalum nitride film 37b and the tantalum oxide film 37a may be laminated in this order from the lower side in the drawing to bring the tantalum nitride film 37b into contact with the channel 32.

In the TFT 36, steps S31 and S32 of FIG. 3 are applied to the formation of the gate protection film 31, and the same processes as those of steps S34 and S35 of FIG. 3 are applied to the formation of the etching resist layer 37. By using a hafnium tetrachloride gas and oxygen gas which do not contain hydrogen atoms in the film formation of the hafnium oxide films 31b and 37a, tetrachloride which does not contain a hydrogen atom is used for film formation of the tantalum nitride films 31a and 37b. The helium gas and the nitrogen gas do not enter the defects of the tantalum oxide film 31b, 37a or the tantalum nitride films 31a, 37b, and the oxygen atoms are prevented from being detached from the channel 32.

Figure 6 is a view showing the application of the multilayer protective film of this embodiment. A cross-sectional view showing the structure of a gate-type TFT formed by the formation method.

In FIG. 6, the TFT 38 is provided with an undercoat layer 39 composed of a plurality of protective films formed on the substrate S, a channel 40 partially formed on the undercoat layer 39, and a source electrode 41 and a drain electrode. 42. The undercoat layer 39 is respectively formed on both sides of the channel 40. The gate protective film 43 is composed of a multilayer protective film formed to cover the channel 40, the source electrode 41 and the drain electrode 42; the gate electrode 44 The gate protective film 43 is formed to be disposed directly above the via 40; and the passivation layer 45 is formed to cover the gate electrode 44 and the gate protective film 43.

In the TFT 38, the channel 40 is composed of IGZO, and the undercoat layer 39 has a tantalum nitride film 39a and a tantalum oxide film 39b laminated from the lower side in the drawing, and the gate protective film 43 has a layer from the lower side in the drawing. The tantalum oxide film 43a and the tantalum nitride film 43b are formed. In the undercoat layer 39, the yttrium oxide film 39b is in contact with the channel 40, and in the gate protective film 43, the yttrium oxide film 43a is in contact with the channel 40. Thereby, mutual peeling of the channel 40, the undercoat layer 39, and the gate protective film 43 can be suppressed.

Further, in the undercoat layer 39, the tantalum oxide film 39b and the tantalum nitride film 39a may be sequentially laminated from the lower side in the drawing to bring the tantalum nitride film 39a into contact with the channel 40, in the gate protective film 43. Alternatively, the tantalum nitride film 43b and the tantalum oxide film 43a may be laminated in this order from the lower side in the drawing, and the tantalum nitride film 43b may be in contact with the channel 40.

The TFT 38 applies the same processing as the steps S31 and S32 of FIG. 3 to the formation of the undercoat layer 39, and applies the same processing as the steps S34 and S35 of FIG. 3 to the formation of the gate protective film 43. Because of this, As the film formation of the hafnium oxide films 39b and 43a, hafnium tetrachloride gas and oxygen gas which do not contain hydrogen atoms are used, and in the film formation of the tantalum nitride films 39a and 43b, hafnium tetrachloride gas and nitrogen gas which do not contain hydrogen atoms are used. Therefore, the hydrogen atoms do not enter the defects of the yttrium oxide film 39b, 43a or the tantalum nitride films 39a, 43b, and the oxygen atoms are prevented from being detached from the channel 40.

Fig. 7 is a cross-sectional view showing a configuration of a modification of the gate-type TFT formed by the method of forming the multilayer protective film of the embodiment.

In FIG. 7, the TFT 46 is provided with an undercoat layer 39 composed of a plurality of protective films formed on the substrate S, a channel 40 partially formed on the undercoat layer 39, and a source electrode 47 and a drain electrode. 48, connected to the channel 40; the gate protective film 43 is formed to cover the undercoat layer 39 and the channel 40; the gate electrode 44 is formed on the gate protective film 43 to be disposed on the channel 40; the interlayer insulating film 49 is formed The gate electrode 44 and the gate protective film 43 are covered; and the passivation layer 50 is formed to cover the interlayer insulating film 49, the source electrode 47, and the drain electrode 48.

The TFT 46 is also the same as the TFT 38. In the undercoat layer 39, the yttrium oxide film 39b is in contact with the channel 40, and in the gate protective film 43, the yttrium oxide film 43a is in contact with the channel 40. Thereby, mutual peeling of the channel 40, the undercoat layer 39, and the gate protective film 43 can be suppressed.

Further, similarly to the TFT 38, the tantalum nitride film 39a may be brought into contact with the channel 40 in the undercoat layer 39, and the tantalum nitride film 43b may be brought into contact with the channel 40 in the gate protective film 43.

TFT46, which is the same as TFT38, will follow the steps of Figure 3. The same processes as S31 and S32 are applied to the formation of the undercoat layer 39, and the same processes as those of steps S34 and S35 of Fig. 3 are applied to the formation of the gate protective film 43. Thereby, hydrogen atoms do not enter defects of the yttrium oxide films 39b, 43a or the tantalum nitride films 39a, 43b, and oxygen atoms can be prevented from being detached from the channel 40.

Further, an object of the present invention is to supply a memory medium on which a software program code for realizing the functions of the above-described embodiments is stored to a computer such as a controller 27, and the CPU of the controller 27 reads the code stored in the memory medium and Execution to achieve.

At this time, the code itself read from the memory medium can realize the functions of the above-described embodiments, and the code and the memory medium storing the code can constitute the present invention.

Further, as the memory medium for supplying the code, for example, it is a memory RAM, an NV-RAM, a floppy disk (registered trademark), a hard disk, an optical disk, a CD-ROM, a CD-R, a CD-RW, The above-mentioned code such as a disc (DVD-ROM, DVD-RAM, DVD-RW, DVD+RW) such as a DVD, a magnetic tape, a non-volatile memory, or another ROM may be used. Alternatively, the code may be downloaded to the controller 27 by downloading from another computer or database (not shown) connected to the Internet, a commercial network, or a regional network.

Further, by executing the program code read by the controller 27, not only the functions of the above-described embodiments but also the OS (operation system) operating on the CPU in accordance with the instruction of the program code are included. Or all of the cases in which the functions of the above-described embodiments are realized by this processing.

Moreover, the program code read from the memory medium is written to the memory of the function expansion card inserted into the controller 27 or the function expansion unit connected to the controller 27, and the function expansion card or the function expansion unit is provided. The CPU or the like performs part or all of the actual processing based on the instruction of the code, and the function of the above embodiment is realized by the processing.

The form of the above code is also formed by the form supplied to the object code, the code executed by the compiler, the script data of the OS, and the like.

Claims (14)

A method for forming a multilayer protective film, which is a method for forming a multilayer protective film which contacts an oxide semiconductor and at least comprises a tantalum nitride film and a tantalum oxide film, and has the following steps: a step of forming a film of ruthenium oxide film, using four a ruthenium chloride (SiCl ₄ ) gas or a silicon germanium tetrafluoride (SiF ₄ ) gas and an oxygen-containing gas containing no hydrogen atom to form the ruthenium oxide film; and a ruthenium nitride film formation step using the foregoing ruthenium tetrachloride gas Or the above-described tantalum nitride gas and a nitrogen-containing gas containing no hydrogen atom form the tantalum nitride film, and the step of forming the tantalum oxide film and the film forming step of the tantalum nitride film are continuously performed. The method for forming a multilayer protective film according to the first aspect of the invention, wherein the ruthenium oxide film forming step is performed before the step of forming the tantalum nitride film. The method for forming a multilayer protective film according to the second aspect of the invention, wherein the step of forming the ruthenium oxide film is switched to the step of forming the tantalum nitride film, while continuing the gas or the PTFE The supply of the enthalpy gas is stopped while the supply of the oxygen-containing gas is stopped, and then the supply of the nitrogen-containing gas is started. a method for forming a multilayer protective film according to item 3 of the patent application, wherein When the film formation step of the ruthenium oxide film is switched to the film formation step of the tantalum nitride film, the temperature of the substrate on which the oxide semiconductor is formed is temporarily lowered. The method for forming a multilayer protective film according to the first aspect of the invention, wherein the step of forming the tantalum nitride film is performed before the step of forming the ruthenium oxide film. The method for forming a multilayer protective film according to the fifth aspect of the invention, wherein the step of forming the tantalum nitride film is switched to the film forming step of the ruthenium oxide film while continuing the gas or the PTFE The supply of the argon-containing gas stops the supply of the nitrogen-containing gas, and then the supply of the oxygen-containing gas is started. The method for forming a multilayer protective film according to claim 6, wherein the temperature of the substrate on which the oxide semiconductor is formed is temporarily made when the film forming step of the tantalum nitride film is switched to the film forming step of the tantalum oxide film decline. The method for forming a multilayer protective film according to any one of claims 1 to 7, wherein the nitrogen-containing gas containing no hydrogen atom is nitrogen. The method for forming a multilayer protective film according to any one of claims 1 to 7, wherein the oxygen-containing gas not containing a hydrogen atom is oxygen. The method for forming a multilayer protective film according to any one of claims 1 to 7, wherein the oxide semiconductor contains an oxide of indium, gallium, and zinc. The method for forming a multilayer protective film according to any one of claims 1 to 7, wherein the multilayer protective film is at least an undercoat layer, a gate protective film, a barrier layer, and a passivation layer in a transistor structure. One. A method for forming a multilayer protective film, which is a method for forming a multilayer protective film which is in contact with an oxide semiconductor and is composed of a film containing at least nitrogen and ruthenium and a film containing oxygen and ruthenium, and is characterized in that ruthenium tetrachloride (SiCl) is used. ₄ ) at least one of a gas or a silicon tetrafluoride (SiF ₄ ) gas and an oxygen-containing gas containing no hydrogen atom and a nitrogen-containing gas containing no hydrogen atom, formed of a hafnium oxide film, a tantalum nitride film, and a tantalum nitride gas The multilayer protective film comprising at least two films in the film, the at least two films constituting the multilayer protective film are formed by performing a continuous film forming process. A multilayer protective film forming apparatus which is a device for forming a multilayer protective film which is in contact with an oxide semiconductor and includes at least a tantalum nitride film and a hafnium oxide film, and is characterized in that it is provided with a helium-containing gas supply portion for supplying antimony tetrachloride a gas or a ruthenium tetrafluoride gas; an oxygen-containing gas supply unit that supplies an oxygen-containing gas that does not contain a hydrogen atom; and a nitrogen-containing gas supply unit that supplies a nitrogen-containing gas that does not contain a hydrogen atom, supplies the ruthenium tetrachloride gas or the Neodymium tetrafluoride gas and the foregoing The oxygen gas is formed into the yttrium oxide film, and the ruthenium tetrachloride gas or the ruthenium tetrafluoride gas and the nitrogen gas-containing gas are supplied to form the tantalum nitride film, and the film formation and the nitridation of the ruthenium oxide film are continuously performed. Film formation of the enamel film. The apparatus for forming a multilayer protective film according to claim 13, comprising an ICP (Inductively Coupling Plasma) antenna, wherein the yttrium oxide film and the nitrogen are formed by an inductively coupled plasma generated by the ICP antenna.矽 film.