JPH08176819A - Thin film forming device - Google Patents

Abstract

PURPOSE: To excellently control the temp. of a substrate by supporting the substrate to be worked with a holder, providing a member with the conductivity changed by a magnetic field between the substrate and holder and impressing a magnetic field. CONSTITUTION: A magneto-resistance effect member 1 is formed on the supporting face of a substrate holder 3 in a sputtering chamber 10. A substrate 2 to be coated with a thin film is supported by the holder 3. The rear of the holder 3 is heated by an IR lamp 5 to heat the substrate 2 through the member 1. A thin film is formed on the substrate 2 by sputtering using sputtering sources 71 and 72. The member 1 is impressed with an electromagnet 41 to change its conductivity, and the temp. of the substrate 2 is controlled. This device is excellent in high-speed responsiveness, high precision and adaptability to a large area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film processing apparatus for performing thin film processing such as thin film formation or thin film processing on a thin film element.

[0002]

2. Description of the Related Art Sputtering equipment, vapor deposition equipment, CVD
Devices, thin film forming devices such as MBE devices, and thin film processing devices such as RIE devices, ion milling devices, CDE devices, and ashing devices include DRAMs, TFT-LCDs, semiconductor lasers, magnetic heads, magnetic disks, optical disks, etc.
It is widely used for manufacturing thin film devices, which are extremely important in industry.

In any of the processes of forming and processing a thin film, the substrate temperature during the process is one of the main determinants of thin film element function, such as film quality, film forming speed, film processing speed, and processing shape, and temperature distribution. Prescribed management is required including the above.

In addition, in a multilayer laminated film represented by an artificial lattice film, which has been particularly attracting attention in recent years, when the different film materials are sequentially laminated or processed, the optimum forming temperature of each layer or It is desired to control the substrate temperature quickly according to the processing temperature.

In a conventional thin film processing apparatus such as a thin film forming apparatus and a thin film processing apparatus, a heater is provided in the substrate supporting base or an infrared lamp is irradiated toward the substrate from outside the substrate supporting base to heat the substrate. The substrate support is provided with a liquid nitrogen introduction passage, and liquid nitrogen is allowed to flow therethrough to cool the substrate, thereby controlling the temperature of the substrate.

However, none of these methods can be said to satisfy high-speed responsiveness, large area uniformity, and required accuracy, and the film formation or processing is not necessarily performed in an optimum state.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is a thin film process that has a good substrate temperature controllability during a thin film process, that is, high-speed response, large area uniformity, and control accuracy. The purpose is to provide a device.

[0008]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a process chamber, a support provided in the chamber for supporting a substrate on which a thin film process is performed, and the support. Means for performing a thin film process on the substrate supported by the substrate, means for applying a magnetic field to the support base, and means provided inside the support base or on the support surface of the support base for applying the magnetic field. A thin film processing apparatus, comprising: a member whose thermal conductivity changes according to a magnetic field.

INDUSTRIAL APPLICABILITY The present invention can be applied to all thin film processing apparatuses in which a substrate having a relatively small heat capacity is subjected to a thin film process. For example, sputtering, vapor deposition, PVD processes such as MBE, thermal CVD, Plasma C
It is applicable to temperature control of a substrate in an apparatus that performs thin film formation and thin film processing such as a CVD process such as VD, photo CVD, MOCVD, a plasma polymerization process, an ashing process, a CDE process, and an RIE process.

In the present invention, the target substrate (thin film process substrate) is not particularly limited, but the smaller the heat capacity, the more remarkable the effect of applying the present invention. There are various forms of the support base of the substrate according to the purpose of the process, and there is no particular limitation when the present invention is applied, and it may be grounded or floating in terms of potential, or may be one to which a high voltage is applied. Also,
It may be mechanically stationary or moving.

Regarding the thermal condition of the substrate in the apparatus according to the present invention, it may be cooling or heating. In particular, an embodiment in which the substrate temperature is controlled at high speed during the process, for example, formation of a multi-layer film made of different materials or batch processing The present invention is effective when performing

The means for applying a magnetic field to the support base is not particularly limited, but it is common to dispose an electromagnet or a permanent magnet near the substrate support base, and what is needed is a thermal conductivity changing member (magnetic field) to be described later. It is possible to apply a magnetic field to a member whose thermal conductivity changes by the application of, and preferably to change the magnitude of the applied magnetic field.

When an electromagnet is used as the magnetic field applying source, the magnitude of the magnetic field may be changed by the current supplied to the electromagnet, and when a permanent magnet is used, the relative positions of the heat conductivity changing member and the magnet may be changed. Good.

The member whose thermal conductivity changes by the application of a magnetic field is arranged on the supporting surface of the supporting table, that is, between the substrate and the supporting table, or inside the supporting table. Typically, a material exhibiting a magnetoresistive effect is used. obtain. For example, a suitable substrate (a substrate different from the thin film process substrate, hereinafter referred to as a thermal control substrate)
Above, a material exhibiting an anisotropic magnetoresistive effect, such as NiFe
Film, or a magnetic artificial lattice film in which a ferromagnetic layer and a non-magnetic metal layer are periodically laminated, for example, a Co / Cu periodic laminated film, or a spin valve film composed of one laminated unit of a magnetic artificial lattice material (that is, Co / Cu / This is a member provided with (a sandwich film in which a non-magnetic metal layer typified by Cu / CoFe is sandwiched between magnetic layers) and the like.

In the materials exhibiting the magnetoresistive effect, the electric resistance is changed by the application of the magnetic field, and at the same time, the thermal conductivity is changed according to the Wiedemann-Franz rule. That is, the Wiedemann-Franz law states that the ratio of the thermal conductivity and the electrical conductivity of a material is constant at a constant temperature, so that a material exhibiting the above-mentioned magnetoresistive effect changes the electrical resistance due to the application of a magnetic field. As a result, the thermal conductivity changes.
This change in the thermal conductivity basically follows the change in the applied magnetic field, and thus is extremely fast.

When the heat capacity of the substrate on which the thin film is to be formed is not so large (generally not so large), is a heat control substrate provided with a material exhibiting a magnetoresistive effect placed in a substrate support base? If it is provided between the substrate support and the thin film substrate, it is possible to control the temperature of the thin film process substrate by changing the thermal conductivity of the material exhibiting the magnetoresistive effect.

As one of the concrete embodiments, a sheath heater or the like which has been generally used for controlling the substrate temperature is embedded in the substrate supporting table, and the thermal control for the heat control as described above is performed on the supporting surface of the supporting table. A member (hereinafter referred to as a magnetoresistive member) on which a material exhibiting a magnetoresistive effect is formed is provided on the substrate,
A thin film substrate is placed on it.

When the sheath heater is energized in this state,
The thin film process substrate reaches a certain temperature with a time response determined by thermal constants such as heat capacity and thermal conductivity of the system. At this time, the thin film process substrate has a temperature difference determined by the thermal constant of the system, and becomes a steady value at a lower temperature than the heater and the support.

For example, the thin film process substrate is heated to a predetermined temperature without applying a magnetic field to the magnetoresistive member, and for example, the film member A whose predetermined temperature is the optimum film forming temperature has a predetermined thickness on the thin film process substrate. Then, for example, when a predetermined magnetic field is applied to the magnetoresistive effect member to bring it into a state of high thermal conductivity, the thermal constant of the system changes, so that the temperature of the thin film process substrate changes the magnetic field to the magnetoresistive effect member. It will be higher than in the non-applied state.

The time response at this time is extremely quick as compared with the case where the energizing current of the heater is changed. This is because when heating and cooling with a heater, it is generally necessary to wait for the thermal response of the heater itself and the substrate support, which have a very large heat capacity, whereas the change in thermal conductivity of the magnetoresistive effect member is extremely sharp. This is because the thermal capacities of the heat control substrate and the thin film process substrate are generally small, and at least smaller than that of the heater / support.

In this way, the thin film process substrate can be held at the second predetermined temperature with a rapid thermal response, and the film member B whose second predetermined temperature is the optimum film forming temperature is the above film member. By forming it on A, the optimum thin film can be formed.

In addition to such film formation, when the present invention is applied to, for example, batch processing of a multilayer film, the optimum processing can be performed by the same idea, and the present invention is also applied when forming or processing a single layer film. This enables highly accurate temperature control with good responsiveness.

As described above, according to the thin film processing apparatus of the present invention, the member whose thermal conductivity is changed by the magnetic field applied from the means for applying the magnetic field is provided in the vicinity of the substrate on which the thin film process is performed. Method, CVD method, plasma polymerization method, CDE method, RIE method, ashing method, etc. In all thin film processes, it is possible to control the substrate temperature with high-speed response, high accuracy and large area, and to form and process the optimum thin film. Can be performed with high industrial productivity.

[0024]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a configuration diagram of a thin film processing apparatus according to an embodiment of the present invention, more specifically, a sputtering apparatus, and FIG. 2 is a horizontal sectional view thereof. As shown in these figures, this apparatus has a sputtering chamber 10 in which an upper part of a substrate support base 3 is arranged with its surface horizontal. The substrate support base 3 is for rotating the substrate support base. It is connected to the motor 6. On the support surface of the substrate support base 3, the magnetoresistive effect member 1 as a member whose thermal conductivity changes with a magnetic field
Is provided, and the thin film process substrate 2 is supported thereon.

An infrared lamp 5 for heating the substrate support 3 is provided above the substrate support 3. Also,
A pair of electromagnets 41 as magnetic field applying means are provided on the outer peripheral side of the substrate support base 3, and these electromagnets 41 are fed from an electromagnet power source 42.

Four sputtering sources 71, 72, 73, 74 are arranged at the bottom of the sputtering chamber 10, and sputtering targets 81, 82, 8 are placed on the four sputtering sources 71, 72, 73, 74, respectively.
3, 84 are arranged, and shutters 91, 92, 93, 94 are respectively provided above them. Further, sputtering power sources 101, 102, 103, 104 are connected to the respective sputtering sources 71, 72, 73, 74 (only the sputtering power sources 101, 102 are shown).

A gas introduction system 11 and a gas exhaust system 12 are connected to the side surface of the sputtering chamber 10. FIG.
FIG. 3 is a sectional view showing an example of a thin film formed on the magnetoresistive member 1 and the thin film process substrate 2 thereon.
That is, it shows the state after the sputtering process is completed. In the magnetoresistive member 1 in this example, a magnetization rotation film 1b, a non-magnetic metal film 1c, a magnetization fixed film 1d, and a magnetization fixed film 1e are sequentially formed on a heat control substrate 1a, and a spin valve type magnetic film is formed. It is made of a material that exhibits a resistance effect. A thin film process substrate 2 is supported on the magnetoresistive member 1, and a transparent electrode film 21, an insulating film 22, an electroluminescent (EL) film 23, and
Further, the electron emission electrode film 24 is sequentially formed, and constitutes a thin film cold cathode device.

As a specific material of the magnetoresistive effect member 1 of this embodiment, the heat control substrate 1a is a Si wafer, and the magnetization rotation film 1 is used.
b is CoFe, non-magnetic metal film 1c is Cu, and magnetization fixed film 1
d is CoFe, the magnetization fixed film 1e is FeMn, and each film was formed by a sputtering apparatus different from that shown in FIG.

As the material used for the thin film cold cathode device, the thin film process substrate 2 is a Si substrate and the transparent electrode film 21 is ITO.
(Indium tin oxide), insulating film 22 is Ta ₂ O
₃ , the EL film 23 is ZnS, and the electron emission electrode film 24 is Au. The optimum deposition temperature for these films was 200 ° C. for ITO and 180 ° for Ta ₂ O _{5 as} a result of preliminary experiments conducted in advance.
C., ZnS is 160.degree. C., Au is 180.degree.

In forming the above-mentioned thin film cold cathode device by the apparatus of the present invention, the four sputtering sources 71, 72, 73 and 74 described above are provided with targets of ITO target 81 and Ta ₂ O ₅ target 82, respectively. Z
An nS target 83 and an Au target 84 are attached.

Prior to explaining the procedure for carrying out the present invention,
The relationship between the magnetic field (H) and the thermal conductivity (k) of the magnetoresistive member 1 will be described. The initial magnetization direction of each magnetic layer of the magnetoresistive effect member 1 of FIG. 3 used in this example is the direction shown by the arrow in FIG. 3, and such a magnetization direction has the highest coercive force in the magnetic layer. The magnetization direction of the magnetization pinned film 1e can be set in the direction shown in the figure by applying, for example, an external magnetic field, and the magnetization of the magnetization pinned film 1d is exchanged with the magnetization pinned film 1e by the exchange magnetic field from the magnetization pinned film 1e. The magnetizations of the magnetization rotation film 1b are arranged in the same direction, and the magnetization of the magnetization rotation film 1b is fixed.
The leakage magnetic field from the magnetization fixed film 1d causes the magnetization fixed film 1d to be arranged in the opposite direction to the magnetization.

In this state, when a magnetic field is applied from the outside in the direction opposite to the direction of the initial magnetization of the magnetization rotation film 1b, the magnetization of the magnetization rotation film 1b rotates in the magnetization direction of the magnetization fixed film 1d, and the magnetization of the magnetization rotation film 1b. The electrical conductivity of the magnetoresistive effect member 1 changes according to the relative angular relationship between the magnetization of the magnetization fixed film and
As a result, the thermal conductivity of the magnetoresistive effect member 1 changes according to the Wiedemann-Franz rule described above.

FIG. 4 is a diagram schematically showing the change of the thermal conductivity k with respect to the magnetic field H together with the magnetization direction of the magnetization rotation film and the magnetization direction of the magnetization fixed film. The initial state in which the magnetization is antiparallel is the lowest k, and when the magnetization of the magnetization rotation film starts to rotate in the direction of the magnetization fixed film, k gradually increases, reaches half the saturation value in the orthogonal state, and continues rotation. The maximum saturation value is reached in the parallel state. There is almost no time delay in the change of k with respect to H.

Next, a procedure for actually forming the thin film with the sputtering apparatus having the above structure will be described. First, the thin film process substrate 2 on which each thin film is not formed is mounted on the magnetoresistive effect member 1 previously installed on the substrate support 3 of the sputtering apparatus, and then the sputtering chamber 10 is closed and the gas exhaust system 12 is installed. Is evacuated until the pressure in the sputtering chamber 10 becomes 10 ⁻⁶ Torr, and then a 1% O ₂ —Ar mixed gas is added to the gas through the gas introduction system 11 to 20
It was introduced into the sputtering chamber 10 at a flow rate of 0 sccm, and the pressure in the sputtering chamber 10 was maintained at 5 mTorr.

Next, the infrared lamp 5 was turned on and the power source 42 was turned on to energize the electromagnet 41 to set the thermal conductivity k of the magnetoresistive effect member 1 to a high saturation value. After allowing the thin film process substrate 2 to reach a temperature of 200 ° C., I
A DC voltage is applied from a power source 101 to a sputtering source 71 having a TO target 81 installed, plasma is generated on the target, and after conditioning for a while with the shutter 91 closed, the thin film process substrate 2 is rotated by a motor 6 to release the shutter. 91 was opened, and sputtering was continued for 10 minutes to form an ITO film having a film thickness of 100 nm on the thin film process substrate 2.

After that, when the current passed through the electromagnet 41 was decreased to decrease k, the temperature of the thin film process substrate 2 reached a constant value of 180 ° C. in several tens of seconds. While adjusting the temperature, a high frequency power is applied from a power source 102 to a sputtering source 72 in which a Ta ₂ O ₅ target 82 is installed to generate plasma, and the shutter 92 is conditioned to close the substrate to reach a constant substrate temperature. After a few tens of seconds, the shutter 92 is opened, and spatter for 30 minutes is continued to perform IT.
A Ta ₂ O ₅ film having a film thickness of 300 nm was formed on the O film 21.

Next, when the current passing through the electromagnet 41 is further reduced and k is further reduced, the thin film process substrate 2 is produced in several tens of seconds.
The temperature reached a constant value of 160 ° C. Introduced gas is 1% O
After replacing the _2- Ar mixed gas with pure Ar, the power source 1 is supplied to the sputtering source 73 in which the ZnS target 83 is installed.
High frequency power from 03. After conditioning, open the shutter 93 and continue sputtering for 20 minutes.
A ZnS film having a film thickness of 500 nm was formed on the ₂ O ₅ film.

After that, the current supplied to the electromagnet 41 is changed to Ta ₂
After returning to the same value as when the O ₅ film was formed, a DC voltage was applied from the power source 104 to the sputtering source 74 on which the Au target 84 was installed, the shutter 94 was opened, and sputtering was performed for 30 seconds to form a film on the ZnS film. An Au film having a thickness of 10 nm was formed.

After the film formation is completed in this manner, the energization of the electromagnet 41 is stopped, the infrared lamp 5 is turned off, the motor 6 is stopped, and the gas supply is stopped until the substrate temperature is cooled to near room temperature. The thin film process substrate was left to stand, then the sputtering chamber 10 was opened to the atmosphere, and the thin film cold cathode device having the above thin film formed on the substrate 2 was taken out.

FIG. 5 shows the relationship between the elapsed time t in forming each of the above films, the substrate temperature T of the thin film process substrate, and the thermal conductivity k of the magnetoresistive effect member. As shown in this figure, it was confirmed that the thermal conductivity k of the magnetoresistive member changes extremely sharply by changing the magnetic field, and the substrate temperature T is controlled with extremely high responsiveness accordingly. .

The characteristics of the thin-film cold cathode device thus formed were measured by using a measuring device in which the anode was placed so as to face the Au film surface of the device, and a frequency of 1 kHz was applied between the ITO film and the Au film.
A pulse voltage of z was applied and a direct current voltage of several kV was applied between the Au film and the anode, and the relationship between the pulse voltage value and the electron current emitted from the thin film cold cathode device was investigated and evaluated.

As a result, the electron current rose from a pulse voltage of about 120 V at pp, and an emission current density of about 30 nA / cm ^{2 at} maximum was obtained. Next, for comparison, a similar thin film cold cathode device was formed by the sputtering apparatus of FIG. 1 according to the conventional technique. That is, in this comparative example, thermal control using the magnetoresistive member of the present invention is not performed,
The temperature of the thin film process substrate 2 during film formation was constant at 160 ° C., which is the optimum condition for the ZnS film, and everything else was carried out according to the above-described embodiment of the present invention.

The thin-film cold cathode device thus formed was evaluated by the same method as the temperature-controlled thin film cold-cathode device using the magnetoresistive effect member, and the rising voltage of the emission current was about 180V. The emission current density was high and the emission current density was as low as about 10 nA / cm ² .

The reason for this is that even if only the ZnS film, which is the heart of the thin-film cold cathode device, which has the electron accelerating function, is formed at the optimum temperature, the electrode film and the insulating film are not formed at the optimum temperature, and the film quality is poor. If it is sufficient, it can be considered that, for example, any of the electron storage function at the interface between the ZnS film and the insulating film, the electrical conductivity of the ITO electrode, the electron tunneling property of the Au film, and the like will be hindered.

Next, for further comparison, a thin film cold cathode device was formed also according to the prior art. In this comparative example, the formation temperature of each film was set to the same optimum temperature as that of the above-described embodiment of the present invention. However, the substrate temperature control was performed not by the heat control using the magnetoresistive member of the present invention, but simply by changing the amount of electric power supplied to the infrared lamp 5 in FIG.

In this example, while the films were formed, they were left in an Ar stream until the substrate temperature became constant, but at most 20 ° C.
Even if the temperature is lowered or raised to some extent, it takes 10 minutes or more because the heat capacity of the entire heating system is large.

The characteristics of the thin film cold cathode device thus formed were evaluated by the same method as described above. In this example, the rising voltage of the electron current was a value of about 120 V, which was the same as that of the above-mentioned embodiment of the present invention, but the maximum value of the emission current density was 20 nA / cm ^2, which was 30 n obtained in the embodiment of the present invention.
It did not reach A / cm ² .

The reason for this is that, even in the Ar flow, since the ZnS film before the Au film formation was exposed for a long time of 10 minutes, impurities remaining in the sputtering chamber, particularly water-based impurities, were adsorbed on the film surface. It is considered that the surface-altered layer was formed.

As described above, it was confirmed that when the device of the present invention was used, it was possible to perform highly accurate temperature control with better response than in the conventional case. In the above-described embodiments and comparative examples of the present invention, the substrate temperature control technique of the present invention is applied.
Although an example applied to a sputtering apparatus, which is a representative of VD apparatuses, has been described in detail, the present invention is applicable to vapor deposition apparatuses other than sputtering apparatuses, PVD apparatuses such as MBE apparatuses, and thermal CVD, plasma CVD, photo CVD, MOCVD, and the like. It is obvious from the gist of the present invention that it can be applied to all thin film processing apparatuses such as a CVD apparatus, a plasma polymerization apparatus, and a thin film processing apparatus such as a milling apparatus, a CDE apparatus, an RIE apparatus, and an ashing apparatus.

Further, the present invention is effective not only in the continuous formation of the multilayer film described in the examples but also in the formation of a single layer film from the viewpoint of substrate temperature controllability. Further, the same applies to the batch processing of a multilayer film and the processing of a single layer film, and the present invention is applicable without particular limitation to the target film material.

[0051]

According to the present invention, there is provided a thin film processing apparatus capable of controlling a substrate temperature which is excellent in high-speed response, high accuracy and large area. Is improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a thin film processing apparatus according to an embodiment of the present invention.

2 is a horizontal cross-sectional view of the device of FIG.

FIG. 3 is a cross-sectional view showing an example of a magnetoresistive member as a member whose thermal conductivity is changed by a magnetic field used in the device of the present invention and a thin film formed on the thin film process substrate thereon.

FIG. 4 is a diagram showing an example of characteristics of a magnetoresistive effect member used for implementing the present invention.

FIG. 5 is a diagram showing changes in the temperature history of the thin film process substrate and the thermal conductivity of the magnetoresistive effect member when a thin film is formed by the apparatus according to the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetoresistive effect member, 1a ... Heat control substrate, 1b ... Magnetization rotation film, 1c ... Nonmagnetic metal film, 1d ... Magnetization fixed film, 1
e ... Magnetization fixing film, 2 ... Thin film process substrate, 3 ... Substrate support, 5 ... Infrared lamp, 6 ... Motor, 10 ... Sputtering chamber, 11 ... Gas introduction system, 12 ... Gas exhaust system, 21 ... Transparent electrode film, 22 ... Insulating film, 23 ... EL film, 24 ... Gas discharge electrode film, 41 ... Electromagnet, 42 ... Electromagnet power supply, 71, 7
2, 73, 74 ... Sputtering source, 81, 82, 8
3, 84 ... Sputtering target, 101, 102
… Sputter power supply.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // G11B 5/31 M 8940-5D

Claims (1)

[Claims] 1. A process chamber, a support table provided in the chamber for supporting a substrate on which a thin film process is performed, a means for performing a thin film process on the substrate supported by the support table, and a magnetic field on the support table. And a member that is provided inside the support base or on the support surface of the support base and whose thermal conductivity is changed by the magnetic field applied from the means for applying the magnetic field. Thin film processing equipment.