JP5256466B2 - Film forming apparatus and oxide thin film forming substrate manufacturing method - Google Patents

Description

  The present invention relates to a film forming apparatus and a method for manufacturing a substrate for forming an oxide thin film, and in particular, a film forming apparatus and a film for forming an oxide thin film that can form a metal film having excellent crystallinity and flatness on a substrate. The present invention relates to a method for manufacturing a substrate.

Hereinafter, a conventional method for manufacturing a substrate for forming an oxide thin film will be described.
First, a first Pt thin film having a thickness of about 5 to 10 nm is formed on a substrate by sputtering. The substrate temperature at this time is about 650 ° C. Next, a second Pt thin film having a thickness of about 100 to 200 nm is formed on the first Pt thin film by a vacuum deposition method. The substrate temperature at this time is 300 ° C. or less.

  In the conventional method for manufacturing a substrate for forming an oxide thin film, a first Pt thin film excellent in crystallinity and orientation is formed by high-temperature sputtering at 650 ° C., and then the second Pt is formed at a low temperature of 300 ° C. or lower. Deposit a thin film. Thereby, the second Pt thin film can inherit the crystallinity and orientation of the first Pt thin film, and as a result, a second Pt thin film having excellent crystallinity and orientation can be produced (for example, (See Patent Documents 1 and 2).

JP 2003-213402 (paragraphs 0029 to 0039, FIG. 3) JP-A-3-39014 (paragraphs 0033-0037, FIG. 1)

  However, in the conventional method for manufacturing a substrate for forming an oxide thin film, the first Pt thin film is formed by sputtering at a high substrate temperature of 650 ° C., so that the surface of the first Pt thin film is uneven. It becomes large and flatness deteriorates. Since the second Pt thin film formed on the first Pt thin film inherits the crystallinity and morphology of the first Pt thin film as they are, the surface of the second Pt thin film becomes uneven and flat. Sexuality gets worse.

  Further, even when Pt is replaced with Ir or Ru by the conventional method for manufacturing a substrate for forming an oxide thin film, there is a problem similar to the case of Pt described above.

  The present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to form a film forming apparatus and an oxide thin film film forming substrate capable of forming a metal film having excellent crystallinity and flatness on the substrate. It is in providing the manufacturing method of.

In order to solve the above problems, a film forming apparatus according to the present invention includes a process chamber,
A sputtering target disposed in the process chamber;
A power source for applying power to the sputtering target;
A deposition source disposed in the process chamber;
An evacuation mechanism for evacuating the process chamber;
A gas introduction mechanism for introducing gas into the process chamber;
A substrate holding mechanism disposed in the process chamber and holding a substrate;
A heating mechanism for heating the substrate provided in the substrate holding mechanism;
A film forming apparatus comprising:
The film forming apparatus holds the substrate by the substrate holding mechanism, and after forming the first metal film on the substrate at a temperature of 300 ° C. or lower by applying electric power to the sputtering target and discharging it, A second metal film is formed on the first metal film at a temperature of 500 ° C. to 1000 ° C. by applying electric power to the sputtering target and discharging, and the first metal film is deposited by a deposition method using the deposition source. A third metal film is formed on the second metal film.

  According to the film forming apparatus of the present invention, since the first metal film can be formed on the substrate by sputtering at a temperature of 300 ° C. or lower, the flatness of the surface of the first metal film can be improved. . Since the second and third metal films formed on the first metal film inherit the crystallinity and morphology of the first metal film as they are, the surfaces of the second and third metal films are also flat. Can be improved. In addition, since the second metal film is formed on the first metal film by sputtering at a temperature of 500 ° C. to 1000 ° C., the crystallinity of the second metal film can be improved. The crystallinity of the third metal film formed on the metal film can also be improved.

  Further, in the film forming apparatus according to the present invention, the sputtering target may be a pair of opposed targets, and the first and second targets are discharged by applying electric power to the pair of targets. It is also possible to form a second metal film. Thereby, plasma damage to the substrate can be reduced as compared with a parallel plate type sputtering apparatus having a high ion density.

  In the film forming apparatus according to the present invention, each of the first to third metal films is preferably made of any one of Pt, Ir, and Ru.

The method for manufacturing a substrate for forming an oxide thin film according to the present invention includes a step of forming a first metal film on a substrate by a sputtering method at a temperature of 300 ° C. or lower,
Forming a second metal film on the first metal film by a sputtering method at a temperature of 500 ° C. to 1000 ° C .;
Forming a third metal film on the second metal film by vapor deposition at a temperature of 300 ° C. or lower;
It is characterized by comprising.

  Moreover, in the manufacturing method of the substrate for forming an oxide thin film according to the present invention, the first metal film is formed between the step of forming the first metal film and the step of forming the second metal film. It is preferable to further comprise a step of firing the metal film at a temperature of 500 ° C to 1000 ° C.

  Moreover, in the manufacturing method of the oxide thin film film-forming substrate according to the present invention, the sputtering method is preferably sputtering using a pair of opposing targets.

  In the method for manufacturing a substrate for forming an oxide thin film according to the present invention, each of the first to third metal films is preferably made of any one of Pt, Ir, and Ru.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a configuration diagram showing an outline of a film forming apparatus according to an embodiment of the present invention. This film formation apparatus is an apparatus capable of performing film formation by sputtering of an opposing target and film formation by an evaporation method.

  As shown in FIG. 1, the film forming apparatus has a process chamber 1, and a substrate holding mechanism 2 is disposed in the process chamber 1. The substrate holding mechanism 2 includes a substrate holding unit 3 that holds a substrate, a substrate heating heater 4 that heats a substrate provided in the substrate holding unit 3, and a substrate cooling mechanism (not shown) that cools the substrate. A substrate rotation mechanism (substrate rotation mechanism) 5 that rotates the substrate holding part 3 as indicated by an arrow 5a and a moving mechanism 6 that moves the substrate holding part 3 as indicated by an arrow 6a are provided.

  An adhesion prevention plate 7 is attached to the inner wall of the process chamber 1. This deposition preventing plate 7 is for preventing the thin film from directly adhering to the inner wall of the process chamber 1 when the film forming apparatus is operated.

  An opposing sputter cathode 8 is provided on the side of the process chamber 1. A counter sputtering cathode shutter 9 is disposed between the counter sputtering cathode 8 and the process chamber 1, and the counter sputtering cathode shutter 9 is for partitioning the counter sputtering cathode 8 and the process chamber 1. .

  The counter sputter cathode 8 includes a counter target, and the counter target is a pair of targets 11 and 12 that face each other in parallel with a predetermined space therebetween. The targets 11 and 12 are targets made of any one of Pt, Ir, and Ru. Permanent magnets (not shown) as magnetic field generating means are arranged on the back side of each of the targets 11 and 12. The magnetic field generating means generates a magnetic field in a direction substantially perpendicular to the back surfaces of the targets 11 and 12, and is configured to generate a magnetic field between the target 11 and the target 12. Further, the substrate holding mechanism 2 can position the substrate on the side surface side of the counter target.

  A pulse power source (not shown) for applying a pulse wave is connected to the counter target, and power by the pulse wave is applied to the counter target by this pulse power source. The power source is not limited to the pulse power source, and other power sources such as a power source that applies an asymmetric pulse wave, a power source that applies a sine wave, and the like can also be used.

  The counter sputter cathode 8 is provided with a gas introduction mechanism (not shown). This gas introduction mechanism has a mass flow controller (MFC).

  A deposition source 10 of any one of Pt, Ir, and Ru is disposed below the process chamber 1. The vapor deposition source 10 has a crucible and an electron gun (EBgun) containing any of Pt, Ir and Ru. A cooling mechanism (not shown) is attached to the crucible. The vapor deposition source 10 irradiates and heats the evaporation material with an electron beam from an electron gun to evaporate any of Pt, Ir, and Ru.

  The process chamber 1 is connected to an exhaust pump system (evacuation mechanism) (not shown) for reducing the internal pressure of the process chamber 1 to a predetermined pressure.

  Next, a method for forming a thin film on a substrate using the film forming apparatus shown in FIG. 1 will be described with reference to FIGS. An oxide thin film deposition substrate is finally produced using this deposition apparatus. 2A to 2D are cross-sectional views for explaining a method for manufacturing a substrate for forming an oxide thin film according to an embodiment of the present invention.

  First, the substrate is held by the substrate holding unit 3 shown in FIG. 1, the substrate holding unit 3 is moved by the pendulum by the moving mechanism 6, and the substrate held by the substrate holding unit 3 is opposed to the counter sputter cathode 8. That is, the substrate is opposed to the side surfaces of the pair of targets 11 and 12. Next, the process chamber 1 is evacuated by an exhaust pump system while an inert gas (for example, Ar) is introduced into the process chamber 1 by adjusting the flow rate by the mass flow controller by the gas introduction mechanism. The pressure is reduced to a predetermined pressure to obtain a vacuum state.

  Next, a predetermined power is applied to the counter target from the pulse power source, and the target 11 and the target 12 are discharged, and sputtering is performed while confining the plasma between the targets by the magnetic field generating means. The substrate temperature at this time is controlled by the substrate heating heater 4 to 300 ° C. or less (preferably about 200 ° C.). In this way, as shown in FIG. 2A, the first metal film 14 having a thickness of 5 to 25 nm made of any one of Pt, Ir, and Ru is formed on the substrate 13.

  Next, the first metal film 14 is heated to a temperature of 500 ° C. to 1000 ° C. (preferably 500 ° C. to 750 ° C., more preferably 650 ° C.) by the substrate heating heater 4. Thereby, as shown in FIG. 2B, the first metal film 14 is fired and crystallized. At this time, the atmosphere in the process chamber 1 may be a vacuum state into which an inert gas is introduced, or may be an air atmosphere.

  Next, the process chamber 1 is evacuated by an exhaust pump system while an inert gas (for example, Ar) is introduced into the process chamber 1 by adjusting the flow rate by the mass flow controller by the gas introduction mechanism. The pressure is reduced to a predetermined pressure to obtain a vacuum state.

  Next, a predetermined power is applied to the counter target from the pulse power source, and the target 11 and the target 12 are discharged, and sputtering is performed while confining the plasma between the targets by the magnetic field generating means. The substrate temperature at this time is controlled by the substrate heating heater 4 to 500 ° C. to 1000 ° C. (preferably 500 ° C. to 750 ° C., more preferably 650 ° C.). In this way, as shown in FIG. 2C, the second metal film 15 having a thickness of 5 to 25 nm made of any one of Pt, Ir, and Ru is formed on the first metal film 14.

  Next, the output supply to the counter target is stopped, and the sputtering is finished. The supply of inert gas is also stopped. The substrate heating heater 4 is also turned off.

  Thereafter, the substrate holding unit 3 shown in FIG. 1 is moved by the moving mechanism 6 as indicated by an arrow 6 a so that the substrate holding unit 3 faces the vapor deposition source 10. Next, the substrate 13 is cooled by the substrate cooling mechanism to lower the substrate temperature to 300 ° C. or lower.

  Next, an output is supplied to the evaporation source 10 to evaporate any one of Pt, Ir, and Ru to perform evaporation on the substrate. As a result, the third metal film 16 having a thickness of about 100 to 200 nm made of any one of Pt, Ir, and Ru is deposited on the second metal film 15. At this time, in order to improve the in-plane film thickness distribution of the third metal film, the substrate rotation mechanism 5 rotates the substrate 13 in the plane. That is, while rotating the substrate 13 in the plane, the electron gun is irradiated with an electron beam and heated to evaporate any of Pt, Ir, and Ru, and the third metal is formed on the second metal film 15. A film 16 is formed.

  Subsequently, the output supply to the vapor deposition source 10 is stopped, and vapor deposition is complete | finished. In this way, a substrate for forming an oxide thin film is manufactured.

  The oxide thin film deposition substrate shown in FIG. 2D has a substrate 13, and a first metal film 14 having a thickness of about 5 to 25 nm is formed on the substrate 13 by sputtering. A second metal film 15 having a thickness of about 5 to 25 nm is formed on the first metal film 14 by sputtering, and a second metal film 15 having a thickness of about 100 to 200 nm is formed on the second metal film 15 by vapor deposition. 3 metal film 16 is formed.

  According to the above embodiment, since the first metal film 14 is formed on the substrate 13 by sputtering at a temperature of 300 ° C. or lower (preferably about 200 ° C.), damage to the substrate 13 is reduced. Flatness can be improved by reducing the unevenness of the surface of the first metal film 14. Since the second and third metal films 15 and 16 formed on the first metal film 14 inherit the crystallinity and morphology of the first metal film 14 as they are, the second and third metal films The flatness of the surfaces 15 and 16 can also be improved.

  In the above embodiment, the second metal film 15 is formed on the first metal film 14 by sputtering at a temperature of 500 ° C. to 1000 ° C. (preferably 500 ° C. to 750 ° C., more preferably 650 ° C.). Therefore, the crystallinity of the second metal film 15 can be improved. Further, the crystallinity of the third metal film 16 formed on the second metal film 15 can be improved.

  In the above embodiment, since the first and second metal films 14 and 15 are formed by the opposed sputtering cathode 8 having the pair of opposed targets 11 and 12, the parallel plate type sputtering having a high ion density. Compared with the apparatus, plasma damage to the substrate 13 can be reduced. Therefore, it is effective when a semiconductor element or the like is formed on the substrate 13. Further, by using the counter sputter cathode 8, it is easy to control the film thickness when forming the first and second metal films 14 and 15 having a small film thickness.

  In the above embodiment, an electron beam evaporation (EB evaporation) method using an electron beam is used. However, other evaporation methods can be used, for example, a resistance heating method can be used. .

[Example]
Next, an experiment for manufacturing a substrate for forming an oxide thin film according to the above embodiment was performed. The experimental conditions are as follows.

(Deposition conditions for first metal film)
Apparatus: Film forming apparatus shown in FIG. 1 Substrate: Si substrate with SiO ₂ film formed on the surface Material of first metal film: Pt
Substrate temperature: 200 ° C
Inert gas: Ar
Ar flow rate: 20 cc / min Pressure: 0.4 Pa
Film thickness: 25nm
DC power of pulse power supply: 100W

(Baking conditions for the first metal film)
Apparatus: Film forming apparatus shown in FIG. 1 Baking temperature: 650 ° C.
Atmosphere: Atmosphere

(Conditions for forming the second metal film)
Apparatus: Film forming apparatus shown in FIG. 1 Material of second metal film: Pt
Substrate temperature: 650 ° C
Inert gas: Ar
Ar flow rate: 20 cc / min Pressure: 0.4 Pa
Film thickness: 25nm
DC power of pulse power supply: 100W

(Conditions for forming the third metal film)
Apparatus: Film forming apparatus shown in FIG. 1 Deposition source: Electron beam deposition Electron gun output: 10 kV, 240 mA
Material of the third metal film: Pt
Substrate temperature: 150 ° C
Film thickness: 150nm

[Comparative example]
Next, a substrate for forming an oxide thin film was manufactured by the method described in the related art as a comparative example. The conditions will be described.

(First Pt thin film deposition conditions)
Sputtering apparatus: Parallel plate type Substrate: Si substrate with SiO ₂ film formed on the surface Substrate temperature: 650 ° C.
Inert gas: Ar
Ar flow rate: 20 cc / min Pressure: 0.4 Pa
Film thickness: 50nm
DC power: 100W

(Deposition conditions for the second Pt thin film)
Deposition source: Electron beam deposition Electron gun output: 10 kV, 240 mA
Substrate temperature: 150 ° C
Film thickness: 150nm

  3 and 4 are diagrams showing the results of X-ray diffraction (Pt-XRD evaluation results) of the oxide thin film deposition substrates according to the examples and the comparative examples, respectively.

  As shown in FIG. 3, the reflection intensity of the Pt thin film of the oxide thin film deposition substrate according to the conventional method of the comparative example is 200000 cps, whereas the Pt thin film of the oxide thin film deposition substrate according to the present invention of the embodiment is used. The reflection intensity of was 400000 cps. That is, it was confirmed that the strength of the Pt thin film of the example was doubled as compared with the Pt thin film of the comparative example. This indicates that the flatness of the Pt thin film of the example has been remarkably improved.

  As shown in FIG. 4, the half-value width of the Pt thin film of the substrate for forming an oxide thin film according to the conventional method of the comparative example is 1.5 °, whereas the film for forming an oxide thin film according to the present invention of the embodiment is used. The half width of the Pt thin film of the substrate was 0.6 °. This indicates that the Pt thin film of the example is as close to a single crystal as possible.

  In addition, this invention is not limited to the said embodiment and Example, It can be implemented in various changes within the range which does not deviate from the main point of this invention.

It is a block diagram which shows the outline of the film-forming apparatus by embodiment which concerns on this invention. (A)-(D) are sectional drawings for demonstrating the manufacturing method of the board | substrate for oxide thin film film formation by embodiment of this invention. It is a figure which shows the Pt-XRD evaluation result by an Example and each comparative example. It is a figure which shows the Pt-XRD evaluation result by an Example and each comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Process chamber 2 ... Substrate holding mechanism 3 ... Substrate holding part 4 ... Heater for substrate heating 5 ... Substrate rotation mechanism (substrate rotation mechanism)
DESCRIPTION OF SYMBOLS 6 ... Moving mechanism 5a, 6a ... Arrow 7 ... Deposit board 8 ... Opposite sputtering cathode 9 ... Opposite sputtering cathode shutter 10 ... Deposition source 11, 12 ... A pair of target 13 ... Substrate 14 ... 1st metal film 15 ... 1st 2 metal film 16 ... 3rd metal film

Claims (7)

A process chamber,
A sputtering target disposed in the process chamber;
A power source for applying power to the sputtering target;
A deposition source disposed in the process chamber;
An evacuation mechanism for evacuating the process chamber;
A gas introduction mechanism for introducing gas into the process chamber;
A substrate holding mechanism disposed in the process chamber and holding a substrate;
A heating mechanism for heating the substrate held by the substrate holding mechanism;
A method of manufacturing a substrate for forming an oxide thin film using a film forming apparatus comprising:
The substrate is held by the substrate holding mechanism, and after the first metal film is formed on the substrate at a temperature of 300 ° C. or less by applying electric power to the sputtering target and discharging it, the electric power is applied to the sputtering target. By applying and discharging, a second metal film is formed on the first metal film at a temperature of 500 ° C. to 1000 ° C., and on the second metal film by an evaporation method using the evaporation source. A method of manufacturing a substrate for forming an oxide thin film, comprising forming a third metal film.   2. The manufacturing method of an oxide thin film deposition substrate according to claim 1, wherein the sputtering target is a pair of opposing targets, and an electric power is applied to the pair of targets to be discharged between the pair of targets. Method. Forming a first metal film on the substrate by sputtering at a temperature of 300 ° C. or lower;
Forming a second metal film on the first metal film by a sputtering method at a temperature of 500 ° C. to 1000 ° C .;
Forming a third metal film on the second metal film by vapor deposition at a temperature of 300 ° C. or lower;
The manufacturing method of the board | substrate for oxide thin film film formation characterized by comprising.   4. The method according to claim 3, wherein the first metal film is baked at a temperature of 500 ° C. to 1000 ° C. between the step of forming the first metal film and the step of forming the second metal film. The manufacturing method of the board | substrate for oxide thin film film formation which further comprises the process.   5. The method for manufacturing a substrate for forming an oxide thin film according to claim 3, wherein the sputtering method is sputtering using a pair of opposing targets.   6. The method for manufacturing a substrate for forming an oxide thin film according to claim 1, wherein each of the first to third metal films is made of any one of Pt, Ir, and Ru. A process chamber,
A sputtering target disposed on the side of the process chamber;
A power source for applying power to the sputtering target;
A vapor deposition source disposed below the process chamber;
An evacuation mechanism for evacuating the process chamber;
A gas introduction mechanism for introducing gas into the process chamber;
A substrate holding mechanism disposed in the process chamber and holding a substrate;
By moving the substrate holding mechanism with a pendulum, the substrate is moved between a position where the substrate held by the substrate holding mechanism faces the sputtering target and a position where the substrate faces the vapor deposition source. A moving mechanism;
A heating mechanism for heating the substrate held by the substrate holding mechanism;
A film forming apparatus comprising: