JP2937187B1 - Superconducting thin film forming method, heater unit used in the method, and superconducting thin film forming apparatus - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To form a superconducting thin film on a substrate by sputtering while heating the substrate using a heater unit. SOLUTION: In a heater unit 1 for heating a substrate 30 on which a film is to be formed, a heating element 11 is held on one surface side of a transparent member 12, and a heat reflection film 1 is formed on the other surface of the transparent member 12.
3 is formed. As a result, the heating element 1
The radiant heat from 1 is reflected at the interface between the heat reflection film 13 and the transparent member 12 and is irradiated onto the substrate 30. Heat reflection film 13
Since the interface between the transparent member 12 and the transparent member 12 is in a mirror state even if the surface of the heat reflection film 13 is deformed, the reflection characteristics of the heat reflection film 13 can be improved. Also, the substrate holder 2
In addition, the substrate 30 and the dummy substrate 31 are arranged on the outer periphery thereof so that even if metal scatters from the substrate holder 20 during sputtering, the scattered metal can be prevented from adhering to the substrate 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a film forming method for forming a superconducting thin film on a substrate, a heater unit suitable for the method, and a film forming apparatus.

[0002]

2. Description of the Related Art When a superconducting thin film is formed on a substrate, the substrate is held in a substrate holder, oxygen and argon are introduced into a sputtering apparatus, and the substrate is treated with YBCO as a target. A superconducting film is formed by sputtering while heating to a predetermined temperature.

However, the formation of a superconducting thin film using sputtering has the following problems. (1) The above-described heating of the substrate can be performed using a heater unit. As the heater unit, for example, as shown in FIG.
And a heat ray radiating from the heating element 103 directly and by the heat ray reflection film 10.
One configured to irradiate on the substrate 105 held by the substrate holder 104 by reflection from 1 can be used.

However, in the heater unit having such a configuration, when the surface of the heat ray reflective film 101 becomes non-mirror due to heat or the formation of an oxide film, there is a problem that the reflection characteristics of the heat ray reflective film 101 deteriorate. . (2) The substrate holder 104 is usually made of metal. However, during sputtering, oxygen ions (negative ions) collide with the substrate holder 104 and the scattered metal adheres to the surface of the substrate 101. Problem.

[0005] The present invention has been made in view of the above problems, and has as its object to make it possible to favorably form a superconducting thin film by sputtering.

[0006]

[0007]

[0008]

[0009]

Means for Solving the Problems To achieve the above object,
According to the first and second aspects of the present invention, the substrate (30) and the dummy substrate (31) made of a ceramic material are arranged on the substrate holding portion (20) of the heater unit (1). And heating the substrate (30), and forming a superconducting thin film on the substrate (30) by sputtering in this heated state.

[0010] By arranging the dummy substrate (31) in this manner, scattered matter generated by the collision of negative ions with the substrate holding part (20) during sputtering can be reduced.
Since it can be attached to 1), it is possible to prevent scattered matter from attaching to the substrate (30). According to the third aspect of the present invention, it is possible to provide a heater unit used in the method for forming a superconducting thin film according to the first aspect .
In this case, as in the invention according to claim 4, for heating the substrate
The heater (10) includes a heating element (11) and the heating element (1).
1) A transparent member (12, 121,
122) and the transparent member (12, 121, 122).
The heat ray reflection film (13) formed on the surface on the other surface side is
If configured, the surface of the heat ray reflective film (13) is exposed to heat.
Therefore, or due to the formation of an oxide film, it is no longer a mirror surface
Even if the heat ray reflective film (13) and the transparent member (12, 1
21, 122) does not change the state of the interface,
The reflection characteristics of the projection film (13) are maintained well and the superconducting film is
The formation can take place. Also, the front surface of the heating element (11)
The transparent cover (16) covering the transparent member (12, 121,
122), if it is detachably attached to
The work of replacing the heating element (11) can be facilitated.
You.

According to the fifth and sixth aspects of the present invention, it is possible to provide a film forming apparatus for performing the film forming method according to the first aspect . Note that the reference numerals in parentheses described above indicate the correspondence with specific means described in the embodiment described later.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. FIG. 1 shows a conceptual configuration of a heater unit 1 according to an embodiment of the present invention. In the heater unit 1, the heating element 1 is provided on one surface side of the transparent member 12.
1 and a heat ray reflective film 13 such as Au is formed on the other surface of the transparent member 12. And
The heat rays radiated from the heating element 11 are reflected directly and at the interface between the heat ray reflection film 13 and the transparent member 12 and are irradiated onto the substrate 30 held by the substrate holder 20.

As described above, the heat ray reflective film 13 and the transparent member 12
Is configured to reflect heat rays radiated from the heating element 11 at the interface of the heat ray reflection film 13.
Even if the mirror surface is lost due to heat or due to the formation of an oxide film, the interface between the heat ray reflective film 13 and the transparent member 12 maintains a mirror state, so that the reflection characteristics of the heat ray reflective film 13 should be maintained well. Can be.

In this embodiment, the substrate 30 and the dummy substrate 31 are arranged on the substrate holder 20 at the outer periphery thereof, and a superconducting thin film is formed by sputtering. Thereby, even if oxygen ions collide with the substrate holder 20 during sputtering and metal is scattered,
Since the metal adheres to the dummy substrate 31, it is possible to prevent the metal scattered on the substrate 30 from adhering.

Next, a specific configuration of the heater unit 1 will be described. FIG. 2 shows a cross-sectional configuration of the heater unit 1. The heater unit 1 includes a heating element 11
A first transparent refractory material 121 having a groove shaped to accommodate the heating element 11, a second transparent refractory material 122 on which a heat ray reflective film 13 such as Au is formed, and a third transparent refractory material 14
And a heat insulating material 15. These first to third transparent refractory materials 121, 122, and 14 and the heat insulating material 15
It is fixed by bolting using a through hole not shown in FIG. The first and second transparent refractory materials 12
Reference numerals 1 and 122 correspond to the transparent member 12 in FIG.

The above-mentioned heating element 11 can be formed using a nichrome wire, tungsten, platinum, Kanthal or the like. Further, the first to third transparent refractory materials 121 and 12
Reference numerals 2 and 14 are made of quartz glass, and the heat insulating material 15 is made of a sintered body of alumina. FIG.
1 shows a plan view of a transparent refractory material 121 shown in FIG. This figure is a view of the first transparent refractory material 121 as viewed from the side where it is attached to the second transparent refractory material 122. A groove 121a is formed in a hatched area in the drawing, and a spiral heating element 1 is formed in the groove 121a.
1 is stored. In addition, the through-hole 1 shown in black in the figure
21b is used for bolting with the second and third transparent refractory materials 122 and 14 and the heat insulating material 15, and another through-hole 121c is used to fix the cover holder 17 and the substrate holder 20 described later by bolting. It is for.

The first to third transparent refractory materials 12
1, 122, 14 and insulation 15 are bolted on,
The heating element 11 is housed in the groove 121a of the first transparent refractory material 121. In this state, the heating element 11 and the groove 12
The heating element 11 is formed into a groove 121a by friction with the surface inside 1a.
Maintain the state stored in. However, substrate 3
If the heating element 11 expands at the time of the heating of 0, there is a problem that the heating element 11 hangs down from the groove 121a. Further, if the heating element 11 is exposed, there is a problem that metal evaporated from the heating element 11 during heating adheres to the back surface of the substrate 30.

Therefore, in this embodiment, as shown in FIG. 2, a transparent cover 16 for covering the heating element 11 is provided on the front surface of the heating element 11, and the transparent cover 16 allows the heating element 11 to hang from the heating element 11. Evaporated metal substrate 3
The problem of adhesion to zero has been solved. The above-mentioned transparent cover 16 is adapted to be detachably attached to the first transparent refractory material 121 by the cover holder 17 by bolting, so that when the heating element 11 is disconnected and needs to be replaced. The replacement is easy. The transparent cover 16 is made of quartz glass, and the cover holder 17 is made of Inconel (metal).
It is constituted by.

FIG. 4 is a plan view of the transparent cover 16. This figure is a view seen from the side where the transparent cover 16 is attached to the first transparent refractory material 121. As shown in this figure, a notch 16 a is formed in the transparent cover 16. The notch 16a is used for the first to third transparent refractory materials 1.
Bolts for fixing the first, second and fourth heat insulating materials 21, 122 and 14, the bolts for fixing the transparent cover 16 to the first transparent fireproof material 121, and the bolts for fixing the substrate holder 20 to the first transparent fireproof material 121. Bolts are formed so as not to hit the transparent cover 16.

FIG. 5A is a plan view of the cover holder 17, and FIG. 5B is a sectional view taken along line AA in FIG. FIG. 5A is a view of the cover holder 17 viewed from the side where the cover holder 17 is attached to the first transparent fireproof material 121. The cover holder 17 has a configuration in which the center is opened and an end of the transparent cover 16 is held by a step 17a formed on the outer periphery. When the transparent cover 16 is held by the cover holder 17, the upper surfaces of the cover holder 17 and the transparent cover 16 are flush with each other.

The cover holder 17 also has the first
Bolts for fixing the third to third transparent refractory materials 121, 122, 14 and the heat insulating material 15, and the substrate holder 2
A notch 17 b is formed to prevent a bolt for fixing O to the first transparent refractory material 121 from hitting the cover holder 17. The cover holder 17 has a through hole 1 for fixing the cover holder 17 to the first transparent refractory material 121 by bolting.
7c is formed.

The heating element 11, the first to third transparent refractory materials 121, 122, 14, the heat insulating material 15, the transparent cover 16, and the cover holder 17 constitute a substrate heating heater 10 for heating the substrate 30. The substrate holder 20 is detachably attached to the substrate heating heater 10. 6A shows a plan view of the substrate holder 20, and FIG. 6B shows a cross-sectional view taken along line BB in FIG. FIG. 6A shows that the substrate holder 20 is connected to the substrate heating heater 10.
It is the figure seen from the side to be attached to. This substrate holder 20 has a substrate 30 and a dummy substrate 31 in the center.
Is provided. Steps 20b for holding the substrate 30 and the dummy substrate 31 are formed at four corners of the region. FIG. 7 shows a state where the substrate 30 and the dummy substrate 31 are arranged on the substrate holder 20.

FIG. 6A shows the substrate holder 20.
As shown in the figure, the substrate holder 20 is placed in the first transparent refractory material 1.
21, a first through third transparent refractory material 121 through 1, a first through third transparent refractory material 121,
Bolts for fixing 22, 14 and insulation 15;
In addition, a notch 20d for preventing a bolt for fixing the cover holder 17 to the first transparent fireproof material 121 from being applied thereto is formed.

Next, a method of forming a superconducting thin film on the substrate 30 using the above-described heater unit 1 will be described. Before the film formation, the above-described substrate heating heater 10 is attached and fixed to a rotating shaft (indicated by reference numeral 2 in FIG. 8) in the sputtering apparatus by a joint (not shown).

Then, the substrate 30 and the dummy substrate 31 are set on the substrate holder 20 as shown in FIG. 7, and thereafter the substrate holder 20 is attached to the substrate heating heater 10 by bolting. The substrate 30 is made of, for example, MgO, and the dummy substrate 31 is made of MgO of the same material as the substrate 30 on which a film is to be formed. Thereafter, a superconducting thin film is formed on the substrate 30 by an off-axis sputtering method. In this case, as shown in FIG. 8, the substrate 30 is heated by direct and reflected heat rays by the substrate heating heater 10, oxygen and argon are introduced into the sputtering apparatus, and the substrate 3 is heated using the YBCO target 3.
A superconducting film is formed on zero.

In this film formation, the temperature of the substrate 30 needs to be about 650 ° C. to 750 ° C. If a sufficient temperature cannot be obtained by heating with the substrate heating heater 10, as shown in FIG. Convection heating is generated by the heater 4 to bring the temperature of the substrate 30 to a desired temperature. In this case, if the pressure in the sputtering apparatus is set to about 10 mTorr to several Torr, convection heating can be generated.

The dummy substrate 31 is made of the same material as the substrate 30 on which a film is to be formed as described above, or a material having an extremely low etching rate by negative ions and an extremely small amount of desorbed elements by heating. A ceramic material is preferably used as such a material.

[Brief description of the drawings]

FIG. 1 shows a heater unit 1 according to an embodiment of the present invention.
FIG. 3 is a diagram showing a conceptual configuration of FIG.

FIG. 2 is a heater unit 1 according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a specific configuration of FIG.

FIG. 3 is a plan view of the transparent refractory material 121 in FIG.

FIG. 4 is a plan view of a transparent cover 16 in FIG.

5A is a plan view of the cover holder 17, and FIG.
FIG. 2 is a sectional view taken along line AA in FIG.

6A is a plan view of the substrate holder 20, and FIG. 6B is a cross-sectional view taken along the line BB in FIG.

7 is a diagram showing a state where a substrate 30 and a dummy substrate 31 are arranged on the substrate holder 20 shown in FIG.

FIG. 8 is a diagram showing a state in which a superconducting thin film is formed on a substrate 30.

FIG. 9 is a diagram showing a conceptual configuration of a conventional heater unit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Heater unit, 11 ... Heating element, 12 ... Transparent member,
13: heat ray reflective film, 121: first transparent refractory material, 122
... second transparent refractory material, 14 ... third transparent refractory material, 15 ...
Insulation material, 16: transparent cover, 17: cover holder, 2
0: substrate holder, 30: substrate, 31: dummy substrate.

Continuation of the front page (56) References JP-A-63-266071 (JP, A) JP-A-4-60544 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 39 / 00 H01L 39/22 H01L 21/203 C23C 14/50

Claims (6)

(57) [Claims] 1. A heater unit (1) comprising a substrate heating heater (10) for heating a substrate (30) on which a film is to be formed, and a substrate holder (20) for holding the substrate (30). The substrate (30) is attached to the substrate holding unit (20).
And a dummy substrate (3
1) is disposed, and the substrate (3) is heated by the substrate heating heater (10).
0), and a superconducting thin film is formed on the substrate (30) by sputtering in the heated state. 2. The film formation as said dummy substrate (31).
It is particularly preferable to use the same material as the substrate (30) to be formed.
The method for forming a superconducting thin film according to claim 1. 3. A substrate heating heater (10) for heating a substrate (30) on which a film is to be formed, and a substrate holder (10) for holding the substrate (30) and detachably attached to the substrate heating heater (10). 20), wherein the substrate holding unit (20) includes the held substrate (30).
A dummy substrate (31) is arranged on an outer peripheral portion of the heater unit. 4. A heater (10) for heating a substrate, wherein the heater (10) generates heat.
The body (11) and the heating element (11) are held on one surface side
Transparent member (12, 121, 122) and the transparent portion
Formed on the surface on the other surface side of the material (12, 121, 122)
And a heat-reflecting film (13) formed on the substrate, and the heater (10) for heating the substrate is provided with the heating element (1).
The transparent cover (16) covering the front surface of 1) is the transparent member
Removably attached to (12, 121, 122)
The heater unit according to claim 3, wherein the heater unit is provided.
knit. 5. A heater unit (1) for holding a substrate (30) on which a film is to be formed and heating the substrate (30).
A superconducting thin film forming apparatus for forming a superconducting thin film by sputtering on a substrate (30) held by the heater unit (1), wherein the heater unit (1) comprises: ) Heater for heating the substrate (10)
And a substrate holding unit (20) for holding the substrate (30), wherein the substrate holding unit (20) holds the substrate (30)
Characterized in that a dummy substrate (31) is arranged on an outer peripheral portion of the superconducting thin film. 6. The heater (10) for heating the substrate is capable of generating heat.
The body (11) and the heating element (11) are held on one surface side
Transparent member (12, 121, 122) and the transparent portion
Formed on the surface on the other surface side of the material (12, 121, 122)
And a heat-reflecting film (13) formed on the substrate, and the heater (10) for heating the substrate is provided with the heating element (1).
The transparent cover (16) covering the front surface of 1) is the transparent member
Removably attached to (12, 121, 122)
The superconducting thin film according to claim 5, wherein
Film forming equipment.