JP2001011607A - Apparatus and method for film formation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus and method for film formation, capable of homogeneous film formation and also capable of facilitating the embedding of grooves and holes. SOLUTION: A hearth body 53 consists of a cylindrical vessel 53a for storing a metal liquid ML as a film material and is disposed in a supporting part 51a which is a recessed part formed in the upper part of the hearth 51. A heat- insulating member 54 with low thermal conductivity is inserted as a heat transfer controlling means between the rear 53b of the vessel 53a and the bottom 51b of the supporting part 51a. The heat-insulating member 54 has a plate-like shape and is allowed to adhere to the bottom 51b and the rear 53b, and, e.g. a conducting ceramic plate made of TiC can be used as the member. Because the heat transferred from the hearth body 53 to the supporting part 51a can be suppressed when such a heat-insulating member 54 is used, the hearth body 53 approaches a thermally isolated state, and the temperature distribution of the metal liquid ML held in the hearth body 53 can be made relatively uniform and stable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film forming apparatus and a method for performing ion plating using plasma, and more particularly to a film forming method suitable for forming metal wiring in grooves or holes having a high aspect ratio. Apparatus and method.

[0002]

2. Description of the Related Art As a conventional film forming apparatus, a plasma beam from a pressure gradient type plasma gun is guided to a hearth, and a deposition material in an evaporating crucible on the hearth is evaporated and ionized. There is known an ion plating apparatus that attaches a substance to a surface of a substrate arranged opposite to a hearth.

Japanese Patent Application Laid-Open No. 7-138743 discloses an ion plating apparatus of this type in which an incident beam direction adjusting means is composed of a bar magnet arranged in a hearth and a permanent magnet arranged concentrically around the hearth. Which form a cusp magnetic field above the incident surface of the hearth. In this ion plating apparatus, the plasma beam incident on the hearth is corrected by the cusp magnetic field above the hearth, and the plasma beam is linearly incident from directly above the hearth, so that the thickness of the film formed on the surface of the substrate is uniform. Can be

[0004]

However, when the vapor deposition material is melted and evaporated by the above-mentioned ion plating apparatus, the vapor deposition material forms fine droplets and jumps out of the evaporation crucible and adheres to the substrate as it is. May be. Such deposits are referred to as splashes or droplets, making it difficult to form a uniform film even with a very small size. Holes may not be completely filled.

Accordingly, the present invention enables uniform film formation,
It is an object of the present invention to provide a film forming apparatus and a method in which grooves and holes can be easily filled, and in particular to expand applications of an ion plating apparatus in a semiconductor device manufacturing field.

[0006]

In order to solve the above-mentioned problems, a film forming apparatus according to the present invention comprises a plasma source for supplying a plasma beam into a film forming chamber, a material evaporating source capable of containing a film material, It has a support member for supporting the evaporation source, heat transfer control means for controlling heat conducted from the material evaporation source to the support member, and a hearth arranged in the film forming chamber to guide the plasma beam.

In the above-described film forming apparatus, since the hearth has heat transfer control means for controlling heat conducted from the material evaporation source to the support member, the material evaporation source approaches a thermally isolated state. Thereby, the temperature distribution of the film material contained in the material evaporation source can be made relatively uniform and stable. That is, the use of such a heat transfer control means can prevent the generation of splashes and droplets, which are considered to be caused by uneven heating of the melt.

In a preferred aspect of the above-mentioned apparatus, the heat transfer control means is a heat insulating member made of a material having a low thermal conductivity inserted between the material evaporation source and the supporting member. here,
When the material evaporation source is made of a metal such as tungsten (W) or another conductive material, a conductive ceramic plate or the like may be used as the heat insulating member. By using such a conductive ceramic plate, the amount of heat conducted from the material evaporation source to the support member can be limited, and the material evaporation source is electrically isolated, that is, the plasma incident on the material evaporation source can be reduced. It is possible to prevent the amount from being limited. Examples of the conductive ceramic plate include titanium carbide (TiC) and a ceramic plate having an insulating ceramic surface on which a TiC layer is formed. The same effect can be expected by inserting porous graphite as a heat transfer control means between the material evaporation source and the support member.

In a preferred embodiment of the above-mentioned device, the heat transfer control means is an adiabatic space partially formed between the material evaporation source and the support member. Here, the heat insulating space may be a recess formed shallowly on the lower surface of the material evaporation source or the upper surface of the support member. When the pressure in the film forming chamber is reduced, heat insulation using vacuum is performed. When the heat insulating space is used, the contact area between the material evaporation source and the support member is reduced. However, if the conductivity of the material evaporation source and the support member is sufficiently high, no problem is considered to occur.

In a preferred embodiment of the above-mentioned device, at least one of a magnet and a coil is annularly disposed around the hearth and controls a magnetic field above and close to the hearth. An auxiliary anode disposed adjacent and above, wherein the plasma source comprises:
It is a pressure gradient type plasma gun.

In the above-described film forming apparatus, the film having a more uniform thickness can be formed by correcting the plasma beam incident on the hearth with the cusp-shaped magnetic field by the magnetic field control member.

Further, according to the film forming method of the present invention, the film material of the material evaporation source is evaporated by supplying a plasma beam toward a material evaporation source arranged as an anode in the film formation chamber, and And controls the conduction of heat from a material evaporation source to a support member that supports the material evaporation source in a film forming chamber.

In the above-mentioned film forming method, since the conduction of heat from the material evaporation source to the supporting member supporting the material evaporation source is controlled,
The material evaporation source approaches a thermally isolated state, and the temperature distribution of the film material contained therein can be made relatively uniform and stable. That is, the use of such a heat transfer control means can prevent the generation of splashes and droplets, which are considered to be caused by uneven heating of the melt.

In a preferred embodiment of the film forming method,
The plasma source is a pressure gradient type plasma gun, and a magnetic field control member in which at least one of a magnet and a coil is annularly arranged around the hearth can control a magnetic field above and close to the hearth.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] Hereinafter, the structure of a film forming apparatus according to a first embodiment of the present invention will be described.

FIG. 1 is a diagram schematically illustrating the overall structure of a film forming apparatus according to an embodiment. The film forming apparatus includes a vacuum container 10 as a film forming chamber, a plasma gun 30 as a plasma source for supplying a plasma beam PB into the vacuum container 10,
The plasma beam PB disposed at the bottom in the vacuum vessel 10
An anode member 50 for controlling the flow of the gas, a holding mechanism 60 arranged above the vacuum vessel 10 for holding the substrate WA, and a main control device 80 for controlling these operations in a unified manner.

The plasma gun 30 has a plasma beam PB
This is a pressure gradient type plasma gun that generates a gas pressure, and its main body is mounted on a cylindrical portion 12 provided on the side wall of the vacuum vessel 10. The main body is composed of a glass tube 32 whose one end is closed by a cathode 31. In the glass tube 32, a cylinder 33 made of molybdenum is fixed to the cathode 31 and arranged concentrically, and in this cylinder 33, a disk 34 made of LaB ₆ and a tantalum are formed. A pipe 35 is built in. Of both ends of the glass tube 32, the end opposite to the cathode 31 and the vacuum vessel 10
Between the end of the cylindrical portion 12 extending from
Intermediate electrodes 41 and 42 are concentrically arranged in series.
An annular permanent magnet 44 for converging the plasma beam PB is built in one first intermediate electrode 41. An electromagnet coil 45 for converging the plasma beam PB is also built in the second intermediate electrode 42. In addition, around the cylindrical portion 12, the first and second gas generated on the cathode 31 side are formed.
Plasma beam P extracted to intermediate electrodes 41 and 42
A steering coil 47 for guiding B into the vacuum vessel 10 is provided.

The operation of the plasma gun 30 is controlled by a gun driving device 48. This gun driving device 48
Can turn on / off the power supply to the cathode 31 and adjust the supply voltage to the cathode 31, and further supply the power to the first and second intermediate electrodes 41 and 42, the electromagnet coil 45, and the steering coil 47. adjust. The state of the plasma beam PB supplied into the vacuum chamber 10 is controlled by such a gun driving device 48.

It should be noted that the pipe 35 disposed at the innermost side is
Is for introducing a carrier gas such as Ar as a source of the plasma beam PB into the plasma gun 30, and is connected to a gas supply source 39 via a flow meter 37 and a flow control valve 38. The flow rate of the carrier gas detected by the flow meter 37 is monitored by the main controller 80 and is used for adjusting the flow rate of the carrier gas by the flow rate control valve 38 and the like. An exhaust pump 77 is attached to the side of the vacuum vessel 10 facing the plasma gun 30 via a vacuum gate 76 to reduce the pressure inside the vacuum vessel 10 to a desired pressure.

The anode member 50 disposed in the lower portion of the vacuum vessel 10 includes a hearth 51 as a main anode for guiding the plasma beam PB downward, and an annular auxiliary anode 52 disposed around the hearth 51.

The former hearth 51 is formed of a conductive material having good thermal conductivity and is supported by a grounded vacuum vessel 10 via an insulator (not shown). The hearth 51 is controlled to an appropriate positive potential by the anode power supply device 58 and sucks the plasma beam PB emitted from the plasma gun 30 downward. The hearth 51 is
A hearth body 53 serving as a crucible-shaped material evaporation source is provided in the formed concave portion at the upper center where the plasma beam PB from the plasma gun 30 is incident. Inside the hearth body 53, a metal such as copper, which is a film material, is stored in a molten state.

The latter auxiliary anode 52 is constituted by an annular container arranged concentrically around the hearth 51. In this annular container, an annular permanent magnet 55 made of ferrite or the like and a coil 56 concentrically stacked therewith are housed. The permanent magnet 55 and the coil 56 are magnetic field control members, and form a cusp-shaped magnetic field immediately above the hearth 51. Thereby, the direction and the like of the plasma beam PB incident on the hearth 51 can be corrected.

A coil 56 in the auxiliary anode 52 constitutes an electromagnet, and is supplied with power from an anode power supply 58. In this case, the direction of the magnetic field on the center side of the excited coil 56 is configured to be the same as the magnetic field on the center side generated by the permanent magnet 55. The anode power supply 58 includes a coil 56
Of the plasma beam PB incident on the hearth 51 can be finely adjusted.

The container of the auxiliary anode 52 is also made of a conductive material having good thermal conductivity, similarly to the hearth 51. The auxiliary anode 52 is attached to the hearth 51 via an insulator not shown. The anode power supply device 58 can control the electric field above the hearth body 53 by changing the voltage applied to the auxiliary anode 52, particularly the auxiliary anode body above the auxiliary anode 52.

A holding mechanism 60 disposed on the upper portion of the vacuum vessel 10 has a substrate holder 61 for holding the substrate WA with the film-forming surface on the lower side above the hearth 51, and fixed to the upper portion of the substrate holder 61. And a temperature controller 62 for controlling the temperature of the substrate WA from the back side. Substrate holder 6
1 is supplied with power from the substrate power supply device 68 in an insulated state with respect to the vacuum
Are biased to a negative potential. Temperature control device 6
2 is controlled by a temperature control device 69, which supplies power to a heater built in the temperature control device 62 or supplies a cooling medium to a built-in pipe, thereby controlling the temperature control device 62. Further, the substrate holder 61 is maintained at a desired temperature.

The general operation of the film forming apparatus shown in FIG. 1 will be described below. In this film forming apparatus, a discharge is generated between the cathode 31 of the plasma gun 30 and the hearth 51 in the vacuum vessel 10, thereby generating a plasma beam PB. This plasma beam PB is applied to the steering coil 4
7 is guided by the magnetic field determined by the permanent magnet 55 in the auxiliary anode 52 and reaches the hearth 51. Evaporated substance (film material) stored in the hearth body 53 as a material evaporation source
Are heated by the plasma beam PB and emitted from the hearth body 53 as vapor. This vapor is ionized by the plasma beam PB and a substrate W to which a negative voltage is applied.
A film adheres to the surface of A and is formed.

FIG. 2 is a side sectional view for explaining the structure of the hearth body 53 and its surroundings. The hearth body 53 is formed of a cylindrical container 53a for storing the metal melt ML of the film material, and the support portion 51a is a concave portion formed on the hearth 51.
Is located within. Note that the metal melt ML is a metal such as copper (Cu), for example, and the container 53a has conductivity such as tungsten (W) or graphite (C), for example.
It is formed of a material that does not easily react with the metal melt ML.

The back surface 53b of the container 53a and the support portion 51a
A heat insulating member 54 having a low thermal conductivity is inserted as a heat transfer control means between the bottom surface 51b and the bottom surface 51b. The heat insulating member 54
It has a flat plate shape and is in close contact with both the bottom surface 51b and the back surface 53b. For example, the surface of a conductive ceramic plate made of TiC or an insulating ceramic plate is
It may be one having a C layer formed thereon.

Note that a cooling tank 51d for cooling the entire hearth 51 is formed below the support portion 51a of the hearth 51. An appropriate amount of a cooling medium is supplied to the cooling tank 51d from a temperature controller (not shown).

When the heat insulating member 54 shown is used, the heat conducted from the hearth body 53 to the support portion 51a can be suppressed, so that the hearth body 53 approaches a thermally isolated state and the metal housed in the hearth body 53 The temperature distribution of the melt ML can be made relatively uniform and stable.

This will be described in more detail. The hearth body 53 is heated on the one hand by the incidence of the plasma beam PB and on the other hand is cooled from below by the cooling tank 51d. Therefore, it can be said that a steep temperature gradient in the vertical direction is easily formed in the metal melt ML in the hearth body 53. However, in the present embodiment, the heat insulating member 5 is provided between the back surface 53b of the container 53a and the bottom surface 51b of the support portion 51a.
4, the hearth body 53 and the hearth 51
And the hearth body 53 approaches a thermal equilibrium state. As a result, the temperature distribution of the metal melt ML in the hearth body 53 can be made relatively uniform and stable, and the splash or drop which is considered to be caused by uneven heating of the metal melt ML is considered to be a remote cause. The generation of let can be prevented beforehand.

For reference, the following table lists the electrical resistance and thermal conductivity of tungsten, graphite, and titanium carbide. [Table] Material Resistance [Ω • cm] Thermal conductivity [cal / s • k • cm] 20 ℃ 1000 ℃ 100 ℃ 1000 ℃ Graphite 1 × 10 ^-3 1 × 10 ^-3 0.30 0.10 TiC 1 × 10 ^-4 0.08 0.02 W 5.5 × 10 ^-6 25 × 10 ^-6 0.40 0.30 Thus, it can be seen that titanium carbide has low thermal conductivity, despite its low resistance, which is comparable to tungsten and graphite. .

[Second Embodiment] Hereinafter, a second embodiment according to the present invention will be described.
The structure of the film forming apparatus according to the embodiment will be described. Note that the device of the second embodiment is a modification of the hearth body of the device of the first embodiment, and the same portions are denoted by the same reference numerals and redundant description will be omitted.

FIG. 3 is a side sectional view for explaining the structure of the hearth body 153 and its surroundings. This hearth body 15
An annular projection 153d is formed on the back surface 153b of the container 153a constituting the third container 3 along its outer periphery. The protrusion 153d has a concave portion at the center side, so that heat conduction from the container 153a to the support portion 51a as the heat insulating space IS is suppressed.

In the case where the illustrated heat insulating space IS is formed, the heat conducted from the hearth body 153 to the support portion 51a can be suppressed as in the case of the first embodiment.
3 approaches a thermally isolated state, the temperature distribution of the metal melt ML contained in the hearth body 153 can be made relatively uniform and stable, and the generation of splashes and droplets can be suppressed.

Although the present invention has been described with reference to the embodiment, the present invention is not limited to the above embodiment. For example, in the above embodiment, the hearth bodies 53, 153
Although the metal melt ML to be accommodated is Cu, the present invention is not limited to the above-described embodiment, and is also applicable to a case where a film is formed by a metal that evaporates without melting. Also in this case, the hearth body 5
Since the heat conducted from 3 to the support portion 51a can be suppressed, the temperature of the film material is more uniform and stable, and it is possible to prevent the particles of the film material from scattering from the hearth body 53 to generate a splash or the like.

The hearth body 53, that is, the container 53
The shape of a can be any shape as long as it can accommodate the metal melt ML.

The heat insulating member 54 can be made of any material as long as it has a lower thermal conductivity than the hearth body 53, has a certain degree of electric conductivity, and does not contaminate the film forming chamber. At this time, the heat conductivity of the hearth body 53 itself can be reduced.

The shape of the projection 153d formed on the back surface 153b of the container 153a, that is, the shape of the heat insulating space IS, may be arbitrarily set as long as the heat conduction from the container 153a to the support 51a can be restricted to some extent. Can be.

[0040]

According to the film forming apparatus of the present invention, since the hearth has the heat transfer control means for controlling the heat conducted from the material evaporation source to the supporting member, the material evaporation source approaches a thermally isolated state. In addition, the temperature distribution of the film material accommodated therein can be made relatively uniform and stable. That is, the use of such a heat transfer control means can prevent the generation of splashes and droplets, which are considered to be caused by uneven heating of the melt.

Further, according to the film forming method of the present invention, since the conduction of heat from the material evaporation source to the supporting member for supporting the material evaporation source in the film forming chamber is controlled, the film material accommodated in the material evaporation source is controlled. Can be made relatively uniform and stable, and it is possible to prevent the generation of splashes and droplets which are considered to be caused by uneven heating of the melt.

[0042]

[Brief description of the drawings]

[0043]

FIG. 1 is a diagram illustrating a structure of a film forming apparatus according to a first embodiment.

[0044]

FIG. 2 is a side cross-sectional view illustrating a structure of a hearth body and its surroundings.

[0045]

FIG. 3 is a side cross-sectional view illustrating a hearth body and its peripheral structure that constitute a film forming apparatus according to a second embodiment.

[0046]

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vacuum container 30 Plasma gun 47 Steering coil 48 Gun drive device 50 Anode member 51 Hearth 51a Support part 51d Cooling tank 52 Auxiliary anode 53 Hearth body 53a Container 54 Insulation member 58 Anode power supply 60 Holding mechanism 77 Exhaust pump 80 Main control device 153 Haas body 153d protrusion

Claims (5)

[Claims] A plasma source for supplying a plasma beam into a film forming chamber; a material evaporation source capable of containing a film material; a support member for supporting the material evaporation source; and a support member from the material evaporation source to the support member. A film forming apparatus, comprising: a heat transfer control unit configured to control heat to be conducted; and a hearth arranged in the film forming chamber to guide the plasma beam. 2. The heat transfer control means is a heat insulation member inserted between the material evaporation source and the support member and having a low heat conductivity and made of a conductive material. The film forming apparatus according to claim 1. 3. The film forming apparatus according to claim 1, wherein said heat transfer control means is an adiabatic space partially formed between said material evaporation source and said support member. 4. A magnetic field control member having at least one of a magnet and a coil arranged annularly around the hearth and controlling a magnetic field near and above the hearth, and disposed near and above the magnetic field control member. The film forming apparatus according to any one of claims 1 to 3, further comprising an auxiliary anode to be provided, wherein the plasma source is a pressure gradient type plasma gun. 5. A surface of a substrate disposed in a film forming chamber by supplying a plasma beam to a material vapor source disposed as an anode in the film forming chamber to vaporize a film material of the material vapor source. A method of controlling the conduction of heat from a material evaporation source to a support member that supports the material evaporation source in the film formation chamber.