WO2021182638A1

WO2021182638A1 - Sputtering device

Info

Publication number: WO2021182638A1
Application number: PCT/JP2021/010234
Authority: WO
Inventors: 靖典安東; 大介東
Original assignee: 日新電機株式会社
Priority date: 2020-03-13
Filing date: 2021-03-12
Publication date: 2021-09-16
Also published as: JP2021143409A; CN115279938A; KR20220139362A

Abstract

In the present invention, a target can be efficiently sputtered while improving film formation rate and treatment efficiency by placing an antenna outside a vacuum vessel and reducing the distance from the target to a workpiece. This sputtering device 100 is for forming a film on a workpiece W by means of sputtering of a target T with plasma P, said device being provided with a vacuum vessel 1 to be evacuated, an antenna 5 disposed outside the vacuum vessel 1, a dielectric plate 6 disposed on an outer wall 1a of the vacuum vessel 1 at a position facing the antenna 5, and a target holding part 3 for holding the target T inside the vacuum vessel 1, and being configured such that the target T is disposed on one or both positions sandwiching the dielectric plate 6, with a sputter surface Ta thereof obliquely extending toward the opposite side from the antenna 5 with respect to the dielectric plate 6.

Description

Sputtering equipment

The present invention relates to a sputtering apparatus that uses plasma to sputter a target to form a film on an object to be processed.

As a conventional sputtering apparatus, as shown in Patent Document 1, an antenna is arranged outside the vacuum vessel, and a high-frequency magnetic field generated from the antenna is applied to the inside of the vacuum vessel via a dielectric plate provided on the outer wall of the vacuum vessel. In some cases, the target is sputtered to form a film on the object to be processed by transmitting the material and generating plasma in the vacuum vessel.

In the configuration in which the antenna is arranged outside the vacuum vessel in this way, the target can be brought closer to the object to be processed as compared with the configuration in which the antenna is arranged inside the vacuum vessel, and the film formation speed and the processing efficiency are improved. Can be planned. In addition, by arranging the antenna outside the vacuum container, sputter particles do not adhere to the antenna, so that dirt and reduction of life can be suppressed, and the mounting structure of the antenna can be simplified. Can produce the effects of.

However, when the antenna is arranged outside the vacuum vessel, as shown in FIG. 5A, if the antenna is arranged behind the sputtered surface of the target, the high frequency magnetic field spreading from the antenna can be efficiently guided to the sputtered surface. It cannot be done, and the sputtering efficiency deteriorates.

Therefore, in order to improve the sputter efficiency while arranging the antenna outside the vacuum vessel, the present inventor dents the outer wall of the vacuum vessel outward as shown in FIG. 5 (B) and forms the bottom of the antenna. A configuration in which the target is arranged and the antenna is arranged so as to face the dielectric plate on the side wall thereof was considered intermediately on the way to the present invention. With such a configuration, the antenna can be positioned in front of the target sputtering surface, and the sputtering efficiency can be improved.

However, in the configuration shown in FIG. 5 (B), since the distance from the target to the object to be processed becomes long, the film formation speed and the processing efficiency decrease, and there is an advantage that the antenna is arranged outside the vacuum vessel. Is diluted.

Japanese Unexamined Patent Publication No. 2000-226655

Therefore, the present invention has been made to solve the above problems at once, and by arranging an antenna outside the vacuum vessel and shortening the distance from the target to the object to be processed, the film forming speed and the processing efficiency The main task is to make it possible to efficiently sputter the target while improving the above.

That is, the sputtering apparatus according to the present invention is a sputtering apparatus that sputters a target using plasma to form a film on an object to be processed, and includes a vacuum vessel that is evacuated and an antenna provided outside the vacuum vessel. A dielectric plate provided on the outer wall of the vacuum vessel at a position facing the antenna and a target holding portion for holding the target in the vacuum vessel are provided, and the target is located at a position where the dielectric plate is sandwiched. It is provided on one or both, and is characterized in that its sputtered surface extends obliquely toward the side opposite to the antenna with respect to the dielectric plate.

According to the sputtering apparatus configured in this way, the sputtering surface of the target extends diagonally toward the side opposite to the antenna with respect to the dielectric plate, so that the high-frequency magnetic field spreading from the antenna is efficiently guided to the sputtering surface. be able to.
As a result, in a configuration in which the antenna is provided outside the vacuum vessel, the target can be efficiently sputtered while improving the film forming speed and the processing efficiency by shortening the distance to the object to be processed.
Further, by making the sputtered surface slanted, it is possible to suppress the spread of sputtered particles with respect to the object to be processed, and the sputtered source can be made highly utilized.

In order to further improve the film forming speed and the processing efficiency, the targets are provided at both positions where the dielectric plate is sandwiched, and each of the sputter surfaces of the targets is relative to the dielectric plate. It is preferable that it extends diagonally toward the side opposite to the antenna.

In order to exert the above-mentioned action and effect more remarkably, it is preferable that the inclination angle of the sputtered surface of the target with respect to the dielectric plate is 10 degrees or more and 45 degrees or less.

It is preferable that the dielectric plate is placed on a slit plate in which a plurality of slits are formed.
With such a configuration, the magnetic field transmission window is formed by superimposing the slit plate and the dielectric plate, so that the magnetic field transmission window has a function as a magnetic field transmission window only by the dielectric plate. The thickness can be reduced. As a result, the distance from the antenna to the inside of the vacuum vessel can be shortened, and the high-frequency magnetic field generated from the antenna can be efficiently supplied into the vacuum vessel.

According to the present invention configured in this way, by arranging the antenna outside the vacuum vessel and shortening the distance from the target to the object to be processed, the target can be made more efficient while improving the film formation speed and the processing efficiency. Can be sputtered well.

The schematic diagram which shows the structure of the sputtering apparatus of this embodiment. The schematic diagram which shows the arrangement of the target of the sputtering apparatus of this embodiment. The schematic diagram which shows the structure of the sputtering apparatus in another embodiment. The schematic diagram which shows the structure of the sputtering apparatus in another embodiment. The schematic diagram which shows the structure examined intermediately on the way to this invention.

Hereinafter, an embodiment of the sputtering apparatus according to the present invention will be described with reference to the drawings.

<Device configuration>
In the sputtering apparatus 100 of the present embodiment, the target T is sputtered using an inductively coupled plasma P to form a film on an object W to be processed such as a substrate. Here, the object W to be processed is, for example, a substrate for a flat panel display (FPD) such as a liquid crystal display or an organic EL display, a flexible substrate for a flexible display, or the like.

Specifically, as shown in FIGS. 1 and 2, the sputtering apparatus 100 holds the vacuum vessel 1 forming the processing chamber S to be evacuated and introduced with gas, and the object W to be processed in the processing chamber S. A substrate holding unit 2, a target holding unit 3 that holds the target T in the processing chamber S, a target bias power supply 4 that applies a bias voltage to the target T, an antenna 5 provided outside the vacuum vessel 1, and a vacuum. It includes a dielectric plate 6 provided on the outer wall of the container 1 at a position facing the antenna, and a high-frequency power source 7 for applying a high frequency to the antenna 5. With this configuration, by applying a high frequency from the high frequency power supply 7 to the antenna 5, a high frequency current flows through the plurality of antennas 5, an inductive electric field is generated in the vacuum vessel 1, and an inductively coupled plasma P is generated. ..

The vacuum container 1 is, for example, a metal container, and the inside thereof is evacuated by the vacuum exhaust device 8. The vacuum vessel 1 is electrically grounded in this example.

Sputtering gas or reactive gas is introduced into the vacuum vessel 1 from a gas supply mechanism 9 having, for example, a flow rate regulator (not shown) via a gas introduction port 10. The sputtering gas and the reactive gas may be those according to the treatment content to be applied to the object W to be processed. The sputtering gas is, for example, an inert gas such as argon (Ar), and the reactive gas is, for example, oxygen (O ₂ ) or nitrogen (N ₂ ).

The substrate holding portion 2 is a holder that holds the flat object W to be processed in the vacuum vessel 1 so as to be in a horizontal state, for example. This holder is electrically grounded in this example.

The target holding unit 3 holds the target T facing the object W held by the substrate holding unit 2. The target T of the present embodiment is a flat plate having a rectangular shape in a plan view. The target holding portion 3 is provided on an outer wall (for example, an upper wall) 1a forming the vacuum container 1. Further, an insulating portion 31 having a vacuum sealing function is provided between the target holding portion 3 and the upper wall 1a of the vacuum container 1.

In the present embodiment, a plurality of target holding portions 3 are provided, and specifically, a pair of target holding portions 3 are provided at positions where the antenna 5, which will be described later, is sandwiched.

The target bias power supply 4 is connected to the target T via the target holding unit 3, and applies a bias voltage to the target T. This bias voltage is a voltage at which ions in the plasma P are drawn into the target T and sputtered. Although a common target bias power supply 4 is connected to the pair of targets T here, different target bias power supplies 4 may be connected to each target T.

The antenna 5 is for generating plasma P in the processing chamber S, and is, for example, a linear antenna having a length of several tens of centimeters or more. In this embodiment, as shown in FIG. 1, one antenna 5 is arranged between the pair of targets T. Here, the longitudinal direction of the antenna 5 and the longitudinal direction of each target T are the same direction, and the antenna 5 is arranged so that the distances from the respective targets T are equal.

The material of each antenna 5 is, for example, copper, aluminum, alloys thereof, stainless steel, etc., but is not limited thereto. It is also possible to make the antenna 5 hollow and allow a refrigerant such as cooling water to flow through the antenna 5 to cool the antenna 5.

A high-frequency power supply 7 is connected to one end of the antenna 5 in the longitudinal direction via a matching circuit 71, and the other end in the longitudinal direction is directly grounded. An impedance adjustment circuit such as a variable capacitor or a variable reactor may be provided at one end or the other end of the antenna 5 to adjust the impedance of each antenna 5. By adjusting the impedance of each antenna 5 in this way, the density distribution of plasma P in the longitudinal direction of the antenna 5 can be made uniform, and the film thickness of the antenna 5 in the longitudinal direction can be made uniform.

With the above configuration, a high frequency current can be passed from the high frequency power supply 7 to the antenna 5 via the matching circuit 71. The frequency of the high frequency is, for example, 13.56 MHz, which is common, but is not limited to this.

The dielectric plate 6 constitutes a magnetic field transmission window for transmitting a high-frequency magnetic field generated from the antenna 5 into the processing chamber S, and closes an opening formed in the outer wall (here, the upper wall) 1a of the vacuum vessel 1. It is provided as follows.

The dielectric plate 6 here has a rectangular shape when viewed from the antenna 5 side, and is arranged so that its longitudinal direction is the same as the longitudinal direction of each target T. As the material constituting the dielectric plate 6, ceramics such as alumina, silicon carbide and silicon nitride, inorganic materials such as quartz glass and non-alkali glass, and resin materials such as fluororesin (for example, polytetrafluoroethylene) are used. Can be mentioned.

Then, in the sputtering apparatus 100 of the present embodiment, as shown in FIGS. 1 and 2, the sputtering surface Ta of the target T extends obliquely with respect to the dielectric plate 6 toward the side opposite to the antenna 5. It is characterized by that.

More specifically, the sputtered surface Ta of the target T is inclined so as to approach the object to be processed W held by the substrate holding portion 2 as the distance from the dielectric plate 6 increases. As shown in 2, the inclination angle θ of the sputtering surface Ta of the target T with respect to the dielectric plate 6 is 10 degrees or more and 45 degrees or less. The acute angle θ here is defined as the surface 61 of the sputter surface Ta and the dielectric plate 6 facing the object W to be processed in a configuration in which the sputter surface Ta approaches the object W to be processed as it moves away from the dielectric plate 6. It is an acute angle of the intersection angles of.

In the present embodiment, each of the sputtered surfaces Ta of the pair of targets T extends obliquely toward the side opposite to the antenna 5 with respect to the dielectric plate 6. These pairs of targets T are arranged line-symmetrically with respect to the dielectric plate 6, and specifically, they are arranged in a C shape extending from the dielectric plate 6 side toward the object W side. That is, these pair of targets T are arranged so that their sputtered surfaces Ta face the surface of the object to be processed W while their respective sputtered surfaces Ta are inclined in the direction facing each other.

<Effect of this embodiment>
According to the sputtering apparatus 100 of the present embodiment configured in this way, since the sputtering surface Ta of the target T extends obliquely toward the side opposite to the antenna 5 with respect to the dielectric plate 6, it extends from the antenna 5. A high-frequency magnetic field can be efficiently guided to the sputtering surface Ta.
As a result, in a configuration in which the antenna 5 is provided outside the vacuum vessel 1, the target T is efficiently sputtered while improving the film forming speed and the processing efficiency by shortening the distance to the object W to be processed. Can be done.
Further, by making the sputtering surface Ta slanted, it is possible to suppress the spread of the sputtering particles with respect to the object W to be processed, and the sputtering source can be made highly utilized.

Further, since the target T is held at both positions sandwiching the dielectric plate 6, the film forming speed and the processing efficiency can be further improved.

<Other modified embodiments>
The present invention is not limited to the above embodiment.

For example, in the above-described embodiment, the target T is provided at both positions where the dielectric plate 6 is sandwiched, but the target T may be provided only at one of the positions where the dielectric plate 6 is sandwiched.

Further, although the sputtering apparatus 100 of the above embodiment includes one antenna 5 and a pair of targets T, for example, a plurality of antennas 5 provided in parallel with each other may be provided, or these. A plurality of sets of a pair of targets T may be provided corresponding to the antenna 5.

Further, in the above-described embodiment, the magnetic field transmission window is formed by the dielectric plate 6, but as shown in FIG. 3, the dielectric plate 6 is placed on the slit plate 11 in which a plurality of slits 11s are formed. Therefore, the magnetic field transmission window may be formed by the slit plate 11 and the dielectric plate 6.
With such a configuration, the magnetic field transmission window is formed by superimposing the slit plate 11 and the dielectric plate 6, so that the magnetic field is higher than the case where only the dielectric plate 6 functions as the magnetic field transmission window. The thickness of the transparent window can be reduced. As a result, the distance from the antenna 5 to the inside of the vacuum vessel 1 can be shortened, and the high-frequency magnetic field generated from the antenna 5 can be efficiently supplied into the vacuum vessel 1.

In addition, the sputtering apparatus 100 may include a moving mechanism for transporting the object W to be processed into the vacuum vessel 1 or swinging the object W in the vacuum vessel 1.

Further, as shown in FIG. 4, as the sputtering apparatus 100, for example, the vacuum vessel 1 is formed into a tubular shape, and the object W to be processed is rotationally moved around an axis parallel to the axial direction of the vacuum vessel 1. It may be provided with the mechanism 12.
With such a configuration, for example, the object W to be processed such as a tool can be formed, and the life can be improved by forming a film on the surface of the tool or the like.

In addition, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

100 ・・・ Sputtering device W ・・・ Target T ・・・ Target Ta ・・・ Sputtering surface 1 ・・・ Vacuum container 3 ・・・ Target holding part 5 ・・・ Antenna 6 ・・・ Dielectric plate θ・・・ Tilt angle S ・・・ Slit 11 ・・・ Slit plate

Claims

A sputtering device that sputters a target using plasma to form a film on an object to be processed.
A vacuum container that is evacuated and
An antenna provided outside the vacuum vessel and
A dielectric plate provided on the outer wall of the vacuum vessel at a position facing the antenna, and
A target holding portion for holding the target in the vacuum vessel is provided.
A sputtering apparatus in which the target is provided at one or both of the positions where the dielectric plate is sandwiched, and the sputtering surface thereof extends obliquely toward the side opposite to the antenna with respect to the dielectric plate. ..
The targets are provided at both positions sandwiching the dielectric plate, and each of the sputtered surfaces of the targets extends obliquely with respect to the dielectric plate toward the side opposite to the antenna. The sputtering apparatus according to claim 1.
The sputtering apparatus according to claim 1 or 2, wherein the inclination angle of the sputtering surface of the target with respect to the dielectric plate is 10 degrees or more and 45 degrees or less.
The sputtering apparatus according to any one of claims 1 to 3, wherein the dielectric plate is placed on a slit plate in which a plurality of slits are formed.