JPH0390568A - Plasma treating device - Google Patents

Abstract

PURPOSE:To stabilize generation of plasma and actuation of an evaporation source and to enhance quality of a formed film by partitioning a plasma generating chamber from the sample chamber containing an evaporation source and the base plate a sample with a pulling window and pulling plasma out through this window. CONSTITUTION:Prescribed reactive gas is introduced into a plasma generating chamber 1 and plasma is generated in this chamber 1 by utilizing a microwave plasma source having a magnetic field. At this time, the chamber 1 is held at the degree of vacuum not lower than about 5X10<-5>Torr. An electronic cyclotron resonance plasma flow P is pulled out into a sample chamber 5 containing the base plate 7 of a sample and an evaporation source 6 through the communication hole 11a of a pulling window 11 by the magnetic field of a coil 4 therefor and difference in the degree of vacuum, between the chamber 1 and the sample chamber 5. At this time, the plasma flow P starts to be spread but is squeezed by a magnet 8. The chambers 1, 5 are partitioned by the window 11 and vacuum exhaust conductance is made small. Therefore when the chamber 5 is vacuumized and exhausted, the difference is caused in the degree of vacuum between the chambers 1, 5 and the aim cam be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a plasma processing apparatus, for example, a plasma processing apparatus as a reactive vapor deposition apparatus using non-equilibrium plasma.

(Prior Art) Conventional plasma processing apparatuses of this type are used for manufacturing semiconductor integrated circuits, optical disks, etc.
The one described in JP-A-135126 is known.

This method converts a reactive gas into plasma and reacts it with metal vapor to form a thin film of nitride or oxide on a sample substrate. A magnetic field microwave plasma source that does not use a hot filament is used as a plasma source to generate plasma, and an electron beam heating type is used as an evaporation source to generate metal vapor. Although the plasma source and the evaporation source are provided in the same container, they are spatially separated, thereby preventing malfunctions due to mutual interference between the plasma source and the evaporation source.

In this case, the distance between the plasma source and the sample substrate inevitably becomes longer, and the plasma flow spreads, resulting in sample contamination due to so-called tube wall spatter and a decrease in the evaporation rate. An electromagnet or a permanent magnet is provided on the opposite side of the magnet, and the magnetic field generated by the electromagnet or permanent magnet narrows the plasma flow to eliminate the above-mentioned problems.

(Problem to be Solved by the Invention) However, in the conventional plasma processing apparatus of this type, the plasma source and the evaporation source were provided in the same container, so the plasma source and the evaporation source were placed in the same vacuum. It was placed under the control.

Here, in order to stabilize the generation of plasma in the plasma source, a vacuum of 7xto-"r o r r or more is required, while the evaporation source, that is, the electron gun, has a vacuum of 5x1O-5T.
.

If it is not used in a vacuum below rr, there is a possibility of abnormal discharge.

As a result, there has been a problem in that it is not possible to achieve both stable operation of the plasma source and stable operation of the evaporation source, resulting in a decrease in the quality of film formation.

(Purpose of the Invention) Therefore, the present invention has a structure in which a plasma generation chamber as a plasma source and a sample chamber containing an evaporation source and a sample substrate are partitioned by a drawer window, and the plasma in the plasma generation chamber is drawn out through the communication hole of the drawer window. By doing so, the purpose is to create a difference in the degree of vacuum between the plasma generation chamber and the sample chamber, stabilize the plasma generation and the operation of the evaporation source, and improve the quality of film formation.

In addition, a plasma CVD (Chemical Vapor Depot) in which the plasma generation chamber and the sample chamber are separated
Japanese Patent Publication No. Sho 62-43335 describes a device (situation), but this device does not use an evaporation source and draws the plasma in the plasma generation chamber into the sample chamber using a diverging magnetic field, so it is similar to the one described above. Sample contamination due to tube wall spatter cannot be prevented.

(Structure of the Invention) In order to achieve the above object, the plasma processing apparatus according to the present invention has the following features:
A plasma generation chamber that introduces a predetermined reaction gas to generate and activate plasma, an evaporation source that evaporates a predetermined substance that is installed adjacent to the plasma generation chamber, a sample substrate to be plasma processed, and a sample substrate sandwiched therebetween. a sample chamber housing a magnet disposed on the opposite side of the plasma generation chamber; A drawer window having a communication hole that partitions the chamber and the sample chamber and communicates the plasma generation chamber and the sample chamber is provided, and the plasma in the plasma generation chamber is drawn out into the sample chamber through the communication hole of the drawer window. Further, a microwave introducing means for introducing microwaves into the plasma generation chamber and a magnetic field means for generating a magnetic field that causes electron cyclotron resonance are provided,
Just as the plasma generation chamber becomes a microwave cavity resonator,
The shape and dimensions of the plasma generation chamber may be set.

Hereinafter, the present invention will be specifically explained based on examples.

The figure shows an embodiment of a plasma processing apparatus according to the present invention.

First, the configuration will be explained.

In the figure, l denotes a plasma generation chamber, and a plasma generation chamber 1 introduces a predetermined reaction gas through a mass flow controller and a gas introduction pipe (none of which are shown) to generate and activate plasma. Microwaves are introduced into the plasma generation chamber 1 from a waveguide 2 through a microwave introduction window 3 made of quartz glass or the like. As a microwave source (not shown), for example, a magnetron with a frequency of 2.45 GIIz can be used.

Further, a magnetic field coil 4 is provided around the outer periphery of the plasma generation chamber 1, and the strength of the magnetic field generated by the magnetic field coil 4 is set to cause electron cyclotron resonance due to microwaves. For example, frequency 2.45GHz
Since the microwave condition is a magnetic flux density of 875G, the magnetic field coil 4 can obtain a maximum magnetic flux density of about 1000G. That is, the above-mentioned waveguide 2 and microwave introduction window 3 constitute microwave introduction means for introducing microwaves into the plasma generation chamber l, and the magnetic field coil 4
constitutes a magnetic field means for generating a magnetic field that causes electron cyclotron resonance. The shape and dimensions of the plasma generation chamber 1 are set such that the plasma generation chamber 1 becomes a microwave cavity resonator, for example a circular cavity resonance mode T E + + 3 can be adopted.

On the other hand, 5 is a sample chamber provided adjacent to the plasma generation chamber 1, and the sample chamber 5 houses an evaporation source 6, a sample substrate 7 to be plasma treated, and a magnet 8. The evaporator a6 is a so-called electron gun evaporation source that evaporates a predetermined metal or other compound, and irradiates the sample substrate 7 with vapor S of metal or the like.

The sample substrate 7 is supported by a substrate holder 9 so that the substrate surface faces both the plasma generation chamber 1 and the evaporation source 6.

The magnet 8 is an electromagnet or a permanent magnet, and is disposed on the opposite side of the plasma generation chamber 1 with the sample substrate 7 in between. l
O is an exhaust port, and the sample chamber 5 is evacuated through the exhaust port IO.

Here, 11 is a drawer window that partitions the plasma generation chamber 1 and the sample chamber 5, and the drawer window 11 has one or more communication holes 11a that communicate the plasma generation chamber 1 and the sample chamber 5. There is. The plasma in the plasma generation chamber 1 is transmitted through the communication hole 11.
It is designed to be drawn out to the sample chamber 5 through a.
It is expressed as a plasma flow P. The diameter and number of the communication holes 11a are set so that when the sample chamber 5 is evacuated through the exhaust port 10, a predetermined difference in the degree of vacuum occurs between the plasma generation chamber 1 and the sample chamber 5.

Next, the action will be explained.

First, microwaves introduced into the plasma generation chamber are resonantly absorbed by electrons moving in a cyclotron due to the magnetic field formed by the magnetic field coil 4. Electrons obtained energy from microwaves excite the reactant gas and dissociate it,
Ionizes and creates plasma. At this time, the plasma generation chamber 1 is maintained at a degree of vacuum of about 5xlO-'T or r or more, and this vacuum is created by evacuation through the exhaust port 10. Then, the plasma in the plasma generation chamber 1 becomes an ECR (electron cyclotron resonance) plasma flow P due to the magnetic field of the magnetic field coil 4 and the difference in the degree of vacuum between the plasma generation chamber 1 and the sample chamber 5.
a into the sample chamber 5, reaches the sample substrate 7, reacts with the metal vapor S, and plasma-processes the sample substrate 7. Furthermore, when the ECR plasma flow P is drawn out into the sample chamber 5, the ECR plasma flow P is in a beam shape.
However, since the magnet 8 is provided, the ECR plasma flow P that is trying to spread can be constricted.

As described above, in this embodiment, the plasma generation chamber l and the sample chamber 5 are partitioned by the drawer window 11 to reduce the evacuation conductance, so when the sample chamber 5 is evacuated through the exhaust port 10, the plasma generation chamber It is possible to create a difference in the degree of vacuum between the sample chamber 5 and the sample chamber 5. For example, the plasma generation chamber 1 can be made to have a vacuum of 7×10 −5 Torr or more, and the sample chamber 5 can be made to be a vacuum of 5×10 −′ Torr or less. Therefore, it is possible to achieve both stable plasma generation and stable operation of the evaporation source 6, that is, prevention of abnormal discharge, and it is possible to improve the quality of film formation by plasma processing.

In addition, since microwaves are introduced and a magnetic field coil 4 is provided, electron cyclotron resonance plasma can be generated, and since the plasma generation chamber 1 is a microwave cavity resonator, the electric field strength of the microwave is It is possible to increase the efficiency of microwave discharge and generate highly active plasma in a high vacuum. As a result, simultaneous use with the evaporation source 6 is possible, and this embodiment can be applied to a reactive evaporation apparatus using plasma.

In this example, if the plasma flow and the metal vapor from the evaporation source 6 are irradiated simultaneously or alternately, a thin film having a layered structure of a compound and a metal can be formed.

Further, in this embodiment, if an electric field application means such as an ion extraction electrode that changes the kinetic energy of plasma particles extracted from the plasma generation chamber 1 is provided, a thin film with higher performance can be formed.

(Effects) According to the present invention, the plasma generation chamber and the sample chamber containing the evaporation source and the sample substrate are partitioned by the drawer window, and the plasma in the plasma generation chamber is drawn out through the communication hole of the drawer window. The generation chamber and the sample chamber can each be maintained at an appropriate degree of vacuum.

Therefore, the generation of plasma and the operation of the evaporation source can be stabilized, and the quality of film formation can be improved.

Further, when the shape and dimensions of the plasma generation chamber are set so that the plasma generation chamber becomes a microwave cavity resonator, the electric field strength of the microwave can be increased.

Therefore, the efficiency of microwave discharge can be increased, and highly active plasma can be generated in a high vacuum.

[Brief explanation of drawings]

The figure is a sectional view showing an embodiment of a plasma processing apparatus according to the present invention. l...Plasma generation chamber, 4...Magnetic field coil (magnetic field means) 5...
- Sample chamber, 6... Evaporation source, 7... Sample substrate, 8... Magnet, 11... Drawer window, 11a... Communication hole. agent

Claims (2)

[Claims] (1) A plasma generation chamber that introduces a predetermined reaction gas to generate and activate plasma, an evaporation source that is installed adjacent to the plasma generation chamber and evaporates a predetermined substance, and a sample substrate and sample to be plasma treated. A plasma processing apparatus comprising a sample chamber housing a magnet disposed on the opposite side of the plasma generation chamber with a substrate in between, and performs plasma processing by drawing plasma in the plasma generation chamber toward the sample substrate into the sample chamber, partitioning the plasma generation chamber and the sample chamber;
A plasma processing apparatus characterized in that a drawer window having a communication hole that communicates a plasma generation chamber and a sample chamber is provided, and plasma in the plasma generation chamber is drawn out into the sample chamber through the communication hole of the drawer window. (2) Microwave introduction means for introducing microwaves into the plasma generation chamber and magnetic field means for generating a magnetic field that causes electron cyclotron resonance are provided, and the plasma generation chamber is configured to serve as a microwave cavity resonator. 2. The plasma processing apparatus according to claim 1, wherein the shape and dimensions of the generation chamber are set.