JPH06168699A - Ecr plasma processing device - Google Patents

Abstract

PURPOSE:To generate highly accurate ECR plasma, and downsize a plasam source. CONSTITUTION:Plural permanent magnets 2, 3 and 4 having different magnetic force are arranged around a plasma generating chamber 8 in which a microwave 1 is introduced. A distance at which electric field strength distribution of the propagating microwave is uniformized, is shortened by these permanent magnets 2, 3 and 4, and a length dimension of the plasma generating chamber 8 is shortened, and a plasma source is downsized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ECR plasma processing apparatus for generating a high density plasma by applying a microwave and a magnetic field and using electron cyclotron resonance, and in particular, an ECR plasma processing apparatus capable of downsizing a plasma chamber. Regarding

[0002]

2. Description of the Related Art Conventionally, as an ECR plasma processing apparatus of this type, as shown in FIGS. 22a and 22b are provided, and the permanent magnets 21 and 2 are provided.
Microwave transmission windows 20a, 20b by 2a, 22b
A magnetic field B intersecting the electric field E of the microwaves transmitted through the microwave transmission windows 20a and 20b at a right angle was formed in the lower part of the above (Japanese Patent Laid-Open No. 63-288022).

As another conventional example, as shown in FIG. 7, at least four permanent magnets 31 are provided on the outer circumference of a vacuum container 30, and the permanent magnets 31 form a multicusp magnetic field. Further, the permanent magnet 31 is slidable in the axial direction of the vacuum container 3 by the combination of the rack 32a and the pinion 32 and the drive motor 33.

[0004]

However, only one magnet is provided in the traveling direction of the microwave in the above-mentioned conventional device, and the magnetic field gradient from the microwave introduction portion is steep, Moreover, since the magnetic field distribution is non-uniform with respect to microwave propagation, the absorption efficiency of microwaves into plasma is low and the density of generated plasma is low. Also,
Since the plasma generation is non-uniform, there is a problem that the etching uniformity is not sufficient.

An object of the present invention is to provide an ECR plasma processing apparatus which realizes generation of highly accurate ECR plasma and downsizing of a plasma source.

[0006]

In order to achieve the above-mentioned object, an ECR plasma processing apparatus according to the present invention has a set of permanent magnets and applies a microwave and a magnetic field to achieve high density using electron cyclotron resonance. An ECR plasma processing apparatus for generating plasma, wherein a set of permanent magnets has a plurality of different magnetic forces and is arranged around a plasma generation chamber to enhance the efficiency of microwave absorption in plasma.

The permanent magnets forming the set are sequentially arranged along the microwave introduction direction into the plasma generating chamber.

The permanent magnets forming the set have a magnetic force of 2: 1: 1.5.

[0009]

Function: A plurality of permanent magnets 2, 3 and 4 having different magnetic forces are provided around the plasma generation chamber 8 into which the microwave 1 is introduced. The permanent magnets 2, 3 and 4 shorten the distance in which the electric field strength distribution of the propagating microwaves is made uniform, and shorten the length dimension of the plasma generation chamber 8 to downsize it.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention.

In the figure, a substrate holder 9 is installed below the plasma generating chamber 8, and a substrate to be processed is set on the substrate holder 9. In addition, the holder 9 is R
It is electrically connected to the F power source 6 via a capacitor 7. Further, a microwave waveguide 10 is connected to the upper part of the plasma generation chamber 8, and an introduction window 11 is provided at the connection point between the two.

Further, three permanent magnets 2, 3, 4 having different magnetic forces are provided on the outer circumference of the plasma generating chamber 8 side by side in the vertical direction. Then, by setting the magnetic field strength ratio by the permanent magnets 2, 3, 4 to 2: 1.0: 1.5, a magnetic field gradient of 20 G / cm or less in which the microwave 1 is completely absorbed is formed. Reference numeral 5 is an ECR area. Figure 2
Shows the relationship between the magnetic field gradient and the microwave absorption efficiency.

The arrangement of the permanent magnets 2, 3 and 4 makes the magnetic field distribution in the plasma generating chamber 8 uniform as shown in FIG.

As shown in FIG. 4, the introduced microwave 1 has a uniform electric field intensity distribution from the introduction window 11 to about 8 cm, so that 20 G /
A uniform plasma is formed by forming an 875 G ECR region 5 with a cm gradient. The magnetic field arrangement is 2000G, 1000G, 1500G as shown in FIG.
It is achieved by the combination of.

With the arrangement of these magnetic fields, a sufficiently stable ECR plasma is generated while the ECR plasma source is downsized.

The inner diameter of the plasma generating chamber 8 is 8
It is 300 mmφ for processing an inch substrate. The length dimension of the plasma generation chamber 8 is 10 cm.
The reason is as follows. That is, the electric field intensity distribution of the microwave 1 introduced by the waveguide 10 is made uniform by mode conversion after propagating for about one wavelength.

Further, the plasma generation chamber 8 is provided with a gas introduction system for introducing a gas for generating plasma. The introduction window 11 is made of quartz glass, ceramics or the like, and the microwave 1 sent through the introduction window 11 is introduced into the plasma generation chamber 8. In addition, the magnetic field gradient in the plasma generation chamber 8 is 20 G / cm.
The ECR region 5 is formed below and 8 cm from the introduction window 11 and its uniformity is ± 3% or less.

The substrate holder 9 on which the substrate to be further processed is placed is placed about 2 cm from the ECR area 5. The position of the holder 9 is variable.

The substrate to be processed is loaded into the plasma generation chamber 8 from the outside by a transport system (not shown) and placed on the substrate holder 9. Further, the substrate holder 9 has an RF
A high frequency voltage is applied from a (high frequency) power supply 6 through a capacitor 7.

[0020]

As described above, according to the present invention, by arranging a plurality of magnets having different magnetic forces in the ECR plasma processing apparatus in combination, a magnetic field of 875 G having a flat magnetic field gradient of 20 G / cm or less is generated. The waves can be formed in a uniformed portion, and uniform and high-density plasma can be generated in the small ECR plasma source.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an ECR plasma processing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a magnetic field gradient in a resonance region and a microwave absorption efficiency in the resonance region.

FIG. 3 is a diagram showing a combination of magnetic forces and a magnetic field strength in-plane distribution.

FIG. 4 is a diagram showing a microwave propagation state in a plasma chamber.

FIG. 5 is a diagram showing magnet strength and magnetic field distribution.

FIG. 6 is a diagram showing a conventional example.

FIG. 7 is a diagram showing a conventional example.

[Explanation of symbols]

 1 Microwave 2 Permanent Magnet 3 Permanent Magnet 4 Permanent Magnet 5 ECR Region 6 RF Power Supply 7 Capacitor 8 Plasma Generation Chamber 9 Substrate Holder 10 Waveguide 11 Introduction Window

Claims (3)

[Claims] 1. An ECR plasma processing apparatus having a set of permanent magnets, wherein a microwave and a magnetic field are applied to generate high-density plasma by using electron cyclotron resonance, and the set of permanent magnets is different from each other. An ECR plasma processing apparatus which has a magnetic force and is arranged around a plasma generation chamber to enhance the efficiency of microwave absorption into plasma. 2. The ECR plasma processing apparatus according to claim 1, wherein the pair of permanent magnets are sequentially arranged along a microwave introduction direction into the plasma generation chamber. 3. The pair of permanent magnets have a magnetic force of 2:
The ECR plasma processing apparatus according to claim 2, wherein the ECR plasma processing apparatus has a ratio of 1: 1.5.