JPH025523A - Plasma treating device - Google Patents

Abstract

PURPOSE:To make it possible to treat the surface of a sample to be treated at high speed, with good anisotropy and with good accuracy by a method wherein light if a prescribed wavelength, which is decided according to the contents of treatment, is irradiated on the surface of the sample to be treated while the sample is rotated with the direction vertical to the surface to be treated as the rotating shaft. CONSTITUTION:A plasma lead-out window 14 is provided between a plasma chamber 1 for generating ECR plasma and a treating chamber 2 wherein a sample stand 7 for placing a sample 8 is provided. Moreover, electromagnetic coils 5 and electromagnetic coils 6 installed behind the sample 8 are respectively covered with each ferrormagnetic material 10 to form a cusp type electric field. The sample 8 is put in a neutral active species region 20 and is rotated round a shaft 30 of the stand 7 by a rotative driving mechanism. Moreover, a light source 17 and a light-introducing window 18 are provided and light 16 emitted from the source 17 is made to pass through the window 18 and the light of a prescribed wavelength is irradiated on the surface of the sample 8. As the source 17, a mercury-arc lamp, a laser and so on are selectively used according to the contents of treatment.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides an electron cyclotron resonance (ECR) plasma treatment for the surface of a sample to be processed (hereinafter simply referred to as a sample) such as a semiconductor, metal, or insulator. This invention relates to improvements in plasma processing equipment that performs processes such as etching, film deposition, and surface cleaning.

(Prior Art) Plasma processing apparatuses that utilize ECR plasma have become widely used in the manufacture of semiconductor devices.

JP-A-61-13634 discloses that at least one cusp type reversal magnetic field is provided between the ECR plasma generation source and the object to be processed, and charged particles in the plasma are targeted by the cusp type magnetic field. A plasma processing apparatus has been disclosed in which a workpiece is treated only with active species by confining them in a region. This avoids damage to the treated object caused by the impact of electric particles.

The outline of this type of apparatus will be explained using FIG. 3 (the apparatus is rotationally symmetrical about the axis 30, except for the gas introduction system and the exhaust system).
1 and 11'' into the vacuum vessel 1'', and the microwave is guided through the waveguide 4 into the discharge tube section 111, which is a part of the vacuum vessel.Discharge tube section! Inside 2', a magnetic field that satisfies the ECR resonance condition is set in advance by the electromagnetic coil 5, so that iE CR plasma is generated here.

Charged particles in the ECR plasma are transported along magnetic lines of force 18 formed by the electromagnetic coil 5, but an electromagnetic coil 6 is installed behind the sample stage 7 and the sample 8 on it. Since the electromagnetic coil 6 and the previous electromagnetic coil 5 are excited to create a magnetic field with the same direction and opposite direction, a cusp-shaped magnetic field 15 is formed between the sample 8 and the discharge tube part IIT, and the magnetic field 15 is generated in the plasma. charged particles are trapped here.

Therefore, the surface of the sample 8 is irradiated with only the neutral active species 20 from which charged particles have been removed from the plasma, and processes such as etching and film deposition are performed exclusively with this neutral active species 1. Sample 8 can escape the impact damage of charged particles.

(Problems to be Solved by the Invention 1) However, problems also occur because only neutral active species are involved in surface treatment.

For example, we will explain the case where this equipment is used for etching processing of Poly-Si, but the etching characteristics of this equipment are similar to those of chemical dry etching equipment (Y,
Horiike et al; Jan, J., ApplP.
hys, 5upp1.15 (1976) 1.3), and inherits the advantages and disadvantages of isotropic etching. Furthermore, the processing speed is extremely slow.

(Objective of the Invention) The present invention solves the above-mentioned problems in the conventional apparatus, and although it uses neutral active species in ECR plasma as in the conventional apparatus, it can process the surface of a sample at high speed and in a different way. It is an object of the present invention to provide a plasma processing apparatus that enables processing with good direction and accuracy.

(Means for Solving the Problems) The present invention provides a sample stage on which a sample to be processed is placed adjacent to a plasma chamber in which processed i-gas is plasma quenched by electron cyclotron resonance, and the magnetic field of the plasma chamber is directed In a plasma processing apparatus that is equipped with a processing chamber provided with magnetic fields of equal and opposite polarity and performs a predetermined treatment on the surface of a sample to be processed using active species of plasma generated in the plasma chamber, The above object is achieved by using a plasma processing apparatus equipped with a device for irradiating a surface with light of a predetermined wavelength determined by the content of the processing.

A knife equipped with a mechanism for rotating a sample to be processed about a rotation axis in a direction perpendicular to the surface to be processed can further enhance the functions of the present invention.

(Function) By irradiating light with a predetermined wavelength determined by the content of the process, the speed of the process can be increased, directionality can be given to the process, and anisotropic process can be realized. Furthermore, by rotating the sample, it is possible to improve the uniformity of the processing or to add a selective processing function to the processing.

(Example) Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic front sectional view of a plasma processing apparatus according to an embodiment of the present invention. The outline of the apparatus is the same as the conventional plasma processing apparatus shown in FIG. A window 14 is provided to facilitate plasma generation.

Further, the electromagnetic coil 5 and the electromagnetic coil 6 installed behind the sample 8 are each covered with a ferromagnetic material 10, and a cusp type magnetic field I
5 is made more effective.

The current applied to the electromagnetic coil 6 is designed to create a magnetic field in the sample portion that is equal in direction and opposite to the magnetic field # generated by the electromagnetic coil 5, as in the conventional case, in order to create a cusp type magnetic field. In order to enlarge the region 20 of neutral active species, the magnetic field is made slightly larger than the magnetic field generated by the electromagnetic coil 5.

Sample 8 is placed within neutral active species region 20 . In addition,
The sample stage 7 is rotated around an axis 30 during processing by a rotational drive mechanism (not shown).

The apparatus shown in FIG. 1 is significantly different from the conventional apparatus in that a light source 17 and a light introduction window 18 are newly installed, and the light ray 16 emitted from the light source 17 passes through the introduction window 18 to the sample. The surface of the device is irradiated with light of a predetermined wavelength.

As the light ff17, various types such as mercury lamps and lasers are selected and used according to the contents of the intended process, and if necessary, a 1-nons system or a filter system can be interposed between the light R17 and the window 1.8. .

In the apparatus of the present invention having this configuration, for example, when forming a thin film using this apparatus, charged particles in the plasma are trapped and removed by the cusp-type magnetic field, and only neutral active species reach the sample 8. When the surface of the sample is irradiated with the light beam 16 of a predetermined wavelength from the light R17, the reaction is particularly rapid on this irradiated surface.

For example, when forming a film of 5i021j%, gas inlet 1
1 to 02, and SiH4 is introduced from the gas inlet 111, and when using an I(g-Xe lamp with high light intensity at wavelengths of 250 to 400 nm), charged particles SiH4+, Si( , O+, O2+, etc. are removed, and only the neutral active species sit, O2:, etc. react on the sample surface and are destroyed.

Therefore, the iAW having this configuration is particularly advantageous when, for example, 11) the poor step coverage of the wall surface 25 of the stepped portion shown in FIG. 1a is to be corrected. This is because film deposition progresses strongly only on the wall surface that is irradiated with light.

Rotating the sample 8 is effective in depositing the film evenly over the entire surface of the wall surface 25 of the step.

FIG. 2 is a front cross-sectional view of a plasma processing apparatus according to a second embodiment of the present invention.

In the case of this device, a sample stage 7 on which a sample 8 is placed is arranged perpendicularly to the plane of a plasma extraction window 14, and a light source 17 irradiates a light beam 16 perpendicularly to the surface of the sample 8. It has become.

Furthermore, a mesh-like microwave reflecting plate 21 is provided in front of the processing chamber to prevent charged particles trapped in the cusp-type magnetic field from entering the processing chamber.

In the apparatus of this second embodiment, the light beam 16 is irradiated perpendicularly to the surface of the sample 8, so that, for example, in the case of etching, a finer pattern and improved anisotropy can be achieved.

Taking the case of etching P o 1 y-S i as an example, if C072 gas is introduced from the gas inlet 11, charged particles such as Cα+ and electrons are removed by the cusp type magnetic field, and one neutral active species C is removed. etc. reach the sample surface. For example, as shown in Figure 2a, on the fitting surface, ArF laser or SO
Since only the portion 26 that is irradiated with the light beam 16 such as the R light (the other surface of the Po1y-5i 18 is covered with the photoresist 27) is quickly etched, etching with good anisotropy is possible. be.

As in the case of the first embodiment, by rotating Ci1 and sample N8, uniform treatment can be performed over the entire surface of the sample.

In the first and second embodiments described above, by changing the type of neutral active species, that is, by changing the type of gas introduced, and by selecting the wavelength of the irradiated light, 5i02ffX and Po1
It goes without saying that it is possible to select and perform desired treatments such as etching, thin film formation, surface oxidation, cleaning, etc. on the outside of the y-Si film. For example, In the formation of Si, N, thin films, SiH and N2 are used as reaction gases, and the wavelengths of 250 to 40
The light from a Hg-Xe lamp with a high light intensity of 0 ntn is irradiated, and in the oxidation of the surface modification treatment, 02 gas is introduced to generate active species of acid accumulation, and the light from a deuterium lamp with a wavelength of 130 to 400 nrn is applied. All you have to do is irradiate it.

(Effects of the Invention) The present invention utilizes neutral active species in the ECR plasma as in the past to fully suppress irradiation damage to the sample caused by U main particles, while speeding up the surface treatment of the sample. This has the effect of providing a novel plasma processing apparatus that enables processing with good anisotropy and high precision.

FIG. 2 is a schematic front sectional view.

FIG. 1a is a diagram illustrating film deposition.

FIG. 2 is a schematic front sectional view of a plasma processing apparatus according to another embodiment.

FIG. 2a is a diagram illustrating the etching process of the film.

FIG. 3 is a schematic front sectional view of a conventional plasma processing apparatus.

1... Plasma chamber, 2...-processing chamber, 3... Microwave introduction tube, 4... Waveguide, 5, 6... Electromagnetic coil, 7... Trial)'l1 unit, 8... Test H0, 9... Plasma chamber side wall, 10... Ferromagnetic material, 11, 11'.
...Gas inlet, 14...Plasma drawer window, 15.
... Cusb type magnetic field, 16... Light ray, 17... Light source,
18...Window, 19...-Magnetic field lines, 20...Neutral active species region, 21...Mesh-like microwave reflecting plate.

[Brief explanation of the drawing]

Claims (2)

[Claims] (1) Providing a sample stage on which the sample to be processed is placed adjacent to the plasma chamber in which processing gas is turned into plasma by electron cyclotron resonance, and providing a magnetic field with the same direction and opposite polarity as the magnetic field of the plasma chamber. Equipped with a processing room equipped with
In a plasma processing apparatus that performs a predetermined treatment on the surface of the sample to be processed using active species of plasma generated in the plasma chamber, a beam of a predetermined wavelength determined by the content of the process is applied to the surface of the sample to be processed. A plasma processing device characterized by being equipped with a device for irradiating light. (2) The plasma processing apparatus according to claim 1, further comprising a mechanism for rotating the sample to be processed about a rotation axis in a direction perpendicular to the surface to be processed.