JPS62260329A - Surface treating method - Google Patents

Abstract

PURPOSE:To prevent the component atoms of a solid for scattering from mixing in scattered particle beams, by varying the intensity of ion beams falling on the scattering solid on a time basis when the ion beams emitted from an ion source are made to fall on the scattering solid and scattered thereby so as to obtain the scattered particle beams incident on a sample. CONSTITUTION:In a space surrounded by a vacuum tank wall 9, ion beams 2 are led out of an ion source 1 and made to fall on a scattering body 3. Most of beams 4 of particles scattered on the scattering solid body 3 become those of particles of neutralized the incident ions and fall on a sample 5. A gas is introduced from a gas supply source 8 into a reaction chamber 10 wherein the sample 5 is set, and gas particles act on the sample irradiated with the scattered beams, thus advancing surface treatment. By varying the ion beams 2 incident on the scattering solid body 3 cooled by a cooling device 6, as shown in the figure, atoms constituting the surface of the scattering solid body 3 are not coiled by incident ions to mix in the scattered particle beams 4 even when the temperature of the scattering solid body rises above the temperature of liquefaction of the introduced gas.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to solid surface treatment technology, and in particular, to a technology suitable for high-precision etching, surface modification, surface cleaning, and thin film deposition on the surface. Concerning surface treatment methods for semiconductors, metals, and insulators.

[Conventional technology]

Conventionally, plasma or ion beams have been used for etching processing in the manufacture of semiconductor devices. That is, a processing method has been adopted in which ions and electrons from the plasma are incident on the surface of a sample to be processed, or ions are made to enter the surface of the sample when an ion beam is used. The phenomenon of these charged particles entering the sample surface and the associated problems in semiconductor device manufacturing will be discussed in the Dry Process Symposium Proceedings.
ssSymposium Proceedings) *
(1985) t V5+132P. That is, in the etching process by injecting charged particles onto the sample surface, there is a problem in that the sample surface is charged and the insulating thin film is deteriorated. This problem commonly occurs not only in etching processes, but also in surface cleaning using charged particles, impurity injection into the surface, surface modification, thin film deposition, and other processes.

[Problem that the invention seeks to solve]

The present invention solves the above-mentioned problem with the conventional technology, that is, when charged particles are incident on the surface of a sample, the surface of the material to be processed is charged, causing damage to the surface of the material to be processed, such as deterioration of the insulating thin film. By injecting the ion beam into a solid surface separate from the sample to obtain a scattered particle beam consisting mostly of neutral particles, and by injecting this beam into the surface of the sample to be processed, the charge on the sample surface can be reduced. It is an object of the present invention to provide a surface treatment method that can reduce surface damage and prevent surface damage caused by charging.

In particular, an object of the present invention is to prevent atoms constituting the scattering solid from being mixed into the scattered particle beam.

[Means for resolving issues]

The above purpose is to use ions emitted from an ion source! This is achieved by temporally changing the intensity of the ion beam incident on the scattering solid when the ion beam is incident on the scattering solid to obtain a scattered particle beam that is scattered and incident on the sample.

[Effect]

The scattering solid is cooled and the introduced gas is adsorbed on its surface.

When the cooling temperature of the scattering solid is lower than the liquefaction temperature of the introduced gas, constituent atoms from the scattering solid under the adsorption layer will not mix into the scattered particle beam. On the other hand, at temperatures above the liquefaction temperature of the introduced gas, the number of gases that are incident on the scattering solid surface and adsorbed on the scattering solid per unit time is greater than the number of incident ions that are incident on the scattering solid. It was necessary to prevent the layer from being depleted. However, even under these conditions, some constituent atoms of the scattering solid that were recoiled by the ion beam were mixed in6.Therefore, the intensity of the ion beam incident on the scattering solid was changed over time during the irradiation time. This can prevent the gas adsorption layer from being even partially depleted from the surface of the scattering solid, and the atoms constituting the scattering solid below the gas adsorption layer.

Contamination with the scattered particle beam can be prevented.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

Figure 1 shows that the ion beam is 0,4
(mA/cxl) and tZ
Temporal changes in the current density of incident ions on the scatterer for the treatment performed at a current density of 0, 1 (mA/ryl) for a period of seconds, and 11 and tZ were repeated 7 times, with a total processing time of to seconds. This is what is shown. FIG. 2 shows the apparatus used to carry out the above embodiment.

In a space surrounded by a vacuum chamber wall 9, ion beads tz 2 are extracted from an ion source 1 and made to enter a scatterer 3.

The scattering particles scattered by the scattering solid 3, [4, are mostly composed of particles in which the incident ions have been neutralized, and the particles scattered by the sample 5 with some divergence.
incident on . Gas is introduced from the gas supply source 8 into the reaction chamber 10 in which the sample 5 is placed, and gas particles act on the sample irradiated with the scattering bees 11, thereby proceeding with surface treatment. The scatterer 3 can be cooled by a cooling device 6 and a gas supply source 7
The introduced gas is adsorbed on the cooled scatterer surface.

If the ion beam 3 incident on the cooled scattering solid 3 is changed as shown in FIG. It was found that there was no contamination with the scattered particle beam, 4. In other words, by changing the intensity of the incident ion beam, stt and tZ, which had the effect of not mixing one random solid constituent atom into the scattered particle beam incident on the sample surface, depend on the incident ion current density and the substrate material of the scattering solid 3. and varies depending on the combination of introduced gas and scattering solid temperature. Effective for improving processing speed. On the other hand, when the values of tl and /lz are made small, there is an advantage that a gas adsorption layer is formed and maintained on the surface of the scattering solid even if the temperature of the scattering solid becomes relatively high.

Furthermore, processing was possible even when the ion beam intensity was set to tL+t2 twice the shortest controllable time, and it was effective in preventing the atoms constituting the scattered solid from being mixed into the scattered particle beam.

As means for changing the intensity of the ion bee 11, there are a method of changing the energy, a method of changing the gas pressure introduced into the ion source 1, and a method of changing the plasma maintenance power in the ion source.

When the ion beam is pulsed, the effect of the above embodiment becomes even greater. In this case, it is further easier to control the end of the process.

It is also possible to control the plasma sustaining power and ion extraction voltage of the ion source using a sine wave. This has the advantage that it is easier to generate an ion beam below 1M than a pulsed ion beam or a rectangular wave ion beam.

〔Effect of the invention〕

According to the present invention, since the surface of a sample can be treated with a scattering particle beam consisting of neutral particles, G' charges on the sample surface are small, surface destruction due to charging can be prevented, and constituent atoms of the scattering solid are Since mixing with the scattered particle beam can be prevented, highly accurate surface treatment is possible.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a temporal change in ion beam current density in an embodiment of the present invention, and FIG. 2 is a schematic diagram of an apparatus used in an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Ion source, 2...-ion beam, 3...Scattered solid, 4...Scattered particle beam, 5...Sample, 6...
Cooling device, 7... gas supply source, 8... gas supply source,
9... Vacuum chamber wall, 10... Reaction chamber. Figure 1 Figure 7 Takucha Figure 2

Claims (1)

[Claims] 1. A scattering solid is irradiated with an ion beam to cause scattering, the resulting scattered particle beam is incident on a sample to be processed, and the intensity of the ion beam incident on the scattering solid is varied over time. surface treatment method.