JPH0542813B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a surface treatment apparatus for forming a thin film on the surface of a sample or etching the surface of a sample in a gas phase.

In recent years, gas phase (gas) surface treatment apparatuses have been developed mainly in the field of semiconductor device manufacturing. The main surface treatment process is to form a thin film on the surface of the sample or to etch the surface of the sample.
In addition, surface treatment processes include processes that change the physical and chemical properties of the surface of the sample (surface modification) and processes that inject impurities into the surface of the sample.

Devices that perform surface treatment in the gas phase include devices that place a sample in an atmosphere of particles involved in surface treatment (treated particles), and devices that perform surface treatment using a particle beam from a source where a large amount of the treated particles are present. There is a device that extracts the particle beam and makes it incident on the sample surface.

The former surface treatment equipment has excellent mass productivity, but
The latter surface treatment device is superior in controllability. Therefore, in the future, when high-quality thin films and ultrafine processing (etching) become necessary, it is thought that surface treatment equipment using the latter type of particle beam will become mainstream.

Conventional surface treatment devices using particle beams use ions or chemically stable atoms and molecules as treatment particles.

Figure 1 shows the basic configuration of a conventional surface treatment device that uses ions as processing particles [for example, J.Vac.Sci.Technol., 18(1), Jan./
See Feb. 1981, pp. 17-22]. In this apparatus, an ion beam 3 is extracted from an ion source 1 by an ion extraction system 2, and irradiated onto the surface of a sample 5 placed in a surface treatment chamber 4 to treat the surface. The surface treatment chamber 4 is evacuated to the required vacuum pressure (10 ⁻⁶ Torr) by an exhaust system 30 . Types of surface treatment performed with this apparatus include thin film formation, etching, surface modification, and ion implantation.

Figure 2 shows an example of the configuration of a conventional surface treatment device that uses chemically stable atoms and molecules as treatment particles [for example, J.Appl.Phys., 51(2), Feb. 1980,
See pp.1102-1110]. In the figure, an atomic or molecular source 8 is filled with treated particles generated by heating a solid or liquid substance 6 containing treated particles with a heater 7 connected to a power source 31. atom,
Atoms and molecules in the molecular source 8 are ejected from the ejection port 9 due to the pressure difference to form an atomic and molecular beam (molecular beam) 29, which is incident on the surface of the sample 5 to treat the surface of the sample 5. Let's do it. Note that the surface treatment chamber 4 is evacuated to a necessary vacuum pressure by an exhaust system 30. The type of surface treatment performed with this apparatus is mainly thin film formation.

The device shown in Figure 2 above (Molecular beam 29
However, since the chemical reactivity of the treated particles reaching the surface of the sample 5 is poor, only a limited amount of surface treatment can be performed. That is, only thin film formation can be performed as surface treatment, and other etching and surface modification are not possible. Furthermore, the properties of the formed thin film are also limited.

On the other hand, the apparatus shown in Fig. 1 (which uses the ion beam 3) allows various surface treatments, but due to the large kinetic energy (>100 eV) of the ions incident on the sample 5, The disadvantage is that many damages (such as lattice defects) remain on the surface.
Furthermore, when forming a thin film using the ion beam 3, it becomes difficult to form a thin film of polymer because the incident ions break the bonds of molecules forming the thin film.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a surface treatment apparatus that eliminates the above-mentioned drawbacks.

The gist of the present invention is to provide a surface treatment apparatus for forming chemically active radical rays and irradiating the radical rays to an object to be irradiated with the radical rays, wherein the radical rays are formed from a first chemical substance. and a second radical made of a second chemical substance that is a different chemical substance from the first chemical substance, and the radical line is formed from the position where the radical line is formed. A first chopping means and a second chopping means are provided for periodically repeating passage and blocking of the radical ray on the path of the radical ray until it is irradiated to the irradiation object, and the first and second chopping means The chopping means has first and second disc-shaped members having openings through which the radical rays can pass, and after the first and second radicals have passed through the first disc-shaped member, Based on the difference in time required to reach the second disc-shaped member, the first radical passes through the second disc-shaped member and reaches the irradiated object. It is characterized by comprising means for creating a correlation between the hopping frequency of the first hopping means and the hopping frequency of the second hopping means so that radicals are blocked by the second disc-shaped member. It is in the surface treatment equipment.

In addition, hereinafter, "chemically active neutral particles" means:
Refers to atoms and molecules that have unbonded bonds (unpaired electrons). This is also called a "radical."

Due to the characteristic structure of the present invention, chemically active processing particles are used, so a wide range of surface treatments such as thin film formation, etching, and surface modification can be performed compared to the conventional apparatus shown in FIG. becomes. Furthermore, since the kinetic energy of the incident particle beam is low, damage to the surface is extremely reduced compared to the conventional device shown in FIG. Furthermore, when forming a thin film, the bonds of the molecules forming the thin film are not broken, so it is possible to form a thin film with extremely high molecular weight and chemical stability. Furthermore, by chemically reacting the surface of the sample substrate with the treated particles, it is also possible to change the physical and chemical properties of the surface. Note that the radicals include F, Cl, Br, O, H,
Atomic substances such as N, C _o F _n , C _o Cl _n , C _o Br _n ,
There are molecular types such as C _o H _n and C _h H _i F _j Cl _k Br _l where all the C bonds are not closed.
It is also possible to use the above molecular radicals in which C is replaced with Si, S, or B.

Hereinafter, the present invention will be explained in detail using figures.

FIG. 3 shows the basic configuration of a surface treatment apparatus that is a reference example of the present invention. Radical source 10
Create chemically active neutral particles using one of the methods described below, and eject them from one or more ejection ports 9 to form radical lines 11 (having a certain range of directions at each point in space). (a collection of active neutral particles that fly). This radical line 1
The surface of the sample 5 is treated by irradiating the sample 5 placed in the surface treatment chamber 4 which has been evacuated with the exhaust system 30 with the sample 1. A substance containing radical components is supplied into the radical source 10 in a gaseous state via the leak valve 12, or is placed in the radical source 10 in solid or liquid form. Further, depending on the case, it is possible to make the wall of the radical source 10 from a substance containing a radical component.

4 to 6 show specific configurations for generating radicals in the radical source 10 in FIG. 3, which shows a reference example of the present invention. In Figure 4,
The light 14 from the light source 13 activates or decomposes atoms and molecules within the radical source 10 to generate radicals.

Note that 15 is a light passing window, and 16 is a light non-reflection termination.

In FIG. 5, an electrode 17 is inserted into a radical source 10, a discharge is generated between the electrodes by a power source 18, and atoms and molecules are activated or decomposed during the discharge to form radicals. be.

Figure 6 shows the high frequency cable (or guide) 19
Electrolysis by the high frequency wave 20 is applied to the radical source 10 to generate a discharge within the radical source 10. Radicals are formed by activating or decomposing atoms and molecules during electric discharge. Radical source 10
By applying a magnetic field inside the coil 21, the efficiency of radical generation can be increased. The magnetic field is
The voltage can also be applied using a permanent magnet instead of the coil 21.

FIG. 7 shows a specific configuration of the radical source 10 in FIG. 3, which shows a reference example of the present invention.
A spout guide 22 is attached to the outlet of the spout 9, so that the diameter of the spout 9 gradually widens. By doing so, the flight directions of the radical rays 11 can be further aligned, making it possible to perform etching and thin film formation with good directionality.

FIG. 8 shows an embodiment of the present invention.
This device uses a radial separator 23 to select only the necessary radical (e.g., radical A) ray 11' from a radical ray 11 containing multiple types of radicals (e.g., radical A and radical B), and irradiates it onto the sample 5. The surface of sample 5 is then treated. Note that the radical source 10 and the radical separator 2
3. The surface treatment chamber 4 in which the sample 5 is placed is evacuated to a vacuum by the exhaust system 30. By doing so, it becomes possible to perform surface treatments such as thin film formation, etching, and surface modification with less impurities and surface contamination.

FIG. 9 shows the radical separator 23 shown in FIG.
This figure shows the specific configuration of . Exhaust system 30'
A plurality of rotary plates 25 and 26 are installed in a radical separation chamber 24 that is evacuated by a vacuum pump.
The rotary plate 25 constitutes a part of the first hopping means, and the rotary plate 26 constitutes a part of the second hopping means. The rotary plates 25 and 26 are provided with one or more passage ports 27 and 28,
The orbit of the radical ray 11 is periodically passed through the passage ports 27 and 2.
8 crosses it. Only when the passage port 27 of the rotating plate 25 comes to the orbital position of the particle beam 11, the radical beam 11 containing multiple types of radicals passes through the rotating plate 25.
pass through. Since the flight velocity of the radical ray 11 (the velocities of radicals A and B are v _A and v _B, respectively) differs depending on the radical species, the time at which it reaches the rotary plate 26 differs depending on the radical species. At this time, exactly
Only the radical ray 11' (for example, radical A) whose passage port 28 of the rotary plate 26 is located at the orbital position of the particle beam 11 can pass through the rotary plate 26. thus,
Separation of radical rays 11 is performed. Now, let τ be the time from when the passage port 27 of the rotating plate 25 crosses the trajectory of the particle beam 11 until the passage port 28 of the rotating plate 26 crosses the trajectory of the particle beam 11. Further, the distance between the rotary plates 25 and 26 is assumed to be d.

In order for the radical A to pass through the radical separator 24, it is necessary to satisfy the following equation τ=d/v _A (1). Furthermore, if the temperature of the gas phase of the radical source 10 is T _S , the velocity v _A is However, m _A is the mass of radical A, and k is Boltzmann's constant. Now, T _S = 500K, radical A
If we take the fluorine radical F (mass number 19) as, m _A = 19×1.67×10 ^-27 [Kg] = 3.17×10 ^-26 [Kg] v _A = 7.44×10 ² [m]. Therefore, τ=7.44×10 ^-2 d[sec]. For example, if d=10cm=0.1m, τ=7.44×10 ^-3 [sec]. By changing this time τ, it is also possible to allow other radical rays to pass through.

FIG. 10 shows the configuration of yet another reference example of the present invention. By irradiating the sample 5 with a radical beam 11 from a radical source 10, a chemically stable atom from a molecular source 8, a particle beam which is an appropriate combination of a molecular beam 9 and an ion beam 3 from an ion source 1. This is a device that performs surface treatment on sample 5. This device enables surface treatment with characteristics that cannot be obtained with a single particle beam.

An alternative structure of the radical source 10 is shown in FIG. In this reference example, when the gas passes through the heating furnace 32, radicals are generated by excitation or decomposition. The generated radicals become radical lines 11 by being ejected from the ejection port 9 . The heating furnace 32 is heated to a high temperature by a heating means 33. As the heating means 33, a heating wire,
Infrared lamps, infrared lasers, high frequency heating, etc. can be used. For example, when F ₂ gas is passed through the heating furnace 32 heated to 400° C. or higher, 1% or more is decomposed to generate F radicals. Further, when the temperature of the heating furnace 32 is increased to 600° C. or higher, more than 50% of the F radicals are decomposed and F radicals are generated.

Furthermore, when SF ₆ gas is passed through the heating furnace 32 heated to 1000°C or higher, 20% or more decomposes into F, S, SF, etc.
Generates radicals such as SF ₂ , SF ₃ , SF ₄ , SF ₅ etc.

In this reference example, molecules and gas for generating radicals were supplied, but it is also possible to supply the molecules by installing or introducing a solid or liquid into the furnace. Further, it is also possible to include molecules for generating radicals in a part of the constituent material of the heating furnace 32 itself.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a conventional surface treatment apparatus using ion beams, Fig. 2 is a block diagram of a conventional surface treatment apparatus using chemically stable atoms and molecular beams, and Fig. 3 is a block diagram of a conventional surface treatment apparatus using chemically stable atoms and molecular beams. A basic configuration diagram of a surface treatment apparatus as a reference example, FIGS. 4 to 7 are specific configuration diagrams of a radical source in the apparatus shown in FIG. 3, and FIGS. 8 and 9 are basic configuration diagrams of a surface treatment apparatus of the present invention. Block diagram and specific block diagram of the radical separator, Figures 10 and 11
The figure is a basic configuration diagram according to another reference example of the present invention. 1...Ion source, 2...Ion extraction system, 3
...Ion beam, 4...Surface treatment chamber, 5...Sample,
6...Object to be heated, 7...Heater, 8...Chemically stable atom, molecule source, 9...Ejection port, 10...Radical source, 11, 11'...Radical ray, 12...
...Leak valve, 13...Light source, 14...Light, 1
5... Light passing window, 16... Non-reflection termination, 17...
Electrode, 18... High frequency power supply, 19... High frequency cable (guide), 20... High frequency, 21... Coil, 22... Jet outlet guide, 23... Radical separator, 24... Radical separation chamber, 25, 26...
Rotating plate, 27, 28... Passing port, 29... Molecular beam, 30, 31'... Exhaust system, 31...
...AC power source, 32...heating furnace, 33...heating means.

Claims (1)

[Scope of Claims] 1. A surface treatment device that forms a chemically active radical ray and irradiates an object with the radical ray to be irradiated with the radical ray, wherein the radical ray is a first chemical substance. and a second radical consisting of a second chemical substance that is a different chemical substance from the first chemical substance, and the radical line is formed from the position where the radical line is formed. A first chopping means and a second chopping means are provided for periodically repeating passing and blocking of the radical beam on the path of the radical beam until it is irradiated to the object to be irradiated, and the first and second chopping means are provided. The second chopping means includes first and second disc-shaped members having openings through which the radical rays can pass, and the first and second radicals pass through the first disc-shaped member. The first radical passes through the second disc-shaped member and reaches the irradiated object based on the difference in time required from It is characterized by having means for creating a correlation between the hopping frequency of the first hopping means and the hopping frequency of the second hopping means so that the radicals are blocked by the second disc-shaped member. surface treatment equipment.