JPH01123076A - Thin film forming method - Google Patents

Abstract

PURPOSE:To form a thin film contg. impurities at a lesser extent with good adhesiveness by decomposing the reaction gas of a main material by UV light to form an active seed and decomposing a reaction gas, which is hardly decomposed by UV light, by X-rays, then bringing both into reaction with each other on a substrate. CONSTITUTION:The UV light is irradiated from a UV light generator 1 through a condenser lens 3 onto the substrate 5 in a reaction vessel 4. The reaction gas of the main material supplied from a reaction gas supplying device 8 is decomposed by the UV light to form the 1st active seed. The gaseous hydrogen or the like which is hardly decomposed by the UV light is introduced from a reaction gas supplying device 13 into a radical generator 15 where the hydrogen molecules in the reaction gas are excited by the X-rays generated from an X-ray generator 16 to form the 2nd active seed. Both the active seeds are brought into reaction on the substrate 5 to form the thin film such as diamond- like hard carbon film at a high speed on the substrate 5. The graphitic carbon deposited simultaneously is gasified by reaction with the hydrogen radicals and is thereby removed from the thin film. As a result, the high-quality thin film is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a thin film forming method for forming a thin film such as a hard carbon:l/I film on a substrate.

[Prior Art J] As a conventional method for forming this type of thin film, there is, for example, a method using a photochemical vapor phase reaction. FIG. 2 is a schematic explanatory diagram showing an apparatus for carrying out the conventional method disclosed, for example, in Japanese Patent Laid-Open Publication No. 112697/1983. In the figure, (1) is an ultraviolet light generator, (2) is a reflector for changing the optical path of the ultraviolet light emitted by the ultraviolet light generator (1), and (3) is the reflector (2). This is a condensing lens used to adjust the energy density of ultraviolet light after the optical path has been changed at . Further, (4) is a reaction vessel in which a substrate (5) on which a hard carbon film is to be formed is disposed, and the reaction vessel (4) includes a reactor for supplying a reaction gas into the vessel (4). A gas supply device (8) and an exhaust device (9) for discharging the reaction gas from inside the container (4) to the outside of the system are attached. A light entrance window (10) is provided for passing the ultraviolet light after the energy density has been adjusted by the condensing lens (3) and introducing it into the container (4), and
A heater (6) for heating the substrate (5) whose temperature is controlled by a temperature controller (7) is arranged below the substrate (5).

When forming a diamond-shaped thin film of hard carbon (hard carbon film) on the substrate (5) using such an apparatus,
After the ultraviolet light (and vacuum ultraviolet light) emitted by the ultraviolet light generator (1), for example, the argon excimer laser beam, is changed in its optical path by the reflecting mirror (2), it is passed through the condenser lens (
3) and the substrate (5) through the light entrance window (10).
) Upper KJll! It is made to shine. And the reaction vessel (
4) A reactive gas, for example, a hydrocarbon gas, which is the main raw material of the film, is supplied into the interior by the reactive gas supply device (8), and the reactive gas is photolyzed by the ultraviolet light and carbon atoms in an active state are The hard carbon film is formed on the substrate (5) by being deposited on the substrate (5). Note that since the quality of the hard carbon film formed on the substrate (5) is greatly influenced by the temperature of the substrate (5), the substrate (5) is heated to an optimum temperature using the heater (6). Further, the used reaction gas is exhausted by an exhaust device (9).

[Problem to be Solved by the Invention J] However, when forming a thin film on the substrate (5) using the apparatus shown in FIG. Since the carbon atoms to be deposited on the film are liberated, not only the desired diamond-like carbon but also unnecessary gutphite-like carbon are deposited at the same time, resulting in the problem that the desired film quality cannot be obtained.

This invention was made to solve the above-mentioned problems, and it is possible to increase the deposition rate and reduce impurities present in the resulting thin film, thereby making it possible to form a high-quality thin film. The purpose is to provide a forming method.

The # film forming method according to the present invention decomposes a reactive gas, which is the main raw material of a thin film, out of two or more reactive gases on a substrate using ultraviolet light. The method is characterized in that a reactive gas that is difficult to decompose with light is decomposed using X-rays and then introduced onto a substrate, and then two or more active species obtained on the substrate are reacted.

Then, the first activated oak obtained by decomposition using ultraviolet light is deposited on the substrate to form a thin film.

[Operation J] When using the thin film forming method of the present invention, both of the active species react on the substrate, and as a result, the first
Deposition of active species on the substrate is promoted, and thin film formation on the substrate can be performed at high speed. Furthermore, the second active species reacts with impurity components in the thin film and removes the impurity components, resulting in a high quality thin film containing few impurity components being formed on the substrate.

[Example] The present invention will be described in detail below based on the drawings. FIG. 1 is a schematic explanatory diagram showing the configuration of an apparatus used in a thin film forming method according to an embodiment of the present invention.

In the figure, (1) is an ultraviolet light generator, and (3) is a condenser lens for adjusting the energy density of the ultraviolet light emitted by the ultraviolet light generator (1). Also, (4) is
This is a reaction vessel in which a substrate (5) on which a hard carbon film is to be formed is placed, and a substrate heating device with humidity controlled by a temperature controller (7) is placed below the substrate (5) in the reaction vessel (4). A heater (6) for this purpose is arranged. In addition, (10) is a light beam provided on the side of the reaction vessel (4) for passing the ultraviolet light whose energy density has been adjusted by the condensing lens (3) and introducing the ultraviolet light into the reaction vessel (4). The ultraviolet light introduced into the reaction vessel (4) from the light entrance window (10) is an entrance window, and the ultraviolet light is prevented from diffusing the reaction products in the direction of the light entrance window (10). 24), the ultraviolet light is irradiated onto the substrate (5), and then the ultraviolet light damper (21) is placed at a position opposite to the light incidence window (10) of the reaction vessel (4). It is supposed to be treated with a spoon.

Further, (8) is a reaction gas supply device for supplying a reaction gas, which is the main raw material of the thin film, into the reaction vessel (4), and the reaction gas supplied from the reaction gas supply device (8) has a flow rate. After the flow rate is adjusted by the controller (11), the reaction volume! The liquid is sprayed onto the substrate (5) from a nozzle /l/(12) disposed obliquely above the substrate (5) in 44(4). Further, (9) is a reaction device for exhausting the reaction gas from inside the reaction vessel (4), and the exhaust device (
The reaction gas exhausted from the reaction vessel (4) in step 9) is appropriately processed in a gas processing device (20) and then discharged to the outside of the system. Further, (13) is a reaction gas supply device that serves as a raw material for activating the reaction,
The reaction gas supplied from the reaction gas supply device (13) is adjusted in flow rate by a flow rate controller (14), and then transferred to the physical generator f (
15), the reaction gas is decomposed by the X-rays generated from the X-ray generator (16), and the active Fuji force p
and is introduced onto the substrate (5). Also (17)
is a purge gas supply device for supplying a purge gas into the reaction vessel (4) to prevent reaction products from adhering to the inner surface of the light entrance window (10), and from the purge gas supply device (17) The purge gas supplied is
After the flow rate is adjusted by a flow rate controller (18), it is supplied into the reaction vessel (4) (specifically, to the upstream side of the slit (24)). Also (19)
is an infrared light generating device for activating a surface reaction on the substrate (5), and the infrared light generating device (19)
The infrared light emitted from the reaction vessel (4) is introduced into the reaction vessel (4) through an infrared light transmitting window (22) installed in the reaction vessel (4), and is irradiated onto the substrate (5). The infrared light reflected on the substrate (5) is processed by an infrared light damper (23) provided outside the reaction vessel (4).

When forming a thin film of diamond-shaped hard carbon on the substrate (5) in the reaction vessel (4) using such an apparatus, ultraviolet light (and vacuum ultraviolet light) emitted from the ultraviolet light generator (1) is used. For example, after the argon fluorine excimer laser light is focused by the condenser lens (3), the light entrance window (10)
The concentrated light is irradiated onto the substrate (5) in the reaction vessel (4) through the irradiation. Then, on the substrate (5), a reactive gas, which is the main raw material of the thin film, supplied from the reactive gas supply device (8), such as acetylene, ethylene, methane, propane, acetone, methyl, etc. , ethyl alcohol-μ, etc., or a mixture thereof is adjusted to a constant flow rate by a flow controller (11), and the nozzle /' (12
), but the reaction gas is decomposed by the ultraviolet light to produce active carbon atoms 'f (first active species). On the other hand, a reactive gas that is difficult to decompose by ultraviolet light, specifically hydrogen gas, is supplied from the reactive gas supply device (13) and is regulated at a constant flow rate by the flow rate controller (14) inside the radical generator (15). It will be introduced into
In the radical generator (15), an X-ray generator (1
6) The hydrogen molecules in the reaction gas are excited by the X-rays generated, and hydrogen atoms in an active state, that is, hydrogen radio/
A large amount of I/ (second active species) is produced.

The hydrogen radicals are then introduced onto the substrate (5). However, on the substrate (5), there are active carbon glucides generated by ultraviolet light and hydrogen radicals generated by the X-rays emitted from the X-ray generator (16) and guided onto the substrate (5). As a result, the two react actively on the substrate (5), and a thin diamond-shaped hard carbon film is formed on the substrate (5) at a high speed. At the same time, the graphite-like carbon deposited on the substrate (5) reacts with the hydrogen radicals, gasifies, and is removed from the thin film, resulting in the resulting # film having extremely high quality. Note that the quality of the thin film is greatly affected by the temperature of the substrate (5), so the temperature of the heater (6) may be controlled.
(7) Control the board (5) to a predetermined temperature I
I have CS.

In addition, the reaction product in the reaction vessel (4) is exposed to the light entrance window (10).
If the reaction product adheres to the light entrance window (10), the transmittance of ultraviolet light in the light entrance window (10) will decrease.
), the purge gas supply device (17)
The purge gas supplied from the flow controller (18)
The liquid is introduced into the reaction vessel (4) while being adjusted to a constant flow rate, and is sprayed onto the inner surface of the light entrance window (10). It should be noted that the above-mentioned purge gas may have the disadvantage that the reaction gas is distorted;
(24) makes it as small as possible.

In addition, in order to activate the reaction with the activated carbon atoms and hydrogen radicals on the surface of the substrate (5), infrared light, such as carbon dioxide laser light, emitted from the infrared light generator (19) is applied to one reaction vessel (4 ) installed infrared light transmitting window (2
2) into the reaction vessel (4), and the substrate (5)
irradiated onto the surface. As a result, the reaction on the surface of the substrate (5) is activated and a thin film with high adhesion can be obtained.

Further, in the above-mentioned apparatus, ultraviolet light emitted from the reaction vessel (4) is processed by the ultraviolet light damper (21), and infrared light is processed by the infrared light damper (23). On the other hand, safety measures are taken such that the reaction gas exhausted by the exhaust device (9) after use is treated by the gas treatment device (20).

The ultraviolet light used to decompose the reactive gas, which is the main raw material of the thin film, can be obtained not only by using the argon fluorine excimer laser but also by krypton fluorine excimer laser, fluorine excimer laser, argon excimer laser, and krypton excimer laser. It can be obtained using a laser such as a laser. It can also be obtained by using harmonics of a high-power YAG laser, harmonics of a dye laser, harmonics of a glass laser, or the like.

The infrared light used to activate the substrate surface can be obtained not only by using the carbon dioxide laser light but also by using high-power YAG laser light.
Lasers, glass lasers, infrared lamps, halogen lamps,
It can be obtained using a lamp such as a krypton lamp.

Said again? In addition to the above-mentioned hydrocarbon gases, the reactive gases that are the main raw materials for the J membrane include carbon tetrachloride, methyl chloride, and ria.
Chlorinated carbide gases such as roform, vinyl chloride, chloromethane, or mixed gases thereof, and hamethylamine,
Possible gases include amine-based carbide gases such as dimefylamine and trimethylamine, or mixed gases thereof.

[Effects of the Invention] As described above, according to the present invention, the reaction gas that is the main raw material of the thin film among two or more types of reaction gases is decomposed on the substrate using ultraviolet light, and the first active species is generated. , a reactive gas that is difficult to decompose with ultraviolet light is decomposed using X-rays, a second active species is generated, and the second active species is introduced onto the substrate, and while these two active species are reacted, the first active species is transferred onto the substrate. Since the K was used for deposition, the thin film can be formed on the substrate at high speed, and a high quality thin film with few impurity components is formed on the substrate with good adhesion to the substrate.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an apparatus used in a thin film forming method according to an embodiment of the present invention, and FIG. 2 is a schematic explanatory diagram showing an apparatus used in a conventional thin film forming method. (1)...Ultraviolet light generator, (4)...Reaction container,
(5)...Substrate, (8)...Reaction gas supply device, (
13) Reaction gas supply device, (15) Radical generator, (16) X-ray generator, (19)
...Infrared light generator In the figures, the same reference numerals indicate the same or equivalent parts. l゛v External Planning Show 1 /f: Radical generator 4,
i Sales container /A: X-ray receiver device j: K
*i/9:4F) flit@z
and/j: Z+之η example U Figure 2

Claims (1)

[Scope of Claims] (1) Two or more types of reaction gases are supplied to a reaction vessel, and among the reaction gases, the reaction gas that is the main raw material for the thin film is decomposed on the substrate using ultraviolet light. While generating one active species, a reactive gas that is difficult to decompose with ultraviolet light among the reactive gases is decomposed using X-rays to generate a second active species, and then the second active species is attached to a substrate. 1. A method for forming a thin film, comprising depositing the first active species on a substrate while causing both active species to react with each other to form a thin film. (2) The ultraviolet light used to decompose the reactive gas, which is the main raw material of the thin film, is an excimer laser such as argon fluorine excimer laser, krypton fluorine excimer laser, fluorine excimer laser, argon excimer laser, or krypton excimer laser. The method of forming a thin film according to claim 1, wherein the ultraviolet light is obtained by: (3) The ultraviolet light used to decompose the reactive gas that is the main raw material of the thin film is ultraviolet light obtained by using harmonics of a high-power YAG laser. Thin film formation method. (4) The thin film forming method according to claim 1, wherein the ultraviolet light used to decompose the reactive gas that is the main raw material of the thin film is ultraviolet light obtained by using harmonics of a dye laser. (5) Thin film formation according to claim 1, wherein the ultraviolet light used to decompose the reactive gas that is the main raw material of the thin film is ultraviolet light obtained by using harmonics of a glass laser. Method. (6) The thin film forming method according to any one of claims 1 to 5, characterized in that the substrate surface is activated by irradiating infrared light onto the substrate surface. (7) The thin film forming method according to claim 6, wherein the infrared light for activating the substrate surface is infrared light obtained by using a carbon dioxide laser. (8) Thin film formation according to claim 6, wherein the infrared light for activating the substrate surface is infrared light obtained by using a high-power YAG laser. Method. (9) The thin film forming method according to claim 6, wherein the infrared light for activating the substrate surface is infrared light obtained by using a glass laser. (10) The infrared light for activating the substrate surface is infrared light obtained by using any one of an infrared lamp, a halogen lamp, and a krypton lamp. thin film formation method. (11) The two or more reaction gases consist of a hydrocarbon gas and a hydrogen gas, and while the hydrocarbon gas is decomposed using ultraviolet light, the hydrogen gas is decomposed using A thin film forming method according to any one of claims 1 to 10, which forms a carbon film. (12) Claim 1, wherein the hydrocarbon gas is any one of acetylene, ethylene, methane, propane, acetone, methyl alcohol, and ethyl alcohol, or a mixture of multiple gases selected from these. 1
The method for forming a thin film according to item 1. (13) The two or more reaction gases are composed of chlorine-based carbide gas and hydrogen gas, and while the chlorine-based carbide gas is decomposed using ultraviolet light, the hydrogen gas is decomposed using X-rays, and the A thin film forming method according to any one of claims 1 to 10, wherein a hard carbon film is formed on a thin film. (14) Claim 1, wherein the chlorine-based carbide gas is any one of carbon tetrachloride, methyl chloride, chloroform, vinyl chloride, and chloromethane, or a mixture of multiple gases selected from them. The method for forming a thin film according to item 13. (15) the two or more reactive gases are composed of an amine-based carbide gas and hydrogen gas, the amine-based carbide gas is decomposed using ultraviolet light, and the hydrogen gas is decomposed using X-rays;
A thin film forming method according to any one of claims 1 to 10, which comprises forming a hard carbon film on a substrate. (16) The thin film forming method according to claim 15, wherein the amine-based carbide gas is any one of methylamine, dimethylamine, and trimethylamine, or a mixed gas of multiple types of gases selected from them. .