JPH10203897A - Preliminary treatment on formation of thin film and device for forming thin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for preliminarily treating a substrate to improve adhesivity of a thin film to the substrate, and to provide a device for simply forming the thin film at a low cost. SOLUTION: The surface of a substrate 3 is preliminarily irradiated with hydrogen ions. Impurities, etc., on the surface of the substrate 3 are thus cleaned off by the reduction reaction of the hydrogen ions. The substrate 3 is again irradiated with dissociated carbon and carbon ions and with dissociated hydrogen and hydrogen ions to form a diamond-like carbon(DLC) thin film 80. A switching means for switching a gas charged into a gas ion source into a cleaning gas or into a DLC thin film-forming gas is disposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pretreatment method and a thin film forming apparatus for forming a thin film such as a diamond-like carbon thin film, and more particularly to a method of cleaning a substrate and forming a thin film suitable for the method. Related to the device.

[0002]

2. Description of the Related Art Conventionally, molds, tools, sliding members,
A diamond-like carbon (DLC) thin film has been used as a hard coating film for protecting the surface of a recording medium or the like of a magnetic disk device. FIG. 18 is a sectional view of a conventional DLC thin film forming apparatus using microwave plasma disclosed in Japanese Patent Application Laid-Open No. 63-185893. In the figure, reference numeral 1 denotes a vacuum chamber for keeping the inside vacuum, 1
Reference numeral 01 denotes a substrate holder for holding the substrate 3 in the vacuum chamber 1;
1 is a heater provided on the substrate holder 101 to heat the substrate 3, 103 and 104 are reaction gas inlets for introducing a reaction gas into the vacuum chamber 1, and 102 are microwaves applied to the vacuum chamber 1. 105 is an electromagnet for generating a magnetic field in the vacuum chamber 1.

Next, the operation will be described. The substrate 3 is held by the substrate holder 101 in the vacuum chamber 1. Next, the substrate 6 is heated to 300 to 900 ° C. by the heater 6 and the degree of vacuum in the vacuum chamber 1 is reduced to 10 ⁻³ to 10 ⁻⁵ Torr.
To hold. Subsequently, the reaction gas inlets 103 and 104
Supply a reaction gas such as CH ₄ and C ₂ H ₂ into the vacuum chamber 1, apply a magnetic field to the vacuum chamber 1 by the electromagnet 105, and apply a microwave having an output of 300 to 600 W from the waveguide 102. Then, microwave plasma is generated in the vacuum chamber 1, and the excited carbon reaches the substrate 3, thereby forming a DLC thin film on the substrate 3.

[0004]

SUMMARY OF THE INVENTION As described above, diamond-like carbon (D
LC) The thin film forming apparatus and the forming method have a problem that adhesion of the thin film to the substrate is poor. The present invention has been made in order to solve the above-described problems, and it is an object of the present invention to provide a pretreatment method of a base material for improving adhesion to a base material and a simple, low-cost thin film forming apparatus. Aim.

[0005]

According to a first aspect of the present invention, there is provided a pretreatment method for forming a thin film, wherein a cleaning process is performed by irradiating a substrate surface with hydrogen ions before forming the thin film. The pretreatment method according to claim 2 performs a cleaning process by irradiation with inert gas ions and a cleaning process by irradiation with hydrogen ions before film formation.

According to a third aspect of the present invention, a cleaning process is performed by irradiation of mixed gas ions of inert gas ions and hydrogen ions before film formation. According to a fourth aspect of the present invention, there is provided a pretreatment method in which a cleaning process by irradiation with inert gas ions and a cleaning process by irradiation with mixed gas ions of inert gas ions and hydrogen gas are performed before film formation.

According to a fifth aspect of the present invention, the above-mentioned cleaning treatment is performed before the formation of a diamond-like (DLC) thin film. The pre-processing method according to claim 6,
The above cleaning is performed before the formation of the underlayer such as silicon and the formation of the DLC thin film. The pretreatment method according to claim 7 includes forming a treatment layer containing carbon,
The above cleaning is performed before forming the LC thin film. An apparatus for forming a diamond-like carbon thin film according to claim 8 is provided with switching means for switching the gas introduced into the gas ion source for cleaning or film formation.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram schematically showing a process of forming a diamond-like carbon (DLC) thin film according to Embodiment 1 of the present invention. First, as a pretreatment, a substrate is subjected to cleaning treatment by irradiation with hydrogen ions. , A case where a DLC thin film is formed. In the figure, 3 is a substrate such as a cemented carbide, and 80 is a DLC thin film formed on the substrate 3.

Next, the details will be described. FIG. 2 is a sectional view of a DLC thin film forming apparatus suitable for use in this embodiment. In the figure, reference numeral 1 denotes a vacuum chamber for maintaining the inside of the vacuum chamber at a vacuum, 2 denotes an exhaust system for exhausting the vacuum chamber 1,
Is a substrate holder for holding the substrate 3 in the vacuum chamber 1 with its vapor deposition surface (thin film forming surface) facing down. Reference numeral 5 is a substrate holder 3 for a later-described acceleration electrode 15 via the substrate holder 4. Biasing means for applying a bias voltage to the substrate holder 4
A substrate temperature adjusting mechanism for heating and cooling the substrate 3 to adjust the temperature thereof; 7, an insulating ceramic for electrically insulating between the vacuum chamber 1 and the substrate holder 4;
Is a rotation mechanism for rotating.

Reference numeral 10 denotes a gas ion source provided below the substrate 3 in the vacuum chamber 1 so as to oppose the substrate 3. Reference numeral 11 denotes a reaction gas introduction chamber into which a reaction gas is introduced, which can release ions and the like. An orifice (not shown) is provided toward the base material 3 so as to increase the flow path resistance and apply a pressure difference between the flow path resistance and the vacuum chamber 1. Numeral 12 denotes a thermionic emission means provided in the reaction gas introduction chamber 11 and made of, for example, a tungsten wire. Numeral 13 comprises a thin metal wire arranged in parallel, and a thermoelectron extractor provided in the reaction gas introduction chamber 11. An electrode 14 is a reaction gas introduction pipe connected to the reaction gas introduction chamber 11 to introduce a reaction gas into the inside, and an acceleration electrode 15 is provided outside the reaction gas introduction chamber 11 and accelerates ions toward the substrate 3. The reaction gas introduction chamber 11, thermionic emission means 12, thermionic extraction electrode 13, the reaction gas introduction tube 14, and the acceleration electrode 15 constitute the gas ion source 10. Reference numeral 16 denotes a valve as switching means provided in the middle of a pipe connected to the reaction gas introduction pipe. One end of the bias means 5, the vacuum chamber 1, and the acceleration electrode 15 are grounded.

Next, the operation will be described. A pretreatment is performed prior to the formation of the DLC thin film. First, the substrate 3 is attached to the substrate holder 4, and the inside of the vacuum chamber 1 is 1 × 1 by the exhaust system 2.
After evacuating to a degree of vacuum of about 0 ⁻⁶ Torr, the temperature of the substrate 3 is adjusted to about 300 ° C. by the substrate temperature adjusting mechanism 6.
Then, for cleaning the surface of the substrate 3, one of the valves 16 is opened and the other is closed, and hydrogen gas is introduced from the reaction gas introduction pipe 14 into the reaction gas introduction chamber 11. Vacuum degree of 1 × 10 ^-2 to 1 × 10 ^-1 To
rr.

Then, the thermoelectron emission means 12 is operated,
A bias voltage of about +50 to 800 V is applied to the thermoelectron extraction electrode 13 to the thermoelectron emission means 12 by a power supply (not shown). In addition, in order to extract ions from the gas ion source 10, a voltage of about +200 to 500 V is applied to the accelerating electrode 15, that is, to the thermionic emission means 12 with respect to the ground potential by a power supply (not shown). The electrons emitted from the thermionic emission unit 12 are accelerated toward the thermionic extraction electrode 13 to ionize the hydrogen gas. The substrate 3 is irradiated with the hydrogen ions for about 10 to 30 minutes to remove impurities on the surface of the substrate 3 by a reduction reaction. At this time, the biasing means 5 moves the substrate 3 to -200 with respect to the ground potential.
The amount and energy of the hydrogen ions to be applied to the substrate 3 are controlled by adjusting the bias at about -3000 V. By setting the energy of the hydrogen ions to 200 to 3000 eV, the reduction reaction of the surface oxide by the hydrogen ions can efficiently proceed, and the cleaning treatment can be performed effectively. By the above treatment, impurities such as water, oils and fats, and surface oxides on the surface of the substrate 3 can be removed. In particular, since oxides on the surface can be removed by a reduction reaction, the adhesion between the substrate 3 and the DLC thin film can be reduced. The performance is improved.

Next, the valve 16 that has been opened is closed, the supply of the ion cleaning gas to the gas ion source 10 is stopped, and the cleaning process on the surface of the substrate 3 is terminated. The temperature of the substrate 3 is adjusted to 100 ° C. to 250 ° C. for the reason described below. Here 2
00 ° C. The bias means 5 gives the potential of the substrate 3 to the ground potential as a function V (t) of time t. FIG. 3 shows an example of a bias voltage waveform applied to the base material 3. 3 (a) to 3 (c) show the case where a DC or half-wave rectified or full-wave rectified negative voltage is applied. The voltage value was within several kV, and was -1 kV here. The frequency is set to about several tens Hz to several tens kHz in (b), here, 60 Hz and 1 kHz. By controlling the voltage value of V (t), the energy given to the ions can be adjusted. Thereby, the adhesion strength and hardness of the thin film can be controlled.

Subsequently, the other valve 16 is opened, and the DLC
A hydrocarbon-based gas containing carbon (C), which is a material constituting the thin film, is supplied from the reaction gas introduction pipe 14 to the reaction gas introduction chamber 11.
And the degree of vacuum in the reaction gas introduction chamber 11 is reduced to 1 × 10 ^-2.
１1 × 10 ⁻¹ Torr. As a reaction gas introduced at this time, for example, a gas such as benzene, toluene, or xylene is used. Then, the thermoelectron emission means 12 is operated, and the thermoelectron extraction electrode 13 is
, A bias voltage of about +50 to 800 V is applied. The thermoelectron emitting means 12 has +200 to 50 with respect to the ground potential.
A voltage of about 0 V is applied. The electrons emitted from the thermionic electron emitting means 12 are accelerated toward the thermionic extraction electrode 13, and excite, dissociate, and ionize the hydrocarbon-based gas by discharging or irradiating the electrons, thereby dissociating the dissociated carbon and carbon. The ions and the dissociated hydrogen and hydrogen ions are irradiated toward the substrate 3 to form a DLC thin film 80 on the substrate 3. Since the ions are positively charged, they are accelerated and extracted from the gas ion source 10 by the accelerating electrode 15 and the base material 3
By controlling the negative bias voltage, the energy given to the ions can be adjusted.

FIG. 4 shows the results of Raman analysis of the DLC thin film when the temperature of the substrate is used as a parameter. When the temperature of the substrate 3 is 250 ° C., a typical spectrum of DLC is shown, whereas when the temperature of the substrate 3 is 300 ° C. or 400 ° C., the spectrum is graphite. For this reason, the temperature of the substrate 3 should be 250 ° C. or lower, but it is not preferable to lower the temperature too much for another reason. That is, if the temperature is lower than 100 ° C.,
The adhesion of the C thin film 80 becomes weak. Therefore, the temperature of the substrate 3 during film formation is controlled from 100 ° C. to 250 ° C. by using the substrate temperature adjusting mechanism 6. By doing so, graphitization of the DLC thin film 80 can be suppressed, and a high-hardness, high-quality DLC thin film 80 can be formed. Note that the temperature range is different from the temperature range of the conventional device shown in FIG. 18 because the type of the device is different.

Further, the rotating mechanism 100 allows the base material 3 to be formed during film formation.
By rotating, the film thickness distribution can be made uniform, and at the same time, it is possible to improve the throwing power to the end of the base material 3, that is, to reduce the film thickness non-uniformity due to the direction and position of the surface. In addition, as described above, the gas supplied to the gas ion source 10 is switched from the gas for ion cleaning of the base material 3 to the gas for film formation of the DLC thin film 3, so that one gas ion source 10 performs ion cleaning processing and gas cleaning. Both the formation of the DLC thin film can be performed, and the apparatus configuration can be simplified and the cost can be reduced. Further, it is not necessary to expose the substrate 3 after the cleaning process to the atmosphere. In addition, the relative positional relationship between the base material 3 and the gas ion source 10 of the DLC thin film forming apparatus of FIG. Is easy to handle when is large.

Embodiment 2 FIG. In this embodiment, after performing the same cleaning treatment by hydrogen ion irradiation as in the first embodiment as a pretreatment, an underlayer is formed on a base material,
The case where a DLC thin film is formed thereon will be described. FIG.
FIG. 6 is an explanatory view showing a process of forming a DLC thin film according to the second embodiment, and FIG. 6 is a sectional view of a DLC thin film forming apparatus used in the process shown in FIG.

In these figures, 50 is an underlayer, 30
Is a metal vapor generation source such as an electron beam evaporation source, an ion plating device, and a metal ion source, which is provided in the vacuum chamber 1 so as to face the substrate 3 and can form a metal thin film or a ceramic thin film. Ion source is used. 31 is a crucible for putting metal materials, 32 is a crucible 3
1, a thermoelectron emission means for emitting thermoelectrons; 34, a thermoelectron extraction means for extracting thermoelectrons from the thermoelectron emission means 33; 35, a heat shield for insulating them; 36, a metal vapor generation source The metal vapor generating source 30 includes a crucible 31, a heater 32, a thermoelectron emission unit 33, and a thermoelectron extraction unit 3.
4. It is composed of a heat shield 35 and an acceleration electrode 36. The other parts are the same as those in FIG. 2 and will not be described.

Next, the operation will be described. Embodiment 1
In the same manner as in the above case, the inside of the vacuum chamber 1 is
After evacuation to a degree of vacuum of about 10 ⁻⁶ Torr, the temperature of the base material 3 is adjusted to about 300 ° C. by the base material temperature adjustment mechanism 6. Next, in the same manner as in the first embodiment, the surface of the substrate 3 is cleaned by irradiation with hydrogen ions to remove moisture, oil components, surface oxides, and the like on the surface of the substrate 3. Next, the open valve 16 is closed, and the supply of the ion cleaning gas to the gas ion source 10 is stopped.
The cleaning process of the surface of the substrate 3 is completed. Next, the base layer 50 is formed using silicon (Si), tungsten (W), titanium (Ti), or aluminum (Al) having good adhesion. A voltage of about −0.5 to −3 kV with respect to the ground potential is applied to the base material 3 by the bias means 5, and Si, W,
The metal of Ti or Al is heated to generate steam, and thermionic electrons emitted from thermionic electron emitting means 33 are extracted and accelerated by thermionic electron extracting means 34 to generate metal ions, which are then converted to the base material 3. To form a metal thin film of Si, W, Ti or Al as a base layer 50 on the surface thereof.

Next, in the same manner as in the first embodiment, the gas ion source 10 is operated, and the DL is formed on the intermediate layer on the surface of the substrate 3.
A C thin film is formed. In forming the underlayer 50,
Excitation, dissociation and ionization of the hydrocarbon-based gas by the gas ion source 10 while irradiating the dissociated carbon and carbon ions toward the base material 3 or setting the vacuum chamber 1 to a hydrocarbon-based gas atmosphere By operating the metal vapor generation source 30 as described above, a ceramic thin film of silicon carbide, tungsten carbide, titanium carbide or aluminum carbide having good adhesion may be formed as the underlayer 50 on the surface of the base material 3. Good. In this case, the DLC thin film 8 is formed by increasing the carbon composition in the ceramic toward the surface.
The growth of 0 and the adhesion are improved. FIG. 7 shows the process.

As shown in the process of FIG.
0 is an adhesion layer 6 made of a metal thin film having good adhesion to the substrate 3.
0 and a DLC pretreatment layer 70 made of a metal thin film having good adhesion to the DLC thin film 80. In this case, the first and second metal vapor sources 30 as shown in FIG.
a, a contact layer 60 is formed by a first metal vapor source 30a in the same manner as described above, and then a DLC thin film is formed by a second metal vapor source 30b thereon. A pretreatment layer 70 is formed. Alternatively, the underlayer 50 may be constituted by an adhesion layer 60 made of a metal thin film and a DLC pretreatment layer 70 made of a ceramic thin film. The process in this case is shown in FIG. As described above, the metal vapor generation source 30 and the gas ion source 10 are provided in the same vacuum chamber 1 and the switching means for switching the gas introduced into the gas ion source 10 is provided. The formation of the underlayer and the formation of the DLC thin film can be performed continuously without opening to the atmosphere.

Embodiment 3 FIG. In this embodiment, a case is described in which, after performing the same cleaning treatment by hydrogen ion irradiation as in the first embodiment, a treatment layer containing carbon is formed on the surface of the base material, and a DLC thin film is formed thereon. It shows about. FIG. 11 shows a process of forming a DLC thin film according to the second embodiment, in which an ion implantation layer is formed as a treatment layer. Next, the operation will be described. After the interior of the vacuum chamber 1 is evacuated to a degree of vacuum of about 1 × 10 ⁻⁶ Torr by the exhaust system 2 using a DLC thin film forming apparatus as shown in FIG. 300 temperature
The temperature is adjusted to about ° C., and cleaning is performed by irradiating the base material 3 with hydrogen ions in the same manner as in the first embodiment.

Next, ion implantation with carbon ions is performed. First, the temperature of the substrate 3 is set to about 300 ° C., and a hydrocarbon-based gas containing a carbon (C) element such as benzene, toluene, or xylene is introduced into the reaction gas introduction chamber 11 through the reaction gas introduction pipe 14, The degree of vacuum in the gas introduction chamber 11 is 1 ×
10 ⁻² to 1 × 10 ⁻¹ Torr. Then, the thermoelectron emission means 12 is operated, and the thermoelectron emission means 12 is connected to the thermoelectron extraction electrode 13 by a power source (not shown).
A bias voltage of about 0 V is applied. Further, in order to extract ions from the gas ion source 10, the thermoelectron emission means 12 has a positive voltage with respect to the acceleration electrode 15, that is, with respect to the ground potential.
A voltage of about 200 to 500 V is applied by a power supply (not shown). The electrons emitted from the thermionic emission means 12 are accelerated toward the thermionic extraction electrode 13 to excite, dissociate, and ionize a hydrocarbon-based gas containing a carbon element. The substrate 3 is irradiated with the ionized carbon ions. At this time, the base member 3 is biased in the negative direction with respect to the ground potential by about −10 to −30 kV by the bias means 5, thereby performing ion implantation and forming an ion-implanted layer as the processing layer 51. Subsequent to this processing, a DLC thin film as described in the first embodiment is formed. As described above, by forming the ion-implanted layer with the energy of carbon ions at 10 to 30 keV before forming the DLC thin film 80, a region in which the material of the base material 3 and the carbon atoms are mixed is formed. And the DLC thin film 80 can be improved in adhesion.

The relationship between the ion implantation energy and the distribution of the implantation amount in the depth direction has a relationship as shown in FIG. 12, and the distribution of the implantation amount in the implantation depth direction depends on the implantation energy. With the depth as the peak point, it gradually decreases to both sides. As the implantation energy increases, the peak point moves to a deeper implantation depth. Therefore, for example, the ion implantation energy is shown in FIG.
As shown in FIG. 14, the distribution of carbon atoms in the depth direction is obtained by giving a distribution as shown in FIG. 3, that is, performing low-energy implantation for a long time and high-energy implantation for a short time. The closer to the surface, the higher the density, and the distribution can be such that the carbon injection amount is maximum near the surface of the substrate 3. Thus, the DLC thin film 80
In the process of ion implantation before formation, by giving carbon ions an energy distribution, the distribution of carbon atoms in the depth direction from the surface of the substrate 3 of the implanted layer can be controlled, and the substrate 3 and the DLC thin film can be controlled. 80 can be improved. Further, in the process of ion implantation into the base material 3, by using hydrogen ions together with carbon ions, the hydrogen ions selectively etch the graphite component of the ion-implanted layer. As a result, the adhesion strength between the substrate 3 and the DLC thin film 80 can be improved. By performing the ion cleaning process using hydrogen gas before the ion implantation process, the impurity layer on the surface of the base material 3 is removed, so that the adhesion strength between the base material 3 and the DLC thin film 80 can be improved. .

Also, as shown below, when a carbonized layer containing carbon is formed on the surface of the substrate 3 as the treatment layer 51,
Cleaning by hydrogen ions can be applied. Next, the operation will be described. Using the DLC thin film forming apparatus shown in FIG. 2, the inside of the vacuum chamber 1 is set to 1 × 10 ⁻⁶ Torr by the exhaust system 2.
After evacuating to a degree of vacuum, the temperature of the base material 3 is adjusted to about 300 ° C. by the base material temperature adjustment mechanism 6, and cleaning is performed by irradiating the base material 3 with hydrogen ions in the same manner as in the first embodiment. I do.

Next, carbonization by carbon ions is performed.
First, the temperature of the substrate 3 is set to about 300 ° C., and benzene,
A hydrocarbon-based gas containing a carbon element such as toluene or xylene is introduced into the reaction gas introduction chamber 11 through the reaction gas introduction pipe 14, and the degree of vacuum in the reaction gas introduction chamber 11 is set to 1 × 10 ⁻² to 1 ×.
10 ^-1 Torr. Then, the thermoelectron emission unit 12 is operated, and a bias voltage of about 50 to 800 V is applied to the thermoelectron extraction electrode 13 to the thermoelectron emission unit 12 by a power supply (not shown). Further, in order to extract ions from the gas ion source 10, the thermoelectron emission means 12 with respect to the accelerating electrode 15, that is, with respect to the ground potential, is + 200-50
A voltage of about 0 V is applied by a power supply (not shown).
The electrons emitted from the thermionic emission means 12 are accelerated toward the thermionic extraction electrode 13 to excite, dissociate, and ionize a hydrocarbon-based gas containing a carbon element. The substrate 3 is irradiated with the ionized carbon ions. At this time, the substrate 3 is biased in the negative direction with respect to the ground potential by about -50 to
By irradiating the surface of the base material 3 with an ion current of about 2000 mA, carbon is diffused to the surface of the base material 3 and a carbonized layer is formed by carbon ions. Subsequent to this processing, a DLC thin film 80 as described in the first embodiment is formed.

As described above, the cleaning with hydrogen ions improves the adhesion of the DLC thin film 80,
Before the thin film 80 is formed, the surface of the substrate 3 is irradiated with carbon ions irradiated from the gas ion source 10 at an acceleration energy of about 50 eV to about 1000 eV and a current of about 100 to about 2,000 mA to perform carbonization. Since a carbonized layer is formed on the surface of the base material 3 and the hardness of the surface of the base material 3 is increased, the presence of a carbon component in the surface layer of the base material 3 facilitates the growth of the DLC thin film 80. And the DLC thin film 80 can be improved in adhesion strength.

Embodiment 4 In this embodiment, first, cleaning using inert gas ions is performed as a first cleaning process, and then cleaning using hydrogen ions is performed as a second cleaning process. FIG. 15 shows the process. The operation will be described. In the same manner as in the first embodiment, the inside of the vacuum chamber 1 is evacuated to a degree of vacuum of about 1 × 10 ⁻⁶ Torr by using the DLC thin film forming apparatus of FIG. The temperature of the substrate 3 is adjusted to about 300 ° C. Next, a sputter cleaning process using inert gas ions is performed. First, an inert gas such as argon is introduced into the reaction gas introduction chamber 11 through the reaction gas introduction pipe 14, and the degree of vacuum in the reaction gas introduction chamber 11 is set to 1 × 10 ⁻² to 1 × 10 ⁻¹ Torr. Then, the thermoelectron emitting means 12 is operated, and the thermoelectron emitting means 12 is connected to the thermoelectron extracting electrode 13 by a power source (not shown).
A bias voltage of about 800 V is applied. Further, in order to extract ions from the gas ion source 10, the acceleration electrode 15
The thermionic emission means 12 with respect to the ground potential.
A voltage of about +200 to 500 V is applied from a power supply (not shown). The electrons emitted from the thermoelectron emitting means 12 are accelerated toward the thermoelectron extraction electrode 13 and ionize the inert gas. The substrate 3 is irradiated with the inert gas ions. At this time, the substrate 3 is biased in a negative direction with respect to the ground potential by about −10 to −30 kV with respect to the ground potential by the bias means 5, so that the substrate 3 is made of inert gas ions.
Can be performed, and impurities on the surface of the substrate 3 can be sputter-cleaned.

Subsequently, in the same manner as in the first embodiment, cleaning treatment with hydrogen ions and DLC
A thin film 80 is formed. As described above, after removing impurities such as moisture, oil and fat components, and surface oxides on the surface of the base material 3 by sputter cleaning of inert gas ions, cleaning using a reduction reaction of hydrogen ions is further performed.
The adhesion between the substrate 3 and the DLC thin film 80 can be improved.

Embodiment 5 In this embodiment, the cleaning of the base material is performed by using mixed gas ions of hydrogen ions and inert gas ions such as argon. FIG. 16 shows the process. First, using the DLC thin film forming apparatus shown in FIG. 2 or an apparatus provided with two gas ion sources,
After evacuating the vacuum chamber 1 to a degree of vacuum of about 1 × 10 ⁻⁶ Torr, the temperature of the substrate 3 is adjusted to about 300 ° C. by the substrate temperature adjusting mechanism 6. Then both valves 1
6. Open hydrogen gas and inert gas to reactant gas introduction pipe 1
4 into the reaction gas introduction chamber 11 and the reaction gas introduction chamber 1
The degree of vacuum of 1 is 1 × 10 ⁻² to 1 × 10 ⁻¹ Torr.
Here, 50% of hydrogen and 50% of argon were used. Then, the thermoelectron emission means 12 is operated, and the thermoelectron extraction electrode 13 is supplied to the thermoelectron emission means 12 by a power source (not shown).
, A bias voltage of about 50 to 800 V is applied. In addition, in order to extract ions from the gas ion source 10, a voltage of about +200 to 500 V is applied to the accelerating electrode 15, that is, to the thermionic emission means 12 with respect to the ground potential by a power supply (not shown). The electrons emitted from the thermionic electron emission means 12 are accelerated toward the thermionic extraction electrode 13 and ionize the hydrogen gas and the inert gas. The mixed gas ions are irradiated toward the substrate. At this time, the substrate 3 is moved in the negative direction with respect to the ground potential by the bias means 5.
By applying a bias of about 200 to -3000 V, the ion amount and energy can be controlled, so that the treatment can be performed effectively and the cleaning effect can be improved.

Subsequently, the DLC is performed in the same manner as in the first embodiment.
A thin film 80 is formed. As described above, by performing a cleaning process using a mixed gas of hydrogen gas and an inert gas such as helium, argon, or xenon as an ion cleaning gas, the surface oxide is removed by hydrogen ions by a reduction reaction. At the same time, the impurity layer on the surface of the base material can be ground and removed by sputtering of inert gas ions, so that the adhesion between the base material 3 and the DLC thin film 80 can be improved.

Embodiment 6 FIG. In this embodiment, first, cleaning is performed using inert gas ions such as argon as a first cleaning process, and then cleaning is performed using mixed gas ions of hydrogen ions and inert gas ions as a second cleaning process. FIG. 17 shows the process. The operation will be described. First, in the same manner as in the fourth embodiment, cleaning with inert gas ions is performed. Subsequently, in the same manner as in the fifth embodiment, cleaning is performed using mixed gas ions of a hydrogen gas and an inert gas. After that, the DLC thin film 80 is formed as in the first embodiment.

As described above, sputter cleaning using inert gas ions is performed, and subsequently, cleaning using a reduction reaction of hydrogen ions and sputter cleaning using inert gas ions are simultaneously performed. The adhesion is improved.

In the fourth to sixth embodiments, the case where the base layer 50 and the treatment layer 51 are not provided on the base material 3 has been described, but as described in the second or third embodiment, The same applies to the case where the underlayer 50 or the processing layer 51 is formed. In the above embodiment,
Although the case where the DLC thin film 80 is formed is shown, titanium carbide (TiC), titanium nitride (TiN), chromium nitride (Cr)
The present invention can be applied to the case of forming a thin film such as N) or aluminum oxide (Al ₂ C ₃ ).

[0035]

As described above, according to the first aspect of the present invention, before the thin film is formed on the substrate, the cleaning is performed by irradiating with hydrogen ions. Cleaning treatment to improve the adhesion between the substrate and the thin film. Further, according to the invention of claims 2 to 4, since cleaning is carried out by both inert gas ions and hydrogen ions, cleaning by sputter cleaning and reduction reaction is carried out, so that the base material and the thin film are cleaned. The adhesion is improved.

According to the invention of claim 5, the present invention is applied to the formation of a DLC thin film, and has an effect of improving the adhesion. According to the sixth and seventh aspects of the present invention, even when an underlayer or a treatment layer is formed on a substrate, the adhesion between the substrate and the DLC thin film is improved in the same manner as described above.

According to the eighth aspect of the present invention, since the switching means for switching the introduced gas to the gas for the cleaning process and the gas for forming the DLC thin film is provided, both the cleaning process and the DLC thin film formation can be performed by one gas ion source. It can be implemented, and the apparatus can be simplified and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a thin film forming process according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a DLC thin film forming apparatus used in the first embodiment.

FIG. 3 is a waveform diagram of a voltage applied by a bias unit in the first embodiment.

FIG. 4 is a Raman spectrum diagram showing the deposition temperature dependence of a thin film formed by the DLC thin film forming apparatus according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a thin film forming process according to a second embodiment of the present invention.

FIG. 6 is a sectional view of a DLC thin film forming apparatus used in the second embodiment.

FIG. 7 is an explanatory diagram showing a thin film forming process according to a second embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a thin film forming process according to a second embodiment of the present invention.

FIG. 9 is a sectional view of a DLC thin film forming apparatus used in the second embodiment.

FIG. 10 is an explanatory diagram showing a thin film forming process according to a second embodiment of the present invention.

FIG. 11 is an explanatory diagram showing a thin film forming process according to a third embodiment of the present invention.

FIG. 12 is a diagram illustrating a relationship between ion implantation energy and a distribution of an implantation amount in a depth direction.

FIG. 13 is a diagram showing a distribution of ion implantation energy with respect to time in Embodiment 3 of the present invention.

FIG. 14 is a diagram showing a distribution of carbon atoms in a depth direction of a base material according to Embodiment 3 of the present invention.

FIG. 15 is an explanatory diagram showing a thin film forming process according to Embodiment 4 of the present invention.

FIG. 16 is an explanatory diagram showing a thin film forming process according to a fifth embodiment of the present invention.

FIG. 17 is an explanatory diagram showing a thin film forming process according to a sixth embodiment of the present invention.

FIG. 18 is a sectional view showing a conventional thin film forming apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Vacuum tank, 3 base materials, 4 base material holders, 5 bias means, 6 temperature adjustment mechanism, 10 gas ion source, 11
Reaction gas introduction chamber, 12 thermoelectron emission means, 13 thermoelectron extraction electrode, 15 acceleration electrode, 16 switching means, 50
Underlayer, 51 processing layer, 80 DLC thin film.

Claims (8)

[Claims] In a pretreatment method for forming a thin film on a substrate, a pretreatment including a cleaning process by irradiating hydrogen ions to the surface of the substrate is performed before forming the thin film on the substrate. A pretreatment method for forming a thin film, which is performed. 2. A first cleaning treatment by irradiating the surface of the base material with an inert gas ion before forming a thin film on the base material, and a subsequent hydrogen ion formation on the surface of the base material. 2. The pretreatment method according to claim 1, wherein a pretreatment comprising a second cleaning treatment by irradiation is performed. 3. A pretreatment method for forming a thin film on a substrate, wherein a mixed gas ion of an inert gas ion and a hydrogen ion is formed on the surface of the substrate before forming the thin film on the substrate. A pretreatment method for forming a thin film, comprising performing a pretreatment including a cleaning treatment by irradiating light. 4. A first cleaning process by irradiating the surface of the base material with inert gas ions before forming a thin film on the base material, 4. The pretreatment method according to claim 3, wherein a pretreatment comprising a second cleaning treatment by irradiating mixed gas ions with hydrogen ions is performed. 5. The pretreatment method according to claim 1, wherein the thin film formed on the substrate is a diamond-like carbon thin film. 6. A base layer comprising a metal thin film selected from the group consisting of silicon, tungsten, titanium, and aluminum, or a ceramic thin film selected from the group consisting of silicon carbide, tungsten carbide, titanium carbide, and aluminum carbide. A pretreatment method for forming a thin film, wherein the pretreatment according to claim 5 is performed before the formation on the material and the formation of the diamond-like carbon thin film on the underlayer. 7. The pretreatment according to claim 5, wherein before the formation of the treatment layer containing carbon on the surface of the base material and the formation of the diamond-like carbon thin film on the treatment layer. Pretreatment method for forming a thin film. 8. A thin film forming apparatus for forming a diamond-like carbon thin film on a substrate, comprising: a vacuum chamber for holding the inside at a predetermined degree of vacuum; a substrate holder for holding the substrate in the vacuum chamber; A substrate temperature adjusting mechanism for adjusting the temperature of the substrate, a gas ion source provided opposite to the substrate in the vacuum chamber, and a gas introduced into the gas ion source for cleaning the substrate. Alternatively, the gas ion source is provided with a switching means capable of switching for film formation of the diamond-like carbon thin film, wherein the gas ion source is provided with an orifice toward the base material, and a reaction gas introduction chamber into which a gas is introduced; A thermionic emission means provided in the gas introduction chamber for emitting thermoelectrons, a thermionic extraction electrode for extracting thermoelectrons from the thermoelectron emission means, and a thermoelectron extraction electrode provided outside the reaction gas introduction chamber; An apparatus for forming a diamond-like carbon thin film, comprising: an acceleration electrode for accelerating ions toward the substrate; and bias means for applying a voltage to the substrate with respect to the acceleration electrode.