JP4560693B2 - Surface treatment apparatus and surface treatment method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface treatment apparatus and a surface treatment method for treating a surface of an insulator by implanting ions, and a surface treatment product obtained by the surface treatment method.
[0002]
[Prior art]
In the field of optical recording apparatuses such as optical disk apparatuses, research and development for improving the surface recording density is being actively conducted. In particular, in recent years, a blue-violet laser with a short light source wavelength (around 410 nm) has been developed. By using this laser and increasing the numerical aperture (NA) of the objective lens provided in the optical pickup, surface recording is performed. Attempts have been made to increase the density. Thus, when the NA of the objective lens is increased, it is required to avoid an adverse effect on signal reproduction due to an increase in coma aberration, which is a kind of ray aberration.
[0003]
By the way, conventionally, an insulating material such as polycarbonate has been used as a constituent material of a substrate of an optical disk represented by CD (Compact Disk) or MD (Mini Disk). In these CDs and MDs, the thickness of the disk substrate (portion through which the laser beam passes) needs to be reduced to about 0.1 mm in order to prevent the increase in coma aberration described above. However, when the disk substrate becomes thin, there is a problem that it is easily scratched and an error occurs when reading and writing. Further, as the surface recording density is improved, the distance between the optical disc and the optical pickup is shortened, so that they may come into contact with each other. As described above, when the optical disk and the optical pickup come into contact with each other, the optical disk and the optical pickup may be damaged, or dust generated due to the damage may adhere to the optical disk or the optical pickup, resulting in an error in reading and writing. There was a problem that occurred. Therefore, it is necessary to protect the surface of the optical disc and further the optical pickup.
[0004]
In general, methods for protecting the surface of a substance (object to be processed) include a method of forming a protective film on the surface, or surface treatment by injecting ions into the surface, and hardness, elasto-plastic characteristics, electrical conduction Techniques for improving various properties such as degree, lubricity, durability, moisture resistance, corrosion resistance, wettability or gas permeability are known.
[0005]
As a method for injecting ions into an object to be processed, a technique for injecting ions into the object to be processed by directly irradiating the object to be processed (hereinafter referred to as an ion beam implantation method) is known. . However, the ion beam implantation method has a problem that it is difficult to uniformly implant ions on the surface of the object to be processed when the object to be processed has a three-dimensional structure.
[0006]
Therefore, as a technique that can solve such problems and can uniformly inject ions even if the object to be processed has a three-dimensional structure, plasma containing the ions to be injected is generated on the substrate. A technique has been devised in which ions contained in the plasma are accelerated by applying a bias and drawn into a workpiece to be implanted (hereinafter referred to as a plasma implantation method).
[0007]
In the plasma implantation method, an object to be processed is arranged in plasma containing ions to be injected, and a negative pulsed bias voltage as shown in FIG. 24 is applied to the object to be processed. When a negative voltage is applied to the object to be processed, ions in the plasma are drawn into the object to be processed, and ions are implanted into the object to be processed.
[0008]
In such a plasma implantation method, if the plasma containing ions to be implanted is uniformly generated around the object to be processed, the surface of the object to be processed can be obtained even if the object to be processed has a three-dimensional structure. It is possible to implant ions uniformly.
[0009]
[Problems to be solved by the invention]
However, conventionally, the plasma injection method can be applied only when the object to be processed is a conductor such as metal. This is because, when the object to be processed is an insulator, if ion implantation is performed by the plasma implantation method, charges are immediately accumulated in the object to be processed, so that a so-called charge-up state occurs, and ions are drawn into the object to be processed. Because it will disappear.
[0010]
  The present invention has been made in view of such problems, and the purpose thereof is a surface treatment capable of performing a surface treatment by implanting ions by a plasma implantation method even if the object of the surface treatment is an insulator. Equipment and surface treatmentThe lawIt is to provide.
[0011]
[Means for Solving the Problems]
  A surface treatment apparatus according to the present invention is a surface treatment apparatus that treats the surface of an insulator by injecting ions into the insulator, and supports the insulator in the vacuum vessel and the inside of the vacuum vessel, and cools the inside. A holder that incorporates a water introduction pipe and suppresses the temperature rise of the insulator by circulating cooling water, a plasma generating means for generating plasma containing ions to be injected into the insulator in the vacuum vessel, and the insulator Voltage application means for applying a pulse voltage,The voltage application means is a pair of high-voltage vacuum tubes for outputting positive and negative pulsed voltage across the coil, and a pair of charging devices connected to the high-voltage vacuum tubes via a controller, respectively, for outputting positive and negative DC voltages The timing signal is supplied to the charger and the controller, and the positive / negative DC voltage output from the charger is turned on / off to convert it into a positive / negative pulse voltage, and the positive pulse voltage and negative pulse voltage are also converted. A timing signal generator that performs switching control of the controller so that the voltage is alternately output,By generating a plasma containing ions to be injected into the insulator by the plasma generating means, and applying a pulsed voltage including a positive pulse voltage and a negative pulse voltage to the insulator by the voltage applying means in the plasma, Ions are implanted into the insulator.
[0012]
  The surface treatment method according to the present invention is a surface treatment method for treating the surface of an insulator by implanting ions into the insulator, and in a plasma containing ions to be implanted,By voltage application meansBy applying a pulse voltage including a positive pulse voltage and a negative pulse voltage to the insulator, ions are injected into the insulator, and a cooling water introduction pipe is incorporated inside the holder that supports the insulator, Cooling water circulation suppresses temperature rise of insulator during ion implantationAnd the voltage applying means is connected to a pair of high voltage vacuum tubes for outputting positive and negative pulsed voltages with the coil in between, and the high voltage vacuum tubes via a controller, respectively. A timing signal is supplied to the controller, and a positive / negative DC voltage output from the charger is turned on / off to be converted into a positive / negative pulse voltage, and a positive A timing signal generator that performs switching control of the controller so that a pulsed voltage and a negative pulsed voltage are alternately output.It is what I did.
[0014]
  In the surface treatment apparatus according to the present invention, when a pulsed voltage including a positive pulse voltage and a negative pulse voltage is applied to the insulator by the voltage applying unit, ions in the plasma generated by the plasma generating unit are insulated. Uniformly injected.At this time, since the cooling water circulates inside the holder that supports the insulator, the temperature rise of the insulator during ion implantation is suppressed.
[0015]
  In the surface treatment method according to the present invention, ions in the plasma are implanted into the insulator in the plasma.At this time, since the cooling water circulates inside the holder that supports the insulator, the temperature rise of the insulator during ion implantation is suppressed.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0018]
[First Embodiment]
FIG. 1 shows the configuration of the surface treatment apparatus according to the first embodiment of the present invention. The surface treatment apparatus 1 is for treating the surface of the object to be treated 2 by implanting ions to the object to be treated 2 made of an insulating material by a plasma implantation method.
[0019]
Here, examples of the material of the object 2 to be processed by ion implantation include amorphous polyolefin (APO), polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene, and the like. Examples include terephthalate (PET), acrylic resin, polyimide resin, carbon or glass. Examples of ion species implanted into the workpiece 2 include carbon (C), nitrogen (N), tungsten (W), tantalum (Ta), chromium (Cr), molybdenum (Mo), and cobalt (Co). , Platinum (Pt), nickel (Ni), iron (Fe), titanium (Ti), manganese (Mn), copper (Cu) or samarium (Sm).
[0020]
The surface treatment apparatus 1 includes a vacuum vessel 3, a cryopump 4 for exhausting the inside of the vacuum vessel 3, a holder 5 that supports the workpiece 2 inside the vacuum vessel 3, and an injection into the workpiece 2. An ion generator 6 for supplying ions to be turned on, a shutter 7 for switching on / off of the ion supply, and a pulse power supply circuit for applying a pulsed voltage including a positive pulse voltage and a negative pulse voltage to the workpiece 2 8 and.
[0021]
The vacuum container 3 is a container that is evacuated to a high vacuum state. In the surface treatment apparatus 1, plasma containing ions to be injected into the object to be processed 2 is generated inside the vacuum vessel 3, and ions contained in the plasma are injected into the object to be processed 2.
[0022]
The cryopump 4 is a vacuum pump for exhausting the inside of the vacuum vessel 3 to obtain a high vacuum state. In this surface treatment apparatus 1, the degree of vacuum before the inside of the vacuum vessel 3 is exhausted by the cryopump 4 and ions are introduced into the inside of the vacuum vessel 3, that is, the degree of background vacuum is, for example, 1.33 × 10 6.^-FivePa (10^-7Torr). The degree of vacuum when the inside of the vacuum vessel 3 is evacuated by the cryopump 4 and ions are introduced into the inside of the vacuum vessel 3 to generate plasma, that is, the degree of vacuum when performing ion implantation is, for example, 1 .33 × 10^-3Pa (10^-FiveTorr).
[0023]
The holder 5 is for supporting the workpiece 2 and is supported inside the vacuum vessel 3 by an insulating support member 9 attached to the vacuum vessel 3. When the surface treatment is performed on the workpiece 2 made of an insulator, the workpiece 2 is attached to the holder 5. In addition, the support member 9 is attached to the vacuum vessel 3 through a lever, for example.
[0024]
The holder 5 incorporates a cooling water introduction pipe, and the workpiece 2 attached to the holder 5 can be cooled by flowing cooling water through the pipe. The cooling water introduction pipe is led out of the vacuum vessel 3 through the support member 9. Therefore, as shown by the arrow A in the figure, the cooling water can be circulated by the cooling water introduction pipe.
[0025]
By using the holder 5 having the water cooling function in this manner, even when the temperature of the workpiece 2 rises when performing ion implantation on the workpiece 2, it is possible to control the temperature. is there. Therefore, even when the object to be processed 2 is made of a material that is not preferable to be processed at a high temperature, such as plastic, the temperature increase of the object to be processed 2 can be suppressed and ion implantation into the object to be processed 2 can be performed.
[0026]
The ion generator 6 is a plasma generation unit that supplies ions to be injected into the object to be processed 2 and generates plasma containing ions to be injected into the object to be processed 2, and generates ions to be injected into the object to be processed 2. In addition to the ion source 10, a mass separator 11 is provided for guiding only ions to be injected into the workpiece 2 out of the particles generated from the ion source 10 into the vacuum vessel 3. Although not illustrated, the vacuum vessel 3 and the ion generator 6 are configured to be adjacent to each other through, for example, an insulator.
[0027]
Here, as the ion generation source 10, for example, a Kaufman type ion source, a magnetron sputtering source, a cathodic arc source, or the like can be used. Here, in the Kaufman ion source and the magnetron sputtering source, an operating gas serving as an ion source is introduced, and ions are generated from the operating gas. On the other hand, cathodic arc sources generate ions without using a working gas. Specifically, in a cathodic arc source, an arc discharge is generated using a cathode made of a material serving as an ion source, and the cathode is evaporated and ionized particles are taken out by the arc discharge. Such a cathodic arc source has an advantage that ions can be generated while maintaining a high vacuum state because no operating gas is used for generating ions.
[0028]
When a cathodic arc source is used as the ion generation source 10, the generation of droplets due to melting of the cathode may be a problem. In order to solve such a problem of droplet generation, there is one in which droplets are removed using an electromagnetic filter, and such a cathodic arc source is called a filtered cathodic arc source. . In the surface treatment apparatus 1, a filtered cathodic arc source may be used as the ion generation source 10.
[0029]
From the ion generation source 10, neutral particles and macro particles with a large mass are generated simultaneously with desired ions. However, it is not preferable that particles other than the desired ions reach the workpiece 2. Therefore, the ion generator 6 guides only the desired ions out of the particles from the ion generation source 10 to the inside of the vacuum vessel 3 by the mass separator 11.
[0030]
The mass separator 11 has a path bent by, for example, about 45 degrees, and a magnet is arranged along the path. In the mass separator 11, desired ions are guided into the vacuum vessel 3 along a bent path by a magnetic field from a magnet. On the other hand, neutral particles and macro particles with large mass are not restrained by a magnetic field, and are thus blocked without passing through a bent path.
[0031]
By disposing such a mass separator 11 between the ion source 10 and the vacuum vessel 3, neutral particles and macro particles having a large mass are blocked, and only desired ions are stored in the vacuum vessel 3. It is possible to lead inside. Thereby, the influence of neutral particles or macro particles having a large mass can be removed, and the quality of the surface treatment can be improved.
[0032]
The shutter 7 is disposed in the vicinity of the ion emission port of the ion generator 6 and switches on / off the ion supply. That is, when the shutter 7 is opened, the ion supply from the ion generator 11 is performed, and when the shutter 7 is closed, the ion supply from the ion generator 6 is stopped.
[0033]
The pulse power supply circuit 8 is a voltage applying unit that applies a pulse voltage including a positive pulse voltage and a negative pulse voltage to the workpiece 2 supported by the holder 5. That is, the pulse power supply circuit 8 applies a pulse voltage as a bias voltage to the workpiece 2 when ions are implanted into the workpiece 2. When a negative pulse voltage is applied to the workpiece 2, ions in the plasma are drawn into the workpiece 2, and ions are implanted into the workpiece 2.
[0034]
The pulse power supply circuit 8 includes a first power supply 21 serving as a positive direct current (DC) voltage source, a second power supply 22 serving as a negative direct current voltage source, and a direct current voltage from the first power supply 21. The first inverter circuit 23 for converting the pulse voltage into a pulse voltage, the second inverter circuit 24 for converting the DC voltage from the second power supply 22 into the pulse voltage, and the first and second inverter circuits 23, 24 Are provided with a pulse transformer 25 that boosts the pulse voltage from the control circuit 26, a control circuit 26 that controls the first and second inverter circuits 23 and 24, and a computer 27 that controls the operation of the control circuit 26.
[0035]
In the pulse power supply circuit 8, the first inverter circuit 23 converts the positive DC voltage from the first power supply 21 into a pulse voltage, and the second inverter circuit 24 supplies the voltage from the second power supply 22. Converts negative DC voltage to pulsed voltage.
[0036]
Outputs from these inverter circuits 23 and 24 are controlled by a control circuit 26 as waveform control means. That is, the pulse power supply circuit 8 includes a first inverter circuit 23 that outputs a positive pulsed voltage and a second inverter circuit 24 that outputs a negative pulsed voltage, which operate in parallel. By controlling the circuits 23 and 24 by the control circuit 26, the positive and negative pulse voltages output from the inverter circuits 23 and 24 are independently obtained from their pulse peak value (pulse wave height), pulse rise time, pulse interval and It is possible to change the pulse width and the like.
[0037]
Specifically, for example, the control circuit 26 outputs a positive voltage pulse output from the first inverter circuit 23 and a negative voltage pulse output from the second inverter circuit 24 alternately. The output from the first inverter circuit 23 and the output from the second inverter circuit 24 are switched. The pulse voltage controlled by the control circuit 26 and output from the first and second inverter circuits 23 and 24 is supplied to the primary winding of the pulse transformer 25.
[0038]
The pulse voltage supplied to the pulse transformer 25 is boosted by the pulse transformer 25. Here, the terminal from the secondary winding of the pulse transformer 25 passes through the inside of the support member 9 that supports the holder 5 and is installed on the workpiece support surface of the holder 5. Therefore, when the workpiece 2 is attached to the holder 5, a pulsed voltage boosted by the pulse transformer 25 is applied to the workpiece 2.
[0039]
Here, the pulse voltage applied to the workpiece 2 includes a pulse obtained by boosting a positive voltage pulse output from the first inverter circuit 23 and a negative voltage output from the second inverter circuit 24. And a pulse obtained by boosting the voltage pulse. That is, a pulse voltage including a positive pulse voltage and a negative pulse voltage is applied to the workpiece 2.
[0040]
In this way, when the voltage applied to the object to be processed 2 is a pulse voltage including a positive pulse voltage and a negative pulse voltage, when the ion implantation is performed on the object 2 to be processed, There is no charge accumulation. That is, even if charges are accumulated in the workpiece 2 by applying a negative pulse voltage, the charges are immediately neutralized by the positive pulse voltage. Similarly, even if charges are accumulated in the workpiece 2 by applying a positive pulse voltage, the charges are immediately neutralized by the negative pulse voltage. Therefore, ions can be continuously implanted into the workpiece 2 without being in a so-called charge-up state.
[0041]
In this pulse power supply circuit 8, the pulse peak value of the pulse voltage applied to the workpiece 2, the pulse rise time, the pulse interval, the pulse width, the order of the positive and negative pulses, etc. can be changed by an instruction input to the computer 27. It is said. That is, when this pulse power supply circuit 8 is used, what waveform pulse voltage is applied to the workpiece 2 is input to the computer 27. Based on this input, the computer 27 controls the operation of the control circuit 26. The control circuit 26 controls the outputs from the first and second inverter circuits 23 and 24 based on an instruction from the computer 27 so that a pulsed voltage having a desired waveform is applied to the workpiece 2. .
[0042]
Specifically, for example, the pulse peak voltage of the pulse voltage applied to the workpiece 2 can be changed independently from positive to negative to about 0 V to 40 kV. The pulse width is variable in the range of several μsec to several sec. The pulse interval is variable in the range of several tens of microseconds to several seconds. Further, the order of positive and negative pulses can be controlled by a computer 27 connected to the control circuit 26.
[0043]
In the pulse power supply circuit 8, it is preferable to use a circuit configured using a semiconductor element for the inverter circuits 23 and 24. Since an inverter circuit configured using a semiconductor element is inexpensive, the pulse power circuit 8 can be configured at low cost by using a circuit configured using a semiconductor element as the inverter circuits 23 and 24 incorporated in the pulse power circuit 8. It becomes possible to do. In addition, since a circuit configured using a semiconductor element is easily miniaturized, it is preferable to use a circuit configured using a semiconductor element as the inverter circuits 23 and 24 in order to reduce the size of the pulse power supply circuit 8.
[0044]
In addition, when using the circuit comprised using the semiconductor element as the inverter circuits 23 and 24, it becomes difficult to obtain a high output voltage from the inverter circuits 23 and 24. As described above, the output from the inverter circuits 23 and 24 may be boosted by the pulse transformer 25.
[0045]
That is, when a circuit configured using semiconductor elements is used as the inverter circuits 23 and 24, for example, the pulse peak voltage of the pulse voltage output from the inverter circuits 23 and 24 is about several hundred V to several kV. To do. This is boosted by the pulse transformer 25 to obtain a pulsed voltage having a pulse peak voltage of about several tens of kV. Then, the pulse voltage boosted by the pulse transformer 25 in this way is applied to the workpiece 2.
[0046]
Next, a surface treatment method of the workpiece 2 using the surface treatment apparatus 1 having such a configuration will be described.
[0047]
First, the workpiece 2 made of an insulator to be surface-treated is attached to a holder 5 disposed inside the vacuum vessel 3. Thereafter, the inside of the vacuum vessel 3 is evacuated by the cryopump 4 to be in a high vacuum state. The degree of vacuum inside the vacuum container 3 at this time, that is, the degree of vacuum before introducing ions into the inside of the vacuum container 3 (background vacuum degree) is, for example, 1.33 × 10.^-FivePa (10^-7Torr).
[0048]
In addition, when the to-be-processed object 2 consists of material which is not preferable to process at high temperature, for example, a plastic etc., a cooling water is poured into the cooling water introduction pipe built in the holder 5, and the to-be-processed object 2 Do not let the temperature rise too high.
[0049]
Next, ions to be injected into the workpiece 2 are generated by the ion generator 6, and the ions are introduced into the vacuum container 3. As a result, plasma containing ions to be injected into the workpiece 2 is generated inside the vacuum vessel 3. The degree of vacuum inside the vacuum vessel 3 at this time, that is, the degree of vacuum when performing ion implantation is, for example, 1.33 × 10 6.^-3Pa (10^-FiveTorr).
[0050]
Then, in a state where the workpiece 2 is arranged in the plasma containing the ions to be implanted, the pulse power supply circuit 8 generates a pulsed bias voltage including a positive pulse voltage and a negative pulse voltage, and the pulsed A voltage is applied to the workpiece 2. Thereby, ions are drawn into the object to be processed 2 and ion implantation into the object to be processed 2 is performed. More specifically, when a negative pulse voltage is applied to the object to be processed 2, positive ions contained in the plasma are drawn into the object to be processed 2, and the positive ions are injected into the object to be processed 2. The
[0051]
In this way, when positive ions are drawn into the object to be processed 2 and ion implantation is performed on the object to be processed 2, charges are accumulated in the object to be processed 2. For this reason, if a negative voltage is continuously applied to the workpiece 2, the ion implantation into the workpiece 2 made of an insulator cannot be continued. Therefore, in this surface treatment apparatus 1, the bias voltage applied to the object to be treated 2 is a pulsed voltage including a positive pulse voltage and a negative pulse voltage, and the charge accumulated in the object to be treated 2 is converted into a positive pulse voltage. Neutralize. More specifically, when a positive pulse voltage is applied to the workpiece 2, electrons are drawn into the workpiece 2, and the charges accumulated in the workpiece 2 are neutralized by the electrons. In this way, if the charges accumulated in the workpiece 2 are neutralized, then, when a negative pulse voltage is applied thereafter, positive ions are again drawn into the workpiece 2 and the workpiece 2 Will be implanted.
[0052]
As described above, the bias voltage applied to the object to be processed 2 is a pulsed voltage including a positive pulse voltage and a negative pulse voltage, so that even if the object to be processed 2 is an insulator, it is in a charged-up state. Therefore, ion implantation into the workpiece 2 can be performed.
[0053]
In the present embodiment, the ion implantation amount, implantation depth, implantation profile, and the like of the object to be processed 2 are the pulse peak value of the negative pulse voltage applied to the object 2 to be processed, the pulse rise time, the pulse interval, or the pulse. Depends on width etc. Therefore, by controlling the waveform of the pulse voltage applied to the object 2 to be processed, it is possible to control the injection amount, the injection depth, the injection profile, and the like when implanting ions into the object 2 to be processed.
[0054]
FIG. 2 shows an implantation profile obtained when ion implantation is performed by the plasma treatment method using the surface treatment apparatus 1 (relationship between the depth from the surface of the workpiece 2 and the concentration of ions implanted into the workpiece 2). ) Is an example. As can be seen from this figure, in the plasma implantation method, the implantation voltage, implantation depth, implantation profile, etc. of ions implanted into the workpiece 2 are controlled by controlling the pulse voltage applied to the workpiece 2. be able to. Accordingly, the concentration peak of ions to be implanted can be present near the surface of the workpiece 2.
[0055]
In addition, since the ion implantation here is based on the plasma implantation method in which ions contained in the plasma are implanted into the workpiece 2, the workpiece 2 has a three-dimensional structure unlike the ion beam implantation method. Even in this case, it is possible to uniformly inject ions into the surface of the workpiece 2.
[0056]
FIG. 3 shows an example of an implantation profile obtained when ions are implanted by the ion beam implantation method. In the case of the ion beam implantation method, an ion beam having a constant energy is accelerated and implanted into the object to be processed, so that the implantation profile has a Gaussian distribution having a peak at a certain depth from the surface. .
[0057]
Examples of the object 2 to be processed by ion implantation as described above support, for example, a rotating drum used for recording / reproducing of a magnetic tape by a helical scan method or a recording layer of a recording medium. A base material, a recording medium in which a recording layer is formed on the base material, a recording layer (magnetic layer) made of, for example, a magnetic material is formed on the base material, and a protective film is formed on the recording layer. Recording panels, panel substrates for encapsulating liquid crystals in a liquid crystal panel, printed matter obtained by printing an insulator, and various micromachines made of an insulating material such as plastic.
[0058]
FIG. 4 shows the appearance of a magnetic recording / reproducing apparatus based on the helical scan method. This magnetic recording / reproducing apparatus is provided with the rotating drum 30 formed of, for example, plastic as described above. When recording / reproducing the magnetic tape using the rotary drum 30, as shown by an arrow B1 in FIG. 4, the magnetic tape 31 is wound around the rotary drum 30 and traveled, and the arrow B2 in FIG. As shown, the rotating drum 30 is rotated by a motor. Then, recording / reproduction of the magnetic tape 31 is performed by a magnetic head mounted on the rotary drum 30.
[0059]
By subjecting the rotating drum to surface treatment by the surface treatment method according to the present embodiment, the surface hardness can be greatly improved, and a plastic rotating drum that is not easily worn by sliding with the magnetic tape is provided. Obtainable. As a result, the weight can be significantly reduced as compared with a conventional rotating drum made of an aluminum alloy, and the load on the motor that rotates the rotating drum can be significantly reduced to, for example, about 1/10. it can. In this way, by reducing the load on the motor, it is possible to significantly reduce the power required for driving the helical scan type magnetic recording / reproducing apparatus. Therefore, for example, the battery driving time can be significantly increased. In addition, it is very preferable for the global environment because it requires less power.
[0060]
By the way, when the rotating drum is made of plastic, there may be a problem that the magnetic tape sticks to the rotating drum due to the insulating property of the surface. In that case, metal ions such as titanium are also introduced when performing ion implantation. Thereby, the surface of the rotating drum can be made conductive, and the problem of sticking of the magnetic tape can be solved.
[0061]
Specifically, for example, methane gas (CH_Four ) And the like to generate ions, together with methane gas, Ti (CH_Three )₂ Cl₂ Alternatively, an organic metal such as tetramethylaminotitanium, tetrakisdimethylaminotitanium (TDMAT), or tetrakisdiethylaminotitanium (TDEAT) is introduced to supply titanium ions into the plasma. Thereby, the surface of a rotating drum can be titanized and the problem of magnetic tape sticking can be eliminated.
[0062]
Note that even if a conductive thin film is formed on the surface of the rotating drum, the problem of sticking magnetic tape can be solved. However, when a conductive thin film is formed on plastic, the plastic and conductive thin film Adhesion is poor and the durability of the rotating drum is poor. Therefore, in order to eliminate the problem of sticking the magnetic tape, as described above, metal ions such as titanium are also introduced when ion implantation is performed, so that the surface of the rotating drum is made conductive. Is preferred.
[0063]
In addition, when a thin film is formed later on the rotating drum, the surface processing accuracy changes depending on the film forming conditions of the thin film. On the other hand, in the case of ion implantation, since ions are implanted along the surface of the rotating drum, the surface processing accuracy of the rotating drum hardly changes. For example, when the surface roughness after machining is 0.8S, the surface roughness after ion implantation is maintained at approximately 0.8S. Therefore, it is preferable to perform only the surface treatment by ion implantation from the viewpoint of maintaining the surface processing accuracy.
[0064]
When the workpiece 2 is a disk-shaped recording medium in which a magnetic layer is formed on a substrate, when performing ion implantation, the waveform of a pulsed voltage applied to the disk-shaped recording medium is controlled, It is preferable to implant more ions near the surface of the magnetic layer. Thereby, mainly the surface vicinity of the magnetic layer can be modified, and the surface hardness of the magnetic layer can be greatly increased.
[0065]
When performing ion implantation using the present invention, as will be described in detail later, by controlling the waveform of the pulse voltage applied to the workpiece 2, only ions are implanted into the workpiece 2. In addition, film formation can be performed simultaneously. Therefore, when performing the surface treatment on the disk-shaped recording medium described above, the waveform of the pulse voltage applied to the disk-shaped recording medium is controlled, and simultaneously with the surface modification by ion implantation, a protective film for protecting the magnetic layer is formed. The formation and the like may be performed simultaneously.
[0066]
In addition, when the workpiece 2 is a disk-shaped recording medium in which a magnetic layer and a protective film are formed on a base material, by implanting ions into the protective film, the surface hardness of the protective film is increased, The durability and reliability of the disc-shaped recording medium can be improved. Then, by increasing the surface hardness of the protective film of the disk-shaped recording medium in this way, for example, a disk-shaped recording medium that has been conventionally used in a caddy for preventing scratches can be put into the caddy. It can also be used.
[0067]
When performing surface treatment on this disk-shaped recording medium, the waveform of the pulse voltage applied to the disk-shaped recording medium is controlled so that more ions are implanted near the surface of the protective film. Is preferred. Thereby, mainly the surface vicinity of the protective film can be modified to greatly increase the surface hardness of the protective film.
[0068]
Further, when the object to be processed 2 is a plastic panel substrate for encapsulating liquid crystal in the liquid crystal panel, the moisture permeability and oxygen permeability can be increased by performing a surface treatment of the plastic panel substrate, so that the conventional glass panel substrate is used. As a result, the plastic panel substrate can be improved. Therefore, a plastic panel substrate can be used, and the liquid crystal panel can be reduced in weight and cost.
[0069]
Moreover, when the to-be-processed object 2 is a printed matter formed by printing on an insulator, ions are implanted into the printed matter to modify the printed ink and make it difficult to drop the print. be able to. Since the ion implantation of this embodiment is based on the plasma implantation method, unlike the ion beam implantation method, it is possible to uniformly implant ions even if the workpiece 2 has a three-dimensional structure. It is. Therefore, even when the printed material has a three-dimensional structure, it is possible to uniformly ion-implant the entire surface of the printed material and make it difficult to drop the print on the entire printed surface.
[0070]
Next, the pulse voltage applied to the workpiece 2 when ion implantation is performed by the surface treatment apparatus 1 will be described with reference to specific examples (FIGS. 5 to 12).
[0071]
In the example shown in FIG. 5, first, a negative pulse voltage is applied, and immediately thereafter, a positive pulse voltage having substantially the same absolute value of the pulse peak is applied, and thereafter, a period in which no voltage is applied is provided. Such a pulse train is repeatedly applied to the workpiece 2.
[0072]
When the pulsed voltage has a waveform as shown in FIG. 5, positive ions are accelerated and drawn into the workpiece 2 when a negative pulse voltage is applied. Thereby, ion implantation to the workpiece 2 is performed. At this time, positive ions are drawn into the object to be processed 2, so that charges are accumulated in the object to be processed 2. On the other hand, when a positive pulse voltage is applied, electrons are drawn into the workpiece 2. Thereby, the electric charge accumulated in the workpiece 2 is neutralized.
[0073]
Therefore, by applying a pulsed voltage having a waveform as shown in FIG. 5 to the workpiece 2 as a bias voltage, even if the workpiece 2 is an insulator, the charge-up state is not caused. Ion implantation into the workpiece 2 can be continued.
[0074]
The example shown in FIG. 6 is an example in which the order of positive and negative is reversed from the example shown in FIG. That is, first, a positive pulse voltage is applied, and immediately thereafter, a negative pulse voltage having substantially the same absolute value of the pulse peak is applied, and thereafter, a period in which no voltage is applied is provided. Such a pulse train is repeatedly applied to the workpiece 2.
[0075]
Also in the case where the pulse voltage has a waveform as shown in FIG. 6, as in the example shown in FIG. 5, when a negative pulse voltage is applied, positive ions are accelerated and drawn into the workpiece 2. Thereby, ion implantation to the workpiece 2 is performed. At this time, positive ions are drawn into the object to be processed 2, so that charges are accumulated in the object to be processed 2. On the other hand, when a positive pulse voltage is applied, electrons are drawn into the workpiece 2. Thereby, the electric charge accumulated in the workpiece 2 is neutralized.
[0076]
Therefore, by applying a pulse voltage having a waveform as shown in FIG. 6 to the workpiece 2 as a bias voltage, the workpiece 2 is an insulator as in the example shown in FIG. Also, the ion implantation into the workpiece 2 can be continued without being charged up.
[0077]
In the example shown in FIG. 7, after a negative pulse voltage is first applied, a period in which no voltage is applied is provided. Subsequently, after applying a negative pulse voltage and a positive pulse voltage having substantially the same absolute value of the pulse peak, a period in which no voltage is applied is provided. Such a pulse train is repeatedly applied to the workpiece 2.
[0078]
Even in the case where the pulse voltage has a waveform as shown in FIG. 7, even if the workpiece 2 is an insulator, as in the example shown in FIG. 5 and FIG. Ion implantation into the workpiece 2 can be continued.
[0079]
In the example shown in FIG. 7, a period in which no voltage is applied after a negative pulse voltage is applied is provided, and a positive pulse voltage is applied after a certain period of time. As described above, when a period in which no voltage is applied is provided after the negative pulse voltage is applied, the charge accumulated in the workpiece 2 is removed to some extent during the period. Therefore, it becomes easy to neutralize charges by applying a positive pulse voltage.
[0080]
In the example shown in FIG. 8, a negative pulse voltage is first applied, and immediately thereafter, a positive pulse voltage whose absolute value of the pulse peak is smaller than that of the negative pulse voltage is applied, and then the voltage is applied. There is no period. Then, such a pulse train is repeatedly applied to the workpiece 2.
[0081]
Even when the pulse voltage has a waveform as shown in FIG. 8, when a negative pulse voltage is applied, ions are implanted into the workpiece 2 as in the examples shown in FIGS. At the same time, charges accumulate on the workpiece 2 and a positive pulse voltage is applied to neutralize the charges accumulated on the workpiece 2.
[0082]
In the example shown in FIG. 8, the absolute value of the pulse peak of the positive pulse voltage is made smaller than the absolute value of the pulse peak of the negative pulse voltage. The sum can be sufficiently obtained even if the positive pulse is reduced as in this example. In particular, when a period in which no voltage is applied between the pulses is provided, charges accumulated in the object to be processed 2 are lost during the period, so that the charges accumulated in the object to be processed 2 are neutralized. The positive pulse voltage may be smaller.
[0083]
The example shown in FIG. 9 is an example in which the order of positive and negative is reversed from the example shown in FIG. That is, in the example shown in FIG. 8, first, a positive pulse voltage is applied, and immediately after that, a negative pulse voltage with a small absolute value of the pulse peak is applied, and then a period in which no voltage is applied is provided. . Then, such a pulse train is repeatedly applied to the workpiece 2. In this case as well, as in the example shown in FIGS. 5 to 8, even if a charge is accumulated on the object 2 to be processed, it is neutralized.
[0084]
In the example shown in FIG. 9, the absolute value of the pulse peak of the positive pulse voltage is larger than the absolute value of the pulse peak of the negative pulse voltage. The sum can be obtained by increasing the positive pulse as in this example. In the case of this example, when a positive pulse voltage is applied, more electrons than neutralize charges accumulated in the object 2 are drawn into the object 2. Therefore, in this example, the effect of surface treatment by electron irradiation can be obtained.
[0085]
In the example shown in FIG. 10, first, a plurality of negative pulse voltages are applied. At this time, pulses with gradually increasing negative voltage are continued, and viewed as a whole, the waveform is composed of a pulse train having a gentle negative slope as shown by a dotted line in the figure. Immediately after applying these negative pulse voltages, a positive pulse voltage is applied, and then a period in which no voltage is applied is provided. Such a pulse train is repeatedly applied to the workpiece 2.
[0086]
When the pulsed voltage has a waveform as shown in FIG. 10, positive ions are accelerated and drawn into the workpiece 2 when a plurality of negative pulse voltages are applied. Thereby, ion implantation to the workpiece 2 is performed. At this time, positive ions are drawn into the object to be processed 2, so that charges are accumulated in the object to be processed 2. On the other hand, when a positive pulse voltage is applied, electrons are drawn into the workpiece 2. Thereby, the electric charge accumulated in the workpiece 2 is neutralized.
[0087]
As shown in this example, a negative pulse voltage that is a bias voltage for accelerating positive ions and drawing them into the object to be processed 2 is a combination of a plurality of pulses. The injection profile at the time of injection can be controlled more finely.
[0088]
In the example shown in FIGS. 5 to 10, a period in which no voltage is applied between the pulses is provided. However, in the period in which no voltage is applied, ions that have reached the object 2 with the initial energy remain. Is deposited on the workpiece 2 as it is. Therefore, during a period in which no voltage is applied, film formation on the object to be processed 2 is performed instead of ion implantation to the object to be processed 2. That is, in the example shown in FIGS. 5 to 10, both the ion implantation effect and the film forming effect can be obtained.
[0089]
On the other hand, when it is not desired to form a film on the workpiece 2, a DC voltage component may be superimposed on the pulse voltage applied to the workpiece 2. An example of a pulse voltage on which a DC voltage component is superimposed is shown in FIG. As in this example, by superimposing a positive DC voltage component on the pulse voltage, only ion implantation into the workpiece 2 can be performed without forming a film formation state between pulses. it can.
[0090]
By the way, in the above description, it has been described that ions are implanted when a negative voltage is applied to the object 2 to be processed. However, depending on conditions, when a negative voltage is applied to the object 2 to be processed, Ions do not enter the inside of the object 2 and can be in a sputtering state.
[0091]
That is, when a sufficiently large negative voltage is applied to the object to be processed 2, the energy of ions reaching the object to be processed 2 becomes sufficiently large so that ions enter the object to be processed 2, However, when the negative voltage applied to the object to be processed 2 is small, the energy of ions reaching the object to be processed 2 is small, so that ions do not enter the object to be processed 2 and a sputtering state is established.
[0092]
Specifically, for example, when the object to be processed 2 is made of plastic and the ion species is carbon, when the negative voltage applied to the object to be processed 2 is about 10 kV, the ions are sufficiently accelerated and become an ion-implanted state. When the negative voltage applied to the object to be processed 2 is about several hundred volts, the acceleration of ions is insufficient, so that ions do not enter the object to be processed 2 and a sputtering state is obtained.
[0093]
And when performing surface treatment to the to-be-processed object 2, you may make it utilize such sputtering positively. FIG. 12 shows an example of a pulse voltage when sputtering is actively used. In the example shown in FIG. 12, when a negative pulse voltage is applied, first, a bias of about −several hundred volts is applied, and thereby the surface of the workpiece 2 is sputtered. Thereafter, a pulse of about −10 kV is applied, and thereby, ion implantation into the workpiece 2 is performed.
[0094]
In this way, by adjusting the voltage applied to the workpiece 2, not only ion implantation into the workpiece 2 but also sputtering of the workpiece 2 can be performed. That is, by adjusting the voltage to be applied to the workpiece 2, surface treatment combining sputtering and ion implantation can be performed on the workpiece 2.
[0095]
By the way, in the said surface treatment apparatus 1, the ion inject | poured into the to-be-processed object 2 can be intermittently supplied by carrying out the pulse operation of the ion generator 11, or controlling the opening / closing operation | movement of the shutter 7. FIG. Therefore, the supply of ions to be injected into the object to be processed 2 may be performed in synchronization with a pulse of a bias voltage applied to the object to be processed 2. Accordingly, for example, pure ion implantation is performed on the workpiece 2 or surface treatment is performed by combining ion implantation with film formation or sputtering under desired conditions. The surface treatment can be performed with finer control.
[0096]
As described above, in this embodiment, when ion implantation is performed by the plasma ion implantation method, a pulse voltage including a positive pulse voltage and a negative pulse voltage is applied to the workpiece 2. Even if the processed material 2 is an insulator, there is no possibility that a charge accumulates inside and a so-called charge-up state occurs. Further, since the plasma ion implantation method is used, unlike the ion beam implantation method, it is possible to implant ions uniformly even if the workpiece 2 has a three-dimensional structure. Therefore, various characteristics such as hardness, elasto-plastic characteristics, electrical conductivity, lubricity, durability, moisture resistance, corrosion resistance, wettability, and gas permeability of the surface of the insulator can be modified. Therefore, many parts conventionally made of a conductor can be made of an inexpensive material such as plastic.
[0097]
[Second Embodiment]
The second embodiment of the present invention relates to a surface treatment method for an object to be processed made of an insulating material having optical transparency and a surface treatment object obtained thereby. Here, a case where the object to be processed is an optical disk substrate will be described. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted here.
[0098]
FIG. 13 is a flowchart showing the surface treatment method of the present embodiment. In the present embodiment, first, a transparent substrate made of, for example, polycarbonate or amorphous polyolefin is prepared, and this transparent substrate is subjected to ultrasonic cleaning using, for example, alcohol (step S1 in FIG. 13).
[0099]
Next, a protective film is formed on the cleaned transparent substrate (step S2). Specifically, first, a thermosetting silicone (for example, Toshiba Tosgard 510) is applied by, for example, a spin coating method (step S2-1). Subsequently, for example, after drying the silicone in a drying cabinet whose humidity is controlled to 40% or less (step S2-2), the silicone is cured by heating at 80 ° C. for 3 hours, for example (step S2-). 3) A protective film formed by curing silicone is formed.
Thus, the to-be-processed object 2 in which the protective film was formed on the transparent substrate is produced.
[0100]
Here, instead of the thermosetting silicone, ultraviolet curable silicone (for example, TUV6020 manufactured by Toshiba) may be used. In that case, for example, using a high-pressure mercury lamp, the silicone is cured by irradiation with ultraviolet rays for 10 minutes under the conditions of an irradiation distance of 10 cm and an output of 80 W / cm. In addition to the method of applying and curing silicone, as shown in FIG. 14, a protective film is formed by a CVD (Chemical Vapor Deposition) method using a liquid or gaseous silicone raw material as a precursor (precursor). (Step S2a in FIG. 14).
[0101]
Next, the surface treatment of the workpiece 2 is performed as follows using the surface treatment apparatus 1 as shown in FIG. 1 (step 3). That is, first, for example, the workpiece 2 is attached to a holder 5 that is cooled with cooling water supplied through a cooling water introduction pipe, and the inside of the vacuum vessel 3 is evacuated by a cryopump 4 to be in a high vacuum state. To do. Subsequently, for example, methane gas (CH_Four ) Or the like is used as an ion source, carbon ions are generated from the Kaufman type ion generation source 10, and the generated ions are introduced into the vacuum vessel 3. As a result, plasma containing ions to be injected into the workpiece 2 is generated inside the vacuum vessel 3. At this time, the degree of vacuum inside the vacuum vessel is, for example, 10^-2-10^-6Pa. Here, it is also useful to generate nitrogen ions and oxygen ions in addition to carbon ions. When generating nitrogen ions, for example, N₂ (Nitrogen) or NH_Three In the case of using (ammonia) and generating oxygen ions, for example, the ion source is O₂ (Oxygen) and H₂ O is used. Instead of the Kaufman type ion generation source 10, an ion generation apparatus 6 including a cathodic arc source can be used as the ion generation source 10.
[0102]
After making the inside of the vacuum vessel 3 a plasma atmosphere containing implanted ions, for example, a pulsed bias voltage is applied to the workpiece 2 for 1 to 20 minutes by a pulse power supply. As a result, ions such as carbon ions, nitrogen ions or oxygen ions are drawn into the object to be processed 2, and ions are implanted into the object to be processed 2. Also in this embodiment, it is preferable to apply a pulse voltage including a positive pulse voltage and a negative pulse voltage from the pulse power supply 8 as in the first embodiment. The voltage is applied, for example, under the conditions of a pulse width of about 5 μs, a positive pulse voltage of about 10 kV, a negative pulse voltage of about −10 kV, and a frequency of 1 to 100 kHz.
[0103]
On the surface of the surface treatment product (treatment object 2) obtained in this way, the chemical structure changes due to the implantation of ions. As a result, the yield stress (yield point) is higher than that without ions implanted, the hardness is high, and the wear resistance is excellent. In addition, the adhesion between the transparent substrate and the protective film is increased.
[0104]
Furthermore, moisture permeability and oxygen permeability are very small, and it is possible to prevent absorption of water vapor and oxygen in the atmosphere. Therefore, conventionally, in a plastic disk substrate, there has been a problem that the disk substrate absorbs water vapor and oxygen in the atmosphere, and the disk substrate is deformed due to the influence, which can be solved. .
[0105]
On the other hand, this surface-treated product has optical characteristics equivalent to those in which ions are not implanted despite the change in chemical structure. For example, in the wavelength region of 380 to 900 nm, the light transmittance is approximately equal to the light transmittance of the ions not implanted.
[0106]
As described above, according to the surface treatment method according to the present embodiment, by implanting ions into the object 2 having optical transparency (here, the optical disk substrate), the hardness and wear resistance of the object surface. In addition, the adhesion can be improved as compared with those in which ions are not implanted. On the other hand, the optical properties of the obtained surface-treated product are kept equal to those obtained without ion implantation. Therefore, even when the thickness of the disk substrate is reduced, it is difficult to be damaged, and the life of the optical disk can be extended.
[0107]
In the second embodiment, the case where the object to be processed 2 is an optical disk substrate in which a protective film is formed on a transparent substrate has been described. However, a recording having light transmittance on a transparent substrate is described. An optical disk provided with a layer or an optical disk provided with a protective film on the recording layer can also be used as the object to be processed. When an optical disc is used as an object to be processed, even when foreign matter such as dust adheres to the surface of the optical disc, the optical disc is less likely to be damaged, and the life of the optical disc can be extended. The occurrence of this error can be avoided, and the reliability of the optical disk can be improved. Further, the present invention can be applied in the same manner when a surface treatment is performed on an object to be processed mainly composed of silicon oxide such as glass.
[0108]
[Third Embodiment]
The third embodiment of the present invention relates to an objective lens as a surface treatment product and a surface treatment method thereof. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted here.
[0109]
FIG. 15 illustrates a schematic configuration of an optical pickup using an objective lens as a surface treatment product according to the present embodiment. This optical pickup is, for example, for guiding an optical signal emitted from a laser diode (not shown) and reflected by the mirror 53 to the recording / reproducing surface of the optical disc 40, and is an objective lens made of an insulating material having optical transparency. 50. The objective lens 50 includes, for example, a transparent substrate 51 made of an acrylic resin and a surface protective layer 52 formed on the transparent substrate 51.
[0110]
The surface protective layer 52 is formed, for example, by applying a surface treatment to the transparent substrate 51 using the surface treatment apparatus 1 as shown in FIG. Specifically, for example, a cathodic arc source is used as the ion generation source 10, and desired ions such as carbon ions, oxygen ions, or nitrogen ions are generated from the ion generation source 10, and the generated ions are in a high vacuum state. After being introduced into the vacuum vessel 3, it is formed by applying a pulse voltage to the transparent substrate 51 attached to the holder 5.
[0111]
Similar to the protective film of the second embodiment, the surface protective layer 52 is different in chemical structure from that in which ions are not implanted (that is, in which ions are not implanted into the transparent substrate 51). Yes. Therefore, the yield stress (yield point) is larger than that in which ions are not implanted, the hardness is high, and the wear resistance is excellent. On the other hand, the surface protective layer 52 has optical characteristics equivalent to those in which ions are not implanted.
[0112]
As described above, according to the objective lens and the surface treatment method thereof according to the present embodiment, the surface protective layer 52 is formed by implanting ions into the surface of the transparent substrate 51, so that the ions are not implanted. In addition, the hardness and wear resistance of the objective lens surface can be improved. Therefore, the objective lens surface can be prevented from being damaged by the collision between the objective lens 50 and the optical disk 40, and an optical pickup having excellent durability can be obtained.
[0113]
【Example】
Further, specific embodiments of the present invention will be described in detail. In each of the following examples, the surface treatment was performed using the surface treatment apparatus 1 shown in FIG.
[0114]
[Example 1]
In this embodiment, the workpiece 2 is a plastic substrate in which amorphous polyolefin is formed into a disk shape. Further, the ion species to be injected into the workpiece 2 was carbon, and a filtered cathodic arc source manufactured by Commonwealth Scientific Corp. was used as the ion generation source 10.
[0115]
First, the plastic substrate to be subjected to the surface treatment is attached to the holder 5 disposed inside the vacuum vessel 3, and the holder 5 is provided so that the temperature of the plastic substrate does not rise too much when ion implantation is performed. The cooling water was allowed to flow through the cooling water introduction pipe incorporated in the pipe. And after attaching the plastic substrate used as the object of surface treatment to the holder 5, the inside of the vacuum vessel 3 was exhausted with the cryopump 4, and it was set as the high vacuum state. The degree of vacuum inside the vacuum container 3 at this time, that is, the degree of vacuum before introducing ions into the inside of the vacuum container 3 (background vacuum degree) is about 1.33 × 10.^-FivePa (10^-7Torr).
[0116]
Next, carbon ions were generated by the ion generator 6, and the carbon ions were introduced into the vacuum vessel 3. Here, the ion current due to the carbon ion flow was set to about 10 A, and the energy of the carbon ions was set to about 25 eV. Then, carbon ions were introduced into the vacuum vessel 3 in this way to generate plasma containing carbon ions. The degree of vacuum inside the vacuum vessel 3 at this time, that is, the degree of vacuum when performing ion implantation is about 1.33 × 10.^-3Pa (10^-FiveTorr).
[0117]
Then, in a state where the plastic substrate is arranged in the plasma containing carbon ions, a pulse voltage is generated by the pulse power source 8 and the pulse voltage is applied to the plastic substrate as a bias voltage. Thereby, carbon ions were drawn into the plastic substrate, and ion implantation into the plastic substrate was performed.
[0118]
In addition, when performing ion implantation in this way, it was observed that a plasma sheath was generated pale on the surface of the plastic substrate which is the workpiece 2.
[0119]
In this example, the waveform of the pulse voltage applied to the plastic substrate was changed and the comparison was made. Specifically, as a first example, first, as shown in FIG. 16, a pulse voltage in which positive and negative pulses alternately appear was applied to a plastic substrate. Here, the positive and negative pulse peak values of the pulse voltage were ± 10 kV, the width of each positive and negative pulse was 5 μsec, and the pulse interval was 0.1 msec (10 kHz). Further, as a second example, as shown in FIG. 17, a pulse voltage consisting of only a negative pulse was applied to the plastic substrate. Here, the negative pulse peak value of the pulse voltage was −10 kV, the pulse width was 5 μsec, and the pulse interval was 0.1 msec (10 kHz).
[0120]
And about the plastic substrate which ion-implanted on these two conditions, those surface hardness was measured. Here, the surface hardness was measured by an indentation hardness test using an NEC thin film hardness tester “MHA-400”.
[0121]
FIG. 18 shows the measurement results when ion implantation is performed by applying the pulsed voltage shown in FIG. 16, and the measurement results when ion implantation is performed by applying the pulsed voltage shown in FIG. It shows in FIG. 18 and 19, the horizontal axis indicates the indentation depth (unit: nm) of the indentation hardness test indenter, and the vertical axis indicates the magnitude of the indentation load (unit: indentation) applied to the indentation hardness test indenter. μN).
[0122]
As can be seen from FIG. 18 and FIG. 19, pulses in which positive and negative pulses appear alternately as compared with the case where ion implantation is performed by applying a pulse voltage consisting of only negative pulses to the plastic substrate (in the case of FIG. 19). When the ion voltage is applied to the plastic substrate and the ion implantation is performed (in the case of FIG. 18), the amount of displacement when the load is applied is small, and the surface hardness is improved.
[0123]
That is, the surface modification effect of the plastic substrate is greatly obtained when ion implantation is performed by applying a pulse voltage in which positive and negative pulses appear alternately to the plastic substrate. This is because when a pulse voltage consisting only of negative pulses is applied to a plastic substrate and ion implantation is performed, ion implantation is not performed very much due to charge-up, whereas positive and negative pulses alternate. This is because the ion implantation is stably performed without entering the charge-up state when the pulse-like voltage appearing on is applied to the plastic substrate and the ion implantation is performed.
[0124]
[Example 2]
In this example, oil-based ink was applied onto a plastic substrate obtained by forming amorphous polyolefin into a disk shape, and this was used as the object 2 to be processed. Here, the film thickness of the oil-based ink applied on the plastic substrate was about 10 μm. Similarly to Example 1, the ion species to be injected into the workpiece 2 was carbon, and a filtered cathodic arc source manufactured by Commonwealth Scientific was used as the ion generation source 10.
[0125]
First, the plastic substrate coated with the oil-based ink is attached to the holder 5 disposed inside the vacuum vessel 3, and the holder 5 is kept so that the temperature of the plastic substrate does not rise too much when ion implantation is performed. The cooling water was allowed to flow through the cooling water introduction pipe incorporated in the pipe. Then, after attaching a plastic substrate coated with oil-based ink to the holder 5, the inside of the vacuum vessel 3 was evacuated by the cryopump 4 to be in a high vacuum state. The degree of vacuum inside the vacuum container 3 at this time, that is, the degree of vacuum before introducing ions into the inside of the vacuum container 3 (background vacuum degree) is about 2.79 × 10.^-FivePa (2.1 × 10^-7Torr).
[0126]
Next, carbon ions were generated by the ion generator 6, and the carbon ions were introduced into the vacuum vessel 3. Here, the ion current due to the carbon ion flow was set to about 10 A, and the energy of the carbon ions was set to about 25 eV. Then, carbon ions were introduced into the vacuum vessel 3 in this way to generate plasma containing carbon ions. The degree of vacuum inside the vacuum vessel 3 at this time, that is, the degree of vacuum when performing ion implantation is about 6.65 × 10.^-3Pa (5 × 10^-FiveTorr).
[0127]
Then, in a state where the plastic substrate is arranged in the plasma containing carbon ions, a pulse voltage in which positive and negative pulses alternately appear is generated by the pulse power supply 8, and the pulse voltage is applied to the plastic substrate as a bias voltage. . Thereby, carbon ions were drawn into the plastic substrate, and ion implantation into the plastic substrate was performed. Here, as in the first embodiment, the pulse voltage applied to the plastic substrate was set to a positive / negative pulse peak value of ± 10 kV, a pulse width of 5 μsec, and a pulse interval of 0.1 msec (10 kHz).
[0128]
When ion implantation was performed in this way, it was observed that a plasma sheath was generated pale on the surface of the plastic substrate coated with oil-based ink.
[0129]
And before and after performing the surface treatment by ion implantation with respect to the plastic substrate which apply | coated the oil-based ink as mentioned above, the infrared spectroscopy characteristic was measured by the attenuated total reflection method (ATR: attenuated total reflectance). . For measurement of infrared spectral characteristics, an ATR measuring microscope “FTIRAIM8000” manufactured by Shimadzu Corporation was used. The measurement results of the infrared spectral characteristics are shown in FIG. As shown in FIG. 20, it is understood that the surface treatment by the plasma ion implantation method changes the surface characteristics of the plastic substrate coated with the oil-based ink, and the surface modification is performed by the ion implantation. .
[0130]
In addition, a scratch test was performed using a surface evaluation apparatus manufactured by Haydon before and after the surface treatment by ion implantation was performed on the plastic substrate coated with the oil-based ink. As a result, the surface treatment was scratched with a load of 0.01 g, but the surface treatment was not scratched up to a load of 1 g.
[0131]
In addition, after the surface treatment by ion implantation as described above, the plastic substrate on which the oil-based ink was applied was placed in a solvent such as acetone or ethanol, and was subjected to an ultrasonic cleaner for about 1 hour. It was confirmed that no longer melts. This indicates that the oil-based ink applied on the plastic substrate is modified so as to be insoluble in a solvent such as acetone or ethanol by the surface treatment by ion implantation.
[0132]
In addition, also when the surface treatment is performed on the object 2 formed by applying an oil-based ink on a plastic substrate made of polycarbonate, polymethyl methacrylate, polyethylene terephthalate, acrylic resin, or a silicon substrate or a glass substrate, Similar results are obtained. Similar results can be obtained when an ultraviolet curable resin or a mixture of magnetic powder and binder is applied instead of applying the oil-based ink. Furthermore, silicon oxide (SiO₂ ) Film and silicon nitride (Si_x N_y ) Similar results can be obtained when ions are implanted into these thin films after film formation.
[0133]
[Example 3]
In this embodiment, the rotating drum 30 shown in FIG. 4 is made of plastic, and the rotating drum 30 is used as the workpiece 2.
[0134]
In this example, first, the rotating drum 30 was made of plastic. Then, an RF plasma source was used as the ion generation source 10 and methane gas was introduced at a flow rate of 50 sccm to generate carbon, hydrogen, and hydrocarbon ions from the methane gas. Then, ions were implanted into the surface of the rotating drum 30. In addition, when ion implantation was performed, it was observed that the plasma sheath was generated on the surface of the rotating drum 30 in pale.
[0135]
Next, in order to confirm that the surface hardness of the rotating drum 30 has been improved by performing ion implantation on the plastic rotating drum 30, a plastic test piece made of the same material as the rotating drum 30 is used. The surface hardness before and after ion implantation under the above conditions was measured with a thin film hardness meter “MHA-400” manufactured by NEC. As a result, the surface hardness before ion implantation was 0.5 GPa, whereas the surface hardness after ion implantation was 20 GPa. This is enough hardness to put the rotating drum into practical use. That is, by applying the present invention, it has been confirmed that the problem of wear can be solved and a plastic rotating drum can be put to practical use.
[0136]
Furthermore, except that an organic metal gas containing titanium in addition to methane gas was introduced into the RF plasma source, the rotating drum was manufactured under the above conditions, and this rotating drum was incorporated into the running test apparatus. A running test was conducted over 1000 hours. The running test device is a device that performs a running test by rotating the rotating drum and running the magnetic tape in the same manner as when recording and reproducing the magnetic tape by the helical scan method. The rewinding is automatically repeated, and the magnetic tape is continuously run.
[0137]
As a result of the running test, it was confirmed that the problem of wear of the rotating drum and the problem of sticking the magnetic tape did not occur, and it was possible to ensure a life of 1000 hours or more. From this running test result, by applying surface treatment by applying the present invention, in the plastic rotating drum, the problem of wear and the problem of sticking magnetic tape can be solved, and the plastic rotating It was found that the drum could be put to practical use.
[0138]
[Example 4]
In this embodiment, a plastic disk substrate used for a disk-shaped recording medium such as an optical disk, a magneto-optical disk, or a magnetic disk is used as the object 2 to be surface-treated. That is, here, the insulator to be subjected to the surface treatment is a base material that supports the recording layer of the recording medium. The ion species to be injected into the workpiece 2 was carbon, and the ion generation source 10 was a filtered cathodic arc source manufactured by Commonwealth Scientific.
[0139]
First, the degree of vacuum before introducing ions into the vacuum vessel 3 is about 1.33 × 10 6.^-FivePa (10^-7Except that it was set to Torr), ions were implanted into the surface of the workpiece 2 in the same manner as in Example 2. The degree of vacuum at the time of ion implantation is about 1.33 × 10.^-3Pa (10^-FiveTorr). Further, when ion implantation was performed, it was observed that a plasma sheath was generated pale on the surface of the rotating drum 30.
[0140]
The moisture permeability and oxygen permeability of the disk substrate were measured before and after the surface treatment by ion implantation on the disk substrate.
[0141]
As a result, the moisture permeability is 10 g · m before the surface treatment by ion implantation.^-2・ 24h^-1And oxygen permeability is 1 / 1.33 × 10^-14 cm² / S · Pa (1 × 10^-11 cm^Three ・ Cm / cm² · S · cmHg). On the other hand, after the surface treatment by ion implantation, the moisture permeability is 0.007 g · m.^-2・ 24h^-1And the oxygen permeability is 3 / 1.33 × 10^-17 cm² / S · Pa (3 × 10^-14 cm^Three ・ Cm / cm² ・ S · cmHg). Thus, by performing the surface treatment by ion implantation, the moisture permeability and oxygen permeability of the disk substrate became very small.
[0142]
[Example 5]
In this example, a magnetic disk having a magnetic layer formed on a disk substrate was used as an object 2 to be surface-treated, and ions were implanted into the protective film formed on the magnetic layer. . In other words, here, the insulator to be surface-treated is a recording medium in which a recording layer is formed on a base material. The ion species to be injected into the workpiece 2 was carbon, and the ion generation source 10 was a filtered cathodic arc source manufactured by Commonwealth Scientific.
[0143]
In this example, first, magnetic powder was mixed with a binder and coated on a plastic disk substrate to produce a magnetic disk having a magnetic layer formed on the disk substrate.
[0144]
The magnetic disk is attached to the holder 5 disposed inside the vacuum vessel 3, and cooling water incorporated in the holder 5 is introduced so that the temperature of the magnetic disk does not rise too much when ion implantation is performed. Cooling water was poured into the pipe. And after attaching the magnetic disk used as surface treatment object to the holder 5, the inside of the vacuum vessel 3 was exhausted with the cryopump 4, and it was set as the high vacuum state. The degree of vacuum inside the vacuum container 3 at this time, that is, the degree of vacuum before introducing ions into the inside of the vacuum container 3 (background vacuum degree) is about 1.33 × 10.^-FivePa (10^-7Torr).
[0145]
Next, carbon ions were generated by the ion generator 6, and the carbon ions were introduced into the vacuum vessel 3. Here, the ion current due to the carbon ion flow was set to about 10 A, and the energy of the carbon ions was set to about 25 eV. Then, carbon ions were introduced into the vacuum vessel 3 in this way to generate plasma containing carbon ions. The degree of vacuum inside the vacuum vessel 3 at this time, that is, the degree of vacuum when performing ion implantation is about 1.33 × 10.^-3Pa (10^-FiveTorr).
[0146]
Then, in a state where the magnetic disk is arranged in the plasma containing carbon ions, a pulsed voltage including a positive pulse voltage and a negative pulse voltage is generated by the pulse power supply 8, and the pulsed voltage is used as a bias voltage to generate magnetic pulses. Applied to the disc. As a result, carbon ions were drawn into the magnetic disk, and ions were implanted into the magnetic layer of the magnetic disk.
[0147]
When ion implantation was performed in this way, it was observed that a plasma sheath was generated pale on the surface of the magnetic disk to be surface-treated.
[0148]
As described above, by implanting ions into the magnetic layer of the magnetic disk, the surface hardness of the magnetic layer was increased, and the durability and reliability of the magnetic disk could be improved.
[0149]
[Example 6]
In this embodiment, the protective film that protects the recording layer in the disk-shaped recording medium such as an optical disk, a magneto-optical disk, or a magnetic disk is the object 2 to be surface-treated. That is, a recording medium in which a recording layer is formed on a base material and a protective film is formed on the recording layer is subjected to surface treatment, and ion implantation is performed on the protective film formed on the recording layer. Went. The ion species to be injected into the workpiece 2 was carbon, and the ion generation source 10 was a filtered cathodic arc source manufactured by Commonwealth Scientific.
[0150]
In this embodiment, first, a recording layer is formed on a plastic disk substrate, and then a protective film made of an ultraviolet curable resin is formed on the recording layer by using a spin coater. A disc-shaped recording medium in which a recording layer and a protective film were laminated was produced.
[0151]
In the same manner as in Example 5, ions were implanted into the surface of the disk-shaped recording medium. During the ion implantation, it was observed that the plasma sheath was bluish on the surface of the disk-shaped recording medium.
[0152]
[Example 7]
In this example, a panel substrate for encapsulating liquid crystal in a liquid crystal panel was made of plastic, and the panel substrate was used as the object 2 to be surface-treated. The ion species to be injected into the workpiece 2 was carbon, and the ion generation source 10 was a filtered cathodic arc source manufactured by Commonwealth Scientific.
[0153]
First, ions were implanted into the surface of the panel substrate in the same manner as in Example 5. During the ion implantation, it was observed that the plasma sheath was generated pale on the surface of the panel substrate.
[0154]
And before and after performing the surface treatment by ion implantation with respect to a panel board | substrate as mentioned above, the water vapor transmission rate and oxygen permeability of the said panel board | substrate were measured. As a result, the moisture permeability is 10 g · m before the surface treatment by ion implantation.^-2・ 24h^-1And oxygen permeability is 1 / 1.33 × 10^-14 cm² / S · Pa (1 × 10^-11 cm^Three ・ Cm / cm² S · cmHg), but after the surface treatment by ion implantation, the water vapor transmission rate is 0.007 g · m.^-2・ 24h^-1And the oxygen permeability is 3 / 1.33 × 10^-17 cm² / S · Pa (3 × 10^-14 cm^Three ・ Cm / cm² ・ S · cmHg). Thus, by performing the surface treatment by ion implantation, the moisture permeability and oxygen permeability of the panel substrate become very small, and the moisture permeability and oxygen permeability of the plastic panel substrate can be reduced with the panel substrate made of glass. It was possible to make it comparable.
[0155]
[Example 8]
In this example, printing was performed on a plastic substrate, which was used as the object 2 to be surface-treated. That is, a printed material obtained by printing on an insulator was subjected to surface treatment, and ion implantation was performed on the printed surface. The ion species to be injected into the workpiece 2 was carbon, and the ion generation source 10 was a filtered cathodic arc source manufactured by Commonwealth Scientific.
[0156]
In this example, first, in the same manner as in Example 5, ions were implanted into the surface of the printed plastic substrate. When ion implantation was performed in this way, it was observed that a plasma sheath was generated pale on the surface of the plastic substrate to be surface-treated.
[0157]
Then, a scratch test was performed by using a Haydong Type 22 type surface evaluation device manufactured by Shinto Kagaku before and after performing surface treatment by ion implantation on the printed plastic substrate. As a result, the printed surface was scratched with a load of about 0.01 g before the surface treatment, but after the surface treatment, the load was not scratched up to 1 g.
[0158]
In addition, after the surface treatment by ion implantation as described above, the plastic substrate was put in a solvent such as acetone or ethanol and subjected to an ultrasonic cleaner for about 1 hour. It was. This indicates that the ink printed on the plastic substrate was modified so as to be insoluble in a solvent such as acetone or ethanol by the surface treatment by ion implantation.
[0159]
[Example 9]
In this example, first, a transparent substrate made of polycarbonate was prepared, and this transparent substrate was subjected to ultrasonic cleaning using alcohol for 30 minutes. Next, silicone (Toshiba 510 manufactured by Toshiba) was applied to the cleaned transparent substrate by a spin coating method. Subsequently, after the silicone was dried in a drying cabinet whose humidity was controlled to 40% or less (drying time 30 minutes), the silicone was cured by heating at 80 ° C. for 3 hours using an oven to obtain a transparent substrate. A protective film having a thickness of about 2 μm was formed thereon.
[0160]
Next, the surface treatment of the workpiece 2 was performed using the surface treatment apparatus 1 as follows. That is, first, a transparent substrate was attached to a holder cooled with cooling water supplied through a cooling water introduction pipe, and the inside of the vacuum vessel was evacuated by a cryopump to be in a high vacuum state. Subsequently, carbon ions were generated from the ion generation source using methane gas as an ion source, and the carbon ions were introduced into the vacuum vessel. Thereby, plasma containing carbon ions was generated inside the vacuum vessel. At this time, the degree of vacuum inside the vacuum vessel is 5 × 10.^-3It was about Pa.
[0161]
After making the inside of the vacuum vessel a plasma atmosphere containing carbon ions, a pulsed voltage in which positive and negative pulses alternately appear was applied to the transparent substrate on which the protective film was formed by a pulse power supply for 3 minutes. At this time, the positive and negative pulse peak values of the pulse voltage were ± 10 kV, the width of each positive and negative pulse was 5 μsec, and the pulse interval was 0.1 msec (10 kHz). As a result, carbon ions were drawn into the protective film and implanted.
[0162]
Furthermore, N is applied to the transparent substrate.₂ Or NH_Three The surface treatment of the transparent substrate was performed under the same conditions as above except that nitrogen ions were generated from the ion generation source using as the ion source.
[0163]
As Comparative Example 1 for this example, the surface treatment was performed in the same manner as in this example except that ions were implanted into the transparent substrate without forming a protective film. Further, as Comparative Example 2 with respect to the present example, a protective film made of DLC (Diamond Like Carbon) was formed on quartz glass, and light transmittance described later was measured.
[0164]
Thereafter, in order to investigate the characteristics of the obtained surface treated product, the surface treated product before and after the surface treatment (surface treated product) of this example and the surface treated product of Comparative Example 1 are described in detail below. As described, light transmittance measurements, infrared absorption spectrum measurements and scratch tests were performed.
[0165]
The light transmittance was measured using a spectrophotometer (Lambda19 manufactured by PERKIN ELMER). The obtained results are shown in FIG. In FIG. 21, the vertical axis indicates the light transmittance (unit:%), and the horizontal axis indicates the wavelength of light (unit: nm). Further, data A shows the light transmittance before the surface treatment of this example, data B shows the light transmittance after the surface treatment with carbon ions of this example, and data C shows the surface treatment of Comparative Example 1. The light transmittance of the object is shown, and the data D shows the light transmittance of Comparative Example 2. As can be seen from FIG. 21, there is almost no change in the light transmittance between the sample before and after the surface treatment of this example, and both are 80% or more in the visible light region (wavelength 380 to 900 nm). It had light transmittance. Therefore, it was confirmed that the surface treated product of this example can be applied to an optical disc substrate used in an optical disc apparatus provided with a blue-violet laser.
[0166]
The infrared absorption spectrum was measured by the attenuated total reflection method in the same manner as in Example 2. Here, the measurement depth was set to around 0.5 to 2.5 μm. The obtained result is shown in FIG. In FIG. 22, the vertical axis indicates the infrared absorption spectrum (arbitrary unit), and the horizontal axis indicates the wave number (unit: cm).^-1). Data A shows the spectrum of this example before the surface treatment, data B shows the spectrum of this example after the surface treatment with carbon ions, and data E shows the spectrum after the surface treatment with nitrogen ions of this example. The spectrum of the thing is shown. In data A, data B, and data E, a change was observed in the infrared absorption intensity in the wave number region indicated by the arrow in FIG. For example, before ion implantation (data A), 1100 cm^-1A shoulder (S in FIG. 22) associated with the maximum peak can be seen in the vicinity, but this shoulder disappears by ion implantation. This indicates that the chemical structure changes near the surface of the protective film as a result of ion implantation.
[0167]
The scratch test was performed using a scratch test device (Tribogear (HEIDON-22) manufactured by Shinto Kagaku Co., Ltd.). Specifically, the frictional force is measured when the surface of the sample is scratched at a speed of 10 mm / min with a probe while changing the load from 0 to 0.49 N (0 to 50 g weight). (Continuous load mode). For the probe, alumina (Al₂ O_Three In addition, a normal probe having a tip radius of 0.05 mm and a tip angle of 60 ° was used. The obtained results are shown in FIG. 23, the vertical axis represents the frictional force (unit; N), and the horizontal axis represents the load (unit; N.) Data A represents the frictional force before the surface treatment of this example. The data B shows the frictional force of the surface treated with carbon ions in this example, and the surface before the surface treatment has a yield point of 0.23 N (23 g weight), and the force exceeding this is the load. On the other hand, it was found that the yield point of the surface treatment was 0.33 N (34 g weight), that is, by implanting ions, the hardness of the protective film, It was confirmed that the wear resistance and the adhesion between the protective film and the transparent substrate were improved.
[0168]
From the above results, if ion implantation is performed on the protective film by the surface treatment method of the present embodiment, the obtained surface treatment product has higher hardness and wear resistance than that before the surface treatment. I found it excellent. It was also found that the light transmittance of this surface-treated product was almost the same as that before the surface treatment.
[0169]
[Example 10]
In this example, first, a transparent substrate 51 made of an acrylic resin is prepared, and using the surface treatment apparatus 1, carbon ions are implanted into the surface of the transparent substrate 51 in the same manner as in Example 9 to form the surface protective layer 52. Formed. Thereby, the objective lens 50 was produced.
[0170]
After that, the objective lens 50 obtained was measured with a thin film hardness tester from the surface protective layer 52 side with a Barkovic indenter having a tip radius of 0.5 μm to a pushing distance of 100 nm and further measured to a load of 290 μN. No indentation was found in the protective layer 52, indicating that there was almost no deformation than the strain displacement curve. This indicates that there is no plastic deformation of the protective film 52 due to stress and the yield point is large, suggesting that such a surface treatment is effective.
[0171]
[Fourth Embodiment]
  The fourth embodiment of the present invention is a modification of the surface treatment apparatus used in the first embodiment.As shown in FIG.The inverter circuit is configured using a vacuum tube. When a vacuum tube is used as the inverter circuit, the pulse voltage output from the inverter circuit can be directly applied to the object to be processed without using the pulse transformer as in the first embodiment. In addition, when the vacuum tube method is employed in this way, it becomes possible to measure a current waveform that could not be measured due to resonance in the pulse transformer method. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted here.
[0172]
In the present embodiment, only ions are irradiated into the vacuum chamber 3 from the Kaufman type ion source 10 having a 5 cm grid toward the substrate holder 5 and the substrate 2 having a diameter of 150 mm, for example, at 200 V and 1 mA. The inside of the vacuum chamber 3 is, for example, 10 by a vacuum pump (not shown).^-FourAlthough the vacuum is drawn up to Pa, since the methane gas is decomposed by the filament into carbon and hydrogen ions when the ion source 10 is operated, the degree of vacuum is 10^-2Pa. The substrate holder 5 is insulated from the vacuum chamber 3 by an insulator and cooled by the refrigerant liquid nitrogen. A high voltage pulse is applied to the substrate holder 5 from the pulse power supply circuit 60.
[0173]
The pulse power supply circuit 60 includes high-voltage vacuum tubes 61 and 62 for outputting positive and negative pulse voltages with the coil 63 interposed therebetween. Chargers 66 and 67 are connected to these high voltage vacuum tubes 61 and 62 via controllers 64 and 65, respectively. One charger 66 outputs a positive DC voltage, and the other charger 67 outputs a negative DC voltage. The timing signals are supplied from the timing signal generator 68 to the controllers 64 and 65, thereby performing on / off control of positive and negative DC voltages output from the chargers 66 and 67, and converting them into positive and negative pulse voltages. At the same time, the switching control of the controllers 64 and 65 is performed so that a positive pulse voltage and a negative pulse voltage are alternately output.
[0174]
That is, in this pulse power supply circuit 60, positive and negative DC voltages output from the chargers 66 and 67 are controlled to be turned on / off based on the timing signal supplied from the timing signal generator 68 and converted into a pulse voltage. Then, it is amplified by the high voltage vacuum tubes 61 and 62. Thus, positive and negative pulse voltages are alternately output and applied to the workpiece 2 via the support member 9 and the substrate holder 5. Other operations are the same as those in the first embodiment.
[0175]
25 to 30 show specific examples of voltage waveforms output from the pulse power supply circuit 60, and FIGS. 31 to 36 show current waveforms when the voltage waveforms shown in FIGS. 25 to 30 are applied. The voltage can be measured by a high voltage probe manufactured by Tektronix, and the current can be measured by a CT probe manufactured by Pearson. In FIG. 25, Td1 indicates that the rise time of the negative pulse is 2 μsec. Tn indicates that the pulse width is 10 μsec including rising and falling, Tp indicates that the positive pulse width is 5 μsec, and Tc indicates that the period is 1 msec. As shown in FIG. 31, the current waveform at this time is such that the pulse current is steadily measured by about 0.2A.
[0176]
FIG. 26 shows that the negative pulse fall time Tb is 100 μsec. The current waveform at this time is as shown in FIG. FIG. 27 shows that the fall time Td2 of the positive pulse is 2 μsec as in the case of the negative pulse. The current waveform at this time is as shown in FIG. 28, 29, and 30 are waveforms when the positive and negative polarities are inverted with respect to FIGS. 25, 26, and 27, respectively. The values of the pulse widths Tp and Tn described above are preferably in the range of 1 μsec to 1000 μsec. Further, specific values of the positive and negative voltages in the figure are, for example, + V is 10 KV, and -V is -20 KV. Note that + V is preferably in the range of 0 KV to 200 KV, and -V is preferably in the range of 0 to -200 KV.
[0177]
In the present embodiment, since a vacuum tube is used instead of the transformer as the pulse power supply circuit 60, a high output voltage can be obtained, and the positive and negative pulse widths can be controlled. Therefore, a voltage having an appropriate pulse width can be applied according to the type of the object to be processed, and surface treatment by ion implantation can be performed more appropriately. Other functions and effects are the same as those of the first embodiment.
[0178]
The present invention has been described with reference to some embodiments and examples. However, the present invention is not limited to the above embodiments and examples, and various modifications can be made. For example, in the third embodiment, ions are implanted into the surface of the transparent substrate 51 to form the surface protective layer 52. However, as in the second embodiment, the surface protective layer 52 is formed in advance on the transparent substrate. Ions may be implanted into the formed protective film.
[0179]
In the second embodiment, an optical disk substrate is taken as an example of the object 2 to be processed, and in the third embodiment, an objective lens 50 constituting an optical pickup is taken as an example of the object 2 to be processed. However, the present invention can be widely applied to other objects having optical transparency such as a magneto-optical disk.
[0180]
【The invention's effect】
  As explained in detail above,Of the present inventionSurface treatment equipment orIs a tableAccording to the surface treatment method, ions are implanted into an object to be processed mainly composed of an insulator or silicon oxide by applying a pulse voltage including a positive pulse voltage and a negative pulse voltage in plasma. As a result, when ions are implanted, charges are accumulated inside the object to be processed mainly composed of an insulator or silicon oxide, so that there is no possibility of a so-called charge-up state, and ions are uniformly implanted on the surface. There is an effect that. In particular, it is possible to perform surface treatment by ion implantation even on plastic which is an insulator. That is, according to the surface treatment apparatus or the surface treatment method of the present invention, the plastic is subjected to surface modification by ion implantation, and hardness, elastoplastic properties, electrical conductivity, lubricity, durability, moisture resistance, and corrosion resistance. Various properties such as wettability and gas permeability can be modified. Therefore, many parts conventionally made of metal or glass can be replaced with inexpensive plastics, which is extremely effective in the industry.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of a surface treatment apparatus according to a first embodiment of the present invention.
FIG. 2 is a characteristic diagram showing an implantation profile when ion implantation is performed by the surface treatment method (plasma implantation method) according to the first embodiment of the present invention.
FIG. 3 is a characteristic diagram showing an implantation profile when ion implantation is performed by an ion beam implantation method.
FIG. 4 is a perspective view showing the appearance of a rotating drum that performs surface treatment by the surface treatment method according to the first embodiment of the invention.
FIG. 5 is a diagram illustrating an example of a waveform of a pulse voltage applied when surface treatment is performed by the surface treatment method according to the first embodiment of the present invention.
FIG. 6 is a diagram illustrating another example of a waveform of a pulse voltage applied when surface treatment is performed by the surface treatment method according to the first embodiment of the invention.
FIG. 7 is a diagram illustrating still another example of a waveform of a pulse voltage applied when performing a surface treatment by the surface treatment method according to the first embodiment of the present invention.
FIG. 8 is a diagram illustrating still another example of a waveform of a pulse voltage applied when surface treatment is performed by the surface treatment method according to the first embodiment of the present invention.
FIG. 9 is a diagram showing still another example of a waveform of a pulse voltage applied when surface treatment is performed by the surface treatment method according to the first embodiment of the present invention.
FIG. 10 is a diagram illustrating still another example of a waveform of a pulse voltage applied when surface treatment is performed by the surface treatment method according to the first embodiment of the invention.
FIG. 11 is a diagram illustrating still another example of a waveform of a pulse voltage applied when surface treatment is performed by the surface treatment method according to the first embodiment of the invention.
FIG. 12 is a diagram illustrating still another example of a waveform of a pulse voltage applied when surface treatment is performed by the surface treatment method according to the first embodiment of the invention.
FIG. 13 is a flowchart showing a surface treatment method according to a second embodiment of the invention.
FIG. 14 is a flowchart showing another surface treatment method according to the second embodiment of the invention.
FIG. 15 is a cross-sectional view illustrating a configuration of an optical pickup including an objective lens as a surface-treated product according to a third embodiment of the present invention.
FIG. 16 is a diagram showing a first example of a pulse voltage applied to a plastic substrate in Example 1 of the present invention.
FIG. 17 is a diagram showing a second example of the pulse voltage applied to the plastic substrate in Example 1 of the present invention.
18 is a characteristic diagram showing a result of an indentation hardness test when ion implantation is performed by applying the pulse voltage shown in FIG.
FIG. 19 is a characteristic diagram showing a result of an indentation hardness test when ion implantation is performed by applying the pulse voltage shown in FIG.
FIG. 20 is a characteristic diagram showing measurement results of infrared absorption spectra according to Example 2 of the present invention.
FIG. 21 is a characteristic diagram illustrating a relationship between light transmittance and wavelength according to Example 9 of the present invention.
FIG. 22 is a characteristic diagram showing measurement results of infrared absorption spectra according to Example 9 of the present invention.
FIG. 23 is a characteristic diagram showing a result of a scratch test according to Example 9 of the present invention.
FIG. 24 is a diagram showing a configuration of a surface treatment apparatus according to a fourth embodiment of the present invention.
FIG. 25 is a diagram illustrating an example of a waveform of a pulsed voltage applied in the fourth embodiment of the present invention.
FIG. 26 is a diagram illustrating another example of a waveform of a pulse voltage applied in the fourth embodiment of the present invention.
FIG. 27 is a diagram illustrating still another example of the waveform of the pulse voltage applied in the fourth embodiment of the present invention.
FIG. 28 is a diagram illustrating still another example of a waveform of a pulse voltage applied in the fourth embodiment of the present invention.
FIG. 29 is a diagram illustrating still another example of a waveform of a pulse voltage applied in the fourth embodiment of the present invention.
FIG. 30 is a diagram illustrating still another example of a waveform of a pulse voltage applied in the fourth embodiment of the present invention.
31 is a diagram showing a current waveform when the voltage shown in FIG. 25 is applied. FIG.
32 is a diagram showing a current waveform when the voltage shown in FIG. 26 is applied. FIG.
33 is a diagram showing a current waveform when the voltage shown in FIG. 27 is applied. FIG.
34 is a diagram showing a current waveform when the voltage shown in FIG. 28 is applied. FIG.
35 is a diagram showing a current waveform when the voltage shown in FIG. 29 is applied. FIG.
36 is a diagram showing a current waveform when the voltage shown in FIG. 30 is applied. FIG.
FIG. 37 is a diagram showing a waveform of a pulse bias voltage applied to an object to be processed in a conventional plasma injection method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Surface treatment apparatus, 2 ... To-be-processed object, 3 ... Vacuum container, 4 ... Cryopump, 5 ... Holder, 6 ... Ion generator, 7 ... Shutter, 8 ... Pulse power supply circuit

Claims (16)

A surface treatment apparatus for treating the surface of an insulator by implanting ions into the insulator,
A vacuum vessel;
A holder that supports the insulator in the vacuum vessel and incorporates a cooling water introduction pipe therein, and suppresses the temperature rise of the insulator by circulating the cooling water;
Plasma generating means for generating plasma containing ions to be injected into the insulator in the vacuum vessel;
Voltage application means for applying a pulse voltage to the insulator,
The voltage applying means is connected to a pair of high voltage vacuum tubes for outputting positive and negative pulsed voltages with a coil therebetween, and a pair of high voltage vacuum tubes connected to the high voltage vacuum tubes via a controller, respectively, for outputting positive and negative DC voltages. A timing signal is supplied to the controller, and a positive / negative DC voltage output from the charger is turned on / off to be converted into a positive / negative pulse voltage, and a positive pulse voltage A timing signal generator that performs switching control of the controller so that a negative pulse voltage is alternately output;
A plasma containing ions to be injected into the insulator is generated by the plasma generating means, and a pulse voltage including a positive pulse voltage and a negative pulse voltage is applied to the insulator by the voltage applying means in the plasma. A surface treatment device that implants ions into the insulator.   The surface treatment apparatus according to claim 1, wherein the voltage application unit includes a waveform control unit that controls a waveform of a pulse voltage applied to the insulator. A surface treatment method for treating a surface of an insulator by implanting ions into the insulator,
In a plasma containing ions to be implanted, a voltage application means applies a pulse voltage including a positive pulse voltage and a negative pulse voltage to the insulator, thereby implanting ions into the insulator,
A cooling water introduction pipe is installed inside the holder that supports the insulator, and the temperature rise of the insulator during ion implantation is suppressed by circulating the cooling water , and
The voltage applying means is connected to a pair of high voltage vacuum tubes for outputting positive and negative pulsed voltages with a coil therebetween, and a pair of high voltage vacuum tubes connected to the high voltage vacuum tubes via a controller, respectively, for outputting positive and negative DC voltages. A timing signal is supplied to the controller, and a positive / negative DC voltage output from the charger is turned on / off to be converted into a positive / negative pulse voltage, and a positive pulse voltage A surface treatment method comprising: a timing signal generator that performs switching control of the controller so that negative pulsed voltages are alternately output .   The surface treatment method according to claim 3, wherein a period in which no voltage is applied is provided between voltage pulses when a pulse voltage is applied to the insulator.   The surface treatment method according to claim 3, wherein when a pulse voltage is applied to the insulator, a DC voltage component is superimposed on the pulse voltage.   4. The surface according to claim 3, wherein the waveform of the pulsed voltage applied to the insulator is a waveform obtained by combining a plurality of pulses different in at least one of a pulse peak value, a pulse rise time, a pulse interval, and a pulse width. Processing method.   The at least one of the implantation amount, implantation depth, and implantation profile when ions are implanted into the insulator is controlled by controlling the waveform of the pulse voltage applied to the insulator. Surface treatment method.   The surface treatment method according to claim 3, wherein the insulator to be surface-treated is a rotating drum used for at least one of recording and reproduction of a magnetic tape by a helical scan method.   The surface treatment method according to claim 3, wherein the insulator to be surface-treated is a base material that supports a recording layer of a recording medium.   The surface treatment method according to claim 3, wherein the insulator to be surface-treated is a recording medium having a recording layer formed on a substrate. The insulator to be surface-treated is a recording medium in which a recording layer is formed on a substrate and a protective film is formed on the recording layer,
The surface treatment method according to claim 3, wherein the surface treatment is performed by implanting ions to at least the protective film of the recording medium.   The surface treatment method of Claim 3 whose insulator used as the object of surface treatment is a panel board | substrate for enclosing a liquid crystal in a liquid crystal panel.   The surface treatment method according to claim 3, wherein the insulator to be surface-treated is a printed matter obtained by printing on the insulator.   The surface treatment method of Claim 3 with which the insulator used as the object of surface treatment has a light transmittance.   The surface treatment method according to claim 14, wherein the insulator includes a substrate and a protective film that is provided on the substrate and forms a surface of the insulator. A surface treatment method for treating a surface of an object to be processed by implanting ions into the object to be processed mainly composed of silicon oxide,
In a plasma containing ions to be implanted, a voltage application means applies a pulse voltage including a positive pulse voltage and a negative pulse voltage to the workpiece, thereby implanting ions into the workpiece,
A cooling water introduction pipe is incorporated inside the holder that supports the object to be processed, and the temperature rise of the object to be processed at the time of ion implantation is suppressed by circulating the cooling water , and
The voltage applying means is connected to a pair of high voltage vacuum tubes for outputting positive and negative pulsed voltages with a coil therebetween, and a pair of high voltage vacuum tubes connected to the high voltage vacuum tubes via a controller, respectively, for outputting positive and negative DC voltages. A timing signal is supplied to the controller, and a positive / negative DC voltage output from the charger is turned on / off to be converted into a positive / negative pulse voltage, and a positive pulse voltage A surface treatment method comprising: a timing signal generator that performs switching control of the controller so that negative pulsed voltages are alternately output .

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