JPH0774442B2 - Surface treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is directed to the surface of a substrate by irradiating the substrate with an accelerated ion beam in a vacuum or by using it together with vapor deposition of metal vapor. The present invention relates to a surface treatment apparatus that treats the surface of a substrate by implanting ions or forming a thin film.

[Conventional technology]

FIG. 4 is a schematic diagram showing an example of a conventional surface treatment apparatus. A holder 4 is provided in a vacuum container 2 that is evacuated by a vacuum exhaust device (not shown), and a substrate 6 to be surface-treated is held therein. An ion source 8 for irradiating the substrate 6 with an accelerated metal or non-metal ion beam 10 is attached to the vacuum container 2 at a position facing the substrate 6.

The substrate 6 receives the ion beam 10 from the ion source 8 as described above.
When irradiated with, the ion-implanted layer (coating) is formed on the surface of the substrate 6, and the surface treatment of the substrate 6 is thereby performed.
In that case, the bias of the substrate 6 or the holder 4 may be grounded as in the illustrated example (no bias),
In some cases, a negative DC bias voltage is applied.

[Problems to be solved by the invention]

However, in the above-described apparatus, the surface (coating surface) of the substrate 6 is charged (charged up) to a positive potential by the implanted ions during the surface treatment, which causes a potential difference between the surface to be treated and the holder 4 for the treatment. There is a problem in that a minute discharge occurs on the surface, and as a result, the treated surface is broken and other problems occur. Such a problem also exists in a surface treatment apparatus which forms a thin film on the surface of the substrate 6 by using the irradiation of the substrate 6 with the ion beam 10 and the vapor deposition of metal vapor in combination.

Therefore, the main object of the present invention is to suppress charging on the surface of the substrate.

[Means for solving problems]

In the surface treatment apparatus of the present invention, the substrate on the holder or the holder, from the bias power supply, a positive bias voltage of 1 KV or less and a value smaller than the voltage corresponding to the acceleration energy of the ion beam or the peak value is 1 KV or less. Moreover, an alternating bias voltage having a value smaller than the voltage corresponding to the acceleration energy of the ion beam is applied. In addition to this, electrons are supplied from the electron supply means to the substrate on the holder.

[Action]

By applying a positive bias voltage of the above value to the substrate etc., secondary electrons emitted from the substrate etc. due to ion beam irradiation are pulled back to the substrate etc., thereby suppressing charging on the substrate surface. To be done.

By applying the above-mentioned AC bias voltage having the peak value to the substrate or the like, the secondary electrons as described above are pulled back to the substrate or the like in the positive cycle, thereby suppressing the charging on the substrate surface. Moreover, the AC bias voltage can accurately control the acceleration / deceleration state of the ion beam.

In addition to applying the bias voltage as described above,
By supplying electrons to the substrate from the electron supply means,
The charge of the substrate is further suppressed by both the electrons and the secondary electrons.

〔Example〕

FIG. 1 is a schematic view showing an example of the surface treatment apparatus according to the present invention. The same or equivalent portions as those in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted.

In this example, an evaporation source 14 for depositing metal vapor 16 on the substrate 6 and a film thickness monitor 18 for monitoring the film thickness deposited on the substrate 6 are further provided in the vacuum container 2 as described above. There is. Between the holder 4 and the ground, when processing the substrate 6, a bias voltage as described below is applied to the substrate 6 (when it is conductive) or to the holder 4 (when the substrate 6 is non-conductive). Bias power supply 12 is connected.

In the above-mentioned apparatus, if the ion beam 10 is used to irradiate the substrate 6 alone with the ion source 8, the surface treatment of the substrate 6 by the ion implantation is performed as described above. When the ion source 8 and the evaporation source 14 are used together, the vapor deposition of the metal vapor 16 and the irradiation of the ion beam 10 are simultaneously or alternately performed on the substrate 6 to form a thin film on the surface of the substrate 6. In that case, a mixed layer (mixing layer) of the two is formed near the interface between the substrate b and the thin film due to the pushing (knock-on) action of the implanted ions, so that a thin film having high adhesion can be obtained.

In the above case, the bias voltage supplied from the bias power supply 12 can be the following two types.

One is a positive DC bias voltage. Ion beam 10
The secondary electrons are emitted from the substrate 6 or the holder 4 by the irradiation of. However, when a positive DC bias voltage is applied to the substrate 6 or the like, the secondary electrons are pulled back to the substrate 6 or the like (call-in). Rarely, it neutralizes the positive charge on the treated surface of the substrate 6, thus suppressing charge on the surface of the substrate 6. As a result, it is possible to prevent the treated surface of the substrate 6 from being destroyed by the minute discharge.

Further, by controlling the magnitude of the bias voltage, the energy of the ion beam 10 with which the substrate 6 is irradiated can be accurately and easily controlled (in this case, reduced).
You can also

In the above case, the magnitude of the positive bias voltage is about several tens V to several hundreds V, and at most 1 KV or less. If there is such a degree,
This is because the above-mentioned secondary electron pullback and control of the ion beam 10 can be effectively performed. Further, since the acceleration energy of the ion beam 10 with which the substrate 6 is irradiated may be 1 KeV or less, the value of the positive bias voltage is a voltage corresponding to the acceleration energy of the ion beam 10 (for example, the acceleration energy is X [eV]). In the case of, it is made smaller than X [V]). By doing so, the energy of the ion beam 10 with which the substrate 6 is irradiated is always larger than the energy of pushing back the ion beam 10 by the positive bias voltage, regardless of the acceleration energy of the ion beam 10. The ion beam 10 can be made incident with the energy existing in the substrate 6, and ion irradiation is not hindered.

The other bias voltage supplied from the bias power supply 12 is an AC bias voltage. For example, a square wave as shown in FIG. 2 (A), a sine wave as shown in FIG. 2 (B), or a part of a sine wave as shown in FIG. 2 (C) is extracted. A corrugated one, and a serrated tooth or the like (not shown) can be adopted.

In any of the AC bias voltages, in the positive cycle, secondary electrons emitted from the substrate 6 or the like due to ion beam irradiation are pulled back to the substrate 6 or the like, thereby suppressing charging on the processed surface of the substrate 6. As a result, the processed surface of the substrate 6 is prevented from being destroyed by the minute discharge. Moreover, in the negative cycle, since the ion beam 10 is accelerated by the bias voltage, it is possible to increase the thickness of the ion implantation layer or the mixed layer described above.

In the above case, the peak value of the AC bias voltage is set to 1 KV or less and smaller than the voltage corresponding to the acceleration energy of the ion beam 10 for the same reason as in the case of the positive bias voltage described above. Further, by controlling the peak value, the period, etc., the ion beam can be suppressed while suppressing the charging of the substrate 6.
The acceleration / deceleration states of 10 can be controlled more accurately and easily than when controlled by the ion source 8. For example, the range of implanted ions into the substrate 6 can be accurately controlled, and when the vapor deposition of the metal vapor 16 and the irradiation of the ion beam 10 are used together, the excessive energy of the ion beam 10 is reduced. As a result, the sputtering rate of the deposited film can be reduced. As a result, a good quality processed surface can be obtained.

In particular, if a sine wave as shown in FIG. 2 (B) is used for the AC bias voltage, electron attraction and ion beam 10 acceleration / deceleration can be made smoother and smoother than in the case of FIG. 2 (A). There is an advantage that it can be done.

Further, if the AC bias voltage as shown in FIG. 2 (C) is used, the ion beam 10 is generated in the same manner as in FIG. 2 (B).
In addition to the advantage that the acceleration and deceleration can be smoothly performed, there is an advantage that the processing state of the surface of the substrate 6 can be variously controlled according to the processing purpose and the like. This is the deceleration bias state (period T ₁ ) and the acceleration bias state (period T ₁ ) of the ion beam 10.
This is because, in addition to T ₂ ), a non-biased state (period T ₃ ) can be obtained, and the periods T _{1 to} T ₃ can be arbitrarily set by known means.

FIG. 3 is a schematic diagram showing another example of the surface treatment apparatus according to the present invention. The difference from the apparatus shown in FIG. 1 will be mainly described. Here, a heater 20 is provided near the front side of the substrate 6 as an example of an electron supply means, and this is heated by a heating power source 22 and then heated. The thermoelectrons 24 are generated and supplied to the substrate 6 on the holder 4. In this case, as in the case of FIG. 1, the bias voltage applied from the bias power source 12 to the substrate 6 or the like may be either a positive DC bias voltage or the AC bias voltage described above.

In the above device, the thermoelectrons 24 from the heater 20 are the same as in the case of the secondary electrons due to the ion beam irradiation described above,
When the substrate 6 or the like is negatively biased, it is drawn into the substrate 6 or the like. The positive charges on the substrate 6 are neutralized by both the thermal electrons 24 and the secondary electrons described above, so that the substrate 6
It is possible to further suppress the charging of the surface of the.

Although FIGS. 1 and 3 each show an example in which the evaporation source 14 is provided, the above-described bias power supply 12, heater 20 and the like are used by the surface treatment apparatus which does not include the evaporation source 14. Needless to say, the following operational effects can be obtained.

〔The invention's effect〕

As described above, according to the present invention, by applying the positive bias voltage having the above value to the substrate or the like, the charge on the treated surface of the substrate is suppressed, and the destruction of the treated surface due to the minute discharge is prevented. To be done.

Further, by applying an AC bias voltage of the above-mentioned peak value to the substrate, etc., the charge on the treated surface of the substrate is suppressed, the destruction of the treated surface due to minute discharge is prevented, and the acceleration of the ion beam is accelerated. -Because the deceleration state can be controlled with high precision, a high quality processing surface can be obtained.

Further, by supplying electrons from the electron supply means to the substrate in addition to applying the bias voltage as described above,
The charging of the substrate is further suppressed.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of the surface treatment apparatus according to the present invention. FIG. 2 is a diagram showing an example of the waveform of the AC bias voltage. FIG. 3 is a schematic diagram showing another example of the surface treatment apparatus according to the present invention. FIG. 4 is a schematic diagram showing an example of a conventional surface treatment apparatus. 2 ... Vacuum container, 4 ... Holder, 6 ... Substrate, 8 ... Ion source, 10 ... Ion beam, 12 ... Bias power supply, 14
…… Evaporation source, 16 …… Metal vapor, 20 …… Heater.

Claims (4)

[Claims] 1. A vacuum container, a holder provided in the vacuum container for holding a substrate to be processed, an ion source for irradiating a substrate on the holder with an accelerated ion beam, and a substrate or holder on the holder. And a bias power supply for applying a positive bias voltage of 1 KV or less and a value smaller than the voltage corresponding to the acceleration energy of the ion beam. 2. A vacuum container, a holder provided in the vacuum container for holding a substrate to be processed, an ion source for irradiating a substrate on the holder with an accelerated ion beam, and a substrate or holder on the holder. And a bias power supply for applying an alternating bias voltage having a peak value of 1 KV or less and a value smaller than a voltage corresponding to the acceleration energy of the ion beam. 3. A vacuum vessel, a holder provided in the vacuum vessel for holding a substrate to be processed, an ion source for irradiating a substrate on the holder with an accelerated ion beam, and a substrate or holder on the holder. In addition, a bias power supply for applying a positive bias voltage of 1 KV or less and a value smaller than the voltage corresponding to the acceleration energy of the ion beam, and an electron supply means for supplying electrons to the substrate on the holder are characterized by And surface treatment equipment. 4. A vacuum container, a holder provided in the vacuum container for holding a substrate to be processed, an ion source for irradiating a substrate on the holder with an accelerated ion beam, and a substrate or holder on the holder. In addition, a crest value is a bias power supply for applying an alternating bias voltage having a peak value of 1 KV or less and a value smaller than the voltage corresponding to the acceleration energy of the ion beam, and an electron supply means for supplying electrons to the substrate on the holder. A surface treatment device comprising: