JP2011124215A - Ion beam generator, and cleaning method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique which can remove an adhesion film adhered to a third electrode without damaging the same in an ion beam generator having an extraction electrode composed of three porous-plate electrodes. <P>SOLUTION: In the ion beam generator, a first electrode 7a is set at a positive potential, a second electrode 7b is set at a negative potential, and a third electrode 7c is set at a grounding potential. When a current value flowing in the third electrode 7c measured with an ammeter 9 exceeds the set value during the measurement, an absolute value of voltage applied to the second electrode 7b is increased by a feedback control section 10. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ion beam generator used in an ion beam processing apparatus that performs ion beam etching, ion milling, and the like, and a cleaning method thereof.

  An ion beam processing apparatus that processes a substrate using an ion beam, such as an ion beam etching apparatus or an ion milling apparatus, includes an ion beam generation apparatus that generates an ion beam by extracting positive ions from plasma generated in a discharge chamber. Yes. In such an ion beam generator, in order to extract positive ions from plasma, an extraction electrode composed of three porous plate electrodes is disposed at one end of the discharge chamber. The extraction electrodes are arranged at desired intervals, respectively, and are referred to as a first electrode (screen grid), a second electrode (accelerator grid), and a third electrode (dexel grid) from the plasma chamber side. Patent Document 1 discloses an ion beam generator provided with an extraction electrode composed of such three perforated plate electrodes.

  The ion beam is generated by applying a voltage to each electrode and accelerating positive ions in the plasma by an electrostatic field between the electrodes. Therefore, the first electrode is set to a positive potential, the second electrode is set to a negative potential, the third potential is set to a ground potential, and the applied voltage is adjusted so that the characteristics of the ion beam are suitable. In addition, the electrode shape and the like (plate thickness, hole diameter, hole pitch, and electrode interval) are designed so that the characteristics of the ion beam are suitable under desired conditions. The characteristic of the ion beam referred to here is the divergence angle of the ion beam extracted from the plasma (the straightness of the extracted beam) and the deflection angle of the extracted ion beam with respect to the center line of the electrode hole. To tell.

  The extracted ion beam is applied to the substrate to be processed, and the substrate surface is etched. At that time, the divergence angle of the ion beam is important, and the divergence angle is generally required to be as small as 4 ° or less. When the divergence angle is large, problems such as poor etching uniformity and a structure such as a photoresist on the substrate surface cause the substrate surface shape after etching to be different from the desired shape.

  Further, it is known that the electrode material adheres to the second electrode side of the first electrode and the third electrode by sputtering the second electrode. This is because the neutral gas floating between the electrodes is ionized by a charge exchange reaction with the extracted ions, and the unaccelerated low-speed ions are accelerated by the electric field of the second electrode to sputter the second electrode. It is a phenomenon caused by If extraction of the ion beam is continued for a long time, the attached film attached to the first electrode and the third electrode becomes thick, and film peeling occurs, which may cause a short circuit between the electrodes, thereby making it impossible to extract ions.

  In order to solve such a problem caused by the adhesion film, the adhesion film adhered to the third electrode by adjusting the potential of the second electrode to increase the divergence angle of the ion beam and irradiate the third electrode with the ion beam. A method of removing (cleaning) is taken.

Special table 2001-502468 gazette

  However, if the ion beam is excessively incident on the third electrode, the third electrode may be consumed and thermally deformed by sputtering, which may cause variation in etching rate and distribution.

  An object of the present invention is to provide a technique for removing an adhesion film adhering to a third electrode without damaging the third electrode in an ion beam generator having an extraction electrode composed of three porous plate electrodes. It is in.

The first of the present invention is a plasma generation source,
A first electrode, a second electrode, and a third electrode, which are arranged in order from the plasma generation source side, each of which is a perforated plate electrode, and an extraction electrode for extracting ions generated in the plasma generation source;
Control means for independently controlling the potentials of the first and second electrodes;
Current measuring means for measuring a current flowing through the third electrode;
A feedback control unit that feedback-controls the potential of the second electrode based on a measurement value by the current measurement unit;
The third electrode is at ground potential;
The control means controls the first electrode to a positive potential, the second electrode to a negative potential, causes an ion beam to enter the third electrode, and performs cleaning of the third electrode. Because
The feedback control unit controls to increase the absolute value of the voltage of the second electrode when the current value of the third electrode measured by the current measuring unit exceeds a threshold value.

The second of the present invention is a plasma generation source,
A first electrode, a second electrode, and a third electrode, which are arranged in order from the plasma generation source side, each of which is a perforated plate electrode, and an extraction electrode for extracting ions generated in the plasma generation source;
Control means for independently controlling the potentials of the first and second electrodes;
Current measuring means for measuring a current flowing through the third electrode;
A feedback control unit that feedback-controls the potential of the second electrode based on a measurement value by the current measurement unit;
The third electrode is at ground potential;
The control means controls the first electrode to a positive potential, the second electrode to a negative potential, causes an ion beam to enter the third electrode, and performs cleaning of the third electrode. Cleaning method,
The feedback control unit controls to increase the absolute value of the voltage of the second electrode when the current value of the third electrode measured by the current measuring unit exceeds a threshold value.

  In the present invention, the amount of beam incident on the third electrode can be quantified by performing cleaning while constantly monitoring the current flowing through the third electrode, and the consumption of the third electrode and thermal deformation due to excessive beam incidence during cleaning. Can be prevented. Further, by constantly monitoring the current flowing through the third electrode, the divergence angle of the ion beam can be estimated, and the measurement of the divergence angle that has been experimentally obtained conventionally can be simplified.

It is the schematic which shows the whole structure of the ion beam generator of this invention. It is the schematic explaining the detail of the extraction electrode in one Embodiment of the ion beam generator of this invention. It is the schematic explaining the principle of operation of an ion beam generator. It is the schematic explaining the principle which an adhesion film deposits on the 1st electrode and the 3rd electrode. It is the schematic explaining the principle of the cleaning of the 3rd electrode. It is a flowchart explaining the procedure of feedback control in the ion beam generator of this invention. In the cleaning method of this invention, it is a figure which shows the fluctuation | variation of the electric current of the 3rd electrode by the voltage of a 2nd electrode. It is the schematic explaining the detail of the extraction electrode in the reference embodiment of an ion beam generator. FIG. 9 is a flowchart illustrating a procedure for automatically stopping the operation of the apparatus by an alarm display in the ion beam generator of FIG. 8. FIG. 9 is a flowchart for explaining a procedure for manually stopping the operation of the apparatus by an alarm display in the ion beam generator of FIG. 8. It is a cross-sectional schematic diagram which shows the patterning process of the TMR stack | stuck of the sensor for magnetic read heads using an ion beam. It is the schematic which shows the hard bias film | membrane film-forming apparatus using an ion beam processing apparatus.

(Embodiment)
With reference to FIG. 1, the whole structure of the ion beam generator of this invention is demonstrated. The ion beam generator 1 includes a metal discharge chamber 5 for confining plasma, a cusp magnet (permanent magnet) 6 for preventing plasma loss on a wall surface, and an RF coil 3 (plasma) for generating inductively coupled plasma (ICP). Source). Furthermore, a dielectric window 4 for introducing a high-frequency electromagnetic field into the vacuum, an electromagnet 2 for controlling the distribution of the generated plasma, and an extraction electrode 7 for extracting ions in the plasma are provided. Although not shown, an electron source (neutralizer) is provided for neutralizing a space potential generated by an ion beam (positive potential ions) extracted from the plasma generation source.

  When an inert gas (argon, xenon, krypton, etc.) is introduced into the discharge chamber 5 from a gas introduction means (not shown) and high frequency power is applied to the RF coil 3, plasma is generated in the discharge chamber 5. Ions are extracted from the plasma by the extraction electrode 7 to which a predetermined voltage is applied, and the target member (substrate) is irradiated as an ion beam. The extraction electrode 7 includes a first electrode 7a, a second electrode 7b, and a third electrode 7c in order from the discharge chamber 5 side. The first electrode 7a, the second electrode 7b, and the third electrode 7c are perforated plate electrodes having a grid structure having a plurality of holes. From the viewpoint of extending the life and durability, molybdenum or carbon having a low sputtering rate is used as the constituent member (grid material).

  The ion beam processing apparatus includes an ion beam generating apparatus 1 according to the present invention and a vacuum chamber (not shown) on the third electrode 7c side of the apparatus, and an ion beam process such as ion etching is performed in the vacuum chamber. A substrate holder for mounting the processing substrate is provided.

  FIG. 2 is a schematic diagram for explaining a detailed configuration of the extraction electrode 7 at the time of cleaning the third electrode 7c. As shown in FIG. 2, the first electrode 7a is connected to the first power source 11 and maintained at a positive potential, the second electrode 7b is connected to the second power source 12 and maintained at a negative potential, and the third electrode 7c. Is connected to ground via a low-pass filter 8 and an ammeter 9. In this way, the potentials of the first to third electrodes 7a to 7c are controlled independently. The current flowing from the third electrode 7c toward the ground is measured by an ammeter 9 as current measuring means and transmitted to the feedback control unit 10. The feedback control unit 10 uses the second power supply based on the current value. 12 can be controlled.

  In this example, the first power source 11 is set to a positive potential (for example, 100 to 1000V) for the first electrode 7a, and the second power source 12 is set to a negative potential (for example, −1000 to −3000V) for the second electrode 7b. Thus, the third electrode 7c is maintained at the ground potential.

  The operation principle of the ion beam generator 1 will be described with reference to FIG. As shown in FIG. 3, when plasma is generated in the discharge chamber 5 and a positive voltage is applied to the first electrode 7a and a negative voltage is applied to the second electrode 7b, the plasma is generated by the potential difference between the first electrode 7a and the second electrode 7b. Only the ions 23 inside are extracted by electrostatic acceleration. Since the ions 23 extracted from the plasma are decelerated on the contrary by the potential difference between the second electrode 7a and the third electrode 7c, the ions 23 passing through the third electrode 7c have energy corresponding to the potential of the first electrode 7a. It is ejected as an ion beam 24. The ion beam 24 extracted from the third electrode 7c is deflected by an electrostatic field (not shown) due to the voltage of each electrode. The deflection angle of the ion beam 24 extracted from the third electrode 7c with respect to the central axis of the hole is referred to as a beam divergence angle θ.

  With reference to FIG. 4, the principle of depositing an adhesion film on the electrode will be described. On the side of the first electrode 7a and the third electrode 7c facing the second electrode 7b, the electrode material of the second electrode 7b is sputtered and adheres as adhesion films 21a and 21b. Specifically, some of the neutral gases introduced into the discharge chamber 5 are ionized by charge exchange reaction with the ions 23 drawn between the electrodes to become low-speed ions (+ L). The charge exchange reaction is a phenomenon in which only charges are exchanged while preserving the momentum of each particle. The ion beam 24 is referred to as fast ions (+ H) for distinction, and the fast ions are accelerated and deflected by an electrostatic field (not shown) due to the voltage of each electrode, and do not collide with the electrode, and the third beam 7c. Be injected. On the other hand, unaccelerated low-speed ions are accelerated by the negative potential of the second electrode 7b, collide with the second electrode 7b, and cause sputtering. The material of the sputtered second electrode 7b becomes particles and adheres to the first electrode 7a and the third electrode 7c, thereby forming adhesion films 21a and 21b. “N” in FIG. 4 indicates a neutral gas.

  If the adhesion film 21b adhering to the third electrode 7c is deposited in a large amount, it may be short-circuited with the second electrode 7b. Therefore, it is necessary to periodically remove (clean) the film attached to the third electrode 7c.

  The principle of cleaning the third electrode 7c will be described with reference to FIG. The extracted ion beam is accelerated and deflected by an electrostatic field generated by the voltage of each electrode, and has a predetermined divergence angle θ. The electrostatic field between the first electrode 7a and the second electrode 7b converges ions that are extracted by the shape of the electric field. Conversely, the electrostatic field between the second electrode 7b and the third electrode 7c causes ions to diverge. Since the voltage of the first electrode 7a is usually used to determine the energy of the extracted ion beam, the voltage is set to a predetermined value. The voltage of the second electrode 7b is adjusted so that the beam divergence angle is minimized by the predetermined voltage of the first electrode 7a. In addition, the divergence angle can be increased by intentionally setting the voltage of the second electrode 7b lower than the voltage value at which the divergence angle of the ion beam is minimized, and the ion beam can be incident on the third electrode 7c.

  Thus, when the ion beam is directly incident on the third electrode 7c by setting the voltage of the second electrode 7b lower than usual, the adhesion film 21b on the surface of the third electrode 7c is sputtered, and the adhesion film 21b can be removed (cleaned).

  However, if the voltage of the second electrode 7b is made smaller than necessary, the ion beam is excessively incident on the third electrode 7c, causing the third electrode 7c to be consumed and thermally deformed by sputtering. The same applies to the cleaning time, and if the cleaning is performed for a longer time than necessary, the third electrode 7c is consumed, so it is important to manage both the amount of ion beam used for cleaning and the cleaning time.

  In the first embodiment of the present invention, in the cleaning process, the value of the current flowing through the third electrode 7c is measured, and the second electrode 7b is feedback-controlled based on the measured value.

  A specific processing procedure will be described with reference to FIG. In step S1, as described above, the voltage of the second electrode 7b is set lower than the voltage value at which the divergence angle of the ion beam is minimized, thereby increasing the divergence angle and irradiating the third electrode 7c with the ion beam. The cleaning process is started.

  In step S <b> 2, the ammeter 9 shown in FIG. 2 measures the current flowing through the third electrode 7 c and transmits the measured value to the constant feedback control unit 10.

  When measuring the current flowing through the third electrode 7c, it is necessary to stop the operation of the neutralizer. This is because during the operation of the neutralizer, electrons supplied from the neutralizer flow into the third electrode 7c, making it difficult to measure current due to positive ions incident on the third electrode 7c for cleaning. .

  In step S3, the feedback control unit 10 determines whether or not the current value transmitted from the ammeter 9 is equal to a set value (threshold value). When the current value is equal to the set value (Yes), the process proceeds to the timer process in step S5. On the other hand, when the current value is not equal to the set value (No), the process proceeds to the second electrode voltage control process in step S4.

  With respect to the second electrode voltage control process in step S4, the current value measured by the ammeter 9 is divided into a case where the current value is larger than a set value and a case where the current value is smaller than the set value. Explained.

  FIG. 7 shows the current value of the second electrode 7b and the current value of the third electrode 7c when the voltage of the first electrode 7a is set to +100 V, the current is set to 325 mA, and the voltage of the second electrode 7b is changed. Showed changes. In the second electrode voltage (−2400 V) which is a beam condition (Normal) used normally, the current values (60 mA) of the second electrode 7 b and the third electrode 7 c are close to the minimum value as shown in FIG. From this, it can be determined that the incidence of the ion beam on the third electrode 7c is small, that is, the divergence angle of the ion beam is small. In FIG. 7, the second electrode voltage is shown as an absolute value.

  When the voltage of the second electrode 7b is lowered from the normal beam condition, the current value of the third electrode 7c increases as shown in FIG. 7, and from this, the incidence of the ion beam on the third electrode 7c increases. That is, it can be seen that the divergence angle of the ion beam is increased. As a condition (Defocus) used for proper cleaning, a voltage (−1900 V) of the second electrode 7b is used in which the current (110 mA) of the third electrode 7c is about twice the normal condition. Under these conditions, it has been confirmed that the attached film of the third electrode 7c is removed by cleaning for 1 minute corresponding to 3% for the use of an ion beam for 30 minutes.

  Further, when the voltage of the second electrode 7b is further reduced from the proper cleaning conditions, the current of the third electrode 7c is further increased. However, since the increase in the current value of the third electrode 7c is steep, in order to use it for cleaning, care must be taken in the cleaning time so that the third electrode 7c is not consumed.

  Further, when the voltage of the second electrode 7b is reduced, the value of the current flowing through the second electrode 7b increases as shown in FIG. If the voltage of the second electrode 7b is reduced from -1900V to -1200V while the voltage of the first electrode 7a is maintained at 100V, the current value of the third electrode 7c increases from 110mA to 300mA. At the same time, the current value of the second electrode 7b increases from 60 mA to 70 mA. In this way, under the condition that the current of the second electrode 7b increases (−1400 V or more), fast ions that are not decelerated are incident on the second electrode 7b, so that the second electrode 7b is consumed greatly by sputtering. Therefore, it is not desirable to use the condition (−1400 V or more) in which the current of the second electrode 7b increases for cleaning.

  The above conditions are summarized as follows.

  As described above, in this example, when the ammeter 9 is lower than the set value (110 mA) used in the cleaning condition, the feedback control unit 10 performs control so that the voltage of the second electrode 7b is appropriately reduced. On the other hand, when the ammeter 9 is higher than the set value (110 mA) used in the cleaning condition, the absolute value of the voltage of the second electrode 7b is controlled to be appropriately increased.

  When the second electrode voltage control process of step S4 is completed, the processes of step S2 and step S3 are repeated again until the current of the third electrode 7a matches the set value (110 mA).

  In step S5, timer processing is started when it is determined in step S4 that the current value is equal to the set value (110 mA). When a predetermined time (for example, 1 minute) elapses in the timer process, the process proceeds to step S6 and the cleaning process is stopped.

(Reference embodiment)
The reference embodiment will be described with reference to FIGS. 8, 9, and 10.

  This embodiment differs from the embodiment shown in FIG. 2 in that, as shown in FIG. 8, the display means 15 for displaying the value measured by the ammeter 9 and the first value based on the measured value of the ammeter 9 are used. Power supply stopping means 16 for automatically stopping the power supply 11 and the second power supply 12 is added. The other configuration is basically the same as the configuration shown in FIG.

  With reference to FIG. 9, the operation | movement procedure which performs an alarm display in a cleaning process is demonstrated. In step S1, a cleaning process for the third electrode 7c similar to that of the first embodiment is performed. As described above, the conditions of the voltage of the first electrode 7a and the voltage of the second electrode 7b are set to be + 100V and −1900V, respectively.

  In step S2, the current flowing through the third electrode 7c is measured by the ammeter 9. The measured current value is transmitted to the control unit 14.

  In step S3, the control unit 14 determines whether or not the measured current value is larger than the set value. If the current value is larger than the set value in step S3 (Yes), the divergence angle of the ion beam is increased, and a large amount of ion beam is incident on the third electrode 7c. indicate. In step S5, the power supply stopping unit 16 automatically stops the first power supply 11 and the second power supply 12 to stop the cleaning process. If the current value is smaller than the set value in step S3 (No), the cleaning process is continued.

  FIG. 10 differs from FIG. 9 in that step S6 (stop operation alarm) is added after step S4 (alarm display), and the first power supply 11 and the second power supply 12 are manually stopped by the display device user. In this example, the cleaning process is stopped (S7).

  As described above, when the current flowing through the third electrode reaches the threshold value, an alarm is displayed, or a means for automatically stopping the operation is provided, so that the beam divergence angle is reduced due to thermal deformation of the electrode or an assembly failure. Even when it becomes larger, the influence on the ion beam processing can be prevented.

  As described above, while measuring the current flowing through the third electrode 7c, if a predetermined set value is exceeded, the voltage applied to the second electrode 7b is controlled, or the process is stopped to stop the third. It is possible to prevent an excessive ion beam from entering the electrode 7c. Since such an effect can be obtained by controlling the divergence angle θ of the ion beam, the divergence angle θ of the ion beam can be controlled appropriately by using the same method even in normal ion beam processing such as etching. Can be processed. That is, in the ion beam processing, the voltage of the first electrode 7a is set to + 100V, the current is set to 325mA, and the voltage of the second electrode 7b is set to the second electrode voltage (-2400V) which is a beam condition (Normal) that is normally used. . Ion beam treatment is performed under these conditions, and the current flowing through the third electrode 7c is measured at the same time. If the measured value exceeds the set value (60 mA), the second electrode voltage is controlled or an alarm is displayed. The processing will be stopped automatically or manually.

  The ion beam generator of the present invention is used in an ion beam processing apparatus that performs ion beam etching and ion milling. The cleaning process of the third electrode according to the present invention can be appropriately performed during the ion beam processing of a plurality of substrates to be processed in such an ion beam processing apparatus. It is necessary to avoid the influence on the substrate to be processed. Therefore, when performing the cleaning process, the substrate to be processed is retracted from the vacuum chamber, or a shutter that can be opened and closed is provided in advance between the substrate holder and the extraction electrode, and the shutter is closed. Perform a cleaning process.

  The ion beam processing apparatus according to the present invention is suitably used, for example, for patterning a TMR (Tunnel Magneto-Resistance) stack of a sensor for a magnetic head or a magnetic reading head. Below, the patterning process which concerns is demonstrated.

  FIG. 11 is a schematic cross-sectional view showing the patterning process of the TMR stack. As shown in FIG. 11A, after a TMR stack 31 is formed on the wafer 30, a photoresist 32 is formed on the stack 31, and is developed and patterned. The illustrated photoresist 32 has a recess 32a at the bottom, and may be one or two layers. In the case of a two-layer photoresist, the lower layer is usually thinner and overetched to form the recess 32a. This facilitates the photoresist lift-off process.

  Next, as shown in FIG. 11B, the portion of the TMR stack 31 that is not covered with the resist 32 is etched by an ion beam. By changing the incident angle of the beam, the side wall shape of the joint portion 33 can be controlled. When the incidence is almost normal, the joint 33 is narrow like the skirt and becomes wider as it approaches the lower layer. By further aligning the aim of the ion beam to an acute angle, the joint 33 can be made more vertical and the spread of the lower portion can be reduced, and a substantially vertical joint sidewall can be obtained. In FIG. 11, 34 is a free layer.

  The sensor is patterned by ion beam milling (IBE) at various angles to obtain a profile of the junction 33 with the desired sidewalls. Milling causes redeposition on the photoresist 32 and the side wall of the junction. Therefore, milling is usually performed at a separate acute angle so that the side wall is cleaned and an electrical short circuit does not occur at the junction 33.

Next, as shown in FIG. 11C, for example, an insulating layer 35 selected from Al ₂ O ₃ , SiO ₂ , Si—N, HfO _2, or a combination thereof is formed, and the sidewalls are electrically connected. Insulate.

  The insulator layer 35 can be formed by physical vapor deposition (PVD). However, since control of the thickness of the sidewall is extremely important, a more suitable film formation technique such as ion beam film formation (IBD) or atomic layer film formation (ALD) is preferable. Atomic layer deposition has a very low deposition rate, but can provide conformal coverage. In ion beam film formation at an intermediate incident angle (45 ° or less), the sensor side wall coverage is increased. Because this coverage is thin, the inboarding and outboarding issues are less important.

  Next, FIG. 12 shows a schematic diagram of a magnetic head manufacturing apparatus in which an ion beam processing apparatus and a hard bias film forming apparatus according to the present invention are incorporated.

  As shown in FIG. 12, the manufacturing apparatus 40 of this example includes a PVD chamber 41, an ion beam etching (IBE) chamber 45, an insulator film forming chamber 46, a load lock (LL) chamber 44, and an unload lock (ULL) chamber. 42 is provided. That is, in the manufacturing apparatus 40 of this example, the PVD chamber 41, the IBE chamber 45, the insulator film forming chamber 46, the LL chamber 44, and the UL chamber 42 are connected to the robot chamber 43 disposed in the center. Accordingly, the wafer is transferred to the wafer processing unit 42, the PVD chamber 41, the IBE chamber 45, the insulator film forming chamber 46, the LL chamber 44, and the UL chamber 42 by operating the handling robot in the robot chamber 43. Done. The IBE chamber 45 is an ion beam processing apparatus provided with the ion beam generator of the present invention.

  Next, the case where the manufacturing apparatus 40 of FIG. 12 is used and the process of FIG. 11 and the film forming process of the hard bias film are performed successively will be described. In the film forming method of this example, first, the handling robot in the robot chamber 43 takes out the wafer from the cassette in the LL chamber 44 and transfers it to the IBE chamber 45. A TMR stack 31 and a patterned photoresist 32 shown in FIG. 11A are formed on this wafer.

  In the IBE chamber, the TMR stack 31 is etched to form a sensor joint 33 (FIG. 11B). After the formation of the sensor joint 33, the wafer is transferred to the insulator film forming chamber 46 by a robot.

  In the insulator film forming chamber 46, a thin non-reactive layer having electrical insulation is formed and surface stabilization is performed (see FIG. 11C).

  Next, the sensor subjected to the surface stabilization treatment is transported to the PVD chamber 41 by the robot in order to form a three-layer hard bias film (underlayer / permanent magnet layer / cap layer). In the PVD chamber 41, a hard bias film (underlayer / permanent magnet layer / cap layer) is formed using each target (Cr, Co—Pt, Ta, etc.) of the three magnetron / cathode units. After the hard bias film is formed, the completed wafer is stored in the UL chamber 42.

  According to the manufacturing apparatus 40 of the present example, since the IBE chamber 45 and the insulator film forming chamber 46 are connected to the robot chamber 43, the formation of the joint portion 33 of the sensor, the film formation of the insulator layer 35, and the hard bias A series of steps of film formation can be performed continuously.

  In the manufacturing apparatus 40 of this example, after a predetermined number of wafers are etched in the IBE chamber 45, the wafers may be retracted from the IBE chamber 45 and the cleaning process described above with reference to FIG. 5 may be performed. Alternatively, the IBE chamber 45 may be provided with a freely openable / closable shutter mechanism between the substrate holder and the extraction electrode, and the above-described cleaning process may be performed with the shutter closed.

  The cleaning process may be performed when a plurality of substrates are processed in succession with the shutter closed for each substrate, each time a certain number of substrates are processed, or when the apparatus is not in operation. Well, the timing for performing cleaning is not limited.

  1: ion beam generator, 7: extraction electrode, 7a: first electrode, 7b: second electrode, 7c: third electrode, 9: ammeter, 10: feedback control unit, 24: ion beam

Claims (4)

A plasma source;
A first electrode, a second electrode, and a third electrode, which are arranged in order from the plasma generation source side, each of which is a perforated plate electrode, and an extraction electrode for extracting ions generated in the plasma generation source;
Control means for independently controlling the potentials of the first and second electrodes;
Current measuring means for measuring a current flowing through the third electrode;
A feedback control unit that feedback-controls the potential of the second electrode based on a measured value by the current measuring unit;
The third electrode is at ground potential;
The control means controls the first electrode to a positive potential, the second electrode to a negative potential, causes an ion beam to enter the third electrode, and performs cleaning of the third electrode. Because
The feedback control unit performs control to increase the absolute value of the voltage of the second electrode when the current value of the third electrode measured by the current measuring unit exceeds a threshold value. Beam generator. And a neutralizer for supplying electrons to neutralize the ion beam,
The ion beam generator according to claim 1, wherein the neutralizer is turned off so as not to supply electrons during the cleaning. A plasma source;
A first electrode, a second electrode, and a third electrode, which are arranged in order from the plasma generation source side, each of which is a perforated plate electrode, and an extraction electrode for extracting ions generated in the plasma generation source;
Control means for independently controlling the potentials of the first and second electrodes;
Current measuring means for measuring a current flowing through the third electrode;
A feedback control unit that feedback-controls the potential of the second electrode based on a measurement value by the current measurement unit;
The third electrode is at ground potential;
The control means controls the first electrode to a positive potential, the second electrode to a negative potential, causes an ion beam to enter the third electrode, and performs cleaning of the third electrode. Cleaning method,
The feedback control unit performs control to increase the absolute value of the voltage of the second electrode when the current value of the third electrode measured by the current measuring unit exceeds a threshold value. Cleaning method for beam generator. The ion beam generator further includes a neutralizer that supplies electrons to neutralize the ion beam,
4. The method of cleaning an ion beam generator according to claim 3, wherein the neutralizer is turned off so that electrons are not supplied during the cleaning.

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