JP4006739B2 - Glow discharge drilling apparatus and glow discharge drilling method - Google Patents

Description

  The present invention provides a glow discharge excavation that can form a good observation surface even when the sample surface is suitable for observation by excavating the sample surface by sputtering accompanying glow discharge, even if the sample is susceptible to heat. The present invention relates to an apparatus and a glow discharge excavation method.

  Conventionally, when visually observing the structure and structure of a sample, various microscopes such as a transmission electron microscope (TEM) and a secondary electron microscope (SEM) are sometimes used. In order to observe a sample with such a microscope, it is necessary to prepare a surface (observation surface) suitable for observation as a preparatory process. For example, in the case of observing a sample cross section, the sample is broken to become an observation surface. Polishing must be performed until the exposed cross section is clean and has a certain level of smoothness.

  A polishing agent is generally used for polishing the sample, but there is a concern that the working environment is deteriorated due to the influence of the polishing agent and polishing powder generated by the polishing operation. In addition, since the polishing work takes time, a long time is required at the stage of the preparation process in which the sample is observed with various microscopes. Furthermore, depending on the structure of the sample to be observed, it may not be possible to obtain a surface suitable for observation even after polishing. For example, the sample is composed of a hard material such as glass and a soft material such as gold. In such a case, the soft material is deformed by polishing and flows to the hard material side, and it is very difficult to form a good observation surface.

In order to avoid the above-mentioned problems related to sample polishing and obtain a clean observation surface of the sample, the surface to be observed of the sample is scraped off with the power of sputtering by glow discharge instead of polishing, and the sample surface is finished to a desired smoothness Such an apparatus and method are disclosed in the following Patent Documents 1 to 3.
JP 54-131539 A JP 2002-310959 A JP 2004-61163 A

  There are various types of samples to be observed. For example, samples that are easily melted by heat, such as rubber and synthetic resins, or those that are easily cured by heat, should be used for observation. There is. When such a sample is scraped off (drilled) to form an observation surface due to the power of sputtering, the sample is exposed to excessive heat from sputtering (when the sample surface exceeds a temperature that can withstand the heat). There is a problem that it is difficult to obtain a good observation surface because the surface is melted or hardened and the sample is altered.

  It is also possible to measure the discharge time (sputtering time) related to glow discharge against the thermal effect on the sample during excavation processing by glow discharge, and to stop excavation after a predetermined time in order to avoid the thermal effect . However, the measurement of time is only a material for indirectly judging whether a heat-sensitive sample is really about to be altered, so there is no certainty that a good observation surface can be formed by avoiding thermal damage. .

  The present invention has been made in view of such a problem, and by measuring the temperature of the excavation site of the sample using the infrared radiation temperature measurement method, the thermal effect of sputtering accompanying the glow discharge is generated on the sample surface. It is an object of the present invention to provide a glow discharge excavation apparatus and a glow discharge excavation method that can reliably avoid the above.

  In order to solve the above problems, a glow discharge excavation apparatus according to a first aspect of the present invention is a glow discharge excavation apparatus for excavating a sample by glow discharge generated by applying a voltage between a hollow electrode and a sample disposed opposite to the hollow electrode. In the discharge excavation apparatus, an infrared sensor that receives infrared rays that have been radiated from the excavation site of the sample and passed through the hollow portion of the hollow electrode, and a temperature that measures the temperature of the excavation site of the sample based on the infrared light received by the infrared sensor And measuring means.

  A glow discharge excavation apparatus according to a second aspect of the invention is characterized in that the glow discharge excavation apparatus includes moving means for moving the infrared sensor so that the light receiving portion of the infrared sensor can be moved closer to and away from the excavation site of the sample.

A glow discharge excavation apparatus according to a third aspect of the present invention includes a holding body that holds the hollow electrode, and the holding body faces a cavity that communicates with the hollow part of the hollow electrode, and the hollow part via the cavity. A light transmitting member is provided, and the infrared sensor is configured to receive infrared light that has passed through the hollow portion, the cavity, and the light transmitting member.
A glow discharge excavation apparatus according to a fourth aspect of the present invention includes a light shielding member that covers and shields the infrared sensor and the translucent member.

A glow discharge excavator according to a fifth aspect of the present invention is characterized in that the glow discharge excavator includes stop means for stopping the application of voltage when the temperature measuring means measures temperature.
According to a sixth aspect of the present invention, there is provided a glow discharge excavation device comprising means for intermittently applying a voltage, and the temperature measuring means determines a temperature based on infrared rays received by the infrared sensor when the voltage is intermittently applied. It is characterized by being measured.

  A glow discharge excavator according to a seventh aspect of the present invention is a receiving means for receiving a reference temperature, a means for comparing and determining the reference temperature received by the receiving means and the temperature measured by the temperature measuring means, and the temperature measuring means When it is determined that the measured temperature is equal to or higher than the reference temperature accepted by the accepting means, a reducing means for reducing the value related to the applied voltage is provided.

  According to an eighth aspect of the present invention, there is provided a glow discharge excavation apparatus comprising: a means for intermittently applying a voltage; a receiving means for receiving a reference temperature; a reference determination received by the receiving means and a temperature measured by the temperature measuring means And when the temperature measured by the temperature measuring unit is determined to be equal to or higher than the reference temperature received by the receiving unit, the duty ratio and / or the applied voltage related to the intermittent application of voltage Reduction means for reducing the power value, wherein the temperature measurement means measures the temperature based on infrared rays received by the infrared sensor when the voltage is intermittently applied.

  A glow discharge excavation method according to a ninth aspect of the present invention is a glow discharge excavation method in which a sample is excavated by glow discharge generated by applying a voltage between a hollow electrode and a sample opposed to the hollow electrode. Infrared light radiated from the spot and passed through the hollow portion of the hollow electrode is measured, and the temperature of the excavation spot of the sample is measured based on the received infrared ray, and the measured temperature and the reference temperature received in advance are compared. As a result, when it is determined that the measured temperature is equal to or higher than the reference temperature, a value related to the applied voltage is reduced.

  In the first aspect of the invention, since the infrared ray radiated from the sample passes through the hollow portion of the hollow electrode and is received by the infrared sensor, the infrared ray is radiated from the excavation point in the deep position facing the hollow electrode. Infrared light can be received smoothly. Moreover, since the temperature measuring means measures the temperature of the excavation site based on the infrared rays received by the infrared sensor, the temperature of the excavation site itself can be measured based on the infrared rays emitted from the excavation site of the sample. Therefore, if the measured temperature is confirmed, it becomes possible to perform excavation while adjusting the voltage application so that the temperature at which the thermal effect is generated is not reached. An observation surface can be formed. In addition, since the temperature at which the thermal effect occurs varies depending on the sample, it is preferable to check in advance the temperature at which the thermal effect of the sample to be drilled is processed, so that the measured temperature does not reach the measured temperature. This is important for forming a simple observation surface.

  In the second invention, since the position of the light receiving surface of the infrared sensor can be adjusted with respect to the excavation site of the sample by the moving means, the area (measurement visual field) where the infrared rays are radiated can be optimally adjusted, and the excavation location of the sample It is possible to reliably receive infrared rays radiated from the temperature and improve the accuracy of temperature measurement.

  In the third aspect of the invention, since the holding body that holds the hollow electrode is provided with a cavity through which the infrared ray radiated from the sample can pass and a translucent member, the outside of the holding body is arranged so as to receive the infrared light through the translucent member. An infrared sensor can be arranged on the side. As a result, the infrared sensor is not directly affected by sputtering, stable light reception can be performed, and the position adjustment and maintenance of the infrared sensor can be easily performed.

  In the fourth invention, since the infrared sensor and the light-shielding member that covers the light-transmitting member are provided, the bright light is blocked from entering when receiving the infrared sensor, and the measurement accuracy is deteriorated by the ambient bright light. It can be eliminated and the accuracy of temperature measurement can be maintained.

  In the fifth invention, when temperature measurement is performed, the application of voltage is stopped, so that light emission accompanying sputtering does not occur, and it is possible to create a state where the infrared sensor can receive only the infrared rays emitted from the sample satisfactorily, Therefore, the temperature at the excavation site of the sample can be appropriately measured without being affected by sputtering. In addition, as a form related to the voltage application stop, after applying the voltage for a certain period, the voltage application is stopped for temperature measurement, and if the measured temperature does not exceed the allowable temperature of the sample, the voltage is applied again. Can be assumed.

  In the sixth invention, since the voltage application is intermittently performed, the generation of sputtering is also intermittent, and the degree of the thermal influence (thermal damage) that the sample receives compared to the case where the voltage application is continuously performed. Since it is relaxed, it is possible to perform processing while suppressing the power of sputtering when excavating a sample that is easily affected by heat and a material that is easily destroyed by an external force of a certain level or more. Furthermore, when the voltage is applied intermittently, the temperature is measured based on the infrared light received when the application is interrupted during intermittent application. Therefore, only the infrared light emitted from the sample is received without receiving the light emission associated with the sputtering. The light can be received and high-precision temperature measurement can be performed when the application is interrupted, and since the time when the application is interrupted is used as the temperature measurement time, excavation processing including temperature measurement can be performed efficiently.

  In the seventh and ninth inventions, the reference temperature is compared with the measured temperature, and when the measured temperature is equal to or higher than the reference temperature, the value related to the applied voltage is lowered, so that the sample is altered. When there is a fear, the amount of heat applied to the sample can be suppressed. As a result, the temperature rise of the sample is automatically suppressed during the excavation process, and it is possible to reliably prevent the excavated sample from being altered so that it is not suitable for observation. In order to prevent thermal damage to the sample, it is important to set an allowable temperature in the range where the thermal influence is not exerted on the sample to be drilled or a temperature slightly lower than the allowable temperature as the reference temperature.

  In the eighth invention, when the measured temperature is equal to or higher than the reference temperature, either or both of the duty ratio and the power value related to the application during the intermittent application of the voltage are reduced. When the sample is excavated by the method, the amount of heat applied to the sample can be surely reduced even when the temperature rises to such an extent that the sample is thermally damaged. Therefore, the temperature rise at the excavation site of the sample can be suppressed, and stable automatic excavation processing can be realized even for a sample that is easily affected by heat.

In the first invention, since the infrared ray radiated from the sample passes through the hollow portion of the hollow electrode and is received by the infrared sensor, the infrared ray radiated from the excavation point can be received well, and the thermal damage is caused accordingly. The temperature at the excavation site can be measured reliably.
In the second invention, since the position of the light receiving portion of the infrared sensor can be adjusted with respect to the excavation location of the sample, the position of receiving infrared rays can be flexibly changed according to the sample in order to measure the temperature of the excavation location. .

In the third invention, since the hollow electrode is held by the holding body including the cavity and the translucent member, the infrared sensor can be isolated from the sputtering accompanying the glow discharge by the translucent member, and the infrared sensor is damaged by the sputtering. This can be avoided, and infrared light can be stably received.
In the fourth aspect of the invention, since the infrared sensor and the light shielding member that covers the translucent member are provided, the infrared sensor can prevent the influence of the ambient bright light from being received, and the temperature measurement accuracy can be kept good. .

  In the fifth invention, since voltage application is stopped when performing temperature measurement, infrared radiation emitted from the sample can be received in a state where light emission accompanying sputtering does not occur, and temperature measurement can be performed. The temperature at the excavation site of the sample can be measured appropriately without being affected by sputtering.

  In the sixth invention, since the voltage application is intermittently performed, the generation of sputtering is also intermittent, and the degree of the thermal influence (thermal damage) that the sample receives compared to the case where the voltage application is continuously performed. In addition to being able to relax, the temperature is measured based on the infrared rays received when the application is interrupted during intermittent application, so that the temperature of the excavation site can be accurately measured while avoiding the influence of light emission associated with sputtering.

  In the seventh and ninth inventions, when the measured temperature is equal to or higher than the reference temperature, the value related to the applied voltage is lowered. Therefore, it is possible to avoid a situation in which the sample is altered due to the influence of heat. It is possible to excavate even weak samples.

  In the eighth invention, when the measured temperature is equal to or higher than the reference temperature, since at least one of the duty ratio and the power value related to the intermittent application of voltage is reduced, when performing excavation processing by intermittent application of voltage, Stable automatic machining can be realized by reliably preventing the sample from being altered due to heat.

  FIG. 1 shows the overall configuration of a glow discharge excavator 1 according to an embodiment of the present invention. The glow discharge excavation apparatus 1 is based on a glow discharge tube 2 that generates glow discharge for excavating a sample S, a power supply unit 4 that generates power related to voltage application, and the temperature of the excavation site based on infrared rays emitted from the sample S. A radiation temperature measuring device 30 for measuring and a computer 7 for controlling the entire apparatus are provided. The glow discharge excavation apparatus 1 of the present embodiment is characterized in that the temperature of the excavation site of the sample S excavated by glow discharge can be measured.

  The power supply unit 4 of the glow discharge excavator 1 includes a generator 6 and a matching box 5 that are connected to an AC power supply AC (220 V in this embodiment) to generate high-frequency power, and the radiation temperature measuring instrument 30 is an infrared sensor. 31, an AD converter 32, and a microcomputer 33 (corresponding to temperature measuring means). Further, in FIG. 1, a portion surrounded by a broken line indicates peripheral devices that do not belong to the essential configuration of the glow discharge excavator 1, and the peripheral devices include vacuum evacuation for evacuating the inside of the glow discharge tube 2. The apparatus 8 includes a gas supply adjusting unit 9 and a gas supply source 10 for supplying an inert gas (argon gas) to the inside of the glow discharge tube 2 after evacuation. The gas supply adjusting unit 9 includes a valve for adjusting the flow rate, and the gas supply source 10 corresponds to a cylinder filled with an inert gas such as argon gas or a mixed gas of inert gas.

  FIG. 2 shows an attachment structure of the glow discharge tube 2 and the infrared sensor 31 of the radiation temperature measuring device 30. The glow discharge tube 2 includes a combination of a short cylindrical lamp body 11, an electrode 12 (corresponding to a hollow electrode), a ceramic member 13, and a pressing block 15.

  The lamp body 11 corresponds to a holding body for holding the electrode 12, and a recess 11 b for holding the electrode 12 is provided in the center of the end surface 11 a where the pressing block 15 is combined, and at the center of the recess 11 b. A cavity 11c is formed. Further, the lamp body 11 is provided with a plurality of vacuum suction holes 11e and 11f radially from the center toward the peripheral wall part 11d. Some of the suction holes 11e communicate with the cavity 11c, and other suction holes 11f It communicates with the recess 11b. Further, the lamp body 11 is formed so that a gas supply hole 11g for supplying an inert gas communicates with the cavity 11c from the peripheral wall portion 11d toward the center. Furthermore, in the lamp body 11, a glass member 40 (corresponding to a translucent member) is attached to a location corresponding to the cavity 11c on the end surface 11h opposite to the side where the sample S is arranged, thereby sealing the cavity 11c. .

  The electrode 12 held by the lamp body 11 has a shape in which the cylindrical portion 12b protrudes from the center of the disc portion 12a, and a through hole 12c (corresponding to a hollow portion) that penetrates the cylindrical portion 12b and the disc portion 12a. ). The disc portion 12a is formed with a hole 12d communicating with the vacuum suction hole 11f of the lamp body 11. Further, when the electrode 12 is attached to the recess 11 b of the lamp body 11, the electrode 12 becomes ground potential, and the through hole 12 c communicates with the cavity 11 c of the lamp body 11 and faces the glass member 40. In order to maintain the sealing property of the cavity 11c of the lamp body 11 and the through hole 12c of the electrode 12 with the electrode 12 held, the first O-ring (seal member) 16 is interposed between the lamp body 11 and the electrode 12. It is attached.

  The ceramic member 13 is a disk-shaped member having a large thickness. The ceramic member 13 is arranged on the lamp body 11 with the electrode 12 covered from the cylindrical portion 12b side, and the flange portion covering the disk portion 12a of the electrode 12. 13d, and an insertion hole 13c through which the cylindrical portion 12b is inserted is formed at the center. The ceramic member 13 has a ring groove 13b for mounting an O-ring on the end surface 13a on the exposed side. The ceramic member 13 is disposed to face the disc portion 12a of the electrode 12 via the heat-resistant first insulator 17, and in the disposed state, the insertion hole 13c of the ceramic member 13 and the cylindrical portion of the electrode 12 are disposed. A predetermined gap is formed between the end portion 12 b and the end portion 12 e which is the tip of the cylindrical portion 12 b so as to be slightly recessed from the end surface 13 a of the ceramic member 13. A second O-ring 18 is also attached between the first insulator 17 and the disk portion 12a of the electrode 12 in order to maintain hermeticity.

  The pressing block 15 is an annular member for fixing the electrode 12 and the ceramic member 13 to the lamp body 11, and presses the flange portion 13 d of the ceramic member 13 toward the lamp body 11 with the protruding portion 15 a on the inner peripheral edge side. I have to. The pressing block 15 itself is attached to the end surface 11a of the lamp body 11 with a bolt. Further, a heat-resistant second insulator 19 is interposed between the protruding portion 15 a of the pressing block 15 and the flange portion 13 d of the ceramic member 13.

  On the other hand, the sample S to be excavated attached to the glow discharge tube 2 is arranged so that the sample surface Sa abuts on the third O-ring 20 attached to the end surface 13a of the ceramic member 13. Further, in this state, the oscillator 3 is pressed against the back surface Sd of the sample S, and the sample S is pressed toward the glow discharge tube 2 side. The sample S arranged in this way is opposed to the through hole 12c and the end 12e of the electrode 12, and a space K surrounded by the third O-ring 20 is formed. As shown in FIG. 1, the oscillator 3 is connected to the power supply unit 4 by a power supply line D, and presses the sample S against the glow discharge tube 2 with an optimal pressing force by a predetermined locking means (not shown). is doing.

  In the glow discharge tube 2 configured as described above, the suction holes 11 e and 11 f of the lamp body 11 are connected to the vacuuming device 8 shown in FIG. 1, and the gas supply hole 11 g is connected to the gas supply adjusting unit 9. Therefore, when the vacuuming device 8 performs vacuuming, the space K is evacuated through the suction holes 11e and 11f, the cavity 11c, and the through hole 12c of the electrode 12. Further, when the gas supply adjusting unit 9 starts gas supply in a state where the space K is evacuated, an inert gas is supplied to the space K through the gas supply hole 11g, the cavity 11c, and the through hole 12c of the electrode 12. . At this time, since the space K is closed by the third O-ring 20 to have a small volume, a sufficient inert gas is supplied to the space K.

  Further, an infrared sensor 31 of the radiation temperature measuring device 30 is disposed on the end surface 11 h side of the lamp body 11 of the glow discharge tube 2. The infrared sensor 31 includes an optical lens 31a that serves as a light receiving unit for the infrared ray R emitted from the sample S, a thermopile 31b that receives the infrared ray R that has passed through the optical lens 31a, and a housing 31c that houses the optical lens 31a and the thermopile 31b. Is provided. As shown in FIG. 2, by making the optical lens 31 a face the glass member 40, the infrared sensor 31 receives the infrared ray R emitted from the sample S and passing through the through hole 12 c of the electrode 12, the cavity 11 c, and the glass member 40. To do.

  Further, a rail member 35 projects from the end surface 11h of the lamp body 11 in parallel with the infrared ray R from the sample S toward the infrared sensor 31, and the rail member 35 is provided with a slide unit 36 that can slide. The housing 31c of the infrared sensor 31 is attached to the slide unit 36. By sliding the slide unit 36 in the direction of the arrow in FIG. The infrared sensor 31 is movable so as to be able to contact and separate. A fixing screw 37 is attached to the slide unit 36. The position of the slide unit 36 can be fixed by tightening the fixing screw 37, and the slide unit 36 can be slidable by loosening the fixing screw 37. .

  The thermopile 31b of the infrared sensor 31 generates an analog signal according to the energy of the incident infrared ray R, and also generates an analog signal according to the temperature of the thermopile 31b itself. The data is output to the AD converter 32 through L4.

  Furthermore, a cup-shaped light shielding member 34 is attached to the end surface 11 h of the lamp body 11. The light shielding member 34 is attached to the end surface 11h of the lamp body 11 with the peripheral edge 34a covered with the infrared sensor 31, the rail member 34, and the glass member 40. As a result, the optical lens 31a of the infrared sensor 31 Stable light reception of infrared rays R is achieved by preventing bright light from entering. The light shielding member 34 forms a passage hole through which the signal line L4 extending from the infrared sensor 31 passes, and the signal line L4 is pulled out to the AD converter 32 of the radiation temperature measuring device 30 (see FIG. 1). Connected to. The light shielding member 34 can be shaped so as to cover the entire glow discharge tube 2, and when the excavation process itself is performed in a place such as a dark room where bright light around can be excluded, the light shielding member 34. May be omitted.

  The AD converter 32 of the radiation temperature measuring device 30 shown in FIG. 1 converts the analog signal output from the infrared sensor 31 into a digital signal, and sends the converted digital signal to the microcomputer 33 through the signal line L5. . The microcomputer 33 corresponds to a temperature measuring means, and corrects the transmitted digital signal by the reference temperature and the emissivity, and the surface temperature of the sample S (infrared ray R based on the infrared ray R received by the infrared sensor 31). The temperature of the radiated portion) is converted (calculated), and the temperature is measured and output to the computer 7 through the signal line L5.

  Note that the microcomputer 33 of the radiation temperature measuring device 30 performs calculation processing of the measured temperature when receiving a temperature measurement start instruction from the computer 7 through the signal line L5. The temperature is measured based on the digital signal sent from the AD converter 32. In addition, when the microcomputer 33 receives a stop instruction for stopping the temperature measurement from the computer 7, the microcomputer 33 stops the process related to the temperature measurement. In this way, the microcomputer 33 performs temperature measurement based on the control (instruction) of the computer 7, so that temperature measurement is not performed when sputtering is occurring, and temperature measurement is performed when sputtering is not occurring. Therefore, the reliability of the measured temperature value can be ensured while avoiding the influence of sputtering.

  FIG. 3 shows the internal configuration of the generator 6 constituting the power supply unit 4. The generator 6 includes a high frequency power generation unit 6a, a control unit 6b, and a power measurement unit 6c. The high frequency power generation unit 6a is connected to the AC power source AC and generates high frequency power to apply the alternating current (high frequency) voltage changing to positive (+) and negative (−) shown in FIG. 4 to the sample S and the electrode 12. . The high-frequency power generation unit 6a is connected to the control unit 6b through the first internal connection line 6d, and adjusts the output mode and power value related to the high-frequency power under the control of the control unit 6b. In addition, the high frequency electric power production | generation part 6a of this embodiment produces | generates the electric power which concerns on the high frequency voltage of 13.56 MHz.

  The control unit 6b is composed of an IC (integrated circuit), and is connected to the computer 7 through the first connection cord L1. The power supply form to the glow discharge tube 2 and the sample S based on various signals output from the computer 7 (Voltage application mode) is determined, and the output mode of the high-frequency power generation unit 6a is controlled based on the determination result.

  FIG. 5A is a graph showing a first output mode by the control unit 6b, and continuously outputs high-frequency power (power value P) to the sample S and the electrode 12 within a predetermined time. In this mode, a high frequency voltage is applied (hereinafter, this mode is referred to as a continuous mode). FIG. 5B is a graph showing the second output mode by the control unit 6b, which outputs high-frequency power (power value P) in a pulsed (on / off) manner within a predetermined time. In this mode, intermittent high frequency voltage is applied to the sample S and the electrode 12 (hereinafter, this mode is referred to as intermittent mode).

  Note that, in the intermittent mode, the control unit 6b alternately performs power supply and power supply suspension by performing pulse processing with an internal IC as means for intermittently applying voltage. By such processing, high-frequency power is output at a power feeding time T1 corresponding to the rod-shaped protruding portion shown in FIG. 5B, a voltage is applied to the sample S, one power feeding (voltage application), and one time. The output (voltage application) of the high-frequency power is stopped and the voltage application is cut off at time T3 obtained by subtracting the power supply time T1 from the unit time T2 including the power supply stop (application stop).

  Further, the control unit 6b performs switching between the above-described continuous mode and intermittent mode based on a signal output from the computer 7 as a switching unit. Furthermore, in the continuous mode, the control unit 6b can change the power value P related to power supply as a value related to the applied voltage, and in the intermittent mode, power supply per unit time (1 second) as a value related to the applied voltage. The number of times (power supply frequency), the duty ratio related to intermittent power supply, and the power value P can be changed. The control unit 6b changes (sets) a value related to the applied voltage based on a signal output from the computer 7.

  Note that the control unit 6b can adjust the power supply frequency in the range of about 30 Hz to about 3000 Hz with respect to the change of the power supply frequency, and when the power supply frequency is changed, the time T3 in the graph of FIG. Change. Regarding the change of the duty ratio, the ratio (T1 / T2) occupied by one feeding time T1 to the unit time T2 during intermittent feeding can be adjusted as appropriate.

  Further, as the excavation of the sample S progresses, the distance between the excavation site surface of the sample S and the end 12e of the electrode 12 becomes longer, and the impedance value related to the sample S in voltage application changes as needed. The control unit 6b also performs adjustment processing for the value change.

  Specifically, the control unit 6b calculates the difference between the power value Pf and the reflection value Pr transmitted from the power measurement unit 6c described later, and the high frequency power generated by the high frequency power generation unit 6a based on the calculated difference. Control to change the power value (power value Pf) of the traveling wave fed to the sample S is performed. The control unit 6b adjusts the power value Pf so that the calculated difference (Pf−Pr) is constant. In this embodiment, the calculated difference (Pf−Pr) is transmitted from the computer 7 described later. The power value Pf generated by the high frequency power generation unit 6a is adjusted by software processing of an IC built in the control unit 6b so as to be equal to the reference power value that has been performed.

  As described above, the control unit 6b performs soft adjustment, so that appropriate power supply can be performed in response to a change in the impedance value of the sample S in the intermittent mode. The control unit 6b performs adjustment corresponding to the change in the impedance value of the sample S in the intermittent mode. In the continuous mode, the matching box 5 performs adjustment as described later.

  Returning to FIG. 3, the power measurement unit 6 c of the generator 6 is connected to the control unit 6 b and the high-frequency power generation unit 6 a by the second and third internal connection lines 6 e and 6 f. The power measuring unit 6c detects the power value Pf which is the power value of the traveling wave of the high frequency power generated by the high frequency power generating unit 6a and traveling toward the oscillator 3 shown in FIG. The reflection value Pr, which is the power value of the incoming reflected wave, is detected, and the detected value is transmitted to the control unit 6b.

  The matching box 5 of the power supply unit 4 shown in FIG. 6 includes a variable capacitor 5a for adjusting the output form of the high frequency power generated by the generator 6 in the continuous mode as the power supply unit 4, and a motor 5b for adjusting the electric capacity of the variable capacitor 5a. And a capacitor controller 5c for controlling the driving of the motor 5b.

  The variable capacitor 5a can change its own electric capacity according to the driving of the motor 5b, and the module and the phase are adjusted by changing the electric capacity. The capacitor control unit 5c is connected to the computer 7 by the second connection cord L2, and controls the driving of the motor 5b based on the notification signal for setting the intermittent mode transmitted from the computer 7 to the matching box 5. .

  Specifically, when the notification signal of the intermittent mode is received, the capacitor control unit 5c performs control to maintain the motor 5b in a constant state so that the electric capacity of the variable capacitor 5a is fixed. Therefore, the high-frequency power module and phase are not adjusted in the matching box 5 in the intermittent mode. Further, when the notification signal of the intermittent mode is not received, that is, when the continuous mode is set, the drive of the motor 5b is controlled so that the reflection value Pr from the sample S is minimized, and the electric capacity of the variable capacitor 5a is increased. The capacitor control unit 5c performs control to be changed. If the reflection value Pr is minimum, the capacitor controller 5c does not perform control to change the electric capacity of the variable capacitor 5a.

  On the other hand, the computer 7 shown in FIG. 1 is provided with an interface board 7b to which a first connection cord L1 extending from the generator 6 and a second connection cord L2 extending from the matching box 5 are connected. Are connected to an internal bus 7g to which a CPU 7a, an external connection unit 7c, a RAM 7d, a ROM 7e, and a hard disk device 7f are connected. Note that a monitor unit 7h is also connected to the internal bus 7g via a monitor connection line L3.

  The external connection portion 7c is for connecting an external device, and in this embodiment, the microcomputer 33 of the radiation temperature measuring device 30 is connected through the signal line L6. The temperature measured by the radiation temperature measuring device 30 is displayed on the monitor unit 7h as needed under the control of the CPU 7a. The RAM 7d temporarily stores data associated with various control processes performed by the CPU 7a, and the ROM 7e previously stores data necessary for the process (reference time) and programs that define the basic process contents performed by the CPU 7a. The hard disk device 7f stores a drilling program 21 and the like that define the control content related to the drilling process performed by the CPU 7a.

  The interface board 7b has a circuit for continuous mode and a circuit for intermittent mode. When the mode set by the operator is notified to the interface board 7b based on the control of the CPU 7a, the circuit corresponding to the notified mode is activated. The control signal related to the mode switching is output to the generator 6 by the processing by the activated circuit.

  Further, parameters such as a power supply frequency, a duty ratio, and a power value set by the operator 7 for the intermittent mode are transmitted to the intermittent mode circuit of the interface board 7b. Are generated and output to the generator 6, and a notification signal called manual adaptation for notifying the intermittent mode is output to the matching box 5. The transmitted parameter includes a peak power value of high-frequency power, a reference power value (reference value) used for adjustment processing corresponding to a varying impedance value, and the like.

  The CPU 7a has a timekeeping function, performs various processes based on the excavation program 21 stored in the hard disk device 7f, and performs predetermined processing based on instructions input by the operator by operating a keyboard or a mouse not shown in FIG. Set and control.

  For example, when the excavation program 21 is activated, the CPU 7a performs a process of displaying the setting menu 22 shown in FIG. 7 on the monitor unit 7h. When either the intermittent mode or the continuous mode is received from the setting menu 22 by the operator's operation, the CPU 7a performs a process of operating the circuit in the interface board 7b corresponding to the received setting content.

  When the intermittent mode is set in the setting menu 22, the CPU 7a performs processing for accepting numerical values for the excavation processing time, frequency (power feeding frequency) and duty ratio from the operator, and stores the accepted contents in the RAM 7d. The interface board 7b is notified and a predetermined signal is transmitted to the generator 6. The duty ratio is preferably set to a value lower than 0.5 when the excavation target sample S is particularly easily dissolved and easily broken. Furthermore, in addition to the setting menu 22 in FIG. 7, the CPU 7b can set other parameters such as a peak value (power value) of the high-frequency power in another menu. In addition, when the intermittent mode is set in the setting menu 22, the CPU 7a performs control to output a notification signal indicating the setting of the intermittent mode from the interface board 7b to the matching box 5.

  On the other hand, when the continuous mode is set in the setting menu 22, the CPU 7a performs control to cause the generator 6 to output an instruction signal so as to continuously generate power. When the continuous mode is set, the power value related to power feeding can be set as a value related to the applied voltage.

  Regardless of which mode is set, the setting menu 22 allows the reference temperature and processing time for the sample S to be set (see FIG. 7), and the computer 7 allows the reference temperature and processing from the operator using the keyboard or mouse. When receiving the time input, the CPU 7a stores the received numerical value in the RAM 7d. The input reference temperature value must be determined according to the type of the sample S to be excavated, and if the sample S is susceptible to heat, the allowable temperature is at a level that does not cause the heat. (Temperature lower than the temperature at which the influence of heat occurs).

  In the present embodiment, when the continuous mode is set, if the power supply (voltage application) is performed for a predetermined time by a manual operation of the operator, the power supply (voltage application) is temporarily stopped, and in conjunction with the suspension. Based on the control of the computer 7, the radiation temperature measuring device 30 measures the temperature of the excavation site of the sample, and the computer 7 performs processing for displaying the measurement result on the monitor unit 7h. Therefore, in the continuous mode, when the operator stops the power supply, the temperature displayed on the monitor unit 7h is confirmed, and the power supply is continued or the value (voltage value P) related to the power supply (output voltage) is decreased. Or whether or not to finish the excavation process.

  On the other hand, when the intermittent mode is set, the CPU 7a measures time with the start of machining, compares the measured time with the machining time stored in the RAM 7d, and applies voltage when the measured time reaches the machining time. Control to stop and finish excavation.

  Further, as shown in FIG. 5 (b), the CPU 7a performs temperature measurement at time T3 at the time of power supply interruption at the time of intermittent power supply (at the time of application interruption during intermittent application of a high-frequency voltage) as shown in FIG. The radiation temperature measuring device 30 is controlled. Specifically, the CPU 7a outputs a temperature measurement start instruction from the external connection unit 7c to the microcomputer 33 of the radiation temperature measuring device 30 at the end of the power feeding time T1 so that the temperature can be measured in synchronization with the time T3. A temperature measurement stop instruction is output to the microcomputer 33 at the end of time T3. Since the CPU 7a outputs an instruction in this way, when the radiation temperature measuring device 30 performs measurement (when the infrared sensor 31 receives the infrared ray R), no light emission is caused by the glow discharge, so that the glow discharge sputtering is performed. The temperature can be measured without being affected by the light emission caused by.

  Further, in the intermittent mode, the CPU 7a compares and determines the temperature measured by the radiation temperature measuring device 30 and the reference temperature set by the setting menu 22, and determines that the measured temperature is equal to or higher than the reference temperature. On the other hand, control is performed to reduce the power value P relating to the intermittently applied voltage. In the present embodiment, the set value is halved as the amount to be reduced. For example, when the set power value is 1 W, the power value is set to 0.5 W when the measured temperature is equal to or higher than the reference temperature. The defined signal is output from the computer 7 to the generator 6.

  Furthermore, when the CPU 7a outputs a signal for reducing the power value, the CPU 7a measures time from the signal output and determines whether or not the reference time stored in the ROM 7e has elapsed. At this time, even if the measurement time after outputting the signal for reducing the power value has passed the reference time, if the measurement temperature is maintained at the reference temperature or higher, the CPU 7a uses the voltage to prevent the sample S from being altered. The application is stopped and the excavation process is terminated. The excavation program 21 stored in the hard disk device 7f defines various processes performed by the CPU 7a.

Next, an overall processing procedure according to the glow discharge excavation method using the glow discharge excavation apparatus 1 having the above-described configuration will be described based on the first flowchart of FIG.
First, the glow discharge excavator 1 receives input from the operator in the setting menu 22 shown in FIG. 7, etc., and sets various parameters such as frequency and duty ratio when the mode, reference temperature, and intermittent mode are set (S1). ) The operator sets the sample S in the glow discharge tube 2 as shown in FIG. 2 (S2).

  Next, the operator evacuates the inside of the glow discharge tube 2 with the evacuation device 8, and then supplies an inert gas (argon gas) from the gas supply source 10 to the inside of the glow discharge tube 2 (S3). Then, the operator receives infrared rays R emitted from the sample surface Sa before excavation as a preparation stage of the radiation temperature measuring device 30, confirms whether the temperature can be measured properly, and adjusts the position of the infrared sensor 31. The sample surface temperature before excavation is also measured. Then, the glow discharge excavation apparatus 1 applies power according to the set contents and applies a voltage (S4), and excavates the sample surface Sa exposed in the space K of the sample S (S5).

  FIG. 9 shows the excavation state of the sample S, and in the space K closed by the third O-ring 20, the argon gas is smoothly guided through the through hole 12 c of the electrode 12, and between the electrode 12 and the sample S. A voltage is applied to generate glow discharge, and argon ions contained in the argon gas jump out toward the sample surface Sa and collide with each other, causing sputtering. The sample surface Sa is excavated by the collision of argon ions by the sputtering, and a recess Sb is generated. Further, since the infrared ray R is radiated from the bottom surface Sc of the recess Sb, the radiation temperature measuring device 30 measures the temperature of the bottom surface Sc of the recess Sb that is the excavation site of the sample S.

  The second flowchart of FIG. 10 relates to a glow discharge excavation method showing a detailed processing procedure when excavation is performed in the intermittent mode in the excavation process (S5) of the first flowchart of FIG. Hereinafter, the excavation process in the intermittent mode will be described based on the second flowchart. The glow discharge excavator 1 applies voltage during the power feeding time T1 as shown in FIG. 5B (S10), and at the next time T3. The voltage application is suspended as a voltage application interruption state (S11). The microcomputer 33 measures the temperature based on the infrared ray R received by the infrared sensor 31 during the time T3 when the voltage application is stopped (S12). Note that the computer 7 (CPU 7a) of the glow discharge excavator 1 has started measuring the time for processing along with the start of the excavation process.

  Next, the computer 7 of the glow discharge excavator 1 determines whether or not the measured temperature of the microcomputer 33 is equal to or higher than the reference temperature stored in the RAM 7d (S13). When the measured temperature is not equal to or higher than the reference temperature (S13: NO), the computer 7 determines whether or not the measured time has passed the machining time stored in the RAM 7d (S14). If the machining time has not elapsed (S14: NO), the process returns to the voltage application stage (S10) and the excavation process is continued. If the machining time has elapsed (S14: YES), excavation is stopped (S19) and the machining is terminated.

  Further, when the computer 7 (CPU 7a) determines that the measured temperature is equal to or higher than the reference temperature in the temperature comparison step (S13) (S13: YES), the computer 7 reduces the power value in a step (S18) described later. It is determined whether the time measured after the start of processing has passed the reference time stored in the RAM 7d (S15). If the reference time has passed (S15: YES), excavation is stopped (S19), and the sample S Protect.

  On the other hand, when the measured time has not passed the reference time (S15: NO), the CPU 7a determines whether or not the time measurement after the process of reducing the power value is being performed (S16), and the time measurement. If it is in the middle (S16: YES), the process returns to the voltage application stage (S10) and the excavation process is continued. Further, when the time measurement is not being performed (S16: NO), the CPU 7a performs a process of reducing (halving) the power value P (output value) related to intermittent application (S17), and starting the process of reducing the power value. Is started (S18), the process returns to the voltage application stage (S10), and the excavation process is continued.

  As described above, the glow discharge excavation apparatus 1 according to the present embodiment performs temperature measurement when the voltage application is interrupted in the intermittent mode, and thus can accurately measure the temperature of the excavation site of the sample S without being affected by the emission of sputtering. By performing the temperature measurement using the voltage application interruption time T3, the time required for the temperature measurement can be included in the excavation processing time, and efficient processing can be realized.

  Further, the glow discharge excavator 1 reduces the power value of the electric power applied to the sample S when the measured temperature is equal to or higher than the reference temperature (allowable temperature set for the sample S). The amount of heat applied is also reduced, creating a situation in which the temperature is difficult to rise, and avoiding the sample S from being damaged by heat. Furthermore, when the measured temperature does not drop (when it does not become lower than the reference temperature) even if a certain time (reference time) elapses after the power value is lowered, the excavation process is stopped, so the sample S is affected by heat. Therefore, it is possible to reliably prevent the sample from being deteriorated so that it cannot be used for observation (the sample S is wasted).

  Note that the excavation process is stopped when the measured temperature is equal to or higher than the reference temperature even after the reference time has elapsed since the power value is lowered. This is because the determination of the temperature of the sample S is performed when the reference time has elapsed since the decrease in the temperature. In addition, since the reference temperature is set to a lower allowable value than the temperature at which the sample S is affected by heat, even if excavation is performed until the reference time elapses after the measured temperature exceeds the reference temperature, the heat effect is actually generated. The sample S is not affected by heat because there is a margin until the temperature reaches the required temperature.

  Therefore, since the glow discharge excavation apparatus 1 according to the present embodiment can automatically perform excavation processing so that the sample S is not affected by heat in the intermittent mode, the sample to be excavated is a synthetic resin such as polycarbonate, and synthetic rubber. Even with such a rubber material, an observation surface suitable for observation can be stably formed.

  On the other hand, the excavation process in the continuous mode of the glow discharge excavator 1 is in accordance with the operation of the operator. After applying the voltage for a certain time at the set power value P, the voltage application is temporarily stopped, and the monitor unit The operator checks the measured temperature displayed in 7h, and restarts voltage application if the allowable temperature is not reached. Thereafter, such processing is performed to excavate a desired amount. Further, when the measured temperature is equal to or higher than the allowable temperature, the voltage is applied by reducing (for example, halving) the power value P of the voltage applied to the sample by the operator's operation. By performing such processing, excavation can be performed while reliably avoiding thermal effects on the sample S even in the continuous mode.

  In addition, the glow discharge excavation apparatus 1 according to the present invention is not limited to the above-described embodiment, and various modifications can be applied. For example, the voltage applied between the electrode 12 and the sample S in the glow discharge excavation apparatus 1 may be a DC voltage, and in this case, the power supply unit 4 is changed to a configuration that generates and supplies DC power. . In addition, the glow discharge excavator 1 does not necessarily have to have both the continuous mode and the intermittent mode with respect to the voltage application, and the voltage application is performed only in one of the modes to reduce the apparatus cost. May be. Further, when the CPU 7a determines that the measured temperature is equal to or higher than the reference temperature by providing a sound output unit for outputting a warning sound to the computer 7 in order to reliably notify the operator that the measured temperature is higher than the reference temperature. May be configured to emit a warning sound from the sound output unit.

  Furthermore, when the measured temperature is equal to or higher than the reference temperature in the intermittent mode, not only the power value P applied to the sample S but also the value of the duty ratio related to voltage application may be reduced. For example, when the measured temperature is equal to or higher than the reference temperature when the power value is 1 W and the duty ratio is 0.5 as the value related to the applied voltage, the power value is 0.5 W and the duty ratio is 0.25. The thermal burden on the sample S may be further reduced by reducing the temperature. In addition, as a value related to the applied voltage, it is possible to reduce only the numerical value of the duty ratio.

  Further, in order to reduce the operation burden on the operator in the continuous mode, as shown in FIG. 11, when excavation is performed for a certain time (T10, T12, etc., for example 1 minute), the next time (T11, T13, etc., for example, (2 seconds) may be programmed to measure the temperature so that it can be automatically excavated in continuous mode. In this case, the time required for excavation (voltage application) (T10, T12, etc.) is set at the preparation stage, and the CPU 7a measures each time (T10-T13, etc.) and applies the voltage (T10, T12, etc.). When the time elapses, voltage application is stopped based on the control of the computer 7 (CPU 7a), temperature measurement is performed, and when temperature measurement is completed (when the time T11, T13, etc. required for temperature measurement elapses), voltage application is resumed. To do. In addition, when the measured temperature is equal to or higher than the reference temperature, the next time excavation (voltage application) is performed, the power value of the applied voltage is reduced by the control of the computer 7 (CPU 7a), and a thermal effect occurs on the sample S. Do not.

  FIG. 12 shows a modified example related to the arrangement of the infrared sensor 31, and the position of the infrared sensor 31 can be adjusted by driving the motor. Specifically, a ball screw 51 is mounted in parallel to the rail member 56 on the one end face 11h side of the lamp body 11 of the glow discharge tube 2 via a bearing portion 52, and the end of the ball screw 51 is coupled. The motor shaft of the motor 54 disposed outside the light shielding member 34 is connected via the portion 53. The housing 31 c of the infrared sensor 31 is attached to the first slide unit 50 provided on the ball screw 51 and the second slide unit 55 attached to the rail member 56. The drive of the motor 54 is controlled by a motor driver 57, and the motor driver 57 is connected to the computer 7 and performs drive control of the motor 54 based on an instruction from the computer 7.

  By applying the structure shown in FIG. 12, the infrared sensor 31 can be moved closer to and away from the glass member 40 that seals the cavity 11 without removing the light blocking member 34, and the position of the infrared sensor 31 can be moved to the motor 54. It is possible to reduce the preparation burden for temperature measurement by adjusting the drive.

  FIG. 13 shows another modification. When a thin fiber-shaped infrared sensor 60 is used, the infrared sensor 60 may be disposed inside the lamp body 11 ′ of the glow discharge tube 2 ′. In this case, in the lamp body 11 ′, a communication hole 11 i ′ communicating with the cavity 11 c ′ is formed in the end surface 11 h ′ opposite to the side where the sample S is arranged, and the infrared sensor 60 is inserted into the communication hole 11 i ′. At the same time, an annular sealing member 41 is attached between the inner edge of the communication hole 11 i ′ and the outer surface of the infrared sensor 60 to close the cavity 11 c ′.

  The glow discharge tube 2 ′ shown in FIG. 13 is the same as that shown in FIG. 2 except for the above, and includes an electrode 12, a ceramic member 13, and a pressing block 15, and a sample by pressing the oscillator 3 thereon. S is attached. By attaching the infrared sensor 60 in this way, the light receiving portion 60a of the infrared sensor 60 is opposed to the sample surface Sa through the through hole 12c formed in the cylindrical portion 12b of the electrode 12, and is connected to the light receiving portion 60a and the sample S. The distance can be remarkably shortened compared to the cases shown in FIGS. 2 and 12, and the infrared rays emitted from the excavation site of the sample S can be reliably received to improve the measurement accuracy.

It is the schematic which shows the whole structure of the glow discharge excavation apparatus which concerns on embodiment of this invention. It is the schematic which made a part the cross section which shows a glow discharge tube and an infrared sensor. It is a block diagram which shows the internal structure of a generator. It is a graph which shows the form of the applied high frequency voltage. (A) is a graph which shows the power supply form of a continuous mode, (b) is a graph which shows the power supply form and temperature measurement time of an intermittent mode. It is a block diagram which shows the internal structure of a matching box. It is the schematic which shows the content of the setting menu which receives mode selection, a reference temperature, etc. FIG. It is a 1st flowchart which shows the process sequence of the glow discharge excavation method using a glow discharge excavation apparatus. It is the schematic which shows the excavation state of a sample. It is a 2nd flowchart which shows the procedure of the excavation process in the intermittent mode in a glow discharge excavation method. It is a graph which shows the relationship between the excavation time in continuous mode, and temperature measurement time. It is the schematic which shows the modification regarding attachment of an infrared sensor. It is the schematic which shows the attachment form of the infrared sensor of a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glow discharge excavation apparatus 2 Glow discharge tube 4 Power supply part 7 Computer 11 Lamp body 11c Cavity 12 Electrode 12c Through-hole 30 Radiation temperature measuring device 31 Infrared sensor 32 AD converter 33 Microcomputer 34 Light shielding member 40 Glass member R Infrared S Sample

Claims (9)

In a glow discharge excavation apparatus for excavating a sample with a glow discharge generated by applying a voltage between a hollow electrode and a sample disposed opposite to the hollow electrode,
An infrared sensor that receives infrared rays emitted from the excavation point of the sample and passed through the hollow portion of the hollow electrode;
A glow discharge excavation apparatus comprising: temperature measuring means for measuring the temperature of the excavation site of the sample based on infrared rays received by the infrared sensor.   The glow discharge excavation apparatus according to claim 1, further comprising a moving unit configured to move the infrared sensor so that a light receiving unit of the infrared sensor can move closer to and away from the excavation site of the sample. A holding body for holding the hollow electrode;
The holding body includes a cavity communicating with the hollow portion of the hollow electrode, and a translucent member facing the hollow portion via the cavity,
The glow discharge excavation apparatus according to claim 1 or 2, wherein the infrared sensor is configured to receive infrared light that has passed through the hollow portion, the cavity, and the translucent member.   The glow discharge excavation apparatus according to claim 3, further comprising a light shielding member that covers and shields the infrared sensor and the translucent member.   The glow discharge excavator according to any one of claims 1 to 4, further comprising a stopping unit that stops the application of voltage when the temperature measuring unit measures temperature. Means for intermittently applying voltage;
The glow discharge according to any one of claims 1 to 4, wherein the temperature measuring means measures a temperature based on infrared rays received by the infrared sensor when the voltage is intermittently applied. Drilling rig. A receiving means for receiving a reference temperature;
Means for comparing and determining the reference temperature received by the receiving means and the temperature measured by the temperature measuring means;
The lowering means for lowering the value related to the applied voltage when it is determined that the temperature measured by the temperature measuring means is equal to or higher than the reference temperature accepted by the accepting means. The glow discharge excavator according to claim 1. Means for intermittently applying voltage;
A receiving means for receiving a reference temperature;
Means for comparing and determining the reference temperature received by the receiving means and the temperature measured by the temperature measuring means;
When it is determined that the temperature measured by the temperature measuring unit is equal to or higher than the reference temperature received by the receiving unit, the duty ratio and / or the power value related to the applied voltage during voltage intermittent application are reduced. A lowering means, and
The glow discharge according to any one of claims 1 to 4, wherein the temperature measuring means measures a temperature based on infrared rays received by the infrared sensor when the voltage is intermittently applied. Drilling rig. In a glow discharge excavation method for excavating a sample with a glow discharge generated by applying a voltage between a hollow electrode and a sample arranged opposite to the hollow electrode,
Receives infrared rays emitted from the excavation point of the sample and passed through the hollow portion of the hollow electrode,
Measure the temperature of the excavation point of the sample based on the received infrared light,
Compare the measured temperature and the reference temperature received in advance,
A glow discharge excavation method, wherein, as a result of comparison, when it is determined that the measured temperature is equal to or higher than a reference temperature, a value related to the applied voltage is decreased.

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