JP2008122245A - Sample excavating method and sample excavating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sample excavating method which enables the excavation of a spherical sample by utilizing glow discharge, and to provide a sample excavating apparatus. <P>SOLUTION: The spherical sample S is placed on a placing part 31 arranged under the electrode provided to a glow discharge tube 1 in a counter relation to the electrode in a sample chamber (treatment chamber) 3 into which an argon gas (inert gas) is supplied and, in a state that the movement of the sample S is restricted by a plurality of ceramic balls (spheres) 32, the sample S is arranged in a counter relation to the electrode. Voltage is applied across the sample S and the electrode while applying vibration to the placing part 31 from an ultrasonic oscillator (oscillator) 33 to generate glow discharge and the surface of the sample S is excavated by the ionic shock of argon ions accompanying glow discharge. The sample S is almost isotropically excavated by vibration while rotated at random, the analysis of a component in a radial direction due to glow discharge emission analysis become possible and surface of the cleanly formed sample S can be observed by SEM or the like. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sample excavation method and a sample excavation apparatus for forming a sample in a state suitable for measurement by shaving a material using glow discharge in order to perform surface analysis of a spherical sample.

  Conventionally, in order to analyze a component contained in a sample, a glow discharge emission analysis in which a component is analyzed using a glow discharge has been performed. In glow discharge optical emission analysis, the components of a sample are analyzed by generating a glow discharge between the glow discharge tube and the surface of the sample to be analyzed in an inert gas atmosphere, and analyzing the light generated by the glow discharge. . The sample is gradually excavated from the surface by ion bombardment caused by glow discharge, and light depending on the component contained in the excavated part is generated, so the distribution of the component in the depth direction of the sample can be examined .

In addition, a scanning electron microscope (SEM) may be used to visually observe the structure and structure of a sample. In order to observe the sample using the SEM, it is necessary to prepare the observation surface of the sample as a preparation process. The sample is exposed so that the observation surface is exposed at a desired position of the sample and the exposed observation surface is cleaned. Need to form. Conventionally, a technique for scraping the surface of a sample by ion bombardment associated with glow discharge to form a clean observation surface on the sample surface has been developed, and Patent Documents 1 and 2 disclose this technique.
JP 2002-310959 A JP 2004-61163 A

  Conventional techniques for analyzing components contained in a sample by glow discharge emission analysis and techniques for forming a clean sample surface by glow discharge have been aimed at flat samples such as semiconductor wafers. Therefore, spherical samples such as balls for ball bearings cannot be handled by conventional techniques such as those disclosed in Patent Documents 1 and 2, and component analysis by glow discharge emission analysis and SEM are used. There is a problem that surface observation is difficult.

  The present invention has been made in view of such circumstances, and an object of the present invention is to perform glow discharge emission analysis of spherical samples by enabling excavation of spherical samples using glow discharge. It is an object of the present invention to provide a sample drilling method and a sample drilling apparatus that enable analysis of components by SEM and surface observation by SEM.

  In the sample excavation method according to the first aspect of the present invention, a spherical sample is disposed opposite to an electrode in a processing chamber to which an inert gas is supplied, the sample is rotated randomly, and the sample rotated between the sample and the electrode rotated at random. The sample is excavated by generating a glow discharge by applying a voltage to.

  A sample excavation apparatus according to a second invention excavates the sample by glow discharge generated by applying a voltage between an electrode and a sample disposed opposite to the electrode in a processing chamber to which an inert gas is supplied. The sample excavator includes an arrangement unit that arranges a spherical sample opposite to the electrode in the processing chamber, and a rotation unit that rotates the sample at random.

  In the first and second inventions, a spherical sample is placed opposite to an electrode in an atmosphere of an inert gas such as argon gas, and a voltage is applied between the sample and the electrode while rotating the sample at random. A discharge is generated, and the surface of the sample is excavated by the impact of inert gas ions accompanying the glow discharge. Thereby, the surface of the spherical sample is excavated almost isotropically.

  In a sample excavation device according to a third aspect of the present invention, the placement means is provided below the electrode so as to face the electrode, and a plate-shaped placement portion for placing the sample, and the placement portion And a plurality of spheres that restrain movement of the sample. The sample is placed between the sample and the edge of the placement unit.

  In the third aspect of the invention, a spherical sample is placed on an edged dish-like placement portion provided below the electrode and facing the electrode, and a plurality of spheres are arranged between the sample and the edge of the placement portion. As a result, the spherical sample is constrained to move and is placed opposite to the electrode.

  The sample excavation apparatus according to a fourth aspect of the invention is characterized in that the rotating means includes an oscillator that applies vibration to the mounting portion.

  In the fourth aspect of the invention, by applying vibration from the oscillator to the placement portion on which the spherical sample is placed, the vibration is transmitted to the sample and rotation occurs.

  In the first and second inventions, a glow discharge emission analysis is performed in which a spherical sample is excavated approximately isotropically from the surface toward the center by glow discharge, and the components of the sample are analyzed based on emission from the glow discharge. It can be carried out. Accordingly, the component distribution from the surface to the center can be obtained for a spherical sample such as a ball bearing ball, as in the case of a flat sample. Further, the surface of the spherical sample can be formed almost isotropically, and the surface of the spherical sample can be observed by SEM in the same manner as conventionally performed for a flat sample. .

  In the third invention, the plurality of spheres arranged between the sample and the edge of the mounting portion restrain the movement of the spherical sample in the horizontal direction, so that the spherical sample can be arranged to face the electrode. It becomes possible to excavate a spherical sample by generating a glow discharge between the sample and the electrode.

  In the fourth invention, the spherical sample is rotated by changing the rotation axis at random by the vibration applied from the oscillator, and the portion excavated by the glow discharge in the surface of the sample facing the electrode is randomly replaced. Can be excavated from the surface to the center almost isotropically, and the present invention has an excellent effect.

Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.
FIG. 1 is a block diagram showing the configuration of a sample drilling apparatus used for executing the sample drilling method of the present invention. The sample excavator includes a glow discharge tube 1 for generating glow discharge, a spectroscope 2 for measuring the intensity of light generated by glow discharge and measuring intensity, a sample chamber (processing chamber) 3 for storing a sample, and generating glow discharge. For this purpose, a power supply unit 4 that generates electric power related to the voltage to be applied and a control device 5 that performs overall control of the sample excavator are provided. The power supply unit 4 includes a generator 42 and a matching box 41 that are connected to an AC power supply AC to generate high-frequency power, and the generator 42 and the matching box 41 are connected to the control device 5, respectively. The glow discharge tube 1 and the matching box 41 are set to the same potential.

  The sample drilling device also includes a vacuuming device 61 that evacuates the inside of the glow discharge tube 1 and the sample chamber 3, and supplies argon gas (inert gas) to the inside of the glow discharge tube 1 after evacuation. A gas supply adjusting unit 62 and a gas supply source 63 are provided. The gas supply source 63 corresponds to a cylinder filled with argon gas. A piping for supplying argon gas is arranged from the gas supply source 63 to the glow discharge tube 1, and the gas supply adjusting unit 62 is provided in the middle of the piping from the gas supply source 63 to the glow discharge tube 1. . The gas supply adjusting unit 62 includes an electromagnetic valve for adjusting the flow rate of argon gas supplied from the gas supply source 63 to the glow discharge tube 1.

  The control device 5 uses a computer and includes a CPU 5a, a RAM 5c, a ROM 5d, and a hard disk device 5e, each connected to an internal bus 5f. The control device 5 includes an interface board 5b to which a first connection cord L1 extending from the generator 42 and a second connection cord L2 extending from the matching box 41 are connected. The interface board 5b is connected to the internal bus 5f. Has been. A monitor unit 5g is connected to the internal bus 5f via a monitor connection line L3. Further, an external connection portion 5h that is connected to a device outside the control device 5 and inputs / outputs various signals is connected to the internal bus 5f.

  The RAM 5c temporarily stores data and the like associated with various control processes performed by the CPU 5a, and the ROM 5d stores a program that defines basic processing contents performed by the CPU 5a in advance. The hard disk device 5e stores a control program 51 that defines the contents of control processing executed by the CPU 5a in connection with processing for excavating a sample by glow discharge and analyzing the components of the sample. The CPU 5a loads the control program 51 from the hard disk device 5e to the RAM 5c as necessary, and executes necessary processing according to the control program 51 loaded to the RAM 5c. The CPU 5a performs various settings and controls based on instructions input to an input unit such as a keyboard or a mouse (not shown).

  FIG. 2 is a cross-sectional view showing the internal configuration of the glow discharge tube 1. The glow discharge tube 1 is mounted on the sample chamber 3 and the spectrometer 2, the upper surface of the glow discharge tube 1 is mounted on the spectrometer 2, and the lower surface of the glow discharge tube 1 is mounted on the sample chamber 3. The glow discharge tube 1 is configured by combining a short cylindrical lamp body 11, an electrode 12, a ceramic member 13, and a pressing block 15.

  The lamp body 11 has a recess 11b for attaching the electrode 12 at the center of the end surface 11a with which the pressing block 15 is combined, and a center hole 11c is formed in the center of the recess 11b. The lamp body 11 is provided with a plurality of suction holes 11e and 11f for evacuation from the peripheral wall portion 11d toward the center. Some of the suction holes 11e communicate with the center hole 11c, and the other suction holes 11f are recessed. It communicates with the part 11b side. Further, the lamp body 11 is formed so that a gas supply hole 11g for supplying an inert gas communicates with the center hole 11c from the peripheral wall portion 11d toward the center.

  The electrode 12 housed in the recess 11b of the lamp body 11 has a shape in which a cylindrical portion (end portion) 12b protrudes from the center of the disc portion 12a, and penetrates the disc portion 12a from the inside of the cylindrical portion 12b. A hole (inner hole) 12c is formed. Moreover, the hole 12d is formed also in the disc part 12a. In a state where the electrode 12 is attached to the recess 11b of the lamp body 11, the center hole 11c and the through hole 12c of the lamp body 11 communicate substantially coaxially. When the electrode 12 is attached to the recess 11 b of the lamp body 11, it becomes a ground potential through the lamp body 11. When the electrode 12 is attached to the lamp body 11, the cylindrical portion 12 b protrudes from the end surface 11 a of the lamp body 11. A first O-ring 16 is attached between the lamp body 11 and the electrode 12 in order to maintain the hermeticity of the center hole 11c of the lamp body 11 and the through hole 12c of the electrode 12 in a state where the electrode 12 is accommodated. Yes.

  The ceramic member 13 disposed so as to cover the electrode 12 is a thick disk-shaped member, has a protruding flange portion 13d covering the disk portion 12a of the electrode 12, and has a central portion. Forms an insertion hole 13c through which the cylindrical portion 12b of the electrode 12 is inserted. The ceramic member 13 is disposed with respect to the disk 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 12b of the electrode 12 A predetermined gap is formed between the two. 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 for fixing the electrode 12 and the ceramic member 13 to the lamp body 11 is a member formed in an annular shape with an insulating material such as glass eva, and the flange 15 of the ceramic member 13 is formed by the projecting portion 15a on the inner peripheral side. The portion 13d is pressed toward the lamp body 11 side. 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. As shown in FIG. 2, the pressing block 15 is attached so as to protrude from the end surface 11 a of the lamp body 11, and the ceramic member 13 and the cylindrical portion 12 b of the electrode 12 are disposed inside the pressing block 15. Yes.

  The cylindrical portion 12 b of the electrode 12 is disposed downward, and the insertion hole 13 c of the ceramic member 13 and the through hole 12 c of the cylindrical portion 12 b of the electrode 12 are provided in the sample chamber 3 located below the glow discharge tube 1. Open to the inside. The cylindrical portion 12 b of the electrode 12 performs glow discharge with the sample disposed in the sample chamber 3. A translucent window 21 made of a translucent material such as quartz glass or translucent resin is provided at the end of the central hole 11c formed in the lamp body 11 on the opposite side to the recess 11b. Is provided. The translucent window 21 is a part of the upper surface of the glow discharge tube 1, and the upper surface of the glow discharge tube 1 is in contact with the spectroscope 2 mounted above the glow discharge tube 1. The light generated by the glow discharge passes through the through hole 12c and the center hole 11c, passes through the light transmitting window 21, and enters the spectroscope 2. The translucent window 21 may be formed in the shape of a lens that collects light.

  The spectroscope 2 is mounted above the glow discharge tube 1. The spectroscope 2 splits the light that has passed through the light transmission window 21 of the glow discharge tube 1 and entered the spectroscope 2 using a diffraction grating or the like, and the intensity of the split wavelength light is a photomultiplier tube or the like. Use to measure. The spectrometer 2 is connected to the external connection unit 5 h of the control device 5, and the operation is controlled by the control device 5 and the measurement result is input to the control device 5.

  FIG. 3 is a schematic cross-sectional view showing the internal configuration of the sample chamber 3. On the upper side of the sample chamber 3, the glow block 1 is mounted with the pressing block 15 protruding into the sample chamber 3. Inside the pressing block 15, the ceramic member 13 and the cylindrical portion 12 b of the electrode 12 are the sample chamber 3. It is arranged protruding inside. In the sample chamber 3, a frying plate-shaped placing portion 31 on which a spherical sample S is placed is provided. The placement portion 31 is provided below the electrode 12 so as to face the cylindrical portion 12 b of the electrode 12. A plurality of ceramic balls (spheres) 32 are mounted on the mounting portion 31 together with the spherical sample S. FIG. 4 is a schematic plan view showing a state where the placement unit 31 on which the sample S is placed is viewed from above. The mounting portion 31 is formed in a substantially circular shape in plan view, and a spherical sample S is disposed at a substantially center of the circular shape. Further, a plurality of ceramic balls 32, 32,... Each of the ceramic balls 32, 32,... Is positioned between the sample S located at the center and the edge of the mounting portion 31, and restrains the movement of the sample S in the horizontal direction. In this way, the sample S can be placed opposite to the electrode 12 of the glow discharge tube 1 by restricting the movement of the sample S and placing the center of the mounting portion 31 opposite the cylindrical portion 12 b of the electrode 12. it can. As described above, the mounting portion 31 and the ceramic balls 32, 32,... Constitute an arrangement means in the present invention in which the spherical sample S is arranged opposite to the electrode 12 in the sample chamber 3.

  The placement unit 31 is placed on an ultrasonic oscillator (oscillator) 33 that applies vibration to the placement unit 31, and an insulating sheet 35 is disposed between the placement unit 31 and the ultrasonic oscillator 33. ing. The ultrasonic oscillator 33 applies vibration to the placement unit 31 via the insulating sheet 35, and the placement unit 31 vibrates, so that the sample S and the ceramic balls 32, 32,. Vibrate. The sample S rotates little by little by vibrating, and rotates while changing the rotation axis at random. Thus, the ultrasonic oscillator 33 functions as a rotating means in the present invention that rotates the sample S at random. In order for the sample S to rotate smoothly, it is necessary to prevent the sample S from being completely fixed. Therefore, the ceramic balls 32, 32,... Have a slight gap with the sample S in a stationary state so that the sample S can be rotated by vibration while restricting the movement of the sample S. It is desirable that the size is such that it can be touched lightly. Since the appropriate size of the ceramic balls 32, 32,... Varies depending on the size of the sample S, the ceramic balls 32, 32,. In addition, the mounting part 31 is configured in a shape in which a recess for mounting the spherical sample S is formed, and restrains the movement of the sample S in the horizontal direction by mounting the sample S in the recess. Form may be sufficient.

  The ultrasonic oscillator 33 is installed on a vertical unit 34 that moves the ultrasonic oscillator 33 and the placement unit 31 in the vertical direction. The vertical unit 34 moves the sample S in the vertical direction by moving the placement unit 31. The ultrasonic oscillator 33 and the vertical unit 34 are connected to the external connection portion 5 h of the control device 5, and the operation is controlled by the control device 5. The vertical unit 34 controls the position of the sample S so that the surface of the sample S approaches the tip 12e of the cylindrical portion 12b of the electrode 12 up to a predetermined distance, and the sample S is disposed in close proximity to the cylindrical portion 12b of the electrode 12. Is done.

  The placement unit 31 is made of a conductive material, and the placement unit 31 is connected to a matching box 41. With this configuration, a voltage is applied to the mounting unit 31 from the power supply unit 4, and a voltage is applied between the sample S and the electrode 12 of the glow discharge tube 1. The power supply unit 4 applies a voltage to the mounting unit 31 while the ultrasonic oscillator 33 applies vibration to the mounting unit 31, whereby the sample S can be applied with a voltage while rotating randomly. .

  The suction holes 11e and 11f of the lamp body 11 of the glow discharge tube 1 are connected to the vacuuming device 61 shown in FIG. 1 by piping, and the gas supply holes 11g are connected to the gas supply adjusting unit 62 by piping. . The inside of the sample chamber 3 is connected to the vacuuming device 61 by piping. When the evacuation device 61 performs evacuation with the sample S placed in the sample chamber 3, the suction holes 11e and 11f, the center hole 11c, the through-hole 12c of the electrode 12, and the inside of the sample chamber 3 are evacuated. Is done. When the gas supply adjusting unit 62 starts supplying argon gas in this state, the gas supply hole 11g, the center hole 11c, the through hole 12c of the electrode 12 and the sample chamber 3 are filled with argon gas.

  FIG. 5 is a block diagram showing an internal configuration of the generator 42 constituting the power supply unit 4. The generator 42 includes a high frequency power generation unit 42a, a control unit 42b, and a power measurement unit 42c. The high frequency power generation unit 42 a is connected to the AC power supply AC and generates high frequency power so that a high frequency AC voltage can be applied between the sample S and the electrode 12. The high-frequency power generation unit 42a is connected to the control unit 42b through the first internal connection line 42d, and adjusts the output mode and power value related to the high-frequency power under the control of the control unit 42b. In addition, the high frequency electric power production | generation part 42a of this embodiment is producing | generating the electric power which consists of a high frequency voltage of 13.56 MHz. The control unit 42b is configured by an IC (integrated circuit) and is connected to the control device 5 through the first connection cord L1. The control unit 42b is configured to control the output of the high frequency power generation unit 42a based on various signals output from the control device 5.

  The power measurement unit 42c is connected to the control unit 42b and the high-frequency power generation unit 42a by the second and third internal connection lines 42e and 42f. The power measuring unit 42c detects an output value Pf which is a power value of a traveling wave of the high frequency power generated by the high frequency power generating unit 42a and supplied to the mounting unit 31 and reflects back from the mounting unit 31 to return. 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 42b.

  The control unit 42b can switch between two types of output modes as a method of controlling the output of high-frequency power. One output mode is a mode in which a predetermined high-frequency power is continuously output within a predetermined time and a continuous high-frequency voltage is applied between the sample S and the electrode 12, and this mode is hereinafter referred to as a continuous mode. Say. The other output mode is a mode in which a predetermined high-frequency power is output in a pulsed manner within a predetermined time period to intermittently apply a high-frequency voltage between the sample S and the electrode 12. Say mode.

  The control unit 42b executes a process of switching between the continuous mode and the intermittent mode based on the signal output from the control device 5, and in the intermittent mode, the power supply and the power supply suspension are performed by performing a pulse-like process with an internal IC. Alternately. Further, the control unit 42b can adjust the power supply frequency corresponding to the number of times of power supply per unit time, the duty ratio indicating the ratio of the time during which power is supplied in the intermittent mode, and the power value of the power supply. Regarding the change of the power supply frequency, the control unit 42b can adjust the power supply frequency in a range of about 30 Hz to about 30000 Hz, and when the power supply frequency is changed, the pulsed power supply time interval changes.

  Further, as the excavation of the sample S by glow discharge proceeds, the distance between the surface of the sample S and the tip 12e of the electrode 12 becomes longer, and the impedance value related to the sample S changes as needed. The adjustment processing for the impedance value change at is also executed. Specifically, the control unit 42b transmits the output value Pf and the reflection value Pr described above from the power measurement unit 42c, calculates a difference between the output value Pf and the reflection value Pr, and outputs an output value based on the calculated difference. Control to change Pf is performed. Note that the control unit 42b adjusts the output value Pf so that the difference (Pf−Pr) between the output value Pf and the reflection value Pr is constant. In this embodiment, the calculated difference (Pf−Pr) is The output value Pf generated by the high-frequency power generation unit 42a is adjusted by software processing of an IC built in the control unit 42b so as to be equal to the reference power value transmitted from the control device 5.

  As described above, the control unit 42b 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 42b performs the adjustment corresponding to the change in the impedance value of the sample S in the intermittent mode. In the continuous mode, the matching box 41 performs the adjustment as described later.

  FIG. 6 is a block diagram showing an internal configuration of the matching box 41 that constitutes the power supply unit 4. The matching box 41 includes a variable capacitor 41a that adjusts the output form of the high-frequency power generated by the generator 42 in the continuous mode, a motor 41b that adjusts the electric capacity of the variable capacitor 41a, and a capacitor control unit that controls driving of the motor 41b. 41c. The variable capacitor 41a can change its own electric capacity according to the driving of the motor 41b, and the module and the phase are adjusted by changing the electric capacity.

  The capacitor control unit 41c is connected to the control device 5 by the second connection cord L2, and controls the driving of the motor 41b based on the notification signal for setting the intermittent mode transmitted from the control device 5 to the matching box 41. Specifically, when the notification signal of the intermittent mode is received, the capacitor control unit 41c performs control to maintain the motor 41b in a constant state so that the electric capacity of the variable capacitor 41a is fixed. Therefore, the high frequency power module and phase are not adjusted in the matching box 41 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 capacitor control unit 41c controls the driving of the motor 41b so that the reflection value Pr from the sample S is minimized. Control to change the electric capacity of the variable capacitor 41a is performed. If the reflection value Pr is minimum, the capacitor control unit 41c does not perform control to change the electric capacity of the variable capacitor 41a.

  Next, processing executed by the sample excavating apparatus having the above configuration will be described. The sample drilling device drills from the surface to the center of the spherical sample S by glow discharge, and analyzes the components contained in the sample S by analyzing the generated light. The CPU 5 a of the control device 5 performs processing for controlling the conditions for excavating the sample S according to the control program 51. The control program 51 defines a plurality of types of conditions for the power applied to the sample S. Specifically, the speed at which the sample S is excavated by controlling the power value of the high-frequency voltage applied from the power supply unit 4 to the mounting unit 31, the power supply frequency in the intermittent mode, or the duty ratio. Can be adjusted. The control device 5 inputs information necessary for sample excavation, such as the material of the sample S or the depth to be excavated, by a user operation using an input unit such as a keyboard or a mouse (not shown). The CPU 5a sets the condition of the power value of the high frequency voltage applied from the power supply unit 4 to the mounting unit 31, the power supply frequency, or the duty ratio so that the sample S can be excavated at an appropriate speed.

  FIG. 7 is a schematic diagram showing the positional relationship between the electrode 12 and the sample S. A spherical sample S formed of a conductive material is placed on the placement unit 31 by a user, and the horizontal position of the sample S is substantially fixed by ceramic balls 32, 32,. . The vertical unit 34 whose operation is controlled by the CPU 5a adjusts the position of the sample S in the vertical direction, and the sample S approaches the cylindrical portion 12b of the electrode 12 so as to face the cylindrical portion 12b. A slight space is formed between the tip 12 e of the electrode 12 and the surface of the sample S.

  After the inside of the glow discharge tube 1 and the sample chamber 3 is evacuated by the evacuation device 61, the gas supply source 63 supplies argon gas to the inside of the glow discharge tube 1, and the ultrasonic oscillator 33 controlled by the CPU 5a is provided. The vibration is applied to the placement unit 31, and the power supply unit 4 supplies a high-frequency voltage to the placement unit 31 under the conditions set in the CPU 5a. The sample S is randomly rotated by the vibration applied to the placement unit 31, and a high-frequency voltage is supplied to the sample S through the placement unit 31. Sufficient argon gas is supplied as needed to the space between the tip 12e of the electrode 12 and the surface of the sample S, and a high-frequency voltage is supplied to the sample S from the power supply unit 4, so that the space between the electrode 12 and the sample S is reached. A voltage is applied, and glow discharge is generated between the electrode 12 and the sample S in an atmosphere of argon gas. When the glow discharge is generated, argon ions are generated in the argon gas, and the generated argon ions are accelerated in the through hole 12c of the cylindrical portion 12b of the electrode 12, and the sample S facing the tip 12e of the cylindrical portion 12b. Ion bombardment occurs where accelerated argon ions collide with the surface. In the glow discharge tube 1, since the insulated ceramic member 13 and the pressing block 15 and the cylindrical portion 12 b of the electrode 12 protrude from the end surface 11 a of the lamp body 11, the glow discharge is caused by the adjacent cylindrical portion 12 b and the sample S. It is possible to prevent a discharge that is difficult to control between the lamp body 11 and the sample S or the mounting portion 31.

  Due to the ion bombardment of the argon ions, the constituent material of the sample S jumps out as particles on the surface of the sample S facing the electrode 12, and the portion of the surface of the sample S facing the tip 12 e of the electrode 12 is excavated. Argon ions accelerate in the through-hole 12c and then travel almost straight and collide with the surface of the sample S, and a portion of the surface of the sample S facing the range of the size of the through-hole 12c is excavated in a limited manner. Since the sample S is excavated while being rotated at random by vibration, a portion of the surface of the sample S facing the tip 12e of the electrode 12, that is, a portion to be excavated on the sample S is randomly replaced. Drilled from the surface to the center almost isotropically.

  Further, particles that have jumped out of the sample S by ion bombardment are excited by glow discharge, and emit light having a wavelength that is unique to the element contained in the particles. The emitted light passes through the light transmission window 21 of the glow discharge tube 1 and enters the spectroscope 2. The spectroscope 2 splits the incident light, measures the intensity of light of each wavelength, and displays the measurement result. Input to the control device 5. The CPU 5a of the control device 5 performs a glow discharge emission analysis process for analyzing a component contained in the sample S based on the measurement result input from the spectroscope 2 via the external connection unit 5h.

  Further, the CPU 5a measures the time elapsed since the start of excavation of the sample S, and stores the analysis result of the component of the sample S in association with the measured time in the hard disk device 5e. Since the excavation proceeds from the surface of the sample S toward the center by continuously executing the glow discharge, the elapsed time corresponds to the excavation depth from the surface. Therefore, the control device 5 can acquire the distribution of components from the surface to the center of the spherical sample S, similar to what is conventionally obtained for the flat sample. The sample excavator may further include a means for measuring the excavation amount or the excavation depth, and may excavate the sample S while measuring the excavation amount or the excavation depth.

  The sample excavation apparatus of the present invention can also be used as an apparatus that cleans the surface of the sample S. The CPU 5a of the control device 5 performs excavation while measuring time, and can stop the excavation at the stage of excavation to a desired depth, thereby processing the surface of the sample S to be isotropically clean. The sample S whose surface has been cleaned can be observed from the sample chamber 3 and then the surface can be observed by SEM in the same manner as conventionally performed for a flat sample. For example, surface structures such as the presence or absence of cracks can be observed for spherical materials such as balls for ball bearings.

  In addition, a spherical sample S is excavated to an arbitrary depth using the sample excavator of the present invention, the surface of the sample S formed cleanly by excavation is observed by SEM, and excavation by the sample excavator and observation by SEM are performed. By repeating, the structure of the sample S in the radial direction can be observed. For example, with respect to a spherical material such as a ball for a ball bearing, the internal structure of the spherical material can be observed, such as observation of the shape of the formed crack.

It is a block diagram which shows the structure of the sample drilling apparatus used in order to perform the sample drilling method of this invention. It is sectional drawing which shows the internal structure of a glow discharge tube. It is typical sectional drawing which shows the internal structure of a sample chamber. It is a typical top view which shows the state which looked at the mounting part which mounted the sample from the top. It is a block diagram which shows the internal structure of the generator which comprises a power supply part. It is a block diagram which shows the internal structure of the matching box which comprises a power supply part. It is a schematic diagram which shows the positional relationship of an electrode and a sample.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glow discharge tube 12 Electrode 12b Cylindrical part 12c Through-hole 12e Tip 2 Spectrometer 3 Sample chamber (processing chamber)
31 Placement part 32 Ceramic ball (sphere)
33 Ultrasonic oscillator
4 Power supply 5 Control device S Sample

Claims (4)

A spherical sample is placed opposite the electrode in a processing chamber to which an inert gas is supplied,
Rotate the sample randomly,
A sample excavation method comprising excavating the sample by applying a voltage between the sample rotating at random and the electrode to generate glow discharge. In a sample drilling apparatus for drilling the sample by glow discharge generated by applying a voltage between an electrode and a sample disposed opposite to the electrode in a processing chamber to which an inert gas is supplied,
Arranging means for arranging a spherical sample facing the electrode in the processing chamber;
Rotating means for rotating the sample at random. The arrangement means includes
Opposed to the electrode, provided below the electrode, a frying plate-shaped placing portion for placing the sample,
The plurality of spheres arranged between the sample placed on the placement unit and an edge of the placement unit, and restraining movement of the sample. Sample drilling equipment. The rotating means includes
The sample excavation device according to claim 3, further comprising an oscillator that applies vibration to the mounting portion.

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