JP6498891B2 - Polishing method and polishing apparatus - Google Patents

Description

  The present invention relates to a polishing method and apparatus for avoiding partial polishing of a sample.

  For observation of crystal orientation, an ion beam processing apparatus such as CP (Cross section Polisher) or IM (Ion Milling) is indispensable. Crystal orientation analysis is greatly influenced by the finish of the previous polishing step. In conventional mechanical polishing using abrasive paper and abrasives, surface stress occurs on the sample surface (observation surface) due to polishing, wrinkles and voids (holes), cracks, and amorphous A quality layer may occur.

  Thus, a device for removing the processed layer by electropolishing has been devised. In particular, when analyzing the crystal orientation and strain distribution state by EBSD (Electron Back Scattering Diffraction Pattern), it cannot be accurately evaluated if there is processing strain due to a work-affected layer on the sample surface. For this reason, by reworking with a very weak ion beam, for example, a clean polished surface without irregularities can be obtained even at the interface of hard and soft composite materials, and high magnification observation and crystal orientation analysis of a micro area ( Samples capable of EBSD) have been made.

  The processing method using the ion beam requires a long processing time in addition to an expensive apparatus. Therefore, there is an increasing demand for a mechanical polishing machine that can easily analyze the crystal orientation only by mechanical polishing.

  The mechanical polishing machine faces the sample and the abrasive of the polishing disk, and polishes the sample with the abrasive while rotating the sample and the polishing disk in the same direction or in the opposite direction (for example, Patent Document 1). , Patent Document 2). The abrasive means a member necessary for polishing.

  In the conventional mechanical polishing apparatus, as shown in FIG. 2, a plurality of samples 31 are arranged concentrically on a disk-shaped sample holder 30 and revolved on a polishing plate 32 while rotating, whereby the sample 31 is moved to the above-described state. Polishing was performed with an abrasive on the polishing board 32.

JP 2004-148479 A JP 2004-209564 A

  As apparent from FIG. 2, when the polishing plate 32 rotates around the rotation center O, there is a difference in the peripheral speed between the outer peripheral side 32a of the polishing plate 32 and the inner peripheral side 32b on the rotation center side. . That is, the outer side 31 a of the sample 31 is polished on the outer peripheral side 32 a where the peripheral speed of the polishing plate 32 is fast, and the inner side 31 b of the sample 31 is polished on the inner peripheral side 32 b where the peripheral speed of the polishing plate 32 is low. become.

  Accordingly, the amount of polishing on the outer side 31a of the sample 31 is large, the amount of polishing on the inner side 31b of the sample 31 is reduced, and the amount of polishing between the inner side 31b and the outer side 31a of the sample 31 depends on the difference in peripheral speed of the polishing disc. A difference occurs, and the sample 31 is polished nonuniformly.

  As described above, when the sample 31 is polished nonuniformly, a relatively flat structure of the polished surface must be partially observed with a microscope, and the crystal orientation of the sample 31 is changed over the entire polished surface. There was a problem that observation and analysis could not be performed accurately.

  In addition, even when a relatively flat structure is partially observed with a microscope, the effect of uneven polishing amount due to the difference in peripheral speed is generated in the target planar structure / laminated structure and interface structure, and accurately. There was a problem that it was impossible to observe and analyze.

  Therefore, in order to ensure the accuracy of observation and analysis of the planar structure / laminated structure and interface structure, there is a limit to polishing by a mechanical polishing machine, and it has been necessary to polish by an advanced polishing method by a skilled worker. .

  An object of the present invention is to provide a polishing method and a polishing apparatus that correct non-uniformity in the polishing amount due to a difference in peripheral speed generated between the inner and outer periphery of a polishing disk when a sample is polished.

  Conventionally, attempts have been made to correct non-uniformity in the polishing amount by changing the polishing rate by a mechanical polishing machine, but the current situation is that it has not been improved. The present inventor has determined that the uneven polishing amount is caused by the difference in the peripheral speed of the polishing disc, and the difference in the polishing amount caused by the peripheral velocity difference generated between the inner and outer circumferences of the polishing disc when the sample is polished. The correction is realized.

Specifically, a polishing method for polishing a sample according to the present invention with a disc-shaped abrasive on a polishing disc is based on an X-axis table that moves the sample in the X direction relative to the abrasive and the abrasive. And a Y-axis table that moves the X-axis table in a Y-direction orthogonal to the X-direction, and a synthetic direction of the X-direction and the Y-direction from the starting position for polishing the sample along the abrasive. A first step of moving the sample in a spiral shape and a moving process of the sample in the first step, and changing the polishing region of the sample with respect to the abrasive at the start position and the position after the movement. and second step, said based on a change in the polishing area of the sample with respect to the abrasive in the second step, at the same time it executes a third step of correcting the difference in polishing amount caused by polishing position on the polishing member The polishing area of the sample Is to change the polishing region located on the outer peripheral side of the abrasive at the starting position for polishing the sample to the inner peripheral side and to the inner peripheral side of the abrasive at the starting position for polishing the sample. The polishing region located is changed to the outer peripheral side .

The polishing apparatus according to the present invention is a polishing apparatus that polishes a sample with a disc-shaped abrasive on a polishing disc. The polishing apparatus moves the sample in the X direction with respect to the abrasive and the abrasive. Using the Y-axis table that moves the X-axis table in the Y direction orthogonal to the X direction, the spiral sample that is the combined direction of the X direction and the Y direction from the starting position for polishing the sample. A sample moving mechanism that corrects a difference in polishing amount caused by a polishing position on the abrasive by changing a polishing region of the sample with respect to the abrasive at the start position and the position after the movement through a moving process. Yes, and to alter the polishing region of the sample, as well as changing the polishing region located on the outer peripheral side of the polishing material in the starting position for polishing the sample to the inner peripheral side, starting position for polishing the sample Is to change to the outer peripheral side of the polishing region located on the inner peripheral side of the abrasive material in it is characterized in.

  As described above, according to the present invention, the polishing region of the sample with respect to the abrasive is changed at the start position and the position after the movement through the movement process of the sample from the start position for polishing the sample in the abrasive. Based on the change in the polishing region of the sample with respect to the abrasive, the difference in the amount of polishing caused by the polishing position on the abrasive can be corrected. Polishing instead of processing by CP or IM can be performed by mechanical polishing. There is a remarkable effect that it can be realized.

It is a figure which shows the locus | trajectory of the sample in the grinding | polishing method which concerns on embodiment of this invention. It is a figure which shows the locus | trajectory of the sample in the grinding | polishing method which concerns on a prior art example. 1 is a perspective view showing an entire polishing apparatus according to an embodiment of the present invention. 1 is a top view showing an entire polishing apparatus according to an embodiment of the present invention. It is a perspective view which shows the X-axis drive mechanism used for the grinding | polishing apparatus which concerns on embodiment of this invention. It is a perspective view which shows the Y-axis drive mechanism used for the grinding | polishing apparatus which concerns on embodiment of this invention. It is a perspective view which shows the Z-axis drive mechanism used for the grinding | polishing apparatus which concerns on embodiment of this invention. It is a block diagram which shows in detail the controller used for the grinding | polishing apparatus which concerns on embodiment of this invention. It is a locus diagram which shows the movement pattern of the sample which the controller used for the polisher concerning the embodiment of the present invention draws the sample in the polishing surface of the abrasive. It is a perspective view which shows the weight canceller and weight controller used for the grinding | polishing apparatus which concerns on embodiment of this invention. (A) is the microscope picture which grind | polished with the grinding | polishing method which concerns on embodiment of this invention, and observed the metal structure, (b) is the microscope picture which grind | polished with the grinding | polishing method which concerns on a prior art example, and observed the metal structure. It is the EBSD image which observed the metal structure, Comprising: (a) has shown the EBSD image with a surface processing layer, (b) has shown the EBSD image without a surface processing layer, respectively.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  In FIG. 3 showing the polishing apparatus according to this embodiment, the Z-axis direction is set in the vertical direction of the drawing, the X-axis direction is set in the horizontal direction of the drawing, and the Y-axis direction is set in the depth direction of the drawing. Further, the polishing by the polishing apparatus according to the embodiment of the present invention is not limited to simply polishing a sample, but sample information necessary for observation and removal of a laminated interface structure, multilayer film (thin film), and crystal analysis is obtained. Polishing, semiconductor failure analysis, plating layer structural analysis, and surface polishing and cross-sectional polishing of electronic parts.

In the present embodiment, as shown in FIG. 1, the first step of moving the sample 5 on the polishing material 2 of the polishing board 3 along the polishing material 2 from the start position of polishing is performed by the first step. A second step of changing the polishing region of the sample with respect to the abrasive 2 at the start position S1 and the moved positions S2 to S16 through the moving process of the sample 5, and the polishing in the second step And a third step of correcting a difference in polishing amount caused by a polishing position on the polishing material based on a change in a polishing region of the sample with respect to the material. That is, by changing the polishing region (the inner peripheral side 5b and the outer peripheral side 5a) of the sample 5 with respect to the abrasive 2 at the start position S1 and the positions S2 to S16 after the movement, the sample relative to the abrasive is changed. Based on the change in the polishing region, the difference in polishing amount caused by the polishing position on the abrasive is corrected. Then, by using the sample moving mechanism (4A), the sample is moved from the start position for polishing the sample 5, and the sample 2 is moved to the polishing material 2 at the start position S1 and the positions S2 to S16 after the movement. Polishing caused by the polishing position on the polishing material based on the change of the polishing region of the sample with respect to the polishing material by changing the polishing region (inner peripheral side 5b and outer peripheral side 5a) of the polishing region 5 of the sample The amount difference is corrected. Here, changing the polishing region (inner peripheral side 5b and outer peripheral side 5a) of the sample 5 means changing the polishing region (outer peripheral side 5a) located on the outer peripheral side of the abrasive 2 at the start position S1 where the sample 5 is polished. In addition to changing to the inner peripheral side, the polishing region (inner peripheral side 5b) located on the inner peripheral side of the abrasive 2 at the start position S1 for polishing the sample 5 is changed to the outer peripheral side. Further , not only the sample is polished by using both the movement of the sample 5 by the sample moving mechanism (4A) and the rotation of the abrasive 2 by the polishing disc 3, but also the rotation of the abrasive 2 is stopped to stop the sample moving mechanism ( The sample may be polished only by moving the sample 5 according to 4A). In addition, although the disk-shaped abrasive is used as the abrasive 2, the thing of shapes other than a disk may be used as needed.

The sample moving mechanism is an XY moving mechanism that regulates the moving process of the sample in the combined direction of the X direction and the Y direction or in the X direction or the Y direction. Since it is necessary to move and maintain the polishing state of the sample 5 and the abrasive 2, in the following description, a three-dimensional table is used as the sample moving mechanism.
Specifically, as shown in FIGS. 3 and 4, the polishing apparatus according to the embodiment of the present invention is rotatably supported by the apparatus body 1 and has an abrasive 2 existing on the upper surface of the polishing board 3 (see FIG. 4). The three-dimensional table 4 that moves in the three-axis directions of the X-axis direction, the Y-axis direction, and the Z-axis direction orthogonal to each other, and the sample 5 that is supported by the three-dimensional table 4 and that faces the polishing surface 2a. 8 and a controller C shown in FIG. 8 for controlling the operation of the three-dimensional table 4.
As shown in FIGS. 3 and 4, the three-dimensional table 4 is moved from the start position S1 for polishing the sample 5 on the two orthogonal XY coordinate planes on the polishing board 3 to a position S2 after movement. XY axis moving mechanism 4A for moving 5 and Z axis moving mechanism 4B mounted on the XY axis mechanism 4A for moving the sample holder 6 in the Z direction (vertical direction in FIG. 1).

  As shown in FIG. 4, the upper surface of the polishing disk 3 is formed in a disk shape, and the disk-shaped abrasive 2 is mounted on the upper surface of the polishing disk 3 in a replaceable manner. A ring-shaped partition 11 is formed on the outside of the disk-shaped polishing disk 3 so as to rise. The ring-shaped partition 11 stops the cleaning liquid supplied from the supply nozzle 10 in the range of the polishing surface 2a of the abrasive 2 and appropriately discharges the cleaned cleaning liquid from a discharge port (not shown). It has become. In addition, in order to supply the turbid liquid in which the fine particle size abrasive powder is mixed, the sample 5 may be dripped from the supply nozzle 10 and the sample 5 may be polished by the fine particle size abrasive powder.

  As shown in FIGS. 3 and 4, the three-dimensional table 4 includes an X-axis table 7 shown in FIG. 5, a Y-axis table 8 shown in FIG. 6, and a Z-axis table 9 shown in FIG. . The X-axis table 7 and the Y-axis table 8 move the sample 5 from the start position S1 to polish the sample 5 on the two orthogonal XY coordinate planes on the abrasive 2 to the opposite position S2. An XY axis moving mechanism 4A is configured. Further, the Z-axis table 9 constitutes a Z-axis moving mechanism 4B that is mounted on the XY-axis mechanism 4A and moves the sample holder 6 in the Z direction (vertical direction in FIG. 1).

[Y-axis table]
As shown in FIG. 5, the X-axis table 7 is supported by the Y-axis table 8 and moves in the X-axis direction. First, the Y-axis table 8 will be described.
The Y-axis table 8 is moved in the Y-axis direction of the XY coordinate plane parallel to the upper surface of the polishing board 3, and as shown in FIG. 6, two parallel guide rails 8a and the parallel guides It has a feed screw 8b along the rail 8a, a Y-axis drive motor 8c, two support arms 8d, and a base 8e that rotatably supports the lower surface of the polishing board 3.

As shown in FIG. 6, the two guide rails 8a have a length that covers the Y-axis direction of the upper surface of the polishing board 3, and the Y-axis direction (depth direction in FIG. 3) on the lower surface of the base 8e. It is attached in parallel with each other. Both ends of the feed screw 8a are supported by bearings 8f, and are attached in a posture parallel to one of the two guide rails 8a. The Y-axis drive motor 8c is connected to the feed screw 8b through a transmission mechanism 8j. Accordingly, when the Y-axis drive motor 8c is rotationally driven clockwise or counterclockwise, the driving force is transmitted to the feed screw 8b via the transmission mechanism 8j, and the feed screw 8b is pivoted to the bearing 8f. It will be supported and rotate.
The bases of the two support arms 8d are respectively supported by the guide rails 8a and are guided by the guide rails 8a so as to be reciprocally movable in the Y-axis direction. The feed screw 8b is screwed into the base of one of the two support arms 8d, and the two support arms 8a are reciprocally movable in the Y-axis direction by the rotation of the feed screw 8b. It is supposed to be. Further, as shown in FIGS. 5 and 7, the two support arms 8 d are raised upward with respect to the polishing disc 3, and the two support arms 8 b are at the upper ends thereof as shown in FIG. 7. The X-axis table 7 is supported horizontally.

[X-axis table]
The X-axis table 7 is moved in the X-axis direction of an XY coordinate plane parallel to the upper surface of the polishing disc 3, and as shown in FIG. 5, a base 7a, two guide rails 7b, and a feed screw 7c, an X-axis drive motor 7d, and a moving piece 7g.

  As shown in FIG. 5, the base 7a has a length straddling the two support arms 8a of the Y-axis table 8, and is horizontally supported by the two support arms 8a of the Y-axis table 8. ing. The two guide rails 7b have a length that covers the X-axis direction of the polishing surface 2a of the abrasive 2 loaded on the polishing board 3, and the base 7a has an X-axis direction (left and right in FIG. 3). Direction) and are mounted facing each other in parallel. Both ends of the feed screw 7c are supported by bearings 7e, and are attached in the X-axis direction in a posture parallel to one of the two guide rails 7b. The X-axis drive motor 7d is connected to the feed screw 7c through a transmission mechanism 7f. Accordingly, when the X-axis drive motor 7d is rotationally driven clockwise or counterclockwise, the driving force is transmitted to the feed screw 7c via the transmission mechanism 7f, and the feed screw 7c is pivoted to the bearing 7f. It will be supported and rotate.

  The moving piece 7g is guided by the two guide rails 7b and is attached so as to be movable in the X-axis direction. The moving piece 7g is screwed with the feed screw 7c, and the moving piece 7g has the feeding screw. It can be reciprocated in the X-axis direction by the rotation of 7c.

[Z-axis table]
The Z-axis table 9 is supported by the moving piece 7g of the X-axis table 7 and supports the sample holder 6 so as to be able to reciprocate in the Z-axis direction. As shown in FIG. A rail 9b, a feed screw 9c, and a Z-axis drive motor 9d are provided. In addition, although the stepping motor was illustrated as drive motor 7d, 8c, 9e, it is not restricted to this motor.

  As shown in FIG. 7, the base 9a has a fitting groove 9e at its lower end, and the fitting groove 9e is fitted to the convex piece 7h of the moving piece 7g of the X-axis table 7 (see FIG. 5). The base 9a is fixed to the moving piece 7g of the X-axis table 7 (see FIG. 5). The guide rail 9b is attached to the base 9a in the Z-axis direction, and the base 6a of the sample holder 6 is supported by the upper and lower beams 9g attached to the base 9a so as to be able to reciprocate in the Z-axis direction. . Both ends of the feed screw 9c are supported by bearings and attached to the base 9a in the Z-axis direction, and the Z-axis drive motor 9d is connected to the feed screw 9c through a transmission mechanism 9f. . Therefore, when the Z-axis drive motor 9d is driven to rotate clockwise or counterclockwise, the driving force is transmitted to the feed screw 9c via the transmission mechanism 9f, and the base 6a of the sample holder 6 is Z It can move back and forth in the axial direction.

  The sample holder 6 is moved on the XY coordinate plane parallel to the upper surface of the polishing board 3 by the X-axis table 7 and the Y-axis table 8, and is also moved in the Z-axis direction (up and down in FIG. 3) by the Z-axis table 9. 3), 4 and 7, the base 6a, the moving shaft 6b, the chuck 6c, and the weight canceller 6d are supported. Have. The weight canceller 6d shown in FIG. 7 is used for high-magnification observation of a small area and obtaining the sample 5 with little damage by managing the load when the sample 5 having a relatively large polishing area is polished.

  The base 6a of the sample holder 6 is supported by a vertical beam 9g of the Z-axis table 9 so as to be reciprocable (movable up and down) in the Z-axis direction (vertical direction in FIG. 3). It is connected to the screw 9c. Accordingly, when the Z-axis drive motor 9e is rotated clockwise or counterclockwise, the feed screw 9c of the Z-axis table 9 rotates clockwise or counterclockwise around the Z axis, and this feed screw 9c. , The base 6a of the sample holder 6 is reciprocated (moved up and down) in the Z-axis direction.

  The moving shaft 6b is supported by the base 6a so as to be slidable in the Z-axis direction (vertical direction in FIG. 7), and the holder 6 is mounted on the lower end of the moving shaft 6b via the chuck 6c. The holder 6 holds a sample 5 to be polished. Further, the sample 5 is sandwiched between the sample stage 6c of the holder 6 and held in the holder 6, or the sample 5 is attached to the sample stage 6c and the holder 6c is mounted on the chuck 6c. Hold in holder 6.

The weight canceller 6d shown in FIG. 7 has a horizontal shaft 6e, an L-shaped bracket 6f, a weight 6g, and a connecting member 6h. The horizontal shaft 6e is rotatably supported in a horizontal posture on a bearing 6j provided at the upper end of the base 6a, and the short side 6k of the L-shaped bracket 6f is fixed to one end of the horizontal shaft 6e. .
The connecting member 6h connects the horizontal shaft 6e and the moving shaft 6b so as to convert the vertical movement of the moving shaft 6b into the rotation of the horizontal shaft 6e and transmit it. In the process of moving the moving shaft 6b upward, the connecting member 6h rotates the horizontal shaft 6e counterclockwise, and in the process of moving the moving shaft 6b downward, the connecting member 6h The horizontal shaft 6e is rotated clockwise. Since the total load of the sample holder 6 including the moving shaft 6b and the connecting member 6h acts as a pressing force when the sample 5 is polished by the polishing surface 2a of the abrasive 2, the L-shaped metal fitting 6f By adjusting the weight of the weight 6 g loaded on the long side to a weight that cancels the load of the sample holder 6, the applied pressure is extremely low so that the sample 5 is not damaged (ideally zero). Value). After the pressure applied by the sample holder 6 is canceled by the weight canceller 6d, a weight 6m corresponding to an appropriate contact pressure when the sample 5 is polished is attached to the moving shaft 6b, and the weight of the weight 6m Is added to the sample holder 6. Thereby, it can grind | polish correctly, without damaging the said sample. In addition, it can respond to canceling the load of the said sample holder 6 from which several load differs by changing the position of the pivot point which pivots the said L-shaped metal fitting 6f, and changing an insulator ratio.

  Instead of the weight canceller 6d and the weight 6m shown in FIG. 7, a weight controller shown in FIG. 10 may be used. The weight canceller 6d, which is a combination of the weight canceller 6d shown in FIG. 7 and the weight 6m, is optimal for managing the load when polishing the sample 5 having a relatively large polishing area, but the weight controller shown in FIG. This is optimal for managing the load when polishing the sample 5 having a relatively small area, and the weight controller shown in FIG. 7 or FIG. 10 is selected and used according to the size of the polishing area of the sample 5.

  In the weight controller shown in FIG. 10, a moving shaft 6b is supported on the base 6a of the sample holder 6 shown in FIG. 7 so as to be movable up and down, and the holder 6 is attached to the lower end of the moving shaft 6b. Further, a leaf spring 20 is attached between the holder 6 and the base 6a, and one end 20a of the leaf spring 20 is attached to the chuck 6c, and a middle portion thereof is bent to have a play 20b, and the other end. 20c is attached to the base 6a. The chuck 6c is provided with a sample stage 6k on which the sample 5 is set.

  The weight control shown in FIG. 10 is obtained when the sample 5 of the chuck 6c is brought into contact with the polishing surface 2a while the chuck 6c is supported in a free state without applying bending to the leaf spring 20. In this case, the load of the sample holder 6 applied to the sample 5 becomes almost zero. From this state, when the sample holder 6 is pushed down in the Z-axis direction by the Z-axis table 9 to pressurize the sample 5 and bring it into contact with the polishing surface 2a, a spring force corresponding to the pressure applied to the sample 5 is applied to the plate. The spring 20 accumulates power. Since the sample holder 6 is lowered by the Z-axis table 9 in the Z-axis direction toward the polishing surface 2a of the abrasive 2 in accordance with the polishing amount of the sample 5, the leaf spring 20 is not further bent. The force accumulated in the leaf spring 20 is applied to the sample 5 as a load necessary for polishing while polishing is continued, and polishing can be performed by applying a load necessary for polishing without damaging the sample. .

The weight controller shown in FIG. 10 is in a state where the chuck 6c is supported in a free state without applying bending to the leaf spring 20. The weight canceller 6d shown in FIG. A weight 6m corresponding to an appropriate contact pressure when polishing the sample 5 is attached to the moving shaft 6b, and the weight of the weight 6m is set to the sample holder. Add to 6. Thereby, it can grind | polish correctly, without damaging the said sample.
The weight controller shown in FIG. 10 has a configuration in which only the leaf spring 20 is used in place of the weight canceller 6d and the weight 6m shown in FIG. 7, and the configuration can be simplified.

[controller]
As described above, the controller C that controls the operation of the three-dimensional table 4 specifically controls the XY-axis moving mechanism 4A in the three-dimensional table 4 to drive in the XY directions of two axes orthogonal to each other. The sample 5 is moved away from the rotation center O of the abrasive 2 from the starting position S1 where the polishing is started to the polishing position S2, and the polishing area A on the outer peripheral side 5a of the sample 5 at the playing position S2 and The polishing area B on the inner peripheral side 5b has a function of inverting the polishing area A on the outer peripheral side 5a and the polishing area B on the inner peripheral side 5b of the sample 5 at the start position S1. The specific configuration will be described.

  As shown in FIG. 8, the controller C includes a key switch group 13 attached to the front panel of the apparatus main body 1 shown in FIGS. 3 and 4, a microscope LED 14 provided in the apparatus main body 1, a main CPU board 15, and the like. And a sub CPU board 16.

  As shown in FIG. 8, the main CPU board 15 has a main CPU 15a, a power supply unit, an LED driver 15c, a parameter memory 15d, and a drive motor driver 15e. The main CPU 15a includes an LED driver 15c, a parameter memory 15d, and a drive motor driver 15e. The main CPU 15 a controls the sub CPU 16 a of the sub CPU board 16. The power supply unit includes a power supply unit 15b for stepping down the voltage of the commercial power supply to, for example, AC 24V, a DC / DC converter 15f for converting AC 24V from the power supply unit 15b to DC 5V, and DC 5V from the DC / DC converter 15f to And a linear regulator 15j that steps down to 3 V, and supplies output power from the linear regulator 15j to the main CPU 15a.

  The LED driver 15c illuminates the sample 5 to be observed with a microscope by driving the LED 14 for the microscope based on a command from the main CPU 15a. The drive motor driver 15e drives and controls a drive motor 17 that rotationally drives the polishing board 3 based on a command from the main CPU 15a.

When the parameter memory 15d arbitrarily changes the positions of the sample holder 6 and the sample 5 within the XY coordinate plane parallel to the polishing surface 2a of the abrasive 2 and within the range of the polishing surface 2a of the abrasive. In addition, parameters for driving an X-axis drive motor 7d and a Y-axis drive motor 8c, which will be described later, are stored. The parameters are input by operating the key switch group 13 attached to the front panel of the apparatus main body 1 shown in FIGS.
An example of parameters stored in the parameter memory 15d will be described. The positions of the sample holder 6 and the sample 5 are within the XY coordinate plane parallel to the polishing surface 2a of the abrasive 2 and the abrasive 2 is polished. Within the range of the surface 2a, parameters of a trajectory for moving in an arc-like locus shown in FIG. 1, a spiral curve shown in FIG. 8, an inner trochoidal curve-like locus, or a zigzag shape are stored.

  As shown in FIG. 8, the sub CPU board 16 has a sub CPU 16a, an X-axis drive motor driver 16b, a Y-axis drive motor driver 16c, and a Z-axis based on a control command from the main CPU 15a. A drive motor driver 16d and a power supply unit. The sub CPU 16a drives and controls the driver 16b of the X axis drive motor based on the origin position information of the X axis drive motor 7d detected by the X axis origin sensor S1, and the Y axis origin sensor S2 detects the above. Based on the origin position information of the Y-axis drive motor 8c, the Y-axis drive motor driver 16c is driven and controlled, and based on the origin position information of the Z-axis drive motor 9e detected by the Z-axis origin sensor S3. The driver 16d of the Z-axis drive motor is driven and controlled. The power supply unit includes a DC / DC converter 16f that converts AC24V from the power supply unit 15b to DC5V, and a linear regulator 16j that steps down DC5V from the DC / DC converter 16f to DC3.3V. Output power from the linear regulator 16j is supplied to the sub CPU 16a.

  The X-axis drive motor driver 16b drives and controls the X-axis drive motor 7d of the X-axis table 7 to rotationally drive the X-axis feed screw 7c. The Y-axis drive motor driver 16c drives and controls the Y-axis drive motor 8c of the Y-axis table 8 to rotationally drive the Y-axis feed screw 8b. The Z-axis drive motor driver 16d drives and controls the Z-axis drive motor 9e of the Z-axis table 9 to rotate the Z-axis feed screw 9d.

  Reference numeral 18 denotes a joystick unit. An AC output signal from the joystick unit 18 is converted into a DC signal by an AC / DC converter and output to the sub CPU 16a.

  Next, a case where the sample 5 is polished using the polishing apparatus according to the present embodiment will be described. FIG. 1 shows that the XY axis moving mechanism 4A is driven and controlled in two orthogonal XY directions, and the sample 5 supported by the sample holder 6 avoids the rotation center O of the abrasive 2 and the outer peripheral side of the abrasive 2 An arcuate shape along 5a is moved from the polishing start position S1 to the play position S2, and the polishing area A on the outer peripheral side 5a and the polishing area B on the inner peripheral side 5b of the sample 5 at the play position S2 are moved to the start position. This shows a case of changing (reversing) the polishing area A on the outer peripheral side 5a and the polishing area B on the inner peripheral side 5b of the sample 5 in S1. The parameters of the locus for moving the sample 5 shown in FIG. 3 are input by the key switch group 13, and these parameters are stored in the parameter memory 15d.

  Next, the polishing board 3 with the abrasive 2 attached to the upper surface is attached to the spindle of the drive motor 17. After the fine sample 5 is attached to the corresponding work holder, the work holder is attached to the chuck 6 c of the sample holder 6. When the attachment of the sample 5 is completed, the moving shaft 6b of the sample holder 6 is moved downward so that the sample 5 comes into contact with the polishing surface 2a of the polishing material 2 of the polishing board 3. When the sample 5 is brought into contact with the polishing surface 2a of the abrasive 2, the load of the sample holder 6 is canceled using the weight canceller 6d, and a weight 6m of a load necessary for polishing is mounted on the moving shaft 6b of the sample holder 6. Then, the sample 5 is brought into contact with the polishing surface 2a of the abrasive 2 by the load of the weight of 6 m.

  Next, when a command to start polishing is input to the main CPU 15a mounted on the main substrate 15 by the key switch group 13, the main CPU 15a reads the parameter of the locus of the sample 5 shown in FIG. 1 from the parameter memory 15d, and calculates based on the parameter. The processing is executed, and the sub CPU 16a determines the amount of movement of the sample holder 5 in the X-axis direction by the X-axis table 7 and the amount of movement of the sample holder 5 by the Y-axis table 8 in the polishing surface 2a of the abrasive 2 Output to.

  The sub CPU 16a drives and controls the driver 16b of the X axis drive motor based on the origin position information of the X axis drive motor 7d detected by the X axis origin sensor S1, and the Y axis origin sensor S2 detects the above. Based on the origin position information of the Y-axis drive motor 8c, the Y-axis drive motor driver 16c is driven and controlled, and based on the origin position information of the Z-axis drive motor 9e detected by the Z-axis origin sensor S3. The driver 16d of the Z-axis drive motor is driven and controlled.

  The X-axis drive motor driver 16b drives and controls the X-axis drive motor 7d of the X-axis table 7 to rotationally drive the X-axis feed screw 7c. The Y-axis drive motor driver 16c drives and controls the Y-axis drive motor 8c of the Y-axis table 8 to rotationally drive the Y-axis feed screw 8b.

  As described above, as shown in FIG. 1, the controller C drives and controls the sample 5 in the XY directions of two axes orthogonal to the abrasive 2 by the XY axis moving mechanism 4A, and follows the outer peripheral side 5a of the abrasive 2. The sample 5 is moved from the polishing start position S1 in a circular arc shape to move the sample 5 from the polishing start position S1 for polishing the sample 5 (polishing start position S1 to post-movement position S2 to S15 or S16). Then, the polishing area A on the outer peripheral side 5a and the polishing area B on the inner peripheral side 5b of the sample 5 are changed (replaced) between the start position S1 and the moved positions S2 to S15 or S16. The difference in polishing amount due to the difference in peripheral speed between the inside and outside of the board 3 is corrected.

As shown in FIG. 1, when considering the trajectory of the sample 5, the polishing area A of the outer peripheral side 5a of the sample 5 ₁ in the polishing start position S1 is facing the outer periphery 2a of the abrasive 2, the inner circumferential side of the sample 5 ₁ The polishing area B of 5b faces the inner peripheral side 2b of the abrasive 2. When the sample 5 is moved from the polishing start position S1 based on the locus shown in FIG. 1, the outer circumferences of the samples 5 _{1 to} 5 ₅ (post-movement positions S1, S2, S3, S4, S5) up to 3 o'clock. The polishing area A on the side 5a has a high ratio of facing the outer peripheral side 2a of the abrasive 2, and the samples 5 _{6 to} 5 ₉ (post-movement positions S6, S7, S8, In S9, the polishing area B on the inner peripheral side 5b increases in proportion to the outer peripheral side 2a of the abrasive 2.

When reaching the post-movement position S9 in opposite station, polishing region A of the outer peripheral side 5a of the sample 5 ₉ in the post-movement position S9 is facing the inner periphery 2b of the abrasive 2, the inner circumferential side 5b of the sample 5 ₉ The polishing region B faces the outer peripheral side 2b. That is, the polishing region B of the polishing region A and the inner circumferential side 5b of the outer peripheral side 5a of the sample 5 ₉ at the post-movement position S9 polishing area A of the sample 5 ₁ of the outer peripheral side 5a at the start position S1 and This completely replaces the polishing area B on the inner peripheral side 5b.

Further, when moving from the 6 o'clock direction to the 9 o'clock direction, in the samples 5 _{10 to} 5 ₁₃ (post-movement positions S10, S11, S12, S13), the ratio of the polishing region B on the inner peripheral side 5b to the outer peripheral side 2a Will increase. Further, when moving from the 9 o'clock direction to the 12 o'clock direction (polishing start position S1), in the samples 5 _{14 to} 5 ₁₆ , 5 ₁ (post-movement positions S14, S15, S16, S1), the polishing area A on the outer peripheral side 5a. Increases the ratio of facing the outer peripheral side 2a of the abrasive 2.

  As described above, by moving the sample 5 from the start position S1 for polishing the sample 5 and changing the polishing region of the sample with respect to the abrasive at the start position S1 and the position after the movement, A difference in polishing amount due to a difference in peripheral speed between the inside and outside of the polishing disk is corrected.

  As described above, according to the present embodiment, the polishing region of the sample between the start position S1 and the moved position is changed through the movement process of the sample 5 from the start position S1 where the sample 5 is polished. Thus, since the difference in the polishing amount due to the difference in peripheral speed between the inside and outside of the polishing disk is corrected, the uneven polishing amount due to the peripheral speed difference between the inner and outer peripheral sides of the abrasive can be corrected uniformly.

Further, in FIG. 1, when focusing on an intermediate region between the outer peripheral side 5a and the inner peripheral side 5b of the sample 5 in the movement trajectory of the sample 5 returning from the polishing start position S1 to the original position through the post-movement position S9, the polishing is performed. middle area of the sample 5 ₁ to 5 ₅ in courses from the start position S1 to the 3 o'clock direction is often rate facing the outer peripheral side 2a, an intermediate area of the sample 5 ₁ to 5 ₅ percentage facing the inner periphery 2b Many.

Furthermore, 6 o'clock past 3 o'clock in the process leading to (position S9 after movement), the middle area of the sample ₅ 1 to 5 ₅ Many proportion facing the inner circumferential side 2b, the sample ₅ 1 to 5 ₅ The proportion of the intermediate region facing the outer peripheral side 2a increases.

Also in course of the trajectory of the sample 5-6 o'clock direction after moving the position S9 in the 12 o'clock direction of the polishing start position S1, the sample _{5 10-5} 15, _{5 1} of the intermediate region is in contact with the outer peripheral side 2a and the inner circumferential side 2b The area changes sequentially.

  As described above, since the area where the intermediate region of the sample 5 is in contact with the outer peripheral side 2a and the inner peripheral side 2b sequentially changes, nonuniformity due to the peripheral speed difference between the inner and outer peripheral sides of the polishing disc 3 in the intermediate region of the sample 5 The polishing amount can be corrected uniformly. Describing based on the electronic analysis pattern by EBSD shown in FIG. 12, the conventional mechanical polishing includes a surface processed layer as shown in FIG. 12A, but in the mechanical polishing according to the present embodiment, it is shown in FIG. As shown, polishing without a surface-treated layer is possible.

  Since a non-uniform polishing amount due to a difference in peripheral speed between the inside and outside of the polishing disk can be corrected uniformly, the surface of the sample to be polished does not sag, and the sample can be positioned at any position on the polishing surface. It is possible to accurately observe the crystal orientation of the entire polished surface.

  When observing the interfacial structure of the laminated structure when the sample is a laminated structure, in order to ensure the accuracy of observation and analysis of the interfacial structure of the laminated structure, there is a limit to polishing with a mechanical polishing machine, and it is difficult for experts Although it was necessary to polish by an advanced polishing method, in this embodiment, since the entire polished surface of the sample is polished flat, the accuracy of observation and analysis of the interface structure of the laminated structure is ensured. Observation can be performed accurately.

  Generation | occurrence | production of sagging can be suppressed because the grinding | polishing amount of the grinding | polishing surface of a sample makes the inner periphery side and outer periphery side uniform, As a result, it can grind | polish even if it does not embed resin in a sample.

  Further, as shown in FIG. 7, the sample holder 6 attaches the sample 5 to the lower end of the moving shaft 6b that moves up and down via the chuck 6c, so that the sample 5 is brought into contact with the polishing surface 2a of the abrasive 2. At this time, a load other than the sample 5, that is, a total load of the sample holder 6 such as the moving shaft 6 b and the chuck 6 c is applied to the sample 5, and the sample 5 is applied to the polishing surface 2 a of the abrasive 2 by receiving these loads. End up.

Therefore, in the present embodiment, the weight controller 6d is pivotally supported on the base so that the weight controller 6d can swing, and one end of the weight controller 6d is pivotally supported by the moving shaft 6b, thereby canceling the load applied to the sample 5 at the other end of the weight controller 6d. A weight 6m is attached to be exchangeable.
Therefore, by adjusting the weight 6 m, the load when the sample 5 comes into contact with the polishing surface of the abrasive can be canceled. As described above, after canceling the weight (load), the weight 6m corresponding to the load set when the sample 5 is polished by the polishing surface 2a of the abrasive 2 is mounted on the moving shaft 6b, so that an appropriate amount is obtained. The sample can be polished under load.

  Next, the result of polishing when the weight controller shown in FIG. 7 is used will be described with reference to FIG. FIG. 11 (a) is a view of the surface of the sample polished based on the polishing method according to the present embodiment. As is clear from FIG. 11 (a), there is no plastic fluidized layer on the surface to be polished, It can be seen that a normal tissue (material original tissue) is evident.

On the other hand, when the surface of the metal structure polished according to the polishing method according to the conventional example (see FIG. 2) is observed, the polished surface of the sample has a plastic fluidized bed as shown in FIG. There are many. In particular, an abnormal tissue is observed in a region surrounded by a white frame. Such an abnormal structure is observed by being polished with a large load or having a work-affected layer remaining on the surface of the sample. In order to eliminate this, the present embodiment polishes the sample with as little load as possible, and as shown in FIG. 11A, this is an optimal method capable of performing polishing without a plastic fluidized layer in the metal structure. .
The EBSD (Electron Back Scattering Diffraction) method is a crystal orientation analysis of a minute region, and a detailed crystal analysis can be performed from the generation of an electron beam backscatter diffraction pattern. When there is a surface processed layer, as shown in FIG. 12 (a), only a noisy EBSD image can be obtained, but when there is no surface processed layer, a clean EBSD image is obtained as shown in FIG. 12 (b). can get. As shown in FIG. 12B, an optimum method for polishing so as not to leave a surface processed layer is the polishing method of the present invention.

  According to the present invention, polishing instead of processing by IS or IM could be realized by mechanical polishing.

  By setting the movement trajectory of the sample 5 in the spiral shape shown in FIG. 9, the movement trajectory of the sample 5 can be set on the unused area in the polishing surface 2a on the polishing disc 3, and the sample 5 is polished. The polished surface 2a at the time is in the state of a new layer surface that is not worn away, and it is possible to avoid damaging the sample with shaving powder or the like at the time of polishing.

  When the weight controller using the spring 20b shown in FIG. 10 is used, the sample holder 6 can be supported by the spring 20b and the load of the sample holder 6 can be canceled to zero, and the sample 5 is necessary for polishing by the spring load of the spring 20b. Since a large load can be applied, a sample such as Al, Cu, Mg, which is a soft metal that is easily damaged by a surface, can be polished.

  In the above description, the sample moving process is set by the XY moving mechanism 4A in the combined direction of the X direction and the Y direction on the polishing board 3 as shown in FIG. 1, but the present invention is not limited to this. The sample moving process may be set only in one direction in the X direction or the Y direction by the XY moving mechanism 4A.

  The present invention has been described above with reference to the above embodiment, but the present invention is not limited to the above embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention. Further, the present invention includes a combination of some or all of the configurations of the above-described embodiments as appropriate.

  The polishing apparatus according to the present invention can realize polishing instead of processing by ion milling by mechanical polishing, and is optimal for, for example, EBSD sample preparation, semiconductor failure analysis, polishing of metals and polymer materials, etc. Become.

DESCRIPTION OF SYMBOLS 1 Apparatus body 2 Polishing material 2a Polishing surface 3 of polishing material 4 Polishing board 4 Moving table 4A XY-axis moving mechanism 5 Sample 6 Sample holder 7 X-axis table 8 Y-axis table C Controller

Claims (5)

In a polishing method for polishing a sample with a disc-shaped abrasive on a polishing disk,
Using an X-axis table that moves the sample in the X direction with respect to the abrasive and a Y-axis table that moves the X-axis table in the Y direction perpendicular to the X direction with respect to the abrasive , a first step of moving spirally is the synthetic direction of the X-direction along the said abrasive from the start position of polishing with the Y direction,
A second step of changing a polishing region of the sample with respect to the abrasive at the start position and the position after the movement through the movement process of the sample by the first step;
Simultaneously performing a third step of correcting a difference in polishing amount caused by a polishing position on the abrasive based on a change in a polishing region of the sample with respect to the abrasive in the second step;
Changing the polishing region of the sample means changing the polishing region located on the outer peripheral side of the abrasive at the starting position for polishing the sample to the inner peripheral side, and the polishing material at the starting position for polishing the sample. Is to change the polishing region located on the inner peripheral side to the outer peripheral side,
A polishing method characterized by the above. In the polishing method according to claim 1,
In the second step, through the process of moving the sample from the starting position for polishing the sample, the polishing region of the sample is changed relative to the inside and outside of the abrasive at the starting position and the position after the moving. A polishing method characterized by the above. In the polishing method according to claim 2,
In the second step, during the process of moving the sample from the starting position for polishing the sample, the polishing region of the sample is continuously connected to the inside and outside of the polishing disk at the start position and the position after the movement. A polishing method characterized in that the polishing method is changed. In a polishing apparatus for polishing a sample with a disc-shaped abrasive on a polishing disk,
Using an X-axis table that moves the sample in the X direction with respect to the abrasive and a Y-axis table that moves the X-axis table in the Y direction perpendicular to the X direction with respect to the abrasive , through the X-direction and the movement course of the spiral of the sample is a synthetic direction of the Y-direction from the start position of polishing, changes the polishing region of the sample with respect to the abrasive in position after the movement and the starting position By having a sample moving mechanism that corrects the difference in polishing amount caused by the polishing position on the abrasive,
Changing the polishing region of the sample means changing the polishing region located on the outer peripheral side of the abrasive at the starting position for polishing the sample to the inner peripheral side, and the polishing material at the starting position for polishing the sample. Is to change the polishing region located on the inner peripheral side to the outer peripheral side,
A polishing apparatus characterized by that. The polishing apparatus according to claim 4, wherein
The XY movement mechanism changes the polishing region of the sample with respect to the inside and outside of the abrasive material at the start position and the position after the movement through the movement process of the sample from the start position for polishing the sample. A polishing apparatus characterized by that.

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