JP3945940B2 - Sample polishing method and sample polishing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sample polishing method for polishing one surface of a sample such as a semiconductor substrate, and an apparatus used for carrying out this method.
[0002]
[Prior art]
A lamination process in which a conductor layer, a semiconductor layer, or an insulator layer is laminated on the surface of a semiconductor substrate such as a silicon substrate, and a pattern formation process in which a circuit pattern is formed on the surface of each laminated layer are repeated. In manufacturing a semiconductor device, the surface is polished and flattened so as not to hinder the formation of a circuit pattern on the surface of each layer obtained in the stacking step.
[0003]
In recent years, chemical mechanical polishing has been widely adopted as a polishing method for satisfactorily polishing the surface of such a semiconductor substrate. FIG. 8 is a side view schematically showing a configuration of a main part of a sample polishing apparatus conventionally used for the chemical mechanical polishing as described above. This sample polishing apparatus includes a holding table 1 that holds a sample W such as a semiconductor substrate to be polished on its lower surface by, for example, vacuum suction, and a polishing surface plate 2 that has its upper surface opposed to the lower surface of the holding table 1. It is configured with.
[0004]
The holding table 1 and the polishing surface plate 2 are both disk-shaped and are coaxially supported by the respective supporting shafts 10 and 20 orthogonal to the opposing surfaces thereof. It is designed to rotate around. A polishing pad 3 made of a resin such as polyurethane resin or acrylic resin is stretched over the entire surface of the polishing surface plate 2 that faces the holding table 1. A nozzle 30 for supplying a polishing slurry on the polishing pad 3 is disposed on the upper portion of the substrate.
[0005]
A dressing head 4 for dressing (sharpening) the polishing pad 3 at a position different from the holding table 1 is placed on the upper surface of the polishing surface plate 2 with its lower surface facing the surface of the polishing pad 3. It is arranged. The dress head 4 is coaxially supported by a support shaft 40 orthogonal to the surface facing the polishing surface plate 2, is driven to rotate about the axis of the support shaft 40, and extends in the radial direction of the polishing surface plate 2. It is configured to be movable.
[0006]
In the chemical mechanical polishing using the sample polishing apparatus as described above, the holding table 1 for holding the sample W is positioned on a predetermined circumference on the upper surface of the polishing surface plate 2, and the holding table 1 and the polishing surface plate 2 are rotated. As shown by a two-dot chain line in the figure, the polishing surface (lower surface) of the sample W is pressed against the surface of the polishing pad 3, and both surfaces of the polishing slurry supplied from the nozzle 30 are moved. This is done by sliding through. The polishing slurry supplied from the nozzle 30 contains abrasive particles and a reactive agent selected according to the sample W to be polished, and the polishing surface of the sample W brought into sliding contact with the polishing pad 3 is polished. The surface is flattened by mechanical polishing by the action of particles and chemical polishing by the action of a reactant.
[0007]
In the chemical mechanical polishing performed in this way, the surface properties of the polishing pad 3 attached to the polishing surface plate 2 change due to repeated sliding contact with the sample W, and the polishing particles and the reactant contained in the polishing slurry. In addition, there is a possibility that a desired polishing rate cannot be obtained due to change due to clogging (glazing) caused by polishing scraps generated by polishing.
[0008]
The dressing by the dress head 4 is performed, for example, every time a predetermined number of times of polishing is completed in order to restore the change in surface properties of the polishing pad 3 as described above and restore the polishing rate. The head 4 and the polishing surface plate 2 are rotated close to each other, and the lower surface (dressing surface) of the dressing head 4 is pressed against the surface of the polishing pad 3 whose properties have changed.
[0009]
The dress surface of the dress head 4 is formed by embedding hard particles such as diamond grains in a resin or metal base material with each part exposed on the surface and roughening the surface. Thus, the surface of the polishing pad 3 is recovered to a good surface property by pressing the roughened dress surface. As described above, the dressing head 4 is movable in the radial direction of the polishing surface plate 2, and the dressing of the polishing pad 3 is performed over the entire surface of the polishing pad 3 by the movement of the dressing head 4. Can do. At this time, a cleaning agent such as water may be supplied to the surface of the polishing pad 3 to perform dressing while washing away clogged abrasive particles, reactants, and polishing debris.
[0010]
[Problems to be solved by the invention]
In the sample polishing apparatus as described above, the polishing pad 3 attached to the upper surface of the polishing surface plate 2 gradually deteriorates as the polishing is repeated, and when this deterioration proceeds excessively, polishing by the dressing is performed. Since recovery of the rate cannot be expected, it is necessary to remove the deteriorated polishing pad 3 from the polishing surface plate 2 and replace it with a new polishing pad 3 every time a predetermined number of polishings are performed.
[0011]
However, the new polishing pad 3 immediately after the replacement cannot be said to have a stable surface property, and when the polishing is performed using the polishing pad 3 as it is, a desired polishing rate cannot be obtained. Since there is a problem, the above-described dressing is performed also on the new polishing pad 3, and the polishing is started after the surface properties are stabilized.
[0012]
However, the dressing for the new polishing pad 3 needs to be performed more carefully than the normal dressing performed for the polishing pad 3 in use for recovery of the polishing rate, and this dressing takes a long time, After replacing the polishing pad 3, there is a problem that the start-up time until the polishing is started using the polishing pad 3 becomes long, and the efficiency of the polishing work is reduced.
[0013]
In order to shorten the dressing time, it is effective to use a dressing head having a rough dress surface and increase the dressing amount per unit time. However, when a dressing head having a rough dressing surface is used, it is difficult to manage the time during the above-described normal dressing, the dressing amount is likely to be excessive or insufficient, and the desired dressing effect may not be obtained due to insufficient dressing. On the contrary, there is a problem that excessive dressing is performed, and the amount of wear of the polishing pad 3 during each dressing increases, resulting in a decrease in the life of the polishing pad 3.
[0014]
The present invention has been made in view of such circumstances, and reduces the dressing time at the time of replacement of the polishing pad, and provides a normal dressing performed on the polishing pad in use for recovery of the polishing rate. It is an object of the present invention to provide a sample polishing method and a sample polishing apparatus that can be stably performed.
[0015]
[Means for Solving the Problems]
In the sample polishing method according to the present invention, one surface of a sample held on a sample stage is pressed against the surface of a polishing pad that is stuck to a polishing surface plate, and the sample is slidably contacted while supplying a polishing slurry therebetween. In the sample polishing method for dressing the surface by pressing the dressing surface of the dressing head against the surface of the polishing pad while polishing one surface of the polishing pad, first and second dressing heads having dressing surfaces with different roughnesses The dressing of the surface of the polishing pad that has been leveled by polishing is carried out by the first head for dressing having a relatively fine dress surface and is newly attached to the polishing surface plate. Is implemented by a second dressing head having a relatively rough dressing surface.
[0016]
In the present invention, a first dress head having a relatively fine dress surface and a reduced dressing amount, and a second dress head having a relatively rough dress surface and an increased dressing amount, When dressing the surface of the polishing pad leveled by polishing, the first dressing head is used, and this dressing is performed stably to reduce the wear of the polishing pad and recover the target polishing rate. On the other hand, the dressing of the surface of the polishing pad newly attached to the polishing surface plate is carried out using a second dressing head having a relatively rough dressing surface and increasing the dressing amount. Shorten the time required for dressing and improve the efficiency of polishing work.
[0017]
Further, the dressing by the first dress head is also performed on a polishing pad during polishing of the sample.
[0018]
In the present invention, dressing by the first dressing head on the surface of the polishing pad in use is performed at a position different from this polishing position during polishing of the sample by the polishing pad, and the dressing time is separately set. A stable polishing rate is always obtained without providing it.
[0019]
  Also,The sample polishing apparatus according to the present invention comprises:In a sample polishing apparatus for polishing one surface of a sample held on a sample table against the surface of a polishing pad that is stuck to a polishing surface plate, the surface is pressed against the surface of the polishing pad. The first dressing head and the second dressing head for performing dressing are provided, and the second dressing head has a rough dress surface as compared with the first dressing head.It is characterized by that.
  Further, in the sample polishing apparatus according to the present invention, one surface of the sample held on the sample table is pressed against the surface of the polishing pad attached to the polishing surface plate to polish one surface of the sample, A first dressing head for dressing the surface of a polishing pad leveled by polishing in a sample polishing apparatus that presses the dress surface of a dressing head against the surface and dresses the surface, and the first dressing head And a second dressing head for dressing the surface of the polishing pad newly attached to the polishing surface plate.
[0020]
In the present invention, a first dress head having a relatively fine dress surface and a reduced dressing amount, and a second dress head having a relatively rough dress surface and an increased dressing amount, By using these properly or in combination, the dressing amount according to the purpose can be obtained, the time required for dressing a new polishing pad after replacement is shortened, and polishing in use Regular dressing for the pad is performed stably.
[0021]
The dressing surface of the first dressing head is characterized in that diamond grains having a grain size of 0.4 mm or less are embedded in a base material.
[0022]
The dressing surface of the first dressing head has a structure in which diamond grains having a grain size of 0.4 mm or less are embedded in a resin or metal base material, so that the dressing head is mainly used. The normal dressing for the polishing pad is stably performed. At this time, the dress surface of the second dress head is configured by embedding diamond grains having a grain size larger than the diamond grains used for the dress face of the first dress head in a similar base material.
[0023]
The dressing surface of the second dressing head is characterized in that diamond grains having a grain size of 0.2 mm or more are embedded in a base material.
[0024]
The dressing surface of the second dressing head has a structure in which diamond grains having a grain size of 0.2 mm or less are embedded in a resin or metal base material, so that a polishing pad mainly using this dressing head is used. Reduce the time required for dressing at start-up to such an extent that there is no practical problem. At this time, the dress surface of the first dress head is formed by embedding diamond grains having a grain size smaller than that used for the dress face of the second dress head in the same base material.
[0025]
A sample polishing method according to another invention of the present invention is a method in which one surface of a sample held on a sample table is pressed against the surface of a polishing pad attached to a polishing surface plate, and a sliding slurry is supplied while supplying a polishing slurry therebetween. In the sample polishing method of dressing the surface by pressing a dressing surface of a dressing head against the surface of the polishing pad while polishing one surface of the sample in contact with the surface of the polishing pad, The dressing of the surface of the polishing pad newly attached to the polishing surface plate is performed by changing the pressing surface pressure of the dress surface of the dress head to a large or small.
[0026]
In the present invention, the dressing of the surface of the polishing pad leveled by polishing is carried out in a state in which the pressure of the dressing surface pressed against the surface of the polishing pad is reduced and the dressing amount is suppressed, and the wear of the polishing pad is reduced. The target polishing rate can be recovered while suppressing the above. In addition, the dressing of the surface of the polishing pad newly attached to the polishing surface plate is carried out with the dressing surface pressed against the surface of the polishing pad to increase the dressing amount. To improve the efficiency of polishing work.
[0027]
  Also,Main departureClearlySample polishingapparatusIsIn a sample polishing apparatus that polishes one surface of a sample held on a sample table against the surface of a polishing pad that is stuck to a polishing surface plate, the dress surface is pressed against the surface of the polishing pad. A dressing head for dressing the surface; and a surface pressure changing means attached to the dressing head for changing the pressing surface pressure of the dress surface to a large or small.It is characterized by that.
  Furthermore, the sample polishing apparatus according to the present invention is a sample polishing apparatus for pressing one surface of a sample held on a sample table against a surface of a polishing pad attached to a polishing surface plate, and polishing one surface of the sample. The surface of the polishing pad in which the dressing surface is pressed against the surface of the polishing pad, the dressing amount for dressing the surface, and the dressing amount with respect to the surface of the polishing pad leveled by polishing is newly attached to the polishing surface plate And a means for changing the pressing surface pressure of the dressing surface so as to be suppressed compared to the dressing amount with respect to.
[0028]
In this invention, the surface pressure changing means is attached to the head for dressing, and by the operation of the means, the pressing surface pressure of the dress surface against the polishing pad is changed by the operation of the surface pressure changing means. It is possible to obtain a suitable dressing amount, to shorten the time required for dressing a new polishing pad after replacement, and to stably perform normal dressing on the polishing pad in use.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof. FIG. 1 is a side view schematically showing a configuration of a main part of a sample polishing apparatus used for carrying out a sample polishing method according to the present invention, and FIG. 2 is a plan view of the sample polishing apparatus as viewed from above. Like the conventional sample polishing apparatus shown in FIG. 8, this sample polishing apparatus has a thick disk-shaped holding table 1 that holds a sample W to be polished on its lower surface, and an upper surface on the lower surface of the holding table 1. And a disk-shaped polishing surface plate 2 facing each other. In FIG. 1, the holding table 1 is shown coaxially with the polishing surface plate 2, but actually, as shown in FIG. 2, the holding table 1 is shifted from the center of the polishing surface plate 2 to the front side in FIG. It is arranged.
[0030]
The holding table 1 and the polishing surface plate 2 are coaxially supported by the respective support shafts 10 and 20 orthogonal to the facing surfaces thereof, and are driven to rotate around the shafts of the support shafts 10 and 20. It has been. A polishing pad 3 made of a resin such as polyurethane resin or acrylic resin is stretched over the entire surface of the polishing surface plate 2 facing the holding table 1. In the upper part, a nozzle 30 for supplying a polishing slurry on the polishing pad 3 is arranged.
[0031]
Further, above the polishing platen 2, a mode that passes through the center of the polishing platen 2 and crosses in the radial direction at a position that does not interfere with the holding table 1 in the circumferential direction and does not interfere with the nozzle 30 in the vertical direction. A support frame 5 is installed on the support frame 5, and a first dress head 51 and a second dress head 52 for dressing (sharpening) the polishing pad 3 are provided on the support frame 5. The surface plate 2 is arranged on both sides of the center portion.
[0032]
Both the first and second dress heads 51 and 52 have a disk shape, and keep their lower surfaces (dress surfaces) parallel to the upper surface of the polishing surface plate 2, that is, the surface of the polishing pad 3. In the direction of rotating around the respective support shafts, moving in the radial direction of the polishing surface plate 2 along the support frame 5, and in the direction of contacting and separating from the surface of the polishing pad 3. Is configured to move.
[0033]
In the illustrated apparatus, the first and second dress heads 51 and 52 have different dress surface roughnesses so that the latter dress surface is rougher than the former dress surface. FIG. 3 is a plan view of the dress surface of the first and second dress heads 51 and 52. As shown in the figure, the dress surface is formed by dividing the entire surface into a sector shape in the circumferential direction. Eight dressed parts 5a, 5a ... with diamond grains embedded.
[0034]
FIG. 4 is an enlarged plan view showing a part of the dress portion 5a. As shown in the figure, the dress portion 5a is configured by embedding diamond grains 5b, 5b,... At a plurality of locations in the plane and staggering them at appropriate intervals. The embedding of these diamond grains 5b, 5b,... Can be realized by appropriate means such as electrodeposition and sticking, which can obtain strength that can resist resistance during dressing.
[0035]
The roughness of the dress surfaces of the first and second dress heads 51 and 52 is varied by changing the grain size d of the diamond grains 5b, 5b. The dress surface of the first dress head 51 can be configured by arranging diamond grains 5b, 5b... Having a grain size of 0.4 mm or less on each dress portion 5a. In this case, the dress surface of the second dress head 52 is provided with diamond grains 5b, 5b,... Having a larger grain size than that used in the first dress head 51, so that the first dress head 51 Keep it rougher than the dress surface.
[0036]
Further, the dress surface of the second dress head 52 can be configured by arranging diamond grains 5b, 5b,... Having a grain size of 0.2 mm or more on each dress portion 5a. In this case, the dress surface of the first dress head 51 is provided with diamond grains 5b, 5b... Having a smaller particle diameter than that used in the second dress head 52, and the dress of the second dress head 52 is arranged. Keep it finer than the surface.
[0037]
The difference in the roughness of the dress surfaces of the first and second dress heads 51, 52 is not limited to the means for changing the grain size of the diamond grains 5b, 5b, as described above, but the diamond in each dress portion 5a. It can also be realized by other means such as changing the arrangement interval of the grains 5b, 5b. In the above embodiment, the dress surfaces of the first and second dress heads 51, 52 are divided into eight dress portions 5a, 5a,... In the circumferential direction. Alternatively, the dress surface may be formed by more divisions. Furthermore, the entire lower surface of the first and second dress heads 51 and 52 may be constituted by a single dress surface.
[0038]
In the chemical mechanical polishing using the sample polishing apparatus as described above, as in the conventional apparatus shown in FIG. 8, the holding table 1 and the polishing platen 2 are moved closer to each other while being rotated, and a two-dot chain line in FIG. As shown, the polishing surface (lower surface) of the sample W held on the lower surface of the holding table 1 is pressed against the surface of the polishing pad 3, and both surfaces are brought into sliding contact with the polishing slurry supplied from the nozzle 30. The polishing surface of the sample W is flattened by mechanical polishing by the action of abrasive particles contained in the polishing slurry and chemical polishing by the action of a reactant.
[0039]
In addition, dressing (sharpening) of the surface of the polishing pad 3 is performed by bringing the first dress head 51 or the second dress head 52 and the polishing surface plate 2 closer to each other while rotating, and two points in FIG. As indicated by the chain line, the dress surface of the first dress head 51 or the second dress head 52 is pressed against the surface of the polishing pad 3 stretched on the upper surface of the polishing surface plate 2, and these both surfaces are brought into sliding contact with each other. Done. At this time, dressing of the entire surface of the polishing pad 3 can be performed by moving the first and second dress heads 51 and 52 along the support frame 5 in the radial direction.
[0040]
Such dressing is performed to repair the surface properties of the polishing pad 3 leveled by polishing and restore the desired polishing rate, as described above, while being newly attached to the polishing surface plate 2. This is performed to stabilize the surface properties of the polished polishing pad 3 before the polishing using the polishing pad 3 is started. In the present invention, the first dressing head 51 and the second dressing head 52 are provided in accordance with the state of the target polishing pad 3 and are appropriate in each of the above cases. This is so that dressing is performed.
[0041]
FIG. 5 is a diagram showing a temporal change in the dressing amount by the first and second dress heads 51 and 52. As described above, when the first dress head 51 having a fine dress surface is used, the dressing amount gradually increases with the passage of time as shown by the broken line in the figure, whereas it is rough. When the second dressing head having a dress surface is used, the dressing amount shows a characteristic of increasing sharply as time passes, as indicated by a solid line in the figure.
[0042]
In the present invention, when such a difference in dressing characteristics is used and the polishing pad 3 being used for polishing is targeted, since the required dressing amount is small, the dressing amount is small. The first dress head 51 that suppresses the above is used. As a result, a desired dressing amount can be obtained without a large error by managing the dressing time, and recovery of the target polishing rate can be reliably realized while suppressing unnecessary wear of the polishing pad.
[0043]
On the other hand, when the pre-use polishing pad 3 newly attached to the polishing surface plate 2 is a target, since the required dressing amount is large, it has a rough dress surface and a large dressing amount is obtained. The second dress head 52 is used. As a result, the surface of the new polishing pad 3 immediately after the replacement can be noticed in a short time, and the surface properties necessary for polishing can be quickly realized. After the replacement of the polishing pad 3, the polishing is started. It is possible to shorten the start-up time as much as possible. This is useful for improving the polishing efficiency in the sample polishing apparatus.
[0044]
The first and second dress heads 51 and 52 may be used in an appropriate combination instead of being used alone. For example, when dressing the polishing pad 3 before use, both the first and second dress heads 51 and 52 may be used to further shorten the startup time, and the second dress may be used. After performing rough dressing with the head 52 for a predetermined time, finish dressing with the first head 51 for dressing may be performed so that desired properties can be accurately realized on the surface of the polishing pad 3 before starting polishing.
[0045]
FIG. 6 is a side view schematically showing a main part of another embodiment of the sample polishing apparatus used for carrying out the sample polishing method according to the present invention. This sample polishing apparatus is similar to the sample polishing apparatus shown in FIGS. 1 and 8, the holding table 1 holding the sample W, the polishing surface plate 2 on which the polishing pad 3 is stuck, and the center of the polishing surface plate 2. A polishing slurry supply nozzle 30 disposed on the top, and the lower surface of the sample W held on the holding table 1 is pressed against the upper surface of the polishing pad 3 under the supply of the polishing slurry by the nozzle 30; The bottom surface of the sample W is subjected to chemical mechanical polishing by being brought into sliding contact with rotation of the supporting table 1 and the polishing surface plate 2 around the respective support shafts 10 and 20.
[0046]
Above the polishing surface plate 2, a support frame 6 is installed in parallel with the upper surface of the polishing surface plate 2 from the peripheral portion on the opposite side to the arrangement position of the holding table 1 toward the center portion. A single dressing head 60 for dressing (sharpening) the surface of the polishing pad 3 is supported on the support frame 6 in a suspended manner.
[0047]
The dress head 60 can be rotated about its respective axis similarly to the first and second dress heads 51 and 52 shown in FIG. 1, and further along the support frame 6 in the radial direction of the polishing pad 3. It is possible to move in the direction toward and away from the polishing pad 3. The lower surface (dressing surface) of the dress head 60 is provided with a plurality of diamond grains having a predetermined grain size, as in the first and second dress heads 51 and 52 shown in FIGS. It is configured.
[0048]
In the sample polishing apparatus configured as described above, the dressing on the surface of the polishing pad 3 is performed by bringing the dressing head 60 and the polishing platen 2 closer to each other while rotating, as indicated by a two-dot chain line in the figure. By pressing the lower surface (dressing surface) of the dressing head 60 against the upper surface of the polishing pad 3 stretched to the polishing surface plate 2, and further moving the dressing head 60 in the radial direction along the support frame 6. This is performed over the entire surface of the polishing pad 3.
[0049]
The dressing head 60 is provided with means for changing the pressing surface pressure of the dressing surface against the upper surface of the polishing pad 3 at the time of dressing performed as described above, and the dressing according to the state of the polishing pad 3 is described above. The pressing surface pressure is changed to be larger or smaller.
[0050]
FIG. 7 is a diagram showing the configuration of the dress head 60 and the surface pressure changing means. As shown in the sectional view in the figure, the head for dressing 60 has a piston plate 6b fitted in the cylindrical outer cylinder 6a so as to be slidable in the vertical direction, and the inside of the outer cylinder 6a. Is divided into upper and lower cylinder chambers 6c and 6d to constitute a pneumatic cylinder, while the lower end of the rod 6e extending below the piston plate 6b and passing through the bottom wall of the outer cylinder 6a Is provided with a dress plate 6f provided on the lower surface thereof.
[0051]
A pressure guide ring 62 constrained in a non-rotating state is fitted on a rotating shaft 61 of a dressing head 60 connected to the upper surface of the outer cylinder 6a, and a cylinder chamber is formed above and below the piston plate 6b. 6c and 6d are communicated with different pressure guiding grooves provided on the inner surface of the pressure guiding ring 62 via pressure guiding paths 63 and 64 formed on the peripheral wall of the outer cylinder 6a. Each of the pressure guiding grooves communicates with the outside of the pressure guiding ring 62, and is constituted on the discharge side of the air pump P that is a generation source of the surface pressure by pressure guiding pipes 65 and 66 respectively connected to the communicating portions. The electropneumatic regulator (voltage / pneumatic pressure conversion means) 7 is connected.
[0052]
As shown in the figure, the electropneumatic regulator 7 includes a fixed throttle 71 and a variable throttle 72 in series in this order in the middle of the discharge path 70 of the air pump P. The pressure guiding pipe 66 is connected between the throttle 71 and the variable throttle 72 and on the downstream side of the variable throttle 72, respectively. The opening degree of the variable throttle 72 is increased or decreased in accordance with an open / close signal given from the outside.
[0053]
With the above configuration, there is a gap between the upper cylinder chamber 6c communicating with the pressure guiding pipe 65 via the pressure guiding path 63 and the lower cylinder chamber 6c communicating with the pressure guiding pipe 66 via the pressure guiding path 64. A pressure difference occurs before and after the variable throttle 72, and this pressure difference acts on the piston plate 6b to press the dress plate 6f downward via the rod 6e, and is configured on the lower surface of the dress plate 6f. The dressed surface is pressed against the surface of the polishing pad 3 with a surface pressure corresponding to the pressing force to perform dressing.
[0054]
At this time, the magnitude of the pressing surface pressure of the dressing head 60 corresponds to the magnitude of the pressure difference generated before and after the variable throttle 72, and this pressure difference increases as the throttle area of the variable throttle 72 decreases. It becomes. In addition, when dressing is performed by changing the pressing surface pressure, the same dressing characteristics as in FIG. 5 can be obtained. When the pressing surface pressure is small, as the time passes, as shown by the broken line in the figure, In contrast, when the pressing surface pressure is large, the dressing amount increases sharply with time as shown by the solid line in the figure. Thus, in the sample polishing apparatus including the dressing head 60 shown in FIG. 7, dressing under different characteristics can be performed by changing the aperture of the variable aperture 72 of the electropneumatic regulator 7.
[0055]
Thus, when the polishing pad 3 being used for polishing is targeted, dressing is performed in a state where the opening degree of the variable throttle 72 is increased and the dressing amount is suppressed under a small pressing surface pressure. . Accordingly, a desired dressing amount can be obtained without a large error, and the polishing rate can be reliably recovered while suppressing unnecessary wear of the polishing pad. When the polishing pad 3 newly attached to the polishing surface plate 2 is used as a target, the opening degree of the variable throttle 72 is reduced and dressing is performed under a large pressing surface pressure. As a result, the polishing pad 3 immediately after the replacement can be noticed in a short time, and the surface properties necessary for polishing can be quickly realized, and the startup time can be shortened as much as possible.
[0056]
Note that the open / close signal given to the electropneumatic regulator 7 to change the aperture of the variable throttle 72 may be given by a manual operation by an operator, or from a process control unit for managing the entire polishing process. It is good also as a structure to give. The pressing surface pressure changing means is not limited to the configuration shown in the above embodiment, and can be realized by an appropriate configuration.
[0057]
【The invention's effect】
As described above in detail, in the sample polishing method according to the present invention, the normal dressing made for recovery of the polishing rate with respect to the polishing pad in use has a relatively fine dress surface, and the dressing amount is reduced. Since the first head for dressing is performed, prevention of unnecessary wear of the polishing pad and reliable recovery of the polishing rate can be easily realized under relatively gradual time management. Since the dressing for the polishing pad newly attached to the polishing surface plate is carried out by the second dress head having a relatively rough dress surface and an increased dressing amount, the polishing after this dressing starts The start-up time can be shortened, and the efficiency of the entire polishing operation can be improved.
[0058]
In the sample polishing apparatus according to the present invention, the dressing head used for dressing the polishing pad surface is relatively rough with the first dressing head having a relatively fine dress surface and a reduced dressing amount. Since the second dressing head having a dress surface and an increased dressing amount is provided, the first and second dressing heads are selectively used according to the state of the polishing pad to be polished, or appropriately. Can be used in combination to perform the method described above, ensuring stable dressing on the polishing pad in use to recover the polishing rate and preventing unnecessary wear of the polishing pad In addition to preventing a decrease in service life, the time required for dressing a new polishing pad after replacement can be shortened, improving the efficiency of the entire polishing operation. It can be achieved.
[0059]
In the sample polishing method according to another invention of the present invention, the normal dressing performed for recovering the polishing rate with respect to the polishing pad in use is performed, the pressing surface pressure of the dressing head is reduced, and the dressing is performed. Since the amount is reduced, it is possible to easily prevent unnecessary wear of the polishing pad and to reliably recover the polishing rate under relatively gradual time management. Since the dressing of the surface of the polishing pad newly attached to the board is performed in a state in which the pressing surface pressure of the dressing head is increased and the dressing amount is increased, the start-up time until the start of polishing after this dressing Thus, the efficiency of the entire polishing operation can be improved.
[0060]
Further, in the sample polishing apparatus according to another invention of the present invention, the dressing head used for dressing the polishing pad surface is provided with the surface pressure changing means, so that the dressing head is in accordance with the state of the polishing pad to be polished. By changing the pressing surface pressure, a dressing amount corresponding to the purpose can be obtained, and it becomes possible to carry out the above-described method, which is usually performed for a polishing pad in use for recovering the polishing rate. Stable dressing prevents unnecessary wear of the polishing pad, prevents a decrease in service life, shortens the time required for dressing a new polishing pad after replacement, and improves polishing efficiency The present invention has excellent effects, such as being able to contribute.
[Brief description of the drawings]
FIG. 1 is a side view schematically showing a configuration of a main part of a sample polishing apparatus used for implementing a sample polishing apparatus according to the present invention.
FIG. 2 is a plan view of the sample polishing apparatus shown in FIG. 1 as viewed from above.
FIG. 3 is a plan view of a dress surface of first and second dress heads.
FIG. 4 is an enlarged plan view showing a part of a dress portion.
FIG. 5 is a diagram illustrating a temporal change in the dressing amount by the first and second dressing heads.
FIG. 6 is a side view schematically showing a main part of another embodiment of a sample polishing apparatus used for carrying out a sample polishing method according to the present invention.
7 is a diagram showing a configuration of a dressing head and a surface pressure changing unit used in the sample polishing apparatus shown in FIG. 6;
FIG. 8 is a side view schematically showing a configuration of a main part of a conventional sample polishing apparatus.
[Explanation of symbols]
1 Holding stand
2 Polishing surface plate
3 Polishing pad
5a Dress part
5b diamond grains
6a outer cylinder
6b Piston plate
6c Cylinder chamber
6d cylinder chamber
7 Electro-pneumatic regulator
51 First dress head
52 Second dress head
60 Head for dress

Claims (9)

While pressing one surface of the sample held on the sample table against the surface of the polishing pad stuck to the polishing surface plate, the surface of the sample is polished by being brought into sliding contact while supplying a polishing slurry therebetween, while the polishing In the sample polishing method of pressing the dress surface of the dress head against the surface of the pad and dressing the surface,
Using the first and second dress heads having dress surfaces with different roughnesses, the dressing of the surface of the polishing pad leveled by polishing is performed by the first dress head having a relatively fine dress surface. ,
A sample polishing method, wherein dressing of the surface of a polishing pad newly attached to a polishing surface plate is performed by a second dress head having a relatively rough dress surface.   The sample polishing method according to claim 1, wherein dressing by the first dress head is performed also on a polishing pad during polishing of the sample. In a sample polishing apparatus for pressing one surface of a sample held on a sample table against the surface of a polishing pad attached to a polishing surface plate and polishing one surface of the sample,
A first dressing head and a second dressing head which are pressed against the surface of the polishing pad to perform dressing on the surface;
The sample polishing apparatus , wherein the second dress head has a rough dress surface as compared with the first dress head . One surface of the sample held on the sample table is pressed against the surface of the polishing pad attached to the polishing surface plate to polish one surface of the sample, while the dress surface of the dressing head is pressed against the surface of the polishing pad. In the sample polishing apparatus for dressing the surface,
  A first dressing head for dressing the surface of the polishing pad leveled by polishing;
  A second dressing head having a rough dress surface compared to the first dressing head and performing dressing on the surface of the polishing pad newly attached to the polishing surface plate;
  A sample polishing apparatus comprising: The dress surface of the first head dress, sample polishing apparatus according to claim 3 or claim 4 diamond grains are constituted by embedded in a substrate having a particle size of less than 0.4 mm. The dress surface of the second head dress, sample polishing apparatus according to claim 3 or claim 4 diamond grains are constituted by embedding a substrate having a particle size of more than 0.2 mm. While pressing one surface of the sample held on the sample table against the surface of the polishing pad stuck to the polishing surface plate, the surface of the sample is polished by being brought into sliding contact while supplying a polishing slurry therebetween, while the polishing In the sample polishing method of pressing the dress surface of the dress head against the surface of the pad and dressing the surface,
The dressing on the surface of the polishing pad leveled by polishing and the dressing on the surface of the polishing pad newly attached to the polishing surface plate are changed to a large or small pressure on the dressing surface of the dress head. A method for polishing a sample, comprising: In a sample polishing apparatus for pressing one surface of a sample held on a sample table against the surface of a polishing pad attached to a polishing surface plate and polishing one surface of the sample,
  A dress head for pressing the dress surface against the surface of the polishing pad and dressing the surface;
  A surface pressure changing means attached to the dress head for changing the pressing surface pressure of the dress surface to a large or small;
  A sample polishing apparatus comprising: In a sample polishing apparatus for pressing one surface of a sample held on a sample table against the surface of a polishing pad attached to a polishing surface plate and polishing one surface of the sample,
  A dress head for pressing the dress surface against the surface of the polishing pad and dressing the surface;
  The amount of dressing on the surface of the polishing pad that has been leveled by polishing is newly applied to the polishing surface plate Means for changing the pressing surface pressure of the dress surface so that the dressing amount against the surface of the worn polishing pad is suppressed.
  A sample polishing apparatus comprising:

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