JP3895710B2 - Probe scanning device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a probe scanning apparatus such as a scanning probe microscope, and more particularly to a probe scanning apparatus having a zoom function that has good operability and enables high-accuracy observation of a sample surface without being affected by heat or the like. .
[0002]
[Prior art]
Previously, the present applicant invented a probe scanning device having a zoom function as shown in FIG. 9 and filed a patent application (Japanese Patent Application No. Heisei 8118015). The configuration and operation of this probe scanning device will be briefly described below.
[0003]
A first voice coil motor including a magnet 2 having a mandrel 3, a mover 4 around which a coil 6 is wound, and a membrane 5 is attached to the upper inside of the housing 1. A spindle 8 extending in the z direction is fixed to the mover 4. A displacement detector 9 is attached to the lower end of the spindle 8, and a cantilever and a probe (tip) 10 are attached to the displacement detector 9.
[0004]
On the other hand, the housing 1 has a narrow tube portion 14 protruding into the sample chamber and a thick tube portion 15 connected to the thin tube portion 15, and the middle cylinder 13 is supported inside the thick tube portion 15 via a viscous body 17. The spindle 8 is elastically supported by first and second springs 11 and 12 held by the inner cylinder. The heating coil 16 is energized in order to soften the viscous body 17 when the probe 10 is coarsely moved.
[0005]
A second voice coil motor comprising a magnet 21 having a mandrel 22, a mover 23 around which a coil 25 is wound, and a membrane 24 is attached to the inside of the housing 1. Yes. A spindle 27 extending in the x direction is attached to the mover 23, and the open end of the spindle 27 is fixed to a part 15 a of the thick tube portion 15 via a thin line 26. Although not shown, a third voice coil motor is attached in a direction different from the second voice coil motor by 90 °. Similarly to the above, the thin wire and spindle not shown are connected to the third voice coil motor. The mover of the voice coil motor and the thick tube portion 15 are connected. The probe 10 is scanned in the xy direction by driving the second and third voice coil motors.
[0006]
A sample table 31 is provided at a position facing the probe 10, and a sample 32 to be inspected or processed is placed on the sample table 31. The sample table 31 is installed on a coarse motion x, y, z stage 33.
In the vicinity of the magnet 21, a holder 34, a heating coil 35, a viscous body 36 put in the holder 34, a plate fixed at one end to the spindle 27 and the other end planted in the viscous body 36. A zoom device comprising a spring 37 and a clamp device 38 is provided.
[0007]
According to this zoom device, the heating coil 35 is energized to soften the viscous body 36, the probe 10 is carried over the position of the sample 32 to be zoomed by the x, y scanning mechanism, and then the energization of the heating coil 35 is stopped. Thus, the viscous body 36 is solidified. In this way, the spring constant of the leaf spring 37 is added to the spring constant in the combined lateral direction of the narrow tube portion 14 and the large tube portion 15, and the x scanning width is limited. By operating a zoom device not shown in the y direction as well, the y scanning width is similarly limited, and a zoom function can be realized. The details are described in detail in the specification of the above-mentioned patent application, and the description is omitted.
[0008]
[Problems to be solved by the invention]
However, the above-described apparatus has the following problems. (1) When operating the zoom function, the heating coil 35 is energized to soften the viscous body 36, the probe 10 is carried over the position of the sample 32 to be zoomed, and then the energization of the heating coil 35 is stopped to make the viscosity Since the body 36 is solidified, the time required to soften the viscous body 36 by energizing the heating coil 35 and the time required to solidify the viscous body 36 by stopping the energization of the heating coil 35 are large. Can't get into action. (2) In normal times when the zoom function is not used, the viscous coil 36 is softened by energizing the heating coil 35. At this time, the heat generated by the heating coil 35 is transmitted to the scanner section including the thin tube section 14 and the thick tube section 15 through the leaf spring 37 and the spindle 27, and the members constituting the scanner section are thermally expanded. For this reason, the probe 10 is moved, and the detection image of the sample 32 is distorted.
[0009]
An object of the present invention is to provide a probe scanning apparatus that eliminates the problems of the prior art described above, has good operability, and does not cause distortion in a detected image of a sample.
[0010]
[Means for Solving the Problems]
In order to achieve the above-described object, the present invention provides a probe scanning apparatus having a configuration in which at least power from a voice coil motor arranged in the x and y directions is transmitted to a scanner unit via a spindle. There is a first feature in that a switch means using a low melting point metal for selectively connecting the elastic member is provided, and the switch means is used for zooming by connecting the elastic member to the spindle. A second feature is that the switch means is composed of a cylindrical member provided with a heating member on its outer periphery and a low melting point metal filled in the cylindrical member. Further, in the probe scanning apparatus having a configuration for transmitting at least power from a voice coil motor arranged in the x and y directions to a scanner unit including a narrow tube unit and a large tube unit via a spindle, the narrow tube unit; A cylindrical tube having coaxial elasticity and switch means for selectively connecting the cylindrical tube to the thick tube portion, and by connecting the cylindrical tube to the thick tube portion by the switch means; The third feature is that the zooming is performed.
[0011]
According to the present invention, since the switch means using the low melting point metal is used, the temperature at which the low melting point metal is changed from solidification to softening is low, and the amount of heat required to switch the switch means can be reduced. Therefore, switching of the switch means can be performed quickly, and a zoom mechanism with good operability can be provided. Further, since the amount of heat required to switch the switch means is small, it is possible to prevent this heat from being conducted to the scanner unit and adversely affecting the scanner unit.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 shows a cross-sectional view of a main part of one embodiment of the present invention. The zoom mechanism of the present embodiment is housed in a casing 1 or a voice coil box formed as a separate member, and includes a zoom spring 51, a mechanical zoom switch 52, and a parallel spring 53. It is configured. A fan 54 generates air flow a through a hole formed in the voice coil box. In addition, other code | symbols show the same or equivalent as FIG.
[0013]
Next, a specific example of the mechanical zoom switch 52 will be described with reference to FIGS. 2 is a cross-sectional view of the mechanical zoom switch 52 taken along a plane including the spindle 27, and FIG. 3 is a cross-sectional view taken along the line XX 'of FIG. As shown in the figure, the mechanical zoom switch 52 includes a cylindrical member 61 having a heating coil 60 wound around a part of its outer periphery, and a low melting point metal 62 filled therein. The zoom spring 51 can be made of, for example, SUS, and the spindle 27 can be made of, for example, a low thermal expansion material such as INVAR. The zoom spring 51 has a disk shape in the illustrated example, but may have a cross shape or another shape.
[0014]
The cylindrical member 61 can be made of aluminum, brass or the like, and the low melting point metal 62 can be wood metal (u alloy) or the like. FIG. 4 is a diagram showing an example of the viscosity characteristics of u alloy, in which the horizontal axis indicates temperature and the vertical axis indicates viscosity. As is apparent from the figure, it can be seen that the viscosity of the u alloy of a certain component changes greatly at about 55 ° C as a boundary. That is, it is solidified up to about 55 ° C., and it is understood that when this temperature is exceeded, it softens rapidly. In the above description, the zoom mechanism in the x direction has been described. Of course, a similar zoom mechanism is also provided in the y direction. Next, the operation of this embodiment will be described. When the zoom mechanism of the present embodiment is not used, the heating coil 60 is energized to set the low melting point metal 62 at a temperature slightly above about 55 ° C. Then, since the low melting point metal 62 is softened, the spindle 27 is disconnected from the zoom spring 51 and can be operated in a normal state without zoom.
[0015]
Now, assuming that the spring constant of the narrow tube portion 14 and the large tube portion 15 is k1, the forces in the x and y directions applied to the thick tube portion 15 are Fx and Fy, and the lever magnification is β, the scanning in the x and y directions is performed. The widths x1 and y1 are as follows.
x1 = β · Fx / k1
y1 = β · Fy / k1
At this time, since the fan 54 is operating, an air flow a is generated and the spindle 27 is cooled. For this reason, even if the probe scanning device is used for a long time in this state, the heat generated in the heating coil 60 is transmitted to the scanner section such as the thick tube section 15 and the adverse effects can be reduced as much as possible. On the other hand, when using the zoom mechanism, first, the heating coil 60 is energized to heat and soften the low melting point metal 62 to the above-described temperature. Next, the probe 10 is moved to the sample inspection position by the x, y scanning mechanism, and then the energization to the heating coil 60 is stopped to solidify the low melting point metal 62. As described above, the switch 52 is switched only by raising and lowering the constant temperature of about 55 ° C., so that the switch 52 switching operation is fast. For this reason, the spindle 27 can be connected to the zoom spring 51 in a short time, and the operability is extremely improved.
[0016]
Assuming that the spring constant of the zoom spring 51 is k2, the scanning widths x2 and y2 in the x and y directions at this time are as follows.
x2 = β · Fx / (k1 + k2)
y2 = β · Fy / (k1 + k2)
For example, if the spring constant k2 of the zoom spring 51 is nine times the spring constant k1 (k2 = 9k1), then x2 = x1 · 1/10 and y2 = y1 · 1/10. Double zooming can be realized.
[0017]
Next, a method of accurately holding the probe 10 on the sample position to be zoomed will be described. In order to accurately carry the probe 10 on the sample position for zoom observation, it is necessary to grasp the following properties of the zoom mechanism.
First, when the zoom mechanism is operated, the origin pointed to by the probe 10 moves. In the initial state of the probe scanning device, that is, when the constant melting point metal 62 of the switch 52 is solidified, the probe 10 has the origin of the device at the position C0 as shown in FIG. 5 (a). To do. At this time, in order to operate the zoom mechanism, when the heating coil 60 of the zoom mechanism is energized and the low melting point metal 62 is softened, the probe 10 is displaced by ΔL1 due to the softening and moves to the position C0 ′. That is, the origin when the low melting point metal 62 is softened is C0 ′. On the contrary, when the low melting point metal 62 is softened and solidified, the position of the probe 10 returns from C0 'to C0.
[0018]
Second, in order to bring the probe 10 to the sample position for zoom observation, forces Fx and Fy are applied to the spindles in the x and y directions, and then the low melting point metal 62 is solidified to produce the force Fx. When Fy is set to 0, the probe 10 has the property of returning slightly from the position where the forces Fx and Fy were applied. For example, as shown in FIG. 5 (b), forces Fx and Fy are applied to the spindle in the x and y directions, the probe 10 is carried to the position C2, and the low melting point metal 62 is solidified. When the forces Fx and Fy are set to 0, the probe 10 returns by ΔL2 and comes to the position C3.
[0019]
A method of holding the probe 10 at the zoom start position in consideration of the above two properties is as shown in FIG. Now, assuming that the origin of the initial state of the probe scanning device is C0 and the target zoom start position is Cx, y, when the operator softens the low melting point metal 62 by energizing the heating coil 60, the probe 10 is Come to position C0 '. Here, the operator moves the probe 10 in the direction connecting the origin C0 and Cx, y by the distance L1 between the origins C0 and Cx, y plus the return distance ΔL2 when the forces Fx and Fy are zeroed. To move. That is, the probe 10 is operated so as to come to the position D1 shown in the figure, the current to the heating coil 60 is turned off to solidify the low melting point metal 62, and the forces Fx and Fy applied to the spindle 27 are reduced to zero. . Then, the probe 10 moves from the position D1 to the position D2 when the low melting point metal 62 is solidified, and when the forces Fx and Fy are set to 0, the target position is moved from the position D2. It will be carried by Cx, y.
[0020]
As is clear from the above description, according to the present embodiment, the zoom mechanism uses a low melting point metal that rapidly changes from solidification to softening or vice versa at a certain low temperature. When the heating coil 60 is energized, the low melting point metal can be softened in a short time. Further, since the low melting point metal is rapidly switched from solidification to softening, the heating temperature by the heating coil 60 only needs to slightly exceed the softening start temperature (about 55 ° C.). For this reason, when the energization to the heating coil 60 is stopped, the temperature of the low melting point metal becomes equal to or lower than the softening start temperature in a short time, and the low melting point metal can be switched from the softened state to the solidified state. As a result, the zoom operation can be entered quickly. At this time, the fan 54 also contributes to cooling of the low melting point metal.
[0021]
Further, according to the present embodiment, since the heating temperature by the heating coil 60 is low, the fan 54 is operating, and the spindle 27 is formed of the low thermal expansion material, the heat generated by the heating coil 60 is The spindle 27 is not thermally expanded. For this reason, the scanner unit including the thin tube unit 14 and the thick tube unit 15 is not affected by the heat generated by the heating coil 60. As a result, the probe 10 is moved, and distortion in the detected image of the sample 32 can be prevented.
[0022]
Next, another embodiment of the present invention will be described with reference to FIG. In this embodiment, a cylindrical tube 71 integrally formed coaxially with the housing 1 is provided outside the thin tube portion 14, and heat conduction is performed via a heat insulating member 72 formed of ceramic or the like on the outside. One or a plurality of rods 73 are attached. Further, the heat conduction rod 73 may have a ring shape. A holder 74 formed of a heat insulating member such as ceramic is fixed to the outside of the thick tube portion 15, and a low melting point metal (for example, u alloy) 75 is accommodated in the holder 74. A heating coil 76 is wound around the end of the heat conducting rod 73 on the heat insulating member 72 side, and the other end is inserted into the holder 74. Reference numeral 77 denotes a fan, which cools the thick tube portion 15 by causing an air flow a through the hole 15b. Reference numerals other than those shown above are the same as or equivalent to those in FIG.
[0023]
Next, the operation of this embodiment will be described. When the zoom mechanism is not used, the heating coil 76 is energized to supply heat to the low melting point metal 75 via the heat conducting rod 73. As a result, the low melting point metal 75 in the holder 74 is softened, the cylindrical tube 71 is separated from the thick tube portion 15, and the scanner portion including the thin tube portion 14, the large tube portion 15 and the like operates normally. To do. At this time, since the fan 77 is operating, it is possible to reduce the heat of the low melting point metal 75 transmitted to the scanner unit through the holder 74 as much as possible. When the zoom mechanism is used, energization to the heating coil 76 is stopped and heating of the low melting point metal 75 is stopped. As a result, the low melting point metal 75 is solidified and the cylindrical tube 71 is connected to the thick tube portion 15. In this state, when x and y scanning is performed by the spindle 27 in the x and y directions, the scanning widths x3 and y3 in the x and y directions are as follows.
[0024]
x3 = β.Fx / (k1 + k3)
y3 = β · Fy / (k1 + k3)
Here, k3 is the spring constant of the cylindrical tube 71.
According to this embodiment, since the low melting point metal 75 is accommodated in the holder 74, the low melting point metal 75 can be switched between solidification and softening in a short time, and the zoom operation can be quickly started. It becomes like this. In addition, since the heat generated by the heating coil 76 is transmitted to the scanner unit only through the heat conducting rod 73, in other words, unnecessary heat that does not contribute to the heating of the low melting point metal 75 among the heat generated by the heating coil 76. Is not transmitted to the scanner section at all, so that the heat transmitted to the scanner section can be suppressed as much as possible. The scanner unit is always cooled by the fan 77. For this reason, the problem that the scanner section expands under the influence of heat and the viscous body 17 is softened by the heat is eliminated.
[0025]
Next, a third embodiment of the present invention will be described with reference to FIG. The feature of this embodiment is that the second mechanical zoom switch 55 is added to that of FIG. When the second mechanical zoom switch 55 is operated in parallel with the first mechanical zoom switch 55, the zoom magnification can be significantly increased.
[0026]
For example, assuming that the spring constant of the narrow tube portion 14 and the large tube portion 15 is k1 = k, the spring constant of the zoom spring 51 is k2 = 9 k, and the spring constant of the zoom spring 56 is k3 = 90 k, scanning in the x and y directions. The widths x4 and y4 are as follows, and a 100 × zoom can be realized.
[0027]
x4 = β · Fx / (k1 + k2 + k3) = β · Fx / 100k
y4 = β · Fy / (k1 + k2 + k3) = β · Fy / 100k
In this embodiment, the second mechanical zoom switch 55 is added, but third and fourth mechanical zoom switches may be further added. Further, as another embodiment of the present invention, the zoom mechanism of FIG. 1 or FIG. 8 and the zoom mechanism of FIG. 7 may be used in combination.
[0028]
【The invention's effect】
According to the present invention, since the switch means using the low melting point metal is used, the switch means can be turned on / off by supplying and cooling with a small amount of heat. Therefore, switching of the switch means can be performed quickly, and a zoom mechanism with good operability can be provided. Further, since the amount of heat required for switching the switch means is small, it is possible to prevent the heat used by the switch means from being conducted to the scanner unit and adversely affecting the scanner unit. Therefore, it is possible to provide a probe scanning device having a zoom mechanism with high reliability.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a configuration of a main part of an embodiment of the present invention.
FIG. 2 is a cross-sectional view of an example of the mechanical zoom switch of FIG.
3 is a cross-sectional view taken along line XX ′ of FIG.
FIG. 4 is a diagram showing viscosity characteristics of a low melting point metal (u-alloy).
FIG. 5 is an explanatory diagram of operation characteristics of the embodiment.
FIG. 6 is an explanatory diagram of a zoom alignment method.
FIG. 7 is a cross-sectional view of a configuration of main parts of a second embodiment of the present invention.
FIG. 8 is a cross-sectional view of a configuration of main parts of a third embodiment of the present invention.
FIG. 9 is a cross-sectional view showing an example of a previously applied probe scanning device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Case 10 Probe 14 Narrow pipe part 15 Thick pipe part 17 Viscous body 23 Movable element 27 Spindle 51, 56 Zoom springs 52, 55 Mechanical zoom switch 53 Parallel spring 54 Fan 60 Heating coil 61 Cylindrical member 62 Low melting point metal 71 Cylindrical tube 72 Heat insulation member 73 Heat conduction rod 74 Holder 75 Low melting point metal 77 Fan

Claims (3)

In a probe scanning apparatus having a configuration for transmitting power from at least a voice coil motor arranged in the XY direction to a scanner section including a narrow tube section and a thick tube section connected to the narrow tube section via a spindle,
A cylindrical tube that is coaxial with the thin tube portion and has elasticity provided outside the thin tube portion ;
The cylindrical-shaped tube provided with a switch means for selectively connecting to the thick tube portion,
A probe scanning apparatus characterized in that zooming is performed by connecting the cylindrical tube to the thick tube portion by the switch means. The probe scanning device according to claim 1,
The switch means is provided with a heating member on the outer periphery, and a heat conducting member attached to the cylindrical tube via a heat insulating member;
A heat insulating member fixed to the outside of the thick tube portion and having a recess in which a part of the heat conducting member is accommodated;
And a low melting point metal housed in the recess of the heat insulating member. The probe scanning device according to claim 1 or 2,
A probe scanning apparatus comprising a blower means for preventing heat generated from the switch means from being transmitted to the scanner unit.

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