JP2546026Y2 - Adjustment table for laser interferometer - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for adjusting an object to be measured of a laser interferometer.

[0002]

2. Description of the Related Art In a conventional device for adjusting an object to be measured, a main body of an interferometer is mounted on a column rising from a stand, and a laser interferometer for emitting a laser beam of the interferometer downward has an X-axis as shown in FIG. And an XY stage 100 for adjusting in each direction of the Y axis and the Y axis.
A vertical wall 102 for adjusting in the Z-axis direction (vertical direction) is provided on the upper surface, and a mounting table 103 for mounting an object to be measured is provided on the vertical wall 102.
Was provided.

[0003]

In the conventional device for adjusting the object to be measured, the object to be measured is moved in the optical axis direction when the object to be measured is replaced, so that the object to be measured contacts the reference lens. Either or both could be damaged. Therefore, the present invention prevents the contact with the reference lens when exchanging the DUT, and improves the operability when measuring the DUT, particularly the operation for successively measuring the same type of DUT. It is an object of the present invention to provide a device for adjusting an object to be measured of a laser interferometer, which is improved in performance and compact.

[0004]

In order to achieve the above-mentioned object, the present invention relates to a method of mounting an interferometer having at least a laser and a laser light guiding optical system on a column rising from a stand. An object adjustment table of a laser interferometer provided with a mounting table for mounting an object to be measured in a laser beam emitted from the laser beam, the standing wall rising along the support on a base mounted on the stand Is established,
Providing a pedestal protruding from the upright wall beyond the optical axis of the laser light guiding optical system so as to be able to move up and down along the upright wall, and providing a slide table that slides left and right on the upper surface of the pedestal, XY for adjustment in each direction of X axis and Y axis
A stage is attached.

[0005]

In the present invention, when the inclination of the base is adjusted first and the stand is mounted on the stand, the optical axis of the laser light guide optical system and the vertical wall become parallel, and the base is fixed on the stand in this state. . Movement in the Z-axis direction is performed by moving the pedestal mounted on the vertical wall up and down, and movement in each of the X-axis and Y-axis directions is performed by the XY stage. Next, the object to be measured is mounted on a mounting table (or an upper surface of a biaxial adjustment table) on the XY stage, and the center of the object to be measured is brought to the focal point of the reference lens. This allows
Interference fringes are generated by the reflected light from the reference surface of the reference lens and the reflected light from the measured surface of the device under test. When the interference fringes can be confirmed through a monitor (not shown), the object to be measured is moved in the direction of the optical axis by a Z stage for adjusting the vertical direction. XY so that small interference fringes do not escape from the screen
When the interference fringes begin to look large again while adjusting the stage, the locking knob for coarse adjustment of the Z stage is locked. Next, the interference fringes are made easier to see with a knob for fine adjustment of the Z stage and an adjustment knob for the XY stage. When measuring the same type of DUT and the DUT is approaching the reference lens, move the slide base in the X direction (left / right direction) to move the DUT out of the optical axis of the reference lens. Evacuate to After confirming that the measured object has a sufficient distance from the reference lens, the measured object is replaced with the next measured object. After the replacement, the slide table is moved in the opposite direction so that the next DUT is positioned on the optical axis of the reference lens.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, an interferometer main body 3 (see FIG. 2) having at least a laser and a laser light guiding optical system is attached to a support 2 rising from a stand 1, and a laser light emitted from a laser of the interferometer is used for laser light guiding optics. Guide down through the system. A base 5 mounted on the stand 1 is provided with a standing wall 6 perpendicular to the rising base 5 along the column 2. A receiving stand 7 is provided on the standing wall 6 so as to be vertically movable and extend in parallel with the base 5. An XY stage 8 provided on the receiving table 7 for adjusting the X axis and the Y axis in each direction is provided with a two-axis adjusting table 9.
Is provided. In some cases, the upper surface 9A of the biaxial adjustment table 9 also serves as the mounting surface of the object S (see FIG. 6), and when the object to be measured is small, the mounting table 4 is mounted on the upper surface 9A. .
In this case, the mounting table 4 is located in the optical path of the laser light guiding optical system. Reference numeral 10 indicates an adjustment knob of the XY stage 8, and reference numeral 11 indicates an adjustment knob of the two-axis adjustment table 9. Reference numeral 3A denotes a reference lens provided on the optical axis of the laser light guiding optical system and provided at the laser light exit of the interferometer body 3. A moving block 13 is attached via a rod 12 to a base end 7A attached to the upright wall 6 of the cradle 7. A knob 1 for fine adjustment is provided at the lower end of the rod 12.
4 are provided. The moving block 13 is also attached to the upright wall 6 so as to be vertically movable, and can be roughly adjusted by the fixing knob 15. By releasing the fixing knob 15, the receiving stand 7 is roughly adjusted and fixed at a predetermined position, and the adjusting knob 14 is finely adjusted.
The standing wall 6 is provided with a positioning stopper 16. In this example, the pedestal 7 is raised too much and the reference lens 3
The stopper 16 regulates the height of the pedestal 7 so as not to destroy A. The support 2 has an interferometer body 3
There is provided an adjustment knob 17 for vertically moving the knob. A balancer 18 is provided between the standing wall 6 and the pedestal 7, and the pedestal 7
Is designed to prevent sudden drops. The balancer 18 uses a thin steel plate 18B. The steel plate 18B is wound in a coil shape in the base end portion 7A of the cradle 7, and has the same structure as a steel tape measure. The XY stage 8 is mounted on a slide base 19, and the slide of the slide base 19 is locked by a lock knob 20.

FIG. 3 is a partial cross-sectional view as viewed from the front. A knob 14 for fine adjustment is fixed to the lower end of the rod 12, and the upper half 12A of the rod 12 is threaded. The threaded portion of the upper half 12A is screwed into the sleeve 24. Since the moving block 13 is fixed to the fixing knob 15, the rotation of the rod 12 in one direction pushes down the receiving table 7. This gives 2
The shaft adjustment table 9 is lowered, and the wavefront transmitted through the reference lens 3A is matched with the wavefront of the light reflected from the measurement surface of the measurement object S mounted on the mounting surface 9A. As a result, interference fringes due to the reflected light from the reference surface of the reference lens 3A and the reflected light from the measured surface can be observed. A cushioning leg 7B made of rubber or the like is provided on the lower surface of the receiving table 7. Slide stand 1
As shown in FIGS. 3 to 5, 9 is mounted on the trapezoidal portion 7C of the receiving table 7 so as not to be vertically displaced and to slide along the longitudinal direction of the trapezoidal portion 7C.

FIG. 6 is a side view. A spherical bush 21 is provided at one of the four corners of the base 5, and the base 5 can be adjusted with the spherical bush 21 as a fulcrum. Has become. Screws 22 for adjusting the inclination are provided at three places other than the places where the spherical bushes 21 are provided, and the base 5 after the adjustment is fixed to the stand 1 at the four outer peripheral corners of the spherical bush 21 and the screws 22 for adjusting the inclination. Screw 23 is provided for fixing. To adjust the inclination of the base 5, the three screws 22 are rotated, and the height from the stand 1 is finely adjusted. At this time, the laser interferometer is operated to search for a position where the laser beam becomes parallel to the standing wall 6. After searching for such a position, the base 5 is fixed to the stand 1 with the screws 23. Here, the screw 22 and the spherical bush 2
1 constitutes the adjusting means. The inclination of the base 5 is adjusted in the interferometer main body 3 so that the optical axis of the laser light guiding optical system including a collimator lens and the upright wall 6 are parallel to each other. The base 5 is fixed to the stand 1 with fixing screws 23.

Upper surface (mounting surface) of a two-axis adjustment table (mounting table) 9
Reference lens 9 9A is coaxial with the laser light guiding optical system
In the adjustment method for adjusting the optical axis of the sample A so as to be orthogonal to the optical axis of the sample A, the parallel beam is irradiated from the interferometer main body 3 before the reference lens 3A is attached. The movement of the object to be measured by the vertical movement by the block 13 and the fine adjustment by the knob 14) is adjusted to be parallel. As a procedure, first, neither the reference plate nor the reference lens 3A is attached to the interferometer body 3.
Then, the light emitted from the interferometer main body 3 is applied to the upper surface 9A.
The room is darkened to such an extent that it is clear that the light is hitting and the periphery of the light beam can be clearly seen. The light amount adjustment knob of the interferometer main body 3 is rotated with a finger to make the laser light emitted from the interferometer main body 3 the brightest. Thereafter, on the upper surface 9A of the biaxial adjustment table (mounting table) 9, a board having a pattern in which a cross is drawn in a circle having a diameter of 64 mm is placed. Next, the Z stage is coarsely moved to move the biaxial adjustment table (mounting table) 9 to the lowermost position, so that the outer circumferential circle of φ64 of the laser beam and the circular pattern of the board are matched (the paper is moved). The Z stage is coarsely moved, and the biaxial adjustment table (mounting table) 9 is moved to the uppermost position. At this time, if the position of the outer periphery of the laser beam and the position of the circular pattern of the board are shifted, the adjustment means of the base 5 adjusts them so that they match. The Z stage is roughly moved to the uppermost position and the lowermost position, and the above operation is repeated at both positions until the outer periphery of the laser beam and the circular pattern match. Next, the base 5 is fixed to the stand 1. That is, the screw 22 and the screw 23 are in a relation of a push screw and a pull screw, and a force is applied to each other, thereby firmly fixing the base 5 and the stand 1. Until the fixing screw 23 exerts a force effectively, that is, the range in which the fixing screw 23 turns lightly until immediately before the base 5 is pulled, the respective fixing screw 23 continues to be turned. When a force is applied to rotate the fixing screw 23, move the Z stage to the uppermost position,
The fixing screws 23 are alternately tightened little by little one by one while observing the laser beam and the circular pattern while observing them. If only one screw 23 is strongly tightened at a time, the base 5 will be tilted. Therefore, while confirming that the luminous flux and the circular pattern do not deviate, one screw 23 is reduced to 1/10 at a time.
Tighten by rotation and rotate it in order to fix it at an average. Thus, the upright wall 6 and the optical axis of the laser light guiding optical system become parallel.

When the mounting table 4 shown in FIG. 1 is used, the object to be measured is small like a small-diameter lens or the like. Such a small-diameter lens is mounted on the mounting table 4 and a reference lens is used. The center of the object to be measured is brought to the focal point of 3A. When interference fringes due to the reflected light from the reference lens 3A and the reflected light from the surface to be measured can be confirmed, the object to be measured is moved in the direction of the optical axis on the Z stage. The XY stage 8 is adjusted so that small interference fringes do not escape from the screen. When the interference fringes start to look large again, the coarse adjustment knob 15 is locked. The knob 14 for fine adjustment of the Z axis and the adjustment knob 10 of the XY stage 8 make it easy to see the interference fringes. When measuring the same type of the object to be measured, the above-described operation can be substantially eliminated by replacing only the object to be measured without moving the mounting table 4. When the object to be measured approaches the reference lens 3A, the slide table 19 is used. When the object to be measured enters the inside of the reference lens 3A, the object to be measured and the reference lens 3A are used.
In order to prevent any one or both of them from being damaged by contact with the positioning stopper 16, a positioning stopper 16 is used.

FIG. 7 shows a portion of the balancer 18, in which a thin steel plate 18B is wound around a roller 18A provided at the base end 7A, so that the receiving table 7 is prevented from dropping suddenly and work safety is ensured. ing. The cradle 7 looks like it is suspended by a steel plate 18B.

[0012]

As described above, according to the present invention, since the XY stage is mounted on the slide table that slides to the left and right attached to the receiving table, the slide table is moved when the object to be measured is replaced. By doing so, contact between the object to be measured and the reference lens can be prevented, and the object to be measured can be safely replaced. In addition, if the object to be measured is replaced by sliding the slide table, coarse adjustment in each of the X, Y, and Z directions is not required, and only fine adjustment is required, so that operability is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a preferred embodiment of the present invention.

FIG. 2 is a perspective view showing an interferometer main body.

FIG. 3 is a front view of a partial cross section.

FIG. 4 is a plan view of a partial cross section of the XY stage excluding the upper one.

FIG. 5 is a cross-sectional view taken along line AA ′ of FIG.

FIG. 6 is a partial cross-sectional side view.

FIG. 7 is a sectional view showing a portion of a balancer.

FIG. 8 is a perspective view showing a conventional DUT adjusting table.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stand 2 Prop 3 Interferometer main body 4 Mounting table 5 Base 6 Standing wall 7 Receiving stand 8 XY stage 9 2-axis adjustment table (mounting table) 9A Upper surface of 2 axis adjustment table (mounting surface) 19 slide table

Claims (1)

(57) [Scope of request for utility model registration] An interferometer body having at least a laser and a laser light guiding optical system is mounted on a column rising from a stand, and a laser beam emitted from the laser light guiding optical system is used to mount an object to be measured. An object adjustment table of a laser interferometer provided with a mounting table, provided with a standing wall rising along the support on a base mounted on the stand, from the standing wall to the optical axis of the laser light guide optical system. An XY protruding beyond the erection wall is provided so as to be able to move up and down along the vertical wall, and a slide pedestal is provided on the upper surface of the pedestal so as to slide left and right. An object adjustment table for a laser interferometer, which has a stage attached.