JP2513226B2 - Positioning device and processing device using the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a positioning device for positioning an object at a desired position, and a processing device such as a laser trimmer for processing the object.

[Conventional technology]

As is well known, there are various types of positioning devices.

For example, US Pat. No. 4,423,959 also discloses a positioning device. The positioning device includes a projection device for projecting a light beam toward an object such as a circuit board, eg a semiconductor wafer. In the illustrated positioning device, the mark comprises a group of short lines arranged in one direction.

To perform the positioning operation of the object, the light beam linearly scans the object in another direction selected according to the relative movement between the object and the projection device. Depending on the beam of light, the mark is a diffracted beam (di
It outputs a specific beam called a ffracted beam). The intensity of the diffracted beam is maximum when the light beam crosses the mark. The maximum intensity of the diffracted beam can be detected to position the object.

[Problems to be solved by the invention]

However, such a positioning device cannot quickly perform the positioning operation of the object. This is because scanning is performed by the relative movement of the object and the projection device. That is, until the scanning by the relative movement is completed,
No decision can be made as to whether the intensity of the diffracted beam is maximum.

Further, such a positioning device is included in a processing device such as a laser trimmer. In this case, it goes without saying that the processing device cannot quickly process the predetermined position of the object.

Therefore, an object of the present invention is to provide a positioning device that can quickly position a target member at a desired position without degrading the accuracy of the processing position.

Another object of the present invention is to provide a processing apparatus capable of quickly processing a target member.

[Means and Actions for Solving Problems]

According to the present invention, in a positioning device used for positioning an object having a mark extending in a first predetermined direction, a transfer for moving the object in a second predetermined direction that traverses the first predetermined direction. Means, projection means for projecting a light beam toward the object, optically coupled to the projection means, the light beam scans the object in an annular manner, and the light beam crosses the mark each time the light beam crosses the mark. An annular scanning means for generating a specific beam on a mark, a detecting means for detecting the specific beam and outputting a mark detection signal indicating the detection of the specific beam, and the mark detecting means coupled to the detecting means and the transfer means. A positioning device is obtained which includes control means for controlling the transfer means in response to signals.

According to the present invention, in an apparatus for processing an object having a mark extending in a first predetermined direction, a processing means for processing the object, the object in a second predetermined direction traversing the first predetermined direction. Transfer means for moving an object, projection means for projecting a light beam toward the object, optically coupled to the projection means, the light beam scans the object in an annular shape, and the light beam causes the mark. An annular scanning means for producing a specific beam at the mark each time it crosses
Detecting means for detecting the specific beam and outputting a mark detection signal indicating the detection of the specific beam, and the detecting means, the transfer means and the processing means, and the transfer means and the transfer means in response to the mark detection signal. A processing apparatus including a control means for controlling the processing means is obtained.

〔Example〕

Referring to FIG. 1, a positioning device according to a first embodiment of the present invention is a light source that emits a light beam such as a laser beam.
Including 11 The light beam optically scans an object (circuit board) 12, such as a semiconductor wafer. A mark 13 is formed on the upper surface of the object 12, that is, the main surface extending on the horizontal line in the illustrated example. The mark 13 extends in the first predetermined direction along the main surface of the object 12.

The light beam is emitted toward the reflecting mirror 14. Reflector 14
Is for reflecting the light beam toward the beam splitter 16. The light beam passes through the beam splitter 16 and enters the deflecting member 17. The combination of reflector 14 and beam splitter 16 serves to optically guide the light beam along a predetermined vertical axis perpendicular to the major surface of object 12 and is therefore referred to as guiding means.

The deflecting member 17 includes a tapered transparent glass plate that deflects the light beam from a predetermined axis. Deflection member 17
Is rotated at a constant speed by a motor 18 about a predetermined axis via a force transmission member 19 such as a gear or a pulley. The combination of motor 18 and force transmitting member 19 is referred to herein as a circle drive means.

The light beam passes through the deflecting member 17 and enters the objective lens 21. The objective lens 21 is for directing the light beam parallel to a predetermined axis and is therefore called the directing means.

The light beam passes through the objective lens 21 and is projected as a light spot 22 on the main surface of the object 12. As a result, the object 12 is scanned by the light beam shown in FIG. In FIG. 2, the light spot 22 moves along a circle 23 surrounding a predetermined axis 24. Here, the width of the mark 13 is indicated by two parallel lines. The mark 13 extends vertically in the figure. The circle 23 is larger than the width of the mark 13, as can be seen in FIG.
It has a smaller diameter than its length. The combination of the light source 11, the reflecting mirror 14, the beam splitter 16, and the objective lens 21 is called a projection means. Further, the combination of the deflecting member 17, the motor 18 and the force transmitting member 19 is called an annular scanning means.

Depending on the light beam, the mark 13 outputs a specific beam each time the light beam crosses the mark while the light beam scans the object 12 in an annular shape. The specific beam passes through the objective lens 21 and the deflecting member 17, and is bent by the beam splitter 16.
Move away from the specified axis.

The specific beam is, for example, a reflected beam reflected from the mark 13. The specific beam may be a diffracted beam diffracted by the mark 13. In either case, the specific beam is
When is in the center of the mark 13, it indicates the maximum brightness.

The positioning device further includes a detector 26, a control device 27, and a transfer device 28. The specific beam is supplied to the detector 26. When supplied with the particular beam, the detector 26 outputs a mark detection signal representative of the detection of the mark 13. The mark detection signal is supplied to the control device 27. In response to the mark detection signal, the control device 27 controls the transfer device 28 as described later. The transfer device 28 is for transferring the object 12 in a second predetermined direction that is perpendicular to the first predetermined direction.

In order to position the object 12 freely, this positioning device is such that the circle 23 intersects two points of the mark 13, namely the first and second parts 31, 32, as shown in FIG. , Preset. When the light spot 22 moves continuously along the circle 23 at a constant speed, a specific beam sequence emerges from the mark 13. According to the specific beam sequence, the detector 26 outputs the mark detection signal sequence having the output luminous intensity illustrated in FIG.

In the example of FIG. 3, the mark detection signals P ₃₁ and P ₃₂ are alternately output when the light spot 22 crosses the first and second portions 31 and 32 of the mark 13. As can be seen from FIG. 3, the mark detection signals P ₃₁ , P ₃₂ have first and second time intervals T ₁ , T ₂ between two adjacent ones.

Again in FIGS. 1 and 2, the control device 27 includes a processing means 36 and a driving means 37. The processing means 36 processes the mark detection signal series and outputs an error signal representing the position error of the object 12. The position error is equal to the distance ΔD between the mark 13 and the predetermined axis 24, Given in. Here, r represents the radius of the circle 23, and α represents the angular velocity of the light beam 22. Drive means 37 according to the error signal
Moves the transfer device 28 so that the position error becomes zero. In this case, the processing means 36 is regarded as a calculation means for executing a predetermined calculation according to the mark detection signal.

FIG. 4 shows a positioning device according to a second embodiment of the present invention. The positioning device includes a rotation detection device 38. The rotation detecting device 38 detects the rotation of the deflecting device 17 and outputs an additional detection signal sequence. The rotation detection device 38 is referred to herein as additional detection means. The additional detection signal sequence is supplied to the control device 27.

The control device 27 includes angle detection means 39 for detecting the difference between the angles θ ₁ and θ ₂ in FIG. The angles θ ₁ and θ ₂ are defined by straight lines extending from the predetermined axis 24 toward the first and second portions 31 and 32, respectively. The angle detecting means 39 outputs an angle signal corresponding to the error signal in accordance with the mark detection signal series and the additional detection signal series. The drive means 33 drives the transfer device 28 in response to the angle signal. Actually, the angle detecting means 39 performs a predetermined calculation according to the mark detection signal series and the additional detection signal series and outputs the above-mentioned angle signal. Therefore, this angle detecting means can also be called a calculating means. In response to the angle signal, the driving means 33 drives the transfer device 28 to make the position error zero.

A positioning device according to a third embodiment of the present invention will be described with reference to FIG. This positioning device also includes the same parts as in FIG. In FIG. 5, the controller is a phase detector.
It includes 41, a comparator 43, and a signal generation circuit 44. The phase of the mark detection signal series changes variously as shown in FIG. The phase detector 41 detects the phase of the mark detection device series with reference to the additional detection signal and outputs the first and second time signals. The first and second time signals respectively represent the first and second time intervals T ₁ , T ₂ shown in FIG. First and second
Each of the time signals of 1 is represented by a voltage value and is supplied to the comparator 43.

The comparator 43 compares the first and second time signals and compares the first and second time signals.
The comparison result signal is continuously output only when the time signals of are different from each other. The comparison result signal is supplied to the signal generation circuit 44. The signal generation circuit 44 outputs the above-mentioned error signal according to the comparison result signal. Drive means 37 according to the error signal
Drives the transfer device 28 until the position error is zero.

When the object 12 is positioned at the desired position, the first and second
Since the time signals of are equal to each other, the comparison result signal disappears. When the comparison result signal disappears, the signal generation circuit 44 outputs a completion pulse signal instead of the error signal. The completion pulse signal indicates completion of positioning of the object 12. The drive means 37 stops the operation of the transfer means 28 in response to the completion pulse signal.

The fourth embodiment will be described with reference to FIGS. 2 and 4 again. The deflecting member 17 has a specific mark. According to this specific mark, the rotation detecting device 38 has
A specific detection signal is output each time it rotates. That is, when the rotation detection device 38 detects the specific mark, the specific signal detection occurs.

It is assumed that the laser beam is positioned at the position 48 of the circle 23 shown in FIG. 2 when the specific mark is detected.
When the deflecting member 17 scans the laser beam from the position 48 to the first portion 31, the angle detecting means 39 counts up according to the clock signal. The laser beam is the first part
When scanning from 31 to the second portion 32, angle detecting means 39
Counts down. The laser beam is the second part
When scanning from 32 to the position 48, the angle detecting means 39 counts up. Therefore, the calculated value of the angle detecting means 39 becomes zero only when the angles θ ₁ and θ ₂ are equal to each other.

The angle detecting means 39 outputs an internal output signal representing the calculated value. According to the internal output signal, the driving means 33 drives the driving device 28 until the calculated value becomes zero.

A modified embodiment of the present invention will be described with reference to FIGS. 6 and 7 in addition to FIG. The object 12 has an additional mark 51 in addition to the mark 13. For convenience of description, the mark 13 will be referred to as a main mark below. The additional mark 51 extends in the second direction along the main surface of the object 12 and crosses the main mark 13.

In order to position the object 12 at the desired position, the positioning device is preset so that the circle 23 surrounds the intersection of the main mark 13 and the additional mark 51. As a result, yen 23
Crosses the first and second parts 31, 32 of the main mark 13 as well as the third and fourth parts 53, 54 of the additional mark 51.

When the light spot 22 continuously moves along the circle 23 at a constant speed, a specific beam sequence is output from the main mark 13 and the additional mark 51. Depending on the specific beam sequence, the detector 26
A mark detection signal sequence having an output intensity as shown in FIG. 7 is output.

In FIG. 7, the light spot 22 is the portion 3 from the first to the fourth.
When crossing each of 1, 32, 53, 54, mark detection signal P
₃₁ , P ₃₂ , P ₅₃ , P ₅₄ are output. As can be seen from FIG. 7, the mark detection signals P ₃₁ , P ₃₂ , P ₅₃ , and P ₅₄ include the third and third time intervals T ₁ and T ₂ described in FIG. A fourth time interval T ₃ , T ₄ occurs.

The processing means 36 carries out a first predetermined calculation relating to the first and second time intervals T ₁ and T ₂ , and the first interval ΔX shown in FIG.
Represents The first error signal is output. First interval ΔX
Is Is represented by Here, r represents the radius of the circle 23, and α represents the angular velocity of the light spot 22. In this case, the processing means 36 serves as the first calculation means.

In addition, the processing means 36 is arranged so that the third and fourth time intervals T ₃ , T ₄
A second predetermined calculation regarding the second calculation shown in FIG.
A second error signal representing the interval ΔY of is output. The second interval ΔY is Is represented by Where r is the radius of the circle 23 and α is the light spot.
Indicates the angular velocity of 22. In this case, the processing means 36 serves as the second calculation means.

In response to the first and second error signals, the drive means 37 sets the first and second intervals ΔX and ΔY to zero, respectively.
Drive 28.

Referring to FIG. 8, the processing apparatus according to the embodiment of the present invention is for machining an object 69 such as a semiconductor wafer, and includes first and second mark detecting devices 71 and 72. The object 69 has a circuit pattern and first and second positioning areas. Each of the first and second positioning areas has first and second marks extending in directions perpendicular to each other. Both first marks extend along a predetermined common straight line. As a result, both second marks are parallel to each other.

The first and second mark detecting devices 71 and 72 are for optically detecting each mark in the first and second positioning areas, and include the above-mentioned transfer device, projection means, annular scanning means, and detection device. including. In response to the detection of each mark, the first and second mark detection devices 71, 72 use the first and second mark detection methods described above with reference to FIGS. 1 to 7 and again later. The local mark detection signal of is output.

The processing apparatus further includes a beam delivery device 74 for delivering a processing laser beam having a small diameter toward the reflecting mirror 76. The processing laser beam is reflected by the reflecting mirror 76 and goes to the beam expander 77. The beam expander 77 expands the diameter of the processing laser beam and outputs the expanded beam. The expanded beam is focused on a desired portion of the circuit pattern of the object 69 through the objective lens 78, and serves to perform laser beam processing such as cutting and trimming of the desired portion. The combination of the beam sending device 74, the reflecting mirror 76, the beam expander 77, and the objective lens 78 is called a processing means.

This processing device further includes a stage 81 and a stage drive device 8
2, including a length measuring device 83 and a controller 84. Stage 81
Are rotatable about a predetermined vertical center axis and movable in first and second predetermined horizontal directions perpendicular to each other. The object 69 is supported by the stage 81. The stage drive device 82 is for driving the stage 81. The first and second mark detection devices 71, 72 are straight lines in the first predetermined horizontal direction. The length measuring device 83 measures the position of the stage 81 and outputs a position signal regarding the position of the stage 81. The controller 84 includes the first mark detection device 71,
This is for controlling each of the second mark detecting device 72, the beam transmitter 74, the stage driving device 82, and the length measuring device 83.

Before the laser beam processing is performed in the processing device, the object 69 has its first and second positioning areas first.
And the second mark detecting devices 71 and 72 are respectively set on the stage 81 in advance. In this case, the object
69 is assumed to have position error.

In order to detect the position error of the object 69, the first and second mark detection positions 71, 72 are operative to output the first and second local mark detection signals. In response to the first and second local mark detection signals, the controller 84 outputs various error signals which will be described in detail later. In response to this error signal, the stage drive device 82 drives the stage 81 so that the position error becomes zero.

The first marks in the first and second positioning areas include:
It is assumed that there are first and second local position errors, respectively. Each of the first and second local position errors is equal to the second
It corresponds to the distance between the predetermined axis and each of the first marks indicated by reference numeral 24 in the drawing.

According to the first and second local position errors, the controller 84 outputs an angle error signal representing an angle error determined by the above-mentioned predetermined straight line and the first predetermined horizontal direction.

In response to the angular error signal, the stage driving device 82 drives the stage 81 around a predetermined vertical central axis until the first local position error becomes equal to the second local position error. As a result, the angular error of the object 69 is completely corrected.

Further, the controller 84 outputs the first position error signal according to the first and second local position errors. First
In response to the position error signal of, the stage drive unit 81 operates until the first and second local position errors reach zero.
The stage 81 is moved in the predetermined horizontal direction.

As a result, the position error of the object 69 is completely corrected in the second predetermined horizontal direction.

Furthermore, the controller 84 emits a first position error signal according to the first and second local position errors. In response to the first position error signal, the stage drive unit 81
Until the first and second local position errors become zero, the second
The stage 81 is moved in the predetermined horizontal direction. As a result, the position error of the object 69 is completely corrected in the second predetermined horizontal direction.

Each second mark in the first and second positioning areas is assumed to have a third local position error in the first predetermined horizontal direction. The controller 84 outputs a second position error signal according to the third local position error. Stage drive device according to the second position error signal
82 moves the stage 81 in the first predetermined horizontal direction until the third local position error becomes zero. As a result, the position error of the object 69 in the first predetermined horizontal direction is completely corrected.

Before the laser beam processing is performed in the processing device, the controller 84 is supplied with the original data signal through an input unit (not shown). The original data signal represents information about each position of the portion desired to be processed and each mark. Depending on the original data signal and the above positioning device,
The controller 84 drives the stage 81 by the stage drive device 82 until the desired portion of the object 69 reaches the processing position facing the center of the objective lens 78. At the processing position, the processing means can process a desired portion of the object 69 with the processing laser beam.

Although the present invention has been described above with reference to some embodiments, various other modifications are, of course, possible. For example, the light source 22 may be moved along not only a circle but an annular line such as an ellipse.

[Brief description of drawings]

1 is a schematic side view of a positioning device according to a first embodiment of the present invention, FIG. 2 is a partial plan view of an object processed by the positioning device of FIG. 1, and FIG. 3 is FIG. 4 is a time chart for explaining the operation of the positioning device, FIG. 4 is a schematic side view of the positioning device according to the second embodiment, and FIG. 5 is a block diagram of a part of the positioning device according to the third embodiment.
FIG. 6 is a partial plan view of an object in a modified embodiment,
FIG. 7 is a time chart for explaining the operation of the modified embodiment of FIG. 6, and FIG. 8 is a schematic view showing one embodiment of the processing apparatus according to the present invention. 11 …… Light source, 12,69 …… Target, 13 …… Mark, 17 …… Deflecting member, 18 …… Motor, 22 …… Light spot, 26 …… Detector, 27 …… Control device, 28 …… Transfer device, 38 ... Rotation detecting device, 71 ... First mark detecting device, 72 ... Second mark detecting device, 74 ...
… Beam sending device, 81 …… Stage, 82 …… Stage drive, 83 …… Sensor, 84 …… Controller.

Claims (2)

(57) [Claims] 1. A positioning device used to position an object having a mark extending in a first predetermined direction, wherein the transfer means moves the object in a second predetermined direction that traverses the first predetermined direction. A projection means for projecting a light beam toward the object, and the mark optically coupled to the projection means for scanning the object annularly by the light beam and each time the light beam crosses the mark An annular scanning means for generating a specific beam, a detection means for detecting the specific beam and outputting a mark detection signal indicating the detection of the specific beam, and the mark detection signal coupled to the detection means and the transfer means. A positioning device including control means for controlling the transfer means according to the above. 2. An apparatus for processing an object having a mark extending in a first predetermined direction, a processing means for processing the object, the object being processed in a second predetermined direction crossing the first predetermined direction. Transferring means for moving, projection means for projecting a light beam toward the object, optically coupled to the projection means, the light beam scans the object in an annular manner, and the light beam crosses the mark. An annular scanning means for generating a specific beam for each mark, a detecting means for detecting the specific beam and outputting a mark detection signal indicating the detection of the specific beam, and the detecting means, the transfer and the processing means. A processing apparatus which is coupled and includes a control means for controlling the transfer means and the processing means according to the mark detection signal.