JP2001235309A - Device for optically detecting and processing surface to be processed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for optically detecting and processing an area to be processed such that optical detection of the area to be processed and positioning of the processing device can be achieved at the same time. SOLUTION: A processed area detector 15, having a light projection hole 17a through which light is projected onto a surface to be processed and a light receiving hole 17b for receiving the light reflected from the light projection hole 17a, is mounted integrally with a processor body 11. The detector is mounted in such a manner that the optical axis L1 of the processor body 11 intersects the projected light and the reflected light at one point. As a result, detection of the area to be processed and positioning of the detector body are achieved at the same time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a standard position on a semiconductor wafer surface, a glass substrate such as a liquid crystal substrate, an electrode (pad) such as a bare chip, an IC surface, various ceramic products, and various electronic devices such as an IC lead. Forming various marks for product management or various security, for example, on the surface to be processed, such as parts and ultra-precision small parts, or detecting the surface to be processed suitable for optically reading those marks and various optical The present invention relates to an apparatus for detecting and processing an area to be processed which does not require special positioning of a target processing and does not require special illumination of a surface to be processed.

[0002]

2. Description of the Related Art For example, in a semiconductor manufacturing process, it is necessary to set various and strict manufacturing conditions for each process. Alternatively, a mark composed of a bar code or the like is displayed with a large number of dots, and reading is performed.

On the other hand, various marks made up of the above dots are
Usually, it is formed by irradiating a continuous pulse laser beam to a partial surface of a semiconductor wafer via an optical system. In addition, the marking for that purpose is not limited to one time, and in order to know the history characteristic of each manufacturing process, the minimum necessary history data is often marked in each manufacturing process. However, since the marking area on a semiconductor wafer is limited to an extremely narrow area, the size and number of dots to be marked are also limited, and the marking area, dot size, and number of dots are defined by SEMI standards and the like. Have been.

[0004] A semiconductor wafer on which dot marking has been performed, for example, as disclosed in Japanese Patent Application Laid-Open No. 2-299216, changes in reflectivity due to irradiation of a He-Ne laser beam, or heat waves of a normal laser beam. Is read as a change in the vibration, and various manufacturing conditions in subsequent manufacturing steps are set based on the read information. Therefore, when the above-mentioned reading is not accurately performed and the information is read as erroneous information, all of them are defective unless accidental.

In order to ensure this reading, for example, according to the disclosure of JP-A-59-84515, when forming one dot mark, the dot diameter is successively reduced for each pulse so that the same point is formed. Irradiate multiple times,
Although deep dots are formed while sequentially reducing the hole diameter of the dots, the opening diameter of the first dot is 100 to 200.
Since the depth is 1 μm or less with respect to μm, specifically, it is described that laser beam irradiation is performed four times, the dot depth in this case is at most 3 to 4 μm. From the drawings in the publication, the dot shape formed at one time is also close to the Gaussian shape.

However, even in the dot mark disclosed in this publication, the opening diameter is as large as 100 to 200 μm, and even if the maximum number of dots are formed in a marking area defined by the SEMI standard or the like. ,
The amount of information is limited. In addition, the aspect ratio is as small as 0.02 to 0.03, which means that the visibility is low.

[0007] Under these circumstances, the inventors of the present invention have demanded the efficient use of the wafer surface due to the increase in the size of semiconductor wafers and the increase in the degree of integration of circuits. For example, Japanese Patent Application Laid-Open No. 11-156563 and Japanese Patent Application Laid-Open No.
According to Japanese Patent Application No. -162800 and Japanese Patent Application No. 10-33409, the width along the mark forming surface is 1 to 15 μm,
It proposes a concave dot mark with a large aspect ratio, a dot mark that is not so high but has a raised center, a method of forming the dot mark, and a new formation area.

[0008] The new formation area is, for example, a scribe line, a bevel surface on the outer periphery of a wafer, an inner bevel surface of a notch, and the like, and these dot marks have a peculiar form in spite of a minute form. Thereby, the visibility is excellent, and if the formation region is selected, the form is sufficiently maintained even after various processes.

[0009]

As described above, when the miniaturization of the dot mark is realized, for example, as shown in FIG. 9, the vertical length L1 is set to 5 on the bevel surface on the wafer rear surface on the inner surface of the notch.
8 μm in a rectangular area of 0 μm and a horizontal length L2 of 200 μm
A two-dot mark can be formed.
However, in order to accurately form minute dot marks in the rectangular area, the area needs to be a flat surface close to a mirror surface. Since the bevel surface of a recent notch is formed almost in the vicinity of a mirror surface, it is possible to form the dot mark in the bevel surface region, but the bevel surface of the notch has two substantially S-shaped curved surfaces. , A straight-line portion must be found and it must be confirmed that the region is a flat surface. The same can be said for reading a dot mark formed on the flat surface.

In order to specify the read and write areas and perform a predetermined process, usually, a change in the amount of light by a photoelectric sensor is detected to specify the write area or the read area.
This is performed by making the optical axis of the processing device orthogonal to the surface to be processed in the above-mentioned region and focusing the processing device on the surface to be processed. The smaller the surface to be processed and the finer the processing performed on the surface to be processed, the more complicated the detection of the surface to be processed, and even if the surface to be processed is detected, Adjustment work such as relative positioning and focusing between the processing target surface and the processing apparatus is also extremely complicated.

The present invention has been made for the purpose of solving the above-mentioned problems, and it is needless to say that the present invention can be applied to ordinary optical processing. It is an object of the present invention to provide an optical processing area detection and processing apparatus which can simultaneously perform optical detection of the processing area and positioning of the processing apparatus.

[0012]

The invention according to claim 1 of the present invention optically detects a surface to be processed,
An apparatus for performing processing on the surface to be processed, comprising: a processing unit main body; a light emitting port that is integrally attached to the processing unit main body and that projects light onto the processing surface; A processed area detector having a light receiving port for receiving light,
The optical axis of the processing unit main body and the projection light and the reflected light are arranged so as to intersect at a single point, and the detection of the processing target region and the positioning of the processing unit main body can be performed simultaneously. In the apparatus for optically detecting and processing an area to be processed.

The light-emitting port and the light-receiving port of the processing target area detector are appropriately positioned so that the light-transmitting axis and the light-receiving axis intersect at a predetermined position on a bisector of a line connecting the centers of the light transmitting and receiving ports. It is attached to the processing unit main body with an appropriate inclination angle. At this time, the optical axis of the processor main body also passes through the intersection of the light projecting axis and the light receiving axis. The processor main body and the processing area detector may be integrally mounted such that the optical axis of the processor main body and the light projecting axis and the light receiving axis are on the same plane. Is attached out of the plane including the light emitting axis and the light receiving axis. Generally, the target area detector is attached to the processing unit main body so that the intersection position is adjusted to the focal position of the processing unit main body.

Now, in order to detect the region to be processed and at the same time position the main body of the processing apparatus, first, the processing apparatus of the present invention is installed with its optical axes facing the surface to be processed. At this time, the bisector of the line segment between the light emitting port and the light receiving port of the processing target area detector is adjusted so as to be orthogonal to the processing target surface. Next, while projecting light from the light emitting port toward the surface to be processed, the periphery is irradiated, and the reflected light is received by the light receiving port. The received light amount is converted into an electric amount, and a change in the light amount is detected. The area where the light amount does not change is determined to be a flat surface,
The processed area detector is set toward the area. At this time, the processor body is automatically set at the same time. Here, if the focus of the processor main body is finely adjusted, the setting of the processing apparatus of the present invention is completed.

The present invention is further useful, for example, when the processing device is a device for reading a dot mark formed in a processing target area. That is, the light emitted from the processed area detector serves as illumination light, and it is not necessary to newly provide an illumination device as in a normal reader, and the processed area detector can be used also as an illumination device.

The invention according to a second aspect of the present invention is characterized in that the processor main body and the processing target area detector have a detachable structure. The invention according to claim 1 merely stipulates that the processing target region detector is simply attached to the processing device main body. Therefore, the invention according to claim 1 includes a case where the processing unit main body and the processing target area detector are manufactured as a completely integrated product, and a case where both are manufactured detachably separately. Claim 2
In the invention according to the above, it is specified that both have a detachable structure. As a result, since the processing target area detector is detachable from the processing unit main body, even when the specification of the processing target area detector is changed, it can be easily replaced with a processing target area detector having a required specification. In addition, it is not necessary to perform various maintenances such as cleaning and adjustment of the processing apparatus main body and the target area detector in an integrated manner, and it is possible to individually perform the maintenance in a disassembled state.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 shows a head unit 10 in an optical device for detecting and processing an area to be processed according to the present invention applied to a device for reading a minute dot mark formed on a bevel surface of a notch inner surface of a semiconductor wafer to be processed. 3 shows a specific structure.

The head section 10 includes an image pickup device main body 11 as a processing device main body of the present invention and a light emitting and receiving device 15 as a processed region detector. The image pickup device main body 11 includes a lens unit 12 having a plurality of lenses incorporated at a front end thereof, a cylindrical body 13 screwed into an external screw formed at a rear end of the lens unit 12, and a cylindrical body 13. The image pickup body 14 is screw-fitted to an external screw formed at the rear end of the camera body.

On the other hand, the light emitting and receiving device 15 comprises a cylindrical portion 17 which is fitted to the lens unit 12 in close contact with the lens unit 12 and is fixed by a screw 16. The cylindrical portion 17 has a predetermined inclination angle on its outer peripheral surface. The light emitting port 17a and the light receiving port 17b directed on the center line L1 of the body 13 are
A bisector L2 of a line connecting the centers of a and 17b is provided so as to pass through the center line L1 of the cylindrical body 13. A spherical lens or a convex lens connected to an optical fiber is fitted into each of the light emitting and receiving ports 17a and 17b of the light emitting and receiving device 15.

As described above, in this embodiment, since the lens unit 12 and the light emitting and receiving device 15 can be attached and detached, even if the specifications of various light emitting and receiving devices are changed, necessary specifications are provided. It can be easily exchanged for another emitter / receiver, and it is not necessary to perform various maintenance such as cleaning and adjustment of the lens unit 12 and the emitter / receiver 15 as an integral unit. It becomes possible.

In the mark reading apparatus of the present embodiment, for example, a dot mark on a dot mark forming surface is picked up and subjected to image processing. It does not need to be arranged at the regular reflection position of the illumination light,
As shown in FIG. 2, the optical axis of the imaging body 14 is
It is not necessary to arrange them on a plane including each optical axis of the light receiving port 7a and the light receiving port 17b.

The lens unit 12 according to the present embodiment
Has a unit cylinder body 12a having an outer diameter of 5 mmφ and an inner diameter of 3.5 mmφ, and an outer diameter of 5 mmφ and a diameter of 3 mmφ on the ceiling.
Lid 12b having an imaging window, and the unit body 12
a, a plurality of lens groups 12c incorporated into the unit cylinder body 12a, and an outer thread is also cut on the outer peripheral surface of the distal end of the unit cylinder main body 12a, and the lid 12b is screwed onto the outer thread of the distal end. Have been. Further, an engagement hole for engaging the screw 16 is formed in a part of the outer peripheral surface of the unit cylinder main body 12a. The inner diameter of the cylindrical body 13 is increased stepwise toward the rear end, and the imaging body 14 has a built-in CCD imaging device 18.

By the way, in this embodiment, the light beam area irradiated on the dot mark forming surface is a circle having a diameter of 1 mmφ,
The imaging area is 0.5 mm horizontally and 0.4 m vertically above the formation surface.
m is a rectangular area, and the light emitting port 17a of the light emitting and receiving device 15 is
The position of the intersection of each optical axis of the light receiving port 17b is set at a point of 10.19 mm on the center line from the center of the outer surface of the tip lens incorporated in the lens unit 12. The dimension from the center of the outer surface of the tip lens similarly incorporated in the lens unit 12 to the image forming surface of the CCD image pickup device 18 is set to 41.67 mm. However,
The above dimensions are merely examples, and can be set arbitrarily according to the type of processing and the size of the processing target.

Now, using the head unit 10 in the optical device for detecting and processing an area to be processed according to the present invention having the above-described structure, the dot mark forming surface of the narrow area is detected and formed in the same area. When reading the dot-mark, since the bevel surface of the notch formed on the semiconductor wafer is inclined with respect to the wafer surface as shown in FIG. 3, first, one or both of the semiconductor wafer and the head unit 10 are moved. The light emitting port 17a and the light receiving port 17b
Is previously adjusted so as to be perpendicular to the bevel surface of the notch in which the dot mark is formed.

After completing this preparation work, the light emitting and receiving device 15
Turn on the light source. Next, the light projected from the light emitting port 17a is scanned along the bevel surface on the inner surface of the notch to be read. At this time, the reflected light is received by the light receiving port 17b, and the change in the light amount is detected via the photoelectric conversion element. If dot marks having a predetermined form are formed on the detection surface, the change in the amount of light is perceived as a predetermined change in the amount of light by the dot mark group. Become scarce.

The change in the light amount is within a range of a preset reference value, and in the present invention, the light emitted from the light emitting port 17a is used as illumination light simultaneously with the detection of the change in the light amount. In addition, since the imaging device main body 11 in which the light emitting and receiving device 15 is integrated is used, the surface of the detection surface is imaged and displayed on a monitor or the like, so that a separate illumination device is not required. Can be easily confirmed. Here, the image pickup device main body 11 is finely adjusted to focus on the dot mark formation surface and read the dot marks.

FIGS. 4 to 7 show an optical system head unit 20 in which the apparatus for detecting and processing an optical area to be processed according to the present invention is incorporated in a laser marker for forming a dot mark on a bevel surface inside a notch of a semiconductor wafer. An example is shown. Although not shown, the optical system head unit 20 in the present embodiment is a head unit 1 of the above-described dot mark reading apparatus.
Like the lens unit 0, the lens unit 21 and the light emitting and receiving unit 25 for forming an image of a plurality of fine spot-shaped laser beams formed in a predetermined pattern on a mark forming surface are provided. In the illustrated example, the light emitting and receiving device 25 is an independent light emitting device 25a.
And a light receiver 25b, and a support member 25c for detachably fixing and supporting each of them.

According to the present embodiment, the lens unit 21 is formed of a cylindrical body into which a plurality of lenses (not shown) are incorporated, and the light projector 25a and the light receiver 25b of the light emitter / receiver 25 are shown in FIGS. As shown, it has a substantially mirror-symmetrical form. On the other hand, the support member 2 of the
5c has a substantially convex shape as a whole having a cylindrical space in which the lens unit 21 is screwed and fixed at the center in a front view from three directions on the outer periphery with fixing screws.

The projector 25a has a main body 25a-1 formed of a rectangular parallelepiped, a ball lens 26a connected to an optical fiber 29a, and a convex lens 26b for converging light emitted through the lens 26a. A light port member 25a-2. The main body 25a-1 is provided with the light emitting member 25
A screw hole 28 for screwing a-2 is formed,
Further, the optical fiber 29a is located at the center of the bottom of the screw hole 28.
Is inserted through the fiber insertion hole 28a.

On the other hand, at the part of the main body 25a-1 which is outside the formation part of the screwing hole 28, the main body 25a-1 is orthogonal to the screwing hole 28 and the left and right wing parts 25b of the support member 25c are attached. , 25c is formed with a bolt insertion hole 28b orthogonal to the screw hole 28. A screw hole 2 communicating with the fiber insertion hole 28a is provided on the upper surface of the main body 25a-1 orthogonal to the fiber insertion hole 28a.
8c is formed.

The light receiver 25b has a substantially mirror-symmetrical structure with respect to the light projector 25a as described above, except for the light projector 25a.
The convex lens 26b incorporated in the light source 25 is eliminated.
a, the reflected light of the light projected from
The point is that only a ball lens 26a for sending to the lens 9b is incorporated.

The left and right wing portions 25 of the support member 25c
Height fine adjustment bolts 27a and 27b having external screws for making the optical axes of the projector 25a and the light receiver 25b intersect at the focal point on the optical axis of the lens unit 21 are attached to d and 25e, respectively. ing. Therefore, although not explicitly shown in the illustrated example, each main body 25 of the light emitter / receiver 25 is not shown.
a-1 and 25b-1, the side surface which comes into contact with the height fine adjustment bolts 27a and 27b is provided with the bolt 27
A number of screw grooves meshing with the a and 27b are formed.

Here, the major difference between the operation in the above-described dot mark reading device and the operation in the present embodiment is that in the reading operation, as described above, the optical system head 1 is used.
It is not necessary that the optical axis of the imager main body 11 is perpendicular to the reading surface. However, in the marking operation for forming minute dot marks as in the present embodiment, the optical Lens unit 21 of system head 20
It is necessary to set the optical axis L3 and its focal point at a high precision. In this embodiment, as shown in FIG. 8, the optical axis L3 of the lens unit
5 and the optical axis L3 of the lens unit 21 with respect to the dot mark forming surface while matching the bisector L4 of the line connecting the centers of the light emitting port member 25a-2 and the light receiving port member 25b-2. It is necessary to set vertically with high precision.

Therefore, in the present embodiment, the optical axis L3 of the lens unit 21 is defined as the center of each of the light emitting port member 25a-2 and the light receiving port member 25b-2, and the point where the optical axes intersect. And the light emitter / receiver 25 is positioned on the lens unit 21 with high accuracy so that the optical axis L3 of the lens unit 21 completely matches the bisector L4. It has been incorporated.

With the laser marking optical system head 20 of the present embodiment having the above-described configuration, the detection of the dot mark formation area and the dot marking are performed as follows.

First, the optical system head 2 according to the present embodiment
The area detection and dot marker of the present invention is installed in advance so that each optical axis of 0 is directed to the bevel surface of the notch inner surface of the semiconductor wafer (not shown), which is the surface on which the dot mark is formed. here,
The light source of the light emitter / receiver 25 is inserted, and the optical system head 20 is turned on.
Alternatively, while the semiconductor wafer is moving, the bevel surface is irradiated by the light projector 25a and the reflected light is received by the light receiver 25b. When the light reception amount at this time is within a preset range and the light reception time continues for a predetermined time, the control unit (not shown) determines that the surface is a flat surface and stores the area. At this time, the optical axis L3 of the lens unit 20 integrated with the light emitter / receiver 25 is also perpendicular to the flat surface at the same time, and if the focus is finely adjusted, the marking operation can be started immediately.

As is clear from the above description, according to the optical processing area detection and processing apparatus of the present invention, the processing apparatus is automatically positioned at the same time as the processing area is detected. As described above, it is not necessary to separately perform the operation of detecting the region to be processed and the operation of positioning the processing apparatus, and this kind of complicated work is simplified, and the processing efficiency is further improved. Further, when it is necessary to illuminate the area to be processed, for example, when reading a dot-mark, the detection light of the area to be processed can be used as illumination light for the area according to the present invention. And simplification of the device is achieved.

The above-described embodiment merely shows a typical example of the present invention, and can be naturally applied to, for example, ultra-precision processing such as various film forming steps and wiring steps at the time of manufacturing a semiconductor. Things.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of a head section of a dot mark reading device according to an embodiment of a processing target region detection and processing device of the present invention.

FIG. 2 is an explanatory diagram showing a relationship between optical axes of a lens unit and a light emitting and receiving device in the head unit.

FIG. 3 is a partial three-dimensional view showing an example of a formation area of a minute dot mark.

FIG. 4 is a cross-sectional view showing an example of a head portion of a dot marker according to another embodiment of the apparatus for detecting and processing an area to be processed according to another embodiment of the present invention, with a part thereof cut away;

FIG. 5 is a front view of the same.

FIG. 6 is a structural diagram of a projector of the head unit.

FIG. 7 is a structural diagram of a light receiver of the head unit.

FIG. 8 is an explanatory diagram showing a relationship between optical axes of a lens unit and a light emitting and receiving device in the head unit.

FIG. 9 is a plan view showing an example of the number of marks formed in the dot mark formation area.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 Dot mark reading head unit 11 Imager body 12 Lens unit 12a Unit cylinder body 12b Lid 12c Lens group 13 Cylindrical body 14 Imager 15 Light emitter / receiver 16 Screw 17 Cylindrical part 17a, 17b Light emitting / receiving port 18 CCD image sensor 20 Optical head 21 Lens unit 25 Projector 25a Projector 25a-1 Main body 25a-2 Projector 25b Receiver 25b-1 Main body 25b-2 Light receiver 25c Support members 25d, 25e Left and right wings 26a Ball lens 26b Convex lens 27a, 27b Bolt for fine height adjustment 28 Screw hole 28a Fiber insertion hole 28b Bolt insertion hole 28c Screw hole 29a, 29b Optical fiber L1 Optical axis of imager body L2 Bisector L3 (for marking) Lens unit Optical axis L4 bisector

 ──────────────────────────────────────────────────続 き Continued from the front page F term (reference) 2F065 AA06 BB27 CC19 FF44 GG12 HH04 JJ01 LL02 LL04 MM01 PP22 5F031 CA02 CA05 JA04 JA35 JA38 JA50 PA18

Claims (2)

[Claims] 1. A method for optically detecting an area to be processed,
An apparatus for performing various types of processing on the surface to be processed, comprising: a processing unit main body; a light emitting port that is integrally attached to the processing unit main body and emits light to the surface to be processed; and reflected light from the surface to be processed. A processing area detector having a light receiving port for receiving light, wherein the optical axis of the processing apparatus main body and the projection light and the reflected light are arranged to intersect at one point, and the detection and processing of the processing surface An apparatus for optically detecting and processing an area to be processed on a surface to be processed, wherein positioning of the container body is performed simultaneously. 2. The apparatus for detecting and processing an area to be processed according to claim 1, wherein the processing unit main body and the area to be processed detector have a detachable structure.