JPH0361556B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention provides a method for drawing straight lines using a writing laser beam on a workpiece having a three-dimensional integrated circuit that has been subjected to a metallization process. It relates to a method for setting reference data used for positioning and correction, and to an apparatus for carrying out this method. The above device will be abbreviated as a "laser beam generator".

[Conventional technology]

A method and a device of the above type are known from European Patent No. 0128993. This patent application discloses a method and apparatus that uses a scanning laser beam in addition to a writing laser beam. When processing a workpiece with a writing laser beam, the scanning laser beam is reflected from the surface of the workpiece and is received and evaluated by a beam detector, for example a differentially mounted photodiode. The evaluated measurements are then used to automatically detect or control the relative movement of the workpiece with respect to the writing laser beam.

European Patent No. 0 088 045 describes a method for producing conductive regions in monolithically integrated semiconductor devices and high density semiconductor devices produced by this method.

For the fabrication of user-specific integrated circuits, a commercially available silicon wafer with a structure of P and N type conductivity or N and P conductivity is used and, depending on the intended use, a special It is necessary to form a contact surface. In contrast to known techniques, conductive regions with standardized grooves arranged according to a certain mesh are formed on a silicon wafer, for example by etching or vapor deposition techniques. Depending on the intended circuit structure,
Between these, the aluminum conductive coating is removed directly or indirectly using an electron beam or an electromagnetic beam. Laser beams, which can be easily positioned and controlled and are used to expose photosensitive films, are particularly suitable for this. Further, the silicon wafer is continuously moved relative to the laser beam along a predetermined mesh, and the laser power is intermittently introduced using a modulator depending on the desired shape of removal. The spacing between the meshes is about 1 to 7 μm, the width of the straight line to be removed is 0. to 2 μm, and the processing speed is
It takes about 1 to 2 hours per 10.1 cm silicon wafer. Therefore, the moving speed is 30 to 100 cm/s,
For a travel length of 10.1 cm, the tolerance for position is 0.3-2.5 μm. The above values of positional tolerances cannot be achieved with mechanical feed units. The production of the isolated conductive regions is ultimately carried out using photoetching techniques. This method eliminates the need for expensive, specialized photomasks. The semiconductor device thus fabricated has grooves on its conductive layer that serve as end points and/or corner points of isolated conductive regions arranged according to a predetermined mesh.

[Problem of invention]

The problem of the invention is to ensure precise guidance of the writing laser beam relative to the workpiece, even in three-dimensional structures, and to perform positioning, such as position correction or correction of mechanical non-linear movements. Another object of the invention is to provide a method and a device for setting reference data of the type mentioned at the outset, which makes synchronization possible.

The above method and the above apparatus can be used for example 300
It is necessary to be able to set a separation plane of 2 μm width, ie, an interval between straight lines, at a speed of mm/s or more.

[Means to solve problems]

The above problem can be solved by the method of setting reference data belonging to the type mentioned at the beginning according to the present invention.
The metallized mesh 58 of the workpiece G is exposed to the writing laser beam 7, 49 modulated by the modulator 3 during the linear working motion or the scanning laser beam 9', 55 introduced in the same optical axis. The reflected laser beam 51 is received and evaluated by at least one beam detector 15, 18', 53, and the evaluated signal is sent to the workpiece G and the writing laser beam 7,
49 relative motion positioning and correction.

Furthermore, the above-mentioned problem is solved according to the invention in the case of a device for setting reference data belonging to the type mentioned at the outset, which is equipped with a writing laser device 1 with a subsequent modulator 3, a magnifying optical system 5 and an objective lens 19. a writing laser beam 7 to a detector 53 and an integrated circuit 57 with a laser writing device 51 and a beam splitter 52 of the reflected light 51;
The solution is to have an evaluation device with a control device giving the correct relative position of 49.

Furthermore, the above-mentioned problem is solved according to the invention in the case of a device for setting reference data belonging to the type mentioned at the outset, which is equipped with a writing laser device 1 with a subsequent modulator 3, a magnifying optical system 5 and an objective lens 19. a writing laser beam 7 to a detector 53 and an integrated circuit 57 with a laser writing device 51 and a beam splitter 52 of the reflected light 51;
49, the laser writing device further includes a scanning laser device 9 with a wavelength different from that of the writing laser device 1, and a scanning laser beam 55. This is solved by having a dichroic beam splitter 56 superimposed on the same optical axis as the writing laser beam 49 and yet separating the scanning laser beam 55 later on the detector 53. ing.

Other advantageous developments according to the invention are described in the implementation section.

〔Effect of the invention〕

An advantage of the invention is that the method and apparatus described above can accurately guide the mutual position of the workpiece and the writing laser beam, even in three-dimensional structures where scattered light may occur and the setting of the reference data may be disturbed. The point is that even in the case of writing, the writing laser beam can be used for scanning even in a weakened state depending on the case.

Additionally, the use of a dichroic beam splitter simplifies evaluation when two laser beams with different wavelengths are used.

[Configuration and effects of embodiment]

According to the structure of claim 2, one or more laser beams are made incident perpendicularly to the processing surface of the integrated circuit of the workpiece or at a deviation of ±10° therefrom. Within specified tolerances, the writing or scanning laser beam operates with sufficient accuracy.

According to claims 3 to 6, in order to correct the movement of the workpiece out of a straight line, a controllable beam deflector, for example a controllable deflection mirror placed in front of the objective lens, is provided. This is done either by a controllable parallel plate arranged obliquely after the truncation, or by a controllable movement of the objective lens.
Desired corrections can be easily made through the various processing steps described above.

According to claim 7, the modulation signal of the writing laser beam directly controls the amplification factor of the signal amplifier, so that the same output signal is obtained even with different beam powers.

According to the structure of claim 8, the polarized writing laser beam passes through a polarizing beam splitter, which is a polarizer of a beam splitter of an electro-optical modulator, and is incident on the processing surface of the workpiece, The beam detector detects the same output when the modulator and beam switch are open and closed.

According to an advantageous development of claim 9,
In addition to the writing laser beam, a scanning laser beam is used. This beam is introduced using a dichroic beam splitter on the same optical axis as the writing laser beam and passes through the same optical path. Thus, undesirable surface conditions of the integrated circuit of the workpiece are offset against the wavelength of the writing laser beam, and the wavelength of the scanning laser beam can be selected to be different from the wavelength of the writing laser beam. This configuration is necessary when two significantly different wavelengths are required for the surface of the workpiece being treated.

According to claim 10, in addition to the signal of the reflected laser beam, the scattered light is measured with an auxiliary detector and a ratio of both signals is formed to detect different local regions of the integrated circuit of the workpiece. It is advantageous to offset the reflective and scattering properties of the surface condition, for example the metallized surface and the underlying material. This method eliminates errors caused by different materials.

According to claim 11, a writing laser beam (blue light) and a scanning laser beam (red light) in a laser beam concentrator with a writing laser beam splitter and a scanning laser beam mirror are provided. It is particularly advantageous if a portion of the writing laser beam is reflected onto the objective head and split by a writing laser beam splitter onto a writing laser beam detector. The advantage of this configuration is that both laser beams can be precisely directed in the laser beam concentrator. This pointing orientation is further adjusted or controlled as the writing laser beam passes through the writing laser beam detector. Advantageously, the metallized three-dimensional integrated circuit is coated with a photoresist coating that is exposed to the writing laser beam.

According to claim 12, a writing laser beam and a scanning laser beam are introduced in a laser beam concentrator on the same optical axis into a scanning laser beam splitter of an objective head, from which a scanning laser beam is introduced. The beam and the writing laser beam are introduced onto the workpiece through an objective lens. A portion of the reflected scanning laser beam is reflected to the revolver head via a scanning laser beam splitter. The advantage of this configuration is that co-guiding the writing laser beam and the scanning laser beam further improves the precision of the operation. This is because the same optical elements can be used for both laser beams at least at certain points in the beam path.

According to claims 13 to 15, it is advantageous to evaluate the laser beam signal detected in the detector or from the objective head or from the revolver head and thereby determine or detect the operating position. be.

According to the structure of claim 17, the beam splitter is a polarizing beam splitter used as a polarizer of an electro-optical modulator.

According to an advantageous development of the device according to claim 19, the control device for correcting the correct mutual position of the integrated circuit and the laser beam comprises an operational amplifier with a subsequent high-voltage amplifier and at least one piezoelectric element. It has a control circuit consisting of. This at least one piezoelectric element is particularly suitable for very fine and rapid control of moving parts.

According to another advantageous embodiment of the device according to claim 20, the objective head with the revolver head forms one common optical module;
The coupling part of this module is simply a scanning laser beam splitter. This configuration is particularly advantageous since no deflection mirrors are arranged between the objective head and the revolver head, which would influence the scanning plane and speed of the detector.

According to claim 21, it is advantageous if the laser beam concentrator is equipped with a writing laser beam detector. This structure allows the direction and width of the writing laser beam to be corrected immediately after the writing laser source, and possible inaccuracies to be detected.

According to an advantageous embodiment of patent claim 22, at least two of three units are provided in the revolver head: a scanning laser beam detector, an eyepiece of a shearing interferometer and an eyepiece of a microscope with a crosshair. units are installed. This arrangement places in the immediate vicinity of the objective head at least two instruments useful for checking the operating condition of the apparatus. Connecting this working part to the revolver head saves a lot of space and allows a certain optical unit of the objective head to be selected at will.

According to the structure of claim 23, the writing laser light source and the scanning laser light source each have at least one diaphragm plate inside the magnifying optical system. This configuration ensures a laser beam without enough image information to be reasonable in the case of the new method described above. This aperture hole in the aperture plate is called a "pinhole."

According to claim 24, it is advantageous if a writing laser beam blocking filter is arranged in the eyepiece of the microscope in the objective head. This configuration prevents human eyes from being damaged by the high power of the laser beam.

According to the structure of claim 25, one detector is arranged behind the scanning laser beam in the direction of the writing laser beam and the scanning laser beam introduced on the same optical axis. This separate detector orients the common beam path of the scanning laser beam and the writing laser beam.

According to the embodiment of patent claim 26, it is particularly advantageous if at least one detector is constructed with a number of detection fields. With this configuration, not only the deviation from the desired method but also the direction in which this deviation occurs is signaled.

〔Example〕

The invention will be explained in more detail below with reference to the attached drawings.

According to item 1a, the writing laser light source A and the scanning laser light source B are arranged in a horizontal position parallel to the optical axis. In the writing laser light source A there is a writing laser beam device 1 . A laser beam switch 2 is arranged at the rear of the device, which interrupts the writing laser beam when the device is opened. The aperture plate 2' is arranged in the magnifying optical system 4 of the writing laser beam device 1. A modulator 3 is disposed within the optical axis between these members. The lens of the magnifying optical system 4 is designated by reference numeral 4', and the entire writing laser light source A is housed in a case 5.
The modulator 3 and the magnifying optical system 4 are held in the case 5 together with an adjustable fixing member 6. The entire case 5 is also equipped with an adjustable fixing element 6, by means of which the optical axis of the writing laser light source A can be correctly aligned. The writing laser beam is referenced 7. The scanning laser light source B is housed in a case 8. This light source 8 has a scanning laser device 9 from which a scanning laser beam 9' is emitted from a scanning laser source B.
is introduced into the magnifying optical system 10 of. This magnifying optical system 10 also includes a diaphragm plate 11 in addition to the already mentioned lens 4'. Scanning laser source B is also equipped with the other components mentioned when describing writing laser source A.

Identical parts are given the same reference numerals in all drawings.

A scanning laser beam 9' is introduced from the scanning laser device 9 into the magnifying optical system 10. The components of the scanning laser light source B are housed in a case 8. This case is case 5 of writing laser light source A.
It can be set at the normal position using the adjustable fixing member 6 in the same way. In the direction of the optical axis of the writing laser beam 7 and the scanning laser beam 9' there is a laser beam concentrator C. In the case 12 of this condenser,
A writing laser beam splitter 13 and a scanning laser beam mirror 14 are provided. Both parts, shown in plan view in FIG. 1a, are accommodated in said case 12 so as to be adjustable by means of an adjustment member 16. On the left side of the write laser beam splitter 13 is a write laser beam detector 1 which checks the correct exit position of the write laser beam 7.
5 are arranged. The reflected writing laser beam 7 and the reflected scanning laser beam 9' overlap on the same optical axis 17 and then reach the arrangement shown in FIG. 1b. The mechanism shown in Figure 1b has a vertical optical axis. Common optical path 17 first enters scanning laser beam splitter 18 . From this splitter, the majority of the beam passes to the objective 19 of the objective head D and then to the workpiece G. In the direction 17 of the writing laser beam and the scanning laser beam introduced on the same optical axis, a detector 18' is arranged behind the scanning laser beam splitter 18. The role of this detector is to correct the optical path 1
It is to monitor 7. The objective lens 19 has
Adjustment elements 20 are provided, some of which are equipped with piezoelectric drives 21. Directly above the objective lens head D is the revolver head E.
is arranged rotatably. In this case, the objective head D and the revolver head E form a functional unit, ie an optical module F. Objective lens head D is revolver holder 2
2, and on this holder 22, in this embodiment, a scanning laser beam detector 23, an eyepiece 24 of a shearing interferometer, and an eyepiece 25 of a microscope having a crosshair are rotatably mounted. It has been done. The eyepiece lens 25 of the microscope is equipped with a writing laser beam blocking filter 25' for safety.
is arranged.

Laser beam condenser C, objective lens head D
and the optical module F, which consists of an objective head D and a revolver head E, are shown in more detail in the following figures and will be explained in more detail. In FIG. 1b, the revolver head E is shown unfolded in a straight line for better visibility, but the correct ring-like shape will be confirmed later in FIG.

FIG. 2 shows a front view of the laser beam concentrator C. The write laser beam splitter 13 mentioned above is gimballed from the holder 26. Similarly, the scanning laser beam mirror 14 already mentioned is arranged on the holder 27 as well. Although the numerous supporting parts of the laser beam concentrator C are not critical to the functioning of the method and device, they should of course be made sufficiently sturdy. This also applies to the guide plates 28' of the holders 26, 27 and the coupling body 30. Adjustment screw 2
9 is used to adjust the holders 26, 27. A rigid link 30 connects the support member 28 to a workbench 31. On the left side of FIG. 2, the already described writing laser beam detector 15 is also fixed to a support member 28''.

FIG. 3 shows the structure of FIG. 2 in plan view. The structural parts have already been explained. In Figure 3,
Also shown are the adjusting screw 29' and the guide plate 28'.
The adjustment screw 29 is attached to the optical member 1 together with the adjustment screw 29'.
3 and 14 properly.

FIG. 4 shows a partial longitudinal section of an optical module F, which is formed by an objective head D in its lower part and a revolver head E in its upper part. The components of the objective lens head D are held by four rods 32. These rods 32 are introduced parallel to the optical axis passing through the entire objective head D and are mounted in rod holders 33. At the bottom of the objective head D there are two rod holders 3
3 are fixed relative to each other by two leaf springs 34. Scanning laser beam splitter 18 is supported in holder 35.

A writing laser beam and a scanning laser beam (the common optical path is designated by reference numeral 17) are introduced into the scanning laser beam splitter 18 from the left side on the same optical axis. In order to hold the objective lens 19, an objective lens retaining ring 36 is used in particular. Of course, since the components of the objective head D can be moved along the four rods 32, the relative positions of the optical components can be optimally adjusted. This naturally applies only to the position of the component in the direction of the optical axis. A piezoelectric drive unit 21 is provided for movement perpendicular to the optical axis. The rod holder 33 and other fixing members are secured by screws 37.
are held together. Since these screws are not related to this invention and the screw connection method itself is well known, only some of the screws are illustrated. A rotary table 38 for a revolver head is rotatably connected to the upper part of the objective lens head D. In order to fix the rotary table 38 for the revolver head sufficiently firmly and rotatably, the fixing screw 44 of the holder 43 must be
A revolver holder 22 fixed to is used. In this embodiment, the revolver head E is provided with three independent members.
In particular, a prism 40 is provided which deflects the horizontal optical axis into a vertical optical axis. The shearing interferometer includes an eyepiece 24 with a frosted glass and a parallel plate 39. The revolver head E also has a crosshair microscope eyepiece 25 and a scanning laser beam detector 23. These elements are arranged in a revolver head rotating base 38 which, in this embodiment, has three holes 42 (see FIG. 6). On the vertical optical axis, below the prism 40 there is a writing laser beam blocking filter 25' and a cylindrical lens 4.
1 is arranged.

FIG. 5 shows a cross section taken along the line - in FIG. 4. That is, it is a cross section of the objective lens head D, and the fixed state of the objective lens head D can be well understood from this figure. In the upper part of FIG. 5 there is shown a multi-part holder 43, which has a thick plate and is used to accommodate the fixing screw 44 of the revolver head E.

FIG. 6 shows a simplified top view of the revolver head E. This drawing shows fixing pin 4.
A scanning laser beam detector 23 with 6, a shearing interferometer eyepiece 24 with a flat panel 39, and a microscope eyepiece 25 are shown. These three types of parts are all in holder 45.
Since it is rotatably fixed to the objective lens head D, desired equipment can be freely disposed on the optical axis of the objective lens head D. The holder 43 used for fixing the revolver head E can also be seen in this figure.

FIG. 7 shows a simplified example of a detector, in this case a scanning laser beam detector 23, which consists of a number of detection fields 47.
When the operation is normal, the central detection field is illuminated,
Upon deviation from this desired position, one or more nearby detection fields of view are captured. Since these detection fields 47 can be evaluated individually, this gives information as to in which direction the deviation from the correct position extends.

In this embodiment, the writing laser device 1 is a naturally air-cooled helium-cadmium laser system (Marke Liconix, Sunnyvale CA 94086,
United States) is used. This laser device is
It consists of a current-controlled high voltage source, Liconix model 4200PS, with a time program section and a firing control section, and a laser device, model 4100B. The main performance of the writing laser beam device 1 is as follows. The wavelength of light is 442nm, and the output of light is
At 10 mW (continuous light), the intensity is uniformly distributed over the beam diameter. Polarization direction is horizontal ±5
%, and the beam diameter is 1.1 mm.

The scanning laser device 9 is naturally air-cooled.
Melles Griot (nickname of the device, ILEE, Schlieren,
Helium Neon Laser System (Switzerland), a laser device, model 05-LHP-
111 and power supply, model 05−LPN−340 (1800V,
6.5mA). The wavelength of light is 633nm
The light output is 1 mW. The deviation of the optical axis after rising from the cooling state is less than 200μrad,
After 15 minutes of operation, it is 30μrad. The beam divergence angle is less than 1.3 mrad, and the control error for the light output is within ±5%.

Modulator 3 is a natural air-cooled, electrically controlled controller, a coherent blue laser light blocking system (Coherqnt Associates, Danbury, Conn.).
06810, USA) and consists of a controller model 31 and a modulator model 3010. Inside the modulator tube is a fragile potassium dihydrogen phosphate crystal encapsulated in a liquid of the same refractive index, with two control electrodes and a photodiode integrated on the output side. This crystal acts as a polarizing filter, with the direction of polarization rotated by more than 90° at a voltage of about 600V.

The magnifying optical system 4 is composed of two focusing lenses and an aperture plate having an aperture hole, also called a "pinhole", having a diameter of 10 μm at the common focus of these focusing lenses. This magnifying optical system enlarges the diameter of the laser beam and reduces the divergence angle of the laser beam by the ratio of the divergence angles, that is, the ratio of the focal lengths of both focusing lenses, so that the image of the beam spot in the aperture hole becomes the exit beam. tell. i.e. removing dark parts of the incident beam caused by, for example, dust;
Make the direction of the output beam independent of the direction of the input beam.

As beam splitter 13, a dichroic splitter is used, which is made of parallel glass plates with a dielectric metal coating deposited on one side. This splitter transmits light of a certain wavelength, that is, a certain color, incident in the transmission direction in the same direction, and in that case, the beam exit point is moved by the refractive index of the glass for a certain wavelength depending on the thickness of the glass. .
The piezoelectric drive 21, which is known per se, in this example includes a Burley model PZ70 1000V power supply.
Burley, model PZ40, consists of a piezoelectric transducer. Since the piezoelectric crystal stack extends approximately in proportion to the applied voltage, the objective lens 19 is moved horizontally.

The microscope consists of an objective lens 19 and a microscope eyepiece 25. This objective lens 19 is equipped with a focusing lens system with or without a standard cover glass on the working side, and focuses the concentrically parallel incident blue laser beam and red laser beam as much as possible within the working distance. It focuses on a small spot and provides a magnified image of the green-lit detection field concentric to this spot. This detection field can be observed through the eyepiece 25 of the microscope. The mechanical displacement by the piezoelectric drive 21 is translated into a movement of the center point of the image and the focusing spot.

The eyepiece lens 25 of the microscope is formed as a focusing lens system having the role of a magnifying glass, and forms a visible image magnified from the virtual image of the objective lens 19.

The shearing interferometer is composed of a mirror that moves in the beam path, a parallel flat glass plate 39, and an eyepiece 24, and measures the gap between the focal plane of the objective lens 19 and the aluminum surface where reflection occurs. It forms a shearing interferometer.

Advantageously, the detectors 15, 18' and 23 are each a silicon photodiode, a central structure that is non-photosensitive on the inside and photosensitive on the outside. These detectors determine whether the laser beam is in the correct position or deviates from this position in a certain direction from the laser beam reflected from the workpiece or otherwise obtained. Can be confirmed.

A few possible embodiments of the device according to the invention are shown schematically in FIGS. 8-13.

FIG. 8 shows the simplified operation of a device according to the invention with one writing laser device 1. In FIG. Workpiece G is made of a silicon wafer and has a metal mesh shown in FIG. An arrow 48 indicates the direction of movement of the workpiece G. The writing laser beam is labeled 49. This beam enters the deflection mirror 50 from the writing laser device 1 via the enlarging optical system 4 . This writing laser beam 49 corresponds to the writing laser beam 7, but is shown in broken lines for better visibility. The writing laser beam 49 first passes through an objective head D with an objective lens and is introduced onto the workpiece G to be processed. Light 51 reflected from workpiece G enters beam splitter 52 . From this beam splitter, some light is introduced into the detector 53, passes through the beam splitter 52, and some reflected light is sent to the microscope eyepiece 25.
reach.

FIG. 9 is generally similar to FIG. 8, except that a polarized beam splitter 54 is provided which introduces the polarization component of the light reflected by the objective lens head D into a detector 53.

FIG. 10 shows an embodiment in which a scanning laser beam 55 is also used. This scanning laser beam 55 corresponds to the scanning laser beam 9' in FIG. 1, but is shown in dotted lines for better visibility. Therefore, the role of this scanning laser beam can be understood from the drawing. This configuration is effective when the surface properties of the workpiece G require two different wavelengths. A scanning laser beam 55 is generated in a scanning laser device 9 and further passes through a magnifying optical system 10.
The light is introduced into the deflection mirror 50 via the. From this deflection mirror 50, the scanning laser beam 55 is reflected, passes through a dichroic splitter 56 and an objective head D, and reaches the surface of the workpiece G together with the writing laser beam 49. Both laser beams are
Proceeding along the same optical axis and reaching workpiece G. and,
It is reflected by beam splitter 52 on the same optical axis and reaches detector 53. The reflected writing laser beam 51 enters the microscope and the eyepiece 25.

According to FIG. 11, a beam splitter 52 is arranged in front of the objective lens head D, so that the reflected beam of the writing laser beam 49 is separated from the other beams.
The splitter 52 introduces the light into the detector 53 and into the eyepiece 25 of the microscope.

In the embodiment of FIG. 12, a polarizing beam splitter 54 is arranged directly on the objective head D and directs the polarized component of the reflected light 51 to a detector 53.
In this case, the microscope eyepiece 25 receives the reflected light directly from the beam splitter 52.

According to FIG. 13, a writing laser beam 49 and a scanning laser beam 55 are used and are introduced perpendicularly into the workpiece G. A beam splitter 52 is disposed in the common optical path of these laser beams, and as shown in FIG. simultaneously to the eyepiece lens 25.

FIG. 14 shows an embodiment in which reflected light 51 and scattered light 58 are detected. A detector 57 is used to detect reflected light 51, and a detector 60 is used to detect scattered light 58. As can be well understood from FIG. 14, a detector 60 for scattered light 58
are arranged around the laser beam 49.

In FIG. 15, a part of the workpiece G is shown in a highly simplified manner. The surface bearing the integrated circuit is referenced 61 and a metallized mesh 62 is used as a reference structure.
The first laser spot 63a is placed directly on the mesh 62 which has been subjected to a metallization process, the second laser spot 63b is placed directly on the mesh 62 which has been partially metallized, and the third laser spot 63c is placed directly on the mesh 62 which has been subjected to a metallization process. It's on 61.

Reflection intensity distributions for these are shown in FIGS. 16a to 16c. In FIG. 16a, the ideal curve of the intensity distribution is shown as a broken line, and the actual curve is shown as a solid line 64a. Similar to the curve in Figure 16b. Here, the deviation from the ideal state is curve 64
It is shown in b. Figure 16c shows an ideal situation, meaning that the actual curve of the intensity distribution 64c matches the ideal curve.

A metallized mesh 62 is used as a reference structure in the device of the invention.
For example, the distance between two mesh lines is 7 μm,
The width of the straight line is 5 μm (Figure 15). In the last embodiment, the writing laser beam device 1 is an argon ion laser source (e.g. Spectra Physics,
Moutain View California, Model 162A.0.7;
AmericanLaser Corp., Salt Lake City;
Utah, model 60C) or at a wavelength of 424nm,
The output is 7-40mW or the wavelength is 325nm,
A He-Cd laser source (eg, Liconix, Sunnyvale, California, Model 4200N or Model 4200NB) with a power output of 1-10 mW.

The output of the continuous laser beam can also be switched on and off using an electro-optic modulator, i.e. beam switch 3 (e.g. Coherent
Incorp. Plo Alt, California, Modulator Div. Model 3030) or an acousto-optic modulator, or beam switch (e.g. Coherent Incorp. Plo Alt,
California, Modulator Div. Model 304D). The required opening/closing time is determined by the writing speed and spatial resolution, and is, for example, 2 μs. The subsequent beam expanding optical system 4 has a beam diameter of, for example,
Magnify 10x. Horizontal writing laser beam 49 is vertically deflected by deflection mirror 50.
In this embodiment, the objective lens 19 has a focal length of
It has a diameter of 18mm and a diameter of 10mm. The size of the obtained beam spot is approximately 2 μm, and the depth of focus is approximately 13 μm. The deflection mirror 50 is arranged in a controllable or adjustable manner.

In this embodiment, the scanning laser device 9 has an output of 1 mW and a beam diameter of 0.65 mm. He-Ne
It is a laser light source. This laser beam is expanded to four times its beam diameter by an expanding optical system 10, and a writing laser beam 49 is used by an adjustable deflection mirror 50.
superimposed on

Although the operation of the device according to the invention has already been partially described, many embodiments are possible. In the embodiment of FIG. 8, scanning and writing are performed with the same laser beam 49. In FIG. 9, writing laser beam 49 passes through polarizing beam splitter 54 and is directed onto the workpiece G surface. In this example,
Beam splitter 54 is used as a polarizer for electro-optical modulator 3. That is, the detector 53 receives the same output when the beam switch opens and closes. 1st
Although the scanning laser beam 55 and the writing laser beam 49 are shown separately in FIG. 0, they are introduced on the same optical axis by a dichroic mirror 56. This mirror has 100%
It has the advantage of being transparent and 100% reflective at a different wavelength. Therefore both laser beams 49,5
5 can be focused with the same objective lens.
The embodiments shown in FIGS. 11 to 13 are particularly suitable for processed products with severe undulations.

[Brief explanation of drawings]

1a and 1b are schematic illustrations of a particularly advantageous embodiment of the device according to the invention, FIG. 1a being a plan view of the left-hand part of the device and FIG. 1b being a side view of the right-hand part of the device. FIG. 2 is a side view of the laser beam concentrator of FIG. 1a; FIG. 3 is a plan view of the laser beam concentrator of FIG. 2; FIG. 4 is a partial sectional view of the optical module consisting of the objective lens head and the revolver head. FIG. 5 is a sectional view taken along line segment - in FIG. 4; FIG. 6 is a plan view of the revolver head of FIGS. 6 and 4; FIG. 7 is a drawing of an exemplary shape of a detector with multiple detection fields of view. FIG. 8 is a diagram of an embodiment of the invention in which scanning and writing are performed with the same laser beam. FIG. 9 is a drawing of an embodiment according to the invention using a polarized writing laser beam and a polarizing beam splitter. FIG. 10: A drawing of an embodiment of the device according to the invention with two laser light sources of different wavelengths. FIG. 11 is a drawing of an embodiment of the apparatus according to the invention in which a scanning laser beam is incident perpendicularly on the workpiece and two beam splitters are arranged; Figure 12, 1st using polarizing beam splitter
1 is a drawing of an embodiment in which the configuration of FIG. 1 is changed. Figure 13,
Dichroic beam for two different laser beams
Drawing of another example using a splitter. 14th
Figure 1: Schematic cross-section of an optical head in which both reflected and scattered laser beams are evaluated. FIG. 15: Drawing of a workpiece with a metallized mesh and an exemplary arrangement of laser beam spots. 16th
Figures a to 16c and three types of intensity distribution diagrams corresponding to the positions of the laser beam spots in Figure 15; Reference numbers in the figure: A...Writing laser beam source, B...Scanning laser beam source, C...Laser beam condenser, D...Objective lens head, E
...Revolver head, F...Optical module,
G... Processed product, 1... Writing laser device, 2...
a laser beam switch of the writing laser device 1;
2'... Aperture plate of the magnifying optical system, 3... Modulator, 4
...Enlargement optical system of writing laser device 1, 4'...
Lens of magnifying optical system, 5... Case of writing laser beam light source A, 6... Adjustable fixing member, 7
...writing laser beam, 8...case of scanning laser beam light source B, 9...scanning beam device,
9'... Scanning laser beam, 10... Enlargement optical system for scanning laser beam light source B, 11... Diaphragm plate, 12... Case of laser beam condenser C,
13...Writing laser beam splitter, 14
... Scanning laser beam mirror, 15 ... Writing laser beam detector, 16 ... Adjustment member of laser beam concentrator C, 17 ... Writing laser beam 7 and scanning laser beam introduced on the same optical axis 9', 18...scanning laser beam splitter,
18'...Scanning laser beam splitter 18
Detector of 19...Objective lens of objective lens head D, 20...Adjustment member of objective lens 19, 21
... Piezoelectric drive unit, 22 ... Revolver holder,
23... Scanning laser beam detector, 24... Shearing interferometer eyepiece, 25... Microscope eyepiece with crosshairs, 25'... Writing laser blocking filter, 26... Writing laser beam splitter. Holder of 13, 27... Holder of scanning laser beam mirror 14, 28...
...Supporting member of laser beam concentrator C, 28'...
...Guide plates for holders 26 and 27, 28''...Support member, 29...Adjustment screws for holders 26 and 27,
30... Connecting body, 31... Workbench, 32... Rod, 33... Rod holder, 34... Leaf spring,
35...Holder of scanning laser beam splitter 18, 36...Retaining ring of objective lens, 3
7...screw, 38...rotating table of revolver head, 39...parallel plate, 40...prism, 41
... Cylindrical lens, 42 ... Hole, 43 ... Holder,
44...Fixing screw, 45...Holder, 47...
Detection field of view of detector, 48...Movement direction of workpiece G, 49...Writing laser beam (dashed line), 50
... Deflection mirror for laser beam, 51 ... Reflected light, 52 ... Beam splitter for writing laser beam and scanning laser beam, 53 ... Detector, 54 ... Polarization beam splitter, 55 ...
Scanning laser beam (dotted line), 56... Dichroic mirror, beam splitter, 57... Detector of reflected light, 58... Scattered light, 59... Focused laser beam, 60... Detector of scattered light 58 , 61... integrated circuit, 62... mesh subjected to metallization treatment,
Reference structure, 63a, b, c... Laser spot of processed product G, 64a, b, c... Intensity distribution.

Claims (1)

[Claims] 1. Setting reference data for positioning and correcting mechanical movements when drawing straight lines using a writing laser beam on a workpiece having a three-dimensional integrated circuit subjected to a metallization process. In the method of Scan at 9', 55,
receiving and evaluating the reflected laser beam 51 by at least one beam detector 15, 18', 53;
A method characterized in that the evaluated signal is used for positioning and correcting the relative movement of the workpiece G and the writing laser beam 7, 49. 2 one or more laser beams 7, 9', 4
9, 55 is irradiated perpendicularly to the processing surface of the integrated circuit 61 of the processed product G, or at an inclination of ±10° or less from the vertical direction.
The method described in section. 3. Method according to claim 1 or 2, characterized in that the correction of movements of the workpiece G deviating from a straight line is carried out with a controllable beam deflector. 4. Method according to claim 3, characterized in that said correction is carried out with a controllable deflection mirror 50 placed in front of the objective lens 19. 5. Method according to claim 3, characterized in that said correction is carried out with a controllable parallel plate placed obliquely after the objective lens 19. 6. Method according to claim 3, characterized in that said correction is carried out by a controllable movement of the objective lens (19). 7. Method according to claim 1, characterized in that the modulation signal of the writing laser beam 7, 49 directly controls the amplification factor of the signal amplifier, so that the same output signal is obtained with different beam powers. . 8 The polarized writing laser beam 49 is passed through the polarization beam splitter 5 as a polarizer of the electro-optic modulator 3.
4, the beam detector 53 obtains the same output when the beam switch is open and closed. the method of. 9 In addition to the writing laser beam 7, 49, the writing laser beam 7, 49 is also
49, and the same optical path 1.
7 is used to compensate for surface conditions of the integrated circuit of the workpiece G that are unfavorable for the wavelength of the writing laser beam 7, 49, and the wavelength of the scanning laser beam 7, 55 is 2. The method according to claim 1, wherein the wavelength of the writing laser beam is selected to be different from the wavelength of the writing laser beam. 10 In addition to the signal of the reflected laser beam 49, the scattered light 58 is detected by an auxiliary detector 60 and a ratio of both signals is formed to determine the reflection properties and scattering of the metallized surface and the underlying material. 2. A method according to claim 1, characterized in that different local surface conditions of the integrated circuit of the workpiece G, such as characteristics, are compensated for. 11 Using the writing laser beam splitter 13 and the scanning laser beam mirror 14, the writing laser beam 7 and the scanning laser beam 9' in the laser beam concentrator C are reflected to the objective lens head D, and the writing laser 10. Method according to claim 1, characterized in that a part of the beam 7 is split by a writing laser beam splitter 13 to a writing laser beam detector 15. 12 The writing laser beam 7 and the scanning laser beam 9' in the laser beam concentrator C are introduced with the same optical axis into the scanning laser beam splitter 18 of the objective head D, and from this splitter the writing laser beam 9' and the scanning laser beam 9' are introduced. The scanning laser beam 7 is guided onto the workpiece G via an objective lens 19, and a part of the reflected scanning laser beam 9' is reflected via a scanning laser beam splitter 18 to a revolver head E. 12. The method according to claim 11. 13. The method according to claim 11 or 12, characterized in that the laser light signal detected in the detectors 15, 18', 25 is evaluated and the correct operating position is determined or detected. Method. 14. Method according to claim 11 or 12, characterized in that the laser light signal detected at the objective lens head D is evaluated to determine or detect the correct operating position. 15. Method according to claim 11 or 12, characterized in that the laser light signal detected at the revolver head E is evaluated to determine or detect the correct operating position. 16. When drawing straight lines with a writing laser beam on workpieces with three-dimensional integrated circuits subjected to metallization, in devices for setting reference data for positioning and correcting mechanical movements, subsequent A laser writing device is equipped with a writing laser device 1 having a modulator 3, a magnifying optical system 5 and an objective lens 19, and a beam of reflected light 51.
Writing laser beam 7,49 to detector 53 and integrated circuit 57 with attached splitter 52
and a control device for giving the correct relative position of the device. 17. Claim 16, characterized in that the beam splitter is a polarizing beam splitter arranged as a polarizer of the electro-optical modulator 3.
The equipment described in section. 18. When drawing straight lines with a writing laser beam on workpieces with three-dimensional integrated circuits subjected to metallization, in devices for setting reference data for positioning and correcting mechanical movements, subsequent A laser writing device is equipped with a writing laser device 1 having a modulator 3, a magnifying optical system 5 and an objective lens 19, and a beam of reflected light 51.
Writing laser beam 7,49 to detector 53 and integrated circuit 57 with attached splitter 52
The laser writing device further includes a scanning laser device 9 having a wavelength different from that of the writing laser device 1 and a scanning laser beam 55. A device characterized in that it is equipped with a dichroic beam splitter 56 for superimposing the writing laser beam 49 on the same optical axis and for later separating the scanning laser beam 55 on the detector 53. . 19. The control device according to claim 16, characterized in that the control device is equipped with a control circuit consisting of an operational amplifier with a subsequent high-voltage amplifier and at least one piezoelectric drive 21. Device. 20 Using the writing laser beam splitter 13 and the scanning laser beam mirror 14, the writing laser beam 7 and the scanning laser beam 9' in the laser beam concentrator C are reflected to the objective lens head D, and the writing laser A portion of the beam 7 is split by a writing laser beam splitter 13 to a writing laser beam detector 15, the objective head D forming a common optical module with the revolver head E, the connecting parts of which are 19. Device according to claim 18, characterized in that it comprises only a scanning laser beam splitter (18). 21. Device according to claim 20, characterized in that the laser beam concentrator C carries a writing laser beam detector 15. 22. Claim characterized in that the revolver head E is equipped with at least two of three units: a scanning laser beam detector 23, a shearing interferometer eyepiece 24 and a microscope eyepiece 25 with crosshairs. The device according to item 20. 23. According to claim 20, the writing laser beam source A and the scanning laser beam source B are each equipped with a magnifying optical system 4, 10 and one aperture plate 2', 11. equipment. 24. Device according to claim 22, characterized in that the microscope eyepiece 25 of the objective head E is equipped with a writing laser beam blocking filter 25'. 25 In the direction of the writing laser beam and the scanning laser beam 17 introduced on the same optical axis, there is a detector 1 behind the scanning laser beam splitter 18.
21. Device according to claim 20, characterized in that 8' is provided. 26 At least one detector 15, 18', 2
3 and 60 are composed of a large number of detection fields of view 47, Claims 21 and 2
The device according to any one of Items 2 and 25.