TW202411002A - Laser beam irradiation device for full semiconductor cutting and its operating method - Google Patents

Abstract

In a laser beam irradiation device for semiconductor processing according to one aspect of the technical idea of the present invention, it includes: a laser beam output unit, which makes the laser beam move along the processing direction to perform semiconductor processing, and makes the laser beam vibrate in a manner with a specified amplitude along a vibration direction different from the processing direction; and a focusing lens, which images the laser spot moving along the processing direction and vibrating along the vibration direction onto the semiconductor.

Description

Laser beam irradiation device and operation method thereof for semiconductor full cutting

The technical concept of the present invention relates to a laser beam irradiation device for semiconductor full cutting and an operation method thereof, and more specifically, to a laser beam irradiation device for preventing optical damage to semiconductor devices and an operation method thereof.

With the rapid development of the electronics industry and the needs of users, electronic devices are becoming more miniaturized, highly integrated, and large in size. As a result, the size of semiconductor devices included in electronic devices is entering the nanoscale microstructure.

A semiconductor processing method related to the present invention includes a dicing process (as a type of cutting process) for cutting and separating a large-area wafer into a plurality of chips, a grinding process for thinning the thickness of the wafer, and a grooving process for creating grooves for forming conductive wiring.

Regarding the dicing process, blade dicing is used in which a substrate is cut using a thin dicing blade formed of fine diamond. However, when the substrate dicing process is performed using a dicing blade, chipping occurs on the surface or other surfaces of the substrate, and the performance of the separated wafers is degraded due to the chipping.

In another dicing process, stealth dicing is used to focus the laser on a local area to form internal cracks for cutting. However, since the laser used in stealth dicing has an extremely high peak power, cracks on the semiconductor surface may also be caused during the process of forming the internal cracks, thereby reducing the performance of the wafer.

[Problem the invention is intended to solve]

The problem that the technical concept of the present invention intends to solve is to provide a laser beam irradiation device and an operating method thereof for semiconductor processing, which can improve chip performance by vibrating the laser beam to reduce the heat energy accumulation caused by laser convergence. [Means for solving the problem]

In order to achieve the above-mentioned purpose, in a laser beam irradiation device for semiconductor processing according to one aspect of the technical idea of the present invention, it may include: a laser beam output unit, which makes the laser beam move along the processing direction to perform semiconductor processing, and makes the laser beam vibrate in a manner with a specified amplitude along a vibration direction different from the processing direction; and a focusing lens, which images the laser spot (Laser spot) moving along the processing direction and vibrating along the vibration direction onto the semiconductor.

Furthermore, the laser beam output unit may be configured to output a first laser toward the semiconductor along a processing direction and output a second laser having a different incident angle from the first laser along the processing direction in one processing.

In addition, the laser beam output unit may include: a first laser beam output unit for outputting the first laser to perform a pre-processing process for cutting the semiconductor with high-quality processing; and a second laser beam output unit for outputting the second laser for forming a cutting surface on the semiconductor.

On the other hand, the laser beam output unit may further include: a laser oscillating unit that oscillates and outputs the laser beam; and a vibrating unit that physically vibrates the optical device so that the laser beam emitted from the laser oscillating unit vibrates along the vibration direction.

In addition, the laser oscillator and the focusing lens are fixed in a non-vibrating manner, and the optical device can be vibrated in a simple harmonic manner by the driving force of the motor of the oscillator.

In addition, the optical device includes a horizontal mirror, and the motor can be at least one of an ultrasonic motor and a resonance motor.

In addition, the laser beam irradiation device may include: an input unit for receiving an operation instruction for semiconductor processing; and a control unit for applying a sinusoidal wave input to the motor in a first mode based on the operation instruction, and controlling the vibration unit to apply a triangular wave or a square wave to the motor in a second mode.

In addition, the first mode may be a user mode selected by a user for assigning a priority to the vibration speed of the laser beam, and the second mode may be a user mode selected by a user for assigning a priority to the vibration width of the laser beam.

On the other hand, the optical device includes a pair of polygonal mirrors each having a plurality of reflecting surfaces, and the pair of polygonal mirrors rotate along different directions.

The semiconductor includes a semiconductor substrate, and the focusing lens can output the laser beam so that the laser beam has a specified incident angle in a direction perpendicular to the plane of the semiconductor.

The incident angle is substantially the same as a right angle, and the laser beam output unit can cause the laser beam to vibrate with a vibration width in the vibration direction corresponding to a distance determined as a line width of the semiconductor substrate. [Effect of the invention]

According to an exemplary embodiment of the present invention, unlike a stealth film, damage and deformation of a semiconductor material are prevented by dispersing heat energy by vibrating a laser beam without accumulating heat energy in a local small area.

According to the exemplary embodiment of the present invention, the quality of the irradiated object and the mass production results using the irradiated object can be ensured by pre-processing the laser in advance, and the mass production quality can be achieved by subsequent full cutting by laser.

According to an exemplary embodiment of the present invention, processing parameters (e.g., line width) can be easily determined by using the diameter of a laser spot controlled according to a lens, thereby accurately performing semiconductor processing and reducing a defect rate to improve productivity.

According to an exemplary embodiment of the present invention, ejecta (e.g., dust, particles, and debris) generated during semiconductor processing can be scooped out by vibrating a laser beam, thereby improving process throughput.

According to an exemplary embodiment of the present invention, a customized product that meets the needs of a manufacturer can be obtained by adjusting the incident angle of the vibrating laser beam to a sharp angle, a right angle, or a blunt angle.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a conceptual diagram for describing a laser beam irradiation device 10 according to an exemplary embodiment of the present invention.

1 , the laser beam irradiation device 10 may include an input unit 100, a control unit 200, a laser beam output unit 300, and a condenser lens 400. The laser beam output unit 300 may further include a laser oscillator 310, a vibration unit 320, and an optical device 330.

The laser beam irradiation device 10 can image a laser spot LS onto the irradiated object ST by outputting a laser beam.

The irradiated object ST may include a semiconductor substrate and a wafer. For ease of description, the irradiated object ST may be described below together with a semiconductor, a semiconductor substrate or a semiconductor wafer. In this case, the substrate may be processed in various ways by the heat energy of the laser beam, and the various methods may include a dicing process in which the laser beam irradiation device 10 cuts and separates a large area wafer into a plurality of chips, a grinding process in which the thickness of the wafer is thinned, and a grooving process in which grooves for forming conductive wiring are created.

In addition, the irradiated object ST may include a semiconductor film (eg, an oxide film). For example, the laser beam irradiation device 10 may anneal the semiconductor film.

Hereinafter, the term "processing" may mean a process in which the laser beam of the laser beam irradiation device 10 causes physical deformation to the irradiated object ST, and the irradiated object ST may be processed to have a specified depth D and width W. However, the technical concept of the present invention is not limited to the above examples.

According to an exemplary embodiment of the present invention, the laser beam irradiation device 10 can vibrate the laser beam to reduce the accumulation of heat energy converged according to the laser spot LS.

Specifically, the laser beam irradiation device 10 can make the laser beam travel along the processing direction to perform processing on the irradiated object ST. At the same time, the laser beam irradiation device 10 can make the laser beam vibrate in a manner having a predetermined amplitude (processing amplitude) along a vibration direction different from the processing direction. Thus, the second laser spot LS2 vibrates the irradiated object ST before the irradiated object ST is deformed due to excessive accumulation of heat energy of the first laser spot LS1, thereby reducing the defective rate of the irradiated object ST.

On the other hand, as will be described later in FIG. 3 , the laser beam irradiation device 10 can vibrate the laser beam in a manner having a predetermined amplitude in the same vibration direction as the processing direction. By using the laser beam having the same vibration direction as the processing direction, the laser beam irradiation device 10 can scoop out or remove the ejected matter (e.g., dust, particles, and debris) generated during the processing of the irradiated object ST out of the processing area based on the vibrating laser. Thus, a reduction in the yield due to the ejected matter can be prevented.

The input unit 100 can receive operation instructions from the user. As one example, the operation instructions may include an instruction for determining the line width to be engraved on the object ST by the user, and as another example, the operation instructions may include an instruction for controlling the speed of processing the object ST.

The input unit 100 may receive one of a first mode and a second mode selected by a user. The first mode may be a user mode that assigns a priority to the vibration speed of the laser beam, and the second mode may be a user mode that assigns a priority to the vibration width of the laser beam. The processing methods in the first mode and the second mode will be described later together with the control unit 200.

On the other hand, the input unit 100 can be implemented as a device (e.g., a keyboard) or software (input user interface) that can receive the user's operation command and transmit it to the control unit 200. Alternatively, the input unit 100 can be an input interface of an operating system (O/S). Not limited to this, the input unit 100 can include various input devices such as hardware, software, or firmware.

The control unit 200 may output an oscillation signal SO to control the laser oscillator 310 .

The laser oscillator 310 may include any type of oscillator capable of processing a semiconductor device or semiconductor component or an irradiated object ST of a structure included therein. For example, the laser oscillator 310 may include a laser with an output of several hundred watts to a laser with an output of several hundred kilowatts. The oscillation signal SO may control the overall motion of the laser oscillator 310.

The control unit 200 may output a vibration signal SV to control the vibration unit 320. The vibration signal SV may include information about the vibration width, the vibration speed, and the input waveform. For example, the vibration unit 320 may include a resonance motor. Hereinafter, the resonance motor may refer to a driving device that vibrates by vibrating the vibrator, and may have a higher vibration frequency than a galvo motor.

The control unit 200 may apply different input waveforms to the vibration unit 320 based on a plurality of user modes including a first mode and a second mode. The input waveform may include a waveform of an electrical signal applied to drive a motor.

The control unit 200 may output a vibration signal SV for applying a sine wave input to the motor of the vibration unit 320 in the first mode based on the operation command. The motor to which the sine wave input is applied can maximize the vibration speed of the laser beam. In other words, although the accuracy of the vibration width is lower than in the second mode, the maximum vibration speed (vibration frequency) at which the laser beam can vibrate is further increased.

In addition, the control unit 200 can output a vibration signal SV based on the operation command to apply a triangular wave or a square wave to the motor of the vibration unit 320 in the second mode. The motor to which the triangular wave or square wave input is applied can accurately determine the vibration width. In other words, although the vibration speed is lower than that in the first mode, the laser beam can vibrate with a width closer to the target vibration width.

The laser beam output unit 300 may include a laser oscillator 310 for oscillating and outputting a laser beam. The laser oscillator 310 processes the irradiated object ST by outputting the oscillating laser to the optical device 330. The vibrator 320 may vibrate the optical device 330 so that the laser beam emitted from the laser oscillator 310 vibrates along the vibration direction. This is to vibrate the laser beam input to the condenser 400.

As an example, the irradiated laser beam may be a single ray, and as another example, the laser beam irradiation device 10 may output a plurality of laser beams. When outputting a plurality of laser beams, the laser oscillator 310 may include a plurality of oscillator modules for outputting the plurality of laser beams.

In the process of vibrating the laser beam, only some parts of the laser beam output unit 300 may vibrate. In other words, the laser oscillator 310 and the focusing lens 400 are fixed without vibration, and the optical device 330 may vibrate in a simple harmonic manner by the driving force of the motor of the vibrator 320. With respect to the vibration of the laser oscillator 310 and the focusing lens 400, the processing of the irradiated object ST can be accurately performed, and heat accumulation can be prevented.

The vibration part 320 may determine the vibration width and vibration speed of the optical device 330. For example, the motor of the vibration part 320 may be mechanically directly or indirectly connected to the optical device 330. Since the optical device 330 outputs the laser beam output from the laser oscillation part 310 to the condenser lens 400, the vibration part 320 may control the vibration width and vibration speed of the laser beam by controlling the optical device 330.

The optical device 330 may include a mirror. In other words, the optical device 330 may output the laser beam output from the laser oscillating unit 310 to the focusing lens 400 by reflection. The oscillating unit 320 may be at least one of an ultrasonic motor and a resonance motor. This is because a common motor using electromagnetic force cannot realize the technical idea of the present invention for preventing excessive accumulation of heat energy applied to the irradiated object ST.

The condenser lens 400 may output the laser beam so that the laser beam has a predetermined incident angle in a direction perpendicular to the plane of the irradiated object ST. The predetermined incident angle may be greater than 0 degree (zero degree) and less than 90 degrees.

The condenser lens 400 may be an objective lens, a single focal point lens, or a field lens (F-theta lens). The condenser lens 400 may be one selected from the objective lens, the single focal point lens, and the F-theta lens according to the processing method and the needs of the user. This will be described later.

The laser beam irradiation device 10 according to the exemplary embodiment of the present invention can improve the processing quality and speed by rapidly vibrating in a vibration direction different from the processing direction. In comparison, the prior art has the disadvantage of reduced processing quality and speed.

2a and 2b are diagrams for describing a method for manufacturing the laser beam irradiation device 10 according to an exemplary embodiment of the present invention.

2a and 2b, the laser beam irradiation device 10 may include a first laser beam output unit 300a and a second laser beam output unit 300b, which may respectively correspond to the laser beam output unit 300 described in FIG1. On the other hand, the laser beam irradiation device 10 may include a first condenser lens 400a and a second condenser lens 400b, which may respectively correspond to the condenser lens 400 described in FIG1.

According to an exemplary embodiment of the present invention, the laser beam irradiation device 10 is configured to output a first laser along a processing direction toward the irradiated object ST, and output a second laser having a different incident angle from the first laser along the processing direction in one processing.

According to an exemplary embodiment of the present invention, the second laser beam output unit 300b can output a second laser for cutting the irradiated object ST. For example, the second laser can form a cutting surface on the irradiated object ST. The first laser beam output unit 300a can output a first laser to perform a pre-processing process for cutting the irradiated object ST with mass production quality. Among them, mass production quality can refer to the target quality that the processing subject wants to achieve, and can include, for example, cross-sectional uniformity, cutting speed, cutting size, and line width. In addition, for example, when the irradiated object ST is a wafer, the first laser beam output unit 300a can output a first laser to remove compounds on the surface of the semiconductor.

According to an exemplary embodiment of the present invention, the second laser beam output unit 300b can output the second laser along the path of the pre-processing process performed by the first laser beam output unit 300a. In other words, the second laser beam output unit 300b can process (for example, cut) the irradiated object ST in the area prepared for processing by the first laser beam output unit 300a. In this sense, the first laser can be referred to as a leading laser, and the second laser can be referred to as a trailing laser.

According to the exemplary embodiment of the present invention, the first laser beam output unit 300a can output a laser beam having a smaller wavelength than the second laser beam output unit 300b. According to the experiment, when the first laser beam output unit 300a outputs a first laser beam having a wavelength of 515 nm or more and 532 nm or a wavelength of 266 nm or more and 355 nm or less, the surface of the irradiated object ST can be modified without protruding. This is because the material on the surface of the semiconductor wafer, such as metal, ceramic, compound, etc., is a material that easily absorbs the first laser beam of the above wavelength.

According to an exemplary embodiment of the present invention, the first laser beam output section 300a may have a higher intensity than the second laser beam output section 300b, but may have a lower average output. According to experiments, when the average output of the preceding laser output by the first laser beam output section 300a is high, the irradiated object ST may be processed too deeply. This is because when the second laser beam output section 300b actually performs processing (e.g., cutting), it may hinder the quality of processing. Therefore, the first laser (i.e., the preceding laser) may have a higher intensity than the second laser (i.e., the succeeding laser), but may have a lower average output.

Referring to FIG. 2a , the first laser beam output unit 300a can output the first laser toward the irradiated object ST along the vertical direction of the irradiated object ST, and the second laser beam output unit 300b can output the second laser so as to have a first angle (θa) relative to the processing direction. The first angle (θa) can be greater than 90 degrees and less than 180 degrees.

In addition, the first laser beam output unit 300a may output the first laser in a direction perpendicular to the object ST along the processing direction without vibration, and the second laser beam output unit 300b may output the second laser vibrating in the processing direction.

Referring to FIG. 2b, the first laser beam output unit 300a can output the first laser so as to have a second angle (θb) relative to the processing direction. The second angle (θb) can be greater than 0 degrees and less than 90 degrees. In the case of an irradiated object ST that is sensitive and fragile to the laser beam, the quality of processing the irradiated object ST by the second laser beam output unit 300b can be further improved by outputting the first laser with a sharp incident angle. In addition, compared with the first laser with an incident angle in a vertical direction, the first laser with a sharp incident angle can obtain the target processing quality even if it is output to the irradiated object ST with a higher output. Therefore, surface removal and deep processing can be performed more easily at the same time with more energy.

In addition, unlike FIG. 2a described above, the first laser beam output unit 300a can output a first laser that performs a vibrating motion, that is, vibrates along the processing direction. For example, when the first laser is vibrated, when processing the irradiated object ST of a thick material, more efficient and faster processing (e.g., cutting) can be performed by using the first laser and the second laser simultaneously to perform cutting processing. However, it is not limited to this, and the first laser beam output unit 300a can have a second angle (θb) and can output a non-vibrating first laser.

Referring to FIG. 2a and FIG. 2b, full cutting of the irradiated object ST (e.g., a semiconductor wafer) can be achieved by continuous cutting actions of a leading laser (i.e., a first laser) and a trailing laser (i.e., a second laser). In other words, in the past, when a single laser was used to attempt full cutting of the irradiated object, mass production quality could not be achieved due to excessive laser beam output (e.g., FIG. 12 (a) and FIG. 13 (a)). However, according to an exemplary embodiment of the present invention, the quality of the irradiated object and the mass production results using the object can be ensured by pre-processing by the leading laser, and mass production quality can be achieved by full cutting by the trailing laser. In addition, since the output of each laser can be reduced by using the leading laser and the trailing laser, heat accumulation of the irradiated object ST can be prevented, and material deformation of the irradiated object ST can be prevented.

FIG. 3 is a diagram for describing a blade slice and a hidden slice.

3( a ), the blade scribing device rapidly rotates a thin cutting blade formed of fine diamond. That is, the blade scribing device cuts the object body by using a saw blade formed on the cutting blade.

In this process, the dicing blade may irregularly tear the surface of the substrate or other cutting surfaces of the substrate where the blade is located during the process of cutting the object body (e.g., substrate). In addition, the substrate may generate debris during the process of tearing the object body. This may become a major factor in reducing the performance of the separated wafers after the dicing is completed.

However, since the laser beam is irradiated in such a way that a strong output laser beam is irradiated to a local portion, the above-mentioned performance degradation factor does not occur.

In contrast, referring to FIG. 3( b ), the invisible scribing device can form a tortoise crack C for cutting by focusing the laser L1 on a local area P of the object body S. The object body S can be separated along the tortoise crack C formed in a prescribed pattern. During the separation process, the cutting surface of the area adjacent to the tortoise crack forms an irregular cutting surface. In addition, since the invisible scribing laser has an extremely high peak power, undesirable tortoise cracks C may be further generated on the semiconductor surface, thereby the performance of the chip may be reduced.

However, according to the exemplary embodiment of the present invention, all the irradiated objects ST are cut by the laser beam, and a separate tearing process is not required, thereby eliminating the performance degradation factor. In addition, even if the invisible film has a high peak power, the laser can be kept in a specific area by vibration. The time is greatly reduced, compared with the invisible film, so that the deformation of the irradiated object ST caused by heat energy accumulation can be prevented.

Fig. 4 is a diagram for describing a method for oscillating a laser beam according to an exemplary embodiment of the present invention. Hereinafter, the sequence of (a) to (c) of Fig. 4 is described in a time series.

Referring to (a) to (c) of FIG. 4 , the laser beam irradiation device 10 can output the laser beam LB3 to different positions of the focusing lens 400 by vibrating the laser beam LB3. For the sake of convenience, the laser beams in the first stage LB31, the second stage LB32, and the third stage LB33 are labeled with different reference numerals, but they can also be one laser beam output from the same laser oscillator 310. However, the present invention is not limited thereto, and the laser beams LB31 to LB33 can be laser beams generated by different oscillators.

Described in time series, the laser beam irradiation device 10 initially outputs the laser beam LB31 to the edge region of the condenser lens 400. Then, according to the vibration, the laser beam irradiation device 10 outputs the laser beam LB32 to the central region of the condenser lens 400. Then, according to the vibration, the laser beam irradiation device 10 outputs the laser beam LB33 to the edge region opposite to the edge region in the first stage.

The laser beam irradiation device 10 can image the laser spot LS to different regions a1~a3 of the irradiated object ST. The laser beam irradiation device 10 can process the regions a1~a3 separated by a vibration distance (processing width, line width) along the y-axis direction without being spaced apart by a large distance in the x-axis direction. The vibration distance can correspond to the line width of the conductor. In other words, the laser beam irradiation device 10 can vibrate the width corresponding to the line width along the y-axis direction.

According to an exemplary embodiment of the present invention, the laser beam irradiation device 10 can vibrate the laser beam LB3 so that the laser spot LS stays in a local area (for example, a1) for only a certain time without causing material deformation that meets a preset quality standard.

As an example, the control unit 200 may transmit the vibration signal SV so that the vibration unit 320 has at least one of a vibration speed greater than 0 and less than 20 kHz. At this time, when the control unit 200 outputs the vibration signal SV having a vibration speed greater than or equal to 1 kHz, the vibration unit 320 may be implemented as one of an ultrasonic motor and a resonance motor.

As another example, the control unit 200 may transmit the vibration signal SV so that the vibration unit 320 has at least one of a vibration speed greater than 0 and less than 10 MHz.

According to one embodiment, the laser beam irradiation device 10 receives an irradiated object ST which is a wafer made of a first material through the input unit 100, and the control unit 200 transmits a vibration signal SV including a first vibration frequency, so that the laser spot LS can be controlled to stay in a local area (for example, a1) for a time corresponding to the first vibration frequency.

FIG. 5 is a diagram for describing a vibration method, a focusing lens, and a processing method of a laser beam irradiation device according to an exemplary embodiment of the present invention.

According to an embodiment of the present invention, the laser beam irradiation device 10 can form a cut surface having a width corresponding to the oscillation distance in the y-axis direction by oscillating the laser beam LB4 passing through the condenser lens 400. In other words, the laser beam irradiation device 10 can perform a scribing process.

According to another embodiment of the present invention, the laser beam irradiation device 10 can form a groove having a width corresponding to the vibration distance in the y-axis direction. In other words, the laser beam irradiation device 10 can perform a groove forming process.

According to another embodiment of the present invention, the laser beam irradiation device 10 can perform a polishing process by causing the laser beam LB4 to vibrate more greatly along the y-axis direction.

Hereinafter, a vibration method of the laser beam irradiation device 10 will be described together with FIGS. 6 to 8 , and description will be made about mirror vibration, polygonal vibration, and light source vibration.

The condenser lens 400 will be described together with FIG. 9 , and the cases of being an objective lens, a single focal point lens, and an F-theta lens will be described separately.

FIG. 6 is a diagram for describing mirror vibration in a vibration method according to an exemplary embodiment of the present invention.

6 , the vibration unit 320 may include a motor 321 , and the motor 321 may be at least one of an ultrasonic motor and a resonance motor. In addition, the optical device 330 may include a horizontal mirror 331 .

According to an exemplary embodiment of the present invention, the horizontal mirror 331 is mechanically connected to the motor 321, the driving force of the motor 321 is transmitted to the mirror, and the horizontal mirror 331 can vibrate in a simple harmonic manner. At this time, the frequency of the simple harmonic vibration can be substantially the same as the vibration speed of the laser beam irradiation device 10, and the above-mentioned laser beam irradiation device 10 vibrates along a vibration direction different from the processing direction.

According to an exemplary embodiment of the present invention, the optical device 330 can vibrate in a direction parallel to the condenser 400. Thus, the laser beam can vibrate back and forth at a point symmetrical to the origin based on the center point of the condenser 400.

According to an exemplary embodiment of the present invention, the optical device 330 may vibrate in a direction in which the laser light output from the laser oscillator 310 is incident on the optical device 330. At this time, the optical device 330 may be a plane mirror that reflects the laser light output from the laser oscillator 310 to the condenser lens 400.

According to an exemplary embodiment of the present invention, the motor 321 may be a vibration motor such as an ultrasonic motor and a resonance motor. The vibration motor may generate a driving force by generating a high vibration frequency inside the motor 321. The high vibration frequency driving force may be transmitted to the horizontal mirror 331 directly or indirectly coupled to the structure through the transmission part of the motor 321.

Preferably, the motor 321 can generate a vibration frequency greater than or equal to 1 kHz and less than or equal to 20 kHz. In other words, at least one of the ultrasonic motor and the resonant motor causes the laser beam to vibrate at a vibration frequency greater than or equal to 1 kHz and less than or equal to 20 kHz, thereby scooping out ejected materials (e.g., dust, particles, and debris) generated during semiconductor processing by vibrating the laser beam, thereby improving process yield. The commonly used linear actuator motor cannot achieve the effect according to the exemplary embodiment of the present invention due to the low vibration frequency of less than 1 kHz. However, a large number of experiments have confirmed that the laser beam scoops out the jet at a small vibration frequency greater than or equal to 1 kHz and less than or equal to 20 kHz, while greatly reducing the thermal deformation of the irradiated object ST.

Referring to FIG. 6 (a), in the first stage, the horizontal mirror 331 may be located at point b1. Then, referring to FIG. 6 (b), according to the driving force (vibration) of the motor 321, in the second stage, the horizontal mirror 331 may pass through point b2 and be located at point b3. Thereafter, according to the driving force (vibration) of the motor 321, the horizontal mirror 331 may make a reciprocating motion from point b3 to point b1.

In other words, the laser beam irradiation device 10 according to the exemplary embodiment of the present invention outputs the laser beam vibrating in the vibration direction to the irradiated object ST by utilizing the driving force of the motor 321 and the vibration of the horizontal mirror 331 based thereon.

FIG. 7 is a diagram for describing multi-angle vibration in a vibration method according to an exemplary embodiment of the present invention.

7 , the optical device 330 includes a pair of polygon mirrors 332 , and the pair of polygon mirrors 332 may include a first polygon mirror 332 a and a second polygon mirror 332 b having a plurality of reflective surfaces.

According to an exemplary embodiment of the present invention, the laser oscillator 310 may include a plurality of oscillator modules. For example, the laser oscillator 310 may output a plurality of laser beams including a first laser beam i_a and a second laser beam i_b. The laser oscillator 310 may output the first laser beam i_a to the first polygon mirror 332a, and output the second laser beam i_b to the second polygon mirror 332b.

The first polygon mirror 332a can rotate along a first direction d1_a, and the second polygon mirror 332b can rotate along a second direction d1_b opposite to the first direction d1_a. As an example, the vibration unit 320 can be implemented as a rotary motor, and can rotate the first polygon mirror 332a and the second polygon mirror 332b in different directions. As another example, the vibration unit 320 can be implemented as a vibration motor, and the vibration unit 320 can output a driving force (vibration) to the plurality of polygon mirrors, so that the first polygon mirror 332a and the second polygon mirror 332b vibrate in opposite phases.

According to an exemplary embodiment of the present invention, when the optical device 330 includes a pair of polygonal mirrors 332, the reflected output laser beams o_a and o_b can be output to the irradiated object ST. At this time, the reflected output laser beams o_a and o_b can vibrate in different directions respectively.

In addition, the reflected output laser beams o_a and o_b can vibrate in a single direction, respectively. As an example, the first output laser beam o_a can vibrate in the order of the first point p1_a, the second point p2_a, the third point p3_a, the first point p1_a, the second point p2_a... of the irradiated object ST. The second output laser beam o_b can vibrate in the order of the fourth point p1_b, the fifth point p2_b, the sixth point p3_b, the fourth point p1_b, the fifth point p2_b... In other words, when the output laser beams o_a and o_b reach the third point p3_a and the sixth point p3_b, respectively, they return to the first point p1_a and the fourth point p1_b. This is due to the shape of the polygonal mirror.

In other words, according to the exemplary embodiment of the present invention, when the optical device 330 includes a pair of polygonal lenses 332, the laser beam irradiation device 10 processes the object ST by outputting the laser beams o_a and o_b that oscillate in different directions to the object ST. At this time, the oscillation direction may be different from the direction in which the processing of the object ST is performed.

On the other hand, the output laser beams o_a and o_b are output to the irradiated object ST through the condenser lens 400.

FIG. 8 is a diagram for describing vibration of a light source in a vibration method according to an exemplary embodiment of the present invention.

8 (a) and (b), the optical device 330 may include a fixed horizontal mirror 333.

According to an exemplary embodiment of the present invention, the laser oscillator 310 may be mechanically directly or indirectly connected to the vibrator 320 to transmit a driving force (vibration). Different from FIG. 5 , the fixed horizontal mirror 333 and the focusing lens 400 may be fixed in a non-vibrating manner, and the laser oscillator 310 may be vibrated by the vibrator 320. As an example, the laser oscillator 310 may be vibrated in a simple harmonic manner starting from point d1 to point d3, and then moving from point d3 to point d1 back and forth.

According to the exemplary embodiment of the present invention, the laser oscillator 310 can be vibrated to process the irradiated object ST along the vibration direction from point a1 to point a3.

FIG. 9 is a diagram for describing a condenser lens according to an exemplary embodiment of the present invention.

9( a ), the condenser 400 may be implemented as an F-theta lens 401, and FIG9( b ) is used to describe an achromatic lens 402. Unlike the achromatic lens 402, the F-theta lens 401 may not have a field curvature phenomenon.

The laser beam irradiation device 10 according to the exemplary embodiment of the present invention can be used for nano-scale semiconductor processing. When the field curvature phenomenon occurs, such as the achromatic lens 402, it is difficult to export the invention effect according to the technical idea of the present invention in that the vibration width cannot be finely adjusted. Therefore, the laser beam irradiation device can accurately adjust the vibration width by using the F-theta lens 401.

In addition, the condenser lens 400 according to an exemplary embodiment of the present invention may include a short focal length lens, a singlet lens, and a bi-convex lens.

On the other hand, the condenser 400 according to the exemplary embodiment of the present invention may include an object lens. At this time, the object lens may have a magnification of more than 5 times and less than 100 times. Compared with the above-mentioned F-theta lens 401, the object lens is optimized to form a fine laser spot LS. According to experiments, when the object lens in the above-mentioned lens is implemented as the condenser 400, the diameter of the laser spot LS can be formed to be minimum and sharp. The contents associated with this will be described together with FIG. 9.

FIG. 10 is a diagram for describing a vibration direction and a machining direction according to a determined machining method according to an exemplary embodiment of the present invention.

10( a ), the laser beam irradiation device 10 can vibrate in a wide range in the lateral direction and can also output the laser beam along the processing direction.

Thus, when the irradiated object ST is realized as a wafer, the laser beam irradiation device 10 can perform at least one of grooving, scribing, removal, and grinding.

10( b ), the laser beam irradiation device 10 can vibrate narrowly and deeply in the longitudinal direction (vertical direction), and can also output the laser beam in the lateral direction.

Thus, when the irradiated object ST is realized as a wafer, the laser beam irradiation device 10 can perform a dicing process.

FIG. 11 is a diagram for describing a processing direction and an incident angle according to an exemplary embodiment of the present invention.

Referring to (a), (b) and (c) of FIG. 11 , respectively, the laser beam irradiation device 10 can perform forward processing, right-angle (vertical direction) processing and reverse processing according to the incident angle. In the case of forward processing, the laser beam irradiation device 10 can output the laser beam to the irradiated object ST at a sharp angle (θ1) relative to the processing direction. In the case of right-angle (vertical direction) processing, the laser beam irradiation device 10 can output the laser beam to the irradiated object ST at a right angle (θ2) relative to the processing direction. In the case of reverse processing, the laser beam irradiation device 10 can output the laser beam to the irradiated object ST at a blunt angle (θ3) relative to the processing direction. The purpose and effectiveness of the processing method are as described above, and thus will be omitted.

According to an exemplary embodiment of the present invention, the laser beam irradiation device 10 can have different penetration depths of the irradiated object ST according to the incident angle of the laser beam. For example, if a first depth is to be etched, the laser beam irradiation device 10 can perform right-angle processing, and if a second depth shallower than the first depth is to be etched, the laser beam irradiation device 10 can perform forward processing or reverse processing.

12 and 13 are used to describe microscope images of the quality of semiconductor processing results according to an exemplary embodiment of the present invention together with a comparative example.

FIG. 12( a ) is a cross-sectional view of a slice of an irradiated object ST according to a comparative example, and FIG. 12( b ) is a cross-sectional view of a slice of an irradiated object ST according to an exemplary embodiment of the present invention.

From the comparative example, it can be confirmed that uneven areas appear on the surface and in the cross section, which deteriorates the processing quality.

However, according to the exemplary embodiment of the present invention, a smooth cross section can be confirmed, and it can be confirmed that there is no cracking phenomenon caused by laser on the surface, so the processing quality is good.

(a) and (b) of FIG. 13 are images of a semiconductor having a processing line width according to the comparative example and the exemplary embodiment of the present invention, respectively, taken in the vertical direction.

According to the comparative example, by irradiating a strong laser beam without vibration along the processing direction, it can be confirmed that due to the strong heat of the laser, the irradiated object is damaged even in parts other than the target area.

However, according to the exemplary embodiment of the present invention, since a laser beam having an appropriate intensity is irradiated in the processing direction while being vibrated in the vibration direction, damage caused by the laser will not be found in portions other than the destination area.

Exemplary embodiments have been disclosed in the drawings and descriptions as described above. Although specific terms have been used in this description to describe the embodiments, these are only used for the purpose of explaining the technical concept of the present invention, and are not used to limit the meaning or scope of the present invention described in the scope of the patent application. Therefore, it will be understood by those skilled in the art that various modifications and other equivalent embodiments can be made thereby. Therefore, the true technical protection scope of the present invention should be determined by the technical concept of the attached patent application.

10: Laser beam irradiation device 100: Input unit 200: Control unit 300: Laser beam output unit 300a: First laser beam output unit 300b: Second laser beam output unit 310: Laser oscillator 320: Vibrator 321: Motor 330: Optical device 331: Horizontal mirror 332a: First polygonal mirror 332b: Second polygonal mirror 333: Fixed horizontal mirror 400: Condenser 400a: First condenser 400b: Second condenser 401: F-theta lens 402: Achromatic lens a1, a2, a3: Area b1, b3, d1, d2, d3: Point d1_a: first direction d1_b: second direction o_a, o_b: laser beam p1_a: first point p2_a: second point C: crack D: depth S: object P: area W: width SV: vibration signal ST: irradiated object L1: laser LB4, LB41, LB42, LB43: laser beam LB31, LB32, LB33: laser beam LS: laser spot LS1: first laser spot LS2: second laser spot

FIG. 1 is a conceptual diagram for describing a laser beam irradiation device according to an exemplary embodiment of the present invention.

2a and 2b are diagrams for describing a method for manufacturing the laser beam irradiation device 10 according to an exemplary embodiment of the present invention.

FIG. 3 is a diagram for describing a blade slice and a hidden slice.

FIG. 4 is a diagram for describing a method of vibrating a laser beam according to an exemplary embodiment of the present invention.

FIG. 5 is a diagram for describing a vibration method, a focusing lens, and a processing method of a laser beam irradiation device according to an exemplary embodiment of the present invention.

FIG. 6 is a diagram for describing mirror vibration in a vibration method according to an exemplary embodiment of the present invention.

FIG. 7 is a diagram for describing polygonal vibration in a vibration method according to an exemplary embodiment of the present invention.

FIG. 8 is a diagram for describing vibration of a light source in a vibration method according to an exemplary embodiment of the present invention.

FIG. 9 is a diagram for describing a condenser lens according to an exemplary embodiment of the present invention.

FIG. 10 is a diagram for describing a vibration direction and a machining direction according to a determined machining method according to an exemplary embodiment of the present invention.

FIG. 11 is a diagram for describing a processing direction and an incident angle according to an exemplary embodiment of the present invention.

12 and 13 are used to describe microscope images of the quality of semiconductor processing results according to an exemplary embodiment of the present invention together with a comparative example.

10: Laser beam irradiation device

100: Input department

200: Control Department

300: Laser beam output unit

310: Laser Oscillator

320: Vibration section

330:Optical device

400: Condenser

D: Depth

W: Width

SV: vibration signal

ST: irradiated object

LS: Laser spot

LS1: First laser spot

LS2: Second laser spot

Claims (14)

A laser beam irradiation device for semiconductor processing, wherein the laser beam irradiation device comprises: a laser beam output unit, which causes the laser beam to travel along a processing direction to perform semiconductor processing, and causes the laser beam to vibrate in a vibration direction different from the processing direction with a specified amplitude; and a focusing lens, which images the laser spot traveling along the processing direction and vibrating along the vibration direction onto the semiconductor. The laser beam irradiation device as described in claim 1, wherein the laser beam output unit is configured to: output a first laser along the processing direction toward the semiconductor and output a second laser having a different incident angle from the first laser along the processing direction in one processing. The laser beam irradiation device as described in claim 2, wherein the laser beam output unit includes: A first laser beam output unit that outputs the first laser to perform a pre-processing process for cutting the semiconductor with high processing quality; and A second laser beam output unit that outputs the second laser for forming a cut surface on the semiconductor. A laser beam irradiation device as described in claim 1, wherein the laser beam output unit includes: a laser oscillator unit that oscillates and outputs a laser beam; and a vibrator unit that physically vibrates the optical device so that the laser beam emitted from the laser oscillator unit vibrates along the vibration direction. A laser beam irradiation device as described in claim 4, wherein the laser oscillator and the focusing lens are fixed in a non-vibrating manner, and the optical device vibrates in a simple harmonic manner by the driving force of the motor of the vibrator. A laser beam irradiation device as described in claim 5, wherein the optical device includes a horizontal mirror, and the motor is at least one of an ultrasonic motor and a resonance motor. The laser beam irradiation device as described in claim 6, wherein the laser beam irradiation device further comprises: an input unit for receiving an operation instruction for semiconductor processing; and a control unit for applying a sine wave input to the motor in a first mode based on the operation instruction, and controlling the vibration unit to apply a triangular wave or a square wave to the motor in a second mode. A laser beam irradiation device as described in claim 7, wherein the first mode is a user-selected user mode that assigns a priority to the vibration speed of the laser beam, and the second mode is a user-selected user mode that assigns a priority to the vibration width of the laser beam. A laser beam irradiation device as described in claim 4, wherein the optical device includes a pair of polygonal mirrors each having a plurality of reflective surfaces, and the pair of polygonal mirrors rotate in different directions. A laser beam irradiation device as described in claim 1, wherein the semiconductor includes a semiconductor substrate, and the focusing lens is configured to output the laser beam so that the laser beam has a specified incident angle in a direction perpendicular to the plane of the semiconductor. A laser beam irradiation device as described in claim 10, wherein the incident angle is substantially consistent with a right angle, and the laser beam output unit causes the laser beam to vibrate according to the vibration width in the vibration direction so that the vibration width corresponds to a distance determined as a line width of the semiconductor substrate. The laser beam irradiation device as described in claim 10, wherein the incident angle is greater than 0 degrees and less than 90 degrees, and the laser beam output unit is configured to: cause the laser beam inclined at the incident angle to be processed according to the depth of the incident semiconductor substrate. A method for operating a laser beam irradiation device for semiconductor processing, comprising the following steps: Outputting a first laser beam to perform a pre-processing process for cutting an irradiated object with mass production quality; Outputting a second laser beam to cut an irradiated object along a path for performing the pre-processing process based on the first laser beam; and Outputting the first laser beam at an angle perpendicular to a processing direction, and unlike the second laser beam, not vibrating the first laser beam, and outputting the second laser beam at a first angle to a direction perpendicular to the processing direction, and vibrating the second laser beam along the processing direction. A method of operating a laser beam irradiation device as described in claim 13, wherein the first laser beam has a smaller wavelength than the second laser beam.