TW202138097A - Laser processing apparatus, laser processing method, and wafer - Google Patents

Abstract

This laser processing apparatus includes a support unit, an irradiation unit, and a control unit. The irradiation unit has a forming unit that forms a laser beam so that the shape of a part of a condensing region has a longitudinal direction in a plane perpendicular to an optical axis of the laser beam. The control unit has: a determination unit that determines, as a predetermined direction in which an angle between a longitudinal direction and a movement direction of the part of the condensing region is smaller than 45 DEG, an orientation of the longitudinal direction when the part of the condensing region relatively moves along an annularly extending line inside an outer edge of an object containing a group III-V compound semiconductor; a processing control unit that relatively moves the part of the condensing region along the line to form a modified region and generates an irradiation mark with a shape having the longitudinal direction on the opposite surface of the object opposite to a laser beam incident surface; and an adjustment unit that adjusts the orientation of the longitudinal direction so that the longitudinal direction becomes a predetermined direction determined by the determination unit when the modified region is formed by the processing control unit.

Description

Laser processing device, laser processing method and wafer

The present invention relates to a laser processing device, a laser processing method, and a wafer.

Patent Document 1 describes a laser processing device that includes a holding mechanism that holds a workpiece, and a laser irradiation mechanism that irradiates the workpiece held by the holding mechanism with laser light. In the laser processing device described in Patent Document 1, a laser irradiation mechanism having a condenser lens is fixed to a base, and the workpiece is moved in a direction perpendicular to the optical axis of the condenser lens by the holding mechanism. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 5456510

[The problem to be solved by the invention]

However, for example, in the manufacturing process of a semiconductor element, trimming processing is performed in which the outer edge portion of the effective area of the object is removed as the removal area. In the trimming process, in order to remove the outer edge part from the object, a part of the laser light's condensing area (for example, the condensing point) is relatively moved along the inner side of the outer edge of the object in a ring-shaped line. , Thereby forming a modified area along the line. Here, when the object includes a III-V compound semiconductor, as a result of the trimming process, there may be an irradiation mark along the line on the opposite surface of the object opposite to the laser light incident surface. In this case, it is desirable to suppress the adverse effects of the irradiation marks on the effective area of the object.

Therefore, the subject of the present invention is to provide a laser processing device, a laser processing method, and a wafer in which the adverse effects of irradiation marks are suppressed. When an object containing a III-V compound semiconductor is trimmed, It can suppress the adverse effects of irradiation marks on the object. [Technical means to solve the problem]

A laser processing device of one aspect of the present invention focuses at least a part of the condensing area on an object containing a III-V compound semiconductor to irradiate laser light, thereby forming a modified area on the object. The laser The processing device is provided with: a support part that supports an object, an irradiation part that irradiates laser light to the object supported by the support part, a control part that controls the support part and the irradiation part, and the irradiation part has a shaping part that makes the laser light A part of the condensing area formed in a plane perpendicular to the optical axis of the laser light has a longitudinal direction, and the control part has a determining part that extends in a ring shape along the inner side of the outer edge of the object The direction of the longitudinal direction when a part of the condensing area is moved relatively by the line of, is determined to be a predetermined direction with an angle smaller than 45˚ to the moving direction of a part of the condensing area; the processing control part, It moves a part of the condensing area relatively along the line to form a modified area, and produces an irradiation mark having a shape in the longitudinal direction on the opposite surface of the object opposite to the laser light incident surface of the object; and an adjustment part, When the modified region is formed by the processing control unit, the orientation of the longitudinal direction is adjusted to be the predetermined direction determined by the determination unit.

This laser processing device shapes the laser light into a shape (hereinafter also referred to as "beam shape") of a part of the condensing area in a plane perpendicular to the optical axis of the laser light. The shape of the irradiated mark on the opposite side of the laser light incident surface is also a shape with the same longitudinal direction as the beam shape. In addition, the angle between the moving direction of a part of the condensing area (hereinafter also referred to as the "processing direction") and the long side of the beam shape is set as an angle smaller than 45˚ to match the long side of the beam shape. The direction of travel, the direction of the long side of the irradiation mark also matches the direction of processing. Thereby, compared with the case where the long side direction of the irradiation mark is orthogonal to the processing travel direction, the degree of the irradiation mark entering the inner side of the effective area can be reduced. Therefore, in the case of trimming an object containing a III-V compound semiconductor, it is possible to suppress the adverse effect of irradiation marks on the object.

In the laser processing device of one aspect of the present invention, the processing control section along a part of the line so that the crack extending from the modified area reaches the opposite surface on the side opposite to the laser light incident surface of the object , The modified area can also be formed. With this, when trimming an object containing a III-V compound semiconductor, the object can be accurately cut along the line.

In the laser processing device of one aspect of the present invention, the processing control unit forms a plurality of rows of modified regions in the thickness direction of the object along the line so that the entire area of the object in the thickness direction is covered by the modified regions It can be occupied. With this, when trimming an object containing a III-V compound semiconductor, the object can be accurately cut along the line.

In the laser processing apparatus of one aspect of the present invention, the processing control unit may form the modified region so that the cracks extending from the modified region do not reach the laser light incident surface of the object. With this, when trimming an object containing a III-V compound semiconductor, the object can be accurately cut along the line.

In the laser processing apparatus of one aspect of the present invention, the object may contain gallium arsenide. When the target object contains gallium arsenide, as a result of the trimming process, irradiation marks may be generated on the opposite surface of the target object. Therefore, the above-mentioned effect of suppressing the adverse effects of the irradiation marks on the target object is effective.

In the laser processing device of one aspect of the present invention, the forming part includes a spatial light modulator and an adjustment part, and the orientation of the longitudinal direction can be adjusted by controlling the spatial light modulator. Thereby, the orientation of the long side direction of the beam shape can be reliably adjusted.

In one aspect of the laser processing method of the present invention, an object containing a III-V compound semiconductor is focused on at least a part of the condensing area and irradiated with laser light, thereby forming a modified area on the object. The laser processing method includes: a shaping process, which shapes the laser light so that a part of the shape of the condensing area in a plane perpendicular to the optical axis of the laser light has a longitudinal direction; determining the process, it will be on the outer edge of the object The direction of the longitudinal direction when a part of the light-concentrating area moves relatively along a line extending in a loop is determined to be an angle smaller than 45˚ with the moving direction of a part of the light-concentrating area The predetermined direction; processing process, which moves a part of the condensing area relatively along the line to form a modified area, and produces a shape with a longitudinal direction on the opposite side of the laser light incident surface of the object Irradiation marks; and an adjustment process, which adjusts the orientation of the longitudinal direction to be the predetermined direction determined by the determining part when the modified area is formed by the processing process.

In this laser processing method, the laser light is shaped so that the beam shape has a longitudinal direction, and the shape of the irradiated mark on the side opposite to the laser light incident surface of the object has the same shape as the beam shape. The shape of the same longitudinal direction. Moreover, the angle between the processing direction and the long side direction of the beam shape is set as an angle smaller than 45˚, so that the long side direction of the beam shape matches the processing direction, and the long side direction of the irradiation mark also matches the processing direction. . Thereby, compared with the case where the long side direction of the irradiation mark is orthogonal to the processing travel direction, the degree of the irradiation mark entering the inner side of the effective area can be reduced. Therefore, in the case of trimming an object containing a III-V compound semiconductor, it is possible to suppress the adverse effect of irradiation marks on the object.

In the laser processing method of one aspect of the present invention, in the processing process, along a part of the line, the crack extending from the modified area reaches the opposite surface on the side opposite to the laser light incident surface of the object , The modified area can also be formed. With this, when trimming an object containing a III-V compound semiconductor, the object can be accurately cut along the line.

One aspect of the laser processing method of the present invention may also include a cutting process. After the processing process, a crack that reaches the opposite surface is used as a boundary to separate the object by applying stress to the object, and then along Line to cut the object. In this case, the object can be cut along the line.

In the laser processing method of one aspect of the present invention, in the processing process, a plurality of rows of modified regions are formed along the line in the thickness direction of the object so that the entire area of the object in the thickness direction is covered by the modified region It can be occupied. With this, when trimming an object containing a III-V compound semiconductor, the object can be accurately cut along the line.

In the laser processing method of one aspect of the present invention, in the processing process, the modified region may be formed so that the crack extending from the modified region does not reach the laser light incident surface of the object. With this, when trimming an object containing a III-V compound semiconductor, the object can be accurately cut along the line.

In the laser processing method of one aspect of the present invention, the object may contain gallium arsenide. When the target object contains gallium arsenide, as a result of the trimming process, irradiation marks may be generated on the opposite surface of the target object. Therefore, the above-mentioned effect of suppressing the adverse effects of the irradiation marks on the target object is effective.

A laser processing device of one aspect of the present invention focuses at least a part of the condensing area on an object containing a III-V compound semiconductor to irradiate laser light, thereby forming a modified area on the object. The laser The processing device includes: a support portion that supports an object, an irradiation portion that irradiates laser light to the object supported by the support portion, and a processing portion that controls the support portion and the irradiation portion and is positioned on the outer edge of the object The inner side moves a part of the condensing area relatively along a line extending in a loop to form a modified area, and an irradiation mark having a shape in the longitudinal direction is formed on the opposite side of the laser light incident surface of the object. , The processing part determines the orientation of the longitudinal direction when a part of the condensing area is relatively moved along the line, and the angle with the moving direction of a part of the condensing area is determined to be a predetermined angle smaller than 45˚ Orientation, adjust the orientation of the longitudinal direction to become the predetermined direction.

In this laser processing apparatus, when an object containing a III-V compound semiconductor is trimmed, it is possible to suppress the adverse effect of irradiation marks on the object.

One type of wafer of the present invention is a plate-shaped wafer containing III-V compound semiconductors. It has a first surface and a second surface opposite to the first surface. When viewed from the thickness direction, the The second surface has a plurality of irradiated marks formed along the outer edge that have a part of the shape in the longitudinal direction and overlap the outer edge of the second surface. When viewed from the thickness direction, the longitudinal direction is aligned with the outer The angle between the tangential directions of the edges becomes a predetermined direction that is smaller than 45˚. As described above, according to one aspect of the present invention, it is possible to provide a wafer in which the adverse effects of irradiation marks are suppressed. [Effects of Invention]

According to the present invention, it is possible to provide a laser processing device, a laser processing method, and a wafer in which the adverse effects of irradiation marks are suppressed. When trimming an object containing a III-V compound semiconductor, it is possible to suppress Irradiation marks have an adverse effect on the object.

Hereinafter, the embodiment will be described in detail with reference to the drawings. In addition, in each figure, the same or equivalent parts are assigned the same reference numerals, and redundant descriptions are omitted.

First, the basic structure, function, effect, and modification examples of the laser processing device will be explained.

[Structure of laser processing device] As shown in Fig. 1, the laser processing device 1 includes: a plurality of moving mechanisms 5, 6, a supporting part 7, a pair of laser processing heads (first laser processing head, second laser processing head) 10A, 10B, light source unit 8, control unit 9. Hereinafter, the first direction is referred to as the X direction, the second direction perpendicular to the first direction is referred to as the Y direction, and the third direction perpendicular to the first direction and the second direction is referred to as the Z direction. In this embodiment, the X direction and the Y direction are horizontal directions, and the Z direction is a vertical direction.

The moving mechanism 5 has a fixed part 51, a moving part 53, and a mounting part 55. The fixing part 51 is attached to the device frame 1a. The moving part 53 is mounted on a rail provided in the fixed part 51 and can move in the Y direction. The mounting part 55 is mounted on a rail provided in the moving part 53, and can move in the X direction.

The moving mechanism 6 has a fixed part 61, a pair of moving parts (a first moving part, a second moving part) 63, 64, and a pair of mounting parts (a first mounting part, a second mounting part) 65, 66. The fixing part 61 is attached to the device frame 1a. Each of the pair of moving parts 63 and 64 is attached to a rail provided in the fixed part 61 and can move independently in the Y direction. The mounting part 65 is mounted on a rail provided in the moving part 63 and can move in the Z direction. The mounting part 66 is mounted on a rail provided in the moving part 64 and can move in the Z direction. That is, with respect to the device frame 1a, each of the pair of mounting parts 65 and 66 can be moved in the Y direction and the Z direction, respectively. Each of the moving parts 63 and 64 constitutes first and second horizontal moving mechanisms (horizontal moving mechanisms), respectively. Each of the mounting parts 65 and 66 constitutes a first and a second vertical movement mechanism (vertical movement mechanism), respectively.

The support part 7 is mounted on a rotating shaft of the mounting part 55 provided in the moving mechanism 5, and can rotate with an axis parallel to the Z direction as a center line. In other words, the support part 7 can move in each of the X direction and the Y direction, and can rotate with an axis parallel to the Z direction as the center line. The supporting part 7 supports the object 100. The object 100 is, for example, a wafer.

As shown in FIGS. 1 and 2, the laser processing head 10A is mounted on the mounting portion 65 of the moving mechanism 6. The laser processing head 10A irradiates the object 100 supported by the support 7 with laser light L1 (also referred to as "first laser light L1") in a state facing the support 7 in the Z direction. The laser processing head 10B is attached to the attachment portion 66 of the moving mechanism 6. The laser processing head 10B irradiates the object 100 supported by the support 7 with laser light L2 (also referred to as "second laser light L2") in a state facing the support 7 in the Z direction. The laser processing heads 10A and 10B constitute the irradiation section.

The light source unit 8 has a pair of light sources 81 and 82. The light source 81 outputs laser light L1. The laser light L1 is emitted from the emission part 81a of the light source 81, and is guided by the optical fiber 2 to the laser processing head 10A. The light source 82 outputs laser light L2. The laser light L2 is emitted from the emission part 82a of the light source 82, and is guided to the laser processing head 10B by the other optical fiber 2.

The control part 9 controls each part of the laser processing apparatus 1 (support part 7, plural moving mechanisms 5, 6, a pair of laser processing heads 10A, 10B, light source unit 8, etc.). The control unit 9 is a computer device configured to include a processor, a memory, a storage unit, and a communication element. In the control unit 9, the software (program) read into the memory, etc. is executed by the processor, and the reading and writing of data in the memory and the storage unit, as well as the communication of the communication components, are controlled by the processor. In this way, the control unit 9 realizes various functions.

An example of processing by the laser processing device 1 configured as described above will be described. An example of this processing is an example in which the target 100, which is a wafer, is cut into a plurality of wafers, and a modified region is formed in the target 100 along a plurality of lines set in a grid shape.

First, the moving mechanism 5 moves the support portion 7 in each of the X direction and the Y direction, and causes the support portion 7 supporting the object 100 to face the pair of laser processing heads 10A, 10B in the Z direction. Next, the moving mechanism 5 rotates the support portion 7 with the axis parallel to the Z direction as the center line, and causes the plurality of lines extending in one direction of the object 100 to follow the X direction.

Next, the moving mechanism 6 moves the laser processing head 10A in the Y direction so that the condensing point (part of the condensing area) of the laser light L1 is positioned on a line extending in one direction. On the other hand, the moving mechanism 6 moves the laser processing head 10B in the Y direction, so that the condensing point of the laser light L2 is positioned on another line extending in one direction. Next, the moving mechanism 6 moves the laser processing head 10A in the Z direction so that the condensing point of the laser light L1 is positioned inside the object 100. On the other hand, the moving mechanism 6 moves the laser processing head 10B in the Z direction to position the condensing point of the laser light L2 inside the object 100.

Then, the light source 81 outputs the laser light L1 to cause the laser processing head 10A to irradiate the object 100 with the laser light L1, and the light source 82 outputs the laser light L2 to cause the laser processing head 10B to irradiate the object 100 with the laser light L2. At the same time, the moving mechanism 5 moves the support 7 along the X direction, so that the condensing point of the laser light L1 relatively moves along a line extending in one direction, and the condensing point of the laser light L2 is moved along the direction The other lines extending in one direction move relatively. In this way, the laser processing device 1 forms a modified region in the object 100 along each of the plurality of lines extending in one direction of the object 100.

Next, the moving mechanism 5 rotates the support portion 7 with the axis parallel to the Z direction as the center line, and causes the plurality of lines extending in the other direction orthogonal to one direction of the object 100 to follow the X direction.

Next, the moving mechanism 6 moves the laser processing head 10A along the Y direction so that the condensing point of the laser light L1 is positioned on a line extending in the other direction. On the other hand, the moving mechanism 6 moves the laser processing head 10B in the Y direction, and positions the condensing point of the laser light L2 on another line extending in the other direction. Next, the moving mechanism 6 moves the laser processing head 10A in the Z direction so that the condensing point of the laser light L1 is positioned inside the object 100. On the other hand, the moving mechanism 6 moves the laser processing head 10B in the Z direction to position the condensing point of the laser light L2 inside the object 100.

Then, the light source 81 outputs the laser light L1 to cause the laser processing head 10A to irradiate the object 100 with the laser light L1, and the light source 82 outputs the laser light L2 to cause the laser processing head 10B to irradiate the object 100 with the laser light L2. At the same time, the moving mechanism 5 moves the supporting portion 7 along the X direction, so that the condensing point of the laser light L1 relatively moves along a line extending in the other direction and causes the condensing point of the laser light L2 to follow The other lines extending in the other direction move relatively. In this way, the laser processing apparatus 1 forms a modified region inside the target 100 along each of a plurality of lines extending in the other direction orthogonal to one direction of the target 100.

In addition, in an example of the above-mentioned processing, the light source 81 outputs the penetrating laser light L1 to the object 100 by, for example, a pulse oscillation method, and the light source 82 outputs the laser light L1 to the object 100 by, for example, a pulse oscillation method. The penetrating laser light L2 is output. When such laser light is condensed inside the object 100, the laser light is particularly absorbed at the part corresponding to the condensing point of the laser light, and a modified region is formed inside the object 100. The modified area refers to an area where the density, refractive index, mechanical strength, and other physical properties are different from the surrounding non-modified area. As the modified region, there are, for example, a melting treatment region, a crack region, an insulation failure region, and a refractive index change region.

If the laser light output by the pulse oscillation method is irradiated to the object 100, and the condensing point of the laser light is relatively moved along the line set on the object 100, a plurality of modified points will be aligned along the line. Formed in a row. A modified spot is formed by the irradiation of a pulse of laser light. A row of modified areas is a collection of multiple modified points arranged side by side in a row. Adjacent modified spots may be connected to each other or separated from each other due to the relative movement speed of the condensing point of the laser light with respect to the object 100 and the repetition frequency of the laser light. The shape of the line to be set is not limited to a grid shape, but may be a ring shape, a linear shape, a curved shape, and a shape combining at least any of these. [Structure of laser processing head]

As shown in FIGS. 3 and 4, the laser processing head 10A includes a housing 11, an injection part 12, an adjustment part 13, and a condensing part 14.

The housing 11 has a first wall part 21 and a second wall part 22, a third wall part 23 and a fourth wall part 24, and a fifth wall part 25 and a sixth wall part 26. The first wall 21 and the second wall 22 face each other in the X direction. The third wall portion 23 and the fourth wall portion 24 face each other in the Y direction. The fifth wall portion 25 and the sixth wall portion 26 face each other in the Z direction.

The distance between the third wall portion 23 and the fourth wall portion 24 is smaller than the distance between the first wall portion 21 and the second wall portion 22. The distance between the first wall portion 21 and the second wall portion 22 is smaller than the distance between the fifth wall portion 25 and the sixth wall portion 26. In addition, the distance between the first wall portion 21 and the second wall portion 22 may be equal to the distance between the fifth wall portion 25 and the sixth wall portion 26, or may be greater than the distance between the fifth wall portion 25 and the sixth wall portion 26. The distance is also great.

In the laser processing head 10A, the first wall portion 21 is located on the side of the fixed portion 61 of the moving mechanism 6, and the second wall portion 22 is located on the side opposite to the fixed portion 61. The third wall portion 23 is located on the mounting portion 65 side of the moving mechanism 6, and the fourth wall portion 24 is located on the side opposite to the mounting portion 65, that is, the laser processing head 10B side (refer to FIG. 2). The fifth wall portion 25 is located on the side opposite to the support portion 7, and the sixth wall portion 26 is located on the support portion 7 side.

The housing 11 is configured such that the housing 11 is attached to the attachment portion 65 in a state where the third wall portion 23 is arranged on the attachment portion 65 side of the moving mechanism 6. Specifically, it is as follows. The mounting part 65 has a base plate 65a and a mounting plate 65b. The base plate 65a is attached to a rail provided in the moving part 63 (refer to FIG. 2). The mounting plate 65b is erected on the base plate 65a at the end on the side of the laser processing head 10B (refer to FIG. 2). The housing 11 is attached to the mounting portion 65 by screwing the housing 11 to the mounting plate 65b with bolts 28 through the base 27 in a state where the third wall portion 23 is in contact with the mounting plate 65b. The pedestals 27 are provided on the first wall 21 and the second wall 22, respectively. The housing 11 can be attached to and detached from the mounting part 65.

The injection part 12 is attached to the fifth wall part 25. The incident part 12 injects the laser light L1 into the housing 11. The injection portion 12 is biased toward the second wall portion 22 side (one wall portion side) in the X direction, and biased toward the fourth wall portion 24 side in the Y direction. In other words, the distance between the X-direction injection portion 12 and the second wall 22 is smaller than the distance between the X-direction injection portion 12 and the first wall 21, and the Y-direction injection portion 12 and the fourth wall The distance of the portion 24 is smaller than the distance between the injection portion 12 and the third wall portion 23 in the X direction.

The injection part 12 is configured to connect the connection end 2a of the optical fiber 2. The connection end 2a of the optical fiber 2 is provided with a collimating lens that collimates the laser light L1 emitted from the exit end of the fiber line, and is not provided with an isolator for suppressing retroreflected light. This isolator is provided in the middle of the fiber line on the side of the light source 81 rather than the connection end 2a. In this way, miniaturization of the connecting end 2a and even the miniaturization of the injection portion 12 are achieved. In addition, an isolator may be provided at the connection end 2a of the optical fiber 2.

The adjustment unit 13 is arranged in the housing 11. The adjustment unit 13 adjusts the laser light L1 incident from the incident unit 12. Each member included in the adjustment unit 13 is attached to an optical base 29 provided in the housing 11. The optical base 29 is attached to the housing 11 so as to partition the area in the housing 11 into the area on the third wall 23 side and the area on the fourth wall 24 side. The optical base 29 is integrated with the housing 11. The details of each member of the adjustment portion 13, that is, each member of the adjustment portion 13 attached to the optical base 29 on the side of the fourth wall portion 24 will be described later.

The condensing part 14 is arranged on the sixth wall part 26. Specifically, the condensing portion 14 is arranged in the sixth wall portion 26 in a state of being inserted into the hole 26 a formed in the sixth wall portion 26. The condensing unit 14 condenses the laser light L1 adjusted by the adjustment unit 13 and emits it to the outside of the housing 11. The condensing portion 14 is biased toward the second wall portion 22 side (one wall portion side) in the X direction, and biased toward the fourth wall portion 24 side in the Y direction. In other words, the distance between the light collecting portion 14 in the X direction and the second wall portion 22 is smaller than the distance between the light collecting portion 14 in the X direction and the first wall portion 21, and the light collecting portion 14 in the Y direction and the fourth wall The distance of the portion 24 is smaller than the distance between the light-converging portion 14 and the third wall portion 23 in the X direction.

As shown in FIG. 5, the adjustment unit 13 includes an attenuator 31, a beam expander 32, and a mirror 33. The incident portion 12, and the attenuator 31, the beam expander 32, and the mirror 33 of the adjustment portion 13 are arranged on a straight line (first straight line) A1 extending in the Z direction. The attenuator 31 and the beam expander 32 are arranged between the incident part 12 and the mirror 33 on the straight line A1. The attenuator 31 adjusts the output of the laser light L1 incident from the incident part 12. The beam expander 32 expands the diameter of the laser light L1 whose output has been adjusted by the attenuator 31. The mirror 33 reflects the laser light L1 expanded by the beam expander 32.

The adjustment unit 13 further includes a reflective spatial light modulator 34 and an imaging optical system 35. The reflective spatial light modulator 34 and the imaging optical system 35 of the adjustment unit 13 and the condensing unit 14 are arranged on a straight line (second straight line) A2 extending in the Z direction. The reflective spatial light modulator 34 modulates the laser light L1 reflected by the mirror 33. The reflective spatial light modulator 34 is, for example, a reflective liquid crystal (LCOS: Liquid Crystal on Silicon) spatial light modulator (SLM: Spatial Light Modulator). The imaging optical system 35 constitutes a telecentric optical system on both sides in which the reflective surface 34a of the reflective spatial light modulator 34 and the entrance pupil surface 14a of the condenser 14 are in an imaging relationship. The imaging optical system 35 is composed of three or more lenses.

The straight line A1 and the straight line A2 are located on a plane perpendicular to the Y direction. The straight line A1 is located on the second wall 22 side (one wall side) with respect to the straight line A2. In the laser processing head 10A, the laser light L1 is incident from the incident portion 12 into the housing 11 and travels on the straight line A1, and then is reflected by the mirror 33 and the reflective spatial light modulator 34 in order, and then travels on the straight line A1. A2 travels upward and is emitted from the condensing part 14 to the outside of the housing 11. In addition, the arrangement order of the attenuator 31 and the beam expander 32 may be reversed. In addition, the attenuator 31 may be arranged between the mirror 33 and the reflective spatial light modulator 34. In addition, the adjustment unit 13 may have other optical components (for example, a steering mirror arranged in front of the beam expander 32, etc.).

The laser processing head 10A further includes a dichroic mirror 15, a measuring unit 16, an observation unit 17, a driving unit 18, and a circuit unit 19.

The dichroic mirror 15 is arranged between the imaging optical system 35 and the condenser 14 on the straight line A2. In other words, the dichroic mirror 15 is arranged between the adjustment part 13 and the light-condensing part 14 in the housing 11. The dichroic mirror 15 is attached to the optical base 29 on the side of the fourth wall 24. The dichroic mirror 15 allows the laser light L1 to penetrate. From the viewpoint of suppressing astigmatism, the dichroic mirror 15 may be, for example, a cube shape or a two-piece plate shape having a twisted relationship.

The measuring unit 16 is arranged in the housing 11 on the side of the first wall 21 (the side opposite to the side of the one wall) with respect to the adjustment unit 13. The measuring unit 16 is attached to the optical base 29 on the side of the fourth wall 24. The measuring unit 16 outputs measuring light L10 for measuring the distance between the surface of the object 100 (for example, the surface on the side where the laser light L1 enters) and the light-collecting unit 14, and passes through the light-collecting unit 14, and detects the light on the object 100 Measuring light L10 reflected by the surface. That is, the measurement light L10 output from the measurement unit 16 is irradiated to the surface of the object 100 through the condensing unit 14, and the measurement light L10 reflected on the surface of the object 100 passes through the condensing unit 14 and is detected by the measurement unit 16. arrive.

More specifically, the measurement light L10 output from the measurement section 16 is sequentially reflected by the beam splitter 20 and the dichroic mirror 15 attached to the optical base 29 on the side of the fourth wall 24, and then the light is collected from the beam splitter 20 and the dichroic mirror 15 The part 14 is projected out of the housing 11. The measurement light L10 reflected on the surface of the object 100 is incident from the condensing section 14 into the housing 11, is sequentially reflected by the dichroic mirror 15 and the beam splitter 20, and is incident on the measurement section 16. And it is detected by the measuring part 16.

The observation portion 17 is arranged in the housing 11 on the side of the first wall portion 21 (the side opposite to the side of one wall portion) with respect to the adjustment portion 13. The observation portion 17 is attached to the optical base 29 on the side of the fourth wall portion 24. The observation unit 17 outputs observation light L20 for observing the surface of the object 100 (for example, the surface on the side where the laser light L1 enters), passes through the condensing unit 14, and detects the observation light L20 reflected on the surface of the object 100. That is, the observation light L20 output from the observation unit 17 is irradiated to the surface of the object 100 through the condensing unit 14, and the observation light L20 reflected on the surface of the object 100 passes through the condensing unit 14 and is detected by the observation unit 17. arrive.

More specifically, the observation light L20 output from the observation unit 17 passes through the beam splitter 20 and is reflected by the dichroic mirror 15, and then is emitted from the condensing unit 14 to the outside of the housing 11. The observation light L20 reflected on the surface of the object 100 is incident from the condensing section 14 into the housing 11, is reflected by the dichroic mirror 15, and enters the observation section 17 through the beam splitter 20, and is The observation section 17 detects it. In addition, the wavelengths of the laser light L1, the measurement light L10, and the observation light L20 are different from each other (at least the center wavelengths of each are shifted from each other).

The driving unit 18 is attached to the optical base 29 on the side of the fourth wall 24. It is attached to the sixth wall 26 of the housing 11. The driving part 18 moves the light-condensing part 14 arranged on the sixth wall part 26 in the Z direction by, for example, the driving force of a piezoelectric element.

The circuit portion 19 is arranged on the third wall portion 23 side with respect to the optical base 29 in the housing 11. That is, the circuit unit 19 is arranged on the side of the third wall 23 with respect to the adjustment unit 13, the measurement unit 16 and the observation unit 17 in the housing 11. The circuit unit 19 is, for example, a plurality of circuit boards. The circuit unit 19 processes the signal output from the measurement unit 16 and the signal input to the reflective spatial light modulator 34. The circuit unit 19 controls the drive unit 18 based on the signal output from the measurement unit 16. As an example, the circuit unit 19 controls the drive unit 18 based on the signal output from the measurement unit 16 to maintain the distance between the surface of the object 100 and the condensing unit 14 constant (that is, the surface of the object 100 and the laser light The distance of the condensing point of L1 is kept constant). In addition, the housing 11 is provided with a connector (not shown) to which wiring for electrically connecting the circuit unit 19 to the control unit 9 (refer to FIG. 1) and the like is connected.

The laser processing head 10B, like the laser processing head 10A, includes: a housing 11, an injection unit 12, an adjustment unit 13, a condensing unit 14, a dichroic mirror 15, a measuring unit 16, an observation unit 17, The drive unit 18 and the circuit unit 19. However, the components of the laser processing head 10B, as shown in FIG. 2, regarding the virtual plane passing through the midpoint between the pair of mounting portions 65 and 66 and perpendicular to the Y direction, are arranged so as to be aligned with the laser processing head 10A. Each member has a symmetrical relationship.

For example, the housing (first housing) 11 of the laser processing head 10A is attached to the mounting portion 65, so that the fourth wall portion 24 is positioned on the laser processing head 10B side with respect to the third wall portion 23, and the sixth wall The portion 26 is located on the support portion 7 side with respect to the fifth wall portion 25. In contrast, the housing (second housing) 11 of the laser processing head 10B is attached to the mounting portion 66, so that the fourth wall portion 24 is positioned on the laser processing head 10A side with respect to the third wall portion 23 and the sixth wall portion 23 is positioned on the laser processing head 10A side. The wall portion 26 is located on the support portion 7 side with respect to the fifth wall portion 25.

The housing 11 of the laser processing head 10B is configured by mounting the housing 11 to the mounting portion 66 in a state where the third wall portion 23 is arranged on the mounting portion 66 side. Specifically, it is as follows. The mounting part 66 has a base plate 66a and a mounting plate 66b. The base plate 66a is attached to a rail provided in the moving part 63. The mounting plate 66b is erected on the base plate 66a at the end on the side of the laser processing head 10A. The housing 11 of the laser processing head 10B is attached to the attachment portion 66 in a state where the third wall portion 23 is in contact with the attachment plate 66b. The housing 11 of the laser processing head 10B can be attached to and detached from the mounting part 66. [Function and effect]

In the laser processing head 10A, since the light source that outputs the laser light L1 is not provided in the housing 11, the housing 11 can be reduced in size. In addition, in the housing 11, the distance between the third wall portion 23 and the fourth wall portion 24 is smaller than the distance between the first wall portion 21 and the second wall portion 22, and the condensing portion 14 arranged on the sixth wall portion 26 It is biased toward the fourth wall 24 side in the Y direction. Thereby, when the housing 11 is moved in the direction perpendicular to the optical axis of the light-converging section 14, for example, even if there is another member (for example, the laser processing head 10B) on the side of the fourth wall section 24, The condensing part 14 may be close to this other member. Therefore, the laser processing head 10A can move the condensing section 14 in a direction perpendicular to its optical axis.

In addition, in the laser processing head 10A, the injecting portion 12 is provided on the fifth wall portion 25 and is biased toward the fourth wall portion 24 in the Y direction. Thereby, other members (for example, the circuit portion 19) and the like can be arranged in the area on the third wall portion 23 side of the adjustment portion 13 in the area within the housing 11, and the area can be effectively used.

In addition, in the laser processing head 10A, the light condensing portion 14 is biased toward the second wall portion 22 in the X direction. With this, when the housing 11 is moved along the direction perpendicular to the optical axis of the light-converging section 14, for example, even if there are other members on the side of the second wall section 22, the light-converging section 14 can be brought close to The other components.

In addition, in the laser processing head 10A, the injecting portion 12 is provided on the fifth wall portion 25 and is biased toward the second wall portion 22 in the X direction. Thereby, other members (for example, the measuring part 16 and the observation part 17) etc. can be arrange|positioned with respect to the area|region of the adjustment part 13 on the 1st wall part 21 side in the area|region in the housing|casing 11, and this area can be utilized effectively.

In addition, in the laser processing head 10A, the measuring unit 16 and the observation unit 17 are located in the area of the housing 11 where the adjustment portion 13 is arranged on the side of the first wall 21, and the circuit portion 19 is located in the housing 11. In the region of, the adjustment part 13 is arranged on the third wall part 23 side, and the dichroic mirror 15 is arranged in the housing 11 between the adjustment part 13 and the condensing part 14. Thereby, the area in the housing 11 can be effectively used. In addition, in the laser processing apparatus 1, processing can be performed based on the measurement result of the distance between the surface of the object 100 and the condensing portion 14. In addition, in the laser processing device 1, processing can be performed based on the observation result of the surface of the object 100.

In addition, in the laser processing head 10A, the circuit unit 19 controls the drive unit 18 based on the signal output from the measurement unit 16. Thereby, the position of the condensing point of the laser light L1 can be adjusted based on the measurement result of the distance between the surface of the object 100 and the condensing portion 14.

Moreover, in the laser processing head 10A, the incident portion 12, and the attenuator 31, the beam expander 32, and the mirror 33 of the adjustment portion 13 are arranged on the straight line A1 extending along the Z direction, and the reflection of the adjustment portion 13 The type spatial light modulator 34, the imaging optical system 35, the condenser unit 14, and the condenser unit 14 are arranged on a straight line A2 extending along the Z direction. Thereby, the adjustment unit 13 having the attenuator 31, the beam expander 32, the reflective spatial light modulator 34, and the imaging optical system 35 can be compactly configured.

In addition, in the laser processing head 10A, the straight line A1 is positioned on the second wall 22 side with respect to the straight line A2. Thereby, in the area inside the housing 11 on the side of the first wall portion 21 with respect to the adjustment portion 13, another optical system (for example, the measurement portion 16 and the observation portion 17) using the condensing portion 14 is formed In this case, the degree of freedom in the configuration of the other optical system can be improved.

The above functions and effects can also be exerted in the same manner by the laser processing head 10B.

Moreover, in the laser processing device 1, the condensing section 14 of the laser processing head 10A is located on the side of the laser processing head 10B in the housing 11 of the laser processing head 10A, and the condensing section of the laser processing head 10B 14, is the laser processing head 10A side in the housing 11 of the laser processing head 10B. Thereby, when the pair of laser processing heads 10A and 10B each move in the Y direction, the condensing portion 14 of the laser processing head 10A and the condensing portion 14 of the laser processing head 10B can approach each other. Therefore, according to the laser processing apparatus 1, the object 100 can be processed efficiently.

In addition, in the laser processing apparatus 1, each of the pair of mounting parts 65 and 66 moves in the Y direction and the Z direction, respectively. Thereby, the object 100 can be processed more efficiently.

In addition, in the laser processing device 1, the support portion 7 moves along each of the X direction and the Y direction, and rotates with an axis parallel to the Z direction as the center line. Thereby, the object 100 can be processed more efficiently. [Modifications]

For example, as shown in FIG. 6, the incident part 12, the adjustment part 13, and the condensing part 14 may be arrange|positioned on the straight line A extended along the Z direction. Thereby, the adjustment part 13 can be compactly comprised. In this case, the adjustment unit 13 may have or not have the reflective spatial light modulator 34 and the imaging optical system 35. In addition, the adjustment unit 13 may have an attenuator 31 and a beam expander 32. Thereby, the adjustment part 13 which has the attenuator 31 and the beam expander 32 can be comprised compactly. In addition, the arrangement order of the attenuator 31 and the beam expander 32 may be reversed.

In addition, the housing 11 may be configured such that at least one of the first wall portion 21, the second wall portion 22, the third wall portion 23, and the fifth wall portion 25 is arranged in the mounting portion 65 (or In the state of the mounting portion 66) side, the housing 11 may be mounted to the mounting portion 65 (or the mounting portion 66). In addition, the light condensing portion 14 may be biased toward the fourth wall portion 24 side at least in the Y direction. According to these, when the housing 11 is moved in the Y direction, for example, even if there is another member on the side of the fourth wall portion 24, the condensing portion 14 can be brought close to the other member. In addition, when the housing 11 is moved in the Z direction, for example, the condensing portion 14 can be brought close to the object 100.

In addition, the light condensing portion 14 may be biased to the side of the first wall portion 21 in the X direction. In this way, when the housing 11 is moved along the direction perpendicular to the optical axis of the condensing section 14, for example, even if there are other members on the side of the first wall section 21, the condensing section 14 can be brought close to The other components. In this case, the injection part 12 may be offset to the first wall part 21 side in the X direction. Thereby, other members (for example, the measuring part 16 and the observation part 17) etc. can be arranged in the area|region on the side of the 2nd wall part 22 of the adjustment part 13 in the area|region in the housing|casing 11, and this area can be utilized effectively.

And, the light guide of the laser light L1 from the emission part 81a of the light source unit 8 to the injection part 12 of the laser processing head 10A, and the light guide from the emission part 82a of the light source unit 8 to the injection part 12 of the laser processing head 10B At least one of the light guides of the laser light L2 may be implemented by a mirror. Fig. 7 is a front view of a part of the laser processing device 1 in which the laser light L1 is guided by a mirror. In the structure shown in FIG. 7, the mirror 3 that reflects the laser light L1 is mounted on the moving part 63 of the moving mechanism 6, and faces the emission part 81a of the light source unit 8 in the Y direction and is processed by the laser in the Z direction. The injection portion 12 of the head 10A faces oppositely.

In the structure shown in FIG. 7, even if the moving part 63 of the moving mechanism 6 moves in the Y direction, the mirror 3 and the emitting part 81a of the light source unit 8 are maintained in a state of opposing each other in the Y direction. In addition, even if the mounting portion 65 of the moving mechanism 6 moves in the Z direction, the mirror 3 and the incident portion 12 of the laser processing head 10A are maintained in a state where the mirror 3 faces the incident portion 12 of the laser processing head 10A in the Z direction. Therefore, regardless of the position of the laser processing head 10A, the laser light L1 emitted from the emitting portion 81a of the light source unit 8 can be reliably incident on the incident portion 12 of the laser processing head 10A. Moreover, a light source such as a high-power long and short pulse laser that is difficult to guide light by the optical fiber 2 can be used.

Furthermore, in the structure shown in FIG. 7, the mirror 3 may be attached to the moving part 63 of the moving mechanism 6 so that at least one of angle adjustment and position adjustment is possible. Thereby, the laser light L1 emitted from the emission part 81a of the light source unit 8 can be more reliably injected into the injection part 12 of the laser processing head 10A.

In addition, the light source unit 8 may have one light source. In this case, the light source unit 8 may be configured to emit a part of the laser light output from one light source from the emission part 81a and emit the remaining part of the laser light from the emission part 82b.

In addition, the laser processing device 1 may include one laser processing head 10A. Even the laser processing apparatus 1 equipped with one laser processing head 10A is the same when moving the housing 11 in the Y direction perpendicular to the optical axis of the condensing section 14, for example, even in the fourth wall section. There are other members on the 24 side, and the condensing portion 14 may be close to the other members. Therefore, even with the laser processing apparatus 1 provided with one laser processing head 10A, the object 100 can be processed efficiently. Furthermore, in the laser processing apparatus 1 provided with one laser processing head 10A, as long as the mounting portion 65 moves in the Z direction, the object 100 can be processed more efficiently. Furthermore, in the laser processing apparatus 1 provided with one laser processing head 10A, as long as the support portion 7 moves in the X direction and rotates with an axis parallel to the Z direction as the center line, the object 100 can be processed more efficiently. .

In addition, the laser processing device 1 may include three or more laser processing heads. Fig. 8 is a perspective view of a laser processing apparatus 1 provided with two pairs of laser processing heads. The laser processing device 1 shown in Fig. 8 includes: a plurality of moving mechanisms 200, 300, 400, a support 7, a pair of laser processing heads 10A, 10B, a pair of laser processing heads 10C, 10D, and a light source unit ( Illustration omitted).

The moving mechanism 200 moves the support portion 7 in each of the X direction, the Y direction, and the Z direction, and rotates the support portion 7 with an axis parallel to the Z direction as a center line.

The moving mechanism 300 has a fixed part 301 and a pair of mounting parts (a first mounting part and a second mounting part) 305 and 306. The fixing portion 301 is attached to the device frame (not shown in the figure). Each of the pair of mounting parts 305 and 306 is mounted on a rail provided in the fixed part 301 and can move independently in the Y direction.

The moving mechanism 400 has a fixed part 401 and a pair of mounting parts (a first mounting part and a second mounting part) 405 and 406. The fixing part 401 is attached to a device frame (not shown). Each of the pair of mounting parts 405 and 406 is mounted on a rail provided in the fixed part 401 and can move independently in the X direction. In addition, the track of the fixed portion 401 is arranged to be three-dimensionally staggered with the track of the fixed portion 301.

The laser processing head 10A is mounted on the mounting part 305 of the moving mechanism 300. The laser processing head 10A irradiates the object 100 supported by the support 7 with laser light in a state facing the support 7 in the Z direction. The laser light emitted from the laser processing head 10A is guided by the optical fiber 2 from a light source unit (not shown). The laser processing head 10B is mounted on the mounting part 306 of the moving mechanism 300. The laser processing head 10B irradiates the object 100 supported by the support 7 with laser light in a state facing the support 7 in the Z direction. The laser light emitted from the laser processing head 10B is guided by the optical fiber 2 from a light source unit (not shown).

The laser processing head 10C is mounted on the mounting part 405 of the moving mechanism 400. The laser processing head 10C irradiates the object 100 supported by the support 7 with laser light in a state facing the support 7 in the Z direction. The laser light emitted from the laser processing head 10C is guided by the optical fiber 2 from the light source unit (not shown). The laser processing head 10D is mounted on the mounting part 406 of the moving mechanism 400. The laser processing head 10D irradiates the object 100 supported by the support 7 with laser light in a state facing the support 7 in the Z direction. The laser light emitted from the laser processing head 10D is guided by the optical fiber 2 from a light source unit (not shown).

The structure of the laser processing heads 10A, 10B of the one of the laser processing apparatus 1 shown in FIG. 8 is the same as the structure of the laser processing heads 10A, 10B of the one of the laser processing apparatus 1 shown in FIG. 1. The structure of one of the laser processing devices 1 shown in FIG. 8 on the laser processing heads 10C, 10D is the same as that of the laser processing device 1 shown in Fig. 1 on the laser processing heads 10A, 10B so as to be parallel to Z The structure of a pair of laser processing heads 10A and 10B is the same when the axis of the direction is rotated by 90° from the center line.

For example, the housing (first housing) 11 of the laser processing head 10C is mounted on the mounting portion 65, so that the fourth wall portion 24 is positioned on the laser processing head 10D side with respect to the third wall portion 23, and the sixth wall The portion 26 is located on the support portion 7 side with respect to the fifth wall portion 25. The condensing portion 14 of the laser processing head 10C is offset to the fourth wall portion 24 side (that is, the laser processing head 10D side) in the Y direction.

The housing (second housing) 11 of the laser processing head 10D is attached to the mounting portion 66, so that the fourth wall portion 24 is positioned on the laser processing head 10C side with respect to the third wall portion 23, and the sixth wall portion 26 The fifth wall portion 25 is located on the side of the support portion 7. The condensing portion 14 of the laser processing head 10D is offset to the fourth wall portion 24 side (that is, the laser processing head 10C side) in the Y direction.

As above, in the laser processing device 1 shown in FIG. 8, when the pair of laser processing heads 10A and 10B each move in the Y direction, the condensing portion 14 of the laser processing head 10A and the laser processing head 10B converge The light parts 14 can be close to each other. In addition, when the pair of laser processing heads 10C and 10D each move in the X direction, the condensing portion 14 of the laser processing head 10C and the condensing portion 14 of the laser processing head 10D can be close to each other.

In addition, the laser processing head and the laser processing device are not limited to those that form a modified region inside the object 100, and they may be those that perform other laser processing.

Next, an embodiment will be described. Hereinafter, the description overlapping with the above-mentioned embodiment is omitted.

The laser processing apparatus 101 of the embodiment shown in FIG. 9 focuses a condensing point (at least a part of the condensing area) on the object 100 and irradiates the first laser light to form a modified area on the object 100. The laser processing apparatus 101 performs trimming processing on the object 100 to obtain (manufacture) a semiconductor element. The laser processing device 101 forms a modified region along a line M3 extending in a loop on the inner side of the outer edge of the object 100. The laser processing apparatus 101 includes a stage 107, a first laser processing head 10A, a first Z-axis rail 106A, a Y-axis rail 108, an alignment camera 110, and a control unit 9.

The trimming process is a process of removing unnecessary parts of the object 100. The trimming processing includes a laser processing method in which a focused spot is focused on the object 100 and the first laser light is irradiated to form the modified region 4 on the object 100. The object 100 includes, for example, a semiconductor wafer formed in a disc shape. The target object is not particularly limited, and it may be formed with various materials and may exhibit various shapes. A functional element (not shown) is formed on the surface 100a of the object 100. Functional components, such as light-receiving components such as photodiodes, light-emitting components such as laser diodes, and circuit components such as memory.

As shown in FIG. 10(a) and FIG. 10(b), the effective area R and the removal area E are set in the object 100. The effective region R is the part corresponding to the obtained semiconductor device. The effective area R here is a disc-shaped portion including the central portion when the object 100 is viewed from the thickness direction. The removal area E is an area outside the effective area R of the object 100. The removed area E is the outer edge portion outside the effective area R of the object 100. The removal area E here is the ring-shaped part surrounding the effective area R. The removed area E includes the peripheral edge portion (the chamfered portion of the outer edge) when the object 100 is viewed from the thickness direction. The setting of the effective area R and the removal area E can be performed by the control unit 9. The effective area R and the removal area E may be those designated by coordinates.

The platform 107 is a support part on which the object 100 is placed. The platform 107 has the same structure as the above-mentioned support 7 (refer to FIG. 1). In the platform 107 of this embodiment, the object is placed on the back surface 100b of the object 100 as the laser light incident surface side, that is, the upper side (the surface 100a is the platform 107 side, that is, the lower side).物100. The platform 107 has a rotation axis C provided at the center thereof. The rotation axis C is an axis extending along the Z direction. The platform 107 is rotatable with the rotation axis C as the center. The platform 107 is rotationally driven by the driving force of a known driving device such as a motor.

The first laser processing head 10A irradiates the object 100 placed on the table 107 with the first laser light L1 in the Z direction to form a modified region in the object 100. The first laser processing head 10A is attached to the first Z-axis rail 106A and the Y-axis rail 108. The first laser processing head 10A can move linearly in the Z direction along the first Z-axis rail 106A by the driving force of a known driving device such as a motor. The first laser processing head 10A can move linearly in the Y direction along the Y-axis rail 108 by the driving force of a known driving device such as a motor. The first laser processing head 10A constitutes an irradiation section.

The first laser processing head 10A includes the reflective spatial light modulator 34 as described above. The reflection-type spatial light modulator 34 constitutes a forming part which is formed into a shape of a condensing point in a plane perpendicular to the optical axis of the first laser light L1 (hereinafter also referred to as "beam shape"). The reflective spatial light modulator 34 shapes the first laser light L1 so that the beam shape has a longitudinal direction. For example, the reflective spatial light modulator 34 displays a modulation pattern that makes the beam shape into an elliptical shape on the liquid crystal layer, thereby shaping the beam shape into an elliptical shape.

The shape of the beam is not limited to an elliptical shape, as long as it is a long strip shape. The beam shape may be a flat round shape, an oblong shape or a rectangular shape. The shape of the beam is a long triangle shape, a rectangular shape or a polygonal shape. The modulation pattern of the reflective spatial light modulator 34 that realizes the beam shape may include at least any one of a slit pattern and an astigmatism pattern. In addition, when the first laser light L1 has a plurality of condensing points due to astigmatism, etc., among the plurality of condensing points, the shape of the condensing point on the most upstream side of the optical path of the first laser light L1 is this embodiment The shape of the beam shape (other laser beams are also the same). The long side direction is the long axis direction of the ellipse of the beam shape, also called the long axis direction of the ellipse. The beam shape is not limited to the shape of the condensing point, and it may be a shape near the condensing point, as long as it is a part of the condensing area (a condensed area).

For example, in the case of the first laser light L1 with astigmatism, the beam shape has a longitudinal direction in the area on the side of the laser light incident surface near the condensing point. The beam intensity distribution in the plane of the beam shape (in the plane of the Z-direction position on the side of the laser light incident surface near the condensing point) becomes a direction with a strong intensity distribution in the longitudinal direction and a strong beam intensity. Consistent with the long side direction. In the case of the first laser light L1 with astigmatism, in the area on the opposite side of the laser light incident surface near the condensing point, the beam shape has a length that is perpendicular to the longitudinal direction of the area on the laser light incident surface. Side direction. The beam intensity distribution in the plane of the beam shape (in the plane of the Z-direction position on the side opposite to the laser light incident surface near the condensing point) becomes a strong intensity distribution in the longitudinal direction, and the beam intensity The stronger direction coincides with the long side direction. In the case of the first laser light L1 with astigmatism, in the region between the laser light incident surface side and the opposite surface side near the condensing point, the beam shape becomes a circular shape without a longitudinal direction. In the case of the first laser light L1 with such astigmatism, a part of the condensing area that is the target of this embodiment may also include the area on the side of the laser light incident surface near the condensing point. This embodiment is the target The beam shape may be the beam shape of the area on the side of the laser light incident surface near the condensing point.

In addition, by adjusting the modulation pattern of the reflective spatial light modulator 34, the position of the beam shape having the longitudinal direction may be arbitrarily controlled. The position of the beam shape having the longitudinal direction is not particularly limited, as long as it is located anywhere from the laser light incident surface of the object 100 to the opposite surface.

And, for example, in the case of a slit or elliptical optical system caused by the control of a modulated pattern and/or a mechanical mechanism, the beam shape has a long-side direction in the area on the side of the laser light incident surface near the condensing point . In the case of a slit or elliptical optical system, in the area on the opposite side of the laser light incident surface near the condensing point, the beam shape has a long side in the same direction as the long side of the area on the laser light incident side direction. In the case of using a slit or elliptical optical system, the beam shape 71 has a long side direction perpendicular to the long side direction of the area on the side of the laser light incident surface at the condensing point. In the case of using such a slit or elliptical optical system, a part of the condensing area that is the object of the present embodiment may include the area on the side of the laser light incident surface near the condensing point and the opposite side. The beam shape targeted by the embodiment may be the beam shape of the area on the side of the laser light incident surface near the condensing point and the side opposite to it.

The first laser processing head 10A has a distance measuring sensor 36. The distance measuring sensor 36 emits laser light for distance measurement to the laser light incident surface of the object 100, and detects the light for distance measurement reflected by the laser light incident surface, thereby obtaining the mine of the object 100 Displacement data of the incident surface of the incident light. As the distance measuring sensor 36, in the case of a sensor on a different axis from the first laser light L1, one of the triangular distance measuring method, the laser confocal method, the white confocal method, the spectroscopic interference method, and the astigmatism method can be used. Sensor. As the distance measuring sensor 36, in the case of a sensor coaxial with the first laser light L1, a sensor such as an astigmatism method can be used. The circuit unit 19 of the first laser processing head 10A (refer to FIG. 3) drives the driving unit 18 based on the displacement data obtained by the distance measuring sensor 36 so that the condensing unit 14 follows the laser light incident surface ( Refer to Figure 5). Thereby, the light condensing unit 14 is moved in the Z direction based on the displacement data so that the distance between the laser light incident surface of the object 100 and the condensing point of the first laser light L1 is maintained constant. The sensor 36 for distance measurement and its control (hereinafter also referred to as "following control") are the same for other laser processing heads.

The first Z-axis rail 106A is a rail extending in the Z direction. In the first Z-axis rail 106A, the first laser processing head 10A is mounted through the mounting portion 65. The first Z-axis track 106A moves the first laser processing head 10A in the Z direction such that the condensing point of the first laser light L1 moves in the Z direction. The first Z-axis rail 106A corresponds to the rail of the moving mechanism 6 (refer to FIG. 1) or the moving mechanism 300 (refer to FIG. 8).

The Y-axis rail 108 is a rail along the Y direction. The Y-axis rail 108 is attached to each of the first and second Z-axis rails 106A and 106B. The Y-axis track 108 moves the first laser processing head 10A in the Y direction such that the condensing point of the first laser light L1 moves in the Y direction. The Y-axis track 108 moves the first laser processing head 10A so that the condensing point passes through the rotation axis C or its vicinity. The Y-axis rail 108 corresponds to the rail of the moving mechanism 6 (refer to FIG. 1) or the moving mechanism 300 (refer to FIG. 8).

The registration camera 110 is a camera that obtains images used for various adjustments. The alignment camera 110 photographs the object 100. The alignment camera 110 is installed in the mounting part 65 where the first laser processing head 10A is mounted, and can move synchronously with the first laser processing head 10A.

The control unit 9 is a computer device configured to include a processor, a memory, a storage unit, and a communication element. In the control unit 9, the software (program) read into the memory, etc. is executed by the processor, and the reading and writing of data in the memory and the storage unit, as well as the communication of the communication components, are controlled by the processor. In this way, the control unit 9 realizes various functions.

The control unit 9 controls the platform 107 and the first laser processing head 10A. The control unit 9 controls the rotation of the table 107, the irradiation of the first laser light L1 from the first laser processing head 10A, the beam shape, and the movement of the focusing point. The control unit 9 can perform various controls based on rotation information (hereinafter referred to as "θ information") related to the rotation amount of the platform 107. The θ information may be obtained by the driving amount of the driving device that rotates the platform 107, or may be obtained by other sensors or the like. The θ information can be obtained by various known methods. The θ information here includes the rotation angle based on the state of the object 100 in the 0˚ direction.

The control unit 9 controls the first laser processing based on the θ information while rotating the platform 107 while positioning the condensing point at a position along the line M3 (periphery of the effective area R) of the object 100 By starting and stopping the irradiation of the first laser light L1 of the head 10A, a peripheral treatment of forming a modified area along the periphery of the effective area R is performed. The control unit 9 irradiates the removal area E with the first laser light L1 without rotating the platform 107, and moves the condensing point of the first laser light L1, thereby performing the removal process of forming a modified area in the removal area E .

The control unit 9 controls the rotation of the platform 107 in such a way that the pitch of the plurality of modified points contained in the modified area (the interval between the modified points adjacent in the processing travel direction) is constant, and the rotation of the table 107 is controlled by the first laser processing head 10A At least any one of the irradiation of the first laser light L1 and the movement of the condensing point of the first laser light L1. The control unit 9 obtains the reference position (position in the 0˚ direction) of the rotation direction of the object 100 and the diameter of the object 100 from the image taken by the registration camera 110. The control unit 9 controls the movement of the first laser processing head 10A in such a way that the first laser processing head 10A can move to the rotation axis C of the table 107 along the Y-axis rail 108.

Next, an example of a method of obtaining (manufacturing) a semiconductor element by using the laser processing apparatus 101 to perform trimming processing on the object 100 will be described below.

First, the object 100 is placed on the platform 107 in a state where the back surface 100b is on the side of the laser light incident surface. On the surface 100a side of the object 100 on which the functional element is mounted, a supporting substrate, a holding material, and even an adhesive tape are adhered.

Next, the peripheral processing is executed by the control unit 9. Specifically, as shown in FIG. 11(a), while the stage 107 is rotated at a constant rotation speed, the condensing point P1 is positioned at a position along the periphery of the effective area R of the object 100 Next, based on the θ information, the start and stop of the irradiation of the first laser light L1 of the first laser processing head 10A are controlled. Thereby, as shown in FIGS. 11(b) and 11(c), the modified region 4 is formed along the line M3 (the periphery of the effective region R). The formed modified region 4 includes modified points and cracks extending from the modified points.

Next, the control unit 9 executes the removal process. Specifically, as shown in FIG. 12(a), the removal area E is irradiated with the first laser light L1 without rotating the platform 107, and the first laser processing head 10A is moved along the Y-axis rail 108 to make this The condensing point P1 of the first laser light L1 moves in the Y direction. After rotating the platform 107 by 90˚, the first laser light L1 is irradiated in the removal area E, and the first laser processing head 10A is moved along the Y-axis track 108, so that the condensing point P1 of the first laser light L1 is at Y Move in direction. Thereby, as shown in FIG. 12(b), when viewed from the Z direction, the modified region 4 is formed along a line extending so that the removal region E is divided into four equal parts. The formed modified region 4 includes modified points and cracks extending from the modified points. The crack may reach at least any one of the surface 100a and the back surface 100b, and may not reach at least any one of the surface 100a and the back surface 100b.

After that, as shown in FIG. 13(a) and FIG. 13(b), the removal area E is removed with the modified area 4 as a boundary by, for example, a jig or air. As shown in FIG. 13(c), the peeling surface 100h of the object 100 is subjected to finishing grinding and polishing of an abrasive material KM such as grindstone. When the object 100 is peeled off by etching, the polishing may be simplified. As a result of the above, a semiconductor element 100K is obtained.

Next, the finishing process of this embodiment will be described in more detail.

The object 100 contains a III-V compound semiconductor. The object 100 includes a III-V compound semiconductor through which the first laser light L1 can penetrate. For example, the object 100 contains gallium arsenide (GaAs). As shown in FIG. 14, the object 100 is, for example, in the shape of a plate with a thickness of 300 μm, and has a front surface 100 a and a back surface 100 b as its main surfaces. The object 100 is a wafer whose main surface is (100). The object 100 has a first crystal orientation K1 perpendicular to the (110) plane on one side and a second crystal orientation K2 perpendicular to the (110) plane on the other side. The (110) surface is a split surface. The first crystal orientation K1 and the second crystal orientation K2 are the splitting direction, that is, the direction in which the cracks in the object 100 are most likely to extend. The first crystal orientation K1 and the second crystal orientation K2 are orthogonal to each other. The object 100 may replace gallium arsenide or additionally contain indium phosphide (InP).

The object 100 is provided with an alignment object 100n. For example, the alignment object 100n has a certain relationship with the position of the object 100 in the 0˚ direction in the θ direction (the rotation direction of the platform 107 around the rotation axis C). The position in the 0˚ direction refers to the position of the reference object 100 in the θ direction. The alignment object 100n is, for example, a notch formed in the outer edge portion. In addition, the alignment object 100n is not particularly limited, and it may be the orientation plane of the object 100, or it may be a figure of a functional element.

In the object 100, a line M3 that is a planned line for trimming is set. The line M3 is a line on which the modified region 4 is scheduled to be formed. The line M3 extends inside the outer edge of the object 100 in a ring shape. The line M3 here extends into a ring shape. The line M3 is set at the boundary between the effective area R and the removal area E of the object 100. The setting of the line M3 can be performed in the control unit 9. Although the line M3 is a virtual line, it can also be an actual drawn line. The line M3 can be the coordinate designator.

As shown in Fig. 9, the control unit 9 of the laser processing apparatus 101 includes an acquisition unit 9a, a determination unit 9b, a processing control unit 9c, and an adjustment unit 9d. The acquiring unit 9a acquires line information about the line M3. Line information, including: information about line M3, and information about the direction of movement (also referred to as the "processing travel direction") when the condensing point (part of the condensing area) P1 is relatively moved along the line M3 News. For example, the processing travel direction is the tangent direction of the line M3 passing through the condensing point P1 located on the line M3. The acquisition unit 9a can acquire the line information based on a user's operation or input from an external communication or the like. The line information is not particularly limited, and various other information may be included.

The determination unit 9b determines the longitudinal direction of the beam shape when the condensing point P1 is relatively moved along the line M3, based on the line information acquired by the acquisition unit 9a, as the ratio of the angle to the processing travel direction A predetermined direction at an angle that is less than 45˚.

For example, as shown in FIG. 15(a), the orientation of the longitudinal direction of the beam shape 71 determined by the determining unit 9b, that is, the predetermined direction NH, is rotated counterclockwise from the processing travel direction BD when viewed from the laser light incident surface The direction under the angle of 45˚. For example, as shown in FIG. 15(b), the predetermined direction NH is a direction along the processing travel direction BD when viewed from the laser light incident surface. For example, as shown in Fig. 15(c), the predetermined direction NH, viewed from the laser light incident surface, is a direction rotated clockwise by less than 45˚ from the processing travel direction BD. Hereinafter, the angle of the predetermined direction NH based on the processing travel direction BD is referred to as "beam angle β". The beam angle β is a positive (+) angle from the processing travel direction BD toward the counterclockwise when viewed from the laser light incident surface, and a negative (-) angle from the processing travel direction BD toward the clockwise angle. In addition, the determination unit 9b may determine the direction of the longitudinal direction of the beam shape 71 not based on the line information acquired by the acquisition unit 9a, but based on, for example, a user's operation or an input from an external communication.

The processing control unit 9c controls the start and stop of laser processing on the object 100. The processing control unit 9c relatively moves the condensing point P1 along the line M3 while irradiating the first laser light L1, and forms the modified region 4 along the line M3 inside the object 100. Here, the processing control unit 9c changes the position of the focusing point P1 in the Z direction (the thickness direction of the object 100) to repeatedly perform the relative movement of the focusing point P1 along the line M3 in the Z direction. The line M3 forms a plurality of rows of modified regions 4.

The formation of the modified region 4 and the switching of its stop can be realized as follows. For example, in the first laser processing head 10A, the start and stop (ON/OFF) of the irradiation (output) of the first laser light L1 are switched, thereby switching between the formation of the modified region 4 and the stop of the formation. Specifically, when the laser oscillator is composed of a solid laser, the Q switch (AOM (Acoustic Optical Modulator), EOM (Electro-Optical Modulator), etc.) set in the resonant cavity is turned ON/ OFF is switched, thereby switching the start and stop of the irradiation of the first laser light L1 at a high speed. When the laser oscillator is composed of a fiber laser, the output of the semiconductor laser constituting the seed laser and the amplifier (excitation) laser is switched on/off, thereby switching the first laser light L1 at a high speed The start and stop of the irradiation. When the laser oscillator uses an external modulation element, the ON/OFF of the external modulation element (AOM, EOM, etc.) provided outside the resonant cavity is switched, thereby switching the irradiation of the first laser light L1 at a high speed The ON/OFF.

Alternatively, the formation of the modified region 4 and the switching of its stop can be realized as follows. For example, a mechanical mechanism such as a shutter may be controlled to close the optical path of the first laser light L1 to switch the formation of the modified region 4 and stop the formation. The first laser light L1 may be switched to CW light (continuous wave) to thereby stop the formation of the modified region 4. In the liquid crystal layer of the reflective spatial light modulator 34, the condensed state of the first laser light L1 is displayed as a pattern that cannot be modified (for example, a pattern with a rough pattern of scattered laser light), thereby stopping the modification The formation of area 4 is also possible. The output adjustment unit such as an attenuator may be controlled to reduce the output of the first laser light L1 so that the modified region cannot be formed, thereby stopping the formation of the modified region 4. It is also possible to stop the formation of the modified region 4 by switching the polarization direction. The first laser light L1 may be scattered (dispersed) and cut in a direction other than the optical axis, thereby stopping the formation of the modified region 4.

The processing control unit 9c generates a plurality of irradiation marks having the same longitudinal direction as the longitudinal direction of the beam shape 71 along the line M3 on the side opposite to the laser light incident surface of the target 100. The shape of the irradiation mark corresponds to the beam shape 71. The direction of the irradiation mark is aligned with the direction of the beam shape 71. The shape of the irradiation mark may be a shape similar to the beam shape 71. The processing conditions for the occurrence of such irradiation marks can be appropriately set based on publicly known knowledge and the like. For example, as processing conditions for such a case where irradiation marks are generated, the output of the first laser light L1 of the beam shape 71 becomes a certain output or more, and the condensing point P1 is located inward from the opposite surface (surface 100a) Conditions for locations below a certain distance (near the opposite surface).

The processing control unit 9c forms the modified region 4 along a part of the line M3 such that the crack extending from the modified region 4 reaches the surface opposite to the laser light incident surface of the target 100. The crack that reaches the side opposite to the laser light incident surface of the object 100 is also referred to as BHC (Bottom side half-cut) hereinafter. Generating BHC along a part of the line M3 refers to at least any one of generating BHC intermittently along the line M3 and generating BHC along a part of the line M3. The laser processing conditions for the case where BHC is generated along a part of the line M3 can be appropriately set based on known knowledge or the like.

The processing control unit 9 c forms a plurality of rows of modified regions 4 in the Z direction along the line M3 so that the entire area of the object 100 in the Z direction is occupied by the modified regions 4. The modified region 4 in a plurality of rows is formed so that the entire area of the object 100 in the Z direction is occupied by the modified region 4, and is also simply referred to as "full modification" hereinafter. In the case of full modification, a pair of modified regions 4 adjacent to the Z direction overlap, and there is no gap between the pair of modified regions 4 adjacent to the Z direction, or even if there is such a gap, the amount of the gap is small (Below a certain distance). In the case of full modification, the amount of the gap between the modified region 4 on the side of the laser light incident surface and the laser light incident surface is small (less than a certain distance). In the case of full modification, the amount of gap between the modified region 4 on the side opposite to the side most opposite to the laser light incident surface and the opposite surface is small (less than a certain distance). The certain distance is, for example, about 50 μm, and for example, 52 μm. In the case of full modification, the cross section after the object 100 is cut (trimmed), and the modified region 4 is formed on the entire surface.

In the case of full modification, when the modified region 4 is formed on the side closest to the laser light incident surface, the condensing point P1 is positioned at an internal position within 13 μm from the laser light incident surface of the target 100 in the Z direction . In the case of full modification, when the modified area 4 is formed on the side opposite to the side opposite to the laser light incident surface, the condensing point P1 is positioned 13μm from the opposite side of the object 100 in the Z direction Internal location within. In the case of full modification, among a pair of modified regions 4 adjacent to the Z direction, the position of the light collecting point P1 when the modified region 4 on one side is formed and the light when the modified region 4 on the other side is formed The interval between the positions of the points P1 is an interval within 13 μm in the Z direction. In the case of complete reformation, the conditions regarding the position of the condensing point P1 are not related to the wavelength, pulse width, and output of the first laser light L1.

The processing control portion 9c forms the modified region 4 so that the cracks extending from the modified region 4 do not reach the laser light incident surface of the object 100. In the case where the modified region 4 is formed in such a way that the crack does not reach the laser light incident surface, for example, there is a case where only by forming the modified region 4, the crack that reaches (exposes) the laser light incident surface does not occur Condition. In the case where the modified region 4 is formed so that the cracks do not reach the laser light incident surface, for example, external stress may be applied later to cause the cracks that reach the laser light incident surface to occur. The laser processing conditions in the case where the modified region 4 is formed so that the crack does not reach the laser light incident surface can be appropriately set based on known knowledge or the like.

The adjustment part 9d adjusts the direction of the beam shape 71 by controlling the reflective spatial light modulator 34. The adjustment section 9d, when the modified region 4 is formed by the processing control section 9c, adjusts the orientation of the longitudinal direction of the beam shape 71 to become the predetermined direction NH determined by the determination section 9b. In other words, the adjustment section 9d, when the modified region 4 is formed by the processing control section 9c, adjusts the orientation of the longitudinal direction of the beam shape 71 so that the beam angle β becomes larger than -45˚ and smaller than 45˚ small.

In the trimming process of the present embodiment, first, the line information is obtained by the obtaining unit 9a based on the user's operation or the input from external communication or the like. Based on the obtained line information, the determination unit 9b determines the orientation of the longitudinal direction of the beam shape 71 when the condensing point P1 is relatively moved along the line M3 as the angle with the processing travel direction BD The predetermined direction NH with an angle smaller than 45˚ (determines the project).

Next, the stage 107 is rotated so that the object 100 is positioned in the 0˚ direction. The first laser processing head 10A is moved along the Y-axis rail 108 and the first Z-axis rail 106A so that the condensing point P1 is at a predetermined position for trimming. The predetermined position is trimmed, for example, the predetermined position on the line M3 of the object 100. Next, the rotation of the platform 107 is started. Start the tracking of the back side 100b of the ranging sensor. In addition, before starting the tracking of the distance measuring sensor, it is confirmed in advance that the position of the condensing point P1 is within the detectable range of the distance measuring sensor.

When the rotation speed of the table 107 becomes constant (constant speed), the irradiation of the first laser light L1 by the first laser processing head 10A is started. At this time, the first laser light L1 is formed by the reflective spatial light modulator 34 so that the beam shape 71 has a longitudinal direction (forming process). While rotating the stage 107, the first laser light L1 is irradiated, and the focusing point P1 is relatively moved along the line M3 to form the modified region 4 (processing process). In the processing process, the modified region 4 is formed. On the side opposite to the laser light incident surface of the object 100, a shape having the same longitudinal direction as the longitudinal direction of the beam shape 71 is generated along the line M3. The exposure marks. When the modified region 4 is formed by a processing process, the orientation of the longitudinal direction of the beam shape 71 is adjusted by the adjustment part 9d, and it becomes the predetermined direction NH determined in the determination process. In other words, the beam angle β of the processing process is fixed at an angle larger than -45˚ and smaller than 45˚.

In the processing process, the Z-direction position of the predetermined position of the trimming is changed to repeatedly perform the formation of the modified region 4 along the line M3 described above. Thereby, a plurality of rows of modified regions 4 are formed along the line M3 in the Z direction. In the processing process, a plurality of rows of modified regions 4 are formed by generating BHC along a part of the line M3. In the processing process, a plurality of modified regions 4 are formed in a comprehensive modification manner. In the processing process, a plurality of rows of modified regions 4 are formed so that the cracks extending from the modified region 4 will not reach the laser light incident surface of the object 100.

As an example of laser processing conditions for processing engineering, the wavelength of the first laser light L1 is 1099nm, the pulse width is 45nsec, the processing speed is 700mm/sec, the frequency is 60kHz, the processing energy is 10μJ, there is focusing correction, pulse wave The pitch is 11.7 μm, and the number of columns of the modified region 4 in the Z direction is 7 columns. In addition, the laser wavelength may be 1064 nm or more. The pulse width may be 60 nsec or less. The processing energy can be 5-20μJ. The focusing correction may be the correction caused by the reflective spatial light modulator 34, or the correction caused by the correction ring lens. The pulse wave spacing may be 5 to 15 μm.

Next, the removal area E is irradiated with the first laser light L1 without rotating the table 107, and the first laser processing head 10A is moved along the Y-axis rail 108. After rotating the table 107 by a certain angle, the removal area E is irradiated with the first laser light L1 without rotating the table 107, and the first laser processing head 10A is moved along the Y-axis rail 108. This processing is repeatedly performed, and the modified area 4 is formed in the removed area E along a line extending so as to distinguish the removed area E when viewed from the Z direction. After that, as shown in FIG. 16, in a state where the object 100 is arranged on the holding material HJ, a stress is applied to the object 100 to separate the object 100 with the BHC generated along a part of the line M3 as the boundary. , And cut the object 100 along the line M3 (cutting process). Thereby, a wafer W1 in which the removal area E of the object 100 is removed is formed.

Wafer W1 is a plate-shaped object containing III-V compound semiconductors. The wafer W1 has a back surface 100b (first surface) corresponding to the laser light incident surface, and a surface 100a (second surface) corresponding to the opposite surface of the opposite side. As shown in FIG. 24, when viewed from the thickness direction, on the surface 100a, the irradiation marks SK1 having a part of the shape in the longitudinal direction and overlapping the outer edge GE of the surface 100a are formed in plural along the outer edge GE . The shape of the irradiation mark SK1 is, for example, the shape of a part of one side in the longitudinal direction of an elliptical shape (beam shape 71 and a shape corresponding to the irradiation mark SK). The shape of the irradiation mark SK1 is the shape drawn by the outer edge GE. The direction of the longitudinal direction of the irradiation mark SK1 is a predetermined direction NH whose angle with the tangential direction of the outer edge GE becomes an angle smaller than 45˚.

As described above, in the laser processing device 101 and the laser processing method of this embodiment, the first laser light L1 is formed so that the beam shape 71 has a longitudinal direction, and the first laser light L1 is formed on the side opposite to the laser light incident surface of the object 100 The shape of the irradiation mark generated on the opposite surface is also a shape having the same longitudinal direction as the beam shape 71. Then, the angle between the processing travel direction BD and the longitudinal direction of the beam shape 71 (absolute value of the beam angle β) is set to an angle smaller than 45˚ to make the longitudinal direction of the beam shape 71 follow the processing travel direction BD, so that the longitudinal direction of the irradiation mark is also along the processing travel direction BD.

In this way, when the long side direction of the irradiation mark is orthogonal to the processing direction BD (or the angle between the processing direction BD is 45˚ or more), it is possible to reduce the penetration of the irradiation mark into the effective area. The degree of the inside of R. Regarding the irradiation mark, the size in the direction orthogonal to the processing travel direction can be made smaller than the size in the direction along the processing travel direction. It can reduce the damage caused by the irradiation mark to the effective area R. Therefore, when the object 100 containing the III-V compound semiconductor is trimmed, it is possible to suppress the adverse effect of the irradiation marks on the object 100.

In the laser processing apparatus 101 and the laser processing method of this embodiment, the modified region 4 is formed so that BHC is generated along a part of the line M3. With this, when the object 100 containing the III-V compound semiconductor is trimmed, the object 100 can be accurately cut along the line M3.

In the laser processing apparatus 101 and the laser processing method of the present embodiment, a plurality of rows of modified regions 4 are formed along the line M3 so as to be completely modified. With this, when the object 100 containing the III-V compound semiconductor is trimmed, the object 100 can be accurately cut along the line M3.

In the laser processing device 101 and the laser processing method of this embodiment, the modified region 4 is formed so that the cracks extending from the modified region 4 will not reach the laser light incident surface of the object 100. With this, when the object 100 containing the III-V compound semiconductor is trimmed, the object 100 can be accurately cut along the line M3.

In the laser processing apparatus 101 and laser processing method of this embodiment, the object 100 contains gallium arsenide. When the object 100 contains gallium arsenide, as a result of the trimming process, irradiation marks may be generated on the opposite surface of the object 100, so the above-mentioned effect of suppressing the adverse effects of the irradiation marks on the object 100 is effective. The laser processing apparatus 101 and the laser processing method of the present embodiment are particularly effective for laser processing of the gallium arsenide-containing object 100 that generates irradiation marks.

In the laser processing apparatus 101 of the present embodiment, by controlling the reflective spatial light modulator 34, the orientation of the longitudinal direction of the beam shape 71 is adjusted. Thereby, the orientation of the longitudinal direction of the beam shape 71 can be surely adjusted.

In the laser processing method of the present embodiment, after the processing process, stress is applied to the object 100 to separate the object 100 with the BHC as the boundary, and the object 100 is cut along the line M3. In this case, the object 100 can be cut along the line M3.

In this embodiment, it is possible to provide a wafer W1 in which the adverse effects of the irradiation mark SK1 are suppressed.

In addition, in this embodiment, the first laser light L1 with the beam shape 71 having the shape of the longitudinal direction is irradiated, and the modified area 4 is formed in a way of overall modification, thereby effectively achieving the laser beam The shape of the irradiation mark generated on the opposite surface of the entrance surface has the same longitudinal direction as the beam shape 71.

FIG. 17 is a diagram showing an example of the relationship between the shape of the irradiation mark SK, the damage suppression effect, and whether or not to cut. The photo including the irradiation mark SK in the figure is a picture taken at the opposite side of the laser light incident surface of the object 100 after the processing process and before cutting at a magnification rate of 50 times (the following photo is the irradiation mark SK The picture is also the same). As shown in Figure 17, the beam shape 71 is a shape with a longitudinal direction. When the beam angle β is 0˚, the longitudinal direction of the irradiation mark SK is along the processing travel direction BD, and the irradiation mark SK enters the effective area R. The inner side is less, and the damage suppression effect is higher ("〇" in the figure). In addition, since the longitudinal direction of the beam shape 70 is along the processing travel direction BD, it is expected that the cracks will easily progress along the processing travel direction BD and can be cut along the line M3 ("o" in the figure).

On the other hand, the beam shape 71 is a shape with a longitudinal direction. When the beam angle β is 60˚ and -60˚, the longitudinal direction of the irradiation mark SK does not follow the processing travel direction BD, but makes the irradiation mark SK The long side direction of BD is staggered from the processing travel direction BD. In this case, the extent to which the irradiation trace SK enters the inside of the effective area R is not small, and as a result, the damage suppression effect cannot be sufficiently obtained ("△" in the figure). In addition, since the longitudinal direction of the beam shape 71 does not follow the processing travel direction BD, it is expected that the cracks along the processing travel direction BD are insufficiently stretched and cannot be cut along the line M3 ("×" in the figure).

In addition, even in the case where the beam shape 71 is a perfect circular shape, the extent of the irradiation mark SK entering the inside of the effective area R is not small, and as a result, the damage suppression effect cannot be sufficiently obtained ("△" in the figure). In addition, since the longitudinal direction of the beam shape 71 cannot be made along the processing travel direction BD, it is expected that the cracks along the processing travel direction BD are not stretched enough to be cut along the line M3 ("×" in the figure) .

18, 19, 20, and 21 are diagrams showing examples of irradiation marks SK and cross-sectional states for each beam angle β. In the figure, the cross-sectional state is a photograph taken of the cut object 100 at a position in the 0˚ direction (the same is true for the following cross-sectional state). As shown in Figure 18, when the beam angle β is -75, -60˚ and -45˚, the long side direction of the irradiation mark SK is not along the processing travel direction BD, and the long side direction of the irradiation mark SK is from the processing travel direction BD is staggered, and the extent of the irradiation mark SK entering the inside of the effective area R is not less. In this case, it can be seen that it cannot be cut along the line M3 ("not cut" in the figure).

As shown in Figure 19 and Figure 20, when the beam angle β is -30, -15˚, 0˚, 15˚, and 30˚, the long side direction of the irradiation mark SK is along the processing travel direction BD, and the irradiation The mark SK enters the inner side of the effective area R to a lesser extent. In this case, it can be cut along the line M3, and as shown in the figure, a plurality of rows of modified regions 4 that have been completely modified can be confirmed in the cross section.

As shown in Figure 20 and Figure 21, when the beam angle β is 45˚, 60˚, 75˚, and 90˚, the long side of the irradiation mark SK does not follow the processing travel direction BD, and the long side of the irradiation mark SK The direction is shifted from the processing travel direction BD, and it is known that the irradiation mark SK enters the inner side of the effective area R not less. In this case, it can be seen that it cannot be cut along the line M3 ("not cut" in the figure).

22(a), 22(b), and FIG. 23 are diagrams showing an example of the relationship between the beam shape 71 and the overall modification and cutting ability. As the laser processing conditions for the laser processing in the figure, the wavelength of the first laser light L1 is 1099nm, the pulse width is 45nsec, the processing speed is 720mm/sec, the frequency is 60kHz, and the pulse interval is 12μm. The condensing position in the figure is the position in the Z direction of the condensing point P1 based on the laser light incident surface of the object 100. When there is no elliptical beam, the beam shape 71 is a perfect circle, and when there is an elliptical beam, the beam shape 71 is an ellipse. Power is the output of the first laser light L1. The fact that the HC state has not occurred means that the modified region 4 is formed so that the cracks extending from the modified region 4 will not reach the laser light incident surface of the object 100. The non-occurrence of the BHC state means that BHC has not occurred, and the occurrence of 30% of the BHC state means that the modified region 4 is formed such that BHC occurs in a 30% portion (part of) along the line M3.

In the case of the laser processing conditions of Fig. 22(a) where the beam shape 71 is not an ellipse, BHC does not occur, and it is understood that it cannot be cut along the line M3 ("×" in the figure). In the case of the laser processing conditions of Fig. 22(b), BHC occurs along a part of the line M3, and it is known that the cutting can be reliably performed along the line M3 ("◎" in the figure). In the case of the laser processing conditions of Fig. 23 where the modified region 4 is not formed on the laser light incident surface side, it is known that although BHC occurs along a part of the line M3, it is not easy to cut along the line M3 (in the figure) "△").

In the laser processing apparatus 101, the reflective spatial light modulator (forming part) 34, the determining part 9b, the processing control part 9c, and the adjustment part 9d constitute a processing part. In addition, the processing part is not particularly limited. As long as the processing part moves the condensing point P1 relatively along the line M3 to form the modified area 4, the irradiation mark SK having the shape of the longitudinal direction is generated, and the condensing point P1 is moved along the line M3 The orientation of the longitudinal direction is determined as the predetermined direction NH, and the orientation of the longitudinal direction of the irradiation mark SK is adjusted so as to become the determined predetermined direction NH, it can be configured with various machines or devices.

As mentioned above, one aspect of the present invention is not limited to the above-mentioned embodiment.

In the above-mentioned embodiment, a plurality of laser processing heads may be provided as the irradiation section. In the above embodiment, although BHC is generated along a part of the line M3, BHC may not be generated, or BHC may be generated along the entire line M3.

In the above embodiment, although the reflective spatial light modulator 34 is used as the molded part, the molded part is not limited to the spatial light modulator, and various devices or optical systems may be used. For example, as the shaping part, an elliptical beam optical system, a slit optical system, or an astigmatic optical system may be used. In addition, a grating pattern or the like may be used for the modulation pattern, and the condensing point can be divided to combine two or more condensing points, thereby creating a beam shape 71 having a longitudinal direction. In addition, it is also possible to use polarized light to produce a beam shape 71 having a longitudinal direction. The method of rotating the polarized light direction can be achieved by, for example, rotating a 1/2λ wave plate. Moreover, the spatial light modulator is not limited to the reflective type, and a transmissive spatial light modulator may be used.

In the above-mentioned embodiment, the processing control unit 9c controls the first laser light L1 or the optical system to switch the formation and stop of the modified region 4, but it is not limited to this. Various well-known technologies may be used to realize the formation of the modified region 4 and the switching of its stop. For example, a mask may be directly provided on the object 100 to shield the first laser light L1, thereby switching the formation of the modified region 4 and the stopping thereof.

In the above-mentioned embodiment, the type of the object 100, the shape of the object 100, the size of the object 100, the number and direction of the crystal directions of the object 100, and the plane orientation of the main surface of the object 100 are not Specially limited. In the above embodiment, the shape of the line M3 is not particularly limited. In the above-mentioned embodiment, the object 100 may be formed by containing a crystalline material having a crystalline structure, instead of this or by additionally containing an amorphous material having an amorphous structure (amorphous structure). The crystalline material may be any of anisotropic crystals and isotropic crystals. For example, the object 100 includes gallium nitride (GaN), silicon (Si), silicon carbide (SiC), LiTaO ₃ , diamond, GaOx, sapphire (Al ₂ O ₃ ), gallium arsenide, indium phosphide, glass A substrate formed of at least any one of, and alkali-free glass may also be used.

In the above-mentioned embodiment, although the back surface 100b of the object 100 is used as the laser light incident surface, the surface 100a of the object 100 may be used as the laser light incident surface. In the above-mentioned embodiment, the modified region 4 may be, for example, a crystallization region, a recrystallization region, or a gettering region formed inside the object 100. The crystal region is a region where the structure of the object 100 before processing is maintained. The recrystallized region is a region that evaporates, plasmaizes, or melts first, and then solidifies as a single crystal or polycrystal when it solidifies again. The gettering region is a region where impurities such as heavy metals are collected and captured to exert a gettering effect. It may be formed continuously or intermittently. In addition, the processing device may be suitable for processing such as melting and grinding, for example.

The laser processing apparatus of the above-mentioned embodiment may not include the acquisition unit 9a. The laser processing method of the above-mentioned embodiment may not include the process of acquiring line information (information acquisition process). In this case, for example, the object 100 to be subjected to laser processing is determined in advance, and the line information may be stored in advance. In the above embodiment, when a plurality of rows of modified regions 4 are formed in the thickness direction of the object 100, when at least any one of the plurality of rows of modified regions 4 is formed, the beam shape 71 is made to have a longitudinal direction. Shape and make the direction of the longitudinal direction into the predetermined direction NH, and/or form the irradiation mark SK having the shape of the longitudinal direction on the opposite surface of the laser light incident surface, and make the direction of the longitudinal direction into the predetermined direction NH. Can. For example, when forming the modified region 4 on the most opposite surface side, the beam shape 71 and/irradiation mark SK may be elliptical, and the longitudinal direction may be the predetermined direction NH.

The structures of the aforementioned embodiments and modifications are not limited to the aforementioned materials and shapes, and various materials and shapes can be applied. In addition, each structure of the above-mentioned embodiment or modification can be arbitrarily applied to each structure of other embodiments or modification.

1,101: Laser processing device 4: Modified area 9: Control Department 9a: Acquisition Department 9b: Decision Department 9c: Processing Control Department 9d: Adjustment Department 10A: The first laser processing head (irradiation part) 10B: 2nd laser processing head (irradiation part) 10C: 3rd laser processing head (irradiation part) 10D: 4th laser processing head (irradiation part) 34: Reflective spatial light modulator (forming part) 71: Beam shape (the shape of a part of the condensing area) 100: Object 100a: Surface (opposite surface, second surface) 100b: back side (laser light incident side, first side) 107: Platform (support part) BD: Processing travel direction (moving direction of a part of the spotlight area) L1: 1st laser light (laser light) L2: 2nd laser light (laser light) M3: line NH: established direction P1: Condensing point (part of the condensing area) SK, SK1: Irradiation marks W1: Wafer

[Fig. 1] Fig. 1 is a perspective view of a laser processing apparatus according to an embodiment. [Fig. 2] Fig. 2 is a front view of a part of the laser processing device shown in Fig. 1. [Figure 3] Figure 3 is a front view of the laser processing head of the laser processing device shown in Figure 1. [Figure 4] Figure 4 is a side view of the laser processing head shown in Figure 3. [Fig. 5] Fig. 5 is a configuration diagram of the optical system of the laser processing head shown in Fig. 3. [Fig. 6] Fig. 6 is a configuration diagram of the optical system of a laser processing head of a modification. [Fig. 7] Fig. 7 is a front view of a part of a laser processing device of a modification. [Fig. 8] Fig. 8 is a perspective view of a laser processing apparatus according to a modification. [Fig. 9] Fig. 9 is a plan view showing a schematic structure of the laser processing apparatus according to the first embodiment. [Fig. 10] Fig. 10(a) is a plan view showing an example of an object. Fig. 10(b) is a side view of the object shown in Fig. 10(a). [Fig. 11] Fig. 11(a) is a side view for explaining the object to be trimmed in the first embodiment. Fig. 11(b) is a plan view showing the object following Fig. 11(a). (c) is a side view of the object shown in Fig. 11(b). [Fig. 12] Fig. 12(a) is a side view showing the object following Fig. 11(b). Fig. 12(b) is a plan view showing the object following Fig. 12(a). [Fig. 13] Fig. 13(a) is a plan view showing the object following Fig. 12(b). Fig. 13(b) is a side view of the object shown in Fig. 13(a). Fig. 13(c) is a side view for explaining the object to be polished in the first embodiment. [Fig. 14] Fig. 14 is a plan view of the object to be trimmed in the embodiment. [Fig. 15] Fig. 15(a) is a diagram illustrating the predetermined direction determined by the determining unit. Fig. 15(b) is a diagram illustrating the predetermined direction determined by the determining unit. Fig. 15(c) is a diagram explaining the predetermined direction determined by the determining unit. [Fig. 16] Fig. 16 is a diagram illustrating the cutting process. [Fig. 17] Fig. 17 is a diagram showing an example of the relationship between the shape of the irradiation mark, the damage suppression effect, and whether or not to cut. [Fig. 18] Fig. 18 is a diagram showing an example of an irradiation mark and a cross-sectional state for each beam angle. [Fig. 19] Fig. 19 is a diagram showing an example of an irradiation mark and a cross-sectional state for each beam angle. [Fig. 20] Fig. 20 is a diagram showing an example of an irradiation mark and a cross-sectional state for each beam angle. [Fig. 21] Fig. 21 is a diagram showing an example of an irradiation mark and a cross-sectional state for each beam angle. [Fig. 22] Fig. 22(a) is a diagram showing an example of the relationship between beam shape and overall modification and cut-off ability. Fig. 22(b) is a diagram showing an example of the relationship between beam shape and overall modification and cut-off ability. [Fig. 23] Fig. 23 is a diagram showing an example of the relationship between beam shape and overall modification and cut-off ability. [Fig. 24] Fig. 23 is an enlarged plan view showing the surface of the wafer of the embodiment.

9: Control Department

9a: Acquisition Department

9b: Decision Department

9c: Processing Control Department

9d: Adjustment Department

10A: The first laser processing head (irradiation part)

14: Condenser

34: Reflective spatial light modulator (forming part)

36: Ranging sensor

65: Installation Department

100: Object

100a: Surface (opposite surface, second surface)

100b: back side (laser light incident side, first side)

101: Laser processing device

106A: 1st Z axis track

107: Platform (support part)

108: Y axis track

110: Counterpoint camera

C: Rotation axis

E: Remove area

M3: line

R: effective area

Claims (14)

A laser processing device that focuses at least a part of a condensing area on an object containing a III-V compound semiconductor to irradiate laser light, thereby forming a modified area on the object, and includes: The support part that supports the aforementioned object, The irradiation part that irradiates the laser light to the object supported by the support part, The control unit that controls the aforementioned support unit and the aforementioned irradiation unit, The aforementioned irradiation part, Having a shaping portion for shaping the laser light so that a part of the shape of the condensing area in a plane perpendicular to the optical axis of the laser light has a longitudinal direction, The aforementioned control unit has: A determining portion that determines the orientation of the longitudinal direction when a part of the light-concentrating area is relatively moved along a line extending in a loop on the inner side of the outer edge of the object to be the direction of the longitudinal direction of the light-concentrating area A part of the predetermined direction where the angle between the moving directions is smaller than 45˚; The processing control unit relatively moves a part of the light-concentrating area along the line to form the modified area, and generates a surface with the longitudinal direction on the opposite side of the laser light incident surface of the object. Shaped irradiation marks; and The adjustment unit adjusts the orientation of the longitudinal direction to be the predetermined direction determined by the determination unit when the modified region is formed by the processing control unit. The laser processing device according to claim 1, wherein the processing control unit reaches a side opposite to the laser light incident surface of the object by a crack extending from the modified region along a part of the line In the opposite way, the modified area is formed. The laser processing apparatus according to claim 1 or 2, wherein the processing control unit forms a plurality of rows of the modified regions in the thickness direction of the object along the line such that the modified regions are formed in the thickness direction. The entire area of the object is occupied by the modified area. The laser processing apparatus according to any one of claims 1 to 3, wherein the processing control section is formed so that the cracks extending from the modified region do not reach the laser light incident surface of the object The modified area. The laser processing apparatus according to any one of claims 1 to 4, wherein the object contains gallium arsenide. The laser processing device according to any one of claims 1 to 5, wherein: The aforementioned forming part contains a spatial light modulator, The adjustment unit adjusts the orientation of the longitudinal direction by controlling the spatial light modulator. A laser processing method is to focus at least a part of a condensing area on an object containing a III-V compound semiconductor to irradiate laser light, thereby forming a modified area on the object, including: A forming process, which shapes the laser light into a part of the shape of the light-condensing area in a plane perpendicular to the optical axis of the laser light having a longitudinal direction; The determination process is to determine the orientation of the longitudinal direction of the light-concentrating area when a part of the light-concentrating area is relatively moved along a line extending in a loop on the inner side of the outer edge of the object. A part of the predetermined direction where the angle between the moving directions is smaller than 45˚; The processing process involves relatively moving part of the condensing area along the line to form the modified area, and creating a shape with the longitudinal direction on the opposite side to the laser light incident surface of the object Exposure marks; and In the adjustment process, when the modified region is formed by the processing process, the orientation of the longitudinal direction is adjusted so as to become the predetermined direction determined by the determination process. The laser processing method according to claim 7, wherein in the processing step, along a part of the line, a crack extending from the modified region reaches the side opposite to the laser light incident surface of the object In the opposite way, the modified area is formed. The laser processing method according to claim 8, which includes a cutting process for applying stress to the object in such a way that after the processing process, the crack reaching the opposite surface is used as a boundary to separate the object , And cut the object along the line. The laser processing method according to any one of claims 7 to 9, wherein in the processing step, a plurality of rows of the modified regions are formed along the line in the thickness direction of the object so that the The entire area of the aforementioned object in the thickness direction is occupied by the modified area. The laser processing method according to any one of claims 7 to 10, wherein, in the processing step, the crack extending from the modified region does not reach the laser light incident surface of the object. The modified area. The laser processing method according to any one of claims 7 to 11, wherein the object contains GaAs. A laser processing device that focuses at least a part of a condensing area on an object containing a III-V compound semiconductor to irradiate laser light, thereby forming a modified area on the object, and includes: The support part that supports the aforementioned object, The irradiation part that irradiates the laser light to the object supported by the support part, A processing section that controls the support section and the irradiation section, and relatively moves a part of the light-concentrating area along a line extending in a loop on the inner side of the outer edge of the object to form the modified area. The surface opposite to the laser light incident surface of the aforementioned object produces an irradiation mark having a shape in the longitudinal direction. The aforementioned processing department, The orientation of the longitudinal direction when a part of the light-concentrating area is relatively moved along the aforementioned line is determined to be a predetermined angle that is smaller than 45˚ with the moving direction of a part of the light-concentrating area direction, The orientation of the longitudinal direction is adjusted to be the determined predetermined direction. A kind of wafer is a plate-shaped wafer containing III-V compound semiconductors, Have: a first surface, a second surface on the opposite side of the aforementioned first surface, When viewed from the thickness direction, on the second surface, the irradiation marks having a part of the shape in the longitudinal direction and overlapping with the outer edge of the second surface are formed in plural along the outer edge, When viewed from the thickness direction, the direction of the longitudinal direction is a predetermined direction in which the angle with the tangential direction of the outer edge becomes an angle smaller than 45˚.

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