TW201717263A - Laser marking apparatus and laser marking method using the same - Google Patents

Abstract

Provide are a laser marking apparatus and a laser marking method using the same. A wafer may be prevented from being warped due to a vacuum plate on which the wafer is mounted and a pressure member configured to apply pressure to an edge portion of the wafer. Also, since the wafer is only vertically moved to minimize the amount of movement of the wafer, a marking process may be rapidly and accurately performed without needing to re-check a position of a semiconductor chip. The laser marking apparatus for performing a marking process on semiconductor chips provided on a wafer by using a laser beam according to an embodiment includes: a laser head configured to emit the laser beam; a stage on which the wafer is mounted and comprising an opening through which the laser beam is transmitted to the semiconductor chips; a wafer support configured to support a part of the wafer and to vertically move the wafer with respect to the stage; and a rotating member configured to rotate the stage.

Description

Laser marking device and laser marking method using the same

The present invention relates to a laser marking device and a laser marking method using the same, and to a laser marking device capable of preventing wafer bending (warpage), which can perform rapid and accurate laser marking and A laser marking method using the device.

In the process of a semiconductor device, a large number of wafers are formed on a wafer. In order to distinguish the wafers according to the production lot, characters and/or numbers are marked on the surface of each wafer. A laser marking device using a laser beam is used for this purpose. In the past, after dicing, each wafer was marked with a lot number. However, with the development of cutting-edge technology, the integrated circuit (IC) can be ultra-small and lighter, so in order to improve work efficiency and achieve quantity. Production, marking individual wafers on the wafer and then performing dicing. However, the size of the wafer is increased, and conversely, the thickness of the wafer is thinned and the wafer warpage (warpage) becomes a problem.

On the other hand, a wafer in which a plurality of wafers are formed is bent in a fixed direction due to the influence of its own weight, application of a wafer surface, and other processes. The larger the size of the wafer and the thinner the thickness, the greater the bending behavior, and the greater the amount of shrinkage when the coating material is hardened, the greater the bending behavior. At this time, when the height deviation of the processed surface of the wafer due to the bending phenomenon is larger than the depth of focus of the laser beam, the laser beam density and the laser beam are obtained according to the position of the wafer on the processing surface. The size is different, resulting in a problem that the mark quality is lowered, the line width is not fixed, and the mark position is also incorrect.

On the other hand, when marking the wafer by the laser marking device, it is preferable to mark the entire wafer at one time, but considering the laser shift limit of the laser beam or the quality of the mark text, etc. After a portion of the wafer is marked, the wafer is moved or rotated to mark other portions. That is, after marking a part of the area of the wafer, the wafer is rotated or moved, and the remaining portions are sequentially marked to mark the entire portion. In this case, since the wafer moves, when the mark is resumed, the position of the wafer is confirmed again after the camera located above confirms the position of the wafer. Thereby, there is a problem that the time of the marking process becomes long.

[Problem to be Solved by the Invention] In one aspect of the invention, there is provided a laser marking device that prevents wafer bending and performs a rapid and accurate marking operation on a wafer formed on a wafer.

In another aspect of the invention, a laser marking method for preventing wafer bending and performing a rapid and accurate marking operation on a wafer formed on a wafer is provided. [Means for solving the problem]

A laser marking device according to an embodiment of the present invention performs a marking operation on a semiconductor wafer provided in a wafer by using a laser beam, the laser marking device comprising: a laser head that emits the laser beam; and a platform And mounting the wafer, and including an opening for transmitting the laser beam to the semiconductor wafer; and the wafer support station is configured to support a part of the wafer The wafer is movable in an up and down direction with respect to the platform; and a rotating unit that rotates the platform.

The rotating unit may rotate the wafer to a specific angle after the wafer is moved upward in the wafer support table with respect to the platform.

The rotating unit may rotate the platform by a specific angle after moving the platform downward with respect to the wafer.

The marking operation can be performed by irradiating the semiconductor wafer exposed by the opening portion rotated by a specific angle by the rotation of the stage to the laser beam.

The platform may include a vacuum plate for adsorbing the wafer by vacuum.

Further, a pressurizing member that applies a pressing pressure to the edge portion of the wafer to prevent the wafer from being bent may be further included.

Further, a control unit that controls driving of the wafer support table, the pressing member, and the rotating unit may be further included.

The pressurizing member can be provided to adjust the pressure applied to the wafer by a drive motor.

The wafer support table and the pressurizing member are provided to be interlocked with each other. When the wafer support table moves, the pressurizing member may be in contact with the crystal in a state where the pressing member applies pressure to the wafer. The round support station moves together.

It may further include a mobile station that moves the above-described platform in the horizontal direction.

The opening of the platform can be provided to expose a region of one-fourth of the wafer.

The opening of the platform can be provided to expose a one-half of the area of the wafer.

A laser marking method according to an embodiment of the present invention performs a marking operation on a semiconductor wafer provided in a wafer by using a laser beam, and the laser marking method includes the steps of: mounting the wafer to an opening including an opening a step on the platform; a step of performing a first marking operation by irradiating the laser beam with the semiconductor wafer exposed by the opening; and moving the wafer in an upward direction with respect to the platform to rotate the platform An angle step of: moving the wafer to the platform in a downward direction relative to the platform; and irradiating the semiconductor wafer exposed by the opening due to rotation of the platform The beam is used to perform the step of the second marking operation.

After the completion of the second marking operation, the method further includes the step of: rotating the wafer in an upward direction with respect to the platform, and rotating the platform by a specific angle; and lowering the wafer relative to the platform a step of moving the wafer onto the stage; and a step of performing the third marking operation by irradiating the laser beam by the semiconductor wafer exposed by the opening due to the rotation of the platform.

Further, the method further includes the step of applying a pressing pressure to the edge of the wafer by the pressing member after the wafer is mounted on the stage.

The wafer can be moved in the up and down direction by a wafer support that supports a portion of the wafer.

The pressurizing member can be provided in a state in which pressure is applied to the wafer and interlocked with the wafer support table.

The pressing member can adjust the pressure applied to the wafer by driving the motor.

The platform may include a vacuum plate for adsorbing the wafer by vacuum.

At least one of the above-described platform and the above-described laser beam can be provided to be movable in the horizontal direction. [Effects of the Invention]

According to the above-described problem of the present invention, it is possible to prevent the bending of the wafer from being formed by the vacuum plate on which the wafer is mounted and the pressing member that applies pressure to the edge portion of the wafer.

Moreover, by moving the wafer up and down only, the movement of the wafer can be minimized, and a quick and accurate marking operation can be performed without reconfirming the position of the semiconductor wafer.

Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that they can be easily implemented by those having ordinary knowledge in the technical field to which the present invention pertains. However, the invention can be embodied in a variety of different forms and is not limited to the embodiments described herein. Further, in order to clearly explain the present invention in the drawings, the parts which are not related to the description are omitted, and the same parts are denoted by the same reference numerals throughout the description.

Throughout the specification, when a part is "connected" to another part, it includes not only the case of "direct connection" but also the case where it is "electrically connected" by other elements. In addition, when a certain component "includes" a certain component, unless otherwise indicated, it means that it may include other component, and does not mean that other component is excluded.

Fig. 1 is a cross-sectional view schematically showing a laser marking device 100 according to an embodiment of the present invention.

Referring to Fig. 1, a laser marking device 100 includes a laser head 10, a stage S on which a wafer W is mounted, a vision camera 20, a wafer support table 30, a pressurizing member 40, a moving table 50, a rotating unit 60, and a control unit 80.

The laser head 10 can emit a laser beam. The laser head 10 is disposed below the stage S, and can perform a marking operation by irradiating a laser beam on the semiconductor wafer provided on the wafer W exposed by the opening O of the stage S. A laser system including a laser head 10 can include a laser oscillator (not shown) that produces a laser beam, and a mirror (not shown) that is directed to the lower portion of the wafer to be ejected from the laser oscillator. a laser beam to form a path; a galvanometer scanner (not shown) for deflecting the laser beam by a specific angle; and an f-theta lens (not shown) for correcting the laser beam Aberration, etc. Wafer W can be mounted on platform S. Referring to FIGS. 2a and 2b, the platform S may include a plurality of holes P, and the platform S including the plurality of holes P may become the vacuum plate 70. The lower portion of the vacuum panel 70 can be connected to a vacuum pump, and the wafer W mounted on the vacuum panel 70 can be adsorbed and fixed by the operation of the vacuum pump. The wafer W is vacuum-adsorbed onto the vacuum panel 70, whereby the wafer W can be fixed so as not to move by a force applied from the outside, and the wafer W can be prevented from being bent. Further, on the surface of the vacuum panel 70 that is in contact with the wafer W, an antistatic pad (not shown), for example, carbon rubber, can be attached so as not to affect the circuit of the wafer included in the wafer W. The carbon rubber prevents the wafer W from being broken due to an impact generated during the process of detaching the wafer W from the vacuum panel 70.

An opening O is formed in the stage S. The opening O can be a region in which the semiconductor wafer included in the wafer W mounted on the stage S is exposed. The opening portion O has an area smaller than the entire area of the wafer W to be marked, and is formed to penetrate in the vertical direction of the stage S. The laser beam emitted from the laser head 10 located below the stage S can be irradiated to the semiconductor wafer provided in the wafer W by the opening O. The opening O may be in a form in which one side of the stage S is completely opened as shown in FIG. 2a, or may be formed in a part of the platform S as shown in FIG. 2b.

The area of the opening O is not particularly limited. However, when the area of the opening O is excessively large, the area of the portion of the wafer W itself supported by the stage S is reduced, so that it is difficult to prevent the wafer W from being bent. Further, when the area of the opening O is too small, the entire area to be marked of the semiconductor wafer included in the wafer W is marked, and the number of times the stage S is rotated is increased. Therefore, one wafer W is marked. The time required for the job becomes longer. Therefore, the area of the opening portion O can be less than or less than half of the entire area of the platform S. For example, as shown in FIG. 2a, the opening O can be provided to expose a region of one-fourth of the wafer W. Alternatively, as shown in FIG. 2b, the opening portion O may be provided to expose an area of about one-fourth of the wafer W in a form of connecting the edge portion of the stage S.

Referring again to FIG. 1, the visual camera 20 can capture the semiconductor wafer of the wafer W to identify the position of the semiconductor wafer. The position of the wafer can be grasped based on the position information of the identified semiconductor wafer, and the marking operation can be performed on the semiconductor wafer by using the laser beam emitted from the laser head 10.

Wafer support 30 can support a portion of wafer W. When the wafer support 30 is viewed from above, it can be formed in a ring shape and can be provided in the form of supporting the edge portion of the wafer W. Further, the wafer support table 30 can move the wafer W whose edge portion is supported in the vertical direction A1 with respect to the stage S. The wafer support table 30 can be moved by driving of a drive motor mounted on the wafer support table 30.

The pressing member 40 functions to apply pressure to the edge portion of the wafer W to expand the wafer W. Therefore, it is possible to prevent the occurrence of bending of the wafer W. To this end, the pressing member 40 includes a pressurizing ring 40a. The pressurizing ring 40a may be formed in a ring shape in order to apply a pressing pressure along the edge portion of the wafer W. The pressing member 40 is movable in the vertical direction A2 by the drive motor, and a pressing pressure or a releasing pressure can be applied to the edge portion of the wafer W by the movement in the vertical direction. Further, the pressing member 40 can adjust the pressure applied to the wafer W by driving the motor.

The wafer support table 30 and the pressing member 40 can be provided in conjunction with each other. When the wafer support table 30 moves in the vertical direction, the pressing member 40 connected to the wafer support table 30 can also move in the vertical direction. Further, when the wafer support table 30 is moved in the vertical direction in a state where the pressing member 40 applies a pressing pressure to the edge portion of the wafer W, the pressing member 40 can be combined with the wafer W and the wafer support table 30. Move in the up and down direction.

The mobile station 50 is movable in the horizontal direction, that is, on the X-Y plane. When the laser beam emitted from the laser beam emitted from the laser head 10 is irradiated to the semiconductor wafer provided on the wafer W exposed by the opening O, the laser head 10 itself can be irradiated, but the laser head 10 is also irradiated. The semiconductor wafer can be irradiated with a laser beam by the movement of the mobile station 50 in the horizontal direction in a fixed state.

The rotating unit 60 can rotate the platform S. When the wafer support table 30 is moved upward in a state where the pressing member 40 applies a pressing pressure to the edge portion of the wafer W, the pressing member 40 moves in the upward direction together with the wafer W and the wafer support table 30. Alternatively, in a state where the pressing member 40 applies pressure to the edge portion of the wafer W to fix the wafer W, the rotating unit 60 can move the stage S downward with respect to the wafer W.

Thereby, the wafer W can be spaced apart from the platform S, and at this time, the stage S can be rotated by a specific angle by the rotating unit 60. When the opening O is provided in such a manner that one quarter of the area of the wafer W is exposed, the angle at which the stage S is rotated by the rotating unit 60 can be 90 degrees.

The platform S is rotated by the rotating unit 60, whereby the opening O can also be rotated by a specific angle. The marking operation can be performed by irradiating the semiconductor wafer exposed by the rotating opening O with a laser beam. The irradiation of the laser beam toward the rotating opening portion O can be performed by the movement of the stage S caused by the movement of the laser head 10 or the movement of the moving table 50 in the horizontal direction.

The control unit 80 connected to the wafer support table 30, the pressing member 40, and the rotating unit 60 can control the driving of the wafer support table 30, the pressing member 40, and the rotating unit 60. Based on the signal applied from the control unit 80, the wafer support table 30 is movable in the up and down direction A1 with respect to the stage S, and the pressing member 40 is movable in the up and down direction A2. Further, based on the signal applied from the control unit 80, the rotating unit 60 can rotate the stage S by a specific angle, and can also move the stage S downward with respect to the wafer W.

3a to 3d are diagrams showing a laser marking method according to an embodiment of the present invention in accordance with steps.

Referring to Figure 3a, wafer W is first mounted onto platform S. The platform S can be a vacuum plate 70 containing a plurality of holes P. After the wafer W is mounted on the platform S, the wafer W can be vacuum-adsorbed onto the platform S by the operation of the vacuum pump.

Next, referring to FIG. 3b, the pressing member 40 applies a pressing pressure to the edge of the wafer W. The pressing member 40 includes a pressurizing ring 40a formed in a ring shape to apply a pressing pressure along an edge portion of the wafer W.

Next, the position of the semiconductor wafer is identified by the vision camera 20 capturing the semiconductor wafer included in the wafer W. Next, the position of the wafer is grasped based on the position information of the identified semiconductor wafer, and the semiconductor wafer exposed by the opening O is irradiated with the laser beam emitted from the laser head 10 to perform the first marking operation.

Next, referring to FIG. 3c, the wafer W fixed to the stage S by vacuum suction is released from the vacuum, and the wafer support table is moved upward in a state where the pressing member 40 applies a pressing pressure to the edge portion of the wafer W. 30, the pressing member 40 and the wafer W are moved in the upward direction together with the wafer support table 30. Alternatively, the vacuum may be released from the wafer W fixed to the stage S by vacuum suction, and the pressing force may be applied to the edge portion of the wafer W by the pressing member 40 to cause the stage S to be opposed to the wafer W. Move to the bottom.

Through the above steps, the wafer W and the platform S can be separated from each other. Next, the stage S is rotated by a rotation unit 60 by a specific angle. When the opening O is provided so as to expose a region of one-fourth of the wafer W, the angle at which the stage S rotates can be 90 degrees.

Next, referring to FIG. 3d, in a state where the pressing member 40 applies a pressing pressure to the edge portion of the wafer W, the wafer support table 30 is moved downward to make the pressing member 40 and the wafer W and the wafer support table. 30 moves in the downward direction to mount the wafer W onto the platform S. After the wafer W is mounted on the platform S, the wafer W can be vacuum-adsorbed onto the platform S by the operation of the vacuum pump.

Next, the semiconductor wafer exposed by the opening O due to the rotation of the stage S is irradiated with the laser beam emitted from the laser head 10 to perform the second marking operation. The irradiation of the laser beam toward the rotating opening portion O can be performed by the movement of the stage S caused by the movement of the laser head 10 or the movement of the moving table 50 in the horizontal direction.

Next, after the completion of the second marking operation, the marking process described in FIGS. 3c to 3d can be repeatedly performed to execute the third marking operation. After the completion of the third marking operation, the above steps can be repeated again. If the semiconductor wafer included in the wafer w is marked, the marking operation can be completed. When the opening O is provided so as to expose a region of one-fourth of the wafer W, all the marking operations can be completed when the fourth marking operation is completed.

The laser marking device and the laser marking method according to an embodiment of the present invention can be prevented from being formed in the crystal by the vacuum plate 70 on which the wafer W is mounted and the pressing member 40 that applies pressure to the edge portion of the wafer W. The curvature of the circle W. Further, by merely moving the wafer W up and down, the movement of the wafer W can be minimized, and a prompt and accurate marking operation can be performed without reconfirming the position of the semiconductor wafer.

The above description of the present invention is exemplified, and those skilled in the art to which the present invention pertains can understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. Therefore, the above-described embodiments are to be construed as illustrative only and not limiting. For example, it is to be noted that each constituent element in a single form may be dispersedly implemented. Similarly, the constituent elements in a dispersed form may be implemented in a combined form.

The scope of the present invention is defined by the scope of the claims, and the scope of the claims In the range.

10‧‧‧Ray head
20‧‧‧Visual Camera
30‧‧‧ Wafer Support Desk
40‧‧‧ Pressurized components
40a‧‧‧ Pressurized ring
50‧‧‧Mobile Station
60‧‧‧Rotating unit
70‧‧‧vacuum board
80‧‧‧Control Department
100‧‧‧Laser marking device
A1, A2‧‧‧ up and down direction
O‧‧‧ openings
P‧‧‧ hole
S‧‧‧ platform
W‧‧‧ wafer

Fig. 1 is a cross-sectional view schematically showing a laser marking device according to an embodiment of the present invention. 2a and 2b are perspective views of the vacuum panel shown in Fig. 1. 3a to 3d are diagrams showing a laser marking method according to an embodiment of the present invention in accordance with steps.

10‧‧‧Ray head

20‧‧‧Visual Camera

30‧‧‧ Wafer Support Desk

40‧‧‧ Pressurized components

40a‧‧‧ Pressurized ring

50‧‧‧Mobile Station

60‧‧‧Rotating unit

80‧‧‧Control Department

100‧‧‧Laser marking device

A1, A2‧‧‧ up and down direction

S‧‧‧ platform

W‧‧‧ wafer

Claims (20)

A laser marking device for performing a marking operation on a semiconductor wafer provided on a wafer by using a laser beam, the laser marking device comprising: a laser head that emits the laser beam; a platform that mounts the a wafer including an opening for transmitting the laser beam to the semiconductor wafer; and a wafer support station configured to support a portion of the wafer to enable the wafer to be Moving in the up and down direction relative to the platform; and a rotating unit that rotates the platform. The laser marking device of claim 1, wherein the rotating unit rotates the platform at a specific angle after the wafer support table moves the wafer upward relative to the platform. . The laser marking device of claim 1, wherein the rotating unit rotates the platform by a specific angle after moving the platform downward relative to the wafer. The laser marking device according to claim 2, wherein the marking is performed by irradiating the laser beam with the semiconductor wafer exposed by the opening portion rotated by a specific angle by rotation of the stage . The laser marking device of claim 1, wherein the platform comprises a vacuum plate for adsorbing the wafer by vacuum. The laser marking device according to claim 1, further comprising a pressing member that applies a pressing force to an edge portion of the wafer to prevent the wafer from being bent. The laser marking device according to claim 6, further comprising a control unit that controls driving of the wafer support table, the pressing member, and the rotating unit. The laser marking device according to claim 6, wherein the pressing member is provided to adjust a pressure applied to the wafer by a driving motor. The laser marking device according to claim 6, wherein the wafer support table and the pressing member are provided in a manner of being interlocked with each other, and if the wafer supporting table moves, the pressing is performed The pressing member also moves together with the wafer support table in a state where the member applies pressure to the wafer. The laser marking device of claim 1, further comprising a mobile station that moves the platform in a horizontal direction. The laser marking device according to claim 1, wherein the opening of the stage is provided to expose a region of one-fourth of the wafer. The laser marking device according to claim 1, wherein the opening of the stage is provided to expose a one-half of an area of the wafer. A laser marking method for performing a marking operation on a semiconductor wafer provided on a wafer by using a laser beam, the laser marking method comprising the steps of: mounting the wafer on a platform including an opening; a step of performing a first marking operation by irradiating the laser beam through the semiconductor wafer exposed by the opening; and rotating the wafer after moving the wafer in an upward direction with respect to the platform a step of a specific angle; a step of moving the wafer in a downward direction relative to the platform to mount the wafer onto the platform; and exposing by the opening due to rotation of the platform The semiconductor wafer irradiates the laser beam to perform a second marking operation. The laser marking method according to claim 13, wherein after the end of the second marking operation, the method further comprises the following steps: after moving the wafer in an upward direction with respect to the platform, The step of rotating the platform at a particular angle; the step of moving the wafer to the platform in a downward direction relative to the platform; and by the rotation of the platform The semiconductor wafer exposed at the opening irradiates the laser beam to perform a third marking operation. The laser marking method of claim 13, further comprising the step of applying a pressing pressure to the edge of the wafer by using a pressing member after the wafer is mounted on the platform. A step of. The laser marking method of claim 15, wherein the wafer is moved in an up and down direction by a wafer support that supports a portion of the wafer. The laser marking method according to claim 16, wherein the pressing member is provided in a state of being pressed against the wafer support in a state where pressure is applied to the wafer. The laser marking method of claim 15, wherein the pressing member adjusts a pressure applied to the wafer by driving a motor. The laser marking method of claim 13, wherein the platform comprises a vacuum plate for adsorbing the wafer by vacuum. The laser marking method of claim 13, wherein at least one of the platform and the laser beam is provided to be movable in a horizontal direction.