KR20060079482A - Wafer planarization apparatus using laser - Google Patents

Abstract

The present invention relates to a wafer planarization apparatus using a laser. The wafer planarization apparatus of the present invention flatly polishes the semiconductor wafer by irradiating a laser beam to the surface of the semiconductor wafer in a horizontal direction. This reduces work time and reduces stress on the wafer compared to conventional chemical mechanical polishing methods. In addition, the wafer planarization apparatus of the present invention removes debris generated during the polishing process through air injection and suction, and does not require a separate cleaning process. It is possible.

Wafer Planarization, Laser, Chemical Mechanical Polishing, Air Suction

Description

Wafer Planarization Apparatus Using Laser

1 is a perspective view schematically showing a chemical mechanical polishing apparatus according to the prior art.

2 is a plan view of a wafer planarization apparatus using a laser according to an embodiment of the present invention.

3 is a side view of a wafer planarization apparatus using a laser according to an embodiment of the present invention.

<Description of Reference Number Used in Drawing>

10: chemical mechanical polishing device 11: polishing table

12: polishing pad 13: wafer carrier

14: abrasive feeder 15: abrasive

20: semiconductor wafer 22: polishing region

24: debris 100: wafer flattening device

110: wafer holding chuck 120: laser beam irradiator

122: laser beam generator 124: laser beam attenuator

126: laser beam 128: first feeder

130: inhaler 132: blower

134: air inlet 135: air outlet

136: air 138: second conveyer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing facility, and more particularly, to a wafer planarization apparatus for flatly polishing a semiconductor wafer by irradiating a surface of the semiconductor wafer with a horizontal direction.

In the semiconductor manufacturing process, the planarization of the wafer surface plays a very important role in the high integration and miniaturization of semiconductor devices. The semiconductor wafer is formed of a multi-layered wiring structure. If the flatness of each layer is bad, the contact between the wirings is adversely affected. In addition, as the circuit line width becomes smaller, a wide area planarization technique of the semiconductor wafer is required. Developed by this need is Chemical Mechanical Polishing (CMP) technology. Chemical mechanical polishing technology is a method of polishing the surface of the wafer while at the same time the chemical and mechanical action is performed at the same time.

1 is a perspective view schematically showing a chemical mechanical polishing apparatus 10 according to the prior art.

Referring to FIG. 1, the chemical mechanical polishing apparatus 10 polishes a semiconductor wafer 20 using a mechanical action by the polishing pad 12 and a chemical action by the abrasive 15. A polishing pad 12 is attached onto a polishing table 11, and an abrasive 15 is supplied by an abrasive supplier 14. The wafer 20 is mounted on a wafer carrier 13.

The polishing table 11 simply performs a rotational motion and the wafer carrier 13 performs a rotational motion and a rocking motion at the same time. The semiconductor wafer 20 mounted on the wafer carrier 13 comes into contact with the polishing pad 12 by the self-load of the wafer carrier 13 and the pressing force applied thereto. As the abrasive 15 flows between the wafer 20 and the contact surface of the polishing pad 12, a mechanical removal action is caused by the abrasive particles contained in the abrasive 15 and the surface protrusions of the polishing pad 12. A chemical removal effect is performed by the chemical component in (15).

However, the chemical mechanical polishing process requires a lot of work time and gives a lot of screed to the wafer. For example, the chipping phenomenon in which the edges of the wafer are finely separated is a phenomenon caused by the stress applied to the wafer. The chipping phenomenon produces fine cracks in the wafer, which can break the wafer when cut into individual chips for package assembly. The stress on the wafer continues to accumulate through the various processes, resulting in a drop in yield.

In addition, because the chemical mechanical polishing process must go through a cleaning process, the processing time is longer and additional equipment and resources are required. In addition, as the diameter of the semiconductor wafer becomes larger and larger, uniform planarization becomes more and more difficult, and the likelihood of damaging the wafer increases. Chemical mechanical polishing processes may produce variations between the amount of polishing at the center and the edge of the wafer, which increases as the diameter of the wafer increases. Therefore, as the wafer grows, wafer planarization becomes an increasingly difficult task.

SUMMARY OF THE INVENTION The present invention has been made to solve various problems of the conventional chemical mechanical polishing method, and an object of the present invention is to provide a novel wafer planarization device capable of rapidly performing planarization work while reducing stress on a semiconductor wafer. I would like to.

Another object of the present invention is to provide a wafer planarization apparatus which can perform a cleaning operation simultaneously with a wafer planarization operation.

Still another object of the present invention is to provide a wafer planarization apparatus capable of uniform planarization even if the size of the wafer is increased.

In order to achieve this object, the present invention provides a wafer flattening apparatus for flatly polishing a semiconductor wafer by irradiating a laser beam to the surface of the semiconductor wafer in a horizontal direction.

The wafer planarization apparatus according to the present invention includes a wafer holding chuck for supporting and fixing a semiconductor wafer and rotating the semiconductor wafer at a predetermined speed, and a laser beam irradiator for irradiating a laser beam to the surface of the semiconductor wafer rotating in the wafer holding chuck in a horizontal direction. It is configured to include. Therefore, the wafer planarization apparatus of this invention can grind the surface of a semiconductor wafer by a laser beam.

The wafer planarization apparatus according to the present invention may further include an inhaler. The inhaler is installed on the upper side of the semiconductor wafer, and removes the debris generated by the surface polishing of the semiconductor wafer by the laser beam with a vacuum pressure.

In addition, the wafer planarization apparatus according to the present invention may further include a blower. The blower is installed on the opposite side of the inhaler from above the semiconductor wafer, and blows air to the semiconductor wafer at a predetermined injection pressure.

In the wafer planarization apparatus according to the present invention, it is preferable that the blower is provided at a position close to the laser beam irradiator. By doing so, it is possible to blow air in the direction of irradiation of the laser beam so that debris does not obstruct the irradiation path of the laser beam.

In the wafer planarization apparatus according to the present invention, the laser beam irradiator may include a laser beam generator for generating a laser beam.

In addition, in the wafer planarization apparatus according to the present invention, it is preferable that the laser beam generator is a module in which several kinds of laser beam generators are integrated into one to generate various kinds of laser beams.

In addition, in the wafer planarization apparatus according to the present invention, the laser beam irradiator may further include a laser beam attenuator for adjusting the output of the laser beam irradiated from the laser beam generator.

The wafer planarization apparatus according to the present invention may further include a first conveyer. The first conveyer fixes the laser beam irradiator and moves the laser beam irradiator in a direction perpendicular to the irradiation direction of the laser beam.

The wafer planarization apparatus according to the present invention may further include a second conveyor. The second conveyor moves the inhaler in the same direction as the irradiation direction of the laser beam by fixing the inhaler, or moves the inhaler and the blower in the same direction as the irradiation direction of the laser beam by fixing the inhaler and the blower.

Example

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

In describing the embodiments, descriptions of technical contents which are well known in the technical field to which the present invention belongs and are not directly related to the present invention will be omitted. This is to more clearly communicate without obscure the subject matter of the present invention by omitting unnecessary description. For the same reason, some components in the accompanying drawings are exaggerated, omitted, or schematically illustrated, and the size of each component does not entirely reflect the actual size.

2 and 3 are a plan view and a side view of a wafer planarization apparatus 100 using a laser according to an embodiment of the present invention.

2 and 3, the wafer planarization apparatus 100 according to the present embodiment is a physical polishing apparatus for polishing the wafer 20 by irradiating a laser beam 126 on the surface of the wafer 20. The wafer planarization apparatus 100 includes a wafer holding chuck 110, a laser beam irradiator 120, an inhaler 130, and a blower 132. In the drawing, reference numeral 22 denotes an area where polishing is performed on the surface of the wafer 20.

The semiconductor wafer 20 is mounted on the wafer holding chuck 110. The wafer holding chuck 110 fixes the semiconductor wafer 20 and holds the wafer 20 so that the surface of the wafer 20 can be uniformly polished by the laser beam 126 irradiated to the wafer 20 in a predetermined direction. Rotate at a predetermined speed.

The laser beam irradiator 120 irradiates the laser beam 126 to the surface of the wafer 20 mounted on the wafer holding chuck 110 in the horizontal direction. The laser beam irradiator 120 is fixed to the first conveyor 128 and may move in the X-axis direction by the first conveyor 128. That is, the first conveyor 128 may adjust the irradiation position of the laser beam 126 by moving the laser beam irradiator 120 in the X-axis direction perpendicular to the irradiation direction of the laser beam 126.

The laser beam irradiator 120 includes a laser beam generator 122 and a laser beam attenuator 124.

The laser beam generator 122 is the part that generates the laser beam 126. The laser beam generator 122 is preferably in the form of a module in which several types of laser beam generators are integrated into one to generate various types of laser beams 126. Accordingly, the type of the laser beam 126 may be changed according to the kind of material on the surface of the wafer 20 to be polished.

The output of the laser beam 126 irradiated from the laser beam generator 122 is adjusted by the laser beam attenuator 124. Therefore, the laser beam attenuator 124 may protect the wafer 20 from the instantaneously irradiated high energy laser beam 126, and may adjust the precision and work time of the planarization work.

As described above, the laser beam irradiator 120 irradiates the laser beam 126 in the horizontal direction to the wafer 20 rotating at a predetermined speed, thereby making it possible to uniformly and quickly polish the surface of the wafer 20. In addition, since the type and output of the laser beam 126 can be selected and adjusted, even and different polishing target materials on the surface of the wafer 20 can be uniformly and precisely polished.

The debris 92 generated in the laser polishing process is removed by the blower 132 and the inhaler 130 provided above the semiconductor wafer 20.

The blower 132 blows air 136 into the surface side of the wafer 20 at a predetermined injection pressure, and discharges the wafer scrap 92 polished by the laser beam 126 to the outside. The blower 132 is preferably installed at a position close to the laser beam irradiator 120. By doing so, the air 136 can be jetted in the direction in which the laser beam 126 is irradiated, and the debris 92 shaved by the laser beam 126 does not obstruct the irradiation path of the laser beam 126.

The inhaler 130 is installed opposite the blower 132. The inhaler 130 includes an air inlet 134 facing the wafer 20 and an air outlet 135 facing the outside of the wafer 20. The inhaler 130 sucks the debris 92 blown by the air 136 at a vacuum pressure through the air inlet 134 and discharges it outward through the air outlet 135.

The blower 132 and the inhaler 130 are fixed to the second conveyor 138 and may be moved in the Y-axis direction by the second conveyor 138. That is, the second feeder 138 may move the blower 132 and the inhaler 130 in the Y-axis direction to effectively remove the debris 92 generated during the wafer polishing process.

Referring to the process of polishing the wafer 20 using the wafer planarization device 100 having the above configuration, first, the wafer 20 is mounted and fixed on the upper surface of the wafer holding chuck 110. The wafer holding chuck 110 rotates the wafer 20 at a predetermined speed.

Subsequently, the laser beam irradiator 120 irradiates the laser beam 126 in a direction parallel to the surface of the wafer 20 to perform a polishing process. Before irradiating the laser beam 126, first, the laser beam generator 122 is selected corresponding to the target material on the surface of the wafer 20 to be polished, and the laser beam 126 is irradiated from the selected laser beam generator 122. . The output of the laser beam 126 is adjusted via the laser beam attenuator 124.

Before irradiating the laser beam 126, the position of the laser beam irradiator 120 may be adjusted through the first conveyor 128. In addition, the laser beam 126 may be irradiated in the Y-axis direction while the laser beam irradiator 120 is moved in the X-axis direction through the first conveyor 128 while the laser beam is irradiated. By doing in this way, a grinding | polishing process can be progressed sequentially from the edge side to the center of the wafer 20 which rotates by a predetermined speed. Of course, in the state where the laser beam irradiator 120 is fixed toward the center of the wafer 20 without moving in the X-axis direction, the polishing process may be performed only depending on the rotation of the wafer fixing chuck 110.

While irradiating the laser beam 126, the blower 132 injects air 136 in a direction substantially parallel to the irradiation direction of the laser beam 126. The inhaler 130 sucks the debris 92 blown by the injection pressure of the air 136 at a vacuum pressure through the air inlet 134 and discharges it to the outside through the air outlet 135. At this time, the blower 132 and the inhaler 130 removes the debris 92 while moving in the Y-axis direction through the second feeder 138.

As described through the examples so far, the wafer planarization apparatus of the present invention polishes the surface of the wafer by irradiating a laser beam to the surface of the rotating wafer. As a result, wafer planarization can be performed very quickly and safely compared to conventional chemical mechanical polishing methods. Less time spent on wafer flattening also reduces the stress on the wafer. Therefore, it is possible to effectively prevent or reduce problems such as chipping of the wafer, cracks and breakage of the wafer, and yield reduction.

In addition, the wafer planarization apparatus of the present invention simultaneously performs the cleaning operation in parallel with the wafer polishing operation by the laser beam. That is, since the debris generated during the polishing process is removed through air injection and suction, no separate cleaning process is required and it is more effective in reducing work time and reducing stress.                     

In addition, since the wafer planarization apparatus of the present invention uses a laser beam having straightness, the polishing operation can be performed with a uniform thickness regardless of the position of the wafer surface. Therefore, even if the size of the wafer has an advantage that evenly planarization work is possible.

In the present specification and drawings, preferred embodiments of the present invention have been disclosed, and although specific terms have been used, these are merely used in a general sense to easily explain the technical contents of the present invention and to help the understanding of the present invention. It is not intended to limit the scope. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

Claims (10)

A wafer holding chuck supporting and fixing the semiconductor wafer and rotating the semiconductor wafer at a predetermined speed; A laser beam irradiator irradiating a laser beam in a horizontal direction on a surface of the semiconductor wafer rotating in the wafer holding chuck, And a surface of the semiconductor wafer is polished by the laser beam. The wafer flattener of claim 1, further comprising an inhaler disposed above the semiconductor wafer to remove debris generated by surface pressure of the semiconductor wafer by the laser beam under vacuum pressure. Device. The wafer planarization apparatus according to claim 2, further comprising a blower disposed above the inhaler above the semiconductor wafer and injecting air into the semiconductor wafer at a predetermined injection pressure. [4] The laser of claim 3, wherein the blower is installed at a position close to the laser beam irradiator and sprays air in the irradiation direction of the laser beam so that the debris does not obstruct the irradiation path of the laser beam. Wafer planarization apparatus used. 5. The wafer planarization apparatus as claimed in any one of claims 1 to 4, wherein the laser beam irradiator includes a laser beam generator for generating the laser beam. The wafer planarization apparatus according to claim 5, wherein the laser beam generator is a module in which several kinds of laser beam generators are integrated into one to generate various kinds of the laser beams. 6. The wafer planarization apparatus according to claim 5, wherein the laser beam irradiator further comprises a laser beam attenuator for adjusting the output of the laser beam irradiated from the laser beam generator. The apparatus of any one of claims 1 to 4, further comprising a first conveyor for fixing the laser beam irradiator and moving the laser beam irradiator in a direction perpendicular to the irradiation direction of the laser beam. Wafer planarization apparatus using a laser. The wafer planarization apparatus according to claim 2, further comprising a second conveyer which fixes the inhaler and moves the inhaler in the same direction as the irradiation direction of the laser beam. The laser beam of claim 3 or 4, further comprising a second conveyor for fixing the inhaler and the blower and moving the inhaler and the blower in the same direction as the irradiation direction of the laser beam. Wafer Planarization Device.

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