WO2010071275A1

WO2010071275A1 - Control unit for adjusting a wafer angle in a probe apparatus

Info

Publication number: WO2010071275A1
Application number: PCT/KR2009/002620
Authority: WO
Inventors: Tae-Suk Jung; Ki-Uk Choi
Original assignee: Secron Co., Ltd.
Priority date: 2008-12-19
Filing date: 2009-05-18
Publication date: 2010-06-24
Also published as: KR20100071235A; TW201025476A; TWI515812B

Abstract

In a wafer angle controller, a wafer is positioned on a wafer chuck rotatable on a central axis thereof. A chuck connector is located at a side of the wafer chuck and has a spherical hollow portion. A fixation shaft extends in a tangential direction of the wafer chuck and has a spherical connecting body coupled into the hollow portion at a first end and a screw hole at a second end thereof. A screw shaft is screwed into the screw hole, thus a joint distance between the screw and fixation shafts may be varied as the screw shaft is screwed. A driving unit drives the screw shaft to be screwed relative to the fixation shaft, to rotate the wafer chuck due to the variation of the joint distance. Accordingly, the wafer chuck is rotated by variation of the joint distance caused by the rotation of the screw shaft.

Description

CONTROL UNIT FOR ADJUSTING A WAFER ANGLE IN A PROBE APPARATUS

Example embodiments relate to a control unit for adjusting an object angle, and more particularly, to a control unit for efficiently adjusting a wafer angle in a probe apparatus in which an electrical inspection process is performed on the wafer.

A probe apparatus is generally used for inspecting defects from a wafer in a die sorting process that is a last step for fabricating an integrated circuit device prior to a packaging step. The probe apparatus inspects electric and functional characteristics of the IC on the wafer and checks processing defects on the wafer. Particularly, the probe card and the wafer are relatively moved in a stepped manner according to a chip size and a contact pad of the wafer makes contact with a probe pin of the probe card and every chip on the wafer is inspected.

In the above general probe apparatus for inspecting the chips on the wafer by direct contact between the pin of the probe card and the contact pad of the wafer, the inspection accuracy of the probe apparatus is generally determined by alignment accuracy of the pin and the contact pad as well as by operational accuracy of a stage of the probe apparatus.

The alignment accuracy of the pin and the contact pad usually includes adjustment of a contact angle between the wafer and the pin of the probe card. Thus, the alignment accuracy is determined by the accuracy of the contact angle adjustment and high accuracy of the contact angle adjustment usually requires fine control of a wafer angle.

However, conventional wafer angle controllers in the probe apparatus have difficulties in relation to fine angle control, as well as complex structures. Thus, there is still required an improved wafer angle controller which is much more finely and accurately controlled and may have a much more simple structure.

Accordingly, example embodiments provide a wafer angle controller for a probe apparatus which may be much more finely and accurately controlled and may have a much more simple structure.

According to some example embodiments of the present inventive concept, there is provided a wafer angle controller for a probe apparatus. A wafer chuck rotatable with respect to a central axis thereof is provided and a wafer that is to be inspected is positioned on the wafer chuck. A chuck connector is located at a peripheral portion of the wafer chuck and has a spherical hollow portion therein. A fixation shaft extends in a tangential direction perpendicular to a rotation radius of the wafer chuck. The fixation shaft has a spherical connecting body, which corresponds to the hollow portion of the chuck connector, at a first end portion and a screw hole at a second end portion opposite to the first end portion. A screw shaft is coupled to the screw hole of the fixation shaft by a screw joint, so that a joint distance between the screw shaft and the fixation shaft may be varied in accordance with loosening and fastening of the screw shaft relative to the fixation shaft. A driving unit is positioned around the wafer chuck and drives the screw shaft to be loosened into or fastened from the screw hole of the fixation shaft, so that the wafer chuck is rotated in accordance with the variation of the joint distance between the screw shaft and the fixation shaft.

In an example embodiment of the present invention, the driving unit is rotated with respect to a vertical axis parallel with the central axis of the wafer chuck.

In an example embodiment of the present invention, the chuck connector further includes at least one guide groove that guides the connecting body of the fixation shaft to be rotated in the hollow portion with respect to a vertical axis parallel with the central axis of the wafer chuck.

According to some example embodiments of the present inventive concept, there is provided another wafer angle controller for a probe apparatus. A wafer chuck on which a wafer is positioned is provided and the wafer chuck is rotatable with respect to a central axis thereof. A chuck connector is located at a peripheral portion of the wafer chuck and has a cylindrical portion therein. A fixation shaft extends in a tangential direction perpendicular to a rotation radius of the wafer chuck, and the fixation shaft has a connection hole into which the cylindrical portion of the chuck connector is inserted at a first end portion and a screw hole at a second end portion opposite to the first end portion. A screw shaft is coupled to the screw hole of the fixation shaft by a screw joint, so that a joint distance between the screw shaft and the fixation shaft may be varied in accordance with loosening and fastening of the screw shaft relative to the fixation shaft. A driving unit is positioned around the wafer chuck and driving the screw shaft to be loosened into or fastened from the screw hole of the fixation shaft, so that the wafer chuck is rotated in accordance with the variation of the joint distance between the screw shaft and the fixation shaft.

In an example embodiment of the present invention, the fixation shaft is rotated with respect to the cylindrical portion inserted into the connection hole thereof, so that linear variation of the joint distance between the screw shaft and the fixation shaft is transformed into rotation of the wafer chuck.

According to some example embodiments of the present inventive concept, a wafer angle controller may include a screw shaft driven by a driving unit and a fixation unit having a screw hole into which the screw shaft is screwed. A wafer chuck is rotated by the wafer angle controller due to variation of a joint distance between the screw shaft and a fixation shaft caused by the loosening and fastening of the screw shaft relative to the fixation shaft, and thus a contact angle of a wafer on the wafer chuck may be varied in accordance with the rotation of the wafer chuck. Therefore, the contact angle of the wafer may be controlled by rotation of the screw shaft for performing the loosening and fastening, so that the contact angle of the wafer with respect to a probe card may be finely and accurately controlled merely by the rotation of the screw shaft.

Example embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings. FIGS. 1 to 6 represent non-limiting, example embodiments as described herein.

FIG. 1 is a schematic view illustrating a structure of a wafer angle controller for a probe apparatus in accordance with an example embodiment of the present invention;

FIG. 2 is a view illustrating the operation of the wafer angle controller shown in FIG. 1;

FIG. 3 is a schematic view illustrating a structure of a wafer angle controller for a probe apparatus in accordance with another example embodiment of the present invention;

FIG. 4 is a cross-sectional view illustrating a joint portion of a chuck connector and a fixation shaft of the wafer angle controller shown in FIG. 3;

FIG. 5 is a view illustrating the operation of the wafer angle controller shown in FIG. 3; and

FIG. 6 is a schematic view illustrating a probe apparatus including a wafer angle controller shown in FIG. 1 in accordance with an example embodiment of the present invention.

Various example embodiments will be described more fully hereinafter with reference to the accompanying drawings, in which some example embodiments are shown. The present invention may, however, be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity.

It will be understood that when an element or layer is referred to as being "on," "connected to" or "coupled to"another element or layer, it can be directly on, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly connected to" or "directly coupled to"another element or layer, there are no intervening elements or layers present. Like numerals refer to like elements throughout. As used herein, the term "and/or"includes any and all combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third, etc.may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.

Spatially relative terms, such as "beneath," "below," "lower," "above," "upper" and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below"or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below"can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Example embodiments are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized example embodiments (and intermediate structures). As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, example embodiments should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, an implanted region illustrated as a rectangle will, typically, have rounded or curved features and/or a gradient of implant concentration at its edges rather than a binary change from implanted to non-implanted region. Likewise, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation takes place. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of the present invention.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Hereinafter, example embodiments will be explained in detail with reference to the accompanying drawings.

FIG. 1 is a schematic view illustrating a structure of a wafer angle controller for a probe apparatus in accordance with an example embodiment of the present invention.

Referring to FIG. 1, the wafer angle controller 100 for a probe apparatus in accordance with an example embodiment of the present invention may control a contact angle of a wafer, an inspection object in the probe apparatus, with respect to a probe card of the probe apparatus. Particularly, the wafer angle controller 100 may control the contact angle of the wafer with respect to a pin of the probe card to thereby accurately align the probe card and the wafer in the probe apparatus.

In an example embodiment, the wafer angle controller 100 may include a wafer chuck 110, a chuck connector 120, a fixation shaft 130, a screw shaft 140 and a driving unit 150.

The wafer chuck 110 may be rotated with respect to a vertical axis (hereinafter referred to as z-axis) in the probe apparatus and may be shaped into a contour of the wafer. For example, the wafer chuck 110 may be shaped into a circular shape in accordance with a circular wafer. The wafer may be mounted onto the wafer chuck 110, particularly, on a stage (not shown) on the wafer chuck 110.

The chuck connector 120 may be positioned at a side portion of the wafer chuck 110. In an example embodiment, the chuck connector 120 may be positioned at an edge portion of the wafer chuck 110 and may be extended in a direction perpendicular to a radial direction of the circular wafer chuck 110. Thus, the chuck connector 120 may have a predetermined width w on the wafer chuck 110. The chuck connector 120 may be secured to the wafer chuck 110 and may connect the fixation shaft 130 to the wafer chuck 110. A spherical hollow portion 122 may be positioned in the chuck connector 120 and the fixation shaft 130 may be located at the spherical hollow portion 122 of the chuck connector 120, and thus the fixation shaft 130 and the chuck connector 120 are connected to each other. No limitation may be allowed to the shape of the chuck connector 120 and any other modifications may be allowed to the chuck connector 120, as would be known to one of ordinary skill in the art.

In an example embodiment, a connection body 132 may be positioned at a first end portion of the fixation shaft 130 and may be shaped into an inner contour of the spherical hollow portion 122 of the chuck connector 120. Thus, the fixation shaft 130 may be connected to the chuck connector 120 in such a configuration that the connection body 132 is coupled into the spherical hollow portion 122. As both of the connection body 132 and the hollow portion 122 are shaped into a sphere, the fixation shaft 130 may be rotated with respect to the z-axis in the probe apparatus although the fixation shaft 130 makes contact with the chuck connector 120. The fixation shaft 130 may extend in a direction perpendicular to the radial direction of the circular wafer chuck to thereby have a length ℓparallel with a tangential direction of the wafer chuck 110. A screw hole (not shown) is located at a second end portion of the fixation shaft 130 and a plurality of threads is formed on an inner surface of the screw hole. The second end portion may be opposite to the first end portion of the fixation shaft 130.

The screw shaft 140 may extend in the same direction of the fixation shaft 130 and have the same central axis as the fixation shaft 130. Therefore, the screw shaft 140 may also extend in a direction perpendicular to the radial direction of the wafer chuck 110, and a plurality of threads are formed on an external surface of the screw shaft 140. Thus, the screw shaft 140 may be screwed into the screw hole of the fixation shaft 130 and the screw shaft 140 and the fixation shaft 130 may be combined to each other by a screw joint. That is, the screw shaft may be loosened or fastened in accordance with rotation of the screw shaft 140.

The driving unit 150 may be positioned adjacent to the wafer chuck 110 and a rotational force may be applied to the screw shaft 140 by the driving unit 150. For example, the driving unit 150 may include an electrical motor such as a servo motor. When the rotational force is applied to the screw shaft 140 by the driving unit 150, the screw shaft 140 may be loosened or fastened from or into the screw hole of the fixation screw 130. A joint distance d between the screw shaft 140 and the fixation shaft 130 may be varied in accordance with the loosening and fastening of the screw shaft 140 and the wafer chuck 110 may be rotated with respect to the z-axis in the probe apparatus because the wafer chuck is secured to the fixation shaft 130.

For example, when the screw shaft 140 may be fastened into the screw hole of the fixation shaft 130, the fixation shaft 130 may be screwed down toward the driving unit 150 and the joint distance d becomes short between the fixation shaft 130 and the screw shaft 140. Thus, the wafer chuck 110 may be rotated with respect to the z-axis clockwise since the chuck connector 120 is secured to the wafer chuck 110 and the fixation shaft 130 is movably secured to the chuck connector 120. In contrast, when the screw shaft 140 may be loosened out of the screw hole of the fixation shaft 130, the fixation shaft 130 may be screwed away from the driving unit 150 and the joint distance d is increased between the fixation shaft 130 and the screw shaft 140. Thus, the wafer chuck 110 may be rotated with respect to the z-axis counter clockwise since the chuck connector 120 is secured to the wafer chuck 110 and the fixation shaft 130 is movably secured to the chuck connector 120. That is, the wafer chuck 110 may be rotated in accordance with the loosening and fastening of the screw shaft 140 to thereby control the wafer angle to the pin of the probe card.

In an example embodiment, the driving unit 150 may be installed in the probe apparatus in such a manner that the driving unit 150 may be rotated with respect to the z-axis in the probe apparatus. Thus, the variation of the gap distance d between the screw shaft 140 and the fixation screw 130 may be transformed into the rotation ofthe driving unit 150 when the wafer chuck 110 is rotated clockwise or counter clockwise in the probe apparatus. For example, a vertical shaft 152 may be installed along the z-axis and the driving unit 150 may be movably connected to the vertical shaft in the probe apparatus.

According to the example embodiment of the wafer angle controller for the probe apparatus, the loosening or fastening of the screw shaft 140 relative to the fixation screw 130 by the driving unit 150 may cause the variation of the joint distance between the screw shaft 140 and the fixation screw 130, and thus the wafer chuck 110 may be rotated with respect to the z-axis due to the variation of the joint distanced.

FIG. 2 is a view illustrating the operation of the wafer angle controller shown in FIG. 1.

Referring to FIGS. 1 and 2, the angle of the wafer (not shown) may be controlled by rotation of the wafer chuck 110 on which the wafer is positioned. Particularly, the wafer chuck 110 may be rotated due to the variation of the joint distance d caused by the loosening and fastening of the screw shaft 140 relative to the fixation screw 130, and thus the angle of the wafer on the wafer chuck 110 may be accurately and finely controlled by a linear motion of the screw shaft 140.

The variation of the joint distance d may also be transformed into rotation of the connecting body 132 of the fixation shaft 130 relative to the inner surface of the spherical hollow portion of the chuck connector 120 while the wafer chuck 110 is rotated. In the present example embodiment, the chuck connector120 may include a guide groove 124 that is connected to the spherical hollow portion 122 and guides the rotation of the connecting body 132 with respect to the z-axis in the hollow portion 122. The guide groove 124 may extend in an x-y plane to which the z-axis is normal and with which the bottom of the probe apparatus is parallel. In addition, the variation of the joint distance d may also be transformed into rotation of the driving unit 150 relative to the vertical shaft 152 to which the driving unit 150 is installed while the wafer chuck 110 is rotated.

Accordingly, the rotation of the wafer chuck 110 may be caused by the variation of the joint distance d due to the loosening and fastening of the screw shaft relative to the fixation shaft, and thus the contact angle of the wafer with respect to the pin of the probe card may be continuously controlled without any modifications of shape and location of the wafer. In addition, the wafer angle control may be performed merely by the simple operation of the loosening and fastening of the screw shaft in place of the conventional complicated operation of complex mechanisms.

FIG. 3 is a schematic view illustrating a structure of a wafer angle controller for a probe apparatus in accordance with another example embodiment of the present invention. FIG. 4 is a cross-sectional view illustrating a joint portion of a chuck connector and a fixation shaft of the wafer angle controller shown in FIG. 3, and FIG. 5 is a view illustrating the operation of the wafer angle controller shown in FIG. 3.

Referring to FIGS. 3 to 5, the wafer angle controller 200 of the present example embodiment in FIG. 3 has substantially the same structure as the wafer angle controller 100 shown in FIG. 1 except for the configuration of the joint between the chuck connector and the fixation shaft. Therefore, in FIGS. 3 to 5, the same reference numerals denote the same elements in FIGS. 1 and 2, and thus the detailed descriptions on the same elements will be omitted.

In an example embodiment, the wafer angle controller 200 for a probe apparatus in accordance with another example embodiment of the present invention may include a wafer chuck 110, a chuck connector 220, a fixation shaft 230, a screw shaft 140 and a driving unit 150.

The chuck connector 220 may be positioned at a peripheral portion of the wafer chuck 110 and may include a cylindrical portion 222 to which the fixation shaft 230 may be connected and extending in parallel with the z-axis of the probe apparatus.

The fixation shaft 230 may include a connection hole 232 into which the cylindrical portion 222 of the chuck connector 220 may be inserted. The fixation shaft 230 and the chuck connector 220 may be connected to each other in such a configuration that the cylindrical portion of the chuck connector 220 may be inserted into the connection hole 232 of the fixation shaft 230 and the fixation shaft 230 may be rotated with respect to the cylindrical portion of the chuck connector 220. Therefore, the fixation shaft 230 may be rotated with respect to the z-axis of the probe apparatus while maintaining the joint between the fixation shaft 230 and the chuck connector 220.

The wafer angle controller 200 shown in FIG. 3 may be operated substantially in the same way as the wafer angle controller 100 shown in FIG. 1. That is, the wafer chuck 110 may be rotated by variation of the joint distance d between the fixation shaft 230 and the screw shaft 140 due to the loosening and fastening of the screw shaft 140 relative to the fixation shaft 230, so that the contact angle of the wafer on the wafer chuck 110 may be finely controlled without any modifications of shape and location of the wafer.

Referring to FIG. 6, a probe apparatus 10 in accordance with an example embodiment of the present invention may inspect a wafer W on which various manufacturing processes are performed and detect various processing defects from the wafer W. In an example embodiment, the probe apparatus 10 may include a probe card 1 making contact with the wafer W, a number of

stages

2, 3 and 4 for positioning the wafer W in a three-dimensional direction to thereby align the wafer W with the probe card 1, a wafer angle controller 100, a base 5 to which the

stages

2, 3 and 4 are secured, a central controller 6 for controlling the

stages

2, 3 and 4 and the wafer angle controller 100, a transfer unit 7 for loading/unloading the wafer W to/from the wafer chuck 110, a first camera C1 for sensing a letter on the wafer W, a second camera C2 for sensing the position of the wafer W and a third camera C3 for aligning the wafer W and the pin of the probe card 1 with each other.

The

stages

2, 3 and 4 may move in an x-axis direction, a y-axis direction and a z-axis direction, respectively. Each of the

stages

2, 3 and 4 may include a guide rail, a motor for generating rotational power and a ball screw for moving the stage using the rotational power of the motor.

In the present example, the wafer angle controller 100 may have the same structure as described with reference to FIGS. 1 to 3. Particularly, the wafer angle controller 100 may include a wafer chuck 110, a chuck connector 120, a fixation shaft 130, a screw shaft 140 and a driving unit 150. The wafer chuck 110 may be rotated due to variation of a joint distance between the screw shaft 140 and the fixation shaft 130 caused by the loosening and fastening of the screw shaft 140 relative to the fixation shaft 130, to thereby finely control the angle of the wafer W on the wafer chuck 110. In the present example embodiment, the wafer angle controller100 may be positioned on a support plate 102 protruded from the upper stage 4 in a radial direction of the wafer chuck 110.

The deviation between the pin of the probe card and a contact pad of the wafer W may be detected based on pictures taken by the first to third cameras C1, C2 and C3 and position and the angle of the wafer W may be adjusted in relation with the probe card by the

stages

2, 3 and 4 and the wafer angle controller 110 to thereby calibrate the detected deviation between the pin and the contact pad.

According to the above example embodiment of the present invention, a wafer angle controller may rotate a wafer chuck by variation of a joint distance between a screw shaft and a fixation shaft caused by the loosening and fastening of the screw shaft relative to the fixation shaft, and thus a contact angle of the wafer on the wafer chuck may be varied in accordance with the rotation of the wafer chuck. Therefore, the contact angle of the wafer may be controlled by rotation of the screw shaft for performing the loosening and fastening, so that the contact angle of the wafer with respect to the probe card may be finely and accurately controlled merely by the rotation of the screw shaft.

In addition, the wafer angle control may be performed merely by the simple operation of the loosening and fastening of the screw shaft relative to the fixation shaft in place of the conventional complicated operation of complex mechanisms to thereby reduce manufacturing costs of the probe apparatus.

The foregoing is illustrative of example embodiments and is not to be construed as limiting thereof. Although a few example embodiments have been described, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from the novel teachings and advantages of the present invention. Accordingly, all such modifications are intended to be included within the scope of the present invention as defined in the claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Therefore, it is to be understood that the foregoing is illustrative of various example embodiments and is not to be construed as limited to the specific example embodiments disclosed, and that modifications to the disclosed example embodiments, as well as other example embodiments, are intended to be included within the scope of the appended claims.

Claims

A wafer angle controller for a probe apparatus, comprising:

a wafer chuck on which a wafer is positioned, the wafer chuck being rotatable with respect to a central axis thereof;

a chuck connector located at a peripheral portion of the wafer chuck and having a spherical hollow portion therein;

a fixation shaft extending in a tangential direction perpendicular to a rotation radius of the wafer chuck, the fixation shaft having a spherical connecting body, which corresponds to the hollow portion of the chuck connector, at a first end portion and a screw hole at a second end portion opposite to the first end portion;

a screw shaft coupled to the screw hole of the fixation shaft by a screw joint, so that a joint distance between the screw shaft and the fixation shaft is varied in accordance with loosening and fastening of the screw shaft relative to the fixation shaft; and

a driving unit positioned around the wafer chuck and driving the screw shaft to be loosened into or fastened from the screw hole of the fixation shaft, so that the wafer chuck is rotated in accordance with the variation of the joint distance between the screw shaft and the fixation shaft.
The wafer angle controller of claim 1, wherein the driving unit is rotated with respect to a vertical axis parallel with the central axis of the wafer chuck.
The wafer angle controller of claim 1, wherein the chuck connector further includes at least one guide groove that guides the connecting body of the fixation shaft to be rotated in the hollow portion with respect to a vertical axis parallel with the central axis of the wafer chuck.
A wafer angle controller for a probe apparatus, comprising:

a wafer chuck on which a wafer is positioned, the wafer chuck being rotatable with respect to a central axis thereof;

a chuck connector located at a peripheral portion of the wafer chuck and having a cylindrical portion therein;

a fixation shaft extending in a tangential direction perpendicular to a rotation radius of the wafer chuck, the fixation shaft having a connection hole into which the cylindrical portion of the chuck connector is inserted at a first end portion and a screw hole at a second end portion opposite to the first end portion;

a screw shaft coupled to the screw hole of the fixation shaft by a screw joint, so that a joint distance between the screw shaft and the fixation shaft may be varied in accordance with loosening and fastening of the screw shaft relative to the fixation shaft; and

a driving unit positioned around the wafer chuck and driving the screw shaft to be loosened into or fastened from the screw hole of the fixation shaft, so that the wafer chuck is rotated in accordance with the variation of the joint distance between the screw shaft and the fixation shaft.
The wafer angle controller of claim 4, wherein the driving unit is rotated with respect to a vertical axis parallel with the central axis of the wafer chuck.
The wafer angle controller of claim 4, wherein the fixation shaft is rotated with respect to the cylindrical portion inserted into the connection hole thereof, so that linear variation of the joint distance between the screw shaft and the fixation shaft is transformed into rotation of the wafer chuck.