Patent Description:
With the rapid development of science and technology, semiconductor manufacturing processes become increasingly important. Obviously, it is extremely important for manufacturers to improve production efficiency, shorten production time and reduce production cost for related-art manufacturing processes, in addition to developing new semiconductor technologies. It will involve the transfer of wafers between different workstations due to various types and cumbersome steps of the semiconductor manufacturing processes.

However, there are often two issues regarding the transfer of wafers in the existing manufacturing processes. First, during the transfer process, the wafers are affected by the vibration, shaking, or swaying of the carrier, and thus the stability of the transfer process cannot be maintained effectively stable, which will have slight skewing and lead to scratches and damages of the wafers, or inaccurate positioning in subsequent workstations, etc. Second, most of the related-art wafer transfers rely on a six-axis robotic arm to pick up and place the wafers between each workstation, but due to the high price of the robotic arm, it cannot be used between any two workstations. Therefore, one robotic arm often needs to be responsible for the wafer transfer of many workstations, and the wafers in each workstation need to wait in line to be transferred by the robotic arm after the completion of their processing. As a result, the production efficiency is reduced and the production time is prolonged.

In view of the aforementioned problems, the inventor proposed this disclosure based on his expert knowledge and elaborated researches to overcome the problems of the related art.

The following document is mentioned as being a pertinent prior art illustration:.

<CIT> discloses a rotating device equipped with a suction vacuum system, included in a semiconductor manufacturing process, said rotating device being configured for carrying a plurality of wafers.

The following documents are also mentioned as being a complementary prior art illustration:.

The primary objective of this disclosure is to enable a carrier to stably suck a plurality of wafers without losing the suction effect during the rotating and transferring processes, and to use a turntable to simultaneously transfer the wafers from different workstations to the corresponding next workstation to achieve the effects of improving production efficiency, shortening production time and lowering production cost.

To achieve the aforementioned and other objectives, this disclosure provides a wafer transfer device of a semiconductor manufacturing process for carrying a plurality of wafers, and the wafer transfer device includes a base, a plurality of fixed rings, a rotating shaft, a turntable, an air suction pump, and a driving mechanism. The base is defined with a central axis, each fixed ring is stacked along the central axis on the base, each fixed ring includes a through hole and a channel, each through hole passes through each fixed ring along the central axis, each fixed ring includes a ring groove formed along an inner rim of the corresponding through hole, and each channel is extended from the outer periphery of each fixed ring and communicates to each ring groove. The rotating shaft is rotatably connected to each through hole and includes a plurality of flow passages, each flow passage has an interface and a port, each port is arranged corresponding to each fixed ring and communicates with each corresponding ring groove, the turntable is fixedly connected to the rotating shaft, a side of the turntable away from the base is provided with a plurality of carriers, each carrier is equiangularly arranged around the rotating shaft, a top surface of each carrier is provided for carrying each wafer, each carrier includes a suction passage, two ends of each suction passage are connected to the top surface and corresponding interface of the carrier respectively, each channel is connected to each corresponding ring groove, each flow passage and each suction passage to form a plurality of air suction passages, the air suction pump is connected to each channel and provided for extracting air from each air suction passage to form a negative pressure to suck each wafer, the driving mechanism drives and rotates the turntable and rotating shaft using the central axis as an axis, and when the turntable and rotating shaft rotate, each port rotates with each corresponding fixed ring and keeps communicating with each ring groove.

In an embodiment of this disclosure, a sidewall is disposed between two ends of the rotating shaft, and each port is disposed on the sidewall.

In an embodiment of this disclosure, the rotating shaft connected to an end of the turntable has an end surface, and each interface is disposed on the end surface and arranged corresponding to each carrier.

In an embodiment of this disclosure, the wafer transfer device further includes a plurality of connecting pipes, each suction passage includes a main passage and a plurality of branches, each branch of each suction passage is parallel to the central axis and perpendicularly connected to the corresponding wafer and main passage, and two ends of each connecting pipe are connected to each interface and each main passage respectively.

In an embodiment of this disclosure, the fixed rings include a first fixed ring, the flow passages include a first flow passage, the first fixed ring is disposed on the base, the remaining fixed rings are stacked on the first fixed ring, and the port of the first flow passage communicates with the ring groove of the first fixed ring.

In an embodiment of this disclosure, the carriers are arranged correspondingly.

In an embodiment of this disclosure, the driving mechanism includes a driver, a driving gear and a driven gear, the driver has a drive shaft, the driving gear is installed to the drive shaft, the driven gear is fixedly connected to the turntable and engaged with the driving gear, the driver is provided for driving the driving gear to rotate the driven gear.

In an embodiment of this disclosure, the wafer transfer device further includes a carrying platform and a circular slide, the carrying platform is disposed on the base, the circular slide includes a rail and a slide block, the rail is installed on the carrying platform, and the slide block is installed onto the turntable and slidably sheathe the rail.

To achieve the aforementioned and other objectives, this disclosure further provides a wafer transfer method of a semiconductor manufacturing process, applied for simultaneously transferring a plurality of wafers from different workstations to the corresponding next workstation of each wafer. The wafer transfer method includes the steps of: providing a plurality of wafers, a plurality of workstations and the aforementioned wafer transfer device of the semiconductor manufacturing process, wherein the wafer transfer device includes a base, a plurality of fixed rings, a rotating shaft, a turntable, an air suction pump and a driving mechanism; the base is defined with a central axis each fixed ring is stacked on the base along the central axis and includes a through hole and a channel, each through hole passes along the central axis through each fixed ring, an inner rim of each through hole is provided with a ring groove, each channel extends from an outer periphery of each fixed ring to each ring groove; the rotating shaft is rotatably connected to each through hole and includes a plurality of flow passages, each flow passage has an interface and a port, and each port is configured to be corresponsive to each fixed ring and communicated with each corresponding ring groove; the turntable is fixedly connected to the rotating shaft, a side of the turntable away from the base is provided with a plurality of carriers, each carrier is equiangularly arranged around the rotating shaft, a top surface of each carrier is provided for carrying each wafer, each carrier has a suction passage with two ends connected to the top surface and corresponding interface of the carrier respectively, and each channel is connected to each corresponding ring groove, each flow passage and each suction passage to form a plurality of air suction passages; the air suction pump is connected to each channel for extracting air from each air suction passage to form a negative pressure in order to suck each wafer; the driving mechanism is provided for driving the turntable, the rotating shaft rotates using the central axis as an axis, when the turntable and rotating shaft rotate, each port rotates relative to each corresponding fixed ring and keeps communicating with each ring groove, each carrier carries and sucks each wafer, each workstation is arranged at a position above each carrier and a rotation angle is defined between any two adjacent carriers; and each workstation processes each wafer on each corresponding carrier; after completing the work of each workstation, the driving mechanism drives the turntable to rotate along a rotational direction to a rotation angle, such that each carrier moves to a position at the bottom of the next work station in the rotational direction; and each workstation processes each wafer on each corresponding carrier.

In the wafer transfer device of the semiconductor manufacturing process in accordance with this disclosure, when the turntable rotates, each port rotates relative to each corresponding fixed ring, and each port still keeps communicates with each ring groove, so that the carrier may stably suck the carried wafers without losing the suction effect during the processes of rotation and transfer, so as to prevent the wafers from being scratched or damaged, or unable to be positioned in subsequent workstations.

In the wafer transfer method of the semiconductor manufacturing process in accordance with this disclosure, the turntable of the wafer transfer device is provided for simultaneously transferring a plurality of wafers from different workstations to the corresponding next workstation, and thus the wafers in each workstation need not to wait sequentially for the transfer, so as to achieve the effects of greatly reducing the overall transfer time, effectively improving production efficiency, shortening production time, and lowering production cost.

The technical contents of this disclosure will become apparent with the detailed description of embodiments accompanied with the illustration of related drawings as follows. It is intended that the embodiments and drawings disclosed herein are to be considered illustrative rather than restrictive.

With reference to <FIG> for a wafer transfer device of a semiconductor manufacturing process in accordance with this disclosure, the wafer transfer device is provided for carrying a plurality of wafers A and includes a base <NUM>, a plurality of fixed rings 20A~20D, a rotating shaft <NUM>, a turntable <NUM>, an air suction pump <NUM> and a driving mechanism <NUM>.

The base <NUM> is defined with a central axis Y. In <FIG>, the central axis Y is extended vertically up and down and disposed at the middle of the base <NUM>, but this disclosure is not limited to such arrangement only, for example, the central axis Y is not necessarily disposed at the middle of the base <NUM>, as long as it is extended vertically up and down relative to the base <NUM>. It is noteworthy that although the base <NUM> of this embodiment is a cuboid, the base <NUM> of this disclosure is not limited to this shape only, but the shape can be adjusted as needed.

In this embodiment, there are four fixed rings 20A~20D, but the quantity is not limited, for example, there may be two, three, five or more fixed rings 20A~20D depending on the requirements. Each fixed ring 20A~20D uses the central axis Y as the center and is stacked sequentially along the central axis Y on the base <NUM>. Specifically, the fixed rings 20A~20D of this embodiment include a first fixed ring 20A, a second fixed ring 20B, a third fixed ring 20C and a fourth fixed ring 20D, the first fixed ring 20A is installed on the base, the second fixed ring 20B is stacked onto the first fixed ring 20A, the third fixed ring 20C is stacked onto the second fixed ring 20B, and the fourth fixed ring 20D is stacked onto the third fixed ring 20C. Each fixed ring 20A~20D includes a through hole <NUM> and a channel <NUM>. Each through hole <NUM> passes along the central axis Y through each fixed ring 20A~20D, and an inner rim of each fixed ring 20A~20D is provided with a ring groove <NUM> along the corresponding through hole <NUM>. Each channel <NUM> is extended from an outer periphery of each fixed ring 20A~20D and communicates to each ring groove <NUM>, that is, the configuration direction of each channel <NUM> is perpendicular to the configuration direction of each through hole <NUM>.

The rotating shaft <NUM> is in a cylindrical shape. The rotating shaft <NUM> is rotatably connected to each through hole <NUM>. An end of the rotating shaft <NUM> is fixedly connected to the turntable <NUM>. In this embodiment, an end of the rotating shaft <NUM> fixedly connected to the turntable <NUM> slightly protrudes from the turntable <NUM> and has an end surface <NUM>, but this disclosure is not limited to such arrangement only, for example, the rotating shaft <NUM> is fixedly connected to an end of the turntable <NUM> or buried in the turntable <NUM> or connected to a side of the turntable <NUM>. The rotating shaft <NUM> has a sidewall <NUM> between its two ends. The rotating shaft <NUM> is provided with a plurality of flow passages 33A~33D. The quantity of flow passage 33A~33D is arranged corresponding to the quantity of fixed rings 20A~20D, so that the quantity of flow passage 33A~33D in this embodiment is four. Each flow passage 33A~33D has an interface <NUM> and a port <NUM>. Each interface <NUM> is disposed on the end surface <NUM> of the rotating shaft <NUM> and arranged corresponding to each carrier. Each port <NUM> is disposed on the sidewall <NUM> of the rotating shaft <NUM>. Specifically, each flow passage 33A~33D is downwardly extended from the interface <NUM> of the end surface <NUM> and parallel to central axis Y and perpendicularly bent to the port <NUM> on the sidewall <NUM> to form an L-shape. Each port <NUM> is arranged corresponding to each fixed ring 20A~20D and communicates with each corresponding ring groove <NUM>. Specifically, the flow passages 33A~33D of this embodiment include a first flow passage 33A (see <FIG>), a second flow passage 33B, a third flow passage 33C and a fourth flow passage 33D, the port <NUM> of the first flow passage 33A communicates to the ring groove <NUM> of the first fixed ring 20A, the port <NUM> of the second flow passage 33B communicates to the ring groove <NUM> of the second fixed ring 20B, the port <NUM> of the third flow passage 33C communicates to the ring groove <NUM> of the third fixed ring 20C, and the port <NUM> of the fourth flow passage 33D communicates to the ring groove <NUM> of the fourth fixed ring 20D.

A side of the turntable <NUM> away from the base <NUM> is provided with a plurality of carriers 41A~41D. The quantity of carriers 41A~41D matches the quantity of flow passages 33A~33D, so that there are four relatively configured carriers 41A~41D in this embodiment. Each carrier 41A~41D is equiangularly arranged around the rotating shaft <NUM>, and a top surface of each carrier 41A~41D is provided for carrying each wafer A, that is, the carriers 41A~41D of this embodiment divide the turntable <NUM> into four equal parts. Each carrier 41A~41D has a suction passage <NUM>. Two ends of each suction passage <NUM> are connected to the top surface and corresponding interface <NUM> of the carrier 41A~41D. Each channel <NUM> is connected to each corresponding ring groove <NUM>, each flow passage 33A~33D and each suction passage <NUM> to form a plurality of air suction passages <NUM>. Specifically, the air suction passages <NUM> include a first air suction passage (not labelled in the figures), a second air suction passage (not labelled in the figures), a third air suction passage (not labelled in the figures) and a fourth air suction passage (not labelled in the figures). The first air suction passage is formed by the channel <NUM> of the first fixed ring 20A, the ring groove <NUM> of the first fixed ring 20A, the first flow passage 33A and the corresponding suction passage <NUM> of the first flow passage 33A. The second air suction passage is formed by the channel <NUM> of the second fixed ring 20B, the ring groove <NUM> of the second fixed ring 20B, the second flow passage 33B and the corresponding suction passage <NUM> of the second flow passage 33B. The third air suction passage is formed by the channel <NUM> of the third fixed ring 20C, the ring groove <NUM> of the third fixed ring 20C, the third flow passage 33C and the corresponding suction passage <NUM> of the third flow passage 33C. The fourth air suction passage is formed by the channel <NUM> of the fourth fixed ring 20D, the ring groove <NUM> of the fourth fixed ring 20D, fourth flow passage 33D and the corresponding suction passage <NUM> of the fourth flow passage 33D.

For the convenience of describing the specification of this disclosure, each carrier 41A~41D is further defined. The first air suction passage corresponding to the first flow passage 33A is referred to as a first carrier 41A, the second air suction passage corresponding to the second flow passage 33B is referred to as a second carrier 41B, the third air suction passage corresponding to the third flow passage 33C is referred to as a third carrier 41C, and the fourth air suction passage corresponding to the fourth flow passage 33D is referred to as a fourth carrier 41D.

The air suction pump <NUM> is connected to each channel <NUM>. In this embodiment, there is one air suction pump <NUM>, which communicates to each channel <NUM> through a control valve <NUM> and is used for controlling the air extraction of each channel, but this disclosure is not limited to such arrangement only, for example, the quantity of air suction pumps <NUM> may also be corresponding to the quantity of channels <NUM> and each air suction pump <NUM> is used directly to extract air for each channel <NUM>. Specifically, the air suction pump <NUM> of the embodiment may use the control valve <NUM> to extract air from each air suction passage as needed to form a negative pressure to suck each wafer A on each carrier 41A~41D.

The driving mechanism <NUM> is provided for driving and rotating the turntable <NUM> and rotating shaft <NUM> using the central axis Y as an axis. The driving mechanism <NUM> of this embodiment includes a driver <NUM> (which may be a servomotor or stepper motor), a driving gear <NUM> and a driven gear <NUM>. The driver <NUM> has a drive shaft <NUM>. The driving gear <NUM> is installed on the drive shaft <NUM>. The drive gear <NUM> is fixed on the turntable <NUM> and engaged with the driving gear <NUM>. The driver <NUM> is provided for driving and rotating the drive shaft <NUM>, so as to rotate the driving gear <NUM>, and drive the driving gear <NUM> to rotate the driven gear <NUM> altogether. As a result, the turntable <NUM> and the rotating shaft <NUM> may rotate with the driven gear <NUM> to achieve the effect of rotating the turntable <NUM>. It is noteworthy that the driver <NUM> of this disclosure adopts a servomotor or stepper motor, so that the rotation angle of the drive shaft <NUM> may be controlled to accurately control the rotation angle of the turntable <NUM>.

When the turntable <NUM> and the rotating shaft <NUM> are driven by the driving mechanism <NUM> to rotate, each port <NUM> of each flow passage 33A~33D also rotates relative to each corresponding fixed ring 20A~20D, and each port <NUM> may still keep communicating with each ring groove <NUM> to achieve the effect of continuously sucking each wafer A on each carrier 41A~41D.

With reference to <FIG> for a wafer transfer device of a semiconductor manufacturing process in accordance with this disclosure, the wafer transfer device further includes a plurality of connectors B and a plurality of connecting pipes C. Each suction passage <NUM> includes a main passage <NUM> and a plurality of branches <NUM>. Each branch <NUM> of each suction passage <NUM> is parallel to the central axis Y and perpendicularly connected to the corresponding wafer A and the main passage <NUM>. Two ends of each connecting pipe C are connected to each interface <NUM> and each main passage <NUM> respectively. Specifically, an end of each main passage <NUM> away from each branch <NUM>, each interface <NUM> and each port <NUM> are provided with a connector B. Therefore, a part of the connecting pipe C is connected between each interface <NUM> and each connector B of each main passage <NUM>, and another part of the connecting pipe C is connected between each port <NUM> and the control valve <NUM> of the air suction pump <NUM> to effectively ensure the sealing to achieve a good negative pressure effect.

In some embodiments of this disclosure, the wafer transfer device further includes a carrying platform <NUM> and a circular slide <NUM>. In this embodiment, the carrying platform <NUM> is connected to the base <NUM> for supporting the turntable <NUM>, but this disclosure is not limited to such arrangement. The circular slide <NUM> includes a rail <NUM> and a slide block <NUM>. The rail <NUM> is arranged on the carrying platform <NUM>, the slide block <NUM> is disposed at the bottom of the turntable <NUM> and slidably sheathe the rail <NUM>. In this way, the turntable <NUM> may stably rotate relative to the carrying platform <NUM> through the positioning between the slide block <NUM> and the rail <NUM> without any deviation or skew, thereby ensuring a stable transfer of each wafer A.

In the wafer transfer device of the semiconductor manufacturing process in accordance with this disclosure, when the turntable <NUM> rotates, each port <NUM> rotates relative to each corresponding fixed ring 20A~20D, and each port <NUM> still keeps communicating with each ring groove <NUM>, so that the carriers 41A~41D may stably suck the carried wafers A without losing the suction effect during the rotating and transferring process, so as to prevent the wafers A from scratching or damaging or unable to be positioned in subsequent workstations.

With reference to <FIG> and <FIG> for a wafer transfer method of a semiconductor manufacturing process in accordance with this disclosure, the wafer transfer method is applied for simultaneously transferring a plurality of wafers from different workstations W1~W4 to the corresponding next workstation W1~W4 of each wafer, and the wafer transfer method includes the following steps.

The aforementioned plurality of wafers A, a plurality of workstations W1~W4, and the aforementioned wafer transfer device for the semiconductor manufacturing process are provided. Each carrier 41A~41D is provided for carrying and sucking each corresponding wafer A. Each workstation W1~W4 is arranged above each carrier 41A~41D, and a rotation angle θ is defined between any two adjacent carriers 41A~41D.

The work of each wafer A on each corresponding carrier 41A~41D in each workstation W1~W4 is performed.

After each workstation W1~W4 completes its work, the driving mechanism <NUM> drives the turntable <NUM> to rotate along a rotational direction D to the aforementioned rotation angle θ, so that each carrier 41A~41D moves to the bottom of the next workstation W1~W4 of the rotational direction D.

Each workstation W1~W4 processes each wafer A on each corresponding carrier 41A~41D.

Further, the quantity of workstations W1~W4 matches with the quantity of carriers 41A~41D, so that there are four workstations W1~W4 of this embodiment. Specifically, the workstations W1~W4 include a first workstation W1, a second workstation W2, a third workstation W3 and a fourth workstation W4 for carrying out different work. For example, the first workstation W1 carries out the feeding work (that is, placing the wafers A into position manually or by machine), the second workstation W2 and the third workstation W3 perform the manufacturing work (such as coating, laminating, stripping, etching, developing, polishing grinding, etc., of the wafer A), the fourth workstation W4 inspects the output (that is, to classify and collect good and defective products manually or by machine), but the quantity and work content of these workstations W1~W4 are not limited to the above arrangement, and adjustments may be made as needed.

With reference to <FIG> for the above embodiments, the transfer flow of this disclosure is described below:
In the initial state as shown in <FIG>, the first carrier 41A is situated at the bottom of the first workstation W1, the second carrier 41B is situated at the bottom of the second workstation W2, the third carrier 41C is situated at the bottom of the third workstation W3, the fourth carrier 41D is situated at the bottom of the fourth workstation W4, and each carrier 41A~41D has not yet carried any wafer A.

In <FIG>, the first workstation W1 places the first wafer A1 onto the first carrier 41A.

In <FIG>, the turntable <NUM> rotates along the rotational direction D to the aforementioned rotation angle θ, so that the first carrier 41A is situated at the bottom of the second workstation W2, the second carrier 41B is situated at the bottom of the third workstation W3, the third carrier 41C is situated at the bottom of the fourth workstation W4, and the fourth carrier 41D is situated at the bottom of the first workstation W1. The first workstation W1 places the second wafer A2 on the fourth carrier 41D, and the second workstation W2 processes the first wafer A1 on the first carrier 41A.

In <FIG>, after the first workstation W1 and second workstation W2 complete their own work, the turntable <NUM> rotates along the rotational direction D to the aforementioned rotation angle θ, so that the first carrier 41A is situated at the bottom of the third workstation W3, the second carrier 41B is situated at the bottom of the fourth workstation W4, the third carrier 41C is situated at the bottom of the first workstation W1, the fourth carrier 41D is situated at the bottom of the second workstation W2. The first workstation W1 places the third wafer A3 onto the third carrier 41C, the second workstation W2 processes the second wafer A2 on the fourth carrier 41D, the third workstation W3 processes the first wafer A1 on the first carrier 41A.

In <FIG>, after the first workstation W1, second workstation W2 and third workstation W3 complete their own work, the turntable <NUM> rotates along the rotational direction D to the aforementioned rotation angle θ, so that the first carrier 41A is situated at the bottom of the fourth workstation W4, the second carrier 41B is situated at the bottom of the first workstation W1, the third carrier 41C is situated at the bottom of the second workstation W2, and the fourth carrier 41D is situated at the bottom of the third workstation W3. The first workstation W1 places the fourth wafer A4 onto the second carrier 41B, the second workstation W2 processes the third wafer A3 on the third carrier 41C, the third workstation W3 processes the second wafer A2 on the fourth carrier 41D, and the fourth workstation W4 inspects and classifies the first wafer A1 on the first carrier 41A.

In <FIG>, after the first workstation W1, second workstation W2, third workstation W3 and fourth workstation W4 complete their own work, the turntable <NUM> rotates along the rotational direction D to the aforementioned rotation angle θ, so that the first carrier 41A returns to the position below the first workstation W1, the second carrier 41B returns to the position below the second workstation W2, the third carrier 41C returns to the position below the third workstation W3, and the fourth carrier 41D returns to the position below the fourth workstation W4. The fifth wafer A5 in the first workstation W1 is placed on the first carrier 41A, the second workstation W2 processes the fourth wafer A4 on the second carrier 41B, the third workstation W3 processes the third wafer A3 on the third carrier 41C, and the fourth workstation W4 inspects and classifies the second wafer A2 on the fourth carrier 41D.

In this way, the first workstation W1 may continuously input new wafers A and manufacture the wafers A through the processing work of the second workstation W2 and the third workstation W3, and then the fourth workstation W4 detects and classifies the manufactured wafers A. At the same time, each wafer A on each carrier 41A~41D is transferred by the rotation of the turntable <NUM> and simultaneously moves to the next workstation W1~W4 along the rotational direction D respectively to form a continuous production flow, thereby achieving the effects of greatly reducing the transfer time of each wafer A between different workstations W1~W4, improving production efficiency and lowering production cost.

Claim 1:
A wafer transfer device of a semiconductor manufacturing process, for carrying a plurality of wafers (A), and the wafer transfer device comprising:
a base (<NUM>), defined with a central axis (Y);
a plurality of fixed rings (20A~20D), stacked on the base (<NUM>) along the central axis (Y), each fixed ring (20A~20D) comprising a through hole (<NUM>) and a channel (<NUM>), each through hole (<NUM>) passing through each fixed ring (20A~20D) along the central axis (Y), a ring groove (<NUM>) disposed in each fixed ring (20A~20D) along an inner rim of the through hole (<NUM>), and the channel (<NUM>) extended from an outer periphery of each fixed ring (20A~20D) and communicating to the ring groove (<NUM>);
a rotating shaft (<NUM>), rotatably coupled to each through hole (<NUM>), and comprising a plurality of flow passages (33A~33D), each flow passage (33A~33D) comprising an interface (<NUM>) and a port (<NUM>), and the port (<NUM>) arranged corresponding to each fixed ring (20A~20D) and communicating with the ring groove (<NUM>);
a turntable (<NUM>), fixedly connected to the rotating shaft (<NUM>), and comprising a plurality of carriers (41A~41D) disposed on a side thereof away from the base (<NUM>), each carrier (41A~41D) equiangularly installed around the rotating shaft (<NUM>), a top surface of each carrier (41A~41D) carrying each wafer (A), each carrier (41A~41D) comprising a suction passage (<NUM>), two ends of each suction passage (<NUM>) coupled to the top surface of the carrier (41A~41D) and the interface (<NUM>) correspondingly, a plurality of channels (<NUM>) correspondingly communicating with a plurality of ring grooves (<NUM>), the flow passages (33A~33D) and the suction passages (<NUM>) to define a plurality of air suction passages (<NUM>);
an air suction pump (<NUM>), coupled to each channel (<NUM>), and configured to extract air from each air suction passage (<NUM>) to form a negative pressure to suck each wafer (A); and
a driving mechanism (<NUM>), configured to drive the turntable (<NUM>) and the rotating shaft (<NUM>) to rotate around the central axis (Y);
wherein, when the turntable (<NUM>) and the rotating shaft (<NUM>) rotate, the port (<NUM>) rotates relative to each fixed ring (20A~20D) and keeps communicating with each ring groove (<NUM>).