KR102207397B1 - Wafer turning apparatus after chemical mechanical polishing process and substrate treating method using same - Google Patents

Abstract

The present invention relates to a wafer inversion device and a wafer processing method using the same, as a wafer inversion device for flipping the wafer in an unloading unit of a chemical mechanical polishing system in order to supply a wafer that has been subjected to a chemical mechanical polishing process to a cleaning process. A gripper for gripping the wafer from the carrier head when the wafer after the mechanical process is moved to the unloading unit by the carrier head; When the holder of the unloading unit is moved downward, a gripper operating means for turning the gripper holding the wafer 180 degrees to reverse the wafer; When the wafer after the chemical mechanical polishing process is moved to the unloading unit, the holder of the unloading unit moves downward while the gripper grips the wafer from the carrier head on the spot, and the holder moves downward to rotate the gripper. When this possible space is provided, the gripper is rotated 180 degrees by the gripper operation means to turn the wafer, thereby reducing the time required to reverse the wafer while controlling only a small number of components, thereby improving process efficiency. It provides a wafer inversion device, characterized in that.

Description

Wafer reversing device after chemical mechanical polishing process and wafer processing method using the same {WAFER TURNING APPARATUS AFTER CHEMICAL MECHANICAL POLISHING PROCESS AND SUBSTRATE TREATING METHOD USING SAME}

The present invention relates to a device for reversing a wafer that has been subjected to a chemical mechanical polishing process, and more particularly, a wafer having a process surface facing downward during a chemical mechanical polishing process and a wafer processing surface facing upward in a subsequent cleaning process. It relates to a wafer inversion device for inverting by 180 degrees and a wafer processing method using the same.

The chemical mechanical polishing (CMP) process is used for wide area planarization and circuit formation that removes the height difference between the cell area and the surrounding circuit area due to irregularities on the wafer surface that are generated by repeatedly performing masking, etching, and wiring processes during the semiconductor device manufacturing process. This is a process of precisely polishing the surface of the wafer in order to improve the surface roughness of the wafer due to the separation of contact/wiring films and high-integration elements.

This CMP process is performed by pressing the wafer with the process surface of the wafer facing the polishing pad to simultaneously perform chemical and mechanical polishing of the process surface, and the wafer after the polishing process is held by the carrier head. As a result, it undergoes a cleaning process to clean foreign substances on the process surface.

That is, as shown in Fig. 1, in general, in the chemical mechanical polishing process of the wafer, when the wafer is supplied to the chemical mechanical polishing system X1 in the loading unit 20, the wafer W is transferred to the carrier heads S1, S2, and S1', S2'; A chemical mechanical polishing process is performed on a number of polishing plates (P1, P2, P1', P2') while moving (66-68) along a predetermined path (Po) in close contact with S). Made by The wafer W subjected to the chemical mechanical polishing process is transferred to the cradle 10 of the unloading unit by the carrier head S, and transferred to the cleaning unit X2 where the subsequent cleaning process is performed, and a plurality of cleaning modules ( In step 70), a process of cleaning the foreign matter on the wafer W is performed.

At this time, during the chemical mechanical polishing process, the process surface of the wafer faces downward to contact the surfaces of the polishing plates (P1, P2,...), but during the cleaning process, cleaning is performed while the cleaning liquid is supplied in the direction of gravity. The process surface faces upward. To this end, in the unloading unit, a reversing operation of flipping the wafer 180 degrees is performed by the wafer reversing device 50.

More specifically, the wafer reversing device 50 of FIG. 2 is provided in the unloading unit U of FIG. 1. The cradle 10 located in the unloading unit U is installed to be movable in the up-down direction 10d by a moving means Mo using electric force, hydraulic pressure or pneumatic pressure. At the same time, the gripper 52 for gripping the wafer W is also movable in the vertical direction 52d along the guide column 55 by the operating means M1, and is installed so as to grip the wafer by the gripper 52. .

Accordingly, as shown in FIG. 3A, when the wafer W having the chemical mechanical polishing process completed is supplied to the cradle 10 of the unloading unit by the carrier head S, the cradle ( 10) The upper wafer W is held by the gripper 52. Then, when the carrier head S is out of the unloading unit U, the gripper 52 moves upwards 52d2 and the holder 10 of the unloading unit U as shown in FIG. 3C. Moves downward (10d1) to secure the rotation space of the gripper 52. Then, as shown in Fig. 3D, the gripper 52 is rotated (52r) 180 degrees by the moving means Mo, so that the posture of the wafer W in which the process surface Sw of the wafer is facing downward is shown in Fig. 3E. As shown, the process surface Sw of the wafer faces upward.

Then, as shown in Fig. 3F, after moving the gripper 52 downward (52d1) and moving the holder of the unloading unit upward (10d2), the wafer W held by the gripper 52 is removed. Mount it on the cradle of the unloading unit. Then, since a difference occurs between the time required for the chemical mechanical polishing process and the time interval input to the cleaning process in most cases, a separate facility is used to hold the wafer on the cradle 10 of the unloading unit, and Fig. 3G Transfer to the wafer wetting device 40 shown in. In the wafer wetting device 40, liquid is supplied through a plurality of holes 40p, and the liquid 91 is filled on the bottom surface 41s of the wetting device by the height of the step 42, so that the liquid 91 is filled. Thus, the process surface of the wafer is kept wet. Then, the transfer unit grips the wafer W and moves it to the region X2 where the cleaning process is performed.

In the prior art constructed as described above, the gripper 52 moves up and down in the unloading unit U, and at the same time, the holder also moves up and down to secure a rotational space to flip the wafer, thereby controlling two components at the same time. There was a problem that the control method became complicated because it had to be done.

In particular, if there is a time difference between the unloading unit (U) turning over the wafer (W) and entering the next cleaning process, the unloading unit (U) is used to prevent damage to the process surface due to drying of the wafer. A holder for maintaining the wet state of the wafer must be separately provided at an adjacent location. It is not only costly to provide a separate device for dipping the wafer or spraying pure water on the process surface of the wafer to maintain the wet state of the wafer. It is also difficult to install it within a predetermined area of the area X1 where the chemical mechanical polishing process is performed.

Therefore, while controlling the process of flipping the wafer 180 degrees in the unloading unit (U) more easily, it is a way to reduce the cost and space required for equipment for supplying liquid to the wafer waiting before being put into the cleaning process. The necessity is desperately demanded.

The present invention is to solve the above-described problem, in inverting the wafer by 180 degrees so that the process surface of the wafer faces downward during the chemical mechanical polishing process, and the process surface of the wafer faces upward in the next cleaning process, An object of the present invention is to provide a wafer inversion device in which a process of inverting a wafer by 180 degrees is performed by a simpler control method, and a wafer processing method using the same.

First of all, the present invention is a case where a waiting time occurs before a wafer subjected to a chemical mechanical polishing process is put into the cleaning process, and the wet state of the wafer is not provided within the space occupied by the unloading unit. It aims to keep it firmly.

In order to achieve the above-described technical problem, the present invention is a wafer reversing device for flipping the wafer in an unloading unit of a chemical mechanical polishing system in order to supply a wafer that has been subjected to a chemical mechanical polishing process to a cleaning process. A gripper for gripping the wafer from the carrier head when the finished wafer is moved to the unloading unit by the carrier head; When the holder of the unloading unit is moved downward, a gripper operating means for turning the gripper holding the wafer 180 degrees to reverse the wafer; It provides a wafer inversion device, characterized in that it is configured to include.

This is a space in which the gripper of the unloading unit moves downward while the wafer after the chemical mechanical polishing process is moved to the unloading unit, and the holder of the unloading unit moves downward, so that the gripper can rotate. When this is provided, the gripper is rotated 180 degrees by the gripper operation means to turn the wafer, thereby reducing the time required for reversing the wafer while controlling only a smaller number of components, thereby further improving process efficiency.

Here, a liquid supply device may be installed in the gripper to maintain a wet state by supplying a liquid to the process surface of the wafer. Through this, a liquid such as pure water is supplied to the process surface of the wafer while holding the wafer after the chemical mechanical polishing process has been completed with a gripper to maintain the process surface of the wafer in a wet state, thereby drying and damaging the process surface of the wafer. Can be prevented.

In particular, conventionally, in order to maintain a wet state with a liquid on the process surface of the wafer, in a state in which the wafer is inverted 180 degrees and the wafer is placed in a separate area, the wafer is immersed in liquid or a liquid is applied. By providing a liquid feeder to the gripper, a separate space is not provided, the efficiency of the process is not impaired, and the transfer process of the wafer is simplified compared to the prior art, and an advantageous effect of maintaining the wafer in a wet state can be obtained.

On the other hand, the gripper includes two or more grip members movably installed to contact the edge of the wafer at two or more locations, and the liquid supply is mounted on the grip member, so that pure water or the like is directly placed on the process surface of the wafer. Supply liquid.

At this time, the liquid supply unit supplies liquid while the gripper is rotated by the gripper operation means to maintain the wafer in an inclined or vertical position, so that the liquid supplied from the liquid supply unit is supplied to the process surface of the wafer and flows. By lowering, it is possible to obtain the advantage of keeping the process surface of the wafer wet with a smaller amount of liquid.

On the other hand, according to another field of the invention, the present invention is a wafer supply method for supplying a wafer that has been subjected to a chemical mechanical polishing process to a cleaning process, wherein the wafer on which the chemical mechanical polishing process has been performed is held by a gripper from a carrier head. Step and; When the wafer gripping step is performed, a cradle downward moving step of moving the cradle downward; A wafer inversion step in which the gripper rotates in place and turns the wafer upside down so that the processing surface of the wafer faces downward when the step of moving the holder downward is performed; A step of moving the cradle upward in which the cradle moves upward; A second wafer mounting step of placing the wafer held by the gripper on the holder; A wafer transfer step of transferring the wafer mounted on the cradle to a cleaning process; It provides a wafer processing method, characterized in that configured to include.

In this way, by directly transferring and holding the wafer from the carrier head to the gripper, the time required for holding the wafer can be shortened. In addition, if the holder of the unloading unit is moved downward after the wafer gripping step is performed, the gripper rotates 180 degrees in place to invert the wafer, thereby minimizing the components that control the wafer for reversal. It is possible to obtain the advantage of simpler control because the components that must be moved for reversal of are minimized.

At this time, if there is a waiting time before transfer to the cleaning process after the chemical mechanical polishing process is performed, the wafer wetting step of spraying a liquid onto the process surface of the wafer to keep it wet is the wafer inversion step. It can be configured to be included in.

This means that if there is a difference in the time required for the chemical mechanical polishing process and the cleaning process for one wafer, a waiting time occurs before transfer to the cleaning process after the chemical mechanical polishing process is performed. Since the wafer processing surface is damaged when the wafer is left unattended, the wafer processing surface is kept wet by supplying liquid to the processing surface of the wafer using a liquid feeder provided in the gripper. This is to prevent damage due to drying of the wafer even if a separate space is not provided inside.

As described above, according to the present invention, when a wafer that has undergone a chemical mechanical polishing process is transferred to the unloading unit by the carrier head, the gripper receives and grips the wafer directly from the carrier head, and the holder of the unloading unit moves downward. When in the state or moving downward, the gripper minimizes the number of components controlled by rotating 180 degrees in place without moving up and down, while reducing the time required for wafer reversal to obtain an advantageous effect of improving process efficiency. I can.

In addition, the present invention is provided with a liquid supply device for supplying liquid to a gripper that flips the wafer 180 degrees, so that when the gripper receives a wafer that has reached the unloading unit while being held by the carrier head and rotates the wafer by 180 degrees , In a state where the wafer is positioned vertically or obliquely, liquid such as pure water is supplied to the process surface of the wafer from a liquid supply device provided in the gripper, without occupying a separate space and without moving the wafer to a specific position. It is possible to obtain an advantageous effect of keeping the process surface of the wafer wet.

That is, in the present invention, there is a difference in the time required for the chemical mechanical polishing process and the cleaning process for one wafer, so that the liquid provided in the gripper during the waiting time before the transfer to the cleaning process after the chemical mechanical polishing process is performed. By supplying liquid to the process surface of the wafer from the feeder to maintain the wafer process surface in a wet state, damage due to drying of the wafer can be prevented even if a separate space is not additionally provided within the space defined in the mass production process.

1 is a plan view showing the layout of a region in which a chemical mechanical polishing process and a cleaning process are performed.
2 is a schematic diagram showing the configuration of a wafer reversing device installed in a conventional unloading unit;
3A to 3G are views sequentially showing a transfer process of a wafer transferred to an unloading unit;
4 is a schematic diagram showing the configuration of a wafer reversing device installed in an unloading unit according to an embodiment of the present invention;
Figure 5 is a plan view of Figure 4;
6A to 6E are views sequentially showing a transfer process of a wafer transferred to an unloading unit according to an embodiment of the present invention.

Hereinafter, a wafer reversing apparatus 100 and a wafer processing method using the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, in the description of the present invention, known functions or configurations are omitted in order to clarify the gist of the present invention, and the same or similar functions or configurations are denoted with the same or similar reference numerals.

As shown in Fig. 4, the wafer flipper 100 according to an embodiment of the present invention includes a gripper 110 for holding the wafer W in contact with the edge of the wafer W, and the gripper 110 A gripper operation means that horizontally moves the grip members 111a, 111b; 111 in place without moving the upper and lower positions to hold or release the wafer W, and reverses the grip members 111a, 111b 180 degrees in place. (M) and a liquid supply unit 115 installed on the grip member 111 to spray or flow a liquid such as pure water.

The gripper 110 is a pair of grip members 111a, 111b; 111, an operation member 113 extending in one direction from one end of the grip members 111a, 111b, as shown in FIG. It is composed of a casing 118 accommodating a part of the member 113. The gripper 110 may be configured to hold the wafer W while rotating in the form of a hinge with respect to the casing 118, and according to a preferred embodiment of the present invention, the gripping position of the wafer W is always kept constant. The grip member 111 reciprocates with respect to the casing 118 in the direction indicated by 111d so as to maintain a firmly held state while holding the wafer W.

The gripper operation means (M) moves the operation member 113 relative to the casing 118 in an up-down direction (a direction inserted or withdrawn from the casing) relative to the casing 118 so that the grip members 111a and 111b become close to each other or While moving 111d in the away direction 111d, the grip member 111 serves to grip the wafer W or release the gripped wafer W.

Here, in order to move the operation member 113 in opposite directions within the casing 118, a pressure chamber is formed inside the casing 118 to control the pressure inside the pressure chamber, and the operation member 113 is operated by pneumatic or hydraulic pressure. ) Can be operated to be inserted or withdrawn. According to another embodiment of the present invention, a threaded rod (not shown) in which threads in opposite directions are formed in the casing 118 are installed in engagement with the threads of the operation member 113, and the gripper operation means M The operation member 113 may be configured to move in opposite directions to each other by rotating the thread rod. In this way, the grip member 111 may be moved in opposite directions by reciprocating movement of the operation member 113 by various configurations.

In this way, by reciprocating the operation member 113 in a linear shape, the wafer W is gripped by the grip member 111 or the gripped state is released, so that the edge of the wafer W is always gripped at a certain position. The advantage of obtaining a stable gripping state is obtained.

On the other hand, the gripper operation means (M) does not move the casing 118 in the up-down direction (direction closer to or away from the support) indicated by 52D in Fig. 2, but is gripped by rotating the casing 118 by 180 degrees (111r). The wafer W held by the member 111 is turned over and inverted by 180 degrees.

The liquid supply device 115 is installed on the grip member 111 to receive a liquid such as pure water or a cleaning liquid from the liquid supply unit L, and provides pure water to the process surface of the wafer W held by the grip member 111. The liquid 99, such as the like, is supplied in a form of spraying or flowing, thereby maintaining the process surface of the wafer W in a wet state. Maintaining the process surface of the wafer (W) in a wet state in this way creates a difference between the time required for the chemical mechanical polishing process and the time required for the cleaning process for the unit wafer. A waiting time must occur before transferring to the next cleaning process, and this is to prevent damage to the wafer processing surface due to drying during this waiting time. Therefore, by providing the liquid supply device 115 to the gripper 110 as described above, it is possible to prevent the process surface of the wafer W from being dried and damaged during the waiting time until it is transferred to the cleaning process.

The liquid 99 supplied from the liquid supplier 115 may be supplied in a state in which the posture of the wafer W is horizontal or vertical, but a small amount of liquid 99 is used and is buried on the surface of the wafer W. In order to remove large foreign matter from the surface of the wafer W, the liquid 99 is supplied from the liquid supply unit 115 when the wafer W is in a vertical direction or inclined to have a component in the vertical direction. In this case, in order for the supplied liquid 99 to flow while sweeping the process surface of the wafer W together with foreign substances by gravity, the inclined angle of the wafer W is preferably 45 degrees or more with respect to the horizontal plane.

At this time, in order to prevent the foreign matter remaining on the wafer W from falling on the holder 10 along with the flowing down 99d of the liquid 99 supplied to the wafer processing surface, the holder 10 and the gripper ( The blocking member 199 may move 62 between the 110 and may be interposed therebetween. Alternatively, while the liquid is supplied to the process surface of the wafer held by the gripper 110, the cradle 10 may be moved by the moving part Mo to move outward from the lower side of the gripper 110. Through this, it is possible to prevent the cradle 10 of the unloading unit U from being contaminated by contaminated liquid and foreign substances separated from the wafer process surface and falling downward.

As described above, even if the gripper 110 supplies the liquid 99 to the process surface of the wafer W while holding the wafer W in the air, the entire wafer process surface is wetted with a small amount of liquid 99. It can be maintained in a state, and at the same time, the chemical mechanical polishing process can even function to wash out large foreign substances remaining on the surface of the wafer W that has just been completed.

In this way, the wafer on which the chemical mechanical polishing process has been completed is transferred to the unloading unit U, and fixed to the grip member 111 while the wafer W is held by the gripper 110 in the unloading unit U. By supplying the liquid from the liquid supply device 115 to the process surface of the wafer, the process surface of the wafer W is kept in a wet state, thereby preventing the process surface of the wafer W from being dried and damaged. In particular, in order to maintain the wet state of the process surface of the wafer W with liquid, in a state in which the wafer is inverted 180 degrees and the wafer is placed in a separate area, the wafer is immersed in liquid or liquid is applied. Although configured, by providing a liquid supply device to the gripper, a separate space is not provided, the efficiency of the process is not impaired, and the transfer process of the wafer is simplified compared to the conventional one, and an advantageous effect of maintaining the wafer in a wet state can be obtained.

Meanwhile, a curved surface 115s equal to the edge curvature of the wafer W is protruded on the gripper 110 so that the wafer W can be stably gripped. In this case, the curved surface 115s may be formed separately on the grip member 111, but may be formed as the inward surface 115s of the liquid supply device 115. Accordingly, while holding the wafer W stably, the liquid 99 can be accurately supplied to the surface of the wafer W. A flexible material such as urethane may be coated on the inward surface 115s of the liquid supplier 115 to increase friction with the wafer W.

A wafer processing method using the wafer reversing apparatus 100 according to an embodiment of the present invention configured as described above will be described in detail.

Step 1 : First, as shown in Fig. 6A, when the wafer W after the chemical mechanical polishing process is transferred 69 to the unloading unit U by the carrier head S, the gripper 110 is It moves to the lower side of (S), receives the wafer (W) held by the carrier head (S) and is gripped by the grip member (111). At this time, the process surface Sw of the wafer W is in a downward-facing state.

Step 2 : Simultaneously or after step 1 is performed, the cradle 10 of the unloading unit U moves downward (10d1), as shown in Fig. 6B, so that the grip member 111 is rotated. Make a space for it. On the other hand, step 2 may be performed in advance before step 1 is performed.

Step 3 : Then, when a time difference between the chemical mechanical polishing process and the cleaning process occurs, and a predetermined waiting time is required before the wafer is transferred to the cleaning process, as shown in Fig. 6C, the gripper operation means M ) Rotates the gripper 110 90 degrees in place so that the wafer W is erected in a vertical direction. In some cases, the wafer W may be rotated only to a position in which the posture has a sharp inclination of about 30 degrees or less with respect to the vertical surface.

As described above, as the gripper 110 is configured to rotate only in place, the control of the gripper 110 becomes easier and the time required for reversing the wafer W can be shortened.

Step 4 : At the same time as or after step 3 is performed, the blocking member 199 is transferred 62 between the cradle 10 and the gripper 110 to be interposed.

Step 5 : Then, as shown in Fig. 6D, a liquid such as pure water is sprayed toward the wafer processing surface Sw from the liquid supply unit 115 installed in the grip members 111a and 111b. At this time, the liquid injection amount may be supplied only in a small amount sufficient for the process surface Sw of the wafer W to become wet, and may be supplied intermittently at intervals of time. Accordingly, the liquid supplied to the process surface Sw of the wafer W flows down along the direction of gravity (99d) to maintain the process surface Sw in a wet state, and at the same time Large foreign matter is washed away with liquid (99) and falls down. The contaminated liquid falling together with the foreign material falls on the blocking member 199 to prevent contamination of the cradle 10.

Step 5 is preferably performed until immediately before all the waiting time for the wafer W to be supplied to the cleaning process has elapsed.

Step 6 : Then, as shown in Fig. 6D, the grip member 111 is completely rotated 180 degrees to invert the wafer W so that the process surface Sw of the wafer W faces upward.

Step 7 : Then, as shown in Fig. 6E, the holder 10 moves upward (10d2), and the wafer W placed in the gripper 110 is ready to be transferred to the next cleaning process. Then, the cradle 10 moves downward and transfers the wafer W with the process surface Sw facing upward to a cleaning process by a transfer means not shown in the drawing.

In the wafer reversing device according to the present invention configured as described above and a wafer processing method using the same, when the wafer having completed the chemical mechanical polishing process is transferred to the unloading unit U by the carrier head S, the gripper 110 is transferred to the carrier. When the wafer (W) is received and held directly from the head (S), and the holder (10) of the unloading unit (U) moves downward (10d1) or moves downward (10d1), the gripper (110) It is possible to obtain an advantageous effect of improving process efficiency by shortening the time required for wafer reversal while minimizing the number of components controlled by rotating 180 degrees in place without moving up and down.

Above all, in the present invention, the liquid 99 is applied to the gripper 110 that turns the wafer W 180 degrees so that the process surface Sw of the wafer W is from a downward-facing position to an upward-facing position. By providing the liquid supply device 115 to supply Sw), liquid 99 such as pure water from the liquid supply device 115 installed in the gripper 110 without transferring the wafer W to a device that occupies a separate space. By supplying and flowing down the process surface of the wafer, it keeps the process surface of the wafer wet and prevents it from being damaged by drying during the waiting time before being transferred to the cleaning process. You can get the beneficial effect that you can.

In the above, the preferred embodiments of the present invention have been exemplarily described, but the scope of the present invention is not limited to the specific embodiments as described above, and the present invention is It is possible to change appropriately within the scope described in the claims.

100: wafer reversing device 110: gripper
111: grip member 113: operation member
118: casing 115: liquid supply
M: gripper operation means

Claims (9)

A wafer reversing device for turning over the wafer in an unloading unit of a chemical mechanical polishing system in order to supply a wafer after a chemical mechanical polishing process to a cleaning process,
A gripper for gripping the wafer from the carrier head when the wafer after the chemical mechanical process is moved to the unloading unit by the carrier head;
When the holder of the unloading unit is moved downward, a gripper operation means for turning the gripper holding the wafer 180 degrees to turn the wafer over;
And the gripper rotates without moving up and down.
The method of claim 1,
The wafer reversing apparatus, wherein a liquid supply unit is installed in the gripper to maintain a wet state by supplying a liquid to the process surface of the wafer.
The method of claim 1,
The wafer reversing apparatus, wherein a curved surface equal to the edge curvature of the wafer is protruded from the gripper.
The method of claim 2,
The gripper includes two or more grip members movably installed to contact the edge of the wafer at two or more locations, and the liquid supply unit is mounted on the grip member.
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