Semiconductor device manufacturing apparatus and manufacturing method

Abstract

The present invention provides a semiconductor device manufacturing apparatus capable of properly picking up a target wafer in a non-contact manner. The semiconductor device manufacturing apparatus (10) includes: a wafer holder (12) for holding a dicing tape (110) to which a plurality of wafers (100) are attached in a posture in which the plurality of wafers (100) are oriented downward in the direction of gravity; and a picking tool (20) for picking up a target wafer (100a) as one of the plurality of wafers (100) from below the wafer holder (12) in a non-contact manner.

Description

[Technical Field]

[0001] This specification discloses a manufacturing apparatus and a manufacturing method for a semiconductor device that picks up a target wafer in a non-contact manner. [Previous Technology]

[0002] In recent years, to achieve further miniaturization and high density of semiconductor devices, there is a need for technologies that hold wafers in a non-contact manner. For example, Patent Document 1 discloses a non-contact chuck that uses ultrasonic vibration to hold a workpiece (wafer) in a non-contact manner. This type of non-contact chuck can also be considered for use in pick-up tools for self-dicking tape wafers. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2006-73654 [Patent Document 2] Japanese Patent Application Publication No. 2002-184721 [Summary of the Invention]

[0004] [Problem to be solved by the invention] However, the force with which a non-contact chuck attracts the wafer is usually weak. Therefore, it is difficult to properly peel the wafer off the dicing tape by means of the attraction force of the non-contact chuck alone.

[0005] Furthermore, Patent Document 2 discloses a technique for vertically positioning a chuck stage for holding a wafer on the ground. However, Patent Document 2 does not make any indication of wafer pickup.

[0006] Therefore, this specification discloses a manufacturing apparatus and a manufacturing method for a semiconductor device capable of properly picking up a target wafer in a non-contact manner. [Means of Solving the Problem]

[0007] The semiconductor device manufacturing apparatus disclosed in this specification is characterized by comprising: a wafer holder for holding a dicing tape to which a plurality of wafers are attached in an attitude in which the plurality of wafers are oriented downward in the direction of gravity; and a pick-up tool for picking up an object wafer, which is one of the plurality of wafers, from below the wafer holder in a non-contact manner.

[0008] In this case, it may also include a bonding tool, which receives the object wafer from the pick-up tool and bonds it to the substrate, and the pick-up tool transfers the object wafer to the bonding tool without lifting or lowering after picking it up.

[0009] Alternatively, it may also include a movable stage, which suctions a portion of the plurality of wafers via the dicing tape, wherein the movable stage does not suction the target wafer, but rather suctions the wafers surrounding the target wafer.

[0010] Alternatively, the pickup tool may have: a holding surface for holding the object wafer; a vibration source for applying ultrasonic vibration to the holding surface and applying ultrasonic holding force to the object wafer; and a suction source for suctioning the object wafer to the holding surface.

[0011] Alternatively, after picking up the wafer, the picking tool may transfer the target wafer to the bonding tool while maintaining the ultrasonic holding force and the suction force based on the suction source at a constant state.

[0012] Alternatively, it may also include a controller that controls the driving of the picking tool, the controller pre-stores the weight of the wafer, and controls the suction force of the picking tool according to the weight of the wafer.

[0013] The method for manufacturing a semiconductor device disclosed in this specification is characterized in that a dicing tape to which multiple wafers are attached is held by a wafer holder in a position in which the multiple wafers are oriented downwards in the direction of gravity, and a pick-up tool picks up one of the multiple wafers from below the wafer holder in a non-contact manner. [Effects of the Invention]

[0014] According to the technology disclosed in this specification, the weight of the target wafer can be used as an auxiliary force for picking up, thus enabling the target wafer to be picked up properly in a non-contact manner.

Implementation Method

[0016] Hereinafter, the semiconductor device manufacturing apparatus 10 will be described with reference to the drawings. FIG1 is a schematic diagram showing the structure of the manufacturing apparatus 10. The manufacturing apparatus 10 manufactures a semiconductor device by bonding a wafer 100 to a substrate. In this manufacturing process, the wafer 100 is picked up one by one from the wafer supply section 11 by the pick-up tool 20 and transferred to the bonding tool 26. The bonding tool 26 manufactures a semiconductor device by bonding the wafer 100 to a substrate (not shown) placed on a stage.

[0017] In the wafer supply section 11, a plurality of wafers 100 are attached to a dicing tape 110. The dicing tape 110 is a sheet material with an adhesive layer formed on one side and having moderate elasticity. A plurality of wafers 100 are formed by cutting and separating the wafers attached to the dicing tape 110.

[0018] Multiple wafers 100 are held by a wafer holder 12 while attached to the dicing tape 110. The wafer holder 12 is, for example, a wafer ring 14. The wafer ring 14 is an annular member that holds the dicing tape 110 while surrounding the multiple wafers 100 (i.e., wafers). Here, as shown in FIG1, in this example, the wafer holder 12 holds the dicing tape 110 in an orientation in which the multiple wafers 100 are oriented downwards in the direction of gravity. The reason for arranging the wafer holder 12 in this orientation will be described later.

[0019] A pickup tool 20 and a camera 34 are disposed on the underside of the wafer holder 12. The pickup tool 20 picks up the wafer (hereinafter referred to as "object wafer 100a") to be picked up from the dicing tape 110 and transfers it to the bonding tool 26. In addition, the pickup tool 20 is capable of moving in both the horizontal and vertical directions. Here, in this example, the pickup tool 20 holds the object wafer 100a in a non-contact manner. The detailed structure of the pickup tool 20 will be described later.

[0020] The camera 34 captures images of the plurality of wafers 100 held by the wafer holder 12. The controller 28 performs calculations on the position or tilt in the horizontal plane of each of the plurality of wafers 100 based on the images acquired by the camera 34.

[0021] A movable stage 22 is disposed on the opposite side of the wafer 100 across the dicing tape 110. The movable stage 22 suctions a portion of the plurality of wafers 100 via the dicing tape 110. That is, suction holes 24 are partially formed in the movable stage 22, and the wafers 100 are suctioned by applying negative pressure to the suction holes 24 using a pump or the like. In this example, the movable stage 22 does not suction the target wafer 100a, but rather suctions the wafers 100 around the target wafer 100a. Furthermore, the target wafers 100a, that is, the wafers 100 that become the objects of pickup, are switched sequentially during the manufacturing process of the semiconductor device. The movable stage 22 changes its position according to the switching of the target wafers 100a. Moreover, by providing this movable stage 22, it is possible to effectively prevent wafers 100 other than the target wafer 100a from being mistakenly peeled off from the dicing tape 110.

[0022] The bonding tool 26 bonds the wafer 100 received by the pick-up tool 20 to the substrate. In this example, the bonding tool 26 receives and bonds the wafer 100 to the substrate with the electrode surface 102 facing the substrate, i.e., in a face-down state.

[0023] The controller 28 controls the drive of the manufacturing apparatus 10. For example, the controller 28 controls the drive of the vibration source 36 or the suction source 42, which will be described later. In addition, the controller 28 detects the position of the wafer 100 or controls the position of the pick-up tool 20 and the bonding tool 26 based on the image captured by the camera 34. The controller 28 is physically a computer with a processor 30 and a memory 32. Furthermore, in FIG1, the controller 28 is illustrated as a single computer, but the controller 28 can also be constructed by combining multiple physically separate computers.

[0024] Next, the structure of the pick-up tool 20 will be described in detail with reference to FIG2. As described above, the pick-up tool 20 holds the wafer 100 in a non-contact manner. As shown in FIG2, the pick-up tool 20 includes a vibration source 36 and a suction source 42. The upper end surface of the pick-up tool 20 functions as a holding surface 46 (not shown) for holding the wafer 100.

[0025] A suction hole 48 is formed on the holding surface 46. The suction hole 48 is fluidly connected to the suction source 42 via the suction path 50. The suction source 42 is, for example, a vacuum pump. The suction source 42 applies a negative pressure to the suction hole 48 via the suction path 50. By means of this negative pressure, the wafer 100 is drawn to the holding surface 46.

[0026] The pressure sensor 44 detects the pressure in the suction path 50. The controller 28 determines whether the target wafer 100a has been successfully picked up based on the detected pressure output from the pressure sensor 44. That is, when the target wafer 100a is not present on the holding surface 46, the detected pressure is close to atmospheric pressure. On the other hand, when the target wafer 100a is picked up by the picking tool 20 and the wafer 100a is close to the holding surface 46, the detected pressure drops sharply. When the detected pressure drops sharply, the controller 28 determines that the target wafer 100a has been successfully picked up.

[0027] The vibration source 36 applies ultrasonic vibration to the holding surface 46 via the ultrasonic transducer 38. The vibration source 36 includes, for example, the ultrasonic transducer 38 and an AC power supply 40. The ultrasonic transducer 38 is a vibration source that generates longitudinal vibration by receiving a drive signal as a voltage signal. The ultrasonic transducer 38 is, for example, a bolt-fastened Langevin type transducer (commonly referred to as a BLT (Bolt Clamped Langevin Type Transducer) or BL (Bolt clamped Langevin Type) transducer that has a lead zirconate titanate (commonly referred to as PZT) that vibrates by receiving an AC voltage and is clamped by a metal block and fastened with screws (bolts). The AC power supply 40 applies an alternating voltage at a frequency equivalent to a predetermined resonant frequency to the ultrasonic transducer 38.

[0028] By driving the vibration source 36, the holding surface 46 undergoes ultrasonic vibration along the axial direction. Furthermore, by performing ultrasonic vibration on the holding surface 46, an ultrasonic extrusion film Sf is formed between the holding surface 46 and a plane approximately facing the holding surface 46 (e.g., the end face of the target wafer 100a). Through this extrusion film Sf, the target wafer 100a is held on the holding surface 46 in a state where it is separated from the holding surface 46.

[0029] The controller 28 controls the driving of the vibration source 36 and the suction source 42 so that the holding surface 46 can hold the target wafer 100a in a non-contact manner. That is, as described above, when an alternating voltage is applied to the ultrasonic oscillator 38, the holding surface 46 undergoes ultrasonic vibration. When the target wafer 100a is brought close to the holding surface 46, an ultrasonic squeezing effect is generated between the holding surface 46 and the target wafer 100a. The ultrasonic squeezing effect is as follows: when one of two plates facing each other with a small gap is vibrated, a higher pressure than the outside is generated in the gap due to the viscosity within the gap. If this ultrasonic squeezing effect occurs, an air film, i.e., an ultrasonic squeezing film Sf, is formed between the target wafer 100a and the holding surface 46 to prevent contact between the two, thereby generating a holding force that holds the target wafer 100a by the holding surface 46.

[0030] Here, the holding force generated by ultrasonic vibration (hereinafter referred to as "ultrasonic holding force") is generated in two directions: perpendicular to the holding surface 46 and parallel to it (i.e., the surface direction). That is, when an ultrasonic squeezing effect is generated, a force is applied to the object wafer 100a, causing the object wafer 100a to float off the holding surface 46. In addition, when an ultrasonic squeezing effect is generated, the object wafer 100a is intended to be fixed within the vibrating surface. Therefore, even if the object wafer 100a is temporarily displaced in the surface direction by an external force, the object wafer 100a will move along the surface direction with its entire body located within the vibrating surface, and intend to return to a state facing the holding surface 46. In other words, by generating an ultrasonic squeezing effect, automatic alignment can be performed to automatically correct the surface direction position of the object wafer 100a.

[0031] Furthermore, the greater the ultrasonic energy, the greater the thickness of the ultrasonic extrusion film Sf, i.e., the greater the amount of the object wafer 100a floating from the holding surface 46. In addition, the greater the ultrasonic energy, the greater the ultrasonic holding force.

[0032] In this example, in order to assist this ultrasonic holding force, the holding surface 46 also generates a suction force based on negative pressure. The controller 28 controls the drive of the suction source 42 and the vibration source 36 so that the suction force, the ultrasonic holding force, and the gravity acting on the object wafer 100a are balanced when the object wafer 100a is floating from the holding surface 46.

[0033] Thus, by utilizing ultrasonic vibration, the wafer 100 is held in a non-contact manner by the pick-up tool 20, thereby preventing foreign objects from adhering to the target wafer 100a and reducing the mechanical load acting on the target wafer 100a. As a result, higher quality bonding can be achieved.

[0034] However, when the pickup tool 20 is non-contact, there is a problem that it is difficult to peel the target wafer 100a from the dicing tape 110. That is, when peeling the target wafer 100a from the dicing tape 110, it is necessary to attract the target wafer 100a by means of the pickup tool 20. However, when the pickup tool 20 is non-contact, the force of attracting the target wafer 100a is small, so it is impossible to peel the target wafer 100a from the dicing tape 110.

[0035] Therefore, for example, it is possible to peel the target wafer 100a from the dicing tape 110 by using a pin to push it out from the back side of the dicing tape 110. However, in this case, the mechanical load acting on the target wafer 100a increases, which may lead to damage to the target wafer 100a. Alternatively, as another countermeasure, it is possible to use a dicing tape 110 with low adhesion. However, in this case, there is a problem that the types of dicing tapes 110 that can be used are limited.

[0036] Therefore, in this example, in order to properly peel off the target wafer 100a by means of the non-contact pick-up tool 20, as shown in FIG1, the plurality of wafers 100 are held with the gravity direction facing downward. Then, the pick-up tool 20 picks up the target wafer 100a from the underside of the wafer holder 12. With this structure, the target wafer 100a can be effectively peeled off from the dicing tape 110. This will be explained by comparison with a comparative example.

[0037] Figure 5 is a schematic diagram showing the manufacturing apparatus 10* of the comparative example. In the manufacturing apparatus 10* of the comparative example, the wafer holder 12* holds the dicing tape 110 with multiple wafers 100 facing upwards in the direction of gravity by means of the wafer ring 14*. In addition, the pick-up tool 20* picks up the target wafer 100a from the upper side of the wafer holder 12*.

[0038] The lower part of Figure 3 illustrates the case where the target wafer 100a is picked up by the manufacturing apparatus 10* of the comparative example. As shown in the lower part of Figure 3, in this case, the adhesive force Fv of the dicing tape 110, the weight Fg of the target wafer 100a, and the attractive force Fp based on the pick-up tool 20* act on the target wafer 100a. In the case of the manufacturing apparatus 10* of the comparative example, the adhesive force Fv and the weight Fg are downward in the direction of gravity, and the attractive force Fp is upward in the direction of gravity. In order to peel the target wafer 100a from the dicing tape 110, the attractive force Fp needs to exceed the resultant force of the adhesive force Fv and the weight Fg. However, as will be repeated, in the case of the non-contact pick-up tool 20, it is difficult to peel the target wafer 100a from the dicing tape 110 because the attractive force Fp is small.

[0039] The upper part of Figure 3 illustrates the case where the target wafer 100a is picked up by the manufacturing apparatus 10 of this example. As shown in the upper part of Figure 3, in this case, the adhesive force Fv is upward in the direction of gravity, while the weight Fg and the attractive force Fp are downward in the direction of gravity. That is, the attractive force Fp of the picking tool 20 is oriented in the same direction as the weight Fg, and the weight Fg assists in the peeling of the target wafer 100a. As a result, even if the attractive force Fp is small, the target wafer 100a can be properly peeled from the cutting tape 110.

[0040] As explained above, by holding the plurality of wafers 100 with the direction of gravity downward, even a non-contact pick-up tool 20 can properly pick up the target wafer 100a. In particular, in the manufacturing apparatus 10* of the comparative example, it is difficult to pick up large and heavy wafers 100. The manufacturing apparatus 10 of this example can also easily pick up such large and heavy wafers 100.

[0041] Furthermore, as the pick-up tool 20 moves or the target wafer 100a is peeled off, tiny foreign objects 120 may sometimes be generated. In the case of the manufacturing apparatus 10* of the comparative example, as shown in the lower part of FIG3, such foreign objects 120 may fall toward the dicing tape 110 and adhere to the wafer 100. Moreover, since the foreign objects 120 adhere to the wafer 100, it may cause a deterioration in the quality of the semiconductor device.

[0042] On the other hand, in the case of the manufacturing apparatus 10 in this example, as shown in the upper part of FIG3, the tiny foreign matter 120 falls away from the cutting strip 110. In this way, it is possible to effectively prevent the foreign matter 120 from adhering to the wafer 100 and thus prevent the quality of the semiconductor device from deteriorating.

[0043] Furthermore, as shown in FIG1, in the manufacturing apparatus 10 of this example, the pick-up tool 20 picks up the target wafer 100a in the same posture as when transferring the target wafer 100a to the bonding tool 26. This effectively prevents the target wafer 100a from shifting position or falling off. This will be explained with reference to FIG4.

[0044] FIG4 is a schematic diagram showing the pickup and delivery of the target wafer 100a. In the case of the manufacturing apparatus 10* of the comparative example, as shown in the lower part of FIG4, the pickup tool 20* picks up the target wafer 100a from the top (S1). Then, the pickup tool 20* flips up and down to deliver the target wafer 100a to the bonding tool 26 (S2). For example, in order to flip up and down, the pickup tool 20* rotates around the rotation axis 52 shown in FIG5. Then, the pickup tool 20* moves to the delivery position (S4) and delivers the target wafer 100a to the bonding tool 26 (S5).

[0045] That is, in the case of the manufacturing apparatus 10* of the comparative example, the pick-up tool 20* must be reversed. During this reversal, the target wafer 100a is subjected to centrifugal force or inertial force, and sometimes it shifts position from the holding surface 46 or falls off from the holding surface 46. In the case where an ultrasonic extrusion film Sf is formed, even if some position shift occurs, the position shift is automatically corrected by the automatic alignment function. However, since the correction of the position shift takes some time, the pick-up tool 20* needs to be temporarily stopped after reversing (S3). In addition, in order to confirm whether the target wafer 100a has fallen off, the holding surface 46 is sometimes photographed by the camera 34. At this time, the pick-up tool 20* also needs to be stopped after reversing (S3). As a result, in the case of the manufacturing apparatus 10* of the comparative example, the time required for the handover of the target wafer 100a increases, which may lead to an increase in the lead time of semiconductor device manufacturing.

[0046] Furthermore, when the pickup tool 20* is reversed, an inertial force or centrifugal force is applied to the target wafer 100a, and the angular relationship between the target wafer 100a and the direction of gravity also changes. In order to stably hold the target wafer 100a in a non-contact manner in this state, the manufacturing apparatus 10* of the comparative example must change the ultrasonic holding force and suction force according to the rotation angle or rotation speed. As a result, in the case of the manufacturing apparatus 10* of the comparative example, the control of the vibration source 36 and the suction source 42 easily becomes complicated.

[0047] On the other hand, in the case of the manufacturing apparatus 10 in this example, as shown in the upper part of FIG4, the target wafer 100a is picked up in the same posture as when handing over the target wafer 100a (S1). Therefore, it can be moved directly to the handover position without reversing the pick-up tool 20 (S4). In this way, the positional shift or detachment of the target wafer 100a can be effectively prevented. In addition, according to the manufacturing apparatus 10 in this example, since vertical reversal (S2) or temporary pausing (S3) is not required, the time required for these processes can be reduced, thereby further shortening the lead time.

[0048] Furthermore, in the case of the manufacturing apparatus 10 in this example, since the pick-up tool 20 is not reversed vertically, the target wafer 100a can be transferred to the bonding tool 26 after pick-up while maintaining the ultrasonic holding force and suction force at a constant state. As a result, the control of the vibration source 36 and the suction source 42 can be simplified.

[0049] Furthermore, as will be repeated, in the manufacturing apparatus 10 disclosed in this specification, the weight Fg of the target wafer 100a serves as the auxiliary force for pickup. Additionally, the adhesive force Fv that secures the target wafer 100a to the dicing tape 110 is proportional to the contact area between the target wafer 100a and the dicing tape 110. Therefore, the suction force during pickup can also be varied according to the weight Fg of the target wafer 100a and the contact area. In order to control this suction force, the controller 28 can pre-store the weight Fg and contact area of ​​the wafer 100a.

[0050] Furthermore, the structures described so far are all examples. Other structures can be changed as long as they include the structure of claim 1. For example, the movable stage 22 can be omitted as long as it can prevent the chip 100 from accidentally falling off. [Simplified Explanation of the Diagram]

[0015] Figure 1 is a schematic diagram showing the structure of the manufacturing apparatus. Figure 2 is a diagram showing the structure of the pick-up tool. Figure 3 is a diagram showing the pick-up of the target wafer. Figure 4 is a schematic diagram showing the pick-up and handover of the target wafer. Figure 5 is a schematic diagram showing the manufacturing apparatus of a comparative example.

Claims

1. A semiconductor device manufacturing apparatus, characterized in that it comprises: A wafer holder for holding a dicing tape to which multiple wafers are attached, with the first face of the wafers facing downward in the direction of gravity, the wafers having a first face for joining an object and a second face held by the dicing tape; and a pick-up tool for non-contactly picking up an object wafer, one of the multiple wafers, from below the wafer holder.

2. The semiconductor device manufacturing apparatus of claim 1, further comprising a bonding tool, the bonding tool receiving the target wafer from the pick-up tool and bonding it to a substrate, the pick-up tool transferring the target wafer to the bonding tool without lifting or lowering after the pick-up.

3. The semiconductor device manufacturing apparatus of claim 1 further includes a movable stage that suctions a portion of a plurality of said wafers via the dicing tape, wherein the movable stage does not suction the target wafer, but rather suctions wafers surrounding the target wafer.

4. The semiconductor device manufacturing apparatus as claimed in claim 1, wherein, The pickup tool includes: a holding surface for holding the object wafer; a vibration source for applying ultrasonic vibration to the holding surface and applying ultrasonic holding force to the object wafer; and a suction source for suctioning the object wafer to the holding surface.

5. The semiconductor device manufacturing apparatus as claimed in claim 4, wherein, After picking up the wafer, the picking tool transfers the target wafer to the bonding tool while maintaining the ultrasonic holding force and the suction force based on the suction source at a constant state.

6. The semiconductor device manufacturing apparatus of claim 1 further includes a controller that controls the driving of the pick-up tool, the controller pre-stores the weight of the wafer, and controls the suction force of the pick-up tool according to the weight of the wafer.

7. A method for manufacturing a semiconductor device, characterized in that a dicing tape to which a plurality of wafers are attached is held by a wafer holder in a posture in which a first face of the wafers faces downward in the direction of gravity, the wafers having a first face for joining to an object and a second face held by the dicing tape, and an object wafer, which is one of the plurality of wafers, is picked up from below the wafer holder in a non-contact manner by a pick-up tool.

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