JP5445160B2 - Wafer processing apparatus, wafer processing method, and device manufacturing method - Google Patents

Description

  The present invention relates to a wafer processing apparatus and a device manufacturing method.

  One technique for improving the effective mounting density of devices is a three-dimensional structure in which a plurality of semiconductor chips are stacked. In particular, a semiconductor chip manufactured by a procedure of laminating a plurality of wafers in the state of a wafer as a semiconductor substrate and joining them into individual pieces has recently attracted attention because of its high productivity. When two wafers are overlapped, alignment is performed while measuring each other's surface with a microscope (see, for example, Patent Document 1).

JP 2005-251972 A

  When two wafers are overlaid after being processed, there is a demand for a structure in which the wafers are efficiently processed and overlaid for the purpose of improving product yield.

  In order to solve the above problems, a wafer processing apparatus according to a first aspect of the present invention includes a first stage that holds a first wafer, a surface that faces the first stage, and faces the first stage. A second stage that holds the second wafer and moves relative to the first stage in at least one direction, and a second wafer that is fixed relative to the first stage and held on the second stage. A first processing apparatus that performs processing on the first wafer and a control unit that controls processing performed on the second wafer by the first processing apparatus when the first stage and the second stage move relative to each other.

  Moreover, in order to solve the said subject, the manufacturing method of the device which concerns on the 2nd aspect of this invention is a manufacturing method of the device manufactured by superimposing a several wafer, Comprising: The process of superimposing a several wafer Moves relative to the first stage in at least one direction within a plane disposed opposite to the first stage and facing the first stage, and a first placement step of placing the first wafer on the first stage. The second stage of placing the second wafer on the second stage and the first processing apparatus fixed relative to the first stage, and the second stage when the first stage and the second stage move relative to each other. And a processing step for processing the wafer.

  It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

It is a top view which shows roughly the whole structure of a wafer processing apparatus. It is a perspective view which shows the structure of a conveying apparatus roughly. It is a perspective view which shows the structure of a conveying apparatus roughly. It is sectional drawing which shows roughly the structure of an upper stage and a 2nd movement stage. It is a perspective view which shows roughly the structure of an upper activation apparatus and a lower activation apparatus. It is sectional drawing which shows roughly operation | movement of an upper stage and a 2nd movement stage. It is sectional drawing which shows roughly operation | movement of an upper stage and a 2nd movement stage. It is a flowchart which shows the control procedure of a wafer processing apparatus. It is sectional drawing which shows roughly the structure of the upper stage and 2nd movement stage provided with the heating apparatus.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 is a plan view schematically showing an overall structure of a wafer processing apparatus 100 according to the present embodiment. In the present embodiment, the wafer processing apparatus 100 is a superposition apparatus that precisely aligns two wafers with their bonding surfaces facing each other in a vacuum environment, and activates and bonds the respective wafer bonding surfaces. The wafer processing apparatus 100 includes an atmospheric environment unit 102 and a vacuum environment unit 202 inside a common housing 101.

  The atmospheric environment unit 102 includes an EFEM (Equipment Front End Module) 105 and a holder rack 110 facing the outside of the housing 101. The EFEM 105 includes three load ports 106, 107, 108 and a robot arm 109. A FOUP (Front Opening Unified Pod) is attached to each load port. The FOUP is a sealed substrate storage pod and can accommodate a plurality of wafers 120.

  A plurality of wafers 120 are accommodated in the FOUP attached to the load ports 106 and 107, and are carried into the atmospheric environment unit 102 by the robot arm 109. With this configuration, the wafer 120 can be transferred from the FOUP to the atmosphere environment unit 102 without being exposed to the outside air, and dust can be prevented from adhering to the wafer 120. The two wafers 120 bonded by the vacuum environment unit 202 are stored in a FOUP attached to the load port 108.

  Here, the wafer 120 is a single silicon wafer, a compound semiconductor wafer or the like in which a plurality of circuit patterns are already formed periodically. Further, the loaded wafer 120 may be a laminated substrate that is already formed by laminating a plurality of wafers.

  The holder rack 110 includes a shelf on which a plurality of holder cases 111 that accommodate the wafer holders 130 are placed. The holder case 111 can be pulled out from the shelf, and the user pulls out the holder case 111 from the shelf, thereby putting the wafer holder 130 in and out of the holder case 111. The holder case 111 is provided with an opening / closing door on the atmosphere environment section 102 side, and the opening / closing door is opened / closed when a holder slider 152 (to be described later) moves the wafer holder 130 in and out.

  The atmospheric environment unit 102 includes a pre-aligner 140, a wafer mounting unit 150, a robot arm 160, load lock chambers 170 and 180, and a control unit 190, which are disposed inside the housing 101. A known air filter is provided inside the housing 101, and a high cleanliness is maintained.

  The pre-aligner 140 includes a turntable 141 and an imaging unit 142. On the turntable 141, the wafer 120 unloaded from the FOUP by the robot arm 109 of the EFEM 105 is placed. The imaging unit 142 is fixed to a place that is not easily affected by vibration, such as the ceiling frame of the pre-aligner 140, and acquires the captured image by imaging the wafer 120 placed on the turntable 141. Then, the pre-aligner 140 adjusts the position of the wafer 120 in the rotational direction by controlling the turntable 141 based on the captured image.

  The wafer mounting unit 150 includes an arm 151 having support pins and a holder slider 152 that slides the arm 151 in the Y direction. The wafer mounting unit 150 moves the arm 151 and the holder slider 152 up and down in the Z direction to align the position with the height of each holder case 111 of the holder rack 110. Then, the arm 151 is slid in the Y direction by the holder slider 152 to support the wafer holder 130, and the arm 151 and the holder slider 152 are returned to their home positions and waited.

  The wafer 120 after alignment by the pre-aligner 140 is placed on the wafer holder 130 waiting at a fixed position by the robot arm 109. A power supply pin is provided at the tip of the support pin that supports the wafer holder 130, and is connected to a power supply terminal provided on the back surface of the wafer holder 130 so that power is supplied to the wafer holder 130. The wafer holder 130 supplied with electric power generates a potential difference on the wafer holding surface by an electrostatic chuck provided therein, and electrostatically attracts the wafer 120. The wafer 120 and the wafer holder 130 integrated in this way are collectively called a workpiece.

  The robot arm 160 includes a gripping unit 161 that grips the wafer holder 130 or the workpiece and a reversing unit 162 that reverses the gripped wafer holder 130 or the workpiece. The gripper 161 includes a vacuum and negative pressure suction unit so that the wafer holder 130 or the workpiece can be sucked. The wafer holder 130 or the workpiece is attached or detached by controlling the suction by the suction unit. Note that gripping by the gripping unit 161 is not limited to suction, and may be configured to perform suction by electrostatic suction, for example.

  The reversing unit 162 rotates the gripping unit 161 that grips the wafer holder 130 or the workpiece with a rotary motor, thereby inverting the wafer holder 130 or the workpiece. The robot arm 160 conveys the gripped wafer holder 130 or workpiece between the wafer mounting unit 150 and the load lock chambers 170 and 180.

  The load lock chamber 170 has shutters 171 and 172 that open and close alternately on the atmosphere environment unit 102 side and the vacuum environment unit 202 side. When the work is carried into the vacuum environment unit 202 from the atmospheric environment unit 102, first, the shutter 171 on the atmospheric environment unit 102 side is opened, and the robot arm 160 loads the work carried out from the wafer mounting unit 150 into the load lock chamber 170. Carry in. Next, the shutter 171 on the atmosphere environment unit 102 side is closed, and the air in the load lock chamber 170 is exhausted to make a vacuum state.

  After the load lock chamber 170 is in a vacuum state, the shutter 172 on the vacuum environment unit 202 side is opened, and the work is carried into the vacuum environment unit 202 by the transfer device 210 described later. With such a loading operation into the vacuum environment unit 202, the workpiece can be loaded into the vacuum environment unit 202 without leaking the internal atmosphere of the air environment unit 102 to the vacuum environment unit 202 side.

  The load lock chamber 180 includes shutters 181, 182, 183 and a separation mechanism 184. The shutter 181 is provided on the robot arm 160 side, the shutter 182 is provided on the vacuum environment unit 202 side, and the shutter 183 is provided on the EFEM 105 side. The separation mechanism 184 is installed inside the load lock chamber 180 and separates the two wafers 120 bonded in the vacuum environment unit 202 from the two wafer holders 130. In the vacuum environment unit 202, the two wafers 120 and the two wafer holders 130 after the two workpieces are bonded to each other are collectively referred to as a workpiece pair. The separation mechanism 184 has support pins for supporting the wafer holder 130, the workpiece or the workpiece pair on the upper portion thereof.

  When the work is carried into the vacuum environment unit 202 from the atmospheric environment unit 102, the shutter 181 on the robot arm 160 side is first opened, and the robot arm 160 carries the work carried out from the wafer mounting unit 150 into the load lock chamber 180. Then, it is placed on the support pin above the separation mechanism 184. The load lock chamber 180 is in a vacuum state by closing the shutter 181 and discharging the air inside. After the load lock chamber 180 is in a vacuum state, the shutter 182 on the vacuum environment unit 202 side is opened, and a transfer device 210 (to be described later) carries the workpiece into the vacuum environment unit 202.

  When the work pair is unloaded from the vacuum environment unit 202 to the atmospheric environment unit 102, first, the shutter 182 is opened while the load lock chamber 180 is in a vacuum state. Then, the transfer device 210 carries the workpiece pair into the separation mechanism 184, and the separation mechanism 184 separates the bonded wafer 120 from the wafer holder 130.

  Thereafter, the wafer holder 130 constituting the upper workpiece is unloaded by the robot arm 160 and loaded into the wafer mounting unit 150. The wafer mounting unit 150 returns the wafer holder 130 to the holder rack 110. Next, the robot arm 109 unloads the bonded wafer 120 from the separation mechanism 184 and stores it in the FOUP attached to the load port 108.

  The wafer holder 130 constituting the lower workpiece is unloaded from the separation mechanism 184 by the robot arm 160 and loaded into the wafer mounting unit 150. The wafer holder 130 carried into the wafer mounting unit 150 waits to hold the next wafer 120 or returns to the holder rack 110.

  The control unit 190 governs overall control and calculation of the wafer processing apparatus 100. Each element of each apparatus included in the wafer processing apparatus 100 operates when the control unit 190 or a control calculation unit provided for each element performs integrated control and cooperative control.

  The vacuum environment unit 202 includes a vacuum chamber 203, a transfer device 210, a first moving stage 230, an upper stage 220, and a second moving stage 240. The vacuum chamber 203 includes an exhaust port and a vacuum pump, and the vacuum pump exhausts the gas in the vacuum chamber 203 from the exhaust port, thereby bringing the vacuum chamber 203 into a vacuum state. The transfer device 210, the first moving stage 230, the upper stage 220, and the second moving stage 240 are installed in the vacuum chamber 203.

  The transfer device 210 is fixed to the ceiling portion of the vacuum chamber 203, and unloads the workpieces from the load lock chambers 170 and 180 and loads them into the vacuum environment unit 202. Further, the transfer device 210 carries the workpiece pair from the vacuum environment unit 202 to the atmospheric environment unit 102. A specific configuration of the transport device 210 will be described later.

  The upper stage 220 is installed on the ceiling of the vacuum chamber 203 and holds a workpiece with the wafer holding surface facing downward. A workpiece held on the upper stage 220 is called an upper workpiece, and a wafer 120 constituting the upper workpiece is called an upper wafer 121. The first moving stage 230 can move in the XY plane. Here, the illustrated position is the initial position. The first moving stage 230 moves immediately below the transfer device 210 by moving in the X direction from the initial position. Then, by raising the push-up pin directly below the transfer device 210, the upper work held by the transfer device 210 is received. The push-up pin is set at a position that supports the outer side of the upper workpiece than the wafer holding surface.

  The first moving stage 230 that supports the upper work moves up to just below the upper stage 220 and raises the push-up pin, thereby pressing the upper work against the upper stage 220. A power supply terminal is installed at the tip of the push-up pin. By supplying power to the upper work while the upper work is pressed against the upper stage 220, the upper work and the upper stage 220 are fixed by electrostatic adsorption. To do. Thus, the upper stage 220 holds the upper wafer 121 via the wafer holder 130 that constitutes the upper workpiece.

  The second moving stage 240 can move in the XY plane. Here, the illustrated position is the initial position. The second moving stage 240 moves immediately below the transfer device 210 by moving in the −Y direction from the initial position. And the workpiece | work hold | maintained at the conveying apparatus 210 is received by raising a push up pin directly under the conveying apparatus 210. FIG. Thus, the 2nd movement stage 240 hold | maintains the wafer 120 via the wafer holder 130 which comprises a workpiece | work. The workpiece supported by the second moving stage 240 is called a lower workpiece, and the wafer 120 constituting the lower workpiece is called a lower wafer 122.

  The upper stage 220 includes an upper activation device 224 that activates the surface of the lower wafer 122 held by the second moving stage 240. The second moving stage 240 includes a lower activation device 245 that activates the surface of the upper wafer 121 held by the upper stage 220. Then, the upper activation device 224 and the lower activation device 245 activate the surfaces of the lower wafer 122 and the upper wafer 121, respectively, while moving the second moving stage 240 directly below the upper stage 220. Details will be described later.

  The second moving stage 240 moves to a position immediately below the upper stage 220 and then raises the lower work so that the surfaces of the activated upper wafer 121 and lower wafer 122 are brought into contact with each other and bonded. The bonded upper wafer 121 and lower wafer 122 are collectively referred to as a bonded wafer 123. The workpiece pair thus formed is transported to the position immediately below the transport device 210 by the second moving stage 240. The transfer device 210 holds the workpiece pair and carries it into the load lock chamber 180.

  The separation mechanism 184 of the load lock chamber 180 separates the bonded wafer 123 from the two wafer holders 130 constituting the work pair. The separated bonded wafer 123 is stored in the FOUP by the robot arm 109, and the wafer holder 130 is returned to the holder rack 110 by the robot arm 160 and the holder slider 152.

  FIG. 2 is a perspective view schematically showing the structure of the transport device 210. The transport device 210 includes a holding unit 211, a slider 212, a rotation driving unit 213, and an imaging unit 214. The holding unit 211 includes a suction unit 215, and sucks and fixes a workpiece or a workpiece pair placed on the holding unit 211. The slider 212 is connected to the holding portion 211 and can be moved in the longitudinal direction by a linear motor.

  The rotation drive unit 213 is constituted by a rotation motor, and can rotate the entire slider 212 around the center axis 216. The slider 212 can move the holding unit 211 to a position where at least the central axis of the workpiece or workpiece pair held by the holding unit 211 and the rotation central axis 216 of the rotation driving unit 213 coincide. The rotation driving unit 213 rotates the holding unit 211 and the slider 212 while moving to this position, whereby the workpiece or the workpiece pair can be rotated about the central axis of the workpiece or the workpiece pair.

  The imaging unit 214 can capture an image of a work held on the holding unit 211 or a part of a work pair. The wafer holder 130 constituting the workpiece or the workpiece pair has a notch in a part of the outer periphery thereof, and the imaging unit 214 is disposed at a position where the notch of the wafer holder 130 can be imaged. The transfer device 210 includes a position adjustment mechanism that adjusts the position of the wafer 120 with respect to the wafer holder 130 by imaging the notch of the wafer holder 130 constituting the held workpiece with the imaging unit 214.

  FIG. 3 is a perspective view schematically showing the transfer device 210 in a state where the upper work is held. The wafer holding surface of the upper workpiece is held downward by the transfer device 210. The notch 131 of the wafer holder 130 is located in the imaging field of the imaging unit 214, and the imaging unit 214 images the notch 131.

  The transfer device 210 grasps the position of the wafer 120 on the basis of the position of the wafer holder 130 by analyzing the position and angle of the notch 131 from the captured image of the imaging unit 214. If there is a positional shift, the rotational drive unit 213 adjusts the position.

  FIG. 4 is a cross-sectional view schematically showing the structures of the upper stage 220 and the second moving stage 240. The upper stage 220 includes an upper base 221, an upper mounting table 222, and an upper microscope 223. The upper mounting table 222 holds the upper work that is pressed and electrostatically attracted by the first moving stage 230. The upper microscope 223 is an observation device that observes the surface of the wafer 120 held by the second moving stage 240.

  Further, the upper activation device 224 and the upper capture unit 226 are fixed relatively to the upper stage 220. In the present embodiment, the upper activation device 224 and the upper capture unit 226 are fixed on the upper base 221, but may be configured to be fixed to the ceiling of the vacuum chamber 203, for example. The upper activation device 224 is an example of a processing device that processes the lower wafer 122 held by the second moving stage 240, and is a device that activates the surface of the lower wafer 122.

  The second moving stage 240 includes a lower base 241, push-up pins 242, a lower mounting table 243, and a lower microscope 244. The lower base 241 includes a drive unit that drives the second moving stage 240 in the XY directions. The push-up pin 242 is a pin that can be moved up and down in the Z direction, and lifts and holds the workpiece held by the transfer device 210. The work is placed on the lower mounting table 243 by the push-up pin 242 being lowered while holding the work. The lower microscope 244 is an observation device that observes the surface of the wafer 120 that constitutes the upper work placed on the upper stage 220.

  Further, the lower activation device 245 and the lower capture unit 246 are fixed relatively to the second moving stage. In the present embodiment, the lower activation device 245 and the lower capture unit 246 are fixed on the lower base 241. However, the lower activation device 245 and the lower capture unit 246 may be configured to be fixed to other members that are linked with the movement of the second moving stage. .

  The lower activation device 245 performs the same type of processing as the processing performed by the upper activation device 224 on the upper wafer 121 held on the upper stage 220. Specifically, the surface of the upper wafer 121 is activated by irradiating the surface of the upper wafer 121 with an inert gas and scraping off a part of the surface of the upper wafer 121.

  In general, a natural oxide film exists on the surface of the wafer 120. Conventionally, the bonding surfaces of the two wafers 120 are brought into contact with each other, heated to a high temperature, and bonded by being pressurized at a high pressure. In the present embodiment, the upper activation device 224 and the lower activation device 245 irradiate the upper wafer 121 and the lower wafer 122 with an inert gas while the second moving stage 240 moves immediately below the upper stage 220. With this inert gas, the natural oxide film which is a part of the surface of the upper wafer 121 and the lower wafer 122 is scraped off, and the electrode metal is exposed.

  Then, the upper wafer 121 and the lower wafer 122 are brought into contact with the electrode metal exposed. By comprising in this way, a joining surface can be joined by low temperature and a constant pressure with respect to the past. The electrode metal refers to a metal that is a contact portion on the bonding surface of wafers to be laminated unless specifically described. For example, it corresponds to a bump formed on the surface of the wafer. Therefore, “joining the joining surfaces” means that these surface metals are joined together.

  Here, when a part of the surface of the upper wafer 121 or the lower wafer 122 that has been shaved off adheres to the surface of the upper wafer 121 or the lower wafer 122, a problem such as non-uniform bonding occurs. There is. Therefore, the upper capture unit 226 and the lower capture unit 246 capture a part of the surfaces of the upper wafer 121 and the lower wafer 122 scraped off by the upper activation device 224 and the lower activation device 245. Specifically, the upper capturing unit 226 includes the upper adhesive layer 227, and the lower capturing unit 246 includes the lower adhesive layer 247, and adheres and captures parts of the surface of the upper wafer 121 and the lower wafer 122 that have been scraped off.

  FIG. 5 is a perspective view schematically showing the structure of the upper activation device 224 and the lower activation device 245. The upper activation device 224 and the lower activation device 245 include line-shaped irradiation ports 225 and 248. The upper activation device 224 supplies an inert gas to the lower wafer 122, and the lower activation device 245 supplies an inert gas to the upper wafer 121. Irradiate in line. The lengths of the irradiation ports 225 and 248 in the line direction are longer than the diameter of the wafer 120.

  Since the upper activation device 224 and the lower activation device 245 irradiate the inert gas while the second moving stage 240 moves immediately below the upper stage 220, the surfaces of the upper wafer 121 and the lower wafer 122 are sequentially from the end. When the second moving stage 240 reaches just below the upper stage, the entire surface is activated.

  In the present embodiment, with such a configuration, the upper wafer 121 and the lower wafer 122 can be brought into contact and bonded immediately after the entire surfaces of the upper wafer 121 and the lower wafer 122 are activated. Thereby, contamination of the surfaces of the upper wafer 121 and the lower wafer 122 over time can be suppressed.

  Here, as a method for activating the surface of the wafer 120, a configuration in which the entire bonding surface is irradiated with an inert gas at one time is also conceivable. However, in this case, the surface of the wafer 120 is not uniformly activated because the intensity and irradiation amount of the inert gas irradiated differ depending on the position on the surface of the wafer 120 due to the difference in distance from the irradiation port. In the present embodiment, since the distance between the irradiation port 225 and the surface of the wafer 120 that receives irradiation is always constant, the intensity and irradiation amount of the irradiated inert gas can be constant.

  FIG. 6 is a cross-sectional view schematically showing the operations of the upper stage 220 and the second moving stage 240. The second moving stage 240 moves directly below the upper stage 220 under the control of the control unit 190. In synchronization with the movement of the second moving stage 240, the control unit 190 observes the surface of the lower wafer 122 with the upper microscope 223 and observes the surface of the upper wafer 121 with the lower microscope 244.

  The upper wafer 121 and the lower wafer 122 have alignment marks serving as alignment references on their surfaces. However, the alignment mark is not necessarily a dedicated figure or the like, and may be a wiring, bump, scribe line, or the like formed on the upper wafer 121 and the lower wafer 122.

  The controller 190 activates the upper activation device 224 for the lower wafer 122 held by the second moving stage 240 while moving the second moving stage 240 directly below the upper stage 220, and The lower activation device 245 controls the activation performed on the upper wafer 121 held on the upper stage 220 at the same time.

  The upper activating device 224 and the lower activating device 245 irradiate the upper wafer 121 and the lower wafer 122 with an inert gas at a certain angle rather than perpendicularly. When irradiated vertically, there is a high possibility that part of the surfaces of the upper wafer 121 and the lower wafer 122 scraped off by the inert gas will float and enter the irradiation region of the inert gas. If it enters into the irradiation area | region of an inert gas, the force which goes to the upper wafer 121 or the lower wafer 122 will be added, and it will adhere to the surface.

  On the other hand, when the inert gas is irradiated at a certain angle as in the present embodiment, a part of the surface of the upper wafer 121 and the lower wafer 122 that have been scraped off travels in the reflection direction. Can be prevented from entering the irradiation region.

  Further, in the present embodiment, at the initial position of the second moving stage 240, the irradiation port 225 of the upper activation device 224 has an inclination angle facing the direction of the lower wafer 122, and the irradiation port 248 of the lower activation device 245 is upper. It has an inclination angle facing the direction of the wafer 121. With this configuration, since the upper wafer 121 and the lower wafer 122 do not exist in the direction of reflection with respect to the surface of the upper wafer 121 or the lower wafer 122 of the inert gas, a part of the scraped surface is removed. It can prevent adhesion.

  As the upper activating device 224 and the lower activating device 245 irradiate the inert gas at a certain angle, the upper capturing unit 226 and the lower capturing unit 246 also move with respect to the surfaces of the upper wafer 121 and the lower wafer 122. It is not parallel but has a certain angle. This angle is adjusted to be perpendicular to the direction in which the irradiated inert gas is reflected by the upper wafer 121 or the lower wafer 122.

  It is desirable that the upper adhesive layer 227 is disposed in the vicinity of the lower wafer 122 and the lower adhesive layer 247 is disposed in the vicinity of the upper wafer 121. This is because the parts of the surfaces of the upper wafer 121 and the lower wafer 122 that have been scraped off can be captured before being diffused by disposing them in the vicinity. If a part of the scraped surface is diffused, it may adhere to the surface of the upper wafer 121 or the lower wafer 122 as it is. Further, there is a case where a force directed to the upper wafer 121 or the lower wafer 122 is applied by entering the irradiation region of the upper activation device 224 or the lower activation device 245 and adheres to the surface of the upper wafer 121 or the lower wafer 122.

  Therefore, the upper adhesive layer 227 is installed in the vicinity of the lower wafer 122, and the lower adhesive layer 247 is installed in the vicinity of the upper wafer 121. Note that a cooling plate may be provided instead of the adhesive layer. In this case, a part of the scraped surface can be captured by using a thermophoresis phenomenon.

  FIG. 7 is a cross-sectional view schematically showing the operations of the upper stage 220 and the second moving stage 240. When the second moving stage 240 moves to just below the upper stage 220, the upper wafer 121 and the lower wafer 122 face each other based on the alignment marks of the upper wafer 121 and the lower wafer 122 observed by the upper microscope 223 and the lower microscope 244. Align precisely. After the alignment, the second moving stage 240 raises the lower mounting table 243 and brings it into contact with the lower wafer 122 and the upper wafer 121 held by the upper stage 220 for bonding.

  In this embodiment, the inert gas is irradiated in a line shape, and the surface of the upper wafer 121 and the lower wafer 122 is activated sequentially from the end by moving the second moving stage 240, and thereby the entire surface is activated. The inert gas is uniformly irradiated. However, if the upper activating device 224 and the lower activating device 245 exist in close proximity and are irradiated with an inert gas, the concentration of the inert gas may locally increase and become non-uniform. Conceivable.

  Therefore, the control unit 190 controls to reduce the inert gas irradiation concentration of at least one of the upper activation device 224 and the lower activation device 245 as the mutual distance between the upper activation device 224 and the lower activation device 245 is shorter. May be. By controlling in this way, the amount of the inert gas that contacts the entire surface of the upper wafer 121 or the lower wafer 122 is made uniform, and the activation is performed uniformly.

  In addition, the control unit 190 may control to increase the moving speed of the second moving stage 240 as the distance between the upper activating device 224 and the lower activating device 245 is shorter. By controlling in this way, the amount of the inert gas that contacts the entire surface of the upper wafer 121 or the lower wafer 122 is made uniform, and the activation is performed uniformly. The closer the distance between the upper activating device 224 and the lower activating device 245 is, the faster the moving speed of the second moving stage 240 may be controlled, and the inert gas irradiation concentration may be reduced.

  In addition, when the entire bonding surface is irradiated with an inert gas at a time, a large amount of inert gas exists in the vacuum chamber 203, so that the degree of vacuum is lowered. On the other hand, in this embodiment, by irradiating the inert gas in a line shape, the amount of the inert gas irradiated at a time is reduced, and the degree of vacuum of the vacuum chamber 203 is easily maintained.

  FIG. 8 is a flowchart showing a control procedure of the wafer processing apparatus 100. Each control is mainly performed by the control unit 190, and is executed by cooperative control and integrated control with a control unit included in each apparatus included in the wafer processing apparatus 100. In step S <b> 801, the robot arm 109 of the EFEM 105 unloads the wafer 120 from the FOUP attached to the load port 106 and loads it into the pre-aligner 140. The pre-aligner 140 images the loaded wafer 120 with the imaging unit 142 and aligns the rotational direction with the turntable 141.

  In step S <b> 802, the robot arm 109 unloads the aligned wafer 120 from the pre-aligner 140 and places it on the wafer holder 130 mounted on the wafer mounting unit 150. The wafer slider 130 is unloaded from the holder rack 110 in parallel with the unloading and alignment of the wafer 120. The wafer holder 130 is supplied with electric power from the wafer mounting unit 150 and electrostatically attracts the wafer 120.

  In step S803, the robot arm 160 unloads the upper work from the wafer mounting unit 150, and loads the upper work into the load lock chamber 170 with the wafer holding surface facing down. The load lock chamber 170 closes the shutter 171 and discharges air to make the load lock chamber 170 in a vacuum state.

  In step S <b> 804, the transfer device 210 unloads the upper work from the load lock chamber 170 where the shutter 172 is opened, and loads the upper work into the vacuum environment unit 202. The transfer device 210 adjusts the position of the wafer 120 with reference to the wafer holder 130 constituting the upper work.

  In step S805, the first moving stage 230 holds the upper workpiece with the push-up pin. The first moving stage 230 moves to just below the upper stage 220 while holding the upper workpiece. Then, the first moving stage 230 raises the upper work and presses it against the upper stage 220. The upper work is supplied with electric power by a push-up pin and is held on the upper stage 220 by electrostatic attraction.

  In step S <b> 806, the transfer device 210 unloads the lower work from the load lock chamber 180 and loads it into the vacuum environment unit 202. The position of the lower work is accurately adjusted by the transfer device 210. The lower workpiece is formed in parallel with at least a part of the steps so far and is carried into the load lock chamber 180. Specifically, first, the wafer 120 is loaded into the pre-aligner 140 by the robot arm 109. After alignment by the pre-aligner 140, the wafer 120 is placed on the wafer holder 130 supported by the arm 151 of the wafer mounting unit 150 by the robot arm 109.

  In response to the supply of electric power from the arm 151, the wafer holder 130 electrostatically attracts the wafer 120. The lower work thus formed is carried into the load lock chamber 170 by the robot arm 160. In this embodiment, by providing the two load lock chambers of the load lock chamber 170 and the load lock chamber 180, at least a part of the steps of forming the upper work and forming the lower work can be performed in parallel. Can be achieved.

  In step S807, the second moving stage 240 holds the lower workpiece. This step can be executed in parallel with the transfer of the upper work as long as the first moving stage 230 has unloaded the upper work from the transfer device 210. Then, the second moving stage 240 returns to the initial position.

  In step S808, as the second moving stage 240 moves directly below the upper stage 220, detection of alignment marks by the upper microscope 223 and the lower microscope 244 and activation of the upper wafer 121 and the lower wafer 122 are started. . In step S809, the distance d between the upper activating device 224 and the lower activating device 245 is measured and compared with a predetermined threshold D. If it is smaller than the predetermined threshold D, the process proceeds to step S810, and if it is larger than the predetermined threshold D. The process proceeds to step S811.

  In step S810, the control unit 190 moves the second moving stage 240 at the moving speed V1. In step S811, the control unit 190 moves the second moving stage 240 at a moving speed V2 that is faster than the moving speed V1. In step S812, it is determined whether activation and position detection are completed. If not completed, the process returns to step S809 to continue activation and position detection. If completed, the process proceeds to step S813. By controlling in this way, the moving speed of the second moving stage 240 becomes faster when the distance between the upper activating device 224 and the lower activating device 245 is longer than when the distance is shorter.

  In step S813, the control unit 190 drives the second moving stage 240 based on the position information detected by the upper microscope 223 and the lower microscope 244, thereby accurately aligning the upper wafer 121 and the lower wafer 122. In step S <b> 814, the second moving stage 240 raises the lower wafer 122, thereby bringing the bonding surfaces of the upper wafer 121 and the lower wafer 122 into contact and bonding.

  In step S815, the work pair is unloaded from the vacuum environment unit 202. The unloaded workpiece pair is carried into the load lock chamber 180, and the bonded wafer 123 is separated from the wafer holder 130 by the separation mechanism 184. The bonded wafer 123 is stored in a FOUP attached to the load port 108 by the robot arm 109.

  In the above embodiment, the controller 190 activates the upper activation device 224 for the lower wafer 122 held by the second moving stage 240, and the lower activation device 245 is held by the upper stage 220. Although an example in which the activation performed on the upper wafer 121 is controlled to operate simultaneously has been described, the operation control performed by the control unit 190 is not limited to this. When the second moving stage 240 moves, either the upper activating device 224 or the lower activating device 245 may be controlled to operate.

  In that case, the processing flow after the upper stage 220 holds the upper wafer 121 and the second moving stage 240 holds the lower workpiece is as follows, for example. First, the second moving stage 240 moves directly below the upper stage 220. Then, as the second moving stage 240 moves toward the initial position, the upper activation device 224 activates the lower wafer 122. Then, after the second moving stage 240 moves to the initial position, it moves again directly below the upper stage 220, and the lower activation device 245 activates the upper wafer 121 along with this movement. The alignment mark detection by the upper microscope 223 and the lower microscope 244 is executed with any movement.

  In this way, by controlling the activation by the upper activation device 224 and the lower activation device 245 one by one, the total amount of the inert gas irradiated at one time is halved compared to the simultaneous activation. Therefore, it is possible to reduce the decrease in the degree of vacuum in the vacuum chamber 203. Furthermore, the activation can be performed without considering the influence of the inert gas irradiated by the other activation device.

  Further, either the upper activation device 224 or the lower activation device 245 may be provided, and the activation device may be controlled to operate when the second movement stage 240 is moved. For example, when the lower activation device 245 is not provided and the upper activation device 224 is provided, the control is performed as follows. In addition, the part which performs control different from the said embodiment is demonstrated especially here, and description is abbreviate | omitted about a common part. First, the robot arm 160 carries the upper work carried out from the wafer mounting unit 150 into the load lock chamber 170 without being inverted. Then, the transfer device 210 carries the upper work into the vacuum environment unit 202, and the second moving stage 240 holds it.

  While the second moving stage 240 returns to the initial position and moves immediately below the upper stage 220, the upper activation device 224 activates the upper wafer 121 constituting the upper workpiece held by the second moving stage 240. . Thereafter, the second moving stage 240 moves directly below the transfer device 210, and the transfer device 210 holds the upper workpiece again. Then, the first moving stage 230 receives the upper work from the transfer device 210. Here, the transfer device 210 or the first moving stage 230 includes a reversing mechanism, and the first moving stage 230 holds the upper workpiece in a reversed state. The first moving stage 230 moves directly below the upper stage 220, and the upper work is held by the upper stage 220.

  Subsequently, the lower work carried into the vacuum environment unit 202 by the transfer device 210 is held by the second moving stage 240. As the second stage returns to the initial position and moves directly below the upper stage 220, the upper microscope 223 and the lower microscope 244 detect the alignment marks of the upper wafer 121 and the lower wafer 122, and the lower wafer 122 Perform activation.

  Thereafter, the control unit 190 drives the second moving stage 240 based on the position information of the alignment marks detected by the upper microscope 223 and the lower microscope 244 so that the upper wafer 121 and the lower wafer 122 are accurately aligned, The upper wafer 121 and the lower wafer 122 are bonded. Thus, the structure of the 2nd movement stage 240 can be simplified with respect to the said embodiment by comprising not including the lower activation apparatus 245 but including the upper activation apparatus 224. FIG.

  In the above embodiment, an example in which the upper stage 220 is fixed to the ceiling portion of the vacuum chamber 203 has been described. However, the present invention is not limited to this. The upper stage 220 may include a drive unit and be configured to move in the XY plane direction. With such a configuration, the upper stage 220 and the second moving stage 240 can be relatively moved, and the upper wafer 121 and the lower wafer 122 are activated when the upper stage 220 and the second moving stage are relatively moved. Can be controlled.

  Further, the upper stage 220 is configured to be movable in the XY plane direction, the second moving stage 240 is fixed, and the upper stage 121 and the upper wafer 121 and the second moving stage 240 are moved immediately above the second moving stage 240. The lower wafer 122 may be activated.

  Moreover, in the said embodiment, although the activation apparatus which irradiates and activates the inert gas to the wafer 120 as an example of a processing apparatus was mentioned and demonstrated, it is not restricted to this, As a heating apparatus which heats the surface of the wafer 120 Also good.

  FIG. 9 is a cross-sectional view schematically showing the structure and operation of the upper stage and the second moving stage provided with the heating device. The elements other than the heating device are the same as those in the above-described embodiment except that there is no capture unit, and thus the same reference numerals are used. The heating device 901 is fixed on the upper base 221 and heats the surface of the wafer 120 held on the second moving stage 240. The heating device 902 heats the surface of the wafer 120 that is fixed on the lower base 241 and held on the upper stage 220.

  Since the surface of the wafer 120 is directly heated, the amount of heat may be small, and the two wafers 120 are heated at the same time, so that bonding can be performed immediately after the heating. In addition, since it heats in order from this side, the temperature of the part heated previously becomes lower than the part heated later, and joining may not be performed uniformly. Therefore, the temperature after heating is kept uniform by gradually lowering the heating temperature. By comprising in this way, surface temperature becomes uniform at the time of joining, and highly accurate joining can be implement | achieved.

  Moreover, a cleaning apparatus can also be mentioned as an example of a processing apparatus. In the case of a cleaning device, a cleaning device including a cleaning nozzle and a collecting unit that collects the cleaning liquid is installed instead of the heating device 901 and the heating device 902 so that the cleaning liquid is sprayed onto the wafer 120. With this configuration, the observation of the wafer 120 by the microscope and the cleaning of the surface of the wafer 120 can be realized in parallel.

  In the above-described embodiment, the upper stage 220 and the second moving stage 240 have been described with an example provided with a processing apparatus that performs the same type of processing, but the present invention is not limited thereto. For example, the upper stage 220 may include an activation device that activates the lower wafer 122, and the second moving stage may include a heating device that heats the upper wafer 121.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  The order of execution of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior to”. It should be noted that the output can be realized in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for convenience, it means that it is essential to carry out in this order. It is not a thing.

100 wafer processing apparatus, 101 housing, 102 atmospheric environment section, 105 EFEM, 106, 107, 108 load port, 109 robot arm, 110 holder rack, 111 holder case, 120 wafer, 121 upper wafer, 122 lower wafer, 123 bonding Wafer, 130 Wafer holder, 131 Notch, 140 Pre-aligner, 141 Turntable, 142 Imaging unit, 150 Wafer mounting unit, 151 Arm, 152 Holder slider, 160 Robot arm, 161 Gripping unit, 162 Reversing unit, 170 Load lock chamber, 171, 172 Shutter, 180 Load lock chamber, 181, 182, 183 Shutter, 184 Separation mechanism, 190 Control unit, 202 Vacuum environment unit, 203 Vacuum chamber, 210 Transport device, 211 Holding unit, 12 Slider, 213 Rotation drive unit, 214 Imaging unit, 215 Suction unit, 216 Center axis, 220 Upper stage, 221 Upper base, 222 Upper mounting table, 223 Upper microscope, 224 Upper activation device, 225, 248 Irradiation port, 226 Upper capture unit, 227 Upper adhesive layer, 230 First moving stage, 240 Second moving stage, 241 Lower base, 242 Push-up pin, 243 Lower mounting table, 244 Lower microscope, 245 Lower activation device, 246 Lower capturing unit, 247 Lower adhesive layer, 901, 902 Heating device

Claims (20)

A wafer processing apparatus for processing a first semiconductor wafer having a first bonding surface and a second semiconductor wafer having a second bonding surface, which are overlapped and bonded to each other,
A first stage for holding the first semiconductor wafer;
A second stage for holding the second semiconductor wafer such that the second bonding surface faces the first bonding surface;
Irradiating at least one of the first joint surface and the second joint surface, which move relative to each other, with an inert gas when moving relative to at least one of the first stage and the second stage. A wafer processing apparatus comprising: an activating device that sequentially activates at least one of the first bonding surface and the second bonding surface in order from the end . The first stage and the second stage are orthogonal to the direction in which the first bonding surface and the second bonding surface face each other in order to align and overlap the first semiconductor wafer and the second semiconductor wafer. Relative movement is possible including the direction to
The wafer processing apparatus according to claim 1, wherein the activation device activates the first bonding surface and the second bonding surface when the first semiconductor wafer and the second semiconductor wafer are aligned with each other. .   Observation of observing a plurality of alignment marks respectively provided on the first semiconductor wafer and the second semiconductor wafer to perform the alignment when the first stage and the second stage are relatively moved. The wafer processing apparatus of Claim 2 provided with an apparatus.   The first stage and the second stage are set such that at least one of a distance between the first bonding surface and the activation device and a distance between the second bonding surface and the activation device is constant. The wafer processing apparatus according to claim 1, wherein the wafer processing apparatus is relatively moved. The activation device comprises:
A first activation device that activates the entire first bonding surface in order from the end by irradiating an inert gas with relative movement with respect to the first stage;
5. The apparatus according to claim 1, further comprising: a second activation device that activates the entire second bonding surface in order from the end by irradiating an inert gas with relative movement with the second stage. 2. The wafer processing apparatus according to item 1. The second stage is movable relative to the first stage;
The wafer processing apparatus according to claim 5, wherein the second activation device is fixed relative to the second stage and moves integrally when the second stage moves.   The wafer processing apparatus according to claim 6, wherein the moving speed of the second stage is increased as the mutual distance between the first activation device and the second activation device is shorter.   The inert gas irradiation concentration of at least one of the first activation device and the second activation device is decreased as the mutual distance between the first activation device and the second activation device is shorter. The wafer processing apparatus described in 1.   9. The wafer processing apparatus according to claim 5, wherein the first activation device and the second activation device are operated simultaneously when the second stage moves. The first activation device and the second activation device are arranged to face the first semiconductor wafer and the second semiconductor wafer at a position shifted from a position where the first stage and the second stage face each other. Has been placed,
The first joint surface and the second joint surface are each entirely activated by the relative movement of the first activation device and the second activation device from the shifted positions. 10. The wafer processing apparatus according to any one of 9 above.   11. The irradiation port according to claim 5, wherein the irradiation port of the first activation device and the irradiation port of the second activation device are inclined with respect to a direction orthogonal to the direction of relative movement. Wafer processing equipment.   The irradiation port of the first activation device and the irradiation port of the second activation device are respectively inclined in a moving direction when the first bonding surface and the second bonding surface are activated. 11. The wafer processing apparatus according to 11.   13. The wafer processing apparatus according to claim 5, further comprising a first capture unit that captures a part of the second semiconductor wafer shaved by irradiation with an inert gas of the first activation device.   The wafer processing apparatus of any one of Claim 5 to 13 provided with the 2nd capture part which captures a part of said 1st semiconductor wafer shaved by irradiation of the inert gas of the said 2nd activation apparatus.   The wafer processing apparatus according to claim 5, wherein the first stage, the second stage, the first activation device, and the second activation device are installed in a vacuum chamber. A first semiconductor wafer holder for holding the first semiconductor wafer and a transfer device for transferring the second semiconductor wafer holder for holding the second semiconductor wafer, which are installed in the vacuum chamber;
The transport device includes a position adjusting mechanism that adjusts a position of the first semiconductor wafer with reference to the first semiconductor wafer holder and adjusts a position of the second semiconductor wafer with reference to the second semiconductor wafer holder. The wafer processing apparatus described in 1. A wafer processing method for processing a first semiconductor wafer having a first bonding surface and a second semiconductor wafer having a second bonding surface, which are overlapped and bonded to each other,
A first holding step of holding the first semiconductor wafer on a first stage;
A second holding step of holding the second semiconductor wafer on the second stage so that the second bonding surface faces the first bonding surface;
Irradiating at least one of the first joint surface and the second joint surface, which move relative to each other, with an inert gas when moving relative to at least one of the first stage and the second stage. An activation step of sequentially activating at least one of the first bonding surface and the second bonding surface in order from the end ,
A wafer processing method comprising: a bonding step of overlapping and bonding the first semiconductor wafer and the second semiconductor wafer activated by the activation step. The first stage and the second stage are moved relative to each other in a direction including a direction orthogonal to a direction in which the first joint surface and the second joint surface face each other, whereby the first semiconductor wafer and the second semiconductor wafer And an alignment step of aligning each other with each other,
The wafer processing method according to claim 17 , wherein the activation step is performed in the alignment step. The wafer processing method according to claim 18 , wherein in the alignment step, a plurality of alignment marks respectively provided on the first semiconductor wafer and the second semiconductor wafer are observed. The activation step includes
A first activation step of activating the entire first bonding surface in order from the end by irradiating an inert gas along with the relative movement with the first stage;
A second activation step of activating the entire second bonding surface in order from the end by irradiating an inert gas along with the relative movement with the second stage;
The wafer processing method according to claim 17, comprising:

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