JP2016129195A - Bonding method, program, computer storage medium, bonding device and bonding system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly bond a plurality of chips arranged on a substrate with the substrate.SOLUTION: A bonding device includes: a processing chamber for storing a wafer W; a table 150 provided inside the processing chamber, for holding the wafer by suction; a heating mechanism 156 provided in the table 150, for heating the wafer W; a vacuum line 152 provided in the table 150, for sucking the wafer W by vacuuming; an electrode 155 provided in the table 150, for electrostatically sucking the wafer W; and a gas supply mechanism for supplying a pressurized gas to the inside of the processing chamber. In the bonding device, after the wafer W is sucked on the table 150 by vacuuming by the vacuum line 152, voltage is applied to the electrode 155 to make the wafer W be electrostatically sucked on the table 150. Subsequently, the inside of the processing chamber is pressured by the pressurized gas supplied from the gas supply mechanism and the wafer W and a plurality of chips are bonded.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a bonding method for bonding a plurality of chips arranged on a substrate to the substrate, a program, a computer storage medium, a bonding apparatus for executing the bonding method, and a bonding system including the bonding apparatus.

  In recent years, in semiconductor devices, semiconductor chips (hereinafter referred to as “chips”) are highly integrated. When a plurality of highly integrated chips are arranged in a horizontal plane and these chips are connected by wiring to produce a product, the wiring length increases, thereby increasing the wiring resistance and wiring delay. Is concerned.

  Therefore, it has been proposed to manufacture a semiconductor device using a three-dimensional integration technique in which chips are three-dimensionally stacked. In this three-dimensional integration technique, bumps of stacked chips are joined together, and the stacked chips are electrically connected.

  As the three-dimensional integration method, for example, a method of bonding and stacking a plurality of chips on a semiconductor wafer (hereinafter referred to as “wafer”) is used. In this method, a bonding apparatus shown in Patent Document 1 is used to press and bond a wafer and a chip while heating. That is, a plurality of chips are arranged on a wafer, a plate-like body is brought into contact with the plurality of chips, and then the wafer and the chip-like body are pressed while heating the wafer and the chip, thereby Join.

JP 2004-122216 A

  However, when a plurality of chips are arranged on the wafer, the height of the plurality of chips may vary. In such a case, if a plate-like body is used as in Patent Document 1, the wafer and the plurality of chips cannot be pressed uniformly. For example, if the pressure when pressing the wafer and the chip is too small, the bonding strength between the wafer and the chip becomes insufficient. On the other hand, for example, if the pressure when pressing the wafer and the chip is too large, the bumps may be deformed, and further, the semiconductor device may be damaged.

  Therefore, for example, it is conceivable to pressurize the wafer and a plurality of chips by supplying a pressurized gas to the inside of the processing chamber while heating the wafer on the mounting table inside the processing chamber. In such a case, for example, even if the heights of the plurality of chips on the wafer vary, the plurality of chips are pressed by the pressurized gas filled in the processing chamber, so that the wafer and the plurality of chips are uniformly and appropriately arranged. It can be pressed with an appropriate pressure.

  However, the heated wafer may be warped. In such a case, the wafer on the mounting table cannot be heated uniformly within the wafer surface, and cannot be uniformly pressed. If it does so, a wafer and a plurality of chips cannot be joined appropriately.

  This invention is made | formed in view of this point, and it aims at joining the some chip | tip arrange | positioned on a board | substrate appropriately with the said board | substrate.

  In order to achieve the above object, the present invention is a bonding method for bonding a plurality of chips arranged on a substrate to the substrate, and the substrate is carried into the processing chamber to seal the inside of the processing chamber. Then, in the mounting table heated to a predetermined temperature by the heating mechanism, the first step of evacuating and sucking the substrate by the vacuum line provided in the mounting table, and the electrode provided in the mounting table described above A second step of stopping the evacuation of the substrate by the vacuum line after applying a voltage and electrostatically adsorbing the substrate; supplying a pressurized gas from the gas supply mechanism to the inside of the processing chamber; A third step of bonding the substrate and the plurality of chips to a predetermined pressure, and in the third step, the pressure inside the vacuum line and the inside of the processing chamber Pressure is It is characterized in that Shii.

  The inventors supply a pressurized gas to the inside of the processing chamber while heating the substrate on the mounting table, and suppress the warping of the substrate due to heating when pressing and bonding the substrate and the plurality of chips. The idea was to electrostatically attract the substrate with the mounting table. In order to electrostatically adsorb the substrate in this way, it is necessary to bring the substrate as close as possible to the mounting table. Therefore, the inventors have vacuum-adsorbed the substrate with the mounting table (first step of the present invention), It was further conceived that the substrate is electrostatically adsorbed (second step of the present invention). In such a case, since the warpage of the substrate is suppressed, the substrate on the mounting table can be heated uniformly within the substrate surface and can be pressed uniformly.

  When vacuum suctioning the substrate, it is necessary to form a suction port or a suction groove on the mounting surface of the mounting table at a position corresponding to the vacuum line. Here, when a pressurized gas is supplied to the inside of the processing chamber to pressurize the inside of the processing chamber, the pressed substrate is recessed at the position where the suction port and the suction groove are formed. For this reason, a board | substrate and a some chip | tip cannot be joined appropriately.

  Therefore, in the third step of the present invention, when the inside of the processing chamber is pressurized with a pressurized gas, the pressure inside the vacuum line is made equal to the pressure inside the processing chamber. In such a case, the substrate is not recessed even at the position where the suction port and the suction groove are formed. Therefore, the substrate and the plurality of chips can be appropriately bonded.

  The vacuum line is connected to an exhaust line for exhausting the inside of the processing chamber through a valve. After the second step and before the third step, the valve is opened, A vacuum line and the exhaust line may be communicated, and in the third step, the pressure inside the vacuum line may be equal to the pressure inside the processing chamber.

  After the third step, the inside of the vacuum line and the inside of the processing chamber may be exhausted from the exhaust line with the valve opened.

  According to another aspect of the present invention, there is provided a program that operates on a computer of a control unit that controls the joining device so that the joining method is executed by the joining device.

  According to another aspect of the present invention, a readable computer storage medium storing the program is provided.

  According to still another aspect, the present invention provides a bonding apparatus for bonding a plurality of chips arranged on a substrate to the substrate, the processing chamber accommodating the substrate, the inside of the processing chamber, and adsorbing the substrate A holding table to be held, a heating mechanism provided on the mounting table, for heating the substrate, a vacuum line provided on the mounting table for vacuuming and sucking the substrate, and provided on the mounting table, An electrode for electroadsorption, a gas supply mechanism for supplying a pressurized gas into the processing chamber, a substrate is loaded into the processing chamber and the processing chamber is sealed, and then the heating mechanism In the mounting table heated to a predetermined temperature, after the first step of vacuum-adsorbing the substrate by the vacuum line, the substrate is electrostatically adsorbed by applying a voltage to the electrode, and then the vacuum line. A second step of stopping evacuation of the substrate, a pressurized gas is supplied from the gas supply mechanism to the inside of the processing chamber, the inside of the processing chamber is pressurized to a predetermined pressure, and the vacuum line A controller that controls the bonding apparatus to perform a third step of bonding the substrate and the plurality of chips by equalizing the internal pressure and the internal pressure of the processing chamber. It is said.

  The bonding apparatus further includes an exhaust line for exhausting the inside of the processing chamber, the vacuum line and the exhaust line are connected via a valve, and the control unit is after the second step. Prior to the third step, the valve is opened to allow the vacuum line and the exhaust line to communicate with each other. In the third step, the pressure inside the vacuum line is equal to the pressure inside the processing chamber. In this way, the joining device may be controlled.

  The controller may control the bonding apparatus so that the interior of the vacuum line and the interior of the processing chamber are exhausted from the exhaust line with the valve opened after the third step. Good.

  Another aspect of the present invention is a bonding system including the bonding apparatus, including the bonding apparatus and a temperature adjustment apparatus that adjusts the temperature of a substrate on which a plurality of chips are bonded by the bonding apparatus. It has a processing station and a loading / unloading station that can hold a plurality of substrates and loads / unloads the substrates to / from the processing station.

  According to the present invention, a plurality of chips arranged on a substrate can be appropriately bonded to the substrate.

It is a top view which shows the outline of a structure of the joining system concerning this Embodiment. It is a side view which shows the outline of the internal structure of the joining system concerning this Embodiment. It is a perspective view of a wafer and a plurality of chips. It is a side view of a wafer and a plurality of chips. It is a longitudinal cross-sectional view which shows the outline of a structure of a joining apparatus. It is a top view which shows the outline of a structure of a joining apparatus. It is a longitudinal cross-sectional view which shows the outline of the internal structure of a processing chamber. It is explanatory drawing of the longitudinal cross-sectional view which shows the outline of a structure around a mounting base. It is a flowchart which shows the main processes of a joining process. It is explanatory drawing which shows the temperature of a heating mechanism, the temperature of a wafer, the internal pressure of a process chamber, and the internal pressure of a suction groove in each process of a joining process. It is explanatory drawing of joining operation | movement by a joining apparatus. It is explanatory drawing of joining operation | movement by a joining apparatus. It is explanatory drawing of joining operation | movement by a joining apparatus. It is explanatory drawing which shows operation | movement of a vacuum line and an exhaust line. It is explanatory drawing which shows operation | movement of a vacuum line and an exhaust line. It is explanatory drawing which shows operation | movement of a vacuum line and an exhaust line. It is explanatory drawing of joining operation | movement by a joining apparatus. It is explanatory drawing which shows operation | movement of a vacuum line and an exhaust line. It is explanatory drawing which shows operation | movement of a vacuum line and an exhaust line.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The present invention is not limited to the embodiments described below.

<1. Structure of joining system>
First, the configuration of the joining system according to the present embodiment will be described. FIG. 1 is a plan view illustrating the outline of the configuration of the joining system 1. FIG. 2 is a side view illustrating the outline of the internal configuration of the joining system 1. In the following, in order to clarify the positional relationship, the X-axis direction, the Y-axis direction, and the Z-axis direction that are orthogonal to each other are defined, and the positive direction of the Z-axis is the vertically upward direction.

  In the bonding system 1, a wafer W as a substrate and a plurality of chips C are bonded as shown in FIGS. The wafer W is a semiconductor wafer (device wafer) in which devices are formed on, for example, a silicon wafer or a compound semiconductor wafer. A plurality of bumps are formed on the surface of the wafer W. In addition, a plurality of bumps are formed on the surface of the chip C, and the chip C is arranged upside down so that the surface on which the plurality of bumps are formed faces the wafer W side. In other words, the surface of the wafer W on which the plurality of bumps are formed and the surface of the chip C on which the plurality of bumps are formed are arranged to face each other. The bumps on the wafer W and the chips C are formed at corresponding positions, and the bumps are bonded to bond the wafer W and the plurality of chips C together. The bump is made of, for example, copper. In this case, the bonding between the wafer W and the plurality of chips C is a bonding between copper and copper.

  On the surface of the wafer W carried into the bonding system 1, a plurality of chips C are arranged in advance at predetermined positions. And the film F is affixed on the some chip | tip C, and the position of the some chip | tip C with respect to the wafer W is being fixed. The means for fixing the plurality of chips C to the wafer W is not limited to the film F, and any means such as coating can be used.

  As shown in FIG. 1, for example, the bonding system 1 is used for a loading / unloading station 2 where a cassette Cs capable of accommodating a plurality of wafers W is loaded / unloaded, and a wafer W loaded with a plurality of chips C. It has a configuration in which a processing station 3 including various processing devices for performing predetermined processing is integrally connected.

  The loading / unloading station 2 is provided with a cassette mounting table 10. The cassette mounting table 10 is provided with a plurality of, for example, two cassette mounting plates 11. The cassette mounting plates 11 are arranged in a line in the Y-axis direction (vertical direction in FIG. 1). The cassette Cs can be placed on these cassette placement plates 11 when the cassette Cs is carried into and out of the joining system 1. Thus, the carry-in / out station 2 is configured to be able to hold a plurality of wafers W. The number of cassette mounting plates 11 is not limited to the present embodiment, and can be arbitrarily determined.

  In the loading / unloading station 2, a wafer transfer unit 20 is provided adjacent to the cassette mounting table 10. The wafer transfer unit 20 is provided with a wafer transfer device 22 that is movable on a transfer path 21 extending in the Y-axis direction. The wafer transfer device 22 is also movable in the vertical direction and around the vertical axis (θ direction), a cassette Cs on each cassette mounting plate 11, a position adjusting device 32 and a transition device 33 of the processing station 3 described later, The wafer W can be transferred between the two.

  The processing station 3 is provided with a joining device 30, a temperature adjusting device 31, a position adjusting device 32, and a transition device 33. For example, a bonding device 30 is provided on the front side of the processing station 3 (Y-axis direction negative direction side in FIG. 1), and on the back side of the processing station 3 (Y-axis direction positive direction side in FIG. 1), the temperature is An adjusting device 31 is provided. Further, a position adjusting device 32 and a transition device 33 are provided on the loading / unloading station 2 side of the processing station 3 (the positive side in the X-axis direction in FIG. 1). As shown in FIG. 2, the position adjusting device 32 and the transition device 33 are provided in two stages in this order from the top. The number and arrangement of the joining device 30, the temperature adjusting device 31, the position adjusting device 32, and the transition device 33 can be arbitrarily set.

  The bonding apparatus 30 is an apparatus that bonds the wafer W and a plurality of chips C. The configuration of the joining device 30 will be described later.

  The temperature adjustment device 31 is a device that adjusts the temperature of the wafer W heated by the bonding device 30. The temperature adjustment device 31 includes a cooling member such as a Peltier element, and includes a temperature adjustment plate (not shown) capable of adjusting the temperature.

  The position adjusting device 32 is a device that adjusts the orientation of the wafer W in the circumferential direction. The position adjusting device 32 has a chuck (not shown) for rotating and holding the wafer W and a detection unit (not shown) for detecting the position of the notch portion of the wafer W. In the position adjustment device 32, the position of the notch portion of the wafer W is detected by the detection unit while the wafer W held by the chuck is rotated, thereby adjusting the position of the notch portion and the circumferential direction of the wafer W. The direction of is adjusted.

  The transition device 33 is a device for temporarily placing the wafer W thereon.

  As shown in FIG. 1, a wafer transfer area 40 is formed in an area surrounded by the bonding apparatus 30, the temperature adjustment apparatus 31, the position adjustment apparatus 32, and the transition apparatus 33. For example, a wafer transfer device 41 is disposed in the wafer transfer region 40.

  The wafer transfer device 41 has, for example, a transfer arm that is movable in the vertical direction, horizontal direction (X-axis direction, Y-axis direction), and around the vertical axis (θ direction). The wafer transfer device 41 moves in the wafer transfer region 40 and can transfer the wafer W to the surrounding bonding device 30, temperature adjustment device 31, position adjustment device 32, and transition device 33.

  The above joining system 1 is provided with a control unit 50. The control unit 50 is, for example, a computer and has a program storage unit (not shown). The program storage unit stores a program for controlling the bonding process between the wafer W and the plurality of chips C in the bonding system 1. The program storage unit also stores a program for controlling the operation of drive systems such as the above-described various processing apparatuses and transfer apparatuses to realize the below-described joining process in the joining system 1. The program is recorded on a computer-readable storage medium H such as a computer-readable hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical desk (MO), or a memory card. May have been installed in the control unit 50 from the storage medium H.

<2. Structure of joining device>
Next, the structure of the joining apparatus 30 mentioned above is demonstrated. FIG. 5 is a longitudinal sectional view showing an outline of the configuration of the bonding apparatus 30. FIG. 6 is a plan view illustrating the outline of the configuration of the bonding apparatus 30.

  As shown in FIG. 5, the bonding apparatus 30 includes a processing chamber 100 that can seal the inside. The processing chamber 100 has an upper chamber 101 and a lower chamber 102. The upper chamber 101 is provided above the lower chamber 102.

  As shown in FIG. 7, the upper chamber 101 has a hollow structure in which the inside of the lower surface is opened. On the lower surface of the upper chamber 101, a sealing material 103 for maintaining the airtightness inside the processing chamber 100 is provided in an annular shape. The seal material 103 is provided so as to protrude from the lower surface of the upper chamber 101. The lower chamber 102 has a hollow structure in which the inner side of the upper surface and the inner side of the lower surface are opened. The lower surface of the upper chamber 101 and the upper surface of the lower chamber 102 are arranged to face each other. Then, by bringing the sealing material 103 and the upper surface of the lower chamber 102 into contact with each other, the inside of the processing chamber 100 is formed in a sealed space.

  As shown in FIG. 5, the upper chamber 101 is supported by an upper chamber base 110 provided on the upper surface of the upper chamber 101. The upper chamber base 110 has a larger diameter than the upper surface of the upper chamber 101.

  The upper chamber 101 has a tapered shape whose diameter increases concentrically from the upper side to the lower side, and the tapered portion has a convex shape inward in a side view. On the outer peripheral portion of the upper chamber 101, ribs 111 are provided at, for example, four locations between the upper chamber base 110 and the upper chamber base 110. In other words, the upper chamber 101 and the rib 111 are fixed and supported on the upper chamber base 110.

  Here, since the upper chamber 101 is supported by the central portion of the upper chamber base 110, for example, when the inside of the processing chamber 100 is pressurized, if there is no rib 111, stress is applied to the central portion of the upper chamber base 110. concentrate. In this regard, in the present embodiment, the internal pressure of the processing chamber 100 is distributed and transmitted to the central portion and the outer peripheral portion of the upper chamber base 110 via the upper chamber 101 and the rib 111. For this reason, it can suppress that stress concentrates on the specific location of the upper chamber base 110. FIG.

  An upper cooling mechanism 112 that cools the upper chamber base 110 is provided at the center of the upper surface of the upper chamber base 110. More specifically, a recess is formed in the center of the upper surface of the upper chamber base 110 in order to reduce the weight of the upper chamber base 110, and the upper cooling mechanism 112 is provided in the recess. A coolant channel (not shown) through which a cooling medium such as cooling water flows is formed inside the upper cooling mechanism 112. The upper cooling mechanism 112 is not limited to the present embodiment, and various configurations can be adopted as long as the upper chamber base 110 can be cooled. For example, the upper cooling mechanism 112 may incorporate a cooling member such as a Peltier element.

  The lower chamber 102 is supported by a lower chamber base 120 provided on the lower surface of the lower chamber 102. The lower chamber base 120 has a larger diameter than the lower surface of the lower chamber 102.

  A lower cooling mechanism 121 for cooling the lower chamber base 120 is provided at the center of the lower surface of the lower chamber base 120. A coolant channel (not shown) through which a cooling medium such as cooling water flows is formed inside the lower cooling mechanism 121. The lower cooling mechanism 121 is not limited to the present embodiment, and various configurations can be adopted as long as the lower chamber base 120 can be cooled. For example, the lower cooling mechanism 121 may incorporate a cooling member such as a Peltier element.

  The upper chamber base 110 is provided with a moving mechanism 130 that moves the upper chamber base 110, that is, the upper chamber 101 in the vertical direction. The moving mechanism 130 includes a shaft 131, a support plate 132, and a vertical moving unit 133. For example, four shafts 131 are provided on the outer periphery of the upper chamber base 110. Each shaft 131 extends in the vertical direction, passes through the lower chamber base 120, and is supported by a support plate 132 provided below the lower chamber base 120. The support plate 132 is provided with a vertical moving part 133 such as an air cylinder. The vertical moving unit 133 moves the support plate 132 and the shaft 131 in the vertical direction, and the upper chamber base 110 and the upper chamber 101 are configured to be movable in the vertical direction.

  The shaft 131 is provided with a lock mechanism 140 that restricts the movement of the shaft 131. As shown in FIG. 6, the lock mechanisms 140 are provided at, for example, four locations corresponding to the shaft 131. The lock mechanism 140 is provided on the lower chamber base 120.

  As shown in FIGS. 5 and 6, the lock mechanism 140 includes a lock pin 141, a horizontal moving part 142, and a casing 143. The lock pin 141 is inserted into a through hole formed in the shaft 131. At the base end portion of the lock pin 141, a horizontal moving portion 142 such as an air cylinder for moving the lock pin 141 in the horizontal direction is provided. A casing 143 that supports a lock pin 141 inserted in a through hole of the shaft 131 is provided on the outer peripheral surface of the shaft 131.

  As shown in FIG. 7, a mounting table 150 that holds the wafer W by suction is provided inside the processing chamber 100. The mounting table 150 is configured to vacuum-suck the wafer W and electrostatically attract the wafer W.

  As shown in FIG. 8, on the upper surface of the mounting table 150, a suction groove 151 for vacuuming and sucking the wafer W is formed. The layout of the suction grooves 151 is not limited, and any layout may be used as long as the entire surface of the wafer W is attracted to the mounting table 150.

  A vacuum line 152 is connected to the suction groove 151. The vacuum line 152 passes through the mounting table 150 and further passes through a mounting table base 158, a lower chamber base 120, and a lower cooling mechanism 121, which will be described later. The vacuum line 152 is provided with a valve 153. The vacuum line 152 is connected to a vacuum device 154 such as a vacuum pump. Then, the wafer W is attracted to the mounting table 150 by using the negative pressure generated by the suction of the vacuum device 154.

  An electrode 155 for electrostatically adsorbing the wafer W is provided inside the mounting table 150. For example, a direct current high voltage power source (not shown) is connected to the electrode 155. Then, by applying a voltage to the electrode 155, a Johnson Rabeck force is generated on the upper surface of the mounting table 150, and the wafer W is attracted to the mounting table 150. Note that the number of the electrodes 155 is not limited to this embodiment, and is arbitrarily set. Further, the mounting table 150 may be a Johnson Rabeck type monopolar electrostatic chuck or a bipolar electrostatic chuck.

  A heating mechanism 156 for heating the wafer W is provided inside the mounting table 150. For example, a heater is used as the heating mechanism 156. The mounting table 150 is divided into a plurality of regions, and the heating mechanism 156 may be divided into a plurality of regions so as to correspond to the divided regions. In such a case, the temperature of the plurality of regions in which the mounting table 150 is partitioned can be adjusted for each region.

  A heat insulating plate (not shown) may be provided below the mounting table 150. With this heat insulating plate, it is possible to suppress the heat when the wafer W is heated by the heating mechanism 156 from being transmitted to the mounting base 158 and the lower chamber base 120 described later.

  The mounting table 150 is supported by a mounting table base 158 provided below the mounting table 150 via a plurality of rods 157. The mounting table base 158 is mounted on the lower chamber base 120. Then, by providing an air layer between the mounting table 150 and the mounting table base 158 in this way, heat when the wafer W is heated by the heating mechanism 156 is transmitted to the mounting table base 158 and the lower chamber base 120. Can be suppressed.

  The mounting table base 158 is not fixed to the lower chamber base 120. In such a case, for example, even if the inside of the processing chamber 100 is heated during the bonding process, the mounting base 158 can be freely thermally expanded, and thermal stress and deflection that can be generated by fixing can be suppressed. .

  As shown in FIG. 5, below the mounting table 150, for example, three raising / lowering pins 160 for supporting the wafer W from below and raising / lowering it are provided. The elevating pins 160 are supported by a support plate 161 provided below the lower cooling mechanism 121 through the mounting table 150, the mounting table base 158, the lower chamber base 120, and the lower cooling mechanism 121. The support plate 161 is provided with an elevating drive unit 162 incorporating a motor or the like, for example. The lift drive unit 162 moves the support plate 161 and the lift pins 160 up and down, and the lift pins 160 can protrude from the upper surface of the mounting table 150.

  The processing chamber 100 is provided with a gas supply mechanism 170 that supplies pressurized gas into the processing chamber 100. The gas supply mechanism 170 includes a gas supply unit 171, a gas supply line 172, and a gas supply device 173. The gas supply unit 171 is provided above the mounting table 150 and supplies pressurized gas into the processing chamber 100. The gas supply unit 171 communicates with the gas supply device 173 via the gas supply line 172. The gas supply line 172 is provided through the upper chamber 101, the upper chamber base 110, and the upper cooling mechanism 112. The gas supply device 173 stores pressurized gas therein and supplies the pressurized gas to the gas supply unit 171.

  The processing chamber 100 is provided with an exhaust mechanism 180 that exhausts the inside of the processing chamber. The exhaust mechanism 180 includes an exhaust line 181, a valve 182, and an exhaust device 183. The exhaust line 181 is connected to exhaust ports formed at, for example, two locations on the upper surface of the lower chamber base 120, and is provided through the lower chamber base 120 and the lower cooling mechanism 121. A valve 182 is provided in the exhaust line 181. The exhaust line 181 is connected to an exhaust device 183 such as a vacuum pump.

  As shown in FIG. 8, the vacuum line 152 and the exhaust line 181 are connected by a connection line 190. The connection line 190 is connected to the suction groove 151 side from the valve 153 in the vacuum line 152, and is connected to the exhaust port side from the valve 182 in the exhaust line 181. Further, the connection line 190 is provided with a valve 191.

  The operation of each unit in the bonding apparatus 30 is controlled by the control unit 50 described above.

<3. Operation of joining system>
Next, a method for bonding the wafer W and the plurality of chips C performed using the bonding system 1 configured as described above will be described. FIG. 9 is a flowchart showing an example of main steps of the joining process. FIG. 10 is an explanatory diagram showing the temperature of the heating mechanism 156 (mounting table 150), the temperature of the wafer W, the pressure inside the processing chamber 100, and the pressure inside the suction groove 151 in each step of the bonding process.

  In the present embodiment, a plurality of chips C are arranged in advance on the surface of the wafer W carried into the bonding system 1 as shown in FIG. 3 and FIG. The position of the chip C is fixed.

  First, a cassette Cs containing a plurality of wafers W is placed on a predetermined cassette placement plate 11 in the carry-in / out station 2. Thereafter, the wafer W in the cassette Cs is taken out by the wafer transfer device 22 and transferred to the position adjusting device 32 of the processing station 3. In the position adjusting device 32, the position of the notch part of the wafer W is adjusted to adjust the circumferential direction of the wafer W (step S1 in FIG. 9). By adjusting the circumferential direction of the wafer W in step S1 in this manner, for example, when a defect occurs in the bonding process in steps S2 to S10 described later, it becomes easier to identify the cause of the defect following the wafer history, and bonding The processing conditions can be improved.

  In step S1, as shown in FIG. 10, in the bonding apparatus 30, the temperature of the heating mechanism 156 is maintained at a predetermined temperature, for example, 250 ° C. The temperature of the heating mechanism 156 is maintained at a predetermined temperature throughout the bonding process (steps S2 to S8 described later). Through the bonding process, the temperature of the upper cooling mechanism 112 and the temperature of the lower cooling mechanism 121 are also maintained at room temperature, for example, 25 ° C., and the upper chamber base 110 and the lower chamber base 120 are cooled. The temperature of the wafer W is normal temperature, for example, 25 ° C. The processing chamber 100 is closed, but the internal pressure is, for example, 0.1 MPa (atmospheric pressure). The pressure inside the suction groove 151 is also 0.1 MPa, for example.

  Thereafter, in the bonding apparatus 30, the upper chamber 101 is moved upward by the moving mechanism 130 as shown in FIG. 11, and the processing chamber 100 is opened. Then, the wafer W is carried into the processing chamber 100 by the wafer transfer device 41 and transferred to the lift pins 160 that have been lifted and waited in advance.

  Subsequently, as shown in FIG. 12, the upper chamber 101 is moved downward by the moving mechanism 130, and the processing chamber 100 is closed. At this time, the sealing material 103 and the upper surface of the lower chamber 102 are brought into contact with each other to seal the inside of the processing chamber 100 (step S2 in FIG. 9).

  Thereafter, as shown in FIG. 12, the temperature of the wafer W is adjusted while lowering the lift pins 160 by the lift drive unit 162, so that the temperature of the wafer W is adjusted (step S3 in FIG. 9). In step S3, since the atmosphere inside the processing chamber 100 is heated by the heating mechanism 156, the wafer W is also heated. The wafer W is adjusted to about 250 ° C. immediately before being placed on the mounting table 150. The temperature adjustment of the wafer W may be controlled by adjusting the lowering speed of the lifting pins 160, or may be adjusted by lowering the lifting pins 160 in a stepwise manner.

  Here, in step S3, if the wafer W is mounted on the heated mounting table 150 without leveling the wafer W, the temperature of the wafer W rapidly increases and the wafer W is warped. In this regard, by performing the temperature adjustment of the wafer W, the warpage of the wafer W can be suppressed. From the viewpoint of suppressing the warpage of the wafer W, the wafer W only needs to be heated to around 250 ° C. and does not need to be strictly adjusted to 250 ° C.

  Thereafter, as shown in FIG. 13, the wafer W is sucked and held by the mounting table 150. Then, the wafer W is heated to 250 ° C.

  When the wafer W is sucked and held by the mounting table 150, vacuum suction and electrostatic suction are performed in this order. As described above, as a countermeasure against the warp of the wafer W due to heating, the temperature of the wafer W is adjusted in step S3. In order to more reliably suppress the warp of the wafer W, the wafer W is electrostatically adsorbed by the mounting table 150. . Since electrostatic adsorption of the wafer W is performed by generating a Johnson Rabeck force on the upper surface of the mounting table 150, it is necessary to bring the wafer W as close as possible to the mounting table 150. For this reason, the wafer W is vacuum-sucked prior to the electrostatic suction of the wafer W.

  Specifically, as shown in FIG. 14, the valve 153 of the vacuum line 152 is opened and the vacuum device 154 is operated to vacuum-suck the wafer W onto the mounting table 150 (step S4 in FIG. 9). At this time, the pressure inside the suction groove 151 becomes 0.02 MPa, for example. In step S4, the valve 182 of the exhaust line 181 and the valve 191 of the connection line 190 are closed.

  Thereafter, a voltage is applied to the electrode 155 to generate a Johnson Rabeck force, and the wafer W is electrostatically attracted to the mounting table 150 (step S5 in FIG. 9). When the wafer W is electrostatically attracted, the valve 153 of the vacuum line 152 is closed as shown in FIG. 15, and the vacuum suction of the wafer W is stopped. At this time, the pressure inside the suction groove 151 returns to 0.1 MPa, for example.

After that, as shown in FIG. 16, the valve 191 of the connection line 190 is opened, and the vacuum line 152 and the exhaust line 181 are communicated (step S6 in FIG. 9). Then
The pressures inside the suction groove 151 (inside the vacuum line 152) and inside the processing chamber 100 (inside the exhaust line 181) become equal.

  In parallel with the communication between the vacuum line 152 and the exhaust line 181 in step S <b> 6, the lock pin 141 is inserted into the through hole of the shaft 131 by the horizontal moving portion 142 of the lock mechanism 140. Then, the shaft 131 is fixed in the vertical direction.

  The shaft 131 is fixed by the lock mechanism 140 immediately before the pressurized gas is supplied from the gas supply unit 171 to the inside of the processing chamber 100 in step S7 described later. The upper chamber 101 is thermally expanded by heat from the heating mechanism 156. Therefore, the position of the upper chamber 101 can be appropriately fixed by fixing the shaft 131 while the thermal expansion of the upper chamber 101 is stable.

  Thereafter, as shown in FIG. 17, a pressurized gas is supplied from the gas supply unit 171 to the inside of the processing chamber 100, and the inside of the processing chamber 100 is pressurized to a predetermined pressure, for example, 0.9 MPa (step S7 in FIG. 9). ). This pressurization may be performed at a constant pressurization speed, for example, or may be performed stepwise by repeatedly maintaining the pressure for a predetermined time and increasing the pressure. Further, this pressurization control may be performed, for example, by adjusting the opening of a valve (not shown) provided in the gas supply line 172, or an electropneumatic regulator provided in the gas supply line 172. You may carry out by controlling (not shown).

  In step S7, since the valve 191 of the connection line 190 is opened as shown in FIG. 18, the pressurized gas inside the processing chamber 100 is sucked into the suction groove via the exhaust line 181, the connection line 190, and the vacuum line 152. It flows to 151. Then, the pressure inside the suction groove 151 and the inside of the processing chamber 100 become equal, that is, the pressure inside the suction groove 151 becomes, for example, 0.9 MPa.

  Here, in step S7, for example, when the wafer W is evacuated from the suction groove 151 without causing the vacuum line 152 and the exhaust line 181 to communicate with each other, the pressure applied to the wafer W on the suction groove 151 in the wafer plane and the suction The pressure applied to the wafer W on the portion other than the groove 151 is different. If it does so, there exists a possibility that the wafer W and several chip | tip C cannot be joined uniformly within a wafer surface.

  Further, for example, when the vacuum line 152 and the exhaust line 181 are not communicated with each other, even if the evacuation of the wafer W from the suction groove 151 is stopped and the pressure inside the suction groove 151 is set to 0.1 MPa, for example, A pressure difference occurs in the pressure applied to the lower surface. Then, the wafer W may be bent downward in the suction groove 151 and the wafer W and the plurality of chips C may not be appropriately bonded.

  In this regard, in the present embodiment, the pressure inside the suction groove 151 and the inside of the processing chamber 100 are made equal, so that the pressure applied to the wafer W is uniform in the wafer surface, and the wafer in the suction groove 151 W does not bend downward.

  In step S <b> 7, pressure is applied to the upper chamber 101 in the vertically upward direction, and a force in the vertically upward direction is also applied to the upper chamber base 110. In this respect, since the lock pin 141 is inserted into the through hole as described above, the lower surface of the lock pin 141 contacts the lower surface of the through hole, and the shaft 131 does not move vertically upward. Therefore, the upper chamber base 110 and the upper chamber 101 do not move vertically upward, the inside of the processing chamber 100 can be appropriately sealed, and the internal pressure can be maintained at a predetermined pressure.

  Then, the inside of the processing chamber 100 is maintained at 0.9 MPa, for example, for 30 minutes. Then, even if the height of the plurality of chips C on the wafer W varies, the plurality of chips C are pressed by the pressurized gas filled in the processing chamber 100, so that the wafer W and the plurality of chips C are Can be pressed uniformly at an appropriate pressure. For this reason, the wafer W and the plurality of chips C can be appropriately pressed while being heated to a predetermined temperature, and the wafer W and the plurality of chips C are appropriately bonded (step S8 in FIG. 9).

  Thereafter, the supply of the pressurized gas from the gas supply mechanism 170 is stopped, and the inside of the suction groove 151 and the inside of the processing chamber 100 are exhausted by the exhaust mechanism 180 (step S9 in FIG. 9). Specifically, as shown in FIG. 19, with the valve 191 of the connection line 190 opened, the valve 182 of the exhaust line 181 is opened and the exhaust device 183 is operated. Then, the inside of the suction groove 151 and the inside of the processing chamber 100 are exhausted, and the pressure is reduced to, for example, 0.1 MPa. Note that this decompression may be performed at a constant decompression speed, for example, or may be performed stepwise by repeatedly maintaining the pressure for a predetermined time and decreasing the pressure. The pressure reduction control may be performed, for example, by adjusting the opening of a valve (not shown) provided in the gas supply line 172, or an electropneumatic regulator (provided in the gas supply line 172). You may carry out by controlling (not shown).

  In step S9, the wafer W is raised by the lift pins 160. At this time, the wafer W is cooled.

  When the inside of the processing chamber 100 is depressurized to 0.1 MPa, the fixing of the shaft 131 by the lock mechanism 140 is released, and the upper chamber 101 is moved upward by the moving mechanism 130 to open the processing chamber 100. . Thereafter, the wafer W is carried out of the processing chamber 100 by the wafer transfer device 41. When the wafer W is unloaded from the processing chamber 100, the processing chamber 100 is closed again.

  Thereafter, the wafer W is transferred to the temperature adjustment device 31 by the wafer transfer device 41. In the temperature adjusting device 31, the temperature of the wafer W is adjusted to room temperature, for example, 25 ° C. (step S10 in FIG. 9).

  Thereafter, the wafer W is transferred to the transition device 33 by the wafer transfer device 41 and further transferred to the cassette Cs of the predetermined cassette mounting plate 11 by the wafer transfer device 22 of the loading / unloading station 2. In this way, the joining process of the series of wafers W and the plurality of chips C is completed.

  According to the above embodiment, after the wafer W is vacuum-sucked by the mounting table 150 in step S4, the wafer W is electrostatically suctioned by the mounting table 150 in step S5, so that warpage of the wafer W due to heating is suppressed. Can do. If it does so, the wafer W of the mounting base 150 can be heated uniformly within a wafer surface in process S7, and it can press uniformly. Therefore, the wafer W and the plurality of chips C can be appropriately bonded.

  Further, since the vacuum line 152 and the exhaust line 181 are connected in step S6, even if pressurized gas is supplied to the inside of the processing chamber 100 in step S7, the pressure inside the processing chamber 100 and the inside of the suction groove 151 are increased. Can be equalized. Then, the pressure applied to the wafer W becomes uniform in the wafer surface, and the wafer W does not bend downward in the suction groove 151. Therefore, the wafer W and the plurality of chips C can be bonded more appropriately.

  In the bonding system 1, the loading / unloading station 2 can hold a plurality of wafers W, and the wafers W can be continuously transferred from the loading / unloading station 2 to the processing station 3. Moreover, since the bonding system 1 includes the bonding device 30 and the temperature adjustment device 31, the steps S1 to S10 described above can be sequentially performed to bond the wafer W and the plurality of chips C continuously. In addition, while a predetermined process is performed in one bonding apparatus 30, another process can be performed in another temperature adjustment apparatus 31. That is, a plurality of wafers W can be processed in parallel within the bonding system 1. Therefore, the wafer W and the plurality of chips C can be bonded efficiently, and the throughput of the bonding process can be improved.

<4. Other Embodiments>
In the above embodiment, when the inside of the processing chamber 100 is pressurized in step S7, the pressure inside the suction groove 151 and the inside of the processing chamber 100 are made equal by connecting the vacuum line 152 and the exhaust line 181. However, the method of equalizing the pressure in this way is not limited to this.

  For example, the pressurized gas may be positively supplied also into the suction groove 151. However, in this case, a separate gas supply mechanism is required, and it is also necessary to monitor the pressure inside the suction groove 151 and the pressure inside the processing chamber 100, so that the apparatus configuration becomes large.

  In this regard, in the above embodiment, the pressure inside the suction groove 151 and the inside of the processing chamber 100 can be made equal in step S7 only by providing the connection line 190 and the valve 191 between the vacuum line 152 and the exhaust line 181. Therefore, the apparatus configuration can be simplified and useful.

  In the above embodiment, when exhausting the inside of the suction groove 151 and the inside of the processing chamber 100 in step S9, it is not necessary to provide a separate exhaust mechanism, and the common exhaust device 183 can be used. Therefore, this point is also useful.

  In the above embodiment, the suction grooves 151 are formed in an arbitrary layout on the upper surface of the mounting table 150. However, a plurality of suction ports (not shown) may be formed uniformly in the surface, that is, The upper surface of the mounting table 150 may be porous. In such a case, in step S7, the wafer W and the plurality of chips C can be pressed more uniformly within the wafer surface.

  In the above embodiment, in the joining apparatus 30, the moving mechanism 130 moves the upper chamber 101. However, the upper chamber 101 and the lower chamber 102 may be moved relatively. For example, the moving mechanism 130 may move the lower chamber 102, or may move both the upper chamber 101 and the lower chamber 102.

  Further, the processing chamber 100 is divided into the upper chamber 101 and the lower chamber 102 in the vertical direction, but may be divided in the horizontal direction.

  In the bonding process of the above embodiment, the predetermined temperature (250 ° C.) for heating the wafer W, the pressurizing pressure inside the processing chamber 100 (0.9 MPa), the pressurizing time inside the processing chamber 100 ( (30 minutes) is an example, and can be arbitrarily set according to various conditions.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the idea described in the claims, and these naturally belong to the technical scope of the present invention. It is understood.

DESCRIPTION OF SYMBOLS 1 Bonding system 2 Loading / unloading station 3 Processing station 30 Bonding apparatus 31 Temperature adjustment apparatus 32 Position adjustment apparatus 33 Transition apparatus 41 Wafer transfer apparatus 50 Control part 100 Processing chamber 150 Mounting stand 151 Suction groove 152 Vacuum line 155 Electrode 156 Heating mechanism 170 Gas Supply mechanism 180 Exhaust mechanism 181 Exhaust line 190 Connection line 191 Valve C Chip F Film W Wafer

Claims (9)

A bonding method for bonding a plurality of chips arranged on a substrate to the substrate,
After carrying the substrate into the processing chamber and sealing the inside of the processing chamber, the substrate is evacuated by a vacuum line provided on the mounting table in the mounting table heated to a predetermined temperature by the heating mechanism. A first step of adsorbing;
A second step of stopping evacuation of the substrate by the vacuum line after applying a voltage to the electrode provided on the mounting table and electrostatically adsorbing the substrate;
A third step of supplying a pressurized gas from the gas supply mechanism to the inside of the processing chamber, pressurizing the inside of the processing chamber to a predetermined pressure, and bonding the substrate and the plurality of chips;
In the third step, the pressure inside the vacuum line is equal to the pressure inside the processing chamber. The vacuum line is connected to an exhaust line for exhausting the inside of the processing chamber via a valve,
After the second step and before the third step, the valve is opened to connect the vacuum line and the exhaust line,
2. The bonding method according to claim 1, wherein, in the third step, the pressure inside the vacuum line is made equal to the pressure inside the processing chamber. 3. 3. The bonding method according to claim 2, wherein after the third step, the inside of the vacuum line and the inside of the processing chamber are exhausted from the exhaust line while the valve is opened. The program which operate | moves on the computer of the control part which controls the said joining apparatus so that the joining method as described in any one of Claims 1-3 is performed with a joining apparatus. A readable computer storage medium storing the program according to claim 4. A bonding apparatus for bonding a plurality of chips arranged on a substrate to the substrate,
A processing chamber containing a substrate;
A mounting table provided inside the processing chamber for adsorbing and holding a substrate;
A heating mechanism provided on the mounting table for heating the substrate;
A vacuum line which is provided on the mounting table and sucks and sucks the substrate;
An electrode provided on the mounting table for electrostatically adsorbing the substrate;
A gas supply mechanism for supplying a pressurized gas into the processing chamber;
A first step of bringing the substrate into the processing chamber and sealing the inside of the processing chamber, and then vacuum-adsorbing the substrate with the vacuum line in the mounting table heated to a predetermined temperature by the heating mechanism. A second step of stopping evacuation of the substrate by the vacuum line after applying a voltage to the electrode to electrostatically adsorb the substrate, and a pressurized gas from the gas supply mechanism to the inside of the processing chamber A third step of joining the substrate and the plurality of chips by supplying, pressurizing the inside of the processing chamber to a predetermined pressure, and equalizing the pressure inside the vacuum line and the pressure inside the processing chamber And a control unit that controls the joining device so as to perform the following. An exhaust line for exhausting the interior of the processing chamber;
The vacuum line and the exhaust line are connected via a valve,
The control unit opens the valve after the second step and before the third step, and causes the vacuum line and the exhaust line to communicate with each other. The bonding apparatus according to claim 6, wherein the bonding apparatus is controlled so that a pressure inside a line is equal to a pressure inside the processing chamber. The controller controls the joining apparatus so that the interior of the vacuum line and the interior of the processing chamber are exhausted from the exhaust line with the valve opened after the third step. The bonding apparatus according to claim 7, wherein the bonding apparatus is characterized. A joining system comprising the joining device according to any one of claims 6 to 8,
A processing station comprising: the bonding apparatus; and a temperature adjustment apparatus that adjusts the temperature of a substrate on which a plurality of chips are bonded by the bonding apparatus;
A bonding system comprising: a plurality of substrates, and a loading / unloading station for loading / unloading the substrates to / from the processing station.

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