JP6145317B2 - Metal filling equipment - Google Patents

Description

  The present invention relates to a metal filling apparatus for filling molten metal in a minute space formed on the surface of an object to be processed.

  2. Description of the Related Art In recent years, in a through silicon via (Through Silicon via) technique, a technique for filling a via or a through hole (hereinafter referred to as “microspace”) formed on a semiconductor wafer (object to be processed) with a metal is required. According to this silicon through electrode technology, it is possible to develop a chip stacking technology using the through electrode, and it is expected to realize a high-functional and high-speed semiconductor system by three-dimensional mounting.

  As described above, for example, an apparatus disclosed in Japanese Patent Application Laid-Open No. 2010-283034 has been proposed as an apparatus for filling a metal in a minute space on an object to be processed. Hereinafter, this conventional metal filling apparatus will be described with reference to FIG. FIG. 12 is a schematic view showing a configuration of a conventional metal filling apparatus 100.

  As shown in FIG. 12, the metal filling apparatus 100 includes first and second supports 101 and 102, a molten metal supply unit 103, a pressure control unit 104, a pressurizing unit 105, and the like. A processing chamber 106 is formed by the body 101 and the second support 102. The molten metal supply unit 103 is configured to supply molten metal into the processing chamber 106 through a metal supply path 102 a provided in the second support 102. The pressure control unit 104 is configured to supply the second support Through the pressure transmission path 102 b provided in 102, the pressure in the processing chamber 106 is reduced, the gas is supplied into the processing chamber 106, and the gas is pressurized. Further, the pressurizing means 105 is configured to apply a press pressure to the second support 102, move the second support 102 toward the first support 101, and apply pressure to the processing chamber 106. .

According to this metal filling apparatus 100, first, the object 107 in which a minute space is formed is placed on the surface of the first support 101, and the second support 102 is covered with the object 107 so as to cover the object 107. The processing chamber 106 is formed around the object 107 in combination with the object 101. Next, after the pressure inside the processing chamber 106 is reduced to a pressure of about 10 ⁻³ Pa by the pressure control unit 104, the molten metal is supplied into the processing chamber 106 by the molten metal supply unit 103 on the surface of the object 107 to be processed. Supply to occur. As a result, the molten metal is filled in the minute space with a differential pressure. Thereafter, the filled molten metal is cured. At this time, pressure is applied to the molten metal until the molten metal is cured by the pressure control unit 104 and the pressurizing means. Finally, by removing the residual metal thin film on the object 107, the object in which the metal is filled in the minute space is obtained.

JP 2010-283034 A

As described above, according to the conventional metal filling apparatus 100, although the metal can be filled in the minute space formed in the object 107, the metal filling apparatus 100 has a high vacuum of about 10 ⁻³ Pa. In order to secure the degree, the apparatus becomes complicated, the maintenance and management of the apparatus is not easy, and it takes a long time for decompression, so there is a problem in cost and processing efficiency.

  In addition, when trying to avoid the above problem by reducing the pressure from a medium vacuum to a low vacuum of about 10 to 100 Pa (abs.), For example, it is difficult to fill the minute space of the entire surface to be processed with metal. Problems arise.

That is, a vacuum state of about 10 ⁻³ Pa is classified into a high vacuum range in JIS, and a special pump such as a turbo molecular pump or a cryopump is required. Further, in a high vacuum region, a gas at a molecular level is required. Since exhaust gas is required and management of gas molecules adhering to the pressure transmission path 102b and the inner wall of the processing chamber 106 is required, it is necessary to pay attention to the surface treatment and constituent materials of the inner wall. And expensive.

Further, by injecting gas or molten metal into the pressure transmission path 102b or the processing chamber 106, or by opening the processing chamber 106 to remove or insert the object 107, a large amount of gas molecules are transferred to the pressure transmission path. Since it adheres to the inner wall of 102b and the processing chamber 106, it is necessary to discharge almost all of them in order to reach a vacuum degree of about 10 ⁻³ Pa. As a result, most of the processing time is spent on the decompression time, resulting in a reduction in processing efficiency.

  On the other hand, in order to avoid this problem, the degree of vacuum in the processing chamber 106 is lowered, and filling is performed at a degree of vacuum of about 0.1 to 200 (abs.), Which is classified from medium vacuum to low vacuum in JIS. The reduced pressure space can be obtained in a short time with a simple apparatus configuration, but it is difficult to efficiently fill the minute space of the entire surface to be processed with the residual gas component in the processing chamber 106. Occurs.

  That is, in the metal filling apparatus 100, after the inside of the processing chamber 106 is depressurized, molten metal is supplied into the processing chamber 106, but the inside of the processing chamber 106 is about 10 to 200 Pa (abs.). When the degree of vacuum is medium to low, gas components remain in the processing chamber 106.

  Here, when the pressure in the processing chamber 106 is reduced to 100 Pa (abs.), The gas component in the processing chamber 106 is approximately 1/1000 at the atmospheric pressure, the object 107 has a disk shape, and the processing chamber 106. If the height of the gas does not change, the residual gas component has a volume with a diameter of about 1/33 of the original diameter.

  If the diameter of the object 106 is 300 mm and the pressure in the processing chamber 106 is reduced to 100 Pa (abs.), The molten metal is supplied to fill the processing chamber 106 with the molten metal, and then the processing chamber 106 When the inside of 106 is at atmospheric pressure, a volume space composed of residual gas components corresponding to a diameter of about 9 mm × height is generated in the processing chamber.

  Therefore, when the molten metal is supplied into the processing chamber 106 and the supplied molten metal spreads into the processing chamber 106, as shown in FIG. 13 and FIG. As a result, the molten metal thin film breaks. As a result, since there is no molten metal thin film in the minute space in contact with the gap S, the molten metal is not filled and is not filled (defective portion).

  In addition, the diameter of the minute space formed on the object in the through silicon via technique is usually about several μm to several tens of μm, and in the filling of the molten metal into such a fine hole, the presence of the void S is present. It will be fatal.

  Note that by increasing the height of the processing chamber 106 and increasing the thickness of the molten metal on the object 107, the gap S is moved away from the object 107, and the molten metal is placed in the minute space of the entire surface to be processed. Although it can be filled, the film thickness of the residual metal thin film formed on the object 107 is also increased. Therefore, remelting removal and mechanical removal used when removing the residual metal thin film are not easy, resulting in problems in terms of cost and processing efficiency. Furthermore, the amount of molten metal supplied (used amount) Increased costs due to the increase in the cost will also be a problem.

  Thus, in the metal filling apparatus 100, it is impossible to achieve both a high filling rate and a thin residual metal thin film formed on the object 107 as much as possible.

  The present invention has been made in view of the above circumstances, and it is possible to increase the thickness of the molten metal on the workpiece even in a reduced pressure state of about 10 to 200 Pa (abs.) From a medium vacuum to a low vacuum. In addition, a metal filling apparatus that can keep a gap made of residual gas components away from the surface to be processed, cover the entire surface to be processed with a molten metal thin film, and can fill the minute space of the entire surface to be processed with molten metal. The purpose is to provide

The present invention for solving the above problems
The object to be processed front surface micro space formed so as to open to the, a metal filling apparatus for filling a molten metal supplied onto該被treated,
A holding portion for holding the object to be processed so that the surface to be processed is inclined with respect to a horizontal direction, and a processing chamber formed facing the surface to be processed of the object to be processed held by the holding portion. A processing unit body provided;
A pressure reducing mechanism that includes an air passage having one end opened in the inner wall surface of the processing chamber, and that decompresses the processing chamber through the air passage;
The liquid passage having one end opened to the inner wall surface of the processing chamber, and a storage tank that is connected to the other end of the liquid passage and in which a molten metal is stored, are decompressed by the decompression mechanism. a molten metal supply mechanism for supplying molten metal through the liquid passing path in the processing chamber,
A pressurizing mechanism for pressurizing the molten metal supplied into the processing chamber,
The air passage opens at a height position above the uppermost end of the surface to be processed of the workpiece and above the opening of the liquid passage,
The molten metal supply mechanism relates to a metal filling device configured to supply molten metal into the processing chamber so that at least a surface to be processed of the object to be processed is completely filled with the molten metal.

  According to this metal filling apparatus, first, an object to be processed in which a minute space is formed on the surface to be processed is held by the holding unit so that the surface to be processed is inclined with respect to the horizontal direction. Next, the pressure in the processing chamber is reduced by exhausting the gas in the processing chamber through the ventilation path by the decompression mechanism.

  After that, when the molten metal supply mechanism starts supplying the molten metal stored in the storage tank into the processing chamber via the liquid flow path, at least when the metal is filled up to the upper end of the surface to be processed, In other words, the supply is stopped when the residual gas component does not contact the surface to be processed. Note that the exhaust of the gas in the processing chamber through the ventilation path may be stopped before starting the supply of the molten metal into the processing chamber, or after the supply of the molten metal into the processing chamber is started, In order to prevent the molten metal from being sucked in, it may be stopped at an appropriate timing.

  In this metal filling apparatus, since the surface to be processed of the object to be processed is inclined with respect to the horizontal direction, the molten metal is gradually filled into the processing chamber from the lower end side of the surface to be processed. The gas component remaining in the processing chamber is collected above the liquid level of the molten metal. Therefore, the space | gap which consists of a residual gas component is kept away from a to-be-processed surface, and the whole to-be-processed surface will be in the state covered with the molten metal. In order to reduce the residual gas component in the processing chamber as much as possible, it is preferable to open the opening of the ventilation path at the top of the processing chamber.

  Thereafter, after the processing chamber is hermetically sealed, the molten metal supplied into the processing chamber is pressurized by the pressurizing mechanism to fill the minute space with the molten metal. The pressurizing mechanism may be a mechanism that pressurizes the molten metal by moving the pressing member toward the object to be processed and narrowing the processing chamber, or supplying a pressurized gas into the processing chamber. A mechanism that pressurizes the molten metal with a pressurized gas supplied into the processing chamber may be used.

  Thus, in the metal filling apparatus according to the present invention, the object to be processed is held by the holding portion in a state where the surface to be processed is inclined with respect to the horizontal direction, and from the lower end side of the surface to be processed. The molten metal is filled in the processing chamber toward the upper end side. Therefore, it is possible to collect residual gas components in the processing chamber above the liquid surface of the molten metal and prevent the gap from coming into contact with the surface to be processed. Without increasing the thickness of the molten metal on the object to be processed, the entire surface to be processed can be covered with molten metal, and the molten metal can be filled into the minute space of the entire surface to be processed, improving the filling rate. Can be achieved.

  In order to minimize the residual metal thin film formed on the surface to be processed after filling, it is preferable to reduce the space volume of the processing chamber in the metal filling apparatus as much as possible.

  Moreover, in the said metal filling apparatus, it is preferable that the inclination | tilt angle of the to-be-processed surface with respect to a horizontal direction shall be 30 degrees-150 degrees. In this way, when the molten metal is supplied into the processing chamber, the residual gas component can be more reliably collected above the liquid surface of the molten metal.

  Furthermore, it is preferable that the decompression mechanism in the metal filling apparatus is configured to decompress the processing chamber within a range of 10 to 200 Pa (abs.). In this way, since it is not necessary to use a special pump or the like, it is possible to suppress the complexity of the apparatus and the increase in cost related to the maintenance of the apparatus.

  Further, the liquid passage in the metal filling device is formed such that the opening on the processing chamber side opens at a height position below the intermediate height position between the lower end and the upper end of the surface to be processed. It is preferable. In this way, the molten metal can be more reliably filled from the lower end side of the surface to be processed.

  Furthermore, it is preferable to provide a buffer part in the opening part by the side of the process chamber of the ventilation path in the said metal filling apparatus. In this way, by forming the buffer portion in the opening on the processing chamber side of the ventilation path, the residual gas component can be trapped in the buffer portion, so that the gap is more reliably in contact with the surface to be processed. Can be prevented.

  Further, the molten metal supply mechanism is preferably provided with a supply pump that is interposed in the liquid passage and that measures the molten metal in the storage tank into the processing chamber through the liquid passage. In this way, an appropriate amount of molten metal can be supplied to the processing chamber until the surface to be processed is filled with the molten metal above the upper end, and the processing chamber is decompressed and melted in the processing chamber. When supplying the metal, it is possible to prevent the molten metal from being sucked into the air passage.

  Further, a degassing mechanism for degassing the molten metal in the storage tank may be provided. By depressurizing the inside of the storage tank by this degassing mechanism and degassing the molten metal, the gas component in the molten metal can be reduced in advance. Therefore, it is possible to prevent the gaseous component from being supplied into the processing chamber by the molten metal supplied into the processing chamber.

  As described above, according to the metal filling device according to the present invention, without increasing the thickness of the molten metal on the object to be processed, the gap due to the residual gas component in the processing chamber is kept away from the surface to be processed. A molten metal thin film can be formed on the entire surface to be processed, and the entire minute space can be filled with the molten metal, so that the filling rate and the processing efficiency can be improved. Moreover, since it can process without increasing the film thickness of the molten metal on a to-be-processed object, the quantity of the residual metal thin film formed in the to-be-processed surface after a process can be decreased. Further, the reduction in the amount of the residual metal thin film reduces the amount of molten metal to be used and contributes to cost reduction. Furthermore, since the removal of the residual metal thin film becomes easy, it is possible to realize cost reduction and improvement in processing efficiency.

It is sectional drawing which showed schematic structure of the metal filling apparatus which concerns on one Embodiment of this invention. It is explanatory drawing for demonstrating the process filled with a molten metal with the metal filling apparatus which concerns on one Embodiment. It is explanatory drawing for demonstrating the process filled with a molten metal with the metal filling apparatus which concerns on one Embodiment. It is explanatory drawing for demonstrating the process filled with a molten metal with the metal filling apparatus which concerns on one Embodiment. It is explanatory drawing for demonstrating the process filled with a molten metal with the metal filling apparatus which concerns on one Embodiment. It is explanatory drawing for demonstrating the process filled with a molten metal with the metal filling apparatus which concerns on one Embodiment. It is explanatory drawing for demonstrating the process filled with a molten metal with the metal filling apparatus which concerns on one Embodiment. It is sectional drawing which showed schematic structure of the metal filling apparatus which concerns on other embodiment of this invention. It is explanatory drawing for demonstrating the supply process of the molten metal in the process chamber in the metal filling apparatus which concerns on other embodiment. It is explanatory drawing for demonstrating the supply process of the molten metal in the process chamber in the metal filling apparatus which concerns on other embodiment. It is explanatory drawing for demonstrating the height position of the opening part of piping. It is sectional drawing which showed schematic structure of the conventional metal filling apparatus. It is the elements on larger scale for demonstrating the subject in the conventional metal filling apparatus. It is sectional drawing between arrow AA of FIG.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. In the following description, “right” and “left” refer to the right side and the left side as viewed in the drawing.

[1. Configuration of metal filling equipment]
As shown in FIG. 1, the metal filling apparatus 1 of this example is a metal filling apparatus that fills a molten space with a minute space formed so as to open on a processing surface of a semiconductor wafer (processing object) K. In addition, the semiconductor wafer K is formed with a holding base H in which the surface to be processed is held at an angle of 90 ° with respect to the horizontal direction, an internal space is formed, and a right end face is disposed facing the holding base H. The cylindrical housing C formed, the piston P provided so as to be able to advance and retreat with respect to the surface to be processed of the semiconductor wafer K held by the holding table H, and the moving mechanism 5 for moving the holding table H closer to and away from the housing C. And the advancing / retreating mechanism 6 for advancing and retracting the piston P. The holding table H, the housing C, and the piston P function as a processing unit main body, and the semiconductor wafer K, the housing C, and the piston P that are held by the holding table H. By means of the airtight processing chamber 2 It is made. The surface to be processed of the semiconductor wafer K refers to a portion of the surface of the semiconductor wafer K where a minute space to be filled with molten metal is formed, and is not limited to the entire surface of the object to be processed.

  In addition, the metal filling apparatus 1 includes a decompression mechanism 10 that exhausts the gas in the processing chamber 2 to decompress the processing chamber 2, and a molten metal supply mechanism 15 that supplies the molten metal M into the processing chamber 2. And a degassing mechanism 20 for degassing the molten metal M, and a moving mechanism 5, an advancing / retreating mechanism 6, a pressure reducing mechanism 10, a molten metal supply mechanism 15 and a control device 25 for controlling the operation of the degassing mechanism 20. Yes.

  The holding table H has an object holding mechanism such as a vacuum chuck or an electrostatic chuck that can hold the semiconductor wafer K without deforming the semiconductor wafer K against deformation of the processing chamber 2, and a housing The semiconductor wafer K can be held on the holding surface facing C. The holding table H is moved by the moving mechanism 5. The holding table H is moved in a direction approaching the housing C (left direction), and the semiconductor wafer K held on the holding table H is moved. By bringing the surface into contact with the right end surface of the housing C, an airtight processing chamber 2 is formed.

  The piston P is advanced and retracted in the axial direction by an advance / retreat mechanism 6 inside the housing C. Two airtight seals 7 and 8 are interposed between the outer peripheral surface of the piston P and the inner peripheral surface of the housing C.

  The advance / retreat mechanism 6 is, for example, a hydraulic cylinder mechanism or the like that provides a driving force for moving the piston P back and forth, and can move the piston P forward and backward toward the semiconductor wafer K with a predetermined pressing force. .

  The decompression mechanism 10 is provided through the upper side wall on the right end side of the housing C, a pipe 12 having a buffer portion 12a formed in an opening on the housing C side, and a vacuum connected to the processing chamber 2 by the pipe 12. It consists of a pump 11 and a control valve 13 provided between the vacuum pump 11 and the processing chamber 2 in the pipe 12. The air in the processing chamber 2 is exhausted by the vacuum pump 11 to depressurize the processing chamber 2. It is a mechanism to do. The operation of the vacuum pump 11 and the opening / closing of the control valve 13 are controlled by a control device 25.

  The molten metal supply mechanism 15 passes through the lower side wall on the right end side of the housing C, and is connected to the processing chamber 2 by a pipe 17 provided so that the opening thereof faces the buffer part 12 a of the pipe 12. With the pressure control function interposed between the storage tank 16 and the control valve 18, the control valve 18 interposed between the storage tank 16 and the processing chamber 2 of the storage tank 16 and the pipe 17. This mechanism comprises a supply pump 19 and supplies molten metal from the storage tank 16 into the processing chamber 2 with a predetermined supply pressure. The control valve 18 is an on-off valve capable of controlling the flow rate, and the operation of the supply pump 19 and the operation of the control valve 18 are controlled by the control device 25.

  In the storage tank 16, the molten metal M used for metal filling is heated at a temperature higher than its melting point and stored in a liquid state. In this example, the molten metal M used for metal filling is lead-free solder having a melting point of about 200 ° C. However, the type of the molten metal M is not limited to solder, Depending on the function, any material such as Au, Ag, Cu, Pt, Pd, Ir, Al, Ni, Sn, In, Bi, Zn, and alloys thereof can be adopted.

  The deaeration mechanism 20 includes a vacuum pump 21 connected to the storage tank 16 by a pipe 22, and exhausts air in the storage tank 16 to degas the molten metal M in the storage tank 16. Mechanism.

[2. Metal filling process]
Next, with reference to FIG. 2 to FIG. 7, the process of filling the molten metal M into the minute space by the metal filling device 1 of this example will be described.

  According to the metal filling apparatus 1 of the present example, first, in a state where the holding base H is moved in the direction away from the housing C (right direction) by the moving mechanism 5, the semiconductor wafer K is moved to the housing C side. And held on the holding surface of the holding table H (see FIG. 2). Next, the holding base H is moved in a direction (left direction) closer to the housing C by the moving mechanism 5, and the right end surface of the housing C is pressed against the surface of the semiconductor wafer K to be in close contact therewith, thereby forming the processing chamber 2.

  In order to minimize the amount of molten metal M supplied into the processing chamber 2, the piston P is moved toward the semiconductor wafer K by the advance / retreat mechanism 6 so that the volume of the processing chamber 2 becomes as small as possible. It is preferable to keep it.

  Next, the vacuum pump 11 is operated and the control valve 13 is opened to decompress the inside of the processing chamber 2 and the minute space (see FIG. 3). At this time, the inside of the processing chamber 2 may be set to a high vacuum, or the degree of vacuum in the processing chamber 2 is set to 10 to 200 Pa (in order to shorten the time required for decompression and improve the processing efficiency. abs.) or so.

  Next, as shown in FIG. 4, the control valve 13 is closed, the control valve 18 is opened, and the supply of the molten metal M from the storage tank 16 into the processing chamber 2 is started using the supply pump 19. The supply of the molten metal M into the processing chamber 2 is performed in a state adjusted to an appropriate supply speed by the control valve 18. Further, the molten metal M in the storage tank 16 is in a degassed state, so that the gas component in the molten metal M supplied into the processing chamber 2 is reduced as much as possible.

  Then, the surface of the semiconductor wafer K in the processing chamber 2 is completely filled with the molten metal M, in other words, until the liquid level of the molten metal M is located above the upper end of the surface to be processed. Then, the operation of the supply pump 19 is stopped (see FIG. 5).

  Thus, in the metal filling apparatus 1 of this example, the molten metal M is supplied from the lower side of the processing chamber 2 and is gradually filled from the lower side of the processing chamber 2. The residual gas component is collected above the liquid level of the molten metal M. And since the buffer part 12a is provided and the residual gas component is trapped in the buffer part 12a, the surface to be processed of the semiconductor wafer K in the processing chamber 2 is filled with the molten metal M. It is possible to prevent the gap made of the residual gas component from coming into contact with the surface to be processed.

  Thereafter, the piston P is moved toward the semiconductor wafer K to a predetermined position by the advance / retreat mechanism 6 as shown in FIG. At this time, excess molten metal M in the processing chamber 2 is pushed back to the storage tank 16 while the molten metal is appropriately pressurized by the flow rate control function of the control valve 18 or the pressure control function of the supply pump 19. The molten metal M is pressurized and filled in the minute space.

  Thereafter, the temperature of the molten metal M filled in the minute space is cooled until the temperature becomes equal to or lower than the melting point, and the process waits until the molten metal M is cooled and hardened. After that, as shown in FIG. 7, the holding table H is moved rightward by the moving mechanism 5 to open the processing chamber 2, and the semiconductor wafer K is removed from the holding unit of the holding table H.

  As described above, in the metal filling apparatus 1 of this example, the residual gas components in the processing chamber 2 are collected above the liquid surface of the molten metal M. Without supplying an excessive amount of molten metal M, it is possible to keep the entire surface to be processed with the molten metal M away from the surface to be processed, so that the molten metal M is melted in the minute space of the entire surface to be processed. Metal M can be filled.

  As mentioned above, although one Embodiment of this invention was described, the specific aspect which this invention can take is not limited to this at all.

  For example, in the above example, the configuration is such that excess molten metal M in the processing chamber 2 is pushed back to the storage tank 16, but a recovery tank may be provided as appropriate, and the excess molten metal M may be recovered in this recovery tank. good.

  In addition, the metal filling apparatus 1 pressurizes the molten metal M in the processing chamber 2 by moving the piston P toward the semiconductor wafer K, but the mechanism for pressurizing the molten metal M is the same. It is not limited. For example, when it is not necessary to push back or discharge excess molten metal M, the control valve 18 is closed and the piston P is fixed so as not to move, and then pressurized gas is supplied into the processing chamber 2. A mechanism that pressurizes the molten metal M with a pressurized gas can be used.

  In addition, the metal filling apparatus 1 in the above example closes the control valve 13 and stops the decompression in the processing chamber 2 before starting the supply of the molten metal M into the processing chamber 2. It is not limited to this.

  That is, the supply pump 19 in the metal filling apparatus 1 is a supply pump capable of metering the molten metal M, and after supplying a predetermined amount of the molten metal M into the processing chamber 2, the decompression in the processing chamber 2 is stopped. Anyway. By doing so, the pressure in the processing chamber 2 can be kept substantially constant until the decompression in the processing chamber 2 is stopped, and the residual gas component in the processing chamber 2 can be reduced as much as possible. .

  Moreover, you may make it provide the backflow prevention valve for preventing inflow of the molten metal M between the piping 12 and the buffer part 12a in the metal filling apparatus 1. FIG. In this way, it is possible to effectively prevent the molten metal M from flowing into the pipe 12.

  Furthermore, in this example, the semiconductor wafer K is configured to be held in a state where the surface to be processed is inclined by 90 ° with respect to the horizontal direction, but the inclination angle of the surface to be processed with respect to the horizontal direction is not necessarily limited to 90 °. Is not something That is, when the molten metal is supplied into the processing chamber, the molten metal is gradually filled from below the processing chamber, and the residual gas component is collected above the liquid level of the molten metal M. Depending on the properties, surface properties of the object to be processed, surface properties of the piston P, etc., the predetermined angle may be set as appropriate. This will be described below by taking a metal filling device 30 according to another embodiment shown in FIG. 8 as an example.

  As shown in FIG. 8, the metal filling device 30 includes a holding base H ′ that holds the semiconductor wafer K in a state in which the processing target surface is inclined by θ with respect to the horizontal direction, and a space is formed therein. On the other hand, a cylindrical housing C ′ having an end face opposed to the holding table H ′, and a piston P ′ provided to be movable back and forth with respect to the surface to be processed of the semiconductor wafer K held by the holding table H ′. And a moving mechanism (not shown) for moving the holding base H ′ toward and away from the housing C ′ and an advancing / retreating mechanism (not shown) for moving the piston P ′ back and forth, and is held by the holding base H ′. An airtight processing chamber 32 is formed by the semiconductor wafer K, the housing C ′ and the piston P ′.

  In the metal filling device 30, an airtight seal 37 is interposed between the outer peripheral surface of the piston P ′ and the housing C ′, and the space between both is sealed by the airtight seal 37.

  Further, similar to the metal filling device 1, the metal filling device 30 includes a decompression mechanism 40 that depressurizes the inside of the processing chamber 32, a molten metal supply mechanism 45 that supplies the molten metal M to the processing chamber 32, A deaeration mechanism (not shown) for performing gas and a control device (not shown) for controlling the operation of each mechanism are provided.

  The decompression mechanism 40 includes a vacuum pump 41, a pipe 42 in which a buffer portion 42a is formed, and a control valve 43. The decompression mechanism 40 has substantially the same configuration as the decompression mechanism 10 in the metal filling apparatus 1, but the pipe 42 has a housing C ′. It is provided so as to penetrate the side wall on the other end side.

  The molten metal supply mechanism 45 also has substantially the same configuration as the molten metal supply mechanism 15 in the metal filling device 1, and includes a storage tank 46, a pipe 47, a control valve 48, and a supply tank 49. The piping 47 is provided so as to penetrate the side wall on one end side of the housing C ′, and the opening of the piping 42 on the processing chamber 32 side is above the opening of the piping 47 on the processing chamber 32 side, and It is located further above the uppermost part of the processing chamber 2.

  Next, the process of supplying the molten metal M into the processing chamber 32 in the metal filling apparatus 30 will be described with reference to FIGS.

  According to this metal filling device 30, like the metal filling device 1, after forming the processing chamber 32 with the semiconductor wafer K held on the holding base H ′, the vacuum pump 41 is operated and the control valve 43 is opened. Then, the gas in the processing chamber 32 is exhausted, and the pressure in the processing chamber 32 and the minute space is reduced to a substantially vacuum state.

  Next, as shown in FIG. 9, the control valve 43 is closed, the control valve 48 is opened, the supply pump 49 is operated, and supply of the molten metal M from the storage tank 46 into the processing chamber 32 is started. .

  Also in the metal filling device 30, the molten metal M is supplied from below the processing chamber 32, and the molten metal M is gradually filled from below the processing chamber 32, so that the processing chamber 32 is concerned. The residual gas components inside are collected above the liquid level of the molten metal M.

  Then, after the supply of the molten metal M is continued until the surface to be processed of the semiconductor wafer K in the processing chamber 32 is completely filled with the molten metal M, the control valve 48 is closed as shown in FIG. 49 is stopped.

  As described above, even if the surface to be processed is inclined by the angle θ with respect to the horizontal direction, the residual gas components are collected above the liquid surface of the molten metal M and processed by the molten metal M in the same manner as described above. The entire surface can be covered, and there is a corresponding effect. In order to collect the residual gas component above the liquid level of the molten metal M more reliably, the value of the angle θ is preferably set to a value within the range of 30 ° to 150 °.

  Further, in the metal filling apparatus 1, the opening on the processing chamber 2 side of the pipe 17 opens at the same position as the height position of the lowermost end of the surface to be processed, but is not limited to this. As shown in FIG. 11, the height position is lower than the middle height position (dotted line n) between the height position of the uppermost end (dotted line l) and the height position of the lowermost end (dotted line m) of the surface to be processed. By making it open, there exists a corresponding effect that the molten metal M is gradually filled from the lower side of the processing chamber 2.

DESCRIPTION OF SYMBOLS 1 Metal filling apparatus 2 Processing chamber 5 Movement mechanism 6 Advance / retreat mechanism 10 Decompression mechanism 11 Vacuum pump 12 Piping 12a Buffer part 13 Control valve 15 Molten metal supply mechanism 16 Storage tank 17 Piping 18 Control valve 19 Supply pump 20 Deaeration mechanism 21 Vacuum pump 22 Piping H Holding stand C Housing P Piston

Claims (7)

The object to be processed front surface micro space formed so as to open to the, a metal filling apparatus for filling a molten metal supplied onto該被treated,
A holding portion for holding the object to be processed so that the surface to be processed is inclined with respect to a horizontal direction, and a processing chamber formed facing the surface to be processed of the object to be processed held by the holding portion. A processing unit body provided;
A pressure reducing mechanism that includes an air passage having one end opened in the inner wall surface of the processing chamber, and that decompresses the processing chamber through the air passage;
The liquid passage having one end opened to the inner wall surface of the processing chamber, and a storage tank that is connected to the other end of the liquid passage and in which a molten metal is stored, are decompressed by the decompression mechanism. a molten metal supply mechanism for supplying molten metal through the liquid passing path in the processing chamber,
A pressurizing mechanism for pressurizing the molten metal supplied into the processing chamber,
The air passage opens at a height position above the uppermost end of the surface to be processed of the workpiece and above the opening of the liquid passage,
The molten metal supply mechanism supplies the molten metal into the processing chamber so that at least the surface to be processed of the object to be processed is completely filled with the molten metal.   The metal filling apparatus according to claim 1, wherein an inclination angle of the surface to be processed with respect to the horizontal direction is 30 ° to 150 °.   The metal filling apparatus according to claim 1, wherein the pressure reducing mechanism is configured to depressurize the processing chamber within a range of 10 to 200 Pa (abs.).   The liquid passage is formed such that the opening on the processing chamber side opens at a height position below a middle height position between a lower end and an upper end of the surface to be processed. The metal filling device according to any one of claims 1 to 3.   The metal filling apparatus according to any one of claims 1 to 4, wherein a buffer portion is formed in an opening portion of the ventilation path on the processing chamber side.   The molten metal supply mechanism is provided with a supply pump that is interposed in the liquid flow path and supplies the molten metal in the storage tank into the processing chamber via the liquid flow path. The metal filling device according to any one of claims 1 to 5.   The metal filling device according to any one of claims 1 to 6, further comprising a deaeration mechanism that depressurizes the storage tank and degass the molten metal in the storage tank.

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