Patent Publication Number: US-2007105459-A1

Title: Joining method and joining device

Description:
TECHNICAL FIELD  
      The present invention relates to a bonding method and a bonding apparatus, in particular to a bonding method and a bonding apparatus used in an assembling step of a semiconductor device.  
     BACKGROUND ART  
      As electronic equipments such as cellular phones, portable information terminals or high-performance servers are spread, semiconductor devices used therein have been required higher function, higher processing speed and more miniaturization. Herein, in order to achieve the higher function and the higher processing speed in one semiconductor device, a large-scale chip development is necessary, which may involve a longer length and a higher cost of the development. Thus, a packaging structure such as a system-in-package (SiP) has been proposed, wherein a plurality of chips and/or passive components that have different functions is contained in one package.  
      In such a small high-density packaging structure, if a connection between chips or a connection between a chip and a wiring board such as an interposer is conducted by a bonding wire, it may be impossible to increase a wiring density thereof, inductance thereof may be too great, and radio-frequency noise caused by a switching operation may be too great. In addition, if a soldered bump is used instead of the bonding wire, a size in height thereof may be larger by a size of the bump, the number of steps may be increased because of a bump forming step, and reliability of the bonded part may be low.  
      Thus, instead of using the bonding wire and/or the soldered bump, wiring structures and/or outside connection electrodes, which are made of Cu or the like and exposed at a surface of a semiconductor wafer, a chip or a wiring board, are directly connected in a packaging structure (For example, Japanese Patent Laid-Open publication No. 2001-53218, preprint of “2001 International Conference on Electronics packaging” on pages 39 to 43).  
      However, when a wiring structure of a silicon chip and a wiring structure of an interposer are connected to each other, or when wiring structures of silicon chips are connected to each other, it may be difficult to conduct a bonding operation with high reliability, because an oxide film or the like is formed at a connecting (bonding) part from a completion of manufacture of individual chips to a start of the bonding step.  
     DISCLOSURE OF THE INVENTION  
      Accordingly, it is an object of the present invention to solve the aforesaid problems and to provide a bonding technology capable of removing the effect of an oxide film or the like at a bonding part and achieving a bonded structure with high reliability.  
      In addition, it is an object of the present invention to provide a bonding technology capable of achieving improved reliability and yield in an assembling step of a semiconductor device or the like in which wiring structures of objects to be bonded are directly bonded to each other.  
      In order to solve the above problems, the present invention is a bonding method of bonding a first object to be bonded and a second object to be bonded by a pressurizing operation, the bonding method comprising: a first step of causing a first holding member and a second holding member to respectively hold the first object to be bonded and the second object to be bonded in such a manner that a bonding surface of the first object to be bonded and a holding surface of the second object to be bonded face to each other; a second step of treating the bonding surface of the first object to be bonded and the holding surface of the second object to be bonded with a treatment liquid under a condition wherein the first object to be bonded and the second object to be bonded are held by the first holding member and the second holding member; and a third step of pressurizing the first object to be bonded and the second object to be bonded toward each other by the first holding member and the second holding member in order to bond both the bonding surfaces close to each other.  
      According to the present invention, when the first object to be bonded and the second object to be bonded are bonded, a removing operation of oxide films on both the bonding surfaces, a cleaning operation of both the bonding surfaces and a treating operation such as application of a surface active agent are conducted at a place wherein the bonding step is carried out, i.e., in an apparatus wherein the bonding step is carried out, and then the first object to be bonded and the second object to be bonded are pressurized to each other. Thus, the bonding surfaces can be bonded closely under a clean condition wherein the oxide films or the like have been removed. Thus, failure in electrical bonding and/or strength that may be caused by the oxide films can be surely prevented, so that a bonding operation with high reliability can be achieved.  
      Preferably, the first step includes a step of detecting an image of the bonding surface of the first object to be bonded and an image of the bonding surface of the second object to be bonded under the condition wherein the first object to be bonded and the second object to be bonded are held by the first holding member and the second holding member, and of positioning the first object to be bonded and the second object to be bonded based on both the images.  
      In addition, preferably, the second step includes a step of forming a treatment space for containing the first object to be bonded and the second object to be bonded, and of introducing the treatment liquid into the treatment space.  
      In addition, preferably, the second step includes a step of removing oxide films on both the bonding surfaces by a medicament, and a step of cleaning both the bonding surfaces by a cleaning liquid.  
      In addition, preferably, the third step includes a heating step of heating the first holding member and the second holding member in order to promote bonding between both the bonding surfaces.  
      In addition, preferably, the heating step includes a step of heating the first holding member and the second holding member at a first temperature just after both the bonding surfaces are brought in close contact with each other, and a step of heating the first holding member and the second holding member at a second temperature higher than the first temperature.  
      In addition, preferably, a wiring structure is formed and exposed on each of the bonding surfaces, and both the wiring structures are brought in close contact with each other when both the bonding surfaces are brought in close contact with each other. In the case, preferably, the wiring structure is made of Cu. Alternatively, preferably, each of the bonding surfaces is, at least partly, made of Cu.  
      For example, the first object to be bonded is any of a semiconductor wafer, an interposer, a semiconductor tip, a package and a printed wiring board, and the second object to be bonded is any of a semiconductor wafer, an interposer, a semiconductor tip, a package and a printed wiring board.  
      In addition, the present invention is a bonding apparatus comprising: a first holding member and a second holding member that respectively hold a first object to be bonded and a second object to be bonded in such a manner that a bonding surface of the first object to be bonded and a holding surface of the second object to be bonded face to each other; a pressurizing mechanism that conducts a pressurizing operation of both the bonding surfaces toward each other by bringing the first holding member and the second holding member closer to each other; a treatment chamber that forms a treatment space for containing the first object to be bonded and the second object to be bonded respectively held by the first holding member and the second holding member; a treatment-liquid supplying mechanism that supplies a treatment liquid into the treatment chamber; and a treatment-liquid discharging mechanism that discharges the treatment liquid from the treatment chamber.  
      Preferably, the bonding apparatus further comprises a positioning mechanism that conducts a relative positioning operation of the first object to be bonded and the second object to be bonded respectively held by the first holding member and the second holding member.  
      In addition, preferably, the bonding apparatus further comprises a first head member that supports the first holding member, and a second head member that supports the second holding member, wherein the treatment chamber includes: a first chamber wall supported by the first head member and arranged so as to surround the first holding member; a second chamber wall supported by the second holding member and arranged so as to surround the second object to be bonded held by the second holding member; a first sealing member that seals a connection part between the first chamber wall and the second chamber wall; and a second sealing member that seals a gap between the first holding member and the first chamber wall.  
      In addition, preferably, the treatment-liquid supplying mechanism and the treatment-liquid discharging mechanism cooperate to sequentially conduct an operation of removing oxide films on both the bonding surfaces by supplying a medicament as a treatment liquid, and an operation of cleaning both the bonding surfaces by supplying a cleaning liquid as a treatment liquid.  
      In addition, preferably, the first head member is further provided with a first heating mechanism arranged capably of abutting with a back side of the first holding member, the first heating mechanism heating the first object to be bonded held by the first holding member, and a first heater-driving mechanism that conducts an abutting operation and a separating operation of the first heating mechanism to the back side of the first holding member, and the second head member is further provided with a second heating mechanism arranged capably of abutting with a back side of the second holding member, the second heating mechanism heating the second object to be bonded held by the second holding member, and a second heater-driving mechanism that conducts an abutting operation and a separating operation of the second heating mechanism to the back side of the second holding member.  
      In addition, preferably, the first heating mechanism is capable of abutting with the first holding member and heating the first holding member under a condition wherein the first heating mechanism has been heated at a predetermined first temperature in advance, and then capable of heating the first holding member at a second temperature higher than the first temperature, and the second heating mechanism is capable of abutting with the second holding member and heating the second holding member under a condition wherein the second heating mechanism has been heated at a predetermined first temperature in advance, and then capable of heating the second holding member at a second temperature higher than the first temperature.  
      In addition, preferably, the first holding member is provided with a absorbing-and-holding member that absorbs and holds the first object to be bonded in a removable manner, and the second holding member is provided with a absorbing-and-holding member that absorbs and holds the second object to be bonded in a removable manner.  
      In addition, preferably, the positioning mechanism includes a first camera that takes an image of the second object to be bonded held by the second holding member and a second camera that takes an image of the first object to be bonded held by the first holding member, and is adapted to align both the bonding surfaces by relatively moving the first head member and the second head member in accordance with positional recognition based on both the images. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a sectional view showing an example of structure of a bonding apparatus carrying out a bonding method according to an embodiment of the present invention;  
       FIG. 2  is a sectional view showing an example of operation of the bonding apparatus shown in  FIG. 1 ;  
       FIG. 3  is a sectional view showing the example of operation of the bonding apparatus shown in  FIG. 1 ;  
       FIG. 4  is a sectional view showing the example of operation of the bonding apparatus shown in  FIG. 1 ;  
       FIG. 5  is a sectional view showing the example of operation of the bonding apparatus shown in  FIG. 1 ;  
       FIG. 6  is a sectional view showing the example of operation of the bonding apparatus shown in  FIG. 1 ;  
       FIG. 7  is a substantially plan view showing an example of the whole structure of a bonding system including the bonding apparatus according to the embodiment of the present invention;  
       FIG. 8  is a flow chart showing an example of operation of the bonding system shown in  FIG. 7 ; and  
       FIG. 9  is a substantially sectional view showing an example of object to be bonded that is supplied for a bonding apparatus according to an embodiment of the present invention. 
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION  
      Preferred embodiments of the present invention will be described hereinafter with reference to the attached drawings.  
       FIG. 1  is a sectional view showing an example of structure of a bonding apparatus carrying out a bonding method according to an embodiment of the present invention. FIGS.  2  to  6  are sectional views showing an example of operation of the bonding apparatus shown in  FIG. 1 .  FIG. 7  is a substantially plan view showing an example of the whole structure of a bonding system including the bonding apparatus of the present embodiment.  FIG. 8  is a flow chart for showing an example of operation of the bonding system shown in  FIG. 7 .  FIG. 9  is a substantially sectional view showing an example of object to be bonded.  
      In the present embodiment, as an example, a bonding operation of an interposer and a semiconductor wafer is explained.  
      As shown in  FIG. 7 , the bonding system of the present embodiment comprises a bonding mechanism  30 , a loading/unloading part  10 , and a transferring mechanism  20  located between them.  
      The bonding mechanism  30  includes: a bonding apparatus  40  arranged at a center of the bonding mechanism  30 , a treatment-liquid supplying mechanism  60   a  that supplies a treatment liquid or the like into the bonding apparatus  40 , and a treatment-liquid retrieving mechanism  60   b  that retrieves (discharges) the treatment liquid or the like.  
      The loading/unloading part  10  has: a wafer-supplying cassette  11  which a carrier (not shown) is supplied from an outside to and held by, the carrier containing a semiconductor wafer  100  as an example of first object to be bonded; an interposer-supplying cassette  12  which another carrier (not shown) is supplied from an outside to and held by, the carrier containing an interposer  200  as an example of second object to be bonded; and an outputting cassette  13  from which the semiconductor wafer  100  and the interposer  200  that have been integrally bonded are outputted as a finished piece.  
      The transferring mechanism  20  has a transfer way  21  arranged in a direction along the arrangement of the wafer-supplying cassette  11 , the interposer-supplying cassette  12  and the outputting cassette  13  of the loading/unloading part  10 . An arm robot  22  is provided movably on the transfer way  21 . A holding arm  23  is provided on the arm robot  22  and is capable of pivoting from a position facing the loading/unloading part  10  to a position facing the bonding mechanism  30 .  
      The holding arm  23  is adapted to take out the semiconductor wafer  100  to be bonded from the wafer-supplying cassette  11  and the interposer  200  to be bonded from the interposer-supplying cassette  12 , hold them, and set them at the bonding apparatus  40 . In addition, the bolding arm  23  is adapted to take out a bonded finished piece from the bonding apparatus  40  and set it into the outputting cassette  13 .  
      On the other hand, as shown in  FIG. 1 , the bonding apparatus  40  of the present embodiment has: a lower head  41  connected to a positioning mechanism  41 P, which mechanism can achieve a parallel displacement in a horizontal plane (X-Y plane in  FIG. 7 ) and a positioning in a vertical direction (vertical (Z) direction in  FIG. 1 ), a rotation table  42  connected to a positioning mechanism  42 P, which mechanism is supported by the lower head  41  and can achieve a rotational positioning (θ direction in  FIG. 7 ) in the X-Y plane, a lower chuck  43  supported by the rotation table  42  and having a cylindrical shape with a ceiling, whose surface forms an absorption surface  43   a  on which the first object to be bonded such as the semiconductor wafer  100  is placed, and a lower heater  44  arranged in the lower chuck  43 . The positioning mechanism  41 P consists of: a cylindrical part  41   z  supporting the lower head  41  and positioning the lower head  41  in a vertical direction; an X-stage  41   x  supporting the cylindrical part  41   z  and positioning the cylindrical part  41   z  in an X direction; and a Y-stage  41   y  supporting the X-stage  41   x  and positioning the X-stage  41   x  in a Y direction. The lower heater  44  can freely control a heating temperature by a control of amount of electric conduction or the like. In addition, the lower heater  44  is supported by the rotation table  42  via a heater-elevating mechanism  44   a , and is movable between a heating position in close contact with a back surface of the ceiling that forms the absorption surface  43   a  of the lower chuck  43  and a non-heating position apart from the ceiling.  
      A ventilation hole  43   b  is opened at a lateral wall of the lower chuck  43 . A temperature control of the lower chuck  43  is achieved by causing an air or the like for cooling or heating to flow from the ventilation hole  43   b  into the lower chuck  43 , if necessary.  
      A plurality of vacuum-absorption holes  49   a  (see  FIG. 9 ) is opened at the absorption surface  43   a  of the lower chuck  43 , correspondingly to an area where the semiconductor wafer  100  as the first object to be bonded is placed. By means of the vacuum absorption via the vacuum-absorption holes  49   a , the semiconductor wafer  100  delivered from the arm robot  22  is adapted to be held on the absorption surface  43   a  in a removable manner.  
      On the other hand, above the lower chuck  43 , an upper head  45  is oppositely provided, which is movable up and down in the Z direction (vertical direction). An upper chuck  46  having a cylindrical shape with a bottom is supported by the upper head  45  via a pressuring mechanism  45   a  that generates a pressurizing force in the Z direction. The bottom of the upper chuck  46  forms an absorption surface  46   a  opposite and parallel to the absorption surface  43   a  of the lower chuck  43 .  
      A plurality of vacuum-absorption holes  49   a  is opened at the absorption surface  46   a  of the upper chuck  46 , correspondingly to an area where the interposer  200  as the second object to be bonded is placed. By means of the vacuum absorption via the vacuum-absorption holes  49   a , the interposer  200  delivered from the arm robot  22  is adapted to be held on the absorption surface  46   a  in a removable manner.  
      The upper chuck  46  and the lower chuck  43  opposite to each other are adapted to pressurize and bond the semiconductor wafer  100  and the interposer  200  as the objects to be bonded, by means of the pressurizing force in the Z direction generated by the pressurizing mechanism  45   a.    
      An upper heater  47  is provided in the upper chuck  46 . The upper heater  47  can freely control a heating temperature by a control of amount of electric conduction or the like. In addition, the upper heater  47  is supported by the upper head  45  via a heater-elevating mechanism  47   a , and is movable between a heating position in close contact with an upper surface of the bottom that forms the absorption surface  46   a  of the lower chuck  46  and a non-heating position apart from the bottom.  
      A ventilation hole  45   b  is formed at the upper head  45  so as to communicate with the inside of the upper chuck  46 . A temperature control of the upper chuck  46  is achieved by causing an air or the like for cooling or heating to flow from the ventilation hole  45   b , if necessary.  
      An upper chamber wall  48   a  is projected from the upper head  45  so as to surround the upper chuck  46  absorbing and holding the interposer  200 . A lower chamber wall  48   b  corresponding to the upper chamber wall  48   a  is projected from the lower chuck  43  so as to surround a holding area for the semiconductor wafer  100 . Then, a treatment chamber  48  is adapted to be formed when the upper chamber wall  48   a  and the lower chamber wall  48   b  are brought in close contact with each other.  
      A sealing member  48   c , such as an O-ring, is arranged fully circumferentially at an opening part of the lower chamber wall  48   b . Thus, air tightness is maintained when the upper chamber wall  48   a  and the lower chamber wall  48   b  are brought in close contact with each other. In addition, a sealing member  48   d , such as an O-ring, for hermetically sealing a gap between the upper chuck  46  and the upper chamber wall  48   a  is fitted on an outside periphery of the upper chuck  46 . In addition, outside the lower chamber wall  48   b , an overflow-preventing wall  48   e  is provided for retrieving a treatment liquid that has overflown over the lower chamber wall  48   b.    
      A treatment-liquid supplying way  45   f  is opened at the upper chuck  45  inside the upper chamber wall  48   a . The treatment-liquid supplying way  45   f  is connected to a treatment-liquid supplying mechanism  60   a . Thus, a medicament or a cleaning liquid can be introduced from the treatment-liquid supplying mechanism  60   a  into the treatment chamber  48 .  
      On the other hand, a treatment-liquid discharging way  48   f  is opened at the lower chuck  43  inside the lower chamber wall  48   b . The treatment-liquid discharging way  48   f  is connected to a treatment-liquid retrieving mechanism  60   b . Thus, the medicament or the cleaning liquid or the like introduced from the treatment-liquid supplying mechanism  60   a  into the treatment chamber  48  can be discharged to the treatment-liquid retrieving mechanism  60   b  after the treatment.  
      The treatment-liquid supplying mechanism  60   a  comprises: a medicament supplying part  61  that supplies a medicament  61   a  such as hydrochloric acid, a cleaning-liquid supplying part  62  that supplies a cleaning liquid  62   a  such as purified water, and a surface-treatment-liquid supplying part  63  that supplies a surface treatment liquid  63   a  such as PGME (propyleneglycol monomethyl ether).  
      The treatment-liquid retrieving mechanism  60   b  has a retrieving part  64  for retrieving the respective discharged liquids after the treatment from the treatment chamber  48 .  
      The medicament supplying part  61  is adapted to supply the medicament  61   a  via a valve  61   b . The cleaning-liquid supplying part  62  is adapted to supply the cleaning liquid  62   a  via a valve  62   b . The surface-treatment-liquid supplying part  63  is adapted to supply a surface treatment liquid  63   a  via a valve  63   b . The retrieving part  64  is adapted to retrieve the discharged liquids via a valve  64   a.    
      The vacuum absorption by the vacuum-absorption holes  49   a  of the lower chuck  43  and the upper chuck  46  is turned on and off, so that the semiconductor wafer  100  and the interposer  200  can be absorbed and held in a removable manner. In the present embodiment, it is possible that the medicament or the like is sucked out from the vacuum-absorption holes  49   a . Thus, instead of a vacuum pump having a complex structure, an ejector  49  having a simple structure and relatively easy to achieve sufficient resistance to chemicals is connected to the vacuum-absorption holes  49   a.    
      A lower alignment mechanism  51  is provided on a lateral surface of the lower chuck  43 . The lower alignment mechanism  51  consists of a lower camera that has an image-taking part  51   a  oriented upward in order to take an image of the interposer  200  held by the upper chuck  46  and to detect positional information thereof.  
      In addition, an upper alignment mechanism  50  is arranged at a position higher than the lower chuck  43 . The upper alignment mechanism  50  comprises a camera that has an image-taking part  50   a  oriented downward in order to take an image of the semiconductor wafer  100  held by the lower chuck  43  and to detect positional information thereof.  
      Next, with reference to  FIG. 9 , an example of structure of the semiconductor wafer  100  and the interposer  200  as the objects to be bonded in the present embodiment is explained.  
      The semiconductor wafer  100  has a silicon substrate  101 , a wiring pattern  102  formed on a surface of the silicon substrate  101 , and a plurality of connection electrodes  103  buried in throughholes  104  piecing through the silicon substrate  101 . One ends of the connection electrodes  103  are connected to the wiring pattern  102 , and the other ends of the connection electrodes  103  are exposed at a back surface of the silicon substrate  101 . The connection electrodes  103  consist of a conductive material such as Cu.  
      On the other hand, the interposer  200  has an insulating substrate  201 , a wiring pattern  202  formed on a surface of the insulating substrate  201 , and a plurality of connection electrodes  203  piecing through the insulating substrate  201 . One ends of the connection electrodes  203  are connected to the wiring pattern  202 , and the other ends of the connection electrodes  203  are exposed at a back surface of the insulating substrate  201 . The connection electrodes  203  consist of a conductive material such as Cu. If necessary, an adhesive  204  is applied on the back surface of the insulating substrate  201  where the connection electrodes  203  are exposed. The adhesive  204  may be omitted.  
      Then, in the bonding apparatus  40  of the present embodiment, the connection electrodes  103  exposed at the back surface of the semiconductor wafer  100  and the connection electrodes  203  exposed at the back surface of the interposer  200  are aligned, brought in close contact with each other, and hence electrically connected to each other.  
      Then, with reference to the flow chart of  FIG. 8  or the like, an example of operation of the bonding apparatus of the present embodiment is explained.  
      At first, as shown in  FIG. 1 , the lower chuck  43  (lower head  41 ) and the upper chuck  46  (upper head  45 ) are made apart. At that time, the upper chuck  46  is located (withdrawn) in the upper chamber wall  48   a . In addition, the lower heater  44  and the upper heater  47  are respectively located apart from the absorption surface  43   a  and the absorption surface  46   a , and preheated at a predetermined first temperature T 1  (for example, 120° C.).  
      Under the condition, by means of the arm robot  22 , the semiconductor wafer  100  and the interposer  200  are respectively set on the absorption surface  43   a  of the lower chuck  43  and the absorption surface  46   a  of the upper chuck  46 , and absorbed and held by them (STEP  301 ).  
      Specific positions of the semiconductor wafer  100  and the interposer  200  respectively set on the lower chuck  43  and the upper chuck  46  (specifically, for example, positioning marks thereof that have been formed in advance) are detected by the upper alignment mechanism  50  and the lower alignment mechanism  51  (STEP  302 ), and positional differences between them in the horizontal (X-Y) direction and in the rotational (θ) direction are detected. So as to cancel the positional differences, the lower head  41  and the rotation table  42  are suitably moved and positioned with respect to the upper head  45  (STEP  303 ).  
      Thus, the individual connection electrodes  103  of the semiconductor wafer  100  and the corresponding individual connection electrodes  203  of the interposer  200  are positioned to be correctly overlapped in the vertical direction.  
      Then, for example by moving up the lower head  41 , the lower chamber wall  48   b  and the upper chamber wall  48   a  are made in close contact with each other, so that the hermetically closed treatment chamber  48  is formed (STEP  304 ). Then, the medicament  61   a  such as hydrochloric acid is introduced from the medicament supplying part  61  into the treatment chamber  48  (STEP  305 ) ( FIG. 3 ). Thus, oxide films on surfaces of the individual connection electrodes  103  of the semiconductor wafer  100  and the corresponding individual connection electrodes  203  of the interposer  200  are removed by the medicament  61   a.    
      Then, the medicament  61   a  in the treatment chamber  48  is discharged, and the cleaning liquid  62   a  is introduced from the cleaning-liquid supplying part  62  in order to conduct a cleaning operation of removing the medicament  61   a  or the like (STEP  306 ) ( FIG. 4 ). After the cleaning operation, if necessary, the surface treatment liquid  63   a  such as PGME is introduced from the surface-treatment-liquid supplying part  63  in order to conduct a surface treatment such as an anti-oxidant treatment onto the surfaces to be bonded (STEP  307 ).  
      Then, after the cleaning liquid  62   a  and the surface treatment liquid  63   a  and the like in the treatment chamber  48  are completely discharged to the retrieving part  64  (STEP  308 ), by means of the pressurizing mechanism  45   a , the upper chuck  46  is moved down, and hence the semiconductor wafer  100  and the interposer  200  are pressurized between the upper chuck  46  and the lower chuck  43  with a pressure of, for example, 3.48 kg/mm 2  (STEP  309 ) ( FIG. 5 ). Then, the lower heater  44  is moved up so as to abut with the back surface of the ceiling that forms the absorption surface  43   a  of the lower chuck  43 , and the upper heater  47  is moved down so as to abut with the upper surface of the bottom that forms the absorption surface  46   a  of the upper chuck  46 . Thus, the semiconductor wafer  100  and the interposer  200  are rapidly heated to the first temperature T 1  (for example, 120° C.). By means of the pressurizing force and the heat of the first temperature T 1 , the individual connection electrodes  103  of the semiconductor wafer  100  and the corresponding individual connection electrodes  203  of the interposer  200  are bonded (STEP  310 ) ( FIG. 6 ).  
      In addition, if necessary, the heating temperature of the upper heater  47  and the lower heater  44  is increased to a higher second temperature T 2  (&gt;T 1 : for example, 150° C.). Thus, the adhesive  204  is hardened to excise its adhesive force (STEP  311 ).  
      Then, the upper heater  47  and the lower heater  44  are respectively made apart from the upper chuck  46  and the lower chuck  43  (STEP  312 ). Then, the vacuum absorption of the absorption surface  46   a  is released, and the upper chuck  46  is moved up and withdrawn into the inside of the upper chamber wall  48   a  to be separated from the lower chuck  43 . That is, the lower head  41  and the upper head  45  are made apart. Thus, the treatment chamber  48  is opened (STEP  313 ).  
      Then, the semiconductor wafer  100  and the interposer  200  that have been integrally bonded are taken out by the holding arm  23  of the arm robot  22 , and transferred into the outputting cassette  13  (STEP  314 ).  
      As described above, according to the bonding apparatus of the present embodiment, when the individual connection electrodes  103  of the semiconductor wafer  100  and the corresponding individual connection electrodes  203  of the interposer  200  are directly bonded, in the bonding apparatus, on the surfaces of the connection electrodes  103  and the connection electrodes  203 , the removing operation of the oxide films, the cleaning operation, the applying operation of the anti-oxidant if necessary, and the like are conducted. Thus, direct bonding of the connection electrodes  103  and the connection electrodes  203  can be achieved with a high reliability and a high bonding strength, without interposition of the oxide films.  
      In addition, the lower heater  44  and the upper heater  47  are heated at 120° C. in advance, and made in contact with the upper chuck  46  and the lower chuck  43 , so that the semiconductor wafer  100  and the interposer  200  are rapidly heated. Thus, oxidation of the connection electrodes  103  and the connection electrodes  203  can be prevented, after the removing operation of the oxide films.  
      As a result, reliability and yield of products can be improved in an assembling step of a semiconductor device or the like including the bonding step.  
      Herein, the present invention is not limited to the above embodiment, but may be variously modified. For example, in the above embodiment, the semiconductor wafer and the interposer are bonded as the objects to be bonded. However, not limited thereto, the present invention is applicable to a bonding step of a semiconductor wafer and a semiconductor chip, a bonding step of an interposer and a semiconductor chip, a bonding step of an interposer and a package, a bonding step of a semiconductor wafer and a package, a bonding step of a semiconductor wafer and a printed wiring board, a bonding step of an interposer and a printed wiring board, a bonding step of a semiconductor chip and a package, a bonding step of a semiconductor chip and a printed wiring board, and a bonding step of any elements in an assembling step of a semiconductor device.  
      In addition, in the above embodiment, the lower chamber wall  48   b  and the upper chamber wall  48   a  that forms the treatment chamber  48  are provided integrally with the lower chuck  43  and the upper head  45 , respectively. However, not limited thereto, the treatment chamber may be formed so as to be movable independently from the bonding apparatus. For example, at a cleaning operation just before a bonding operation, it is possible that members for forming a treatment chamber are inserted and held between the lower chuck  43  and the upper chuck  46 , and that the semiconductor wafer  100  and the interposer  200  held by the lower chuck  43  and the upper chuck  46  are contained in the treatment chamber formed by the members.  
      As a medicament, hydrochloric acid, sulfuric acid, or the like may be used. In addition, oxide-film-removing liquid may be used.  
      As a cleaning liquid, purified water, lactic acid, THF (5,6,7,8-tetrahydrofolic acid), ethanol, IPA (isopropyl alcohol), cyclohexane, toluene, or the like may be used, corresponding to a material of a wiring pattern and/or adhesive.  
      In addition, the flow of the bonding step shown in the above embodiment may be variously modified within a scope of summary of the present invention.  
      In addition, according to the present invention, in an assembling step of a semiconductor device or the like wherein wiring structures of objects to be bonded are directly bonded, reliability and/or yield can be improved.