Abstract:
A room temperature bonding method of the present invention includes a step of activating two substrates to prepare two activated substrates; a step of bonding the two activated substrates to produce a bonding resultant substrate; a step of performing annealing of the bonding resultant substrate to reduce residual stress of the bonding resultant substrate. According to such a room temperature bonding method, the residual stress of the bonding resultant substrate can be reduced and the quality can be improved.

Description:
TECHNICAL FIELD 
       [0001]    The present invention is related to a room temperature bonding apparatus and a room temperature bonding method, especially, to a room temperature bonding apparatus and a room temperature bonding method, which are used to bond a plurality of substrates. 
       BACKGROUND ART 
       [0002]    MEMS (Micro Electro-Mechanical System) is known in which minute electrical parts and mechanical parts are integrated. As the MEMS, a micro-machine, a pressure sensor, a micro motor and so on are exemplified. A technique of the room temperature bonding is known in which activated wafers are brought into contact in a vacuum ambience and the wafers are bonded. Such room temperature bonding is suitable to produce the MEMS. The MEMS formed by bonding the wafers with large warpage sometimes becomes a defective product. It is desired to produce devices with good quality stably. 
         [0003]    In JP 2003-318219A, a mounting method is disclosed in which bonding planes can be cleaned efficiently and uniformly with energy waves or energy particles, and the impurity absorption through etching of an opposing chamber wall can be avoided in case of cleaning in the chamber. In the mounting method, the energy waves or the energy particles are emitted between bonded objects opposing to each other from a single irradiation means to clean the bonding planes substantively simultaneously, and one of the bonded objects is rotated during the cleaning, and the bonded objects are bonded after alignment of the cleaned bonded objects. 
         [0004]    In JP 2006-73780A is disclosed a room temperature bonding method by which it is possible to bond without warpage. The room temperature bonding method in which the bonding is carried out after surface activation processing of the bonding planes of bonded objects by energy wave, an atomic beam, an ion beam or plasma, includes preliminary bonding at a room temperature and heating for substantially bonding. 
       CITATION LIST 
       [0005]    [Patent Literature 1] JP 2003-318219A 
         [0006]    [Patent Literature 2] JP 2006-73780A 
       SUMMARY OF THE INVENTION 
       [0007]    One object of the present invention is to provide a room temperature bonding apparatus and a room temperature bonding method, in which the quality of a product produced by bonding objects can be improved. 
         [0008]    Another object of the present invention is to provide a room temperature bonding apparatus and a room temperature bonding method, in which the product can be produced stably, by using the bonding of objects. 
         [0009]    Still another object of the present invention is to provide a room temperature bonding apparatus and a room temperature bonding method, in which the product can be produced at higher speed, by using the bonding of objects. 
         [0010]    The room temperature bonding apparatus of the present invention is provided with a bonding chamber in which a bonding resultant substrate is formed by bonding two substrates which are activated; and a heat chamber in which the bonding resultant substrate is annealed to reduce residual stress of the bonding resultant substrate. According to such a room temperature bonding apparatus, the residual stress of the bonding resultant substrate can be reduced and the quality can be improved. 
         [0011]    The room temperature bonding apparatus of the present invention is further provided with a control unit. The heat chamber is provided with a pressurization mechanism configured to pressurize the bonding resultant substrate. The control unit controls the pressurization mechanism to pressurize the bonding resultant substrate when the bonding resultant substrate is annealed. According to such a room temperature bonding apparatus, the bonding resultant substrate can be formed to have a predetermined shape. 
         [0012]    The room temperature bonding apparatus of the present invention is further provided with a sensor configured to measure the load applied to the bonding resultant substrate when the bonding resultant substrate is annealed. The control unit controls the pressurization mechanism such that the load does not exceed a predetermined load. Such a room temperature bonding apparatus can prevent that the bonding resultant substrate breaks by increasing the load applied to the bonding resultant substrate. 
         [0013]    The room temperature bonding apparatus of the present invention is further provided with a chamber in which desorption of absorption material from the two substrates is carried out before activating the two substrate. According to such a room temperature bonding method, it is possible to prevent voids from generating in the bonding plane of the bonding resultant substrate when the bonding resultant substrate is annealed and the bonding strength of the bonding resultant substrate can be improved. 
         [0014]    A room temperature bonding apparatus of the present invention is further provided with a cooling unit configured to cool the two substrates after desorption of the absorption material from the two substrates is carried out. The control unit controls the bonding chamber such that the two substrates are activated after the two substrates are cooled. 
         [0015]    The heat chamber is also used as the chamber where desorption of the absorption material from the two substrates is carried out before activating the two substrates. Such a room temperature bonding apparatus is desirably compact in size, compared with another room temperature bonding apparatus in which a chamber which anneals the bonding resultant substrate and a chamber for desorption of the absorption material from the two substrates are different. 
         [0016]    The heat chamber includes a first holding device configured to hold a first substrate as one of the two substrates; a second holding device configured to hold a second substrate as the other of the two substrates; a first heater configured to carry out desorption of the absorption material from the first substrate, when said first holding device holds the first substrate; and a second heater configured to carry out desorption of the absorption material from the second substrate when said second holding device holds the second substrate. When the bonding resultant substrate is annealed by the first heater, the control unit controls the pressurization mechanism such that the bonding resultant substrate is sandwiched and pressured by the first holding device and the second holding device. 
         [0017]    The room temperature bonding method of the present invention includes a step of activating two substrates to prepare two activated substrates; a step of bonding the two activated substrates to produce a bonding resultant substrate; and a step of annealing the bonding resultant substrate to reduce residual stress. According to such a room temperature bonding method, the residual stress of the bonding resultant substrate can be reduced and the quality can be further improved. 
         [0018]    The room temperature bonding method of the present invention is further provided with a step of pressurizing the bonding resultant substrate while the annealing is carried out to the bonding resultant substrate. According to such a room temperature bonding method, the bonding resultant substrate can be formed to have a predetermined shape. 
         [0019]    The room temperature bonding method of the present invention is further provided with a step of measuring a load to pressurize the bonding resultant substrate when the bonding resultant substrate is annealed; and a step of controlling the pressure such that the rises pressure to a predetermined pressure or above. According to such a room temperature bonding method, it is possible to prevent that the bonding resultant substrate breaks that the load applied to the bonding resultant substrate increases. 
         [0020]    The room temperature bonding method of the present invention is further provided with a step of carrying out desorption of absorption material from the two substrates before the step of activating the two substrates. According to such a room temperature bonding method, it is possible to prevent voids from generating in the bonding plane of the bonding resultant substrate when the bonding resultant substrate is annealed, and the bonding strength of the bonding resultant substrate can be improved. 
         [0021]    The room temperature bonding method of the present invention is further provided with a step of cooling the two substrates after a step of carrying out desorption of the absorption material from the two substrates. The two substrates are activated after the cooling. According to such a room temperature bonding method, a product can be produced at higher speed and the throughput can be improved. 
         [0022]    The bonding resultant substrate is annealed by using the heat chamber for carrying out desorption of the absorption material from the two substrates. A main portion of the room temperature bonding apparatus which executes such a room temperature bonding method is compact in size and desirable, compared with a main portion of another room temperature bonding apparatus in which a unit for annealing the bonding resultant substrate is different from a unit for carrying out desorption of the absorption material from the two substrates. 
         [0023]    The heat chamber is provided with a first holding device which holds a first substrate as one of the two substrates; a second holding device which holds a second substrate as the other of the two substrates; a first heater for carrying out desorption of the absorption material from the first substrate when the first holding device holds the first substrate; and a second heater for carrying out desorption of the absorption material from the second substrate when the second holding device holds the second substrate. The bonding resultant substrate is pressurized between the first holding device and the second holding device and the annealing is carried out by the first heater. 
         [0024]    The room temperature bonding apparatus and the room temperature bonding method of the present invention can reduce the residual stress of a product produced by bonding objects and it is possible to improve the quality of product. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]      FIG. 1  is a sectional view showing a main portion of a room temperature bonding apparatus; 
           [0026]      FIG. 2  is a sectional view showing a bonding chamber; 
           [0027]      FIG. 3  is a sectional view showing a heat chamber; 
           [0028]      FIG. 4  is a plan view showing an upper cartridge; 
           [0029]      FIG. 5  is a sectional view showing the upper cartridge; 
           [0030]      FIG. 6  is a plan view showing a lower cartridge; 
           [0031]      FIG. 7  is a sectional view showing the lower cartridge; 
           [0032]      FIG. 8  is a block diagram showing the configuration of a control unit of the room temperature bonding apparatus; 
           [0033]      FIG. 9  is a flow chart showing a room temperature bonding method of the present invention; 
           [0034]      FIG. 10  is a sectional view showing another heat chamber; 
           [0035]      FIG. 11  is a sectional view showing another heat chamber; 
           [0036]      FIG. 12  is a sectional view showing another heat chamber; 
           [0037]      FIG. 13  is a sectional view showing another main portion of the room temperature bonding apparatus; and 
           [0038]      FIG. 14  is a sectional view showing another main portion of the room temperature bonding apparatus. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0039]    Hereinafter, the room temperature bonding apparatus according to embodiments of the present invention will be described with reference to the drawings. The room temperature bonding apparatus is provided with a main portion of the room temperature bonding apparatus and a control unit of the room temperature bonding apparatus. As shown in  FIG. 1 , the main portion of the room temperature bonding apparatus is provided with a load lock chamber  1 , a bonding chamber  2 , and a heat chamber  3 . The load lock chamber  1 , the bonding chamber  2  and the heat chamber  3  are containers which seal their internal spaces from environment. Moreover, the main portion of the room temperature bonding apparatus is provided with a gate valve  5  and a gate valve  6 . The gate valve  5  is interposed between the load lock chamber  1  and the bonding chamber  2 , and configures a first gate which connects the inner space of the bonding chamber  2  and the inner space of the load lock chamber  1 . The gate valve  5  closes the first gate or opens the first gate under the control of the control unit of the bonding apparatus. The gate valve  6  is interposed between the load lock chamber  1  and the heat chamber  3  and configures a second gate which connects the inner space of the heat chamber  3  and the inner space of the load lock chamber  1 . The gate valve  6  closes the second gate or opens the second gate under the control of the control unit of the bonding apparatus. 
         [0040]    The load lock chamber  1  is provided with a lid which is not shown. The lid closes the gate which connects environment and the inner space of the load lock chamber  1  or opens the gate. The load lock chamber  1  is provided with a vacuum pump which is not shown. The vacuum pump is controlled by the control unit of the bonding apparatus when the lid, the gate valve  5  and the gate valve  6  are closed, to exhaust gas from the inner space of the load lock chamber  1 . As the vacuum pump, a turbo-molecular pump, a cryopump, an oil diffusion pump is exemplified. 
         [0041]    Moreover, the load lock chamber  1  is provided with a plurality of shelves  7  and a conveyance robot  8  in its inner space. A plurality of cartridges are put on the plurality of shelves  7 . When the gate valve  5  is open, the conveyance robot  8  is controlled by the control unit of the bonding apparatus, to convey the cartridge arranged in the plurality of shelves  7  to the bonding chamber  2 , or to convey the cartridge arranged in the bonding chamber  2  to the plurality of shelves  7 . Moreover, when the gate valve  6  is open, the conveyance robot  8  is controlled by the control unit of the bonding apparatus, to convey the cartridge arranged in the plurality of shelves  7  to the heat chamber  3  or to convey the cartridge arranged in the heat chamber  3  to the plurality of shelves  7 . 
         [0042]    The bonding chamber  2  is provided with a vacuum pump  10 . When the gate valve  5  is closed, the vacuum pump  10  is controlled by the control unit of the bonding apparatus to exhaust gas from the inner space of the bonding chamber  2 . As the vacuum pump  10 , a turbo-molecular pump, a cryopump, and an oil diffusion pump are exemplified. 
         [0043]    The heat chamber  3  is provided with the vacuum pump which is not shown. When the gate valve  6  is closed, the vacuum pump is controlled by the control unit of the bonding apparatus to exhaust gas from the inner space of the heat chamber  3 . As the vacuum pump, a turbo-molecular pump, a cryopump, and an oil diffusion pump are exemplified. 
         [0044]    As shown in  FIG. 2 , the bonding chamber  2  is further provided with a positioning stage carriage  11  and a position adjusting mechanism  12 . The positioning stage carriage  11  is formed in a plate manner. The positioning stage carriage  11  is arranged in the inner space of the bonding chamber  2  and is supported to be rotatable around a rotation axis parallel to a vertical direction and to be movable in parallel to a horizontal direction. The positioning stage carriage  11  is used to hold a cartridge. The position adjusting mechanism  12  is controlled by the control unit of the bonding apparatus to move the positioning stage carriage  11  in such a manner that the positioning stage carriage  11  moves in the horizontal direction or the positioning stage carriage  11  rotates around the rotation axis parallel to the vertical direction. 
         [0045]    Moreover, the bonding chamber  2  is provided with a pressure welding axis  14 , an electrostatic chuck  15 , a pressure welding mechanism  16  and load meters  17 . The pressure welding axis  14  is supported to be movable in parallel to the vertical direction to the bonding chamber  2 . The electrostatic chuck  15  is arranged in the bottom of the pressure welding axis  14 . The electrostatic chuck  15  is formed from a dielectric layer in which an inner electrode is arranged. The dielectric layer is formed of alumina-based ceramic and a flat surface is formed in the bottom. The electrostatic chuck  15  is controlled by the control unit of the bonding apparatus, and is applied with a predetermined voltage to the inner electrode. The electrostatic chuck  15  holds the wafer arranged in the neighborhood of the flat surface of the dielectric layer by the electrostatic force when the predetermined voltage is applied to the inner electrode. The pressure welding mechanism  16  is controlled by the control unit of the bonding apparatus to move the pressure welding axis  14  in parallel to the vertical direction to the bonding chamber  2 . Moreover, the pressure welding mechanism  16  measures a position of the electrostatic chuck  15  and outputs the measured position to the control unit of the bonding apparatus. The load meter  17  measures a load which is applied to the wafer held by electrostatic chuck  15  by measuring the load applied to the pressure welding axis  14 , and outputs the measured load to the control unit of the bonding apparatus. 
         [0046]    Moreover, the bonding chamber  2  is provided with an ion gun  18  and an electron source  19 . The ion gun  18  is controlled by the control unit of the bonding apparatus to emit the accelerated argon ions. The ion gun  18  is fixed on the bonding chamber  2  in such a manner that the argon ions are emitted in the space between the positioning stage carriage  11  and the electrostatic chuck  15 , that is, the argon ions are irradiated to the wafer held by the positioning stage carriage  11  and the wafer held by the electrostatic chuck  15 . The electron source  19  is controlled by the control unit of the bonding apparatus to emit accelerated electrons. The electron source  19  is fixed on the bonding chamber  2  in such a manner that the electrons are emitted in the space between the position adjusting mechanism  12  and the electrostatic chuck  15 , that is, the electrons are irradiated to the wafer held by the positioning stage carriage  11  and the wafer held by the electrostatic chuck  15 . 
         [0047]    Moreover, the ion gun  18  is provided with a metal target which is not shown. The metal target is formed of a plurality of metals and is arranged in the position where the argon ions are irradiated. The metal target emits the atoms of the plurality of metals to the inner space of the bonding chamber  2  when the argon ions are irradiated. It should be noted that a metal grid may be used in substitution for the metal target. The metal grid is a metal member which has openings and is arranged at an outgoing radiation end of the ion gun  18 . The metal grid emits the atoms of the plurality of metals into the inner space of the bonding chamber  2  by the irradiated argon ions, like the metal target. It should be noted that the metal target may be omitted when it is not necessary to adhere the metal atoms to the bonding planes of the wafers. 
         [0048]      FIG. 3  shows the heat chamber  3 . The heat chamber  3  is provided with a chamber base  21 , a heat sink  22 , an adiabatic member  23 , a sample stand  24  and a heater  25 . The chamber base  21  is a basis to form a part of the heat chamber  3  and to support the heat sink  22 , the adiabatic member  23 , the sample stand  24  and the heater  25 . The heat sink  22  is fixed on the chamber base  21 . The adiabatic member  23  is formed of quartz and is fixed on the chamber base  21  through the heat sink  22 . It should be noted that the adiabatic member  23  can be formed from another thermal protection system with a high thermal shock which is different from quartz. As the thermal protection system, quartz glass is exemplified. The adiabatic member  23  is provided with passages  26 . The passage  26  configures a conduit line through which nitrogen gas flows. The nitrogen gas is supplied from outside the heat chamber  3  by the cooling unit which is not shown. The sample stand  24  is formed of aluminum nitride AlN and is fixed on the chamber base  21  through the adiabatic member  23 . It should be noted that the sample stand  24  can be formed of other materials different from aluminum nitride AlN and having an excellent heat transfer rate. As the material, carbonization silicon SiC is exemplified. In the sample stand  24 , a holding surface  27  is formed on the side opposite to the side which is connected to the adiabatic member  23 . The holding surface  27  is formed in such a manner that the cartridge is held by the sample stand  24 . A heater  25  is arranged in the sample stand  24 . The heater  25  is controlled by the control unit of the room temperature bonding apparatus to generate heat and to heat the wafer put on the cartridge. At this time, the cooled coolant is always supplied from the outside of the heat chamber  3  and prevents that the heat chamber  3  is heated when the heater  25  is turned on. 
         [0049]    Moreover, the heat chamber  3  is provided with a substrate hold element  31 , a heat sink  32 , an angle adjusting mechanism  33 , a load cell  34  and a pressurizing mechanism  35 . The substrate hold element  31  is formed of quartz. A holding surface  36  is formed on the side of the substrate hold element  31  opposite to the sample stand  24 . The holding surface  36  is formed flatly. The substrate hold element  31  is connected to the heat sink  32  on the side opposite to the side on which the holding surface  36  is formed. The heat sink  32  is connected to the angle adjusting mechanism  33  on the side opposite to the side which is connected to the substrate hold element  31 . The angle adjusting mechanism  33  is connected to the load cell  34 . The load cell  34  is supported to be moveable into the perpendicular direction to the upper surface of the chamber base  21 . At this time, the cooled coolant is always supplied from the outside of the heat chamber  3  to the heat sink  32  and prevents that the angle adjusting mechanism  33  and the load cell  34  are heated when the substrate hold element  31  is heated. 
         [0050]    The pressurization mechanism  35  is controlled by the control unit of the room temperature bonding apparatus to move the angle adjusting mechanism  33  into the perpendicular direction to the upper surface of the chamber base  21 , that is, to move the substrate hold element  31  in the perpendicular direction to the upper surface of the chamber base  21 . The load cell  34  is provided with a piezoelectric element, and measures the load applied to the holding surface  36  and a bias of the load applied to the substrate hold element  31 . The load cell  34  outputs the load and the bias to the control unit of the room temperature bonding apparatus. The angle adjusting mechanism  33  is controlled by the control unit of the room temperature bonding apparatus to change the orientation of the holding surface  36 . 
         [0051]    In the load cell  34 , when the piezoelectric element is heated, an error of a measurement value sometimes becomes large. The load cell  34  can measure the load and the bias in high accuracy by preventing the heat by the heat sink  32 . 
         [0052]    The plurality of cartridges put on the plurality of shelves  7  contains an upper cartridge and a lower cartridge.  FIG. 4  shows an upper cartridge. The upper cartridge  41  is formed of aluminum, stainless steel or aluminum nitride, and is formed to have a disk-like shape. In the upper cartridge  41 , a plurality of islands  42 - 1  to  42 - 4  are formed on the upper surface of the disk. The plurality of islands  42 - 1  to  42 - 4  are formed as prominences which protrude from the upper surface of the disk such that the upper ends of the prominences are on one plane. 
         [0053]    As shown in  FIG. 5 , the upper cartridge  41  has a flange  44  and a main portion  45 . The main portion  45  is formed like a circular column. The flange  44  is formed to extend from the side of the circular column of the main portion  45  and to have a disk shape. That is, the upper cartridge  41  is held by the conveyance robot  8  by scooping the flange  44 . 
         [0054]    The upper cartridge  41  is used by putting an upper wafer  46  on the plurality of islands  42 - 1  to  42 - 4 . That is, the plurality of islands  42 - 1  to  42 - 4  are formed along the periphery of the upper wafer  46 . The upper cartridge  41  is formed such that the lower surface of the upper wafer  46  touches the upper cartridge  41  in as a less area as possible, or the lower surface of the upper wafer  46  is not polluted by the upper cartridge  41 , when the upper wafer  46  is put on the plurality of islands  42 - 1  to  42 - 4 . The plurality of islands  42 - 1  to  42 - 4  are formed in such a manner that at least one passage is formed in the space between the upper cartridge  41  and the upper wafer  46  so as to be connected with the outside, when the upper wafer  46  is put on the plurality of islands  42 - 1  to  42 - 4 . That is, the plurality of islands  42 - 1  to  42 - 4  are formed so as not to connect to each other. 
         [0055]      FIG. 6  shows a lower cartridge  51 . The lower cartridge  51  is formed of aluminum, stainless steel or aluminum nitride, is formed to have a disk-like shape and is used to put a lower wafer. Moreover, islands  52  are formed in the upper surface of the disk on the lower cartridge  51 . The islands  52  are formed as prominences which protrude from the upper surface of the disk, and are formed to have the almost same shape as the lower wafer put on the lower cartridge  51 . The upper ends of the prominences are in a same plane. Ditches  53  are provided for the upper portion of the islands  52 . The ditches  53  are formed in a grid shape between the islands. Moreover, the ditches  53  are formed to be connected with the sides of the islands  52 . 
         [0056]    The lower cartridge  51  is formed to have a flange  54  and a main portion  55 , as shown in  FIG. 7 . The main portion  55  is formed to have a circular column shape. The flange  54  is formed to extend from the side of the circular column of the main portion  55  and is formed to have a disk shape. That is, the lower cartridge  51  is held by the conveyance robot  8  by scooping the flange  54 . 
         [0057]    The lower cartridge  51  is used by putting the lower wafer  56  on the islands  52 . That is, the islands  52  are formed along the periphery of the lower wafer  56 . Moreover, the island s 52  are formed in the lower cartridge  51  in such a manner that any passage extending to the outside is formed in the space between the lower cartridge  51  and the lower wafer  56  when the lower wafer  56  is put on the islands  52 . That is, the islands  52  are formed so as not to connect to each other. 
         [0058]      FIG. 8  shows the control unit  61  of the room temperature bonding apparatus. The control unit  61  of the room temperature bonding apparatus is a computer and is provided with a CPU, a storage, a removable memory drive, a communication unit, an input unit, an output unit and an interface, which are not shown. The CPU executes a computer program which is installed in the control unit  61  of the room temperature bonding apparatus, and controls the storage, the removable memory drive, the communication unit, the input unit, the output unit and the interface. The storage stores the computer program. Moreover, the storage stores data which are used by the CPU. The removable memory drive is used to install the computer program in the control unit  61  of the room temperature bonding apparatus when a storage medium in which the computer program is recorded is inserted. The communication unit is used to download the computer program in the control unit  61  of the room temperature bonding apparatus from another computer which is connected with the control unit  61  of the room temperature bonding apparatus through a communication network and installs the computer program in the control unit  61  of the room temperature bonding apparatus. The input unit outputs data generated by a user to the CPU. As the input unit, a keyboard and a mouse are exemplified. The output unit outputs data generated by the CPU in the form with which it is possible to be recognized by the user. As the output unit, a display which displays images generated by the CPU is exemplified. 
         [0059]    The interface outputs the data generated by the CPU to an external unit connected with the control unit  61  of the room temperature bonding apparatus and the data generated by the external unit to the CPU. The external unit is provided with the gate valve  5 , the gate valve  6 , the conveyance robot  8 , the vacuum pump which exhausts from the load lock chamber  1 , the vacuum pump which exhausts from the heat chamber  3 , the vacuum pump  10 , the position adjusting mechanism  12 , the electrostatic chuck  15 , the pressure welding mechanism  16 , the load meter  17 , the ion gun  18 , the electron source  19 , the heater  25 , the cooling unit which supplies the coolant to the passages  26 , the heater  25 , the angle adjusting mechanism  33 , the load cell  34 , and the pressurization mechanism  35 . 
         [0060]    The computer program is installed in the control unit  61  of the room temperature bonding apparatus and is formed from a plurality of computer programs for the control unit  61  of the room temperature bonding apparatus to realize a plurality of functions. The plurality of functions contain a conveying section  62 , a pre-heating section  63 , a bonding section  64  and a post-heating section  65 . 
         [0061]    When the gate valve  5  and the gate valve  6  are closed, the conveying section  62  controls the vacuum pump of the load lock chamber  1  such that a preliminary atmosphere of a given degree of vacuum is generated in the inner space of the load lock chamber  1  or an atmospheric pressure atmosphere is generated in the inner space of the load lock chamber  1 . When the preliminary atmosphere is generated in the inner space of the load lock chamber  1 , the conveying section  62  controls the gate valve  5  to be opened and closed and the gate valve  6  to be opened and closed. 
         [0062]    When the gate valve  5  is opened, the conveying section  62  controls the conveyance robot  8  such that the upper cartridge  41  or lower cartridge  51  arranged in the plurality of shelves  7  is conveyed to the positioning stage carriage  11  in the bonding chamber  2 , or the upper cartridge  41  or lower cartridge  51  held by the positioning stage carriage  11  is conveyed to the plurality of shelves  7  in the load lock chamber  1 . When the gate valve  6  is opened, the conveying section  62  controls the conveyance robot  8  such that the upper cartridge  41  or lower cartridge  51  arranged in the plurality of shelves  7  is conveyed to the sample stand  24  in the heat chamber  3  or the upper cartridge  41  or lower cartridge  51  held by the sample stand  24  of the heat chamber  3  is conveyed to the plurality of shelves  7  in the load lock chamber  1 . 
         [0063]    When the gate valve  6  is closed, the pre-bonding heating section  63  controls the vacuum pump of the heat chamber  3  such that a desorption atmosphere of a given degree of vacuum is generated in the inner space of the heat chamber  3 . When the desorption atmosphere is generated in the inner space of the heat chamber  3  and the upper cartridge  41  is held by the sample stand  24  in the heat chamber  3 , the pre-bonding heating section  63  controls the heater  25  such that the upper wafer  46  put on the upper cartridge  41  is heated to a predetermined desorption temperature, that is, desorption of absorption material is carried out from the upper wafer  46 . The absorption material is material which is adhered to the upper wafer  46  and water and atmosphere components are exemplified. As the desorption temperature, 200° C. is exemplified. The pre-bonding heating section  63  controls the heater  25  such that the upper wafer  46  is not heated after the upper wafer  46  is heated for a predetermined time period, that is, after desorption of the absorption materials are sufficiently carried out from the upper wafer  46 , and controls a cooling unit of the heat chamber  3  such that nitrogen gas flows through the passages  26 , that is, the upper wafer  46  is cooled to the bonding temperature. The bonding temperature is set to be contained in a temperature range in which a product produced from the upper wafer  46  is used. 
         [0064]    When the desorption atmosphere is generated in the inner space of the heat chamber  3  and the lower cartridge  51  is held by the sample stand  24  in the heat chamber  3 , the pre-bonding heating section  63  controls the heater  25  in such a manner that the lower wafer  56  put on the lower cartridge  51  is heated at a predetermined desorption temperature, that is, desorption of the absorption material is carried out from the lower wafer  56 . After the lower wafer  56  is heated for a predetermined time period, that is, after desorption of the absorption material is sufficiently carried out from the lower wafer  56 , the pre-bonding heating section  63  controls the heater  25  not to heat the lower wafer  56 , and controls a cooling unit of the heat chamber  3  such that the nitrogen gas flows through the passages  26 , that is, the lower wafer  56  is cooled to the bonding temperature. 
         [0065]    When the upper cartridge  41  is put on the positioning stage carriage  11 , the bonding section  64  controls the pressure welding mechanism  16  such that the electrostatic chuck  15  falls down. When the electrostatic chuck  15  falls down, the bonding section  64  controls the load meter  17  to measure the load applied to the electrostatic chuck  15 . The bonding section  64  calculates based on the load, a timing at which the load reaches a given contact load, namely, calculates the timing at which the upper wafer  46  on the upper cartridge  41  touches the electrostatic chuck  15 . The bonding section  64  controls the pressure welding mechanism  16  to stop the electrostatic chuck  15  at the timing. The bonding section  64  controls the electrostatic chuck  15  such that the electrostatic chuck  15  holds the upper wafer  46  when the upper wafer  46  on the upper cartridge  41  is in contact with the electrostatic chuck  15 . The bonding section  64  controls the pressure welding mechanism  16  to raise the electrostatic chuck  15  when the electrostatic chuck  15  holds the upper wafer  46  on the upper cartridge  41 . 
         [0066]    The bonding section  64  controls the vacuum pump  10  such that a bonding atmosphere of a given degree of vacuum is generated in the inner space of the bonding chamber  2  when the gate valve  5  is closed. Moreover, when the bonding atmosphere is generated in the inner space of the bonding chamber  2 , the bonding section  64  controls the ion gun  18  such that the argon ions are irradiated to the upper wafer  46  and the lower wafer  56 . Moreover, the bonding section  64  controls the electron source  19  such that electrons are emitted while the argon ions are emitted. 
         [0067]    Moreover, when the electrostatic chuck  15  holds the upper wafer  46  and the lower cartridge  51  is put on the positioning stage carriage  11 , the bonding section  64  controls the pressure welding mechanism  16  such that the lower wafer  56  and upper wafer  46  on the lower cartridge  51  approach to each other to a given adjustment distance. Moreover, when the upper wafer  46  is apart from the lower wafer  56  by an adjustment distance, the bonding section  64  controls the position adjusting mechanism  12  such that the lower wafer  56  is arranged in the adjustment position from the upper wafer  46 . An adjustment position is set such that the upper wafer  46  and the lower wafer  56  are bonded as designed when the electrostatic chuck  15  falls down. 
         [0068]    Moreover, the bonding section  64  controls the pressure welding mechanism  16  for the electrostatic chuck  15  to descend when the lower wafer  56  is arranged in the adjustment position. The bonding section  64  controls the load meter  17  to measure the load applied to the electrostatic chuck  15  when the electrostatic chuck  15  falls down. The bonding section  64  calculates the timing when the load reaches a given bonding load. The bonding section  64  controls the pressure welding mechanism  16  such that the electrostatic chuck  15  stops at the calculated timing, that is, the bonding load is applied to the upper wafer  46  and the lower wafer  56 . 
         [0069]    After the bonding load is applied to the upper wafer  46  and the lower wafer  56  for the given bonding time period, the bonding section  64  controls the electrostatic chuck  15  such that a bonding resultant wafer produced from the upper wafer  46  and the lower wafer  56  leave the electrostatic chuck  15 . The bonding section  64  controls the pressure welding mechanism  16  to raise the electrostatic chuck  15  after the bonded wafer leaves the electrostatic chuck  15 . 
         [0070]    When the lower cartridge  51  is held by the sample stand  24  in the heat chamber  3 , the post-bonding heating section  65  controls the pressurization mechanism  35  to fall down the substrate hold element  31 . When the substrate hold element  31  falls down, the post-bonding heating section  65  controls the load cell  34  to measure the load applied to the substrate hold element  31 , and to measure the bias of the load applied to the substrate hold element  31 . The post-bonding heating section  65  controls the pressurization mechanism  35  such that a given hold load is applied to the bonding resultant wafer. The post-bonding heating section  65  controls the angle adjusting mechanism  33  based on the bias such that the holding surface  36  of the substrate hold element  31  becomes parallel to the upper surface of the bonding resultant wafer, that is, the hold load is uniformly applied to the bonding wear. 
         [0071]    When the given hold load is applied to the bonding resultant wafer, the post-bonding heating section  65  controls the heater  25  such that the bonding resultant wafer is heated at a predetermined annealing temperature, that is, the bonding resultant wafer is subjected to an annealing. As the annealing temperature, 480° C. is exemplified. The post-bonding heating section  65  controls the heater  25  such that the lower cartridge  51  is not heated after the bonding resultant wafer is heated for a predetermined time period, that is, after the bonding resultant wafer is annealed, and controls the cooling unit of the heat chamber  3  such that the nitrogen gas flows through the passages  26 , that is, the lower cartridge  51  is cooled to a transportable temperature. Moreover, the post-bonding heating section  65  controls the pressurization mechanism  35  such that the substrate hold element  31  rises after the bonding resultant wafer is annealed. 
         [0072]      FIG. 9  shows an embodiment of the room temperature bonding method of the present invention. The room temperature bonding method is executed by using the room temperature bonding apparatus of the present invention. The control unit  61  of the room temperature bonding apparatus controls the gate valve  5  to close the first gate which connects the inner space of the load lock chamber  1  and the inner space of the bonding chamber  2 , and controls the gate valve  6  to close the second gate which connects the inner space of the load lock chamber  1  and the inner space of the heat chamber  3 . When the gate valve  5  and the gate valve  6  are closed, the control unit  61  of the room temperature bonding apparatus controls the vacuum pump of the load lock chamber  1  such that an atmospheric pressure atmosphere is generated in the inner space of the load lock chamber  1 , and controls the vacuum pump  10  such that a bonding atmosphere is generated in the inner space of the bonding chamber  2 , and controls the vacuum pump of the heat chamber  3  such that a desorption atmosphere is generated in the inner space of the heat chamber  3 . 
         [0073]    When the atmospheric pressure atmosphere is generated in the inner space of the load lock chamber  1 , the user opens the lid of the load lock chamber  1  and arranges a plurality of cartridges on the plurality of shelves  7 . The plurality of cartridges contain a plurality of upper cartridges  41  and a plurality of lower cartridges  51 . The upper wafers  46  are put on the upper cartridges  41 . The lower wafers  56  are put on the lower cartridges  51 . The user closes the lid of the load lock chamber  1  after arranging the plurality of cartridges on the plurality of shelves  7 . When the lid of the load lock chamber  1  is closed, the control unit  61  of the room temperature bonding apparatus controls the vacuum pump of the load lock chamber  1  such that the preliminary atmosphere is generated in the inner space of the load lock chamber  1  (Step S 1 ). 
         [0074]    The control unit  61  of the room temperature bonding apparatus controls the gate valve  6  such that the gate valve  6  is opened when the preliminary atmosphere is generated in the inner space of the load lock chamber  1 . When the gate valve  6  is opened, the control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that an upper cartridge  41  as one of the plurality of cartridges which have been arranged on the plurality of shelves  7  is conveyed on the sample stand  24  of the heat chamber  3  (Step S 2 ). 
         [0075]    The control unit  61  of the room temperature bonding apparatus controls the gate valve  6  to close the gate valve  6  after the upper cartridge  41  is held by the sample stand  24  of the heat chamber  3 . When the gate valve  6  is closed, the control unit  61  of the room temperature bonding apparatus controls the vacuum pump of the heat chamber  3  such that the desorption atmosphere is generated in the inner space of the heat chamber  3 . When the desorption atmosphere is generated in the inner space of the heat chamber  3 , the control unit  61  of the room temperature bonding apparatus controls the heater  25  such that the upper wafer  46  put on the upper cartridge  41  is heated to the predetermined desorption temperature, that is, desorption of the absorption material is carried out from the upper wafer  46  (Step S 3 ). The control unit  61  of the room temperature bonding apparatus controls the heater  25  not to heat the upper wafer  46 , after the upper wafer  46  is heated for the predetermined time period, that is, after desorption of the absorption material is sufficiently carried out from the upper wafer  46 , and controls the cooling unit of the heat chamber  3  such that the nitrogen gas flows through the passages  26 , that is, the upper wafer  46  is cooled to the bonding temperature. 
         [0076]    The control unit  61  of the room temperature bonding apparatus controls the gate valve  6  such that the gate valve  6  is opened after the desorption of the absorption material is sufficiently carried out from the upper wafer  46 . The control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the upper cartridge  41  is conveyed from the sample stand  24  of the heat chamber  3  to the plurality of shelves  7  after the upper wafer  46  is cooled to the bonding temperature. 
         [0077]    Next, after the upper cartridge  41  is conveyed from the sample stand  24  of the heat chamber  3 , the control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that a lower cartridge  51  as a next one of the plurality of cartridges arranged in the plurality of shelves  7  is conveyed to the sample stand  24  of the heat chamber  3  (Step S 2 ). The control unit  61  of the room temperature bonding apparatus controls the gate valve  6  such that the gate valve  6  is closed after the lower cartridge  51  is held by the sample stand  24  of the heat chamber  3 . When the gate valve  6  is in the closed state, the control unit  61  of the room temperature bonding apparatus controls the vacuum pump of the heat chamber  3  such that the desorption atmosphere is generated in the inner space of the heat chamber  3 . When the desorption atmosphere is generated in the inner space of the heat chamber  3 , the control unit  61  of the room temperature bonding apparatus controls the heater  25  such that the lower wafer  56  put on the lower cartridge  51  is heated at the predetermined desorption temperature, that is, desorption of absorption material is carried out from the lower wafer  56  (Step S 3 ). After the lower wafer  56  is heated for the predetermined time period, that is, after the desorption of the absorption material is sufficiently carried out from the lower wafer  56 , the control unit  61  of the room temperature bonding apparatus controls the heater  25  such that the lower wafer  56  is not heated, and controls the cooling unit of the heat chamber  3  such that nitrogen gas flows through the passages  26 , that is, the lower wafer  56  is cooled to the bonding temperature. 
         [0078]    The control unit  61  of the room temperature bonding apparatus controls the gate valve  6  such that the gate valve  6  is opened after the desorption of the absorption material is sufficiently carried out from the lower wafer  56 . The control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the lower cartridge  51  is conveyed from the sample stand  24  of the heat chamber  3  to the plurality of shelves  7  after the lower wafer  56  is cooled to the bonding temperature. 
         [0079]    The control unit  61  of the room temperature bonding apparatus controls the gate valve  5  such that the gate valve  5  is opened after the desorption of the absorption material is sufficiently carried out from the upper wafer  46  and the lower wafer  56 . The control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the upper cartridge  41  on which the upper wafer  46  subjected to the desorption is put is conveyed from the plurality of shelves  7  to the positioning stage carriage  11  of the bonding chamber  2 . Next, the control unit  61  of the room temperature bonding apparatus controls the pressure welding mechanism  16  such that the electrostatic chuck  15  falls down. The control unit  61  of the room temperature bonding apparatus controls the load meter  17  such that the load applied to the electrostatic chuck  15  is measured when the electrostatic chuck  15  falls down. The control unit  61  of the room temperature bonding apparatus calculates based on the load, a timing at which the load reaches a predetermined contact load, i.e. the timing at which the upper wafer  46  on the upper cartridge  41  touches the electrostatic chuck  15 . The control unit  61  of the room temperature bonding apparatus controls the pressure welding mechanism  16  such that the electrostatic chuck  15  stops at the timing. 
         [0080]    The control unit  61  of the room temperature bonding apparatus controls the electrostatic chuck  15  such that the electrostatic chuck  15  holds the upper wafer  46  when the electrostatic chuck  15  touches the upper wafer  46  on the upper cartridge  41 . The control unit  61  of the room temperature bonding apparatus controls the pressure welding mechanism  16  such that the electrostatic chuck  15  rises when the electrostatic chuck  15  holds the upper wafer  46  on the upper cartridge  41 . The control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the upper cartridge  41  with no upper wafer  46  is conveyed from the positioning stage carriage  11  to the plurality of shelves  7  after the electrostatic chuck  15  rises to a given activation position. 
         [0081]    The control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the lower cartridge  51  on which the lower wafer  56  subjected to the desorption is put, from the plurality of shelves  7  to the positioning stage carriage  11  after the upper cartridge  41  has been conveyed to the plurality of shelves  7 . The control unit  61  of the room temperature bonding apparatus controls the gate valve  5  such that the gate valve  5  is closed after the lower cartridge  51  is held by the positioning stage carriage  11  (Step S 4 ). 
         [0082]    When the gate valve  5  is closed, the control unit  61  of the room temperature bonding apparatus controls the vacuum pump  10  such that the bonding atmosphere is generated in the inner space of the bonding chamber  2 . When the bonding atmosphere is generated in the inner space of the bonding chamber  2 , the control unit  61  of the room temperature bonding apparatus controls the ion gun  18  such that argon ions are irradiated to the upper wafer  46  and the lower wafer  56 . Moreover, the control unit  61  of the room temperature bonding apparatus controls the electron source  19  such that electrons are emitted while the argon ions are emitted (Step S 5 ). 
         [0083]    The control unit  61  of the room temperature bonding apparatus controls the pressure welding mechanism  16  such that the lower wafer  56  and the upper wafer  46  approach to the given adjustment distance. When the upper wafer  46  and the lower wafer  56  leave by the adjustment distance, the control unit  61  of the room temperature bonding apparatus controls the position adjusting mechanism  12  such that the lower wafer  56  is arranged in a given adjustment position to the upper wafer  46 . 
         [0084]    Moreover, the control unit  61  of the room temperature bonding apparatus controls the pressure welding mechanism  16  such that the electrostatic chuck  15  falls down after the lower wafer  56  is arranged in the adjustment position. The control unit  61  of the room temperature bonding apparatus controls the load meter  17  such that the load applied to the electrostatic chuck  15  is measured when the electrostatic chuck  15  falls down. The control unit  61  of the room temperature bonding apparatus calculates the timing at which the load reaches the predetermined bonding load. The control unit  61  of the room temperature bonding apparatus controls the pressure welding mechanism  16  such that the electrostatic chuck  15  stops at the timing, that is, the bonding load is applied to the upper wafer  46  and the lower wafer  56  (Step S 6 ). The lower wafer  56  and the upper wafer  46  are bonded by applying the bonding load to form a bonding resultant wafer. 
         [0085]    The control unit  61  of the room temperature bonding apparatus controls the electrostatic chuck  15  such that the bonding resultant wafer leaves the electrostatic chuck  15  after the bonding load is applied for a given bonding time period. The control unit  61  of the room temperature bonding apparatus controls the pressure welding mechanism  16  such that the electrostatic chuck  15  rises after the bonding resultant wafer leaves the electrostatic chuck  15 . 
         [0086]    The control unit  61  of the room temperature bonding apparatus controls the gate valve  5  such that the gate valve  5  is opened after the electrostatic chuck  15  rises sufficiently. When the gate valve  5  is opened, the control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the lower cartridge  51  on which the bonding resultant wafer is put is conveyed from the positioning stage carriage  11  to the load lock chamber  1 . 
         [0087]    The control unit  61  of the room temperature bonding apparatus controls the gate valve  6  such that the gate valve  6  is opened when the preliminary atmosphere is generated in the inner space of the load lock chamber  1 . The control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the lower cartridge  51  on which the bonding resultant wafer is put is conveyed from the load lock chamber  1  to the sample stand  24  of the heat chamber  3  when the gate valve  6  is opened (Step S 7 ). 
         [0088]    The control unit  61  of the room temperature bonding apparatus controls the pressurization mechanism  35  such that the substrate hold element  31  falls down when the lower cartridge  51  is held on the sample stand  24  of the heat chamber  3 . When the substrate hold element  31  falls down, the control unit  61  of the room temperature bonding apparatus controls the load cell  34  such that the load applied to the substrate hold element  31  is measured, and the bias of the load applied to the substrate hold element  31  is measured. The control unit  61  of the room temperature bonding apparatus controls the pressurization mechanism  35  in a predetermined sampling period such that a given pressing load is applied to the bonding resultant wafer. The control unit  61  of the room temperature bonding apparatus controls the angle adjusting mechanism  33  in the predetermined sampling period such that the holding surface  36  of the substrate hold element  31  becomes parallel to the upper surface of the bonding resultant wafer based on the bias, that is, the pressing load is uniformly applied to the bonding resultant wafer. When the pressing load is applied to the bonding resultant wafer, the control unit  61  of the room temperature bonding apparatus controls the heater  25  in the predetermined sampling period such that the bonding resultant wafer is heated at a predetermined annealing temperature, that is, the bonding resultant wafer is annealed (Step S 8 ). 
         [0089]    The bonding resultant wafer is heated for a predetermined annealing time period, and the residual stress is reduced. The annealing time for several minutes is exemplified. After the bonding resultant wafer is annealed, the control unit  61  of the room temperature bonding apparatus controls the heater  25  not to heat the lower cartridge  51 , and controls the cooling unit of the heat chamber  3  such that nitrogen gas flows through the passages  26 , that is, the lower cartridge  51  is cooled to the transportable temperature. As the transportable temperature, the room temperature is exemplified. After the bonding resultant wafer is annealed, the control unit  61  of the room temperature bonding apparatus controls the pressurization mechanism  35  to raise the substrate hold element  31 . After the substrate hold element  31  rises sufficiently, the control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the lower cartridge  51  on which the annealed bonding resultant wafer is put is conveyed from the positioning stage carriage  11  to the plurality of shelves  7  (Step S 9 ). 
         [0090]    When the upper cartridge  41  on which the upper wafer  46  is put and the lower cartridge  51  on which the lower wafer  56  is put are arranged in the plurality of shelves  7  (Step S 10 , YES), the control unit  61  of the room temperature bonding apparatus executes the operation of the steps S 2  to S 9  repeatedly again. 
         [0091]    When the wafer to be bonded is not arranged in the plurality of shelves  7  (Step S 10 , NO), the control unit  61  of the room temperature bonding apparatus controls the gate valve  5  such that the gate valve  5  is closed, and controls the gate valve  6  such that the gate valve  6  is closed. The control unit  61  of the room temperature bonding apparatus controls the vacuum pump of the load lock chamber  1  such that an atmospheric pressure atmosphere is generated in the inner space of the load lock chamber  1  after the gate valve  5  and the gate valve  6  are closed. The user opens the lid of the load lock chamber  1  after the atmospheric pressure atmosphere is generated in the inner space of the load lock chamber  1  and takes out the plurality of cartridges from the plurality of shelves  7 . The plurality of cartridges contain the plurality of upper cartridges  41  and the plurality of lower cartridges  51 . The bonding resultant wafer is put on the lower cartridge  51 . 
         [0092]    Moreover, when the upper wafer  46  and the lower wafer  56  should be bonded at the room temperature, the user executes the above room temperature bonding method once again after arranging the upper cartridge  41  on which the upper wafer  46  is put and the lower cartridge  51  on which the lower wafer  56  are put in the plurality of shelves  7 . 
         [0093]    The contact area in the room temperature bonding becomes small when the warpage is large in the lower wafer  56  and the upper wafer  46 , and there is a case that enough bonding strength is not obtained. When the upper wafer  46  and the lower wafer  56  are bonded while a sufficiently large load is applied, these wafers are bonded in the enough bonding strength even when the warpage is large. When the upper wafer  46  and the lower wafer  56  should be bonded while the sufficiently large load is applied, the residual stress sometimes occurs even when the warpage is large. Such a residual stress sometimes affects a product which is made from the upper wafer  46  and the lower wafer  56 . As an adverse influence, a flaw, and a malfunction on the function are exemplified. 
         [0094]    According to such a room temperature bonding method, the residual stress can be reduced even if the residual stress occurs in the bonding resultant wafer when the upper wafer  46  and the lower wafer  56  have been bonded, and the products with good quality can be made stably. 
         [0095]    In the bonding resultant wafer in which two wafers with absorption materials are bonded at the room temperature, voids are generated due to the absorption material in the bonding plane through the annealing and the bonding strength is sometimes reduced. In such a room temperature bonding method, the absorption material remaining in the bonding plane of the bonding resultant wafer can be reduced through the operation (steps S 2 -S 3 ) of carrying out desorption of the absorption material from the upper wafer  46  and the lower wafer  56 . As a result, the void generation in the bonding plane can be prevented and the bonding strength can be improved. 
         [0096]    It should be noted that in the room temperature bonding method of the present invention, the operation (steps S 2  and S 3 ) of carrying out the desorption of the absorption material from the upper wafer  46  and the lower wafer  56  can be omitted, when the absorption material absorbed to the upper wafer  46  and the lower wafer  56  is sufficiently little. Even by such a room temperature bonding method, the product with good quality can be made stably, like the room temperature bonding method according to the previously embodiment. 
         [0097]    It is sometimes required that the product which is produced from the bonding resultant wafer has a predetermined shape. Even when the warpage of the bonding resultant wafer before the annealing is large, the bonding resultant wafer can be formed flatly by annealing while the pressing load is applied, and can be applied to such a product. 
         [0098]    It should be noted that in the room temperature bonding method of the present invention, when the bonding resultant wafer before the annealing is enough flat, that is, the room temperature bonding is possible to be carried out such that the bonding resultant wafer is flat sufficiently, it is possible to omit the application of the pressing load in the annealing. Such a room temperature bonding method can stably produce the product with good quality, like the room temperature bonding method according to the previous embodiments. 
         [0099]    The load applied to the bonding resultant wafer sometimes increases, because the bonding resultant wafer and a unit which treats the bonding resultant wafer thermally expands while the bonding resultant wafer is subjected to the annealing. The bonding resultant wafer sometimes breaks when the applied load is large sufficiently. According to the room temperature bonding method of the present invention, because the load applied to the bonding resultant wafer is controlled to a pressing load, it is possible to prevent the bonding resultant wafer from breaking and the product with good quality can be produced stably. It should be noted that in the room temperature bonding method of the present invention, when a unit which treats the bonding resultant wafer deforms elastically so that the load applied to the bonding resultant wafer does not become larger than the predetermined load, a feeding-back operation can be omitted in which the load applied to the bonding resultant wafer is controlled to the pressing load after controlling to the pressing load once. 
         [0100]    In another embodiment of the room temperature bonding apparatus of the present invention, another heat chamber is substituted for the heat chamber  3  in the previous embodiments. The heat chamber  70  is provided with the chamber base  21 , the heat sink  22 , the adiabatic member  23 , the sample stand  24  and the heater  25  as shown in  FIG. 10 , like the heat chamber  3  in the above embodiments. 
         [0101]    Also, the heat chamber  70  is further provided with an electrostatic chuck  71 , an adiabatic member  72 , a heat sink  73 , an angle adjusting mechanism  74 , a load cell  75 , a pressurization mechanism  76  and a heater  77 . In the electrostatic chuck  71 , the holding surface  78  is formed on the side opposing to the sample stand  24 . The holding surface  78  is formed to be flat. In the electrostatic chuck  71 , the adiabatic member  72  is formed on the side opposite to the side on which the holding surface  78 . The electrostatic chuck  71  is controlled by the control unit  61  of the room temperature bonding apparatus, to hold the wafer arranged in the neighborhood on the holding surface  78  with electrostatic force. The adiabatic member  72  is formed of quartz and is connected to the heat sink  73 . The adiabatic member  72  is provided with passages  79 . The passages  79  form conduit lines through which nitrogen gas flows. The nitrogen gas is supplied from the outside of the heat chamber  70  by a cooling unit which is not shown. The side of the heat sink  73  opposite to the side on which is connected to the electrostatic chuck  71 , is connected to the angle adjusting mechanism  74 . The angle adjusting mechanism  74  is connected to the load cell  75 . The load cell  75  is supported to be moveable into a perpendicular direction to the surface of the chamber base  21 . At this time, cooled coolant is always supplied from outside the heat chamber  70  so that the heat sink  73  prevents that the angle adjusting mechanism  74  and the load cell  75  are heated when the electrostatic chuck  71  is heated. 
         [0102]    The pressurization mechanism  76  is controlled by the control unit of the room temperature bonding apparatus, to move the angle adjusting mechanism  74  into the perpendicular direction to the top surface of the chamber base  21 , that is, to move the electrostatic chuck  71  into the perpendicular direction to the top surface of the chamber base  21 . The load cell  75  is provided with a piezoelectric element, measures the load applied to the holding surface  78  and measures the bias of the load applied to the electrostatic chuck  71 . The load cell  75  outputs the load and the bias to the control unit of the room temperature bonding apparatus. The angle adjusting mechanism  74  is controlled by the control unit of the room temperature bonding apparatus, to change the orientation of the holding surface  78 . 
         [0103]    When the piezoelectric element of the load cell  75  is heated, an error of the measured value sometimes becomes large. The load cell  75  can measure the load and the bias in higher accuracy by preventing from heating by the heat sink  73 . 
         [0104]    The heater  77  is arranged in the inner space of the electrostatic chuck  71 . The heater  77  is controlled by the control unit  61  of the room temperature bonding apparatus, to heat the wafer held by the electrostatic chuck  71 . At this time, the cooled coolant is always supplied from outside the heat chamber  70  to the heat sink  73 , to prevent that the load cell  75  is heated when the heater  77  is heated. 
         [0105]    Another embodiment of the room temperature bonding method of the present invention is executed by using a main portion of the room temperature bonding apparatus to which the heat chamber  70  is applied, to substitute another operation for steps S 2  and S 3  in the previous embodiments. In the operation, the control unit  61  of the room temperature bonding apparatus controls the gate valve  6  such that the gate valve  6  is opened when the preliminary atmosphere is generated in the inner space of the load lock chamber  1 . When the gate valve  6  is opened, the control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the upper cartridge  41  of the plurality of cartridges which are arranged in the plurality of shelves  7  is conveyed to the sample stand  24  of the heat chamber  70 . 
         [0106]    The control unit  61  of the room temperature bonding apparatus controls the pressurization mechanism  76  such that the electrostatic chuck  71  falls down after the upper cartridge  41  is held on the sample stand  24  of the heat chamber  70 . The control unit  61  of the room temperature bonding apparatus controls the load cell  75  such that the load applied to the electrostatic chuck  71  is measured, when the electrostatic chuck  71  falls down. The control unit  61  of the room temperature bonding apparatus calculates based on the load, the timing when the load reaches a given contact load, that is, the timing at which the upper wafer  46  on the upper cartridge  41  touches the electrostatic chuck  71 . The control unit  61  of the room temperature bonding apparatus controls the pressurization mechanism  76  to stop the electrostatic chuck  71  at the timing. 
         [0107]    When the electrostatic chuck  71  touches the upper wafer  46  on the upper cartridge  41 , the control unit  61  of the room temperature bonding apparatus controls the electrostatic chuck  71  such that the electrostatic chuck  71  holds the upper wafer  46 . The control unit  61  of the room temperature bonding apparatus controls the pressurization mechanism  76  such that the electrostatic chuck  71  rises when the electrostatic chuck  71  holds the upper wafer  46  on the upper cartridge  41 . The control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the upper cartridge  41  is conveyed from the sample stand  24  to the plurality of shelves  7  on which the upper wafer  46  is not present after the electrostatic chuck  71  rises to a predetermined position. 
         [0108]    After the upper cartridge  41  is conveyed to the plurality of shelves  7 , the control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the lower cartridge  51  on which the lower wafer  56  is put is conveyed from the plurality of shelves  7  to the sample stand  24 . The control unit  61  of the room temperature bonding apparatus controls the gate valve  6  such that the gate valve  6  is closed after the lower cartridge  51  is held on the sample stand  24 . 
         [0109]    The control unit  61  of the room temperature bonding apparatus controls the vacuum pump of the heat chamber  70  such that the desorption atmosphere is generated in the inner space of the heat chamber  70  when the gate valve  6  is in the closed state. When the desorption atmosphere is generated in the inner space of the heat chamber  70 , the control unit  61  of the room temperature bonding apparatus controls the heater  77  such that the upper wafer  46  held by the electrostatic chuck  71  is heated at a predetermined desorption temperature, and controls the heater  25  such that the lower wafer  56  put on the lower cartridge  51  is heated at the desorption temperature. 
         [0110]    The control unit  61  of the room temperature bonding apparatus controls the heater  77  such that the upper wafer  46  is not heated after the upper wafer  46  is heated for a predetermined time period, controls the cooling unit of the heat chamber  70  such that nitrogen gas flows through the passages  79 , that is, the upper wafer  46  is cooled to the bonding temperature. The control unit  61  of the room temperature bonding apparatus controls the heater  25  such that the lower wafer  56  is not heated after the lower wafer  56  is heated for a predetermined time period, and controls the cooling unit of the heat chamber  70  such that nitrogen gas flows through the passages  26 , that is, the lower wafer  56  is cooled to the bonding temperature. 
         [0111]    The control unit  61  of the room temperature bonding apparatus controls the gate valve  6  such that the gate valve  6  is opened after desorption of the absorption material is sufficiently carried out from the upper wafer  46  and the lower wafer  56 . The control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the lower cartridge  51  is conveyed from the sample stand  24  of the heat chamber  70  to the plurality of shelves  7  after the lower wafer  56  is cooled to the bonding temperature. 
         [0112]    After the lower cartridge  51  is conveyed from the sample stand  24  of the heat chamber  70 , the control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the upper cartridge  41  on which any wafer is not put is conveyed to the sample stand  24  of the heat chamber  70 . The control unit  61  of the room temperature bonding apparatus controls the pressurization mechanism  76  such that the electrostatic chuck  71  falls down after the upper cartridge  41  is held by the sample stand  24  of the heat chamber  70 . The control unit  61  of the room temperature bonding apparatus controls the load cell  75  such that the load applied to the electrostatic chuck  71  is measured when the electrostatic chuck  71  falls down. The control unit  61  of the room temperature bonding apparatus calculates based on the load, the timing at which the load reaches the given contact load, that is, the timing at which the upper wafer  46  held by the electrostatic chuck  71  touches the upper cartridge  41 . The control unit  61  of the room temperature bonding apparatus controls the pressurization mechanism  76  such that the electrostatic chuck  71  stops at the timing. 
         [0113]    When the electrostatic chuck  71  touches the upper wafer  46  on the upper cartridge  41 , the control unit  61  of the room temperature bonding apparatus controls the electrostatic chuck  71  such that the upper wafer  46  leave the electrostatic chuck  71 . The control unit  61  of the room temperature bonding apparatus controls the pressurization mechanism  76  such that the electrostatic chuck  71  rise after the upper wafer  46  leaves the electrostatic chuck  71 . After the electrostatic chuck  71  rises to a predetermined position, the control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the upper cartridge  41  on which the upper wafer  46  is put is conveyed from the sample stand  24  to the plurality of shelves  7 . 
         [0114]    The room temperature bonding method to which such an operation is applied can produce a product with good quality stably, like the room temperature bonding method of the above-mentioned embodiments. Moreover, such an operation can be executed in a shorter time than the operation time of the step S 2 -S 3  in the above-mentioned embodiments. Therefore, according to the room temperature bonding method to which the operation is applied, the bonding resultant wafer can be produced at higher speed. 
         [0115]    Moreover,  FIG. 11  shows another heat chamber. The heat chamber  80  is provided with the chamber base  21 , the heat sink  22 , the adiabatic member  23 , the sample stand  24  and the heater  25 , like the heat chamber  3  in the above-mentioned embodiments. Moreover, the heat chamber  80  is provided with a substrate hold element  81 , an angle adjusting mechanism  82 , a load cell  83 , a pressurization mechanism  84  and a cooling mechanism  85 . The substrate hold element  81  is formed of quartz. The holding surface is formed on the side of the substrate hold element  81  which is opposite to the sample stand  24 . The holding surface is formed to be flat. The side of the substrate hold element  81  opposite to the side on where the holding surface is formed is connected to the angle adjusting mechanism  82 . The angle adjusting mechanism  82  is connected to the load cell  83 . The load cell  83  is supported such that it can move into the perpendicular direction to the surface of the chamber base  21 . 
         [0116]    The pressurization mechanism  84  is controlled by the control unit  61  of the room temperature bonding apparatus to move the angle adjusting mechanism  82  into the perpendicular direction to the surface of the chamber base  21 , that is, to move the substrate hold element  81  into the perpendicular direction to the surface of the chamber base  21 . The load cell  83  is provided with a piezoelectric element, measures the load applied to the holding plane and measures the bias of the load applied to the substrate hold element  81 . The load cell  83  outputs the measured load and bias to the control unit  61  of the room temperature bonding apparatus. The angle adjusting mechanism  82  is controlled by the control unit of the room temperature bonding apparatus to change the orientation of the holding plane. 
         [0117]    The cooled coolant is always supplied from outside the heat chamber  80  to the cooling mechanism  85  and that the load cell  83  is prevented from being heated when the substrate hold element  81  is heated. In the load cell  83 , when the piezoelectric element is heated, an error of the measured value sometimes becomes large. The load cell  83  can measure the load and the bias in higher accuracy by preventing from heating by the heat sink  32 . 
         [0118]    The main portion of the room temperature bonding apparatus to which the heat chamber  80  is applied can be used like the main portion of the room temperature bonding apparatus to which the heat chamber  3  in the above-mentioned embodiments is applied. Therefore, when the main portion of the room temperature bonding apparatus to which the heat chamber  80  is applied is used, the room temperature bonding method of the present invention can produce a product with good quality stably, like the room temperature bonding method in the above-mentioned embodiments. Moreover, because the load cell  83  of the heat chamber  80  is cooled from a closer position than in the heat chamber  3  of the above-mentioned embodiments, the load cell  83  can be cooled surely. Therefore, the load cell  83  can measure the load and bias in higher accuracy and the controllability when the pressurization mechanism  84  is controlled such that a pressing load is applied to the bonding resultant wafer can be improved. Also, the controllability when the angle adjusting mechanism  82  is controlled such that the pressing load is uniformly applied to the bonding wear can be improved. 
         [0119]    Moreover,  FIG. 12  shows another heat chamber. The heat chamber  90  is provided with a chamber base  91 , an adiabatic member  92 , a sample stand  93  and a heater  94 . The chamber base  91  is a base to form a part of the heat chamber  90  and to support the adiabatic member  92 , the sample stand  93  and the heater  94 . The adiabatic member  92  is formed of quartz and is fixed on the chamber base  91 . The adiabatic member  92  is provided with passages  95 . The passage  95  forms a conduit line through which nitrogen gas flows. The nitrogen gas is supplied from outside the heat chamber  90  by the cooling unit which is not shown. The sample stand  93  forms of aluminum nitride AlN and is fixed on the chamber base  91  through the adiabatic member  92 . The holding plane  96  is formed on the side of the sample stand  93  opposite to the side which is connected to the adiabatic member  92 . A holding surface  96  is formed for a cartridge to be held by the sample stand  93 . The heater  94  is arranged in the inner space of the sample stand  93 . The heater  94  is controlled by control unit  61  of the room temperature bonding apparatus to heat the wafer which is put on the cartridge. 
         [0120]    Moreover, the heat chamber  90  is provided with an angle adjusting mechanism  102 , a load cell  103 , a pressurization mechanism  104  and a cooling unit  105 , and a substrate hold element  101 . The substrate hold element  101  is formed of quartz. The holding surface is formed on the side of the substrate hold element  101  opposite to the sample stand  93 . The holding surface is formed to be flat. The opposite side of the substrate hold element  101  to the side on which the holding surface is formed is connected to the angle adjusting mechanism  102 . The angle adjusting mechanism  102  is connected to the load cell  103 . The load cell  103  is supported to be moveable into the perpendicular direction to the surface of the chamber base  21 . 
         [0121]    The pressurization mechanism  104  is controlled by the control unit  61  of the room temperature bonding apparatus to move the angle adjusting mechanism  102  into the perpendicular direction to the surface of the chamber base  21 , that is, to move the substrate hold element  101  into the perpendicular direction to the surface of the chamber base  21 . The load cell  103  is provided with a piezoelectric element, measures the load applied to the holding surface and measures the bias of the load applied to the substrate hold element  101 . The load cell  103  outputs the load and the bias to the control unit  61  of the room temperature bonding apparatus. The angle adjusting mechanism  102  is controlled by control unit  61  of the room temperature bonding apparatus to change the direction of the holding surface. 
         [0122]    In the cooling unit  105 , the cooled coolant is always supplied from outside the heat chamber  90  to cool the heat chamber  90  and prevents that the load cell  103  is heated. The load cell  103  can measure the load and the bias in higher accuracy by preventing over-heating by the heat sink  32 . 
         [0123]    The main portion of the room temperature bonding apparatus to which the heat chamber  90  is applied can be used, like the main portion of the room temperature bonding apparatus to which the heat chamber  3  is applied in the above-mentioned embodiments. Therefore, when the main portion of the room temperature bonding apparatus to which the heat chamber  90  is applied is used, the room temperature bonding method of the present invention can produce a product with good quality stably, like the room temperature bonding method in the above-mentioned embodiments. Moreover, the inner space of the heat chamber  90  can be simply formed for the heat sink  32  and the heat sink  22 , as compared with the heat chamber  3  in the above-mentioned embodiments and can be made small in size. 
         [0124]    In the room temperature bonding apparatus according to another embodiment of the present invention, as shown in  FIG. 13 , the main portion of the room temperature bonding apparatus in the above-mentioned embodiments is further provided with another heat chamber  110 . The heat chamber  110  is a container in which its inner space is sealed from the environment. Moreover, the main portion of the room temperature bonding apparatus is provided with a gate valve  111 . The gate valve  111  is interposed between the load lock chamber  1  and the heat chamber  110  to form a gate which connects the inner space of the heat chamber  110  and the inner space of the load lock chamber  1 . The gate valve  111  is controlled by the control unit  61  of the room temperature bonding apparatus to close the gate or to open the gate. 
         [0125]    The heat chamber  110  is provided with the chamber base  21 , the heat sink  22 , the adiabatic member  23 , the sample stand  24  and the heater  25 , like the heat chamber  3  in the above-mentioned embodiments. Moreover, the heat chamber  110  is further provided with the substrate hold element  31 , the heat sink  32 , the angle adjusting mechanism  33 , the load cell  34  and the pressurization mechanism  35 . 
         [0126]    Another embodiment of the room temperature bonding method of the present invention is added with the heat chamber  110  to the main portion of the room temperature bonding apparatus and another operation is substituted for the steps S 2 -S 3  in the above-mentioned embodiments. 
         [0127]    In the operation, the control unit  61  of the room temperature bonding apparatus controls the gate valve  6  such that the gate valve  6  is opened when the preliminary atmosphere is generated in the inner space of the load lock chamber  1 . When the gate valve  6  is opened, the control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the upper the upper cartridge  41  as one of the plurality of cartridges which are arranged in the plurality of shelves  7  is conveyed to the sample stand  24  of the heat chamber  3 . Next, the control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the lower cartridge  51  as one of the plurality of cartridges which are arranged in the plurality of shelves  7  is conveyed to the sample stand  24  of the heat chamber  110 . 
         [0128]    The control unit  61  of the room temperature bonding apparatus controls the gate valve  6  such that the gate valve  6  is closed after the upper cartridge  41  is held by the sample stand  24  of the heat chamber  3 . When the gate valve  6  is closed, the control unit  61  of the room temperature bonding apparatus controls the vacuum pump of the heat chamber  3  such that the desorption atmosphere is generated in the inner space of the heat chamber  3 . When the desorption atmosphere is generated in the inner space of the heat chamber  3 , the control unit  61  of the room temperature bonding apparatus controls the heater  25  such that the upper wafer  46  put on the upper cartridge  41  is heated at a predetermined desorption temperature, that is, desorption of absorption material is carried out from the upper wafer  46 . After the upper wafer  46  is heated for a predetermined time period, that is, after the desorption of the absorption material is sufficiently carried out from the upper wafer  46 , the control unit  61  of the room temperature bonding apparatus controls the heater  25  such that the upper wafer  46  is not heated, and controls the cooling unit of the heat chamber  3  such that the nitrogen gas flows through the passages  26 , that is, the upper wafer  46  is cooled to the bonding temperature. The control unit  61  of the room temperature bonding apparatus controls the gate valve  6  such that the gate valve  6  is opened after the desorption of the absorption material is sufficiently carried out from the upper wafer  46 . 
         [0129]    The control unit  61  of the room temperature bonding apparatus controls the gate valve  111  such that the gate valve  111  is closed after the lower cartridge  51  is held by the sample stand  24  of the heat chamber  110 . The control unit  61  of the room temperature bonding apparatus controls the vacuum pump of the heat chamber  110  such that the desorption atmosphere is generated in the inner space of the heat chamber  110  when the gate valve  111  is closed. When the desorption atmosphere is generated in the inner space of the heat chamber  110 , the control unit  61  of the room temperature bonding apparatus controls the heater  25  such that the lower wafer  56  put on the lower cartridge  51  is heated at the predetermined desorption temperature, that is, desorption of the absorption material is carried out from the lower wafer  56 . After the lower wafer  56  is heated for a predetermined time period, that is, the desorption of the absorption material is sufficiently carried out from the lower wafer  56 , the control unit  61  of the room temperature bonding apparatus controls the heater  25  such that the lower wafer  56  is not heated, and controls the cooling unit of the heat chamber  110  such that the nitrogen gas flows through the passages  26 , that is, the lower wafer  56  is cooled to the bonding temperature. Next, the control unit  61  of the room temperature bonding apparatus controls the gate valve  111  such that the gate valve  111  is opened after the desorption of the absorption material is sufficiently carried out from the lower wafer  56 . 
         [0130]    The operation that the desorption of the absorption material is carried out from the lower wafer  56  is concurrently executed with the operation that the desorption of the absorption material is carried out from the upper wafer  46 . 
         [0131]    After the upper wafer  46  is cooled to the bonding temperature, the control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the upper cartridge  41  is conveyed from the sample stand  24  of is the heat chamber  3  to the plurality of shelves  7 . Next, the control unit  61  of the room temperature bonding apparatus controls the conveyance robot  8  such that the lower cartridge  51  is conveyed from the sample stand  24  of the heat chamber  110  to the plurality of shelves  7 , after the lower wafer  56  is cooled to the bonding temperature. 
         [0132]    The room temperature bonding method to which such an operation is applied can be produce a product with good quality stably, like the room temperature bonding method in the above-mentioned embodiments. The operation can be performed in a shorter time than the operation of the steps S 2  to S 3  in the above-mentioned embodiments. Therefore, according to the room temperature bonding method to which such an operation is applied, the bonding resultant wafer can be produced at higher speed. 
         [0133]    It should be noted that the heat chamber  110  can be used for the operation (steps S 7  to S 8 ) that the bonding resultant wafer is annealed. It should be noted that when not used for the operation that the bonding resultant wafer is annealed, another heat chamber in which the substrate hold element  31 , the heat sink  32 , the angle adjusting mechanism  33 , the load cell  34  and the pressurization mechanism  35  are omitted, is substituted for the heat chamber  110 . Preferably, the main portion of the room temperature bonding apparatus to which such a heat chamber is applied is rather simpler than the main portion of the room temperature bonding apparatus to which the heat chamber  110  is applied, and the manufacturing cost is lower. 
         [0134]    As shown in  FIG. 14 , in the room temperature bonding apparatus according to another embodiment of the present invention, a transfer chamber  120  and a load lock chamber  121  are substituted for the load lock chamber  1  of the main portion of the room temperature bonding apparatus in the above-mentioned embodiments, and the plurality of heat chambers  122 - 1  to  122 - 4  are substituted for the heat chamber  3 . The transfer chamber  120 , the load lock chamber  121  and the plurality of heat chambers  122 - 1  to  122 - 4  are respectively the containers which seal the inner space from the environment. Moreover, the main portion of the room temperature bonding apparatus is provided with a gate  123  and the gate valves  124 - 1  to  124 - 4 . The gate  123  is interposed between the transfer chamber  120  and the load lock chamber  121  and connects the inner space of the transfer chamber  120  and the inner space of the load lock chamber  121 . The gate valve  124 - i  (i=1, 2, 3, and 4) is interposed between the transfer chamber  120  and the heat chamber  122 - i  and forms a gate which connects the inner space of transfer chamber  120  and the inner space of the heat chamber  122 - i . The gate valve  124 - i  is controlled by the control unit  61  of the room temperature bonding apparatus to close the gate or to open the gate. 
         [0135]    The load lock chamber  121  is provided with a lid which is not shown. The lid closes the gate or opens the gate, which connects the environment and the inner space of the load lock chamber  121 . The load lock chamber  121  is provided with a vacuum pump which is not shown. When the lid and the gate valve  121  are closed, the vacuum pump is controlled by the control unit  61  of the room temperature bonding apparatus, to exhaust gas from the inner space of the load lock chamber  121 . Moreover, the load lock chamber  121  is provided with a plurality of shelves  7  therein, like the load lock chamber  1 . 
         [0136]    The transfer chamber  120  is provided with the conveyance robot  8  therein. When the gate valve  5  is opened, the conveyance robot  8  is controlled by the control unit  61  of the room temperature bonding apparatus, to convey the cartridge arranged in the plurality of shelves  7  to the bonding chamber  2 , or to convey the cartridge arranged in the bonding chamber  2  to the plurality of shelves  7 . Moreover, when the gate valve  124 - i  is opened, the conveyance robot  8  is controlled by the control unit  61  of the room temperature bonding apparatus, to convey the cartridge arranged in the plurality of shelves  7  to the heat chamber  122 - i , or to convey the cartridge arranged in the heat chamber  122 - i  to the plurality of shelves  7 . 
         [0137]    The room temperature bonding method according to another embodiment of the present invention is executed by using such a body of the room temperature bonding apparatus. In the room temperature bonding method, the other operation is substituted for the steps S 2  to S 3  in the above-mentioned embodiments. In the operation, the control unit  61  of the room temperature bonding apparatus controls the heat chamber  122 - 1  to carry out desorption of the absorption material from the upper wafer  46  and controls the heat chamber  122 - 2  to carry out desorption of the absorption material from the lower wafer  56 . The control unit  61  of the room temperature bonding apparatus controls the heat chamber  122 - 3  to carry out the desorption of the absorption material from the other upper wafer  46  and the heat chamber  122 - 4  to carry out the desorption of the absorption material from the other lower wafer  56 , while the desorption operation is carried out by using the heat chambers  122 - 1  and  122 - 2 . 
         [0138]    Moreover, in the room temperature bonding method, the other operation is substituted for steps S 4  to S 6 . The control unit  61  of the room temperature bonding apparatus bonds the upper wafer  46  from which the absorption material is detached by using the heat chamber  122 - 1  and the lower wafer  56  from which the absorption material is detached by using the heat chamber  122 - 2  through the room temperature bonding. The control unit  61  of the room temperature bonding apparatus detaches the absorption material from another upper wafer  46  by using the heat chamber  122 - 1  and the absorption material from another lower wafer  56  by using the heat chamber  122 - 2 , while the bonding resultant wafer is being produced. 
         [0139]    Moreover, in the room temperature bonding method, another operation is substituted for the steps S 7  to S 8 . In the operation, the control unit  61  of the room temperature bonding apparatus anneals the bonding resultant wafer by using the heat chamber  122 - 1 . While the annealing is carried out by the heat chamber  122 - 1 , the control unit  61  of the room temperature bonding apparatus produces the bonding resultant wafer through the room temperature bonding of the upper wafer  46  from which the absorption material is detached by using the heat chamber  122 - 3 , and the lower wafer  56  from which the absorption material is detached by using the heat chamber  122 - 4 . 
         [0140]    According to the room temperature bonding method to which such an operation is applied, a product with good quality can be produced stably like the room temperature bonding method in the above-mentioned embodiments. According to the room temperature bonding method to which the operation is applied, the bonding resultant wafers can be produced more for a predetermined time period than the room temperature bonding method in the above-mentioned embodiments. 
         [0141]    It should be noted that the present application claims a priority on convention based on Japanese Patent Application No. JP 2010-217441 which was filed on Sep. 28, 2010. The disclosure thereof is incorporated herein by reference.