JP2009010263A - Substrate bonding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable selecting and using various bonding techniques in a single vacuum chamber while making it possible to jointly use them. <P>SOLUTION: This substrate bonding device has substrate holders 2, 3 to hold a pair of substrates 6, 7 to be bonded so that they face each other, ion radical sources 11, 11 disposed by turning them toward the surfaces-to-be-bonded of the substrates 6, 7, and a movement mechanism to bring the surfaces-to-be-bonded of the substrates 6, 7 with each other and pressurize them by moving at least one of the substrate holders 2, 3. The ion radical sources 11, 11 have plasma chambers 12, 12 for ionizing and/or radicalizing gas in plasma, ion extraction electrodes 14, 14 to discharge ions generated in the plasma chambers 12, 12 toward the surface-to-be-bonded of the substrates 6, 7, and ion trap electrodes 15, 15 to trap the ions and discharge only radicals generated in the plasma chambers 12, 12 toward the surface-to-be-bonded of the substrates 6, 7. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a substrate bonding apparatus for bonding a pair of substrates, and in particular, by irradiating the bonding surfaces of the substrates with argon ions or hydrogen radicals, the surfaces of the substrates to be bonded are activated, and then the substrates to be bonded. It is related with the board | substrate joining apparatus which can implement | achieve a anodic bonding and a heating and pressurizing joining in a single vacuum chamber.

  As representative means for bonding a substrate such as a semiconductor wafer, there are anodic bonding, heat-pressure bonding, and surface activation bonding. In anodic bonding, the substrate is heated to a temperature of several hundred degrees Celsius and a voltage of several hundred V to 1 kV is applied to the stacked substrates to generate a large electrostatic attractive force on the substrates and chemically bond at the substrate interface. It is a technology to join with. Heating and pressure bonding is a technique in which the substrates are heated to a temperature of several hundred degrees Celsius and pressure is applied to the stacked substrates to bond the interfaces of the substrates by diffusion bonding. In the surface activated bonding, for example, charged particles such as argon ions collide with the surface to be bonded of the substrate in a vacuum to remove impurities such as an oxide film on the surface and activate the surface. This is a technique in which the surfaces of a pair of substrates are bonded by molecular bonding by bringing the bonding surfaces into contact with each other.

  In the conventional apparatus, the above-described anodic bonding, heat-pressure bonding, and surface activation bonding are separate apparatuses. For this reason, in order to implement a joining technique according to the type of substrate and the purpose of use, several joining apparatuses are required, which is inconvenient in terms of labor and cost. It has also been difficult to use these joining techniques together. Furthermore, in surface activated bonding, there is a problem that appropriate activation means cannot be selected or used as necessary, such as means for activating the surface of the substrate is limited to means by ion irradiation. .

2007-115825 gazette 2006-339363 2006-222436 2006-73780 gazette 2005-294800 2004-342855

  In the present invention, in view of the problems in the conventional substrate bonding apparatus, various bonding techniques can be selected and used in a single vacuum chamber, and their combined use is possible. This makes it possible to appropriately select and use ion irradiation and radical irradiation for activating the surfaces of the substrates to be bonded together.

  In order to achieve the above-mentioned object, the present invention provides an ion / radical source capable of appropriately selecting and irradiating ions and radicals as necessary toward the substrates 6 and 7 held by the substrate holders 2 and 3, respectively. 11 and 11 and a moving mechanism for moving the substrates 2 and 3 held by the substrate holders 2 and 3 to bring the activated surfaces into contact with each other are provided in a single vacuum chamber 1. In this example, various bonding techniques can be selected and used in a single vacuum chamber 1 by heating the substrates 6 and 7 and applying a voltage.

  The substrate bonding apparatus according to the present invention includes a substrate holder 2 and 3 for holding a pair of substrates 6 and 7 to be bonded so as to face each other, and an ion / radical source disposed toward the surface of the substrates 6 and 7 to be bonded. 11 and 11 and a moving mechanism for moving at least one of the substrate holders 2 and 3 to contact and pressurize the surfaces to be bonded of the substrates 2 and 3 to each other. The ion / radical sources 11 and 11 join the plasma chambers 12 and 12 for ionizing and / or radicalizing a gas in plasma and the ions generated in the plasma chambers 12 and 12 to the substrates 6 and 7. Ion extraction electrodes 14 and 14 for firing toward the power surface, and ion trap electrodes for trapping ions and firing only radicals generated in the plasma chambers 12 and 12 toward the surface to be bonded to the substrates 6 and 7 15 and 15.

  In such a substrate bonding apparatus according to the present invention, ions or ions are directed toward the surfaces to be bonded of the substrates 6 and 7 held by the substrate holders 2 and 3 that hold the pair of substrates 6 and 7 to be bonded so as to face each other. Since the vacuum chamber 1 is equipped with the ion / radical sources 11 and 11 for irradiating radicals, the surface of the substrates 2 and 3 can be activated by selecting either ion irradiation or radical irradiation, or a combination thereof. In other words, ions are extracted from the plasma chambers 12 and 12 by the ion extraction electrodes 14 and 14 and are emitted to the substrates 6 and 7, whereby the surface activation of the substrates 6 and 7 by ions can be performed. Further, the ions generated in the plasma chambers 12 and 12 are trapped by the ion trap electrodes 15 and 15, and only radicals are emitted to the substrates 6 and 7, whereby the surfaces of the substrates 6 and 7 can be activated by radicals. After these activations, the surfaces of the surfaces of the substrates 6 and 7 are completely bonded.

  Further, in this substrate bonding apparatus, the substrate holders 2 and 3 are provided with heaters 4 and 5 for heating the substrates 6 and 7 held thereon, and a substrate voltage application power supply 28 for applying a voltage to the substrates 6 and 7. , 29 are connected. Thereby, the substrates 6 and 7 held on the substrate holders 2 and 3 can be heated and a voltage can be applied. Therefore, not only the bonding of the surfaces by the movement of the substrates 2 and 3 but also the application of a voltage to the substrates 6 and 7 for anodic bonding and the heating and pressurization of the substrates 2 and 3 for heating and pressurizing bonding are simple. This can be done in one vacuum chamber 1.

  As described above, in the substrate bonding apparatus according to the present invention, activation by ions on the surface of the substrates 2 and 3 and activation by radicals can be performed in the single vacuum chamber 1. Surface activation means can be appropriately selected and used in the single vacuum chamber 1. In addition, by providing the moving mechanism for the substrate holders 2 and / or 3, activation of the surface of the substrate and subsequent bonding of the substrates 2 and 3 can be performed continuously in the single vacuum chamber 1. Further, since the substrates 6 and 7 held on the substrate holders 2 and 3 can be heated and a voltage can be applied, anodic bonding and heat-pressure bonding can be performed in the single vacuum chamber 1. Therefore, a multipurpose joining apparatus capable of selecting and using various joining means can be obtained.

In the present invention, the ion / radical sources 11 and 11 for irradiating ions and radicals toward the substrates 6 and 7 held by the substrate holders 2 and 3 and the substrates 2 and 3 held by the substrate holders 2 and 3 are moved. The above-described object is achieved by providing a single vacuum chamber 1 with a moving mechanism for bringing the activated surfaces into contact with each other. In addition, the above-mentioned object is achieved by providing the substrate holders 2 and 3 with heaters 4 and 5 for heating the substrates 6 and 7 held by the substrate holders 2 and 3 and connecting power sources 28 and 29 for applying substrate voltage.
Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

FIG. 1 shows an embodiment of a substrate bonding apparatus according to the present invention, in which two ion / radical sources 11 and 11 for irradiating ions toward substrates 6 and 7 are provided.
A pair of substrate holders 2 and 3 are disposed in the vacuum chamber 1 so as to face each other in the vertical direction. The upper substrate holder 2 is attached to the lower end of the transfer rod 26 connected to the air cylinder 21 via the load cell 22. A bellows 23 is provided at the upper end of the transfer rod 26, and the upper substrate holder 2 is moved up and down by the operation of the air cylinder 21. On the other hand, the lower substrate holder 3 is fixed to the bottom wall of the vacuum chamber 1 via a support column 27. Of course, the substrate holders 2 and 3 having the moving mechanism as described above may be turned upside down, or a moving mechanism may be provided on both the substrate holders 2 and 3.

  A turbo molecular pump 9 is connected to the vacuum chamber 1 via a gate valve 8, and a rotary pump 10 is connected to the turbo molecular pump 9. The inside of the vacuum chamber 1 is evacuated and decompressed by the turbo molecular pump 9 and the rotary pump 10 and maintained at a high vacuum.

  Substrates 6 and 7 such as semiconductor wafers are attached to the substrate holders 2 and 3, respectively, and these substrates 6 and 7 face each other in the vertical direction in the vacuum chamber 1. The substrate holders 2 and 3 are provided with heaters 4 and 5, respectively, and the substrates 6 and 7 are heated by the heaters 4 and 5. Further, the substrate holders 2 and 3 are connected to substrate voltage application power sources 28 and 29 for applying a voltage to the substrates 6 and 7 held thereon.

  A pair of ion / radical sources 11 and 11 for emitting ions and radicals toward the substrates 6 and 7 are provided. These ion / radical sources 11 and 11 have cylindrical container-like plasma chambers 12 and 12 made of a thermally and chemically stable material such as quartz glass, and the periphery of the plasma chambers 12 and 12 is a high-frequency coil 13. , 13. High frequency power supplies 30 and 30 are connected to the high frequency coils 13 and 13.

  Gas supply sources 16, 16 for supplying a gas such as argon or hydrogen to the plasma chambers 12, 12 are connected to the plasma chambers 12, 12 via a mass flow controller 20 and a valve 19. Plasma is formed in the plasma chambers 12 and 12 by sending a rare gas such as argon or hydrogen to the plasma chambers 12 and 12 through the mass flow controller 20 and causing the high-frequency coils 13 and 13 to flow with the high-frequency power sources 30 and 30. Then, argon gas molecules in the ionization are ionized to generate argon ions. Alternatively, hydrogen gas molecules are radicalized to generate hydrogen radicals. A radical is an atom or molecule with a higher energy level than a normal atom or molecule with unpaired electrons.

  A window-like opening is provided on the front end side of the plasma chambers 12 and 12 facing the substrates 6 and 7, and an ion extraction electrode 14 and ion trap electrodes 15 and 15 are provided at the tip. The ion extraction electrode 14 is an electrode for accelerating and emitting ions generated in the plasma chambers 12 and 12 toward the substrates 6 and 7, respectively, and is given a negative potential by the ion extraction power sources 31 and 31. The ion trap electrodes 15 and 15 are electrodes for trapping ions and suppressing only the discharge of ions to discharge only radically neutral radicals toward the surfaces of the substrates 6 and 7 to be bonded. A positive potential is applied by the trap power sources 32 and 32.

  For example, when ions such as argon are emitted from the plasma chambers 12 and 12, argon is supplied from the gas supply sources 16 and 16 to the plasma chambers 12 and 12, and the plasma chambers 12 and 12 are in a lean gas atmosphere. In this state, plasma is formed in the plasma chambers 12 and 12 by causing the high-frequency power sources 30 and 30 to pass a high frequency through the high-frequency coils 13 and 13. In this plasma, argon gas molecules are ionized to generate argon ions. At this time, a negative potential can be applied to the ion extraction electrodes 14 and 14 by the ion extraction power source 31, whereby argon ions are extracted from the window-shaped opening on the tip side of the plasma chambers 12 and 12 and directed toward the substrates 6 and 6. Fired.

  On the other hand, when radicals such as hydrogen are emitted from the plasma chambers 12 and 12, hydrogen is supplied from the gas supply sources 16 and 16 to the plasma chambers 12 and 12, and the plasma chambers 12 and 12 are made a lean gas atmosphere. In this state, plasma is formed in the plasma chambers 12 and 12 by causing the high-frequency power sources 30 and 30 to pass a high frequency through the high-frequency coils 13 and 13. In this plasma, hydrogen gas molecules are radicalized and radical hydrogen having unpaired electrons is generated. At this time, by applying a positive potential to the ion trap electrodes 15 and 15 by the ion trap power sources 32 and 32, the emission of ions is suppressed, and only radicals are generated from the window-like opening on the tip side of the plasma chambers 12 and 12. Fired toward the substrates 6 and 6.

  In this way, the surfaces of the substrates 6 and 7 are activated by the ions or radicals, and then the substrate 6 is moved by the moving mechanism described above to bring the surfaces of the substrates 6 and 7 into contact with each other. The surfaces are joined together. The heaters 4 and 5 provided in the substrate holders 2 and 3 heat the substrates 6 and 7 to a required temperature when activating the surfaces of the substrates 6 and 7 or joining the surfaces of the substrates 6 and 7. Used to do.

  In order to move the substrate 6 when the substrates 6 and 7 are bonded, the ion / radical sources 11 and 11 are arranged at positions away from the movement path of the substrate 6. That is, the ion / radical source 11 directed toward the upper substrate 6 is disposed obliquely downward toward the substrate 6 and is disposed so that ions and radicals are incident on the substrate 6 with a certain degree of accuracy. The ion / radical source 11 directed toward the lower substrate 7 is disposed obliquely upward toward the substrate 7 and is also disposed so that ions and radicals are incident on the substrate 7 with a certain degree of accuracy. ing.

  In this substrate bonding apparatus, it is possible to select the activation means on the surface of either the ion or radical substrate 6 or 7 or to use them together. Further, the substrate holders 2 and 3 are respectively provided with heaters 4 and 5, and the substrates 6 and 7 are heated by the heaters 4 and 5, so that not only surface activation bonding but also heat-pressure bonding can be performed. Further, since the substrate holders 2 and 3 are connected to substrate voltage application power sources 28 and 29 for applying a voltage to the substrates 6 and 7 held thereon, anodic bonding can also be performed. For this reason, it can be applied to the joining test of the substrates 6 and 7 and the examination of the joining process in various cases.

  FIG. 2 shows another embodiment of the substrate bonding apparatus according to the present invention, in which one ion / radical source 11 for irradiating ions and radicals toward the substrates 6 and 7 is provided. The rest is basically the same as the embodiment described above with reference to FIG. 1, and the same parts are indicated by the same reference numerals. The description of the same part is omitted, and the difference will be mainly described below.

  In this embodiment, there is one ion / radical source 11, and this ion / radical source 11 is held between the substrate holders 2, 3 and is inserted between the substrates 6, 7 arranged facing each other. The ion / radical source 11 has window-like openings at positions above and below the side wall of the plasma chamber 12, and ion extraction electrodes 14 and 14 for extracting ions generated in the plasma chamber 12 and trapping ions. The ion trap electrodes 15 and 15 are provided above and below the opening on the side wall of the plasma chamber 12, respectively. Accordingly, ions and radicals can be emitted from the ion / radical source 11 toward the substrates 6 and 7 disposed above and below the ion / radical source 11.

  However, since the ion / radical source 11 is inserted between the substrates 6 and 7 that are held by the substrate holders 2 and 3 and are opposed to each other, the ion / radical source 11 is used when bonding the surfaces of the substrates 6 and 7. Get in the way. Therefore, the ion / radical source 11 can be retracted from the position where the substrates 6 and 7 face each other by the moving mechanism 18. This moving mechanism includes a bellows 17, and by this expansion and contraction, the ion / radical source 11 can be moved left and right in FIG. 2 with a required stroke.

  In the substrate bonding apparatus according to the present invention, the surfaces of the substrates to be bonded can be activated not only by irradiating ions but also by irradiating radicals. Therefore, bonding using several activation means in a single vacuum chamber is possible. Is possible. Furthermore, since heat-pressure bonding and anodic bonding can be performed in a single vacuum chamber, industrial use in the technical field of bonding substrates can be performed as a multipurpose bonding apparatus.

1 is a schematic longitudinal sectional side view showing one embodiment of a substrate bonding apparatus according to the present invention. It is a schematic longitudinal cross-sectional side view which shows the other Example of the board | substrate bonding apparatus by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum chamber 2 Substrate holder 3 Substrate holder 4 Heater 5 Heater 6 Substrate 7 Substrate 11 Ion / radical source 12 Plasma chamber 14 Ion extraction electrode 15 Ion trap electrode 18 Ion / radical source moving mechanism 28 Substrate voltage application power source 29 Substrate voltage Power supply for application

Claims (3)

In a substrate bonding apparatus for bonding the surfaces of substrates (6) and (7) in contact with each other in a vacuum chamber (1) held in a vacuum state, a pair of substrates (6) and (7) to be bonded are Substrate holders (2) and (3) held so as to face each other, ion / radical sources (11) and (11) arranged toward the surfaces to be joined of the substrates (6) and (7), A moving mechanism that moves the at least one of the substrate holders (2) and (3) to contact and press the surfaces of the substrates (2) and (3) to be joined to each other, and the ion / radical source (11 ) And (11) are plasma chambers (12) and (12) for ionizing and / or radicalizing gas in plasma, and ions generated in the plasma chambers (12) and (12) are converted into the substrate (6). , (7) Io launching toward the surfaces to be joined The extraction electrodes (14) and (14) and ions are trapped, and only radicals generated in the plasma chambers (12) and (12) are emitted toward the surfaces to be joined of the substrates (6) and (7). A substrate bonding apparatus comprising ion trap electrodes (15) and (15) to be operated. Substrate bonding according to claim 1, characterized in that the substrate holders (2), (3) are provided with heaters (4), (5) for heating the substrates (6), (7) held thereon. apparatus. A substrate voltage application power supply (28), (29) for applying a voltage to the substrate (6), (7) held by the substrate holder (2), (3) is connected to the substrate holder (2), (3). The substrate bonding apparatus according to 1 or 2.

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