JP2007294755A - Vertical film deposition device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vertical deposition device adapted to stably make a boat magnetically float during deposition processing so as to prevent external vibrations from being transmitted to the boat. <P>SOLUTION: The vertical film deposition apparatus 100 comprises a lower permanent magnet 101/an upper permanent magnet 103, mounted on the lower surface/upper surface of a boat 14; a built-in lower electromagnet 102, provided on a boat bench 13 and connected electrically to a lower electromagnet control part 105; an upper electromagnet 104 disposed externally and upward of a reaction tube 5 and electrically connected to an upper electromagnet control part 106; and boat floating means constructed with the upper/lower permanent magnets 103, 101 and the upper/lower electromagnets 104, 102, arranged on a vertical line that includes the center of gravity of the boat 14, for accommodating the wafer 2 for floating the boat 14 from the boat bench 13. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vertical film forming apparatus, and more particularly to a vertical film forming apparatus that suppresses generation of particles due to external vibration during film forming processing.

  FIG. 3 shows a schematic configuration of an example of a conventional vertical film forming apparatus. FIG. 3 is a vertical cross-sectional view, and the boat ascending state is indicated by a broken line.

  In FIG. 3, 1 is a conventional vertical film forming apparatus, 2 is a semiconductor wafer (hereinafter simply referred to as a wafer), 3 is a cassette, 4 is a vacuum chamber, 5 is a reaction tube, 6 and 11 are vacuum pumps, 7 is Piping (and valve), 8 is a raw material gas supply unit, 9 is a gas supply pipe, 10 is a gas exhaust pipe, 12 is a heater, 13 is a boat stand, 14 is a boat, 15 is a boat elevator, and 16 is an adsorption conveyance mechanism. .

  The vertical film forming apparatus 1 includes a vacuum chamber 4 into which a cassette 3 containing a large number of wafers 2 is loaded and evacuated, and a reaction tube 5 arranged adjacent to the upper side of the vacuum chamber 4. Yes.

  The vacuum chamber 4 is connected to a vacuum pump 6 for evacuating the inside thereof by a pipe (and valve) 7.

  Further, on the boat table 13, a vertically long boat 14 that stores a large number of wafers 2 in a horizontal and vertical direction is placed, and the wafer 2 is transferred between the cassette 3 and the boat 14 by the suction transfer mechanism 16. It is possible to post.

  Further, the boat table 13 is moved up and down by the boat elevator 15 (indicated by white arrows in the figure), and the boat 14 is inserted into and removed from the reaction tube 5, and the reaction tube 5 and the vacuum chamber 4 are in close contact with the opening. It serves as a partition.

  Further, in the reaction tube 5, a gas supply pipe 9 for introducing the source gas from the source gas supply unit 8 (upward broken arrow in the figure) and the reaction product gas generated in the film forming process are exhausted (in the figure, A gas exhaust pipe 10 is arranged for a downward broken arrow).

  The gas exhaust pipe 10 is connected to the vacuum pump 11 by a pipe (and valve) 7.

  A heater 12 is disposed on the outside of the reaction tube 5.

  Next, the operation of the vertical film forming apparatus 1 will be described.

  First, the suction transfer mechanism 16 is operated to transfer a wafer 2 that has not been subjected to film formation processing from the cassette 3 to the boat 14, and then the vacuum pump 6 is operated so that the vacuum chamber 4 has a predetermined degree of vacuum.

  Next, the boat elevator 15 is operated to raise the boat 14 and insert it into the reaction tube 5.

  Thereafter, the vacuum pump 11 is operated while supplying the raw material gas at a constant pressure from the gas supply pipe 9, and a predetermined film forming process is performed while exhausting the reaction product gas.

  When the film forming process is completed, the boat elevator 15 is operated again and the boat 14 is lowered.

Thereafter, the suction conveyance mechanism 16 is operated, and the wafer 2 after the film formation process is transferred from the boat 14 to the cassette 3. (For example, refer to Patent Document 1).
JP 2004-179447 A FIG. JP 08-316157 A JP-A-10-303134

  However, in the vertical film forming apparatus 1 described in Patent Document 1 described above, the vacuum pump 11 is generated because the vacuum pump 11 for exhausting the reaction product gas is operated during the film forming process. External vibrations such as vibrations are transmitted to the boat table 13 and the boat 14 through the pipe (and valve) 7 and the housing, and the friction generated between the wafer 2 and the boat 14 causes particles to be generated. When the particles adhere to the wafer 2 during the film forming process, there is a risk of pattern defects.

  For this reason, it is important to devise so that external vibration is not transmitted to the boat 14, especially during the film forming process, and for that purpose, magnetically levitating the boat 14 from the boat table 13 has become an effective means. .

  Here, as another conventional configuration, in Patent Document 2, as shown in FIG. 4, the boat 14 is supported by a plurality of support bars 41, and a support magnet 42 is attached to the lower end of the support bar 41. There is disclosed a configuration in which the up and down drive magnet 43, the rotation drive magnet 44, and the correction magnet 45 outside the magnetically coupled chamber are moved up and down by an up-and-down rotation mechanism 46 to convey the boat 14 up and down. FIG. 4 is a longitudinal sectional view and a transverse sectional view, and shows a state where the boat is lifted by a broken line. The same parts as those in FIG.

  However, in this configuration, since the boat 14 is magnetically levitated over the entire stroke of the lifting and lowering operation, a space for the support rod 41 having a length corresponding to the stroke length and the double structure portion 47 for accommodating it is necessary. As a result, the height of the device increased.

  Further, the posture of the vertically long boat 14 is determined by using the magnets 42, 43, 44 having different diameters arranged concentrically at a position far away from the boat 14 by substantially the stroke length. ) Must be controlled with a force in the vertical direction (horizontal direction), and there is a risk that stable balance control cannot be performed.

  In addition, since the central support magnet 42 is attracted and balanced by the magnets 43 and 44 having different sizes from both sides with equal force, if the balance is lost even a little, this unbalance is a magnetic coupling form that further changes in the increasing direction. there were.

  Further, when the position of the center of gravity of the boat 14 slightly varies depending on the loading state of the wafers 2 and deviates from the center position of the support magnet 42, there is a possibility that stable balance control cannot be performed.

  In Patent Document 3, as shown in FIGS. 5 (a) and 5 (b), an internal magnet 51 is disposed on the side or lower portion of the boat 14, and an external magnet 52 is disposed outside the chamber. A configuration is disclosed in which the boat 14 is transported up and down in accordance with the up-and-down movement of the boat 52. However, during the film forming process, the boat base 13 is in contact with the reaction tube 5, and thus external vibration is transmitted to the boat. However, this does not solve the problem of the present invention. 5 is a longitudinal sectional view, and the same parts as those in FIG.

  SUMMARY OF THE INVENTION A main object of the present invention is to provide a vertical film forming apparatus that stably floats a boat during film forming processing, prevents external vibrations from being transmitted to the boat, and allows easy balance control of the boat. That is.

  The vertical film forming apparatus of the present invention is disposed at a lower position of a boat for storing an object to be processed, and is disposed at a position above the boat and a pair of magnetic force generating means for generating a repulsive force. A vertical film forming apparatus comprising boat floating means having a pair of generated magnetic force generating means.

  According to the vertical film forming apparatus of the present invention, during film forming processing, the boat is stably magnetically levitated so that external vibrations are not transmitted to the boat, and the boat is easily controlled in balance. An apparatus can be provided.

  A schematic configuration of an example of a vertical film forming apparatus of the present invention is shown in FIG. In addition, FIG. 1 is a longitudinal cross-sectional view, and the magnetic levitation state of the boat is indicated by a broken line. The same parts as those in FIG.

  In FIG. 1, 100 is a vertical film forming apparatus of the present invention, 2 is a semiconductor wafer (hereinafter simply referred to as a wafer), 3 is a cassette, 4 is a vacuum chamber, 5 is a reaction tube, 6 and 11 are vacuum pumps, 7 Is a pipe (and valve), 8 is a source gas supply section, 9 is a gas supply pipe, 10 is a gas exhaust pipe, 12 is a heater, 13 is a boat stand, 14 is a boat, 15 is a boat elevator, 16 is an adsorption transport mechanism, 101 is a lower permanent magnet as a first magnetic force generating means, 102 is a lower electromagnet as a second magnetic force generating means, 103 is an upper permanent magnet as a third magnetic force generating means, and 104 is a fourth magnetic force generating means. The upper electromagnet, 105 is the lower electromagnet control unit, 106 is the upper electromagnet control unit, and 107 is an impact mitigating means comprising a cushion spring.

  The vertical film forming apparatus 100 includes a vacuum chamber 4 into which a cassette 3 containing a large number of wafers 2 is loaded and evacuated, and a reaction tube 5 arranged adjacent to the upper side of the vacuum chamber 4. Yes.

  The vacuum chamber 4 is connected to a vacuum pump 6 for evacuating the inside thereof by a pipe (and valve) 7.

  Further, on the boat table 13, a vertically long boat 14 that stores a large number of wafers 2 in a horizontal and vertical direction is placed, and the wafer 2 is transferred between the cassette 3 and the boat 14 by the suction transfer mechanism 16. It is possible to post.

  Here, a lower permanent magnet 101 and an upper permanent magnet 103 are attached to the lower surface and the upper surface of the boat 14, respectively.

  Further, the boat table 13 is moved up and down by the boat elevator 15 (indicated by white arrows in the figure), and the boat 14 is inserted into and removed from the reaction tube 5, and the reaction tube 5 and the vacuum chamber 4 are in close contact with the opening. It serves as a partition.

  Here, the boat base 13 incorporates a lower electromagnet 102 at a position facing the lower permanent magnet 101.

  The lower electromagnet 102 is a wiring drawn out from the lower surface of the boat table 13 through the vacuum chamber 4 with good airtightness. The lower electromagnet control for controlling the strength of the current flowing through the lower electromagnet 102 disposed outside the chamber. The unit 105 is electrically connected.

  Further, in the reaction tube 5, a gas supply pipe 9 for introducing the source gas from the source gas supply unit 8 (upward broken arrow in the figure) and the reaction product gas generated in the film forming process are exhausted (in the figure, A gas exhaust pipe 10 is arranged for a downward broken arrow).

  The gas exhaust pipe 10 is connected to the vacuum pump 11 by a pipe (and valve) 7.

  A heater 12 is disposed on the outside of the reaction tube 5.

  In addition, an upper electromagnet 104 is disposed at a position opposite to the upper permanent magnet 103 on the outer upper side of the reaction tube 5.

  The upper electromagnet 104 is electrically connected to an upper electromagnet control unit 106 that controls the intensity of current flowing through the upper electromagnet 104.

  The upper / lower permanent magnets 103 and 101 and the upper / lower electromagnets 104 and 102 are arranged on a vertical line passing through the center of gravity (black dot in the figure) of the boat 14 housing the wafer 2. It constitutes the boat ascent means to ascend from the boat.

  The upper / lower electromagnet control units 106 and 105 then generate a repulsive force (upward thick arrow in the figure) generated between the lower permanent magnet 101 / lower electromagnet 102 and an attractive force generated between the upper permanent magnet 103 / upper electromagnet 104 ( In the drawing, the resultant force of the upward thick arrow) is balanced with the gravity of the boat 14 (downward thick arrow in the drawing), and current control is performed so that the boat 14 is stably levitated from the boat table 13.

  Here, the size (planar area) of the upper / lower permanent magnets 103 and 101 and the upper / lower electromagnets 104 and 102 is approximately the same as the bottom area of the boat 14, and the magnetic force acts on the entire bottom surface of the boat 14. Make sure you do.

  With such a magnetic coupling configuration, the lower permanent magnet 101 and the lower electromagnet 102 face each other close to each other, so that a stable and strong magnetic force can be obtained.

  Further, as described above, since the magnetic force acts on the entire bottom surface of the boat 14, even if the position of the center of gravity of the boat 14 varies slightly depending on the loading state of the wafers 2, a large rotational moment is not generated.

  Further, since the upper part of the vertically long boat 14 is pulled by a magnetic force (attraction force) having a magnitude that can be adjusted from directly above, the posture of the boat 14 can be easily maintained in an upright posture.

  In the above description, the permanent magnets 101 and 103 are used as the first and third magnetic force generating means, and the electromagnets 102 and 104 are used as the second and fourth magnetic force generating means. However, the present invention is not limited to this. .

  Although the fourth magnetic force generating means is described as being arranged outside the chamber, it may be arranged inside the chamber as long as the coating for ensuring the durability of the wiring against the source gas is provided.

  Next, the operation of the vertical film forming apparatus 100 as described above will be described.

  First, the suction transfer mechanism 16 is operated to transfer a wafer 2 that has not been subjected to film formation processing from the cassette 3 to the boat 14, and then the vacuum pump 6 is operated so that the vacuum chamber 4 has a predetermined degree of vacuum.

  Next, the boat elevator 15 is operated to raise the boat 14 and insert it into the reaction tube 5.

  When the ascending operation of the boat 14 is completed, the upper / lower electromagnet control units 106 and 105 are operated, the repulsive force is generated between the lower permanent magnet 101 and the lower electromagnet 102, and the attraction is generated between the upper permanent magnet 103 and the upper electromagnet 104. Each force is generated to keep the boat 14 magnetically levitated from the boat table 13 by several mm.

  Thereafter, the vacuum pump 11 is operated while supplying the raw material gas at a constant pressure from the gas supply pipe 9, and a predetermined film forming process is performed while exhausting the reaction product gas.

  When the film forming process is completed, the upper / lower electromagnet controllers 106 and 105 are gradually stopped, and the boat 14 that has been levitated is slowly landed on the boat table 13.

  Then, the boat elevator 15 is operated again and the boat 14 is lowered.

  Thereafter, the suction conveyance mechanism 16 is operated, and the wafer 2 after the film formation process is transferred from the boat 14 to the cassette 3.

  In the above example, the upper / lower electromagnet control units 106 and 105 are gradually stopped to softly land the boat 14 that has been levitated on the boat table 13. However, as a modification of the present invention, As shown in FIG. 2, it is preferable to further provide an impact mitigating means including a cushion spring 107 between the boat 14 and the boat table 13.

  Needless to say, such impact mitigation means may be disposed on the boat 14 side, and may be a coil spring or a leaf spring.

  The present invention can be used in a film forming apparatus such as a CVD apparatus or a sputtering apparatus. In particular, a reduced-pressure film forming apparatus that reduces the pressure during film formation (less than atmospheric pressure) is highly effective because the wafer in the boat is easily affected by the vibration of the vacuum pump.

  The present invention can be applied to a vertical film forming apparatus in which a boat is magnetically levitated during film forming processing so that external vibration is not transmitted to the boat.

The longitudinal cross-sectional view which shows schematic structure of an example of the vertical-type film-forming apparatus of this invention The longitudinal cross-sectional view which shows schematic structure of the modification of this invention A longitudinal sectional view showing a schematic configuration of an example of a conventional vertical film forming apparatus A longitudinal sectional view and a transverse sectional view showing a schematic configuration of another example of a conventional vertical film forming apparatus A longitudinal sectional view and a transverse sectional view showing a schematic configuration of another example of a conventional vertical film forming apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conventional vertical film-forming apparatus 2 Semiconductor wafer 3 Cassette 4 Vacuum chamber 5 Reaction tube 6,11 Vacuum pump 7 Piping (and valve)
DESCRIPTION OF SYMBOLS 8 Source gas supply part 9 Gas supply pipe 10 Gas exhaust pipe 12 Heater 13 Boat stand 14 Boat 15 Boat elevator 16 Adsorption conveyance mechanism 41 Support rod 42 Support magnet 43 Vertical drive magnet 44 Rotation drive magnet 45 Correction magnet 46 Elevation rotation mechanism 47 Two Heavy structure portion 51 Internal magnet 52 External magnet 100 Vertical film forming apparatus 101 of the present invention 101 Lower permanent magnet 102 Lower electromagnet 103 Upper permanent magnet 104 Upper electromagnet 105 Lower electromagnet controller 106 Upper electromagnet controller 107 Cushion spring

Claims (6)

  A pair of magnetic force generating means disposed at a lower position of the boat for storing the object to be processed and generating a repulsive force, and a pair of magnetic force generating means disposed at an upper position of the boat and generating an attractive force to each other. A vertical film forming apparatus provided with a boat floating means.   The lower position of the boat is a position below the center of gravity on a vertical line passing through the center of gravity of the boat, and the upper position of the boat is a position above the center of gravity on a vertical line passing through the center of gravity of the boat. The vertical film-forming apparatus according to claim 1.   The pair of magnetic force generating means at the lower position includes a first magnetic force generating means disposed on the lower surface of the boat and a second magnetic force generating means built in a boat table on which the boat is placed. The pair of magnetic force generating means comprises a third magnetic force generating means disposed on the upper surface of the boat and a fourth magnetic force generating means provided vertically above the third magnetic force generating means. The vertical film forming apparatus according to claim 1 or 2.   4. The vertical film forming apparatus according to claim 3, wherein the first and third magnetic force generation means are permanent magnets, and the second and fourth magnetic force generation means are electromagnets.   The vertical film-forming apparatus according to any one of claims 1 to 4, further comprising an impact relaxation means provided between the boat and a boat table on which the boat is placed. The vertical film forming apparatus according to claim 5, wherein the impact relaxation means is a cushion spring.

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