JP4294609B2 - Substrate heating device - Google Patents

Description

  The present invention relates to a substrate heating apparatus, and more particularly to a substrate heating apparatus that can uniformly heat a semiconductor substrate or the like.

  FIG. 3 shows a conventional substrate heating apparatus, wherein 1 is a vacuum chamber, 2 is a tube provided in the vacuum chamber 1, 3 is a substrate heating processing space surrounded by the tube 2, and 4 is the vacuum chamber 1 and the tube. A plurality of halogen lamps provided between 2 and 5, 5 is a semiconductor substrate door, 6 is a susceptor disposed in the space 3, 7 protrudes out of the vacuum chamber 1 through the tube 2 and the vacuum chamber 1. The rotating shaft of the susceptor, 8 is a semiconductor substrate supported by the susceptor 6, 9 is a rotating mechanism for rotating the rotating shaft 7 of the susceptor 6, 10 is a pyrometer for controlling the temperature of the substrate heat treatment space 3, 11 Is a vacuum seal of the rotary shaft 7, the vacuum chamber 1 and the tube 2.

In the conventional substrate heating apparatus, the substrate 8 is heated by the halogen lamp 4 while the susceptor 6 is rotated by the rotating mechanism 9, and the temperature distribution of the substrate 8 is made uniform. As such a substrate heating apparatus, there is one described in Patent Document 1.
JP-A-5-152307

  However, in the conventional substrate heating apparatus, it is difficult to vacuum seal the rotating shaft 7 of the susceptor 6, and it is difficult to stably maintain an ultra-high vacuum state for a long time.

  In addition, when the process gas is introduced into the vacuum chamber 1, there are disadvantages such as disturbance of the air flow due to the rotation of the susceptor 6, static electricity due to the rotation, and fine particles adhering to the substrate 8. It was.

  The present invention eliminates the above-mentioned drawbacks.

The substrate heating apparatus of the present invention includes a vacuum chamber, an opening provided on the wall of the vacuum chamber, a lid that hermetically closes the opening, and a laser light transmitting window that is formed on the lid and transmits laser light. A semiconductor laser oscillator provided outside the vacuum chamber; a holder fixed to the lid for holding the semiconductor laser oscillator; and a rotating means for rotating the semiconductor laser oscillator about its laser optical axis. When more becomes a substrate holder provided in the vacuum chamber, the laser beam emitted from the semiconductor laser oscillator via the laser beam transmission window allowed irradiating the substrate held on the substrate holder, the substrate heating It is characterized by damaging.

  The substrate heating apparatus of the present invention further includes reciprocating means for reciprocating the semiconductor laser oscillator in a direction perpendicular to the laser optical axis.

  The substrate heating apparatus of the present invention is characterized in that the semiconductor laser oscillator is formed by laminating a plurality of laser diode bars.

  Moreover, the substrate heating apparatus of the present invention is characterized in that the vacuum chamber further includes an infrared transmission window for a radiation thermometer provided on a wall of the vacuum chamber.

  According to the substrate heating apparatus of the present invention, by providing the substrate in the vacuum chamber and rotating or reciprocating the laser of the heating source, the laser distribution irradiated to the substrate becomes uniform, and the substrate is uniformly distributed on the substrate. There is a great advantage that a film can be formed.

  Embodiments of the present invention will be described below with reference to the drawings.

  The substrate heating apparatus of the present invention includes a vacuum chamber 1, an opening 12 provided on the upper wall of the vacuum chamber 1, and a detachable lid 14 having a laser light transmission window 13 that hermetically closes the opening 12. A laser oscillator holder 15 fixed to the upper surface of the lid 14, a continuous oscillation high output direct semiconductor laser oscillator 17 provided on the holder 15 via a bearing 16 so as to be rotatable around its laser optical axis, An optical lens system 18 fixed on the laser exit side of the laser oscillator 17, a motor 19 provided on the holder 15 for rotating the laser oscillator 17 at a rotational speed of, for example, 5 to 30 rpm, and a rotating shaft of the laser oscillator 17. And a belt 20 stretched between the motor 19 and the drive shaft of the motor 19, and a substrate holder 22 fixed to the back surface of the lid 14 via a support bar 21.

  Further, a laser beam aperture 23 for adjusting the laser beam and the irradiation area is provided between the lower end of the support bar 21 and the substrate holder 22 as necessary. The diaphragm 23 is preferably made of a material having good thermal conductivity, and the surface thereof is preferably ceramic coated.

  Further, an infrared transmission window 24 having a size equal to or larger than the substrate size is provided on the lower wall of the vacuum chamber 1, and a radiation thermometer 25 provided below the transmission window 24 allows the substrate to pass through the infrared transmission window 24. The temperature is measured from the infrared rays emitted from 8. As a material for the infrared transmission window 24, barium fluoride, sapphire, calcium fluoride, germanium, zinc selenide, or the like is preferable.

  The substrate 8 is made of silicon, sapphire, zinc oxide or the like.

  In addition, 26 is a sub chamber provided on the side of the vacuum chamber 1, 27 is an openable / closable gate valve capable of airtightly blocking between the vacuum chamber 1 and the sub chamber 26, and 28 is provided in the sub chamber 26. A sample exchange port 29 is provided in the sub chamber 26, a transfer means for transferring the substrate 8 from the sub chamber 26 into the vacuum chamber 1, and 30 is an auxiliary exhaust system provided in the sub chamber 26. .

The continuous wave high output direct semiconductor laser oscillator 17 is formed by laminating a plurality of laser diode bars, and has a high output of 1 kW or more. Such a continuous-wave high-power direct semiconductor laser oscillator 17 is conventionally known as disclosed in, for example, Japanese Patent Application Laid-Open No. 10-94892.

  Further, it is preferable that the laser oscillator holder 15 can adjust the height of the laser oscillator 17 and the support bar 21 can adjust the height of the substrate holder 22.

  The laser light transmitting window 13 is preferably made of high purity quartz provided with an antireflection film, and the window diameter is preferably at least equal to or larger than the diameter of the substrate.

  The rotation speed of the motor 19 may be constant or variable, and may be changed according to the heating temperature and the heating time. The rotation of the motor 19 is reverse rotation in addition to rotation in a certain direction. It is good.

  Since the substrate heating apparatus of the present invention is configured as described above, the laser oscillator holder 15 and the support rod 21 are operated in a state where the lid 14 is removed from the vacuum chamber 1, and the substrate 8 and the laser are operated. After accurately determining the positional relationship of the oscillator 17, the lid 14 is attached to the vacuum chamber 1, the inside of the vacuum chamber 1 is set to a high vacuum, and the laser oscillator is rotated by the motor 19. A laser beam is emitted, and the substrate 8 in the vacuum chamber 1 is irradiated and heated through the laser beam transmission window 13 to form a film on the substrate 8.

  Note that the laser light emitted from the laser oscillator 17 may be defocused to a predetermined size by the optical lens system 18, and the substrate may be irradiated while rotating the defocused light.

  According to the present invention, for example, when a semiconductor laser having a power of 1.2 kW is used, the temperature of a 2-inch substrate can be raised to 1000 ° C. within one minute in a vacuum.

  According to the present invention, since the holder 15 of the laser oscillator 17 and the substrate holder 22 are fixed to the lid 14, the lid 14 can be removed and the relative position between the substrate 8 and the laser oscillator 17 can be accurately adjusted. Therefore, the work time for adjustment can be significantly shortened.

  Moreover, since the infrared transmission window 25 is provided in the lower part of the vacuum chamber 1 so that the substrate temperature can be measured with a radiation thermometer, the substrate temperature and the temperature distribution can be measured in real time.

  Further, by fixing the substrate in the vacuum chamber 1 and rotating the laser of the heating source, the laser distribution irradiated on the substrate becomes uniform, and a uniform film can be formed on the substrate.

  In addition, unlike a conventional substrate heating apparatus that rotates a substrate, a vacuum seal for the rotating shaft is unnecessary, and heating unevenness due to eccentricity of rotation of the substrate can be prevented.

  Further, there is no fear of turbulence of process gas or the like accompanying rotation of the substrate, generation of static electricity, or generation of dust.

  Further, the substrate can be heated regardless of whether it is circular or rectangular.

  The laser beam emitted from the laser oscillator 17 in which a plurality of laser diode bars are stacked has different laser emission angles in the fast axis direction (laser bar stacking direction) and the slow axis direction (perpendicular to the fast axis). Therefore, since the energy distribution of the laser is different between the fast axis and the slow axis, uniform heating of the substrate is difficult, but in the present invention, by rotating the laser beam irradiated to the substrate and irradiating and heating the substrate, The influence of the difference in energy distribution between the fast axis direction and the slow axis direction of the laser light can be eliminated, and the temperature distribution of the substrate can be made uniform. Since the slow axis direction and the fast axis direction of the laser are different from each other by 90 degrees, the same effect can be obtained even when the laser beam is rotated 90 degrees. This also facilitates the design of the laser oscillator and makes it possible to provide a substrate heating apparatus at a low cost.

  In addition, since the substrate is stationary, the infrared light emitted from the substrate can be accurately captured by the radiation thermometer during heating, so that the correct substrate temperature and substrate temperature distribution can be measured.

  FIG. 2 shows a second embodiment of the present invention. In this second embodiment, instead of rotating the laser oscillator 17 by the bearing 18, the motor 19 and the belt 20 of the first embodiment, A laser oscillator 17 is provided on the holder 15 through a slide mechanism 31 so as to be slidable in a direction perpendicular to the laser optical axis, and the laser oscillator 17 is reciprocated by the slide mechanism 31.

  The reciprocating motion of the laser oscillator may be constant speed or variable speed, and may be changed according to the heating temperature and the heating time. Further, the amplitude of the reciprocating motion may be a constant amplitude or an arbitrary amplitude.

  Also in the substrate heating apparatus of the present invention, the laser distribution can be made uniform and a uniform film can be formed on the substrate.

  In addition, the area that can be irradiated onto the substrate can be enlarged.

  In addition to the slide mechanism 31 of the second embodiment, the rotation means of the first embodiment is provided so that the laser oscillator 17 reciprocates and rotates with respect to the holder 15. May be.

It is a vertical side view of the substrate heating apparatus of the present invention. It is a vertical side view of the other Example of the substrate heating apparatus of this invention. It is a vertical side view of the conventional substrate heating apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum chamber 2 Tube 3 Substrate heating processing space 4 Halogen lamp 5 Semiconductor substrate entrance / exit door 6 Susceptor 7 Rotating shaft 8 Semiconductor substrate 9 Rotating mechanism 10 Pyrometer 11 Vacuum seal 12 Opening 13 Laser light transmitting window 14 Cover 15 Laser oscillator holder 16 Bearing 17 Laser oscillator 18 Optical lens system 19 Motor 20 Belt 21 Support rod 22 Substrate holder 23 Laser light aperture 24 Infrared transmission window 25 Radiation thermometer 26 Sub chamber 27 Gate valve 28 Sample exchange port 29 Conveying means 30 Auxiliary exhaust system 31 Slide mechanism

Claims (4)

A vacuum chamber, an opening provided on the wall of the vacuum chamber, a lid that hermetically closes the opening, a laser light transmission window that transmits laser light, and is provided outside the vacuum chamber. A semiconductor laser oscillator, a holder fixed to the lid for holding the semiconductor laser oscillator, a rotating means for rotating the semiconductor laser oscillator about its laser optical axis, and provided in the vacuum chamber. more becomes substrate holder was, substrate heating, characterized in that the semiconductor laser laser beam emitted from the oscillator via the laser beam transmission window allowed irradiating the substrate held on the substrate holder, allowed to heat the substrate apparatus. 2. A substrate heating apparatus according to claim 1 , further comprising reciprocating means for reciprocating said semiconductor laser oscillator in a direction perpendicular to the laser optical axis. 3. The substrate heating apparatus according to claim 1, wherein the semiconductor laser oscillator is formed by laminating a plurality of laser diode bars. The vacuum chamber is further substrate heating apparatus according to claim 1, wherein characterized in that it has an infrared transmission window for the radiation thermometer provided on its walls.

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