JP2005276998A - Semiconductor device manufacturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a substrate, which is heated via a susceptor, to be heated to in the order of 500-850°C, and thereby to improve processing capability of a substrate processing furnace. <P>SOLUTION: The substrate processing furnace comprises a processing furnace 202A, and a susceptor 217 which is disposed in the processing furnace 202A to carry a wafer 200 and has a heater 218 capable of heating the wafer 200. In the substrate processing furnace, an upper container 210A, which constitutes the processing furnace 202A, is formed of quartz of an optically transparent material. A light source 10 for irradiating the wafer 200, placed on the susceptor 217, is also disposed outside the upper container 210A. In this way, the wafer 200 is configured to be able to be heated from both the susceptor 217 and the light source 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor manufacturing apparatus for improving the heating capability of a substrate, and more particularly to an apparatus suitable for a plasma apparatus.

  FIG. 4 shows an example of a processing furnace constituting a conventional semiconductor manufacturing apparatus, which is a modified magnetron type plasma processing apparatus (hereinafter referred to as an MMT apparatus) capable of generating high-density plasma by an electric field and a magnetic field (for example, Patent Document 1). reference). This MMT apparatus has a reaction chamber 1 in which airtightness is ensured, and a susceptor 6 as a substrate mounting table on which a substrate 200 is mounted is installed in the reaction chamber 1. A heater (not shown) for heating the substrate 200 placed on the susceptor 6 is provided inside the susceptor 6.

  A processing gas is introduced into the reaction chamber 1 through a gas shower plate 2 provided in the upper part of the reaction chamber 1, the inside of the reaction chamber 1 is maintained at a certain pressure, and a cylindrical electrode 3 provided on the outer periphery of the reaction chamber 1. A high-frequency power is supplied to form an electric field, and a magnetron discharge is generated by applying a magnetic field by the magnet 5 provided around the cylindrical electrode 3. The electrons emitted from the discharge electrode 3 continue to circulate in a cycloid motion while drifting, thereby extending the lifetime and increasing the ionization generation rate, so that high-density plasma can be generated. A gas for film formation is excited and decomposed by this plasma to cause a chemical reaction to form a thin film on the surface of the substrate.

A high-density plasma can be obtained as compared with a plasma CVD processing apparatus as well as a capacitively coupled plasma processing apparatus that has been widely used. Here, the temperature limit of the wafer 200 that can be heated by the heater in the susceptor 6 is about 400 ° C. to 500 ° C. under a reaction chamber pressure of 1 Pa to 200 Pa.
JP-A-11-121198

  By the way, in order to form a thick oxide film or nitride film of, for example, about 5 nm to 15 nm on the substrate, it is necessary to heat the substrate to about 800 ° C. In addition, the substrate needs to be heated to 700 to 750 ° C. for activation annealing performed for the purpose of recovering damage to the Poly-Si (polycrystalline silicon) film.

  However, in the conventional semiconductor manufacturing apparatus that heats the substrate through the substrate mounting table, the substrate heating temperature is about 400 ° C. to 500 ° C. at the maximum as described above. Could not be formed. In addition, activation annealing for recovering the damage of the polycrystalline silicon film could not be performed, and the high temperature treatment could not be handled.

  An object of the present invention is to provide a semiconductor manufacturing apparatus capable of solving the above-described problems of the prior art and increasing the heating temperature of the substrate to improve the high-temperature processing capability.

  According to a first aspect of the present invention, there is provided a substrate processing container formed of a light transmissive material, and a substrate mounting provided inside the substrate processing container, including a substrate and a heating body for heating the substrate. A semiconductor manufacturing apparatus comprising: a mounting table; and a light source that is provided outside the substrate processing container and irradiates the substrate surface mounted on the substrate mounting table with light through the substrate processing container to heat the substrate surface. It is.

  The substrate is heated by a heating body of the substrate mounting table, and is also heated by a light source provided outside the substrate processing container. Therefore, the substrate can be heated to a higher temperature than in the case of heating only by the heating body.

  A second invention is the semiconductor manufacturing apparatus according to the first invention, wherein the material forming the substrate processing container is quartz. The material forming the substrate processing container is particularly preferably quartz.

A third invention is the semiconductor manufacturing apparatus according to the first or second invention, wherein the substrate processing container is provided with a lens for condensing or diffusing light of the light source on the substrate surface. is there.
If a lens for condensing or diffusing the light from the light source is provided, the light from the light source can be irradiated more efficiently and uniformly on the substrate surface.

  According to a fourth invention, in the first to third inventions, the gas supply means for supplying a processing gas from the upper part of the substrate processing container to the inside of the substrate processing container, and provided below the substrate mounting position, An exhaust means for exhausting the atmosphere inside the substrate processing container, a discharge electrode provided on an outer periphery of the substrate processing container, a high frequency power applying means for applying a high frequency power to the discharge electrode, and the discharge electrode Magnetic line forming means for forming magnetic lines of force inside the substrate processing vessel provided around, an impedance variable electrode provided on the substrate mounting table, and an impedance variable electrode connected to the impedance variable electrode can vary the impedance. The semiconductor manufacturing apparatus includes a variable impedance mechanism that generates plasma in the substrate processing container.

  The substrate is heated by a heating body of the substrate mounting table and also by a light source provided outside the substrate processing container. Therefore, in the semiconductor manufacturing apparatus (MMT apparatus) having this configuration, the substrate can be heated to a higher temperature, so that applications that can be handled by the MMT apparatus can be expanded.

  According to the present invention, the heating temperature of the substrate can be raised to improve the high temperature processing capability.

  In the following, an embodiment in which the semiconductor manufacturing apparatus of the present invention is applied to an MMT apparatus will be described. FIG. 3 is a cross-sectional view for explaining a processing furnace constituting an MMT apparatus which is a premise of the present invention.

  The processing furnace 202 processes the wafer 200 by magnetron discharge with a magnetron type plasma source. The processing furnace 202 includes at least a processing chamber (substrate processing container) 201, a susceptor (substrate mounting table) 217, a cylindrical electrode (discharge electrode) 215, a cylindrical magnet (magnetic line forming means) 216, and a shower head (gas supply means) 236. , And an exhaust port (exhaust means) 235.

  A processing chamber 201 for plasma processing the wafer 200 is formed by the lower container 211 and the upper container 210 that covers the lower container 211. The upper container 210 has a dome shape. The upper container 210 is made of aluminum oxide or quartz, and the lower container 211 is made of aluminum. A heater 218 (heating body) integrated susceptor 217 described later is made of aluminum nitride, ceramics, or quartz. With this configuration, metal contamination taken into the film during processing is reduced.

  A shower head 236 that forms a buffer chamber 237 that is a gas dispersion space is provided above the upper container 210. A gas inlet 234 that is an inlet for introducing gas is provided on the upper wall of the shower head 236. The lower wall is a shower plate 240 having gas ejection holes 234a which are ejection holes for ejecting gas. The gas introduction port 234 is connected to a gas cylinder of the reaction gas 230 (not shown) through a gas supply pipe 232 that supplies the reaction gas 230 via a valve 243a that is an on-off valve and a mass flow controller 241 that is a flow rate control means.

  Further, a wafer mounting position on the side wall of the lower container 211 so that the gas after the substrate processing flows from the periphery of the susceptor 217 toward the bottom of the processing chamber 201 and on the susceptor 217 described later. A gas exhaust port 235 for exhausting gas is provided on the lower side. The gas exhaust port 235 is connected to a vacuum pump 246 which is an exhaust device via a gas exhaust pipe 231 via an APC 242 which is a pressure regulator and a valve 243b which is an on-off valve.

  A gate valve 244 serving as a gate valve is provided on the side wall of the lower container 211. When the gate valve 244 is open, the wafer 200 can be loaded into the processing chamber 201 or unloaded from the processing chamber 201 by a transfer means (not shown). When the gate valve 244 is closed, the processing chamber 201 can be hermetically closed.

  A cylindrical electrode 215 is provided as discharge means for exciting the supplied reaction gas 230. The cylindrical electrode 215 has a cylindrical cross section (preferably a cylindrical shape). The cylindrical electrode 215 is installed on the outer periphery of the processing chamber 201 and surrounds the plasma generation region 224 in the processing chamber 201. A high frequency power source 273 that applies high frequency power is connected to the cylindrical electrode 215 via a matching unit 272 that performs impedance matching.

  The cylindrical magnet 216 that is a magnetic field forming unit is a cylindrical permanent magnet. The cross section of the cylindrical magnet 216 is cylindrical (preferably cylindrical). The cylindrical magnet 216 is disposed near the upper and lower ends of the outer surface of the cylindrical electrode 215. The upper and lower cylindrical magnets 216 and 216 have magnetic poles at both ends (inner peripheral end and outer peripheral end) along the radial direction of the processing chamber 201, and the magnetic poles of the upper and lower cylindrical magnets 216 and 216 are reversed. ing. Therefore, the magnetic poles in the inner peripheral portion are different from each other, and magnetic lines of force are formed in the cylindrical axial direction along the inner peripheral surface of the cylindrical electrode 215.

  Around the cylindrical electrode 215 and the cylindrical magnet 216, an electric field and magnetic field formed by the cylindrical electrode 215 and the cylindrical magnet 216 are provided so as not to adversely affect the external environment and other processing furnaces. And a shielding plate 223 that effectively shields the magnetic field.

  A susceptor 217 that holds the wafer 200 is disposed at the bottom center of the processing chamber 201. The susceptor 217 is made of, for example, aluminum nitride, and a heater 218 for resistance heating as a heating body is integrally embedded therein. By applying high frequency power to the heater 218, the wafer 200 can be heated to about 500 ° C. from the back surface.

  The susceptor 217 is equipped with an impedance variable electrode (not shown) for varying the impedance. The impedance varying electrode is grounded via an impedance varying mechanism 274. The impedance variable mechanism 274 includes a coil and a variable capacitor, and controls the potential of the wafer 200 via the impedance variable electrode and the susceptor 217 by controlling the number of coil patterns and the capacitance value of the variable capacitor.

  Further, the susceptor 217 is insulated from the lower container 211. The susceptor 217 is provided with a susceptor lifting mechanism 268. The susceptor 217 has a through hole 217a. At the bottom surface of the lower container 211, wafer push-up pins 266 for pushing up the wafer 200 are provided in at least three places. When the susceptor 217 is lowered by the susceptor elevating mechanism 268, the through-hole 217a and the wafer push-up pin 266 are in a positional relationship such that the wafer push-up pin 266 penetrates the through-hole 217a without contacting the susceptor 217.

  The controller 121 applies high-frequency power to the heater 218 embedded in the high-frequency power source 273, the matching unit 272, the valve 243a, the mass flow controller 241, the APC 242, the valve 243b, the vacuum pump 246, the susceptor lifting mechanism 268, the gate valve 244, and the susceptor 217. It is connected to a high frequency power source (not shown).

Next, a method for performing a predetermined plasma process on the surface of the wafer 200 (or the surface of the base film formed on the wafer 200) at a processing temperature of 500 ° C. or less will be described.
The wafer 200 is carried into the processing chamber 201 from the outside of the processing chamber 201 by the transfer means and is placed on the susceptor 217.

The details of the loading / mounting operation are as follows.
Initially, the susceptor 217 is lowered, and the tip of the wafer push-up pin 266 protrudes from the surface of the susceptor 217 by a predetermined height through the through hole 217a of the susceptor 217. First, the gate valve 244 provided in the lower container 211 is opened. Next, the wafer 200 is placed on the tip of the wafer push-up pin 266 by the transfer means. Thereafter, the transfer means is retracted out of the processing chamber 201. Next, the gate valve 244 is closed, and the susceptor 217 is raised by the susceptor lifting mechanism 268. As a result, the wafer 200 is placed on the surface of the susceptor 217. The wafer 200 placed on the susceptor 217 is raised to a processing position.

  Since the heater 218 embedded in the susceptor 217 is preheated, the wafer 200 is heated to a wafer processing temperature within a range of room temperature to 500 ° C. The pressure of the processing chamber 201 is maintained within a range of 0.1 to 100 Pa using the vacuum pump 246 and the APC 242.

  After heating the wafer 200 to the wafer processing temperature, the processing gas is directed from the gas inlet 234 toward the surface (processing surface) of the wafer 200 disposed in the processing chamber 201 through the gas ejection holes 234a of the shower plate 240. Supply in shower form. At the same time, high frequency power is applied to the cylindrical electrode 215 from the high frequency power supply 273 via the matching unit 272. The applied power is 150 to 200W. The impedance variable mechanism 274 is set to a desired impedance value in advance.

  Magnetron discharge is generated by the magnetic fields of the cylindrical magnets 216 and 216, charges are trapped in the upper space of the wafer 200, and high-density plasma is generated in the plasma generation region 224. By this high-density plasma, plasma processing such as formation of an oxide film or nitride film, formation of a thin film, or etching on the surface of the wafer 200 on the susceptor 217 is performed. The wafer 200 that has been processed is transferred to the outside of the processing chamber 201 by the transfer means in an operation reverse to the loading of the wafer 200.

  The controller 121 turns on / off the high-frequency power supply 273, adjusts the matching unit 272, opens / closes the valve 243a, flows the mass flow controller 241, opens the valve of the APC 242, opens / closes the valve 243b, and starts / stops the vacuum pump 246. The susceptor elevating mechanism 268 is moved up and down, the gate valve 244 is opened and closed, and the high frequency power supply for applying high frequency power to the heater 218 embedded in the susceptor is controlled.

  By the way, in the processing furnace having the above-described configuration, the temperature of the wafer 200 can be heated only up to about 500 ° C. by the heater 218 embedded in the susceptor 217. For this reason, substrate processing requiring a processing temperature exceeding 500 ° C. cannot be performed.

  Therefore, in the present embodiment, a light source that emits infrared light is added to the processing furnace having the above-described configuration, which is a premise of the present invention, in addition to the heater 218 as a wafer heating body.

  FIG. 1 is a conceptual diagram showing a cross section of the main part of a substrate processing furnace according to the first embodiment to which such a light source is added. In addition, the same code | symbol is attached | subjected to the part which is common in the substrate processing furnace (MMT apparatus) shown in FIG. 3, and the description is abbreviate | omitted.

The processing chamber 201 that forms the processing furnace 202 </ b> A includes a lower container 211 and a dome-shaped upper container 210 </ b> A that covers the lower container 211.
The dome-shaped upper container 210A is formed of quartz that can transmit infrared light, not aluminum oxide that does not transmit infrared light. The lower container 211 is made of aluminum.

  A light source 10 for irradiating the surface of the wafer 200 placed on the susceptor 217 is disposed outside the upper container 210 </ b> A so as to face the wafer 200. In the illustrated example, a plurality of light sources 10 are arranged outside the corner portion of the dome-shaped upper container 210A. One light source may be used, but two or more light sources are preferably arranged.

  The light source 10 includes a lamp 11 and a lamp house 13. The lamp 11 has a spherical shape, a ring shape, or a rod shape. As the lamp 11, a halogen lamp (wavelength region: 0.8 to 1.5 μm) that emits infrared light, a xenon lamp, or the like is used. The lamp house 13 is provided with a spherical or aspherical reflector 12. The reflecting plate 12 irradiates the surface of the wafer 200 almost uniformly through the upper container 210A. The wafer 200 can be heated by the light irradiated on the surface of the wafer 200. The lamp control is performed by ON / OFF control of the power applied to the lamp 11 by the controller 121 (see FIG. 3). However, when adjusting the heating, the power applied to the lamp 11 is controlled by PWM control or the like. May be.

  As described above, the heater 218 is integrally provided in the susceptor 217 on which the wafer 200 is placed. The wafer 200 can be heated to about 500 ° C. by applying electric power to the heater 218.

  Accordingly, when the back surface of the wafer 200 is heated by the heater 218 and the surface of the wafer 200 is further heated by the lamp 11, the wafer 200 can be heated to about 500 to 850 ° C.

  Next, a case where a film is formed on a wafer using a substrate processing furnace to which a light source as described above is added will be described. Electric power is applied to the heater 218 in advance. When the wafer 200 is loaded into the processing chamber 201 and placed on the susceptor 217, the wafer 200 is heated by the heater 218 within a range of room temperature to 500 ° C. Further, when the wafer 200 is carried into the processing chamber 201, power is applied to the lamp 11 to irradiate the surface of the wafer 200 placed on the susceptor 217 with infrared light transmitted through the upper container 210A. Then, the surface of the wafer 200 is heated. Then, the wafer 200 is heated to about 500 to 850 ° C. This temperature is the film forming temperature. At this time, the pressure of the processing chamber 201 is maintained within a range of 1 to 200 Pa.

After the wafer 200 is heated to about 500 to 850 ° C., a film forming process gas is applied from the gas inlet 234 to the surface of the wafer 200 disposed in the process chamber 201 through the gas ejection holes 234a of the shower plate 240. Supply to shower.
Here, as a processing gas for film formation, a gas containing O ₂ or O is used when forming an oxide film on the surface of the wafer 200, and a gas containing N ₂ or N is used when forming a nitride film on the surface of the wafer 200. (For example, NH ₃ ) and a gas containing Si (for example, SiH ₂ Cl ₂ ) are respectively supplied toward the surface of the wafer 200. In this case, Kr or Ar is added to O ₂ or N ₂ as necessary.

  At the same time, high-frequency power is applied to the cylindrical electrode 215 (see FIG. 3) to form an electric field in the processing chamber 201. The applied power is 150 to 200W. Magnetron discharge is generated by this electric field and the magnetic field formed in the processing chamber 201 by the cylindrical magnets 216 and 216, and charges are trapped in the upper space of the wafer 200, and the plasma generation region 224 (see FIG. 3) has a high density. Plasma is generated. By this high density plasma, an oxide film or a nitride film is formed on the surface of the wafer 200 on the susceptor 217.

  According to the first embodiment, since the wafer 200 can be heated to 500 to 850 ° C., a thick film having a film thickness of 5 nm to 15 nm or more can be formed. Therefore, by adding a light source to an existing MMT processing furnace, the applicable range (thickness, type of thin film) of the thin film that can be created can be expanded, and the processing capability of the substrate processing furnace can be improved. Moreover, since high temperature processing becomes possible, low temperature processing and high temperature processing can be continuously performed using the same substrate processing furnace. Therefore, contamination of the wafer can be reduced and throughput can be improved.

FIG. 2 is a conceptual diagram showing a cross-section of the main part of the substrate processing furnace according to the second embodiment in which a light source is added.
The second embodiment is different from the first embodiment in that a convex lens (lens) 20 is provided in the upper container 210B.

  The convex lens 20 is provided at a corner portion of the upper container wall on the optical axis of the light source 10, and condenses the light emitted from the light source 10 on the surface of the wafer 200. The convex lens 20 is formed integrally with the upper container 210B by thickening a part of the container wall into a convex lens shape by insert molding, for example.

According to the second embodiment, the same effects as those of the first embodiment can be obtained, and the wafer 200 can be efficiently and uniformly heated to the wafer processing temperature.
Although the convex lens 20 is used as the lens in the second embodiment, a thin concave lens (not shown) is used depending on the position of the lamp 11 and the shape of the reflecting plate 12. Also in this case, the light is uniformly diffused on the wafer 200, and the wafer can be efficiently heated at a high temperature and uniformly as in the case where the convex lens 20 is used.

  In the first embodiment and the second embodiment, the entire upper container is made of light transmissive quartz. However, a window hole is provided in at least the upper container wall on the optical axis, and a quartz window or lens is provided in the window hole. In such a manner, only a part of the upper container may be formed of a light transmissive material. In this way, portions other than the upper container wall on the optical axis can be made of aluminum oxide that does not transmit light.

  In the first and second embodiments, the case where an oxide film or a nitride film is formed has been described. However, in the present invention, since the wafer can be heated to 700 to 750 ° C., Poly-Si (multiple Of course, activation annealing performed for the purpose of recovering the damage of the (crystalline silicon) film can also be performed.

  In the above-described embodiment, the case where the substrate processing furnace is a dome-type MMT apparatus has been described. This is because, particularly when a dome-type MMT apparatus is used, the metal contamination taken into the film is reduced. This is because it is an excellent apparatus capable of forming a film. However, the invention is not limited to this type of device. For example, the present invention can be applied to other types of MMT apparatuses, thermal CVD apparatuses other than MMT apparatuses, and the like.

It is a conceptual diagram which shows the principal part cross section of the substrate processing furnace which concerns on 1st Embodiment. It is a conceptual diagram which shows the principal part cross section of the substrate processing furnace which concerns on 2nd Embodiment. It is sectional drawing explaining the schematic structure of the substrate processing furnace which makes the premise of the semiconductor manufacturing apparatus by embodiment. It is a conceptual diagram which shows the principal part cross section of the conventional substrate processing furnace.

Explanation of symbols

10 Light source 11 Lamp 200 Wafer (substrate)
201 processing chamber (substrate processing container)
218 Heater (Heating body)
217 Susceptor (substrate mounting table)

Claims (1)

A substrate processing container formed of a light transmissive material;
A substrate mounting table provided inside the substrate processing container, for mounting the substrate and having a heating body for heating the substrate;
A semiconductor manufacturing apparatus, comprising: a light source that is provided outside the substrate processing container and that irradiates the substrate surface mounted on the substrate mounting table with light through the substrate processing container to heat the substrate surface.

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