JP5235934B2 - Semiconductor manufacturing apparatus and semiconductor device manufacturing method - Google Patents

Description

  The present invention relates to a semiconductor manufacturing apparatus for processing a substrate using plasma, and more particularly to a structure for improving the substrate heating capability.

  In general, a plasma processing furnace that constitutes a semiconductor manufacturing apparatus, for example, a plasma processing furnace using a modified magnetron type plasma source, is a process chamber that is a gas-tight reaction chamber. A processing substrate is installed and a reaction gas is introduced into the processing chamber. Maintaining the processing chamber at a certain pressure, supplying high frequency power to the discharge electrode to form an electric field, applying a magnetic field to generate a magnetron discharge to generate plasma, and processing the substrate using this plasma It has become.

  As such a plasma processing furnace, conventionally, there is one that supplies gas in a shower shape from a shower plate having a large number of holes to a processing chamber (reaction chamber).

  As shown in FIG. 6, this is because the reaction chamber 20 that accommodates the substrate 6, the shower head 11 that supplies discharge gas to the reaction chamber 20 from the gas inlet (gas supply pipe) 12, and the reaction chamber 20 are exhausted. A gas exhaust port (exhaust pipe) 14 and plasma generating means 17 for generating plasma in the reaction chamber 20 using gas.

  The processing container 10 forming the chamber of the reaction chamber 20 is composed of a metal lower container 1 and a dome-shaped upper container 2 made of an insulating material (alumina in this case), and is opened and closed for internal component replacement and cleaning. It has a structure that can be done.

  The upper container 2 is provided with a shower plate 3 for supplying the reaction gas in a shower shape at the upper part thereof, and a metal upper lid 4 is installed on the upper container 2 via an O-ring 9. Between the shower plate 3 and the upper lid 4 of the upper container 2, a buffer chamber for introducing gas, that is, a gas dispersion chamber 13, is formed, and gas can be mixed here. The shower plate 3 is provided with a large number of round holes serving as gas outlets in a lattice shape or concentric circles on the entire surface of a metal disc. Therefore, the round hole is exposed in the reaction chamber 20.

  In the plasma processing furnace, the upper cover 4 of the reaction chamber 20 is grounded in order to stabilize the plasma. If the shower plate 3 is made of metal, the shower plate 3 is also grounded via the upper lid 4. When the shower plate 3 is grounded, the electric field formed by the plasma generation means 17 is directed not only to the substrate 6 but also to the shower plate 3. Therefore, the shower plate 3 is sputtered by direct ion impact.

  In addition, if the shower plate 3 exposed to the plasma atmosphere has a gas outlet having a metal corner portion where the electric field tends to concentrate, the electric field directed to the shower plate 3 is generated by the round hole of the gas outlet provided in the shower plate 3. Since the ions concentrate in the corners, ions in the plasma collide with the corners of the round hole, and the corners are easily sputtered by the ions. Substances repelled by sputtering fall on the wafer as particles. This particle becomes a harmful metal contamination source, and the wafer is contaminated with metal. In view of this, it has been considered that the shower plate is made of a dielectric material such as quartz instead of metal to reduce spatter at the gas outlet (for example, see Patent Document 1).

  In the reaction chamber 20, a susceptor 5 serving as a substrate mounting table having a mounting portion for setting a substrate 6 to be processed such as a silicon wafer, and lift pins (substrates) that penetrate the through holes 5 a and separate the substrate 6 from the susceptor 5 during substrate transfer. Elevating pins) 8 and a block 7 for fixing these lift pins 8 to the lower container 1 are arranged. The susceptor 5 has a built-in ceramic heater, and has a temperature of about 400 to 500 ° C. when the substrate is processed.

JP 2001-196354 A (FIGS. 1, 5, 6, 8, and 10)

  However, in a conventional semiconductor manufacturing apparatus that heats a substrate via a substrate mounting table, the substrate heating temperature by the heater is at most about 400 ° C. to 500 ° C., and thus cannot cope with high temperature processing.

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

  In order to achieve the above object, the present invention is configured as follows.

  A semiconductor manufacturing apparatus according to the present invention includes a reaction chamber provided with a light transmissive window on at least an upper surface, a discharge electrode disposed on the outer periphery of the reaction chamber, and a magnetic field disposed on the outer periphery of the discharge electrode. A forming means; a lamp heating device disposed outside the reaction chamber corresponding to the light-transmitting window; and a substrate to be processed to receive light from the lamp heating device facing the lamp heating device in the reaction chamber. A substrate mounting table placed on the substrate, a gas supply pipe for supplying a discharge gas to the reaction chamber, and an exhaust pipe for exhausting the atmosphere in the reaction chamber, while exhausting the reaction chamber with the exhaust pipe A discharge gas is supplied from the gas supply tube, and the discharge gas is plasma-discharged by an interaction between an electric field from the discharge electrode and a magnetic field by the magnetic field forming means, and is placed on the substrate mounting table and Lamp heating device The substrate to be processed is heated by the light irradiation is obtained by configured to perform a plasma treatment.

  In the above invention, it is preferable to further provide means for reducing the temperature rise of the peripheral member of the lamp heating device in the reaction chamber. In the above invention, a light-transmitting shower plate is further provided in the reaction chamber facing the light-transmitting window to form a gas dispersion chamber with the light-transmitting window, and the shower plate has the above-mentioned It is preferable that a gas supply unit is provided at an outer peripheral position of the substrate to be processed.

  The means for reducing the temperature rise of the peripheral member of the lamp heating device in the reaction chamber includes the following modes.

  The first is a form in which the mounting member for arranging the lamp heating device outside the reaction chamber is made of a material having low thermal conductivity while ensuring heat resistance.

The second is a mode in which a heat dissipating mechanism such as a water cooling mechanism is provided on the peripheral member of the lamp heating device in the reaction chamber, and the heat of the lamp heating device is absorbed by this through the heat transfer member. As a specific configuration, a cooling liquid passage is formed in the upper lid of the reaction chamber, and heat is pumped out from the cooling liquid passage. Here, examples of the peripheral member of the lamp heating device in the reaction chamber that can form the coolant passage include an upper cover edge member and a light-transmitting window member.

  Thirdly, the mounting member that arranges the lamp heating device outside the reaction chamber is not only composed of a material with low thermal conductivity while ensuring heat resistance, but also acts as a heat insulation mechanism such as creating a gap with pins etc. It is the form comprised so that it may do. Also in this embodiment, a coolant passage can be formed in the upper lid of the reaction chamber as a water cooling mechanism.

  According to the semiconductor manufacturing apparatus of the present invention, the light transmissive window is provided on the upper surface of the reaction chamber, and the lamp heating device is disposed outside the reaction chamber corresponding to the light transmissive window. The substrate to be processed can be heated by being irradiated with light through a transmissive window.

  In addition, since the means for reducing the temperature rise is provided in the peripheral member of the lamp heating device in the reaction chamber, the temperature rise in the peripheral member of the lamp heating device in the reaction chamber, for example, the upper lid edge member or the light transmissive window member, etc. And the life of a sealing member such as an O-ring can be increased. As a result, it is possible to increase the processing temperature of the substrate to be processed that is mounted on the substrate mounting table and heated by receiving the light irradiation from the lamp heating device. Therefore, the processable temperature range of the semiconductor manufacturing apparatus is widened and can be applied to a wider range of uses.

  The number of heating lamps constituting the lamp heating device is not particularly limited, and in a plasma processing device for forming a thin film on a substrate in a vacuum-held processing vessel having a reaction gas introduction port and an exhaust port, the outside of the processing vessel At least one heating lamp as a light source for heating the substrate may be provided on the atmosphere side.

It is the figure which showed the structure which provided the window and the lamp heating apparatus in the substrate processing furnace (MMT apparatus) which concerns on 1st embodiment of this invention. It is the elements on larger scale of FIG. The structure of the shielding plate which concerns on embodiment of this invention is shown, (a) is a top view, (b) is a principal part perspective view. It is the figure which showed the structure which provided the window and the lamp heating apparatus in the substrate processing furnace (MMT apparatus) which concerns on 2nd embodiment of this invention. It is the elements on larger scale of FIG. It is the figure which showed the structure of the conventional substrate processing furnace (MMT apparatus).

  Embodiments of the present invention will be described below. The plasma processing furnace constituting the semiconductor manufacturing apparatus according to the embodiment is a substrate processing furnace (hereinafter referred to as an MMT apparatus) that performs plasma processing on a substrate such as a wafer using a modified magnetron type plasma source capable of generating high-density plasma by an electric field and a magnetic field. Called). In this MMT apparatus, a substrate is installed in a processing chamber that is a reaction chamber ensuring airtightness, a reaction gas is introduced into the processing chamber through a shower plate, the processing chamber is maintained at a certain pressure, and a high frequency is applied to a discharge electrode. Electric power is supplied to form an electric field, and a magnetic field is applied to cause magnetron discharge. The electrons in the vicinity of the discharge electrode continue to circulate around the cycloid while drifting and are captured by the magnetic field, so that the ionization generation rate is increased and high-density plasma generation is possible. The reactive gas is excited and decomposed by the high-density plasma. Various plasma treatments are performed on the substrate, such as by performing diffusion treatment such as oxidation or nitridation on the substrate surface, forming a thin film on the substrate surface, or etching the substrate surface by the reaction gas that has been excited and decomposed be able to.

[Embodiment 1]
The configuration of Embodiment 1 of the present invention is shown in FIG. This MMT apparatus includes a shower plate 3 and an upper lid 4
The configuration is basically the same as that of the apparatus shown in FIG.

  The MMT apparatus includes a processing container 10 composed of a first container and a second container. A reaction chamber (processing chamber) 20 for processing the substrate 6 is formed from the lower container 1 as the second container and the upper container 2 as the first container placed on the lower container 1. . The upper container 2 is formed in a dome shape with a dielectric of aluminum nitride, aluminum oxide or quartz, and the lower container 1 is formed of aluminum. Further, the susceptor 5 which is a heater-type substrate holding means described later is made of aluminum nitride, ceramics or quartz, thereby reducing metal contamination taken into the film during processing.

  In FIG. 1, an opening 2 a is provided in the upper part of the upper container 2, and a metal upper lid 4 that covers the opening 2 a and is provided with a light transmissive window is installed via an O-ring 9. . The upper lid 4 includes an upper lid edge member 41 made of an aluminum alloy having an opening, and a light transmissive window member 42 that covers the opening in an airtight manner.

  As shown in an enlarged view in FIG. 2, a stepped portion 43 is formed on the inner edge of the upper lid edge member 41, and the periphery of the light transmissive window member 41 is a Teflon (registered trademark) serving as a seal member. It is supported via a sealing material 44 and an O-ring 45. The upper lid edge member 41 can also be used as an electrode and can supply high-frequency power.

  On the other hand, a shielding plate 240 that functions as a shower plate that covers the upper opening 2a of the upper container 2 and supplies the reaction gas in a shower form from the side is disposed on the lower surface of the metal upper lid 4. As shown in FIG. 3, the shielding plate 240 is made of a disk-shaped member, and has a pair of notch recesses 301 that do not penetrate on the upper and lower surfaces of the outer periphery. The notch recess 301 on the upper surface is configured to collect gas that has flowed radially outward along the upper surface of the shielding plate 240. The notch recess 301 on the lower surface is accumulated in the notch recess 301 on the upper surface, and the gas flowing down through the side surface of the shielding plate 240 is blown out into the processing chamber 20 from the opening 2a.

  A plurality of notch recesses 301 are provided at equal intervals in the circumferential direction of the shielding plate 240. The notch shape is substantially semicircular in the illustrated example, but is not limited thereto. If the gas flow path in which the gas outlet is formed is formed, the shape of the notch is arbitrary. In the illustrated example, a pair of notch recesses 301 is provided on both the upper surface and the lower surface, but may be provided only on the lower surface. Further, the notch recess 301 may be provided by shifting the circumferential position between the upper surface and the lower surface.

  In the above description, the gas dispersion chamber (buffer chamber) 13 is formed between the light transmissive window member 42 and the shielding plate 240 (shower plate). When two or more kinds of gases are used, the gas dispersion chamber 13 Gas can be mixed.

  On the other hand, as shown in FIG. 1, as the plasma generation means 17, a cylindrical shape that forms a high-frequency electric field for magnetron discharge on the outer wall of the processing vessel 10 and discharges the gas supplied into the processing vessel 10. The discharge electrode 15 is provided. The discharge electrode 15 is connected to a high frequency power source so that a high frequency is supplied to the electrode.

  Similarly, a magnetic field forming means 16 formed in a cylindrical shape is provided on the outer wall of the processing vessel 10. The magnetic field forming means 16 is arranged in a cylindrical shape so as to surround the cylindrical discharge electrode 15. Thereby, magnetic lines of force having a magnetic field having a component substantially parallel to the axial direction of the cylindrical discharge electrode 15 are formed along the inner surface of the cylindrical discharge electrode 15 in the cylindrical axis direction.

Plasma can be generated inside the dome-shaped upper container 2 by introducing a predetermined gas in a vacuum state in the chamber and applying a high frequency to the cylindrical electrode 15 by the apparatus having the above configuration. As shown in FIG. 6, a susceptor 5 serving as a substrate mounting table is disposed in the lower container 1, and a substrate 6 to be processed such as a silicon wafer is placed thereon. The plasma generated inside the upper container 2 is diffused to obtain a substantially uniform plasma density on the substrate 6 to be processed, so that uniform processing is possible.

  Usually, in order to accelerate this process, the substrate 6 to be processed is heated from below the susceptor 5 and can be heated to about 500 ° C. However, when it is desired to form a thick silicon oxide film, it is advantageous to heat to a higher temperature.

  Therefore, in the present invention, as described above, the upper lid 4 is provided with the light transmissive window (more precisely, the light transmissive window member 42), and the lamp heating device 50 is provided above, that is, outside the reaction chamber corresponding to the light transmissive window. The substrate to be processed 6 is heated by a lamp from the outside of the reaction chamber through a light transmissive window.

  In the embodiment of FIG. 1, a lamp heating device 50 composed of at least one heating lamp is mounted above the light transmissive window member 42 through a stainless steel mounting member 51 that constitutes a window frame together with the upper lid edge member 41. . That is, a stepped portion 52 is formed on the inner edge of the lower surface of the mounting member 51, a window frame is formed together with the stepped portion 43 of the upper lid edge member 41, and the edge portion of the light transmissive window member 42 is fitted therein. At that time, a seal material 44 made of Teflon (registered trademark) is provided between the upper surface of the light transmissive window member 42 and the lower surface of the stepped portion of the mounting member 51, and the edge of the light transmissive window member 42 is pressed down. Since the light transmissive window member 42 is completely sealed by the O-ring 45 on the lower surface side, the O-ring 45 is not particularly provided on the upper surface side.

  With this configuration, the heating light 53 from the lamp heating device 50 was introduced into the reaction chamber through the light transmissive window, and the substrate to be processed was irradiated with light to be heated to a high temperature.

  However, when the heating temperature is increased, the temperature of the lamp heating device peripheral members in the reaction chamber, that is, the temperature of the lamp heating device peripheral members such as the upper lid edge member 41 and the light transmissive window member 42 increases, and contributes to the sealing structure of the processing vessel 10. The O-ring 9 and the O-ring 45 are damaged, and the life of the sealing function is shortened.

  Therefore, as shown in FIG. 2, the mounting member 51 is made of stainless steel, which is a material having low thermal conductivity and heat resistance, as means for reducing the temperature rise of the peripheral member of the lamp heating device in the reaction chamber. In addition, a lamp heating device that is heated by the lamp heating device 50 is formed with a coolant channel (water channel in this embodiment) 61 in the window frame portion of the light transmissive window in the upper lid of the reaction chamber, that is, in the upper lid edge member 41. The heat of the peripheral members (the upper lid edge member 41, the light transmissive window member 42, the shielding plate 240, etc.) is absorbed by this cooling liquid and pumped out of the apparatus. By these means, the temperature rise of the lamp heating device peripheral member can be reduced. Further, since the material of the upper lid edge member 41 is aluminum having high thermal conductivity, it can be cooled more efficiently.

  Aluminum and stainless steel cannot be welded. Therefore, in actuality, a stainless steel flange plate 60 is provided on the upper surface of the upper lid edge member 41, a stainless steel coolant passage 61 and a cap 62 portion are formed on the stainless steel flange plate 60, and the stainless steel mounting member 51 is integrated. As a structure, the upper lid edge member 41 made of aluminum is bolted to the flange plate 60.

  In the first embodiment, as a means for reducing the temperature rise of the peripheral member of the lamp heating device in the reaction chamber, the mounting member 51 is made of stainless steel having a low thermal conductivity and heat resistance, and the lamp heating device. A structure is adopted in which cooling water is allowed to flow through the upper lid edge member 41, which is one of the peripheral members, to actively pump out heat.

The effect of adopting such a structure is that the portion where heat and light are concentrated is around the lamp heating device 50 as a light source, and therefore, by flowing cooling water to the local portion, the upper lid edge member 41 is centered. It is in the point which can reduce the temperature rise of the peripheral member to do. In order to absorb much light (heat) emitted from the light source into the cooling water, the material of the upper lid edge member 41 is a material having high thermal conductivity, for example, aluminum.

[Embodiment 2]
FIG. 4 shows the configuration of the second embodiment of the present invention, and FIG. This second embodiment is different from the case of FIG. 2 in that the structure for attaching the lamp heating device 50 to the upper lid 12 has a pin structure (pin 74) with good heat dissipation.

  That is, as shown in an enlarged view in FIG. 5, the attachment member 71 of the lamp heating device 50 is integrally formed with a vertical stainless steel plate from the inner peripheral edge of the stainless steel flange plate 60 provided on the upper surface of the upper lid edge member 41. A plate-like attachment member 71 is erected, and an inward flange portion 72 made of stainless steel is provided at the upper end thereof. That is, a vertical plate-shaped mounting member 71 made of stainless steel having an outward flange (flange plate 60) at the lower end and an inward flange (inward flange portion 72) at the upper end is provided on the outer periphery of the light transmissive window member 42. . On the other hand, a horizontal plate-like attachment member 73 made of stainless steel is provided on the bottom surface of the lamp heating device 50, and a stainless steel pin 74 is fixed to this by welding and suspended. And the lower end of this pin 74 is fixed to the inward flange part 72 of the upper end of the attachment member 71 by welding.

  As a means for reducing the temperature rise of the peripheral members of the lamp heating device in the reaction chamber 20 as described above, a plate (attachment member 71, attachment member 73, pin 74) with protrusions (pins) is provided outside the processing vessel 10. A structure that supports the lamp heating device 50 that is a light source is adopted, and stainless steel, which is a material having a low thermal conductivity and a heat resistance as much as possible, is used as a material of the plate.

  When such a structure is adopted, the surface (the mounting member 71, the mounting member 73, and the pin 74) with protrusions (pins) can reduce the surface area due to heat conduction, and heat from the lamp heating device 50 can be processed. Since it is not directly conducted to the upper lid 4, the temperature rise of the lamp heating device peripheral members (the upper lid edge member 41 and the light transmissive window member 42) in the reaction chamber 20 is reduced, and materials outside the processing vessel (O-rings 9, 45, etc.) ) Can be reduced due to heat.

  In the above embodiment, the lamp heating and the plasma treatment are performed at the same time. However, the lamp treatment may be performed after the plasma treatment, or the plasma treatment may be performed after the lamp heating.

  In the above embodiment, the light transmission window member 42 is provided at the center of the upper lid 4 of the ground potential for forming the electric field of the discharge electrode, so that the entire surface is not metal, so to speak, a structure in which the upper lid is omitted in FIG. It is close to. For this reason, although the formation state of the electric field is different from the conventional one, an electric field is mainly formed between the discharge electrode and the substrate mounting table (susceptor), and between the discharge electrode and the container under the ground potential.

4 Top cover (made of metal)
5 Susceptor 6 Substrate 9 O-ring 10 Processing vessel 17 Plasma generating means 20 Reaction chamber (processing chamber)
41 Upper lid edge member 42 Light transmissive window member 43 Stepped portion 44 Teflon (registered trademark) sealing material 45 O-ring 50 Lamp heating device 51 Mounting member 52 Stepped portion 60 Flange plate 61 Coolant passage 62 Cap 71 Mounting member 72 Inward Flange part 73 Mounting member 74 pin

Claims (2)

A reaction chamber provided with a light transmissive window on at least the upper surface;
A lamp heating device disposed outside the reaction chamber corresponding to the light transmissive window;
A heat-resistant mounting member provided between the lamp heating device and the light transmissive window, and constituting an upper part of a window frame of the light transmissive window;
Provided between the reaction chamber and the light-transmitting window, constituting the lower part of the window frame, made of a material having higher thermal conductivity than the heat-resistant mounting member, and provided with a cooling channel An upper lid edge member;
A window pressing portion provided between the heat-resistant mounting member and the light-transmitting window and between the upper lid edge member and the light-transmitting window ;
A substrate mounting table for mounting the substrate to be processed so as to receive light irradiation from the lamp heating device so as to face the lamp heating device in the reaction chamber;
A semiconductor manufacturing apparatus. Placing a substrate to be processed on a substrate placement table provided in a reaction chamber having a light transmissive window on at least the upper surface;
Heating the substrate to be processed by irradiating light through the light transmitting window from a lamp heating device provided outside the reaction chamber and facing the substrate mounting table;
Provided between the lamp heating device and the light transmissive window, and provided between the reaction chamber and the light transmissive window, a heat resistant mounting member constituting an upper part of the window frame of the light transmissive window. An upper lid edge member which is formed of a material having a lower thermal conductivity than the heat resistant mounting member and provided with a cooling channel, and which constitutes a lower portion of the window frame, the heat resistant mounting member, and the light transmitting member. A cooling liquid in the cooling channel while holding the light-transmitting window by a window pressing portion provided between the transparent window and between the upper lid edge member and the light-transmitting window. Cooling the window frame by flowing
A method for manufacturing a semiconductor device comprising:

Images