JP4460939B2 - Substrate heater - Google Patents

Description

  The present invention relates to a substrate heater and a vacuum processing apparatus using the same.

  As a vacuum processing apparatus, a plasma CVD (Chemical Vapor Deposition) apparatus, a sputtering apparatus, a dry etching apparatus, and the like are known. When a substrate is processed in these vacuum processing apparatuses, the substrate is heated by a substrate heater. Thereby, appropriate substrate processing conditions are satisfied.

  In a film forming apparatus, for example, a plasma CVD apparatus for forming a large-sized solar cell panel, a substrate to be subjected to a film forming process is installed on a heater cover, and is opposite to the substrate with respect to the heater cover. Heated by a heater. Then, a film forming process is performed under a predetermined temperature condition. It is preferable that the entire substrate has a uniform temperature. When the size of the substrate is large, it is necessary to control the entire substrate to have a uniform temperature.

  FIG. 1 is a schematic diagram showing the structure of a vacuum processing apparatus and a substrate heater described in Patent Document 1. The substrate processing apparatus 111 includes a film forming chamber 112, and the film forming chamber 112 is decompressed by a vacuum pump (not shown). A film forming unit 114 including a ladder electrode (discharge electrode) 113 and the like is installed in the film forming chamber 112. A substrate heater 116 is installed on both sides of the film forming unit 114 via a heater cover 115. The heater cover 115 is a ground electrode. The substrate K, which is the object to be processed, is disposed so as to face the ladder electrode 113 and is supported by the heater cover 115. After the substrate K is carried in by a substrate carrying device (not shown) and placed on the heater cover 115, the substrate carrying carriage is carried out, and the heater cover 115 moves from the substrate heater 116 toward the film forming unit 114. As a result, the distance between the heater cover 115 and the ladder electrode (discharge electrode) 113 is a predetermined distance. A film forming process or the like is performed while the substrate K is heated by the substrate heater 116.

  As shown in FIG. 1, the substrate heater 116 includes a plurality of heater units 121. The heater unit 121 includes a current collection box 123 to which an introduction pipe 122 is connected, and a plurality of cartridge heaters (bar heaters) 124. The introduction pipe 122 is connected to the outside through the wall surface of the film forming chamber 112, and wirings for supplying electric power to the heat generating element are led out to the outside of the film forming chamber 112. At this time, the film forming chamber 112 is sealed with a vacuum seal (not shown). The plurality of cartridge heaters 124 are installed substantially parallel to each other with a space therebetween. Each cartridge heater 124 includes a tubular body and a heating element (heating body) disposed in the tubular body. Electric power is supplied to the heat generating element, and the cartridge heater 124 generates heat. The tube is configured to be airtight together with the current collection box 123, and the inside thereof is maintained at substantially atmospheric pressure.

  Such a cartridge-type substrate heater 116 is excellent in terms of weight reduction and cost reduction. In addition, by elongating the cartridge heater 124 and increasing the number of cartridge heaters 124, it is easy to make such a substrate heater 116 compatible with an increase in the size of the substrate K that is the object to be processed. . Furthermore, the substrate heater 116 can be configured to have a distribution in the amount of heat generated by presetting the winding density distribution of the heating elements (coils).

JP 2002-212738 A

  An object of the present invention is to provide a substrate heater that can control the distribution of heat generation in accordance with substrate processing conditions, and a vacuum processing apparatus including the substrate heater.

  Another object of the present invention is to provide a substrate heater capable of adjusting the distribution of the substrate temperature to be optimum, and a vacuum processing apparatus including the substrate heater.

  Still another object of the present invention is to provide a substrate heater that can be easily enlarged and a vacuum processing apparatus including the same.

  Still another object of the present invention is to provide a substrate heater and a vacuum processing apparatus that suppress temperature hunting.

  Still another object of the present invention is to provide a substrate heater that achieves the above object when the tact time of the film forming process (the average time taken for the substrate to be subjected to the film forming process) is short, and A vacuum processing apparatus is provided.

  In the following, means for solving the problem will be described using the numbers used in [Best Mode for Carrying Out the Invention] in parentheses. These numbers are added to clarify the correspondence between the description of [Claims] and [Best Mode for Carrying Out the Invention]. However, these numbers should not be used to interpret the technical scope of the invention described in [Claims].

  The substrate heater according to the present invention includes a heater cover (60) for holding a substrate and a heater (40) facing the heater cover (60). The heater (40) includes rod-shaped heaters (10, 210) each of which is long in the first direction and arranged in parallel in a second direction perpendicular to the first direction. Here, for example, the case where the temperature control is performed by dividing the heating region of the substrate heater into five regions 1, 2, 3, 4, and 5 in the horizontal direction as the second direction will be described. And The substrate heater further includes a temperature detector (63) for detecting the temperature in the central region of the heater cover (60), and the central heating density of the heater (40) in a position corresponding to the central region (3) in response to the temperature. The adjacent heat generation density of the heater (40) at a position corresponding to the adjacent area (1, 2, 4, 5) adjacent to the central area (3) in the second direction is proportional to the central heat generation density. And a control unit (65, 67) for controlling.

  In the substrate heater according to the present invention, the central heat generation density is controlled by PID (Proportional, Integral, Differential) control in order to bring the temperature close to the target temperature.

  In the substrate heater according to the present invention, the central region (3) is a position corresponding to the central portion of the heater. The adjacent areas (1, 2, 4, 5) are positions corresponding to the peripheral edge of the heater rather than the central area. The adjacent heat density is greater than the central heat density.

  In the substrate heater according to the present invention, each of the rod heaters (10, 210) includes a first heat generating part (11, 256), a second heat generating part (12, 257), and a third heat generating part (13, 258). Including. The second heat generating part (12, 257) is located between the first heat generating part (11, 256) and the third heat generating part (13, 258). The control units (65, 67) perform control so that the first heat generation density of the first heat generation unit (11) is proportional to and larger than the second heat generation density of the second heat generation unit (12).

  In the substrate heater according to the present invention, each of the rod heaters (10, 210) includes a first heat generating part (11, 256), a second heat generating part (12, 257), and a third heat generating part (13, 258). Including. The second heat generating part (12, 257) is located between the first heat generating part (11, 256) and the third heat generating part (13, 258). The control units (65, 67) are controlled so that the third heat generation density of the third heat generation unit (13, 258) is proportional to and larger than the second heat generation density of the second heat generation unit (12, 257). To do. In addition, the operation conditions are relatively constant, and the heat generation density ratio of the first heat generating portion (256), the second heat generating portion (247), and the third heat generating portion (258) can be fixed and operated under a constant condition. For the above, the heat density of the first heat generating part (256), the second heat generating part (247) and the third heat generating part (258) is set in advance by the number of turns of the heat generating element, thereby simplifying the control. Can do.

A substrate heater according to a reference example of the present invention includes a heater cover (60) that holds a substrate (61), a heater that faces the heater cover (60), and a temperature that detects a temperature in a central region of the heater cover (60). An adjacent region (1, 2, 4, 5) adjacent to the central region (3) by controlling the central heat generation density of the heater at a position corresponding to the central region (3) in response to the detection unit (63) And a control section (65, 67) for controlling the adjacent heat generation density of the heater at a position corresponding to 1 to be proportional to the central heat generation density.

In the substrate heater according to the reference example of the present invention, the central heat generation density is controlled by PID (Proportional, Integral, Differential) control that brings the temperature close to the target temperature.

In the substrate heater according to the reference example of the present invention, the central region (3) is a position corresponding to the substantially central region of the substrate (61). The adjacent areas (1, 2, 4, 5) are positions corresponding to the peripheral edge of the heater rather than the central area. The adjacent heat density is greater than the central heat density.

In the substrate heater according to the reference example of the present invention, the heater (40) has a third region (1 ′, 2 ′, 3 ′, 4 ′) which is a peripheral portion of the heater cover (60) located above the central region. 5 ′) is provided with a third heat generating portion (13, 258) that heats at a third heat generation density that is proportional to the central heat generation density and larger than the central heat generation density.

In the substrate heater according to the reference example of the present invention, the heater (40) includes a first region (1 ", 2", 3 ", 4) which is a peripheral portion of the heater cover (60) below the central region. "5") is provided with a first heat generating portion (11, 256) that heats at a first heat generation density that is proportional to the central heat generation density and greater than the central heat generation density.

  The vacuum processing apparatus (111) according to the present invention is described in any one of claims 1 to 10, wherein the film forming chamber (112) is decompressed by a vacuum pump, and the film forming chamber (112) is installed. A substrate heater, and a film forming apparatus for performing a film forming process on the substrate heated by the substrate heater.

  The vacuum processing apparatus (111) according to the present invention has a tact time indicating a time from when the substrate (61) is introduced into the film forming chamber (112), subjected to the film forming process, and taken out from the film forming chamber (112). , A storage unit for storing a table (62) for associating a proportional coefficient of the adjacent heat generation density with the central heat generation density, a tact time and a central heat generation density are collected, and a proportional coefficient corresponding to the collected tact time in the table is obtained. And an adjacent heat generation density control unit (67) that sets the value integrated with the collected central heat generation density as the adjacent heat generation density.

  The operation method of the vacuum processing apparatus according to the present invention includes a tact time indicating a time from when the substrate (61) is introduced into the film forming chamber (112), subjected to the film forming process, and taken out from the film forming chamber (112). The tact time and the central heat generation density are collected with reference to the table (62) that associates the proportional heat generation density of the adjacent heat generation density with the central heat generation density, and the proportional coefficient corresponding to the collected tact time in the table is collected. A value integrated with the obtained central heat generation density is set as the adjacent heat generation density.

  ADVANTAGE OF THE INVENTION According to this invention, the substrate heating heater which can control distribution of the emitted-heat amount according to a substrate processing condition, and a vacuum processing apparatus provided with the same are provided.

  Furthermore, according to the present invention, there is provided a substrate heater that can be adjusted so that the distribution of the substrate temperature becomes optimal, and a vacuum processing apparatus including the substrate heater.

  Furthermore, according to this invention, the substrate heater which can be enlarged easily and a vacuum processing apparatus provided with the same are provided.

  Furthermore, according to this invention, the substrate heater and the vacuum processing apparatus which suppress the hunting of temperature are provided.

  Furthermore, according to the present invention, when the takt time of the film forming process (the average time taken for the substrate to be subjected to the film forming process) is short, the substrate heater that achieves the above object, and the vacuum process An apparatus is provided.

  Hereinafter, a substrate heater according to the present invention and a vacuum processing apparatus including the same will be described with reference to the accompanying drawings.

  FIG. 2 is a schematic view showing an example of the configuration of the substrate processing apparatus according to the present invention. The substrate processing apparatus 100 includes a film forming chamber 80. The film forming chamber 80 is depressurized by a vacuum pump (not shown). A film forming unit 82 including a discharge electrode (ladder electrode) 81 is installed in the film forming chamber 80. A heater cover 60 is installed to face the discharge electrode 81. The heater cover 60 is a ground electrode. A substrate heater 40 is installed on the opposite side of the discharge electrode 81 with respect to the heater cover 60. The substrate 61 as the object to be processed is supported by the heater cover 60 and is disposed so as to face the discharge electrode 81.

  The substrate 61 is carried into the film forming chamber 80 by a substrate transfer carriage (not shown). After the substrate transport carriage has left the film forming chamber 80, the heater cover 60 moves toward the film forming unit 82 and is set at a predetermined position during film formation.

  In the present invention, the substrate heater 40 includes a plurality of bar heaters (heater cartridges) 10 and a plurality of temperature control units 50 connected to supply power to each of the plurality of bar heaters 10. As shown in FIG. 2, the substrate heater 40 may include a plurality of heater units 41. The heater unit 41 includes a plurality of bar heaters 10 and a plurality of temperature control units 50 connected to supply power to each of the plurality of bar heaters 10 as one unit. The plurality of temperature control units 50 may be in an air atmosphere outside the film forming chamber 80. By dividing the substrate heater 40 into the heater units 41, assembly work and maintenance work are facilitated.

  Referring to FIG. 3, the configuration of the rod heater 10 is shown. The arrow A in the figure indicates the direction in which the heater cover 60 exists. In the present embodiment, the rod heater 10 has a plurality of heat generating portions. For example, in FIG. 3, the rod heater 10 includes an upper heat generating portion 11, a central heat generating portion 12, and a lower heat generating portion 13. These heat generating portions are distributed along the longitudinal direction of the rod heater 10. Further, the central heat generating portion 12 is located between the upper heat generating portion 11 and the lower heat generating portion 13. Here, the length of the upper heat generating portion 11 and the lower heat generating portion 13 of the rod heater 10 is set to a value 0.1 to 0.2 times the length of the central heat generating portion 12. Further, an upper non-heat generating portion 14 and a lower non-heat generating portion 15 are present at the end of the rod-shaped heater 10 so as to sandwich the heat generating portions, whereby power can be stably supplied to the heat generating portions. Yes.

  The outer shell of the rod heater 10 is constituted by a tubular body 30. The tubular body 30 has a bent portion 31 and is bent at a part of the lower heat generating portion 13 and the lower non-heat generating portion 15. As will be described later, this is to isolate the lower non-heat generating portion 15 from the heater cover 60 (in the direction of arrow A). One end of the rod heater 10 is connected to the current collection box 32. The current collection box 32 includes a terminal block 33. The terminal block 33 is connected to the conductive wire 35 that passes through the wall surface of the film forming chamber 80 that is a vacuum atmosphere and is passed to the outside in the atmosphere using the introduction pipe 34. Here, the rod-shaped heater 10, the current collecting box 32, and the introduction pipe 34 are hermetically sealed with an O-ring seal (not shown) or the like so that the inside thereof has a substantially atmospheric pressure. , Gas or the like is treated so as not to leak into the film forming chamber 80. Thereby, since the inside of the rod heater becomes atmospheric pressure, heat transfer inside the rod heater is promoted and the discharge voltage is increased, so that the occurrence of abnormal discharge in the vicinity of the heating element described later is suppressed.

  A plurality of heat generating elements (heat generating elements) whose heat generation density is adjusted by, for example, winding a heat generating element wire in a coil shape are provided inside the tube body 30 so as to correspond to the plurality of heat generating portions. An upper heat generating element 21 is disposed at a position corresponding to the upper heat generating portion 11. A central heating element 22 is disposed at a position corresponding to the central heating unit 12. A lower heat generating element 23 is disposed at a position corresponding to the lower heat generating portion 13. For example, as shown in FIG. 3, two conductive wires 20 a and 20 b are disposed inside the tube body 30. The conductive wire 20 a includes an upper heating element 21 and a lower heating element 23. Conductive wire 20 b includes a central heating element 22. The conductive wires 20 a and 20 b are connected to the terminal block 33.

  Electric power is supplied to the conductive wires 20a and 20b from the plurality of temperature control units 50 (see FIG. 2) via the conductive wires 35. When power is supplied to the conductive wire 20a, the upper heating element 21 and the lower heating element 23 generate heat. When electric power is supplied to the conductive wire 20b, the central heating element 22 generates heat. Here, the power supplied to the conductive wire 20 a and the power supplied to the conductive wire 20 b are controlled separately by the plurality of temperature control units 50. That is, the amount of heat generated in the upper and lower heat generating elements 21 and 23 and the amount of heat generated in the central heat generating element 22 are controlled separately. Thereby, it becomes possible to control the distribution of the heat generation amount of the rod heater 10, particularly the distribution of the heat generation amount in the longitudinal direction.

  As shown in FIG. 3, the tube body 30 has a bent portion 31. Wiring portions such as the lower non-heat generating portion 15 and the current collecting box 32 are located away from the heater cover 60 (in the direction of arrow A). As a result, the heater cover 60 faces a portion where the heat generation is controlled except for some upper non-heat generating portions 14. At this time, since the upper non-heat generating portion 14 is also located away from the heater cover 60, the upper portion of the heater cover 60 is also heated by the radiant heat transfer from the upper heat generating portion 11 and the heat conduction in the heater cover 60. become. Therefore, the heater cover 60 can be heated more uniformly. However, the shape of the rod heater 10 is not limited to the shape shown in FIG. For example, if the installation space of the lower non-heat generating portion 15 is allowed in the vacuum vessel 80, the rod-shaped heater 10 may have a straight pipe structure without a bent portion as a shape in which the space is installed on the heater cover 60 side. Conversely, bent portions may be provided above and below the bar heater 10 in order to reduce the space of the upper non-heat generating portion 14.

  Referring to FIG. 4, there is shown a configuration of control means for controlling the bar heater 10 shown in FIG. A heater cover 60 is disposed so as to face the rod heater 10 (substrate heater 40). The substrate 61 is supported on the opposite side of the rod-shaped heater 10 by the heater cover 60. Reflecting plates 45 are provided on the upper, lower, back and non-illustrated substrate heater ends of the rod-shaped heater 10 to enable effective uniform heating of the heater cover 60.

  In FIG. 4, a central temperature controller 65 and an ambient temperature regulator 67 are connected to the rod heater 10 via a conductive wire 35. The central temperature control unit 65 is further connected to the host computer 69. The host computer 69 can instruct operating conditions of the substrate heater 40 such as a target set temperature, and further can instruct function values such as P, I, and D values used in the calculation of the central temperature controller 65. . A central temperature sensor 63 to which a central temperature measuring thermocouple 57 is connected is connected to a region 3 to be described later of the heater cover 60. Here, the measurement thermocouple 57 in the central region 3 is preferably near the center of the substrate 61. Further, in order to detect the temperature of the entire region 3, the measurement thermocouples 57 are installed at a plurality of locations. The average value or maximum value of the front part or part of the representative part may be used. The central temperature control unit 65 includes an arithmetic control device (not shown), and controls the amount of heat generated in a region 3 described later of the substrate heater 40 based on the temperature detected by the central temperature sensor 63.

  The ambient temperature regulator 67 receives a signal from the central temperature control unit 65. The ambient temperature regulator 67 includes a storage device (not shown), and a function table 62 is stored in the storage device. The ambient temperature adjuster 67 includes a calculation control device (not shown), and uses the signal received from the central temperature control unit 65 and the function table, areas 1, 1 ′, 1 ″, 2, 2, to be described later of the substrate heater 40. Control the amount of heat generated at '2 ", 4', 4 ', 5, 5', and 5".

  For example, the central temperature control unit 65 controls the amount of heat generated in the central heating element 22 by controlling the amount of current flowing through the conductive wire 20b of the bar heater 10 in the region 3 to be described later. The ambient temperature control unit 66 controls the amount of heat generated in the regions 1, 2, 4, and 5 by controlling the amount of current flowing through the bar heater 10 corresponding to the position. The ambient temperature control unit 66 further controls the amount of heat generated in the upper heat generating element 21 and the lower heat generating element 23 by controlling the amount of current flowing through the conductive wire 20a.

  Referring to FIG. 5, a function table 62 is shown. The function table 62 includes several functions plotted on a coordinate axis with the tact time on the horizontal axis and the heat generation density ratio on the vertical axis. FIG. 5 shows, for example, three types of functions Z1, Z2, and Z3 for setting the heat generation density ratio, and these are used to control the heat generation density at the ambient temperature. The tact time is an average time required for a series of operations from when the substrate is carried into the film forming chamber 80 until the film forming process is performed and the film forming chamber 80 is carried out.

  Each region of the substrate heater 40 will be described with reference to FIG. The upward direction in the drawing is the upward direction in the vertical direction. The substrate heater 40 is divided into, for example, a region divided into five in the horizontal direction, and further divided into three regions in the vertical direction and 15 regions, and the amount of generated heat is controlled. The center of the substrate heater 40 is a region 3, which is a heating region by the central heating portion 12 of the rod heater 10. The regions on both sides adjacent to the region 3 in the horizontal direction are the region 2 and the region 4, respectively. A region 1 adjacent to the region 2 in the horizontal direction is a side end portion of the substrate heater 40. A region 5 adjacent to the region 4 in the horizontal direction is a side end portion of the substrate heater 40. The widths of the areas 1 and 5 are set to a value of 0.1 to 0.2 times the total width of the areas 2, 3, and 4.

  A region 1 '(2', 3 ', 4', 5 ') is adjacent to the region 1 (2, 3, 4, 5) in the vertical direction. A region 1 ′ (2 ′, 3 ′, 4 ′, 5 ′) is an upper end portion of the substrate heater 40, and is a heating region by the upper heat generating portion 11 of the rod heater 10. The region 1 ″ (2 ″, 3 ″, 4 ″, 5 ″) is adjacent to the region 1 (2, 3, 4, 5) in the vertical direction. The region 1 ″ (2 ″, 3 ″) 4 ″, 5 ″) is a lower end portion of the base heater 40 and is a heating region by the lower heat generating portion 13 of the rod heater 10.

  Referring to FIG. 7, the operation of the substrate heater having the above-described configuration and the vacuum processing apparatus including the substrate heater are shown in a flowchart.

  Step S1: It is set by a recipe, or it is self-measured according to the operation status of the vacuum processing apparatus.

  Step S2: A substrate 61 is introduced into the film forming chamber 80 by a substrate transfer carriage (not shown).

  Step S4: The central temperature sensor 63 generates a signal indicating the temperature of the heater cover 60 at a position corresponding to the region 3 of the substrate heater 40. The generated signal is transmitted to the central temperature control unit 65.

Step S6: The central temperature control unit 65 generates heat generated by the central heating unit 12 of the bar heater 10 corresponding to the region 3 so that the temperature of the region 3 approaches the predetermined target temperature by PID control or the like (hereinafter referred to as region). 3 is called a calorific value control value 3).
The operator who operates the vacuum processing apparatus monitors the temperature of each region of the heater cover 60, and appropriately sets the PID control P, I, D values and the function values from the host computer 69 to the central temperature control unit 65. It is possible to change to Alternatively, such control change may be performed by a predetermined program stored in the host computer 69.

  Step S <b> 8: The central temperature control unit 65 transmits the heat generation amount control value for the region 3 to the ambient temperature regulator 67. The ambient temperature regulator 67 reads the function table 62.

  Step S <b> 10: The ambient temperature adjuster 67 calculates a heat generation amount control value for a region other than the region 3 using the function table 62 and the heat generation amount control value for the region 3 received from the central temperature control unit 65. For example, the function Z1 shown in FIG. 5 is a function applied to the region 2 and the region 4. When the tact time is 5 minutes, the heat generation amount control values of the region 2 and the region 4 are calculated by multiplying the heat generation amount of the region 3 by the value of Z2 when the tact time is 5 minutes. The function Z3 is a function applied to the region 1 and the region 5. When the tact time is 5 minutes, the heat generation amount control values for the region 1 and the region 5 are calculated by multiplying the heat generation amount of the region 3 by the value of Z3 when the tact time is 5 minutes. Further, in order to make the temperature distribution of the heater cover 60 more uniform by the operation of the apparatus, it is possible to provide a function Z2 and use it for calculating the amount of heat generated in the areas 2, 4 and areas 1, 5.

  The function table 62 further includes a function Z4 indicating the ratio of the heat generation amount control value of 2 ′, 3 ′, 4 ′ and the heat generation amount control value of the region 3, and the heat generation amount control value of 1 ′, 5 ′ and the region 3 A function Z5 indicating the ratio of the heat generation amount control value, a function Z6 indicating the ratio of the heat generation amount control value of 2 ″, 3 ″, 4 ″ and the heat generation amount control value of the region 3, and heat generation of 1 ″, 5 ″ It is preferable to include a function Z7 indicating a ratio between the amount control value and the heat generation amount control value of the region 3. In this case, the ambient temperature regulator 67 is configured to receive the heat generation amount control value of the region 3. (1) Regions 2 and 4, (2) Regions 1 and 5, (3) Regions 2 'and 3' and 4 ', (4) Regions 1' and 5 ', (5) Regions 2 "and 3" and 4 ", And (6) the calorific value control value of each of the regions 1" and 5 "is calculated.

  It is preferable that the heat generation amount control value of the regions 1 and 5 is 2 to 6 times the heat generation amount control value of the region 3. The heat generation amount control values of the regions 2 ′, 3 ′, 4 ′, 2 ″, 3 ″, and 4 ″ are preferably 2 to 6 times the heat generation amount control value of the region 3. The regions 1 ′, 5 ′. The heating value control values of 1 ″ and 5 ″ are preferably 8 to 12 times the heating value control value of the region 3.

  Step S12: The central temperature control unit 65 performs PID control on the heat generation amount of the central heat generation unit 12 of the rod heater 10 corresponding to the region 3 based on the calculated heat generation amount control value. The ambient temperature regulator 67 controls each region other than the region 3 to a heat generation amount proportional to the heat generation amount of the region 3 based on the calculated heat generation amount control value. Each region of the heater cover 60 is heated by each region of the substrate heater 40, and the entire heater cover 60 is controlled to a substantially constant temperature.

  Preferably, a temperature sensor is attached to each area of the heater cover 60, the temperature of each area is monitored in real time, and the uniformity of the in-plane temperature distribution of the heater cover 60 is monitored.

  Step S14: The procedure from step S4 to step S12 is continued during the film forming process. When the film forming process is completed, the substrate 61 is led out of the film forming chamber 80 by a substrate transfer carriage (not shown).

  By the procedure shown above, the substrate is subjected to film formation in a state where the entire substrate is heated almost uniformly.

(Explanation of phenomenon)
With reference to FIG. 8, the reason for changing the amount of heat generation in the vicinity according to the tact time will be described. 8, the horizontal axis represents the tact time, and the vertical axis represents the maximum deviation of the in-plane temperature of the heater cover 60 in the horizontal direction. A curve 91 indicates a case where the heat generation amount of the substrate heater 40 at the position corresponding to the regions 1, 2, 3, 4, 5 is 3: 1: 1: 1: 3. A curve 92 indicates a case where the amount of heat generated by the substrate heater 40 at the position corresponding to the regions 1, 2, 3, 4, 5 is 2: 1: 1: 1: 2.

  Referring to FIG. 8, when the tact time is about 3 to 6 minutes, the temperature deviation of the heater cover 60 is smaller in the case where the calorific value is shown by the curve 92 having a heat generation amount of 2: 1: 1: 1: 2. preferable. Although the case where the tact time is 6 minutes or more is not shown, if the curve 91 and the curve 92 intersect and invert when the time is 6 minutes or more, then the calorific value is 3: 1: 1: 1: 3 is preferable because the temperature deviation of the heater cover 60 is small. This is because if the tact time is long, the amount of heat transfer from the substrate heater cover 60 to the substrate 61 during each batch process is relatively small, so that the temperature drop at the center of the heater cover 60 where the substrate 61 exists is reduced. This is because the heat generation density of the regions 2, 3, and 4, which are the central regions, is suppressed to be lower than that of the regions 1 and 5 that are the regions.

In order to perform film formation on a large substrate exemplified by a large solar cell panel, it is difficult to control the whole to a uniform temperature for the following reason.
(1) The heat transfer amount is low in the high vacuum state during substrate transfer, and in the film formation state, a film forming gas (SiH ₄ , H _2, etc.) is introduced to promote heat transfer, so the film forming time is short (tact) Under conditions where the time is short, the change cycle of the heat transfer state from the substrate heater to the heater cover becomes short, and the temperature distribution tends to be disturbed.
(2) Although the substrate put into the film forming chamber is heated from the heater cover and heated to a predetermined film forming temperature, the heat in the central region of the heater cover where the substrate is set is taken away by the substrate, so the tact time When becomes short, heat transfer from the substrate heater to the substrate (or heater cover) cannot catch up, and the temperature near the center of the heater cover tends to decrease. In the description made with reference to FIG. 8, the reason why the peripheral heat generation density ratio is controlled to be lower when the tact time is shorter than when the tact time is long, and the central heat generation density is increased. .
(3) In order to cope with the above phenomena (1) and (2), it is conceivable to divide the heater cover into a plurality of areas when the tact time is short, and perform, for example, PID control on each area. In this case, in order to control the temperature adjustment of a large structure having a large heat capacity while suppressing temperature hunting, it is necessary to increase the integral parameter: I, but it is difficult to follow a film forming process repeated in a few minutes. Become.

  In the experiment using the substrate heater according to the present invention, the unbalance between the central temperature and the left and right and upper and lower temperatures in the control transient state was suppressed despite the above-described difficulties. Furthermore, the imbalance due to the asymmetry of the temperature distribution on the left and right and the top and bottom was suppressed, and a stable temperature distribution could be obtained. In addition, the temperature control mechanism is simple and the temperature is not disturbed by hunting or unexpected abnormal control, improving reliability.

  Although FIG. 6 shows the control in which the substrate heater 116 is divided into 15 parts in the left and right and up and down directions, the temperature of the heater cover 60 may be made uniform by further dividing control. On the other hand, when the operation state is relatively constant, as shown in FIG. 9, the upper and lower heat generation density ratios of the rod heater 210 are fixed from the beginning, and the substrate heater 116 is divided into five parts in the left-right direction. It is also possible. That is, referring to FIG. 9, it is possible to use bar heater 210 instead of bar heater 10 in the present embodiment. The outer shell of the rod heater 210 is composed of a tube 245. One end of the bar heater 210 is connected to the current collection box 232. The current collection box 232 includes a terminal block 233. For the terminal block 233, an O-ring seal (not shown) is used around the periphery of the terminal pipe 234 by using an introduction pipe 234, so that the conductive material passed through the wall surface of the film forming chamber 80 which is a vacuum atmosphere to the outside in the atmosphere. Line 235 is connected. Reflecting plates 245 are provided on the upper and lower sides, the rear surface side, and both ends of the substrate heater (not shown) of the rod heater 210, so that the heater cover 260 can be effectively heated.

  The bar heater 210 includes an upper heat generating part 256, a central heat generating part 257, and a lower heat generating part 258. These heat generating portions are distributed along the longitudinal direction of the rod heater 210. Further, the central heat generating part 257 is located between the upper heat generating part 256 and the lower heat generating part 258.

  Inside the tube body 245, a plurality of heating elements (heating elements) whose heating density is adjusted by winding a heating element wire in a coil shape, for example, are provided so as to correspond to the plurality of heating portions. An upper heat generating element 221 is disposed at a position corresponding to the upper heat generating portion 256. A central heating element 224 is disposed at a position corresponding to the central heating unit 257. A lower heat generating element 223 is disposed at a position corresponding to the lower heat generating portion 258.

  Unlike the rod-shaped heater 10 shown in FIG. 3, one conductive wire 220 is disposed inside the tube 245 of the rod-shaped heater 210. The conductive wire 220 extends to form a lower heating element 223, a central heating element 224, and an upper heating element 221. Both ends of the conductive wire 220 are connected to the terminal block 233.

  The substrate heater formed by arranging such rod-shaped heaters 210 in parallel has a higher central region than the central region near the upper end facing the upper heating element 221 and the lower end facing the lower heating element 223. Heat is generated at a predetermined high rate. Such a bar heater has a simple configuration and is easy to manufacture. Further, when it is necessary to change the heat generation density of the upper heat generating element 221 and the lower heat generating element 223 due to the change of the operation state, the heat transfer amount to the heater cover 260 is reduced by providing the porous reflector 271. It is possible.

FIG. 1 shows the configuration of a vacuum processing apparatus in the background art. FIG. 2 shows the configuration of a vacuum processing apparatus according to the present invention. FIG. 3 shows the configuration of the bar heater. FIG. 4 shows the configuration of the control device for the bar heater. FIG. 5 shows a function table. FIG. 6 shows the area of the substrate heater. FIG. 7 is a flowchart showing operations of the substrate heater and the vacuum processing apparatus. FIG. 8 shows the temperature deviation in the heater cover with respect to the tact time. FIG. 9 shows the configuration of the rod heater.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Bar heater 11 ... Upper heating part 12 ... Central heating part 13 ... Lower heating part 14 ... Upper non-heating part 15 ... Lower non-heating part 20a, 20b ... Conductive wire 21 ... Upper heating element 22 ... Central heating element 23 ... Lower part Heating element 30 ... Tube 31 ... Bending part 32 ... Current collecting box 33 ... Terminal block 34 ... Introducing pipe 35 ... Conducting wire 40 ... Substrate heater 41 ... Heater unit 45 ... Reflector plate 50 ... Temperature control part 60 ... Heater cover 61 ... Substrate 62 ... Function table 63 ... Central temperature sensor 65 ... Central temperature controller 67 ... Ambient temperature controller 80 ... Film forming chamber 81 ... Discharge electrode 82 ... Film forming unit 100 ... Substrate processing apparatus 111 ... Substrate processing apparatus 112 ... made Film chamber 113 ... Ladder electrode 114 ... Film forming unit 115 ... Heater cover 116 ... Substrate heater 121 ... Heater unit 122 ... Introducing pipe 123 ... Current collecting box 124 ... Cartridge heater 220 ... Conductive wire 221 ... Heater unit 223 ... Current collecting box 224 ... Rod heater 224a ... Tube 231 ... Heating element 232 ... Terminal block 234 ... Introducing pipe 235 ... Reflecting plate K ... Substrate

Claims (8)

A heater cover for holding the substrate;
A heater opposed to the heater cover, and each heater is provided with a plurality of rod heaters arranged in parallel in a second direction that is long in the first direction and perpendicular to the first direction,
A temperature detector for detecting the temperature in the central region of the heater cover;
In response to the temperature, the central heat generation density of the heater at a position corresponding to the central region is controlled, and the adjacent heat generation density of the heater at a position corresponding to the adjacent region adjacent to the central region in the second direction. A substrate heater comprising: a control unit that controls so that is proportional to the central heat generation density. A substrate heater according to claim 1,
The central heating density is a substrate heater controlled by PID (Proportional, Integral, Differential) control that brings the temperature close to a target temperature. The substrate heater according to any one of claims 1 and 2,
The central region is a position corresponding to a central portion of the heater;
The adjacent region is a position corresponding to a peripheral portion of the heater rather than the central region,
The adjacent heater density is a substrate heater larger than the central heat density. A substrate heater according to claim 3,
Each of the rod heaters
A first heat generating part;
A second heat generating part;
A third heat generating part,
The second heat generating part is located between the first heat generating part and the third heat generating part,
The controller is a substrate heater that controls the first heat generation density of the first heat generation section to be proportional to and larger than the second heat generation density of the second heat generation section. A substrate heater according to claim 3 or 4,
Each of the rod heaters
A first heat generating part;
A second heat generating part;
A third heat generating part,
The second heat generating part is located between the first heat generating part and the third heat generating part,
The controller is a substrate heater that controls the third heat generation density of the third heat generation section to be proportional to and larger than the second heat generation density of the second heat generation section. A film forming chamber depressurized by a vacuum pump;
The substrate heater described in any one of claims 1 to 5 installed in the film forming chamber,
A vacuum processing apparatus comprising: a film forming apparatus that performs a film forming process on the substrate heated by the substrate heater. The vacuum processing apparatus according to claim 6 ,
Furthermore, a tact time indicating a time from when the substrate is introduced into the film forming chamber and subjected to a film forming process to being led out from the film forming chamber, and a proportional coefficient of the adjacent heat density with respect to the central heat density. A storage unit for storing a table to be associated;
The adjacent heat density is obtained by collecting the tact time and the central heat density, and setting the proportional coefficient corresponding to the collected tact time in the table to the collected central heat density as the adjacent heat density. A vacuum processing apparatus comprising a control unit. An operation method of the vacuum processing apparatus according to claim 6 ,
The tact time indicating the time from when the substrate is introduced into the film forming chamber, the film forming process is performed, and the substrate is taken out from the film forming chamber is associated with the proportional coefficient of the adjacent heat generation density to the central heat generation density. Browse the table
Vacuum processing for collecting the tact time and the central heat generation density, and setting a value obtained by adding the proportional coefficient corresponding to the collected tact time in the table to the collected central heat density as an adjacent heat generation density How to operate the device.

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