JP7101718B2 - Manufacturing method for heating unit, temperature control system, processing equipment and semiconductor equipment - Google Patents

Description

The present disclosure relates to a heating unit, a temperature control system, a processing device, and a method for manufacturing a semiconductor device.

It is known that there is a semiconductor manufacturing apparatus as an example of a substrate processing apparatus, and there is a vertical type apparatus as an example of a semiconductor manufacturing apparatus. In the vertical device, a boat as a substrate holding unit that holds a plurality of substrates (hereinafter, also referred to as wafers) in multiple stages is carried into a processing chamber in a reaction tube while holding the substrates, and the temperature is controlled in a plurality of zones. At the same time, the substrate is processed at a predetermined temperature.

For example, in Patent Document 1, the control valve is opened and closed to adjust the flow rate and the flow velocity of the gas ejected from the opening toward the reaction tube, thereby making the temperature difference at the time of temperature decrease uniform among a plurality of zones. The technology is disclosed. Further, Patent Document 2 describes a technique in which heating by a heater unit and cooling by a gas supplied from a control valve are performed in parallel to follow a predetermined temperature rise rate and a predetermined temperature decrease rate. As described above, in recent years, the demand for the uniformity of the film thickness between wafers has increased with the miniaturization, and the uniformity of the temperature distribution in the furnace during the substrate processing has been improved.

International release 2018/105113 International Publication No. 2018/100926

An object of the present disclosure is to provide a configuration that further improves the uniformity of the temperature distribution in the furnace.

According to one aspect of the present disclosure
It is divided into a plurality of control zones, includes at least a heat generating portion provided for each control zone and raises the temperature in the reaction tube by heat generation, and the resistance circuit in each control zone is a parallel circuit, and the parallel circuit is used. A configuration is provided in which an output variable element is provided in any one or more of the constituent circuits.

According to the configuration according to the present disclosure, the uniformity of the temperature distribution in the furnace can be improved.

It is a partially cut front view which shows the substrate processing apparatus in one Embodiment of this disclosure. It is a front sectional view of the substrate processing apparatus in one Embodiment of this disclosure. It is a figure which shows the hardware composition of the control computer in the substrate processing apparatus in one Embodiment of this disclosure. It is a figure which shows the flowchart which shows an example of the process about temperature among the film formation process in one Embodiment of this disclosure. It is a figure which shows the temperature change in the furnace in the flowchart shown in FIG. It is a figure which shows the resistance circuit in one Embodiment of this disclosure. It is a figure which shows the temperature distribution in a furnace in a state where the electric power output of all control zones is common, and the temperature is stable. It is a figure which shows the power output distribution of each control zone of the comparative example. It is a figure which shows the temperature distribution in a furnace corresponding to the electric power distribution of FIG. It is a figure which shows the power output distribution which adjusted the power output balance using the resistance circuit of FIG. It is a figure which shows the temperature distribution in a furnace corresponding to the electric power distribution of FIG. It is a figure which shows the resistance circuit in the comparative example. It is a figure which shows the resistance circuit in another embodiment (modification example) of this disclosure. It is a figure which shows the structure of the temperature controller in the other embodiment (modification example) of this disclosure. It is a figure which shows an example of the balance parameter in another embodiment (modification example) of this disclosure. It is a figure which shows the calculation example which uses the parameter of the temperature zone of 600 degreeC in FIG. (A) is a figure which shows the electric power distribution and the temperature distribution in a furnace in a comparative example. (B) is a figure which shows the electric power distribution and the temperature distribution in a furnace in a modification. (C) is a figure which shows the balance parameter for each control zone.

Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

In the present embodiment, as shown in FIGS. 1 and 2, the substrate processing apparatus 10 in the present disclosure is configured as a processing apparatus that carries out a film forming step in a method for manufacturing a semiconductor device.

The substrate processing apparatus 10 shown in FIG. 1 includes a process tube 11 as a supported vertical reaction tube, and the process tube 11 is composed of an outer tube 12 and an inner tube 13 arranged concentrically with each other. Has been done. Quartz (SiO ₂ ) is used for the outer tube 12, and the outer tube 12 is integrally molded into a cylindrical shape in which the upper end is closed and the lower end is open. The inner tube 13 is formed in a cylindrical shape with both upper and lower ends open. The hollow portion of the inner tube 13 forms a processing chamber 14 into which the boat, which will be described later, is carried in, and the lower end opening of the inner tube 13 constitutes a furnace port 15 for taking in and out the boat. As will be described later, the boat 31 is configured to hold a plurality of wafers in a long aligned state. Therefore, the inner diameter of the inner tube 13 is set to be larger than the maximum outer diameter (for example, a diameter of 300 mm) of the wafer 1 as a substrate to be handled.

The lower end portion between the outer tube 12 and the inner tube 13 is hermetically sealed by a manifold 16 constructed in a substantially cylindrical shape. The manifold 16 is detachably attached to the outer tube 12 and the inner tube 13 for replacement of the outer tube 12 and the inner tube 13, respectively. By supporting the manifold 16 to the housing 2, the process tube 11 is in a vertically installed state. Hereinafter, in the figure, only the outer tube 12 may be shown as the process tube 11.

The exhaust passage 17 is formed in a circular ring shape having a constant cross-sectional shape due to the gap between the outer tube 12 and the inner tube 13. As shown in FIG. 1, one end of the exhaust pipe 18 is connected to the upper part of the side wall of the manifold 16, and the exhaust pipe 18 is in a state of being connected to the lowermost end portion of the exhaust passage 17. An exhaust device 19 controlled by a pressure controller 21 is connected to the other end of the exhaust pipe 18, and a pressure sensor 20 is connected in the middle of the exhaust pipe 18. The pressure controller 21 is configured to feedback control the exhaust device 19 based on the measurement result from the pressure sensor 20.

A gas introduction pipe 22 is arranged below the manifold 16 so as to communicate with the furnace port 15 of the inner tube 13, and a gas supply device 23 for supplying a raw material gas or an inert gas is connected to the gas introduction pipe 22. ing. The gas supply device 23 is configured to be controlled by the gas flow rate controller 24. The gas introduced from the gas introduction pipe 22 to the furnace port 15 flows through the processing chamber 14 of the inner tube 13 and is exhausted by the exhaust pipe 18 through the exhaust passage 17.

A seal cap 25 that closes the lower end opening is in contact with the manifold 16 from the lower side in the vertical direction. The seal cap 25 is constructed in a disk shape substantially equal to the outer diameter of the manifold 16, and is configured to be vertically moved up and down by a boat elevator 26 installed in the waiting chamber 3 of the housing 2. The boat elevator 26 is configured by a motor-driven feed screw shaft device, bellows, and the like, and the motor 27 of the boat elevator 26 is configured to be controlled by a drive controller 28. A rotary shaft 30 is arranged and rotatably supported on the center line of the seal cap 25, and the rotary shaft 30 is configured to be rotationally driven by a rotary mechanism 29 as a motor controlled by a drive controller 28. There is. A boat 31 is vertically supported at the upper end of the rotating shaft 30.

The boat 31 includes a pair of upper and lower end plates 32 and 33, and three holding members 34 vertically erected between them, and the three holding members 34 have a large number of holding grooves 35 longitudinally. Engraved at equal intervals in the direction. In the three holding members 34, the holding grooves 35, 35, 35 carved in the same step are opened so as to face each other. By inserting the wafer 1 between the holding grooves 35 of the same stage of the three holding members 34, the boat 31 holds the plurality of wafers 1 horizontally and aligned with each other. It has become. A heat insulating cap portion 36 is arranged between the boat 31 and the rotating shaft 30. The rotary shaft 30 is configured to support the boat 31 in a state of being lifted from the upper surface of the seal cap 25 so that the lower end of the boat 31 is separated from the position of the furnace opening 15 by an appropriate distance. The heat insulating cap portion 36 is designed to insulate the vicinity of the furnace opening 15.

On the outside of the process tube 11, the heater unit 40 as a heating unit is arranged concentrically and is installed in a state of being supported by the housing 2. The heater unit 40 includes a case 41. The case 41 is made of stainless steel (SUS) and is formed in a cylindrical shape, preferably a cylindrical shape, in which the upper end is closed and the lower end is opened. The inner diameter and the total length of the case 41 are set to be larger than the outer diameter and the total length of the outer tube 12. Further, as shown in FIG. 2, from the upper end side to the lower end side of the heater unit 40, the heater unit 40 is divided into seven control zones U1, U2, CU, C, CL, L1 and L2 as a plurality of heating regions (heating control zones). Has been done.

A heat insulating structure 42, which is an embodiment of the present disclosure, is installed in the case 41. The heat insulating structure 42 according to the present embodiment is formed in a cylindrical shape, preferably in a cylindrical shape, and the side wall portion 43 of the cylindrical body is formed in a multi-layer structure. That is, the heat insulating structure 42 includes a side wall outer layer 45 arranged on the outside of the side wall portion 43 and a side wall inner layer 44 arranged on the inside of the side wall portion 43, and is between the side wall outer layer 45 and the side wall inner layer 44. A partition portion 105 that isolates the side wall portion 43 into a plurality of zones (regions) in the vertical direction, and an annular buffer 106 as a buffer portion provided between the partition portion 105 and the partition portion 105 adjacent to the partition portion 105 are provided.

Further, the annular buffer 106 is configured to be divided into a plurality of parts by a partition portion 106a as a slit according to the length thereof. That is, a partition portion 106a that divides the circular buffer 106 into a plurality of parts according to the length of the zone is provided. In the present specification, the partition portion 105 is also referred to as a first partition portion 105, and the partition portion 106a is also referred to as a second partition portion 106a. Further, the partition portion 105 may be an isolated portion that isolates the partition portion 105 into a plurality of cooling zones. The control zones CU, C, CL, L1, L2 and the circular buffer 106 are provided so as to face each other, and the height of each control zone and the height of the circular buffer 106 are substantially the same. On the other hand, the heights of the control zones U1 and U2 above the control zones and the heights of the circular buffer 106 facing these control zones are configured to be different. Specifically, since the height of the annular buffer 106 facing the control zones U1 and U2 is lower than the height of each zone, the cooling air 90 can be efficiently supplied to each control zone. can. As a result, the cooling air 90 supplied to the control zones U1 and U2 can be made equal to the cooling air 90 supplied to the other control zones, and the control zones CU, C, CL, can also be used in the control zones U1 and U2. The same temperature control as L1 and L2 can be performed.

In particular, since the height of the annular buffer 106 facing the control zone U1 for heating the inner space 75 on the exhaust duct 82 side is lower than 1/2 of the height of each zone, the cooling air 90 is set in the control zone U1. Can be efficiently supplied. As a result, even in the control zone U1 closest to the exhaust side, the same temperature control as in other control zones can be performed.

Further, the partition portion 105 arranged at the uppermost position is located higher than the substrate processing area of the boat 31 and lower than the height of the process tube 11 (at substantially the same position as the height of the inner tube 13), and is arranged at the second upper position. Since the partition portion 105 is located at substantially the same height as the wafer 1 mounted on the upper end of the boat 31, the cooling air 90 is applied to the exhaust side (the portion where the wafer 1 is not mounted) of the process tube 11. It can be applied efficiently and can be cooled in the same manner as the process tube 11 corresponding to the substrate processing area of the boat 31. As a result, the entire process tube 11 can be cooled evenly.

Further, a check damper 104 is provided in each zone as a reverse diffusion prevention unit. The cooling air 90 is configured to be supplied to the annular buffer 106 via the gas introduction path 107 by opening and closing the reverse diffusion prevention body 104a. The cooling air 90 supplied to the annular buffer 106 flows through a gas supply flow path provided in the side wall inner layer 44 (not shown in FIG. 2), and is an opening hole that is a part of the supply path including the gas supply flow path. The cooling air 90 is configured to be supplied to the inner space 75.

When the cooling air 90 is not supplied from a gas source (not shown), the reverse diffusion preventing body 104a serves as a lid so that the atmosphere of the inner space 75 does not flow backward. The opening pressure of the reverse diffusion preventive body 104a may be changed according to the zone. Further, a heat insulating cloth 111 as a blanket is provided between the outer peripheral surface of the side wall outer layer 45 and the inner peripheral surface of the case 41 so as to absorb the thermal expansion of the metal.

The cooling air 90 supplied to the annular buffer 106 flows through a gas supply flow path provided in the side wall inner layer 44 (not shown in FIG. 2), and is configured to supply the cooling air 90 to the inner space 75 from the opening hole. Has been done.

As shown in FIGS. 1 and 2, a ceiling wall portion 80 as a ceiling portion is covered on the upper end side of the side wall portion 43 of the heat insulating structure 42 so as to close the inner space 75. An exhaust port 81 as a part of an exhaust path for exhausting the atmosphere of the inner space 75 is formed in a ring shape on the ceiling wall portion 80, and the lower end of the upstream end of the exhaust port 81 leads to the inner space 75. .. The downstream end of the exhaust port 81 is connected to the exhaust duct 82.

Next, the operation of the substrate processing apparatus 10 will be described.

As shown in FIG. 1, when a predetermined number of wafers 1 are loaded into the boat 31, the boat 31 holding the wafer 1 group has a seal cap 25 raised by the boat elevator 26. It is carried into the processing chamber 14 of the inner tube 13 (boat loading). The seal cap 25 that has reached the upper limit is pressed against the manifold 16 to seal the inside of the process tube 11. The boat 31 is left in the processing chamber 14 while being supported by the seal cap 25.

Subsequently, the inside of the process tube 11 is exhausted by the exhaust pipe 18. Further, the temperature controller (temperature control unit) 64 controls the heating element driving device 63 in sequence, and the heating element 56 provided on the side wall portion 43 heats the inside of the process tube 11 to the target temperature. The error between the actual temperature rise inside the process tube 11 and the target temperature of the sequence control of the temperature controller 64 is corrected by the feedback control based on the measurement result of the thermocouple 65. Further, the boat 31 is rotated by the rotation mechanism 29. Although only four thermocouples 65 are shown in FIG. 1, they are provided in the vicinity of the heating element 56 for each of the control zones U1, U2, CU, C, CL, L1, and L2 shown in FIG. .. Details of the configuration and control of the heater unit 40 will be described later. Further, in addition to the thermocouple 65, a thermocouple may be provided in the process tube 11.

When the internal pressure and temperature of the process tube 11 and the rotation of the boat 31 become stable as a whole, the raw material gas is introduced into the processing chamber 14 of the process tube 11 from the gas introduction pipe 22 by the gas supply device 23. The raw material gas introduced by the gas introduction pipe 22 flows through the processing chamber 14 of the inner tube 13, passes through the exhaust passage 17, and is exhausted by the exhaust pipe 18. When flowing through the processing chamber 14, a predetermined film is formed on the wafer 1 by a thermal CVD reaction caused by contact of the raw material gas with the wafer 1 heated to a predetermined processing temperature.

When the predetermined treatment time elapses, after the introduction of the treatment gas is stopped, a purge gas such as nitrogen gas is introduced into the inside of the process tube 11 from the gas introduction pipe 22. At the same time, the cooling air 90 as the cooling gas is supplied from the intake pipe 101 to the gas introduction path 107 via the reverse diffusion preventive body 104a. The supplied cooling air 90 is temporarily stored in the annular buffer 106 and blown out from the plurality of opening holes 110 to the inner space 75 via the gas supply flow path 108. The cooling air 90 blown out from the opening hole 110 into the inner space 75 is exhausted by the exhaust port 81 and the exhaust duct 82.

Since the entire heater unit 40 is forcibly cooled by the flow of the cooling air 90, the heat insulating structure 42 is rapidly cooled together with the process tube 11. Since the inner space 75 is isolated from the processing chamber 14, the cooling air 90 can be used as the cooling gas. However, an inert gas such as nitrogen gas may be used as the cooling gas in order to further enhance the cooling effect and prevent corrosion of the heating element 56 under high temperature due to impurities in the air.

When the temperature of the processing chamber 14 drops to a predetermined temperature, the boat 31 supported by the seal cap 25 is lowered by the boat elevator 26 and is carried out (boat unloading) from the processing chamber 14.

After that, by repeating the above operation, the film forming process on the wafer 1 is carried out by the substrate processing apparatus 10.

As shown in FIG. 3, the control computer 200 as a control unit includes a computer main body 203 including a CPU (Central Pressing Unit) 201 and a memory 202, a communication IF (Interface) 204 as a communication unit, and a storage unit. It has a storage device 205 and a display / input device 206 as an operation unit. That is, the control computer 200 includes a component as a general computer.

The CPU 201 constitutes the center of the operation unit, executes a control program stored in the storage device 205, and records a recipe (for example, a process recipe) recorded in the storage device 205 according to an instruction from the display / input device 206. To execute. Needless to say, the recipe for the process includes temperature control from step S1 to step S6, which will be described later, shown in FIG.

Further, as the recording medium 207 for storing the operation program of the CPU 201 or the like, a ROM (Read Only Memory), an EEPROM (Electrically Erasable Programmable Read Only Memory), a flash memory, a hard disk, or the like is used. Here, the RAM (Random Access Memory) functions as a work area of the CPU or the like.

The communication IF 204 is electrically connected to the pressure controller 21, the gas flow rate controller 24, the drive controller 28, and the temperature controller 64 (these may be collectively referred to as a sub controller), and can exchange data related to the operation of each component. can. It is also electrically connected to the valve control unit 300, which will be described later, and can exchange data for controlling the multi-cooling unit.

In the embodiment of the present disclosure, the control computer 200 has been described as an example, but the present invention is not limited to this, and can be realized by using a normal computer system. For example, the above-mentioned processing can be executed by installing the program from a recording medium 207 such as a CDROM or USB in which the program for executing the above-mentioned processing is stored in a general-purpose computer. Further, a communication IF 204 including a communication line, a communication network, a communication system, and the like may be used. In this case, for example, the program may be posted on a bulletin board of a communication network and provided by superimposing it on a carrier wave via the network. Then, by starting the program provided in this way and executing it under the control of the OS (Operating System) in the same manner as other application programs, the above-mentioned processing can be executed.

Next, an example of the film forming process performed by the substrate processing apparatus 10 will be described with reference to FIGS. 4 and 5. Reference numerals S1 to S6 shown in FIG. 5 indicate that each step S1 to S6 in FIG. 4 is performed.

Step S1 is a process of stabilizing the temperature in the furnace to a relatively low temperature T0. In step S1, the wafer 1 has not yet been inserted into the furnace.

Step S2 is a process of inserting the wafer 1 held in the boat 31 into the furnace. Since the temperature of the wafer 1 is lower than the temperature T0 in the furnace at this point, the temperature in the furnace is temporarily lower than T0 as a result of inserting the wafer 1 into the furnace, but the temperature in the furnace is temporarily lowered by the temperature controller 64 or the like. The temperature stabilizes at the temperature T0 again after some time. For example, when the temperature T0 is room temperature, this step may be omitted and is not an essential step.

Step S3 is a process of raising the temperature in the furnace by the heater unit 40 from the temperature T0 to the target temperature T1 for performing the film forming process on the wafer 1.

Step S4 is a process of maintaining and stabilizing the temperature in the furnace at the target temperature T1 in order to perform the film forming process on the wafer 1.

Step S5 is a process of gradually lowering the temperature in the furnace from the temperature T1 to the relatively low temperature T0 again by the cooling unit 100 and the heater unit 40, which will be described later, after the film formation process is completed. Further, it is also possible to rapidly cool from the processing temperature T1 to the temperature T0 by the cooling unit 100 while turning off the heater unit 40.

Step S6 is a process of pulling out the wafer 1 which has been subjected to the film forming process from the inside of the furnace together with the boat 31.

When the unprocessed wafer 1 to be subjected to the film forming process remains, the processed wafer 1 on the boat 31 is replaced with the unprocessed wafer 1, and the series of processes of steps S1 to S6 are repeated.

In each of the processes of steps S1 to S6, after obtaining a stable state in which the temperature inside the furnace is in a predetermined minute temperature range with respect to the target temperature and the state continues for a predetermined time, the next step is performed. You are supposed to go to the steps. Alternatively, recently, in steps S1, S2, S5, S6 and the like, it is possible to move to the next step without obtaining a stable state for the purpose of increasing the number of wafers 1 to be film-formed in a certain period of time. It is done.

The heater unit 40 has a resistance circuit provided for each of the control zones U1, U2, CU, C, CL, L1 and L2. FIG. 6 shows the resistance circuits of the control zones CU and C, but the control zones U2, CU, CL and L1 have the same configuration as the control zone C. Since U1 and L2 are not parallel circuits, their circuit configurations are different from those of CU and C. Each resistance circuit includes at least a heating element 56 that raises the temperature in the process tube 11 by heat generation, and is set so that the resistance values of the heating elements 56 in each control zone are equal. That is, the heating element 56 as the heat generating portion is divided into a plurality of control zones (U1, U2, CU, C, CL, L1, L2). The heating element 56 is composed of, for example, a resistance heating heater such as a carbon heater.

As shown in FIG. 6, the resistance circuit 51 as an output circuit in the control zone CU is a parallel circuit including heating elements 56a-1, 56b-1 connected in parallel between the terminals 51a and 51b. The heating element 56 in the control zone CU is composed of heating elements 56a-1 and 56b-1 having the same resistance value. More specifically, one end of the heating element 56a-1 is connected to the terminal 51a, and the other end is connected to the terminal 51b. Further, one end of the heating element 56b-1 is connected to the terminal 51b, and the other end is connected to the terminal 51a via the power regulator 51c which is an output variable element. This makes it possible to make the electric power output to the heating element 56a different from the electric power output to the heating element 56b-1. For example, if the power regulator 51c is a resistance with a predetermined resistance value, the power output to the heating element 56a-1 can be larger than the power output to the heating element 56b-1.

Further, the heating element 56a-1 is arranged above the control zone CU, and the heating element 56b-1 is arranged below the control zone CU. As a result, the electric power output to the heating element 56a on the upper side of the control zone CU can be made larger than the electric power output to the heating element 56b-1 on the lower side of the control zone CU, and the electric power can be increased in the vertical direction in the control zone CU. In, it becomes possible to output different electric power to the heating element.

The heating element driving device 63 supplies the output of the AC power supply 63a-1 to the voltage adjusted by the power regulator 63b between the terminals 51a and 51b. The power regulator 63b is composed of a thyristor, the anode of the thyristor is connected to one end of the AC power supply 63a-1, the cathode of the thyristor is connected to the terminal 51a, and the gate of the thyristor is a control signal from the temperature controller 64. Is entered. The other end of the AC power supply 63a-1 is connected to the terminal 51b.

As shown in FIG. 6, the resistance circuit 52 as an output circuit in the control zone C is a parallel circuit including heating elements 56a-2, 56b-2 wired in parallel between the terminals 52a and 52b. The heating element 56 in the control zone C is also composed of heating elements 56a-2 and 56b-2. More specifically, one end of the heating element 56a is connected to the terminal 52a and the other end is connected to the terminal 52b. Further, one end of the heating element 56b is connected to the terminal 52b, and the other end is connected to the terminal 52a via the power regulator 52c which is an output variable element. This makes it possible to make the electric power output to the heating element 56a-2 different from the electric power output to the heating element 56b-2. For example, if the power regulator 52c is a resistance with a predetermined resistance value, the power output to the heating element 56a-2 can be larger than the power output to the heating element 56b-2.

Further, the heating element 56b-2 is arranged above the control zone C, and the heating element 56a-2 is arranged below the control zone C. As a result, the electric power output to the heating element 56b-2 on the upper side of the control zone C can be made smaller than the electric power output to the heating element 56a-2 on the lower side of the control zone C, and the electric power in the control zone C can be reduced. It is possible to output different electric powers to the heating element in the vertical direction.

The heating element driving device 63 supplies the output of the AC power supply 63a-2 to the voltage adjusted by the power regulator 63c between the terminals 52a and 52b. The power regulator 63c is composed of a thyristor, the anode of the thyristor is connected to one end of the AC power supply 63a-2, the cathode of the thyristor is connected to the terminal 52a, and the control signal from the temperature controller 64 is connected to the gate of the thyristor. Is entered. The other end of the AC power supply 63a-2 is connected to the terminal 52b.

In FIG. 6, two heating elements are connected in parallel, but three or more heating elements may be connected in parallel. That is, two or more heating elements are arranged and wired in the control zone. Further, the power regulator may be provided on at least one heating element. That is, the resistance circuits 51 and 52 are parallel circuits, and the power regulators 51c and 52c are provided in one or more of the circuits constituting the parallel circuit.

The temperature controller 64 adjusts the electric power supplied to the heating element 56 based on the temperature detected by the thermocouple 65, and controls the temperature to the detected temperature. Further, the temperature controller 64 supplies different power to each resistance circuit of the control zone by supplying different voltage to the terminals of the resistance circuit of each control zone. Further, since the resistance circuit is configured to output the power output to the circuit to which the power regulator is not provided to be larger than the power output to the circuit to which the power regulator is connected, each of the temperature controllers 64 is configured. By simply supplying voltage to the terminals of the resistance circuit in the control zone, it is possible to supply different power to each circuit constituting the parallel circuit in each control zone. This allows the temperature controller 64 to supply different power in the vertical direction within each control zone.

The necessity of power balance adjustment in the control zone of the heater unit 40 will be described with reference to FIG. 7. FIG. 7 shows the temperature distribution in the furnace in a state where the power output (wall load density) of all control zones is common and the temperature is stable. Here, the wall load density is the heater output per unit area of the wall surface. At this time, _N2 gas is supplied into the furnace, and the pressure inside the furnace is 33 Pa. Even if the resistance value of the heating element and the applied voltage are constant and the power output is constant, the temperature at the upper and lower ends (control zones L1 and L2) of the process tube 11 due to the influence of heat radiation from the ceiling portion and the furnace mouth portion of the process tube 11. A decrease has occurred, and a temperature difference of 200 ° C. or more has occurred in the temperature distribution in the furnace of the process tube 11.

The power balance adjusting method in the control zone of the heater unit 40 will be described with reference to FIGS. 8 to 12. The power outputs of the control zones U1, U2, CU, C, CL, L1 and L2 are adjusted so that the temperature distributions of the control zones U2, CU, C, CL and L1 located in the wafer region are uniform.

First, a case where the power output in each control zone is constant by using the resistance circuit of the comparative example of FIG. 12 will be described with reference to FIGS. 8 and 9. FIG. 8 shows the power output distribution of the control zones U1, U2, CU, C, CL, L1, L2 of the comparative example in which the temperature distribution of the wafer region of the control zones U2, CU, C, CL, and L1 is adjusted to be uniform. Is.

As shown in FIG. 12, each of the resistance circuits 61 and 62 of the comparative example includes a power regulator 51c between the heating element 56b and the terminal 51a with respect to the resistance circuits 51 and 52 of the embodiment of FIG. Therefore, the power regulator 52c is not provided between the heating element 56b and the terminal 52a. Since the heating element 56a and the heating element 56b have the same resistance value, the power output in each control zone is constant, so that the power output distribution has a stepped shape as shown in FIG. In FIG. 8, this power distribution is shown as a solid reality. On the other hand, the ideal power output distribution for making the temperature inside the furnace uniform is shown as a broken line DREAM. DREAM is an estimated value based on the temperature distribution in FIG. 7 and the measured power value in FIG. REALTY outputs power so as to match DREAM near the center of each control zone. The difference between REALITY and DREAM increases toward the upper and lower control zones of the process tube 11.

FIG. 9 shows the temperature distribution in the furnace corresponding to the power distribution in FIG. Similar to FIG. 7, _N2 gas is supplied into the furnace at this time, and the pressure inside the furnace is 33 Pa. As shown in FIG. 9, the difference between REALITY and DREAM in FIG. 8 causes a temperature difference of 0.4 to 1.0 ° C.

Next, the adjustment of the power output balance using the resistance circuit of FIG. 6 will be described with reference to FIGS. 10 and 11. The solid line NEW in FIG. 10 shows the power output distribution in which the power output balance is adjusted by using the resistance circuit of FIG. The dashed DREAM in FIG. 10 has the same ideal power output distribution as the DREAM in FIG.

The control zone CU uses the resistance circuit of FIG. 6 to make the output power of the upper heating element 56a larger than the output power of the lower heating element 56b. The resistance circuit of the control zone U2 is the same as the resistance circuit 51 of the control zone CU of FIG. 7, and the output power of the upper heating element is larger than the output power of the lower heating element. Further, the resistance circuit of the control zone U1 is the same as the resistance circuit 61 of the control zone CU of FIG. 12, and the output powers of the upper and lower heating elements are the same.

In the control zone C, the output power of the lower heating element 56a is made larger than the output power of the upper heating element 56a by using the resistance circuit of FIG. The resistance circuit of the control zone CL is the same as the resistance circuit 52 of the control zone C of FIG. 6, and the output power of the lower heating element is larger than the output power of the upper heating element. Further, the resistance circuit of the control zone L1 is the same as the resistance circuit 52 of the control zone C of FIG. 7, and the output power of the lower heating element is larger than the output power of the upper heating element. Further, the resistance circuits of the control zones U1 and L2 are connected in series, and the output powers of the upper and lower heating elements are the same.

As a result, the power output distribution as shown in NEW in FIG. 10 can be obtained. In the control zones U1 and L2, NEW outputs power in the vicinity of the center so as to coincide with DREAM. In the control zones U2 to L1, NEW outputs power so as to coincide with DREAM near the center of each of the upper side and the lower side. The difference between NEW and DREAM in FIG. 10 can be made smaller than the difference between REALITY and DREAM in FIG.

FIG. 11 shows the temperature distribution in the furnace in the power output distribution of FIG. Similar to FIG. 7, _N2 gas is supplied into the furnace at this time, and the pressure inside the furnace is 33 Pa. The temperature difference in the wafer region of each control zone U2, CU, C, CL, L1 is 0.2 ° C. or less, and the uniformity of the temperature distribution in the furnace is improved as compared with the comparative example. As described above, according to the present embodiment, not only the power output can be adjusted between the control zones in the wafer region, but also the power output in each control zone can be adjusted, so that the temperature distribution in the furnace can be adjusted. Can be made uniform between wafers. In FIG. 10, each control zone U2, CU, C, CL, L1 is divided into two, but the present invention is not limited to this form, and each control zone U2, CU, C, CL, L1 is not limited to this form. The number of divisions can be set individually, and the number of divisions can be made different in each control zone U2, CU, C, CL, L1.

The example in which the power regulators 51c and 52c are composed of resistors has been described, but the present invention is not limited to this, and the power regulators 51c and 52c may be composed of a thyristor, an IGBT, or the like. FIG. 13 shows a resistance circuit in the case where the power regulator is configured by a thyristor as another embodiment.

As shown in FIG. 13, the resistance circuit 71 as an output circuit in the control zone CU is a parallel circuit including heating elements 56a and 56b wired in parallel between the terminals 51f and 51b. The heating element 56 in the control zone CU is composed of heating elements 56a and 56b having the same resistance value. More specifically, one end of the heating element 56a is connected to the terminal 51f via the terminal 51a and the power regulator 63b, and the other end is connected to the terminal 51b. Further, one end of the heating element 56b is connected to the terminal 51b, and the other end is connected to the terminal 51f via the power regulator 51e which is an output variable element. The power regulator 51e is composed of a thyristor like the power regulator 63b.

The resistance circuit 71 of the modified example is composed of a part of the heater unit 40 and a part of the heating element driving device 63. That is, unlike the resistance circuit 51, the resistance circuit 71 includes a power regulator 51e. The resistance circuit 71 supplies a voltage obtained by adjusting the output of the AC power supply 63a by the power regulator 63b between the terminals 51a and 51b based on the control signal from the temperature controller 64. Further, a voltage adjusted by the power regulator 51e for the output of the AC power supply 63a based on the control signal from the temperature controller 64 is supplied between the terminals 51d and 51b. Since the heating element 56a and the heating element 56b share the terminal 51b and are supplied with power from the AC power supply 63a having the same phase, the resistance circuit 71 is also a kind of parallel circuit.

If the power output to the heating element 56a and the electric power output to the heating element 56b differ depending on the control signal input to the gate of the thyristor of the power regulator 63b and the control signal input to the gate of the thyristor of the power regulator 51e. It is possible to make it. For example, by making the voltage input to the gate of the thyristor of the power regulator 63b higher than the voltage input to the gate of the thyristor of the power regulator 51e, the power output to the heating element 56a is output to the heating element 56b. Can be greater than the power generated.

Further, the heating element 56a is arranged above the control zone CU, and the heating element 56b is arranged below the control zone CU. As a result, the electric power output to the heating element 56a on the upper side of the control zone CU can be made larger than the electric power output to the heating element 56b on the lower side of the control zone CU, and in the vertical direction in the control zone CU, It is possible to output different power to the heating element.

As shown in FIG. 13, the resistance circuit 72 in the control zone C is a parallel circuit including heating elements 56a and 56b wired in parallel between the terminals 52f and 52b. The heating element 56 in the control zone C is composed of heating elements 56a and 56b having the same resistance value. More specifically, one end of the heating element 56a is connected to the terminal 52f via the terminal 52a and the power regulator 63c, and the other end is connected to the terminal 52b. Further, one end of the heating element 56b is connected to the terminal 52b, and the other end is connected to the terminal 52f via the power regulator 52e which is an output variable element. The power regulator 52e is composed of a thyristor like the power regulator 63c.

The resistance circuit 72 of the modified example is composed of a part of the heater unit 40 and a part of the heating element driving device 63. That is, unlike the resistance circuit 52, the resistance circuit 72 includes the power regulator 63c. The resistance circuit 72 supplies the output of the AC power supply 63a based on the control signal from the temperature controller 64 between the terminals 52a and 52b with the power adjusted by the power regulator 52e. Further, the output of the AC power supply 63a based on the control signal from the temperature controller 64 is supplied with the power adjusted by the power regulator 52e between the terminals 52d and 52b.

If the power output to the heating element 56a and the electric power output to the heating element 56b differ depending on the control signal input to the gate of the thyristor of the power regulator 63c and the control signal input to the gate of the thyristor of the power regulator 52e. It is possible to make it. For example, by making the control signal input to the gate of the thyristor of the power regulator 63c different from the control signal input to the gate of the thyristor of the power regulator 52e, the power output to the heating element 56a is transmitted to the heating element 56b. It can be larger than the output power.

Further, the heating element 56b is arranged above the control zone C, and the heating element 56a is arranged below the control zone C. As a result, the electric power output to the heating element 56b on the upper side of the control zone C can be made smaller than the electric power output to the heating element 56a on the lower side of the control zone C, and the like can be made different. It is possible to output different electric powers to the two heating elements in the vertical direction of.

Hereinafter, a configuration for adjusting the electric power output to the heating element 56a and the electric power output to the heating element 56b in the modified example will be described with reference to FIGS. 14 and 15. Here, the CU zone of each control zone will be described below.

As shown in FIG. 14, the temperature controller 64 captures the temperature detected by the temperature detection unit 641 (thermocouple 65 in FIG. 2). Further, the temperature controller 64 receives a balance parameter in addition to the set temperature value from the control computer 200 as the host controller.

The control computer 200 sets the output ratios at the upper part and the lower part as balance parameters for one control zone, respectively. Hereinafter, the upper output ratio is referred to as Upper_Ratio, and the lower output ratio is referred to as Lower_Ratio. As shown in FIG. 15, the balance parameter can be switched according to an instruction from the control computer 200 by holding the parameter for each temperature zone. According to the balance parameter instructed by the control computer 200, the power balance adjusting unit 642 determines the upper and lower outputs for one control zone. Note that FIG. 15 is a numerical example of the balance parameter of the CU zone in each control zone.

In the temperature controller 64, the temperature control calculation unit 643 performs a temperature control calculation so that the set temperature instructed by the control computer 200 and the temperature detected by the temperature detection unit 641 match, and the control calculation result is determined. ..

Next, the power balance adjusting unit 642 determines the upper and lower power (effective value) for one control zone by the following equations (1) to (3).
Upper power output = Control calculation result × Upper_Ratio ・ ・ ・ (1)
Lower power output = Control calculation result × Lower_Ratio ・ ・ ・ (2)
Upper_ratio + Lower_Ratio = 2.0 ・ ・ ・ (3)
Here, the control calculation result, the upper power output and the lower power output are numbers expressed as percentages.

An example of calculating the output of the upper part and the lower part of the power balance adjusting unit 642 will be described with reference to FIG.

FIG. 16 is a calculation example using a parameter having a temperature zone of 600 ° C. in FIG. Assuming that the control calculation result of the temperature control calculation unit 643 is 75.0%, the power balance adjustment unit 642 uses Upper_Ratio = 1.07 and Lower_Ratio = 0.93 as the balance parameters at 600 ° C. as shown in FIG. Then, the upper power output and the lower power output are calculated by the equations (1) to (3).
Upper power output = 75.0% x 1.07 = 80.25%
Lower power output = 75.0% x 0.93 = 69.75%
80.25% of the calculated upper power output is supplied to the first power supply unit 644, and 69.75% of the calculated lower power output is supplied to the second power supply unit 645.

By always setting the sum of Upper_Ratio and Lower_Ratio to 2.0, the total voltage as one control zone does not change even if the upper and lower power balance changes, so the temperature waveform does not change significantly, for example, during PID control. There is no need to readjust control parameters such as the PID value of. As a result, although the power supply from the temperature controller 64 is supplied to each control zone as before, it is possible to supply different power in the vertical direction in each control zone.

As shown in FIG. 15, the balance parameter can be switched by an instruction from the control computer 200 by holding a plurality of parameters for each temperature zone. Also, by setting more than two balance parameters for one control zone, it is easy to supply different powers for finer zone division.

FIG. 17A shows the temperature distribution in the furnace and the electric power of each control zone in the comparative example, and FIG. 17B shows the temperature distribution in the furnace and the electric power of each control zone in the modified example. FIG. 17C is an example of a balance parameter showing the power balance in the product area of the control zones U2 to L1.

As described above, in the above-mentioned two embodiments of the present disclosure, since a plurality of output circuits can be provided in each control zone and the power output from each output circuit can be adjusted, the inside of each control zone is divided. It is possible to output different wall load densities. As a result, the temperature difference in the wafer region of each control zone U2, CU, C, CL, L1 with respect to the target temperature can be suppressed to 0.2 ° C. or less.

That is, taking FIG. 17 as an example, by reducing the Lower_Ratio of the CU zone, the influence from the CU zone to the C zone is reduced, and the (temperature) near the boundary between the CU zone and the C zone (upper part of the C zone). The waveform drops. By lowering the temperature of the upper part of the C zone, the waveform of the entire C zone can be raised (= more power can be supplied), and the C zone is within 0.2 ° C. Further, in the CL zone, by reducing the Upper_Ratio of the L1 zone, the waveform near the boundary between the CL zone and the L1 zone is lowered, and by lowering the waveform of the entire CL zone, the CL zone is kept below 0.2 ° C. As described above, in the present embodiment using the variable output element, the balance parameter is set in consideration of the influence of the temperature waveforms of the adjacent zones, so that the temperature difference is extremely close to 0 ° C. The temperature difference in the wafer area of the zone can be reduced.

Similar to the above-mentioned two embodiments in the present disclosure, as a method of applying different electric powers to the upper part and the lower part of one control zone, a control zone expansion method in which two control zones are formed can be considered. Comparing the control zone expansion method with this modified example, the following are the advantages of this modified example.
(1) In the present embodiment, one control zone is provided with a thermocouple and a temperature detection unit, respectively, but since a plurality of outputs can be calculated by the power balance adjustment unit, the cost is higher than that of the control zone expansion method. It is superior in that.
(2) In the present embodiment, since the total voltage for one control zone does not change, the temperature waveform does not change significantly, and the complexity of adjustment is alleviated as compared with the control zone expansion method.
(3) In particular, by treating the balance parameter as one of the control parameters in this modification, it is possible to change whether or not the power balance function is used without modifying the device. For example, if Upper_Ratio = 100% and Lower_Ratio = 100% are set, the same power supply as when there is no power balance function can be performed.

Further, the present disclosure can be applied not only to semiconductor manufacturing equipment but also to equipment for processing glass substrates such as LCD equipment.

Further, the present disclosure relates to a semiconductor manufacturing technique, particularly a heat treatment technique in which a substrate to be processed is housed in a processing chamber and treated in a state of being heated by a heating device, and for example, a semiconductor integrated circuit device (semiconductor device) is incorporated. Applicable to semiconductor wafers that are effective for substrate processing equipment used for oxidation treatment, diffusion treatment, reflow and annealing for carrier activation and flattening after ion implantation, and film formation processing by thermal CVD reaction. can do.

<Preferable aspect of the present disclosure>
Hereinafter, preferred embodiments of the present disclosure will be described.

(Appendix 1)
According to one aspect of the present disclosure
A heating unit (heater unit 40) divided into a plurality of control zones, which is provided for each control zone and raises the temperature in the reaction tube (process tube 11) by heat generation (heating element 56). The output circuit in each control zone is a parallel circuit, and a heating unit (heater unit 40) configured to provide an output variable element in any one or more of the circuits constituting the parallel circuit. Is provided.

(Appendix 2)
In the heating section of Appendix 1, preferably
At least one of the output variable elements is selected from the group consisting of a resistor, a thyristor, and an IGBT.

(Appendix 3)
In the heating section of Appendix 1, preferably
Two or more output circuits are wired in parallel in the control zone.

(Appendix 4)
According to another aspect of the present disclosure.
A heating unit (heater unit 40) divided into a plurality of control zones, which is provided for each control zone and raises the temperature inside the reaction tube (process tube 11) by heat generation (heat generating body 56). ) Is included, and the output circuit in each control zone is a parallel circuit, and a heating unit (heater unit 40) configured to provide an output variable element in any one or more of the circuits constituting the parallel circuit. ), A detection unit (thermocouple 65) provided for each control zone and provided in the vicinity of the heat generation unit, and the power supplied to the heat generation unit based on the temperature detected by the detection unit is adjusted. A temperature control system including a temperature control unit (temperature controller 64) that controls the detected temperature is provided.

(Appendix 5)
In the temperature control system of Appendix 4, preferably
The temperature control unit is configured to output different electric power for each control zone.

(Appendix 6)
In the temperature control system of Appendix 4, preferably
The temperature control unit is configured to output different electric powers in the vertical direction in the control zone.

(Appendix 7)
In the temperature control system of Appendix 5, preferably
The temperature control unit is configured to output different electric power for each output circuit constituting the parallel circuit in the control zone.

(Appendix 8)
In the temperature control system of Appendix 4, preferably
The temperature control unit is configured to output electric power according to the resistance value of each output circuit constituting the parallel circuit in the control zone.

(Appendix 9)
In the temperature control system of Appendix 8, preferably
The temperature control unit is configured so that the power output to the circuit to which the output variable element is not provided is larger than the power output to the output circuit to which the output variable element is connected.

(Appendix 10)
In the temperature control system of Appendix 4, preferably
Further, it has an adjusting unit for adjusting the power output from the output circuit to which the output variable element is connected.
The adjusting unit is configured to be able to output different electric power for each output circuit.

(Appendix 11)
In the temperature control system of Appendix 10, preferably
Further, it has a temperature control calculation unit 643 that performs a temperature control calculation so that the set temperature instructed in advance and the temperature detected by the temperature detection unit 641 (thermocouple 65) match.
The adjusting unit is configured to determine the output to the output circuit based on the ratio of the control signals calculated by the temperature control calculation unit 645.

(Appendix 12)
According to yet another aspect of the present disclosure.
A heating unit (heater unit 40) divided into a plurality of control zones, which is provided for each control zone and raises the temperature in the reaction tube (process tube 11) by heat generation (heat generating body 56). The output circuit in each control zone is a parallel circuit, and a heating unit (heater unit 40) configured to provide an output variable element in any one or more of the circuits constituting the parallel circuit. A processing device equipped with at least the above is provided.

(Appendix 13)
According to yet another aspect of the present disclosure.
A heating unit (heater unit 40) divided into a plurality of control zones, which is provided for each control zone and raises the temperature in the reaction tube (process tube 11) by heat generation (heat generating body 56). The output circuit in each control zone is a parallel circuit, and a heating unit (heater unit 40) configured to provide an output variable element in any one or more of the circuits constituting the parallel circuit. Provided a method for manufacturing a semiconductor device, which comprises a step of treating a substrate arranged in the reaction tube while heating it.

11: Process tube (reaction tube)
40: Heater unit (heating unit)
51: Resistance circuit 51c: Power regulator (element for variable output)
56: Heating element (heating part)
56a-1: Heating element 56a-2: Heating element 56b-1: Heating element 56b-2: Heating element

Claims (20)

It is divided into a plurality of control zones, and each control zone is a heating unit provided with an output circuit .
A heating unit provided for each control zone and raising the temperature inside the reaction tube by heat generation,
The output circuit of the control zone located in the board region of each of the control zones is a parallel circuit, and is provided in any one of the circuits constituting the parallel circuit, and the control located in the board region is provided. An output variable element configured to adjust the power output from the heat generating portion arranged in the circuit constituting the parallel circuit of the zone, and
The heating part having . The heating unit according to claim 1, wherein the heat generating unit is provided in a plurality of control zones located in the substrate region. The heating unit according to claim 1, wherein the output circuit is wired in parallel in two or more in a control zone located in the substrate region. The heating unit according to claim 1, wherein the output circuit is a resistance circuit. The heating unit according to claim 1, wherein the output variable element is at least one of a resistance, a thyristor, and an IGBT. Each control zone is divided into a plurality of control zones, and each control zone is a heating unit provided with an output circuit. The output circuit of the control zone located in the board region of the zone is a parallel circuit, and the output circuit of the control zone located in the board region is provided in any one of the circuits constituting the parallel circuit. A heating unit having an output variable element configured to adjust the power output from the heat generating unit arranged in the circuit constituting the parallel circuit , and a heating unit provided at least for each control zone to generate the heat generation. A temperature control system including a temperature control unit that controls the heating unit by adjusting the power supplied to the heat generating unit based on the temperature detected by the detection unit provided in the unit . The temperature control system according to claim 6, wherein the temperature control unit is configured to output different electric power for each control zone. Further, it has an adjusting unit for adjusting the power output from the circuit to which the output variable element is connected.
The temperature control system according to claim 6, wherein the adjusting unit is configured to be able to output different electric power for each of the circuits constituting the parallel circuit. Further, it has a temperature control calculation unit that performs a temperature control calculation so that the set temperature instructed in advance and the temperature detected by the temperature detection unit match.
The temperature control system according to claim 8, wherein the adjusting unit is configured to determine an output to the circuit constituting the parallel circuit by a ratio of control signals calculated by the temperature control calculation unit. It is divided into a plurality of control zones, and each control zone is a heating unit provided with an output circuit .
The heat generating portion provided for each control zone and raising the temperature in the reaction tube by heat generation and the output circuit of the control zone located in the substrate region of each of the control zones are parallel circuits, and the parallel circuit is used. It is provided in any one of the constituent circuits and is configured to adjust the power output from the heat generating portion arranged in the circuit constituting the parallel circuit of the control zone located in the substrate region. A processing device including at least a heating unit having a variable output element . The processing device according to claim 10, wherein the heating unit is configured to output different electric powers in the vertical direction of the control zone located in the substrate region. The processing device according to claim 10, wherein the heating unit is configured to output different electric power for each circuit constituting the parallel circuit. The processing device according to claim 10, wherein the heating unit is configured to output electric power according to a resistance value of each circuit constituting the parallel circuit. The processing device according to claim 10, wherein the heating unit is configured to have a larger power output to a circuit not provided with the output variable element than a power output to the circuit to which the output variable element is connected. The processing device according to claim 10, wherein the output variable element is at least one of a resistance, a thyristor, and an IGBT. The output variable element is provided for each circuit constituting the parallel circuit.
The processing apparatus according to claim 10, further comprising a control unit configured to input different control signals to the output variable element. The output variable element is provided for each circuit constituting the parallel circuit.
The processing apparatus according to claim 10, wherein the electric power output from each of the output variable elements can be adjusted by a parameter. The processing apparatus according to claim 17, wherein the parameters are configured to be changeable according to a preset set temperature. The processing apparatus according to claim 17, further comprising a control unit configured to input the same control signal to the output variable element. Each control zone is divided into a plurality of control zones, and each control zone is a heating unit provided with an output circuit. The output circuit of the control zone located in the board region of the zone is a parallel circuit, and is provided in any one of the circuits constituting the parallel circuit, and the output circuit of the control zone located in the board region is described. A substrate arranged in the reaction tube is heated by a heating unit having an output variable element configured to adjust the power output from the heat generating unit arranged in the circuit constituting the parallel circuit. A method for manufacturing a semiconductor device having a processing step.

Images