JP6625005B2 - Temperature measurement method - Google Patents

Description

The present invention relates to a temperature measuring how.

  2. Description of the Related Art Conventionally, a heat treatment apparatus on which a plurality of semiconductor wafers (hereinafter, referred to as “wafers”) as substrates are mounted in a rotation direction of a turntable provided in a processing container is known. The heat treatment apparatus includes a gas supply unit that is provided along a radial direction of a turntable and supplies a processing gas, and a heater that is provided below the turntable and heats a wafer. Then, the film is formed on the wafer by rotating the rotary table while discharging the gas by the gas supply unit and heating the wafer by the heater.

  In this heat treatment apparatus, temperature measurement is performed to confirm whether the wafer is heated to an appropriate temperature. As a method of temperature measurement, a temperature measurement wafer provided with a thermocouple is placed on a rotary table, and then the temperature of the heater is increased, and the temperature of the temperature measurement wafer is measured by the thermocouple. In this method, since the thermocouple is connected to the temperature measurement wafer, the temperature cannot be measured while the rotary table is rotated.

  Therefore, a radiation temperature measuring unit is provided which measures the temperature of a plurality of spot areas by repeatedly scanning one surface side of the rotary table in the radial direction while the rotary table provided in the processing container is rotating. A temperature measuring device is disclosed (for example, see Patent Document 1). In this temperature measuring device, a wafer made of SiC (silicon carbide) (hereinafter, referred to as “SiC wafer”) is placed on a rotary table, and infrared rays radiated from the surface of the SiC wafer are detected. A measurement is taken.

  Conventionally, silicon, quartz, and the like have been used as targets for measuring the temperature by the radiation temperature measurement unit, in addition to SiC.

JP 2012-248634 A

  However, in the above apparatus, even when the temperature of the plurality of SiC wafers placed on the turntable is measured in a state where the temperature in the processing chamber is stable, each of the plurality of SiC wafers has a different temperature. As shown, there was a problem that accurate temperature measurement was difficult. This is considered to be because the emissivity of each wafer varies when the manufacturing histories of the wafers are different, such as when a plurality of SiC wafers are manufactured from different ingots.

  In addition, when silicon is used as a target when measuring the temperature by the radiation temperature measurement unit, it is difficult to perform a detailed temperature measurement in a low temperature region (for example, in a range of 200 ° C to 400 ° C). This is because silicon transmits infrared rays in a low temperature region. Further, since SiC and quartz have different heat capacity and thermal behavior from silicon, it has been difficult to estimate the temperature of silicon using SiC and quartz instead of silicon.

  In view of the above problem, an object of the present invention is to provide a temperature measurement method capable of measuring a wafer temperature with high accuracy even when using wafers having different manufacturing histories.

In order to achieve the above object, in one embodiment, in a temperature measurement method, a plurality of substrates are placed on a surface of a turntable provided in a processing container, and heat treatment is performed on the plurality of substrates while rotating the turntable. A method for measuring temperature in a heat treatment apparatus, comprising: mounting a plurality of low-resistance silicon wafers having different manufacturing histories having a resistivity at room temperature (20 ° C.) of 0.02 Ω · cm or less on a surface of the rotary table. And a rotating step of rotating the rotary table on which the plurality of low-resistance silicon wafers are mounted; and while the rotary table is rotating, radiation is emitted from each surface of the plurality of low-resistance silicon wafers. look including a measuring step of measuring the temperature of the low-resistance silicon wafer by detecting infrared rays, the resistivity of the plurality of low-resistance silicon wafer Flip it.

  According to the present embodiment, it is possible to provide a temperature measuring method capable of measuring the temperature of a wafer with high accuracy.

FIG. 2 is a schematic vertical sectional view of the heat treatment apparatus according to the first embodiment. FIG. 2 is a schematic perspective view of the heat treatment apparatus according to the first embodiment. FIG. 2 is a schematic plan view of the heat treatment apparatus according to the first embodiment. FIG. 3 is a partial cross-sectional view illustrating a temperature measuring unit in the heat treatment apparatus according to the first embodiment. It is a figure explaining operation of a radiation temperature measurement part. FIG. 4 is a diagram illustrating a relationship between a turntable and a temperature measurement region. It is a schematic longitudinal section of the heat processing apparatus concerning a 2nd embodiment. It is an outline longitudinal section showing an example of the heat treatment device concerning a 3rd embodiment. It is an outline longitudinal section showing other examples of the heat treatment equipment concerning a 3rd embodiment. It is an outline longitudinal section of a heat treatment device concerning a 4th embodiment. It is a schematic longitudinal section of the heat processing apparatus concerning a 5th embodiment. 4 is a graph illustrating a relationship between a radial position of the rotary table and a temperature in the first embodiment. 9 is a graph showing a relationship between a radial position of a rotary table and a temperature in Embodiment 2. 14 is a graph showing a relationship between a radial position of a rotary table and a temperature in the third embodiment. 14 is a graph showing a relationship between a radial position of a rotary table and a temperature in Embodiment 4. 9 is a graph showing a relationship between a radial position of a rotary table and a temperature in Comparative Example 1. 9 is a graph showing a relationship between a radial position of a rotary table and a temperature in Comparative Example 2.

  Hereinafter, the present embodiment will be described with reference to the accompanying drawings. In the specification and the drawings, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted.

  The temperature measuring method of the present embodiment is a temperature measuring method of measuring the temperature in a processing container in a semiconductor manufacturing apparatus by a radiation temperature measuring unit that detects infrared rays emitted from an object and measures the temperature. A low-resistance silicon wafer having a resistivity of 0.02 Ω · cm or less at room temperature (20 ° C.) is used as an object whose temperature is to be measured by the temperature measurement unit. Thus, the temperature inside the processing container can be measured with high accuracy even in a low temperature region (for example, in the range of 200 ° C. to 400 ° C.). Further, in the low-resistance silicon wafer, since the variation in the emissivity among the wafers is small, the temperature in the processing chamber can be measured with high accuracy even when the manufacturing histories of the wafers are different.

  Hereinafter, a case where the temperature measurement method of the present embodiment is applied to a heat treatment apparatus which is an example of a semiconductor manufacturing apparatus will be described as an example. However, the present invention is not limited to this and is applicable to various other semiconductor manufacturing apparatuses. is there.

[First Embodiment]
In the first embodiment, a film forming process is performed on a wafer by supplying a plurality of reaction gases that react with each other to a plurality of wafers placed along a rotation direction of a turntable provided in a processing container. A temperature measurement method in a semi-batch type heat treatment apparatus to be performed will be described.

  (Configuration of heat treatment device)

  FIG. 1 is a schematic vertical sectional view of the heat treatment apparatus according to the first embodiment. FIG. 2 is a schematic perspective view of the heat treatment apparatus according to the first embodiment. FIG. 3 is a schematic plan view of the heat treatment apparatus according to the first embodiment.

  The heat treatment apparatus 1 of the present embodiment includes a substantially circular flat processing container 11 and a disk-shaped rotary table 12 provided horizontally in the processing container 11. The processing container 11 is provided in the atmosphere, and includes a top plate 13 and a container main body 14 that forms a side wall and a bottom of the processing container 11. In FIG. 1, reference numeral 11a denotes a seal member for keeping the inside of the processing container 11 airtight, and reference numeral 14a denotes a cover for closing a central portion of the container main body 14. In FIG. 1, reference numeral 12a denotes a rotary drive mechanism for rotating the rotary table 12 in the circumferential direction.

  Five recesses 16 are formed on the surface of the turntable 12 along the rotation direction of the turntable 12. In the figure, reference numeral 17 denotes a transfer port. Reference numeral 18 in FIG. 3 denotes a shutter that can open and close the transfer port 17 (omitted in FIG. 2). When the transfer mechanism 2A enters the processing container 11 from the transfer port 17 while holding the wafer W, the lift pins (not shown) project onto the rotary table 12 from the holes 16a of the concave portions 16 at positions facing the transfer port 17 so that the wafer W W is pushed up, and the wafer W is transferred between the concave portion 16 and the transfer mechanism 2A.

  A series of operations by the transfer mechanism 2 </ b> A, the lifting pins, and the rotary table 12 are repeated, and the wafer W is transferred to each recess 16. When the wafer W is unloaded from the processing container 11, the elevating pins push up the wafer W in the recess 16, and the transfer mechanism 2 </ b> A receives the pushed wafer W and unloads the wafer W out of the processing container 11.

A first reaction gas nozzle 21, a separation gas nozzle 22, a second reaction gas nozzle 23, and a separation gas nozzle 24 each having a rod shape extending from the outer periphery of the rotation table 12 toward the center are provided on the turntable 12 in the circumferential direction in this order. It is arranged. Each of the gas nozzles 21 to 24 has an opening below, and supplies a gas along the diameter of the turntable 12. The first reaction gas nozzle 21 discharges BTBAS (Bicester butylaminosilane) gas, and the second reaction gas nozzle 23 discharges O ₃ (ozone) gas. The separation gas nozzles 22 and 24 discharge N ₂ (nitrogen) gas.

  The top plate 13 of the processing container 11 includes two fan-shaped protrusions 25 projecting downward, and the protrusions 25 are formed at intervals in the circumferential direction. The separation gas nozzles 22 and 24 are provided so as to sink into the projection 25 and divide the projection 25 in the circumferential direction. The first reactant gas nozzle 21 and the second reactant gas nozzle 23 are provided separately from the protruding portions 25.

  When the wafer W is placed in each of the concave portions 16, a position on the bottom surface of the container body 14, which is located radially outward of the rotary table 12 from a region between the separation regions D <b> 1 and D <b> 2 below the protrusion 25. The inside of the processing container 11 is evacuated from the exhaust port 26 opened to the vacuum atmosphere. Then, as the turntable 12 rotates, the wafer W is heated to, for example, 760 ° C. via the turntable 12 by the heater 20 provided below the turntable 12. An arrow 27 in FIG. 3 indicates a rotation direction of the turntable 12.

Subsequently, gas is supplied from each of the gas nozzles 21 to 24, and the wafer W is connected to the first processing region P <b> 1 below the first reaction gas nozzle 21 and the second processing region P <b> 2 below the second reaction gas nozzle 23. Pass alternately. Accordingly, BTBAS gas is adsorbed on the wafer W, then the O ₃ gas is then BTBAS molecules are oxidized adsorbed molecular layer of silicon oxide is formed one layer or plural layers. In this manner, the molecular layers of silicon oxide are sequentially stacked to form a silicon oxide film having a predetermined thickness.

The N ₂ gas supplied to the separation regions D 1 and D 2 from the separation gas nozzles 22 and 24 during the film forming process spreads in the separation regions D 1 and D 2 in the circumferential direction, and the BTBAS gas and the O ₃ gas are mixed on the rotary table 12. To be done. Further, excess BTBAS gas and O ₃ gas are flushed to the exhaust port 26. During the film forming process, the N ₂ gas is supplied to the space 28 above the central area of the turntable 12. The N ₂ gas is supplied to the outside of the turntable 12 in the radial direction outside of the turntable 12 through the top of the top plate 13 below the projecting portion 29 projecting downward in a ring shape, and the BTBAS gas and the O ₃ gas in the central region C are Is prevented from mixing. In FIG. 3, the arrows indicate the flow of each gas during the film forming process. Further, although not shown, N ₂ gas is supplied to the cover 14a and the rear surface side of the rotary table 12, the reaction gas is adapted to be purged.

  Subsequently, a description will be given also with reference to FIG. 4 showing an enlarged longitudinal side surface of the top plate 13 and the turntable 12. FIG. 4 is a partial cross-sectional view illustrating a temperature measurement unit in the heat treatment apparatus according to the first embodiment. Specifically, FIG. 4 shows a cross section between a first processing region P1 in which the first reaction gas nozzle 21 is provided and a separation region D2 adjacent to the first processing region P1 on the upstream side in the rotation direction. ing.

  A slit 31 extending in the radial direction of the turntable 12 is opened in the top plate 13 at a position indicated by a chain line in FIG. 3. A lower window 32 and an upper window 33 cover the slit 31 up and down. Is provided. The lower window 32 and the upper window 33 are made of, for example, sapphire so as to transmit infrared rays radiated from the surface side of the turntable 12 and measure the temperature by a radiation temperature measuring unit 3 described later. The surface side of the turntable 12 also includes the surface side of the wafer W.

  Above the slit 31, a radiation temperature measuring unit 3, which is an example of a non-contact thermometer, is provided. The height H from the surface of the turntable 12 in FIG. 4 to the lower end of the radiation temperature measuring unit 3 is, for example, 500 mm. The radiation temperature measuring section 3 guides infrared rays radiated from a temperature measuring area of the turntable 12 to a detecting section 301 described later, and the detecting section 301 acquires a temperature measurement value according to the amount of the infrared rays. Therefore, this temperature measurement value differs depending on the temperature of the acquired location, and the acquired temperature measurement value is sequentially transmitted to the control unit 5 described later.

  Next, the radiation temperature measuring section 3 will be described with reference to FIG. FIG. 5 is a diagram illustrating the operation of the radiation temperature measurement unit.

  As shown in FIG. 5, the radiation temperature measuring section 3 includes a rotating body 302 composed of a servomotor rotating at 50 Hz. The rotating body 302 is formed in a triangular shape in plan view, and three side surfaces of the rotating body 302 are formed as reflection surfaces 303 to 305. As shown in FIG. 5, when the rotating body 302 rotates around the rotation axis 306, the infrared rays in the temperature measurement area 40 of the turntable 12 including the wafer W are reflected on the reflection surfaces 303 to 305 as indicated by arrows in the drawing. The scanning is performed by moving the position of the temperature measurement area 40 in the radial direction of the turntable 12 while guiding the light to the detection unit 301.

  The detection unit 301 is configured to be able to detect the temperature at a predetermined location (for example, 128 locations) in the radial direction of the turntable 12 by continuously receiving infrared rays a predetermined number of times (for example, 128 times) from one reflection surface. . Scanning can be repeatedly performed from the inside to the outside of the rotary table 12 by the reflection surfaces 303 to 305 being sequentially positioned on the optical path of the infrared ray by the rotation of the rotating body 302, and the scanning speed is 150 Hz. . That is, the radiation temperature measurement unit 3 can perform 150 scans per second. The temperature measurement area 40 is a spot having a diameter of 5 mm. The scanning is performed in a range from a position further inside the concave portion 16 where the wafer W is placed on the rotary table 12 to the outer peripheral end of the rotary table 12. In addition, chain lines 34 and 35 in FIG. 4 indicate infrared rays traveling from the temperature measurement region 40 moved to the innermost side and the outermost side of the turntable 12 toward the radiation temperature measurement unit 3.

  The scan by the radiation temperature measuring unit 3 is performed while the turntable 12 is rotating. The rotation speed of the turntable 12 is 240 rotations / minute in this example. FIG. 6 is a plan view showing the relationship between the turntable 12 and the temperature measurement area 40. In the drawing, reference numeral 41 denotes a row (scan) of the temperature measurement area 40 when the n-th (n is an integer) scan is performed from the inside to the outside of the turntable 12 while the turntable 12 is rotating. Line). In the figure, reference numeral 42 denotes a scan line when scanning is performed n + 1 times (n is an integer). Due to the rotation of the turntable 12, the scan lines 41 and 42 are shifted from each other by an angle θ1 corresponding to the rotation speed of the turntable 12 about the rotation center P of the turntable 12. By repeating the scan while rotating the turntable 12 in this manner, temperature measurement values at many positions on the turntable 12 are sequentially acquired.

  Further, the heat treatment apparatus 1 is provided with a control unit 5 composed of a computer for controlling the operation of the entire apparatus. In the memory of the control unit 5, a program for performing a temperature measurement described later is stored. The program has a group of steps for executing various operations of the apparatus, and is installed in the control unit 5 from a storage medium such as a hard disk, a compact disk, a magneto-optical disk, a memory card, and a flexible disk.

(Temperature measurement method)
An example of a temperature measuring method in the heat treatment apparatus 1 of the present embodiment will be described.

  The temperature measuring method according to the present embodiment is a method for measuring a temperature in the above-described heat treatment apparatus. A mounting step of mounting, a rotating step of rotating a rotary table on which the plurality of low-resistance silicon wafers are mounted, and radiation from each surface of the plurality of low-resistance silicon wafers while the rotating table is rotating. Measuring the temperature of the low-resistance silicon wafer by detecting the infrared rays to be emitted.

  Hereinafter, each step will be described.

  The placing step is a step of placing a plurality of low-resistance silicon wafers having a resistivity at room temperature of 0.02 Ω · cm or less on the surface of the turntable 12.

  Specifically, first, the shutter 18 provided in the transfer port 17 is opened, and the low-resistance silicon wafer is transferred from the outside of the processing chamber 11 into the recess 16 of the turntable 12 via the transfer port 17 by the transfer mechanism 2A. . This delivery is performed by raising and lowering a lift pin (not shown) from the bottom side of the processing container 11 through the through hole in the bottom surface of the concave portion 16 when the concave portion 16 stops at a position facing the transfer port 17. The transfer of the low-resistance silicon wafer is performed by intermittently rotating the turntable 12, and the low-resistance silicon wafer is placed in each of the five recesses 16 of the turntable 12.

  The rotation step is a step of rotating the rotation table 12 on which a plurality of low-resistance silicon wafers are mounted.

Specifically, after the low-resistance silicon wafer is placed in each of the five recesses 16 of the rotary table 12, the shutter 18 is closed, and the inside of the processing chamber 11 is opened by a vacuum pump (not shown) connected to the exhaust port 26. Make a state of withdrawal. Then, ejecting N ₂ gas is separated gases from the separation gas nozzles 22, 24 at a predetermined flow rate, supplying the N ₂ gas at a predetermined flow rate in the center space 28 on the region of the rotary table 12. Accordingly, the pressure inside the processing chamber 11 is adjusted to a preset pressure (for example, the same pressure as when a heat treatment is performed on the wafer W) by a pressure adjusting unit (not shown) connected to the exhaust port 26. Next, the heater 20 heats the low-resistance silicon wafer to a predetermined temperature (for example, 760 ° C.) while rotating the turntable 12 clockwise.

  The measuring step is a step of measuring the temperature of the low-resistance silicon wafer by detecting infrared rays radiated from the surfaces of the plurality of low-resistance silicon wafers while the turntable 12 is rotating.

  Specifically, by rotating the rotating body 302 of the radiation temperature measuring unit 3 around the rotating shaft 306 while the rotating table 12 is rotating, the temperature measurement area on the rotating table 12 including the low-resistance silicon wafer is rotated. The infrared ray 40 is reflected by one of the reflecting surfaces 303 to 305 and guided to the detection unit 301, and the position of the temperature measurement area 40 is moved in the radial direction of the turntable 12 for scanning. At this time, the detection unit 301 continuously receives infrared light a predetermined number of times (for example, 128 times) from one reflection surface, thereby detecting a temperature at a predetermined position (for example, 128 positions) in the radial direction of the turntable 12. In this manner, by repeating the scan by the radiation temperature measuring unit 3 while rotating the rotary table 12, infrared rays emitted from each surface of the plurality of low-resistance silicon wafers placed on the rotary table 12 are detected, The temperatures of a plurality of low-resistance silicon wafers are sequentially measured.

  In the first embodiment, the radiation temperature measurement unit 3 moves the position of the temperature measurement region 40 in the radial direction of the turntable 12 and scans the temperature to measure the temperature. However, the embodiment is not limited to this. For example, the radiation temperature measurement unit 3 may measure the temperature at any one point in the radial direction of the rotary table 12 without moving the position of the temperature measurement area 40 in the radial direction of the rotary table 12. Further, as the radiation temperature measuring unit 3, a known infrared radiation thermometer or a thermal image measuring device (thermography) may be used.

[Second embodiment]
In the second embodiment, a description will be given of a temperature measuring method in a batch-type heat treatment apparatus in which one batch is constituted by a large number of wafers placed on a wafer boat and a film formation process is performed in a processing container in batches.

(Configuration of heat treatment device)
FIG. 7 is a schematic longitudinal sectional view of the heat treatment apparatus according to the second embodiment.

  As shown in FIG. 7, the heat treatment apparatus of the second embodiment has a substantially cylindrical processing container 104 whose longitudinal direction is a vertical direction. The processing container 104 has a double-pipe structure including a cylindrical inner cylinder 106 and an outer cylinder 108 having a ceiling concentrically arranged outside the inner cylinder 106. The inner tube 106 and the outer tube 108 are formed of a heat-resistant material such as quartz.

  The lower ends of the inner cylinder 106 and the outer cylinder 108 are held by a manifold 110 formed of stainless steel or the like. The manifold 110 is fixed to, for example, a base plate (not shown). Since the manifold 110 forms a substantially cylindrical internal space together with the inner cylinder 106 and the outer cylinder 108, it is assumed that the manifold 110 forms a part of the processing container 104. That is, the processing container 104 includes an inner cylinder 106 and an outer cylinder 108 formed of a heat-resistant material such as quartz, and a manifold 110 formed of stainless steel or the like. It is provided at the lower part of the side surface of the processing vessel 104 so as to hold 108 from below.

  The manifold 110 has, in the processing container 104, a gas introduction unit 120 that introduces various gases such as a processing gas such as a film forming gas and an additional gas used for a film forming process and a purge gas used for a purging process. FIG. 7 shows a mode in which one gas introduction unit 120 is provided. However, the present invention is not limited to this, and a plurality of gas introduction units 120 may be provided according to the type of gas used and the like.

The type of the processing gas is not particularly limited, and can be appropriately selected according to the type of the film to be formed. The type of the purge gas is not particularly limited, and for example, an inert gas such as a nitrogen (N ₂ ) gas can be used.

  An introduction pipe 122 for introducing various gases into the processing container 104 is connected to the gas introduction unit 120. The introduction pipe 122 is provided with a flow rate adjusting unit 124 such as a mass flow controller for adjusting a gas flow rate, a valve (not shown), and the like.

  Further, the manifold 110 has a gas exhaust unit 130 that exhausts the inside of the processing container 104. The gas exhaust unit 130 is connected to an exhaust pipe 136 including a vacuum pump 132 capable of controlling the pressure in the processing container 104 and a variable opening degree valve 134.

  At the lower end of the manifold 110, a furnace port 140 is formed. The furnace port 140 is provided with a disk-shaped lid 142 formed of, for example, stainless steel. The lid 142 is provided so as to be able to move up and down by, for example, an elevating mechanism 144 functioning as a boat elevator, and is configured to hermetically seal the furnace port 140.

  On the lid 142, a thermal insulation tube 146 made of, for example, quartz is installed. A wafer boat 148 made of, for example, quartz and holding, for example, about 50 to 175 wafers W at predetermined intervals in a horizontal state is placed on the heat retaining cylinder 146. The wafer boat 148 is configured to be rotatable via a heat retaining cylinder 146 by a rotating mechanism (not shown) provided on the lid 142.

  The wafer boat 148 is carried into the processing container 104 by raising the lid 142 using the lifting mechanism 144, and various film forming processes are performed on the wafers W held in the wafer boat 148. After the various film forming processes are performed, the lid 142 is lowered using the elevating mechanism 144, so that the wafer boat 148 is unloaded from the inside of the processing container 104 to the lower loading area. A large number of wafers W mounted on the wafer boat 148 constitute one batch, and various film forming processes are performed in batch units.

  On the outer peripheral side of the processing container 104, for example, a cylindrical heater 160 that can control heating of the processing container 104 to a predetermined temperature is provided. The heater 160 is divided into seven zones, and heaters 160a to 160g are provided from the upper side to the lower side in the vertical direction. The heaters 160a to 160g are configured such that the heat generation amounts can be independently controlled by the power controllers 162a to 162g, respectively. Further, on the inner wall of the inner cylinder 106 and / or the outer wall of the outer cylinder 108, temperature sensors (not shown) are provided corresponding to the heaters 160a to 160g. Although FIG. 7 shows a case where the heater 160 is divided into seven zones, the number of zones of the heater 160 is not limited to this, and may be, for example, six or less, and eight. It may be the above. Further, heater 160 may not be divided into a plurality of zones.

  Above the processing container 104, a radiation temperature measuring unit 3A, which is an example of a non-contact thermometer, is provided. The radiation temperature measuring unit 3A measures the temperature of the low-resistance silicon wafer by detecting infrared rays radiated from the low-resistance silicon wafer held in the wafer boat 148. The radiation temperature measurement unit 3A may have the same configuration as the radiation temperature measurement unit 3 described in the first embodiment, for example, or may be a known infrared radiation thermometer or thermography.

  The heat treatment apparatus is provided with a control unit 190 composed of a computer for controlling the operation of the entire apparatus. A program for performing temperature measurement is stored in the memory of the control unit 190. The program has a group of steps for executing various operations of the apparatus, and is installed in the control unit 190 from a storage medium such as a hard disk, a compact disk, a magneto-optical disk, a memory card, and a flexible disk.

  The control unit 190 may perform feedback control of the heater 160 based on the temperature of the low-resistance silicon wafer measured by the radiation temperature measurement unit 3A. If the difference between the temperature at the position where the low-resistance silicon wafer is provided and the temperature in the processing chamber 104 is large, the temperature of the low-resistance silicon wafer is corrected, and the heater 160 is turned on based on the corrected temperature. Feedback control may be performed.

(Temperature measurement method)
An example of a temperature measuring method in the heat treatment apparatus according to the second embodiment will be described.

  The temperature measuring method according to the second embodiment is the temperature measuring method in the heat treatment apparatus described above, and includes a placing step, a loading step, a rotating step, and a measuring step.

  Hereinafter, each step will be described.

  In the placing step, a low-resistance silicon wafer having a resistivity at room temperature (20 ° C.) of 0.02 Ω · cm or less is placed in the wafer boat 148. The position where the low-resistance silicon wafer is placed in the wafer boat 148 is preferably the uppermost position of the wafer boat 148 (position A1 in FIG. 7). Accordingly, even when the product wafer, the dummy wafer, and the like are held at other positions in the wafer boat 148, the radiation temperature measuring unit 3A can detect the infrared radiation radiated from the low-resistance silicon wafer. The position where the low-resistance silicon wafer is placed may be any other position as long as the radiation temperature measuring unit 3A can detect infrared rays emitted from the low-resistance silicon wafer.

  In the loading step, the wafer boat 148 on which the low-resistance silicon wafer is placed is loaded into the processing container 104.

  In the rotation step, the wafer boat 148 carried into the processing container 104 is rotated by the rotation mechanism, and the low-resistance silicon wafer is heated to a predetermined temperature by the heater 160.

  In the measurement step, while the wafer boat 148 is rotating, the temperature of the low-resistance silicon wafer is measured by detecting infrared rays radiated from the surface of the low-resistance silicon wafer by the radiation temperature measuring unit 3A.

[Third embodiment]
In the third embodiment, one batch is composed of a large number of wafers placed on a wafer boat, and the temperature in the processing vessel in a batch-type heat treatment apparatus that performs a film forming process in the processing vessel in batches is controlled. Another example of the temperature measurement method to be measured will be described.

  The heat treatment apparatus according to the third embodiment is different from the heat treatment apparatus according to the second embodiment in that a radiation temperature measuring unit is provided below a processing container. Other configurations can be the same as those of the heat treatment apparatus of the second embodiment.

  FIG. 8 is a schematic vertical sectional view showing an example of the heat treatment apparatus according to the third embodiment.

  As shown in FIG. 8, the radiation temperature measuring unit 3B is attached below the processing container 104, for example, on the upper surface of the elevating mechanism 144. The cover 142 has a slit 150 opened at a position corresponding to the position where the radiation temperature measuring unit 3B is provided, and a lower window 152 and an upper window 154 are provided so as to cover the upper and lower portions of the slit 150. ing. The lower window 152 and the upper window 154 are made of, for example, sapphire so that infrared radiation emitted from the surface of the low-resistance silicon wafer can be transmitted and the temperature can be measured by the radiation temperature measuring unit 3B.

  When the radiation temperature measuring unit 3B is provided below the processing container 104 as in the present embodiment, the position where the low-resistance silicon wafer is placed is the lowest position of the wafer boat 148 (position A2 in FIG. 8). It is preferable that Thus, even when the product wafer, the dummy wafer, and the like are held at other positions in the wafer boat 148, the infrared radiation emitted from the low-resistance silicon wafer can be detected by the radiation temperature measuring unit 3B. The position where the low-resistance silicon wafer is placed may be any other position as long as the radiation temperature measuring unit 3B can detect infrared rays emitted from the low-resistance silicon wafer.

  FIG. 9 is a schematic longitudinal sectional view showing another example of the heat treatment apparatus according to the third embodiment.

  As shown in FIG. 9, the radiation temperature measuring unit 3 </ b> C is attached below the processing container 104, for example, on the upper surface of the elevating mechanism 144. Above the radiation temperature measuring unit 3C, there is provided a tubular member 156 that is inserted into the processing vessel 104 from below the lid 142 through the lid 142, and the tip of which is disposed on the outer peripheral side of the wafer boat 148. Is provided. The tubular member 156 functions as a transmission path for transmitting infrared light.

  When the radiation temperature measuring unit 3C is provided below the processing container 104 and the tubular member 156 is provided as in the present embodiment, the position where the low-resistance silicon wafer is placed is at the tip end inside the tubular member 156. (Position A3 in FIG. 9). At this time, the low-resistance silicon wafer is processed into a size that can be accommodated inside the tubular member 156, and is attached to a tip end inside the tubular member 156. Note that a plurality of tubular members 156 may be provided, and a plurality of radiation temperature measuring units 3C may be provided for each of the plurality of tubular members 156. In this case, it is preferable that the position of the distal end of the tubular member 156 be provided so as to be different in the vertical direction. Thereby, the temperature at different positions in the vertical direction can be measured.

[Fourth embodiment]
In the fourth embodiment, one batch is composed of a large number of wafers placed on a wafer boat, and the temperature in the processing vessel in a batch-type heat treatment apparatus that performs a film forming process in the processing vessel in batches is controlled. Another example of the temperature measurement method to be measured will be described.

  The heat treatment apparatus according to the fourth embodiment is different from the heat treatment apparatus according to the second embodiment in that a radiation temperature measuring unit is provided on a side of a processing container. Other configurations can be the same as those of the heat treatment apparatus of the second embodiment.

  FIG. 10 is a schematic longitudinal sectional view of the heat treatment apparatus according to the fourth embodiment.

  As shown in FIG. 10, the radiation temperature measuring unit 3D is provided on the side of the processing container 104. Specifically, a plurality of radiation temperature measuring units 3D-a to 3D-g are inserted from outside of the heaters 160a to 160g toward the processing container 104 so as to penetrate the heaters 160a to 160g, respectively. A temperature detection unit) is arranged near the outer wall of the outer cylinder 108. Note that the number of the radiation temperature measuring unit 3D may be one.

  When the distal end of the radiation temperature measurement unit 3D is arranged near the outer wall of the outer cylinder 108 as in the present embodiment, the position where the low-resistance silicon wafer is mounted is determined by the radiation temperature measurement unit 3D on the outer wall of the outer cylinder 108. Is preferably a position corresponding to the position provided with. That is, as shown in FIG. 10, the low-resistance silicon wafer is preferably attached to positions A4-a to A4-g corresponding to the positions where the radiation temperature measuring units 3D-a to 3D-g are provided. Thereby, the temperature at different positions in the vertical direction can be measured. The method of attaching the low-resistance silicon wafer to the outer wall of the outer cylinder 108 is not particularly limited. For example, the low-resistance silicon wafer can be attached to the outer wall of the outer cylinder 108 while being held by the holder. The position where the low-resistance silicon wafer is placed may be a position corresponding to the position where the radiation temperature measuring unit 3D is provided in the wafer boat 148.

[Fifth Embodiment]
In the fifth embodiment, one batch is composed of a large number of wafers placed on a wafer boat, and the temperature in the processing vessel in a batch-type heat treatment apparatus that performs a film forming process in the processing vessel in batches is controlled. Another example of the temperature measurement method to be measured will be described.

  The heat treatment apparatus according to the fifth embodiment is different from the heat treatment apparatus according to the second embodiment in that the distal end (temperature detection section) of the radiation temperature measurement section is provided inside the processing container. Other configurations can be the same as those of the heat treatment apparatus of the second embodiment.

  FIG. 11 is a schematic longitudinal sectional view of the heat treatment apparatus according to the fifth embodiment.

  As shown in FIG. 11, the radiation temperature measuring unit 3 </ b> E has a distal end provided inside the processing container 104. More specifically, the radiation temperature measuring unit 3E is inserted into the processing container 104 from below the lid 142 through the lid 142, and the distal end thereof is arranged near the lowermost position of the wafer boat 148. Optical fiber portion 3E1. The radiation temperature measuring unit 3E is configured to be able to detect infrared light incident from the tip of the optical fiber unit 3E1.

  When the tip of the radiation temperature measuring unit 3E is located near the lowermost position of the wafer boat 148 as in the present embodiment, the position where the low-resistance silicon wafer is placed is at the lowermost position of the wafer boat 148. It is preferably at the position (position A5 in FIG. 10).

  Hereinafter, the present invention will be described in detail with reference to examples, but the present invention should not be construed as being limited to these examples.

[Example 1]
In Example 1, the temperature was measured by the above-described temperature measuring method of the first embodiment. In this embodiment, the rotary table 12 in which six concave portions 16 (Slot1, Slot2, Slot3, Slot4, Slot5, and Slot6) are formed along the rotation direction of the rotary table 12 is used.

  First, a low-resistance silicon wafer was placed on each of the six concave portions 16 of the turntable 12. In this embodiment, six P-type silicon wafers to which B (boron) is added as an impurity and whose resistivity at room temperature is less than 0.02 Ω · cm are used as low-resistance silicon wafers. In addition, six silicon wafers manufactured from different ingots were used.

  Next, the low-resistance silicon wafer was heated by the heater 20 while rotating the rotary table 12 on which the plurality of low-resistance silicon wafers were mounted. In this embodiment, the turntable 12 is rotated clockwise at a rotation speed of 20 rpm, and the set temperature of the heater 20 is set to 760 ° C. to heat the low-resistance silicon wafer.

  Next, while the temperature in the processing chamber 11 was stable, infrared rays emitted from the respective surfaces of the six low-resistance silicon wafers were detected to measure the temperatures of the six low-resistance silicon wafers.

  FIG. 12 is a graph illustrating the relationship between the radial position of the rotary table and the temperature in the first embodiment. In the graph of FIG. 12, the horizontal axis is the distance (mm) from the rotation center P of the turntable 12, and the vertical axis is the temperature (° C.). The range where the low-resistance silicon wafer is placed (wafer range) is a range where the distance from the rotation center P of the turntable 12 is 160 mm or more and 460 mm or less.

  Specifically, FIG. 12 shows a temperature distribution of six low-resistance silicon wafers in the radial direction of the rotary table 12 when a low-resistance silicon wafer is placed in each of the six concave portions 16 of the rotary table 12. ing. In the drawing, solid lines, dotted lines, dashed lines, dashed lines, long dashed lines, and two-dot dashed lines indicate the rotation of the rotation table 12 for the low-resistance silicon wafer placed on Slot1, Slot2, Slot3, Slot4, Slot5, and Slot6, respectively. The relationship between the distance from the center P and the temperature is shown.

  As shown in FIG. 12, the six low-resistance silicon wafers have almost the same temperature at any position in the radial direction of the turntable 12, and have the largest temperature difference (position of about 420 mm in the figure). However, the temperature difference was 1.2 ° C.

[Example 2]
In Example 2, the temperature was measured by the same temperature measurement method as in Example 1 except that the low-resistance silicon wafer was heated at a set temperature of the heater 20 of 620 ° C.

  FIG. 13 is a graph showing the relationship between the radial position of the rotary table and the temperature in the second embodiment. In the graph of FIG. 13, the horizontal axis is the distance (mm) from the rotation center P of the turntable 12, and the vertical axis is the temperature (° C.). The range where the low-resistance silicon wafer is placed is a range where the distance from the rotation center P of the turntable 12 is 160 mm or more and 460 mm or less.

  Specifically, FIG. 13 shows a temperature distribution of six low-resistance silicon wafers in the radial direction of the rotary table 12 when a low-resistance silicon wafer is placed in each of the six concave portions 16 of the rotary table 12. ing. In the drawing, solid lines, dotted lines, dashed lines, dashed lines, long dashed lines, and two-dot dashed lines indicate the rotation of the rotation table 12 for the low-resistance silicon wafer placed on Slot1, Slot2, Slot3, Slot4, Slot5, and Slot6, respectively. The relationship between the distance from the center P and the temperature is shown.

  As shown in FIG. 13, the six low-resistance silicon wafers have almost the same temperature at any position in the radial direction of the turntable 12, and even at the position where the temperature difference is the largest (at a position of 420 mm in the figure). The temperature difference was 0.9 ° C.

[Example 3]
In Example 3, the temperature was measured by the same temperature measuring method as in Example 1 except that the low-resistance silicon wafer was heated at a set temperature of the heater 20 of 155 ° C.

  FIG. 14 is a graph showing the relationship between the radial position of the rotary table and the temperature in the third embodiment. In the graph of FIG. 14, the horizontal axis is the distance (mm) from the rotation center P of the turntable 12, and the vertical axis is the temperature (° C.). The range where the low-resistance silicon wafer is placed is a range where the distance from the rotation center P of the turntable 12 is 160 mm or more and 460 mm or less.

  Specifically, FIG. 14 shows the temperature distribution of six low-resistance silicon wafers in the radial direction of the rotary table 12 when a low-resistance silicon wafer is placed in each of the six concave portions 16 of the rotary table 12. ing. In the drawing, solid lines, dotted lines, dashed lines, dashed lines, long dashed lines, and two-dot dashed lines indicate the rotation of the rotation table 12 for the low-resistance silicon wafer placed on Slot1, Slot2, Slot3, Slot4, Slot5, and Slot6, respectively. The relationship between the distance from the center P and the temperature is shown.

  As shown in FIG. 14, the six low-resistance silicon wafers have almost the same temperature at any position in the radial direction of the turntable 12, and have the largest temperature difference (position of about 340 mm in the figure). However, the temperature difference was 0.5 ° C.

[Example 4]
Example 4 Example 4 was repeated except that Sb (antimony) was added as an impurity and six N-type silicon wafers having a resistivity at room temperature of 0.02 Ω · cm were used as the low-resistance silicon wafer. The temperature was measured by the same temperature measurement method as in Example 3. Note that six silicon wafers manufactured from different ingots were used.

  FIG. 15 is a graph showing the relationship between the radial position of the rotary table and the temperature in the fourth embodiment. In the graph of FIG. 14, the horizontal axis is the distance (mm) from the rotation center P of the turntable 12, and the vertical axis is the temperature (° C.). The range where the low-resistance silicon wafer is placed is a range where the distance from the rotation center P of the turntable 12 is 160 mm or more and 460 mm or less.

  Specifically, FIG. 15 shows a temperature distribution of six low-resistance silicon wafers in the radial direction of the rotary table 12 when a low-resistance silicon wafer is placed in each of the six concave portions 16 of the rotary table 12. ing. In the drawing, solid lines, dotted lines, dashed lines, dashed lines, long dashed lines, and two-dot dashed lines indicate the rotation of the rotation table 12 for the low-resistance silicon wafer placed on Slot1, Slot2, Slot3, Slot4, Slot5, and Slot6, respectively. The relationship between the distance from the center P and the temperature is shown.

  As shown in FIG. 15, the six low-resistance silicon wafers have almost the same temperature at any position in the radial direction of the turntable 12, and have the largest temperature difference (position of about 440 mm in the figure). However, the temperature difference was 0.7 ° C.

  In addition, as shown in FIG. 15, at a position (in the drawing) where the distance from the rotation center P of the turntable 12 is 370 mm, a temperature fluctuation not seen in FIG. 14 was confirmed. This is because a low-resistance silicon wafer to which Sb is added as an impurity slightly transmits infrared rays at a low temperature, so that infrared rays radiated from elevating pins, heaters 20 and the like disposed below the low-resistance silicon wafer are slightly low. It is considered that the light is transmitted through the resistance silicon wafer and enters the radiation temperature measuring unit 3.

[Comparative Example 1]
In Comparative Example 1, the temperature was measured by the same temperature measuring method as in Example 2 except that a SiC wafer was used instead of the low-resistance silicon wafer. Note that six SiC wafers manufactured from different ingots were used.

  FIG. 16 is a graph showing the relationship between the radial position of the rotary table and the temperature in Comparative Example 1. In the graph of FIG. 16, the horizontal axis is the distance (mm) from the rotation center P of the turntable 12, and the vertical axis is the temperature (° C.). The range where the SiC wafer is placed is a range where the distance from the rotation center P of the turntable 12 is 160 mm or more and 460 mm or less.

  Specifically, FIG. 16 shows the temperature distribution of six SiC wafers in the radial direction of the rotary table 12 when the SiC wafer is placed in each of the six concave portions 16 of the rotary table 12. In the drawing, the solid line, the dotted line, the dashed line, the one-dot chain line, the long dashed line, and the two-dot chain line indicate the rotation center P of the rotary table 12 of the SiC wafer placed on Slot1, Slot2, Slot3, Slot4, Slot5, and Slot6, respectively. It shows the relationship between the distance from and the temperature.

  As shown in FIG. 16, at almost all positions in the radial direction of the turntable 12, the temperature difference measured by the six SiC wafers is large, and at a position where the distance from the rotation center P of the turntable 12 is 420 mm, The temperature difference was 12 ° C. This temperature difference was a value that was at least 10 times greater than 0.9 ° C. in Example 2.

[Comparative Example 2]
In Comparative Example 2, the temperature was measured by the same temperature measurement method as in Example 3 except that a high-resistance silicon wafer was used instead of the low-resistance silicon wafer. As the high-resistance silicon wafer, six P-type silicon wafers to which B was added and whose resistivity at room temperature was 1 Ω · cm to 50 Ω · cm were used. Note that six silicon wafers manufactured from different ingots were used.

  FIG. 17 is a graph showing the relationship between the radial position of the rotary table and the temperature in Comparative Example 2. In the graph of FIG. 17, the horizontal axis is the distance (mm) from the rotation center P of the turntable 12, and the vertical axis is the temperature (° C.). The range where the high-resistance silicon wafer is placed is a range where the distance from the rotation center P of the turntable 12 is 160 mm or more and 460 mm or less.

  Specifically, FIG. 17 shows a temperature distribution of six high-resistance silicon wafers in the radial direction of the rotary table 12 when a high-resistance silicon wafer is placed in each of the six concave portions 16 of the rotary table 12. ing. In the drawing, solid lines, dotted lines, broken lines, dashed lines, long dashed lines, and two-dot dashed lines indicate the rotation of the high-resistance silicon wafer rotating table 12 placed on Slot1, Slot2, Slot3, Slot4, Slot5, and Slot6, respectively. The relationship between the distance from the center P and the temperature is shown.

  As shown in FIG. 17, when a high-resistance silicon wafer is used, the measured temperature is lower than the set temperature of the heater 20 (155 ° C.) at almost all positions in the radial direction of the turntable 12. It was confirmed that it became. It is considered that this is because the high-resistance silicon wafer does not emit infrared rays at a low temperature, and hence the amount of infrared rays emitted from the high-resistance silicon wafer and incident on the radiation temperature measuring unit 3 is small. In addition, as shown in FIG. 17, it was confirmed that the measured temperature greatly differs depending on the distance from the rotation center P of the turntable 12. This is because high-resistance silicon wafers transmit infrared rays at low temperatures, so that infrared rays radiated from elevating pins, heaters 20 and the like arranged below the high-resistance silicon wafers pass through the high-resistance silicon wafer to measure radiation temperature. It is considered that the light enters the part 3.

  According to the results of Example 2 and Comparative Example 1 and the results of Example 3, Example 4 and Comparative Example 2 described above, a low-resistance silicon wafer having a sufficiently low resistivity can be used to manufacture from a different ingot. It was confirmed that even when a wafer was used, the variation in the temperature measured by each of the plurality of wafers could be suppressed. That is, even when wafers having different manufacturing histories are used, the temperature of the wafer can be measured with high accuracy.

  Further, from the results of Examples 1 to 3, it was confirmed that in a temperature range from a low temperature (for example, 155 ° C.) to a high temperature (for example, 760 ° C.), it is possible to suppress a variation in the temperature measured for each of the plurality of wafers. did it. That is, the temperature of the wafer can be measured with high accuracy in a temperature range from a low temperature to a high temperature.

  As described above, according to the temperature measuring method and the heat treatment apparatus of the present embodiment, even when wafers having different manufacturing histories are used, the temperature of the wafer can be measured with high accuracy.

  In each of the above embodiments, the wafer is an example of a substrate, and the wafer boat is an example of a substrate holder.

  As described above, the temperature measuring method and the heat treatment apparatus have been described with the embodiments. However, the present invention is not limited to the above embodiments, and various modifications and improvements can be made within the scope of the present invention.

  In each of the above embodiments, a P-type silicon wafer doped with B as an impurity and an N-type silicon wafer doped with Sb as an impurity have been described as low-resistance silicon wafers, but the present invention is not limited to this. . The low-resistance silicon wafer may be any silicon wafer to which a trivalent element or a pentavalent element is added as an impurity. As the trivalent element, for example, Al (aluminum) can be used, and as the pentavalent element, for example, P (phosphorus) or As (arsenic) can be used.

  In the second to fifth embodiments, the case where the position where the radiation temperature measurement unit is provided is different has been described. However, the present invention is not limited to the configurations of the second to fifth embodiments. The radiation temperature measuring units of these embodiments may be combined.

DESCRIPTION OF SYMBOLS 1 Heat treatment apparatus 3 Radiation temperature measurement part 5 Control part 11 Processing container 12 Rotary table W Wafer

Claims (4)

A temperature measurement method in a heat treatment apparatus that performs heat treatment on a plurality of substrates while rotating the rotation table by mounting a plurality of substrates on a surface of a rotation table provided in a processing container,
A mounting step of mounting a plurality of low-resistance silicon wafers having different manufacturing histories whose resistivity at room temperature (20 ° C.) is 0.02 Ω · cm or less on the surface of the rotary table;
A rotation step of rotating the rotation table on which the plurality of low-resistance silicon wafers are mounted,
Wherein in a state where the rotary table is rotating, saw including a measurement step of measuring the temperature of the low-resistance silicon wafer by detecting infrared radiation emitted from the surface of each of the plurality of low-resistivity silicon wafer,
The resistivity of the plurality of low-resistance silicon wafers is the same,
Temperature measurement method. The measuring step measures temperatures in a plurality of regions in a direction along a radial direction of the rotary table,
The method for measuring temperature according to claim 1. The low-resistance silicon wafer is a silicon wafer to which a trivalent element or a pentavalent element is added as an impurity,
The temperature measurement method according to claim 1. The measuring step measures the temperature of the low-resistance silicon wafer in a state where the temperature of the low-resistance silicon wafer is heated by a heater,
The temperature measuring method according to claim 1.

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