JP4563728B2 - Heat flux measurement board - Google Patents

Description

  The present invention relates to a technique for measuring a thermal environment in a process chamber used in a semiconductor heat treatment process.

  For example, in a semiconductor process, a substrate to be processed (for example, a semiconductor wafer) is generally processed in a heat treatment container called a process chamber. In the process chamber (hereinafter referred to as “chamber”), for example, a plate-shaped temperature control device (hereinafter referred to as “temperature control plate”) for adjusting the temperature of the substrate to be processed is provided. The substrate to be processed is placed on the temperature adjustment plate at a certain distance (for example, 50 μm). In this case, the back surface of the substrate to be processed is a heat input surface that receives heat generated from the temperature control plate, and the surface thereof is a heat dissipation surface that generates heat.

  The temperature of the substrate to be processed can be represented by the sum of the heat input flow rate from the back surface and the heat radiation flow rate from the front surface (in other words, the surface heat flux). The temperature distribution of the substrate to be processed is determined by the balance between the heat input flow rate and the surface heat flux.

  Usually, in a semiconductor process, it is required to make the temperature distribution of a substrate to be processed uniform for reasons such as improving product yield. Further, since the temperature control plate and the substrate to be processed are separated from each other, the temperature of the substrate to be processed is delayed.

  For example, Patent Document 1 (Japanese Patent No. 2998460) discloses a temperature measurement substrate on which a plurality of temperature sensors are mounted. By placing such a temperature measurement substrate on the temperature adjustment plate and measuring the substrate temperature based on the control state of the temperature adjustment plate in advance, based on the measurement result, in the actual process, It is possible to control the temperature adjustment plate so that the temperature distribution is uniform.

  Further, for example, in Patent Document 2 (Japanese Patent No. 2759116), a temperature sensor is attached to the temperature adjustment plate, and a heat flux sensor is attached to a place away from the substrate to be processed. It is disclosed that a delay in temperature of the substrate to be processed is avoided by simulating the heat input to the substrate to be processed.

Japanese Patent No. 2998460 Japanese Patent No. 2759116

  By the way, normally, the back surface of the substrate to be processed is a heat input surface that receives heat from the temperature control plate, and the surface thereof is a heat dissipation surface that generates heat.

  The temperature per unit area on the surface of the substrate to be processed can be represented by the sum of the heat input flow rate to the unit area and the heat dissipation from the unit area (in other words, the surface heat flux). it can. The temperature distribution of the substrate to be processed is determined by the balance between the heat input flow rate and the surface heat flux.

  However, in the substrate to be processed, the balance between the heat input flow rate and the surface heat flux may differ depending on the location. Further, in the substrate to be processed, the surface heat flux of the substrate to be processed may become non-uniform due to, for example, at least one of the following reasons (1) to (4).

  (1) A purge gas for discharging a gas (hereinafter referred to as a resist gas) generated from a resist applied to the surface of the substrate to be processed may flow into the chamber. Therefore, the gas flow on the surface of the substrate to be processed becomes non-uniform, and therefore the surface heat flux of the substrate to be processed becomes non-uniform.

  (2) When a plurality of chambers are used in a semiconductor process, the plurality of chambers may be mounted at different positions in a rack prepared in advance, and in a certain direction (for example, downward direction) outside the rack ) May be generated. In this case, the surface heat flux of the substrate to be processed becomes non-uniform due to the place where the chamber is mounted, the airflow outside the rack, and the thermal interference between the chambers.

  (3) A lid of a temperature adjustment plate may be provided above the surface of the substrate to be processed in the chamber. The temperature of the lid affects the surface heat flux of the substrate to be processed. The temperature distribution of the substrate to be processed may vary due to the temperature from the lid, and thereby the surface heat flux of the substrate to be processed becomes non-uniform.

  (4) The surface heat flux of the substrate to be processed becomes non-uniform due to an abnormality in the flow rate of the purge gas.

  In addition, the heat input flow rate of the substrate to be processed may be uneven. This is due to, for example, at least one of the following (A) to (B).

  (A) When the temperature sensor in the temperature adjustment plate changes (eg, deteriorates) over time, the temperature adjustment plate is controlled based on the temperature detected by the temperature sensor, so the heat input flow rate to the substrate to be processed Will change.

  (B) When the gap distance between the substrate to be processed and the temperature adjustment plate differs depending on the location due to dust adhering to a certain location on the surface of the temperature adjustment plate (for example, the substrate to be processed is The heat input flow rate to the substrate to be processed changes.

  For example, according to the technique disclosed in Patent Document 1, if the temperature distribution of the temperature measurement substrate becomes non-uniform, it will be detected. However, in order to determine whether the cause of the uneven temperature distribution is due to variations in the surface heat flux or the heat input flow rate, not only the temperature but also at least one of the surface heat flux and the heat input flow rate is determined. It is considered necessary to provide a new measurement substrate that can be measured. Because, as described above, the temperature of the substrate to be processed can be schematically represented by the sum of the heat input flow rate to the substrate to be processed and the surface heat flux. This is because if at least one of the heat input flow rates is known, the other is also known.

  However, neither of the techniques disclosed in Patent Documents 1 and 2 can measure at least one of the surface heat flux and the heat input flow rate on the substrate. This is because the technique disclosed in Patent Document 1 can measure only the substrate temperature. Further, in the technique of Patent Document 2, since there is a heat flux sensor at a location away from the substrate to be processed, it is not possible to measure the heat flux on the substrate surface. This is because it is difficult to make the in-plane distribution of the substrate uniform. Therefore, conventionally, when the temperature distribution on the surface of the temperature measurement substrate varies, for example, first, the substrate surface is cleaned by suspecting that dust has adhered to the surface of the temperature measurement substrate, and the temperature distribution still varies. In some cases, it may then be necessary to repeat the process of suspecting a possible cause and resolving it, such as suspecting another cause.

  As a method for measuring the surface heat flux of the substrate, it is conceivable to mount a conventionally known heat flux sensor on a temperature measurement substrate as disclosed in Patent Document 2.

  However, it is assumed that the conventional heat flux sensor itself is used alone, and is unsuitable for mounting on a temperature measurement board in terms of size, heat capacity, etc. (for example, conventional heat flux sensor) The size of the bundle sensor is on the order of centimeters). If such a heat flux sensor is mounted on a temperature measurement board, for example, when strict temperature control with an error of 0.1 degrees or less is required, it cannot be realized. This is because the in-plane temperature distribution of the temperature measurement substrate changes more than the required error due to the influence of the heat flux sensor.

  Accordingly, it is an object of the present invention to be able to measure the surface heat flux of a substrate in addition to the temperature of the substrate.

  Other objects of the present invention will become clear from the following description.

  In the description of this column, the reference numerals in parentheses exemplify the correspondence with the elements described in the accompanying drawings, but this is merely an example for explanation and the technical scope of the present invention. It is not intended to limit.

  The heat flux measurement substrate according to the present invention is a semiconductor substrate (5) and includes a heat flux sensor (11) for measuring the heat flux from the surface of the substrate (5). The heat flux sensor (11) includes a first temperature sensor (11A) and a second temperature sensor (11B). Note that the temperature measured by the first temperature sensor (11A) can be used as it is as the temperature of the heat flux measurement substrate (5).

  In the first embodiment of the present invention, the first temperature sensor (11A) is provided at a position shifted in the surface direction of the heat flux measurement substrate (5) with respect to the second temperature sensor (11B).

  In the second embodiment of the present invention, a plurality of the heat flux sensors (11) are provided at different positions on the heat flux measurement substrate (5).

  In the third embodiment of the present invention, the first temperature sensor (11A) and the second temperature sensor (11B) are provided in the same place, and moreover than the second temperature sensor (11B). The first temperature sensor (11A) is also provided below.

  In the fourth embodiment of the present invention, the first temperature sensor (11A) has a first area (S1) of the heat dissipation surface, and the second temperature sensor (11B) has a second area ( S2), and the value (K1) of the first thermal resistance (91A) between the first temperature sensor (11A) and the heat flux measurement board is divided by the first area (S1). The value obtained by dividing the value (K2) of the second thermal resistance (91B) between the second temperature sensor (11B) and the heat flux measurement substrate by the second area (S2) is larger. .

  In the fifth embodiment of the present invention, the distance between the first temperature sensor (11A) and the second temperature sensor (11B) is within 1 cm.

  In the sixth embodiment of the present invention, at least one of the first temperature sensor (11A) and the second temperature sensor (11B) is provided so as not to protrude from the surface of the heat flux measurement substrate (5).

  In the seventh embodiment of the present invention, the second temperature sensor (11B) has a second thermal resistance value (K2) that is larger than the thermal resistance value of the heat flux measurement substrate (5). (91B) is provided on the heat flux measurement substrate (5).

  In the eighth embodiment of the present invention, the first temperature sensor (11A) and the second temperature sensor (11B) are provided in the same place, and moreover than the second temperature sensor (11B). The first temperature sensor (11A) is also provided below. A first thermal resistance (91A) having a first thermal resistance value (K1) is interposed between the first temperature sensor (11A) and the heat flux measurement substrate (5), and the first temperature sensor A second thermal resistance (91B) having a second thermal resistance value (K2) larger than the first thermal resistance value (K1) is between the (11A) and the second temperature sensor (11B). Intervene.

  According to this invention, the measurement board | substrate (5) which can measure a surface heat flux is provided.

  According to the first embodiment of the present invention, the first temperature sensor (11A) is provided at a position shifted in the surface direction of the heat flux measurement substrate (5) with respect to the second temperature sensor (11B). The heat flux can be measured based on the temperatures at different positions in the surface direction of the heat flux measurement substrate (5). Further, the temperature measured by the first temperature sensor (11A) can be set as the temperature of the heat flux measurement substrate (5) as it is.

  According to the second embodiment of the present invention, since a plurality of heat flux sensors (11) are provided, the distribution of heat flux on the heat flux measurement substrate (5) can be examined.

  According to the third embodiment of the present invention, since the first temperature sensor (11A) and the second temperature sensor (11B) are provided in the same place, the area of the heat flux sensor (11) is suppressed. Can do.

  According to the fourth embodiment of the present invention, the value (K1) of the first thermal resistance (91A) between the first temperature sensor (11A) and the heat flux measurement substrate is divided by the first area (S1). The value obtained by dividing the value (K2) of the second thermal resistance (91B) between the second temperature sensor (11B) and the heat flux measurement board by the second area (S2) is larger than the value. Therefore, even if the first temperature sensor (11A) and the second temperature sensor (11B) are in the same vicinity, the detected temperatures can be made different.

  According to the fifth embodiment of the present invention, the first temperature sensor (11A) exists because the distance between the first temperature sensor (11A) and the second temperature sensor (11B) is as short as 1 cm or less. The first temperature detected by the first temperature sensor (11A) assuming that the surface heat flux at the location where the second temperature sensor (11B) is present is substantially the same as the value of the surface heat flux at the location where the second temperature sensor (11B) is present. The surface heat flux can be obtained based on the second temperature detected by the second temperature sensor (11B).

  According to the sixth embodiment of the present invention, at least one of the first temperature sensor (11A) and the second temperature sensor (11B) does not protrude from the surface of the heat flux measurement substrate (5). This can contribute to preventing the substrate temperature distribution from varying.

  According to the seventh embodiment of the present invention, the temperature detected by the second temperature sensor (11B) can be made lower than the actual substrate temperature.

  According to the eighth embodiment of the present invention, the area of the heat flux sensor (11) can be reduced as in the third embodiment, and the first temperature sensor as in the fourth embodiment. The temperature detected by (11A) and the second temperature sensor (11B) can be made different.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an overall configuration diagram of an embodiment of the present invention.

  A process space 8 is provided in the chamber 1. In the process space 8, a plate-like temperature control device (hereinafter referred to as a temperature control plate) 7 is provided. In the semiconductor process, the substrate to be processed (not shown) is processed in the process space 8 while the temperature is adjusted by the temperature adjustment plate 7.

  The temperature control plate 7 has a front surface and a back surface. A plurality of (for example, three) support pins 9 for mounting a substrate 5 such as a substrate to be processed and a measurement substrate described later are mounted on the surface of the temperature adjustment plate 7. The substrate 5 placed on the temperature adjustment plate 7 is supported by the plurality of support pins 9. That is, the substrate 5 is placed on the temperature control plate 7 with a certain distance from the surface thereof (in other words, the height of the support pins 9). The distance is, for example, several tens to several hundreds μm (for example, about 50 to 100 μm).

  Various types of temperature control plate 7 can be employed. For example, the temperature control plate 7 has a cavity inside thereof, and a heat medium (for example, gas or liquid) whose temperature is controlled passes through the cavity, thereby heating the substrate 5 through the surface. Alternatively, cooling may be performed. Further, for example, the temperature adjustment plate 7 is attached to the surface thereof with a foil heater (heated wire heater with a foil-like pattern wiring), and by controlling the amount of current flowing through the foil heater, Heating may be performed. Further, for example, the temperature control plate 7 is a heat exchange plate that has P-type semiconductor elements and N-type semiconductor elements arranged in series and two-dimensionally and heats or absorbs heat from the substrate 5 by the Peltier effect. There may be. Further, for example, the temperature adjustment plate 7 may include a plurality of temperature adjustment regions independent of each other, thereby adjusting the temperature of the substrate 5 for each region.

  The process space 8 is formed by being partitioned from another space in the chamber 1 by a lid 3 that covers the sky of the temperature control plate 7 on which the substrate 5 is placed. Note that the temperature of the lid 3 has a radiation effect on the substrate 5, thereby affecting the heat flux on the surface of the substrate 5.

  Further, the process space 8 is provided with a gas inlet 72 and a gas outlet 74. At least one of the gas inlet 72 and the gas outlet 74 may be configured to be openable and closable by, for example, a temperature controller described later. Gas of a predetermined component (for example, purge gas) enters from the gas inlet 72 and gas (for example, purge gas) in the process space 8 flows out of the gas outlet 74, so that a gas flow (in other words, on the surface of the substrate 5). Wind), thereby changing the surface heat flux of the substrate 5.

  The substrate 5 has a front surface and a back surface. The back surface of the substrate 5 serves as a heat input surface that receives heat from the temperature control plate 7, and the surface of the substrate 5 serves as a heat dissipation surface from the substrate 5. The temperature of each unit area on the surface of the substrate 5 can be schematically represented by the sum of the heat input flow rate to the unit area and the heat flux in the unit area (that is, the heat flow flowing out from the unit area). it can.

  In the present embodiment, as one type of the substrate 5, the measurement substrate 5 configured to be able to measure the heat flux at each predetermined position on the substrate surface is used. Hereinafter, the measurement substrate 5 will be described in detail.

  FIG. 2A shows a top view of the measurement substrate 5 according to this embodiment. FIG. 2B shows a BB cut surface of the measurement substrate 5 shown in FIG. 2A and 2B, illustration of a connection configuration (for example, a wiring pattern) between each temperature sensor 11A and 11B described later and a temperature adjustment controller 49 described later is substantially omitted. .

  The measurement substrate 5 is a substrate made of one or more kinds of predetermined materials, for example, a semiconductor wafer. A plurality of heat flux sensors 11 are arranged on the measurement substrate 5. The plurality of heat flux sensors 11 are, for example, densely arranged over substantially the entire area of the measurement substrate 5, for example. The distance between each heat flux sensor 11 and the nearest heat flux sensor 11 is, for example, 50 mm (millimeters), in other words, the plurality of heat flux sensors 11 are arranged in a 50 mm bitch. Each heat flux sensor 11 may be placed on the surface of the measurement substrate 5 or embedded in the measurement substrate 5.

  Each heat flux sensor 11 includes a plurality of temperature sensors, for example, a first temperature sensor 11A and a second temperature sensor 11B. The second temperature sensor 11B is provided in the vicinity of the first temperature sensor 11A. In addition, between the second temperature sensor 11B and the measurement substrate 5, a first thermal resistance (not shown) existing between the first temperature sensor 11A and the measurement substrate 5 is larger than the value K1. A second thermal resistance 91B having two thermal resistance values K2 is interposed. The second thermal resistance 91 </ b> B is, for example, the low thermal conductive material 13 having a second thermal conductivity smaller than the first thermal conductivity between the first temperature sensor 11 </ b> A and the measurement substrate 5. The low thermal conductive material 13 is, for example, a material smaller than the thermal conductivity of the measurement substrate 5, for example, polyimide, ceramics, silicon dioxide, air, or a combination thereof. More specifically, for example, a second sensor hole (or groove) 15 for embedding the second temperature sensor 11 </ b> B is formed on the surface of the measurement substrate 5, and low thermal conductivity is formed at the bottom of the second sensor hole 15. The material 13 is laid, and the second temperature sensor 11B is mounted on the low thermal conductive material 13, and the second temperature sensor 11B is joined to the measurement substrate 5 via the low thermal conductive material 13.

With the above configuration, for example, even if the temperature of the measurement substrate 5 region including a certain heat flux sensor 11 is the same, the certain heat flux sensor 11 is detected and output by the first temperature sensor 11A. The first temperature T1 (for example, “° C.” or “K (Kelvin)”) is different from the second temperature T2 detected and output by the second temperature sensor 11B. Each heat flux value Q detected by each heat flux sensor 11 includes a first temperature T1 and a second temperature T2 output from each heat flux sensor 11, a first heat resistance value K1, and a second heat resistance value K2. Using the following equation (1), assuming that the first thermal resistance value K1 is very small compared to the second thermal resistance value K2.
Q = (T1-T2) / K2 (1)
Can be calculated. In addition, this (1) type | formula is the surface area S1 (for example, area of a thermal radiation surface) of 11 A of 1st temperature sensors which has a surface and a back surface, and the surface area S2 (for example, thermal radiation surface) of the 2nd temperature sensor 11B which has a surface and a back surface. ) Is the same formula. The calculation using the equation (1) can be performed by, for example, the temperature adjustment controller 49 connected to the temperature sensors 11A and 11B of each heat flux sensor 11 via a conductor or the like. The temperature adjustment controller 49 includes, for example, a CPU and a memory, and the memory includes, for example, the following data (A) to (D):
(A) a heat flux sensor ID for identifying each of the plurality of heat flux sensors 11;
(B) Position data representing the position of each of the plurality of heat flux sensors 11;
(C) 1st thermal resistance value K1 (When the 1st thermal resistance value K1 is different about several 1st temperature sensors 11A, each 1st thermal resistance value K1),
(D) 2nd thermal resistance value K2 (when the 2nd thermal resistance value K2 is different about a plurality of 2nd temperature sensors 11B, each 2nd thermal resistance value K2),
At least one of is stored. The CPU of the temperature controller 49 is based on the information (A) to (D) stored in the memory and each of the first temperature T1 and the second temperature T2 from each heat flux sensor 11. The surface heat flux value at each location is calculated, and the distribution of the surface heat flux is measured based on the calculation result. For example, when the first temperature sensor 11A is in contact with the measurement substrate 5, the value of the first thermal resistance K1 can be handled as infinitely small (substantially zero). In this case, for example, the data (C) may not be stored. In this case, for example, the CPU of the temperature adjustment controller 49 treats each first temperature T1 input from each first temperature sensor 11A as an actual temperature at each position on the measurement substrate 5, and each first temperature T1. Alternatively, the temperature adjustment plate 7 is controlled based on the calculation result of each surface heat flux value (for example, the amount of heating of the temperature adjustment plate 7 with respect to the measurement substrate 5 is controlled). Further, the CPU of the temperature adjustment controller 49 can control the first temperature (T1) measured by the first temperature sensor 11A as it is as the temperature of the measurement substrate (5).

  Hereinafter, the heat flux sensor 11 will be further described.

  FIG. 3 shows the configuration of the heat flux sensor 11.

  As described above, the second temperature sensor 11B is disposed in the vicinity of the first temperature sensor 11A. The distance D between the first temperature sensor 11A and the second temperature sensor 11B is, for example, within 10 mm (for example, 2 to 3 mm), or 10 mm to 20 mm. The second temperature sensor 11B can be arranged adjacent to the first temperature sensor 11A in the surface direction of the measurement substrate 5 or in a direction (for example, orthogonal direction) across the measurement substrate 5 surface.

  As 1st temperature sensor 11A and 2nd temperature sensor 11B, an electrical resistor, a thermocouple, a thermoelectric element, or a thermistor is employable, for example. As the electric resistor, for example, a metal thin film resistor or a resistor formed by doping impurities on the surface of the measurement substrate 5 may be used. Note that the types of the first temperature sensor 11A and the second temperature sensor 11B are not necessarily the same.

  Both the first temperature sensor 11A and the second temperature sensor 11B have an area. Here, the area of the first temperature sensor 11A is defined as a first area S1, and the area of the second temperature sensor 11B is defined as a second area S2. The first area S1 and the second area S2 may be the same or different.

  The second thermal resistance value K2 is the thickness of the interposed member (here, the low thermal conductive material 13) interposed in the thickness direction of the measurement substrate 5 between the second temperature sensor 11B and the measurement substrate 5. It is a value obtained by dividing by the thermal conductivity of. Similarly, the value of the first thermal resistance value K1 is the thickness of the intervening member interposed in the thickness direction of the measurement substrate 5 between the first temperature sensor 11A and the measurement substrate 5, and the heat of the intervening member. It can be determined by dividing by conductivity. As illustrated in FIG. 3, when there is no intervening member between the first temperature sensor 11 </ b> A and the measurement substrate 5, in other words, when the first temperature sensor 11 </ b> A is in contact with the measurement substrate 5. The first resistance value K1 can be handled as substantially zero.

  With the above configuration, the first temperature sensor 11 </ b> A of the heat flux sensor 11 can be handled as, for example, a temperature sensor that detects the substrate temperature of the measurement substrate 5. That is, each first temperature T <b> 1 detected by each first temperature sensor 11 </ b> A can be handled as the substrate temperature at each position of the measurement substrate 5. Thereby, the temperature distribution of the measurement substrate 5 can be grasped.

  Also, since the first temperature sensor 11A and the second temperature sensor 11B are close to each other, the heat flux Q1 in the region where the first temperature sensor 11A exists and the heat flux Q2 in the region where the second temperature sensor 11B exists Are considered to be completely or substantially the same. Thereby, the heat flux Q in the place where the heat flux sensor 11 exists is computable using (1) Formula mentioned above. If the value of the first temperature T1 is larger than the value of the second temperature T2, it means that heat is released from the surface of the measurement substrate 5, and conversely, the value of the first temperature T1. If the value of the second temperature T2 is larger than that, it means that heat is absorbed through the surface of the measurement substrate 5.

Moreover, about the 1st temperature sensor 11A and the 2nd temperature sensor 11B, the relationship of the following (2) Formula,
K2 / S2> K1 / S1 (2)
Holds. This is because the second thermal resistance value K2 is larger than the first thermal resistance value K1, and the second area S2 and the first area S1 can be the same value. Note that the value of K2 / S2 is, for example, at least twice the value of K1 / S1.

  According to this embodiment, the substrate temperature and the surface heat flux at each position of the measurement substrate 5 can be measured together.

  Further, according to this embodiment, the heat flux sensor 11 of the measurement substrate 5 is suitable for measuring a plurality of temperature sensors (in other words, measuring the temperature of the measurement substrate 5) that does not substantially affect the temperature distribution of the measurement substrate 5. A plurality of temperature sensors). For this reason, the surface heat flux at each position of the measurement substrate 5 can be measured without greatly affecting the temperature distribution of the measurement substrate 5.

  By the way, several variations can be considered for the mounting method of the heat flux sensor 11. It is also conceivable that a temperature sensor for measuring the substrate temperature of the measurement substrate 5 is provided separately from the heat flux sensor 11 described above. Furthermore, some variations are conceivable for the control method of the temperature adjustment controller 49. These will be described below.

  FIG. 4 shows a first variation of the mounting method of the heat flux sensor.

  In the first embodiment, a first sensor hole (or a recess such as a groove) 21 for embedding the first temperature sensor 11 </ b> A is formed on the surface of the measurement substrate 5. The first temperature sensor 11A is placed in the first sensor hole 21, and an adhesive 23 such as dootite is poured into the first sensor hole 21. Thus, the first temperature sensor 11A is fixed to the measurement substrate 5 while the back surface of the first temperature sensor 11A is in contact with the measurement substrate 5.

  The second temperature sensor 11 </ b> A is bonded (for example, bonded) to the surface of the measurement substrate 5 through the low thermal conductive material 13.

  FIG. 5 shows a second variation of the mounting method of the heat flux sensor.

  In the second embodiment, the first temperature sensor 11A is mounted in the same manner as in the first embodiment.

  And the 2nd temperature sensor 11B is mounted by the method for the same use as embodiment mentioned above.

  With the above configuration, the surface of the measurement substrate 5 becomes flat.

  FIG. 6A shows a third variation of the mounting method of the heat flux sensor. FIG. 6B is a top view of the second sensor hole 15.

  In the third embodiment, the first temperature sensor 11A is mounted in the same manner as in the first embodiment.

  A second sensor hole 15 is formed on the surface of the measurement substrate 5. The second sensor hole 15 in the third embodiment is a cavity formed by etching or the like. A bridge 25 for joining the second temperature sensor 11B to the measurement substrate 5 is provided at the entrance of the second sensor hole 15. The second temperature sensor 11B is bonded (for example, bonded) to the measurement substrate 5 through the bridge 25. Air is interposed as a low thermal conductive material between the back surface of the second temperature sensor 11 </ b> B and the bottom of the second sensor hole 15.

That is, between the second temperature sensor 11 </ b> B and the measurement substrate 5, the bridge 25 and air exist as two types of thermal resistors. Here, when the thermal resistance value of the bridge 25 is K21 and the thermal resistance value of the air is K22, the second thermal resistance value K2 described above is expressed by the following equation (3):
K2 = 1 / {(1 / K21) + (1 / K22)} (3)
Can be calculated.

  FIG. 7 shows a fourth variation of the mounting method of the heat flux sensor.

  In the fourth embodiment, both the first temperature sensor 11A and the second temperature sensor 11B are joined to the measurement substrate 5 via a heat conductive material. However, in that case, the second thermal resistance value K2 is made larger than the first thermal resistance value K1. The heat conducting material 12 used for the first temperature sensor 11A and the heat conducting material 14 used for the second temperature sensor 11B may be the same type or different types.

  For example, the two heat conducting materials 12 and 14 are low heat conducting materials made of the same material. The heat conductive material 14 used for the second temperature sensor 11B is thicker than the heat conductive material 12 used for the first temperature sensor 11A. In other words, the thin low thermal conductive material 12 is interposed between the first temperature sensor 11A and the measurement substrate 5 surface, and the thick low thermal conductive material 14 is interposed between the second temperature sensor 11B and the measurement substrate 5 surface. Is interposed.

  In the fourth embodiment, even if a low thermal conductive material is used for the first temperature sensor 11A, the low thermal conductive material is thin, so the first temperature T1 detected by the first temperature sensor 11A is used as the substrate temperature. It can be adopted.

  FIG. 8 shows a fifth variation of the mounting method of the heat flux sensor.

  In the fifth embodiment, a common sensor hole 27 is provided on the surface of the measurement substrate 5 for receiving both the first temperature sensor 11A and the second temperature sensor 11B. That is, in the fifth embodiment, the temperature sensors 11A and 11B (that is, one heat flux sensor 11) are mounted at the same position (for example, one hole 27). It is not always necessary to form the hole 27. For example, the heat flux sensor 11 shown in FIG. 8 may be placed on the surface of the measurement substrate 5.

  In the fifth embodiment, the heat flux sensor 11 has a laminated structure. If the front side of the measurement substrate 5 is the upper side and the back side is the lower side, specifically, the first temperature sensor 11A is positioned at the lowest level, and the second temperature sensor 11B is positioned at the highest level. The low thermal conductive material 13 is located in a layer between the first temperature sensor 11A and the second temperature sensor 11B. More specifically, the back surface of the first temperature sensor 11 </ b> A contacts the measurement substrate 5, and the low heat conductive material 13 is bonded (for example, bonded) to the surface of the first temperature sensor 11 </ b> A. The second temperature sensor 11B is bonded (for example, bonded). In this case, for example, the surface of the second temperature sensor 11 </ b> B positioned at the top is mounted so as not to form irregularities on the surface of the measurement substrate 5. In other words, at least one of the thickness of the low thermal conductive material 13 and the depth of the common sensor hole 27 is adjusted so that it can be realized.

  According to the fifth embodiment, since the area of the heat flux sensor 11 can be suppressed, the heat flux sensor 11 can be more densely arranged on the surface of the measurement substrate 5.

  FIG. 9 shows a sixth variation of the mounting method of the heat flux sensor.

  In the sixth embodiment, the first temperature sensor 11A is formed by vapor-depositing a metal or the like (for example, platinum or nickel) on the surface of the measurement substrate 5 using a semiconductor processing technique. On the other hand, the second temperature sensor 11B is bonded (for example, bonded) to the measurement substrate 5 via a low thermal conductive material 13 such as polyimide, as in the first embodiment.

  FIG. 10 is an explanatory diagram of variations of the connection configuration between the temperature sensors 11A and 11B of each heat flux sensor 11 and the temperature controller 49.

  In the above-described embodiment, signals (hereinafter, temperature detection signals) output from the temperature sensors 11A and 11B are transmitted to the temperature controller 49 via wiring. Then, the temperature detection signal is transmitted to the temperature controller 49 wirelessly.

  For example, the measurement substrate 5 includes a detector 31 connected to each temperature sensor 11A and 11B. Although not shown, the detector 31 includes a signal processing unit, a memory, and a wireless communication unit. The signal processing unit processes the temperature detection signals from the temperature sensors 11A and 11B, and stores data related to the processing results (for example, the substrate temperature and the heat flux value at each position of the measurement substrate 5) in the memory. The wireless communication unit wirelessly transmits the data stored in the memory to an external device such as the temperature controller 49.

  Note that the temperatures detected by the temperature sensors 11A and 11B may be transmitted to a predetermined external device, for example, the temperature controller 49, in a wired or wireless manner by a method different from the method described so far. .

  FIG. 11 shows a top view of a measurement substrate according to the eighth embodiment of the present invention. FIG. 12 shows the configuration of the temperature control system according to the eighth embodiment of the present invention. In FIG. 11, as an example, seven heat flux sensors 11-1 to 11-7 are shown, and a connection mechanism with the temperature controller 49 is not shown. FIG. 12 includes a cross-sectional view taken along the line AA of FIG.

  In the eighth embodiment, the temperature adjustment plate 7 is provided with a plurality of temperature adjustment regions (hereinafter simply referred to as “zones”), for example, three zones Z1 to Z3. Specifically, for example, the first zone Z <b> 1 is a region including the center of the temperature control plate 7. The second zone Z2 is half of a donut-shaped region including the periphery of the temperature control plate 7 excluding the first zone Z1 from the temperature control plate 7. The third zone Z3 is the other half of the donut-shaped region. The temperature adjustment plate 7 includes a zone temperature sensor 61 for detecting the temperature of each of the plurality of zones Z1 to Z3. The reference number 61A in FIG. 12 is a zone temperature sensor corresponding to the first zone Z1, the reference number 61B is a zone temperature sensor corresponding to the second zone Z2, and the reference number 61C corresponds to the third zone Z3. Zone temperature sensor.

  The temperature adjustment controller 49 is a device that controls the temperature adjustment plate 7. The temperature controller 49 includes a storage unit 40, a zone temperature measurement unit 63, a substrate temperature measurement unit 41, a heat flux measurement unit 45, a substrate thermal state analysis unit 47, and a substrate temperature control unit 43.

  The storage unit 40 is a memory, a hard disk, or the like, and stores data. The data structure of the memory | storage part 40 is illustrated in FIG. According to the example shown in FIG. 13, the storage unit 40 includes the IDs of the heat flux sensors 11-1 to 11-7, the substrate temperature detected by the first temperature sensor 11A of the heat flux sensor, and the heat flow. The heat flux value detected by the bundle sensor, the ID for each zone, and the temperature of the zone (temperature detected by each zone temperature sensor 61A to 61C) are stored. The storage unit 40 can continue to store them as a history. Moreover, according to the example shown in FIG. 13, the memory | storage part 40 memorize | stores ID for each zone, its target temperature, and ID of the heat flux sensor which belongs to the zone. In addition, although not particularly illustrated, the storage unit 40 may store position information indicating the area ranges of the zones Z1 to Z3 and position information indicating the positions of the heat flux sensors 11-1 to 11-7.

  Refer to FIGS. 11 and 12 again. The zone temperature measuring unit 63 is connected to the plurality of zone temperature sensors 61A to 61C, and the zone temperature signal indicating the zone temperature detected by each of the plurality of zone temperature sensors 61A to 61C is sent to each zone temperature sensor 61A to 61A. Receive from 61C. The zone temperature measurement unit 63 writes the zone temperature represented by each received zone temperature signal in the storage unit 40.

  The substrate temperature measuring unit 41 is connected to each first temperature sensor 11A of each heat flux sensor 11-1 to 11-7, and the first temperature detected by each first temperature sensor 11A (this eighth embodiment). Then, a first temperature signal representing the substrate temperature is received from each first temperature sensor 11A. The substrate temperature measurement unit 41 writes the first temperature represented by each received first temperature signal in the storage unit 40.

  The first and second temperatures detected by the temperature sensors 11A and 11B are connected to the temperature sensors 11A and 11B of the heat flux measuring unit 45 and the heat flux sensors 11-1 to 11-7, respectively. A first temperature signal and a second temperature signal respectively represented are received from the temperature sensors 11A and 11B. And the heat flux measuring unit 45 is based on the first temperature represented by the received first temperature signal and the second temperature represented by the second temperature signal for each of the heat flux sensors 11-1 to 11-7. The heat flux value is calculated from the above-described equation (1), and the calculated heat flux value is written in the storage unit 40.

  The substrate thermal state analysis unit 47 is based on data stored in the storage unit 40, for example, a plurality of substrate temperatures and heat flux values respectively corresponding to the plurality of heat flux sensors 11-1 to 11-7. 5 distribution of temperature, heat input flow rate distribution, and heat flux distribution is specified (heat input flow rate can be obtained by calculating the difference between the substrate temperature and the heat flux value, for example) The identified distribution is written into the storage unit 40. In addition, for example, when the substrate thermal state analysis unit 47 detects that the element value (substrate temperature, heat input flow rate, or heat flux value) of the distribution is varied from the specified distribution, for example, Based on a plurality of substrate temperatures and heat flux values corresponding to the plurality of heat flux sensors 11-1 to 11-7, the cause of the variation is estimated, and the estimation result is displayed on a display screen (for example, temperature It may be displayed on the monitor screen of the adjustment controller 49.

  The substrate temperature control unit 43 corresponds to data stored in the storage unit 40, for example, a plurality of substrate temperatures and heat flux values respectively corresponding to the plurality of heat flux sensors 11-1 to 11-7, and each zone ID. Based on each target temperature or each zone temperature, each zone Z1 to Z3 of the temperature control plate 7 (in other words, a heating amount for each region on the measurement substrate 5 corresponding to each zone Z1 to Z3) (Or endothermic amount) is controlled. For example, the substrate temperature control unit 43 controls the zones Z1 to Z3 so that the plurality of substrate temperatures and the heat flux values do not vary.

  Hereinafter, the eighth embodiment will be described in more detail by taking some examples.

  (1) First example.

When the three target temperatures respectively corresponding to the three zones Z1 to Z3 are set to 110 ° C., examples of normal values of the substrate temperature and the heat flux value detected by the heat flux sensors 11-1 to 11-7 are as follows: Assume that it is as shown in FIG. FIG. 14 shows that the substrate temperature and the heat flux value have a certain correlation. That is, for example, when the heat flux value is different by 10 [W / m ² ], it can be seen that the substrate temperature changes by about 0.1 ° C.

  In this case, for example, as shown in FIG. 15, the person sets the target temperature of the first zone Z1 to 109.0 ° C., the target temperature of the second zone Z2 to 110.5 ° C., and the target temperature of the third zone Z3 to 110.degree. It is assumed that the temperature is reset to 5 ° C. Then, according to the above theory, as illustrated in FIG. 15, the substrate temperature detected by the heat flux sensor 11-7 is approximately 110.0 ° C., and is detected by the other heat flux sensors 11-1 to 11-6. Each substrate temperature is increased by approximately 0.5 ° C., and therefore the substrate temperature distribution is within the range of ± 0.2 ° C.

  According to the eighth embodiment, the target temperature of each zone Z1 to Z3 of the temperature control plate 7 is set to an appropriate value with a small number of measurements (for example, one measurement), in other words, in a short time. Can do.

  (2) Second example.

  The second example is an example in the case where an abnormality occurs in the substrate temperature of the measurement substrate 5 due to inspection or periodic diagnosis when the semiconductor thermal process apparatus is started up.

  It is assumed that after the target temperatures of the zones Z1 to Z3 are reset to the values illustrated in FIG. 15, the substrate temperatures and the heat flux values become the values illustrated in FIG.

  According to FIG. 16A, the substrate temperature of the heat flux sensors 11-1 and 11-6 decreases by 0.3 ° C., and the substrate temperature distribution varies more than the target error range of ± 0.2 ° C. It was.

  However, according to FIG. 16 (A), each heat flux value measured based on the heat flux sensors 11-1 and 11-6 does not change.

  From this, the substrate temperature in the heat flux sensors 11-1 and 11-6 did not decrease because the heat flux value from the substrate surface changed, but the heat input flow rate from the temperature adjustment plate 7 changed. It is thought that it fell to. As the cause of the change in the heat input flow rate, either the zone temperature sensor 61B in the second zone Z2 has changed over time or the gap between the second zone Z2 and the measurement substrate 5 has changed for some reason.

  Here, if the former is the cause, the substrate temperature in the heat flux sensor 11-5 should also change, but since the substrate temperature has not changed, the possibility of the former is low. . Therefore, the latter cause, for example, dust larger than the initial gap may have adhered between the measurement substrate 5 and the second zone Z2, which may be the cause of the increase in the gap. Can be determined to be high. This determination is performed by the substrate thermal state analysis unit 47 (for example, a CPU that has read a certain computer program) based on the actually measured values as described above, but may be performed by a human instead. When such a determination is made, for example, the surface of the second zone Z2 of the temperature control plate 7 may be cleaned with a chemical such as methanol.

  (3) Third example.

  The third example is another example in the case where an abnormality occurs in the substrate temperature of the measurement substrate 5 due to inspection or periodic diagnosis when the semiconductor thermal process apparatus is started up.

  Assume that after the target temperatures of the zones Z1 to Z3 are reset to the values illustrated in FIG. 15, the substrate temperatures and the heat flux values become the values illustrated in FIG.

  According to FIG. 17A, the substrate temperatures of the heat flux sensors 11-2 and 11-3 are reduced by 0.5 ° C. to 0.7 ° C., and the substrate temperature distribution is less than the target error of ± 0.2 ° C. Has also varied greatly.

  Moreover, according to FIG. 16 (A), each heat flux value measured based on the heat flux sensors 11-2 and 11-3 increased.

  Moreover, according to FIG. 16 (A), the heat flux value measured based on the heat flux sensor 11-7 decreased.

It can be seen immediately from the above results that the substrate temperature has changed due to the change in the heat flux from the surface of the measurement substrate 5. In the heat flux sensors 11-2 and 11-3, the increase in the heat flux value by about 50 [W / m ² ] is considered that air flow disturbance has occurred on the surface of the measurement substrate 5. In particular, in the heat flux sensors 11-2 and 11-3, the heat flux increases and the substrate temperature decreases accordingly, whereas in the heat flux sensor 11-7, on the contrary, the heat flux is As a result, the substrate temperature increases. As shown in FIG. 17B, for example, it is conceivable that the inclination of the lid 3 has changed and an air flow has entered from the outside. Therefore, it can be seen that it is necessary to quickly correct the inclination of the lid 3.

  Such a determination is made by the substrate thermal state analysis unit 47 (for example, a CPU that reads a computer program) based on the actually measured values as described above, but instead, it may be made by a human.

  As described above, according to the eighth embodiment, when an abnormality occurs in the temperature distribution of the measurement substrate 5, from the plurality of substrate temperature measurement values and the heat flux measurement values respectively corresponding to the plurality of locations of the measurement substrate 5, The cause of the abnormality can be quickly identified. For example, it is possible to quickly identify whether the abnormality is due to heat flux or heat input flow rate, and thereby quickly determine how to deal with the abnormality.

  FIG. 18 shows a modification of the eighth embodiment.

  In the ninth embodiment, apart from the heat flux sensor 11, a substrate temperature sensor 51 for measuring the substrate temperature in the vicinity of the heat flux sensor 11 is provided on the measurement substrate 5.

  The substrate temperature sensor 51 may be of the same type as the first temperature sensor 11A. The substrate temperature sensor 51 may be embedded in the measurement substrate 5 or may be bonded to the surface.

  On the other hand, as a mounting method of the heat flux sensor 11, for example, one of the above-described embodiment and the first to eighth examples can be adopted. Incidentally, the heat flux sensor 11 shown in FIG. 18 is a case where the mounting method of the fifth embodiment is adopted.

  As described above, in any of the above-described embodiment and the first to ninth examples, the heat flux value can be calculated by the above-described equation (1). Further, the relationship of the above-described formula (2) always holds. Further, the mounting method of the heat flux sensor 11 (for example, the mounting method of the first temperature sensor 11A and the second temperature sensor 11B) can be appropriately combined with the above-described embodiment and the first to ninth embodiments. .

  The preferred embodiment of the present invention has been described above, but this is an example for explaining the present invention, and the scope of the present invention is not limited to this embodiment. The present invention can be implemented in various other forms. For example, the wiring of each temperature sensor 11 </ b> A and 11 </ b> B may be embedded in the measurement substrate 5.

1 is an overall configuration diagram of an embodiment of the present invention. FIG. 2A shows a top view of the measurement substrate 5 according to this embodiment. FIG. 2B shows a BB cut surface of the measurement substrate 5 shown in FIG. The structure of the heat flux sensor 11 is shown. The 1st variation of the mounting method of a heat flux sensor is shown. The 2nd variation of the mounting method of a heat flux sensor is shown. FIG. 6A shows a third variation of the mounting method of the heat flux sensor. FIG. 6B is a top view of the second sensor hole 15. The 4th variation of the mounting method of a heat flux sensor is shown. The 5th variation of the mounting method of a heat flux sensor is shown. The 6th variation of the mounting method of a heat flux sensor is shown. It is explanatory drawing of the variation of the connection structure between each temperature sensor 11A and 11B of each heat flux sensor 11, and the temperature control controller 49. FIG. The top view of the measurement board | substrate which concerns on 8th Example of this invention is shown. 8 shows a configuration of a temperature control system according to an eighth embodiment of the present invention. The data structural example of a memory | storage part is shown. An example of each value when the target temperature of each zone is 110 ° C. An example of each value after resetting each target temperature shown in FIG. FIG. 16A shows an example of each value when an abnormality occurs after resetting to each target temperature illustrated in FIG. FIG. 16B shows an example of a state analyzed from each value illustrated in FIG. FIG. 17A shows an example of each value when an abnormality occurs after the target temperature illustrated in FIG. 15 is reset. FIG. 17B shows an example of a state analyzed from each value illustrated in FIG. A modification of the eighth embodiment of the present invention will be described.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Chamber, 3 ... Lid, 5 ... Measurement board | substrate, 7 ... Temperature control plate, 11 ... Heat flux sensor, 11A ... 1st temperature sensor, 11B ... 2nd temperature sensor, 13 ... Low heat conductive material, 40 ... Memory | storage part, DESCRIPTION OF SYMBOLS 41 ... Heat flux measurement part, 43 ... Substrate temperature control part, 45 ... Substrate temperature measurement part, 47 ... Substrate thermal condition analysis part, 49 ... Temperature control controller, 61A-61C ... Zone temperature sensor, 63 ... Zone temperature measurement part, 91A ... first thermal resistance, 91B ... second thermal resistance, Z1 ... first temperature adjustment region (first zone), Z2 ... second temperature adjustment region (second zone), Z3 ... third temperature adjustment region (third zone)

Claims (5)

A heat flux measurement substrate (5) formed of the same material as a substrate to be processed in a semiconductor process,
The heat flux measurement substrate (5) is provided with a heat flux sensor (11) for measuring the heat flux from the surface,
The heat flux sensor (11) includes a first temperature sensor (11A), a second temperature sensor (11B), and a thermal resistance (between the second temperature sensor and the heat flux measurement substrate (5) ( 91B), and
The first temperature sensor (11A) is directly disposed on the heat flux measurement substrate (5),
The second temperature sensor (11B) includes a hole (15) formed in the surface of the heat flux measurement substrate (5), and the heat flux measurement substrate (5) through the thermal resistance (91B). Arranged to be flat with the surface,
Heat flux measurement board. The second temperature sensor (11B) is disposed in a hole (15) formed on the surface of the heat flux measurement substrate (5) so as not to contact the side wall of the hole (15).
The heat flux measurement board according to claim 1. The first temperature sensor (11A) is provided at a position shifted in the surface direction of the heat flux measurement substrate (5) with respect to the second temperature sensor (11B).
The heat flux measurement substrate according to claim 1 or 2. A plurality of the heat flux sensors (11) are provided at different positions on the heat flux measurement substrate (5).
The heat flux measurement substrate according to claim 1 or 2. The distance between the first temperature sensor (11A) and the second temperature sensor (11B) is within 1 cm.
The heat flux measurement substrate according to claim 1 or 2.

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