Temperature measurement assembly, substrate processing apparatus, method of processing substrate, and method of manufacturing semiconductor device

Abstract

The present invention provides a technology capable of stably measuring temperature for a long period under high-temperature environments. The invention comprises a gas supply pipe including a flow path through which gas flows, a temperature sensor including a measuring unit disposed outside the gas supply pipe to measure temperature, and a protective pipe in which the gas supply pipe and the temperature sensor are disposed inside. An outlet of the gas supply pipe for injecting the gas into the protective pipe is disposed at a position higher than the temperature sensor, and the gas is configured to descend through the gap between the outer wall of the temperature sensor and the inner wall of the protective pipe.

Description

Technology Field

[0001] The present disclosure relates to a temperature measuring assembly, a substrate processing apparatus, a substrate processing method, and a method for manufacturing a semiconductor device. Background Technology

[0002] In a method for manufacturing a semiconductor device, a vertical substrate processing apparatus may be used as a device for forming an oxide film or a metal film on a substrate (hereinafter referred to as a wafer). When forming a predetermined film on the wafer, the processing chamber is heated to a predetermined temperature while supplying a processing gas into the processing chamber. In order to maintain the processing chamber at a predetermined temperature, a temperature sensor, such as a thermocouple, is provided in the processing chamber to detect the temperature.

[0003] As a thermocouple usable in high-temperature environments, there is, for example, a WRe (tungsten-rhenium) sheathed thermocouple. A WRe thermocouple is a thermocouple that can be used at high temperatures but cannot be used in an oxidizing atmosphere. The sheathed thermocouple is structured such that the thermocouple and an insulator are inserted into a metal sheath tube, and the inside of the sheath tube is filled with an inert gas to seal the end of the sheath, thereby isolating the thermocouple from an oxidizing atmosphere. Prior art literature

[0004] WO2012 / 115170 Publication Japanese Patent Publication No. 2013-207057 The problem to be solved

[0005] However, under high-temperature environments, substances such as oxygen that degrade the sheath tube are generated from materials constituting the processing chamber or deposited membranes. When the sheath tube degrades, oxygen may reach the inside of the sheath tube. As a result, the condition in which the inside of the sheath tube is completely filled with an inert atmosphere is destroyed, which further degrades the thermocouple. This leads to a decrease in the thermocouple's electromotive force or disconnection, making it impossible to accurately measure the temperature. In particular, if the sheath tube is covered with a protective tube, there is a possibility of long-term exposure to gases released from the protective tube that remain inside it. Furthermore, evaporation or gas release from the sheath tube itself may also cause deterioration of the protective tube or contamination of the processing chamber.

[0006] The present disclosure provides a technology capable of stably measuring temperature for a long period under high-temperature environments. means of solving the problem

[0007] According to one aspect of the present disclosure, a technology is provided comprising a gas supply pipe including a flow path through which gas flows, a temperature sensor including a measuring part disposed outside the gas supply pipe to measure temperature, and a protective pipe in which the gas supply pipe and the temperature sensor are disposed inside, wherein the outlet of the gas supply pipe for ejecting the gas into the protective pipe is disposed at a position higher than the temperature sensor, and the gas is configured to flow through the gap between the outer wall of the temperature sensor and the inner wall of the protective pipe. Effects of the invention

[0008] According to the present disclosure, stable temperature measurement for a long period of time is possible under high temperature environments. Brief explanation of the drawing

[0009] FIG. 1 is a cross-sectional view illustrating an example of a processing method according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view illustrating a temperature measuring assembly according to an embodiment of the present disclosure. FIG. 3 is an enlarged longitudinal section view of a main part showing a temperature measuring assembly and the vicinity of an installation part according to an embodiment of the present disclosure. FIG. 4 is an enlarged longitudinal section view of a main part showing the leading edge of a temperature measuring assembly according to an embodiment of the present disclosure. FIG. 5 is a flowchart illustrating a substrate processing method according to an embodiment of the present disclosure. Figure 6 (A) is a cross-sectional view illustrating a modified example of a temperature measuring assembly according to an embodiment of the present disclosure, and (B) is a lower view of (A). Specific details for implementing the invention

[0010] Hereinafter, one aspect of the present disclosure will be described with reference mainly to FIGS. 1 to 5. Furthermore, all drawings used in the following description are schematic, and the dimensional relationships of each element and the ratios of each element shown in the drawings do not necessarily correspond to reality. Also, the dimensional relationships of each element and the ratios of each element do not necessarily correspond to one another among multiple drawings.

[0011] First, in FIG. 1, an embodiment relating to the present disclosure is described. FIG. 1 shows a cross-sectional view of a processing furnace (2) in a substrate processing apparatus (1) relating to the present embodiment. Also, FIG. 2 to FIG. 4 are configured in the same way as the substrate processing apparatus (1) shown in FIG. 1, and elements that are substantially identical to those described in FIG. 1 are given the same reference numerals and their descriptions are omitted.

[0012] In addition, the substrate processing apparatus (1) according to the present embodiment is configured as a so-called batch-type vertical SiC annealing apparatus, which performs annealing on a plurality of SiC substrates aligned in the vertical direction. By configuring it as a batch-type processing apparatus, a large number of substrates can be processed at once, thereby improving productivity.

[0013] The substrate processing device (1) is configured in the same way as the device shown in Fig. 1 of Patent Document 1, for example. The substrate processing device (1) has a processing furnace (2), and a boat (3) serving as a substrate holding support is configured to be insertable and detachable in the processing furnace (2). The boat (3) is composed of a heat-resistant material, for example, carbon graphite or SiC. The boat (3) is configured to hold and support wafers (4) formed as substrates, such as multiple sheets of SiC, by aligning them in a horizontal position and aligning them with each other, and stacking them vertically. In addition, a boat insulation part (5) serving as an insulating part, composed of a heat-resistant material such as quartz or SiC, is disposed at the bottom of the boat (3). The boat insulation part (5) is configured to support the boat (3) from below, making it difficult to transfer heat from the subject (6), described later, to the lower side of the processing furnace (2). The boat (3) loaded with multiple wafers (4) is brought into the processing furnace (2) to perform heat treatment.

[0014] Next, the configuration of the processing furnace (2) equipped with the substrate processing device (1) will be explained.

[0015] As illustrated in FIG. 1, the processing furnace (2) is composed of a heat-resistant material such as quartz or SiC and is provided with a reaction tube (7) formed in a cylindrical shape with the top closed and the bottom open. A reaction chamber (8) serving as a processing chamber is formed in the hollow portion of the reaction tube (7). The reaction chamber (8) is configured to accommodate the aforementioned boat (3) which holds and supports a wafer (4) formed as a substrate such as SiC.

[0016] Below the reaction tube (7), a manifold (11) is arranged concentrically with the reaction tube (7). The manifold (11) is, for example, made of stainless steel and is formed in a cylindrical shape with open top and bottom ends. The manifold (11) is provided to support the reaction tube (7) from below. An O-ring (not shown) serving as a sealing member is provided between the manifold (11) and the reaction tube (7). By supporting the manifold (11) on a support member not shown, the reaction tube (7) is mounted vertically. A reaction vessel is formed by the reaction tube (7) and the manifold (11).

[0017] The processing furnace (2) is equipped with an induction coil (6) as a body to be heated by induction heating, and an induction coil (12) as an induction heating unit, that is, a magnetic field generating unit. The induction coil (6) is formed in a tubular shape using a conductive heat-resistant material, such as carbon, for example, and is arranged to surround a boat (3) contained within a reaction chamber (8), that is, to surround a receiving area of ​​a wafer (4). The induction coil (6) is formed in a cylindrical shape with the upper and lower ends open, or in a cylindrical shape with the upper end closed and the lower end open. The induction coil (12) is supported by a coil support (12a) made of an insulating heat-resistant material and is arranged to surround the outer circumference of a reaction tube (7). The induction coil (12) is configured to be supplied with AC power from an AC power source (13), for example, 10 to 450 kHz and 10 to 200 kW. By flowing an alternating current through an induction coil (12), an alternating magnetic field is generated, causing an induced current, i.e., an eddy current, to flow through the subject (6), thereby causing the subject (6) to heat up due to Joule heating. As the subject (6) heats up, the wafer (4) held and supported in the boat (3) is heated to a predetermined processing temperature, for example, 1500°C to 2000°C, by the radiant heat emitted from the subject (6). Additionally, to prevent heat damage, it is preferable to maintain the temperature of the component below the processing furnace (2) at a temperature of, for example, 200°C or lower.

[0018] Between the reaction tube (7) and the subject to be induced (6), an insulating body (14) composed of, for example, carbon felt that is difficult to conduct is provided. The insulating body (14) is formed in a cylindrical shape with the top closed and the bottom open. By providing the insulating body (14), heat from the subject to be induced (6) can be suppressed from being transferred to the reaction tube (7) or to the outside of the reaction tube (7).

[0019] Additionally, a temperature measuring assembly (15) for detecting the processing temperature is provided between the aforementioned boat (3) that holds and supports the wafer (4) and the subject (6). The temperature measuring assembly (15) extends vertically through the manifold (11) and protrudes upward above the top of the boat (3). The temperature measuring assembly (15) is electrically connected to a temperature control unit not shown. The temperature control unit controls the processing temperature of the wafer (4) to reach a desired temperature by adjusting the degree of current flow from the AC power source (13) to the induction coil (12) based on the temperature information detected by the temperature measuring assembly (15). The heating unit according to this embodiment is mainly composed of the subject (6), the induction coil (12), the AC power source (13), and the temperature measuring assembly (15).

[0020] Additionally, on the outer side of the induction coil (12), an outer insulation wall (16), for example, of a water-cooling structure, is provided to surround the reaction chamber (8) to prevent heat within the reaction chamber (8) from being transferred to the outside. Additionally, on the outer side of the outer insulation wall (16), a magnetic shield (17) is provided to prevent the magnetic field generated by the induction coil (12) from leaking to the outside. The outer insulation wall (16) and the magnetic shield (17) may be formed as a single integrated structure.

[0021] In the processing furnace (2), a first gas nozzle (18) having a first gas supply port (18a) is arranged. The first gas nozzle (18) is located inside the subject (6) and is positioned vertically between the receiving area of ​​the wafer (4) and the subject (6). The first gas nozzle (18) is made of a heat-resistant material, such as carbon graphite. A first gas supply port (18a) is provided at the top (tip) of the first gas nozzle (18). The downstream end of a first gas supply pipe (19) is connected to the upstream end of the first gas nozzle (18). The first gas supply pipe (19) is provided to pass through the manifold (11). A gas supply unit (21) is connected to the upstream end of the first gas supply pipe (19).

[0022] A second gas supply pipe (22) is arranged vertically between the insulation body (14) and the reaction pipe (7) on the outer side of the induction body (6). A second gas supply port (23) is provided at the downstream end of the second gas supply pipe (22). The second gas supply pipe (22) is provided to penetrate the manifold (11). A gas supply unit (21) is connected to the upstream end of the second gas supply pipe (22).

[0023] A first exhaust port (24) is provided on the side wall of the manifold (11) facing the first gas supply port (18a), which is located on the lower side of the boat insulation section (5), that is, the receiving area of ​​the wafer (4). Additionally, a second exhaust port (25) is provided on the wall of the manifold (11) where the reaction tube (7) is loaded, which is located between the insulation body (14) and the reaction tube (7). The upstream ends of the exhaust pipe (26), which are branched, are each connected to the first exhaust port (24) and the second exhaust port (25). In the exhaust pipe (26), a pressure sensor (27) as a pressure detector, an APC (Auto Pressure Controller) valve (28) as a pressure regulator, and a vacuum pump (29) as a vacuum exhaust device are provided in order from the upstream side. The pressure sensor (27), the APC valve (28), and the vacuum pump (29) are electrically connected to a pressure control section (not shown). The pressure control unit controls the opening degree of the APC valve (28) based on pressure information measured by the pressure sensor (27) through feedback control so that the pressure inside the reaction chamber (8) becomes a predetermined pressure at a predetermined timing.

[0024] By providing the first exhaust port (24) as described above, the gas supplied into the reaction chamber (8) from the first gas supply port (18a), i.e., the processing gas, flows downward into the reaction chamber (8), i.e., the inner side of the subject to be induced (6), through the area where the boat insulation part (5) is provided, and is exhausted from the first exhaust port (24). At this time, the entire wafer (4) is efficiently and uniformly exposed to the gas.

[0025] In addition, by providing a second exhaust port (25) as described above, an inert gas such as nitrogen supplied into the reaction chamber (8) from the second gas supply port (23) acts as a purge gas, flows between the reaction tube (7) and the insulating body (14), and is exhausted from the second exhaust port (25). By doing so, the intrusion of the treatment gas between the reaction tube (7) and the insulating body (14) is suppressed, thereby preventing unnecessary products from adhering to their surfaces.

[0026] Additionally, the boat (3) is made capable of being brought into the reaction chamber (8), i.e., loaded, and unloaded, i.e., taken out, by means of an unillustrated lifting mechanism. By bringing the boat (3) into the reaction chamber (8), the opening of the processing furnace (2), i.e., the furnace opening, is configured to be hermetically sealed by a seal cap (31) with a seal member such as an O-ring interposed therein. Furthermore, a boat rotation mechanism (30) supporting the boat insulation part (5) passes through the center of the seal cap (31), so that the boat (3) can be rotated by the boat rotation mechanism (30).

[0027] Next, with reference to FIGS. 2 to 4, details of the temperature measuring assembly (15) will be described. Additionally, the temperature measuring assembly (15) is installed vertically within the reaction tube (7), but in FIGS. 2 and 4, it is shown extending out in a horizontal direction.

[0028] The temperature measuring assembly (15) has a protective tube (32), a sheath thermocouple (33) as a temperature sensor inserted into the protective tube (32), a gas supply tube (34), an exhaust tube (35), and a sealing part (36) that seals the protective tube (32). Additionally, the sheath thermocouple (33) can be positioned further from the axis (central axis) of the protective tube (32) than the gas supply tube (34).

[0029] The protective tube (32) is in the shape of a cylinder with the top closed and the bottom open. The material of the protective tube is appropriately selected from various high-temperature ceramics or metal materials depending on conditions such as processing temperature, such as graphite, oxides such as Al2O3 or MgO, carbides such as TaC, TiC, SiC, nitrides such as BN or AlN.

[0030] The sheathed thermocouple (33) is inserted into the protective tube (32) parallel to the axis of the protective tube (32) so as to penetrate the sealing portion (36). The sheathed thermocouple (33) has a sheath tube (37) and a thermocouple (TC) (38) as a measuring portion for measuring the temperature placed inside the sheath tube (37). The sheath tube (37) is in the shape of a cylinder with the top closed and the bottom open. The sheath tube (37) is formed by a metal such as Ta or Mo. In addition, insulating powder, such as magnesium oxide, is filled inside the sheath tube (37) so that the thermocouple (38) placed inside does not move easily. In addition, the inside of the sheath tube (37) is filled with an inert gas, and the thermocouple cable outlet of the sheath tube (37) is sealed with glass or the like, so that the inside of the sheath tube (37) is completely sealed in a state where it is purged with an inert gas.

[0031] The gas supply pipe (34) is inserted into the protective tube (32) parallel to the axis of the protective tube (32) so as to penetrate the sealing portion (36), and extends outward to the vicinity of the inner wall of the upper end (front end) of the protective tube (32). Accordingly, a space (internal space) (32a) of a predetermined size is formed between the upper end of the gas supply pipe (34) and the upper end of the inner wall of the protective tube (32). Additionally, the gas supply pipe (34) has a flow path formed inside and an outlet (34a) formed at the front end, and is configured to supply an inert gas, such as argon gas (Ar gas) or nitrogen gas (N2 gas), upwardly into the space (32a) inside the protective tube (32) through the outlet (34a). That is, the space (32a) is formed on the upper side inside the gas supply pipe (34), that is, in the direction of gas ejection. The space (32a) is provided to change the direction of flow of the inert gas discharged from the outlet (34a) as smoothly as possible downward, and no solid object is placed therein.

[0032] Additionally, as shown in FIG. 4, the upper end (front end) of the gas supply pipe (34) extends upward beyond the upper end (front end) of the sheath thermocouple (33), and the lower end is connected to an inert gas supply device not shown. The dimension A from the upper end of the gas supply pipe (34) to the upper inner wall of the protective tube (32) is shorter than the dimension B from the upper end of the sheath thermocouple (33) to the upper inner wall of the protective tube (32). Accordingly, the sheath thermocouple (33) and the gas supply pipe (34) are each positioned such that the upper position of the gas supply pipe (34) is higher than the upper end of the sheath thermocouple (33). As a result, the discharged inert gas does not come into direct contact with the sheath thermocouple (33), but rather comes into contact with the sheath thermocouple (33) after being heated to the same temperature as the protective tube (32) while flowing along the inner wall of the protective tube (32).

[0033] The discharge pipe (35) is inserted into the protective tube (32) parallel to the axis of the protective tube (32) so as to penetrate the sealing part (36). The upper end (front end) of the discharge pipe (35) is located near the sealing part (36) and is configured to allow the discharge of gas inside the protective tube (32). That is, the discharge pipe (35), which communicates the atmosphere inside the protective tube (32) with the outside atmosphere, is opened near the sealing part (36) at the bottom of the protective tube (32). In addition, the diameter of the discharge pipe (35) is larger than the diameter of the gas supply pipe (34). By doing so, the increase in pressure inside the protective tube (32) can be suppressed.

[0034] The sealing part (36) is composed of, for example, a heat-resistant adhesive or a heat-resistant resin, and is configured as a sealing material that hermetically seals the opening, i.e., the lower part, of the protective tube (32). By the sealing part (36), the atmosphere inside the protective tube (32), excluding the discharge tube (35), is isolated from the outside atmosphere.

[0035] The inert gas supplied to the gas supply pipe (34) is ejected from the outlet (34a) into the space (32a) inside the protective pipe (32), deflected along the top of the inner wall of the protective pipe (32), descends through the gap (39) between the outer wall of the sheath thermocouple (33) and the inner wall of the protective pipe (32), and is exhausted to the outside through the discharge pipe (35).

[0036] FIG. 3 illustrates an enlarged cross-sectional view of the area around the installation portion of the temperature measuring assembly (15). The manifold (11) has an annular flange portion (11a) that widens outward in the circumferential direction at the top, and a reaction tube (7) is loaded on the flange portion (11a). An O-ring (41) is provided between the reaction tube (7) and the flange portion (11a), and the O-ring (41) ensures airtightness between the reaction tube (7) and the flange portion (11a).

[0037] Additionally, a TC port (42) is formed in the flange portion (11a). The TC port (42) is shaped like a cylinder that extends downward parallel to the axis of the reaction tube (7), and a threaded portion (42a) is formed at the bottom.

[0038] The temperature measuring assembly (15) is held and supported by a TC holder (43). The TC holder (43) has a case portion (40), a cable extraction hole (48) as an exhaust portion, a terminal screw (51), and a sleeve (53) as a vacuum joint.

[0039] The case portion (40) is approximately cylindrical in shape, and its inner diameter is larger than the outer diameter of the protective tube (32). A cylindrical concave portion (44) is formed in the middle of the outer circumference of the case portion (40), and a cap nut (45) is loosely fitted into the concave portion (44) so ​​as not to fall off, allowing the cap nut (45) to slide vertically between the upper and lower ends of the concave portion (44). Additionally, an annular flange portion (40a) that extends outward toward the outer circumference is formed at the upper end of the concave portion (44).

[0040] Inside the case portion (40), an inner flange portion (46) is formed as an adhesive portion that extends and protrudes toward the center, and a hole (47) smaller than the inner diameter of the case portion (40) is formed by the inner flange portion (46). The diameter of the hole (47) is larger than the inner diameter of the protective tube (32) and smaller than the outer diameter of the protective tube (32). Therefore, when the case portion (40) holds and supports the temperature measuring assembly (15), the lower surface of the protective tube (32) comes into contact with the upper surface of the inner flange portion (46). In addition, the protective tube (32) and the inner flange portion (46) are bonded by an adhesive, so that the protective tube (32) and the case portion (40) become an integral unit. Furthermore, the sheath thermocouple (33), gas supply pipe (34), and discharge pipe (35) penetrating the sealing portion (36) extend downward through the hole (47).

[0041] A cable extraction hole (48) is formed below the inner flange portion (46) of the surrounding wall of the case portion (40). The thermocouple cable (49), which serves as a wire for the temperature sensor, extends outward from the bottom of the sheath thermocouple (33) and is drawn out to the outside of the case portion (40) through the cable extraction hole (48). Additionally, the cable extraction hole (48) also functions as an outlet for discharging inert gas discharged from the discharge pipe (35) to the outside.

[0042] On the outer wall of the case portion (40), a flat portion (40b) parallel to the longitudinal direction of the protective tube (32) is formed, and a terminal screw (51) is provided on the flat portion (40b). By providing the terminal screw (51) on the flat portion (40b), the terminal screw (51) can be easily attached or detached. The terminal screw (51) functions as an exposed terminal that is electrically connected to the sheath thermocouple (33). The end of the thermocouple cable (49) extending from the cable extraction hole (48) is detachably attached or detached from the terminal screw (51). Additionally, a measuring instrument (not shown) capable of receiving an electrical signal from the thermocouple (38) can be connected to the terminal screw (51) via a cable (not shown). The cable connected to the terminal screw (51) and the measuring instrument functions as a connector portion that is electrically connected to the sheath thermocouple (33).

[0043] The lower opening of the case section (40) is closed by a holder cap (52) serving as a cover. Additionally, a hole is formed in the holder cap (52) for the gas supply pipe (34) to pass through, and the holder cap (52) closes the case section (40) while penetrating the gas supply pipe (34). Thus, the holder cap (52) also functions as a support member that supports a load in a direction perpendicular to the axial direction of the gas supply pipe (34). Furthermore, one end of the discharge pipe (35) penetrating the sealing section (36) is opened to allow fluid communication within the case section (40) below the inner flange section (46). Additionally, the inside of the case section (40) is purged by an inert gas discharged from the protective pipe (32) via the discharge pipe (35). The inert gas purged within the case section (40) is discharged through the cable extraction hole (48).

[0044] A cylindrical sleeve (53) is provided on the upper side of the case portion (40). A protective tube (32) is inserted through the sleeve (53), and its lower end is in contact with the upper side of the case portion (40). Additionally, the sleeve (53) has a large diameter portion (53a) and a small diameter portion (53b) with a diameter smaller than that of the large diameter portion (53a). The outer diameter of the large diameter portion (53a) is larger than the inner diameter of the TC port (42) and smaller than the outer diameter of the TC port (42). The outer diameter of the small diameter portion (53b) is smaller than the inner diameter of the TC port (42), so that the small diameter portion (53b) can be inserted into the TC port (42). Additionally, an O-ring (54) as a first sealing member is provided along the entire circumference of the inner wall of the large diameter portion (53a), and an O-ring (55) as a second sealing member is provided along the entire circumference of the upper part of the large diameter portion (53a).

[0045] When the protective tube (32) is inserted and penetrated into the sleeve (53), the O-ring (54) is compressed by the outer wall of the protective tube (32), thereby ensuring airtightness between the sleeve (53) and the protective tube (32). Additionally, when the small diameter portion (53b) is inserted into the TC port (42), the O-ring (55) is compressed between the large diameter portion (53a) and the bottom of the TC port (42), thereby ensuring airtightness inside the sleeve (53) and the TC port (42). Thus, by the O-ring (54) and the O-ring (55), airtightness is ensured inside the TC port (42), that is, inside the reaction chamber (8), so that the atmosphere inside the reaction chamber (8) does not leak out from the TC port (42).

[0046] When installing the temperature measuring assembly (15) in the processing furnace (2), the temperature measuring assembly (15) is held and supported in the case portion (40), and with the protective tube (32) inserted through the sleeve (53), the protective tube (32) and the small portion (53b) of the sleeve (53) are inserted into the TC port (42) from below. Additionally, the cap nut (45) is screwed onto the threaded portion (42a) formed on the outer wall of the TC port (42). By screwing the cap nut (45), the flange portion (40a) is pulled upward by the cap nut (45), that is, toward the sleeve (53), and the sleeve (53) in contact with the flange portion (40a) is pressed against the TC port (42). As the sleeve (53) is compressed, the upper surface of the large diameter portion (53a) is compressed against the lower surface of the TC port (42), and the TC port (42) is hermetically sealed through the O-ring (55). The flange portion (40a) and the cap nut (45) function as a locking coupling portion for locking coupling with the sleeve (53).

[0047] Next, with reference to the flowchart of FIG. 5, substrate processing using the substrate processing apparatus (1) described above will be explained. Here, an example is described in which oxygen on the wafer (4) is removed by supplying argon (Ar) gas as a processing gas into the reaction chamber (8) and performing an annealing treatment. In addition, in this specification, the processing temperature refers to the temperature of the wafer (4) or the temperature of the reaction chamber (8), and the processing pressure refers to the pressure inside the reaction chamber (8). Furthermore, in the following description, the operation of each part constituting the substrate processing apparatus (1) is controlled by a controller (not shown).

[0048] The seal cap (31) is lowered by an unillustrated lifting mechanism, and the boat (3) is removed from the reaction tube (7), i.e., the boat is unloaded, and the explanation begins with the state where there is no wafer (4) in the boat (3).

[0049] (Wafer charge and boat load)

[0050] When the FOUP containing the wafer (4) is fed into the substrate processing device (1), the wafer (4) is transported to the boat (3) by a moving loader not shown (STEP: 01). When multiple wafers (4) are loaded into the boat (3), i.e., wafer charged, the seal cap (31) is raised by a lifting mechanism not shown, and the boat (3) is brought into the inside of the subject (6) in the reaction chamber (8), i.e., boat loaded, and the lower opening of the reaction tube (7) is hermetically sealed by the seal cap (31) (STEP: 02).

[0051] (Pressure adjustment and temperature adjustment)

[0052] The reaction chamber (8) is vacuum-exhausted, i.e., depressurized, by a vacuum pump (29). The atmosphere inside the reaction chamber (8) is exhausted through the vacuum pump (29) by flowing in a straight line or approximately a straight line through the exhaust pipe (26). Once the pressure inside the reaction chamber (8) is vacuum-exhausted, Ar gas is supplied into the reaction chamber (8). The Ar gas is controlled to a predetermined flow rate by a gas supply unit (21) and is supplied into the reaction chamber (8) from the tip of the first gas nozzle (18) through the first gas supply pipe (19) and the first gas nozzle (18). In addition, in parallel with the supply of Ar gas, that is, with the seal cap (31) blocking the opening of the manifold (11), the gas supply unit (21) supplies purge gas, controlled to a desired flow rate, between the reaction pipe (7) and the insulation body (14) from the second gas supply port (23) through the second gas supply pipe (22). The purge gas is ejected upward, diffuses perimeter-wise along the ceiling, descends along the perimeter surface, and is exhausted out of the reaction chamber (8) through the second exhaust port (25) and the exhaust pipe (26). The pressure inside the reaction chamber (8) is measured by the pressure sensor (27), and based on this measured pressure information, the APC valve (28) is feedback-controlled to adjust the pressure to a predetermined pressure (vacuum level).

[0053] In order for the wafer (4) inside the reaction chamber (8) to reach a predetermined temperature, a predetermined AC power is supplied from the AC power source (13) to the induction coil (12), and an induction current is passed through the subject (6) to raise the temperature of the subject (6), thereby heating the wafer (4) from the surroundings by the subject (6). By heating by induction heating, the wafer (4) can be heated efficiently. At this time, the degree of current flow to the induction coil (12) is feedback-controlled based on temperature information detected by the sheath thermocouple (33) so that the entire wafer (4) loaded in the boat (3) becomes a predetermined temperature distribution. Additionally, rotation of the boat (3) and the wafer (4) by the boat rotation mechanism (30) is initiated.

[0054] In addition, in parallel with the energization of the induction coil (12), an inert gas is supplied into the protective tube (32) through the gas supply pipe (34). For example, the inert gas is supplied into the protective tube (32) at all times during substrate processing. Alternatively, the supply of inert gas into the protective tube (32) may be started when the temperature detected by the sheath thermocouple (33) becomes higher than the ambient temperature.

[0055] By supplying inert gas, the inside of the protective tube (32) is in an inert gas atmosphere, so the deterioration of the sheath tube (37) is prevented, and the inert gas atmosphere inside the sheath tube (37) can be maintained, thereby preventing oxidation of the sheath thermocouple (33). In addition, by continuously supplying inert gas from the gas supply tube (34) and exhausting inert gas from the exhaust tube (35), the atmosphere inside the protective tube (32) is constantly replaced with new inert gas, so that the inert gas atmosphere can be maintained.

[0056] (Substrate processing)

[0057] A wafer (4) is heated at a predetermined temperature for a predetermined time in an Ar atmosphere. By doing so, ion-implanted impurities are activated or oxygen on the surface is removed, thereby producing an annealed wafer (STEP: 03).

[0058] (Boat Unload and Wafer Discharge)

[0059] After generating the annealed wafer, the current to the induction coil (12) is cut off, and the wafer (4) is cooled until its temperature drops to a predetermined temperature. After the wafer (4) is cooled, the APC valve (28) is closed to return the pressure inside the reaction chamber (8) to atmospheric pressure. Then, the seal cap (31) is lowered by a lifting mechanism not shown, and the boat (3) is removed from the reaction tube (7), i.e., the boat is unloaded (STEP: 04).

[0060] After the boat (3) is removed, that is, when the seal cap (31) is not blocking the opening of the reaction chamber (8), cooling treatment of the wafer (4) and the boat insulation part (5) is performed (STEP: 05).

[0061] When the wafer (4) and the boat insulation part (5) are lowered to a predetermined temperature, the processed wafer (4) loaded into the boat (3) by a mobile loader not shown is stored in the FOUP, the FOUP is removed from the substrate processing device (1) (STEP: 06), and the substrate processing is terminated.

[0062] As for the processing conditions when Ar annealing the wafer (4), for example, the following are exemplified.

[0063] Processing temperature (wafer temperature): 1500℃ to 1900℃

[0064] Processing pressure (pressure inside the processing chamber): 1 Pa to atmospheric pressure

[0065] Ar gas: 1 sccm to 5 SLM

[0066] N2 gas: 1 sccm to 5 SLM

[0067] By setting each treatment condition to a value within its respective range, the film formation treatment can be properly carried out. In addition, the notation of a numerical range such as "1500°C to 1900°C" mentioned above implies that the lower and upper limits are included within that range. For example, "1500°C to 1900°C" means "1500°C or higher and 1900°C or lower." The same applies to other numerical ranges.

[0068] According to the present embodiment, one or more effects as described below are obtained.

[0069] In this embodiment, the temperature measuring assembly (15) provided in the reaction chamber (8) has a protective tube (32), a sheath thermocouple (33) inserted into the protective tube (32), and a gas supply tube (34). Since inert gas is continuously supplied into the protective tube (32) from the gas supply tube (34) to continuously replace the inside of the protective tube (32) with inert gas, an inert gas atmosphere can be maintained inside the protective tube (32). In addition, even if oxygen or impurities volatilize from the protective tube (32) itself, they can be discharged with the constantly supplied inert gas, thus preventing deterioration of the sheath thermocouple (33) and extending the lifespan of the sheath thermocouple (33), thereby allowing the temperature inside the reaction chamber (8) to be measured stably for a long time.

[0070] In addition, since heat transfer within the reaction chamber (8) at 1500°C or higher is dominated by heat radiation rather than heat conduction or heat transfer, responsiveness can be maintained even when the sheath thermocouple (33) does not come into contact with the protective tube (32).

[0071] In addition, the sheath thermocouple (33) is not directly exposed to the reaction chamber (8). Therefore, even if the sheath thermocouple (33) deteriorates under a high-temperature environment, metal contamination of the wafer (4) can be suppressed.

[0072] In addition, since the upper end of the gas supply pipe (34) is located above the upper end of the sheath thermocouple (33), the sheath thermocouple (33) can be placed in the flow of inert gas from above, thereby more reliably creating an inert gas atmosphere around the sheath thermocouple (33), which can further extend the lifespan of the sheath thermocouple (33). Furthermore, since the structure is such that the inert gas comes into contact with the sheath thermocouple (33) after rising to a temperature equivalent to that of the protective pipe (32), the measurement temperature of the sheath thermocouple (33) is not affected by the inert gas, thereby improving the precision of the temperature measurement.

[0073] In addition, the temperature measuring assembly (15) is supported by the case part (40), so that the sealing part (36) is not exposed to the outside, thereby suppressing the external force applied to the sealing part (36) and preventing damage to the sealing part (36).

[0074] In addition, the holder cap (52) is structured to block the case portion (40) while penetrating the gas supply pipe (34), that is, the holder cap (52) restricts the movement of the gas supply pipe (34) in the circumferential direction. Therefore, even if an external force is applied to the gas supply pipe (34), the external force can be received by the holder cap (52), thereby preventing the seal portion (36) from being damaged.

[0075] In addition, the protective tube (32) and the case part (40) are bonded together by an adhesive and integrated, thereby integrating the locking joint part with the sleeve (53), i.e., the flange part (40a) and the cap nut (45), and the connector part, i.e., the thermocouple cable (49) and the terminal screw (51). Therefore, damage caused by tension on the thermocouple cable (49) is prevented, and the thermocouple cable (49) can be easily replaced.

[0076] FIGS. 6 (A) and FIGS. 6 (B) illustrate variations of the present embodiment. In FIGS. 6 (A) and FIGS. 6 (B), the same reference numerals are attached to those equivalent to FIGS. 1 to 4, and their descriptions are omitted. In the variations, the temperature measuring assembly (15) has three sheathed thermocouples (56, 57, 58). The sheathed thermocouples (56, 57, 58) and the discharge pipe (35) are inserted along the inner wall of the protective tube (32) at equal circumferential intervals, for example at 90° intervals as shown in FIG. 6 (B). Additionally, the gas supply pipe (34) is inserted further inward than the sheathed thermocouples (56, 57, 58) and the discharge pipe (35), for example along the axis of the protective tube (32). In addition, although not in a city, the sheath thermocouples (56, 57, 58) each have a sheath tube and a thermocouple as a measuring part placed in the sheath tube, just like the sheath thermocouple (33).

[0077] In addition, cable extraction holes (48) (6 locations in (A) of FIG. 6) are formed at multiple locations on the surrounding wall of the case part (40), and each thermocouple cable (59, 60, 61) of the sheath thermocouple (56, 57, 58) is configured to extend outward from any of the cable extraction holes (48).

[0078] In a modified example, the configuration in which the inert gas ejected from the top of the gas supply pipe (34) diffuses along the top of the inner wall of the protective pipe (32) toward the center or circumference, descends along the inner wall of the protective pipe (32), passes through the discharge pipe (35), and is discharged from the cable extraction hole (48) is the same as in the above-described embodiment.

[0079] In this modified example, the same effect as in the above-described embodiment is obtained. In addition, since each sheath thermocouple (56, 57, 58) is provided in multiple quantities along the inner wall of the protective tube (32), stable temperature measurement can be performed regardless of the rotational position when installing the temperature measuring assembly (15). Explanation of the symbols

[0080] 15: Temperature measuring assembly 32: Protector 33: Sith Heatwave 34: Gas supply pipe 38: Heatwave 39: Gap

Claims

Claim 1 A temperature measuring assembly comprising: a gas supply pipe including a gas flow path inside; a temperature sensor including a measuring part disposed outside the gas supply pipe to measure temperature; a protective pipe in which the gas supply pipe and the temperature sensor are disposed inside; a connector part including an adhesive part attached to the lower part of the protective pipe and an exposed terminal electrically connected to the temperature sensor; and a holder including an exhaust part for exhausting the gas, wherein the outlet of the gas supply pipe for ejecting the gas into the protective pipe is disposed at a position closer to the top of the protective pipe than to the top of the temperature sensor, and the gas is configured to descend through the gap between the outer wall of the temperature sensor and the inner wall of the protective pipe. Claim 2 A temperature measuring assembly according to claim 1, comprising a gas discharge pipe for discharging the gas from within the protective pipe, wherein the diameter of the gas discharge pipe is larger than the diameter of the gas supply pipe. Claim 3 In claim 1, the protective tube is a temperature measuring assembly having an internal space in the direction of gas ejection of the gas supply tube. Claim 4 A temperature measuring assembly according to claim 1, wherein the temperature sensor includes a sheath tube, and the measuring part is disposed inside the sheath tube. Claim 5 delete Claim 6 A temperature measuring assembly according to claim 1, wherein the holder further comprises a locking coupling portion that locks together with a vacuum joint maintaining airtightness between it and the protective tube. Claim 7 In claim 4, the temperature measuring assembly further comprises a gas discharge pipe for discharging the gas from within the protective tube, wherein the gas supply pipe, the sheath pipe, and the gas discharge pipe are arranged to be extended longitudinally within the protective tube, and a portion of each is exposed to the outside of the protective tube, and the space between them and the lower part of the protective tube is sealed with a sealant. Claim 8 In claim 1, the holder includes a case portion that accommodates the wires of the temperature sensor, and the connector portion is a temperature measuring assembly formed in the case portion. Claim 9 In claim 8, the case portion comprises a planar portion parallel to the longitudinal direction of the protective tube, and the terminals are arranged on the planar portion, forming a temperature measuring assembly. Claim 10 A temperature measuring assembly according to claim 8, wherein one end of a gas discharge pipe for discharging the gas from the protective tube is fluidly open within the case portion, and the case portion is purged with the gas, and the case portion includes a planar portion parallel to the longitudinal direction of the protective tube, and the terminals are arranged in the planar portion. Claim 11 A temperature measuring assembly according to claim 1, wherein the temperature sensor is positioned further from the central axis of the protective tube than the gas supply tube. Claim 12 In claim 6, the locking coupling part comprises a flange part that contacts the vacuum joint and a cap nut that is screw-coupled upon attachment to pull the holder closer to the vacuum joint, and the cap nut is loosely fitted into the holder so as not to be detached by the flange part, a temperature measuring assembly. Claim 13 A temperature measuring assembly according to claim 1, wherein the wire of the temperature sensor is drawn out of the case through a hole provided in the case and connected to a terminal screw provided on the outside of the case. Claim 14 A temperature measuring assembly according to claim 8, further comprising a cover that blocks the lower opening of the case portion and supports the gas supply pipe. Claim 15 In paragraph 4, the temperature measuring assembly comprises a plurality of temperature sensors, each separately accommodated in the sheath tube. Claim 16 A substrate processing device comprising: a processing vessel; a heating unit arranged to surround the processing vessel; a tubular heating element disposed within the processing vessel, which accommodates a substrate and is heated by the heating unit; a tubular insulating body disposed between the processing vessel and the heating element; and a temperature measuring assembly disposed within the heating element, extending in the vertical direction of the heating element, wherein the temperature measuring assembly comprises: a gas supply pipe having a gas flow path inside; a temperature sensor having a measuring unit disposed outside the gas supply pipe to measure the temperature; a protective tube disposed within which the gas supply pipe and the temperature sensor extend vertically; a connector part including an adhesive part attached to the lower part of the protective tube and an exposed terminal electrically connected to the temperature sensor; and a holder including an exhaust part for exhausting the gas, wherein the outlet of the gas supply pipe for ejecting the gas into the protective tube is disposed at a position higher than the temperature sensor, and the gas is configured to descend through the gap between the outer wall of the temperature sensor and the inner wall of the protective tube. Claim 17 A substrate processing method comprising: a process of accommodating a substrate inside a cylindrical heating element disposed within a processing vessel; a process of heating a heating unit provided to surround the processing vessel to raise the temperature of the cylindrical heating element; and a process of controlling the heating unit based on a temperature measured by a temperature measuring assembly disposed extending in the vertical direction of the heating element inside the heating element; wherein in the controlling process, a gas supply pipe including a gas flow path inside, a temperature sensor including a measuring unit disposed outside the gas supply pipe to measure the temperature, a temperature measuring assembly including a protective pipe extending vertically inside the gas supply pipe and the temperature sensor, a connector part including an adhesive part attached to the lower part of the protective pipe and an exposed terminal electrically connected to the temperature sensor, and an exhaust part for exhausting the gas are used, wherein the gas ejected into the protective pipe from a nozzle of the gas supply pipe disposed at a position higher than the temperature sensor descends through the gap between the outer wall of the temperature sensor and the inner wall of the protective pipe. Claim 18 A method for manufacturing a semiconductor device, comprising: a process of accommodating a substrate inside a cylindrical heating element disposed within a processing vessel; a process of heating a heating unit provided to surround the processing vessel to raise the temperature of the cylindrical heating element; and a process of controlling the heating unit based on a temperature measured by a temperature measuring assembly disposed extending in the vertical direction of the heating element inside the heating element; wherein in the controlling process, a gas supply pipe including a gas flow path inside, a temperature sensor including a measuring unit disposed outside the gas supply pipe to measure the temperature, a temperature measuring assembly including a protective pipe extending vertically inside the gas supply pipe and the temperature sensor, a connector part including an adhesive part attached to the lower part of the protective pipe and an exposed terminal electrically connected to the temperature sensor, and an exhaust part for exhausting the gas, wherein the gas ejected into the protective pipe from a nozzle of the gas supply pipe disposed at a position higher than the temperature sensor descends through the gap between the outer wall of the temperature sensor and the inner wall of the protective pipe.

Images