KR102800096B1 - Heat treatment method - Google Patents

Abstract

[Task] To provide a heat treatment method that can reliably perform substrate exchange in a chamber.
[Solution] Heat treatment of a preceding wafer is performed in a processing chamber. Return of a subsequent wafer toward a transfer robot that transfers semiconductor wafers into and out of the processing chamber is initiated. Even when the first subsequent wafer reaches the transfer robot and wafer exchange between the preceding wafer and the subsequent wafer becomes possible, the wafer exchange is not performed immediately, but a certain period of time is waited. While waiting for the wafer exchange, the return of the subsequent wafer is continued so as to fill a plurality of return positions. When the predetermined waiting period has elapsed and the wafer exchange is performed, some of the plurality of return positions are occupied by the subsequent wafer. Since the return positions are not blocked by the preceding wafer, the subsequent wafer can be returned smoothly and the wafer exchange in the processing chamber can be performed reliably.

Description

HEAT TREATMENT METHOD

The present invention relates to a heat treatment method for sequentially performing heat treatment on a plurality of subsequent substrates that are to be processed sequentially after performing heat treatment on a preceding substrate that is to be processed alone. The substrates to be processed include, for example, semiconductor wafers, substrates for liquid crystal displays, substrates for flat panel displays (FPDs), substrates for optical disks, substrates for magnetic disks, or substrates for solar cells.

In the manufacturing process of semiconductor devices, flash lamp annealing (FLA), which heats semiconductor wafers in a very short period of time, is attracting attention. Flash lamp annealing is a heat treatment technology that uses a xenon flash lamp (hereinafter, when simply referred to as a “flash lamp,” it means a xenon flash lamp) to irradiate the surface of the semiconductor wafer with flash light to heat only the surface of the semiconductor wafer in a very short period of time (several milliseconds or less).

The radiation spectral distribution of a xenon flash lamp is from the ultraviolet to the near infrared, and has a shorter wavelength than that of a conventional halogen lamp, and almost matches the fundamental absorption band of a silicon semiconductor wafer. Therefore, when a semiconductor wafer is irradiated with flash light from a xenon flash lamp, the semiconductor wafer can be rapidly heated because the transmitted light is small. In addition, it has been found that only the vicinity of the surface of a semiconductor wafer can be selectively heated if the flash light is irradiated for a very short time of several milliseconds or less.

Such flash lamp annealing is used in processes that require extreme heating times, for example, typically for the activation of impurities implanted in semiconductor wafers. When flash light from a flash lamp is irradiated onto the surface of a semiconductor wafer implanted with impurities by ion implantation, the surface of the semiconductor wafer can be heated to an activation temperature for an extreme period of time, so that only impurity activation can be performed without deeply diffusing the impurities.

Patent Document 1 discloses a heat treatment device that preheats a semiconductor wafer accommodated in a chamber by irradiating it with light from a halogen lamp, and then irradiates the surface of the semiconductor wafer with flash light from a flash lamp. In addition, Patent Document 1 discloses a method in which a semiconductor wafer that has undergone a prior heat treatment is taken out of a chamber by one hand of a transport robot, and an unprocessed semiconductor wafer is brought into the chamber by the other hand, thereby performing wafer exchange.

Japanese Patent Publication No. 2020-120078

In order to reliably perform wafer exchange, it is necessary for the return robot to hold the subsequent semiconductor wafer and wait in front of the chamber at the time when the processing of the preceding semiconductor wafer is finished. For this reason, conventionally, in a series of semiconductor wafer processing flows, the processing time of the recipe has been adjusted so that the processing in the chamber becomes the rate-limiting step. In other words, the processing time in the chamber has been adjusted to be longer than the time required until the semiconductor wafer taken out from the carrier is returned to the chamber. Thereby, wafer exchange can be reliably performed, and as a result, a semiconductor wafer always exists in the chamber, and it becomes possible to stabilize the temperature in the chamber.

However, if a new processing unit is added to the semiconductor wafer return path, the return time of the semiconductor wafer from the carrier to the chamber becomes longer. Then, the state in which the processing in the chamber becomes the rate-limiting step is broken, a case occurs in which wafer exchange cannot be performed, and a time period in which no semiconductor wafer exists in the chamber occurs. When no semiconductor wafer exists in the chamber, heating by the halogen lamp and flash lamp is also not performed, so the temperature of the chamber decreases as the time in which no semiconductor wafer exists becomes longer. As a result, the temperature of the chamber becomes different for each of the plurality of semiconductor wafers constituting the lot, and a problem occurs in which the processing results among the plurality of semiconductor wafers become uneven.

Additionally, although it is possible to return the processing in the chamber to a state where it becomes a rate-limiting step by extending the processing time of the recipe, it is not easy to change the conditions of a production recipe that has been determined after much evaluation.

The present invention has been made in consideration of the above problems, and aims to provide a heat treatment method capable of reliably performing substrate exchange in a chamber.

In order to solve the above problem, the invention of claim 1 is a heat treatment method for sequentially performing heat treatment on a plurality of subsequent substrates to be processed sequentially after performing heat treatment on a preceding substrate to be processed alone, comprising: a preceding heating step of irradiating light from a lamp to the preceding substrate in a chamber to heat the preceding substrate; a first transfer step of sequentially transferring the plurality of subsequent substrates from a load port to a transfer robot through a plurality of positions; a waiting step of waiting for a predetermined time for substrate exchange between the first subsequent substrate and the preceding substrate by the transfer robot after the first subsequent substrate among the plurality of subsequent substrates reaches the transfer robot; a second transfer step of transferring the plurality of subsequent substrates from the load port to the transfer robot so as to fill the plurality of positions during the waiting step; an exchange step in which, after the waiting step, the transfer robot exchanges the preceding substrate and the first subsequent substrate within the chamber; and a second transfer step of transferring the preceding substrate from the transfer robot to the load port while transferring the plurality of subsequent substrates from the load port to the load port. It is characterized by comprising a third return process for sequentially returning the substrates toward the return robot, and a subsequent heating process for sequentially heating the plurality of subsequent substrates by light irradiation from the lamp within the chamber.

In addition, the invention of claim 2 is characterized in that, in the heat treatment method according to the invention of claim 1, in the waiting process, the substrate exchange is waited for until a predetermined waiting time has elapsed.

In addition, the invention of claim 3 is characterized in that, in the heat treatment method according to the invention of claim 1, in the waiting process, the substrate exchange is waited for until a specific position among the plurality of positions is filled by the second return process.

In addition, the invention of claim 4 is characterized in that, in the heat treatment method according to any one of the inventions of claims 1 to 3, the plurality of positions include an alignment unit for adjusting the direction of the substrate, a flaw detection unit for detecting flaws in the substrate, and a cooling unit for cooling the substrate.

In addition, the invention of claim 5 is characterized in that, in the heat treatment method according to the invention of claim 4, the preceding substrate is a dummy substrate, and in the preceding heating process, a dummy heating treatment is performed by irradiating light onto the dummy substrate to heat the inside of the chamber.

In addition, the invention of claim 6 is characterized in that, in the heat treatment method according to the invention of claim 5, the plurality of subsequent substrates are dummy substrates, and in the preceding heating process, a warm-up process is performed to keep the inside of the chamber at a constant temperature, and in the subsequent heating process, a conditioning process is performed to control the inside of the chamber to a target temperature.

According to the invention of claims 1 to 6, after the first subsequent substrate reaches the return robot, substrate exchange between the first subsequent substrate and the preceding substrate waits for a predetermined time, and during the waiting process, a plurality of subsequent substrates are returned so as to fill a plurality of positions. Therefore, the plurality of positions are not blocked by the preceding substrates, and the plurality of subsequent substrates can be smoothly returned to ensure substrate exchange in the chamber.

Figure 1 is a plan view showing a heat treatment device according to the present invention.
Figure 2 is a front view of the heat treatment device of Figure 1.
Figure 3 is a cross-sectional view showing the configuration of a heat treatment section.
Figure 4 is a perspective view showing the overall appearance of the maintenance unit.
Figure 5 is a plan view of the susceptor.
Figure 6 is a cross-sectional view of a susceptor.
Figure 7 is a plan view of the transfer mechanism.
Figure 8 is a side view of the transfer mechanism.
Figure 9 is a plan view showing the arrangement of multiple halogen lamps.
Figure 10 is a flow chart showing the semiconductor wafer return sequence in the first embodiment.
Figure 11 is a diagram schematically showing one process of returning a semiconductor wafer.
Figure 12 is a diagram schematically showing one process of returning a semiconductor wafer.
Figure 13 is a diagram schematically showing one process of returning a semiconductor wafer.
Figure 14 is a diagram schematically showing one process of returning a semiconductor wafer.
Figure 15 is a diagram schematically showing one process of returning a semiconductor wafer.
Figure 16 is a diagram schematically showing one process of returning a semiconductor wafer.
Figure 17 is a diagram schematically showing one process of returning a semiconductor wafer.
Figure 18 is a diagram schematically showing one process of returning a semiconductor wafer.
Figure 19 is a diagram schematically showing one process of returning a semiconductor wafer.
Figure 20 is a diagram schematically showing one process of returning a semiconductor wafer.
Figure 21 is a diagram schematically showing one process of returning a semiconductor wafer.
Figure 22 is a diagram schematically showing one process of returning a semiconductor wafer.
Figure 23 is a diagram schematically showing another example of return of a semiconductor wafer.
Figure 24 is a diagram schematically showing a comparative example of return of a semiconductor wafer.
Figure 25 is a diagram schematically showing a comparative example of return of a semiconductor wafer.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, expressions indicating a relative or absolute positional relationship (e.g., “in one direction,” “along one direction,” “parallel,” “orthogonal,” “centered,” “concentric,” “coaxial,” etc.) are intended to not only strictly indicate the positional relationship, unless otherwise specified, but also indicate a state of relative angular or distance displacement within a range in which tolerance or the same level of function is obtained. In addition, expressions indicating the same state (e.g., “identical,” “same,” “homogeneous,” etc.) are intended to not only quantitatively and strictly indicate the same state, unless otherwise specified, but also indicate a state in which there is a difference in which tolerance or the same level of function is obtained. In addition, expressions indicating a shape (e.g., "circular shape", "square shape", "cylindrical shape", etc.) are intended to indicate not only the geometrically strict shape unless specifically stated otherwise, but also a shape within a range where the same degree of effect is obtained, and may, for example, have unevenness or chamfering. In addition, each expression such as "possesses", "is equipped with", "is equipped with", "is included", and "is equipped with" a component is not an exclusive expression that excludes the existence of other components. In addition, the expression "at least one of A, B, and C" includes "A only", "B only", "C only", "any two of A, B, and C", and "all of A, B, and C".

<First embodiment>

First, a heat treatment device according to the present invention will be described. Fig. 1 is a plan view showing a heat treatment device (100) according to the present invention, and Fig. 2 is a front view thereof. The heat treatment device (100) is a flash lamp annealing device that irradiates a semiconductor wafer (W) having a disk shape as a substrate with flash light to heat the semiconductor wafer (W). The size of the semiconductor wafer (W) to be treated is not particularly limited, but is, for example, φ300 mm or φ450 mm. In addition, in Fig. 1 and each drawing thereafter, the dimensions or numbers of each part are exaggerated or simplified as necessary for ease of understanding. In addition, in each drawing of Figs. 1 to 3, an XYZ rectangular coordinate system is attached in which the Z-axis direction is the vertical direction and the XY plane is the horizontal plane in order to clarify their directional relationship.

As shown in FIG. 1 and FIG. 2, the heat treatment device (100) comprises an indexer unit (101) for loading an unprocessed semiconductor wafer (W) into the device from the outside and also for removing a processed semiconductor wafer (W) out of the device, an alignment unit (230) for determining the position of the unprocessed semiconductor wafer (W), a scratch detection unit (300) for detecting the presence or absence of a scratch on the back surface of the semiconductor wafer (W), two cooling units (a first cooling unit (130) and a second cooling unit (140)) for cooling the semiconductor wafer (W) after heat treatment, a heat treatment unit (160) for performing flash heat treatment on the semiconductor wafer (W), and a transfer robot (150) for transferring the semiconductor wafer (W) to the first cooling unit (130), the second cooling unit (140), and the heat treatment unit (160). In addition, the heat treatment device (100) is equipped with a control unit (3) that controls the operating mechanism and the return robot (150) installed in each of the above processing units to perform flash heat treatment of the semiconductor wafer (W).

The indexer unit (101) is equipped with a load port (110) for lining up and storing a plurality of carriers (C), and a hand robot (120) for taking out unprocessed semiconductor wafers (W) from each carrier (C) and storing processed semiconductor wafers (W) in each carrier (C). To be precise, three load ports are installed in the indexer unit (101), and the load port (110) is a general term including a first load port (110a), a second load port (110b), and a third load port (110c) (if the three load ports are not specifically distinguished, they are simply referred to as load ports (110)). Of the three load ports, a carrier (C) containing a semiconductor wafer (W) to be a product (hereinafter, also referred to as a product wafer (W)) is placed in the first load port (110a) and the second load port (110b). Meanwhile, the third load port (110c) is a load port exclusively for a dummy carrier (DC) that accommodates a dummy wafer (DW). That is, only a dummy carrier (DC) is loaded into the third load port (110c). Typically, a dummy carrier (DC) that accommodates a plurality of dummy wafers (DW) is always loaded into the third load port (110c).

A carrier (C) and a dummy carrier (DC) that accommodate unprocessed semiconductor wafers (W) are returned by an unmanned transport vehicle (AGV, OHT) and placed in a load port (110). In addition, a carrier (C) and a dummy carrier (DC) that accommodate processed semiconductor wafers (W) are also taken out from the load port (110) by an unmanned transport vehicle.

In addition, in the load port (110), the carrier (C) and the dummy carrier (DC) are configured to be able to move up and down as indicated by the arrow CU in Fig. 2 so that the water robot (120) can load and unload any semiconductor wafer (W) (or dummy wafer (DW)) to and from the carrier (C) and the dummy carrier (DC). In addition, as for the form of the carrier (C) and the dummy carrier (DC), in addition to a FOUP (front opening unified pod) that stores a semiconductor wafer (W) in a sealed space, a SMIF (Standard Mechanical Inter Face) pod or an OC (open cassette) that exposes the stored semiconductor wafer (W) to the outside may be used.

In addition, the water supply robot (120) is capable of sliding movement as indicated by arrow 120S in Fig. 1, turning movement as indicated by arrow 120R, and lifting movement. The water supply robot (120) is equipped with two transfer hands (121a, 121b) each holding a semiconductor wafer (W). These transfer hands (121a, 121b) are arranged spaced apart from each other by a predetermined pitch in the upper and lower directions, and are each capable of moving forward and backward linearly in the same horizontal direction independently. Accordingly, the water supply robot (120) transfers the semiconductor wafer (W) to and from the carrier (C) and the dummy carrier (DC), and transfers the semiconductor wafer (W) to the alignment unit (230), the flaw detection unit (300), the first cooling unit (130), and the second cooling unit (140). The transfer of a semiconductor wafer (W) to a carrier (C) (or a dummy carrier (DC)) by a water supply robot (120) is performed by the sliding movement of the transfer hand (121a) (or the transfer hand (121b)) and the lifting and lowering movement of the carrier (C). In addition, the transfer of a semiconductor wafer (W) between the water supply robot (120), the alignment unit (230), the flaw detection unit (300), the first cooling unit (130) or the second cooling unit (140) is performed by the forward and backward movement of the transfer hand (121a) (or the transfer hand (121b)) and the lifting and lowering operation of the water supply robot (120).

The alignment unit (230) is installed and connected to the side (+Y side) of the indexer unit (101) along the Y-axis direction. The alignment unit (230) is a processing unit that rotates a semiconductor wafer (W) within a horizontal plane to face a direction appropriate for flash heating. The alignment unit (230) is configured by installing, inside an alignment chamber (231) which is a housing made of aluminum alloy, a mechanism for supporting and rotating a semiconductor wafer (W) in a horizontal position, and a mechanism for optically detecting a notch or orientation flat formed on the periphery of the semiconductor wafer (W).

The semiconductor wafer (W) is transferred to the alignment unit (230) by the transfer robot (120). The semiconductor wafer (W) is transferred from the transfer robot (120) to the alignment chamber (231) so that the center of the wafer is positioned at a predetermined position. In the alignment unit (230), the semiconductor wafer (W) received from the indexer unit (101) is rotated around the vertical axis with the center of the semiconductor wafer (W) as the rotation center, and the orientation of the semiconductor wafer (W) is adjusted by optically detecting notches and the like. The semiconductor wafer (W) whose orientation has been adjusted is taken out from the alignment chamber (231) by the transfer robot (120).

The scratch detection unit (300) is installed and connected to the side (-Y side) of the indexer unit (101) opposite to the alignment unit (230) along the Y-axis direction. The scratch detection unit (300) detects the presence or absence of a scratch on the back surface of a semiconductor wafer (W). In addition, the surface of the main surface of the semiconductor wafer (W) on which a pattern is formed and which is to be processed is the surface, and the surface opposite to that surface is the back surface. The scratch detection unit (300) is configured to include, inside a scratch detection chamber (301) which is a housing made of an aluminum alloy, an imaging unit which captures an image of the back surface of the semiconductor wafer (W), and a judgment unit which performs predetermined image processing on the acquired image data to determine the presence or absence of a scratch.

The semiconductor wafer (W) is transferred to the scratch detection unit (300) by the hand-washing robot (120). The semiconductor wafer (W) is transferred from the hand-washing robot (120) to the scratch detection chamber (301) so that the center of the wafer is positioned at a predetermined position. The scratch detection unit (300) captures an image of the back surface of the semiconductor wafer (W) and analyzes the acquired image data to detect the presence or absence of a scratch. The semiconductor wafer (W) on which the scratch detection is completed is taken out from the scratch detection chamber (301) by the hand-washing robot (120).

A transfer chamber (170) that accommodates a transfer robot (150) is installed as a transfer space for a semiconductor wafer (W) by a transfer robot (150). A processing chamber (6) of a heat treatment unit (160), a first cool chamber (131) of a first cooling unit (130), and a second cool chamber (141) of a second cooling unit (140) are connected to three sides of the transfer chamber (170).

The heat treatment unit (160), which is the main part of the heat treatment device (100), is a substrate treatment unit that performs flash heat treatment by irradiating a semiconductor wafer (W) that has undergone preheating with a flash of light (flash light) from a xenon flash lamp (FL). The configuration of this heat treatment unit (160) will be described further below.

The first cooling unit (130) and the second cooling unit (140) have approximately the same configuration. The first cooling unit (130) and the second cooling unit (140) each have a metal cooling plate and a quartz plate placed on the upper surface thereof, inside the first cool chamber (131) and the second cool chamber (141), which are housings made of aluminum alloy (both not shown). The cooling plate is temperature-controlled to room temperature (approximately 23°C) by a Peltier element or constant-temperature water circulation. A semiconductor wafer (W) that has been subjected to flash heating treatment in the heat treatment unit (160) is introduced into the first cool chamber (131) or the second cool chamber (141), placed on the quartz plate, and cooled.

The first cool chamber (131) and the second cool chamber (141) are both connected to each other between the indexer section (101) and the return chamber (170). Two openings are formed in the first cool chamber (131) and the second cool chamber (141) for loading and unloading a semiconductor wafer (W). Of the two openings of the first cool chamber (131), the opening connected to the indexer section (101) can be opened and closed by a gate valve (181). On the other hand, the opening of the first cool chamber (131) connected to the return chamber (170) can be opened and closed by a gate valve (183). That is, the first cool chamber (131) and the indexer part (101) are connected through a gate valve (181), and the first cool chamber (131) and the return chamber (170) are connected through a gate valve (183).

When transferring a semiconductor wafer (W) between the indexer section (101) and the first cool chamber (131), the gate valve (181) is opened. Also, when transferring a semiconductor wafer (W) between the first cool chamber (131) and the return chamber (170), the gate valve (183) is opened. When the gate valve (181) and the gate valve (183) are closed, the interior of the first cool chamber (131) becomes a sealed space.

In addition, among the two openings of the second cool chamber (141), the opening connected to the indexer part (101) can be opened and closed by a gate valve (182). Meanwhile, the opening connected to the return chamber (170) of the second cool chamber (141) can be opened and closed by a gate valve (184). That is, the second cool chamber (141) and the indexer part (101) are connected through the gate valve (182), and the second cool chamber (141) and the return chamber (170) are connected through the gate valve (184).

When transferring a semiconductor wafer (W) between the indexer section (101) and the second cool chamber (141), the gate valve (182) is opened. Also, when transferring a semiconductor wafer (W) between the second cool chamber (141) and the return chamber (170), the gate valve (184) is opened. When the gate valve (182) and the gate valve (184) are closed, the interior of the second cool chamber (141) becomes a sealed space.

In addition, the first cooling unit (130) and the second cooling unit (140) are each provided with a gas supply mechanism for supplying clean nitrogen gas to the first cool chamber (131) and the second cool chamber (141) and an exhaust mechanism for exhausting the atmosphere within the chamber. These gas supply mechanisms and exhaust mechanisms may be configured to be capable of switching the flow rate in two stages.

The transfer robot (150) installed in the transfer chamber (170) is capable of turning around an axis along a vertical direction as indicated by arrow 150R. The transfer robot (150) has two link mechanisms formed of a plurality of arm segments, and a transfer hand (151a, 151b) for holding a semiconductor wafer (W) is installed at the tip of each of the two link mechanisms. These transfer hands (151a, 151b) are arranged to be spaced apart from each other vertically by a predetermined pitch, and are independently and linearly slidable in the same horizontal direction by the link mechanism. In addition, the transfer robot (150) moves the base on which the two link mechanisms are installed up and down to move the two transfer hands (151a, 151b) up and down while remaining spaced apart by a predetermined pitch.

When a return robot (150) performs transfer (input/output) of a semiconductor wafer (W) to the first cool chamber (131), the second cool chamber (141), or the processing chamber (6) of the heat treatment unit (160) with respect to the handover counterpart, first, both return hands (151a, 151b) are turned to face the handover counterpart, and then (or while turning) are moved up and down so that one of the return hands is positioned at a height at which the handover counterpart and the semiconductor wafer (W) are transferred. Then, the return hand (151a (151b)) is linearly slid horizontally to perform transfer of the semiconductor wafer (W) to the handover counterpart.

The transfer of the semiconductor wafer (W) between the transfer robot (150) and the handing robot (120) can be performed through the first cooling unit (130) or the second cooling unit (140). That is, the first cool chamber (131) of the first cooling unit (130) and the second cool chamber (141) of the second cooling unit (140) also function as a path for transferring the semiconductor wafer (W) between the transfer robot (150) and the handing robot (120). Specifically, the transfer of the semiconductor wafer (W) is performed when one of the transfer robot (150) or the handing robot (120) hands over the semiconductor wafer (W) to the first cool chamber (131) or the second cool chamber (141) and the other receives it. The capital robot (120) serves as a return mechanism that returns a semiconductor wafer (W) from the load port (110) toward the return robot (150).

As described above, gate valves (181, 182) are installed between the first cool chamber (131) and the second cool chamber (141) and the indexer unit (101), respectively. In addition, gate valves (183, 184) are installed between the return chamber (170) and the first cool chamber (131) and the second cool chamber (141), respectively. In addition, a gate valve (185) is installed between the return chamber (170) and the processing chamber (6) of the heat treatment unit (160). When a semiconductor wafer (W) is returned within the heat treatment device (100), these gate valves are opened and closed appropriately. In addition, nitrogen gas is supplied from the gas supply unit to the return chamber (170), the alignment chamber (231), and the flaw detection chamber (301), and the atmosphere inside them is exhausted by the exhaust unit (all not shown).

Next, the configuration of the heat treatment unit (160) will be described. FIG. 3 is a cross-sectional view showing the configuration of the heat treatment unit (160). The heat treatment unit (160) has a processing chamber (6) that accommodates a semiconductor wafer (W) and performs a heat treatment, a flash lamp house (5) that houses a plurality of flash lamps (FL), and a halogen lamp house (4) that houses a plurality of halogen lamps (HL). The flash lamp house (5) is installed on the upper side of the processing chamber (6), and the halogen lamp house (4) is installed on the lower side. In addition, the heat treatment unit (160) has a holding unit (7) that maintains the semiconductor wafer (W) in a horizontal position inside the processing chamber (6), and a transfer mechanism (10) that transfers the semiconductor wafer (W) between the holding unit (7) and the transfer robot (150).

The processing chamber (6) is configured by mounting quartz chamber windows on the upper and lower sides of a cylindrical chamber side (61). The chamber side (61) has a generally cylindrical shape that is open at the top and bottom, and an upper chamber window (63) is mounted on the upper opening and closed, and a lower chamber window (64) is mounted on the lower opening and closed. The upper chamber window (63) constituting the ceiling of the processing chamber (6) is a disc-shaped member formed of quartz, and functions as a quartz window that transmits flash light emitted from a flash lamp (FL) into the processing chamber (6). In addition, the lower chamber window (64) constituting the bottom of the processing chamber (6) is also a disc-shaped member formed of quartz, and functions as a quartz window that transmits light from a halogen lamp (HL) into the processing chamber (6).

In addition, a reflection ring (68) is mounted on the upper part of the inner wall surface of the chamber side (61), and a reflection ring (69) is mounted on the lower part. The reflection rings (68, 69) are both formed in an annular shape. The upper reflection ring (68) is mounted by fitting it in from the upper part of the chamber side (61). On the other hand, the lower reflection ring (69) is mounted by fitting it in from the lower part of the chamber side (61) and fixing it with a screw (not shown). That is, the reflection rings (68, 69) are both removably mounted on the chamber side (61). The inner space of the processing chamber (6), that is, the space surrounded by the upper chamber window (63), the lower chamber window (64), the chamber side (61), and the reflection rings (68, 69), is defined as a heat treatment space (65).

By mounting the reflection ring (68, 69) on the chamber side (61), a concave portion (62) is formed on the inner wall surface of the processing chamber (6). That is, a concave portion (62) is formed by the central portion of the inner wall surface of the chamber side (61) where the reflection ring (68, 69) is not mounted, the lower surface of the reflection ring (68), and the upper surface of the reflection ring (69). The concave portion (62) is formed in an annular shape along the horizontal direction on the inner wall surface of the processing chamber (6) and surrounds the holding portion (7) that holds the semiconductor wafer (W). The chamber side (61) and the reflection ring (68, 69) are formed of a metal material (for example, stainless steel) having excellent strength and heat resistance.

In addition, a return opening (substrate return inlet/outlet) (66) is formed on the chamber side (61) for introducing and removing a semiconductor wafer (W) to and from the processing chamber (6). The return opening (66) can be opened and closed by a gate valve (185). The return opening (66) is connected to the outer surface of the concave portion (62) in communication with it. Therefore, when the gate valve (185) opens the return opening (66), the semiconductor wafer (W) can be introduced from the return opening (66) through the concave portion (62) into the heat treatment space (65) and removed from the heat treatment space (65). In addition, when the gate valve (185) closes the return opening (66), the heat treatment space (65) in the processing chamber (6) becomes a sealed space.

In addition, a through hole (61a) and a through hole (61b) are formed in the chamber side (61). An edge radiation thermometer (edge pyrometer) (20) is mounted in the portion of the outer wall surface of the chamber side (61) where the through hole (61a) is formed. The through hole (61a) is a cylindrical hole for guiding infrared light radiated from the lower surface of a semiconductor wafer (W) held on a susceptor (74) described later to the edge radiation thermometer (20). On the other hand, a center radiation thermometer (center pyrometer) (25) is mounted in the portion of the outer wall surface of the chamber side (61) where the through hole (61b) is formed. The through hole (61b) is a cylindrical hole for guiding infrared light radiated from the susceptor (74) to the center radiation thermometer (25). The through holes (61a) and (61b) are formed so as to be inclined with respect to the horizontal direction that the axes of the through holes intersect the main surface of the semiconductor wafer (W) held on the susceptor (74). Accordingly, the single-section radiation thermometer (20) and the central radiation thermometer (25) are installed obliquely below the susceptor (74). At the ends of the through holes (61a) and (61b) on the side facing the heat treatment space (65), transparent windows (21) and (26) made of a barium fluoride material that transmit infrared light in a wavelength range that the single-section radiation thermometer (20) and the central radiation thermometer (25) can measure are respectively mounted.

In addition, a gas supply hole (81) for supplying a processing gas to a heat treatment space (65) is formed on the upper part of the inner wall of the processing chamber (6). The gas supply hole (81) is formed at a position higher than the concave portion (62), and may be formed on the reflecting ring (68). The gas supply hole (81) is connected to a gas supply pipe (83) through a buffer space (82) formed in an annular shape on the inside of the side wall of the processing chamber (6). The gas supply pipe (83) is connected to a processing gas supply source (85). In addition, a valve (84) is inserted in the middle of the path of the gas supply pipe (83). When the valve (84) is opened, processing gas is supplied from the processing gas supply source (85) to the buffer space (82). The processing gas introduced into the buffer space (82) flows so as to spread within the buffer space (82) having a lower fluid resistance than the gas supply hole (81) and is supplied from the gas supply hole (81) into the heat treatment space (65). As the processing gas, an inert gas such as nitrogen (N ₂ ), a reactive gas such as hydrogen (H ₂ ) or ammonia (NH ₃ ), or a mixed gas containing them can be used (nitrogen in this embodiment).

Meanwhile, a gas exhaust hole (86) for exhausting gas within the heat treatment space (65) is formed at the lower portion of the inner wall of the processing chamber (6). The gas exhaust hole (86) is formed at a lower position than the concave portion (62), and may be formed in the reflecting ring (69). The gas exhaust hole (86) is connected to a gas exhaust pipe (88) through a buffer space (87) formed in an annular shape within the side wall of the processing chamber (6). The gas exhaust pipe (88) is connected to an exhaust mechanism (190). In addition, a valve (89) is inserted in the middle of the path of the gas exhaust pipe (88). When the valve (89) is opened, gas within the heat treatment space (65) is exhausted from the gas exhaust hole (86) through the buffer space (87) to the gas exhaust pipe (88). In addition, the gas supply holes (81) and gas exhaust holes (86) may be formed in multiple numbers along the circumferential direction of the processing chamber (6), and may be slit-shaped. In addition, the processing gas supply source (85) and exhaust mechanism (190) may be mechanisms installed in the heat treatment device (100), or may be utilities of a factory where the heat treatment device (100) is installed.

In addition, a gas exhaust pipe (191) for exhausting gas within the heat treatment space (65) is connected to the tip of the return opening (66). The gas exhaust pipe (191) is connected to an exhaust mechanism (190) through a valve (192). By opening the valve (192), gas within the treatment chamber (6) is exhausted through the return opening (66).

Fig. 4 is a perspective view showing the overall appearance of the retainer (7). The retainer (7) is configured with a base ring (71), a connecting portion (72), and a susceptor (74). The base ring (71), the connecting portion (72), and the susceptor (74) are all formed of quartz. In other words, the entire retainer (7) is formed of quartz.

The anticipation ring (71) is a quartz member having an arc shape with a part missing from the annular shape. This missing part is formed to prevent interference between the transfer arm (11) of the transfer mechanism (10) described later and the anticipation ring (71). The anticipation ring (71) is placed on the bottom surface of the concave portion (62) so as to be supported on the wall surface of the processing chamber (6) (see Fig. 3). On the upper surface of the anticipation ring (71), a plurality of connecting parts (72) (four in this embodiment) are erected and installed along the circumferential direction of the annular shape. The connecting parts (72) are also made of quartz and are fixed to the anticipation ring (71) by welding.

The susceptor (74) is supported by four connecting members (72) installed on the support ring (71). Fig. 5 is a plan view of the susceptor (74). Also, Fig. 6 is a cross-sectional view of the susceptor (74). The susceptor (74) is provided with a retaining plate (75), a guide ring (76), and a plurality of substrate support pins (77). The retaining plate (75) is a substantially circular flat plate-shaped member formed of quartz. The diameter of the retaining plate (75) is larger than the diameter of the semiconductor wafer (W). That is, the retaining plate (75) has a larger planar size than the semiconductor wafer (W).

A guide ring (76) is installed on the upper surface periphery of the retaining plate (75). The guide ring (76) is a circular member having an inner diameter larger than the diameter of the semiconductor wafer (W). For example, when the diameter of the semiconductor wafer (W) is φ300 mm, the inner diameter of the guide ring (76) is φ320 mm. The inner periphery of the guide ring (76) is a tapered surface that widens upward from the retaining plate (75). The guide ring (76) is formed of the same quartz as the retaining plate (75). The guide ring (76) may be welded to the upper surface of the retaining plate (75) or may be fixed to the retaining plate (75) by a separately processed pin or the like. Alternatively, the retaining plate (75) and the guide ring (76) may be processed as an integral member.

The upper surface of the retaining plate (75) is an area inside the guide ring (76) so as to be a flat retaining surface (75a) for retaining a semiconductor wafer (W). A plurality of substrate support pins (77) are installed erectly on the retaining surface (75a) of the retaining plate (75). In the present embodiment, a total of 12 substrate support pins (77) are installed erectly at 30° intervals along the circumference of a circle concentric with the outer circumference of the retaining surface (75a) (the inner circumference of the guide ring (76)). The diameter of the circle in which the 12 substrate support pins (77) are arranged (the distance between the opposing substrate support pins (77)) is smaller than the diameter of the semiconductor wafer (W), and is φ270 mm to φ280 mm (φ270 mm in the present embodiment) when the diameter of the semiconductor wafer (W) is φ300 mm. Each of the substrate support pins (77) is formed of quartz. A plurality of substrate support pins (77) may be installed by welding on the upper surface of the retaining plate (75), or may be processed integrally with the retaining plate (75).

Returning to Fig. 4, the four connecting parts (72) installed on the support ring (71) and the peripheral part of the retaining plate (75) of the susceptor (74) are fixedly connected by welding. That is, the susceptor (74) and the support ring (71) are fixedly connected by the connecting parts (72). The support ring (71) of the support part (7) is supported on the wall surface of the processing chamber (6), so that the support part (7) is mounted on the processing chamber (6). When the support part (7) is mounted on the processing chamber (6), the retaining plate (75) of the susceptor (74) is in a horizontal position (a position in which the normal line coincides with the vertical direction). That is, the retaining surface (75a) of the support plate (75) becomes a horizontal plane.

A semiconductor wafer (W) loaded into the processing chamber (6) is placed and maintained in a horizontal position on a susceptor (74) of a holding member (7) mounted in the processing chamber (6). At this time, the semiconductor wafer (W) is supported by 12 substrate support pins (77) installed upright on a holding plate (75) and maintained on the susceptor (74). More precisely, the upper portions of the 12 substrate support pins (77) contact the lower surface of the semiconductor wafer (W) to support the semiconductor wafer (W). Since the heights of the 12 substrate support pins (77) (the distance from the upper portions of the substrate support pins (77) to the holding surface (75a) of the holding plate (75)) are uniform, the semiconductor wafer (W) can be supported in a horizontal position by the 12 substrate support pins (77).

In addition, the semiconductor wafer (W) is supported at a predetermined distance from the support surface (75a) of the support plate (75) by a plurality of substrate support pins (77). The thickness of the guide ring (76) is greater than the height of the substrate support pins (77). Therefore, horizontal misalignment of the semiconductor wafer (W) supported by the plurality of substrate support pins (77) is prevented by the guide ring (76).

In addition, as shown in FIGS. 4 and 5, an opening (78) is formed through the holding plate (75) of the susceptor (74) so as to penetrate upward and downward. The opening (78) is provided so that the single-piece radiation thermometer (20) (see FIG. 3) can receive radiation light (infrared light) emitted from the lower surface of the semiconductor wafer (W) held on the susceptor (74). That is, the single-piece radiation thermometer (20) receives light emitted from the lower surface of the semiconductor wafer (W) held on the susceptor (74) through the opening (78) to measure the temperature of the semiconductor wafer (W). In addition, four through holes (79) are formed through which lift pins (12) of a transfer mechanism (10) described later pass to transfer the semiconductor wafer (W).

Fig. 7 is a plan view of a transfer mechanism (10). Also, Fig. 8 is a side view of the transfer mechanism (10). The transfer mechanism (10) is provided with two transfer arms (11). The transfer arms (11) are formed in an arc shape that follows a substantially circular concave portion (62). Two lift pins (12) are installed erectly on each transfer arm (11). Each transfer arm (11) is rotatable by a horizontal movement mechanism (13). The horizontal movement mechanism (13) horizontally moves a pair of transfer arms (11) between a transfer operation position (solid line position in Fig. 7) for transferring a semiconductor wafer (W) with respect to a holding unit (7) and a retracted position (double-dotted line position in Fig. 7) that does not overlap with the semiconductor wafer (W) held by the holding unit (7) when viewed in plan. The transfer operation position is below the susceptor (74), and the retreat position is outside the susceptor (74). As the horizontal movement mechanism (13), each transfer arm (11) may be rotated individually by an individual motor, or a pair of transfer arms (11) may be rotated by linking them with one motor using a link mechanism.

In addition, a pair of transfer arms (11) are moved up and down together with a horizontal movement mechanism (13) by a lifting mechanism (14). When the lifting mechanism (14) raises a pair of transfer arms (11) from a transfer operation position, a total of four lift pins (12) pass through a through hole (79) (see FIGS. 4 and 5) formed in a susceptor (74), and the upper ends of the lift pins (12) protrude from the upper surface of the susceptor (74). Meanwhile, when the lifting mechanism (14) lowers a pair of transfer arms (11) from the transfer operation position and pulls the lift pins (12) out of the through hole (79), and the horizontal movement mechanism (13) moves a pair of transfer arms (11) to spread apart, each transfer arm (11) moves to a retracted position. The retreat position of a pair of transfer arms (11) is directly above the support ring (71) of the retainer (7). Since the support ring (71) is placed on the bottom surface of the concave portion (62), the retreat position of the transfer arm (11) is inside the concave portion (62). In addition, an exhaust mechanism (not shown) is installed near the portion where the drive part (horizontal movement mechanism (13) and the lifting mechanism (14)) of the transfer mechanism (10) is installed, and the atmosphere around the drive part of the transfer mechanism (10) is configured to be discharged to the outside of the processing chamber (6).

As shown in Fig. 3, two radiation thermometers, a single-piece radiation thermometer (20) and a central radiation thermometer (25), are installed in the processing chamber (6). Both the single-piece radiation thermometer (20) and the central radiation thermometer (25) are installed below a semiconductor wafer (W) held on a susceptor (74). The single-piece radiation thermometer (20) receives infrared light emitted from the lower surface of the semiconductor wafer (W) through an opening (78), which is a cut-out formed in the susceptor (74), and measures the temperature of the lower surface. That is, the measurement area of the single-piece radiation thermometer (20) is the inside of the opening (78). On the other hand, the measurement area of the central radiation thermometer (25) is within the surface of the holding plate (75) of the susceptor (74). The central radiation thermometer (25) receives infrared light emitted from the susceptor (74) and measures the temperature of the susceptor (74).

The flash lamp house (5) installed above the processing chamber (6) is configured to include a light source formed of a plurality of (30 in this embodiment) xenon flash lamps (FL) on the inside of the housing (51) and a reflector (52) installed to cover the upper portion of the light source. In addition, a lamp light emission window (53) is mounted on the bottom portion of the housing (51) of the flash lamp house (5). The lamp light emission window (53) forming the bottom portion of the flash lamp house (5) is a plate-shaped quartz window formed of quartz. Since the flash lamp house (5) is installed above the processing chamber (6), the lamp light emission window (53) faces the upper chamber window (63). The flash lamp (FL) irradiates flash light to the heat treatment space (65) from above the processing chamber (6) through the lamp light emission window (53) and the upper chamber window (63).

A plurality of flash lamps (FL) are each a rod-shaped lamp having a long cylindrical shape, and are arranged in a plane shape such that their respective longitudinal directions are parallel to each other along the main surface of the semiconductor wafer (W) held by the support member (7) (i.e., along the horizontal direction). Accordingly, the plane formed by the arrangement of the flash lamps (FL) is also a horizontal plane.

A xenon flash lamp (FL) comprises a rod-shaped glass tube (discharge tube) having xenon gas sealed inside and an anode and cathode connected to a condenser at both ends, and a trigger electrode provided on the outer surface of the glass tube. Since xenon gas is an electrical insulator, no electricity flows inside the glass tube under normal conditions even if charges are accumulated in the condenser. However, when a high voltage is applied to the trigger electrode to destroy the insulation, the electricity accumulated in the condenser flows instantaneously inside the glass tube, and light is emitted by the excitation of xenon atoms or molecules at that time. In such a xenon flash lamp (FL), since the electrostatic energy accumulated in the condenser in advance is converted into an extremely short light pulse of 0.1 millisecond to 100 milliseconds, it has the characteristic of being able to irradiate very strong light compared to a continuous light source such as a halogen lamp (HL). In other words, the flash lamp (FL) is a pulse-emitting lamp that emits light instantaneously in an extremely short time of less than 1 second. In addition, the emission time of the flash lamp (FL) can be adjusted by the coil constant of the lamp power supply that supplies power to the flash lamp (FL).

In addition, a reflector (52) is installed above a plurality of flash lamps (FL) so as to cover them entirely. The basic function of the reflector (52) is to reflect flash light emitted from a plurality of flash lamps (FL) toward the heat treatment space (65). The reflector (52) is formed of an aluminum alloy plate, and its surface (the surface facing the flash lamps (FL)) is roughened by blasting.

The halogen lamp house (4) installed at the bottom of the processing chamber (6) has a plurality of halogen lamps (HL) built into the inside of the housing (41) (40 in this embodiment). The plurality of halogen lamps (HL) irradiate light from the bottom of the processing chamber (6) through the lower chamber window (64) into the heat treatment space (65).

Fig. 9 is a plan view showing the arrangement of a plurality of halogen lamps (HL). In the present embodiment, 20 halogen lamps (HL) are arranged in each of the upper and lower tiers. Each halogen lamp (HL) is a rod-shaped lamp having a long cylindrical shape. The 20 halogen lamps (HL) in the upper tier and the lower tier are arranged so that their respective longitudinal directions are parallel to each other along the main surface of the semiconductor wafer (W) held by the holding member (7) (i.e., along the horizontal direction). Therefore, the plane formed by the arrangement of the halogen lamps (HL) in both the upper and lower tiers is a horizontal plane.

In addition, as shown in Fig. 9, the arrangement density of the halogen lamps (HL) in the area facing the periphery is higher than that in the area facing the center of the semiconductor wafer (W) held by the support member (7) at both the upper and lower ends. That is, the arrangement pitch of the halogen lamps (HL) in the periphery is shorter than that in the center of the lamp array at both the upper and lower ends. Therefore, a greater amount of light can be irradiated to the periphery of the semiconductor wafer (W), which is prone to temperature drop when heated by light irradiation from the halogen lamp (HL).

In addition, the lamp group consisting of the upper halogen lamp (HL) and the lamp group consisting of the lower halogen lamp (HL) are arranged to intersect in a grid shape. That is, a total of 40 halogen lamps (HL) are arranged such that the longitudinal direction of each halogen lamp (HL) on the upper side and the longitudinal direction of each halogen lamp (HL) on the lower side are orthogonal to each other.

A halogen lamp (HL) is a filament-type light source that incandescently illuminates a filament placed inside a glass tube by passing current through the filament. The inside of the glass tube is filled with a gas containing a small amount of a halogen element (iodine, bromine, etc.) introduced into an inert gas such as nitrogen or argon. By introducing the halogen element, it is possible to set the temperature of the filament to a high temperature while suppressing filament breakage. Therefore, the halogen lamp (HL) has a longer lifespan than a conventional incandescent bulb and has the characteristics of being able to continuously irradiate strong light. In other words, the halogen lamp (HL) is a continuous-light lamp that continuously illuminates for at least 1 second. In addition, since the halogen lamp (HL) is a rod-shaped lamp, it has a long lifespan, and by arranging the halogen lamp (HL) so that it is horizontal, the radiation efficiency toward the semiconductor wafer (W) above becomes excellent.

In addition, a reflector (43) is installed on the lower side of the two-stage halogen lamp (HL) in the housing (41) of the halogen lamp house (4) (Fig. 3). The reflector (43) reflects light emitted from a plurality of halogen lamps (HL) toward the heat treatment space (65).

In addition to the above configuration, the heat treatment unit (160) is provided with various cooling structures to prevent excessive temperature rise of the halogen lamp house (4), the flash lamp house (5), and the processing chamber (6) due to heat energy generated from the halogen lamp (HL) and the flash lamp (FL) during the heat treatment of the semiconductor wafer (W). For example, a water cooling pipe (not shown) is installed in the wall of the processing chamber (6). In addition, the halogen lamp house (4) and the flash lamp house (5) have an air cooling structure in which a gas flow is formed and arranged inside. In addition, air is also supplied to the gap between the upper chamber window (63) and the lamp light radiation window (53) to cool the flash lamp house (5) and the upper chamber window (63).

The control unit (3) controls the various operating mechanisms installed in the heat treatment device (100). The hardware configuration of the control unit (3) is the same as that of a general computer. That is, the control unit (3) is equipped with a CPU, which is a circuit that performs various types of arithmetic processing, a ROM, which is a read-only memory that stores a basic program, a RAM, which is a read-and-write memory that stores various types of information, and a memory (for example, a magnetic disk or SSD) that stores control software or data. The processing in the heat treatment device (100) progresses when the CPU of the control unit (3) executes a predetermined processing program. In addition, although the control unit (3) is shown in the indexer unit (101) in Fig. 1, it is not limited thereto, and the control unit (3) can be placed at any location in the heat treatment device (100).

Next, the processing operation of the heat treatment device (100) according to the present invention will be described. First, the processing operation for a semiconductor wafer (product wafer) (W) that becomes a product will be described. The processing sequence of the semiconductor wafer (W) described below is performed by the control unit (3) controlling each operating mechanism of the heat treatment device (100).

First, unprocessed semiconductor wafers (W) are placed on the first load port (110a) or the second load port (110b) of the indexer section (101) in a state where multiple unprocessed semiconductor wafers (W) are accommodated on the carrier (C). Then, the water robot (120) takes out the unprocessed semiconductor wafers (W) one by one from the carrier (C) by the transfer hand (121a) (or the transfer hand (121b)) and loads them into the alignment chamber (231) of the alignment section (230). In the alignment chamber (231), the semiconductor wafer (W) is rotated around the vertical axis in a horizontal plane with its center as the rotation center, and notches and the like are optically detected to adjust the orientation of the semiconductor wafer (W).

Next, the water robot (120) of the indexer section (101) takes out the semiconductor wafer (W) whose direction has been adjusted from the alignment chamber (231) and places it into the scratch detection chamber (301) of the scratch detection section (300). In the scratch detection chamber (301), the back surface of the semiconductor wafer (W) is photographed and the obtained image data is analyzed to detect whether there is a scratch. In addition, since there is a risk that the semiconductor wafer (W) in which a scratch has been detected may be broken when irradiated with flash light in the heat treatment section (160), the semiconductor wafer (W) may be returned to the carrier (C).

Next, the water robot (120) takes out the semiconductor wafer (W) from the scratch detection chamber (301) and loads it into the first cool chamber (131) of the first cooling unit (130) or the second cool chamber (141) of the second cooling unit (140). The unprocessed semiconductor wafer (W) loaded into the first cool chamber (131) or the second cool chamber (141) is transferred to the return chamber (170) by the transfer robot (150). When the unprocessed semiconductor wafer (W) is transferred from the indexer unit (101) to the return chamber (170) through the first cool chamber (131) or the second cool chamber (141), the first cool chamber (131) and the second cool chamber (141) function as a path for the transfer of the semiconductor wafer (W).

The return robot (150) that has taken out the semiconductor wafer (W) turns to face the heat treatment unit (160). Subsequently, the return robot (150) transfers the unprocessed semiconductor wafer (W) into the processing chamber (6) of the heat treatment unit (160) by means of the return hand (151a) (or the return hand (151b)).

A semiconductor wafer (W) loaded into a processing chamber (6) is subjected to preheating by a halogen lamp (HL), and then flash heating treatment is performed by flash light irradiation from a flash lamp (FL). By this flash heating treatment, for example, impurities injected into the semiconductor wafer (W) are activated.

After the flash heating treatment is completed, the return robot (150) uses the return hand (151a) (or the return hand (151b)) to transport the semiconductor wafer (W) after the flash heating treatment from the processing chamber (6) to the return chamber (170). The return robot (150) that has taken out the semiconductor wafer (W) turns from the processing chamber (6) toward the first cool chamber (131) or the second cool chamber (141).

Thereafter, the return robot (150) loads the semiconductor wafer (W) after the heat treatment into the first cool chamber (131) of the first cooling unit (130) or the second cool chamber (141) of the second cooling unit (140). At this time, if the semiconductor wafer (W) has passed through the first cool chamber (131) before the heat treatment, it is loaded into the first cool chamber (131) even after the heat treatment, and if it has passed through the second cool chamber (141) before the heat treatment, it is loaded into the second cool chamber (141) even after the heat treatment. In the first cool chamber (131) or the second cool chamber (141), the semiconductor wafer (W) after the flash heat treatment is cooled. Since the temperature of the entire semiconductor wafer (W) at the time of being taken out from the processing chamber (6) of the heat treatment unit (160) is relatively high, it is cooled to near room temperature in the first cool chamber (131) or the second cool chamber (141).

After a predetermined cooling treatment time has elapsed, the water robot (120) takes out the semiconductor wafer (W) after cooling from the first cool chamber (131) or the second cool chamber (141) and returns it to the carrier (C). When the carrier (C) accommodates a predetermined number of processed semiconductor wafers (W), the carrier (C) is taken out from the first load port (110a) or the second load port (110b) of the indexer unit (101).

The explanation of the heat treatment in the heat treatment section (160) continues. Prior to loading the semiconductor wafer (W) into the treatment chamber (6), the valve (84) for supplying air is opened, and the exhaust valve (89, 192) is opened to start supplying and exhausting air into the treatment chamber (6). When the valve (84) is opened, nitrogen gas is supplied to the heat treatment space (65) from the gas supply hole (81). In addition, when the valve (89) is opened, the gas inside the treatment chamber (6) is exhausted from the gas exhaust hole (86). As a result, the nitrogen gas supplied from the upper part of the heat treatment space (65) inside the treatment chamber (6) flows downward and is exhausted from the lower part of the heat treatment space (65).

In addition, by opening the valve (192), the gas inside the processing chamber (6) is exhausted from the return opening (66). In addition, the atmosphere around the driving unit of the transfer mechanism (10) is also exhausted by the exhaust mechanism (not shown). In addition, when the semiconductor wafer (W) is heat-treated in the heat treatment section (160), nitrogen gas is continuously supplied to the heat treatment space (65), and the supply amount is appropriately changed depending on the processing process.

Subsequently, the gate valve (185) is opened to open the return opening (66), and the semiconductor wafer (W) to be processed is transferred into the heat treatment space (65) in the processing chamber (6) through the return opening (66) by the return robot (150). The return robot (150) advances the return hand (151a) (or the return hand (151b)) holding the unprocessed semiconductor wafer (W) to a position just above the holding portion (7) and stops it. Then, a pair of transfer arms (11) of the transfer mechanism (10) move horizontally from the retracted position to the transfer operation position and rise, so that the lift pin (12) passes through the through hole (79) and protrudes from the upper surface of the holding plate (75) of the susceptor (74) to receive the semiconductor wafer (W). At this time, the lift pin (12) rises higher than the upper end of the substrate support pin (77).

After the unprocessed semiconductor wafer (W) is placed on the lift pin (12), the return robot (150) ejects the return hand (151a) from the heat treatment space (65), and the return opening (66) is closed by the gate valve (185). Then, as the pair of transfer arms (11) are lowered, the semiconductor wafer (W) is transferred from the transfer mechanism (10) to the susceptor (74) of the holding portion (7) and held from below in a horizontal position. The semiconductor wafer (W) is held on the susceptor (74) by a plurality of substrate support pins (77) that are installed upright on the holding plate (75). In addition, the semiconductor wafer (W) is held on the holding portion (7) with the surface to be subjected to the heat treatment facing upward. A predetermined gap is formed between the back surface (the main surface opposite to the surface) of the semiconductor wafer (W) supported by a plurality of substrate support pins (77) and the holding surface (75a) of the holding plate (75). A pair of transfer arms (11) lowered to the lower side of the susceptor (74) are retracted to a retract position, i.e., to the inside of the concave portion (62), by a horizontal movement mechanism (13).

After the semiconductor wafer (W) is held from below in a horizontal position by the susceptor (74) of the holding member (7), 40 halogen lamps (HL) are simultaneously turned on to initiate preheating (assist heating). Halogen light emitted from the halogen lamps (HL) passes through the lower chamber window (64) and the susceptor (74) formed of quartz and is irradiated from the lower surface of the semiconductor wafer (W). By receiving light irradiation from the halogen lamps (HL), the semiconductor wafer (W) is preheated and its temperature increases. In addition, since the transfer arm (11) of the transfer mechanism (10) is retracted toward the inside of the concave portion (62), there is no case where heating by the halogen lamps (HL) is hindered.

When preheating by a halogen lamp (HL) is performed, the temperature of the semiconductor wafer (W) is measured by a single-point radiation thermometer (20). That is, the single-point radiation thermometer (20) receives infrared light radiated from the lower surface of the semiconductor wafer (W) held on the susceptor (74) through the opening (78) and measures the temperature of the wafer during heating. The measured temperature of the semiconductor wafer (W) is transmitted to the control unit (3). The control unit (3) controls the output of the halogen lamp (HL) while monitoring whether the temperature of the semiconductor wafer (W) heated by light irradiation from the halogen lamp (HL) has reached a predetermined preheating temperature T1. That is, the control unit (3) feedback-controls the output of the halogen lamp (HL) so that the temperature of the semiconductor wafer (W) becomes the preheating temperature T1 based on the measured value by the single-point radiation thermometer (20). The preheating temperature T1 is, for example, about 600°C to 800°C.

After the temperature of the semiconductor wafer (W) reaches the preheating temperature T1, the control unit (3) temporarily maintains the semiconductor wafer (W) at the preheating temperature T1. Specifically, when the temperature of the semiconductor wafer (W) measured by the single-piece radiation thermometer (20) reaches the preheating temperature T1, the control unit (3) adjusts the output of the halogen lamp (HL) to maintain the temperature of the semiconductor wafer (W) almost at the preheating temperature T1.

By performing preheating using a halogen lamp (HL) as described above, the entire semiconductor wafer (W) is uniformly heated to the preheating temperature T1. In the stage of preheating using the halogen lamp (HL), the temperature of the peripheral portion of the semiconductor wafer (W) where heat dissipation is more likely to occur tends to be lower than that of the central portion, but the arrangement density of the halogen lamps (HL) in the halogen lamp house (4) is higher in the area facing the peripheral portion than in the area facing the central portion of the semiconductor wafer (W). For this reason, the amount of light irradiated to the peripheral portion of the semiconductor wafer (W) where heat dissipation is likely to occur increases, and the in-plane temperature distribution of the semiconductor wafer (W) in the preheating stage can be made uniform.

When the temperature of the semiconductor wafer (W) reaches the preheating temperature T1 and a predetermined time has elapsed, a flash lamp (FL) irradiates flash light to the surface of the semiconductor wafer (W). At this time, some of the flash light emitted from the flash lamp (FL) is directed directly to the processing chamber (6), and some of the flash light is first reflected by a reflector (52) and then directed to the processing chamber (6), and flash heating of the semiconductor wafer (W) is performed by irradiation with these flash lights.

Since flash heating is performed by irradiating flash light (flash) from a flash lamp (FL), the surface temperature of the semiconductor wafer (W) can be increased in a short period of time. That is, the flash light irradiated from the flash lamp (FL) is a very short and strong flash with an irradiation time of 0.1 millisecond or more and 100 milliseconds or less, in which electrostatic energy accumulated in the condenser in advance is converted into a very short light pulse. Then, the surface temperature of the semiconductor wafer (W) that is flash-heated by irradiating flash light from the flash lamp (FL) instantaneously increases to the processing temperature T2, and then the surface temperature rapidly decreases. The processing temperature T2 is, for example, 1000°C or more. In this way, flash heating can increase or decrease the surface temperature of the semiconductor wafer (W) in a very short period of time. Therefore, for example, it is possible to activate the impurities injected into the semiconductor wafer (W) while suppressing diffusion due to heat of the impurities.

After the flash heating process is completed, the halogen lamp (HL) is turned off after a predetermined time has elapsed. As a result, the semiconductor wafer (W) is rapidly cooled from the preheating temperature T1. The temperature of the semiconductor wafer (W) during the cooling is measured by a single-piece radiation thermometer (20), and the measurement result is transmitted to the control unit (3). The control unit (3) monitors whether the temperature of the semiconductor wafer (W) has cooled to a predetermined temperature based on the measurement result of the single-piece radiation thermometer (20). Then, after the temperature of the semiconductor wafer (W) has cooled to a predetermined temperature or lower, a pair of transfer arms (11) of the transfer mechanism (10) are again horizontally moved from the retracted position to the transfer operation position and raised, so that the lift pins (12) protrude from the upper surface of the susceptor (74) to receive the semiconductor wafer (W) after the heat treatment from the susceptor (74). Subsequently, the return opening (66) closed by the gate valve (185) is opened, and the processed semiconductor wafer (W) placed on the lift pin (12) is removed by the return hand (151b) (or the return hand (151a)) of the return robot (150). The return robot (150) advances the return hand (151b) to a position directly below the semiconductor wafer (W) pushed up by the lift pin (12) and stops it. Then, as the pair of transfer arms (11) are lowered, the semiconductor wafer (W) after flash heating is handed over to the return hand (151b) and placed. Thereafter, the return robot (150) removes the return hand (151b) from the processing chamber (6) and removes the processed semiconductor wafer (W).

In this embodiment, a semiconductor wafer (W) unloaded from a carrier (C) placed on a load port (110) is returned to the processing chamber (6) of the heat treatment unit (160) after direction adjustment in the alignment unit (230) and scratch detection in the scratch detection unit (300). Therefore, compared to a conventional configuration such as disclosed in, for example, Patent Document 1, the time for returning the semiconductor wafer (W) from the carrier (C) to the processing chamber (6) is extended by the processing time in the scratch detection unit (300). As a result, conventionally, it was possible to exchange a semiconductor wafer (W) after heat treatment and an unprocessed semiconductor wafer (W) in the processing chamber (6) using the return hand (151a) and the return hand (151b) of the return robot (150), but cases arise in which wafer exchange is not possible due to the extended time for returning the semiconductor wafer (W). That is, there is a case where the subsequent unprocessed semiconductor wafer (W) has not yet reached the transfer robot (150) at the time when the heat treatment of the preceding semiconductor wafer (W) in the processing chamber (6) is completed. Then, a time period in which the semiconductor wafer (W) does not exist in the processing chamber (6) occurs, and the temperature of the processing chamber (6) may decrease, which may affect the heat treatment result of the semiconductor wafer (W). For example, when activation of impurities is performed by flash heat treatment, there is a concern that the sheet resistance value after the heat treatment may not reach the target value.

For this reason, in the first embodiment, the return of the semiconductor wafer (W) is controlled as follows. Fig. 10 is a flowchart showing the return sequence of the semiconductor wafer (W) in the first embodiment. Figs. 11 to 22 are drawings schematically showing one process of return of the semiconductor wafer (W). Hereinafter, the return control of the semiconductor wafer (W) in the first embodiment will be described while appropriately referring to Figs. 11 to 22. In addition, in the heat treatment device (100) of the present embodiment, the control unit (3) controls the hand robot (120) and the return robot (150) so that the wafer is returned according to the operation at the position where the return is to be performed (so-called event-driven method).

First, heat treatment of a preceding wafer is performed in a heat treatment unit (160) (step S1). The preceding wafer is a wafer in which processing is performed alone. In the first embodiment, the preceding wafer is, for example, a dummy wafer (DW). In addition, the heat treatment of the preceding wafer is, for example, a dummy heating treatment in which the dummy wafer (DW) is irradiated with light from a halogen lamp (HL) (and a flash lamp (FL)) to increase the temperature of the dummy wafer (DW), thereby controlling the temperature inside the processing chamber (6). By heat conduction from the dummy wafer (DW) that has been heated by the light irradiation from the halogen lamp (HL), the temperature inside the processing chamber (6) is controlled to a stable temperature at the time of processing a semiconductor wafer (W) to be a product. Hereinafter, the preceding wafer, which is a dummy wafer (DW), is referred to as a preceding wafer (DW).

Next, the return of the subsequent wafer is initiated (step S2). The subsequent wafer is a plurality of wafers that are processed sequentially, and in the first embodiment, it is a semiconductor wafer (product wafer) (W) that becomes a product. After the dummy heat treatment using the dummy wafer (DW) is performed, the heat treatment is sequentially performed on the plurality of semiconductor wafers (W) that become products. Hereinafter, the first semiconductor wafer (W) is denoted as a subsequent wafer (W1), the second semiconductor wafer (W) is denoted as a subsequent wafer (W2), and the third semiconductor wafer (W) is denoted as a subsequent wafer (W3) (the same applies hereinafter).

First, the water robot (120) takes out the first subsequent wafer (W1) from the carrier (C) placed on the load port (110) by the lower transfer hand (121b) (Fig. 11). Subsequently, after the water robot (120) loads the subsequent wafer (W1) into the alignment chamber (231) of the alignment section (230), the water robot takes out the second subsequent wafer (W2) from the load port (110) by the lower transfer hand (121b) (Fig. 12). Thereafter, the water robot (120) takes out the subsequent wafer (W1) whose direction has been adjusted from the alignment section (230) by the upper transfer hand (121a), and also takes in the subsequent wafer (W2) into the alignment section (230) by the lower transfer hand (121b) (Fig. 13). That is, the capital robot (120) performs wafer exchange with respect to the alignment unit (230).

Next, the water robot (120) loads the subsequent wafer (W1) into the scratch detection chamber (301) of the scratch detection unit (300) by the upper transfer hand (121a) (Fig. 14). At this time, the alignment unit (230) adjusts the direction of the subsequent wafer (W2). When the scratch detection of the subsequent wafer (W1) in the scratch detection unit (300) is completed, the water robot (120) removes the subsequent wafer (W1) from the scratch detection chamber (301) of the scratch detection unit (300) by the upper transfer hand (121a).

Next, the water robot (120) loads the subsequent wafer (W1) into the second cool chamber (141) of the second cooling unit (140) by the upper transfer hand (121a). Subsequently, the water robot (120) takes out the third subsequent wafer (W3) from the load port (110) by the lower transfer hand (121b) (Fig. 15). Even at this point, the direction adjustment of the subsequent wafer (W2) in the alignment unit (230) is continuously performed.

Next, the return robot (150) removes the subsequent wafer (W1) from the second cooling unit (140) by the upper return hand (151a). Subsequently, the water robot (120) removes the subsequent wafer (W2) whose direction has been adjusted from the alignment unit (230) by the upper transfer hand (121a), and also introduces the subsequent wafer (W3) into the alignment unit (230) by the lower transfer hand (121b) (Fig. 16). As the return robot (150) removes the subsequent wafer (W1) from the second cooling unit (140), the first subsequent wafer (W1) reaches the return robot (150) (step S3).

As the first subsequent wafer (W1) reaches the transfer robot (150), wafer exchange between the preceding wafer (DW) and the subsequent wafer (W1) by the transfer robot (150) becomes possible. However, in the first embodiment, even if wafer exchange between the preceding wafer (DW) and the subsequent wafer (W1) becomes possible, the wafer exchange is not performed immediately, but the wafer exchange is waited for (step S4). That is, the transfer robot (150) waits while holding the subsequent wafer (W1) by the transfer hand (151a). In addition, the processing chamber (6) of the heat treatment unit (160) also waits while receiving the preceding wafer (DW).

Even while waiting for wafer exchange to the processing chamber (6) by the return robot (150), the return of subsequent wafers after the subsequent wafer (W2) continues (step S5). Then, while waiting for wafer exchange until a preset constant waiting time elapses, the return of subsequent wafers continues (step S6). The waiting time is preset and stored, for example, in the memory of the control unit (3).

After the first subsequent wafer (W1) reaches the return robot (150), the water robot (120) loads the subsequent wafer (W2) into the scratch detection unit (300). When the scratch detection of the subsequent wafer (W2) is completed, the water robot (120) removes the subsequent wafer (W2) from the scratch detection unit (300) by the upper transfer hand (121a). Next, the water robot (120) loads the subsequent wafer (W2) into the first cool chamber (131) of the first cooling unit (130) by the upper transfer hand (121a). Subsequently, the water robot (120) takes out the fourth subsequent wafer (W4) from the load port (110) by the lower transfer hand (121b) (Fig. 17). And, the capital robot (120) takes out the subsequent wafer (W3) whose direction has been adjusted from the alignment unit (230) by the upper transfer hand (121a), and brings in the subsequent wafer (W4) into the alignment unit (230) by the lower transfer hand (121b).

Meanwhile, wafer exchange between the preceding wafer (DW) and the subsequent wafer (W1) is waiting. By continuing to return the subsequent wafer while waiting for the wafer exchange, multiple return positions from the load port (110) to the return robot (150) are gradually filled by the subsequent wafer. The return positions are locations where the semiconductor wafer (W) is to be returned, and in this embodiment, the alignment unit (230), the scratch detection unit (300), the first cooling unit (130), and the second cooling unit (140) correspond to them.

At a point when a certain waiting time has elapsed, the wafer exchange between the preceding wafer (DW) and the first subsequent wafer (W1) is executed (step S7). Specifically, the return robot (150) inserts the lower return hand (151b) into the processing chamber (6) to remove the preceding wafer (DW) from the processing chamber (6), and at the same time, the upper return hand (151a) is used to bring the first subsequent wafer (W1) into the processing chamber (6) (Fig. 18). In other words, after the wafer exchange between the preceding wafer (DW) and the subsequent wafer (W1) becomes possible, a certain waiting time is waited and then the wafer exchange is executed.

After the wafer exchange of the preceding wafer (DW) and the subsequent wafer (W1) is completed, the return of the preceding wafer (DW) and the subsequent wafer is continued (step S8). Specifically, while the preceding wafer (DW) is returned from the return robot (150) toward the load port (110), a plurality of subsequent wafers are sequentially returned from the load port (110) toward the return robot (150). In addition, in parallel with this, a heat treatment for sequentially heating the subsequent wafers is performed (step S9). That is, steps S8 and S9 are executed in parallel.

After the wafer exchange of the preceding wafer (DW) and the succeeding wafer (W1) is performed, the water robot (120) transfers the succeeding wafer (W3) to the scratch detection unit (300) by the transfer hand (121a). In addition, the return robot (150) transfers the succeeding wafer (W2) from the first cooling unit (130) by the upper return hand (151a) and transfers the preceding wafer (DW) to the first cooling unit (130) by the lower return hand (151b) (Fig. 19). That is, the return robot (150) performs the wafer exchange of the succeeding wafer (W2) and the preceding wafer (DW) with respect to the first cooling unit (130).

The preceding wafer (DW) that has been heated by the dummy heating treatment is cooled to near room temperature within the first cool chamber (131) of the first cooling unit (130). Meanwhile, the heating treatment described above is performed on the subsequent wafer (W1) that has been brought into the processing chamber (6). That is, the heating treatment is performed on the subsequent wafer (W1) by light irradiation from a halogen lamp (HL) and a flash lamp (FL) within the processing chamber (6).

Even while the cooling treatment of the preceding wafer (DW) and the heating treatment of the subsequent wafer (W1) are being performed, the wafer return is still ongoing. The water robot (120) removes the subsequent wafer (W3) from the scratch detection unit (300) and places it into the second cooling unit (140). Subsequently, the water robot (120) takes out the fifth subsequent wafer (W5) from the load port (110) by the transfer hand (121b) (Fig. 20).

Next, the water robot (120) takes out the subsequent wafer (W4) whose direction has been adjusted from the alignment unit (230) by the transfer hand (121a), and also loads the subsequent wafer (W5) into the alignment unit (230) by the transfer hand (121b). Subsequently, the water robot (120) loads the subsequent wafer (W4) into the scratch detection unit (300).

When the heat treatment of the first subsequent wafer (W1) in the processing chamber (6) is completed, the transfer robot (150) removes the subsequent wafer (W1) from the processing chamber (6) by the transfer hand (151b), and also loads the subsequent wafer (W2) into the processing chamber (6) by the transfer hand (151a). That is, the transfer robot (150) performs wafer exchange between the first subsequent wafer (W1) and the second subsequent wafer (W2) with respect to the processing chamber (6). The subsequent wafer (W2) loaded into the processing chamber (6) is subjected to heat treatment by light irradiation from a halogen lamp (HL) and a flash lamp (FL). Subsequently, the hand robot (120) removes the preceding wafer (DW) whose cooling treatment has been completed from the first cooling unit (130) by the lower transfer hand (121b) (Fig. 21).

Next, the return robot (150) removes the subsequent wafer (W3) from the second cooling unit (140) by the upper return hand (151a), and loads the subsequent wafer (W1) into the second cooling unit (140) by the lower return hand (151b). That is, the return robot (150) performs wafer exchange between the subsequent wafer (W3) and the subsequent wafer (W1) with respect to the second cooling unit (140). A cooling process is performed on the subsequent wafer (W1) loaded into the second cooling unit (140). In addition, the hand robot (120) stores the preceding wafer (DW) into the dummy carrier (DC) placed in the load port (110). Subsequently, the hand robot (120) removes the subsequent wafer (W4) from the scratch detection unit (300) and loads it into the first cooling unit (130) (FIG. 22). Thereafter, the same sequence is repeated to sequentially process multiple subsequent wafers.

In the first embodiment, even when the first subsequent wafer (W1) reaches the transfer robot (150) and wafer exchange between the preceding wafer (DW) and the subsequent wafer (W1) becomes possible, the wafer exchange is not performed immediately, but is performed after waiting for a certain period of time. In other words, the timing of wafer exchange between the preceding wafer (DW) and the subsequent wafer (W1) by the transfer robot (150) is intentionally delayed for a certain period of time. Then, while waiting for the wafer exchange, the subsequent wafer is returned from the load port (110) toward the transfer robot (150) so as to fill a plurality of transfer positions from the load port (110) to the transfer robot (150). Therefore, when a certain waiting time has elapsed and the wafer exchange between the preceding wafer (DW) and the subsequent wafer (W1) is performed, some of the plurality of transfer positions are occupied by the subsequent wafer.

For example, if the wafer exchange is performed immediately when the wafer exchange between the preceding wafer (DW) and the subsequent wafer (W1) becomes possible without delaying the timing of the wafer exchange, the following problems occur. FIG. 24 and FIG. 25 are drawings schematically showing one process of returning a semiconductor wafer (W) in the case of immediate wafer exchange. When the wafer exchange is performed immediately from the state of FIG. 16 in which the first subsequent wafer (W1) has reached the transfer robot (150), the transfer robot (150) removes the preceding wafer (DW) from the processing chamber (6) by the transfer hand (151b) and also carries the subsequent wafer (W1) into the processing chamber (6) by the transfer hand (151a).

Next, the return robot (150) loads the preceding wafer (DW) taken out from the processing chamber (6) into the first cooling unit (130). In addition, the water robot (120) loads the subsequent wafer (W2) into the scratch detection unit (300), and after the scratch detection is completed, it is removed from the scratch detection unit (300) by the upper transfer hand (121a) (Fig. 24). In the state of Fig. 24, the subsequent wafer (W2) held by the transfer hand (121a) of the water robot (120) is loaded into the first cooling unit (130) in a sequence. However, the cooling process of the preceding wafer (DW) is performed in the first cooling unit (130). Because of this, the subsequent wafer (W2) cannot be loaded into the first cooling unit (130), and the water robot (120) waits until the cooling process of the preceding wafer (DW) is completed while maintaining the subsequent wafer (W2). In other words, since the return position is blocked by the preceding wafer (DW), the return of the subsequent wafer (W2) is hindered.

After waiting for the cooling process of the preceding wafer (DW) in the first cooling unit (130) to be completed, the water robot (120) removes the preceding wafer (DW) from the first cooling unit (130) by the lower transfer hand (121b) and loads the subsequent wafer (W2) into the first cooling unit (130) by the upper transfer hand (121a). Subsequently, the water robot (120) stores the preceding wafer (DW) in a dummy carrier (DC) placed in the load port (110).

Next, the heating treatment of the first subsequent wafer (W1) in the processing chamber (6) is completed, but at that point, the second subsequent wafer (W2) has not yet reached the transfer robot (150). This is because the return of the subsequent wafer (W2) is waiting until the cooling treatment of the preceding wafer (DW) is completed. Therefore, the transfer robot (150) removes the subsequent wafer (W1) from the processing chamber (6) by the transfer hand (151b) without performing a wafer exchange. Meanwhile, the hand robot (120) takes out a new subsequent wafer (W4) from the load port (110) by the transfer hand (121b) (Fig. 25).

As shown in Fig. 25, since the transport robot (150) is not performing wafer exchange in the processing chamber (6), when the subsequent wafer (W1) is removed, there is no semiconductor wafer (W) in the processing chamber (6). When there is no semiconductor wafer in the processing chamber (6), heating by the halogen lamp (HL) and the flash lamp (FL) is not performed, so the temperature in the processing chamber (6) decreases as the time during which the semiconductor wafer (W) is not present increases. As a result, the temperature in the processing chamber (6) becomes different for each of the plurality of subsequent wafers constituting the lot, which causes a problem in that the processing results among the plurality of subsequent wafers become uneven.

As described above, when wafer exchange between the preceding wafer (DW) and the subsequent wafer (W1) becomes possible, if the wafer exchange is performed immediately, the return position is blocked by the preceding wafer (DW), which causes a problem in the return of the subsequent wafer (W2), and when the heat treatment of the subsequent wafer (W1) is completed in the processing chamber (6), the subsequent wafer (W2) cannot reach the return robot (150). As a result, wafer exchange between the first subsequent wafer (W1) and the second subsequent wafer (W2) in the processing chamber (6) cannot be performed, and the temperature inside the processing chamber (6) decreases.

In this regard, in the first embodiment, when wafer exchange between the preceding wafer (DW) and the subsequent wafer (W1) becomes possible, the timing of the wafer exchange is intentionally delayed for a certain period of time so that the return of the subsequent wafer continues, and several of the plurality of return positions are occupied by the subsequent wafer. As a result, the return position is not blocked by the preceding wafer (DW), and the preceding wafer (DW) is basically returned from the return robot (150) toward the load port (110) by wafer exchange with the subsequent wafer. For this reason, the occurrence of an obstacle in the return of the subsequent wafer is prevented, and when the heat treatment of a certain subsequent wafer is completed in the processing chamber (6), the next subsequent wafer will always reach the return robot (150). As a result, wafer exchange can be reliably performed in the processing chamber (6), so that a semiconductor wafer (W) always exists in the processing chamber (6), and the temperature in the processing chamber (6) is maintained at a stable temperature controlled by the dummy heating treatment without decreasing. Accordingly, the temperature in the processing chamber (6) becomes constant for all of the plurality of subsequent wafers constituting the lot, so that the processing results among those plurality of subsequent wafers become uniform.

However, in the first embodiment, since the timing of wafer exchange between the preceding wafer (DW) and the subsequent wafer (W1) is delayed by a certain amount of time, there is a concern that the processing start timing in the processing chamber (6) may be delayed for several subsequent wafers at the beginning of the lot compared to the case where the wafer exchange is performed immediately without delay. However, as described above, if it is performed as in the first embodiment, it becomes possible to smoothly return the subsequent wafer and reliably perform wafer exchange in the processing chamber (6). In addition, the heat treatment in the processing chamber (6) is performed according to the processing time specified in the recipe. Therefore, the processing time is shortened for the entire lot compared to the case where immediate wafer exchange is performed and the return of the subsequent wafer is hindered, and the throughput can be improved. In other words, if it is performed as in the first embodiment, it is possible to improve the throughput while making the processing results uniform.

<Second embodiment>

Next, the second embodiment of the present invention will be described. The configuration of the heat treatment device (100) and the heat treatment unit (160) of the second embodiment are the same as those of the first embodiment. In addition, the order of the heat treatment for the semiconductor wafer (W) in the second embodiment is also the same as that of the first embodiment. In the first embodiment, the wafer exchange was waited for until a predetermined waiting time elapsed after the wafer exchange between the preceding wafer (DW) and the succeeding wafer (W1) became possible, but in the second embodiment, the wafer exchange is waited for until a specific position among a plurality of return positions is filled.

Fig. 23 is a diagram schematically showing another example of returning a semiconductor wafer (W). In the second embodiment as well, when the first subsequent wafer (W1) reaches the return robot (150) and wafer exchange between the preceding wafer (DW) and the subsequent wafer (W1) becomes possible, the wafer exchange is not performed immediately, but the wafer exchange is waited for. In addition, similarly to the first embodiment, while waiting for the wafer exchange, the subsequent wafer is returned from the load port (110) toward the return robot (150) so as to fill a plurality of return positions.

In the second embodiment, as shown in Fig. 23, the wafer exchange between the preceding wafer (DW) and the first succeeding wafer (W1) is performed at a point in time when both the first cooling unit (130) and the second cooling unit (140) among the plurality of return positions are occupied by succeeding wafers. Even in this way, similarly to the first embodiment, at the point in time when the wafer exchange between the preceding wafer (DW) and the succeeding wafer (W1) is performed, some of the plurality of return positions are occupied by succeeding wafers. Therefore, the return positions are not blocked by the preceding wafer (DW), and the succeeding wafer can be smoothly returned to ensure wafer exchange in the processing chamber (6).

<Variation>

Hereinafter, the embodiments of the present invention have been described, but the invention can be modified in various ways other than as described above without departing from the spirit thereof. For example, in the above embodiment, the preceding wafer is a dummy wafer (DW) and the subsequent wafer is a product wafer (W), but instead, the subsequent wafer may also be a dummy wafer (DW). Patent Document 1 proposes dividing the dummy heating treatment into two stages: a warm-up treatment and a conditioning treatment. The warm-up treatment is a first-stage treatment for keeping the inside of the processing chamber (6) warm at a constant temperature. On the other hand, the conditioning treatment is a second-stage treatment for controlling the inside of the processing chamber (6) to a target temperature after the warm-up treatment. The target temperature is a stable temperature at the time of processing the semiconductor wafer (W) that becomes the product. Typically, the warm-up process is performed using one dummy wafer (DW), and the conditioning process is performed using multiple (e.g., 15 to 20) dummy wafers (DW). Therefore, when the warm-up process is performed using a preceding wafer and the conditioning process is performed using multiple subsequent wafers, the same technology as in the above embodiment can be applied.

In addition, in the second embodiment, the wafer exchange is performed at a time when both the first cooling unit (130) and the second cooling unit (140) are occupied by the subsequent wafer, but this is not limited to the above, and the wafer exchange may be performed when any of the plurality of return positions is occupied by the subsequent wafer. For example, the wafer exchange between the preceding wafer (DW) and the first subsequent wafer (W1) may be performed at a time when the first cooling unit (130) is occupied by the subsequent wafer.

In addition, in the above embodiment, although the flash lamp house (5) is provided with 30 flash lamps (FL), it is not limited thereto, and the number of flash lamps (FL) can be any number. In addition, the flash lamp (FL) is not limited to a xenon flash lamp, and may be a krypton flash lamp. In addition, the number of halogen lamps (HL) provided in the halogen lamp house (4) is not limited to 40, and can be any number.

In addition, in the above embodiment, the preheating of the semiconductor wafer (W) is performed using a filament-type halogen lamp (HL) as a continuous-lighting lamp that continuously emits light for 1 second or more, but this is not limited to this, and instead of the halogen lamp (HL), a discharge-type arc lamp (for example, a xenon arc lamp) or an LED lamp may be used as a continuous-lighting lamp to perform the preheating.

3: Control unit 4: Halogen lamp house
5: Flash lamp house 6: Processing chamber
7: Maintenance Department 10: Relocation Organization
20: Radiation thermometer at the tip 25: Radiation thermometer at the center
65: Heat treatment space 66: Return opening
74: Susceptor 100: Heat Treatment Device
101: Indexer 110: Load Port
120: Capital Robot 121a, 121b: Jae Hand
130: 1st cooling section 140: 2nd cooling section
150: Return robot 151a, 151b: Return hand
160: Heat treatment section 185: Gate valve
230: Alignment section 300: Scratch detection section
C: Carrier DW: Dummy Wafer
FL: Flash lamp HL: Halogen lamp
W: semiconductor wafer

Claims (6)

A heat treatment method in which heat treatment is performed on a preceding substrate that is processed alone and then heat treatment is sequentially performed on a plurality of subsequent substrates that are processed continuously,
A pre-heating process for heating the pre-heated substrate by irradiating light from a lamp to the pre-heated substrate within the chamber;
A first return process for sequentially returning the plurality of subsequent substrates from the load port to the return robot through a plurality of positions;
A waiting process for a predetermined time for the substrate exchange between the first subsequent substrate and the preceding substrate by the return robot after the first subsequent substrate among the plurality of subsequent substrates reaches the return robot;
During the above waiting process, a second return process for returning the plurality of subsequent substrates from the load port toward the return robot to fill the plurality of positions;
After the above waiting process, an exchange process in which the return robot exchanges the preceding substrate and the first subsequent substrate within the chamber;
A third return process of sequentially returning the preceding substrate from the return robot toward the load port while sequentially returning the plurality of subsequent substrates from the load port toward the return robot;
A subsequent heating process for sequentially heating the plurality of subsequent substrates by light irradiation from the lamp within the chamber.
A heat treatment method characterized by comprising: In claim 1,
A heat treatment method characterized in that, in the above waiting process, the substrate exchange is waited for until a preset constant waiting time has elapsed. In claim 1,
A heat treatment method characterized in that, in the above waiting process, the substrate exchange is waited for until a specific position among the plurality of positions is filled by the second return process. In any one of claims 1 to 3,
A heat treatment method, characterized in that the above plurality of positions include an alignment unit for adjusting the direction of the substrate, a scratch detection unit for detecting scratches on the substrate, and a cooling unit for cooling the substrate. In claim 4,
The above preceding substrate is a dummy substrate,
A heat treatment method characterized in that, in the above-mentioned preliminary heating process, a dummy heating treatment is performed by irradiating light onto the dummy substrate to heat the inside of the chamber. In claim 5,
The above multiple subsequent substrates are dummy substrates,
In the above-mentioned preheating process, a warm-up process is performed to keep the inside of the chamber warm at a constant temperature.
A heat treatment method characterized in that, in the above subsequent heating process, a conditioning treatment is performed to control the temperature inside the chamber to a target temperature.