TW202021010A - Substrate heating device and substrate heating method - Google Patents

Abstract

When heating a substrate, an object of the invention is to quickly convert the atmosphere around the substrate to a low-oxygen atmosphere. A substrate heating device of the invention comprises: a ring-shaped section which surrounds the sides of a heating plate so as to form a gap with respect to the heating plate around the entire periphery of the heating plate; a processing space forming section which is provided facing the heating plate and the ring-shaped section such that a processing space, which communicates with the above gap and in which heat treatment of the substrate is performed, is formed between the heating plate and the ring-shaped section; a gas supply section which supplies a low-oxygen atmosphere forming gas for converting the processing space to a low-oxygen atmosphere when heating the substrate, from one end of the processing space toward the other end, thereby forming a gas stream that covers the entire width of the substrate and flows from one end of the substrate toward the other; an exhaust port provided at the other end of the processing space; and a replacement section for replacing the gas that accumulates in the gap before formation of the gas stream with a low-oxygen atmosphere forming gas until the substrate is heated.

Description

Substrate heating device and substrate heating method

The present disclosure relates to a substrate heating device and a substrate heating method.

In the manufacturing process of a semiconductor element, a semiconductor wafer (hereinafter referred to as a wafer) serving as a substrate is heated by a heating device, and the heating device may perform this heating process while supplying gas to the substrate. Patent Literature 1 describes a heating device including: a heating portion that heats a mounted substrate; a cover portion covering the heating portion; and supplying an inert gas between the cover portion and the substrate when heating the substrate To form the gas supply part of the inert gas environment. Patent Document 2 describes a heating device including: a heating plate on which a substrate is placed; and a cover covering the heating plate that can form an airflow flowing from one end to the other end of the heating plate. Patent Document 3 describes a heating device in which a top plate for rectification is arranged on a heating plate to form an air flow from one end to the other end of the heating plate to heat the wafer. [Advanced technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2017-107904 [Patent Document 2] Japanese Patent Laid-Open No. 2004-293942 [Patent Document 3] Japanese Unexamined Patent Publication No. 2006-269920

[Problems to be solved by the invention]

The present disclosure is to provide a technology that can quickly turn the environment around the substrate into a low-oxygen environment when the substrate is heated. [Means to solve the problem]

The substrate heating device of the present disclosure has: Heat the plate, place the substrate and heat it; An annular portion surrounding the side of the heating plate so as to surround the entire periphery of the heating plate and form a gap with the heating plate; A processing space forming portion, provided opposite to the heating plate and the ring portion, communicating with the gap, and forming a processing space for heating the substrate with the heating plate and the ring portion; The gas supply unit supplies the low-oxygen environment forming gas from one end to the other end of the processing space to cover the width of the substrate and from the substrate Air flow from one end to the other end; An exhaust port, provided at the other end of the processing space, which sucks and exhausts the low-oxygen ambient gas in the processing space to form the air flow; and In the replacement part, before heating the substrate, the gas remaining in the gap before the formation of the gas flow is replaced with the low-oxygen environment forming gas. [Effect of invention]

According to the present disclosure, it is possible to provide a technique for quickly turning the environment around the substrate into a low-oxygen environment when heating the substrate.

The substrate heating device 1 according to the embodiment of the present disclosure will be described with reference to the longitudinal side view of FIG. 1 and the transverse plan view of FIG. 2. This substrate heating device 1 has a rectangular and elongated casing 10 which is installed in an atmospheric environment. The case 10 is divided into upper and lower parts by the water-cooled plate 2, and the wafer W is heated on the upper side in the case 10. The wafer W transported to the substrate heating device 1 is formed with, for example, an SOC (Spin On Carbon) film. By performing a heat treatment, a cross-linking reaction occurs in the SOC film to harden the SOC film. In order to improve the density of the cured SOC film and to improve the resistance of the subsequent etching step, the surroundings will be in a state of low oxygen environment, and the wafer W is performed at, for example, 450° C. or higher, more specifically 600° C. or higher. Heat treatment. The above-mentioned low-oxygen environment is an environment with a low oxygen concentration in a large gas environment, for example, an environment with an oxygen concentration of 400 ppm or less, preferably 50 ppm or less. In the example shown below, a low oxygen concentration environment is formed by making the inside of the housing 10 an inert gas environment formed by nitrogen (N2).

When the longitudinal direction of the casing 10 described above is used as the front-rear direction, a transport inlet 11 for transporting wafers W in and out is formed at a position above the water cooling plate 2 on the front end face of the housing 10. A gate 12 for opening and closing the entrance/exit 11 is provided on the entrance/exit 11. The gate 12 is located inside the housing 10 and is opened and closed by a gate opening/closing mechanism 13 provided below the water cooling plate 2.

The water cooling plate 2 will be described with reference to the perspective view of FIG. 3. The water cooling plate 2 as a heat shield is formed of a rectangular metal plate, and a cooling channel 22 for circulating cooling water, for example, is arranged inside the cooling plate 2. The cooling channel 22 is connected to, for example, a cooler 23 that circulates cooling water in the cooling channel 22. These cooling channel 22 and the cooler 23 constitute a cooling mechanism 29 for cooling the water-cooled plate 2. At the left and right positions of the water-cooled plate 2, notches 21 extending in the front-rear direction are formed in the thickness direction penetrating the water-cooled plate 2, respectively. In addition, at a position near the front of the water-cooled plate 2, three hole portions 24 for raising and lowering the lifting pins 58 provided in the heating portion 4 described later are formed in the circumferential direction. In addition, a water leakage sensor 25 for detecting water leakage from the cooling channel 22 is provided on the top surface of the water cooling plate 2.

Returning to FIG. 1 to explain, above the water-cooled plate 2, the cooling section 3 for cooling the wafer W and the heating are provided in order from the near side (front side) to the back side (rear side) as viewed from the inlet/outlet 11. The heating portion 4 of the wafer W. That is, the water cooling plate 2 is provided from the lower side of the cooling unit 3 to the heating unit 4.

Next, the cooling unit 3 will be described with reference to the perspective view of FIG. 4 and the longitudinal front view of FIG. 5. As shown in FIG. 4, the cooling unit 3 has a circular metal plate 30, and a cooling channel 31 is provided around the entire bottom surface on the bottom surface of the metal plate 30. In order to avoid overly complicated drawings, only the metal plate 30 is described in FIGS. 1 and 5. The cooling flow path 31 is connected to the cooler 32 and cools the wafer W placed on the metal plate 30 by circulating, for example, cooling water in the cooling flow path 31.

In addition, in order to maintain a certain distance between the wafer W and the cooling unit 3 on the surface of the cooling unit 3, for example, 15 gap pins 33 are dispersedly arranged, and a ring-shaped protrusion is formed around the center of the cooling unit 3状部34。 34. The purpose of providing the convex portion 34 is to ensure that even in the warped wafer W, the central portion of the wafer W can surely contact the cooling portion 3. In order to avoid only partially cooling the central portion of the wafer W, the convex portion 34 is formed into an annular shape.

As shown in FIGS. 4 and 5, in the cooling portion 3, three through holes 35 penetrating in the thickness direction are formed in the circumferential direction, and each through hole 35 is provided with a lifting pin 36 as a lifting member. The lifting pin 36 is raised and lowered by a lifting mechanism 37 and protrudes • is buried on the surface of the cooling unit 3 and is used to transfer crystals between the external transport mechanism of the substrate heating device 1, the cooling unit 3, and the substrate transport mechanism 26 described later Round W. The lifting mechanism 37 is provided on the water cooling plate 2 and is cooled by the water cooling plate 2. 38 in the figure is a supporting member that supports the cooling unit 3 on the water cooling plate 2. As described above, the purpose of transferring the wafer W with the lift pin 36 is to increase the area of the wafer W that overlaps the cooling section 3 in the plane of the wafer W when the wafer W is placed on the cooling section 3, and it is very fast and uniform The wafer W is cooled. More specifically, if the cooling unit 3 is provided with a notch corresponding to the shape of each transport mechanism, the transport mechanism is raised and lowered relative to the cooling unit 3 to transfer the wafer W at the same time. At this time, when the wafer W is placed on the cooling portion 3, the portion corresponding to the notch causes the area where the surface of the wafer W overlaps with the cooling portion 3 to become small, resulting in a decrease in the cooling performance of the wafer W. It is transmitted by the lift pin 36, so that the cooling section 3 does not need to be provided with the notch.

As shown in FIG. 1, a gas supply part 39 that supplies nitrogen gas to the cooling part 3 is provided above the cooling part 3. The gas supply portion 39 has a flat rectangular tube shape, and its bottom surface is a perforated plate formed with a plurality of holes 39A. The gas supply part 39 is connected to the nitrogen gas supply source 15 via the gas supply path 14. M1 and V1 in FIG. 1 are the flow rate adjustment section and the valve provided on the gas supply path 14, respectively, and supply and interruption of nitrogen gas to the gas supply section 39 by opening and closing the valve V1.

In addition to FIGS. 1 and 2 described above, the heating section 4 will be described with reference to the longitudinal front view of FIG. 6 and the transverse plan view of FIG. 7. The heating section 4 is provided apart from the cooling section 3, and has a heating plate 40, a lower support section 44, an annular section 47, a flat plate 51, and a top plate 61 constituting a processing space forming section. The heating plate 40 has a flat cylindrical shape, and is composed of a circular heating body 41 and a heat insulating member 42 stacked in this order from above. The heating body 41 is made of a ceramic material such as SiC (silicon carbide). The upper end of the heating body 41 protrudes outward to form a circular flange 43. On the top surface (surface) of the heating body 41, in order to support the wafer W from the top surface, protrusions not shown in the figure are dispersedly provided, and the wafer W is horizontally supported on these protrusions.

Inside the flange 43 on the top surface of the heating body 41, in order to prevent the position of the wafer W placed on the heating body 41 from shifting, a plurality of spaced apart Deviation prevention pin 67. The wafer W is placed in the area surrounded by this deviation preventing pin 67. The heating body 41 includes a heater. As described above, the placed wafer W is heated by the heating body 41. The heat insulating member 42 is for thermally insulating the lower side of the heating body 41, and the lower side is supported by the lower support 44.

The lower support portion 44 is a circular plate member formed by supporting the heating plate 40 on the water-cooled plate 2 via the support 45 and covering the bottom surface of the heating plate 40. The peripheral portion of the lower support portion 44 is located outside the heating plate 40, and an annular portion 47 is provided on the peripheral portion. The annular portion 47 surrounds the side of the heating plate 40 to form a ring, and is formed using, for example, a hollow heat insulating member. Further, between the annular portion 47 and the side of the heating plate 40, a gap 48 that is annular in plan view is formed around the circumference of the heating plate 40. Furthermore, a ring-shaped plate 49 of a vertical standing plate that is a ring in plan view is provided on the peripheral portion of the lower support portion 44 to divide the gap 48 into two concentric circles. The upper end of the ring plate 49 is slightly spaced from the flange 43 provided on the heating plate 40 and is located below the flange 43.

A flat plate 51 made of a metal such as SUS (stainless steel) is provided on the annular portion 47. This flat plate 51 guides the air flow described later on the heating plate 40 and is horizontally arranged at approximately the same height as the upper end portion of the heating plate 40 to divide the rear side of the housing 10 into upper and lower parts. In order to expose the surface (top surface) of the heating plate 40, the flat plate 51 is provided with a circular opening 52. The lower side of the opening 52 has a larger diameter than the upper side, and the upper and lower sides of the opening 52 have a stepped shape when viewed in the longitudinal section.

The side surface of the opening edge on the lower side of the opening 52 is spaced from the side surface of the flange 43 of the heating plate 40 to face each other. The opening edge on the upper side of the opening 52 is located above the flange 43, and an overlapping annular gap covering portion 53 is formed, which is close to the flange 43. That is, the gap covering portion 53 is provided to cover above the gap 48. The function of this gap cover 53 will be described later. Due to the configuration of the flange 43 and the gap cover 53, the gap 48 communicates with the space above the heating plate 40 (processing space 63 described later). In order to make the drawing easy to understand, the minute gap formed between the flange 43 and the gap cover 53 is drawn larger than the actual size.

For example, in the lower support portion 44, as described above, in the gap 48 divided into concentric circles by the ring plate 49, an opening is formed in the area forming the outer circle to form an exhaust port (exhaust port for gap) )54. As shown in FIG. 7, for example, four exhaust ports 54 are provided at intervals in the circumferential direction of the annular portion 47. The exhaust port 54 is connected to one end of the exhaust pipe 55, and the other end of the exhaust pipe 55 is connected to the exhaust portion 56 via the valve V2. The opening and closing of the suction exhaust to the gap 48 is switched by the opening and closing of the valve V2.

In the heating plate 40 and the lower support portion 44, three through holes 57 are formed along the circumferential direction of the heating plate 40 in the direction penetrating the thickness thereof, and lift pins 58. 3 are respectively arranged on the three through holes 57. 3 Each lifting pin 58 is inserted into the three holes 24 formed in the water cooling plate 2 respectively, is provided below the water cooling plate 2, and is connected to the lifting mechanism 59 provided on the top surface of the bottom plate of the housing 10. The lifting pin 58 is raised and lowered by the lifting mechanism 59, and protrudes and sinks into the top surface of the heating plate 40. Since the lifting mechanism 59 is arranged below the water cooling plate 2 in this way, it is possible to suppress the radiant heat of the heating portion 4 from being transmitted to the lifting mechanism 59.

Above the heating plate 40 and the flat plate 51, a rectangular horizontal top plate 61 is provided facing the heating plate 40 and the flat plate 51. The top plate 61 is opposed to the ring portion 47 via the flat plate 51. As shown in FIGS. 1 and 6, the left and right edges of the top plate 61 extend downward to form legs 62 and are supported by the flat plate 51. The space surrounded by the top plate 61, the legs 62, the heating plate 40, and the flat plate 51 constitutes a flat processing space 63. The top plate 61 and the leg portion 62 are preferably made of a material having high heat resistance and a low linear expansion coefficient. This is to prevent changes in the height of the processing space 63 due to the deformation of these components due to heat during the processing of the wafer W, thereby causing changes in the airflow on the wafer W. Specifically, it is preferable to use ceramic materials such as quartz or SiC to constitute the top plate 61 and the leg portion 62.

As shown in FIGS. 1 and 2, on the top of the housing 10 near the processing space 63, there is provided a gas supply part 7 that ejects a low-oxygen environment forming gas N 2. The gas supply section 7 is a gas nozzle formed to extend in the left-right direction, has a plurality of gas supply ports 71 along the left-right direction, and emits nitrogen gas toward one end of the processing space 63 diagonally rearward. As will be described later, by exhausting the processing space 63 to form a gas flow in the processing space 63, the nitrogen gas ejected as described above is supplied so as to cover the width of the wafer W on the left and right sides. That is, the gas supply port 71 is provided with an opening to supply nitrogen gas to all parts of the wafer W at all places. In FIG. 1, 15 is a nitrogen gas supply source, and is connected to the gas supply unit 7 via the gas supply path 73. M2 and V3 are a flow rate adjustment part and a valve provided in the gas supply path 73, respectively, and supply and interruption of nitrogen gas to the gas supply part 7 by opening and closing the valve V3.

The exhaust block 74 that exhausts the ambient gas in the housing 10 is provided on the flat plate 51 so as to block the rear side of the processing space 63. This exhaust block 74 has a large number of exhaust ports 75 opening forward in the left-right direction. That is, the other end of the processing space 63 is provided with an exhaust port 75. The downstream side of the exhaust block 74 is connected to the exhaust portion 56 via the valve V4. The opening and closing of the exhaust block 74 can be switched by opening and closing the valve V4. The exhaust section 56 is composed of, for example, an exhaust path that constantly exhausts air in a factory where the substrate heating device 1 is installed, and an exhaust mechanism such as a fan and an air box for exhausting the exhaust path. In addition, compared with the exhaust volume per unit time of the gap 48 outside the heating plate 40 described above, in the configuration of this device, the exhaust volume 74 per unit time of the processing space 63 is larger.

Nitrogen gas is ejected from the gas supply part 7 and the exhaust block 74 is exhausted, whereby an air flow that flows along the surface of the wafer W from the front toward the rear can be formed in the processing space 63. Such a gas flow is formed in the processing space 63 where the wafer W is heated, in order to reduce the oxygen concentration around the wafer W and to remove the sublimation generated by the heated wafer W. Hereinafter, the air flow formed in this processing space 63 is described as a unidirectional flow. As described above, the gas supply part 7 and the exhaust block 74 are provided with a plurality of gas supply ports 71 and a plurality of exhaust ports 75 in the left-right direction, respectively. With this configuration, a high-uniformity unidirectional flow is formed in the left-right direction of the processing space 63, and high-uniformity heat treatment can be performed in the plane of the wafer W. The gas supply port 71 and the exhaust port 75 are not limited to this example. A plurality of slits may be provided in the left-right direction. For example, one slit may be formed on the left and right sides. In addition, as mentioned above, the nitrogen gas supplied into the housing 10 by the gas supply unit 39 provided on the cooling unit 3 side also flows into the processing space 63 and is exhausted through the exhaust port 75.

As shown in FIGS. 1 and 6, above the top plate 61 are, for example, two heat insulating plates 64 and a flat heat insulating member 65 spaced apart from each other in sequence in order to overlap each other, and are horizontally provided. The heat insulating member 65 is provided to insulate the upper region in the housing 10 from the heating unit 4, and the inside thereof is, for example, a vacuum environment. The two heat insulating plates 64 are used to relax the heat radiation from the heating unit 4 to the heat insulating member 65 to prevent the heat insulating member 65 from being deformed and damaged. The number of heat insulating plates 64 is not limited to two, and may be three or more, for example. In addition, as shown in FIGS. 2 and 6, heat insulation plates 66 for insulating the side walls of the housing 10 from the heating unit 4 are provided on the left and right side walls of the heating unit 4 in the housing 10, respectively.

The substrate heating device 1 has a substrate transport mechanism 26 for transporting the wafer W between the cooling unit 3 and the heating unit 4. The substrate transfer mechanism 26 will be described below with reference to the perspective view of FIG. 8. In FIG. 8, a part of the water cooling plate 2 is simplified. The substrate transport mechanism 26 has support portions 27A and 27B that extend upward and downward at positions on the left and right sides of the cooling portion 3, respectively. The support portions 27A and 27B face each other in pairs. The front ends of the upper end portions of the support portions 27A and 27B are formed to protrude toward the right side and the left side, respectively. In addition, the top surfaces of the front ends of the support portions 27A and 27B are made of, for example, ceramics or quartz with high heat resistance, and extend from the cooling portion 3 toward the heating portion 4 side (toward the rear), and are provided with respective holding wafers W The plate-shaped left holding member 28A and the right holding member 28B of the left and right peripheral edges of the bottom surface.

As described above, by holding the left and right sides of the wafer W with both the left holding member 28A and the right holding member 28B, it is possible to prevent the held wafer W from tilting and shifting in position due to its weight. The substrate holding portion 28 may be referred to as the left holding member 28A and the right holding member 28B. The processing of the above-mentioned ceramics and quartz constituting the substrate holding portion 28 is not easy, and it is not easy to provide a complicated shape such as a slit so that the lift pins 36 and 58 and the substrate transport mechanism 26 do not interfere with each other. However, since the substrate holding portion 28 has the plate shape as described above, it is easy to manufacture.

As shown in FIG. 8, the support portions 27A and 27B are inserted into the notches 21 formed in the water cooling plate 2, respectively. As shown in FIGS. 1 and 5, the base end sides of the support parts 27A and 27B are connected to a common moving mechanism 16 provided below the water cooling plate 2. The moving mechanism 16 is moved along a guide rail 17 extending in the front-rear direction below the water cooling plate 2 by, for example, a belt drive mechanism not shown in the figure. In the figure, 18 is a table portion for adjusting the height of the guide rail 17. By moving the moving mechanism 16 along the guide rail 17, the substrate holding portion 28 is positioned above the cooling portion 3 (set to the proximal position) shown by the solid line in FIG. 1 and heated by the broken line in FIG. 1 The board 40 moves between the upper position (provided as the back position). By disposing the moving mechanism 16 and the guide rail 17 on the front side of the housing 10 and below the water cooling plate 2, the radiant heat from the heating plate 40 can be suppressed. In addition, as shown in FIG. 2, the arrangement of the substrate holding portion 28 moving forward and backward and the lift pins 36 on the cooling unit 3 side and the lift pins 58 on the heating plate 40 side do not interfere.

The operation of the substrate heating device 1 described later will explain the operation of the substrate transport mechanism 26 in detail. The substrate transport mechanism 26 is located at the near side as long as it does not hinder the transfer of the wafer W between the parts in the housing 10. In other words, it is possible to suppress its operation at the back side position for a long time. This can prevent the radiant heat from the heating part 4 from being accumulated in the substrate conveying mechanism 26 to prevent malfunctions and short maintenance intervals.

However, as shown in FIGS. 1 and 2, an oxygen concentration detection portion 19 is embedded on the top surface of the flat plate 51 forming the processing space 63 to detect the concentration on the downstream side of the unidirectional flow formed in the processing space 63. Specifically, when viewed from the center of the front and back of the heating plate 40 to the rear side, it is located behind the gap 48 and near the exhaust block 74. Therefore, when viewed in the front-back direction, the oxygen concentration detection unit 19 is provided on the downstream side of the processing space 63, that is, closer to the exhaust block 74 than the gas supply unit 7 is. The oxygen concentration detection unit 19 transmits a signal corresponding to the detected oxygen concentration to the control unit 5 described later, and the control unit 5 displays the oxygen concentration based on the signal.

The test performed before the heat treatment of the wafer W is the same as the heat treatment of the wafer W, and nitrogen gas is supplied from the gas supply units 7 and 39 and exhausted from the exhaust block 74. Then, the time from the start of gas supply and exhaust until the detected oxygen concentration reaches below the reference value is measured. Based on this measured time, the standby time from the start of nitrogen gas supply and exhaust until the wafer W is transported from the lift pins 36 to the heating plate 40 is set in the control unit 5. Measuring the time until the oxygen concentration reaches the reference value or less, and setting the standby time based on the measured time is performed by the user of the substrate heating device 1. However, when the user performs a specific operation from the control unit 5, the above-mentioned test may be automatically executed, and the time until the reference value is reached or below may be automatically measured and the standby time may be set.

Since each part of the processing space 63 in the left-right direction (width direction) will form a unidirectional flow with high uniformity, the difference in oxygen concentration between the left and right parts of the processing space 63 will be relatively small. That is, in the example shown in FIG. 2, the oxygen concentration detection unit 19 is provided at a position slightly offset from the left and right of the processing space 63, but it is not limited to this position. Because of the unidirectional flow, the oxygen in the processing space 63 flows to the exhaust block 74. As described above, the oxygen concentration detection unit 19 is provided close to the exhaust block 74. That is, by arranging the oxygen concentration detection unit 19 close to the exhaust block 74, it can be determined more accurately whether the oxygen concentration around the wafer W is below the reference value.

The structure of the heating plate 40 and its surrounding parts will be described in further detail. As described above, an annular portion 47 as a heat insulating member is provided around the heating plate 40. In addition, between this annular portion 47 and the heating plate 40, a gap 48 having a heat insulating effect is formed. In more detail, by providing the gap 48 as described above, since the outer periphery of the heating body portion 41 having the heater on the heating plate 40 does not come into contact with other members, heat conduction from the heating body portion 41 to the outside of the heating body portion 41 can be prevented Components, and get heat insulation effect. As a result, as described above, the heating body 41 can be maintained at a relatively high temperature of 450° C. or higher to heat the wafer W. In addition, the structure of this gap 48 is as described above, and the inner region and the outer region of the concentric circle are divided by the ring-shaped plate 49, and a high heat insulation effect is obtained by forming two gas layers.

Moreover, when processing the wafer W, the members provided around the heating plate 40 and the heating plate 40 both thermally expand. If the members around the heating plate 40 come into contact with the heating body 41 due to thermal expansion, the heating body 41 may be damaged, which may affect the processing of the wafer W. The provision of the gap 48 described above also has a function of preventing damage.

However, when a gas flow necessary for forming a low-oxygen environment is formed on the surface of the wafer W under heating, a device other than the structure that forms a unidirectional flow in the processing space 63 may be used. Specifically, a processing container with an opening and closing mechanism for transporting wafers W into and out is provided in the housing 10. Next, one of the central portion of the top in the processing container and the vicinity of the outer periphery of the wafer W is exhausted, and nitrogen gas is supplied from the other. With this configuration, a device capable of forming an air flow from the edge side of the wafer W to the center side or from the center side to the edge side can be formed in the processing container. On the other hand, the device configuration that forms a unidirectional flow in the processing space 63 may not require the above-described opening and closing mechanism. Therefore, since it is not necessary to take any countermeasures to prevent the heat supplied to the opening and closing mechanism, as described above, when the wafer W is heated at a relatively high temperature, it is advantageous to use a configuration that forms a unidirectional flow.

However, as described above, a gap 48 that opens to the processing space 63 above the heating plate 40 is provided. Since the substrate heating device 1 is installed in an atmospheric environment, the atmosphere will be trapped in the gap 48 before the unidirectional flow is formed. As described above, since the atmosphere stays in the gap 48 and the unidirectional flow is formed above the gap 48, the nitrogen gas forming the unidirectional flow does not easily enter the gap 48. That is, the gap 48 is not easily replaced with nitrogen gas from the atmosphere, and the atmosphere leaks into the processing space 63 through the gap 48, so it may take a longer time for the oxygen concentration around the wafer W to become lower than the reference value.

In the configuration of the substrate heating device 1, when the unidirectional flow is formed, the atmosphere in the gap 48 is exhausted, so that the oxygen concentration around the wafer W can be quickly reduced while flowing in the processing space The unidirectional nitrogen gas is directed into the gap 48. Furthermore, when the bottom surface of the gap 48 provided around the outer side of the heating plate 40 is exhausted by a partially opened exhaust port 54, a gap covering portion 53 covering the gap 48 is provided. By providing the gap covering portion 53, the nitrogen gas flowing from the processing space 63 to the gap 48 will have a higher pressure loss, that is, the flow of nitrogen into the gap 48 will be restricted. This can suppress N2 flowing in from the processing space 63 from being exhausted through the exhaust port 54, and the proportion of the atmosphere in the gas exhausted from the exhaust port 54 becomes large. That is, by the gap covering portion 53, the atmosphere in the gap 48 is quickly and surely removed by the exhaust port 54. Moreover, the risk of the exhaust gas of the gap 48 disturbing to the unidirectional flow flowing in the processing space can be reduced.

However, the flange 43 of the heating plate 40 may not be provided, and the front end (inner peripheral end) of the gap covering portion 53 may face the side wall of the heating plate 40 to form a minute gap. With such a configuration, when the gap 48 is exhausted, the nitrogen flowing between the gap 48 and the processing space 63 may cause a pressure loss. However, because the size of the heating plate 40 in the horizontal direction is larger than the size in the vertical direction, when thermal expansion occurs, the rate of increase in the length in the horizontal direction becomes larger than that in the vertical direction. That is, as described above, when the front end of the gap cover 53 is opposed to the side wall of the heating plate 40, the gap cover 53 and the heating plate 40 may interfere with each other due to thermal expansion.

Therefore, the gap covering portion 53 is located above the peripheral edge portion of the heating plate 40, and it is preferable that a small gap is formed between the gap covering portion 53 and the heating plate 40 here. Moreover, in the above example, the position of the gap covering portion 53 is on the flange 43 of the heating plate 40, but the flange 43 may not be provided, and the position of the inner peripheral end of the gap covering portion 53 may be The example is closer to the center of the heating plate 40. When such a configuration is adopted, it is sufficient to avoid interference between the gap covering portion 53 and the deviation preventing pin 67. To prevent this interference, it is only necessary to adjust the position and size of the deviation preventing pin 67. Another configuration method is to extend the inner peripheral edge portion of the gap covering portion 53 to the position where the deviation preventing pin 67 is provided, and the inner peripheral edge portion faces upward, and a recessed portion that can accommodate the deviation preventing pin 67 is provided. Alternatively, the position of the wafer W may be restricted by the inner peripheral end of the gap cover 53 without providing the deviation prevention pin 67. However, as described above, the configuration in which the flange 43 is provided and the gap covering portion 53 is covered thereon does not need to consider interference with the deviation preventing pin 67. That is, the advantage of providing the flange 43 is that it is easier to design a device that generates the above-mentioned pressure loss.

In addition, as shown in FIG. 1, the substrate heating device 1 includes a control unit 5 that controls the substrate heating device 1. A program stored in a storage medium such as a CD, hard disk, MO (optical disk), memory card, and DVD is installed in the control unit 5. The instructions (each step) included in the installed program transmit control signals to the various parts of the substrate heating device 1 to control the operation of the substrate heating device 1 shown in the description of the action described later.

Next, the operation of the substrate heating device 1 will be described using FIGS. 9 to 12. In the substrate heating device 1, the heating plate 40 is heated to, for example, 600° C., so that the cooling water flows in the cooling unit 3. At this time, the inside of the housing 10 is an atmospheric environment, and the substrate holding portion 28 shown by a solid line in FIG. 1 is in a standby state at a near position. In the substrate heating device 1 in this state, the wafer W having the SOC film is formed by applying the chemical liquid on the surface, and is supported and transported by the transport arm A1 as a transport mechanism. When the shutter 12 is opened, the substrate holding portion 28 will move to the back position. When the transport arm A1 enters the housing 10, the lift pin 36 on the cooling unit 3 side will rise, and the wafer W will be supported by the lift pin 36. Next, the transport arm A1 is withdrawn from the housing 10 (FIG. 9).

When the gate 12 is closed, the valves V1 to V4 will be opened, and nitrogen gas will be ejected from the gas supply parts 7 and 39, exhausted from the exhaust block 74, and the gap 48 is exhausted. By ejecting nitrogen gas from the gas supply part 7 and exhausting gas from the exhaust block 74, a unidirectional flow flowing from the front to the rear is formed in the processing space 63. The solid arrows in FIG. 10 indicate the flow of nitrogen in the housing 10. Also, as indicated by the broken arrows in FIG. 10, when the gap 48 is exhausted, the atmosphere remaining in the gap 48 is removed, and at the same time, nitrogen gas flows into the gap 48 from the processing space 63. As described above, when only one-way flow is generally formed, even the gap 48 that is less prone to gas replacement will be replaced, so that the oxygen concentration in the housing 10 will rapidly decrease to form a low-oxygen environment.

When the inside of the housing 10 is filled with nitrogen so that the oxygen concentration in the processing space 63 reaches the reference value or less, as described above, the substrate is held when a predetermined standby time elapses from the start of nitrogen gas injection and exhaust in the housing 10 The portion 28 will move to the proximal position. Next, the lift pin 36 is lowered, and the wafer W is transferred to the substrate holding portion 28, and the substrate holding portion 28 moves to the back position. After that, the lift pin 58 of the heating plate 40 will rise to receive the wafer W from the substrate holding portion 28, and when the substrate holding portion 28 moves to the proximal position, the lift pin 58 will lower and place the wafer W on the heating plate 40 For example, it is heated for 60 seconds (FIG. 11).

Next, the substrate holding portion 28 moves to the back side position, and the operation is reversed when transferring to the heating plate 40, and the wafer W is transferred from the heating plate 40 to the substrate holding portion 28. Next, the substrate holding portion 28 is moved to the proximal position, and then the lift pin 36 lifts the wafer W upward. When the substrate holding portion 28 moves to the back position, the lift pin 36 will be lowered, the wafer W is placed on the cooling portion 3 for cooling (FIG. 12 ), and then the substrate holding portion 28 will return to the proximal position. For example, when the wafer W is cooled to 110° C. or less for 70 seconds, the valves V1 to V4 are closed, the nitrogen gas supply from the gas supply parts 7 and 39, the exhaust by the exhaust block 74, and the exhaust by the gap 48 Will stop. Then, the substrate holding portion 28 will move to the back side position, and then the shutter 12 will open. By the cooperation of the transport arm A1 and the lift pin 36 entering the housing 10, the wafer W is transferred to the transport arm A1 and then transported out of the housing 10. Then, the shutter 12 will be closed, and the substrate holding portion 28 will return to the proximal position.

According to the substrate heating device 1 described above, a unidirectional flow from the front to the rear is formed on the heating plate 40 to heat the wafer W. The gap 48 formed between the side wall of the annular portion 47 that is insulated around the outer periphery of the heating plate 40 and the side wall of the heating plate 40 is exhausted by the exhaust portion 56. Since the oxygen concentration around the heating plate 40 can be quickly reduced, the time until the wafer W starts to be heated after the wafer W is moved into the substrate heating device 1 can be shortened. Therefore, according to this substrate heating device 1, production efficiency can be improved. In the above example, the wafer W is heated at a relatively high temperature, but it is not limited to use the temperature to heat the wafer W. For example, when the wafer W is heated at about 100°C, substrate heating may be used.装置1。 1 device. However, when the wafer W is heated at 450° C. or higher, as described above, since it is advantageous to form a unidirectional flow, the structure of this substrate heating device 1 is particularly effective.

In addition, the configuration of the heating device of the above-mentioned Patent Document 1 does not generally form a unidirectional flow like the substrate heating device 1, and there is no gap between the heating portion and the annular portion. In the configurations of the heating devices of Patent Documents 2 and 3, no gap is provided outside the heating plate. That is, the configurations of the devices of cited documents 1 to 3 are different from the configurations of the devices of the present disclosure, so the substrate heating device 1 does not obtain the above-mentioned effects.

In the above processing example, the gap 48 is continuously evacuated while the nitrogen supply from the gas supply parts 7 and 39 and the exhaust from the exhaust block 74 are performed. However, as long as the wafer W is heated, the oxygen concentration around the wafer W should be equal to or lower than the reference value, and it is not necessary to evacuate the gap 48 during this period. For example, the gap 48 may be evacuated only at the time when nitrogen gas is discharged from the gas supply units 7 and 39 and the exhaust block 74 is exhausted until the wafer W is placed on the heating plate 40. Alternatively, the exhaust port 54 for exhausting the gap 48 may not be provided at the above-mentioned position. For example, the annular portion 47 may be penetrated in the horizontal direction. The substrate processing apparatus 1 is not limited to heating the wafer W on which the SOC film is formed, but may also be used to heat the wafer W coated with the chemical liquid forming the photoresist or the antireflection film. In addition, the low-oxygen environment forming gas supplied into the housing 10 is not limited to the above-mentioned nitrogen gas, and may be other inert gas such as Ar (argon) gas, for example.

As long as the oxygen concentration of the gap 48 can be reduced, it is not limited to exhausting the gap 48, and a purge gas may be supplied to the gap 48. 13 is a diagram illustrating a configuration example in which a purge gas is supplied instead of exhausting the gap 48 on the substrate heating device 1. In this example, the hole used as the exhaust port 54 in the above-described configuration example is used as the gas supply port 91. This gas supply port 91 is connected to one end of the gas supply pipe 92, and the other end of the gas supply pipe 92 is connected to the above-described nitrogen gas supply source 15 via the valve V5. By opening and closing the valve V5, the nitrogen gas flowing into the gap 48 as the purge gas is interrupted. For example, the nitrogen gas supplied to the gap 48 may be performed from the start of the formation of the unidirectional flow to the end of the formation in the same manner as the exhaust of the gap 48, or until the wafer W is placed on the heating plate 40. In addition, as long as the gap 48 can be replaced from the atmospheric environment to a low-oxygen environment, it is not limited to use the same gas as the gas supplied to the processing space 63 as the purge gas, for example, an inert gas other than nitrogen may also be used as the purge gas Gas gas. That is, the low-oxygen environment forming gas forming the unidirectional flow and the low-oxygen environment forming gas used to replace the environment of the gap 48 are not necessarily the same gas.

Furthermore, as shown in FIG. 14, the exhaust port 54 may not be connected to the exhaust pipe 55 and the exhaust portion 56. In the example shown in FIG. 14, the exhaust port 54 communicates with an outside space (shown as 93 in the figure) located below the lower support portion 44. In addition, the side space 93 is located outside the area surrounded by the annular portion 47 and the lower support portion 44 and is a space provided outside the processing space 63 in the same manner as the gas flow path in the exhaust pipe 55 described above. In such a configuration where the exhaust port 54 communicates with the outer space 93, the atmosphere staying in the gap 48 is discharged to the outer space 93 by the unidirectional wind pressure, and the oxygen around the wafer W can be quickly reduced concentration. However, as described above, the configuration in which the gap 48 is connected to the exhaust portion 56 to suction exhaust gas to the gap 48 and the configuration in which the purge gas is supplied to the gap 48 can reduce the oxygen concentration relatively quickly.

All points of the embodiment disclosed this time should be regarded as an example, rather than limiting. As long as the above-mentioned embodiments do not deviate from the scope and purpose of the attached patent application, various forms can be omitted, replaced, and changed.

(Evaluation test) Next, the evaluation test performed in connection with the present disclosure will be described. The evaluation test 1 uses the substrate heating device 1 described in FIG. 1, and the housing 10 starts from the state of the atmospheric environment. As described above, the nitrogen supply by the gas supply unit 7 and the exhaust by the exhaust block 74 are performed separately. Gas, and the exhaust of the gap 48. Next, when performing the gas supply and exhaust, the detection value is monitored by the oxygen concentration detection unit 19, and the time until the oxygen concentration reaches the target concentration Appm or less from the supply of the gas and exhaust (A is a real number). The gap 48 is exhausted so that the exhaust volume from the four exhaust ports 54 is 0.5 L/min. In addition, the comparison test 1 is the same as the evaluation test 1 except that the gap 48 is not exhausted.

15 is a schematic diagram showing changes in the oxygen concentration measured by the evaluation test 1 and the comparison test 1 respectively. The vertical axis of the graph represents the oxygen concentration, and the oxygen concentration decreases toward the lower side. The horizontal axis of the graph represents the elapsed time from the start of gas supply and exhaust. The solid line in the figure indicates the result of evaluation test 1, and the chain line indicates the result of comparison test 1. As shown in the figure, when the elapsed time is relatively short, the oxygen concentration of Evaluation Test 1 and Comparative Test 1 decreases with time. However, when the elapsed time is longer, the decrease in the elapsed time per hour will become larger for the evaluation test 1 and the comparative test 1, so it will reach the Appm of the target concentration relatively quickly. Specifically, in Comparative Test 1, it took more than 300 seconds from the start of gas and exhaust gas supply to reach the target concentration, but in Evaluation Test 1, it took less than 100 seconds to reach the target concentration. Therefore, from the results of the evaluation test 1, it is confirmed that the gap 48 has atmosphere remaining, and exhausting the gap 48 can effectively remove the atmosphere and quickly reduce the oxygen concentration. That is, the effect of the device of the substrate heating device 1 was confirmed.

M1, M2: Flow adjustment section V1~V4: Valve W: Wafer 1: substrate heating device 10: Shell 11: Shipping in and out 12: Gate 13: Gate opening and closing mechanism 14: Gas supply path 15: Nitrogen supply source 16: mobile mechanism 17: rail 18: Taiwan Department 19: Department of oxygen concentration detection 2: water cooling plate 24: Hole 26: substrate transport mechanism 27B: Support Department 28: substrate holding part 3: Cooling Department 35: through hole 36: Lift pin 37: Lifting mechanism 38: Support component 39: Gas supply department 39A: Hole 4: heating section 40: heating plate 41: Heating the body 42: Thermal insulation 43: flange 44: Lower Support Department 45: Pillar 47: Ring 48: gap 49: Ring plate 5: Control Department 51: Tablet 52: opening 53: gap cover 54: Exhaust 55: Exhaust pipe 56: Exhaust 57: through hole 58: Lifting pin 59: Lifting mechanism 61: top plate 62: feet 63: Processing space 64: Heat insulation board 65: Thermal insulation 67: Deviation prevention pin 7: Gas supply unit 73: Gas supply path 74: Exhaust block 75: exhaust port

[Fig. 1] A longitudinal side view of a substrate heating device in an embodiment of the present disclosure. [Fig. 2] A cross-sectional plan view of the substrate heating device. [Fig. 3] A perspective view illustrating a water-cooled plate provided in the substrate heating device. [Fig. 4] A perspective view illustrating a cooling plate. [Fig. 5] A longitudinal front view illustrating a cooling plate in the heating device. [Fig. 6] A longitudinal front view illustrating a heating portion in the heating device. [Fig. 7] A cross-sectional plan view of a heating plate constituting the heating unit. [Fig. 8] A perspective view of a substrate transport mechanism provided in the substrate heating device. [Fig. 9] An explanatory diagram illustrating the operation of the substrate heating device. [Fig. 10] An explanatory diagram illustrating the operation of the substrate heating device. [Fig. 11] An explanatory diagram illustrating the operation of the substrate heating device. [Fig. 12] An explanatory diagram illustrating the operation of the substrate heating device. 13 is a longitudinal side view illustrating another configuration example of the substrate heating device. [Fig. 14] A longitudinal side view illustrating still another configuration example of the substrate heating device. [Fig. 15] A diagram illustrating evaluation test results in the device of the present disclosure.

M1, M2: Flow adjustment section

V1~V4: Valve

W: Wafer

1: substrate heating device

10: Shell

11: Shipping in and out

12: Gate

13: Gate opening and closing mechanism

14: Gas supply path

15: Nitrogen supply source

16: mobile mechanism

17: rail

18: Taiwan Department

19: Department of oxygen concentration detection

2: water cooling plate

24: Hole

26: substrate transport mechanism

27B: Support Department

28: substrate holding part

3: Cooling Department

35: through hole

36: Lift pin

37: Lifting mechanism

38: Support component

39: Gas supply department

39A: Hole

4: heating section

40: heating plate

41: Heating the body

42: Thermal insulation

43: flange

44: Lower Support Department

45: Pillar

47: Ring

48: gap

49: Ring plate

5: Control Department

51: Tablet

52: opening

53: gap cover

54: Exhaust

55: Exhaust pipe

56: Exhaust

57: through hole

58: Lifting pin

59: Lifting mechanism

61: top plate

62: feet

63: Processing space

64: Heat insulation board

65: Thermal insulation

67: Deviation prevention pin

7: Gas supply unit

73: Gas supply path

74: Exhaust block

75: exhaust port

Claims (9)

A substrate heating device, including: Heating plate, placing the substrate and heating; The ring-shaped portion surrounds the side of the heating plate so as to surround the entire periphery of the heating plate and form a gap with the heating plate; A processing space forming portion, which is provided opposite to the heating plate and the annular portion, communicates with the gap, and forms a processing space for heating the substrate with the heating plate and the annular portion; The gas supply portion supplies a low-oxygen environment forming gas for making the processing space into a low-oxygen environment from one end of the processing space to the other end when heating the substrate, covers the width of the substrate, and forms a substrate Air flow from one end to the other; The exhaust port, when the low-oxygen environment forming gas is supplied from the gas supply part, is provided at the other end of the processing space in order to suction and exhaust the low-oxygen environment gas from the processing space to form the airflow; and The replacement part replaces the gas remaining in the gap before forming the gas flow with the low-oxygen environment forming gas before heating the substrate. For example, the substrate heating device according to item 1 of the patent scope, in which: The replacement part is located outside the area surrounded by the ring part, and has a gap exhaust port for discharging to a space provided separately from the processing space. For example, the substrate heating device according to item 2 of the patent scope, in which: The gap exhaust port is connected to an exhaust section that sucks and exhausts the gas in the gap, The space provided separately from the processing space is a gas flow path connecting the gap exhaust port and the exhaust portion. For example, the substrate heating device according to item 2 of the patent application scope is provided with a gap covering part covering the gap, so that a low-oxygen environment gas from the processing space toward the gap generates a pressure loss. For example, the substrate heating device according to item 1 of the patent scope, in which: The replacement part has a gas supply port, supplies the low-oxygen environment forming gas to the gap, and urges the gas remaining in the gap before forming the gas flow toward the processing space. For the substrate heating device according to any one of the patent application items 1 to 5, wherein: The direction of the airflow is regarded as the front-back direction, and when the processing space is viewed from the front-back direction, the oxygen concentration for detecting the processing space is provided at a position closer to the exhaust port than the gas supply part The oxygen concentration detection section. A substrate heating device as claimed in any one of claims 1 to 5, wherein the heating plate heats the substrate to a temperature above 450°C. The substrate heating device according to any one of the items 1 to 5 of the patent application scope has: The cooling part is provided in a horizontal direction with respect to the annular part, and the substrate heated by the heating plate is placed and cooled; The heat shield is provided from the lower side of the heating plate to the lower side of the cooling part; Cooling mechanism for cooling the heat shield; The substrate transport mechanism has a substrate holding portion that holds the substrate, and transports the substrate between the cooling portion and the heating plate; and The moving mechanism, which constitutes the substrate transport mechanism, is provided on the lower side of the heat shield to move the substrate holding portion in the lateral direction. A substrate heating method includes the following steps: The step of placing the substrate on the heating plate surrounded by the annular portion and surrounding the annular portion with a gap formed around the outer periphery to heat the substrate; A processing space for heating the substrate and communicating with the gap between the "heating plate and the ring-shaped portion" and the "processing space forming portion provided opposite to the heating plate and the ring-shaped portion" , A step of forming a low-oxygen environment when heating the substrate; In order for the low-oxygen environment forming gas for forming the low-oxygen environment to cover the width of the substrate and form a gas flow from one end of the substrate toward the other end, a gas supply part is used from one end of the processing space to the other end The step of supplying the low oxygen environment to form gas; The step of forming the airflow by sucking and exhausting the low-oxygen environment gas in the processing space from the exhaust port provided at the other end of the processing space when the gas supply portion supplies the low-oxygen environment forming gas; and The replacement part is used to replace the gas retained in the gap before the formation of the gas flow with the step of forming a gas in the low-oxygen environment before heating the substrate.

Images