Substrate processing method and substrate processing apparatus

Abstract

To provide a processing method for suppressing outgassing of a heating plate generated when heating a substrate.SOLUTION: A processing method for a substrate processing apparatus having a chamber in which a heating plate for placing and heating a substrate is arranged includes a first step of heating the heating plate to a first temperature, a second step of lowering the temperature of the heating plate from the first temperature to a second temperature, a step of supplying a dry gas into the chamber in the first step to the second step, and a step of loading the substrate onto the heating plate after the second step.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a substrate processing method and a substrate processing apparatus. [Background technology]

[0002] In the photoresist processing step in the manufacture of semiconductor devices, various heating processes are performed to heat and dry the resist after it has been applied to a substrate. Heating processes are performed by placing the substrate to be heated on or close to a heating plate called a hot plate. Aluminum nitride (AlN) is sometimes used as the material for hot plates. When using an aluminum nitride hot plate, the plate material can be made thinner due to its high thermal conductivity and high strength, allowing for faster temperature increases and decreases compared to conventional methods. Patent Document 1 describes technology for a heat treatment device that heats substrates. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-336076 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-272985 Summary of the Invention [Problem to be solved by the invention]

[0004] In the heat treatment apparatus described in Patent Document 1, when an aluminum nitride hot plate is used, depending on the heating temperature, the hot plate may react with moisture in the air, resulting in the generation of outgassing containing ammonia.

[0005] Patent Document 2 discloses a technique for improving the water resistance of a hot plate made of sintered aluminum nitride by firing the aluminum nitride sintered body so that an oxide film is formed on the surface of the sintered body. However, in order to use this sintered body as a hot plate, machining is unavoidable after the firing process, which results in the oxide film on the sintered body being partially scraped off. In other words, even if the sintered body described in Patent Document 2 is incorporated into a hot plate device and a substrate is heated inside the device, there is a risk of outgassing from the portion of the sintered body where the oxide film has been scraped off.

[0006] An object of the present invention is to provide a processing method that suppresses outgassing from a heating plate that occurs when a substrate is heated. [Means for solving the problem]

[0007] In order to achieve the object, a substrate processing method according to one aspect of the present invention includes: placed substrate Add Heating plate was placed A processing method for a substrate processing apparatus having a chamber, comprising: a first step of heating the heating plate to a first temperature; The aforementioned From the first temperature to the second temperature temperature drop a second step of causing the first step and In the second step, a step of supplying a dry gas into the chamber, and after the second step, The aforementioned and a step of carrying in the substrate. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a processing method that suppresses outgassing from a heating plate that occurs when a substrate is heated. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing a substrate processing apparatus according to a first embodiment; [Figure 2]3A to 3C are diagrams illustrating steps of the substrate processing apparatus according to the first embodiment. [Figure 3] 3A to 3C are diagrams illustrating steps of the substrate processing apparatus according to the first embodiment. [Figure 4] FIG. 10 is a view showing a substrate processing apparatus according to a second embodiment. [Figure 5] 10A to 10C are diagrams illustrating steps of a substrate processing apparatus according to a second embodiment. [Figure 6] 10A to 10C are diagrams illustrating steps of a substrate processing apparatus according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0011] First Embodiment 1 shows a substrate processing apparatus 100 according to one embodiment of the present invention. The substrate processing apparatus 100 includes a heating plate 10 that holds and heats a substrate 1, a chamber 20 that surrounds the heating plate 10, and a substrate transport unit 30. The substrate 1 may be a bare silicon wafer or a glass substrate. A resin material is applied onto the substrate 1 using a coater developer or the like. The substrate processing apparatus 100 also includes a control unit 60 that controls the substrate processing operations described below.

[0012] The substrate 1 may be heated by placing it on the heating plate 10 or by bringing it close to the heating plate 10 .

[0013] The substrate 1 may be held by the heating plate 10 using a plurality of suction pins provided on the heating plate 10, or may be held directly by vacuum suction from the heating plate 10. The suction pins may also be equipped with a lifting mechanism and used when carrying the substrate 1 into and out of the heating plate 10. The substrate 1 may be held by the heating plate 10 using an electrostatic method in addition to the vacuum suction method.

[0014] The heating plate 10 must have high thermal conductivity in order to increase the speed of temperature rise and fall, and a thermal conductivity of 150 W / m K or more is desirable. The material of the heating plate 10 is preferably a hot plate containing aluminum nitride. The heating plate may also have a laminated structure made of a glass substrate, a heating element, and a base material such as aluminum nitride. The heating plate 10 has a power supply unit 11, and the heating element and thus the heating plate can be heated by the power supplied from the power supply unit 11.

[0015] The chamber 20 is disposed so as to surround the heating plate 10. The chamber 20 may have a lifting mechanism so that the substrate can be loaded and unloaded, and may be configured so that the upper and lower chambers can be separated. The chamber 20 may also be provided with a limited opening for loading and unloading the substrate 1, separating the heating plate space. The chamber 20 may also be provided with a shutter so that the opening can be closed. It is desirable that the chamber 20 can form a closed space when the heating plate 10 is heated.

[0016] Furthermore, it is desirable to be able to maintain the atmosphere inside the chamber 20 when the substrate 1 is loaded into or unloaded from the heating plate 10, and it is desirable that the opening of the chamber 20 for loading and unloading the substrate 1 be as small as possible and that the loading and unloading be completed in a short time.

[0017] The substrate transport unit 30 has an articulated robot, and can suck and hold the substrate 1 via a hand configured on the articulated robot and transport it into the chamber 20. Furthermore, the substrate processing apparatus 100 has a gas supply unit 40, a gas supply piping unit 41, an exhaust unit 50, and an exhaust piping unit 51.

[0018] The gas supply pipe 41 is disposed in the chamber 20. When the gas supply pipe 41 is provided in the chamber 20 above the substrate 1, the gas is supplied to the substrate 1, thereby preventing foreign matter from adhering to the gas 1. Furthermore, when a structure containing aluminum nitride is used for the heating plate, depending on the heating temperature, it may react with moisture in the air and release outgas containing ammonia.

[0019] Furthermore, depending on the materials used inside, outgassing such as siloxane may occur. The temperature at which outgassing occurs varies depending on the storage condition, usage environment, and frequency of use of the heating plate, but there is a possibility that significant outgassing will occur from around 250 to 300°C. Therefore, by providing a gas supply pipe 41 in the chamber 20 below the heating plate 10 and supplying gas to the heating plate 10, the environment around the heating plate 10 can be made dry, thereby suppressing outgassing.

[0020] The gas supply pipe 41 may be arranged so that gas is supplied to the side surface of the heating plate 10. The gas supplied from the gas supply unit 40 and the gas supply pipe 41 is preferably a dry gas such as clean dry air, nitrogen (N2) gas, or an inert gas.

[0021] The exhaust piping unit 51 is disposed in the chamber 20 and is capable of exhausting the space enclosed by the chamber 20. The exhaust piping unit 51 is desirably disposed below the substrate 1 so that gas components released from the heating plate when the heating plate is in use do not adhere to the substrate 1.

[0022] 2 shows the process up to loading the substrate 1 onto the heating plate 10 in the substrate processing apparatus 100. Fig. 2(A) shows a graph of the relationship between the temperature (Temp.) and the amount of dry gas supplied (Gas.) in the heating process of the heating plate 10 and the gas supply process of the gas supply unit 40. Fig. 2(B) is a flowchart showing the process from the start of heating the heating plate to loading the substrate 1 onto the heating plate 10.

[0023] The substrate processing apparatus 100 starts heating the heating plate 10 at time S0, and increases the temperature from the initial temperature T0 to a first temperature T1 by time S2. The first temperature T1 is higher than a second temperature T2, which is the heating temperature for heating the substrate 1. The first temperature T1 is preferably set to 250° C. or higher to evaporate impurities, including moisture, on the heating plate.

[0024] The heating plate 10 continues to be heated at the first temperature T1 from time S2 to time S3. This is the first step. After the first step is completed, the substrate processing apparatus 100 lowers the temperature of the heating plate 10 to a second temperature T2. This is the second step.

[0025] After the second step is completed, the substrate processing apparatus 100 starts to load the substrate 1 at time S5, places the substrate 1 on the heating plate 10, and starts heating the substrate 1. Here, at time S1, the gas supply unit 40 supplies dry gas to the space enclosed by the chamber 20 via the gas supply piping unit 41. At the same time, the exhaust unit 50 also exhausts the space enclosed by the chamber 20 via the exhaust piping unit 51. The timing of supplying dry gas to the space enclosed by the chamber 20 may start before the heating start time S0 of the heating plate 10.

[0026] In this embodiment, dry gas is supplied into the chamber 20 during the heating period in the first step and during the temperature decreasing period in the second step.

[0027] The timing for supplying dry gas into chamber 20 should be at least before the temperature of heating plate 10 reaches first temperature T1. It is also desirable that the supplying be started earlier than time S1_2 at which heating plate 10 reaches third temperature T3, which causes outgassing. The same applies to the timing for exhausting the space enclosed by chamber 20. The amount of gas supplied from gas supply unit 40 is desirably equal to or greater than the amount of exhaust from exhaust unit 50, in order to prevent moist air from entering from the outside through openings or gaps in chamber 20.

[0028] 3 shows the steps of processing multiple substrates in the substrate processing apparatus 100. Similar to FIG. 2(A), FIGS. 3(A) and 3(B) show the humidity (Hum.) inside the chamber 20 in addition to the relationship between the temperature and the amount of dry gas supplied during the heating step of the heating plate 10 and the gas supply step of the gas supply unit 40. FIG. 3(A) shows the case where, after processing multiple substrates, the heating of the heating plate 10 and the gas supply from the gas supply unit 40 are stopped, the apparatus is left in an idle state for a certain period of time, and then substrate processing is performed again.

[0029] 3(B) shows a case where, after processing a plurality of substrates, heating of the heating plate 10 is stopped while gas supply from the gas supply unit 40 continues, the apparatus is left in an idle state for a certain period of time, and then substrate processing is performed again. FIG. 3(C) shows a processing process of the substrate processing apparatus 100. The process up to time S5 is the same as FIG. 2(A).

[0030] The substrate processing apparatus 100 performs continuous processing of multiple substrates from time S5 to S6. When continuously processing multiple substrates, if gas is continuously supplied into the chamber 20, the humidity inside the chamber 20 is maintained at a low state (H1), so the first step only needs to be performed immediately before the first substrate is loaded, and the second and subsequent substrates do not need to undergo the first step.

[0031] The heating plate 10 stops heating when the continuous processing of multiple substrates is completed. After the heating is completed, the heating plate 10 cools down to the initial temperature T0. At this time, the supply of dry gas into the chamber 20 is stopped, and the humidity inside the chamber 20 returns to H0, the same humidity as the space outside the chamber 20. When substrate processing is to be started again after the time S7 to S0' in the apparatus idle state (apparatus standby time), the same process from S0' to S4' as the process from S0 to S4 must be carried out again before the next substrate is loaded.

[0032] However, if the standby time of the apparatus is short, the period from S2' to S3' in the first step may be shortened. Furthermore, as shown in FIG. 3(B), if gas continues to be supplied into the chamber 20 after heating of the heating plate 10 is stopped at time S6, the first step may not be performed when substrate processing is resumed. Instead, the substrate 1 may be loaded once the heating plate 10 reaches the second temperature T2. The implementation time of the first step may be automatically changed in accordance with the standby time of the substrate processing apparatus. For example, the implementation time of the first step may be automatically changed based on these cases. Furthermore, the substrate processing apparatus may be controlled so that the exposure time of the heating plate to the moisture-containing air is measured and the first step is resumed if the exposure time exceeds a certain period of time.

[0033] Second Embodiment 4 shows a substrate processing apparatus 101 according to one embodiment of the present invention. The substrate processing apparatus 101 has the same configuration as the substrate processing apparatus 100 according to the first embodiment, and further includes a measurement and monitoring unit 60 that measures and monitors the atmosphere around the heating plate 10.

[0034] The measurement monitoring unit 60 may perform measurements after sucking in the atmosphere around the heating plate 10. The heating plate 10 may emit outgassing depending on the heating temperature. Therefore, chromatography may be used to suck in the atmosphere and perform direct gas analysis, or a particle counter may be used. Alternatively, a laser displacement meter or spectroscopic interferometer may be used to utilize the refractive index change caused by outgassing to calculate the concentration from the distance difference from a reference.

[0035] Furthermore, when measuring the amount of moisture in a space, a hygrometer may be used. The hygrometer may determine the dew point temperature from the amount of moisture like a dew point meter, or may determine the absolute humidity or relative humidity.

[0036] 5 shows the process up to loading the substrate 1 onto the heating plate 10 in the substrate processing apparatus 101. Similar to FIG. 3A, FIG. 5(A) shows the relationship between the heating process of the heating plate 10, the gas supply process of the gas supply unit 40, and the humidity (Hum.) in the chamber 20. FIG. 5(B) shows the process from the start of heating the heating plate to loading the substrate 1 onto the heating plate 10.

[0037] The substrate processing apparatus 101 has the same substrate processing steps as those of the substrate processing apparatus 100 in embodiment 1, and further has Judgment 1 and Judgment 2 for determining whether to continue the process at times SJ1 and SJ2. Judgment 1 is performed after time S1 when gas starts to be supplied into the chamber 20, at temperature T4 before the heating plate 10 reaches temperature T3 at which it can release outgas.

[0038] Here, the monitoring unit 60 measures the humidity inside the chamber, and if the humidity inside the chamber 20 is lower than the reference humidity H2, it determines that the process can proceed. On the other hand, if the humidity inside the chamber is higher than the reference humidity H2, the process is stopped until the humidity falls below the reference humidity H2, and heating is performed so that the temperature of the heating plate 10 is maintained at the fourth temperature T4.

[0039] Judgment 2 is performed after the temperature of the heating plate 10 reaches the second temperature T2. As in Judgment 1, the monitoring unit 60 measures the humidity inside the chamber, and if the measurement result of the humidity inside the chamber 20 is lower than the reference humidity H3, it judges that it is OK to carry the substrate into the chamber and proceed with the process, and performs the process of carrying in the substrate 1.

[0040] On the other hand, if the humidity inside the chamber is higher than the reference humidity H2, the process is stopped until the humidity falls below the reference humidity H3, and heating is performed so that the temperature of the heating plate 10 is maintained at the second temperature T2. Here, either one of the determinations 1 and 2 may be performed, or both may be performed. The determinations 1 and 2 may be performed using different measurement methods. Furthermore, the determination may be performed by measuring the humidity inside the chamber 20, or may be performed using chromatography, a particle counter, a laser displacement meter, a spectroscopic interferometer, or the like.

[0041] 6 shows the steps of processing multiple substrates in the substrate processing apparatus 101. Figures 6(A) and 6(B) show the heating step of the heating plate 10, the gas supply step of the gas supply unit 40, and the humidity inside the chamber 20. Figure 6(A) shows the case where, after processing multiple substrates, the heating of the heating plate 10 and the gas supply from the gas supply unit 40 are stopped, the apparatus is left in an idle state for a certain period of time, and then substrate processing is performed again.

[0042] 6(B) shows a case where, after processing a plurality of substrates, heating of the heating plate 10 is stopped while gas supply from the gas supply unit 40 continues, the apparatus is left in an idle state for a certain period of time, and then substrate processing is performed again. FIG. 6(C) shows the processing steps of the substrate processing apparatus 101. The substrate processing apparatus 101 has the substrate processing steps of the substrate processing apparatus 100 in FIG. 3, and further has judgment 1, judgment 2, and judgment 1" that determine whether or not to continue the process at times SJ1, SJ2, SJ1', SJ2', SJ1", and SJ2".

[0043] Judgment 1 and Judgment 2 at times SJ1 and SJ2 are the same as those in Fig. 5. The substrate processing apparatus 101 performs continuous processing of multiple substrates from time S5 to S6. When continuously processing multiple substrates, if dry gas is continuously supplied into the chamber 20, the humidity inside the chamber 20 is maintained at a low level, so that the first step does not need to be performed on the second and subsequent substrates.

[0044] Here, when carrying out the substrate 1, it is necessary to open a part of the chamber 20, and depending on the amount of opening, it is conceivable that the humidity inside the chamber 20 will increase. Therefore, before carrying in a new substrate, judgment 2 is performed again to check whether the humidity inside the chamber 20 is maintained below the reference humidity H3.

[0045] If the humidity inside chamber 20 is below standard humidity H3, the next substrate is carried in, and if it is equal to or higher than standard humidity H3, the process is stopped until the humidity falls below standard humidity H3, and heating is performed so that the temperature of heating plate 10 is maintained at second temperature T2. If an equipment problem occurs when carrying out the substrate and the humidity inside chamber 20 exceeds standard humidity H2, it is desirable to start over from the first process before carrying in the next substrate.

[0046] After the continuous processing of multiple substrates is completed, when the apparatus is in an idle state from time S7 to time S0', and substrate processing is started again, judgment 1 and judgment 2 are performed to determine whether the humidity is below the reference humidity H2 and H3. Here, as shown in FIG. 6(B), if gas supply into chamber 20 continues even when the apparatus is in an idle state, when the fourth temperature T4 is reached at time SJ1'', judgment 1" is performed instead of judgment 1. Here, if the humidity inside chamber 20 is below the reference humidity H3, the first step is skipped, and when the second temperature T2 is reached, the process moves to judgment 2.

[0047] If the humidity is equal to or higher than the reference humidity H3 but lower than H2, the fourth temperature T4 is maintained, and if the humidity falls below the reference humidity H3, the first step is skipped, and once the second temperature T2 is reached, the process moves to judgment 2. If the humidity is equal to or higher than the reference humidity H2, the fourth temperature T4 is maintained, and the process moves to judgment 1, and once the humidity falls below the reference humidity H2, the process starts from the first step. Here, as with FIG. 5, the method of each judgment does not depend on the humidity, and other measurement methods may be used to measure and judge.

[0048] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0049] 1 board 10 Heating Plate 20 chambers 30 Substrate transport section 40 Gas supply section 100 Substrate processing apparatus

Claims

1. A processing method for a substrate processing apparatus having a chamber in which a heating plate for heating a placed substrate is disposed, comprising: a first step of heating the heating plate to a first temperature; a second step of lowering the temperature of the heating plate from the first temperature to a second temperature; In the first step and the second step, a step of supplying a dry gas into the chamber; After the second step, loading the substrate onto the heating plate; A processing method comprising the steps of:

2. 2. The processing method according to claim 1, wherein the substrate processing apparatus carries the substrate into the chamber in a state where the heating plate is heated to the second temperature.

3. 3. The processing method according to claim 1, wherein the first step is carried out only before the first substrate to be loaded when substrates are processed successively.

4. 4. The method according to claim 1, wherein the first step is carried out again when the heating plate is exposed to moisture-containing air for a certain period of time or more.

5. 5. The processing method according to claim 1, wherein the execution time of the first step is changed in accordance with a standby time of the substrate processing apparatus.

6. 6. The method according to claim 1, wherein the first temperature is 250°C or higher.

7. 7. The method according to claim 1, wherein the heating plate is a structure containing aluminum nitride.

8. The processing method according to claim 1 , wherein the dry gas is blown toward the heating plate.

9. 9. The processing method according to claim 1, wherein the dry gas is any one of clean dry air, nitrogen (N2) gas, and inert gas.

10. 10. The processing method according to claim 1, wherein the substrate processing apparatus comprises an exhaust unit that exhausts the atmosphere in the chamber at least in the first step.

11. 11. The processing method according to claim 1, wherein the substrate processing apparatus comprises a measuring unit that measures an atmosphere around the heating plate.

12. 12. The processing method according to claim 11, wherein the substrate processing apparatus determines whether or not the substrate can be loaded into the chamber based on a measurement result of the atmosphere around the heating plate.

13. 13. The substrate processing apparatus according to claim 12, wherein the ambient atmosphere around the heating plate is measured by a particle counter, a chromatography, a laser displacement meter, a spectroscopic interferometer, or a hygrometer.

14. A substrate processing apparatus for processing a substrate using the processing method according to claim 1 .

15. a heating plate on which a substrate is placed and heated; a chamber containing the heating plate; a gas supply unit that supplies a dry gas into the chamber; a transport unit that transports the substrate to the heating plate; A substrate processing apparatus having: a heating unit configured to heat the heating plate to a first temperature and then lower the temperature of the heating plate from the first temperature to a second temperature in accordance with a standby time of the heating plate, and to supply the dry gas into the chamber during the heating and lowering periods.

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