JPH0680630B2 - Rotation processing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotation processing method for processing the surface of a substrate to be processed such as a semiconductor substrate, a liquid crystal substrate, and a ceramic substrate using a rotation processing device, and more particularly, When a large number of substrates to be processed are continuously processed according to a continuous processing program (in this specification, the term “program” means a prescription such as rotation in a rotary processing device and chemical solution discharge).
The present invention relates to prevention of non-uniformity of a processing state of a substrate to be processed in a transient state such as when the apparatus is started, when the apparatus is restarted after being stopped, and when the processing content of a continuous processing program is changed.

(Prior Art) In the above-described transient state of the rotation processing apparatus, the processing state of the substrate to be processed may be different from the processing state in the steady state after processing a large number of substrates for the following reasons. Many. That is, the surplus processing liquid supplied onto the substrate to be processed is scattered and adheres to the wall surface of the cup, which vaporizes to create an atmosphere of the processing liquid vapor in the cup and remove heat of vaporization from the wall surface of the cup. Vary the temperature inside the cup. The atmosphere of these processing liquid vapors and the temperature inside the cup are not stable until a considerable number of substrates are processed. For this reason, the processing state of the substrate to be processed becomes different from the steady state depending on the atmosphere of the processing liquid vapor and the fluctuation of the temperature inside the cup during that time.

As a conventional technique for preventing such non-uniformity of the processing state of the substrate, for example, a technique of filling the developing container with saturated vapor of a developing solution (JP-A-60-216546) or a resist solvent near the substrate. A technique (JP-A-60-10248) of applying a resist after forming a vapor atmosphere has been proposed. Further, as described in JP-A-60-216546,
Conventionally, a method of starting actual development after several idle runs is also known.

(Problems to be Solved by the Invention) However, since a large number of additional members and devices are required to carry out the above technique, the device configuration becomes large. Further, the above publication does not disclose how to deal with a transient state when the processing content of the continuous processing program changes. Further, in the above method, it takes a considerably long time to shift to the steady state, so that the processing efficiency is poor.

The present invention has been made to solve such a problem, and when the substrate is continuously processed according to a continuous processing program by using a rotation processing apparatus, at the time of starting the apparatus and after stopping the apparatus. A non-uniform substrate processing state in a transient state, such as when restarting the machine or when the processing content of a continuous processing program changes, can be easily prevented with a simple configuration, and a rotation processing method with high processing efficiency is provided. The purpose is to provide.

(Means for Solving the Problem) A rotation processing method according to the present invention uses a rotation processing apparatus that processes a substrate to be processed stored in a cup while rotating the substrate, and performs a plurality of processes of a resist coating process or a development process. Of the continuous processing program consisting of the contents, when the specified processing contents are continuously executed to apply or develop the surface of a large number of substrates to be processed, when the apparatus is started,
A rotation processing method for realizing in advance a steady state corresponding to the processing content of a continuous processing program to be performed at the beginning of a transitional state such as when the apparatus is restarted after the apparatus is stopped and when the processing content is changed. The internal temperature of the cup in the steady state during execution of each processing content of the continuous processing program is obtained in advance, a plurality of internal temperatures of the cup are assumed, and the internal temperature of the cup is calculated from the respective estimated temperatures (first temperature) of the cups in the steady state. An initial condition program for supplying a predetermined liquid into the cup and spraying it on the wall surface of the cup so as to change it to the internal temperature (second temperature) is provided for each of the plurality of assumed temperatures and the cup internal temperature in the steady state. Prepared for each group, the actual cup internal temperature is detected before execution of the desired processing contents of the continuous processing program, and the actual cup internal temperature is detected. When the assumed temperature is set, an initial condition program corresponding to a set of the assumed temperature and the cup internal temperature in the steady state corresponding to the desired processing content is selected from a plurality of the initial condition programs, and the continuous processing program is selected. Execute the selected initial condition program before executing.

(Operation) First, an initial condition program for changing the internal temperature of the cup from the estimated temperature to the internal temperature of the cup in the steady state by spraying a predetermined liquid on the cup wall surface is used. Plural items are prepared in advance according to each value.

In addition, the cup internal temperature in the steady state is obtained in advance for each content of each continuous processing of the continuous processing program in the substrate rotation processing, and the actual cup internal temperature is executed before the processing content of the next continuous processing program is executed. To detect.

Using this actual cup internal temperature as the assumed temperature, an optimum initial condition program for changing the actual cup internal temperature from the assumed temperature to the cup internal temperature in the steady state is selected from a plurality of the initial condition programs.

Then, in the case of a continuous processing program for continuously performing resist coating processing or development processing on the surface of a large number of substrates to be processed, when the apparatus is started, when the apparatus is restarted after it is stopped, and when the processing content changes, etc. At the beginning of the transient state, the selected initial condition program is executed before the next continuous processing program is executed. As a result, the actual temperature inside the cup can be made equal to the temperature in the steady state in advance.

At this time, the temperature of the inside of the cup is adjusted by spraying a predetermined liquid, and the vaporization state of the predetermined liquid is also in a steady state inside the cup. Even when sprayed, both the vaporized state and the temperature inside the cup are stably maintained in a steady state.

(Embodiment) FIG. 1 is a schematic configuration diagram showing a resist coating rotation processing apparatus as an example of a rotation processing apparatus applied to the present invention. In the figure, a substrate 1 to be processed is loaded into a resist coating rotation processing device 2 from a processing device (not shown) in the preceding stage,
It is mounted on the spin chuck 4 fitted to the shaft 3a of the rotary drive source 3 and fixed by vacuum suction.

The resist coating rotation processing apparatus 2 operates in accordance with a designated processing content in a continuous processing program including a plurality of processing contents, and coats a resist having a desired film thickness on the substrate 1 to be processed. Each of the plurality of processing contents includes a processing liquid discharge program and a rotation program. FIG. 2A is a timing chart when the continuous processing is performed according to the first processing content of the continuous processing program, and FIG. 3A is a timing chart when the continuous processing is performed according to the second processing content. C1 and C2 indicate the discharge timings of the resist and the rinse liquid according to the processing liquid discharge program, and R indicates the rotation history of the rotary drive source 3 according to the rotation program. The horizontal axis represents time and the vertical axis represents rotation speed.

In the resist spin coating process by the apparatus shown in FIG. 1, first, a predetermined amount of resist 6 is discharged from the nozzle 5 according to the processing liquid discharge program, and is supplied onto the surface of the substrate 1 to be processed. Then, according to the rotation program, the rotation drive source 3
Is activated and the rotation of the substrate 1 to be processed is started. The timing at which the resist 6 is discharged may be after the rotation of the substrate 1 to be processed. In this case, the substrate 1 being rotated is rotated.
The resist 6 will be supplied on top. In any case, in response to this rotation, the supplied resist spreads on the surface of the substrate 1 to be processed, and the rinse liquid 8 is discharged from the nozzle 7 in accordance with the processing liquid discharge program at the timing of forming a uniform film. To be done. The rinsing liquid 8 is composed of the solvent of the resist 6, and thereby the excess resist attached to the periphery of the back surface of the substrate 1 to be processed is melted and removed. Then, the operation of the rotary drive source 3 is stopped according to the rotary program,
The resist spin coating process ends. The substrate 1 to which the resist is applied in this manner is carried out to a subsequent processing device (not shown).

In the above-described rotation process, the resist 6 and the rinse liquid 8 scattered from the substrate 1 to be processed are formed on the inner wall surface of the cup 9.
Adheres. Most of these will flow out through the drainage duct 10, but some will adhere and remain on the inner wall surface of the cup 9. A part of the solvent from the remaining resist 6 and the rinse liquid 8 is vaporized by the air flow exhausted through the exhaust duct 11, and the heat of vaporization is taken from the wall surface of the cup 9,
The inside of the cup 9 is covered with solvent vapor. As a result, in continuous processing, the internal temperature of the cup 9 and the solvent vapor atmosphere in the cup 9 are not constant until the processing of a considerable number of substrates to be processed is completed. For this reason, there is a difference in the resist film thickness on the substrate to be processed between the first several continuous treatments and after the large number of treatments.

This is shown in FIGS. 2B and 3B. Figures 2B and
FIG. 3B shows changes in the temperature T inside the cup and the resist film thickness D when the continuous processing shown in FIGS. 2A and 3A is performed, with respect to the number of processed wafers. In each successive treatment, the cup internal temperature T and the resist film thickness D become T1, T2 and D1, D2, respectively, and settle down. Such a transient state appears when the processing content of the continuous processing program changes significantly compared to the immediately preceding processing content, when the equipment is started up, and when it is restarted after the equipment is stopped. It is not desirable because it causes the change.

Therefore, at the beginning of such a transient state, an initial condition program as shown in FIG. 4A is executed prior to execution of the next continuous processing program. The initial condition program shown in FIG. 4A is composed of a treatment liquid (rinse liquid in this embodiment) discharge program and a rotation program. When the continuous process shown in FIG. 2A is completed and then the continuous process shown in FIG. 3A is started. At the beginning of the transitional state, the process is executed prior to the execution of the continuous process shown in FIG. 3A. In FIG. 4A, C2 represents the rinse liquid discharge timing according to the processing liquid discharge program, and R
Indicates the rotation history of the rotary drive source 3 according to the rotation program.

By executing the initial condition program shown in FIG. 4A, the cup internal temperature T changes from T1 to T2 in a short period of time as shown in FIG. 4B. The most effective rinse liquid discharge amount and discharge timing for causing this change, and the rotation speed and rotation timing of the substrate to be processed are experimentally obtained in advance, and the initial condition program of FIG. 4A is created based on that. Take the method. In general, any one of the internal temperatures of the cup that is expected to occur during the operation of the device is the first temperature (estimated temperature) T1 ', and the other one is the second temperature (steady temperature). The internal temperature of the cup in the state) T2 ', and all combinations of the first and second temperatures T1', T2 'are set to the fifth
It is stored in the cup internal temperature condition table in Fig. C, and the initial condition program corresponding to each combination is stored.
SDD (cup internal temperature from the first temperature T1 'to the second temperature T
A program for changing to 2'in a short period of time) is created in advance and stored in the initial condition program data table of FIG. 5D.

As shown in FIG. 4B, when T1 <T2 instead of T1> T2, the exhaust program is included in the initial condition program. That is, by performing rapid exhaust through the exhaust duct 11 according to the exhaust program, the temperature inside the cup is once raised to T2 or higher, and preferably the inner wall surface of the cup 9 is completely dried, and then as shown in FIG. 4A. By changing the processing liquid discharge program and the rotation program, the temperature inside the cup is changed from T1 to T2 in a short period of time.

On the other hand, FIG. 5A is a continuous processing program data table in which each processing content SD of the continuous processing program is stored.
When a large number of substrates to be processed are successively processed in accordance with these processing contents SD, the cup internal temperature T in a steady state after the processing of a large number of substrates is measured in advance, and the data is associated with each processing contents SD. And stored in advance in the temperature measurement data table of FIG. 5B. Further, a temperature sensor 12 for measuring the temperature inside the cup is provided in the cup 9.

Next, a processing procedure of an embodiment of the rotation processing method according to the present invention will be described with reference to the flowchart of FIG. The process proceeds to step S1 due to the occurrence of a transient state such as when the device is started, when the device is restarted after being stopped, and when the process content of the continuous process program is changed. In step S1, the first temperature T1 'is determined as follows, and this data is stored in the register R1 of the reference table in FIG. 5E. That is, when the apparatus is activated and when the apparatus is restarted after being stopped, the temperature sensor 12 measures the internal temperature of the cup 9, and the data is stored in the register R1 as the first temperature T1 '. If the processing contents of the continuous processing program change, the cup internal temperature measurement data T corresponding to the immediately preceding processing content SD in the continuous processing program data table of FIG. 5A is retrieved from the temperature measurement data table of FIG. 5B. Then, the data T is stored in the register R1 as the first temperature T1 '.

Next, in step S2, the processing content SD to be executed next in the continuous processing program data table in FIG. 5A.
The cup internal temperature measurement data T corresponding to is retrieved from the temperature measurement data table of FIG. 5B, and the data T is the second
Is stored in the register R2 of the lookup table of FIG.

Next, in step S3, the data T in the registers R1 and R2 is
The combination of data that matches 1 ', T2' is searched from the cup internal temperature condition table in Fig. 5C, the corresponding initial condition program SDD is called from the initial condition program data table in Fig. 5D, and that data is retrieved. Store in register R3 of the lookup table of Figure 5E.

Then, in step S4, after mounting the substrate 1 to be processed on the spin chuck 4 within a certain period of time after the instruction to start or restart the apparatus or after the immediately preceding continuous processing is completed, the initial value in the register R3 is set. Execute the conditional program.
As a result, an appropriate amount of rinse liquid is sprayed on the wall surface of the cup, and the temperature inside the cup becomes equal to that in the steady state of the processing content of the next continuous processing program in a short time. Further, since the temperature inside the cup in the above-mentioned steady state is created by spraying the rinse liquid on the wall surface of the cup, the atmosphere of the solvent vapor in the cup 9 at the end of the initial condition program is the content of the processing of the next continuous processing program. Is equal to that in the steady state of. Therefore, in the next step S5, within a certain time after the end of the initial condition program, even if the continuous processing is executed according to the processing content of the continuous processing program to be performed next, the temperature inside the cup and the atmosphere of the solvent vapor in the cup are changed. do not do. as a result,
A uniform resist film thickness can be obtained from the first continuous treatment.

In the above embodiment, an example in which the rotation processing method according to the present invention is applied to a resist coating rotation processing apparatus has been described, but the present invention is also applicable to other rotation processing apparatuses using a processing liquid, such as a rotary developing apparatus. Applicable. For example, in the case of a staff developing device, the processing liquid discharged in the initial condition program is the developing liquid.

(Effects of the Invention) As described above, according to the present invention, the continuous processing program is started at the beginning of a transient state such as when the apparatus is started, when the apparatus is restarted after being stopped, and when the processing content of the continuous processing program changes. By executing the initial condition program that supplies a predetermined liquid such as the processing liquid into the cup and sprays this on the cup wall prior to the execution of the inside of the cup in the steady state of the processing content of the next continuous processing program. Since the temperature is achieved in a short period of time, when the substrate is continuously processed according to the continuous processing program using the rotation processing device, the device is started, restarted after the device is stopped, and continuously. It is possible to prevent unevenness in the processing state of the substrate in a transitional state such as when the processing content of the processing program changes, and to easily prevent it with a simple configuration and to achieve high processing efficiency. There is an effect that a transfer processing method can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a resist spin coating device, 2A.
Figures and 3A are timing charts for continuous processing, 2B
Figures and 3B are diagrams showing changes in cup internal temperature and resist film thickness at that time, FIG. 4A is a timing chart showing an initial condition program, and FIG. 4B is a diagram showing changes in cup internal temperature at that time. 5A to 5E are views showing a data table, and FIG. 6 is a flowchart showing a processing procedure of an embodiment of the rotation processing method according to the present invention. 1 ... Substrate to be processed, 6 ... Resist, 8 ... Rinse liquid, 9 ... Cup, 12 ... Temperature sensor

Claims (1)

[Claims] 1. A specified processing of a continuous processing program consisting of a plurality of processing contents of resist coating processing or development processing using a rotation processing device for processing while rotating a substrate to be processed housed in a cup. When executing the contents continuously to apply or develop the surface of a large number of substrates to be processed, the transient state such as the start-up of the device, the restart after the stop of the device and the change of the processing contents Initially, a rotation processing method for realizing in advance a steady state corresponding to the processing content of a continuous processing program to be performed next, wherein the cup internal temperature in the steady state during execution of each processing content of the continuous processing program is Obtained in advance, assume multiple internal temperatures of the cup, and place the internal temperatures of the cups so that the internal temperatures of the cups can be changed from the estimated temperatures to the internal temperatures of the cups in the steady state. The initial condition program for supplying the liquid of the above and spraying on the cup wall surface is prepared for each set of each of the plurality of assumed temperatures and each of the cup internal temperatures in the steady state, and the desired continuous processing program is set. When the actual cup internal temperature is detected before execution of the processing content and the actual cup internal temperature is set to the assumed temperature, the assumed internal temperature and the cup internal temperature in the steady state corresponding to the desired processing content The initial processing program corresponding to the group is selected from a plurality of the initial processing programs, and the selected initial processing program is executed before the continuous processing program is executed.