JP2011066119A - Apparatus and method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing apparatus and a manufacturing method of a semiconductor device, capable of controlling a resist pattern to a desired dimensional distribution. <P>SOLUTION: The manufacturing apparatus of a semiconductor device includes a chamber 10 for bake processing a substrate 2 to be processed, a plurality of gas supply ports 12 provided on an internal surface of the chamber 10, and a moisture control unit 14 capable of supplying inert gases which differ in humidity, respectively to the plurality of gas supply ports 12. Furthermore, the plurality of gas supply ports 12 are provided at positions opposite to a surface of the substrate 2 mounted inside the chamber 10. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a semiconductor device manufacturing apparatus and manufacturing method, and more particularly to a manufacturing apparatus and manufacturing method related to baking.

  In the manufacturing process of a semiconductor device, a baking process, that is, a process of heating an object to be processed such as a wafer is performed. For example, in photolithography, which is a shape processing method, a photoresist is applied to a wafer, and a baking process is performed before the exposure process.

  In addition, a so-called post exposure bake (PEB) performed after exposure for the purpose of adjusting the film quality of the resist film is also one of the processes for determining the dimensional accuracy of the resist pattern. For example, Patent Document 1 discloses a resist coating and developing apparatus that corrects post-exposure post-baking temperature to enable highly accurate line width control of a resist pattern.

  Further, when performing PEB, a PEB temperature correction technique has been used in which a plurality of heater blocks are arranged to change the baking temperature in the silicon substrate surface to correct the dimensional distribution of the resist pattern after development. However, in the PEB temperature correction, there is a problem that the dimension that can be corrected is limited to a range of several nm, for example, 2.5 nm to 3.0 nm, and sufficient correction cannot be performed.

Japanese Patent Laid-Open No. 10-275755

  An object of the present invention is to provide a semiconductor device manufacturing apparatus and a manufacturing method that improve the dimensional accuracy by controlling the dimension of a resist pattern to a desired distribution.

  According to one embodiment of the present invention, an inert gas having a different humidity is supplied to each of a chamber for baking a substrate to be processed, a plurality of gas supply ports provided on the inner surface of the chamber, and a plurality of gas supply ports. An apparatus for manufacturing a semiconductor device is provided.

  According to another aspect of the present invention, by supplying an inert gas having a different humidity to each of the plurality of surface regions of the substrate to be processed on which the photoresist film is formed, the plurality of surface regions are There is provided a method for manufacturing a semiconductor device, characterized in that baking is performed under different humidity atmospheres.

  ADVANTAGE OF THE INVENTION According to this invention, the dimension of a resist pattern is controlled to desired distribution, and the manufacturing apparatus and manufacturing method of a semiconductor device which improve a dimensional accuracy are realizable.

It is sectional drawing which shows typically the semiconductor manufacturing apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows the structure of the principal part of the semiconductor manufacturing apparatus which concerns on one Embodiment. It is explanatory drawing which shows the characteristic of the photoresist which concerns on one Embodiment. It is explanatory drawing which shows the function of the semiconductor manufacturing apparatus which concerns on one Embodiment. It is sectional drawing which shows typically operation | movement of the semiconductor manufacturing apparatus which concerns on one Embodiment. It is a flowchart which shows the manufacturing method of the semiconductor device which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same parts in the drawings are denoted by the same reference numerals, detailed description thereof will be omitted as appropriate, and different parts will be described as appropriate.

FIG. 1 is a cross-sectional view schematically showing a semiconductor manufacturing apparatus according to an embodiment of the present invention. The semiconductor manufacturing apparatus according to this embodiment is a baking processing apparatus 1 for baking a semiconductor substrate.
The baking apparatus 1 includes a chamber 10 for baking a substrate 2 to be processed, a plurality of gas supply ports 12 provided on the inner surface of the chamber 10, and an inert gas having a different humidity in each of the plurality of gas supply ports 12. And a humidity controller 14 to be supplied.

  The chamber 10 includes a chamber cover 3 and a chamber base 4, and a plurality of gas supply ports 12 are provided on the inner surface of the chamber cover 3. A gas supply pipe 13 is connected to the gas supply port 12, and an inert gas whose humidity is controlled by the humidity control unit 14, for example, air (air) or nitrogen is supplied to the chamber 10 through the gas supply pipe 13. It is configured to be introduced inside.

  The chamber base 4 is provided with a bake heater 5 and support pins 6. The bake heater 5 heats the substrate 2 to be processed to a desired temperature. The support pin 6 is provided so as to be movable in the vertical direction in FIG. 1, and rises when the substrate to be processed 2 is carried in and out, and descends when the substrate to be processed 2 is heated, and the bake heater 5. Contact.

  Further, the humidity control unit 14 has a plurality of control units 15. Each control unit 15 controls the humidity of the inert gas independently for each unit, and supplies the humidity to the gas supply port 12 connected via the gas supply pipe 13. Thereby, the humidity of the inert gas can be changed into each gas supply port 12 and introduced into the chamber 10.

  On the other hand, as shown in FIG. 1, the plurality of gas supply ports 12 are provided at positions facing the surface of the substrate 2 to be processed placed in the chamber 10. Therefore, the inert gas introduced into the chamber 10 is sprayed onto the surface region of the substrate 2 to be processed facing each gas supply port 12. As a result, by changing the humidity of the inert gas supplied from each gas supply port 12, it is possible to perform the baking process by changing the humidity atmosphere for each of the plurality of surface regions of the substrate 2 to be processed.

FIG. 2 is a schematic diagram showing the configuration of the main part of the baking apparatus 1 according to the present embodiment.
FIG. 2A is a schematic diagram illustrating an arrangement example of the gas supply ports 12 provided on the inner surface of the chamber cover 3. The chamber 10 of the baking processing apparatus 1 according to the present embodiment has a substantially cylindrical outer shape, and the inner surface of the chamber cover 3 is circular as shown in FIG. The gas supply ports 12 are arranged in a cross shape along the horizontal and vertical directions in FIG. Further, the number of the gas supply ports 12 can be increased to arrange them more densely. For example, in addition to the arrangement shown in FIG. 2A, the humidity distribution in the chamber 10 can be controlled with higher accuracy by providing the gas supply port 12 along an oblique direction inclined by 45 ° from the horizontal. .

  FIG. 2B is a block diagram showing the configuration of the control unit 15. The control unit 15 includes a first pipe 17 that supplies an inert gas from the outside to the control unit, and a second pipe 18. Further, the first pipe 17 and the second pipe 18 are connected to the gas supply pipe 13 via the flow rate controller 16. Therefore, the flow rate of the inert gas flowing from the first pipe 17 and the second pipe 18 to the gas supply pipe 13 can be controlled by the flow rate controller 16. Thereby, the mixture ratio of the inert gas of the 1st piping 17 and the 2nd piping 18 can be changed arbitrarily.

  The first pipe 17 supplies an inert gas having a humidity higher than the maximum humidity value of the inert gas supplied to the surface of the substrate 2 to be processed. Further, the second pipe 18 supplies an inert gas having a humidity lower than the minimum humidity of the inert gas supplied to the surface of the substrate 2 to be processed. Thus, the substrate 2 to be processed is controlled by controlling the mixing ratio of the inert gas supplied from the first pipe 17 and the inert gas supplied from the second pipe 18 by the flow rate controller 16. It is possible to supply an inert gas having a predetermined humidity to the surface of the substrate.

  As the inert gas supplied from the first pipe 17, for example, air whose humidity is controlled to about 50% by an air conditioner can be used. On the other hand, as the inert gas supplied from the second pipe 18, dry air that has passed through a dryer can be used.

  Further, for example, a mass flow controller can be used as the flow rate controller 16. It is desirable that the flow rate controller 16 has a configuration in which a tape heater is wound around the outlet pipe and heated in order to prevent condensation inside the pipe due to a pressure difference between the inlet side and the outlet side.

FIG. 3 is an explanatory view showing the characteristics of the photoresist applied to the surface of the substrate 2 to be processed.
FIG. 3A schematically shows a resist pattern formed for evaluating the characteristics of the photoresist. FIGS. 3B and 3C show the relationship between the width W of the resist pattern after the development processing shown in FIG. 3A and the humidity of the inert gas supplied to the chamber during the PEB processing. Is shown. In addition, the inert gas used for this experiment is air, and has shown the relative humidity in room temperature (25 degreeC).

  For example, in the case of the resist A shown in FIG. 3B, when the humidity of the supplied inert gas increases, the width W of the resist pattern decreases. The rate of change is -1 nm /%, and it can be seen that W changes by 10 nm when the humidity changes by 10%. On the other hand, in the case of the resist B shown in FIG. 3C, it can be seen that when the humidity of the inert gas increases, the width W of the resist pattern increases, and W changes by 8 nm with respect to a 10% change in humidity.

  In the above-described PEB temperature correction, the baking heater 5 provided in the chamber base 4 is composed of a plurality of block heaters, and the resist pattern size correction is performed by changing the baking temperature in the surface of the substrate 2 to be processed. However, it is difficult to set the difference in the baking temperature in the substrate surface to 2.5 to 3.0 ° C. or more, and the temperature dependence of the dimensional change is as small as 1 nm / ° C. For this reason, the maximum dimension that can be corrected by the PEB temperature correction is limited to 2.5 to 3.0 nm.

  On the other hand, in the bake processing apparatus 1 according to the present embodiment, if the humidity difference of the inert gas supplied to the chamber 10 is about 20%, the maximum correction amount at the time of PEB processing is about 20 nm in the case of the resist A. In the case of resist B, the thickness can be about 16 nm. That is, the dimensional correction can be made an order of magnitude larger than the PEB temperature correction.

  Further, as shown in FIGS. 3B and 3C, when the type of resist is different, the increase / decrease in the resist pattern width W with respect to the change in humidity of the inert gas and the amount of change are also different. Therefore, when using the bake processing apparatus 1 according to the present embodiment, characteristic data as shown in FIGS. 3B and 3C is acquired in advance for a target resist to obtain a desired correction amount. The mixing ratio of the inert gas is set so that the humidity is as high as possible.

FIG. 4 is an explanatory diagram illustrating functions of the baking processing apparatus 1 according to the present embodiment.
As shown in FIG. 4, the chamber 10 of the baking apparatus 1 has a plurality of gas discharge ports 19 in the vicinity of the gas supply port 12. In addition, in order to discharge the gas in the chamber 10, a pipe connected to an exhaust fan 23, which is a discharge unit, is connected to the gas discharge port through the flow rate controller 22. Further, a gas controller 24 is provided to control the flow rate of the inert gas introduced into the chamber 10 from the gas supply port 12 and the inert gas discharged from the gas discharge port 19.

  The exhaust fan 23 forcibly exhausts the gas in the chamber 10, and the flow rate controller 22 controls the flow rate of the inert gas discharged from the gas discharge port 19. The gas controller 24 sends control signals to the humidity control unit 14 and the flow rate controller 22, and is discharged from the gas supply port 12 and the flow rate of the inert gas introduced into the chamber 10 and from the gas discharge port 19. Control the balance of inert gas flow. Thereby, the inert gas introduced into the chamber 10 from the gas supply port 12 can be controlled to be quickly discharged from the adjacent gas discharge port 19.

  As a result, as shown in FIG. 4A, the flow path of the inert gas flowing from each gas supply port 12 to the adjacent gas discharge port 19 is formed, and the inert gases having different humidity are not mixed with each other. A desired humidity distribution can be obtained. In the example shown in FIG. 4A, an inert gas containing moisture corresponding to a humidity of 50% is supplied to the center of the substrate 2 to be processed placed in the chamber 10. On the other hand, an inert gas containing moisture corresponding to a humidity of 30% is supplied to the periphery of the substrate 2 to be processed.

  FIG. 4B shows the humidity distribution of the inert gas in the plane of the substrate 2 to be processed. In this example, an inert gas containing moisture corresponding to a humidity of 30% is supplied to an area A on the outer periphery of the substrate 2 to be processed, and an inert gas containing moisture corresponding to a humidity of 35% is supplied to the area B. Active gas is supplied. An inert gas containing moisture corresponding to a humidity of 40% and 45% is supplied to the D region and E region, which are intermediate regions.

  That is, in the bake processing apparatus 1 according to the present embodiment, an inert gas whose humidity is changed in units of 5%, for example, is supplied to a plurality of surface regions of the substrate 2 to be processed on which a photoresist film is formed. Can be baked under different humidity atmospheres. Thereby, it becomes possible to perform different dimensional correction for each surface region on the developed resist pattern. Further, since the humidity continuously changes at the boundary of each surface region, the dimension of the resist pattern after correction can also be changed continuously.

  The dimension of the resist pattern formed by photolithography is due to various factors such as warpage of the substrate 2 to be processed, film thickness variation of the photoresist film formed on the substrate 2 to be processed, development variation, and baking temperature variation. There is a case where a dimensional distribution having a predetermined tendency appears in the plane of the substrate to be processed.

  For example, in the resist pattern formed using the resist A shown in FIG. 3B, when the outer peripheral dimension is 20 nm thinner than the central part of the substrate 2 to be processed, the inert gas supplied to the central part is reduced. If the humidity is 50%, the humidity of the inert gas supplied to the intermediate part is 40%, and the humidity of the inert gas supplied to the outer peripheral part is 30%, the dimensional correction is 20 nm between the central part and the outer peripheral part. It is possible to obtain a resist pattern having a uniform dimension on the entire surface of the substrate 2 to be processed.

  Further, in order to correct the detailed distribution of the resist pattern, for example, as shown in FIG. 4, the humidity of the inert gas can be finely controlled in units of 5%. Thereby, the uniformity can be further improved.

  Further, when plasma etching is performed on the surface of the substrate 2 to be processed using the resist pattern as a mask, the dimension of the etching pattern transferred onto the surface may be a specific distribution due to the plasma density distribution. In such a case, it is effective to predict the dimension distribution after etching and to incorporate the dimension distribution into the resist pattern in advance. That is, by controlling the humidity distribution of the inert gas, the resist pattern can be controlled to have a predetermined dimensional distribution, and the etching pattern can be made uniform.

FIG. 5 is a cross-sectional view schematically showing the operation of the baking processing apparatus 1 according to the present embodiment.
In FIG. 5A, the chamber cover 3 is raised by a drive mechanism (not shown), and the support pin 6 is held in the raised state. The bake heater 5 is heated to a desired temperature, for example, 100 ° C. An inert gas having a predetermined humidity is supplied from the gas supply port 12.

  Next, as shown in FIG. 5B, the substrate 2 to be processed is carried into the chamber 10 and placed on the support pins 6. The substrate 2 to be processed is carried in and placed by a transfer arm (not shown). Further, the chamber cover 3 is lowered and the chamber 10 is closed. At this time, the support pins 6 are lowered at the same time, and as shown in FIG. 5C, the back surface of the substrate 2 to be processed comes into contact with the bake heater 5 and the baking process is started.

  During the baking process shown in FIG. 5C, inert gas having a predetermined humidity is supplied from the plurality of gas supply ports 12, and baking is performed in a plurality of surface regions of the substrate 2 to be processed in different humidity atmospheres.

  Next, as shown in FIG. 5 (d), the chamber cover 3 is raised and the support pins 6 are raised to separate the substrate 2 to be processed from the bake heater 5. At this point, the baking process ends. That is, the start and end of the baking process are controlled by the lowering and raising of the support pin 6. Furthermore, the to-be-processed substrate 2 which completed the baking process is carried out of the chamber 10 with the transfer arm etc. which are not shown in figure.

  FIG. 6 is a flowchart showing a method for manufacturing a semiconductor device according to an embodiment of the present invention. Here, a photolithography process is shown.

  First, as a first step (S1), a predetermined photoresist is applied to the surface of the substrate 2 to be processed. Next, the substrate to be processed 2 is pre-baked, and the solvent is diffused and solidified from the applied photoresist to form a photoresist film (S2). Pre-baking is performed, for example, in a temperature range of 80 ° C. to 120 ° C. under conditions suitable for each resist.

  Next, an exposure process is performed using a predetermined exposure apparatus to expose the resist film (S3).

  Next, the first post bake 1 is performed (S4). This is a so-called PEB process. At this time, the baking process 1 shown in FIG. 1 is used to perform the baking process by changing the humidity atmosphere for each of the plurality of surface regions of the substrate 2 to be processed.

  Thereafter, development processing (S5) is performed, and finally, post-baking 2 (S6) is performed again to dissipate the solvent from the resist pattern, thereby completing the photolithography process. In the post-baking process performed in the last step (S6), it is not necessary to change the humidity atmosphere of the surface region of the substrate 2 to be processed, and the baking process is performed in a dry inert gas atmosphere.

(Modification)
The pre-baking process (S2) shown in step 2 of FIG. 6 is one of important processes for determining the film quality of the photoresist film. Also in this pre-bake process, if the bake processing apparatus 1 according to this embodiment is used, the film quality of the photoresist film can be distributed in the plane of the substrate 2 to be processed. That is, the amount of moisture contained in the photoresist film can be changed by performing pre-baking treatment in a plurality of surface regions of the substrate 2 to be processed in different humidity atmospheres.

  For example, in EUV (Extreme Ultraviolet) exposure, since exposure is performed in a vacuum, the amount of moisture contained in the photoresist is one of the important factors determining the shape and dimensions of the resist pattern after development. Therefore, the uniformity of the resist pattern can be improved by changing the moisture content of the photoresist film formed on the substrate 2 to be processed in accordance with the shape distribution and dimension distribution of the resist pattern after development. it can.

  As a specific implementation method, first, the bake heater 5 is set to a desired temperature, for example, 120 ° C. in a state where the chamber cover 3 is raised and the support pins 6 are up as shown in FIG. Is done. Further, an inert gas having a desired humidity is supplied from the gas supply port 12 at a flow rate of 7 l / min. For example, an inert gas containing moisture corresponding to 40% humidity is supplied from the gas supply port 12 in the central portion, and moisture corresponding to 50% humidity is supplied from the gas supply port 12 in the outer peripheral portion. Inert gas is supplied.

  Next, as shown in FIG. 5B, the substrate to be processed 2 is placed on the support pins 6. Thereafter, as shown in FIG. 5C, the chamber cover 3 is lowered and the chamber 10 is closed. At the same time, the support pins 6 are lowered and the baking process is started. Inert gas having a desired humidity is continuously supplied from the gas supply port 12, and the central portion of the substrate 2 to be processed is baked in a lower humidity atmosphere than the outer peripheral portion.

  Thereafter, as shown in FIG. 5D, the chamber cover 3 is raised, the support pins 6 are raised, and the baking process is completed.

  Generally, when moisture is contained in the photoresist, the solvent that occupies most of the components of the photoresist is decomposed. For this reason, the resist pattern may not be formed or the resist pattern may be defective due to the decomposition of the solvent. Therefore, by controlling the amount of moisture in the photoresist film before exposure using the bake processing apparatus according to the present embodiment, it is possible to bring out the original defect performance of the photoresist.

  As mentioned above, although this invention was demonstrated with reference to one embodiment which concerns on this invention, this invention is not limited to these embodiment. For example, embodiments that have the same technical idea as the present invention, such as design changes and material changes that can be made by those skilled in the art based on the technical level at the time of filing, are also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Bake processing apparatus 2 Substrate 10 Chamber 12 Gas supply port 14 Humidity control part 15 Control unit 17 Piping 18 Piping 19 Gas exhaust port 23 Exhaust fan

Claims (7)

A chamber for baking a substrate to be processed;
A plurality of gas supply ports provided on the inner surface of the chamber;
A humidity controller capable of supplying an inert gas having a different humidity to each of the plurality of gas supply ports;
An apparatus for manufacturing a semiconductor device, comprising:   The semiconductor device manufacturing apparatus according to claim 1, wherein the plurality of gas supply ports are provided at positions facing a surface of the substrate to be processed placed in the chamber. A plurality of gas discharge ports provided on an inner surface of the chamber, each of the plurality of gas discharge ports being a plurality of gas discharge ports provided in the vicinity of each of the plurality of gas supply ports;
A discharge means for forcibly discharging the gas in the chamber from the plurality of gas discharge ports;
The apparatus for manufacturing a semiconductor device according to claim 1, further comprising:   The said humidity control part has a some control unit which controls independently the humidity of the said inert gas supplied to each of these gas supply ports, The any one of Claims 1-3 characterized by the above-mentioned. The manufacturing apparatus of the semiconductor device as described in one. The control unit is
A first pipe for supplying an inert gas having a humidity higher than a maximum value of the humidity of the inert gas supplied to the surface of the substrate to be processed;
A second pipe for supplying an inert gas having a humidity lower than the minimum humidity of the inert gas supplied to the surface of the substrate to be processed;
Have
An inert gas having a predetermined humidity is supplied by controlling a mixing ratio between the inert gas supplied from the first pipe and the inert gas supplied from the second pipe. An apparatus for manufacturing a semiconductor device according to claim 4.   The plurality of surface regions are baked under different humidity atmospheres by supplying an inert gas having different humidity to each of the plurality of surface regions of the substrate to be processed on which the photoresist film is formed. A method for manufacturing a semiconductor device.   The method of manufacturing a semiconductor device according to claim 6, wherein the photoresist film is exposed before the baking process.

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