JP2005211734A - Organic material applying apparatus and organic material applying method using the same apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic material applying apparatus and an organic material applying method in which material utilization efficiency is good, a homogeneous organic material film can be applied onto a substrate surface and further a chemical amplification resist can be applied without lowering resist characteristics. <P>SOLUTION: A substrate 2 is mounted on a stage 1 equipped with a baking treating mechanism. After decompressing the inside of a chamber 3, first baking treatment is performed to the substrate 2 by the stage 1. After the inside of the chamber 3 is replaced with an inert gas atmosphere, while holding the substrate 2 at a prebaking temperature of an organic material 7 by second baking treatment, a nozzle 6 provided freely movably above the stage 1 is moved above the substrates 2 and ejects the organic material 7 while moving so as to scan in a direction of an arrow 8. By this process, the organic material 7 is applied on a surface of the substrate 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an organic material coating apparatus used in a lithography process used in an integrated circuit manufacturing process or the like and an organic material coating method using the apparatus.

  In general, in a manufacturing process of a semiconductor device or a mask, a resist material (hereinafter referred to as an organic material) is applied on a substrate of a semiconductor wafer, a reticle, or a photomask (hereinafter referred to as a mask). A predetermined circuit pattern is transferred to a film using a photolithography technique or an electron beam lithography technique, and development processing is performed. As an organic material coating method for coating and forming a thin film such as an organic material film on the semiconductor wafer or mask substrate, a spin coating method is mainly used.

  In the spin coating method, a substrate is fixed on a stage having a rotation axis, and an organic material is dropped on the surface of the substrate. After this, the stage is rotated in one direction. Thereby, on the surface of a board | substrate, the organic material dripped at the board | substrate center part is extended in the direction of the edge part of a board | substrate, and a uniform organic material thin film is formed.

  In the organic material coating apparatus using the spin coating method, since the organic material applied to the substrate is extended by rotation in one direction, the organic material is extended on the surface of the substrate, and the edge portion moves toward the periphery of the substrate. May cause unevenness and disturbance. As a result, the film thickness of the organic material becomes non-uniform. That is, the surface of the organic material film formed on the substrate is uneven, and the organic material cannot be uniformly applied to the surface of the substrate.

  In the above spin coating method, since the organic material is extended by rotation, the material utilization efficiency is very poor because the organic material is scattered from the edge of the substrate.

  Therefore, in order to solve the problem of material utilization efficiency in the spin coating method, a nozzle coater using a slit nozzle having a slit-like discharge portion is used (see Patent Document 1). In the nozzle coater, a curtain-like organic material is applied onto the substrate while the slit nozzle moves relative to the substrate held horizontally by the substrate holder. In such a nozzle coater, a necessary organic material can be supplied in the form of a film over the entire surface of the substrate, so that the material utilization efficiency can be improved.

  In the conventional nozzle coater, after the organic material is applied onto the surface of the substrate by the slit nozzle in the applying step, the substrate is baked in the baking step. Thereby, the solvent contained in the organic material is vaporized in the baking process. At this time, the solvent is not uniformly vaporized, and it is considered that the end portion of the applied organic material is vaporized more than the central portion. As a result, surface tension or the like generated in the organic material acts, and interference fringes are generated on the surface of the organic material film. In other words, the surface state of the organic material film formed on the substrate varies, and the uniformity is poor.

  In order to solve the problem of surface state uniformity in the nozzle coater, a method of baking a substrate by the baking mechanism at the same time as applying an organic material using a nozzle coater having a baking mechanism has been studied (see Patent Document 2). . In this method, the organic material is discharged while moving on the substrate so as to scan the slit nozzle, and at the same time, the substrate is baked by the baking mechanism. Thereby, the solvent contained in the organic material can be uniformly vaporized, and the organic material can be applied to the surface of the substrate with good uniformity.

  However, all of the above conventional organic material coating apparatuses and coating methods have been studied to apply the organic material smoothly and uniformly on the substrate, but when applying a chemically amplified resist on the substrate, the resist characteristics Will be reduced. In general, a chemically amplified resist generates an acid that acts as a catalyst for the resist reaction by exposure or drawing, and the resist reaction is carried out. As a result, the resist characteristics are greatly deteriorated. Specific factors for deactivation of the acid include moisture and basic components in the environmental atmosphere, and moisture and basic components attached to the substrate surface. In particular, the mask substrate is formed with a chromium nitride film or the like as a light-shielding film, so moisture and basic components in the film also deactivate the acid that acts as a catalyst for the resist reaction, affecting the resist characteristics of the chemically amplified resist. There is a problem.

The known literature is described below.
JP 56-159646 A JP-A-6-252039

  The present invention has been made in order to solve these problems. The material utilization efficiency is good, an organic material film having good uniformity is applied to the substrate surface, and the resist characteristics of the chemically amplified resist are lowered. Provided are an organic material coating apparatus and a coating method that can be applied without any problem.

  In order to solve the above-described problems in the present invention, an invention according to claim 1 of the present invention includes a stage on which a substrate is placed, and an upper side of the stage, which is movably provided. In an organic material coating apparatus comprising a nozzle for coating an organic material on the surface of the substrate, the organic material is applied to at least a stage for placing the substrate and a surface of the substrate provided movably above the stage. The organic material coating apparatus is characterized in that a nozzle is installed in a sealed chamber.

  The invention according to claim 2 of the present invention is the organic material coating apparatus according to claim 1, wherein at least the atmosphere in the chamber is purged with an inert gas.

  The invention according to claim 3 of the present invention is characterized in that at least a stage for mounting the substrate is provided with a baking processing mechanism, or the organic material application according to claim 1 or 2 Device.

  The invention according to claim 4 of the present invention is the organic material coating method using the organic material coating apparatus according to any one of claims 1 to 3, wherein the organic material is coated on the surface of the substrate, at least before the organic material coating. An organic material application comprising: a step of first baking the substrate in a reduced pressure atmosphere; and a step of applying an organic material while performing a second baking process on the substrate in an inert gas atmosphere. Is the method.

According to the present invention, a stage having a bake processing mechanism for placing a substrate and a nozzle that is movably provided above the stage and that applies an organic material to the surface of the substrate are installed in the chamber. By using an organic material coating device, the substrate is heated in a reduced pressure environment before coating, and then the organic material is coated while heating the substrate in an inert gas atmosphere. An organic material coating apparatus and method capable of coating an organic material film with good uniformity and capable of coating a chemically amplified resist without deteriorating resist characteristics.

  Hereinafter, an example of the organic material coating apparatus and method of the present invention will be described in detail according to the coating process.

  FIG. 1 is a cross-sectional view showing an example of an organic material coating apparatus of the present invention. First, the substrate 2 is placed on the stage 1 provided with a baking mechanism provided in the chamber 3. In the chamber 3, a supply port 4 for supplying an inert gas into the chamber 3 and an exhaust port 5 connected to a vacuum pump 9 for exhausting the atmosphere in the chamber 3 are formed. The supply port 4 and the exhaust port 5 can be provided with control valves for opening and closing, respectively. Here, the vacuum pump 9 is an oil rotary pump, mechanical booster, molecular pump, mercury diffusion pump, oil diffusion pump, sputter ion pump, titanium supplement pump, cryopump, cryosorption pump, sorption pump, etc. They can be used in combination. The bake processing mechanism is a heat processing mechanism that maintains the temperature of the entire stage up to a predetermined temperature and keeps the surface temperature of the substrate placed on the stage constant.

  The stage 1 equipped with a bake processing mechanism is made of a metal having a high thermal conductivity such as copper, chromium, aluminum, gold, or silver. Further, in order to prevent the substrate 2 from being damaged, the stage 1 can be provided with a buffer material 10 on the entire surface or a part of the substrate 2 in contact with the stage 1. As the buffer material 10 in the present invention, a heat-resistant resin such as a fluororesin, polyimide, heat-resistant silicon rubber or the like can be used.

Thereafter, the inside of the chamber 3 is depressurized by the vacuum pump 9 and the exhaust port 5, and the substrate 2 is first baked by the stage 1 equipped with a baking processing mechanism. Degree of vacuum depressurized chamber 3, 1Torr~10 ^-6 Torr, preferably suitably 10 ^-6 Torr~10 ^-6 Torr. In the first baking process, the temperature is 150 ° C. to 300 ° C., preferably 180 ° C. to 250 ° C., and the time is 90 sec to 1800 sec, preferably 180 sec to 300 sec, depending on the substrate size. .

  By performing the first baking process on the substrate 2 under a reduced pressure environment, moisture and basic components adhering to the surface of the substrate 2 are desorbed. Further, when the substrate 2 is formed with a light shielding film or the like on the surface of the substrate like a mask substrate, moisture and basic components in the film are also desorbed.

  Next, an inert gas is supplied into the chamber 3 from the supply port 4 and the inside of the chamber 3 is set to an inert gas atmosphere. Then, the substrate 2 is subjected to the second baking process by the stage 1 equipped with a baking process mechanism. A nozzle 6 movably provided above the stage 1 is moved above the substrate 2 and discharges the organic material 7 while moving so as to scan in the direction of the arrow 8. That is, the substrate 2 is subjected to the second baking process by the stage 1 equipped with the baking processing mechanism in the inert gas atmosphere chamber 3, and at the same time, the nozzle 6 is moved above the substrate 2 so as to scan. However, the organic material 7 is discharged. Thereby, the organic material 7 is applied to the surface of the substrate 2.

As an inert gas supplied into the chamber 3, a rare gas such as He, Ne, Ar, Kr, or Xe, N _2, or the like can be used. In the second baking treatment, the temperature is preferably 50 ° C. to 200 ° C., preferably 90 ° C. to 150 ° C., and the time is 30 sec to 1800 sec, preferably 300 sec, depending on the substrate size and the type of solvent contained in the organic material. -900 sec is suitable.

  Further, as the nozzle 6 from which the organic material is discharged, a discharge nozzle provided with a scanner plate, a spray nozzle, a slit nozzle, a blade nozzle, or the like can be used, and a slit nozzle is preferable.

  An organic material 7 is applied to the surface of the substrate 2 by a nozzle 6 movably provided above the stage 1 while performing a second baking process on the substrate 2 by the stage 1 provided with the baking mechanism. Thus, the solvent contained in the organic material 7 can be uniformly vaporized. As a result, the organic material 7 can be applied to the surface of the substrate 2 with good uniformity. Moreover, since the organic material 7 can be apply | coated to the board | substrate 2 only by the required quantity with the nozzle 6, material utilization efficiency can be improved. At the same time, since the substrate 2 is continuously baked, moisture and basic components can be prevented from reattaching to the substrate 2.

  Furthermore, by making the inside of the chamber 3 as an application environment an inert gas atmosphere, when the organic material 7 is applied to the substrate 2, it is possible to prevent water and basic components from dissolving in the organic material 7. As a result, even when a chemically amplified resist is used as the organic material 7, the acid that acts as a catalyst for the resist reaction is not deactivated, and deterioration of resist characteristics can be prevented.

  Through the above steps, the material utilization efficiency is good, an organic material film with good uniformity can be applied to the substrate surface, and even if a chemically amplified resist is used, it can be applied without deteriorating resist characteristics.

  Next, the organic material coating method of the present invention will be described. FIG. 3 is a flowchart of an organic material coating method using the organic material coating apparatus of the present invention. First, manufacturing conditions such as coating specifications, substrate size, and number of coated substrates are registered in a unit that centrally manages the apparatus of the present invention. Next, the baking process condition values of the first and second baking processes are input. Next, as shown in FIG. 3a, the substrate is placed on the stage in the chamber.

  Next, after the whole chamber was depressurized to a set chamber pressure P, the stage was heated to a first baking process and heated to a stage temperature T. Under the above conditions, the desorption treatment is performed until the treatment time M while the surface temperature of the substrate is kept at the temperature T. This completes the first baking process (see FIGS. 3b to 3c).

  Next, in FIG. 3D, the supply valve was opened, an inert gas was introduced into the chamber, and an inert gas atmosphere with a set chamber internal pressure p was obtained. At the same time, the stage was heated to the stage temperature t set for the second baking process. Under the above conditions, the substrate is baked until the processing time m while maintaining the surface temperature of the substrate. At the same time, the organic material was discharged while the nozzle above the stage moved to scan. Through the above steps, the organic material is applied to the surface of the substrate, and at the same time, the second baking process is completed (see FIGS. 3e to 3g).

  Although a detailed example is shown below, it is not limited to this.

  An embodiment of the present invention will be described with reference to FIG. 1 or FIG. First, a mask substrate with a Cr light-shielding film was placed as a substrate 2 on a stage 1 provided with a buffer material 10 made of fluororesin and provided with a baking processing mechanism made of aluminum (see FIG. 3a).

Thereafter, the control valve of the supply port 4 is closed, and the pressure in the chamber 3 is reduced from the exhaust port 5 to a vacuum degree of 3 × 10 ⁻³ Torr using a dry pump as the vacuum pump 9, and then the first baking process by the stage 1 is performed. Then, the substrate 2 was heated at 250 ° C. for 300 seconds to desorb moisture and basic components in the substrate surface and the Cr light-shielding film (see FIGS. 3b to 3c). This completes the first baking process.

Next, a second baking process is started. First, the control valve of the exhaust port 5 was adjusted, an inert gas Ar was introduced into the chamber 3 from the supply port 4, and the inside of the chamber 3 was set to a vacuum degree of 3 × 10 ⁻³ Torr and an Ar atmosphere (see FIG. 3d). .

  At the same time, the surface temperature of the substrate 2 was lowered to 120 ° C., which is the pre-baking temperature of the organic material 7. While the surface temperature of the substrate 2 is maintained at 120 ° C. by the second baking process by the stage 1, the nozzle 6 composed of a slit nozzle provided movably above the stage 1 is moved above the substrate 2. The organic material 7 made of a chemically amplified negative resist was discharged while moving so as to scan in the direction of the arrow 8. The organic material 7 was apply | coated to the surface of the board | substrate 2 by the above process, and the process of a 2nd baking process was complete | finished (refer FIG. 3 e-g).

  When a chemically amplified negative resist was applied onto a mask substrate with a Cr light-shielding film by this organic material application apparatus and method, the substrate surface was uniform and smooth. In addition, after coating, drawing with an EB drawing machine and development, no dimensional change or residual film change due to a decrease in resist characteristics was observed.

  Below, Example 2 by the organic material application | coating method using the conventional organic material application | coating apparatus was implemented, and it was set as the comparative example.

  A comparative example in the present invention will be described with reference to FIG. First, a mask substrate with a Cr light-shielding film was placed as a substrate 2 on a stage 1 provided with a buffer material 10 made of fluororesin and provided with a baking processing mechanism made of aluminum.

  Then, while the surface temperature of the substrate 2 is heated at 120 ° C. by the stage 1, the nozzle 6 composed of a slit nozzle provided movably above the stage 1 is moved above the substrate 2, and the arrow 8 The organic material 7 made of a chemically amplified negative resist was discharged while moving so as to scan in the direction.

  The organic material 7 was applied to the surface of the substrate 2 through the above steps.

  When a chemically amplified negative resist was applied onto a mask substrate with a Cr light-shielding film by this organic material application apparatus and method, the substrate surface was uniform and smooth. Also, after coating, drawing with an EB drawing machine and development, the basic component adhering to the substrate surface and the moisture and basic component remaining in the Cr light-shielding film serve as a catalyst for the resist reaction. Since the acid was deactivated and the resist characteristics were lowered, the dimension was reduced by about 25 nm, and the remaining film was reduced by about 25%.

It is a sectional side view which shows an example of the structure of the organic material coating device in this invention. It is a sectional side view which shows an example of the structure of the organic material coating device in the comparative example 1. It is a flowchart explaining the organic material application | coating method using the organic material application | coating apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Stage 2 ... Board | substrate 3 ... Chamber 4 ... Supply port 5 ... Exhaust port 6 ... Nozzle 7 ... Organic material 8 ... Nozzle movement direction 9 ... Vacuum pump 10 ... Buffer material

Claims (4)

  In an organic material coating apparatus comprising: a stage for placing a substrate; and a nozzle that is movably provided facing the upper side of the stage and coats the surface of the substrate with an organic material. An organic material coating apparatus, wherein a stage for mounting and a nozzle for coating an organic material on a surface of the substrate provided movably above the stage are installed in a sealed chamber.   The organic material coating apparatus according to claim 1, wherein at least the atmosphere in the chamber is purged with an inert gas.   3. The organic material coating apparatus according to claim 1, wherein a baking processing mechanism is provided at least on a stage for mounting the substrate.   The organic material coating method using the organic material coating apparatus according to any one of claims 1 to 3, wherein the organic material is coated on the surface of the substrate. An organic material coating method comprising: a step of baking the substrate, and a step of applying an organic material while performing a second baking process on the substrate in an inert gas atmosphere.

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