JP4896765B2 - Pre-wet solvent for upper layer coating agent applied to substrate processing method and resist film surface - Google Patents

Description

  The present invention relates to a substrate processing method and a pre-wet solvent for an upper film agent applied to the surface of a resist film.

  For example, in a photolithography process in a semiconductor device manufacturing process, a resist film is formed on a semiconductor wafer (hereinafter referred to as “wafer”), and then a predetermined pattern is exposed on the resist film, and then the resist film is developed and the resist film is developed. A pattern is formed.

  By the way, in the above-described photolithography process, an upper layer film may be formed on the resist film before exposure. This upper layer film is formed, for example, as an antireflection film at the time of exposure or as a protective film for immersion exposure. Immersion exposure is a technique in which exposure is performed between an exposure lens and a wafer via an immersion liquid (for example, water), and has recently been put into practical use as an effective technique for improving pattern resolution (Patent Document 1). reference). This upper layer film such as an antireflection film or a protective film is usually formed by supplying a liquid upper layer film agent onto the rotated wafer after the resist film is formed and diffusing the upper layer film agent over the entire surface of the wafer. (Spin coating method).

JP 2006-317774 A

  However, the upper layer film agent such as a protective film is extremely expensive, and it is necessary to save liquid during application. Therefore, it can be proposed to perform so-called pre-wetting in which a solvent for the upper layer film agent is applied to the surface of the resist film immediately before the upper layer film agent is applied to the surface of the resist film. As a result, the upper layer film agent becomes easy to become familiar with the resist film, and thus liquid saving of the upper layer film agent becomes possible. However, as the pre-wetting solvent for the upper layer film agent, when an organic solvent that also functions as a solvent for the resist film agent is used in the pre-wetting of the resist coating, the surface of the resist film is dissolved by the organic solvent, Finally, a desired resist pattern is not formed. For this reason, the prewetting process at the time of application | coating of an upper layer film | membrane agent has not been implement | achieved until now, and the liquid-saving of the upper layer film | membrane agent was not attained.

  The present invention has been made in view of such points, and an object of the present invention is to realize so-called pre-wetting before application of the upper layer film agent so as not to dissolve the resist film and to save liquid of the upper layer film agent. .

In order to achieve the above object, the present invention is a substrate processing method comprising a step of forming an upper layer film on a resist film by applying an upper layer film agent on the surface of the resist film on the substrate by a spin coating method. Before applying the upper layer film agent, a step of applying a prewet solvent for the upper layer film agent to the surface of the resist film, and the prewet solvent for the upper layer film agent has 1 to 10 carbon atoms. One or more selected from monovalent or divalent alcohols, ethers having an alkyl group which may have a halogen having 1 to 8 carbon atoms as a substituent, and hydrocarbons having 7 to 11 carbon atoms compound all SANYO containing the upper layer film is characterized in that it is a protective film for liquid immersion exposure. The “pre-wet solvent for the upper layer film agent” includes not only the solvent contained in the upper layer film agent as a composition of the upper layer film agent but also a solvent not contained in the upper layer film agent.

  According to the present invention, so-called pre-wetting before application of the upper layer film agent can be performed without dissolving the resist film, so that liquid saving of the upper layer film agent can be achieved.

The protective film refers to the elution of the components in the resist film into the immersion liquid or the resist film of the immersion liquid when the exposure lens and the substrate are exposed via an immersion liquid (for example, water). A membrane that is applied to prevent penetration into the skin.

According to another aspect of the present invention, there is provided a prewetting for an upper film agent applied to the surface of a resist film before an upper film agent for forming an upper film is applied to the surface of the resist film by a spin coating method. The solvent is a protective film for immersion exposure, and has a monovalent or divalent alcohol having 1 to 10 carbon atoms and a halogen having 1 to 8 carbon atoms as a substituent. It contains at least one compound selected from ethers having a good alkyl group and hydrocarbons having 7 to 11 carbon atoms.

  According to the present invention, so-called pre-wetting before the application of the upper layer film agent is realized, and liquid saving of the upper layer film agent is achieved, so that the cost can be reduced.

  Hereinafter, preferred embodiments of the present invention will be described. FIG. 1 is a plan view showing an outline of the configuration of a coating and developing processing system 1 in which a substrate processing method according to the present invention is realized, FIG. 2 is a front view of the coating and developing processing system 1, and FIG. 2 is a rear view of the coating and developing treatment system 1. FIG.

  As shown in FIG. 1, the coating and developing treatment system 1 includes, for example, a cassette station 2 for loading and unloading a plurality of wafers W from the outside to the coating and developing treatment system 1 in units of cassettes, and sheets in a photolithography process. A configuration in which a processing station 3 including a plurality of various processing apparatuses that perform predetermined processing in a leaf type and an interface station 5 that transfers the wafer W between the exposure apparatus 4 adjacent to the processing station 3 are integrally connected. have.

  The cassette station 2 is provided with a cassette mounting table 10, and a plurality of cassettes C can be mounted on the cassette mounting table 10 in a row in the X direction (vertical direction in FIG. 1). The cassette station 2 is provided with a wafer transfer body 12 that can move on the transfer path 11 along the X direction. Wafer carrier 12 is also movable in the arrangement direction (Z direction; vertical direction) of wafers W accommodated in cassette C, and can selectively access a plurality of wafers W in cassette C. Further, the wafer transfer body 12 can rotate around the vertical axis (θ direction), and can access each processing apparatus of a third processing apparatus group G3 of the processing station 3 described later to transfer the wafer W. .

  The processing station 3 includes, for example, five processing device groups G1 to G5 in which a plurality of processing devices are arranged in multiple stages. On the negative side in the X direction (downward in FIG. 1) of the processing station 3, the first processing device group G1 and the second processing device group G2 are sequentially arranged from the cassette station 2 side to the interface station 5 side. Has been placed. On the positive side of the processing station 3 in the X direction (upward in FIG. 1), the third processing device group G3, the fourth processing device group G4, and the fifth processing device group G3 are directed from the cassette station 2 side to the interface station 5 side. The processing device group G5 is arranged in order. A first transfer device 20 is provided between the third processing device group G3 and the fourth processing device group G4. The first transfer device 20 can selectively access each device in the first processing device group G1, the third processing device group G3, and the fourth processing device group G4 to transfer the wafer W. A second transport device 21 is provided between the fourth processing device group G4 and the fifth processing device group G5. The second transfer device 21 can selectively access each device in the second processing device group G2, the fourth processing device group G4, and the fifth processing device group G5 to transfer the wafer W.

  As shown in FIG. 2, in the first processing unit group G1, a liquid processing apparatus that supplies a predetermined liquid to the wafer W and performs processing, for example, resist coating apparatuses 30, 31 that apply a resist solution on the wafer W, 32 and upper film forming apparatuses 33 and 34 for forming an upper film such as a protective film on the resist film are stacked in five stages in order from the bottom. In the second processing unit group G2, liquid processing units, for example, development processing units 40 to 44 for supplying a developing solution to the wafer W and performing development processing are stacked in five stages in order from the bottom. In addition, chemical chambers 50 and 51 for supplying various processing liquids to the liquid processing apparatuses in the processing apparatus groups G1 and G2 are provided at the bottom of the first processing apparatus group G1 and the second processing apparatus group G2. Are provided.

  For example, as shown in FIG. 3, in the third processing unit group G3, a temperature control device 60 for adjusting the temperature of the wafer W by placing the wafer W on a temperature control plate, and a transition for transferring the wafer W The apparatus 61, the temperature control apparatuses 62-64, and the heat processing apparatuses 65-68 which heat-process the wafer W are piled up in nine steps in order from the bottom.

  In the fourth processing unit group G4, for example, a temperature control device 70, pre-baking devices 71 to 74 that heat-treat the wafer W after resist coating processing, and post-baking devices 75 to 79 that heat-process the wafer W after development processing are sequentially arranged from the bottom. It is stacked in 10 steps.

  In the fifth processing apparatus group G5, a plurality of heat treatment apparatuses for heat-treating the wafer W, for example, temperature control apparatuses 80 to 83, and post-exposure bake apparatuses 84 to 89 for heat-treating the wafer W after exposure are stacked in 10 stages in order from the bottom. It has been.

  As shown in FIG. 1, a plurality of processing devices are arranged on the positive side in the X direction of the first transfer device 20, and for example, an adhesion device 90 for hydrophobizing the wafer W as shown in FIG. , 91 are stacked in two steps in order from the bottom. As shown in FIG. 1, a peripheral exposure device 92 that selectively exposes only the edge portion of the wafer W, for example, is arranged on the positive side in the X direction of the second transfer device 21.

  In the interface station 5, for example, as shown in FIG. 1, a wafer transfer body 101 moving on a transfer path 100 extending in the X direction and a buffer cassette 102 are provided. The wafer transfer body 101 is movable in the Z direction and is also rotatable in the θ direction, and with respect to the exposure apparatus 4 adjacent to the interface station 5 and each apparatus of the buffer cassette 102 and the fifth processing apparatus group G5. The wafer W can be transferred by accessing.

  The exposure apparatus 4 includes an XY stage 110 at the center as shown in FIG. 4, for example. On the XY stage 110, for example, a storage container 111 that stores and holds the wafer W is provided. A light irradiation unit 112 that exposes the wafer W is disposed above the container 111. In the vicinity of the light irradiation unit 112, a liquid discharge nozzle 113 that supplies a liquid, for example, pure water H, is disposed in the gap between the light irradiation unit 112 and the wafer W. In addition, a suction nozzle 114 that sucks and removes pure water H supplied onto the wafer W is provided in the vicinity of the light irradiation unit 112. The exposure apparatus 4 fills the space between the wafer W in the storage container 111 and the light irradiation unit 112 with pure water H supplied from the liquid discharge nozzle 113, and irradiates light from the light irradiation unit 112 in this state. The resist film on the surface of W can be exposed (immersion exposure).

  Next, the configuration of the above-described upper layer film forming apparatuses 33 and 34 will be described in detail. FIG. 5 is an explanatory view of a longitudinal section showing an outline of the configuration of the upper layer film forming apparatus 33, and FIG. 6 is an explanatory view of a transverse section of the upper layer film forming apparatus 33.

  For example, as shown in FIG. 5, the upper layer film forming apparatus 33 has a casing 120, and a spin chuck 130 as a rotation holding member that holds and rotates the wafer W is provided at the center of the casing 120. Yes. The spin chuck 130 has a horizontal upper surface, and a suction port (not shown) for sucking the wafer W, for example, is provided on the upper surface. By suction from the suction port, the wafer W can be sucked and held on the spin chuck 130.

  The spin chuck 130 can be rotated at a predetermined speed by, for example, a chuck driving mechanism 131 including a motor. Further, the chuck drive mechanism 131 is provided with an elevating drive source such as a cylinder, and the spin chuck 130 can move up and down.

  Around the spin chuck 130, a cup 132 that receives and collects the liquid scattered or dropped from the wafer W is provided. A discharge pipe 133 that discharges the collected liquid and an exhaust pipe 134 that exhausts the atmosphere in the cup 132 are connected to the lower surface of the cup 132.

  As shown in FIG. 6, a rail 140 extending along the Y direction (left and right direction in FIG. 6) is formed on the X direction negative direction (downward direction in FIG. 6) side of the cup 132. The rail 140 is formed, for example, from the outer side of the cup 132 on the Y direction negative direction (left direction in FIG. 6) to the outer side on the Y direction positive direction (right direction in FIG. 6). For example, two arms 141 and 142 are attached to the rail 140.

  As shown in FIGS. 5 and 6, the first arm 141 supports a first nozzle 143 that discharges a liquid upper layer film agent for forming an upper layer film such as a protective film. The first arm 141 is movable on the rail 140 by a nozzle driving unit 144 shown in FIG. 6, and the first nozzle 143 is installed on the outside of the cup 132 on the Y direction positive direction side. It can be moved from 145 to above the center of the wafer W in the cup 132. The first arm 141 can be moved up and down by the nozzle driving unit 144, and the height of the first nozzle 143 can be adjusted.

  As shown in FIG. 5, the first nozzle 143 is connected to a supply pipe 147 that communicates with an upper film agent supply source 146. The upper film agent supply source 146 stores a liquid upper film agent. In the present embodiment, for example, a protective film agent for immersion exposure (development soluble type protective film agent for immersion exposure) having solubility in a developer is used as the upper layer film agent.

  The second arm 142 supports a second nozzle 150 that discharges a pre-wet solvent for the upper layer film agent. The second arm 142 is movable on the rail 140 by, for example, a nozzle driving unit 151 shown in FIG. It is possible to move from 152 to above the center of the wafer W in the cup 132. Further, the second arm 142 can be moved up and down by the nozzle driving unit 151, and the height of the second nozzle 150 can be adjusted.

  As shown in FIG. 5, a supply pipe 154 that communicates with a solvent supply source 153 is connected to the second nozzle 150. The solvent supply source 153 stores a pre-wet solvent A for the upper layer film agent. In the present embodiment, the prewetting solvent A for the upper layer film agent may have a monovalent or divalent alcohol having 1 to 10 carbon atoms or a halogen having 1 to 8 carbon atoms as a substituent. Those containing one or more compounds selected from ethers having an alkyl group and hydrocarbons having 7 to 11 carbon atoms are used. In addition, the said alcohol may have a C1-C10 substituent.

  Examples of the mono- or dihydric alcohol having 1 to 10 carbon atoms constituting the pre-wet solvent A for the upper layer film agent include, for example, methanol, ethanol, 1-propanol, isopropanol, n-propanol, and 2-methyl. -1-propanol, n-butanol, 2-butanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, n-hexanol, cyclohexanol, 2-methyl-2-butanol, 3-methyl 2-butanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3- Methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl- -Pentanol, 4-methyl-2-pentanol, 2-ethyl-1-butanol, 2,2-dimethyl-3-pentanol, 2,3-dimethyl-3-pentanol, 2,4-dimethyl-3 -Pentanol, 4,4-dimethyl-2-pentanol, 3-ethyl-3-pentanol, 1-heptanol, 2-heptanol, 3-heptanol, 2-methyl-2-hexanol, 2-methyl-3- Hexanol, 5-methyl-1-hexanol, 5-methyl-2-hexanol, 2-ethyl-1-hexanol, methylcyclohexanol, trimethylcyclohexanol, 4-methyl-3-heptanol, 6-methyl-2-heptanol, 1-octanol, 2-octanol, 3-octanol, 2-propyl-1-pentanol, 2, 4, 4 Trimethyl-1-pentanol, 2,6-dimethyl-4-heptanol, 3-ethyl-2, 2-dimethyl-pentanol, 1-nonanol, 2-nonanol, 3,5,5-trimethyl-1-hexanol, Examples include 1-decanol, 2-decanol, 4-decanol, 3,7-dimethyl-1-octanol, 3,7-dimethyl-3-octanol, ethylene glycol, propylene glycol and the like.

  More preferable alcohols include, for example, 2-methyl-1-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 3-pentanol, and 3-methyl-2-pentanol. 4-methyl-2-pentanol, 2-ethyl-1-butanol, 2,4-dimethyl-3-pentanol and the like.

  Further, examples of ethers having an alkyl group which may have a substituent of the halogen having 1 to 8 carbon atoms, constituting the prewetting solvent A for the upper layer film agent, include, for example, diethyl ether, dipropyl ether, Diisopropyl ether, butyl methyl ether, butyl ethyl ether, butyl propyl ether, dibutyl ether, diisobutyl ether, tert-butyl methyl ether, tert-butyl ethyl ether, tert-butyl propyl ether, di-tert-butyl ether, dipentyl ether, diisoamyl Ether, dihexyl ether, dioctyl ether, cyclopentyl methyl ether, cyclohexyl methyl ether, cyclododecyl methyl ether, cyclopentyl ethyl ether, cyclohexyl ethyl ether Ter, cyclopentyl propyl ether, cyclopentyl-2-propyl ether, cyclohexyl propyl ether, cyclohexyl-2-propyl ether, cyclopentyl butyl ether, cyclopentyl tert-butyl ether, cyclohexyl butyl ether, cyclohexyl tert-butyl ether, bromomethyl methyl ether, iodomethyl methyl Ether, α, α-dichloromethyl methyl ether, chloromethyl ethyl ether, 2-chloroethyl methyl ether, 2-bromoethyl methyl ether, 2,2-dichloroethyl methyl ether, 2-chloroethyl ethyl ether, 2-bromoethyl Ethyl ether, (±) -1,2-dichloroethyl ethyl ether, di-2-bromoethyl ether, 2, 2, 2- Trifluoroethyl ether, chloromethyl octyl ether, bromomethyl octyl ether, di-2-chloroethyl ether, ethyl vinyl ether, butyl vinyl ether, allyl ethyl ether, allyl propyl ether, allyl butyl ether, diallyl ether, 2-methoxypropene, ethyl- Examples include 1-propenyl ether, 1-methoxy-1,3-butadiene, cis-1-bromo-2-ethoxyethylene, 2-chloroethyl vinyl ether, allyl-1,1,2,2-tetrafluoroethyl ether.

  More preferred ethers include dipropyl ether, diisopropyl ether, butyl methyl ether, butyl ethyl ether, butyl propyl ether, dibutyl ether, diisobutyl ether, tert-butyl methyl ether, tert-butyl ethyl ether, tert- Butyl propyl ether, di-tert-butyl ether, dipentyl ether, diisoamyl ether, cyclopentyl methyl ether, cyclohexyl methyl ether, cyclopentyl ethyl ether, cyclohexyl ethyl ether, cyclopentyl propyl ether, cyclopentyl-2-propyl ether, cyclohexyl propyl ether, cyclohexyl- 2-propyl ether, cyclopentyl butyl ether, cyclopent Le -tert- butyl ether, cyclohexyl ether, cyclohexyl -tert- butyl ether and the like.

  Examples of the hydrocarbon having 7 to 11 carbon atoms constituting the prewetting solvent A for the upper layer film agent include, for example, octane, isooctane, nonane, decane, methylcyclohexane, decalin, xylene, amylbenzene, ethylbenzene, and diethylbenzene. , Cumene, 2-butylbenzene, cymene, and dipentene.

  The pre-wet solvent A for the upper layer film agent may be originally contained in the upper layer film agent as a composition of the upper layer film agent, or may be not contained in the upper layer film agent. Good.

  The configuration of the upper layer film forming apparatus 34 is the same as that of the upper layer film forming apparatus 33 described above, and a description thereof will be omitted.

  Next, wafer processing performed in the coating and developing processing system 1 configured as described above will be described. FIG. 7 is a flowchart showing the main steps of this wafer processing.

  First, unprocessed wafers W are taken out from the cassette C on the cassette mounting table 10 one by one by the wafer transfer body 12 shown in FIG. 1 and sequentially transferred to the processing station 3. The wafer W is transferred to the temperature control device 60 belonging to the third processing device group G3 of the processing station 3, adjusted to a predetermined temperature, and then sequentially transferred to, for example, the adhesion device 90 and the temperature control device 62 by the first transfer device 20. It is transported and subjected to predetermined processing in each device. Thereafter, the wafer W is transferred to, for example, the resist coating apparatus 30 by the first transfer apparatus 20.

  In the resist coating apparatus 30, first, a resist solution solvent is supplied to the center of the wafer W, the wafer W is rotated, and the resist solution solvent is applied to the surface of the wafer W (pre-wetting). The solvent used for the pre-wetting of the resist solution is different from the solvent used for the pre-wetting of the upper layer film agent described later. Subsequently, a resist solution is supplied to the center of the wafer W, the wafer W is rotated at a high speed, and the resist solution is applied to the surface of the wafer W. As the resist solution at this time, a general photoresist is used. In this embodiment, for example, a resist solution for ArF lithography using PGMEA (1-methoxy-2-acetoxypropane) as a main solvent is used. Thus, a resist film is formed on the surface of the wafer W (step S1 in FIG. 7).

  After the resist film is formed, the wafer W is transferred to, for example, the pre-baking device 71 by the first transfer device 20 and pre-baked, and then transferred to the temperature adjustment device 70 by the first transfer device 20 to a predetermined temperature. Adjusted. Thereafter, the wafer W is transferred to the upper layer film forming apparatus 33 by the first transfer apparatus 20.

  After being loaded into the upper layer film forming apparatus 33, the wafer W is sucked and held by the spin chuck 130 as shown in FIG. Subsequently, as shown in FIG. 8, the second nozzle 150 moves to above the center portion of the wafer W, and a predetermined pre-wetting solvent A for the upper layer film agent is supplied to the center portion of the wafer W. This pre-wet solvent A for the upper layer film agent is stored in the solvent supply source 153 described above, and in this embodiment, for example, 4-methyl-2-pentanol or diisoamyl ether is used. It is done. Thereafter, the wafer W is rotated, and the pre-wet solvent A on the wafer W is spread over the entire surface of the wafer W by centrifugal force. Thus, the pre-wet solvent A is applied to the surface of the resist film R on the wafer W, and so-called pre-wet is performed before the application of the upper-layer film agent (step S2a of the upper-layer film forming process in FIG. 7). At this time, since the resist film R is insoluble in the pre-wet solvent A, the resist film R is not substantially dissolved.

  Next, as shown in FIG. 9, the first nozzle 143 moves to above the center of the wafer W, and a predetermined amount of the upper layer film agent B is supplied to the center of the wafer W. At this time, the rotation speed of the wafer W is increased, and the upper layer film agent B is spread over the entire surface of the wafer W. Thus, the upper layer film agent B is applied to the surface of the resist film R on the wafer W (step S2b of the upper layer film forming process in FIG. 7). In the present embodiment, for example, “NFC TCX041” (product of JSR Corporation) which is a protective film agent for development-soluble immersion exposure is applied as the upper layer film agent B. This “NFC TCX041” contains 4-methyl-2-pentanol. At this time, since the surface of the resist film R is pre-wet by the pre-wet solvent A, the entire surface of the resist film R is applied with an extremely small amount of the upper layer film agent B.

  Next, the rotation speed of the wafer W is once lowered, and the liquid film of the upper layer film agent B is flattened. Thereafter, the rotation speed of the wafer W is increased, and the upper layer film agent B is dried. Thus, the upper layer film P is finally formed on the resist film R of the wafer W as shown in FIG. Thereafter, the rotation of the wafer W is stopped, and a series of upper layer film forming processes is completed.

  After the formation of the upper layer film P, the wafer W is sequentially transferred to, for example, the heat treatment device 67 and the temperature control device 70 by the first transfer device 20, and then the peripheral exposure device 92 and the temperature control device 83 by the second transfer device 21. Are sequentially conveyed, and predetermined processing is performed in each apparatus. Thereafter, the wafer W is transferred to the exposure apparatus 4 by the wafer transfer body 101 of the interface station 5.

  After carrying in the exposure apparatus 4, the wafer W is accommodated and held in the accommodation container 111 as shown in FIG. Next, alignment of the wafer W is performed by the XY stage 110, and then pure water H is supplied between the light irradiation unit 112 and the wafer W by the liquid discharge nozzle 113, and the resist film R of the wafer W is formed. A liquid film of pure water H is formed on the upper film P that is a protective film. A predetermined pattern of light is irradiated from the light irradiation unit 112 to the wafer W through the liquid film, and the resist film R is exposed (step S3 in FIG. 7).

  After the exposure processing is completed, the wafer W is returned to the processing station 3 by the wafer transfer device 101 and transferred to the post-exposure bake device 84 by the second transfer device 21. After completion of the post-exposure baking, the wafer W is transferred to the temperature adjustment device 83 by the second transfer device 21 and then transferred to the development processing device 40. In the development processing apparatus 40, a developing solution is supplied to the surface of the wafer W, and the resist film R on the wafer W is developed (step S4 in FIG. 7). At this time, the upper layer film P on the resist film R is also removed by the developer.

  Thereafter, the wafer W is transferred to the post-bake device 75 by the second transfer device 21 and subjected to post-bake, for example, and then transferred to the temperature adjustment device 62 by the first transfer device 20 to adjust the temperature. Thereafter, the wafer W is returned to the cassette C of the cassette station 2 by the wafer carrier 12. Thus, a series of wafer processing in the coating and developing processing system 1 is completed.

  According to the above embodiment, before applying the upper film agent B on the resist film, the monovalent or divalent alcohol having 1 to 10 carbon atoms and the halogen having 1 to 8 carbon atoms are used as a substituent. A prewet solvent A for an upper layer film agent containing one or more compounds selected from ethers having an alkyl group which may be selected and hydrocarbons having 7 to 11 carbon atoms is applied. Thereby, the so-called pre-wet before the application of the upper layer film agent can be realized without substantially dissolving the underlying resist film. As a result, the wettability of the upper film agent with respect to the resist film is improved, so that the amount of the upper film agent used during coating can be greatly reduced. Thereby, liquid saving of an upper layer film agent is achieved and cost reduction is achieved. In particular, since a protective film agent (a kind of upper layer film agent) for immersion exposure is very expensive, the present invention is applied to a protective film agent forming process in which immersion exposure is performed in a later step as in this embodiment. The merit of applying is great.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be made within the scope of the ideas described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs. For example, in the above embodiment, the pre-wet solvent A applied on the resist film R is 4-methyl-2-pentanol or diisoamyl ether, but the monovalent or divalent carbon number is 1 to 10. Others containing one or more compounds selected from alcohols, ethers having an alkyl group which may have a halogen having 1 to 8 carbon atoms as a substituent, and hydrocarbons having 7 to 11 carbon atoms It may be a solvent. Further, for example, in the above embodiment, the upper layer film of the resist film R is a protective film, but the upper layer film may be used for other applications such as an antireflection film. The present invention can also be applied to an upper layer coating process on a substrate after a resist pattern is formed. Furthermore, although the above embodiment was processing of the wafer W, this invention is applicable also to processing of other board | substrates, such as FPD (flat panel display) other than a wafer, a mask reticle for photomasks.

  Using the prewetting solvent A shown in the above embodiment, the solubility of the resist film in the case of performing prewetting before application of the upper layer film agent was verified. As a pre-wetting solvent, a mixed solvent of 1-methoxy-2-propanol and 1-methoxy-2-acetoxypropane (solvent I) or cyclohexanone (solvent II), which is widely used as a solvent for resist solutions, A film of a resist film in the wafer surface when 4-methyl-2-pentanol (solvent III) or diisoamyl ether (solvent IV), which is an example of the pre-wet solvent A shown in the above embodiment, is used. An experiment for measuring a decrease amount (dissolution amount) was conducted. Note that, for the resist film at this time, a resist for ArF lithography using PGMEA as a main solvent was used. FIG. 11 is a graph showing the results of such an experiment. FIG. 12 is a table showing the average film reduction rate (ratio of the resist film thickness after application of the solvent to the resist film thickness before application of the solvent) in the region of the wafer center ± 20 mm where the film reduction is significant. is there. From FIG. 11 and FIG. 12, it can be confirmed that by using 4-methyl-2-pentanol (solvent III) or diisoamyl ether (solvent IV) as the prewetting solvent A, the film thickness of the resist film is almost eliminated. . In addition, 4-methyl-2-pentanol is an example of a monovalent or divalent alcohol having 1 to 10 carbon atoms in the present invention, and diisoamyl ether is a halogen having 1 to 8 carbon atoms in the present invention. It is an example of ethers having an alkyl group that may be present as a substituent.

  Next, the amount of the upper layer film agent used when pre-wetting was performed using the pre-wet solvent A shown in the above embodiment was verified. The amount of the upper film agent used when the pre-wet solvent A such as 4-methyl-2-pentanol or diisoamyl ether is pre-wet by changing the coating condition of the upper film agent is not changed. An experiment to investigate was conducted. The amount of the upper film agent used in this experiment is the minimum amount necessary for the upper film agent to be applied to the entire surface of the wafer. This experiment was performed using a wafer having a diameter of 300 mm and changing the number of wafer rotations (2000 rpm, 2500 rpm, 3000 rpm) and the upper layer film agent discharge flow rate (0.5 ml / sec, 1.0 ml / sec). In this experiment, “NFC TCX041” (product of JSR Corporation), which is a protective film agent for development-soluble immersion exposure, was used as the upper layer film agent. FIG. 13 is a graph showing the results of this experiment. From FIG. 13, by pre-wetting using 4-methyl-2-pentanol (solvent III) or diisoamyl ether (solvent IV), which is a pre-wetting solvent for the upper layer film agent, an extremely small amount of the upper layer film agent is obtained. It can be confirmed that the upper layer film agent can be applied.

  Since the pre-wet solvent A other than 4-methyl-2-pentanol and diisoamyl ether shown in the above embodiment has the same properties as 4-methyl-2-pentanol and the like, It can be easily estimated that the experimental results are obtained.

  The present invention is useful for reducing the liquid content of the upper layer film agent applied on the resist film.

It is a top view which shows the outline of a structure of a coating-development processing system. FIG. 2 is a front view of the coating and developing treatment system of FIG. 1. FIG. 2 is a rear view of the coating and developing treatment system of FIG. 1. It is explanatory drawing which shows the outline of a structure of exposure apparatus. It is explanatory drawing of the longitudinal cross-section which shows the outline of a structure of an upper layer film forming apparatus. It is explanatory drawing of the cross section which shows the outline of a structure of an upper layer film forming apparatus. It is a flowchart which shows the main processes of a wafer process. It is explanatory drawing which shows a mode that the solvent was supplied on the resist film. It is explanatory drawing which shows a mode that the upper layer film | membrane agent was supplied on the resist film. It is explanatory drawing which shows the state in which the upper layer film was formed on the resist film. It is a graph which shows the film loss amount of the resist film at the time of changing the kind of solvent and performing prewetting before application | coating of an upper layer film | membrane agent. It is a table | surface which shows the film reduction rate of the resist film at the time of changing the kind of solvent and performing prewetting before application | coating of an upper layer film | membrane agent. It is a graph which shows the usage-amount of the upper-layer film | membrane agent at the time of performing the pre-wet before application | coating of an upper-layer film | membrane agent using the solvent in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Application | coating development system 33 Upper layer film forming apparatus 130 Spin chuck 143 1st nozzle 150 2nd nozzle A Pre-wet solvent for upper layer film agent B Upper layer film agent P Upper layer film R Resist film W Wafer

Claims (2)

A substrate processing method comprising a step of applying an upper film agent on a surface of a resist film on a substrate by a spin coating method to form an upper film on the resist film,
Before applying the upper layer film agent, the step of applying a prewet solvent for the upper layer film agent on the surface of the resist film,
The prewetting solvent for the upper layer film agent is a monovalent or divalent alcohol having 1 to 10 carbon atoms, an ether having an alkyl group which may have a halogen having 1 to 8 carbon atoms as a substituent, and all SANYO containing one or more compounds selected from among number 7-11 hydrocarbons carbon,
The substrate processing method, wherein the upper layer film is a protective film for immersion exposure . A pre-wet solvent for the upper layer film agent applied to the surface of the resist film before the upper layer film agent for forming the upper layer film is applied to the surface of the resist film by a spin coating method,
The upper layer film is a protective film for immersion exposure,
Of monovalent or divalent alcohols having 1 to 10 carbon atoms, ethers having an alkyl group which may have a halogen having 1 to 8 carbon atoms as a substituent, and hydrocarbons having 7 to 11 carbon atoms. A pre-wet solvent for an upper layer film agent applied to the surface of a resist film, comprising one or more compounds selected from the group consisting of:

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