JP2006210886A - Development processing method and development processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a pattern collapse and a pattern swelling during drying after a development. <P>SOLUTION: A developer supply nozzle 33 moves on a wafer W from one edge to an opposite edge thereof while expelling developer, and thereby supplies the developer on the wafer W to attain a static development. Subsequently, while rotating the wafer W, rinse liquid is supplied to the wafer W by a rinse liquid supply nozzle 50 to stop the development. Thereafter, liquid containing a polar fluorocarbon system compound is supplied to the wafer W by a liquid supply nozzle 63, and the wafer W is rotated at high speed and is dried. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a substrate developing method and a developing apparatus.

  In the photolithography process in the semiconductor device manufacturing process, for example, a resist coating process for applying a resist solution to the wafer surface to form a resist film, an exposure process for exposing the wafer to a predetermined pattern, a developing solution is supplied to the wafer and a resist is applied. A development process or the like is performed in which a film is selectively dissolved to form a resist pattern on the wafer.

  In the development process described above, a developing solution is supplied onto the wafer to statically develop the wafer, then pure water is supplied onto the wafer to stop development, and then the wafer is rotated at high speed to dry the wafer. However, when the wafer is dried, the wafer surface is rotated at a high speed to scatter water on the wafer surface, so that the pattern on the wafer surface may be tilted by the action of the scattered water. Therefore, it has been proposed that when rotating the wafer at high speed, a surfactant is supplied onto the wafer so that moisture can be easily separated from the wafer to prevent pattern collapse (see Patent Document 1).

  However, in recent years, an extremely fine resist pattern having a line width of 80 nm or less, for example, can be formed. For such fine patterns, even if a surfactant is supplied onto the wafer during drying after development as described above, pattern collapse cannot be sufficiently suppressed. Furthermore, when a surfactant is supplied to the wafer during drying after development, the inventors have confirmed that the resist pattern on the wafer swells greatly due to the influence of the surfactant. When the resist pattern swells, the line width becomes unstable and non-uniform, and a desired resist pattern is not formed on the wafer.

JP-A-6-163391

  The present invention has been made in view of the above points, and provides a development processing method and a development processing apparatus capable of sufficiently suppressing pattern collapse and preventing pattern swelling even for extremely fine resist patterns. That is the purpose.

  In order to achieve the above object, the present invention is a method for developing a substrate, the step of supplying a developing solution to the substrate to develop the substrate, and then supplying the developing stop solution to the substrate to stop the development. And a step of supplying a liquid containing a polar fluorocarbon-based compound to the substrate and then rotating the substrate to dry the substrate.

  According to the present invention, even for a fine pattern, pattern collapse and pattern swelling during drying after development can be suppressed.

  The liquid is a mixture of methyl perfluoroisobutyl ether and methyl perfluorobutyl ether, a mixture of ethyl perfluoroisobutyl ether and ethyl perfluorobutyl ether, a mixture of two or more types of dichloropentafluoropropane having different molecular structures, and tetrafluoroethyl. It may contain either trifluoroethyl ether, decafluoropentane, or heptafluorocyclopentane.

  The liquid preferably has a dielectric constant of 2.1 or more and a solubility in water of 21 ppm (Wt.) Or more. More preferably, the dielectric constant of the liquid is 7 or more, and the solubility in water is 90 ppm (Wt.) Or more.

  According to another aspect of the present invention, there is provided a substrate development processing apparatus comprising: a rotation support member that supports and rotates a substrate; and a fluorocarbon-based compound that is polar with respect to the substrate supported by the rotation support member. And a liquid supply nozzle for supplying a liquid to be constituted.

  According to the present invention, the liquid supply nozzle supplies a polar fluorocarbon compound liquid to the substrate, and the substrate can be rotated to be dried. By doing so, pattern collapse and pattern swelling during drying after development can be suppressed.

  The liquid is a mixture of methyl perfluoroisobutyl ether and methyl perfluorobutyl ether, a mixture of ethyl perfluoroisobutyl ether and ethyl perfluorobutyl ether, a mixture of two or more types of dichloropentafluoropropane having different molecular structures, and tetrafluoroethyl. It may contain either trifluoroethyl ether, decafluoropentane, or heptafluorocyclopentane.

  The liquid preferably has a dielectric constant of 2.1 or more and a solubility in water of 21 ppm (Wt.) Or more. More preferably, the dielectric constant of the liquid is 7 or more, and the solubility in water is 90 ppm (Wt.) Or more.

  According to the present invention, since pattern collapse and pattern swelling during drying after development can be suppressed, a desired pattern can be formed on the substrate.

  Hereinafter, preferred embodiments of the present invention will be described. FIG. 1 is an explanatory diagram of a longitudinal section showing an outline of the configuration of the development processing apparatus 1 according to the present embodiment, and FIG. 2 is a plan view showing an outline of the configuration of the development processing apparatus 1.

  As shown in FIG. 1, the development processing apparatus 1 includes a spin chuck 10 as a rotation support member that holds and rotates a wafer W at the center. The spin chuck 10 has a horizontal upper surface, and a suction port (not shown) for sucking, for example, the wafer W is provided on the upper surface. The wafer W can be sucked onto the spin chuck 10 by suction from the suction port.

  The spin chuck 10 is provided with a chuck drive mechanism 11 for rotating and lifting the spin chuck 10, for example. The chuck drive mechanism 11 is, for example, a rotation drive unit (not shown) such as a motor that rotates the spin chuck 10 around a vertical axis at a predetermined speed, or a lift drive unit such as a motor or cylinder that moves the spin chuck 10 up and down ( (Not shown). By this chuck drive mechanism 11, the wafer W on the spin chuck 10 can be moved up and down at a predetermined timing or rotated at a predetermined speed.

  Around the spin chuck 10, there is provided a cup 12 that receives and collects the liquid scattered or dropped from the wafer W. The cup 12 includes, for example, an inner cup 13 that surrounds the spin chuck 10, an outer cup 14 that further surrounds the outer periphery of the inner cup 13, and a lower cup 15 that covers the inner cup 13 and the lower surface of the outer cup 14. ing. The inner cup 13 and the outer cup 14 can mainly catch the liquid splashing outward of the wafer W, and the lower cup 15 collects the liquid falling from the inner wall of the inner cup 13 and the outer cup 14 and the wafer W. be able to.

  The inner cup 13 is formed, for example, in a substantially cylindrical shape, and its upper end portion is inclined inward and upward. The inner cup 13 can be moved up and down by an elevating drive unit 16 such as a cylinder. For example, as shown in FIG. 2, the outer cup 14 is formed in a substantially rectangular shape that is square when viewed from the plane. As shown in FIG. 1, the outer cup 14 can be moved up and down by an elevating drive unit 17 such as a cylinder. The spin chuck 10 penetrates through the center of the lower cup 15. On the flat surface of the lower cup 15 around the spin chuck 10, for example, an annular member 18 that blocks the flow of liquid that has flowed from the front surface of the wafer W to the back surface is provided. The annular member 18 includes, for example, a top near the back surface of the wafer W, and the liquid that travels on the back surface of the wafer W can be blocked at the top. The lower cup 15 is connected to, for example, a discharge pipe 19 that communicates with a liquid discharge section of a factory, and the liquid collected in the cup 12 can be discharged from the development pipe 1 to the outside of the development pipe 1.

  As shown in FIG. 2, a rail 30 extending along the Y direction (left and right direction in FIG. 2) is formed on the X direction negative direction (downward direction in FIG. 2) side of the cup 12. The rail 30 is formed, for example, from the outer side of the cup 12 in the Y direction negative direction (left direction in FIG. 2) to the outer side of the cup 12 in the Y direction positive direction (right direction in FIG. 2). For example, two arms 31 and 32 are attached to the rail 30. A developer supply nozzle 33 is supported on the first arm 31. The first arm 31 can be moved in the Y direction on the rail 30 by the nozzle driving unit 34. By the first arm 31, the developer supply nozzle 33 can move from the standby unit 35 installed outside the cup 12 on the negative side in the Y direction to the inside of the cup 12 and move on the surface of the wafer W. The first arm 31 is also movable in the vertical direction by, for example, a nozzle driving unit 34, and can raise and lower the developer supply nozzle 33.

  The developer supply nozzle 33 has, for example, an elongated shape along the X direction that is the same as or longer than the diameter of the wafer W. As shown in FIG. 1, a developer supply pipe 41 communicating with the developer supply source 40 is connected to the upper portion of the developer supply nozzle 33. A plurality of discharge ports 33 a formed in a line along the longitudinal direction are formed below the developer supply nozzle 33. The developer supply nozzle 33 allows the developer introduced from the upper developer supply pipe 41 to pass through the inside of the developer supply nozzle 33 and be uniformly discharged from the lower discharge ports 33a.

  As shown in FIG. 2, a rinse liquid supply nozzle 50 is supported on the second arm 32. The second arm 32 can be moved in the Y direction on the rail 30 by, for example, the nozzle driving unit 51. With this second arm 32, the rinsing liquid supply nozzle 50 can be moved onto the wafer W in the cup 12 from the standby portion 52 provided outside the cup 12 on the positive side in the Y direction. The second arm 32 is also movable in the vertical direction by the nozzle driving unit 51.

  As shown in FIG. 1, a rinse liquid supply pipe 54 that communicates with a rinse liquid supply source 53 is connected to the rinse liquid supply nozzle 50. In the present embodiment, for example, the rinsing liquid supply source 53 stores pure water as a developing stop liquid (rinsing liquid).

  As shown in FIG. 2, a rail 60 extending along the Y direction is formed on the X direction positive direction (upward direction in FIG. 2) side of the cup 12. The rail 60 is formed, for example, from the outside of the cup 12 on the Y direction positive direction side to the outside of the cup 12 on the Y direction negative direction side. For example, a third arm 61 is attached to the rail 60. The third arm 61 is movable on the rail 60 by the drive unit 62. A liquid supply nozzle 63 is supported on the third arm 61. A storage container 64 of the liquid supply nozzle 63 is installed outside the cup 12 on the positive side in the Y direction. The liquid supply nozzle 63 moves from the storage container 64 to the inside of the cup 12 by the movement of the third arm 61. It can be moved onto the wafer W. The third arm 61 is also movable in the vertical direction by, for example, the drive unit 62, and the height can be adjusted by moving the liquid supply nozzle 63 up and down.

  As shown in FIG. 1, a liquid supply pipe 66 communicating with a liquid supply source 65 is connected to the liquid supply nozzle 63. The liquid supply source 65 includes a liquid containing a polar fluorocarbon-based compound, for example, a liquid mainly composed of a mixture of methyl perfluorobutyl ether and methyl perfluoroisobutyl ether (for example, liquid A described later), ethyl A liquid mainly composed of a mixture of perfluorobutyl ether and ethyl perfluoroisobutyl ether (for example, liquid B described later), a liquid mainly composed of a mixture of two or more kinds of dichloropentafluoropropane having different molecular structures (for example, described later) Liquid F), a liquid mainly composed of tetrafluoroethyl trifluoroethyl ether (for example, liquid G described later), a liquid mainly composed of decafluoropentane (for example, liquid H described later), or heptafluorocyclopentane and 2- Mainly composed of a mixture with methyl-2-butanol Either the body (e.g., liquid I described below) is stored.

  Next, the development processing performed using the development processing apparatus 1 configured as described above will be described in detail. FIG. 3 is an explanatory diagram of the flow of development processing. In this development process, a chemically amplified resist film is formed on the surface, and the wafer W exposed to a predetermined pattern is developed.

  First, the wafer W is sucked and held on the spin chuck 10 as shown in FIG. Subsequently, as shown in FIG. 2, the developer supply nozzle 33 that has been waiting in the standby portion 35 moves to the Y direction positive direction side, and a position just before the end portion on the Y direction negative direction side of the wafer W as viewed from above. Move to P1 (dotted line portion in FIG. 2). Thereafter, the developing solution is discharged from the developing solution supply nozzle 33, and the developing solution supply nozzle 33 discharges the developing solution while the position P2 outside the end of the wafer W on the positive side in the Y direction (dotted line in FIG. 2). Part). As a result, the developer is deposited on the surface of the resist film on the wafer W, and the static development of the resist film is started (FIG. 3A). By this static development, for example, an exposed portion of the resist film is selectively dissolved, and a resist pattern is formed on the wafer W.

  After a predetermined time has elapsed, for example, the rinsing liquid supply nozzle 50 that has been waiting in the standby unit 52 moves to above the center of the wafer W. A rinse liquid, for example, pure water is discharged from the rinse liquid supply nozzle 50, and at the same time, the wafer W is rotated at a predetermined low speed ((b) in FIG. 3). Thereby, the developer on the wafer surface is replaced with pure water, and the development of the wafer W is stopped.

  Thereafter, the supply of the rinsing liquid from the rinsing liquid supply nozzle 50 is stopped, and the liquid supply nozzle 63 moves to the upper part of the center of the wafer W in place of the rinsing liquid supply nozzle 50. For example, in a state where the rotational speed of the wafer W is maintained at the predetermined low speed, a predetermined liquid containing a polar fluorocarbon-based compound is discharged from the liquid supply nozzle 63 and supplied to the wafer surface. Is replaced by the fluorocarbon compound liquid (FIG. 3C).

  After the wafer surface is replaced with the fluorocarbon compound liquid, the supply of the liquid is stopped. Thereafter, the number of rotations of the wafer W is increased, and the wafer W is rotated at a high speed faster than the predetermined low speed (FIG. 3D). Thereby, the liquid on the surface of the wafer W is scattered and the wafer W is dried. Thereafter, the rotation of the wafer W is stopped, the wafer W is unloaded from the development processing apparatus 1, and a series of development processing is completed.

  Here, after supplying the rinse liquid as in the development processing described above, the effect of supplying the polar fluorocarbon compound liquid to the wafer W and rotating and drying the wafer W will be verified.

  FIG. 4 shows the case where the wafer is dried without supplying the liquid after the rinsing liquid is supplied (only the rinsing liquid), and the surfactant or each of the liquids A to I is supplied after the rinsing liquid is supplied and the wafer is dried. It is experimental data which shows the presence or absence of the pattern collapse in the wafer surface.

Liquid A is a mixture of methyl perfluorobutyl ether and methyl perfluoroisobutyl ether, and liquid B is a mixture of ethyl perfluorobutyl ether and ethyl perfluoroisobutyl ether. Liquid C is perfluorinated hexane, liquid D is perfluoroheptane, and liquid E is perfluorononane. Liquid F consists of 3,3-dichloro-1,1,1,2,2-pentafluoropropane (CF ₃ -CF ₂ -CHCl ₂ ) and 1,3-dichloro-1,1,2,2,3 A liquid G is 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether (CF ₃ —CH ₂ ), a mixture with pentafluoropropane (CClF ₂ —CF ₂ —CHClF) is _{2 -O-CF 2 -CF 2 H} ). Liquid H is 1,1,1,2,2,3,4,5,5,5-decafluoropentane (CH ₃ —CHF—CHF—CF ₂ —CF ₃ ), and liquid I is 1, It is a mixture of 1,2,2,3,3,4-heptafluorocycloheptane and 2-methyl-2-butanol (CH ₃ CH ₂ (CH ₃ ) ₂ COH).

  The liquid A is a mixture of 30 to 50% by mass of methyl perfluorobutyl ether and 50 to 70% by mass of methyl perfluoroisobutyl ether. Liquid B is a mixture of 30 to 50% by mass of ethyl perfluorobutyl ether and 50 to 70% by mass of ethyl perfluoroisobutyl ether. Liquid F is 45% by mass of 3,3-dichloro-1,1,1,2,2-pentafluoropropane and 55% by mass of 1,3-dichloro-1,1,2,2,3-pentafluoropropane. % Mixture. Liquid I is a mixture in which 1,1,2,2,3,3,4-heptafluorocyclopentane is 94% by mass or more and 2-methyl-2-butanol is less than 5% by mass.

  Among liquids A to I, those containing polar fluorocarbon compounds are liquids A, B, F, G, H, and I, and nonpolar ones are liquids C, D, and E.

  Further, the wafer used in the experiment shown in FIG. 4 is subjected to pattern exposure so that the dose (exposure amount) increases in the downward direction and the exposure focus increases in the right direction. As the amount of exposure increases, the line width of the pattern becomes narrower, and when the focus of exposure increases, the width K of the root portion of the pattern becomes thicker as shown in FIG. That is, in the wafer surface shown in FIG. 4, a pattern that tends to collapse is formed as it approaches the lower left corner. As conditions for this experiment, a chemically amplified acrylic resist is used as a resist material, and ArF light is used as an exposure light source.

  According to the experimental results shown in FIG. 4, when the liquids A, B, F, G, H, and I are supplied, only the rinse liquid, the surfactant, or the nonpolar liquids C, D, and E are supplied. Compared to, it can be confirmed that the pattern is less likely to collapse. In addition, when the polar liquids A, B, F, G, H, and I are supplied, the pattern collapse is drastically reduced as compared to when the nonpolar liquids C, D, and E are supplied. I can confirm that.

  FIG. 6 shows a limit line width (the thinnest line) in which pattern collapse does not occur when the liquid is not supplied after the rinsing liquid is supplied (only the rinsing liquid), and when the surfactant and the liquids A to I are supplied after the rinsing liquid is supplied. This is experimental data indicating (width). According to the experimental data shown in FIG. 6, when polar liquids A, B, F, G, H, and I are supplied, only rinse liquid, surfactant or nonpolar liquids C, D, and E are supplied. It can be confirmed that the limit line width is narrower than that in the case of the above. When the polar liquids A, B, F, G, H, and I were supplied, the limit line width was 80 nm or less. This also indicates that the polar liquids A, B, F, G, H, and I are supplied in comparison with the case where the surfactant is supplied or the nonpolar liquids C, D, and E are supplied. It can be confirmed that pattern collapse is unlikely to occur.

  From the above results, it can be confirmed that by supplying a liquid containing a polar fluorocarbon-based compound to the wafer W after the rinsing liquid is supplied, pattern collapse at the time of the wafer W being shaken and dried can be suppressed.

  FIG. 7 is an experiment showing the line width fluctuation amount of the pattern before and after drying of the wafer W when the surfactant and the polar liquids A, B, F, G, H, and I are supplied after the rinse liquid is supplied. It is data. According to the experimental results shown in FIG. 7, the line width fluctuation amount is small when the polar liquids A, B, F, G, H, and I are supplied compared to the case where the surfactant is supplied. I can confirm. From this result, it can be confirmed that the swelling of the pattern can be suppressed when the polar liquids A, B, F, G, H, and I are supplied compared to the case where the surfactant is supplied.

  Therefore, as in the above-described embodiment, after supplying a rinse liquid for development processing, a liquid having a polar fluorocarbon-based compound is supplied, and the wafer W is rotated and dried, so that the pattern collapses at the time of drying. And the swelling of the pattern can be suppressed.

  Next, the results of examining the dielectric constants of the liquids A, B, C, D, E, G, and I are shown in FIG. 8, and the results of examining the solubility [ppm (Wt.)] Of these liquids in water are shown. It is shown in FIG. The numbers in FIG. 8 indicate specific values of the dielectric constant, and the numbers in FIG. 9 indicate specific values of the solubility in water.

  First, regarding the dielectric constants of these liquids, as shown in FIG. 8, the liquids C, D, and E have a dielectric constant of 2 or less, while the liquids A, B, G, and I have The dielectric constant is approximately 7 or more. Therefore, considering this result, the liquids A, B, G, and I having a high dielectric constant are less likely to cause pattern collapse than the liquids C, D, and E having a low dielectric constant of 2 or less. Effective in preventing swelling of Therefore, according to the inventors' inference, a polar liquid is considered to be effective in preventing pattern collapse if the dielectric constant is 2.1 or more, more preferably 7 or more.

  Next, when examining the solubility of these liquids in water, as shown in FIG. 9, the liquids C, D, and E have a water solubility of 10 ppm (Wt.) Or less. On the other hand, the liquids A, B, G and I have a solubility in water of approximately 90 [ppm (Wt.)] Or more. Therefore, considering this result, the liquids A, B, G and I having high water solubility are less likely to cause pattern collapse than the low solubility liquids C, D and E having a solubility of 10 or less. It can be seen that this is effective in preventing the swelling of the material. Therefore, according to the inventors' inference, a polar liquid has a solubility in water of 20 [ppm (Wt.)] Or more, more preferably a solubility in water of 90 [ppm (Wt.)] Or more. The liquid seems to be effective in preventing pattern collapse.

  As inferred from the results and discussion of FIGS. 8 and 9 above, in the liquid containing a polar fluorocarbon compound, the dielectric constant is 2.1 or more, more preferably the dielectric constant is 7 or more, In addition, a liquid having a solubility in water of 20 [ppm (Wt.)] Or more, more preferably a water solubility of 90 [ppm (Wt.)] Or more is effective in preventing pattern collapse, and also prevents pattern swelling. It seems to be effective in prevention. This agrees with the results shown in FIGS.

  The example of the embodiment of the present invention has been described above, but the present invention is not limited to this example and can take various forms. For example, the present invention can also be applied to other substrate development methods other than wafers, such as FPD (flat panel display) and photomask mask reticles.

  The present invention is useful for suppressing pattern collapse and pattern swelling during substrate drying after development.

It is explanatory drawing of the longitudinal cross-section which shows the outline of a structure of the image development processing apparatus concerning this Embodiment. It is a top view which shows the outline of a structure of a development processing apparatus. It is explanatory drawing of the flow of a development process. It is experimental data which shows the presence or absence of pattern collapse at the time of supplying surfactant and predetermined liquid AI at the time of drying after image development. It is explanatory drawing which shows the width | variety of the root part of a pattern. It is an experimental data which shows the limit line width which pattern collapse does not generate | occur | produce about surfactant and predetermined liquid AI. It is experimental data which shows the line | wire width fluctuation amount of the pattern at the time of supplying surfactant, liquid A, B, F, G, H, or I to a wafer at the time of drying after image development. It is a graph which shows the result of having investigated the dielectric constant of the liquid A, B, C, D, E, G, I. It is a graph which shows the result of having investigated the solubility to the water of the liquid A, B, C, D, E, G, I.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Development processing apparatus 10 Spin chuck 33 Developer supply nozzle 50 Rinse solution supply nozzle 63 Liquid supply nozzle W Wafer

Claims (6)

A method for developing a substrate,
Developing a substrate by supplying a developer to the substrate;
Thereafter, a step of supplying development stop solution to the substrate to stop development,
And a step of supplying a liquid containing a polar fluorocarbon-based compound to the substrate and rotating the substrate to dry the substrate. The liquid is a mixture of methyl perfluoroisobutyl ether and methyl perfluorobutyl ether, a mixture of ethyl perfluoroisobutyl ether and ethyl perfluorobutyl ether, a mixture of two or more types of dichloropentafluoropropane having different molecular structures, and tetrafluoroethyl. The development processing method according to claim 1, which contains any one of trifluoroethyl ether, decafluoropentane, and heptafluorocyclopentane. The development processing method according to claim 1, wherein the liquid has a dielectric constant of 2.1 or more and a solubility in water of 21 ppm (Wt.) Or more. A development processing apparatus for a substrate,
A rotation support member for supporting and rotating the substrate;
A development processing apparatus, comprising: a liquid supply nozzle that supplies a liquid containing a polar fluorocarbon-based compound to the substrate supported by the rotation support member. The liquid is a mixture of methyl perfluoroisobutyl ether and methyl perfluorobutyl ether, a mixture of ethyl perfluoroisobutyl ether and ethyl perfluorobutyl ether, a mixture of two or more types of dichloropentafluoropropane having different molecular structures, and tetrafluoroethyl. The development processing apparatus according to claim 4, which contains any one of trifluoroethyl ether, decafluoropentane, and heptafluorocyclopentane. The development processing apparatus according to claim 4, wherein the liquid has a dielectric constant of 2.1 or more and a solubility in water of 21 ppm (Wt.) Or more.

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