WO2007023648A1

WO2007023648A1 - Substrate heating device, coating/development device, and method for heating substrate

Info

Publication number: WO2007023648A1
Application number: PCT/JP2006/315209
Authority: WO
Inventors: Takanori Nishi; Takahiro Kitano; Katsuya Okumura
Original assignee: Tokyo Electron Limited; Octec Inc.
Priority date: 2005-08-24
Filing date: 2006-08-01
Publication date: 2007-03-01
Also published as: JP2007059633A; TW200725694A

Abstract

This invention provides a substrate heating device (2) comprising a substrate mounting part (31) within a treatment container (4), vaporization parts (61, 62, 64, 67) for vaporizing water, a feed route (68) for feeding a carrier gas into the vaporization parts (61, 62, 64, 67), a gas feed route (65) for feeding a treatment gas containing water vapor, obtained by feeding the carrier gas into the vaporization parts (61, 62, 64, 67), into the treatment container (4), and a control unit (100) for conducting control in such a manner that a treatment gas is fed into the treatment container (4) after the substrate is mounted on the substrate mounting part (31) and the treatment container (4) reaches a temperature above the dew temperature of the treatment gas. Since the exposed substrate can be heated in a water vapor atmosphere, even in the case of a resist with a small energy introduction amount, which has been exposed to electron beams for a short period of time, sites as the exposed region can satisfactorily undergo a change in quality upon heat treatment and the line width accuracy can also be improved.

Description

Specification

Substrate heating device, coating and developing device, and substrate heating method

Technical field

TECHNICAL FIELD [0001] The present invention relates to a substrate heating apparatus, a coating and developing apparatus, and a substrate heating method in which a chemically amplified resist is applied and further subjected to heat treatment before developing the exposed substrate. Background art

Conventionally, in a photoresist process, which is one of semiconductor manufacturing processes, for example, a resist is applied in a thin film on the surface of a semiconductor wafer (hereinafter referred to as “wafer”), exposed, and then developed with an image solution. Thus, a mask pattern is formed on the surface. Such processing is generally performed using a system in which an exposure apparatus is connected to a coating and developing apparatus that performs resist coating and development.

One type of resist is a chemically amplified resist. When this resist is used, an acid is generated from the acid generator contained in the resist by exposure, and this acid is diffused into the exposed area by a heat treatment called PEB (Post Exposure Bake). Catalytic reaction proceeds. FIG. 11 is a diagram showing the state of exposure, heating, and development when using a positive resist in which the exposed region is changed to be soluble in a developer by an acid catalyst reaction among chemically amplified resists. First, when exposure is performed through a mask M having an opening corresponding to a pattern on a substrate on which a resist R is applied in a thin film shape, for example, Ueno W, the light passes through the opening of the mask M and light is transmitted. For example, an acid such as proton (H +) is generated on the surface of the contacted part ((a) in FIG. 11). Next, when the wafer W is heated at a predetermined temperature, for example, 90 to 140 ° C., the acid diffuses and the acid catalyzed reaction proceeds, and the base resin, which is the main component of the resist R, decomposes and the acid decomposes the developer. (Fig. 11 (b)). In more detail about this acid-catalyzed reaction, for example, when the acid generated in the exposed area diffuses and decomposes the base resin, at this time, an acid (or a component corresponding to the acid) is newly generated. The amplification reaction proceeds such as decomposing fat. Thereafter, a developer is supplied to the surface of the wafer W, so that an insoluble portion remains in the developer and a resist pattern is formed ((c) in FIG. 11). [0004] By the way, pattern miniaturization tends to progress more and more, and moreover, in recent years, a shift is being made from a production method of low-mix and high-volume production to high-mix low-volume production. If a special mask M is made for each product type, the unit price of the product may increase. Therefore, a maskless drawing technique called character projection using an electron beam (hereinafter referred to as “electron beam exposure”) has been studied and reported (Japanese Patent Laid-Open No. 2002-50567 (Patent Document 1)). )reference). The concept of electron beam exposure is briefly described below using Fig. 12. In the figure, reference numeral 1 denotes an electron gun for irradiating an electron beam. The electron beam irradiated from the electron gun 1 is bent by an electrostatic field formed by the first deflection unit 11, and the upper and lower aperture members 12a , 12b,..., 12b,..., 12b,... By passing through predetermined combinations of openings (not shown) such as circles, triangles, squares, etc. The shape is formed in a predetermined pattern. Thereafter, the electron beam is bent again by the second deflection unit 13 and is irradiated onto a predetermined irradiation region on the surface of the wafer W. As described above, the electron beam exposure has an advantage that an arbitrary pattern can be drawn on the surface of the wafer W without using the mask M by changing the combination of openings through which the electron beam passes.

[0005] However, if the acceleration of the electron beam irradiating the wafer W is too large, the electrons reaching the base of the wafer W are reflected and drawn up to an unscheduled portion (such as this) The phenomenon is called the proximity effect.) To suppress this proximity effect, the acceleration of the electron beam is set small. If the electron beam is set at a low acceleration in this way, the trajectory of the beam is easily bent by the electrostatic field of the deflection units 11 and 13, so that the target opening of the aperture member 12 can be passed with high accuracy. Furthermore, there is an advantage that the beam can be applied with high accuracy to a predetermined position on the surface of the wafer W.

Patent Document 1: Japanese Patent Laid-Open No. 2002-50567

Disclosure of the invention

Problems to be solved by the invention

[0006] Drawing using a low acceleration electron beam with force, however, has the following problems. In other words, the amount of acid that can be a trigger for promoting the amplification reaction in the case of a chemically amplified resist because the energy injected from the electron beam into the resist is reduced in proportion to the low acceleration. However, even if heating is performed after drawing, the acid may not spread sufficiently in the drawing area. For this reason, the resist is not sufficiently altered, and as a result, the pattern is not formed, or even if formed, the line width accuracy is low and the pattern is formed. For this reason, if electron beam exposure is to be carried out, the electron beam irradiation time for the drawing site must be lengthened in order to inject sufficient electron beam energy into the resist, but in that case the throughput will be considerably reduced, This is a factor that prevents realization. In the future, there is a movement to set the beam to lower acceleration in order to control the beam trajectory with higher accuracy, and the problem of trade-off between lower beam acceleration and higher throughput is becoming more prominent. There are concerns.

[0007] Although other problems are not limited to electron beam exposure, in general, as the pattern to be formed becomes finer and the line width becomes smaller, for example, the resist strength and the contact area with the base decrease. Due to these factors, the formed pattern collapses, the line width accuracy is lowered, and a defect that the pattern is not formed is likely to occur.

[0008] The present invention has been made based on such circumstances, and an object of the present invention is to apply a resist when applying a chemically amplified resist, for example, to heat-treat a substrate exposed by a low acceleration electron beam. The present invention provides a substrate heating apparatus, a coating / developing apparatus, and a substrate heating method capable of promoting a chemical amplification reaction to form a resist pattern with high line width accuracy and suppressing collapse of a pattern line width. is there.

Means for solving the problem

[0009] A substrate heating apparatus of the present invention includes a processing container, a substrate mounting portion provided in the processing container, coated with a chemically amplified resist, on which a substrate after exposure and before development is mounted. A heating unit for heating the substrate placed on the substrate placement unit, a vaporization unit for vaporizing water, a carrier gas supply path for supplying a carrier gas to the vaporization unit, and a carrier gas to the vaporization unit A gas supply path for supplying the processing gas containing water vapor obtained by supplying the gas into the processing container, and the substrate are placed on the substrate platform, and the temperature inside the processing container is higher than the dew point temperature of the processing gas. And a control unit for supplying the processing gas into the processing container.

[0010] The vaporization unit may include a container for containing water and publishing a carrier gas, and a unit for heating the water in the container. It may be determined that the temperature inside the processing container has become higher than the dew point temperature of the processing gas based on the elapsed time after the substrate is placed on the part or based on the temperature detection value in the processing container.

[0011] The exposure is electron beam exposure in which a pattern is drawn on the surface of the substrate by, for example, a low acceleration electron beam. The substrate heating apparatus may further include a pressurizing unit that pressurizes the inside of the processing container. Further, the substrate heating apparatus further includes an exhaust unit that exhausts the inside of the processing container, and the control unit is configured to carry the substrate out of the processing container after the processing gas is exhausted by the exhaust unit. The control signal may be output

[0012] The coating and developing apparatus of the present invention includes a carrier station into which a substrate carrier containing a plurality of substrates is carried in, and a delivery unit that delivers the substrate to the substrate carrier carried into the carrier station. Including a carrier stage, a coating unit for applying a resist to the substrate delivered from the delivery unit, a development unit for developing the substrate after exposure, and a substrate before exposure to the exposure apparatus, An interface unit for receiving the substrate from the exposure apparatus and the substrate heating apparatus described above are provided.

The substrate heating method of the present invention is a substrate heating method in which a chemically amplified resist is applied and a substrate before exposure and before development is heated, and the substrate is placed on a substrate placement portion in a processing container. A step of evaporating water with a carrier gas to generate a processing gas containing water vapor, a substrate is carried into the substrate platform, and the inside of the processing container has a temperature higher than the dew point temperature of the processing gas. And a step of supplying the processing gas into the processing container.

[0014] The exposure may be an electron beam exposure in which a pattern is drawn on the surface of the substrate with a low acceleration electron beam. The substrate heating method may further include a step of exhausting the processing gas from the inside of the processing container, and a step of subsequently carrying the substrate out of the processing container.

The invention's effect

In the present invention, a chemically amplified resist is applied, and the exposed substrate is heated in a water vapor atmosphere. Therefore, for example, a short-time electron beam exposure is performed using a low acceleration electron beam. Even in the case of a resist with a small energy injection amount, The portion corresponding to the exposure region can be sufficiently altered by the processing. The reason for this is presumed that the acid generated from the resist by exposure moves in this water, so that the diffusion of the acid in the exposure area of the resist can be activated. . Therefore, since it is possible to cope with the heat treatment stage without increasing the irradiation time of the low-acceleration electron beam, the throughput can be improved. In addition, as described in the evaluation test described later, the pattern formed by the heat treatment by supplying water vapor in this way can be prevented from collapsing even if the line width is low. A resist pattern with high line width accuracy can be formed on the surface of the substrate.

Brief Description of Drawings

FIG. 1 is an explanatory diagram showing a configuration of a substrate heating apparatus according to an embodiment of the present invention.

FIG. 2 is a longitudinal side view showing a configuration of a hot plate and a top plate of the substrate heating apparatus.

FIG. 3 is a graph showing the temperature of the wafer W and the state around the wafer W in the heat treatment performed using the substrate heating apparatus.

FIG. 4 is a plan view showing a coating / developing apparatus in which the substrate heating apparatus of the present invention is incorporated.

FIG. 5 is a perspective view showing a coating / developing apparatus in which the substrate heating apparatus of the present invention is incorporated.

FIG. 6 is a graph showing the relationship between the optimum energy amount of the electron beam during exposure and the absolute humidity during heat treatment.

FIG. 7 is a photograph showing the state of the pattern formed on the wafer at each absolute humidity.

[Fig. 8] A photograph of the pattern of the formed wafer arranged for each line space of the pattern.

FIG. 9 is a graph showing the timing of supplying water vapor to the substrate in the heat treatment of the wafer.

FIG. 10 is a graph showing the relationship between the CD of the pattern formed on the wafer and the dose amount of the electron beam irradiated on the wafer.

FIG. 11 is an explanatory view showing a state when the chemically amplified resist is exposed, heated and developed.

FIG. 12 is an explanatory diagram showing an outline of electron beam exposure.

Explanation of symbols [0017] 2 substrate heating device, 32 heater, 4 processing vessel, 41 top plate, 6 water vapor supply section, 65 gas supply pipe.

BEST MODE FOR CARRYING OUT THE INVENTION

[0018] As an example of an embodiment of a substrate heating apparatus according to the present invention, a substrate such as a wafer after a chemical amplification type resist is applied and a predetermined pattern is drawn with a low acceleration electron beam, for example. A substrate heating apparatus 2 that is a substrate calorie heating apparatus that causes an acid catalytic reaction to proceed while heat-treating W will be described with reference to FIG. The substrate heating apparatus 2 is composed of a main body 2A and a water vapor supply unit 6. The main body 2A includes a rectangular casing 20, and a transfer port 21 for a wafer W is opened on a side wall of the casing 20. Yes. The shirter 21a is provided with 21 transport ports. For example, except for the case where the wafer W is loaded / unloaded through the transfer port 21, the shirter 21a is closed to prevent the outside air from flowing into the housing 20. In addition, a base 22 having a hollow at the bottom is provided in the housing 20.

[0019] If the direction toward the transport port 21 is the front side in the casing 20, the base 22 is provided with lifting mechanisms 23 and 25 in this order on the front side and the rear side in this order. For example, three support pins 24 are connected to the elevating mechanism 23, and the support pins 24 are vertically moved on the base 22 through holes formed on the base 22 by the elevating mechanism 23. It is configured so that it can sink. The lifting mechanism 25 will be described later.

A cooling plate 27 is provided on the front side on the base 22. The cooling plate 27 is provided with a cooling flow path (not shown) for flowing temperature-controlled water, for example, on the back surface side, and is configured to roughly cool the wafer W placed on the cooling plate 27. Yes. The cooling plate 27 is also provided with slits (not shown). For example, the wafer W transfer mechanism (not shown) including an arm body that supports the back surface of the wafer W supports the wafer and the wafer W. When entering the housing 20 through the transfer port 21, the support pins 24 raised as described above pass through the slits to support the back surface of the wafer W, and the support pins 24 support the wafer W. By lowering, the transfer of the wafer W to the cooling mechanism 27 is carried out!

In addition, the cooling plate 27 has a role of transferring the wafer W between the transfer mechanism and a hot plate 31 that heats the wafer W provided on the back side of the housing 20. Provided Along the guide unit (not shown), the base 22 is configured to be able to advance and retreat from the near side to the far side, so that the wafer W can be transferred onto the hot plate 31.

A configuration around the hot plate 31 in the housing 20 will be described with reference to FIG. The hot plate 31 serving as the substrate mounting portion is formed in a circular shape, for example, and has a size that covers the surface of the wafer W. A heater 32 as a heating unit is provided inside the hot plate 31. The hot plate 31 is heated by the heat generated by the heater 32 in response to a control signal from the control unit 100 described later, and the wafer W placed on the hot plate 31 is heated at a predetermined temperature. The support member 33 that supports the hot plate 31 is formed so as to cover the side periphery and the bottom of the hot plate 31. The heat plate 31 is embedded in the base 22 through the support member 33.

[0023] For example, three holes are drilled in the hot plate 31 and the support member 33 so as to penetrate each of them in the vertical direction, and a support pin 26 is provided in each of these holes. Each support pin 26 is connected to the elevating mechanism 25, and can move up and down in the hole through the elevating mechanism 25 so that it can project and sink on the hot plate 31. When the cooling plate 27 holding the wafer W moves onto the hot plate 31, the support pins 26 protrude on the hot plate 31 and pass through the slit of the cooling plate 27 so that the back of the wafer and W can be supported. After the cooling plate 27 is retracted, the support pins 26 are lowered while supporting the back surface of the wafer W, whereby the wafer W is delivered onto the hot plate 31. As shown in FIG. 2, the O-ring 34 is provided on the peripheral edge of the support member 33.

The top plate 41 is provided above the heat plate 31. The top plate 41 constitutes the processing container 4 together with the support member 33, and is formed in a circular lid shape having a flange portion, for example. The drive unit 42 is provided to raise and lower the top plate 41. As described above, when the wafer W is placed on the hot plate 31, the driving plate 42 lowers the top plate 41. Then, as shown in FIG. 2, the periphery of the top plate 41 and the periphery of the support member 33 are in close contact with each other via the O-ring 34, so that the periphery of the wafer W becomes a sealed space! The

A gas supply port 51 is provided at the lower center of the top plate 41, and a gas supply pipe 65 described later is connected to the gas supply port 51. Further, for example, a cylindrical support member 52 is provided below the top plate 41. Rectifying plates 53, 54 are provided in parallel to be spaced apart from each other so as to partition the support member 52 in the vertical direction. Gas discharge ports 53a and 54a are provided at intervals. The first ventilation chamber 55 is partitioned by being surrounded by the rectifying plate 53, the support member 52, and the top plate 41. The second ventilation chamber 56 is partitioned by being surrounded by the current plate 53, the current plate 54, and the support member 52. The heater block 57 is provided on the top plate 41, for example. As will be described later, when processing gas containing water vapor is supplied from the gas supply pipe 65 to the processing container 4, for example, the heater block 57 heats the top plate 41 to a temperature corresponding to the temperature of the processing gas. As a result, the water vapor is prevented from condensing in the processing container 4.

[0026] For example, a gas suction port 43 is provided around the entire circumference of the flange portion of the top plate 41, and an exhaust passage 45 is provided on the outer side of the gas suction port 43. It is provided to communicate with. As will be described later, the exhaust passage 45 is sucked into the exhaust passage 45 through the gas suction port 43 so that a part of the water vapor in the process gas cooled and liquefied can be stored. A gas suction arch I tube 46 is connected to the exhaust passage 45. The gas suction pipe 46 extends to the outside of the housing 20, for example, and is connected to a suction arch I exhaust mute 48 such as a vacuum pump via a pressure adjustment unit 47 !. The pressure adjusting unit 47 and the flow rate controlling unit 69 described later constitute a pressurizing unit within the scope of the claims.

Next, the water vapor supply unit 6 will be described. The water vapor supply unit 6 includes, for example, a container 61 in which pure water is stored. The container 61 is configured so that the inside of the container 61 is hermetically sealed by a cap 62 closing the opening. The temperature sensor 63 is a temperature detection unit that monitors the temperature of pure water in the container 61. The mantle heater 64 is a heating unit provided so as to surround the outer periphery of the container 61. The mantle heater 64 includes a heater 64a, a heat insulating material 64b surrounding the heater 64a, and an exterior part 64c surrounding the heat insulating material. The mantle heater 64 can be set to generate heat at a predetermined temperature. For example, when the temperature sensor 63 detects the water temperature, the temperature detection value is output to the control unit 100 described later, and the output is output. Based on the above, the controller 100 outputs a temperature control signal of the mantle heater 64, so that the water temperature is controlled to become the set temperature. The container 61, the cap 62, the nozzle 67 and the mantle heater 64, which will be described later, constitute a vaporizing section referred to in the claims. [0028] One end of a gas supply pipe 65, which is a gas supply path, is opened in the gas phase portion in the container 61. This gas supply pipe 65 is connected to the gas supply port 51 in the top plate 41 described above. ing. In the figure, reference numeral 66 denotes a tape heater mounted on the gas supply pipe 65 in order to prevent the processing gas passing through the gas supply pipe 65 from condensing in the gas supply pipe 65 as described later. In response to an electrical signal from the control unit 100, for example, it is heated to a temperature corresponding to the temperature of the processing gas.

In addition, a nozzle 67 for publishing is immersed in the liquid phase portion in the container 61, and a carrier gas supply pipe 68 that is a carrier gas supply path is connected to the nozzle 67. The end of the carrier gas supply pipe 68 is inert, for example, N gas as the carrier gas.

2

It is connected to a gas supply source 60 in which gas is stored.

2 flows into the carrier gas supply pipe 68. In this carrier gas supply pipe 68, for example, a flow rate control unit 69, such as a mass flow controller, a valve V2, and a valve VI are provided in this order in the upstream direction. In the figure, reference numeral 71 denotes a no-pass path that is piped by bypassing the vaporizing section, and a nozzle V3 and a flow rate control section 72 are interposed.

[0030] Opening and closing of the valves V1 to V3 is controlled by receiving a control signal from the control unit 100. For example, when the valve V2 is open, the valve V3 is closed, and conversely, the valve V3 is open. Occasionally, the valve V2 closes and the N gas vaporization part

2

It is now possible to alternate between bypassing and bypassing! When valve VI and valve V2 are opened, N (nitrogen) gas is supplied from the gas supply source 60 to the carrier gas supply pipe 68.

2

Is supplied. The N gas is controlled to a preset flow rate by the flow rate control unit 69, for example.

2

Then, it is discharged from the nozzle 67 into the container 61 and is bubbled while being heated by the mantle heater 64. By this publishing, N gas is humidified and treated with water vapor.

2

This processing gas flows into the gas supply pipe 65.

[0031] When the valves VI and V3 are opened, the N gas that has flowed into the carrier gas supply pipe 68 from the gas supply source 60 flows into the bypass 71, and is set by the flow rate control unit 72, for example, as a preset flow.

2

The amount is controlled and flows into the gas supply pipe 65.

The processing gas and N gas that have flowed into the gas supply pipe 65 in this way are supplied to the top plate 41.

2

It flows into the first ventilation chamber 55 through the supply port 51. And flowed into the first vent chamber 55 These gases flow into the second ventilation chamber 56 via the discharge port 53a of the rectifying plate 53, and are then discharged into the housing 20 from the discharge port 54a of the rectifying plate 54. N

2 When the gas and the processing gas are supplied into the housing 20, the suction / exhaust unit 48 exhausts the interior of the housing 20 from the suction port 43 via the pressure adjustment unit 47. For example, the housing 20 The inside is set to atmospheric pressure.

[0033] Then, when the wafer W is placed on the hot plate 31, the top plate 41 is lowered as described above, and the periphery of the wafer W placed on the hot plate 31 is set as a sealed space. Supply of N gas and processing gas

2

For example, an air flow as shown by arrows in FIG. 2 is formed by the supply and suction. Specifically, process gas and N gas are discharged from the discharge port 54a toward the entire surface of the wafer W.

2

After that, the central portion side force of the wafer W is also directed toward the peripheral portion, and flows into the suction port 43 to be exhausted. The wafer W is heated by the heat of the hot plate 31 while such an air flow is formed. As a result, the acid-catalyzed reaction of the chemically amplified resist applied to Weno and W proceeds.

[0034] When the air flow is formed by the processing gas, for example, water vapor is supplied to the entire surface of the wafer W at a constant flow rate, and the absolute humidity (water vapor amount) around the wafer W is kept constant. Is to be heated. If water vapor contained in the processing gas is condensed on the surface of the wafer W, water droplet traces generated by the condensation adhere to the surface of the wafer W, and the water droplet traces adhere during the development processing performed after this heat treatment. Since the development of the pattern may be hindered at the above-mentioned places, when the processing gas is supplied to the wafer W as described above, the wafer W is processed by the heater 32 in order to prevent this water vapor condensation. It shall be heated to a temperature higher than the dew point of the gas!

Note that when the water vapor is supplied to the wafer W in this way, the supply amount of N gas supplied to the processing container 4 is controlled by the flow rate control unit 69, and the processing container is controlled by the pressure adjusting unit 47.

2

4 The amount of N gas exhausted from inside is controlled, so that the inside of the processing container 4

2

The pressure is maintained.

Next, the control unit 100 provided in the substrate heating apparatus 2 will be described. This control unit has a program storage unit that is, for example, computer-powered. The program storage unit includes the action of the substrate heating device 2 as described later, that is, the opening and closing of each valve, the flow rate control unit 69 , 72 N gas flow rate control, heating value control of each heater, top plate 4 via drive unit 42

2

Stored is a program having software commands, for example, in which commands are set so that 1 is moved up and down, each support pin is moved up and down via the drive units 23 and 25, and the cooling plate 27 is moved. The control unit 100 controls the operation of the substrate heating apparatus 2 by reading the program to the control unit 100. This program is stored in the program storage unit while being stored in a recording medium such as a disk, a hard disk, a compact disk, a magnetic optical disk, or a memory card.

[0037] Next, a case where a wafer W on which a chemically amplified resist is coated on the surface using the substrate heating apparatus 2 described above and a predetermined pattern is drawn with an electron beam is heat-treated as an example is shown in FIG. Will be described with reference to FIG. In Fig. 3, the horizontal axis shows time.

twenty two

Show.

[0038] First, for example, before the wafer W is loaded into the housing 20, the valves VI and V3 are opened while the valve V2 is closed. As described above, N gas is bypassed from the gas supply source 60.

2

71 flows into the gas supply pipe 65 after undergoing flow rate control by the flow rate control unit 72. The N gas is discharged into the housing 20 through the vent chambers 55 and 56 of the top plate 41.

2

The amount of suction and exhaust corresponding to the amount of N gas supplied from the gas suction port 43 is performed.

2

Thus, a gas flow is formed in the housing 20.

Subsequently, when the wafer W is loaded into the casing 20 via the transfer port 21 by an external transfer mechanism (not shown), for example, the supply amount of N gas into the casing 20 via the flow rate controller 72 Is

2

As a result, the N concentration in the housing 20 increases. On the other hand, the mantle heater 64

2

For example, the tape heater 66 and the heater block 57 are heated to, for example, a temperature of 70 ° C. or higher. The wafer W carried into the housing 20 is delivered to the cooling plate 27 via the support pins 24. The surface of the hot plate 31 is heated by the heater 32 to a predetermined temperature, for example, 130 ° C., until the cooling plate 27 moves onto the hot plate 31. Then, the support pins 26 are raised by the elevating mechanism 25 and the back surface of the wafer W transferred onto the hot plate 31 is supported by the cooling plate 27. When the cooling plate 27 is retracted, the support pins 26 are lowered, and the wafer W is placed on the hot plate 31 (time 1 in FIG. 3). [0040] After the top plate 41 is lowered and the processing container 4 is sealed, it is filled with N gas as described above.

2 An air flow is formed, and, for example, the pressure in the pressure adjusting unit 47 is adjusted, so that the inside of the processing container 4 is in an atmospheric pressure state. Further, the wafer W is heated by the hot plate 31, and the temperature of the wafer W increases. Then, for example, after 30 seconds have passed since the temperature of the wafer W becomes constant, the valve V3 is closed and the valve V2 is opened at the same time, and the flow of N gas in the bypass passage 71 is stopped.

2

In addition, as described above, the N gas flowing into the carrier gas supply pipe 68 from the N gas supply source 60

2 2 is subjected to flow control by the flow control unit 69, and then publishes in the water heated by the mantle heater 64 to become a processing gas containing water vapor. In this process gas, the above N gas

The amount of water vapor is slightly less than the amount of saturated water vapor at the temperature of the processing gas. Such high-humidity processing gas flows into the gas supply pipe 65, and the pipe is heated to a temperature of 70 ° C or higher, so that the processing gas does not condense in the processing container 4. As a result, the absolute humidity around the wafer W rises, and water vapor is supplied to the wafer W (time t2 in FIG. 3).

[0041] The wafer W is heat-treated in such a high humidity atmosphere. After that, the valve V2 is closed simultaneously with the opening of the valve V3, and the gas constituting the air flow formed in the processing container 4 is switched to the processing gas force N gas, so that the periphery of the wafer W is switched to a dry atmosphere.

2

It changes (time t3 in Fig. 3). Thereafter, the top plate 4 rises and the support pins 26 rise while supporting the back surface of the wafer W. The cooling plate 27 moves again onto the hot plate 31, and the wafer W is transferred onto the cooling plate 27 and retracts from the hot plate 31 (time t4 in FIG. 3). The cooling plate 27 performs rough heat removal of Ueno and W and moves to the front side on the base 22. After the cooling plate 27 moves, the wafer W is transferred from the cooling plate 27 to the transfer mechanism such as a transfer arm through the support pins 24 and is carried out of the housing 20.

[0042] In the substrate heating apparatus 2 described above, a chemically amplified resist is applied, and the exposed wafer W is heated in the processing container 4 by the heater 32, and the temperature of the wafer W is a processing gas containing water vapor. After the dew point temperature is raised, the processing gas is supplied into the processing container and the wafer W is heated in a water vapor atmosphere. For example, a low-acceleration electron beam is used for a short time. Even in the case of a resist with a small amount of energy injection that has undergone beam exposure, this heat treatment can sufficiently alter the portion corresponding to the exposure area. You can. The reason for this is presumed that the acid generated from the resist by exposure moves in this water, so that it is possible to activate the diffusion of the acid in the exposed region of the resist. Accordingly, since it is possible to cope with the heat treatment stage without increasing the irradiation time of the low-acceleration electron beam, the throughput can be improved. In addition, as shown in the evaluation test described later, the pattern formed by heating with steam supplied in this way can be prevented from collapsing even if its line width is narrow. A resist pattern with high line width accuracy can be formed on the surface of the substrate.

In the above-described embodiment, the timing of supplying the processing gas into the processing container 4 is, for example, that the temperature of the wafer W previously placed on the hot plate 31 is raised after being placed on the hot plate 31. Data about the time until the temperature reaches a certain temperature is input to the control unit 100, and the control unit 100 actually puts the wafer W on the hot plate 31 based on the data and waits for a while after the above time has elapsed. As described above, the processing gas is supplied into the processing container 4 by switching the valve. Further, the present invention is not limited to managing the supply of the processing gas based on the time as described above. For example, the temperature of Weno and W on the hot plate 31 is detected, and the temperature is output to the control unit 100. After a while after the temperature of the wafer W detected by the temperature sensor becomes constant, the control unit 100 switches the valve as described above, and the processing gas in the processing container 4 May be supplied.

[0044] As described above, when the wafer W is withdrawn from the hot plate 31, the gas in the processing container 4 is replaced with N gas from the processing gas to raise the top plate 41, and then the cooling plate. Through 27

2

By evacuating Ueno and W from the hot plate 31, the processing gas remaining in the processing vessel 4 is prevented from flowing out of the processing vessel 4 when the top plate 41 is raised, so that water vapor is contained in the housing. There is no risk of condensation in the transport atmosphere inside or outside. For this reason, if water drops adhere to the following Ueno or W, or if a short circuit occurs in the electrical wiring system, there is no concern.

[0045] Further, as described above, when supplying the processing gas into the processing container 4, it is not limited to the inside of the processing container 4 being in a normal pressure state, for example, a pressurized state of about 1.2 X 10 ⁵ Pa And the above airflow You can form it. When the inside of the processing container 4 is in a pressurized state, more water vapor permeates the resist on the wafer W and works than in the case where an air flow is formed with the inside of the processing container 4 at normal pressure. Therefore, shortening of the acid catalyst decomposition reaction by heating can be expected.

[0046] By the way, the supply of the processing gas into the processing container 4 does not cause condensation of water vapor on the processing gas on the wafer W! For example, when the temperature of wafer W becomes higher than the temperature at which water vapor in the process gas is condensed during the temperature rise of wafer W, the process gas is transferred to wafer W. Let's feed it.

[0047] Note that when the wafer W is heated as in the above-described embodiment, the sublimation material sublimated from the resist is raised by the heat of the heater 32. The force is formed by the N gas and the processing gas described above.

2

The gas flows into the gas suction port 43 and is removed from the sealed space. When the air flow is formed by the processing gas, the water vapor in the processing gas reacts with the sublimate. As a result, the sublimate can be placed in the airflow more reliably, so that the attachment of the sublimate to the exhaust line consisting of the top plate 41, the gas suction port 43, the exhaust passage 45, and the exhaust pipe 46 can be further reduced. .

By the way, the wafer W heated by the substrate heating apparatus 2 is not limited to the one drawn by the low acceleration electron beam, for example, the wafer W drawn by the high acceleration electron beam or the exposure via the mask. It can also be applied to a wafer W that has been manufactured. Even in this case, since the acid-catalyzed reaction can be promoted, the throughput can be improved by performing post-exposure heating in a short time. The present invention can also be applied to a heat treatment of a substrate other than the semiconductor wafer W, such as an LCD substrate or a photomask reticle substrate, as the substrate to be processed.

Next, an example of a coating / developing apparatus in which the substrate heating apparatus of the present invention is incorporated will be briefly described with reference to FIGS. 4 and 5. The carrier mounting portion (carrier stage) B1 is a portion for loading and unloading the carrier C1, which is a substrate carrier in which, for example, 13 wafers W and W are hermetically stored. The carrier platform B1 includes a carrier station 90 having a platform 90a on which a plurality of carriers C1 can be placed, an opening / closing unit 91 provided on the front wall as viewed from the carrier station 90, and an opening / closing unit. The delivery unit A1 for taking out the wafer W is also provided through the carrier C force 91. [0050] A processing unit B2 surrounded by a casing 92 is connected to the back side of the carrier mounting unit Bl, and heating and cooling units are arranged in multiple stages in this processing unit B2 in order of the front side force. Shelf units Ul, U2, U3 and main transfer units A2, A3, which are wafer transfer units that transfer wafers W between processing units including the coating and developing units described later, are alternately arranged. It has been. That is, the shelf units Ul, U2, U3 and the main transfer units A2, A3 are arranged in a line in front and rear as viewed from the side of the carrier mounting portion B1, and an opening for wafer transfer (not shown) is formed at each connection site. The wafer W can freely move in the processing section B2 from the shelf unit U1 on one end side to the shelf unit U3 on the other end side. The main transport units A2 and A3 are one side of the shelf unit Ul, U2, U3 side arranged in the front-rear direction when viewed from the carrier mounting part B1, and one side of the right side liquid processing unit U4, U5 side described later, for example. It is placed in a space surrounded by a partition wall 93 composed of a part and a rear part forming one surface on the left side. In the figure, reference numerals 94 and 95 denote temperature / humidity control units equipped with a temperature control device for the coating liquid used in each unit and a duct for temperature / humidity control.

[0051] The liquid processing units U4 and U5 are provided with a coating unit COT and a developing unit on a storage unit 96 that forms a space for supplying a chemical solution such as a coating solution (resist solution) and a developing solution as shown in FIG. -It has a structure in which multiple DEVs, anti-reflection film forming units BARC, etc. are stacked in multiple stages, for example, 5 stages. In addition, the shelf units Ul, U2, U3 described above are configured in such a manner that various units for performing pre-processing and post-processing of the liquid processing units U4, U5 are stacked in multiple stages, for example, 9 stages. The combination includes a post-exposure heating unit (PEB) in which the above-described substrate heating apparatus 2 is turned on, a heating unit for heating (beta) the wafer W, a cooling unit for cooling Weno, and the like.

An exposure unit B4 is connected to the back side of the shelf unit U3 in the processing unit B2 via an interface unit B3 including, for example, a first transfer chamber 97 and a second transfer chamber 98. In addition to the two transfer units A4 and A5 for transferring the wafer W between the processing unit B2 and the exposure unit B4, the shelf unit U6 and the buffer carrier CO are located inside the interface unit B3. Is provided.

An example of the flow of wafers in this apparatus will be described. First, when the carrier C1 storing the wafer W from the outside is mounted on the mounting table 90a, the lid of the carrier C is opened together with the opening / closing portion 91. The body is removed and the wafer W is taken out by the delivery unit Al. Then, the wafer W is transferred to the main transfer unit A2 via a transfer unit (not shown) that forms one stage of the shelf unit U1, and is pre-processed as a coating process on one shelf in the shelf units U1 to U3. For example, after an adhesion process and a cooling process are performed and a resist film is formed in the coating unit, the wafer W is heated by a heating unit that forms one shelf of the shelf units U1 to U3 (beta process). Then, after further cooling, it is carried into the interface B3 via the delivery unit of the rear shelf unit U3. The wafer W is transferred to the interface unit B3 by way of the delivery unit A4 → the shelf unit U6 → the delivery unit A5, for example, to the exposure unit B4 for exposure. After exposure, the substrate heating apparatus of the present invention provided in the shelf unit U3 performs heat treatment as described above, and then the wafer W is carried into the development unit DEV via the main transfer unit A3 and developed. As a result, a resist pattern is formed. After this, Ueno and W are returned to the original carrier C1 on the mounting table 90a.

[0054] (Evaluation test)

In order to confirm the effect of the present invention, the following evaluation test was performed. First, a predetermined pattern was drawn on a wafer W coated with a chemically amplified resist with a low-speed electronic beam having a dose amount of 260 jZm ² . The line width of the pattern was 250 nmLS (line space). Then, as a standard process 1, the wafer W was subjected to a heat treatment using a heating apparatus configured in substantially the same manner as the substrate heating apparatus 2 described above. During this heat treatment, N gas with a relative humidity of 45% and a temperature of 23 ° C was continuously supplied to the wafer W during the heat treatment of the wafer W. Also

2

The pressure of water vapor contained in this N gas is 1 atm, and N calculated based on these values

2

Absolute humidity of the gas is 9gZm ^3. After this heat treatment, development processing is performed on wafer W.

2

A resist pattern was formed.

[0055] Subsequently, as an evaluation test 1, a pattern of 250 nm LS is drawn on each wafer W with a different dose amount, which is lower than 260 jZm ² for each of the wafers W, as in the standard processing 1, and then each wafer W Then, heat treatment was performed using the substrate heating apparatus 2 according to the same procedure as that described in the above-described embodiment. The temperature of the mantle heater 64 was set to 70 ° C. At this time, 70 ° C, which is the temperature of the mantle heater 64, is assumed to be the temperature of water vapor contained in the processing gas, and since the processing gas contains N gas, the phase of the processing gas Humidity was 90%. Furthermore, the absolute humidity of the processing gas calculated using these values, assuming that the pressure of water vapor in the processing gas was 1 atm, was 160 gZm ³ . Thereafter, development processing is performed on each wafer W. When the formed resist patterns are compared, the resist pattern has the same line width as the resist pattern formed by drawing with the optimum dose amount in the standard processing 1 described above. and had are resist patterns formed on the wafer W drawn by Dose of 230jZm ^2, and the optimum Dose amount this 230 j / m ² in the absolute humidity 160 g / m ^3.

[0056] Continuing! Evaluation test 2 Same as evaluation test 1 except that the temperature of the mantle heater was set to 100 ° C for multiple wafers W on which patterns were drawn with electron beams of different doses. The resist pattern was formed by performing the heat treatment and the development treatment according to the procedures described above. Then, the temperature of the mantle heater 64 is set to 100 ° C, and the water vapor pressure and relative humidity values are the same as those in the evaluation test 1 and the absolute humidity in the process gas is calculated. The absolute humidity in the gas was 460 gZm ³ . As in evaluation test 1, the patterns formed on each wafer W are compared, and the resist pattern formed on the wafer W drawn with a dose amount of 200 jZm ² is drawn and formed with the optimum dose amount in the standard process 1. The line width was the same as the line width of this pattern, and this 200jZm ² was taken as the optimum dose amount at an absolute humidity of 460gZm ³ .

[0057] Further, in evaluation test 3, except that the temperature of the mantle heater was set to 130 ° C, a plurality of wafers W on which patterns were drawn with electron beams having different dose amounts were performed in the same procedure as in evaluation test 1. Then, heat treatment and development processing were performed to form a! / ヽ pattern. The temperature of mantle heater 64, 130 ° C, is the temperature of water vapor contained in the process gas, and the values of water vapor pressure and relative humidity are the absolute humidity in the process gas calculated using the same values as in Evaluation Test 1. Was l lOOgZm ³ . The evaluation test 1 and a comparison of Les resist pattern formed on each wafer W similarly optimum Dose volume was 170jZm ^2.

[0058] The optimum dose amount of standard processing 1 is 260 jZm ² which is the dose amount when the pattern is drawn as described above, and is supplied to the wafer W during the heat treatment in standard processing 1 and evaluation tests 1 to 3. Figure 6 shows the correlation between the absolute humidity of the treated gas and the optimum dose. This graph shows that the optimal dose in evaluation test 1, evaluation test 2 and evaluation test 3 is about 12%, about 23%, and about 35% lower than the optimal dose in standard treatment 1, respectively. As a result, it can be said that the optimal dose amount decreases as the amount of water vapor supplied to the wafer W increases. In other words, it is shown that as the amount of water vapor supplied to the wafer W increases, the energy becomes lower and the pattern can be drawn on the wafer W with the beam! /.

[0059] Fig. 7 is a cross-sectional photograph of the pattern formed by drawing with the optimum dose amount in standard processing 1 and evaluation tests 1 to 3. In Fig. 7, (a) is standard processing and (b) ( c) (d) corresponds to evaluation tests 1, 2, and 3, respectively. In this test, patterns with the same shape as standard processing 1 were formed in evaluation tests 1 and 2 for each optimum dose amount. Deterioration of the pattern formed by scraping the area where the beam was irradiated with water with water occurred. In the evaluation tests 1 to 3, the temperature of the mantle heater 64 is calculated as the temperature of water vapor in the process gas. However, this temperature is different from the actual water temperature, and the relative humidity of the process gas is also accurately 9 It ’s not 0%. In addition, since it is heated, the water vapor pressure in the processing gas is not exactly 1 atm. Therefore, the absolute humidity obtained by calculation based on these values is different from the actual absolute humidity in the process gas. However, comparing the results of the above-described evaluation tests 1 to 3 with the results of standard processing 1, it is clear that supplying the humid air to the wafer W will reduce the optimum dose amount, and that the absolute amount in the processing gas It is also clear that the optimal dose decreases with increasing humidity.

[0060] Subsequently, a plurality of wafers W drawn with low-acceleration electron beams so as to have different LS are heated under the same conditions as the standard processing 1 and evaluation tests 1 to 3 described above, and developed. A resist pattern was formed on each wafer W. FIG. 8 shows a cross section of the resist pattern of each wafer W formed in this way, and is a table. In this table, the horizontal axis shows the size of the LS, and from the top, photographs of resist patterns formed by heat treatment under the conditions of standard processing and evaluation tests 1, 2, and 3 are arranged. As shown in Fig. 8, when the LS was processed under the same conditions as the standard processing 1, the formation of a resist pattern was confirmed when the LS ranged from 160 nm to 250 nm, but the LS was drawn with 150 nm and 140 nm, respectively. For C, the resist pattern has collapsed. On the other hand, those processed under the conditions of evaluation tests 1 to 3 showed that the resist pattern was not broken and the normal resist pattern was formed in the LS range of 140 nm to 250 nm, respectively. As a result, the force LS is If the resist pattern becomes smaller, the resist pattern is less likely to be formed. It can be said that the resist pattern can be prevented from collapsing by supplying a predetermined amount of water vapor to the wafer w during the heat treatment of the wafer W.

[0061] Next, in order to investigate the relationship between the timing of supplying water vapor in the heat treatment and the line width of the resist pattern to be formed, as the evaluation test 4, first the chemically amplified resist is prepared using the substrate heating apparatus 2 described above. A predetermined pattern was drawn on each of a plurality of coated wafers W with different dose amounts. Subsequently, each wafer W is subjected to a heat treatment according to a procedure substantially similar to the procedure described in the above-described embodiment using the substrate heating apparatus 2 described above, and then subjected to a development process. A resist pattern was formed. (A) in Fig. 9 shows the timing for supplying the processing gas to the wafer W in the heat treatment of this evaluation test 4 in a graph. In this evaluation test 4, as shown in (a) of FIG. 9, in the heat treatment, the time until the wafer W is placed on the hot plate 31 and the force of the wafer W retracts (from tl to t4 in the drawing). Time) until the heating temperature of the wafer W reaches the dew point of the processing gas supplied to the wafer W, and the time until the wafer W is retracted by the hot plate force is divided into the first half and the second half. In the first half, the processing gas was supplied into the processing container 4 for 20 seconds. The time for supplying the processing gas and the time for stopping the processing gas supply are t 2 and t3, respectively. The pressure in the processing vessel during the heat treatment was 1.8 atm.

[0062] Next, as an evaluation test 5, a chemically amplified resist is applied in substantially the same manner as in the above-described evaluation test 4, and a plurality of wafers W each having a predetermined pattern drawn with different dose amounts are applied. A heat treatment and a development treatment were performed to form a resist pattern. However, unlike the evaluation test 4, the processing gas was supplied into the processing container 4 for 20 seconds in the latter half of the time until the heating temperature of the wafer W reached the dew point and the force Ueno and W retracted the hot plate power. (B) in Fig. 9 is a graph showing the relationship between the temperature of Ueno and W in this evaluation test 5 and the timing of supplying the processing gas.

[0063] Further, as standard treatment 2, a chemically amplified resist is applied in substantially the same manner as in the above-described evaluation test 4, and a plurality of Ueno and W in which a predetermined pattern is drawn with different dose amounts are calo-heat treated. And development processing was performed. As in evaluation tests 4 and 5, the pressure in the processing container 4 during the heat treatment was set to 1.8 atm. However, in this standard treatment 2, during the heat treatment, The process gas was not supplied.

FIG. 10 shows the dose amount of the electron beam irradiated on each wafer W in evaluation tests 4 and 5 and standard processing 2 and the line width of the resist pattern formed on the wafer W after the development processing. nm). As can be seen from this graph, the dose amount of the electron beam necessary to obtain a pattern with a predetermined line width is smaller in the evaluation tests 4 and 5 than in the standard treatment 2, and the evaluation test 4 and the evaluation test. In comparison with 5, evaluation test 5 had a smaller amount of electron beam dose required to obtain a pattern with a predetermined line width.

[0065] From the results of these evaluation tests 4, 5 and standard treatment 2, when humidified air is supplied during the heat treatment, the humidified air is not supplied. It can be seen that this pattern can be formed on the wafer W. In addition, when humidified air is supplied during the heat treatment, the time until the heating temperature of the wafer W reaches the dew point of the processing gas supplied to the wafer W and the force is retracted by the hot plate force is divided into the first half and the second half. In other words, it is obvious that a pattern with a predetermined width can be formed on the wafer W with a lower dose by supplying humidified air in the latter half than supplying humidified air in the first half.

Industrial applicability

[0066] As described above, the present invention is applied to the substrate heating apparatus and the substrate heating method.

Claims

The scope of the claims

[1] Processing container (4),

A substrate mounting portion (31) provided in the processing container (4) and coated with a chemically amplified resist, on which a substrate before exposure and before image formation is mounted;

A heating unit (32) for heating the substrate placed on the substrate placement unit; a vaporization unit (61, 62, 64, 67) for vaporizing water;

A carrier gas supply path (68) for supplying a carrier gas to the vaporization section (61, 62, 64, 67);

A gas supply path (65) for supplying a processing gas containing water vapor obtained by supplying the carrier gas to the vaporization section (61, 62, 64, 67) into the processing container (4);

After the substrate is placed on the substrate platform (31) and the inside of the processing container (4) reaches a temperature higher than the dew point temperature of the processing gas, the processing gas is supplied to the processing container (4). A substrate heating apparatus comprising a control unit (100) for supplying the inside.

[2] The vaporizer (61, 62, 64, 67) contains water (60c) for containing water and publishing the carrier gas, and a unit (64a) for heating the water in the container (64c). The substrate heating apparatus according to claim 1, comprising:

[3] The control unit (100) may be based on an elapsed time after the substrate is placed on the substrate placement unit (31) or based on a temperature detection value in the processing container (4). The substrate heating apparatus according to claim 1, wherein it is determined that the inside of the processing container (4) has reached a temperature higher than a dew point temperature of the processing gas.

4. The substrate heating apparatus according to claim 1, wherein the exposure is an electron beam exposure in which a pattern is drawn on the surface of the substrate with a low acceleration electron beam.

[5] The substrate heating apparatus according to [1], further comprising a pressurizing unit (47, 69) for pressurizing the inside of the processing container (4).

[6] An exhaust unit (48) for exhausting the inside of the processing vessel (4) is further provided,

The substrate according to claim 1, wherein the control unit (100) outputs a control signal for carrying the substrate out of the processing container (4) after the processing gas is exhausted by the exhaust unit. Heating device.

[7] A carrier station (90) into which a substrate carrier (C1) containing a plurality of substrates is loaded and a substrate carrier (C1) loaded into the carrier station (90) for delivering the substrate. A carrier stage (B1) including a unit (A1),

A coating unit (COT) for applying a resist to the substrate delivered from the delivery unit (A1);

A development unit (DEV) for developing the substrate after exposure;

An interface unit (B3) for transferring the substrate before exposure to an exposure apparatus (B4) and receiving the substrate after exposure with the exposure apparatus (B4) force;

A coating / developing device comprising the substrate heating device (2) according to claim 1.

[8] A substrate heating method in which a chemically amplified resist is applied and a substrate before exposure and before development is heated.

Placing the substrate on the substrate placement portion (31) in the processing container (4);

A step of evaporating water with a carrier gas to generate a processing gas containing water vapor; And a step of supplying the processing gas into the processing container (4) after the temperature is reached.

9. The substrate heating method according to claim 8, wherein the exposure is an electron beam exposure in which a pattern is drawn on the surface of the substrate with a low acceleration electron beam.

[10] exhausting the processing gas from the processing container (4);

The substrate heating method according to claim 8, further comprising a step of unloading the substrate out of the processing container (4).