JP2000286190A - Projection aligner, exposure method, and device- manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection aligner and an exposure method for checking exposure quality without developing, even when a substrate with a surface- reflection type photosensitive layer is used, and a device-manufacturing method. SOLUTION: A projection aligner 10 is provided with an atomic force microscope(AFM) for measuring a latent image formed on a wafer W with a surface-reaction type resist subjected to silylation as a photosensitive layer. Then, before actually exposing the pattern of a reticle R onto the wafer W, is the pattern of the reticle R is illuminated with an EUV beam EL to measure a latent image formed on the resist subjected to silylation with the atomic force microscope(AFM).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus and an exposure method, and more particularly, to an exposure apparatus and an exposure method used when a circuit device such as a semiconductor device or a liquid crystal display device is manufactured by a lithography process. The present invention relates to a device manufacturing method.

[0002]

2. Description of the Related Art At present, at a semiconductor device manufacturing site,
The minimum line width is 0.3 using a reduction projection exposure apparatus, a so-called stepper, using i-line of a mercury lamp having a wavelength of 365 nm as illumination light.
Circuit devices of about 0.35 μm (64 M (mega) bit D-RAM and the like) are mass-produced. At the same time, 2
An exposure apparatus for mass-producing a next-generation circuit device having a 56 Mbit, 1 G (giga) bit D-RAM class integration degree and a minimum line width of 0.25 μm or less has been introduced.

As an exposure apparatus for manufacturing the next generation of circuit devices, a wavelength 248 from a KrF excimer laser light source is used.
An ultraviolet pulse laser beam having a wavelength of 193 nm or an ultraviolet pulse laser beam having a wavelength of 193 nm from an ArF excimer laser light source is used as illumination light, and a mask or reticle (hereinafter, collectively referred to as a “reticle”) on which a circuit pattern is drawn and a sensitive substrate By scanning the wafer one-dimensionally relative to the projection field of view of the reduction projection optical system, a scanning exposure operation for transferring the entire reticle circuit pattern into one shot area on the wafer and a stepping operation between shots are repeated. A step-and-scan scanning exposure apparatus has been developed.

There is no doubt that the degree of integration of semiconductor devices will be further increased in the future and will shift from 1 Gbit to 4 Gbit. In that case, the device rule will be about 0.1 μm, that is, about 100 nm L / S. The exposure apparatus using the above-mentioned ultraviolet pulse laser light having a wavelength of 193 nm as illumination light has many technical problems to cope with it.

In response to such a problem, recently, light in a soft X-ray region having a wavelength of 5 to 20 nm (this light is also referred to as "EUV (Extreme Ultra Violet) light" in this specification).
The development of an EUV exposure apparatus that uses light as exposure light has been started, and such an EUV exposure apparatus has a minimum line width of 10 mm.
It is attracting attention as a promising candidate for the next-generation exposure apparatus of 0 nm.

Meanwhile, in a wafer used in an EUV exposure apparatus, there is no material which is transparent at the wavelength of EUV light as a resist applied to the surface thereof. Further, in the case of a photoresist that has been conventionally used in general light exposure, only a very small surface of the resist is exposed, so that a desired resist image cannot be obtained after development. For this reason, in the EUV exposure apparatus, a wafer having a surface reaction (Top Surface Imaging) type resist applied thereto is used.

As such a surface reaction type resist,
For example, there is a silylated resist. As shown in FIG. 5A, in this silylated resist RE, after an image of a reticle is projected and exposed on a wafer W by an exposure apparatus, a silylating agent such as hexamethyldisilazane is diffused on the wafer surface. As shown in FIG. 5C, the portion irradiated with the EUV light is silylated. Thereafter, as shown in FIG. 5D, a desired resist image is formed by etching the silylated portion or a portion other than the silylated portion by dry etching.

[0008]

However, the above-mentioned conventional techniques have the following problems.
That is, it is necessary to perform calibration (adjustment) of the exposure apparatus after the assembly of the exposure apparatus in the exposure apparatus manufacturing factory or after the installation of the exposure apparatus in the semiconductor manufacturing factory. At this time, the pattern is actually exposed by the exposure apparatus, and the exposure result such as focus and exposure amount, and the exposure quality such as aberration of the projection lens and overlay accuracy are checked. At this time, with a conventional general exposure apparatus, the photoresist could be obtained simply by immersing it in a developing solution after exposure and developing the photoresist, so that the check could be easily performed. In contrast, the EU
In the V exposure apparatus, since a silylated resist is used, a resist image cannot be obtained without going through a plurality of steps of exposure, silylation, and dry etching as described above. There is a problem that labor and cost are required.

In addition, when a silylated resist is used, particularly when an exposure apparatus is assembled at an exposure apparatus manufacturing factory, or when a developing apparatus is not yet provided when the exposure apparatus is installed in a semiconductor factory, the development is not performed. Needless to say, it cannot be done. Even if a developing device is present in the factory, unless the developing device is integrated with the exposure device, the pattern must be exposed by the exposure device and then transported to a location away from the exposure device for development. It is impractical to carry out development because the vacuum must be maintained during transport.

The above-mentioned problem is common not only to a silylated resist but also to a wafer using a resist having a plurality of layers of the same surface reaction type, for example, two or three layers.

Due to the above-mentioned problems, it takes a lot of time to start up the exposure apparatus, and as a result, there is also a problem that it takes time to manufacture devices. The present invention has been made in view of the above points, and even when a substrate having a surface reaction type photosensitive layer is used, an exposure apparatus capable of checking exposure quality without performing development. An object of the present invention is to provide an exposure method and an exposure method, and a device manufacturing method capable of accelerating device manufacturing by applying the exposure apparatus and the exposure method.

[0012]

The invention according to claim 1 is
An exposure apparatus (10) for illuminating a pattern formed on a mask (R) with exposure light (EL) and transferring the pattern onto a substrate (W) coated with a photosensitive layer (RE), wherein the photosensitive layer (RE) is provided. )
Is a surface reaction type, and is provided with a measurement unit (AFM) for measuring a latent image (S) formed on the photosensitive layer (RE) by illumination of the exposure light (EL). I have.

According to a seventh aspect of the present invention, the pattern formed on the mask (R) is illuminated with exposure light (EL) and transferred onto the substrate (W) coated with the surface-reactive photosensitive layer (RE). Prior to exposing the pattern on the substrate (W), the pattern is illuminated with exposure light (EL) to form a latent image (S) formed on the photosensitive layer (RE). ) Is measured by measuring means (AFM).

According to such an exposure apparatus (10) and an exposure method, the latent image (S) formed on the surface reaction type photosensitive layer (RE) by irradiating the pattern with the exposure light (EL) is used. The image can be checked without developing the substrate (W) by measuring with the measuring means (AFM).

A device manufacturing method according to a ninth aspect includes a step of transferring a device pattern onto a photosensitive substrate (W) using the exposure apparatus (10) according to any one of the first to sixth aspects. Features.

A device manufacturing method according to a tenth aspect is characterized by including a step of transferring a device pattern onto a photosensitive substrate (W) by using the exposure method according to the seventh or eighth aspect.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an exposure apparatus, an exposure method, and a device manufacturing method according to the present invention will be described below with reference to FIGS.

FIG. 1 shows an exposure apparatus 1 according to this embodiment.
0 is schematically shown. This exposure apparatus 1
0 is a soft X-ray region having a wavelength of 5 to 20 nm as exposure light, for example, light having a wavelength of 13.4 nm or 11.5 nm.
This is a projection exposure apparatus that performs an exposure operation by a step-and-scan method using UV light EL. In this embodiment,
As described later, a reticle (mask) R as a mask
Optical system PO for projecting the reflected light flux from the wafer perpendicularly onto the wafer (substrate, photosensitive substrate) W is used. Hereinafter, EU from the projection optical system PO to the wafer W will be described.
The projection direction of the V light EL is referred to as the optical axis direction of the projection optical system PO, the optical axis direction is the Z axis direction, and the direction in the plane of FIG. It is assumed that the direction of the movement is the X-axis direction.

The exposure apparatus 10 projects a partial image of a circuit pattern drawn on a reflective reticle R as a mask onto a wafer W as a substrate through a projection optical system PO, and Is scanned relative to the projection optical system PO in a one-dimensional direction (here, the Y-axis direction), so that the entire circuit pattern of the reticle R is transferred to the wafer W.
The image is transferred to each of the plurality of upper shot areas by a step-and-scan method. Here, as shown in FIG. 5A, the wafer W has a photosensitive layer on the surface thereof.
It is assumed that a surface reaction type resist, for example, a silylated resist RE is applied.

As shown in FIG. 1, the exposure apparatus 10 is a light source apparatus for horizontally emitting EUV light EL having a wavelength of 5 to 20 nm, more specifically, 13.4 nm or 11.5 nm along the Y direction. 12, the EUV light EL from the light source device 12 is reflected and a predetermined incident angle θ (θ is about 50 m in this case)
fold) so as to be incident on the pattern surface of the reticle R (the lower surface in FIG. 1).
(A part of the illumination optical system), a reticle stage (stage system) RST for holding the reticle R, and reflection optics for projecting the EUV light EL reflected on the pattern surface of the reticle R perpendicular to the surface to be exposed of the wafer W. Optical system PO, a wafer stage (stage system) WST holding a wafer W, and focus sensors (14a, 14a).
b) and an alignment optical system ALG.

The light source device 12 irradiates a high power laser such as a YAG laser or an excimer laser excited by a semiconductor laser onto an EUV light generating material such as a copper tape to excite the EUV light generating material into a plasma state. This is a laser plasma light source that emits EUV light EL emitted at the time of transition to a low potential state so as to be formed into a slit on the reticle R in a predetermined direction. In addition, the light source device 12 is not limited to the tape target,
A gas jet target or the like may be used, and an SOR may be used instead of a laser plasma light source.

The reticle stage RST is driven by a predetermined stroke in the Y direction by an actuator (not shown), and is also driven in a small amount in the X direction and the θ direction (rotation direction around the Z axis). Then, reticle R is held by suction on a reticle holder (not shown) of reticle stage RST by an electrostatic chuck method.

The reticle stage RST includes a reticle R
Blinds 42 (below the EUV light incident side)
And a slit plate 44 as a field stop for defining the EUV light EL emitted from the light source device 12 so as to form an arc-shaped illumination area on the reticle R.

On the surface (pattern surface) of the reticle R held on the reticle stage RST, a reflection film for reflecting EUV light is formed. This reflection film is, for example, a multilayer film in which two kinds of substances are alternately laminated. Here, a wavelength of 13.4 is used using a multilayer film of molybdenum Mo and silicon Si.
A reflective film having a reflectivity of about 70% for EUV light of nm is formed. A material that absorbs EUV light is applied on one surface of the reflective film, and patterning is performed.

FIG. 2 shows an example of the reticle R. The rectangular area at the center in the figure is the pattern area PA.
It is. The hatched arc-shaped area is the exposure light E
This is an arc-shaped illumination area IA irradiated with UV light EL. Here, the reason why the exposure is performed using the arc-shaped illumination region is that only the region where the various aberrations of the projection optical system PO are the smallest can be used. Reticle alignment marks RM1 to RM6 as alignment marks are formed at predetermined intervals along the Y direction at both ends in the X direction of the pattern area PA of the reticle R. Reticle alignment marks RM1 and RM4, RM2 and RM5, RM3 and R
M6 are respectively arranged substantially along the X direction.

As described above, since the reflective layer is formed on the surface of the reticle R, the material of the reticle R itself does not matter. As the material of the reticle R, for example, low expansion glass, quartz glass (including, for example, Zerodur (trade name) of Schott, ULE (trade name) of Corning, fluorine-doped quartz, etc.), ceramics, and silicon wafer are considered. Can be As a criterion for selecting this material,
For example, the same material as the material of the reticle holder (not shown) may be used as the material of the reticle R. In such a case, thermal expansion occurs in the reticle R and the reticle holder due to a temperature rise due to irradiation of the EUV light EL for exposure or the like, but if both materials are the same, they expand by the same amount. There is a merit that a force (thermal stress) that tries to shift does not work. However, the same effect can be obtained by using different materials having the same linear expansion coefficient as the material of the reticle R and the reticle holder. For example, it is conceivable to use a silicon wafer for the reticle R and SiC (silicon carbide) for the reticle holder.
When a silicon wafer is used as the material of the reticle R, there is also an advantage that a processing device such as a pattern drawing device, a resist coating device, and an etching device can be used as it is. In this embodiment, for this reason, a silicon wafer is used as the material of the reticle R, and the reticle holder is formed of SiC.

Returning to FIG. 1, the projection optical system PO comprises only a plurality of, for example, about three to six, reflective optical elements (mirrors), and a reflective optical system in which only the image plane is telecentric is used. Here, a projection magnification of 1/4 is used. Therefore, the EUV light EL including the pattern information reflected on the reticle R and including the pattern information drawn on the reticle R is reduced to one-fourth by the projection optical system PO and irradiated onto the wafer W.

The wafer stage WST is driven by a predetermined stroke in the X and Y directions by an actuator (not shown), and is also driven in a small amount in the θ direction (rotational direction around the Z axis). A wafer holder (not shown) of an electrostatic chuck type is mounted on the upper surface of wafer stage WST, and wafer W is held by suction by the wafer holder.

At one end of the upper surface of wafer stage WST,
An aerial image measuring device FM for measuring a relative position relationship (so-called baseline measurement) of the position where the pattern drawn on the reticle R is projected onto the surface of the wafer W and the alignment optical system ALG is provided. . This aerial image measuring instrument FM corresponds to a reference mark plate of a conventional DUV or VUV exposure apparatus.

FIGS. 3A and 3B show a plan view and a longitudinal sectional view of the aerial image measuring instrument FM, respectively. As shown in these figures, a slit SLT as an opening is formed on the upper surface of the aerial image measuring instrument FM. The slit SLT is patterned on the EUV light reflecting layer 64 formed on the surface of the fluorescent substance 63 having a predetermined thickness fixed on the upper surface of the wafer stage WST. Note that an EUV light absorption layer may be provided instead of the reflection layer 64, and an opening may be formed in this absorption layer.

An opening 66 is formed in the upper surface plate of the wafer stage WST below the slit SLT. Inside the wafer stage WST opposed to the opening 66, a photoelectric conversion element PM such as a photomultiplier is provided. Are located. Therefore, when the aerial image measuring device FM is irradiated with the EUV light EL from above through the projection optical system PO, the EUV light transmitted through the slit SLT reaches the fluorescent substance 63, and the fluorescent substance 63 It emits light with a longer wavelength than. This light is received by the photoelectric conversion element PM and converted into an electric signal corresponding to the intensity of the light. The output signal of the photoelectric conversion element PM is supplied to a control device (not shown).

Further, in exposure apparatus 10 shown in FIG. 1, reticle stage RST and wafer stage W with respect to projection optical system PO are moved by an interferometer system (not shown).
The position and rotation angle of the ST in the XY plane, the position of the reticle R in the Z direction, and the like are measured, and based on the measurement results,
The attitude control of reticle stage RST and wafer stage WST is automatically performed by a control device (not shown).

On the other hand, as shown in FIG. 1, the position of the wafer W in the Z direction with respect to the projection optical system PO is determined by the oblique incident light type focus sensor 14 fixed to the projection optical system PO.
Is to be measured by The focus sensor 14 is fixed to a column (not shown) that holds the lens barrel PP, and detects the detection beam FB from an oblique direction with respect to the wafer W surface.
, And a light receiving system 14b similarly fixed to a column (not shown) and receiving the detection beam FB reflected on the surface of the wafer W. As this focus sensor, for example, a multipoint focal position detection system disclosed in Japanese Patent Application Laid-Open No. 6-283403 or the like is used. The focus sensor 14 (14a, 14b)
The distance between the surface of the wafer W and the projection optical system PO and the inclination with respect to the XY plane are measured, and the wafer stage WST is controlled by the control device ( (Not shown).

Further, in this embodiment, the projection optical system PO
The alignment optical system ALG is fixed to a side surface of the optical disk. The alignment optical system ALG includes, for example, an atomic force microscope (measurement unit) AFM.

As shown in FIG. 4, the atomic force microscope AFM
Has a probe (probe) 70, which can be moved in a direction perpendicular to the wafer W by a driving device (not shown), the amount of movement is converted into an electric signal, and the control device ( (Not shown). The driving device (the probe 70) operates until the distance between the probe 70 and the surface of the wafer W becomes a predetermined value (a distance that generates a repulsive force (interatomic force) between atoms at the tip of the probe 70 and atoms on the wafer W). (Not shown), the wafer W
The wafer W can freely move in a direction perpendicular to the surface of the wafer W by a repulsive force with the upper atom.

In this atomic force microscope AFM, when the wafer stage WST is relatively scanned with the probe 70 in a state where the probe 70 is close to the minute distance on the wafer W, a portion on the wafer W having a step The probe 70 moves in a direction perpendicular to the wafer W so that the repulsive force between the probe W and the wafer W becomes constant, and measures the surface of the wafer W by outputting the amount of movement. The probe 70 is moved to a position at a minute distance from the wafer W only at the time of measurement, and retreats to a position separated from the wafer W when measurement is not performed.

Next, an exposure method using the exposure apparatus 10 according to the present embodiment configured as described above will be described.

In this exposure method, the calibration of the exposure apparatus 10 is performed prior to the main exposure, for example, after assembling the exposure apparatus 10 in an exposure apparatus manufacturing factory or after installing the exposure apparatus 10 in a semiconductor manufacturing factory. In this case, the baseline amount is measured first. For this, first, the reticle R is transported by a reticle transport system (not shown), and is attracted and held by the reticle holder of the reticle stage RST. Next, the positions of wafer stage WST and reticle stage RST are controlled, and reticle alignment marks RM1, RM4, RM2, RM5, RM drawn on reticle R are controlled.
3 and RM6 are sequentially irradiated with two EUV lights EL, respectively, and the reticle alignment marks RM1, RM4, RM
The projection position of the reticle pattern image on the wafer W surface is determined by detecting the projected image of the RM 5, 2, RM3, and RM6 on the wafer W surface by the aerial image measuring device FM. That is, reticle alignment is performed.

Next, the slit SLT of the aerial image measuring instrument FM
Is moved so that is positioned immediately below alignment optical system ALG, and alignment optical system AL is moved.
Based on a detection signal obtained by detecting the slit SLT by G and a measurement value of an interferometer system (not shown) at that time, an image forming position of a pattern image of the reticle R on the surface of the wafer W and an alignment optics indirectly. The relative position of the system ALG, that is, the baseline amount is obtained.

After obtaining the baseline amount, a baseline error is measured using an atomic force microscope AFM. For this purpose, the exposure is performed such that the pattern or alignment mark on the reticle R has a predetermined positional relationship with the alignment mark provided in advance on the wafer W. For example, the alignment mark is detected by the alignment optical system ALG, the position (coordinate value on the orthogonal coordinate system XY) is obtained, and the wafer W is moved based on the position and the previously measured baseline amount. At this time, since the exposure shot uses a region on the wafer W that is not used for manufacturing semiconductor circuits, the wafer W is moved by giving an offset between the region and the alignment mark whose position has been determined earlier.

By performing the exposure as described above, FIG.
As shown in (b), the silylation resist RE of the wafer W is used.
A latent image S of the pattern on the reticle R is formed.
By forming the latent image S, a slight step is formed on the surface of the silylated resist RE.

Next, while the movement of the wafer stage WST is monitored by an interferometer system (not shown), the step of the latent image S on the wafer W is detected by the atomic force microscope AFM. Then, the position of the latent image S (that is, the coordinate value on the orthogonal coordinate system XY defined by the interferometer system) is detected based on the detection results of both the atomic force microscope AFM and the interferometer system. Next, the difference between the position of the latent image S and the position of the previously detected alignment mark is determined. Here, if the baseline error is zero, the difference should correspond to the interval given as an offset prior to the exposure. Therefore, in the present embodiment, a deviation between the difference (actually measured value) and the interval (design value) is obtained as a baseline error. In performing the measurement of the baseline error, exposure is performed on a plurality of shots, a baseline error is detected for each shot, and, for example, the average value is stored as the baseline error. It is desirable to average the measurement error of the latent image S due to. Alternatively, one latent image S may be detected a plurality of times, and the position obtained for each detection may be averaged to determine the position of the latent image S. Further, for example, a line and space pattern on a reticle may be transferred to a resist, a position may be detected by a plurality of lines in the latent image, and the position of the latent image may be determined from the plurality of positions.
The formation of a latent image in a plurality of shots, the detection of a latent image a plurality of times, and the formation of a multi-mark of a latent image may be used alone or in combination of two or more.

Then, a base line error is added to the base line amount, alignment is performed using the base line amount as a new base line amount, and main exposure is performed.

In the atomic force microscope AFM, in addition to the baseline error, the best focus position, the optimum exposure amount,
It is possible to obtain the magnification, aberration, and the like of the projection optical system PO.

In order to determine the best focus position of the projection optical system PO, for example, the optical axis direction (Z
The pattern on the reticle R is transferred to the resist while positioning the wafer W at a plurality of positions different from each other in the axial direction). Then, the plurality of latent images S formed on the wafer W are respectively detected by the atomic force microscope AFM to determine the line width thereof, and the line width becomes the narrowest (in other words, the line width of the pattern is reduced). The position of the wafer W in the Z-axis direction when the latent image S (closest to the line width conversion value on the wafer) is formed is determined as the best focus position. At this time, the depth of focus of the projection optical system PO can also be obtained from the line width of the latent image S formed before and after the best focus position. If a pattern is formed at each of a plurality of points on the reticle R, the latent images S of the plurality of patterns are formed.
Is detected, the curvature of field of the projection optical system PO can be obtained. Furthermore, if the pattern on the reticle R is two sets of line and space patterns arranged in the sagittal direction and the meridional direction, the astigmatism of the projection optical system PO can be obtained.

Further, in order to obtain the optimum exposure amount, the pattern on the reticle R is transferred to a resist while changing the exposure amount, and the formed latent images S are respectively detected by an atomic force microscope AFM. Then, the line width is determined, and the exposure amount when the latent image S having the line width closest to the design value is formed is determined as the optimum exposure amount. Further, a pattern is formed at each of a plurality of points on the reticle R, and the plurality of patterns are transferred to a resist. Then, the magnification and distortion of the projection optical system PO can be obtained by detecting the positions of the plurality of formed latent images S and calculating the mutual distance therebetween.

In the above description, the baseline error (alignment error in a broad sense), the optimum exposure amount, and the optical characteristics (focus position, magnification, aberration, etc.) of the projection optical system PO are measured. The present invention is not limited to these, and can be applied to all measurements in which latent image detection is performed (for example, measurement of a stepping error of wafer stage WST). Further, the pattern on the reticle R to be transferred to the wafer W (resist) is not limited to a line pattern or a line-and-space pattern, but may have any shape, number, etc., for example, using a wedge-shaped pattern. Is also good. Furthermore, a pattern dedicated to measurement may be formed on the reticle R, or an alignment mark formed on the reticle R or a part of a device pattern may be used.

In the above-described exposure apparatus 10 and exposure method, the exposure apparatus 10 is provided with a surface-reactive silylated resist R
In order to measure a latent image S formed on the wafer W having E as a photosensitive layer, an atomic force microscope AFM was provided. Then, for example, after assembling the exposure apparatus 10 in an exposure apparatus manufacturing factory, after installing the exposure apparatus 10 in a semiconductor manufacturing factory, or the like, the exposure apparatus prior to the main exposure of the pattern of the reticle R onto the wafer W is performed. In performing the calibration of No. 10, the latent image S formed on the silylated resist RE by illuminating the pattern of the reticle R with the EUV light EL is measured by the atomic force microscope AFM. Thus, the wafer W can be developed without developing the wafer W.
The upper image can be checked, and for example, a baseline error, a best focus, an optimum exposure amount, and the like can be obtained. Therefore, the calibration of the exposure apparatus 10 can be performed without developing the wafer W, and the time and cost required for the calibration can be significantly reduced. Since the exposure apparatus 10 uses the EUV light EL as the exposure light and uses the silylated resist RE as the photosensitive layer of the wafer W, development is easily performed as in the case where a conventional photoresist is used. The effect is therefore significant. In addition, since the latent image S is formed substantially equal to the pattern actually formed on the wafer W, extremely accurate measurement can be performed.

In addition, as described above, the device is manufactured by transferring the pattern (device pattern) of the reticle R onto the wafer W using the exposure apparatus 10 and the exposure method in which the rise after installation is performed quickly. As a result, a device having a predetermined quality can be manufactured at an early stage.

In the above-described embodiment, the silylated resist RE is used as an example of the surface-reactive photosensitive layer. However, the surface-reactive photosensitive layer in the present invention may be a multiple-layer resist such as a two-layer resist or a three-layer resist. Also includes a layer resist.

In the above embodiment, the exposure apparatus 10
Has been described in the case where no developing device is provided, but the exposure device 10 installed at a production site such as a semiconductor manufacturing factory is provided with a developing device (for example, in-line with a coater / developer is performed). ing)
The present invention can be applied to such cases. Again,
By checking the latent image S without developing the wafer W and performing calibration, quality check, adjustment, and the like, the throughput of the entire manufacturing process can be improved. Of course, if the latent image S can be conveyed to the developing device while maintaining the vacuum state after the measurement, the image of the wafer W can be formed through the silylation → etching process.

Further, although the atomic force microscope AFM was used as a means for measuring the latent image S, a probe type microscope other than the atomic force microscope may be used, or a non-conductive material such as a resist having no conductivity may be used. As long as the step of the latent image S can be observed, another means such as a near-field microscope can be used as the measuring means.

In addition, in the above embodiment, the baseline amount is measured by the aerial image measuring device FM. However, the measurement may be performed by using a reference mark formed on a reference member as in the related art.

In addition, for example, a scanning type exposure apparatus has been described as an example of the exposure apparatus 10, but the technology of the present invention can be similarly applied to, for example, a step-and-repeat type exposure apparatus. Further, the projection optical system PO may be any of a total reflection system, a total refraction system, and a catadioptric system, and the magnification may be not only a reduction system but also an equal magnification or an enlargement system. In addition, although the projection optical system PO is telecentric only on the image plane side, an optical system in which both the object plane and the image plane are telecentric may be used. Further, the shape of the visual field of the projection optical system PO may be arbitrary. When the exposure wavelength is 13.4 nm, the numerical aperture of the projection optical system PO is N.P. A. ≧ 0.1, preferably N.I. A. ≧ 0.1
2. When the exposure wavelength is 11.5 nm, A.
≧ 0.8, preferably N.V. A. It is preferred that ≧ 0.1.

The light source used as the exposure light in the exposure apparatus 10 is not limited to the EUV light EL but may be an ArF excimer laser (193 nm) as long as it passes through a projection optical system having at least one reflective optical element. KrF
Excimer laser (248 nm), F ₂ laser (15
7 nm), a harmonic of an Ar ₂ laser, a YAG laser, or a metal vapor laser, or a charged particle beam such as an ion beam. In addition, the type of the exposure apparatus is not limited to those for semiconductor manufacturing, for example, a liquid crystal display element on a square glass plate, or a projection exposure apparatus for a liquid crystal for transferring a device pattern such as a plasma display, or a thin film Magnetic head and image sensor (CC
D) The technique of the present invention can be widely applied to an exposure apparatus for manufacturing a reticle or a mask, and the like.

Other than this, any configuration may be adopted as long as it does not depart from the gist of the present invention, and it goes without saying that the above-described configurations may be selectively combined as appropriate. No.

[0057]

As described above, according to the exposure apparatus of the first aspect, the latent image formed on the surface reaction type photosensitive layer by illuminating the pattern of the mask with the exposure light is measured by the measuring means. , The image can be checked without developing the substrate, and the baseline error, the best focus, the optimum exposure amount, and the like can be obtained. Therefore, even when the exposure apparatus is assembled at the exposure apparatus manufacturing factory, or when the exposure apparatus is installed in the semiconductor factory and the developing apparatus is not yet provided, the calibration of the exposure apparatus is performed without developing the substrate. This makes it possible to greatly reduce the time and cost required for calibration.

According to the exposure apparatus of the second aspect, the mask and the projection optical system are of a reflection type. Also, according to the exposure apparatus of the third aspect, the exposure light is
e The structure is Ultra Violet light. In such an exposure apparatus that uses EUV light as exposure light, since a silylated resist that is a surface-reaction type resist is used for a photosensitive layer, development can be performed easily as in the case of using a conventional photoresist. Therefore, the effect according to claim 1 is very effective.

According to the exposure apparatus of the fourth aspect, the measuring means relatively scans the surface of the photosensitive layer with the probe held so as to keep the distance in the vertical direction constant with respect to the surface of the photosensitive layer. By doing so, the latent image is measured. According to the exposure apparatus of the fifth aspect, an atomic force microscope is specifically used as the measuring means. Thereby, the latent image on the photosensitive layer can be detected with high accuracy, and the above-described effect can be reliably achieved.

According to a sixth aspect of the present invention, the exposure apparatus further includes a stage system for moving the substrate relative to the emitted exposure light in synchronization with the relative movement of the mask relative to the exposure light. It is configured to scan and expose the substrate with light. Thus, the above effects can be obtained in a step-and-scan type exposure apparatus.

According to the exposure method of the present invention, before the pattern is exposed on the substrate, the latent image formed on the surface reaction type photosensitive layer by illuminating the pattern with exposure light is measured by the measuring means. The measurement can be performed to check the image without developing the substrate. Therefore, even when assembling the exposure apparatus in the exposure apparatus manufacturing factory, or when installing the exposure apparatus in the semiconductor factory and the developing apparatus is not yet provided, the calibration of the exposure apparatus can be performed prior to the main exposure. This makes it possible to greatly reduce the time and cost required for calibration.

According to an eighth aspect of the present invention, there is provided an exposure method, wherein the measuring means includes a probe held so as to keep a constant distance in a vertical direction with respect to the surface of the photosensitive layer, for example, an atomic force microscope. By using the method described above, the latent image on the photosensitive layer can be detected with high accuracy, and the above-described effect can be reliably achieved.

According to a ninth aspect of the invention, there is provided a device manufacturing method including a step of transferring a device pattern onto a photosensitive substrate using the exposure apparatus according to any one of the first to sixth aspects. As described above, by manufacturing a device using an exposure apparatus that quickly starts up after installation, a device having a predetermined quality can be manufactured quickly.

According to a tenth aspect of the present invention, there is provided a device including a step of transferring a device pattern onto a photosensitive substrate using the exposure method according to the seventh or eighth aspect. As described above, by manufacturing a device by an exposure method that can quickly start up an exposure apparatus, a device having a predetermined quality can be manufactured at an early stage.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a configuration of an exposure apparatus in an embodiment of an exposure apparatus, an exposure method, and a device manufacturing method according to the present invention.

FIG. 2 is a schematic plan view of a reticle.

FIG. 3A is a plan view showing an aerial image measuring device, and FIG.
FIG. 2 is a side view showing the aerial image measuring device of FIG.

FIG. 4 is an elevation view showing an atomic force microscope provided as a measuring means.

FIG. 5 is a view showing a wafer developing step.

[Explanation of symbols]

Reference Signs List 10 exposure apparatus 70 probe AFM atomic force microscope (measuring means) EL EUV light (exposure light) R reticle (mask) RE silylated resist (photosensitive layer) S latent image RST reticle stage (stage system) W wafer (Substrate, photosensitive substrate) WST Wafer stage (movable body, substrate stage, stage system)

Claims (10)

[Claims] 1. An exposure apparatus for illuminating a pattern formed on a mask with exposure light and transferring the pattern onto a substrate coated with a photosensitive layer, wherein the photosensitive layer is of a surface reaction type, and An exposure apparatus, comprising: a measuring unit for measuring a latent image formed on the photosensitive layer by the illumination of (1). 2. The exposure apparatus according to claim 1, wherein the mask and the projection optical system are of a reflection type. 3. The exposure apparatus according to claim 2, wherein the exposure light is Extreme Ultra Violet light. 4. The measuring means comprises a probe held so as to keep a constant distance in a vertical direction with respect to the surface of the photosensitive layer, and relatively scans the surface of the photosensitive layer with the probe. 4. The exposure apparatus according to claim 1, wherein the exposure apparatus measures the latent image. 5. An exposure apparatus according to claim 4, wherein said measuring means is an atomic force microscope. 6. A stage system for relatively moving the substrate with respect to the exposure light in synchronization with the relative movement of the mask with respect to the exposure light, wherein the substrate is scanned and exposed with the exposure light. The exposure apparatus according to any one of claims 1 to 5, wherein the exposure is performed. 7. An exposure method for illuminating a pattern formed on a mask with exposure light and transferring the pattern onto a substrate coated with a surface-reactive photosensitive layer, wherein the pattern is exposed on the substrate. An exposure method comprising: measuring a latent image formed on the photosensitive layer by illuminating the pattern with exposure light; 8. A measuring device having a probe which is held so as to keep a constant distance in a vertical direction with respect to the surface of the photosensitive layer, wherein the surface of the photosensitive layer is measured by the probe. The exposure method according to claim 7, wherein the latent image is measured by relatively scanning. 9. A device manufacturing method comprising a step of transferring a device pattern onto a photosensitive substrate using the exposure apparatus according to claim 1. Description: 10. A device manufacturing method, comprising a step of transferring a device pattern onto a photosensitive substrate using the exposure method according to claim 7. Description: