WO2006004135A1

WO2006004135A1 - Exposure apparatus and device manufacturing method

Info

Publication number: WO2006004135A1
Application number: PCT/JP2005/012433
Authority: WO
Inventors: Mitsuro Sugita; Takao Yonehara; Takaaki Terashi; Toshihiko Tsuji
Original assignee: Canon Kabushiki Kaisha
Priority date: 2004-06-30
Filing date: 2005-06-29
Publication date: 2006-01-12
Also published as: GB2437887B; JP2006019412A; TW200615709A; GB0715924D0; GB2437887A

Abstract

This invention relates to an exposure apparatus which transfers a pattern of a mask onto a wafer. The exposure apparatus includes a master stage which holds the mask, and a light source which generates light to illuminate the mask. The light source includes a solid state device which emits light by spontaneous emission.

Description

DESCRIPTION

EXPOSURE APPARATUS AND DEVICE MANUFACTURING METHOD

TECHNICAL FIELD

The present invention relates to an exposure apparatus and device manufacturing method and, more particularly, to an exposure apparatus which illuminates a master with light from a light source including a solid stage device which emits light by spontaneous emission to transfer the pattern of the master onto an object, and a device manufacturing method which uses the exposure apparatus.

BACKGROUND ART

Along with the recent development in IT (Information Technology) and the expansion of the market, demands for a manufacturing apparatus which manufactures semiconductor devices, liquid-crystal display devices, and the like increase more and more. A particularly important factor in the manufacture of such devices is an exposure apparatus which is used to form a pattern. Regarding the exposure apparatus, emphases are put not only on the exposure performance but also on the COO (Cost Of Ownership) which supports the price war of the finished products, i.e., the total operation cost of the manufacturing apparatus. For example, a liquid crystal exposure apparatus employs the apparatus configuration of a scanning type projection exposure apparatus or the like which uses a one-to-one mirror optical system. This apparatus will be schematically described with reference to Fig. 8.

Fig. 8 is a schematic view (U.S.P. No. 3,748,015 and Japanese Patent Laid-Open Nos. 61-74337 and 10-189430) of the main part of a conventional scanning type projection exposure apparatus which uses a one-to-one mirror optical system. The projection exposure apparatus shown in Fig. 8 includes a reflection type projection optical system R and illumination system I. The projection optical system R has a concave mirror 40, convex mirror 41, and mirrors 39 and 42. The illumination system I has a mercury lamp light source 21, elliptic mirror 22, shutter 23, first condenser lens 24, wavelength filter 25, integrator 26, stop 27, second condenser lens 28, field stop 29 having an arcuate or fan-shaped aperture, and relay system (stop imaging lens system) including a first relay lens 30, mirror 31, and second relay lens 32. The illumination system I forms an arcuate or fan-shaped illumination region on a mask 38.

This projection exposure apparatus forms a Kδhler's illumination system in which a secondary light source surface formed by the integrator 26 substantially coincides with the front focal point of the second condenser lens 28 and the field stop 29 substantially coincides with the rear focal point of the second condenser lens 28.

The mask 38 is arranged on the object surface of the projection optical system R and moves in synchronism with a wafer 43 arranged on the image surface of the projection optical system R. The mask 38 and wafer 43 are scanned by light within the object surface and image surface, respectively, in the directions of arrows in Fig. 8 to transfer a pattern formed on the mask 38 onto the wafer 43.

The illumination system I is demanded to irradiate the entire good-image area (which normally forms an arcuate or fan shape) on the mask 38 of the projection optical system R evenly and efficiently with a predetermined numerical aperture.

For this purpose, in the conventional illumination system, the integrator uses cylindrical fly-eye lenses. The illumination beams from the respective cylindrical lenses are overlaid on the field stop 29 to temporarily form a rectangular irradiation region free from illuminance variations on the field stop 29. The beams which are transmitted through the arcuate or fan-shaped slit (aperture) formed in the field stop 29 form an image on the mask 38 through the relay system (stop imaging system) including the elements 30 to 32. As a result, desired arcuate or fan-shaped illumination having a uniform illuminance on all the points in the irradiation region is obtained on the mask 38.

As described above, in the conventional illumination apparatus, a mercury lamp is used as the light source. The employed mercury lamp is of a particularly high-output type among mercury lamps called very high pressure mercury lamps, and has a specification with a service life of 500 hrs to 1,500 hrs and required power (power consumption) of 1 kW to 10 kW.

The conventional illumination apparatus described above which uses the mercury lamp has the following problems. First, the efficiency is as low as about 10%, and accordingly the required power and heat generation are large. High power consumption poses a major problem in the entire manufacturing factory. As the heat generation is large, a large-scale heat dissipation mechanism must be built into the exposure apparatus, leading to a large apparatus size. When the size of the exposure apparatus increases, the cost for ensuring the space for the factory increases, which poses a problem. Second, the mercury lamp has a short service life as a light source for the projection exposure apparatus. For example, a liquid crystal display device manufacturing factory usually operates 24 hrs. Because a mercury lamp takes time until it is stabilized, during operation of the exposure apparatus, the mercury lamp is constantly kept on. Therefore, the mercury lamp must be exchanged several times a year, leading to an increase in cost of the mercury lamp. Moreover, every time the mercury lamp is to be exchanged or the projection exposure apparatus is to be adjusted after the mercury lamp is exchanged, the projection exposure apparatus must be stopped. This leads to a high downtime cost.

Third, mercury which is used in the mercury lamp is a harmful material. This accompanies cost in disposal and recycling, and risks such as contamination when the mercury lamp is broken.

As described above, when the mercury lamp is used as the illumination light source for the projection exposure apparatus, a plurality of problems arise.

In recent years, an attempt to use a laser source as an exposure light source has been put into practice, and an exposure light source using a laser source is used particularly in a line which manufactures devices having a very high integration density and very small feature size. In the exposure apparatus which uses the laser source, the light source has high coherence. To avoid an unwanted interference pattern (speckles) caused by the high coherence, an incoherent means (Japanese Patent Registration No. 02569711) must be built into the exposure apparatus. This increases the number of constituent components as well as the cost.

DISCLOSURE OF INVENTION

The present invention has been made in view of the above problems, and has as its object to provide an exposure apparatus including a light source which has a high light emission efficiency and long service life, and a semiconductor device manufacturing method which uses the exposure apparatus.

According to the first aspect of the present invention, there is provided an exposure apparatus for transferring a pattern of a master onto an object, characterized by comprising a holding unit which holds the master, and a light source which generates light to illuminate the master, wherein the light source includes a solid state device which emits light by spontaneous emission.

According to the second aspect of the present invention, there is provided a device manufacturing method characterized by comprising a step of transferring a pattern onto a substrate by using the exposure apparatus described above, and a step of developing the substrate onto which the pattern has been transferred. Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

Figs. IA and IB are schematic views showing an exposure apparatus according to the first preferred embodiment of the present invention;

Figs. 2A and 2B are schematic views showing a light source according to the first preferred embodiment of the present invention; Figs. 3A and 3B are views exemplifying another structure of the light source according to the first preferred embodiment of the present invention;

Figs. 4A to 4D are schematic views each showing a lighting region and non-lighting region of an LED array, which are obtained when illumination conditions are changed, according to the first preferred embodiment of the present invention; Figs. 5A and 5B are schematic views showing the relationship between a light distribution NFP of LED devices and an illuminance distribution FFP on an irradiation surface in the first preferred embodiment of the present invention;

Figs. 6A and 6B are schematic views showing an exposure apparatus according to the second preferred embodiment of the present invention;

Figs. 7A and 7B are schematic views showing an exposure apparatus according to another embodiment;

Fig. 8 is a schematic view showing an example of a conventional exposure apparatus;

Figs. 9A and 9B are schematic views showing an example of another structure of the light source according to the first preferred embodiment of the present invention;

Figs. 1OA and 1OB are schematic views showing the structure of an exposure apparatus according to still another embodiment; Fig. 11 is a schematic view showing the structure of a device light source according to still another embodiment;

Figs. 12A to 12C are schematic views showing an example of the structure of an LED surface light source according to still another embodiment; and

Fig. 13 is a flowchart showing the flow of an entire semiconductor device manufacturing process. BEST MODE FOR CARRYING OUT THE INVENTION [First Embodiment]

An exposure apparatus according to a preferred embodiment of the present invention will be described with reference to Figs. IA and IB. The exposure apparatus according to this embodiment holds a master having a pattern. Light from a light source including a solid stage device which emits light by spontaneous emission illuminates the master to transfer the pattern of the master onto an object such as a substrate. More specifically, this exposure apparatus is suitable to a projection exposure apparatus employing the step & repeat scheme or the scan scheme including the step & scan scheme, with which a pattern on the mask surface is illuminated appropriately to obtain high resolution easily in a process of manufacturing devices such as semiconductor elements. Particularly, this exposure apparatus can be applied to a process of manufacturing devices such as semiconductor devices, e.g., ICs and LSIs, image sensing devices, e.g., CCDs, display devices, e.g., liquid crystal panels, and magnetic heads.

As shown in Fig. IB, the exposure apparatus according to this embodiment includes an illumination system I and scanning type projection exposure system R. The illumination system I has a light source 101, stop 102, condenser lens 103, field stop 104 having an arcuate or fan-shaped aperture, and relay system (stop imaging system) including elements 105 to 107, and forms an arcuate or fan-shaped illumination region on a mask (master) 38. The projection exposure system R has a one-to-one mirror optical system including elements 39 to 42.

The light source 101 has a solid state device which emits light by spontaneous emission. Desirably, a plurality of solid state devices are formed in the light source 101. More desirably, an array of a plurality of solid state devices is arranged in the light source 101. As the solid state devices, light emitting diodes (to be referred to as "LED devices" hereinafter) or EL devices can be used. As the LED devices, LED devices having various types of emission wavelengths, e.g., GaAs, GaAlAs, GaP/GaP, GaAlAs/GaAs, InGaAlP, InGaAlP/GaP, InGaAlP/GaAs, InGaAlP/GaAs, AlInGaN, AlGaN, InGaN, GaN, AlN, ZnO, ZnSe, or diamond can be used. It is more suitable to use LED devices having emission wavelengths suitable to expose a resist, e.g., AlInGaN, AlGaN, or InGaN, although the present invention is not particularly limited to this. As the EL devices, organic EL and inorganic EL can be used. A case will be described hereinafter wherein LED devices are used to form the light source 101. Note that EL devices can be similarly used to form the light source 101 .

The plurality of solid state devices which form the light source 101 are connected to a driving device 100 through wiring lines. The driving device 100 separately drives the plurality of solid state devices which form the light source 101.

A pattern to be transferred onto the substrate is formed on the mask 38. The mask 38 having the pattern is held in the exposure apparatus by a master stage (holding unit) 108. The master stage 108 can drive the held mask 38 to move it in directions of arrows shown in Fig. IB. The exposure apparatus according to this embodiment is formed as a scan exposure apparatus. The mask 38 arranged on the object surface of the projection optical system R moves in synchronism with a wafer (substrate) 43 arranged on the image surface of the projection optical system R. The mask 38 and wafer 43 are scanned by light within the object surface and image surface, respectively, in directions indicated by arrows shown in Fig. IB to transfer the pattern formed on the mask 38 onto the wafer 43. At this time, the illumination system I is demanded to irradiate the entire good image area (which usually forms an arcuate or fan shape) on the mask 38 of the projection optical system R evenly and efficiently with a predetermined numerical aperture.

The beams emitted from the LED devices arranged in the light source 101 to spread with a predetermined light distribution form substantially parallel beams through the condenser lens 103 and are overlaid on the field stop 104. A rectangular irradiation region free from illuminance variations is formed on the surface of the field stop 104. The beams which are transmitted through an arcuate or fan-shaped slit (aperture) formed in the field stop 104 are relayed (that is, focused on the mask) by the relay lens 105, mirror 106, and relay lens 107 included in the relay system to form an image on the mask 38 serving as the irradiation surface. Desired arcuate or fan-shaped light having a uniform illuminance on all the points in the irradiation region illuminates the mask 38. For example, the light source 101 can include two-dimensional parallel arrays of 50 x 50 LED devices. Fig. IA is a front view of the light source 101. As shown in Fig. IA, the light source 101 is desirably circular. Fig. 2A is an enlarged view of the light source 101. As shown in Fig. 2A, the LED devices are arranged parallel to each other to form a circle as a whole. As described above, this embodiment includes the driving device 100 which can turn on/off and switch the light amount adjustment of each of the plurality of LED devices separately. The lighting states of the respective LED devices can be adjusted by the driving device 100 in accordance with the different types of illumination conditions.

The emission wavelength of the LED devices is desirably set in accordance with the sensitivity of the resist as the exposure target. Typically, as shown in Fig. 2B, LED devices having an emission wavelength with a central wavelength of 365 nm and a spectral half width Δ λ of about 10 nm to about 20 nm can be used. When selecting the emission wavelength of the LED devices, LED devices which have optimal emission wavelength and wavelength width may be selected in accordance with the sensitivity curve of the resist regardless of the type of the resist. LED devices having a plurality of central wavelengths may be used. Furthermore, as exemplified in Figs. 3A and 3B, at least two types of LED devices which generate light having different wavelengths may be dispersedly arranged on the light source 101.

In Fig. IB, since the emission wavelength of the LED devices is optimized by making the most of the LED light source, no wavelength filter is necessary.

Alternatively, a wavelength filter may be used when necessary. The wavelength filter may be monolithically formed with each LED device. Resonator LEDs as disclosed in (non-patent reference 1: Science Vol. 265, pp. 943, 1994) may be used. As the LED devices can control lighting and non-lighting directly, a shutter is omitted in Fig. IB. Alternatively, when necessary. a shutter may be used.

Various types of illumination conditions will be described. Figs. 4A to 4D are schematic views showing differences in distribution of a lighting region 401 and non-lighting region 402 of the LED arrays of this embodiment depending on the illumination conditions. Figs. 4A, 4B, 4C, and 4D show large G illumination, small O illumination, annular illumination, and quadrupole illumination, respectively. The distribution of the lighting region 401 and non-lighting region 402 is controlled by the driving device 100 shown in Fig. 1. The lighting region 401 corresponds to a region where solid stage devices which are controlled by the driving device 100 are present. The non-lighting region 402 corresponds to a region where solid stage devices which are not controlled by the driving device 100 are present. According to the advantage of this embodiment, with the LED arrays of this embodiment, the distribution of the lighting region 401 and non-lighting region 402 can be changed instantaneously without exchanging the LED arrays themselves. The above four illumination conditions shown in Figs. 4A to 4D exemplify typical illumination conditions which are generally used in the projection exposure apparatus. However, this embodiment is not limited to these conditions, but can use various types of illumination conditions by changing the distribution of the lighting region 401 and non-lighting region 402 in various manners.

The position distribution (shape) of the lighting region 401 is converted into an angle distribution by the condenser lens 103. More specifically, the position distribution (shape) of the lighting region 401 corresponds to the numerical aperture and the incident angle of the beams which illuminate the mask 38 as the irradiation surface. This is important in the viewpoint of optimization of image forming using partial coherent illumination. For example, oblique incident illumination or the like which is generally known as a high resolution technique can be realized by adjusting the position distribution (shape) of the lighting region 401.

The switching frequency of a current that drives the LED light source can be switched in 1 msec or less by using a frequency on the order of 100 kHz. Therefore, multiple exposure can be realized under different illumination conditions by switching the lighting region 401 in a 1-shot exposure time (e.g., a time within about 1 sec) .

When the LED light source is driven by a pulse current to perform pulse emission, a high output can be obtained. With pulse driving, the LED devices radiate heat efficiently, so that a larger average current and average power can be supplied to the LED power source. When the repetition frequency is sufficiently high as compared to the exposure time of the exposure apparatus, the resist can be exposed in the same manner as with continuous light. Regarding the typical value of the repetition frequency, for example, when the exposure time is about 0.1 sec and the repetition frequency is 100 kHz (i.e., a period of 10 Msec), the repetition time to the exposure time becomes as very short as 1/10⁴, so that the discreteness is sufficiently negligible. When this high-speed repetition operation is employed, the exposure amount can be adjusted by adjusting the number of pulses.

As shown in Fig. 5A, an exit angle dependency (light distribution) 51 of a light output from each LED device corresponds to an illuminance distribution

(position distribution) 52 on the field aperture and irradiation surface. In the one-to-one mirror system as the projection exposure system of this embodiment, to focus the illumination on an arcuate slit region 53, as shown in Fig. 5B, the respective LED devices are formed such that the vertical and horizontal widening angles (light distribution) 51' of the light outputs of the LED devices are different, so that a rectangular FFP (Far Field Pattern) 52 can be formed. Then, the transmission efficiency of the beams which are transmitted through the arcuate slit region 53 formed in the field stop 104 can be increased. To realize an LED device having such a light distribution, for example, the space mode of the light emitted from the LED device by spontaneous emission may be mode-controlled to change the distribution of the spontaneous emission light. Alternatively, the space mode of the emitted light may be directly controlled by an LED integral with a resonator in accordance with spontaneous emission control or the like which uses a resonator QED effect described in non-patent reference 1 described above, to change the distribution of the spontaneous emission light.

At least two or more types of a plurality of LED devices having different light distributions may be mixed to obtain a desired illuminance distribution (position distribution) on the irradiation surface.

For example, Figs. 9A and 9B show a case wherein three types of LED devices 91 to 93 having different widening angles are prepared and are overlaid on an irradiation surface 90 to obtain a trapezoidal illuminance distribution on an irradiation surface 95 through a lens system 94. Then, a decrease in exposure variations which occurs when scanning exposure is used for switching, as shown in Japanese Patent Registration No. 3316687 (Nikon) and Japanese Patent Laid-Open No. 10-189431 (Canon), can be realized.

As described above, with the structure of the exposure apparatus according to this embodiment, an illumination apparatus which has a smaller number of components than in the prior art and a smaller maintenance load, in terms of exchange of the light source, start-up time, and the like can be obtained. An exposure apparatus having high degrees of freedom in the illumination conditions can be realized without using mercury which is a harmful material. Regarding the power consumption which is a significant factor in the COO performance of the exposure apparatus, lighting can be controlled in an on-demand manner, so that power of about half the conventional power suffices. [Second Embodiment]

Figs. 6A and 6B are views showing an exposure apparatus according to the second preferred embodiment of the present invention. The exposure apparatus according to this embodiment has a structure obtained by adding some functions to the processing device 100 according to the first embodiment. More specifically, in the exposure apparatus according to this embodiment, an optical integrator is added to a light source to further uniform the illuminance.

Fig. 6A is a front view of a light source 101. According to this embodiment, the light source 101 is desirably rectangular, as shown in Fig. 6A. As shown in Fig. 6B, a beam having a predetermined light distribution is emitted by the light source 101 and converted into a parallel beam by a first condenser lens 61. More specifically, the exit surface of the light source 101 is arranged on the front focal plane of the first condenser lens 61. The parallel beam then enters an optical integrator 62 arranged at the rear focal point of the first condenser lens 61. The parallel beam entering the optical integrator 62 is split among the respective element lenses of the optical integrator 62, and the split beams are focused on the second surfaces of the element lenses. The beams emerging from the optical integrator 62 are converted by a second condenser lens 63 into parallel beams to illuminate a field stop 104. The field stop 104 limits the illumination range to a predetermined aperture shape (arcuate shape, fan shape, or the like) . The beams within this illumination range travel through a first relay lens 105, mirror 106, and second relay lens 107, which form a relay system (aperture imaging system), to form an image on a mask 38 serving as an irradiation surface. In this manner, desired arcuate or fan-shaped light having a uniform illuminance on all the points in the irradiation region is obtained on the mask 38.

The exposure apparatus according to this embodiment is formed as a scan exposure apparatus. The mask 38 is arranged on the object surface of a projection optical system R and moves in synchronism with a wafer 43 arranged on the image surface of the projection optical system R. The mask 38 and wafer 43 are scanned by light within the object surface and image surface, respectively, in directions of arrows in Fig. 6B to transfer a pattern formed on the mask 38 onto the wafer 43.

As described above, with the structure of the exposure apparatus of this embodiment, illumination can be performed by exposure light which is emitted from a light source and distributed more uniformly. [Other Embodiments]

The present invention is not limited to the above embodiments, but its sequence and the like can be changed variously as in A or B. For example, as shown in Fig. 1OB, the structure of the second embodiment may be changed, and another structure may be employed. Namely, in place of using the condenser lens 61 (Fig. 6B) between the light source 101 and optical integrator 62, a light source 101 may be arranged directly on the first surface of an optical integrator 62. In this case, the light source 101 is desirably circular, as shown by the front view of Fig. 1OA.

As shown in, e.g.. Fig. 11, the light source 101 may have a lens array structure in which device light sources each formed by a combination of a LED device 1101 and lens 1102 are arranged in arrays. With this structure, using the LED device 1101 which is smaller than the exit area of the device light source, the parallel degree of exit light 1103 emerging from the lens 1102 with respect to the optical axis can be increased.

The light source 101 may have a cooling unit which cools the LED devices 1101. The cooling unit desirably includes a substrate 1104 serving as a supporting unit which supports the LED devices 1101. Desirably, when the substrate 1104 is cooled, the LED devices 1101 are cooled. In this case, as the substrate 1104 on which the LED devices 1101 are to be mounted, a metal plate (e.g., a copper substrate or the like) having good heat radiation performance can be used. The metal plate is desirably arranged on the opposite sides to the light emission surfaces of the LED devices 1101. A cooling device which cools the substrate 1104 directly may be arranged on the substrate 1104. The substrate 1104 is not limited to the metal plate. For example, when necessary, a semiconductor substrate (e.g., a silicon substrate), graphite substrate, or the like may be used by considering its heat emission performance and, e.g., workability.

As shown in Fig. 11, a cooling channel 1105 through which a fluid for cooling the LED devices 1101 flows may be formed in the substrate 1104. In this case, as water cooling is performed at positions close to the LED devices 1101, the cooling effect is enhanced. A cooled fluid is supplied to the cooling channel 1105 from a pipe or the like (not shown) . As the fluid, for example, a cooling solution (e.g., water, pure water, very pure water, or the like) and/or a cooling gas (e.g., an inert gas such as Ar or a gas such as N₂) can be used.

To fill the gaps between the substrate 1104 and lenses 1102, spacers 1106 may be arranged between them. To reflect wide-angle exit light 1108 from the LED devices 1101 in the direction of the optical axis, the substrate 1104 side portions of the lenses 1102 may be cut out in quadrangular prisms and ridge structures 1107 may be arranged along the resultant space. Aluminum films may be formed on the interfaces between the lenses 1102 and ridge structures 1107 so that the interfaces have high reflectance. The ridge structures 1107 may be hollow. In this case, the inclined interfaces serve as reflection surfaces of total reflection or Fresnel reflection in accordance with a difference in refractive index between the lenses 1102 and air. High-reflectance metal films of aluminum, rhodium, silver, or the like may be formed in advance on the inclined surfaces of the lenses 1102.

As the light source, a light source which is formed with a wafer scale, a large-area surface light source formed of a transparent electrode with a wafer scale, or the like can be selected by considering the specification and cost of the exposure apparatus. Figs. 12A to 12C are views schematically showing examples of the structure of an LED surface light source. Pig. 12A shows a light source formed with a wafer scale. As shown in the plan view of Fig. 12A, respective LED devices are formed on LED light emitting portions 1202 on one LED surface light source wafer 1201 by a predetermined device process. Fig. 12B includes a sectional view taken along the line A - A¹ of Fig. 12A. A driving circuit layer 1206 for driving LED devices is formed on a substrate 1207, and the LED devices are formed on the driving circuit layer 1206. Each LED device includes an LED active layer 1203 having a pn junction, isolation/current constriction structure 1204, independent-driving electrodes 1205, and driving IC circuit layer 1206. Fig. 12B shows a wafer having a light source which emits light with its entire surface. As shown in the B - B¹ sectional view of Fig. 12B, an LED active layer 1203' is formed on the entire wafer, and a large-area mesh electrode 1209 is arranged on the surface of the LED active layer 1203" to form an array-shaped surface light source which emits light with its entire surface excluding the mesh electrode 1209. Fig. 12C is a view showing an example of the surface light source in which, in the same manner as in Fig. 12B, an ITO (Indium Tin Oxide) transparent electrode 1210 is formed on a wafer having a surface where an LED active layer 1203' is formed on its entire surface, to emit light with its entire surface. To form the transparent electrode, other materials may be employed. For example, ZnO or the like can be used.

Regarding the projection optical system, although the one-to-one mirror optical system is used in the above embodiments, the present invention is not limited to this. For example, a projection optical system which employs lenses as shown in Fig. 7B, a cata-dioptric system which employs both lenses and mirrors, a proximity exposure system, a near field exposure system, or the like may be appropriately used. In this case, the light source 101 is desirably circular, as shown in Fig. 7A which is a front view of the light source 101.

Regarding the mask, in the above embodiments, a generally employed static mask is used. However, the present invention is not limited to this. An arrangement in which a member serving as a mask that uses a dynamic device such as a MEMS or liquid crystal is illuminated by an illumination apparatus of the present invention to expose the substrate appropriately is also incorporated in the scope of the present invention.

[Application]

A semiconductor device manufacturing process using an exposure apparatus according to a preferred embodiment of the present invention will be described. Fig. 13 is a flowchart showing the flow of the entire semiconductor device manufacturing process. In step 1 (circuit design) , the circuit of a semiconductor device is designed. In step 2 (mask fabrication) , a mask (master) is fabricated on the basis of the designed circuit pattern. In step 3 (wafer manufacture) , a wafer (substrate) is manufactured using a material such as silicon. In step 4 (wafer process) called a preprocess, an actual circuit is formed on the wafer by the exposure apparatus described above in accordance with lithography using the mask and wafer described above. In step 5 (assembly) called a post-process, a semiconductor chip is formed from the wafer fabricated in step 4. This step includes processes such as assembly (dicing and bonding) ad packaging (chip encapsulation). In step 6 (inspection), inspections such as operation check test and durability test of the semiconductor device fabricated in step 5 are performed, a semiconductor device is finished with these steps and shipped in step 7.

The wafer process of step 4 has the following steps, i.e., an oxidation step of oxidizing the wafer surface, a CVD step of forming an insulating film on the wafer surface, an electrode formation step of forming an electrode on the wafer by deposition, an ion implantation step of implanting ions in the wafer, a resist process step of applying a photosensitive agent to the wafer, an exposure step of transferring the circuit pattern by the exposure apparatus described above to the wafer after the resist process step to prepare a substrate having a latent image pattern, a developing step of developing the latent image pattern which is formed on the wafer in the exposure step, an etching step of removing portions other than the resist image developed in the developing step, and a resist removal step of removing any unnecessary resist after etching. These steps are repeated to form multiple circuit patterns on the wafer.

As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the claims.

CLAIM OF PRIORITY

This application claims priority from Japanese Patent Application No. 2004-194231 filed on June 30, 2004, which is hereby incorporated by reference herein.

Claims

1. An exposure apparatus for transferring a pattern of a master onto an object, characterized by comprising: a holding unit which holds the master; and a light source which generates light to illuminate the master, wherein said light source includes a solid state device which emits light by spontaneous emission.

2. The apparatus according to claim 1, wherein said light source includes a cooling unit which cools said solid state device.

3. The apparatus according to claim 2, wherein said cooling unit includes a supporting unit which supports said solid state device, and said cooling unit cools said supporting unit to cool said solid state device.

4. The apparatus according to claim 3, wherein said supporting unit includes a channel through which a fluid for cooing said solid state device flows.

5. The apparatus according to claim 3, wherein said supporting unit includes a metal plate.

6. The apparatus according to claim 5, wherein said metal plate is arranged on an opposite side to a light emission surface of said solid state device.

7. The apparatus according to claim 1, wherein said light source has a plurality of solid state devices, and said plurality of solid state devices are arranged in an array .

8. The apparatus according to claim 7, wherein said plurality of solid state devices include at least two types of solid state devices which have different light distributions.

9. The apparatus according to claim 7, wherein said plurality of solid state devices include at least two types of solid state devices which generate light having different wavelengths.

10. The apparatus according to claim 8, wherein said at least two types of solid state devices are arranged dispersedly.

11. The apparatus according to claim 7, wherein said light source further includes a lens which is arranged on a surface of each of said plurality of solid state devices.

12. The apparatus according to claim 7, further comprising a driving device which drives said plurality of solid state devices separately.

13. The apparatus according to claim 12, wherein said driving device pulse-drives said solid state devices to emit pulsed light beams which are discrete timewise.

14. The apparatus according to claim 13, wherein an output light amount of the pulsed light beam is detected, and the number of pulses is adjusted on the basis of the detected output light amount to control an exposure amount.

15. The apparatus according to claim 1, wherein said solid state device comprises a light emitting diode.

16. The apparatus according to claim 1, wherein said solid state device comprises an EL device.

17. The apparatus, according to claim 1, wherein the apparatus is configured as a scan exposure apparatus.

18. A device manufacturing method characterized by comprising: a step of preparing a substrate on which a latent image pattern is formed by using an exposure apparatus according to claim 1; and a step of developing the latent image pattern.