Exposure system and method of manufacturing electronic devices

Abstract

An exposure system of one aspect of the present disclosure has: a laser device that outputs pulsed laser light; an illumination optical system that guides the pulsed laser light to a reticle; a reticle stage; and a processor that controls the output of the pulsed laser light from the laser device and the movement of the reticle based on the reticle stage. The reticle has a first region configured with a first pattern and a second region configured with a second pattern, the first region and the second region are regions that are continuous in a scanning width direction orthogonal to a scanning direction of the pulsed laser light, respectively, and the first region and the second region are configured side by side in the scanning direction. The processor changes the value of a control parameter of the pulsed laser light according to each of the first region and the second region, and controls the laser device so that it outputs the pulsed laser light corresponding to each of the first region and the second region.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an exposure system and a method of manufacturing electronic devices. BACKGROUND

[0002] In recent years, in a semiconductor exposure apparatus, with miniaturization and high integration of semiconductor integrated circuits, improvement in resolution is required. Therefore, shortening of the wavelength of light emitted from a light source for exposure has been developed. For example, as a gas laser device for exposure, a KrF excimer laser device which outputs laser light having a wavelength of about 248 nm, and an ArF excimer laser device which outputs laser light having a wavelength of about 193 nm are used.

[0003] The spectral line width of the natural oscillation light of the KrF excimer laser device and the ArF excimer laser device is wide, about 350 to 400 pm. Therefore, when a projection lens is configured using a material which transmits ultraviolet rays such as KrF and ArF laser light, chromatic aberration sometimes occurs. As a result, the resolution can be reduced. Therefore, it is necessary to narrow the spectral line width of the laser light output from the gas laser device to the extent that chromatic aberration can be ignored. Therefore, in the laser resonator of the gas laser device, in order to narrow the spectral line width, a line narrow module (LNM) including a narrow band element (etalon, grating, etc.) is sometimes provided. Hereinafter, the gas laser device whose spectral line width is narrowed is referred to as a narrow band gas laser device.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: U.S. Patent Application Publication No. 2015 / 0070673

[0007] Patent Literature 2: U.S. Patent Application Publication No. 2011 / 0205512

[0008] Patent Literature 3: U.S. Patent Application Publication No. 2006 / 0035160

[0009] Patent Literature 4: U.S. Patent Application Publication No. 2003 / 0227607

[0010] Patent Literature 5: U.S. Patent Application Publication No. 2018 / 0196347

[0011] Patent Literature 6: U.S. Patent Application Publication No. 2019 / 0245321

[0012] Patent Literature 7: U.S. Patent Application Publication No. 2004 / 0012844 SUMMARY

[0013] An exposure system of one aspect of the present disclosure irradiates a reticle with pulsed laser light and performs scan exposure on a semiconductor substrate, wherein the exposure system has: a laser device that outputs pulsed laser light; an illumination optical system that guides the pulsed laser light to the reticle; a reticle stage that moves the reticle; and a processor that controls the output of the pulsed laser light from the laser device and the movement of the reticle based on the reticle stage, the reticle having a first region configured with a first pattern and a second region configured with a second pattern, the first region and the second region being regions that are continuous in a scan width direction orthogonal to a scan direction of the pulsed laser light, respectively, the first region and the second region being configured side by side in the scan direction, the processor changing the value of a control parameter of the pulsed laser light according to each of the first region and the second region, and controlling the laser device to output the pulsed laser light corresponding to each of the first region and the second region.

[0014] A manufacturing method of an electronic device of one aspect of the present disclosure includes a step of performing scan exposure on a photosensitive substrate using an exposure system to manufacture an electronic device, the exposure system irradiating a reticle with pulsed laser light, the exposure system having: a laser device that outputs pulsed laser light; an illumination optical system that guides the pulsed laser light to the reticle; a reticle stage that moves the reticle; and a processor that controls the output of the pulsed laser light from the laser device and the movement of the reticle based on the reticle stage, the reticle having a first region configured with a first pattern and a second region configured with a second pattern, the first region and the second region being regions that are continuous in a scan width direction orthogonal to a scan direction of the pulsed laser light, respectively, the first region and the second region being configured side by side in the scan direction, the processor changing the value of a control parameter of the pulsed laser light according to each of the first region and the second region, and controlling the laser device to output the pulsed laser light corresponding to each of the first region and the second region. BRIEF DESCRIPTION OF DRAWINGS

[0015] Hereinafter, several embodiments of the present disclosure will be described as simple examples with reference to the drawings.

[0016] Figure 1 The structure of the exposure system of the comparative example is schematically shown.

[0017] Figure 2 An example of the output mode of the light emission trigger signal transmitted from the exposure control section to the laser control section is shown.

[0018] Figure 3 An example of the exposure mode of the step-and-scan exposure on the wafer is shown.

[0019] Figure 4 The relationship between one scan field on the wafer and the static exposure region is shown.

[0020] Figure 5 is a diagrammatic view of a static exposure area.

[0021] Figure 6 is a diagrammatic view of a scan field in a scan exposure.

[0022] Figure 7 is a plan view schematically showing the relationship between a mask and a scan beam corresponding to the action of the scan exposure shown in Figure 6

[0023] Figure 8 shows a configuration example of a lithography system of Embodiment 1.

[0024] Figure 9 is a diagrammatic view schematically showing a configuration example of a pattern of a mask applied to the lithography system of Embodiment 1.

[0025] Figure 10 shows a configuration example of a laser device.

[0026] Figure 11 shows an example of a trend of a control parameter value of a target laser and a band-shaped mask pattern in the lithography system of Embodiment 1.

[0027] Figure 12 is a flowchart showing an example of a process performed by the lithography control section of Embodiment 1.

[0028] Figure 13 is a conceptual view showing an example of a data structure of a table saved in a file C.

[0029] Figure 14 is a flowchart showing an example of a process performed by the exposure control section of Embodiment 1.

[0030] Figure 15 is a flowchart showing an example of a process performed by the laser control section of Embodiment 1.

[0031] Figure 16 shows an example of a trend of a control parameter value of a target laser and a band-shaped mask pattern in the lithography system of Embodiment 2.

[0032] Figure 17 is a flowchart showing an example of a process performed by the exposure control section of Embodiment 2.

[0033] Figure 18 shows an example of a trend of a control parameter value of a target laser and a band-shaped mask pattern in the lithography system of a modification example of Embodiment 2.

[0034] Figure 19 schematically shows the relationship between a mask pattern applied to the lithography system of Embodiment 3 and a region of a wafer.

[0035] ​Figure 20 is a cross-sectional view schematically showing another example of a cross section of a wafer.

[0036] Figure 21 An example showing a trend of a strip-shaped reticle pattern and a control parameter value of a target laser in the photolithography system of Embodiment 3.

[0037] Figure 22 is a flowchart showing an example of a process executed by the photolithography control section of Embodiment 3.

[0038] Figure 23 is a conceptual diagram showing a data structure of a table saved in file C3.

[0039] Figure 24 is a flowchart showing an example of a process executed by the exposure control section of Embodiment 3.

[0040] Figure 25 An example showing a trend of a strip-shaped reticle pattern and a control parameter value of a target laser in the photolithography system of Embodiment 4.

[0041] Figure 26 is a flowchart showing an example of a process executed by the exposure control section of Embodiment 4.

[0042] Figure 27 Another structural example of a laser device is shown.

[0043] Figure 28 A structural example of a semiconductor laser system is shown.

[0044] Figure 29 is a conceptual diagram of a spectral line width achieved by chirping.

[0045] Figure 30 is a schematic diagram showing a relationship of a current flowing in a semiconductor laser, a wavelength variation based on chirping, a spectral waveform, and light intensity.

[0046] Figure 31 is a graph for explaining a rise time of a semiconductor optical amplifier.

[0047] Figure 32 A structural example of an exposure apparatus is shown schematically. DETAILED DESCRIPTION

[0048] - TABLE OF CONTENTS -

[0049] 1. Explanation of Terms

[0050] 2. Outline of Exposure System of Comparative Example

[0051] 2.1 Structure

[0052] 2.2 Operation

[0053] 2.3 Example of exposure operation on wafer

[0054] 2.4 Relationship between scan field and static exposure area

[0055] 2.5 Subject

[0056] 3. Embodiment 1

[0057] 3.1 Outline of photolithography system

[0058] 3.1.1 Configuration

[0059] 3.1.2 Operation

[0060] 3.2 Example of laser device

[0061] 3.2.1 Configuration

[0062] 3.2.2 Operation

[0063] 3.2.3 Others

[0064] 3.3 Example of trend of mask pattern in strip shape and control parameter value of target laser

[0065] 3.4 Example of processing content of photolithography control section

[0066] 3.5 Example of processing content of exposure control section

[0067] 3.6 Example of processing content of laser control section

[0068] 3.7 Effects

[0069] 3.8 Others

[0070] 4. Embodiment 2

[0071] 4.1 Configuration

[0072] 4.2 Operation

[0073] 4.3 Effects

[0074] 4.4 Modified example

[0075] 5. Embodiment 3

[0076] 5.1 Configuration

[0077] 5.2 Operation

[0078] 5.3 Example of processing content of photolithography control section

[0079] 5.4 Example of processing content of exposure control section

[0080] 5.5 Effects / Advantages

[0081] 5.6 Other

[0082] 6. Embodiment 4

[0083] 6.1 Configuration

[0084] 6.2 Operation

[0085] 6.3 Effects / Advantages

[0086] 7. Example of Excimer Laser Apparatus Using Solid-state Laser Apparatus as Oscillator

[0087] 7.1 Configuration

[0088] 7.2 Operation

[0089] 7.3 Description of Semiconductor Laser System

[0090] 7.3.1 Configuration

[0091] 7.3.2 Operation

[0092] 7.3.3 Other

[0093] 7.4 Effects / Advantages

[0094] 7.5 Other

[0095] 8. Hardware Configuration of Various Control Sections

[0096] 9. Method of Manufacturing Electronic Device

[0097] 10. Other

[0098] Embodiments of the present disclosure will be described below in detail with reference to the accompanying drawings. The embodiments described below show several examples of the present disclosure, and do not limit the scope of the present disclosure. Furthermore, the configuration and operation described in each embodiment are not necessarily all essential to the configuration and operation of the present disclosure. In addition, the same reference numerals are assigned to the same structural elements, and repetitive description is omitted.

[0099] 1. Explanation of Terms

[0100] The terms used in the present disclosure are defined as follows.

[0101] CD (Critical Dimension) refers to the size of a fine pattern formed on a wafer of a semiconductor or the like. In lithography, the CD value of a pattern varies not only depending on the size of the pattern itself but also depending on the patterns located in the periphery. Therefore, for example, the CD after exposure differs in a case where a certain pattern is arranged in isolation on a reticle and in a case where there is a pattern next to it. The degree of variation changes not only depending on the distance, density, kind, and the like between the adjacent other patterns but also depending on the setting of the optical system of the exposure machine used in exposure. This optical proximity effect is referred to as OPE (Optical Proximity Effect). In addition, although not an optical proximity effect, there is a proximity effect in a process such as development at the time of development.

[0102] The OPE curve refers to a graph in which a (pitch) pattern is plotted on the horizontal axis, a CD value is plotted on the vertical axis, or a difference between the CD value and a target CD value is plotted. The OPE curve is also referred to as an OPE characteristic curve.

[0103] OPC (Optical Proximity Correction) refers to the fact that, since the CD value varies depending on the OPE, a bias, an auxiliary pattern is added to a reticle pattern in advance based on exposure experimental data, whereby the CD on a wafer after exposure becomes a target value. In general, OPC is performed at the stage of process development by a device manufacturer.

[0104] As a correction different from OPC, there is also OPE correction. The OPE is also affected by the setting of the optical system (numerical aperture NA of a lens, illumination σ, annular ratio, and the like) used in exposure, and thus, by adjusting the optical system parameters of the exposure machine, adjustment can be made so that the CD value becomes a target. This is referred to as OPE correction. Both OPC and OPE correction can control the CD value, but OPC is mostly performed at the stage of process development including reticle production, and OPE correction is mostly performed after the reticle is produced, at the time of mass production (just before) or in the middle of mass production. In addition, although not an optical proximity effect, there is a proximity effect represented by a micro loading effect in development and the like, and depending on the situation, the CD is sometimes made uniform by adjustment of the optical system together with the optical proximity effect.

[0105] Superposition refers to the superposition of fine patterns formed on a wafer of a semiconductor or the like.

[0106] The spectral line width Δλ is an index value of the spectral line width that affects the exposure performance. The spectral line width Δλ may, for example, be a bandwidth in which the integrated energy of a laser spectrum becomes 95%.

[0107] 2. Outline of exposure system of comparative example

[0108] 2.1 Configuration

[0109] Figure 1 The configuration of the exposure system of the comparative example is schematically shown. The comparative example of the present disclosure is a manner known only to the applicant, not a publicly known example admitted by the applicant himself. The exposure system 10 includes a laser device 12 and an exposure device 14. The laser device 12 is an ArF laser device of a wavelength-variable narrowband oscillation, including a laser control section 20, a laser cavity not shown, and a narrowband module.

[0110] The exposure device 14 includes an exposure control section 40, a beam delivery unit (BDU) 42, a high reflection mirror 43, an illumination optical system 44, a reticle 46, a reticle stage 48, a projection optical system 50, a wafer holder 52, a wafer stage 54, and a focus sensor 58.

[0111] The wafer holder 52 holds a wafer WF. The illumination optical system 44 is an optical system that guides the pulsed laser to the reticle 46. The illumination optical system 44 shapes the laser beam into a scanning beam in which a substantially rectangular light intensity distribution is homogenized. The projection optical system 50 images the reticle pattern on the wafer WF. The focus sensor 58 measures the height of the wafer surface.

[0112] The exposure control section 40 is connected to the reticle stage 48, the wafer stage 54, and the focus sensor 58. In addition, the exposure control section 40 is connected to the laser control section 20. The exposure control section 40 and the laser control section 20 are each configured using a processor not shown, including a storage device such as a memory. The storage device can also be mounted on the processor.

[0113] 2.2 Operation

[0114] The exposure control section 40 controls the movement of the wafer stage 54 in the Z-axis direction in accordance with the height of the wafer WF measured by the focus sensor 58, to correct the focus position in the wafer height direction (Z-axis direction).

[0115] The exposure control section 40 sends the control parameters of the target laser to the laser control section 20 in a step-and-scan manner, controls the reticle stage 48 and the wafer stage 54 while sending a light emission trigger signal Tr, and scans the image of the exposure reticle 46 on the wafer WF. The control parameters of the target laser include, for example, a target wavelength λt and a target pulse energy Et.

[0116] The laser control section 20 controls the selection wavelength of the narrowband module so that the wavelength λ of the pulsed laser light output from the laser device 12 becomes the target wavelength λt, and controls the excitation intensity so that the pulse energy E becomes the target pulse energy Et, and outputs the pulsed laser light in accordance with the light emission trigger signal Tr. Further, the laser control section 20 transmits various measurement data of the pulsed laser light output in accordance with the light emission trigger signal Tr to the exposure control section 40. Among the various measurement data, for example, the wavelength λ and the pulse energy E are included.

[0117] 2.3 Example of exposure operation on a wafer

[0118] Figure 2 An example of the output mode of the light emission trigger signal Tr transmitted from the exposure control section 40 to the laser control section 20 is shown. In the example shown in FIG. 6, after the adjustment oscillation is performed for each wafer WF, the actual exposure mode is entered. That is, the laser device 12 initially performs the adjustment oscillation, and after a prescribed time interval is elapses, burst operation for the first wafer exposure (wafer #1) is performed. Figure 2

[0119] The adjustment oscillation refers to oscillation in which the pulsed laser light for adjustment is output although the pulsed laser light is not irradiated on the wafer WF. With respect to the adjustment oscillation, the oscillation is performed under prescribed conditions until the laser is stabilized in a state in which exposure is possible, and the adjustment oscillation is performed before the batch of wafer production. The pulsed laser light Lp is output at a prescribed frequency of several hundred Hz to several kHz, for example. At the time of wafer exposure, generally, burst operation in which the burst period and the oscillation rest period are repeated is performed. In the adjustment oscillation, too, burst operation is performed.

[0120] In the example shown in FIG. 6, the interval in which the pulses are concentrated is the burst period in which the pulsed laser light is continuously output for a prescribed period. Further, in the example shown in FIG. 6, the interval in which the pulses are not present is the oscillation rest period. In addition, in the adjustment oscillation, the length of each continuous output period of the pulses does not need to be constant, and in order to perform the adjustment, the continuous output operation can be performed with the length of each continuous output period being different. After the adjustment oscillation is performed, a relatively large time interval is elapses, and the first wafer exposure (wafer #1) is performed in the exposure device 14. Figure 2 Figure 2

[0121] The laser device 12 oscillates in the rest in the step in the exposure in the step-and-scan method, and outputs the pulsed laser light in accordance with the interval of the light emission trigger signal Tr in the scan. This mode of laser oscillation is referred to as a burst oscillation mode.

[0122] Figure 3 An example of the exposure mode of the step-and-scan exposure on the wafer WF is shown. Figure 3 ​​​The plurality of rectangular regions shown in the wafer WF are each a scan field. The scan field is an exposure region of the 1st scan exposure, and is also referred to as a scan region. As shown in Figure 3 The wafer WF is divided into a plurality of exposure regions (scan fields) of a prescribed size, and scan exposure is performed on each exposure region during a period between the start (wafer start) and the end (wafer end) of wafer exposure, whereby wafer exposure is performed.

[0123] That is, in wafer exposure, the following steps are repeated: exposure is performed on a 1st prescribed exposure region of the wafer WF by 1st scan exposure (scan #1), and then exposure is performed on a 2nd prescribed exposure region by 2nd scan exposure (scan #2). In 1st scan exposure, a plurality of pulsed laser light Lp (pulse #1, pulse #2,...) can be continuously output from the laser device 12. After the scan exposure (scan #1) of the 1st prescribed exposure region ends, the scan exposure (scan #2) of the 2nd prescribed exposure region is performed with a prescribed time interval. This scan exposure is sequentially repeated, and after the scan exposure of all of the exposure regions of the 1st wafer WF ends, the adjustment oscillation is performed again, and then wafer exposure (wafer #2) of the 2nd wafer WF is performed.

[0124] The step-and-scan exposure is performed in the order of the dashed arrows shown in Figure 3 until the wafer start → scan #1 → scan #2 →... → scan #126 → wafer end. The wafer WF is an example of the "semiconductor substrate" in the present disclosure.

[0125] 2.4 Relationship between scan field and static exposure region

[0126] Figure 4 The relationship between 1 scan field SF and a static exposure region SEA on the wafer WF is shown. The static exposure region SEA is a substantially rectangular substantially uniform beam irradiation region used in scan exposure of the scan field SF. The substantially rectangular substantially uniform scan beam shaped by the illumination optical system 44 is irradiated onto the reticle 46, and the reticle 46 and the wafer WF are moved in the Y-axis direction at different orientations from each other in the Y-axis direction according to the reduction magnification of the projection optical system 50 while exposure is performed. Thus, the reticle pattern is scan-exposed in each scan field SF on the wafer WF. The static exposure region SEA can also be understood as a region that can be uniformly exposed based on the scan beam.

[0127] In Figure 4 , the direction toward the negative side of the Y-axis direction in the longitudinal upward direction is the scan direction, and the direction toward the positive side of the Y-axis direction is the wafer movement direction. The direction of the wafer movement direction is the same as the direction of the wafer conveyance direction. Figure 4A direction (X-axis direction) in which the paper surface is parallel to and orthogonal to the Y-axis direction is referred to as a scanning width direction. The size of the scanning field SF on the wafer WF is, for example, 33 mm in the Y-axis direction and 26 mm in the X-axis direction.

[0128] Figure 5 is an explanatory view of the static exposure region SEA. When the length of the static exposure region SEA in the X-axis direction is Bx and the width in the Y-axis direction is By, Bx corresponds to the size of the scanning field SF in the X-axis direction, and By is much smaller than the size of the scanning field SF in the Y-axis direction. The width By of the static exposure region SEA in the Y-axis direction is referred to as an N gap. The number N of pulses of the resist exposed on the wafer WF SL becomes the following expression.

[0129] N SL = (By / Vy) · f

[0130] Vy: scanning speed in the Y-axis direction of the wafer

[0131] f: repetition frequency of the laser (Hz)

[0132] 2.5 Problem

[0133] Figure 6 is a schematic view of the scanning field SF in the scanning exposure. Figure 7 is a plan view schematically showing the relationship between the mask 46 and the scanning beam SB corresponding to the operation of the scanning exposure shown in Figure 6 is a plan view schematically showing the relationship between the mask 46 and the scanning beam SB corresponding to the operation of the scanning exposure shown in Figure 7 shows an example of the arrangement of the pattern region in the mask 46. In addition, Figure 7 may also be understood as a schematic view showing an example of the pattern of the semiconductor element region within one scanning field SF.

[0134] In the scanning field SF of each wafer WF, for example, there are a region of a semiconductor element for which a high resolution is required and a region of a semiconductor element for which a focus depth is required even if the resolution is low. In the present specification, the region of the semiconductor element for which a relatively high resolution is required within the scanning field SF is referred to as a "high resolution region A", and the region of the semiconductor element for which a focus depth is required even if the resolution is low is referred to as a "low resolution region B". Such a description of the high resolution region A and the low resolution region B is also used for the pattern of the mask 46. Furthermore, the high resolution region A is sometimes simply described as "region A", and the low resolution region B is sometimes simply described as "region B".

[0135] The arrangement of the high resolution region A and the low resolution region B within the scanning field SF depends on the design of the circuit pattern, and typically, as Figure 7As shown, a high-resolution region A and a low-resolution region B are configured in a mixed manner within a uniformly exposed region based on the scanning beam SB.

[0136] The optimal exposure conditions for high-resolution region A and low-resolution region B are different. Therefore, it is preferable to expose each region of high-resolution region A and low-resolution region B under the optimal conditions.

[0137] However, it is difficult to change the exposure conditions (such as wavelength, linewidth, etc.) in a single scan with high speed and precision. Therefore, it is sometimes difficult to perform optimized pulsed laser exposure for the patterned areas of each semiconductor device. Typically, the exposure conditions are changed on a scan field basis, and within one scan field SF, the same exposure conditions are applied to the same areas without distinguishing between regions.

[0138] Furthermore, within the scanning field SF, there is sometimes a step difference in the height direction of the wafer WF. In this case, the wafer stage 54 is tilted significantly during exposure. This can sometimes cause significant adverse effects on overlap. Moreover, when regions with different heights coexist within the scanning field SF, the optimal imaging position of the pulsed laser differs for each region, making it difficult to optimize pulsed laser exposure for each region.

[0139] 3. Implementation Method 1

[0140] 3.1 Overview of the photolithography system

[0141] 3.1.1 Structure

[0142] Figure 8 An example of the structure of the photolithography system 100 of Embodiment 1 is shown. Regarding... Figure 8 The structure shown is for... Figure 1 The differences will be explained. Figure 8 The photolithography system 100 shown is in Figure 1 The structure shown includes an additional photolithography control unit 110, which is configured to add data transmission and reception lines between the photolithography control unit 110 and the exposure control unit 40, and between the photolithography control unit 110 and the laser control unit 20.

[0143] The lithography system 100 includes a laser device 12, an exposure device 14, and a lithography control unit 110. The lithography system 100 is an example of an "exposure system" in this disclosure. In the lithography system 100, a target spectral linewidth Δλt is added as a control parameter for the target laser. Data on the target spectral linewidth Δλt is transmitted from the exposure control unit 40 to the laser control unit 20.

[0144] The lithography control section 110 is configured using a processor not shown. The lithography control section 110 includes a storage device such as a memory. The processor can also include a storage device. The lithography control section 110 is loaded with a program that calculates an exposed resist pattern according to a pure Fourier imaging optical theory.

[0145] Further, the reticle pattern of the reticle 46 used in the lithography system 100 is designed so that a first pattern region configured with a first pattern requiring high resolution and a second pattern region configured with a second pattern requiring a depth of focus are each a region in a band shape that is continuous in a direction orthogonal to a scanning direction. The positions of the regions of the respective patterns are separated in the scanning direction.

[0146] Figure 9 is a schematic view that schematically shows a configuration example of a pattern of the reticle 46 applied to the lithography system 100 of Embodiment 1. The reticle pattern of the reticle 46 is designed so that a high-resolution region A and a low-resolution region B are each configured as a region in a band shape that extends along a direction (X-axis direction) orthogonal to a scanning direction (Y-axis direction). That is, the reticle pattern is divided into regions so that the high-resolution region A and the low-resolution region B are each a region that is continuous in the X-axis direction, and the band-shaped high-resolution region A and the band-shaped low-resolution region B are configured at different positions in the Y-axis direction in a side-by-side manner. The high-resolution region A is a region (first pattern region) configured with a first pattern requiring resolution. The low-resolution region B is a region (second pattern region) configured with a second pattern requiring a depth of focus.

[0147] The first pattern can be, for example, a pattern of a static random access memory (SRAM). The second pattern can be, for example, a pattern of at least one of an isolated pattern, a logic element, and an amplifier. A region in a "band shape" is a region in a shape in which the length of a region in the Y-axis direction (region width) is continuous at a substantially constant width in the X-axis direction. The region in a band shape in the present embodiment is a region in which the length of a region in the X-axis direction is longer than the length of a region in the Y-axis direction. The high-resolution region A is an example of the "first region" in the present disclosure. The low-resolution region B is an example of the "second region" in the present disclosure.

[0148] Figure 9 The reticle face of the reticle 46 shown is divided into 2 x 2 = 4 regions, and each divided region (1 / 4 region) corresponds to one chip. In Figure 9 In the present embodiment, the high-resolution region A of the first divided region DA1 configured at the upper right and the high-resolution region A of the second divided region DA2 configured at the upper left are configured at the same position in the Y-axis direction in a side-by-side manner in the X-axis direction. Further, in the present embodiment, the high-resolution region A of the third divided region DA3 configured at the lower right and the high-resolution region A of the fourth divided region DA4 configured at the lower left are configured at the same position in the Y-axis direction in a side-by-side manner in the X-axis direction. Figure 9In the example shown in FIG. 6, the high-resolution region A of the 3rd divided region DA3 configured in the lower right and the high-resolution region A of the 4th divided region DA4 configured in the lower left are configured in the same position in the Y-axis direction in a side-by-side manner in the X-axis direction. In this way, the high-resolution regions A are collectively configured in a band-shaped region continuous in the X-axis direction in the mask plane.

[0149] In addition, sometimes a low-resolution region B is configured in a very small area between two high-resolution regions A in a side-by-side manner in the X-axis direction and / or outside the X-axis direction boundary (end) of the high-resolution region A, but it is sufficient that the majority of the band-shaped region of the entire X-axis direction length of the mask 46 is occupied by the high-resolution region A. For example, it is preferable that the total of the X-axis direction lengths of the high-resolution regions A along a straight line in the X-axis direction be 50% or more of the X-axis direction length of the mask 46, and further preferably 80% or more. The X-axis direction length of the mask 46 corresponds to the X-axis direction beam width (scanning beam width) of the scanning beam SB.

[0150] Similarly, the low-resolution regions B are collectively configured in a band-shaped region continuous in the X-axis direction in the mask plane. With respect to the band-shaped low-resolution regions B along the X-axis direction, it is preferable that the total of the X-axis direction lengths of the low-resolution regions B along a straight line in the X-axis direction be 50% or more of the X-axis direction length of the mask 46, and further preferably 80% or more. In Figure 9 In the example shown in FIG. 6, the high-resolution region A of the 3rd divided region DA3 configured in the lower right and the high-resolution region A of the 4th divided region DA4 configured in the lower left are configured in the same position in the Y-axis direction in a side-by-side manner in the X-axis direction. In this way, the high-resolution regions A are collectively configured in a band-shaped region continuous in the X-axis direction in the mask plane.

[0151] In summary, the band-shaped high-resolution regions A and the band-shaped low-resolution regions B are configured in different positions in the Y-axis direction, and the band-shaped high-resolution regions A and the band-shaped low-resolution regions B are present in a non-mixed manner (do not mix) in a straight line in the X-axis direction. The notation of the non-mixed manner indicates a state in which the band-shaped high-resolution regions A and the band-shaped low-resolution regions B are not arranged in a superimposed manner in the X-axis direction. In Figure 9 In the example shown in FIG. 6, the high-resolution region A of the 3rd divided region DA3 configured in the lower right and the high-resolution region A of the 4th divided region DA4 configured in the lower left are configured in the same position in the Y-axis direction in a side-by-side manner in the X-axis direction. In this way, the high-resolution regions A are collectively configured in a band-shaped region continuous in the X-axis direction in the mask plane.

[0152] 3.1.2 Action

[0153] The lithography control section 110 calculates the optimum control parameters of the laser light for the band-shaped high-resolution regions A and the band-shaped low-resolution regions B, respectively, by a calculation program, and saves the calculation results in a file C. The control parameters saved in the file C include, for example, the optimum wavelength λb, the optimum spectral width Δλb, and the optimum pulse energy Eb, and the like.

[0154] The lithography control section 110 can also receive data related to the laser device 12 including control parameters of the laser from the laser control section 20 and save it. The lithography control section 110 receives data of the wavelength λ, the spectral linewidth Δλ and the pulse energy E from the laser control section 20 and saves them.

[0155] The exposure control section 40 reads the control parameter values of the laser corresponding to each of the regions A and B within the scan field SF of the wafer WF from the file C of the lithography control section 110.

[0156] The exposure control section 40 transmits the control parameter values of the laser for each pulse at the time of exposure in each of the regions A and B to the laser device 12. The control parameter values transmitted from the exposure control section 40 to the laser device 12 can be, for example, the target wavelength λt, the target spectral linewidth Δλt and the target pulse energy Et, and the like. The subsequent exposure operation is the same as that of the exposure system 10 of Figure 1

[0157] 3.2 Example of laser device

[0158] 3.2.1 Configuration

[0159] Figure 10 The configuration of the laser device 12 is shown. Figure 10 The laser device 12 shown is a narrowband ArF laser device, and includes the laser control section 20, the oscillator 22, the amplifier 24, the monitor module 26 and the shutter 28. The oscillator 22 includes a cavity 60, an output coupling mirror 62, a pulse power module (PPM) 64, a charger 66 and a narrowband module (LNM) 68.

[0160] The cavity 60 includes windows 71, 72, a pair of electrodes 73, 74 and an electrically insulating member 75. The PPM 64 includes a switch 65 and a charging capacitor not shown, and is connected to the electrode 74 via a feed path of the electrically insulating member 75. The electrode 73 is connected to the cavity 60 which is grounded. The charger 66 charges the charging capacitor of the PPM 64 according to an instruction from the laser control section 20.

[0161] The narrowband module 68 and the output coupling mirror 62 constitute an optical resonator. The cavity 60 is arranged in such a manner that a discharge region in which the pair of electrodes 73, 74 is arranged is arranged in an optical path of the resonator. The output coupling mirror 62 is coated with a multilayer film which reflects a part of the laser light generated in the cavity 60 and transmits the other part.

[0162] ​The narrowbanding module 68 includes two prisms 81, 82, a grating 83, and a rotation stage 84 that rotates the prism 82. The narrowbanding module 68 controls the oscillation wavelength of the pulsed laser by rotating the prism 82 using the rotation stage 84, thereby changing the incident angle with respect to the grating 83. The rotation stage 84 can also be a rotation stage including a piezoelectric element that is capable of high-speed response in a manner responsive to each pulse.

[0163] The amplifier 24 includes an optical resonator 90, a cavity 160, a PPM 164, and a charger 166. The cavity 160, the PPM 164, and the charger 166 have the same structures as the corresponding elements of the oscillator 22. The cavity 160 includes windows 171, 172, a pair of electrodes 173, 174, and an electrically insulating member 175. The PPM 164 includes a switch 165 and a charging capacitor not shown.

[0164] The optical resonator 90 is a Fabry-Perot type optical resonator composed of a back mirror 91 and an output coupling mirror 92. The back mirror 91 partially reflects and partially transmits a laser light. The output coupling mirror 92 partially reflects and partially transmits a laser light. The reflectance of the back mirror 91 is, for example, 80% to 90%. The reflectance of the output coupling mirror 92 is, for example, 10% to 30%.

[0165] The monitor module 26 includes beam splitters 181, 182, a spectrum detector 183, and a light sensor 184 that detects the pulse energy of the laser light. The spectrum detector 183 can be, for example, an etalon spectrometer or the like. The light sensor 184 can be, for example, a photodiode or the like.

[0166] 3.2.2 Action

[0167] The laser control section 20 controls the rotation stage 84 of the LNM 68 so that the output wavelength becomes the target wavelength λt, controls the mode described later so that it becomes the target spectral linewidth Δλt, and controls at least the charger 166 of the amplifier 24 so that it becomes the target pulse energy Et after receiving the data of the target wavelength λt, the target spectral linewidth Δλt, and the target pulse energy Et from the exposure control section 40.

[0168] The laser control section 20 imparts a trigger signal to the switch 165 of the PPM 164 and the switch 65 of the PPM 64, respectively, to cause discharge when the pulsed laser light output from the oscillator 22 is incident on the discharge space of the cavity 160 of the amplifier 24 after receiving the light emission trigger signal Tr from the exposure control section 40. As a result, the pulsed laser light output from the oscillator 22 is amplified and oscillated by the amplifier 24. The amplified pulsed laser light is sampled by the beam splitter 181 of the monitor module 26, and the pulse energy E, the wavelength λ, and the spectral linewidth Δλ are measured.

[0169] The laser control section 20 acquires data of the pulse energy E and the wavelength λ measured using the monitor module 26, and controls the charging voltage of the charger 166 and the oscillation wavelength of the oscillator 22 so that the difference between the pulse energy E and the target pulse energy Et, the difference between the wavelength λ and the target wavelength λt, and the difference between the spectral line width Δλ and the target spectral line width Δλt respectively approach 0.

[0170] The laser control section 20 is able to control the pulse energy E, the wavelength λ, and the spectral line width Δλ in a pulse unit. By controlling the delay time Δt of the discharge timing of the cavity 60 of the oscillator 22 and the cavity 160 of the amplifier 24, control of the spectral line width Δλ of the pulsed laser light output from the laser device 12 is possible.

[0171] The pulsed laser light that has passed through the beam splitter 181 of the monitor module 26 is incident on the exposure device 14 via the gate 28.

[0172] 3.2.3 Others

[0173] In Figure 10 , as the optical resonator 90, an example of a Fabry-Perot resonator is shown, but it can also be an amplifier having a ring resonator.

[0174] 3.3 Example of the trend of the control parameter values of the target laser light and the belt-shaped reticle pattern

[0175] Figure 11 The relationship between the control parameter values of the target laser light and the belt-shaped reticle pattern is exemplarily shown. Figure 11 The upper section of FIG. 10 schematically shows the state in which the scan beam SB is scanned and moved in the Y-axis direction of the belt-shaped reticle pattern. In Figure 11 In the middle section of FIG. 10, a graph G1 showing the relationship between the Y-direction position within one scan and the optimum wavelength λb, and a graph G2 showing the relationship between the Y-direction position within one scan and the optimum spectral line width Δλb are shown. In Figure 11 In the lower section of FIG. 10, a graph G3 showing the target wavelength λt of each scan exposure pulse corresponding to the Y-direction position within one scan, and a graph G4 showing the target spectral line width Δλt of each scan exposure pulse are shown.

[0176] In Figure 11 the example shown in FIG. 11, an example in which the exposure control section 40 reads in the data of the file C generated by the lithography control section 110, and uses the values of the optimum wavelength λb and the optimum spectral line width Δλb for each of the high-resolution region A and the low-resolution region B, and directly transmits these values as the target wavelength λt and the target spectral line width Δλt to the laser control section 20 is shown.

[0177] 3.4 Example of the processing content of the lithography control section

[0178] Figure 12 This is a flowchart illustrating an example of the processing performed by the lithography control unit 110 in Embodiment 1. The processor, which functions as the lithography control unit 110, executes the program, thereby achieving... Figure 12 The steps are shown.

[0179] In step S11, the lithography control unit 110 accepts input of data for various parameters, including the parameters of the illumination optical system 44, the parameters of the projection optical system 50, and the parameters of the resist.

[0180] The parameters of the illumination optics system 44 include, for example, the σ value and the illumination shape. The parameters of the projection optics system 50 include, for example, lens data and the number of lens apertures (NA). The parameters of the resist include, for example, photosensitivity.

[0181] In step S12, the photolithography control unit 110 accepts input of pattern information related to the mask pattern of the high-resolution region A. The pattern information includes information such as the shape of the pattern in the high-resolution region A, the arrangement of the patterns, the spacing of the patterns, and the position of the high-resolution region A, and at least includes position information related to the boundary position of the high-resolution region A.

[0182] In step S13, the photolithography control unit 110 calculates the optimal laser control parameters for the high-resolution region A. These control parameters include the optimal wavelength λb, the optimal spectral linewidth Δλb, and the optimal pulse energy Eb.

[0183] In step S14, the lithography control unit 110 writes the values ​​of the control parameters calculated in step S13 into file C.

[0184] In step S15, the photolithography control unit 110 accepts input of pattern information related to the mask pattern of the low-resolution region B. The pattern information here includes information such as the shape of the pattern in the low-resolution region B, the arrangement of the patterns, the spacing of the patterns, and the position of the low-resolution region B, and at least includes position information related to the boundary position of the low-resolution region B.

[0185] In step S16, the lithography control unit 110 calculates the optimal laser control parameters for the low-resolution region B.

[0186] In step S17, the lithography control unit 110 writes the control parameters calculated in step S16 into file C.

[0187] After step S17, the photolithography control unit 110 ends. Figure 12 The flowchart.

[0188] Figure 13 is a conceptual diagram showing an example of a data structure of a table stored in the file C. In the file C, data of the parameters of the optimum wavelength λb, the optimum spectral width Δλb, and the optimum pulse energy Eb are written in accordance with the different regions of the mask 46. As shown in the table of Figure 13 , the data of each parameter is associated with a region.

[0189] 3.5 Example of processing content of exposure control section

[0190] Figure 14 is a flowchart showing an example of the processing performed by the exposure control section 40 of Embodiment 1. The processor that functions as the exposure control section 40 executes a program, whereby the steps shown in Figure 14 are implemented.

[0191] In step S21, the exposure control section 40 reads in the data of the file C stored in the lithography control section 110.

[0192] In step S22, the exposure control section 40 calculates the target values (λt, Δλt, Et) of the control parameters of the laser light of each pulse within each scan field from the data of the file C, the locations of the region A and the region B within the scan field SF. That is, the exposure control section 40 sets the first target wavelength, the first target spectral width, and the first target pulse energy of the pulsed laser light corresponding to the region A, and controls the laser device 12 so as to irradiate the first pulsed laser light to the region A. Further, the exposure control section 40 sets the second target wavelength, the second target spectral width, and the second target pulse energy of the pulsed laser light corresponding to the region B, and controls the laser device 12 so as to irradiate the second pulsed laser light to the region B. The exposure control section 40 controls the control parameters of the laser light in pulse units.

[0193] In step S23, the exposure control section 40 moves the mask 46 and the wafer WF while sending the target values of the control parameters of the laser light of each pulse and the light emission trigger signal Tr to the laser control section 20, and performs exposure within each scan field SF.

[0194] In step S24, the exposure control section 40 determines whether exposure has been performed to all of the scan fields SF within the wafer WF. In the case where the determination result of step S24 is "No", the exposure control section 40 returns to step S23. In the case where the determination result of step S24 is "Yes", the exposure control section 40 ends the flowchart of Figure 14 .

[0195] 3.6 Example of processing content of laser control section

[0196] Figure 15is a flowchart showing an example of the process performed by the laser control section 20 of Embodiment 1. The processor that functions as the laser control section 20 executes the program, whereby the process shown in the flowchart is realized. Figure 15

[0197] In step S31, the laser control section 20 reads in the data of the control parameters (λt, Δλt, Et) of the target laser light transmitted from the exposure control section 40.

[0198] In step S32, the laser control section 20 sets the rotation stage 84 of the narrowbanding module 68 of the oscillator 22 so that the wavelength of the pulsed laser light output from the laser device 12 approaches the target wavelength λt.

[0199] In step S33, the laser control section 20 sets the synchronization timing of the oscillator 22 and the amplifier 24 so that the spectral line width Δλ of the pulsed laser light output from the laser device 12 approaches the target spectral line width Δλt.

[0200] In step S34, the laser control section 20 sets the charging voltage of the amplifier 24 so that the pulse energy approaches the target pulse energy Et.

[0201] In step S35, the laser control section 20 waits for the input of the light emission trigger signal Tr and determines whether the light emission trigger signal has been input. If the light emission trigger signal Tr has not been input, the laser control section 20 repeatedly performs step S35, and after the light emission trigger signal Tr has been input, the laser control section 20 proceeds to step S36.

[0202] In step S36, the laser control section 20 measures the data of the control parameters of the laser light using the monitor module 26. The laser control section 20 acquires the data of the wavelength λ, the spectral line width Δλ, and the pulse energy E by the measurement in step S36.

[0203] In step S37, the laser control section 20 transmits the data of the control parameters of the laser light measured in step S36 to the exposure control section 40 and the lithography control section 110.

[0204] In step S38, the laser control section 20 determines whether to stop the control of the laser light. In the case where the determination result of step S38 is "No", the laser control section 20 returns to step S31. In the case where the determination result of step S38 is "Yes", the laser control section 20 ends the process shown in the flowchart. Figure 15

[0205] 3.7 Action / Effect

[0206] According to the lithography system 100 of Embodiment 1, the following effects are obtained.

[0207] ​​[1] The reticle pattern for forming the same (same kind) semiconductor element is configured in a band shape in a direction orthogonal to the scanning direction, and the control parameter of the laser is changed according to the position of the band-shaped region within the scanning field in the semiconductor process. Thereby, the laser most suitable for the band-shaped reticle pattern can be scanned and exposed per pulse.

[0208] [2] As a result, the performance and yield of the manufactured semiconductor element are improved.

[0209] [3] Within the scanning field, the control parameter of the laser corresponding to the optimum OPE is found for each region pattern, and exposure is performed per pulse, and thus, the OPE characteristics depending on the scanning position can be adjusted at high speed.

[0210] 3.8 Other

[0211] In Embodiment 1, an example of a case in which the functions of the lithography control section 110 and the exposure control section 40 are separated is described, but the example is not limited thereto, and the exposure control section 40 can also include the functions of the lithography control section 110.

[0212] Further, Figure 12 Such a calculation procedure can also be calculated in advance using a computer on which a calculation program is mounted, and the Figure 13 Such a file C is saved in the storage section of the lithography control section 110 or the exposure control section 40. The lithography control section 110 can also be a server that manages various parameters used in the scanning exposure. The server can also be connected to a plurality of exposure systems via a network. For example, the server is configured to perform Figure 12 Such a calculation procedure writes the values of the calculated control parameters in association with the band-shaped regions in the file C.

[0213] Further, in Embodiment 1, regarding the generation of the file C, the optimum wavelength λb, the optimum spectral width Δλb, and the optimum pulse energy Eb of each region A and B are found by optical simulation calculation, but the example is not limited thereto. For example, a test exposure experiment can also be performed while assigning the control parameters of the laser, and according to the results thereof, the optimum control parameters of the laser are saved in the file C for each region.

[0214] 4. Embodiment 2

[0215] 4.1 Structure

[0216] The structure of the lithography system of Embodiment 2 can be the same as that of Embodiment 1.

[0217] 4.2 Action

[0218] Figure 16An example of a trend of a strip-shaped reticle pattern in the lithography system of Embodiment 2 and a control parameter value of the target laser is shown. Regarding Figure 16 , the difference is explained. In Figure 11 , instead of the graph G4 of Figure 16 , a graph G5 becomes. Figure 11

[0219] In the case where the moving direction of the scan beam SB with respect to the reticle 46 is set as the positive direction of the Y axis, the high-resolution region A and the low-resolution region B are respectively configured as strips extending in the X axis direction (the scan width direction) orthogonal to the moving direction of the scan beam SB in the reticle plane.

[0220] The graph G5 is changed compared to the graph G4 of Figure 11 , so that the timing at which the value of the target spectral line width Δλt is switched becomes the timing at which the Y axis direction beam width (By width) of the scan beam SB is advanced more to the negative side (the front side) than the Y axis direction negative side boundary position of the high-resolution region A. This corresponds to setting the target spectral line width Δλt (A) with respect to an imaginary expanded region Ae that is a strip-shaped region in which the boundary region of the region A is expanded by the By width to the Y axis direction negative side from the Y axis direction negative side boundary position of the region A. In addition, the scan beam SB illuminated onto the reticle 46 becomes a scan beam of a size corresponding to the magnification of the projection optical system 50 of the exposure apparatus 14 on the wafer WF. For example, in the case where the magnification of the projection optical system 50 is 1 / 4 times, the scan beam SB illuminated onto the reticle 46 becomes a scan beam of a size of 1 / 4 times on the wafer WF. Further, the scan field region on the reticle 46 becomes a scan field SF of 1 / 4 times on the wafer WF. The Y axis direction beam width (By width) of the scan beam SB illuminated onto the reticle 46 is a beam width that realizes the Y axis direction width By of the static exposure region SEA on the wafer WF.

[0221] In the lowermost block shown in Figure 16 , a graph G6 that shows the moving cumulative spectral wavelength λmv of each scan exposure pulse corresponding to the Y direction position within 1 scan, and a graph G7 that shows the moving cumulative spectral line width Δλmv of each scan exposure pulse are shown. Here, the moving cumulative spectral wavelength λmv and the moving cumulative spectral line width Δλmv are the respective center wavelength and the spectral line width that are calculated from the moving cumulative spectral waveform. Here, the moving cumulative spectral waveform is a spectral waveform obtained by movingly accumulating the spectral waveform with the number N SL of pulses that are exposed on the resist on the wafer WF.

[0222] ​The target spectral line width Δλt is set as shown in the graph G5, and as a result, the moving cumulative spectral line width Δλmv is as shown in the graph G7. In the range of the high resolution region A, the target spectral line width Δλt approaches Δλb, and the moving cumulative spectral line width Δλmv becomes constant.

[0223] Figure 17 is a flowchart showing an example of the process performed by the exposure control section 40 of Embodiment 2. The flowchart shown in Figure 17 is explained with respect to Figure 14 differences. Figure 17 The flowchart shown in Figure 14 is supplemented with a step S20 before the step S21, and instead of the step S22 in contains the step S22b.

[0224] Figure 6 In the step S20, as shown in , the exposure control section 40 moves the position of the negative side boundary of the region A in the Y-axis direction by the beam width (By width) of the scan beam SB in a manner that the range of the region A in the Y-axis direction is enlarged toward the negative side of the Y-axis direction, and changes the region A to an enlarged region Ae.

[0225] Figure 6 In addition, as shown in , the position of the positive side boundary of the region B in the Y-axis direction, which is adjacent to the enlarged region Ae on the negative side of the Y-axis direction, is changed in conjunction with the change of the region A to the enlarged region Ae, and the region B becomes an imaginary reduced region Br. That is, the position of the positive side boundary of the region B in the Y-axis direction, which is a band-shaped region, is moved by the By width toward the negative side of the Y-axis direction, and the range of the region B is reduced and changed to the reduced region Br. The position of the negative side boundary of the region B in the Y-axis direction, which is adjacent to the region A on the positive side of the Y-axis direction, does not need to be changed.

[0226] In the step S22b, the exposure control section 40 calculates the target values (λt, Δλt, Et) of the control parameters of the laser light of each pulse in each scan field SF from the data of the file C, the places of the enlarged region Ae and the reduced region Br in the scan field SF. The subsequent steps are the same as those of the flowchart of Embodiment 1. Figure 14

[0227] 4.3 Action / Effect

[0228] The spectral waveform of the pulsed laser light exposed to the scan field SF becomes a moving cumulative value of the number N SL of exposure pulses. According to Embodiment 2, as the spectral line width Δλ of at least the high resolution region A, exposure can be performed at the optimum spectral line width Δλb.

[0229] 4.4 Modified Example

[0230] Figure 18An example illustrating the trend of the strip-shaped mask pattern and the control parameter values ​​of the target laser in the photolithography system of a variation of Embodiment 2 is shown. Regarding... Figure 18 The variant shown is for the same reason. Figure 16 The differences will be explained. Figure 18 In the middle, to and Figure 16 Identical elements are labeled with the same number, and redundant descriptions are omitted. Figure 16 The text describes configuration examples for two types of regions, Region A and Region B. However, in... Figure 18 In the illustrated variation, a band-shaped intermediate resolution region C is positioned between the high-resolution region A and the low-resolution region B. The intermediate resolution region C is a pattern area with a resolution level intermediate between that required by the high-resolution region A and the low-resolution region B. Sometimes, the intermediate resolution region C is referred to simply as "region C". Corresponding to this arrangement of band-shaped regions A to C, the curve for the optimal spectral linewidth Δλb is curve G8. On the other hand, the target spectral linewidth Δλt can be set as in curve G5.

[0231] As the scanning beam SB moves across the mask 46, it exposes in the order of low-resolution region B → intermediate-resolution region C → high-resolution region A. The cumulative linewidth Δλmv resulting from this movement is plotted as curve G7. (See diagram below.) Figure 18 As shown, the banded intermediate resolution region C is positioned within the region where the moving cumulative linewidth Δλmv varies. Figure 18 In the illustrated variation, exposure with the optimal spectral linewidth is also possible for the high-resolution region A. The intermediate-resolution region C is an example of the "third region" in this disclosure, and the circuit pattern configured in the intermediate-resolution region C is an example of the "third pattern" in this disclosure.

[0232] 5. Implementation Method 3

[0233] 5.1 Structure

[0234] The structure of the lithography system in Embodiment 3 can be the same as that in Embodiment 1.

[0235] In the manufacture of electronic devices such as memory systems and CMOS (Complementary Metal Oxide Semiconductor) image sensors, the main components, such as memory cells and pixels, are generally located in the center of the chip. Furthermore, peripheral circuitry, measurement markings, test patterns, and monitoring patterns are arranged around these main components.

[0236] In the photolithography system of Embodiment 3, the mask pattern is designed according to the same concept as the mask pattern structure described in Embodiments 1 and 2, such that the pattern area of ​​the main part (main pattern area) and the pattern area of ​​the peripheral circuit part (peripheral circuit area) are respectively arranged as strip-shaped areas in a direction orthogonal to the scanning direction (X-axis direction) at different positions in the Y-axis direction. That is, the measurement mark pattern, test pattern, and monitoring pattern are arranged as far as possible in the X-axis direction as possible to overlap with the main parts such as the memory cell part and pixel part, while the peripheral circuit is arranged as far as possible in the X-axis direction as possible not to overlap with the main parts.

[0237] Figure 19 The relationship between the mask pattern applied to the photolithography system of embodiment 3 and the area of ​​the wafer WF is schematically shown. Figure 19 The upper section shows a plan view of mask 46. Figure 19 The lower section shows a cross-sectional view of the region of the wafer WF corresponding to mask 46. Figure 19 In the example shown, the mask 46 corresponding to one scan field is divided into 4 sections, and each section corresponds to the circuit pattern of one chip.

[0238] like Figure 19 As shown, the mask 46 includes a main pattern area D and a peripheral circuit area E. The main pattern area D is the main area where a pattern of main parts Mw, such as storage cell parts and pixel parts, is arranged. The peripheral circuit area E is the area where a pattern of peripheral circuits and the like attached to the main parts Mw is arranged. The arrangement relationship between the main pattern area D and the peripheral circuit area E can be the same as the arrangement relationship between the high-resolution area A and the low-resolution area B in Embodiment 1.

[0239] In embodiment 3, the region of the main portion Mw on the wafer WF corresponding to the main pattern region D and the region of the peripheral circuit portion Pw on the wafer WF corresponding to the peripheral circuit region E have a step difference (height difference) within the surface of the wafer WF. Figure 19 The example illustrates a structure where the main component Mw is higher than the surrounding circuit component Pw; however, it is not limited to this example, such as... Figure 20 As shown, sometimes the main pattern area Mw can be lower than the peripheral circuit area Pw. Furthermore, the main pattern area D is sometimes simply referred to as "Area D," and the peripheral circuit area E is sometimes simply referred to as "Area E." The area of ​​the main pattern area Mw in the wafer WF is an example of the "first height area" in this disclosure. The area of ​​the peripheral circuit area Pw is an example of the "second height area" in this disclosure.

[0240] Figure 21 An example illustrating the trend of the strip mask pattern and the control parameter values ​​of the target laser in the photolithography system of Embodiment 3 is shown. Regarding... Figure 21, to Figure 11 The differences will be explained. Figure 21 The upper section shows Figure 19 The image shows the mask pattern and a cross-sectional view of the wafer WF. Figure 21 Within the box shown in the middle section, graph G11 shows the relationship between the Y-direction position and the optimal wavelength λb in one scan, and graph G12 shows the relationship between the Y-direction position and the optimal spectral linewidth Δλb in one scan.

[0241] exist Figure 21 The lower section shows a graph G13 representing the target wavelength λt of each scan exposure pulse corresponding to the Y-direction position within one scan, and a graph G14 representing the target spectral width Δλt of each scan exposure pulse.

[0242] exist Figure 21 In the example shown, the following situation is illustrated: the exposure control unit 40 reads the data of file C3 generated by the photolithography control unit 110, and uses the optimal wavelength λb and optimal spectral linewidth Δλb values ​​for each region of the main pattern region D and the peripheral circuit region E, and sends these values ​​directly as the target wavelength λt and target spectral linewidth Δλt to the laser control unit 20.

[0243] 5.2 Actions

[0244] In Embodiment 3, the exposure control unit 40 of the photolithography system changes the center wavelength of the pulsed laser based on the step difference between the main part Mw in the wafer WF and the peripheral circuit part Pw.

[0245] The exposure control unit 40 calculates the optimal wavelength λb and optimal spectral linewidth Δλb in a band-shaped region orthogonal to the scanning direction based on the step difference of the wafer WF, the necessary focal depth, the focal position, and the necessary resolution. Based on the optimal wavelength λb and optimal spectral linewidth Δλb, the exposure control unit 40 calculates the target wavelength λt and target spectral linewidth Δλt for each pulse in each scanning field.

[0246] The exposure control unit 40 sends the control parameter values ​​(target wavelength λt, target linewidth Δλt, target pulse energy Et) of each laser pulse to the laser control unit 20 in a step-scan manner.

[0247] The laser control unit 20 controls the laser device 12 so that each pulse becomes the target value of the control parameter, causing it to output pulsed laser according to the emission trigger signal Tr.

[0248] The exposure control unit 40 sends a light emission trigger signal Tr while controlling the mask stage 48 and the wafer stage 54, so that the image of the mask 46 is scanned and exposed on the wafer WF.

[0249] 5.3 Example of processing contents of lithography control section

[0250] Figure 22 is a flowchart showing an example of the processing performed by the lithography control section 110 of Embodiment 3. Regarding the flowchart shown in Figure 22 , the difference is explained. Figure 12 The flowchart shown in Figure 22 contains steps S12c, S14c, S15c, and S17c instead of steps S12, S14, S15, and S17 in Figure 12 .

[0251] In step S12c, the lithography control section 110 receives input of the pattern information relating to the reticle pattern of the main pattern region D and the imaging position F(D). The imaging position F(D) is determined in accordance with the height position (Z position) of the main portion Mw on the wafer WF (refer to Figure 19 and Figure 20 ).

[0252] In step S13, the lithography control section 110 calculates the optimum control parameter of the laser light for the main pattern region D.

[0253] Then, in step S14c, the lithography control section 110 writes the control parameter calculated through the calculation of step S13 in the file C3.

[0254] In step S15c, the lithography control section 110 receives input of the pattern information relating to the reticle pattern of the peripheral circuit region E and the imaging position F(E). The imaging position F(E) is determined in accordance with the height position (Z position) of the peripheral circuit portion Pw on the wafer WF (refer to Figure 19 and Figure 20 ).

[0255] In step S16, the lithography control section 110 calculates the optimum control parameter of the laser light for the peripheral circuit region E.

[0256] In step S17c, the lithography control section 110 writes the control parameter calculated through the calculation of step S16 in the file C3.

[0257] After step S17c, the lithography control section 110 ends the flowchart of Figure 22 .

[0258] Figure 23 is a conceptual diagram showing the data structure of the table saved in the file C3. In the file C3, the data of the imaging position, the optimum wavelength λb, the optimum spectral linewidth Δλb, and the optimum pulse energy Eb of the parameter are written in accordance with the different regions of the reticle 46.

[0259] 5.4 Example of processing content of exposure control section

[0260] Figure 24 is a flowchart showing an example of the processing performed by the exposure control section 40 of Embodiment 3. Regarding the flowchart shown in Figure 24 , the differences are explained. Figure 14 Figure 24 The flowchart shown in replaces steps S21 and S22 in Figure 14 with steps S21c and S22c.

[0261] In step S21c, the exposure control section 40 reads in the data of the file C3 held in the lithography control section 110.

[0262] In step S22c, the exposure control section 40 calculates the target values (λt, Δλt, Et) of the control parameters of the laser light for each pulse in each scan field from the data of the file C3 and the locations of the regions D and E in the scan field. The subsequent steps are the same as the flowchart of Embodiment 2. Figure 14

[0263] 5.5 Action / Effect

[0264] According to the lithography system of Embodiment 3, in the case of manufacturing electronic devices such as a memory system and a CMOS image sensor, the main pattern region D and the peripheral circuit region E are arranged in a band shape in the direction orthogonal to the scan direction, and thus it is possible to perform scan exposure with optimal control parameters of the laser light for each region of the main pattern region D and the peripheral circuit region E.

[0265] As a result, the performance and yield of the semiconductor elements manufactured are improved.

[0266] 5.6 Other

[0267] In Embodiment 3, an example of a case in which the functions of the lithography control section 110 and the exposure control section 40 are separated is explained, but the exposure control section 40 can also include the functions of the lithography control section 110, not limited to this example.

[0268] Figure 22 This calculation procedure of Embodiment 3 can also be calculated in advance using a computer loaded with a calculation program, and the Figure 23 file C3 can be held in the storage device of the lithography control section 110 or the exposure control section 40.

[0269] ​​Further, in Embodiment 3, regarding the generation of the file C3, the optimum wavelength λb, the optimum spectral line width Δλb, and the optimum pulse energy Eb of each of the regions D and E are calculated by optical simulation, but the example is not limited thereto. For example, a test exposure experiment can be performed while assigning the control parameters of the laser, and based on the results thereof, the optimum control parameters of the laser for each region can be saved in the file C3.

[0270] 6. Embodiment 4

[0271] 6.1 Configuration

[0272] The configuration of the lithography system of Embodiment 4 can be the same as that of Embodiment 1.

[0273] 6.2 Operation

[0274] Figure 25 An example of a trend of the values of the control parameters of the target laser and the belt-shaped reticle pattern in the lithography system of Embodiment 4 is shown. Regarding the example of Figure 25 , the difference from Figure 21 is explained. In Figure 25 , instead of the graphs G13 and G14 of Figure 21 , graphs G15 and G16 are made.

[0275] The graph G15 is changed from the graph G13 of Figure 21 in that the timing at which the value of the target spectral line width Δλt is switched becomes the timing at which the Y-direction width (By width) of the scan beam SB is advanced more to the negative side (the front side) than the Y-axis direction negative side boundary position of the main pattern region D. This means that the target wavelength λt(D) and the target spectral line width Δλt(D) are set for an imaginary expanded region De that is a belt-shaped region in which the boundary region of the region D is expanded by the By width to the negative side of the Y-axis direction from the Y-axis direction negative side boundary position of the region D.

[0276] As shown in Figure 25 , in conjunction with the change from the region D to the expanded region De, on the contrary, the Y-axis direction positive side boundary position of the region E is moved by the By width to the negative side of the Y-axis direction, and the region is reduced, changed to an imaginary reduced region Er. Then, the target wavelength λt(E) and the target spectral line width Δλt(E) are set for the reduced region Er.

[0277] In the frame shown in the lowermost row of Figure 25 , a graph G17 that shows the moving cumulative spectral wavelength λmv of each scan exposure pulse corresponding to the Y-direction position within one scan, and a graph G18 that shows the moving cumulative spectral line width Δλmv of each scan exposure pulse are shown.

[0278] The target wavelength λt is set as shown in the graph G15, whereby, as shown in the graph G17, the target spectral width Δλt approaches Δλb in the range of the main pattern region D, and the movement cumulative spectral width Δλmv becomes constant.

[0279] The target spectral width is set as shown in the graph G16, whereby, as shown in the graph G18, the movement cumulative spectral width Δλmv is constant in the range of the main pattern region D.

[0280] Figure 26 is a flowchart showing an example of the process performed by the exposure control section 40 of Embodiment 4. Regarding the flowchart shown in Figure 26 , the difference is explained. Figure 24 Figure 26 The flowchart shown in replaces the step S22c of Figure 24 with the step S22d.

[0281] In the step S20d, the exposure control section 40 moves the Y-axis direction negative side boundary position of the region D in a manner that the range of the region D in the Y-axis direction is enlarged toward the Y-axis direction negative side by the beam width (By width) of the scan beam SB, and changes to an enlarged region De. Concomitantly with the change from the region D to the enlarged region De, the Y-axis direction positive side boundary position of the region E in the Y-axis direction is moved by the By width toward the Y-axis direction negative side, and the range of the region E is reduced, and is changed to a reduced region Er.

[0282] In the step S22d, the exposure control section 40 calculates the target values (λt, Δλt, Et) of the control parameters of the laser of each pulse in each scan field from the data of the file C3, the places of the enlarged region De and the reduced region Er in the scan field. The subsequent steps are the same as those of the flowchart of Embodiment 3. Figure 24

[0283] 6.3 Action / Effect

[0284] The spectral waveform of the pulsed laser exposed to the scan field SF becomes the movement cumulative value of the exposure pulse number N SL According to Embodiment 4, the laser at least irradiated to the main pattern region D is able to be exposed with the optimum laser control parameters (λb, Δλb).

[0285] As explained in Embodiment 4, the technology of the present disclosure is also able to be applied to the case of manufacturing electronic devices such as a memory system, a CMOS image sensor, etc. having a step difference on a wafer at the time of scan exposure. According to Embodiment 4, the performance, yield of the manufactured semiconductor element is improved.

[0286] 7. Example of excimer laser device using solid-state laser device as oscillator ​​

[0287] 7.1 Structure

[0288] Figure 10 The laser device 12 described in the above illustrates a structure using a narrowband gas laser device as the oscillator 22, but the structure of the laser device is not limited to Figure 10 the example.

[0289] Figure 27 Another example of the structure of the laser device is shown. Instead of the laser device 12 shown in Figure 10 , the laser device 212 shown in Figure 27 may be used. As for the structure shown in Figure 27 , the same or similar elements as those in Figure 10 are labeled with the same reference numerals and the description thereof is omitted.

[0290] Figure 27 The laser device 212 shown in is an excimer laser device using a solid laser device as an oscillator, and includes a solid laser system 222, an excimer amplifier 224, and a laser control section 220.

[0291] The solid laser system 222 includes a semiconductor laser system 230, a titanium-doped sapphire amplifier 232, a pump pulse laser 234, a wavelength conversion system 236, and a solid laser control section 238.

[0292] Figure 28 The semiconductor laser system 230 includes a distributed feedback (DFB) semiconductor laser that outputs CW laser light having a wavelength of about 773.6 nm, and a semiconductor optical amplifier (SOA) that pulse-converts the CW laser light. An example of the structure of the semiconductor laser system 230 uses , which is described later.

[0293] The titanium-doped sapphire amplifier 232 includes a titanium-doped sapphire crystal. The titanium-doped sapphire crystal is disposed on the optical path of the pulse laser light that is pulse-amplified by the SOA of the semiconductor laser system 230. The pump pulse laser 234 can also be a laser device that outputs 2nd harmonic light of a YLF laser. YLF (yttrium lithium fluoride) is a solid laser crystal represented by the chemical formula LiYF4.

[0294] The wavelength conversion system 236 includes a plurality of nonlinear optical crystals that wavelength-convert the incident pulsed laser light and output 4th-harmonic pulsed laser light. The wavelength conversion system 236 includes, for example, an LBO crystal and a KBBF crystal. The LBO crystal is a nonlinear optical crystal represented by the chemical formula LiB3O5. The KBBF crystal is a nonlinear optical crystal represented by the chemical formula KBe2BO3F2. Each of the crystals is disposed on a not-shown rotation stage and configured to be able to change the incident angle with respect to the crystal.

[0295] The solid laser control section 238 controls the semiconductor laser system 230, the pulsed laser for pumping 234, and the wavelength conversion system 236 in accordance with an instruction from the laser control section 220.

[0296] The excimer amplifier 224 includes the cavity 160, the PPM 164, the charger 166, the convex mirror 241, and the concave mirror 242. The cavity 160 includes the windows 171, 172, a pair of electrodes 173, 174, and an electrically insulating member 175. An ArF laser gas is introduced into the cavity 160. The PPM 164 includes the switch 165 and a charging capacitor.

[0297] The excimer amplifier 224 is configured to amplify the seed light having a wavelength of 193.4 nm by passing the seed light three times in the discharge space between the pair of electrodes 173, 174. Here, the seed light having a wavelength of 193.4 nm is the pulsed laser light output from the solid laser system 222.

[0298] The convex mirror 241 and the concave mirror 242 are disposed so that the pulsed laser light output from the solid laser system 222 outside the cavity 160 is amplified in three passes.

[0299] The seed light having a wavelength of approximately 193.4 nm that is incident on the excimer amplifier 224 is reflected by the convex mirror 241 and the concave mirror 242, thereby passing three times in the discharge space between the pair of electrodes 173, 174. As a result, the beam of the seed light is expanded and amplified.

[0300] 7.2 Action

[0301] The laser control section 220, upon receiving the target wavelength λt, the target spectral linewidth Δλt, and the target pulse energy Et from the exposure control section 40, calculates the target wavelength λ1ct and the target spectral linewidth Δλ1cht of the pulsed laser light from the semiconductor laser system 230 that become these target values, for example, in accordance with table data or an approximate formula.

[0302] The laser control section 220 sends the target wavelength λ1ct and the target spectral linewidth Δλ1cht to the solid laser control section 238, and sets a charging voltage to the charger 166 so that the pulsed laser output from the excimer amplifier 224 becomes the target pulse energy Et.

[0303] The solid laser control section 238 controls the semiconductor laser system 230 so that the pulsed laser output from the semiconductor laser system 230 approaches the target wavelength λ1ct and the target spectral linewidth Δλ1cht. The manner in which the solid laser control section 238 performs the control uses Figure 28-31 This will be described later.

[0304] Further, the solid laser control section 238 controls two rotary stages not shown so as to become the incident angle at which the wavelength conversion efficiency of the LBO crystal and the KBBF crystal of the wavelength conversion system 236 is the greatest.

[0305] After the emission trigger signal Tr is sent from the exposure control section 40 to the laser control section 220, a trigger signal is input to the SOA of the semiconductor laser system 230, the switch 165 of the PPM 164 of the excimer amplifier 224, and the pulsed laser for pumping 234 in synchronization with the emission trigger signal Tr. As a result, a pulsed current is input to the SOA of the semiconductor laser system 230, and pulsed laser amplified from the SOA is output.

[0306] The pulsed laser is output from the semiconductor laser system 230, and is further amplified in the titanium-doped sapphire amplifier 232. The pulsed laser is incident to the wavelength conversion system 236. As a result, pulsed laser of the target wavelength λt is output from the wavelength conversion system 236.

[0307] The laser control section 220 sends a trigger signal to the SOA 260 of the semiconductor laser system 230, the switch 165 of the PPM 164, and the pulsed laser for pumping 234, respectively, after receiving the emission trigger signal Tr from the exposure control section 402, so that discharge is performed when the pulsed laser output from the solid laser system 222 is incident to the discharge space of the cavity 160 of the excimer amplifier 224.

[0308] As a result, the pulsed laser output from the solid laser system 222 is amplified in the excimer amplifier 224 by three passes. The pulsed laser amplified by the excimer amplifier 224 is sampled by the beam splitter 181 of the monitor module 20, the pulse energy E is measured using the optical sensor 184, and the wavelength λ and the spectral linewidth Δλ are measured using the spectral detector 183.

[0309] The laser control section 220 can also perform correction control of the charging voltage of the charger 166, the wavelength λ1ct and the spectral linewidth Δλ1cht of the pulsed laser output from the semiconductor laser system 230, respectively, so that the difference between the pulse energy E and the target pulse energy Et, the difference between the wavelength λ and the target wavelength λt, and the difference between the spectral linewidth Δλ and the target spectral linewidth Δλt, respectively, approach 0, in accordance with the pulse energy E, the wavelength λ, and the spectral linewidth Δλ measured by the monitor module 20.

[0310] 7.3 Description of the Semiconductor Laser System

[0311] 7.3.1 Configuration

[0312] Figure 28 A configuration example of the semiconductor laser system 230 is shown. The semiconductor laser system 230 includes a single-longitudinal-mode distributed feedback type semiconductor laser 250, a semiconductor optical amplifier (SOA) 260, a function generator (FG) 261, a beam splitter 264, a spectrum monitor 266, and a semiconductor laser control section 268. The distributed feedback type semiconductor laser is referred to as a "DFB laser".

[0313] The DFB laser 250 outputs CW (Continuous Wave) laser having a wavelength of about 773.6 nm. The DFB laser is capable of changing the oscillation wavelength by current control and / or temperature control.

[0314] The DFB laser 250 includes a semiconductor laser element 251, a Peltier element 252, a temperature sensor 253, a temperature control section 254, a current control section 256, and a function generator 257. The semiconductor laser element 251 includes a first cladding layer 271, an active layer 272, and a second cladding layer 273, and includes a grating 274 at the boundary between the active layer 272 and the second cladding layer 273.

[0315] 7.3.2 Operation

[0316] With respect to the oscillation center wavelength of the DFB laser 250, the wavelength can be changed by changing the set temperature T and / or the current value A of the semiconductor laser element 251.

[0317] In the case where the oscillation wavelength of the DFB laser 250 is chirped at high speed to control the spectral linewidth, the spectral linewidth can be controlled by changing the current value A of the current flowing in the semiconductor laser element 251 at high speed.

[0318] That is, the DC component value A1dc, the fluctuation amplitude A1ac of the AC component, the period A1 TThe values of the parameters are used as current control parameters, whereby the center wavelength λ1chc and the spectral linewidth Δλ1ch of the pulsed laser light output from the semiconductor laser system 230 can be controlled at high speed.

[0319] The spectrum monitor 266 can measure the wavelength, for example, using a spectrometer or a heterodyne interferometer.

[0320] The function generator 257 outputs an electrical signal of a waveform corresponding to the current control parameters specified by the semiconductor laser control section 268 to the current control section 256. The current control section 256 performs current control to cause a current corresponding to the electrical signal from the function generator 257 to flow in the semiconductor laser element 251. In addition, the function generator 257 can also be provided outside the semiconductor laser 250. For example, the function generator 257 can also be included in the semiconductor laser control section 268.

[0321] Figure 29 is a conceptual diagram of the spectral linewidth achieved by chirping. The spectral linewidth Δλ1ch is measured as the difference between the maximum wavelength and the minimum wavelength generated by chirping.

[0322] Figure 30 is a schematic diagram showing the relationship between the current flowing in the semiconductor laser, the wavelength change based on chirping, the spectral waveform, and the light intensity. Figure 30 The graph GA shown in the lower left part of shows the change in the current value A of the current flowing in the semiconductor laser element 251. Figure 30 The graph GB shown in the lower center part of shows the chirp generated by the current of the graph GA. Figure 30 The graph GC shown in the upper part of shows the spectral waveform obtained by the chirp of the graph GB. Figure 30 The graph GD shown in the lower right part of shows the change in the light intensity of the laser light output from the semiconductor laser system 230 by the current of the graph GA.

[0323] The current control parameters of the semiconductor laser system 230 include the following values as shown in the graph GA.

[0324] A1dc: DC component value of the current flowing in the semiconductor laser element

[0325] A1ac: variation amplitude of the AC component of the current flowing in the semiconductor laser element (difference between the maximum value and the minimum value of the current)

[0326] A1 T : period of the AC component of the current flowing in the semiconductor laser element

[0327] In Figure 30In the examples shown, the AC component, which is a current control parameter, is an example of a triangular wave, illustrating an example where the variation in the current of the triangular wave results in less variation in the intensity of the CW laser output from the semiconductor laser 250.

[0328] Here, the preferred amplification pulse duration D of SOA260 is... TW Period A1 of AC component T The relationship satisfies the following equation (1).

[0329] D TW =n·A1 T (1)

[0330] n is an integer greater than or equal to 1.

[0331] By satisfying the relationship in equation (1), the SOA260 can suppress changes in the spectral waveform of the amplified pulsed laser even when pulse amplification is performed at any time.

[0332] Furthermore, even if equation (1) is not satisfied, the pulse width range in SOA260 is, for example, 10 ns to 50 ns. The period A1 of the AC component of the current flowing in the semiconductor laser element 251 is... T It is much shorter than the pulse width of SOA260 (the time width D of the amplified pulse). TW The period of ). For example, the preferred period is A1. T The pulse width is greater than 1 / 1000 and less than 1 / 10 compared to that in SOA260. More preferably, it is greater than 1000 and less than 1 / 100.

[0333] Furthermore, the rise time of SOA260 is preferably 2ns or less, and more preferably 1ns or less. Figure 30 As shown, the rise time referred to here is the time Rt required for the amplitude of the pulse current waveform to increase from 10% of the maximum amplitude to 90%.

[0334] 7.3.3 Other

[0335] exist Figure 31 The example shown illustrates a triangular wave as an example of the AC component of the current; however, it is not limited to this example, and any waveform that changes with a certain period can be used. Other examples besides triangular waves include sine waves, square waves, etc. By controlling the waveform of this AC component, various target spectral waveforms can be generated.

[0336] 7.4 Functions / Effects

[0337] The laser device 212 using the solid laser system 222 as an oscillator has the following advantages compared to the case of using an excimer laser as an oscillator.

[0338] [1] The solid laser system 222 is able to control the wavelength λ and the spectral line width Δλ at high speed and with high precision by controlling the current value A of the DFB laser 250. That is, the laser device 212 is able to control the oscillation wavelength and the spectral line width at high speed by controlling the current value A of the DFB laser 250 immediately if data of the target wavelength λtand the spectral line width Δλtis received, and thus is able to change control the wavelength λ and the spectral line width Δλ of the pulsed laser output from the laser device 212 at high speed and with high precision for each pulse.

[0339] [2] Furthermore, by controlling the current value of the DFB laser 250 to be chirped, it is possible to generate spectral waveforms of various functions different from the usual spectral waveform.

[0340] [3] Therefore, in the case of controlling the wavelength λmvor the line width Δλmvoft the moving cumulative spectrum calculated from the spectral waveform of the moving cumulative value of the spectral waveform, as the laser control parameter, it is preferable to have a laser device having an oscillator using a solid laser system 222 including a DFB laser 250 and an excimer amplifier 224.

[0341] 7.5 Other

[0342] As an embodiment of the solid laser device, it is not limited to Figure 30 the example shown, for example, it can be a solid laser system including a DFB laser having a wavelength of about 1547.2 nm and an SOA, and the wavelength conversion system is a laser device outputting 8th harmonic 193.4 nm light. Furthermore, it is sufficient to have a system as another solid laser device, that is, a system including a CW oscillation DFB laser and an SOA, controlling the current value of the current flowing in the DFB laser, and flowing a pulse current in the SOA, whereby the wavelength is amplified in pulses.

[0343] In Figure 27-31 the example, as the excimer amplifier, an example of a multi-channel amplifier is shown, but it is not limited to this embodiment, for example, it can be an amplifier having an optical resonator such as a Fabry-Perot resonator or a ring resonator.

[0344] 8. Hardware structure of various control sections

[0345] The control device functioning as the laser control section 20, the exposure control section 40, the lithography control section 110, the solid-state laser control section 238, the semiconductor laser control section 268, and the other control sections can be realized by a combination of hardware and software of one or a plurality of computers. Software is synonymous with a program. A programmable controller is included in the concept of a computer. The computer can be configured to include a CPU (Central Processing Unit) and a memory. The CPU included in the computer is an example of a processor.

[0346] In addition, a part or all of the processing functions of the control device can also be realized using an integrated circuit typified by an FPGA (Field Programmable Gate Array) and an ASIC (Application Specific Integrated Circuit).

[0347] In addition, the functions of a plurality of control devices can also be realized by one control device. Furthermore, in the present disclosure, the control devices can also be connected to each other via a communication network such as a local area network and the Internet. In a distributed computing environment, program units can also be stored in memory storage devices on both the local and remote sides.

[0348] 9. Method for manufacturing electronic device

[0349] Figure 27 An example of the configuration of the exposure device 14 is schematically shown. The exposure device 14 includes an illumination optical system 44 and a projection optical system 50. The illumination optical system 44 illuminates a reticle pattern of a reticle 46 arranged on a reticle stage 48 not shown by laser light incident from the laser device 12. The projection optical system 50 reduces and projects the laser light after passing through the reticle 46 so as to be imaged on a workpiece not shown arranged on a workpiece stage WT. The workpiece can be a photosensitive substrate such as a semiconductor wafer on which a resist is coated. The workpiece stage WT can be a wafer stage 54.

[0350] The exposure device 14 moves the reticle stage 48 and the workpiece stage WT in parallel in synchronization, thereby exposing the workpiece to laser light reflecting the reticle pattern. After the reticle pattern is transferred on the semiconductor wafer by the above exposure process, a semiconductor device can be manufactured by a plurality of processes. The semiconductor device is an example of the "electronic device" in the present disclosure.

[0351] Figure 32 The laser device 12 in the above-described embodiment can be a laser device 212 including a solid-state laser system 222 described in the above-described embodiment. Figure 32 Figure 27 The laser device 212 including the solid-state laser system 222 described in the above-described embodiment.

[0352] 10. Other

[0353] The above description is not a limitation, but a simple example. Therefore, it will be understood by those skilled in the art that modifications can be made to the embodiments of the present disclosure without departing from the scope of the claims. Furthermore, it will be understood by those skilled in the art that the embodiments of the present disclosure are used in combination.

[0354] The terms used throughout the specification and claims should be interpreted as "non-limiting" terms, unless explicitly stated otherwise. For example, the terms "comprising," "all," "having," "including," and the like should be interpreted as "not excluding the presence of other structural elements not recited." In addition, the modifier "one" should be interpreted as meaning "at least one" or "one or more." Furthermore, the term "at least one of A, B, and C" should be interpreted as "A," "B," "C," "A+B," "A+C," "B+C," or "A+B+C." Furthermore, it should be interpreted as also including combinations of other parts than "A," "B," and "C."

Claims

1. An exposure system which irradiates a reticle with a pulsed laser to perform a scanning exposure on a semiconductor substrate, wherein, The exposure system has: a laser device that outputs the pulsed laser light; an illumination optical system that guides the pulsed laser light to the reticle; a reticle stage that moves the reticle; and a processor that controls the output of the pulsed laser light from the laser device and the movement of the reticle based on the reticle stage, the reticle has a first region configured with a first pattern and a second region configured with a second pattern, the first region and the second region are regions that are continuous in a scan width direction orthogonal to a scan direction of the pulsed laser light, and the first region and the second region are arranged side by side in the scan direction, the processor changes the value of a control parameter of the pulsed laser light according to each of the first region and the second region, and controls the laser device to output the pulsed laser light corresponding to each of the first region and the second region, in a case where the scan direction is set as a Y-axis direction, and a Y-axis direction beam width of a scan beam of the pulsed laser light that scans the reticle toward a positive side of the Y-axis direction is set as a By width, the processor obtains an enlarged region that enlarges the first region by changing a boundary of the first region on a negative side of the Y-axis direction to the negative side of the Y-axis direction by a distance corresponding to the By width, and obtains a reduced region that reduces the second region that is adjacent to a positive side of the first region on the positive side of the Y-axis direction by changing a boundary of the second region on the positive side of the Y-axis direction to the negative side of the Y-axis direction by a distance corresponding to the By width, based on information of a reticle pattern of the reticle, the processor changes the value of the control parameter of the pulsed laser light according to each of the enlarged region and the reduced region, and controls the laser device to output the pulsed laser light corresponding to each of the enlarged region and the reduced region.

2. The exposure system according to claim 1, wherein the length of the scan width direction of each of the first region and the second region is 50% or more of the length of the scan width direction of the reticle.

3. The exposure system according to claim 1, wherein the first region and the second region are each a belt-shaped region whose length in the scan width direction is longer than its length in the scan direction, the first region and the second region exist non-mixed on a straight line in the scan width direction.

4. The exposure system according to claim 1, wherein the control parameter includes at least one of a target wavelength, a target spectral line width, and a target pulse energy.

5. The exposure system according to claim 1, wherein the processor sets a first target wavelength, a first target spectral line width, and a first target pulse energy of the pulsed laser light corresponding to the first region, and controls the laser device to irradiate a first pulsed laser light to the first region, the processor sets a second target wavelength, a second target spectral line width, and a second target pulse energy of the pulsed laser light corresponding to the second region, and controls the laser device to irradiate a second pulsed laser light to the second region.

6. The exposure system according to claim 1, wherein the processor calculates values of the control parameter corresponding to each of the first region and the second region, based on information of a reticle pattern of the reticle.

7. The exposure system according to claim 1, wherein the exposure system further has a server that manages parameters used in the scanning exposure, the server calculates values of the control parameter corresponding to each of the first region and the second region, based on information of a reticle pattern of the reticle, the calculated values of the control parameter are written in a file in association with each of the regions.

8. The exposure system according to claim 1, wherein the processor holds a table that specifies a target wavelength, a target spectral line width, and a target pulse energy of the pulsed laser for each of the first region and the second region, the output of the pulsed laser is controlled for each of the first region and the second region based on the table.

9. The exposure system according to claim 1, wherein the processor controls the laser device based on at least one of a moving cumulative spectral wavelength and a moving cumulative spectral line width of the pulsed laser exposed in a scanning field of the semiconductor substrate.

10. The exposure system according to claim 1, wherein the reticle further has a third region configured with a third pattern, the third region is a region continuous in a scanning width direction orthogonal to a scanning direction of the pulsed laser, and is configured between the first region and the second region.

11. The exposure system according to claim 1, wherein the first pattern is a pattern of a semiconductor element that requires relatively high resolution compared to the second pattern.

12. The exposure system according to claim 1, wherein a pattern of at least one of a static random access memory and a pixel of an image sensor is configured as the first pattern in the first region, a pattern of at least one of an isolated pattern, a logic element, and an amplifier is configured as the second pattern in the second region.

13. The exposure system according to claim 1, wherein a pattern of at least one of a memory cell and a pixel of an image sensor is configured as the first pattern in the first region, a pattern of a peripheral circuit is configured as the second pattern in the second region.

14. The exposure system according to claim 13, wherein at least one of a measurement mark pattern, a test pattern, and a monitoring pattern is further configured as the first pattern in the first region.

15. The exposure system according to claim 1, wherein the semiconductor substrate has a step difference at a position corresponding to each of the first region and the second region in a scanning field subjected to the scanning exposure.

16. The exposure system according to claim 15, wherein The processor acquires information of imaging positions of the pulsed laser that exposes each region of a first height region and a second height region in the scanning field corresponding to each region of the first region and the second region, The processor calculates values of the control parameter corresponding to each region of the first region and the second region based on information of a reticle pattern of the reticle and the information of the imaging positions.

17. The exposure system according to claim 1, wherein The laser device is an excimer laser device including an oscillator and an amplifier that amplifies pulsed laser light output from the oscillator, The oscillator has a narrowband module.

18. The exposure system according to claim 1, wherein The laser device is an excimer laser device including an oscillator and an amplifier that amplifies pulsed laser light output from the oscillator, The oscillator is a solid laser system using a distributed feedback type semiconductor laser.

19. A method of manufacturing an electronic device, wherein The method of manufacturing an electronic device includes a step of scanning exposure of a photosensitive substrate using an exposure system that irradiates a reticle with pulsed laser light to manufacture an electronic device, The exposure system has: a laser device that outputs the pulsed laser light; an illumination optical system that guides the pulsed laser light to the reticle; a reticle stage that moves the reticle; and a processor that controls output of the pulsed laser light from the laser device and movement of the reticle based on the reticle stage, The reticle has a first region configured with a first pattern and a second region configured with a second pattern, The first region and the second region are regions that are continuous in a scanning width direction orthogonal to a scanning direction of the pulsed laser light, respectively, and the first region and the second region are configured side by side in the scanning direction, The processor changes values of a control parameter of the pulsed laser light according to each region of the first region and the second region, and controls the laser device to output the pulsed laser light corresponding to each region of the first region and the second region, In a case where the scanning direction is set as a Y-axis direction, and a Y-axis direction beam width of a scanning beam of the pulsed laser light that scans the reticle toward a positive side of the Y-axis direction is set as a By width, The processor calculates an enlarged region that enlarges the first region by changing a boundary of a Y-axis direction negative side of the first region to the Y-axis direction negative side by a distance corresponding to the By width, and calculates a reduced region that reduces the second region adjacent to a Y-axis direction positive side of the first region by changing a boundary of the Y-axis direction positive side of the second region to the Y-axis direction negative side by a distance corresponding to the By width, based on information of a reticle pattern of the reticle, The processor changes values of a control parameter of the pulsed laser light according to each region of the enlarged region and the reduced region, and controls the laser device to output the pulsed laser light corresponding to each region. ​

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