JP2009238922A - Exposure device, exposure method, and manufacturing method of device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: an exposure device capable of appropriately forming a pattern on a board; an exposure method; and a method of manufacturing a device. <P>SOLUTION: A control device adjusts, in accordance with an expansion amount of a wafer, a formation condition in forming a pattern on the wafer (steps S14, S15) when the wafer is installed on a wafer stage in a second chamber (step S13). Thereafter, the control device projects a pattern image to the wafer in the adjusted formation condition (step S16). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an exposure apparatus, an exposure method, and a device using the exposure method for forming a pattern on a substrate coated with a photosensitive material in a chamber set in a reduced-pressure atmosphere that is depressurized from atmospheric pressure. It is related with the manufacturing method.

In general, an exposure apparatus that projects a pattern image on a substrate using EUV (Extreme Ultraviolet) light, EB (Electron Beam), or the like is installed in a chamber whose interior is set to a vacuum atmosphere. Such an exposure apparatus includes a mask holding device that holds a reflective mask on which a predetermined pattern is formed, and a substrate holding device that holds a substrate such as a wafer or a glass plate on which an image of the predetermined pattern is projected. (For example, refer to Patent Document 1).
JP 2005-276932 A

  By the way, since the pressure applied to the substrate is reduced by the amount released from the atmospheric pressure, the substrate transferred into the chamber set in a vacuum atmosphere from outside the atmospheric pressure atmosphere expands similarly, that is, expands. To do. When the substrate on which the pattern image is projected in the chamber is carried out of the chamber, the substrate contracts similarly when atmospheric pressure is applied again.

  Therefore, the pattern formed on the substrate in the chamber contracts similarly to the amount corresponding to the contraction of the substrate, and with this contraction, the pattern and the alignment mark formed with the pattern are displaced. There was a problem. For example, in the case where a microdevice is manufactured by superposing a plurality of patterns using an exposure apparatus having a plurality of chambers having different internal atmospheres, the first pattern is formed on the substrate in the first chamber whose interior is set to a vacuum atmosphere. Then, the substrate is transferred into a second chamber whose interior is set to an atmospheric pressure atmosphere. When the next second pattern is superimposed on the first pattern and exposed on the substrate in the second chamber, the first pattern formed in the first chamber and the second pattern formed in the second chamber There was a possibility that an overlay error would occur between the two.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an exposure apparatus, an exposure method, and a device manufacturing method capable of suitably forming a pattern on a substrate.

In order to solve the above-described problems, the present invention employs the following configuration corresponding to FIGS. 1 to 7 shown in the embodiment.
The exposure apparatus of the present invention is an exposure apparatus for forming a pattern (61) on a substrate (W) coated with a photosensitive material in a chamber (12) set in a reduced pressure atmosphere that is reduced from atmospheric pressure. 11) The conditions for forming the pattern (61) on the substrate (W) are adjusted according to the deformation of the substrate (W) transferred from the outside of the chamber (12) into the chamber (12). The gist is that an adjusting device (50) is provided.

  Further, the exposure method of the present invention is an exposure in which a pattern (61) is formed on a substrate (W) coated with a photosensitive material in a chamber (12) set in a reduced-pressure atmosphere reduced to atmospheric pressure. According to the method, the formation condition of the pattern (61) on the substrate (W) is adjusted according to the deformation of the substrate (W) transferred from outside the chamber (12) into the chamber (12). After the adjustment step (S14, S15, S20) and the adjustment step (S14, S15, S20), the pattern is applied to the substrate (W) by irradiating the substrate (W) with a radiation beam (EL). And an exposure step (S16) in which (61) is formed.

  According to the above configuration, in the chamber set in a reduced-pressure atmosphere, after the formation conditions of the pattern on the substrate are adjusted according to the deformation of the substrate caused by being transferred from outside the chamber into the chamber, A pattern is formed on the substrate. Therefore, when a substrate on which a pattern is formed in the chamber is carried out of the chamber, a pattern having an appropriate shape is formed on the substrate. Therefore, the pattern can be suitably projected onto the substrate.

  Further, the exposure apparatus of the present invention is an exposure for forming a pattern (61) on a substrate (W) coated with a photosensitive material in a chamber (12) set in a reduced-pressure atmosphere reduced to atmospheric pressure. An exposure apparatus comprising an apparatus (11) comprising a cooling device (23) for cooling the substrate (W) transported from outside the chamber (12) into the chamber (12).

  Further, the exposure method of the present invention is an exposure in which a pattern (61) is formed on a substrate (W) coated with a photosensitive material in a chamber (12) set in a reduced-pressure atmosphere reduced to atmospheric pressure. A cooling step (S20) for cooling the substrate (W) transferred from the outside of the chamber (12) into the chamber (12), and a radiation beam (EL) after the cooling step (S20). An exposure method comprising: an exposure step (S16) for forming the pattern on the substrate (W) by irradiating the substrate (W).

  In general, a substrate transferred from outside the chamber into the chamber is deformed due to a difference in ambient pressure atmosphere. Therefore, in the present invention, the substrate transported into the chamber is cooled to be returned to a shape substantially equivalent to that when the substrate is outside the chamber. In this state, a pattern is projected onto the substrate. Therefore, the pattern can be suitably projected onto the substrate.

  In order to explain the present invention in an easy-to-understand manner, it has been described in association with the reference numerals of the drawings showing the embodiments, but it goes without saying that the present invention is not limited to the embodiments.

  According to the present invention, a pattern can be suitably formed on a substrate.

(First embodiment)
Below, 1st Embodiment which actualized this invention is described based on FIGS. 1-4.
As shown in FIG. 1, the exposure apparatus 11 of the present embodiment is an EUV exposure apparatus that uses extreme ultraviolet light, that is, EUV (Extreme Ultraviolet) light having a wavelength of about 100 nm or less as exposure light EL. The inside of the first chamber 12 is in a vacuum atmosphere. The first chamber 12 includes a first transfer port 13 for transferring a wafer W (a silicon wafer in the present embodiment) into the first chamber 12 and a first transfer port for opening and closing the first transfer port 13. An opening / closing device 14 is provided. Further, on the Y direction side (the right side in FIG. 1) of the first chamber 12, a second chamber 15 that communicates with the inside through the first transfer port 13 is provided. The second chamber 15 includes a second transfer port 16 for transferring the wafer W from the outside into the second chamber 15, a second opening / closing device 17 for opening and closing the second transfer port 16, A mounting table (not shown) for mounting the wafer W transferred into the second chamber 15 through the second transfer port 16 is provided.

  The exposure apparatus 11 includes an exposure light source 18, an illumination optical system 19, a reticle stage 20 that holds a reflective reticle R on which a predetermined pattern is formed, a projection optical system 21, and a photosensitive material such as a resist on the surface. And a wafer stage 22 for holding the wafer W coated with the film. Further, the exposure apparatus 11 has a temperature for adjusting the temperature of the wafer W transferred into the first chamber 12 to a reference temperature (for example, 23 ° C.) equivalent to the temperature of the environment in which the exposure apparatus 11 is installed. An adjustment mechanism 23 is provided. When the wafer W is transferred from the atmospheric pressure atmosphere into the first chamber 12 in the vacuum atmosphere, the wafer W is transferred into the second chamber (load lock chamber) 15 via the second transfer port 16. The second transfer port 16 is closed and the pressure is reduced, that is, the vacuum is drawn by driving a vacuum pump (not shown). At this time, adiabatic expansion of gas occurs in the second chamber 15 and the temperature in the second chamber decreases, and as a result, the temperature of the wafer W decreases. Therefore, when the wafer W is transferred from the second chamber 15 into the first chamber 12, the temperature adjustment mechanism 23 recovers the temperature of the wafer W that has fallen due to adiabatic expansion of the gas in the second chamber 15. Let

A laser-excited plasma light source is used as the exposure light source 18 of the present embodiment, and the light source outputs EUV light having a wavelength of 5 to 20 nm (for example, 13.5 nm).
The illumination optical system 19 includes a reflective collimating mirror 24, a condenser mirror 25, and a pair of fly-eye mirrors (not shown) arranged in order from the exposure light source 18 side. A plurality of reflecting layers for reflecting the exposure light EL are formed on the reflecting surfaces of the mirrors 24 and 25 and the pair of fly-eye mirrors. Then, the exposure light EL reflected by the condenser mirror 25 is guided to the reticle R held on the reticle stage 20 by the reflection mirror 26 for folding, which is disposed on the reticle R side via a pair of fly-eye mirrors.

  The reticle stage 20 is disposed on the object plane side of the projection optical system 21 to be described later, and the electrostatic chuck 27 that electrostatically attracts the reticle R and the reticle R with a predetermined stroke in the Y-axis direction (left-right direction in FIG. 1). A moving mechanism 28 for moving the X direction and the θz direction (rotation direction around the Z axis) in a minute amount is also provided. Then, the exposure light EL reflected by the irradiated surface (that is, the lower surface in FIG. 1) on which the pattern is formed on the reticle R is guided to the projection optical system 21. The reticle R of the present embodiment includes a thin plate such as a silicon wafer, quartz, and low expansion glass, a conductive layer formed on the back side of the thin plate, a reflective layer formed on the surface side of the thin plate, and the reflective layer. And the pattern is formed in the absorption layer.

  The projection optical system 21 includes a plurality (six in this embodiment) of reflective mirrors 29, 30, 31, 32, 33, and 34. Then, the exposure light EL guided from the reticle R side is reflected in the order of the first mirror 29, the second mirror 30, the third mirror 31, the fourth mirror 32, the fifth mirror 33, and the sixth mirror 34, and the wafer stage. Then, the wafer W is guided to the wafer W held by the motor 22. Of the mirrors 29 to 34, the first mirror 29, the second mirror 30, the fourth mirror 32, and the sixth mirror 34 are concave mirrors, while the third mirror 31 and the fifth mirror 33 are convex mirrors.

  In the projection optical system 21, at least one of the plurality of reflection type mirrors 29 to 34 has an optical characteristic of the projection optical system 21 (for example, wavefront aberration, coma aberration, field curvature, distortion, which will be described later). An optical characteristic adjusting mechanism (not shown) for adjusting the projection magnification and the like is provided. This optical characteristic adjusting mechanism can tilt the mirror with respect to the optical axis of the projection optical system 21 or move the mirror in a direction parallel to the optical axis direction. The optical characteristic adjustment mechanism may be configured to change the shape of the mirror itself.

  The wafer stage 22 includes a substantially rectangular parallelepiped stage main body 35, a holding holder 36 that can electrostatically adsorb the wafer W on the stage main body 35 and made of silicon carbide, and the wafer via the holding holder 36. A temperature maintaining mechanism 37 (for example, a Peltier element) that maintains the temperature of W is provided. Then, the surface of the wafer W electrostatically attracted to the holding holder 36 is irradiated with the exposure light EL emitted from the projection optical system 21, whereby the pattern on the reticle R is reduced to a predetermined magnification on the wafer W. A pattern image is projected. That is, a reduced pattern (hereinafter simply referred to as “pattern”) obtained by reducing the above pattern is formed on the wafer W.

  Further, the wafer stage 22 is moved on the XY plane of the wafer stage 22 by a moving mechanism 38 for moving the wafer W in the Y-axis direction with a predetermined stroke via the stage main body 35 and moving it in the X and Z directions. A wafer laser interferometer 39 is provided for detecting the position at. The wafer laser interferometer 39 outputs position information regarding the position of the wafer stage 22 to a control device 50 (see FIG. 2) described later. The wafer stage 22 also incorporates a Z leveling mechanism (not shown) for controlling the holding holder 36 in the Z direction, the tilt angle around the X direction, and the tilt angle around the Y direction. Further, on the stage main body 35, on the −Y direction side (left side in FIG. 1) of the holding holder 36, the height position in the Z direction of the surface is in the Z direction on the surface of the wafer W electrostatically attracted to the holding holder 36. A reference mark plate 40 that is substantially equivalent to the height position is provided. A plurality of reference marks are formed on the surface of the reference mark plate.

  In the present embodiment, an off-axis alignment system 41 for aligning the wafer W on the XY plane is provided in the vicinity of the projection optical system 21. The off-axis alignment system 41 images the alignment mark by irradiating the alignment mark on the wafer W with a laser beam having a wavelength that does not sensitize the reticle, and uses the imaging result to reference the reference mark on the reference mark plate 40. The position of the alignment mark with respect to (ie, the distance between the marks) is measured. That is, the off-axis alignment system 41 of this embodiment is configured to include an FIA (Field Image Alignment) sensor. Information on the position of the alignment mark detected by the off-axis alignment system 41 is output to the control device 50 described later.

Next, a control device 50 that controls the driving of the exposure apparatus 11 of the present embodiment will be described with reference to FIG.
As shown in FIG. 2, the control device 50 includes a digital computer having a CPU, a ROM, a RAM, and the like (not shown), and controls the driving of the exposure apparatus 11 as a whole. That is, when performing the baseline check, the control device 50 controls the driving of the off-axis alignment system 41, the moving mechanism 38, and the wafer laser interferometer 39, thereby aligning the reference mark on the reference mark plate 40 with the alignment on the wafer W. Measure the distance between the marks. When the wafer W is exposed, the control device 50 controls the exposure light source 18, the illumination optical system 19, and the projection optical system 21, and the amount of exposure light EL that irradiates the wafer W and the pattern image on the wafer W are displayed. Adjust the projection magnification. Thereafter, the control device 50 controls the moving mechanisms 28 and 38 of the reticle stage 20 and the wafer stage 22 to project a pattern image on the wafer W.

  Next, among the control processes executed by the control device 50 according to the present embodiment, a process routine executed to adjust the pattern image formation conditions when projecting a pattern image onto one wafer W is illustrated. This will be described based on the flowchart shown in FIG. This processing routine is executed after the first transfer port 13 is closed and the inside of the first chamber 12 is set to a reduced pressure atmosphere that is reduced from the atmospheric pressure, that is, a vacuum atmosphere.

  When the processing routine is executed, the control device 50 controls the driving of the second opening / closing device 17 so as to open the second transport port 16. Then, the control device 50 controls the driving of a substrate transfer device (not shown) so as to transfer the wafer W into the second chamber 15 via the second transfer port 16 on the mounting table (step S10). Subsequently, the control device 50 drives the second opening / closing device 17 to close the second transport port 16, and then reduces the pressure in the second chamber 15 to the pressure in the first chamber 12. Then, when the pressure in the second chamber 15 becomes substantially the same as the pressure in the first chamber 12, the control device 50 drives the first opening / closing device 14 to open the first transfer port 13. Control is performed to drive the substrate transfer apparatus so as to transfer the wafer W in the second chamber 15 into the first chamber 12 (step S11). Thereafter, the control device 50 controls the drive of the first opening / closing device 14 so as to close the first transport port 13.

  Subsequently, the control device 50 controls the driving of the substrate transfer device so as to transfer the wafer W to the temperature adjustment mechanism 23. Then, the control device 50 controls the temperature adjustment mechanism 23 to adjust the temperature T of the wafer W to the reference temperature KT (step S12). Then, the control device 50 controls the drive of the substrate transfer device so as to transfer the wafer W on the temperature adjustment mechanism 23 onto the holding holder 36 of the wafer stage 22, and electrostatically attracts the wafer W to the holding holder 36. (Step S13). Subsequently, the control device 50 controls the optical characteristic adjusting mechanism to form a pattern image to be projected onto the wafer W, for example, the projection magnification of the pattern image (the pattern 61 to be formed on the wafer W (FIG. 4A)). (Reference)) is finely adjusted (step S14).

  Here, the wafer W is transferred from the outside of the second chamber 15 (atmospheric pressure atmosphere) into the first chamber 12 (vacuum atmosphere) through the second chamber 15. Therefore, when the temperature T of the wafer W is maintained at the reference temperature KT by the temperature adjustment mechanism 23, the wafer W expands in a similar manner, that is, expands by the amount released from the atmospheric pressure in the vacuum atmosphere. The relationship between the pressure difference between the inside of the first chamber 12 and the outside (hereinafter referred to as “static pressure”) and the volume fluctuation rate of the wafer W is represented by the following relational expression (Formula 1).

ただし、Ｐ…静圧、Ｋ…体積弾性係数、ΔＶ／Ｖ…ウエハの体積変化率
また、ウエハＷの弾性変形可能な範囲内では、体積弾性係数Ｋと、ウエハＷ（即ち、シリコン）のヤング率（縦弾性係数）及び剛性率（横弾性係数）との各関係は、以下に示す関係式（式２）（式３）に示される。

However, P ... static pressure, K ... volume elastic modulus, .DELTA.V / V ... volume change rate of the wafer. Also, within the range where the wafer W can be elastically deformed, the volume elastic modulus K and the Young of the wafer W (ie, silicon). Each relationship between the modulus (longitudinal elastic modulus) and the rigidity modulus (lateral elastic modulus) is shown in the following relational expressions (formula 2) and (formula 3).

ただし、Ｅ…ヤング率、ν…ポワソン比、Ｇ…剛性率
また、ウエハＷの体積変化率ΔＶ／ＶとウエハＷの長さの変化率との関係は、ウエハＷの膨張収縮が等方性を有し、且つ体積変化率ΔＶ／Ｖが１よりも十分に小さい場合、以下に示す関係式（式４）及び（式５）に示される。

However, E ... Young's modulus, ν ... Poisson's ratio, G ... rigidity ratio The relationship between the volume change rate ΔV / V of the wafer W and the change rate of the length of the wafer W is that the expansion and contraction of the wafer W is isotropic. When the volume change rate ΔV / V is sufficiently smaller than 1, the following relational expressions (Expression 4) and (Expression 5) are shown.

ただし、ΔＬ／Ｌ…ウエハの長さの変化率
そして、静圧Ｐが解放された場合、即ち、真空雰囲気にウエハＷが設置された場合におけるウエハＷの長さの変化率ΔＬ／Ｌは、以下に示す関係式（式６）に示される。

However, ΔL / L: rate of change of the length of the wafer And when the static pressure P is released, that is, when the wafer W is placed in a vacuum atmosphere, the rate of change ΔL / L of the length of the wafer W is It is shown in the following relational expression (Formula 6).

そのため、シリコンは、そのヤング率Ｅが１３０ＧＰａであると共に、ポワソン比νが０．２８であることから、シリコンの体積弾性係数Ｋは９９ＧＰａとなる。すなわち、静圧Ｐ（略１０１３２５Ｐａ）から解放された場合におけるウエハＷの長さの変化率ΔＬ／Ｌ（即ち、伸び率）は、０．３４ｐｐｍ（＝０．００００３４％）となる。

Therefore, since silicon has a Young's modulus E of 130 GPa and a Poisson's ratio ν of 0.28, the volume elastic modulus K of silicon is 99 GPa. That is, when the pressure is released from the static pressure P (approximately 101325 Pa), the change rate ΔL / L of the length of the wafer W (that is, the elongation) is 0.34 ppm (= 0.000034%).

  Therefore, in step S14, the optical characteristics of the projection optical system 21 are adjusted so that the pattern 61 formed on the wafer W is larger by 0.34 ppm than the desired size. Subsequently, the control device 50 performs fine adjustment of the position where the pattern image is projected on the wafer W, that is, the position where the pattern 61 is formed (step S15). Specifically, the control device 50 controls the off-axis alignment system 41, the moving mechanism 38, and the wafer laser interferometer 39 to perform the baseline check, respectively, and the reference mark on the reference mark plate 40 and the alignment mark on the wafer W are controlled. Measure the distance between. At this time, as described above, the wafer W is expanded by being transferred into the first chamber 12 from the outside. Therefore, the control device 50 outputs a correction value, which is shorter by 0.34 ppm than the actual measurement value based on various information from the off-axis alignment system 41 and the wafer laser interferometer 39, as the distance. That is, the control device 50 outputs the distance in consideration of an offset value corresponding to the expansion amount of the wafer W, that is, a value corresponding to 0.34 ppm. As a result, the control device 50 controls the driving of the moving mechanism 38 so as to move the stage main body 35 by an extra amount of 0.34 ppm.

Then, the control device 50 performs exposure to project a pattern image on the wafer W held on the wafer stage 22 (step S16), and then ends the processing routine.
Next, the exposure method by the exposure apparatus 11 of this embodiment is demonstrated based on FIG. 4 (a) (b). As a premise, it is assumed that the temperature T of the wafer W is adjusted to the reference temperature KT by the temperature adjustment mechanism 23. A pattern 61 indicated by a solid line in FIG. 4A is formed in a state where various adjustments are made in consideration of the expansion of the wafer W, while a two-dot chain line in FIG. 4A. It is assumed that the pattern 60 shown is formed without considering the expansion of the wafer W or the like. Further, a pattern 61 indicated by a solid line in FIG. 4B is a desired position and formed in a desired size, while a pattern 60 indicated by a two-dot chain line in FIG. 4B. Is a position shifted from a desired position and smaller than a desired size. 4 (a) and 4 (b), the expansion and contraction of the patterns 60 and 61 are exaggerated for convenience of understanding the description.

  When the wafer W having the temperature T adjusted to the reference temperature KT by the temperature adjustment mechanism 23 is electrostatically attracted to the holding holder 36 of the wafer stage, the projection magnification of the pattern image onto the wafer W by the projection optical system 21 is small. Adjusted. That is, the optical characteristics of the projection optical system 21 are finely adjusted so that the pattern image is projected onto the wafer W by an amount corresponding to the expansion of the wafer W. Next, the position on the wafer W where the pattern image is projected is also finely adjusted by the amount of expansion of the wafer W. Thus, after fine adjustment accompanying the expansion of the wafer W is performed, the wafer W is exposed.

  That is, in this embodiment, as shown in FIG. 4A, the wafer W is similarly enlarged by 0.34 ppm compared to the pattern 60 when the above adjustment is not performed. 61 is formed. In the present embodiment, the pattern 61 is formed at a position on the Y direction side by 0.34 ppm as compared with the pattern 60 when the above adjustment is not performed.

  Therefore, when the wafer W exposed as described above is transferred to the outside of the first chamber 12, that is, in the atmospheric pressure atmosphere, the wafer W has an atmospheric pressure as compared with the case where the wafer W is installed in the first chamber 12. By adding, it shrinks, that is, shrinks similarly. Then, the pattern 61 formed on the wafer W is also contracted based on the contraction of the wafer W, and the position is also displaced. As a result, as shown in FIG. 4B, a pattern 61 having a desired size is formed at a desired position on the wafer W in an atmospheric pressure atmosphere. Therefore, when a plurality of pattern images are overlaid and projected in an atmospheric pressure atmosphere thereafter, a pattern to be overlaid is formed on the wafer W without taking into account the shrinkage of the pattern 61, unlike the conventional case.

Therefore, in this embodiment, the following effects can be obtained.
(1) In the first chamber 12 set in a vacuum atmosphere, the wafer W is changed according to the deformation of the wafer W caused by being transferred from the atmospheric atmosphere to the first chamber 12 through the second chamber 15. After the formation conditions of the pattern 61 on the wafer are adjusted, the pattern 61 is formed on the wafer W. Therefore, when the wafer W on which the pattern 61 is formed is transferred to the outside of the first chamber 12, the wafer W is contracted, but the pattern 61 having an appropriate shape is formed on the wafer W. Therefore, the pattern 61 can be suitably formed on the wafer W.

  (2) The wafer W expands when it is transferred from the atmospheric pressure atmosphere into the first chamber 12 which is a vacuum atmosphere. Therefore, in the present embodiment, a pattern image having a shape larger than the desired size is projected onto the wafer W, taking into account the expansion of the wafer W. When the wafer W exposed in the first chamber 12 is transferred to the outside of the first chamber 12, a pattern 61 having a desired size is formed on the wafer W. Therefore, when another pattern image is superimposed and projected on the pattern 61 thereafter, the step of adjusting the size of the other pattern image can be omitted.

  (3) The position on which the pattern image is projected on the wafer W is adjusted in consideration of the expansion of the wafer W. As a result, when the wafer W that has been exposed in the first chamber 12 is transferred to the outside of the first chamber 12, a pattern 61 is formed on the wafer W at a desired position. Therefore, when another pattern image is superimposed and projected on the pattern 61 after that, the step of adjusting the position of the other pattern image can be omitted.

  (4) Generally, when the wafer W is transferred from the atmospheric pressure atmosphere to the vacuum atmosphere, the temperature is temporarily lowered, and the wafer W is contracted based on the temperature drop. When exposure is performed on the wafer W in this state, it is necessary to adjust the formation conditions of the pattern 61 in consideration of the temperature of the wafer W at the time of exposure, and the adjustment becomes very complicated. In this regard, in the present embodiment, the wafer W is exposed after the temperature T of the wafer W is adjusted to the reference temperature KT. Therefore, since it is not necessary to consider the shrinkage of the wafer W due to the temperature change, it is possible to avoid the complicated formation conditions of the pattern 61 on the wafer W in the first chamber 12.

  (5) During exposure of the wafer W, that is, while the wafer W is irradiated with the exposure light EL, the temperature T of the wafer W and the holding holder 36 is set to the reference temperature KT by the temperature adjustment mechanism 23 by the temperature maintaining mechanism 37. Maintained. Therefore, as a result of avoiding the rise of the wafer W during the exposure, the expansion of the wafer W due to the temperature rise can be avoided. Therefore, it is possible to contribute to preferable formation of the pattern 61 on the wafer W.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment is different from the first embodiment in the contents of the processing routine. Therefore, in the following description, parts different from those of the first embodiment will be mainly described, and the same or corresponding member configurations as those of the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. Shall.

The processing routine of this embodiment will be described based on the flowchart shown in FIG.
In the processing routine, the control device 50 sequentially performs the same processes as those in steps S10 and S11. Subsequently, the control device 50 controls the temperature adjustment mechanism 23 to adjust the temperature T of the wafer W to a temperature lower than the reference temperature KT by a preset adjustment temperature ΔKT (in this embodiment, 0.08 ° C.). (Step S20).

  Here, the thermal expansion coefficient of silicon is approximately 4.3 ppm / K. Therefore, in order to shrink the wafer W by 0.34 ppm by reducing the temperature T of the wafer W, it is necessary to lower the temperature T of the wafer W by 0.08 ° C. from the reference temperature KT. That is, the adjustment temperature ΔKT is set to a temperature necessary for shrinking the wafer W by 0.34 ppm, that is, the amount of expansion.

  When the temperature T of the wafer W becomes lower than the reference temperature KT by the adjustment temperature ΔKT, the control device 50 controls the substrate transfer device to transfer the wafer W onto the holding holder 36 of the wafer stage 22, and the above steps. The process of S16 is executed. Thereafter, the control device 50 ends the processing routine.

  That is, in the present embodiment, the temperature T of the wafer W is set lower than the reference temperature KT by the adjustment temperature ΔKT in the first chamber 12, so that the size of the wafer W is set before the transfer into the chambers 12 and 15. This is equivalent to the size of the wafer W. Therefore, unlike the case of the first embodiment, the pattern image is projected onto the wafer W without adjusting the size and position of the pattern image projected onto the wafer W. When the wafer W on which the pattern 61 is formed under such forming conditions is transferred to the outside of the chambers 12 and 15 and the temperature T of the wafer W is set to the reference temperature KT, the wafer W has a desired position at a desired position. A pattern 61 having a size to be formed is formed.

  Note that the temperature T of the wafer W may become lower than a predetermined temperature that is lower than the reference temperature KT by the adjustment temperature ΔKT due to adiabatic expansion of the gas by evacuation in the second chamber 15. In this case, the temperature adjustment mechanism 23 may increase the temperature of the wafer W until the temperature of the wafer W reaches the predetermined temperature.

Therefore, in this embodiment, in addition to the effects (1) and (5) of the first embodiment, the following effects can be obtained.
(6) When the wafer W is transferred from the atmospheric pressure atmosphere into the first chamber 12 which is a vacuum atmosphere, the wafer W expands. Therefore, in the present embodiment, the temperature T of the wafer W is set lower than the reference temperature KT by the adjustment temperature ΔKT so that the size of the wafer W is equal to the size in the atmospheric pressure atmosphere. Since exposure is performed in this state, a pattern 61 having a desired size is formed at a desired position on the wafer W transferred to the outside of the first chamber 12. Therefore, when another pattern image is superimposed and projected on the pattern 61 thereafter, the step of adjusting the size of the other pattern image and the projection position can be omitted.

  (7) If the wafer T is electrostatically attracted by the holding holder 36 and the temperature T of the wafer W is lowered by the adjustment temperature ΔKT from the reference temperature KT, the holding holder 36 is made of a material different from the wafer W. Therefore, the wafer W and the holding holder 36 may function as a bimetal. As a result, the wafer W may be unnecessarily deformed, and there may be a problem in the projection of the pattern image. In this regard, in the present embodiment, the wafer W adjusted to a temperature T lower than the reference temperature KT by the temperature adjustment mechanism 23 by the adjustment temperature ΔKT is transferred onto the holding holder 36 of the wafer stage 22. Therefore, it is possible to suppress the occurrence of pattern image projection failure due to deformation of the wafer W held by the holding holder 36.

In addition, you may change each said embodiment into another embodiment as follows.
In each embodiment, the holding holder 36 may be configured to be detachable from the stage main body 35. In this case, the wafer W may be transferred together with the holding holder 36. That is, it is desirable that the substrate transfer apparatus transfer the wafer W while the wafer W is placed on the holding holder 36.

  In the second embodiment, the temperature T of the wafer W transferred into the first chamber 12 may be adjusted to a temperature lower by the adjustment temperature ΔKT than the reference temperature KT on the wafer stage 22. In this case, it is desirable that the wafer W be electrostatically attracted to the holding holder 36 after the temperature T of the wafer W becomes lower than the reference temperature KT by the adjustment temperature ΔKT.

Similarly, in the first embodiment, the temperature T of the wafer W transferred into the first chamber 12 may be adjusted to the reference temperature KT by the wafer stage 22.
In each embodiment, the temperature maintenance mechanism 37 may not be provided in the wafer stage 22.

  In each embodiment, the temperature adjustment mechanism 23 may include a fluid pipe through which a cooling fluid (circulating liquid or gas) flows. In this case, in the temperature adjusting mechanism 23, the wafer W is absorbed by the fluid flowing in the pipe through the fluid pipe.

  In each embodiment, the off-axis alignment system 41 irradiates the alignment mark formed on the wafer W with laser light, and uses the diffracted / scattered light to align the reference mark with the reference mark on the reference mark plate 40. A configuration including an LSA (Laser Step Alignment) type sensor for measuring the position of the mark may be used. Further, the off-axis alignment system 41 irradiates the alignment mark on the wafer W with two types of laser beams having different frequencies from two directions, causes the generated two diffracted beams to interfere with each other, and determines the reference mark plate 40 from the phase. A configuration provided with an LIA (Laser Interferometric Alignment) type sensor that measures the position of the alignment mark with respect to the reference mark may be used. Further, the off-axis alignment system 41 may have a configuration in which an FIA sensor, an LSA sensor, and an LIA sensor are arbitrarily combined.

  -In 1st Embodiment, you may abbreviate | omit the process of step S14. In other words, if the fine adjustment of the size of the pattern image is performed, the fine adjustment of the projection position of the pattern image based on the expansion of the wafer W may not be performed.

  -In 1st Embodiment, you may abbreviate | omit the process of step S13. That is, if the fine adjustment of the projection position of the pattern image is performed, the fine adjustment of the size of the pattern image based on the expansion of the wafer W may not be performed.

  In the first embodiment, when finely adjusting the size of the pattern image projected onto the wafer W, not only the adjustment by the projection optical system 21 but also the reticle stage to bring the reticle R closer to the projection optical system 21 The twenty moving mechanisms 28 may be driven. Further, if the moving mechanism 28 of the reticle stage 20 is driven, the projection optical system 21 need not be adjusted.

  In the first embodiment, the method of outputting the distance from the reference mark of the reference mark plate 40 to the alignment mark of the wafer W shorter than the actual measurement value may be a method of processing in software, A method using a special optical system in which the distance is measured short, that is, a method of processing in hardware may be used.

  In each embodiment, the exposure apparatus 11 manufactures a reticle or mask used in not only a microdevice such as a semiconductor element but also a light exposure apparatus, an EUV exposure apparatus, an X-ray exposure apparatus, and an electron beam exposure apparatus. Therefore, an exposure apparatus that projects an image of a circuit pattern from a mother reticle onto a glass substrate or a silicon wafer may be used. The exposure apparatus 11 is used for manufacturing a display including a liquid crystal display element (LCD) and the like, and is used for manufacturing an exposure apparatus that transfers an image of a device pattern onto a glass plate, a thin film magnetic head, and the like. It may be an exposure apparatus that transfers the image to a ceramic wafer or the like, and an exposure apparatus that is used for manufacturing an image sensor such as a CCD.

When exposure is performed on a wafer other than silicon, it is desirable to set pattern image formation conditions according to the material of the wafer.
In the exposure apparatus 11 of each embodiment, the mask pattern is transferred to the substrate with the mask and the substrate relatively moved, and the scanning stepper that sequentially moves the substrate stepwise, and the mask and the substrate are stationary. The present invention can be applied to any step-and-repeat stepper that transfers a mask pattern onto a substrate and sequentially moves the substrate stepwise.

In each embodiment, the exposure light source 18 is, for example, g-line (436 nm), i-line (365 nm), KrF excimer laser (248 nm), F ₂ laser (157 nm), Kr ₂ laser (146 nm), Ar ₂ laser (126 nm) ) Etc. may be output. The exposure light source 18 amplifies infrared or visible single wavelength laser light oscillated from a DFB semiconductor laser or fiber laser, for example, with a fiber amplifier doped with erbium (or both erbium and ytterbium). Alternatively, a light source capable of outputting a harmonic wave converted to ultraviolet light using a nonlinear optical crystal may be used.

In this case, the inside of the chambers 12 and 15 may be set not in a vacuum atmosphere but in a reduced-pressure atmosphere that is reduced from the atmospheric pressure.
Next, an embodiment of a microdevice manufacturing method using the device manufacturing method by the exposure apparatus 11 of the embodiment of the present invention in the lithography process will be described. FIG. 6 is a flowchart showing a manufacturing example of a micro device (a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, a micro machine, or the like).

  First, in step S101 (design step), function / performance design (for example, circuit design of a semiconductor device) of a micro device is performed, and pattern design for realizing the function is performed. Subsequently, in step S102 (mask manufacturing step), a mask (reticle R or the like) on which the designed circuit pattern is formed is manufactured. On the other hand, in step S103 (substrate manufacturing step), a substrate (a wafer W when a silicon material is used) is manufactured using a material such as silicon, glass, or ceramics.

  Next, in step S104 (substrate processing step), using the mask and substrate prepared in steps S101 to S104, an actual circuit or the like is formed on the substrate by lithography or the like, as will be described later. Next, in step S105 (device assembly step), device assembly is performed using the substrate processed in step S104. Step S105 includes processes such as a dicing process, a bonding process, and a packaging process (chip encapsulation) as necessary. Finally, in step S106 (inspection step), inspections such as an operation confirmation test and a durability test of the microdevice manufactured in step S105 are performed. After these steps, the microdevice is completed and shipped.

FIG. 7 is a diagram illustrating an example of a detailed process of step S104 in the case of a semiconductor device.
In step S111 (oxidation step), the surface of the substrate is oxidized. In step S112 (CVD step), an insulating film is formed on the substrate surface. In step S113 (electrode formation step), an electrode is formed on the substrate by vapor deposition. In step S114 (ion implantation step), ions are implanted into the substrate. Each of the above steps S111 to S114 constitutes a pretreatment process at each stage of the substrate processing, and is selected and executed according to a necessary process at each stage.

  When the above-mentioned pretreatment process is completed in each stage of the substrate process, the posttreatment process is executed as follows. In this post-processing process, first, in step S115 (resist formation step), a photosensitive material is applied to the substrate. In step S116 (exposure step), a mask circuit pattern is formed on the substrate by the lithography system (exposure apparatus 11) described above. Next, in step S117 (development step), the substrate exposed in step S116 is developed to form a mask layer made of a circuit pattern on the surface of the substrate. Subsequently, in step S118 (etching step), the exposed member in a portion other than the portion where the resist remains is removed by etching. In step S119 (resist removal step), the photosensitive material that has become unnecessary after the etching is removed. That is, in step S118 and step S119, the surface of the substrate is processed through the mask layer. By repeatedly performing these pre-processing steps and post-processing steps, multiple circuit patterns are formed on the substrate.

1 is a schematic block diagram that shows an exposure apparatus according to a first embodiment. The block diagram which shows the electric constitution of exposure apparatus. The flowchart explaining the processing routine in 1st Embodiment. (A) is a schematic diagram showing a part of a wafer on which a pattern image is projected in the first chamber, and (b) is a schematic diagram showing a part of the wafer carried out of the first chamber to the outside of the chamber. The flowchart explaining a part of processing routine in 2nd Embodiment. The flowchart of the manufacture example of a device. The detailed flowchart regarding the board | substrate process in the case of a semiconductor device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Exposure apparatus, 12 ... 1st chamber, 20 ... Reticle stage as mask holding device, 21 ... Projection optical system, 22 ... Wafer stage as substrate holding device, 23 ... Temperature adjustment mechanism as cooling device, 36 ... Holding Holder: 37 ... Temperature maintenance mechanism, 39 ... Wafer laser interferometer as measurement device, 41 ... Off-axis alignment system as measurement device, 50 ... Adjustment device, Control device as measurement device, 61 ... Pattern, R ... As mask Reticle, T ... temperature, W ... wafer as substrate.

Claims (13)

An exposure apparatus that forms a pattern on a substrate coated with a photosensitive material in a chamber set in a reduced-pressure atmosphere that is depressurized from atmospheric pressure,
An exposure apparatus comprising an adjusting device that adjusts the formation conditions of the pattern on the substrate in accordance with deformation of the substrate conveyed from the outside of the chamber into the chamber. The exposure apparatus according to claim 1, wherein the substrate expands by being carried into the chamber from outside the chamber. A mask holding device for holding a mask on which the pattern is formed;
An optical system for irradiating the substrate with a radiation beam through the pattern;
The exposure apparatus according to claim 2, wherein the adjustment device adjusts at least one of the mask holding device and the optical system based on an expansion amount of the substrate. A substrate holding device capable of holding and moving the substrate;
A measuring device for measuring the position of the substrate holding device;
4. The exposure apparatus according to claim 2, wherein the adjustment device corrects a position of the substrate holding device measured by the measurement device based on an offset value corresponding to an expansion amount of the substrate. A cooling device for cooling the substrate;
The exposure apparatus according to claim 2, wherein the adjustment device controls the cooling device based on an expansion amount of the substrate. A substrate holding device having a holding holder for holding the substrate and a temperature maintaining mechanism for maintaining the temperature of the substrate held by the holding holder;
The exposure apparatus according to claim 5, wherein the cooling device is provided separately from the holding holder. An exposure apparatus that forms a pattern on a substrate coated with a photosensitive material in a chamber set in a reduced-pressure atmosphere that is depressurized from atmospheric pressure,
An exposure apparatus comprising a cooling device for cooling the substrate transported from outside the chamber into the chamber. An exposure method for forming a pattern on a substrate coated with a photosensitive material in a chamber set in a reduced-pressure atmosphere reduced from atmospheric pressure,
An adjustment step of adjusting the formation conditions of the pattern on the substrate in accordance with the deformation of the substrate conveyed from outside the chamber into the chamber;
An exposure method comprising: after the adjusting step, an exposure step of forming the pattern on the substrate by irradiating the substrate with a radiation beam. The exposure method according to claim 8, wherein in the adjustment step, the size of the pattern formed on the substrate is adjusted based on the deformation of the substrate. The exposure method according to claim 8 or 9, wherein, in the adjustment step, a position of a substrate holding device that holds the substrate is adjusted based on an offset value corresponding to deformation of the substrate. The exposure method according to claim 8, wherein in the adjustment step, the substrate is cooled based on deformation of the substrate. An exposure method for forming a pattern on a substrate coated with a photosensitive material in a chamber set in a reduced-pressure atmosphere reduced from atmospheric pressure,
A cooling step of cooling the substrate transported from outside the chamber into the chamber;
And an exposure step of forming the pattern on the substrate by irradiating the substrate with a radiation beam after the cooling step. In a device manufacturing method including a lithography process,
The device manufacturing method according to claim 8, wherein the lithography process uses the exposure method according to claim 8.

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