JP2008124174A - Aligner and process for fabricating semiconductor element or liquid crystal element employing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aligner in which exposure precision is maintained and enhanced by eliminating uneven temperature occurring around the stay latching portion of a mirror cylinder and achieving temperature stability of the mirror cylinder of the aligner thereby drawing the performance of the aligner to the maximum. <P>SOLUTION: The aligner comprises a mirror 11 for reflecting the exposure light 10 into a mirror cylinder 13, a first temperature regulating section 16 for regulating the mirror temperature, a latching member 1d for latching the first temperature control section 16 into the mirror cylinder 13, and a second temperature regulating section 17 for regulating the temperature of the mirror cylinder 13. The second temperature regulating section 17 is located on the outside of the mirror cylinder opposing a position where the latching member 1d is latched to the mirror cylinder 13 without touching the mirror cylinder 13. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus for exposing a semiconductor element or a liquid crystal element, and particularly relates to a lens barrel temperature control in which a mirror of an exposure apparatus is locked. Moreover, it is related with the manufacturing method of the element using the exposure apparatus.

In the lens barrel of the exposure apparatus, the exposure light passing through the mask is reduced by a projection optical system composed of a plurality of mirrors and imaged on the wafer. In this projection optical system reflection mirror, a radiation cooling plate is provided on the back side of the mirror to prevent high temperature due to heat absorption from exposure light, and the radiation cooling plate is cooled by a Peltier element etc. Yes.
It is difficult to fix a support rod (steer) for fixing a mirror cooling device composed of a radiation cooling plate, a Peltier element or the like from outside the lens barrel, and is usually locked and fixed to the inner wall of the lens barrel. For example, six reflection mirrors are also arranged inside the projection optical system, but the temperature of the mirror's radiation cooling plate is controlled to be lower than the temperature of the lens barrel, so that the lens barrel to which these mirror cooling devices are fixed. Heat is transmitted to the inner wall through a support rod. Therefore, conventionally, the heat insulation material, such as PTFE (polytetrafluoroethylene), is arranged in the connection part, and the device which heat-insulates is given.

However, since PTFE is a thermoplastic resin, it is easy to soften in a high temperature atmosphere, and also has cold flow properties. If the tightening pressure is high, there is a concern that the material may flow out or the surface pressure may decrease. Lack. In addition, as long as it is physically connected, the heat insulation effect cannot be said to be perfect, and for this reason, the cross-sectional area of the support member is reduced, the distance is increased, and a SUS member having low thermal conductivity is used to prevent vibration from being transmitted. However, there has been a concern that heat may be transmitted to the lens tube beyond the heat insulating material such as PTFE. Patent Document 1 describes an example of a conventional structure.
JP 2004-39851 A

Due to such heat transfer, the exposure temperature of the exposure apparatus becomes unstable due to the temperature becoming lower or higher than a predetermined temperature to be maintained by the stage locking portion of the lens barrel. Partial expansion and contraction caused the distance between mirrors to be unstable, and there was concern about deterioration in optical characteristics of exposure.
In the present invention, in view of the above-described problems, the temperature non-uniformity generated around the stage locking portion of the lens barrel is eliminated, and the temperature stability of the lens barrel of the exposure apparatus is realized at a high level. It is an object of the present invention to provide an exposure apparatus that maximizes the exposure and maintains and improves the exposure accuracy.

An exposure apparatus according to the present invention includes a mirror that reflects exposure light in a lens barrel, a first temperature adjustment unit that adjusts the mirror temperature, and a latch that locks the first temperature adjustment unit in the lens barrel. And a second temperature adjusting unit that adjusts the temperature of the lens barrel. The second temperature adjusting unit is outside the lens tube and faces the position where the locking member is locked to the lens tube. It is installed in a non-contact manner with the tube.
Preferably, the exposure apparatus according to the present invention further includes a temperature detection unit for detecting a lens barrel temperature at a portion where the locking member and the lens barrel are locked, and for controlling the second temperature adjustment unit. And

Preferably, the exposure apparatus according to the present invention is characterized in that the second temperature adjusting unit includes at least a radiation temperature adjusting plate that receives radiation heat and an electronic cooling element.
The exposure apparatus according to the present invention is preferably characterized in that the exposure light wavelength of the exposure apparatus is in the EUV region.
The method for manufacturing a semiconductor device or a liquid crystal device according to the present invention includes a mirror that reflects exposure light in a lens barrel, a first temperature adjustment unit that adjusts a mirror temperature, and a first temperature adjustment unit that is a mirror. A locking member that locks in the tube, and a second temperature adjusting unit that adjusts the temperature of the lens barrel, and the second temperature adjusting unit is located at a position outside the lens barrel where the locking member is locked to the lens barrel. The temperature detection unit is provided in a non-contact manner with the lens barrel and detects the temperature of the lens barrel at a portion where the locking member and the lens barrel are locked, and the temperature detection unit detects the lens barrel temperature. And a step of controlling the output of the second temperature adjustment unit based on the detected temperature.

  The method of manufacturing a semiconductor device or a liquid crystal device according to the present invention comprises a liquid-cooling and heat-dissipating Peltier device and a radiation temperature control plate, and is provided in a lens barrel in a non-contact manner with a mirror that reflects exposure light. A mirror cooling device, a liquid-cooling heat radiation type Peltier element and a radiation temperature control plate, which are supported outside the lens barrel in a non-contact manner, and lock the mirror cooling device inside the lens barrel. A thermometer provided in contact with the outer side of the rear surface of the locking part for locking the mirror cooling device inside the lens barrel, and a thermometer provided on the outer side of the rear part of the locking part. The method includes a step of detecting the lens barrel temperature, and a step of uniformly holding the lens barrel at a predetermined reference temperature by controlling the output of the lens barrel temperature control device based on the detected temperature.

  In exposure systems that require particularly high accuracy, cooling means such as air cooling are used even when the lens barrel itself to which the cooling device for the lens to be cooled is fixed is installed in a vacuum housing (body). In an environment where this is not possible, temperature unevenness of the lens barrel can be eliminated, and deterioration of exposure accuracy due to lens barrel expansion and contraction due to temperature can be reduced.

A schematic diagram according to an embodiment of the present invention is shown in FIG.
In this figure, a mirror 11 is a mirror of the projection optical system and reflects the exposure light 10. In the EUV exposure apparatus, the reflectance is theoretically about 70%, and most of the remainder is not reflected by Mira-11, but is converted to heat on the surface of Mira-11.
The mirror 11 itself is separately supported on the back side of the mirror 11 by a support stage not shown in the drawing. On the back side of the mirror 11, the temperature difference with the lens barrel 13 is controlled and maintained by the temperature control effect, and the support stage that supports the mirror 11 itself has a leaf spring-like structure portion. Since the temperature is supported by a support stage that is difficult to transmit temperature, the temperature is not transmitted from the main body of Mira-11 to the lens barrel 13.

On the other hand, a radiation temperature control plate 12 is placed on the back side of the mirror 11 so as to face the mirror 11 independently. Since this radiation temperature control plate 12 absorbs the heat of Mira-11 as radiant heat, a high emissivity material having a high emissivity is provided on the surface facing the rear surface side of Mira-11.
Radiant heat is exchanged between the rear surface of Mira-11 and the radiation temperature control plate 12, and continues until thermal equilibrium is reached as long as there is a temperature difference between the two. Therefore, the radiation temperature control plate 12 is controlled to a relatively low temperature so as to receive radiant heat from the rear side of the mirror 11. This temperature control is performed by electronically cooling the radiation temperature adjusting plate 12 using the Peltier element 16, and based on the detection value of a thermometer (not shown) attached to the radiation temperature adjusting plate 12, By controlling the amount of power supplied, the cooling output is accurately controlled. At this time, the radiation temperature control plate 12 has a temperature lower by about 0.1 ° C. to 1 ° C. than the lens barrel reference temperature.

A liquid cooling jacket 15 is attached to the back side of the Peltier element 16, and the Peltier element 16 itself radiates heat through the liquid cooling jacket 15. A circulating refrigerant is supplied to the liquid cooling jacket 15, and finally heat is carried out from the inside of the lens barrel 13 via the circulating refrigerant.
Here, the radiation temperature adjusting plate 12 is maintained at a low temperature by the Peltier element 16 as described above, and this temperature difference is about 1 ° C. at maximum between the lens barrel 13 and the radiation temperature adjusting plate 12. For this reason, heat conduction that takes away the heat around the locking portion 1d to the lens barrel occurs via the support stage 14 of the radiation temperature adjusting plate 12, and as a result, the temperature of the locking portion 1d of the lens barrel 13 is increased. Since the temperature is locally lowered, a distribution occurs in the temperature of the lens barrel 13, so that the lens barrel temperature distribution cannot be kept uniform. Further, the heat taken away via the support station 14 is about 10 mW per one locking portion, but since there are a plurality of locking portions, the total apparatus reaches several tens to several hundreds mW.

  For this reason, by providing another Peltier element 17 and the radiation temperature adjusting plate 18 at an outer position facing the locking portion 1d of the lens barrel, the temperature of the locking portion 1d of the lens barrel is locally controlled. . Further, the radiation temperature adjusting plate 18 provided outside the lens barrel 13 is supported on the body 1c by the locking portion 1e via the support stem-1b. However, the exposure apparatus according to the local temperature change of the locking portion 1e. There is almost no impact on overall performance.

  As with the radiation temperature control plate 18, a material with a high emissivity may be applied to the surface of the lens barrel facing the radiation temperature control plate 18 of the cooling device outside the lens barrel. Since the lens barrel requires precise control, it is necessary to avoid stress generation due to bimetallic coating, but the coating of high emissivity material with a thickness of several μm to 100 μm has a temperature difference. Considering that the temperature is about 1 ° C., the influence is negligible. Rather, it is preferable from the viewpoint of performing transfer by efficient thermal radiation.

  In this embodiment, since the thermometer 1a is provided in contact with the outer position of the locking portion 1d of the lens barrel 13, the temperature change of the lens barrel 13 via the locking portion 1d is detected quickly, and the Peltier element 17 is driven. By performing the control accurately, the temperature of the locking portion 1d of the lens barrel 13 can be stably controlled within a fluctuation range of about 0.01 ° C. with substantially no change. The temperature control in this case is performed by PID control based on the detection value of the thermometer 1a.

In addition, since ambient air adversely affects exposure, it is necessary to perform exposure in a very stable atmosphere close to a vacuum, and high technology is required for such an extreme optical control.
For this reason, the lens barrel 13 itself is placed in the body 1c, but both the body 1c and the lens barrel 13 are kept in a vacuum state, and thus air conditioning is difficult to use for temperature adjustment of the locking portion 1d. Become. However, for example, heating using a heater can be used. In this case, the heater may be brought into contact with the outside of the locking portion 1d. Moreover, it is good also as temperature control by a liquid medium.

  Further, the Peltier element 17 only needs to locally heat the locking portion 1d together with the radiation temperature control plate 18, and a size of about 1 cm square is sufficient, and it is not necessary to have a large size and high output. However, since the locking portions 1d are provided at 3 to 4 positions per one mirror of the projection optical system, 18 to 24 locking portions are generated in the projection optical system having six mirrors. It is preferable that the number of cooling devices corresponding to the number of stop portions be provided independently for each locking portion in order to quickly reduce the temperature distribution of the entire lens barrel.

Although the temperature control of the projection optical system Mira-11 itself is stably controlled within a range of about 0.1 ° C. to 0.2 ° C., the accuracy of the exposure apparatus is maintained, but the temperature control of the lens barrel 13 is It is necessary to carry out more precisely than the temperature control of Mira-11 itself.
That is, for Mira-11, the mirror 11 mounting position itself hardly fluctuates due to the temperature change, but when the temperature of the lens barrel 13 changes, the heat of the entire lens barrel 13 having a height of about 1 m is obtained. The expansion / contraction due to the above causes and influences the relative position fluctuation of the mirror 11 locked to the lens barrel 13.

  In other words, when the mirror 11 is placed on the mounting position, the reflection accuracy of the exposure light is deteriorated. Therefore, the allowable range of the temperature change and temperature distribution of the lens barrel 13 required for the exposure apparatus is strict, and the allowable temperature fluctuation and distribution range are within the range of about 0.01 ° C. Because of such characteristics, the lens barrel 13 is preferably made of a super invar or the like which is an alloy with extremely little thermal expansion and contraction.

Further, other electronic components and structural materials related to the apparatus are arranged around the body 1c and the lens barrel 13 placed in the body 1c, and heat, cooling, and the like are caused by these. It becomes a factor of temperature fluctuation.
Usually, since the exposure apparatus as a whole is placed in the clean room, the room air conditioning is controlled to a stable temperature as a whole of the apparatus, but locally the locking portion 1d of the lens barrel 13 is provided. A temperature distribution is generated due to heat conduction. In this case, it is difficult to quickly maintain the lens barrel 13 at a stable temperature and a stable temperature distribution only by adjusting the temperature of the entire apparatus while the temperature is deprived by the radiation temperature adjusting plate 12 that controls the temperature of the mirror 11. is there.

  Moreover, it is preferable to provide the temperature control apparatus of the latching | locking part 1d non-contacting with the lens-barrel 13 from the necessity to prevent that a vibration is transmitted to the lens-barrel 13. FIG. This is because if the vibration is transmitted to the lens barrel 13, the exposure accuracy itself is adversely affected, such as causing vibrations in the mirror 11-11. Moreover, since it can be structurally independent from the lens barrel 13 by making it non-contact, it can maintain and inspect separately, respectively, and maintenance work becomes easy.

Next, an exposure apparatus conceptual diagram according to the embodiment of the present invention shown in FIG. 2 will be described.
The EUV exposure apparatus 100 uses EUV light as illumination light for exposure. The wavelength of the EUV light is in the range of 0.1 to 400 nm. In this embodiment, EUV light having a wavelength of about 1 to 50 nm is preferably used. The pattern irradiated on the wafer 103 is determined by the reflective reticle 102. As a result, a reduced image of the pattern by the reticle 102 is formed on the wafer 103. The reticle 102 is fixed to the lower side of the reticle stage 104 via an electrostatic chuck (not shown).

The wafer 103 is disposed on the wafer stage 105. For the exposure, for example, a step scan method can be used. The entire exposure apparatus is arranged in a clean room maintained within a predetermined temperature range, and the inside of the apparatus is controlled to be within the predetermined temperature range.
Since EUV light used for illumination light at the time of exposure has low permeability to the atmosphere, an optical path through which the EUV light passes is arranged in a vacuum chamber 106 maintained in a vacuum by a vacuum pump 107. EUV light is generated by a laser plasma X-ray source. The laser plasma X-ray source includes a laser source light 108 (acting as an excitation light source) and a xenon gas supply device 109. This laser plasma X-ray source is surrounded by a vacuum chamber 110, and EUV light generated by the laser plasma X-ray source passes through a window 111 of the vacuum chamber 110.

  The paraboloidal mirror-113 is disposed in the vicinity of the xenon gas discharge portion. The paraboloidal mirror-113 constitutes a condensing optical system that condenses EUV light generated by the plasma. The focal position of the paraboloidal mirror-113 is adjusted to be close to the position where the xenon gas from the nozzle 112 is released. The EUV light is reflected by the multilayer film of the paraboloidal mirror-113 and reaches the condensing mirror-114 through the window 111 in the vacuum chamber 110. The condensing mirror-114 condenses and reflects the EUV light to the reticle 102.

The EUV light is reflected by the condensing mirror-114 and reaches a predetermined portion of the reticle 102. That is, the paraboloidal mirror-113 and the condensing mirror-114 constitute an illumination system of this exposure apparatus. Reflective surfaces such as the reticle 102, paraboloidal mirror-113, and condensing mirror-114 are structured such that quartz processed with high accuracy is used as a substrate and a multilayer film of Mo and Si is formed thereon.
The reticle 102 has a multilayer film that reflects EUV light and an absorber pattern layer for forming a pattern. The EUV light is patterned by reflecting the EUV light on the reticle 102. The patterned EUV light reaches the wafer 103 through the projection optical system 101.

In FIG. 2, the projection optical system 101 includes four projection optical system mirrors (reflection mirrors) of a first mirror-115a, a second mirror-115b, a third mirror-115c, and a fourth mirror-115d. Each of the mirrors 115a to 115d includes a multilayer film that reflects EUV light.
The EUV light reflected by the reticle 102 is sequentially reflected from the first mirror-115a to the fourth mirror-115d, and is a reduced image (for example, 1/4, 1/5, 1/6) of the pattern of the reticle 102. Reduction ratio). The projection optical system 101 is set to be telecentric on the image side (wafer 103 side).

The reticle 102 is supported at least in the XY plane by a movable reticle stage 104. The wafer 103 is preferably supported and fixed by a wafer stage 105 movable in the X, Y, and Z directions.
When exposing the die on the wafer 103, the illumination system irradiates a predetermined region of the reticle 102 with EUV light. Then, the reticle 102 and the wafer 103 move with respect to the projection optical system 101 at a predetermined speed according to the above reduction ratio. In this way, the reticle pattern is exposed to a predetermined exposure range (with respect to the die) on the wafer 103.

  At the time of exposure, the wafer 103 is disposed in the wafer chamber behind the partition 116 so that the gas generated from the resist on the wafer 103 does not affect the mirrors 115a to 115d of the projection optical system 101. Is preferred. The partition 116 has an opening 116a, and EUV light is irradiated from the mirror-115d onto the wafer 103 through the opening 116a.

The space in the partition 116 is evacuated by a vacuum pump 117. In this way, gaseous dust generated during exposure is prevented from adhering to the mirrors 115a to 115d or the reticle 102, and deterioration of optical performance due to these contaminations is prevented.
The projection optical system 101 is equipped with four projection optical system mirrors-115a to 115d. In particular, the projection optical system mirrors-115a to 115d are suitable for the present invention because they require high-precision stability characteristics. is there. However, the effect of the present invention is exhibited even when applied to other mirror systems and masks. Further, the number of projection optical system mirrors is not limited to four, but may be five to eight.

Next, the embodiment of the present invention shown in FIG. 3 will be described in time series.
First, an exposure condition is determined by determining a semiconductor device that is an exposure object. When exposure is started by the exposure apparatus under the exposure condition, exposure light is irradiated and reflected on a mirror in the exposure apparatus (step). 31).
The mirror irradiated with light converts about 30% of the light energy received on the mirror surface into heat energy and reflects the remaining light. The thermal energy is slowly transmitted over the order of several minutes to the back surface of the mirror, so that the heat is stored in the mirror and the temperature on the back surface of the mirror gradually increases.

In order to reduce the increase in the mirror temperature, the Peltier element of the mirror cooling device starts to be driven, and the Peltier element first cools the radiation temperature control plate in direct contact (step 32).
The cooled radiant temperature adjusting plate transfers radiant heat between the mirror facing surface and a high emissivity material such as ceramic provided on the radiant temperature adjusting plate, thereby cooling the mirror. On the other hand, the support stage that supports the radiation temperature adjusting plate is also cooled by removing heat from the radiation temperature adjusting plate by conduction (step 33). This temperature drop is about 1 ° C. at maximum.

Then, the locking portion of the lens barrel to which the support stage is locked is also deprived of heat by the support stage and cooled (step 34), and a thermometer provided outside the locking portion of the lens barrel is used. A temperature drop is detected (step 35).
When the temperature drop is detected, the Peltier element on the outside of the lens barrel locking part is quickly driven to heat the locking part (step 36), and the local temperature change of the locking part is suppressed. The entire lens barrel temperature is stabilized and the temperature distribution is reduced without delay (step 37).

Next, heat transfer according to this embodiment will be described with reference to the schematic diagram of heat transfer in FIG.
The heat 49 generated on the surface of the projection optical system mirror 41 generates a thermal gradient 4a in the thickness direction of the projection optical system mirror 41, and the heat 49 is slowly transmitted to the rear surface side of the projection optical system mirror 41. The speed of transmission varies slightly depending on the mirror material, but roughly an order of minutes is necessary.
The heat 4a that has reached the rear surface of the projection optical system mirror 41 is absorbed by the surface coating material 42 having a high emissivity by radiation (radiation) with high efficiency. Radiation absorption is performed as long as there is a temperature difference over the entire surface of the radiation temperature control plate 43 facing the back surface of the projection optical system mirror 41.

  On the other hand, the joining region 4 c is first cooled by the Peltier element 46 provided in contact with the back surface of the radiation temperature adjusting plate 43. For this reason, the heat 4 d absorbed by the radiation temperature adjusting plate 43 moves toward the Peltier element 46, and a slight thermal gradient is also generated in the radiation temperature adjusting plate 43. Further, a thermometer 44 for monitoring the cooling temperature of the Peltier element 46 is disposed on the back surface of the radiation temperature control plate 43 at a distance L from the center of the Peltier element 46. In this configuration, since the thermometer 44 is installed on the radiation temperature control plate 43, the mirror 41 of the projection optical system is independent except for its supporting stage, and deformation, vibration, heat, etc. via the thermometer 44 are present. It is not affected by.

For this reason, in order to quickly detect the increase / decrease in the cooling output by the Peltier element 46, the distance L from the thermometer 44 attached to the radiation temperature adjusting plate 43 is preferably closer to the Peltier element 46. If the thermometer 44 is installed on the bonding surface of the element 46, it is not preferable because it becomes an impediment to heat conduction between the Peltier element 46 and the radiation temperature adjusting plate 43.
Therefore, it is necessary to provide the thermometer 44 outside the joint surface between the Peltier element 46 and the radiation temperature adjusting plate 43 and within L = 30 mm. If L = 30 mm or less, the Peltier element 46 can be detected within 10 seconds (typically about 6 to 7 seconds), and the detection delay may cause malfunction in mirror temperature control. Does not occur. The heat 4d absorbed by the radiation temperature adjusting plate 43 is discharged as heat radiation 4e through the refrigerant hose 47 by circulating cooling by the liquid cooling jacket 45 toward the Peltier element 46 side.

In this embodiment, a thermometer 48 is separately installed on the back surface of the center of the projection optical system mirror 41 in a pseudo-barrel system using a projection optical system mirror and a cooling device that are mounted on the exposure apparatus in advance. The mirror specific point is controlled to be kept constant at 23 ° C.
At this time, the distance between the rear surface of the projection optical system mirror 41 and the radiation temperature adjusting plate 43 is about 1/100 of the size of the projection optical system mirror 41 and is as short as about 2 mm. It may be considered that the amount of heat released from the back surface and the amount of heat absorbed by the radiation temperature control plate are equal.

However, since there is no thermometer 48 at the time of exposure by an actual exposure apparatus, the thermometer 48 is used for confirmation monitoring, the Peltier element output control is performed based on the detection value of the thermometer 44, and the distance L is 25 mm. Do.
On the other hand, the radiation temperature adjusting plate 43 is cooled by the Peltier element 46, and the projection optical system mirror 41 is of course controlled to be lower than the reference temperature of the lens barrel. For this reason, the support stem 4g of the radiation temperature control plate 43 is also cooled. The support stem-4g uses a heat insulating material to reduce such heat conduction, and has been devised in a shape in which the cross-sectional area is small, the distance is long, and vibration is not easily transmitted. It cannot be blocked, resulting in the lens barrel being cooled.

The lens barrel referred to in this embodiment is typically a vacuum chamber that is mounted in a vacuum body of an exposure apparatus and in which a projection optical system mirror is mounted. However, the present invention may be applied to a case that is held in a vacuum case and that requires temperature stability by locally controlling the temperature.
The exposure light referred to in this embodiment is typically drawn on a resist or the like applied to a semiconductor element or a liquid crystal element, thereby giving a predetermined wiring to the semiconductor element or the liquid crystal element, The light used for the drawing apparatus for modeling in a shape structure. However, the present invention is not limited to this, and any device may be used as long as it supplies light energy to perform a certain process on a semiconductor element or the like.

  In addition, the mirror referred to in this embodiment is, for example, a reflecting mirror having an aspheric reflecting surface, and a Mo / Si multilayer film is formed to improve the reflectivity of EUV light and approach 70%. It may be what you have. A mirror group consisting of high-precision aspherical mirrors having a numerical aperture of 0.2 to 0.3 in order to satisfy a small wavefront aberration required for a projection optical system mirror and capable of withstanding the requirement of a wavefront aberration of 1 nm RMS or less. It is preferable that The multilayer film may be formed of a material such as beryllium or silicon and ruthenium or rhodium.

  In addition, the first temperature adjustment unit referred to in this embodiment is a cooling and heating device for stably controlling the mirror in the lens barrel at a predetermined temperature, for example, 23 ° C., and includes a Peltier element and a radiation temperature control. It may be composed of a plate and a liquid cooling device. Furthermore, a thermometer for temperature detection may be provided, and temperature adjustment by a heater, liquid cooling, or a heat pipe may be used instead of the Peltier element.

  Further, the locking member referred to in this embodiment is preferably made of a material such as SUS having a small outgas and a low thermal conductivity, and a material having a small thermal deformation and thermal expansion and contraction is preferred. For example, it may be a Cr-containing ternary alloy or a Co-containing ternary alloy, which is an alloy made of Fe or Ni, or so-called Kovar (Fe 52%, Ni 29%, Co 17%) or Inconel (Ni 72%, Cr 15%, Fe6). %) May be used. Furthermore, a shape in which the cross-sectional area is small and the distance is long and the vibration does not increase is preferable, for example, a leaf spring shape.

  In addition, the second temperature adjustment unit referred to in this embodiment typically includes a device for heating and cooling the lens barrel, and includes a thermometer such as a radiation thermometer, a platinum resistor, and a thermocouple. May be. It is preferably composed of a Peltier element that can smoothly control the temperature even in a vacuum atmosphere. Furthermore, in order to prevent a decrease in the degree of vacuum and contamination at the atomic level, it is preferably made of a material with low outgas or coated, and a high-temperature treatment or a surface-treated material such as TiN is used. May be. The temperature control may be heated or cooled depending on the situation, and it is more preferable to be able to cope with both.

  Further, the outer side of the lens barrel referred to in this embodiment is an outer shell of the lens barrel and is not limited to being the outermost shell. That is, when the lens barrel has a plurality of layer structures, the outer side of the lens barrel is the outer side including the outer surface of the innermost shell. Preferably, it is a layer having a portion to which the support stage of the radiation temperature control plate is locked, and is the nearest outer layer to which heat is directly or indirectly transmitted. It may be the inner surface side of the outer layer.

In addition, the non-contact referred to in this embodiment typically means a state where they are physically separated. However, the present invention may be applied because it is considered to be substantially non-contact even if the contact portion is physically included as long as it is held to an extent that can prevent generation and transmission of vibration and stress. .
Moreover, the latching | locking part said to this embodiment means the connection location or fastening location for producing a fixed state physically and mechanically. Since local heat transfer is mainly performed through the engaging portion, the second temperature adjusting portion is preferably arranged at a position where the temperature can be adjusted with respect to the engaging portion.

On the other hand, since the in-cylinder device including the inner wall of the lens barrel and the mirror transmits and receives heat through radiation, even if a temperature control device is arranged at a location where a local temperature distribution occurs on the inner surface of the lens barrel. Good. Since the support stage of the mirror radiation temperature control plate of the projection optical system has a complicated structure in the EUV exposure apparatus, it is normally held on the inner wall of the lens barrel and is not pulled out and locked to the body.
In this embodiment, the lens barrel temperature is preferably maintained at 23 ° C. as a reference temperature. However, in an exposure apparatus equipped with a large number of heat sources, heat sinks, and heat transfer media, there may be local temperature distribution and temperature instability, so this effect is eliminated as much as possible. Therefore, the lens barrel is preferably held in the vacuum housing body.

  In addition, the radiation temperature control plate referred to in this embodiment refers to a plate-shaped heat medium that can perform relay transmission of heat exchange in order to cool or heat a mirror, for example. A fan shape or a three-dimensional shape may be used, and the shape is not restricted. Since a material that can efficiently transfer heat and has low outgas and high thermal stability is preferred, a super inverter may be used.

Furthermore, the radiation temperature control board which distribute | arranged the high emissivity raw material for efficiently giving and receiving radiant heat to the one part or all may be sufficient. The high emissivity material may be silicon oxide, nitride, metal oxide, Al ₂ O ₃ , TiC, SiC, ZrC, AlN, TiN, BN, SiO ₂ , ZrO ₂ , MgO, 3Al ₂ O ₃ etc. It may be used.
In addition, a high emissivity material with a radiation rate of 0.6 or more, preferably 0.7 or more, made of glass or an inorganic compound, is coated with a ceramic material using a metal with relatively good thermal conductivity such as an aluminum alloy as a base material. For example, a thickness of several μm to 100 μm may be formed by sputtering, thermal spraying, follow, bonding, or the like. In addition, the base material may be gold, silver, copper, tungsten, molybdenum, zinc, etc., except for the high emissivity material part, the emissivity is 0.3 or less, preferably 0.2 emissivity or less. It is possible to reduce the influence due to the transfer of heat from other than the opposite surface.

  In recent years, fine exposure technology has progressed in semiconductor exposure apparatuses from g-line to i-line, and to an excimer laser (KrF / ArF) exposure apparatus. Furthermore, as a lithography apparatus, EUVL (ultra-fine exposure technique) (Extreme Ultra Violet Lithography) —Extreme Ultraviolet Lithography. In addition, in liquid crystal display exposure apparatuses, the size of liquid crystal panel substrates has been increased to the seventh, eighth, and next generations.

This EUV exposure system is promising for the development of next-generation computer chips along with electron beam lithography as the next generation of 157nm lithography tools as a technology for printing fine circuit images on silicon wafers. This technology uses a light beam having a wavelength of about 1/20 of DUV (far ultraviolet) used for chip manufacture.
According to the present embodiment, the temperature of the lens barrel of the locking portion can be adjusted in a non-contact manner, and the temperature of the entire lens barrel can be kept stable and efficient against local temperature changes transmitted from the locking portion to the lens barrel. It becomes possible to adjust the temperature quickly.

Further, it is possible to quickly detect a temperature change at a position where the locking member of the lens barrel is locked, thereby enabling more accurate target temperature control.
In addition, efficient and quick heat dissipation is possible, and precise cooling control is possible.
Even a fine pattern can be accurately exposed and patterned, and the influence of the heat generated in the process on the lens barrel can be reduced.

Further, it is possible to reduce unevenness and instability of the temperature of the lens barrel, eliminate the influence due to the temperature of the lens barrel on the manufacturing element, and to manufacture a stable element as a whole.
Further, since the temperature of the lens barrel is not uniform and unstable, and the lens barrel can be maintained at the design reference temperature, the above-described influence on the manufacturing element can be eliminated, and the element can be stably manufactured as a whole.
This embodiment can also be applied to an apparatus that is a vacuum microscope or the like and has a mirror cooling mechanism or the like. In addition, since a lens barrel made of SUS or the like has a large expansion and contraction due to a temperature change, the effect is greater when the present invention is applied.

Next, a method for manufacturing a micro device will be described. The microdevice is a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, a micromachine, or the like. In the following description, a semiconductor device is assumed as a typical example of a micro device.
FIG. 5 is a flowchart showing the manufacturing process of the microdevice. As shown in FIG. 5, first, in step S201 (design step), a microdevice function / performance design (semiconductor device circuit design, etc.) is performed, and a pattern design for realizing the function is performed. In the subsequent step S202 (mask manufacturing step), a mask (reticle) having the designed circuit pattern is manufactured. On the other hand, in step S203 (wafer manufacturing step), a wafer is manufactured using a semiconductor material such as silicon.

  Next, in step S204 (wafer processing step), a circuit or the like is formed on the wafer by photolithography using the mask and wafer. In the subsequent step S205 (device assembly step), a device is assembled using the processed wafer. This step S205 includes processes such as a dicing process, a bonding process, and a packaging process (chip encapsulation) as necessary.

Finally, in step S206 (inspection step), inspections such as an operation confirmation test and a durability test of the assembled micro device are performed. After going through each of these steps, the microdevice is completed and shipped.
FIG. 6 is a diagram showing a detailed flow of the wafer processing step (step S204) in FIG. As shown in FIG. 6, in the wafer processing step, a pre-processing process and a post-processing process are repeated over a plurality of stages, and a circuit pattern is laminated on the wafer. In the pre-processing process at each stage, only necessary processes among the following processes are selectively executed as necessary.

  In step S211 (oxidation step) of the pretreatment process, an oxidation process is performed on the surface of the wafer. In step S212 (CVD step) of the pretreatment process, an insulating film is formed on the surface of the wafer. In step S213 (electrode formation step) of the pretreatment process, electrodes are formed on the surface of the wafer by vapor deposition. In step S214 (ion implantation step) of the pretreatment process, electrical properties such as n-type and p-type are formed by implanting ions into the wafer.

In the first step S215 (resist formation step) of the post-processing process, a resist is applied to the wafer. In the subsequent step S216 (exposure step), the resist on the wafer is exposed with the circuit pattern of the mask by the projection exposure apparatus. As the projection exposure apparatus, the EUV exposure apparatus described above can be used.
In the subsequent step S217 (developing step), a developing process for developing the resist is performed on the wafer, and in step S218 (etching step), an etching process using the resist as an etching mask is performed on the wafer. In the final step S219 (resist removal step), the resist remaining after the etching process is removed.

  In this microdevice manufacturing method, since the exposure apparatus described above is used in step S216 (exposure step) in FIG. 6, the microdevice can be manufactured at a high throughput.

  The present invention can be used in a semiconductor manufacturing apparatus manufacturer and a semiconductor manufacturing process using the manufacturing apparatus, and a liquid crystal manufacturing process using the liquid crystal manufacturing apparatus manufacturer and the manufacturing apparatus. In particular, it can be used for a manufacturing apparatus manufacturer related to exposure.

The schematic diagram concerning embodiment of this invention FIG. 1 is a conceptual diagram of an exposure apparatus according to an embodiment of the present invention. Embodiment flow of the present invention Schematic diagram of heat transfer Flow chart showing the manufacturing process of microdevices Wafer processing step description flow

Explanation of symbols

10..Exposure light, 11..Mirror, 12, 18..Radiation temperature control plate, 13..Tube, 14..Supporting stage, 15..19..Liquid cooling jacket, 16. 17..Peltier Element, 1a, thermometer, 1b, support stage, 1c, body, 1d, locking part,

Claims (6)

A mirror that reflects exposure light into the lens barrel;
A first temperature adjustment unit for adjusting the mirror temperature;
A locking member for locking the first temperature adjusting unit in the lens barrel;
A second temperature adjustment unit for adjusting the temperature of the lens barrel;
The exposure is characterized in that the second temperature adjusting unit is disposed outside the lens barrel facing the position where the locking member is locked to the lens barrel and is not in contact with the lens barrel. apparatus. The exposure apparatus according to claim 1, further comprising: a temperature detection unit configured to detect the temperature of the lens barrel at a portion where the locking member and the lens barrel are locked, and to control the second temperature adjustment unit. The exposure apparatus according to claim 1, wherein the second temperature adjusting unit includes at least a radiation temperature adjusting plate that receives radiant heat and an electronic cooling element. The exposure apparatus according to any one of claims 1 to 3, wherein an exposure light wavelength of the exposure apparatus is in an EUV region. A mirror for reflecting exposure light in the lens barrel; a first temperature adjusting portion for adjusting a mirror temperature; a locking member for locking the first temperature adjusting portion in the lens barrel; and the lens barrel. A second temperature adjusting portion for adjusting the temperature, wherein the second temperature adjusting portion is located outside the lens barrel where the locking member is locked to the lens barrel, and is provided in a non-contact manner with the lens barrel A temperature detecting unit for detecting a temperature of a lens barrel at a portion for locking the locking member and the lens barrel;
Detecting the temperature of the lens barrel from a temperature detection unit for detecting the temperature of the lens barrel;
Performing output control of the second temperature adjustment unit based on the detected temperature;
A method for manufacturing a semiconductor device or a liquid crystal device having the following. A liquid cooling and heat dissipation type Peltier element and a radiation temperature control plate, installed in a non-contact manner with a mirror that reflects exposure light, and a mirror cooling device provided in the lens barrel,
The back surface of the locking part which consists of a Peltier element of liquid cooling and heat dissipation and a radiation temperature control plate, is supported outside the lens barrel in contact with the lens barrel, and locks the mirror cooling device inside the lens barrel A lens barrel temperature control device provided on the outside;
A thermometer provided in contact with the outside of the rear surface of the locking portion for locking the mirror cooling device inside the lens barrel;
Detecting the temperature of the lens barrel from the thermometer;
A step of uniformly holding the lens barrel at a predetermined reference temperature by controlling the output of the lens barrel temperature control device based on the detected temperature;
A method for manufacturing a semiconductor device or a liquid crystal device having the following.

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