JP2006108402A - Method for drying and treating fine structure, its device and sample holder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for drying and treating a fine structure without generating pattern collapsing and sticking to a large-diameter substrate forming a fine structure on its surface and being capable of uniformly drying the fine structure, in a short time, because rinsing liquid can be removed in the short time, and to provide a device for the method and a sample holder. <P>SOLUTION: The method for drying and treating the fine structure has a process in which the sample holder with the installed substrate is mounted in a high-pressure vessel, and the process in which a fluid under a gas state at a normal temperature and at a normal pressure and under a liquid state at a high pressure is introduced into the high-pressure vessel up to a set pressure under the liquid state or a supercritical state. The method further has a process in which the rinsing liquid is collected on the upper side or the lower side in the high-pressure vessel through a specified path for the sample holder, formed by inclining the high-pressure vessel and by an inclination, and the process in which the collected rinsing liquid is discharged, from at least one discharge opening formed on the upper side or the lower side in the inclined high-pressure vessel. The method further has a process in which the temperature of the fluid is increased at a critical temperature or higher as the pressure of the fluid is left kept, as it is, at a critical pressure or higher, and the process in which the fluid is discharged as the temperature of the fluid is left as it is kept at the critical temperature or higher. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a novel fine structure drying method and apparatus.

  Conventionally, a large-scale, high-density, high-performance device forms a pattern on a resist formed on a silicon wafer through exposure, development, rinsing, and drying, followed by coating, etching, rinsing, and drying. Manufactured through a process. In particular, the resist is a polymer material that is sensitive to light, X-rays, electron beams, etc., and in each process, a chemical solution such as a developer or a rinse solution is used in the development and rinse cleaning process, so the rinse cleaning process After that, a drying process is essential.

  In this drying process, when the space width between the resist patterns formed on the substrate is about 100 nm or less, the surface tension of the chemical solution remaining between the patterns causes Laplace force (capillary force) to act between the patterns and the pattern collapses. The problem that occurs occurs.

  On the other hand, for example, manufacturing a MEMS (Micro Electromechanical System) part of a three-dimensional microstructure part having a movable part such as an acceleration sensor or an actuator includes a step of forming a microstructure including a movable part with an etching solution such as hydrofluoric acid, It includes a step of cleaning and removing the etching solution with pure water rinse and a drying step. Also in this drying process, the surface tension due to the chemical solution remaining between the fine structures acts like the resist pattern, and the phenomenon that the movable part sticks to the substrate occurs. In order to prevent pattern collapse and sticking due to the action of the surface tension of the chemical solution remaining between the microstructures, as a drying process for reducing the surface tension acting between the microstructures, predetermined processes shown in Patent Documents 1 to 3 There is a method using a supercritical fluid such as carbon dioxide while using a pressure vessel.

This conventional drying method using a supercritical fluid such as carbon dioxide has the following basic steps.
(1) A step in which a remaining liquid such as water in a sample that is not soluble in a liquid or a fluid in a supercritical state is previously replaced with an organic solvent such as ethanol or 2-propanol that is soluble in the fluid.
(2) A step of horizontally transporting and setting in a high-pressure container serving as a drying chamber in a state dipped or wetted in the rinse liquid, specifically, a condition in which the rinse liquid is placed on the substrate.
(3) A step of sealing the high-pressure vessel, introducing a liquid or supercritical fluid into the high-pressure vessel, and increasing the pressure to a predetermined pressure.
(4) A step of replacing the liquid or supercritical fluid introduced into the high-pressure vessel with the rinse liquid.
(5) In the case where a liquid fluid is introduced into the high-pressure vessel, the step of raising the pressure and raising the temperature of the fluid in the high-pressure vessel to a critical point or higher after the replacement of the fluid and the rinse liquid
(6) A step of discharging a fluid in a supercritical state from the high-pressure vessel.
(7) A step of taking out the substrate from the high-pressure vessel.

JP 2003-109933 A JP 09-139374 A JP 05-315241 A

  However, the conventional drying method using a supercritical fluid requires a drying time of about several tens of minutes to 1 hour or more, especially for a fine structure uniformly formed on a large-diameter substrate having a diameter of 100 mm or more. There was no pattern collapse or sticking uniformly, and it was impossible to dry. This is due to the fact that the rinsing liquid on the large-diameter substrate is several hundred ml or more, and the replacement with the liquid or the supercritical fluid cannot be performed uniformly in a short time.

  The object of the present invention is that the rinse liquid can be removed in a short time, and there is no pattern collapse or sticking to a large-diameter substrate having a fine structure formed on the surface, and the fine structure drying can be uniformly dried in a short time. It is to provide a processing method, an apparatus thereof, and a sample holder thereof.

  The present invention includes a step of installing a sample holder in which a substrate having a fine structure immersed or wet in a rinsing solution is installed in a high-pressure vessel, a gas at normal temperature and normal pressure, and a liquid at high pressure in the high-pressure vessel. A fluid or a supercritical state up to a set pressure, and tilting the high-pressure vessel and a specific passage of the sample holder formed by the tilt, preferably along the direction of tilting the high-pressure vessel A step of collecting the rinse liquid on the upper side or the lower side in the high-pressure vessel through an inclined groove formed in the sample holder having a predetermined width and rotating the high-pressure vessel on the substrate in the same direction as the inclination. At least one of the steps of collecting the rinse liquid on the upper side or the lower side in the inclined high-pressure vessel, and the collected rinse liquid on the inclined side. A step of discharging from at least one discharge port provided on the upper side or the lower side in the high-pressure vessel, and a step of raising the temperature of the fluid to a critical temperature or higher while maintaining the pressure of the fluid at a critical pressure or higher. And a step of discharging the fluid while keeping the temperature of the fluid at a critical temperature or higher in order.

  That is, according to the embodiment of the present invention, a substrate on which a fine structure such as a resist pattern, a glass mask, or a MEMS part is formed on the surface through development after exposure or etching and rinsing with a chemical solution is immersed or wetted in the rinse solution. In a high-pressure container, keep the high-pressure container horizontal in the high-pressure container, which is a gas at normal temperature and normal pressure, and a liquid under high pressure. In addition, the pressure increase rate in the high-pressure vessel is controlled to suppress the turbidity of the fluid and the rinse liquid and the pressure impact on the fine structure on the substrate. Thereafter, the high pressure vessel is tilted and rotated and vibrated up and down in the tilt direction, and at least one of the temperature and pressure of the fluid in the high pressure vessel is changed to change the specific gravity of the fluid. In addition, a vortex or convection due to a change in specific gravity is generated to facilitate replacement of the fluid Trins solution, and the time for collecting the rinse liquid on the upper side or the lower side in the high-pressure vessel can be shortened.

  However, some rinsing liquids cannot be separated due to the surface tension between the outer periphery of the substrate, the vicinity of the circumferential contact between the sample holder and the substrate, or between the sample holder and the substrate, even if there is a difference in specific gravity. End up. In order to efficiently separate the remaining rinsing liquid, the rinsing liquid is secured by providing a path for inclining and separating through an inclined groove provided in the sample holder and applying a water-repellent treatment or mirror finish to the sample holder itself. Can be easily separated, and the time for collecting the separated rinse liquid on the upper side or the lower side of the high-pressure vessel can be shortened. For optimal separation, especially in the case of rinsing liquid gathering under the high-pressure vessel, the groove position of the sample holder is inclined, and when the rinsing liquid is gathering upward of the high-pressure vessel, the groove position of the sample holder When the rinsing liquid is tilted and collected at the upper or lower side of the high-pressure container, the rinsing liquid is separated while vibrating the high-pressure container up and down. And a step of performing.

  Furthermore, the temperature is controlled by heaters installed at the top and bottom of the sample holder for installing the substrate, and the temperature of the rinsing liquid and fluid remaining in the vicinity of the fine structure on the substrate is controlled in the process of discharging the rinsing liquid. , To generate a change in state due to vortex or convection due to density change in the rinsing liquid and fluid, to promote replacement of the fluid and rinsing liquid, and to minimize heat conduction to the high-pressure vessel except near the substrate, high-pressure vessel After introducing the fluid into the interior and reaching a predetermined pressure, it is preferable to incline the high-pressure vessel and then stop the introduction of fluid and stop the flow of fluid in the high-pressure vessel.

  Furthermore, according to an embodiment of the present invention, the fluid is liquid or supercritical carbon dioxide, the density is changed to a predetermined density of 0.65 to 0.95 g / ml, and the substrate is silicon or glass. It is preferable to be a mask and to introduce the fluid from the lower side of the sample holder when the fluid is introduced into the high-pressure vessel, thereby controlling the pressure increase rate in the high-pressure vessel to suppress turbidity between the fluid and the rinsing liquid.

  Further, according to the embodiment of the present invention, the rinsing liquid having a specific gravity greater than that of the fluid and the rinsing liquid having a specific gravity smaller than that of the fluid can be used at the same time or one of them, and are collected on the upper side and the lower side of the inclined high-pressure vessel. Can be discharged. It is like a MEMS part that has a process of repeating the specific gravity change of the fluid, a process of suppressing the flow of the fluid in the high-pressure vessel, and a process of introducing the replacement fluid with a pump in order to replace the rinse liquid and the fluid in sequence. This is particularly effective when the three-dimensional structure is dried.

  Further, according to the embodiment of the present invention, sufficient fluid to dissolve the rinsing liquid in the high-pressure vessel is obtained by pumping the fluid to the high-pressure vessel by a plunger pump or a diaphragm pump for compressing and sending the fluid. In order to condense the turbidity of the fluid and the rinse liquid that occurs at the time of fluid introduction in a short time, the flow rate of pumping the fluid to zero is set to zero, and the flow rate of the replacement fluid in the high-pressure vessel is minimized. A step of zeroing.

  Furthermore, when two or more types of rinse liquids having a specific gravity higher than that of the replacement fluid and rinse liquids having a specific gravity lower than that of the replacement fluid are used at the same time by disposing a discharge port for the rinse liquid on at least one of the upper and lower parts of the high-pressure vessel. However, the rinse remaining in the high-pressure vessel without dissolving in the fluid can be selectively discharged from the high-pressure vessel.

  Equipped with temperature regulators for temperature control at the top and bottom of the sample holder for installing the substrate, and the heat control to the high-pressure processing vessel is minimized by adjusting the temperature only in the vicinity of the substrate. The process of zeroing the flow rate of the fluid can minimize the convection in the turbid state of the rinse liquid and the replacement fluid, converge the turbid state of the rinse liquid in a short time, and It can be collected on the upper side or the lower side and discharged.

  In addition, since the concentration of the substitution solvent in the rinse solution can be kept to a minimum, the decrease in solubility can also be minimized, and high substitution efficiency can be obtained by suppressing the decrease in solubility in the rinse solution remaining between the fine structures of the solvent. And the replacement process can be shortened. In addition, various rinse solutions can be used.

  Furthermore, the present invention relates to a high-pressure container in which a substrate having a fine structure immersed or wet in a rinsing liquid is mounted on a sample holder, and a fluid that is a gas at normal temperature and normal pressure and a liquid at high pressure. A fluid storage container for storing in a critical state, a means for inclining the high-pressure container, a means for vibrating the high-pressure container in the inclining direction, and the sample holder through the groove provided on the mounting surface side of the substrate. At least one of the means for collecting the liquid at the upper side or the lower side of the high-pressure vessel and at least one of the upper side or the lower side of the high-pressure vessel for discharging the rinse liquid collected at the upper side or the lower side in the inclined high-pressure vessel And a microstructural drying apparatus characterized by having a discharged outlet.

  In the present invention, a substrate having a fine structure immersed or wet in a rinsing liquid is mounted in a high-pressure vessel, and the rinsing liquid is supplied by a fluid that is a gas at normal temperature and normal pressure and a liquid at high pressure. In the sample holder for a fine structure drying processing apparatus to be dried and removed, an inclined groove having a predetermined width formed along a direction in which the high-pressure vessel is inclined outward from a predetermined position of a contact portion of the mounting portion of the substrate. It is characterized by having.

  According to the present invention, the rinsing liquid can be removed in a short time, so that there is no pattern collapse or sticking to a large-diameter substrate having a fine structure formed on the surface, and the fine structure drying can be uniformly dried in a short time. A processing method, an apparatus thereof, and a sample holder thereof can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to specific examples.

  FIG. 1 is a cross-sectional view showing an example of the fine structure drying apparatus of the present invention. As shown in FIG. 1, a high-pressure vessel 103 in which a substrate 101 having a fine structure immersed or wet in a rinsing liquid 102 is mounted on a sample holder 104 and installed, is a gas at normal temperature and normal pressure, and a liquid at high pressure Fluid storage container 115 for storing fluid in a liquid or supercritical state, means for inclining high-pressure container 103, means for vibrating high-pressure container 103 in an inclining direction, and collecting on the upper side or lower side in inclined high-pressure container 103 And a discharge port 119 provided on at least one of the upper side and the lower side of the high-pressure vessel 103 for discharging the rinse liquid 121. Moreover, the sample holder 104 has the inclined groove 1 provided toward the outer side from the mounting surface of the board | substrate 101 mentioned later.

  The high-pressure vessel 103 serving as a drying processing chamber is composed of an upper lid 105 and a lower vessel 124, and the lid 101 is opened to install the substrate 101. The high-pressure vessel 103 has tilting means that can tilt from horizontal to vertical. The high-pressure vessel 103 is provided with rotating shafts having gears for tilting perpendicular to the paper surface on both sides of the lower container 124, and can be tilted left and right from the horizontal to 90 degrees from the horizontal to the paper surface by a motor. Is. The filter 112 and the valve 113 are fixed to the lower container 124, and are connected to the pressure control device 123 by a high-pressure flexible pipe. Further, the back pressure control valve 109 and the valve 110 are fixed to the lid 105, and the valve 117 and the pressure control valve 118 are fixed to the lower container 124, and their tips are connected by a high-pressure flexible pipe and can rotate.

  The substrate 101 has a fine structure formed on the surface through development and rinsing steps after exposure, and a rinse liquid 102 is placed on the entire surface of the substrate 101. The sample holder 104 provided in the high-pressure vessel 103 is attached to the surface of the substrate 101. Installed. Above and below the sample holder 104 are heaters 106 that can control the temperature of the sample holder 104 and carbon dioxide 115 locally or uniformly. A pump 114 and a liquid carbon dioxide container 115 are connected to the high-pressure container 103 through a valve 113 by piping. The high pressure vessel 103 is connected to the back pressure control valves 109 and 108 via the valve 110 at the upper part and the valve 107 at the lower part, respectively. When the set pressure is exceeded, the fluid in the high pressure vessel 103 or from the discharge port 119 or the discharge port 120 The rinse liquid is discharged.

  The high-pressure vessel 103 has a temperature adjustment function by circulation of a heat medium formed inside the vessel constituent material, can control the temperature of the fluid in the range of 0 to 60 ° C., and has a fine structure in the vicinity of the substrate 101. In order to minimize the convection due to the temperature difference on the surface side, a temperature adjuster 106 capable of controlling the temperature of the sample holder 104 and the carbon dioxide 115 locally or uniformly is provided above and below the sample holder 104.

  FIG. 2 is a plan view (a), a BB sectional view (b), and a CC sectional view (c) of the sample holder according to the present invention. Although the substrate 101 is not mounted in the plan view (a), (b) and (d) show a state where the substrate 101 is mounted. As shown in FIG. 2, a substrate 101 having a fine structure immersed or wetted in a rinsing liquid 102 is mounted in a high-pressure vessel 103 and installed by a fluid that is a gas at normal temperature and normal pressure and a liquid at high pressure. A sample holder for a microstructural drying processing apparatus for drying and removing the rinsing liquid 102, which is formed along a direction in which the high-pressure vessel 103 is inclined from the predetermined position of the contact portion of the mounting portion of the substrate 101 to the outside. An inclined groove 1 having a width is provided.

  The substrate 101 is in a state where no rinse liquid is placed thereon. In the sample holder 104 of this embodiment, the inclined groove 1 having a predetermined width is provided in the flat portion 9, and the four pins of the holding means provided in the high-pressure vessel 103 through the four holding guide holes 2. Is inserted and set. The substrate 101 is inserted into the substrate insertion portion 10 and is fixed by the substrate presser 11 that is pressed to the right side through the guide pins 4 in the slide groove 6 by the two coil springs 5. The substrate holder 11 is held by the holding holder 7. The heater escape groove 3 is inserted so as not to contact the heater escape groove 3 so that the rod-like heater 106 provided in the high-pressure vessel 103 can be brought closer to the substrate 101.

Hereinafter, the drying process of a present Example is demonstrated.
(1) After forming an EB resist (ZEP-7000: manufactured by ZEON CORPORATION) with a film thickness of 220 nm on an LSI silicon substrate having a diameter of 200 mm and drying, the pattern was drawn with an electron beam with a pattern width of 60 nm or less. A lid 105 and a lower container together with the sample holder 104 described above, which is mounted with the substrate 101 that has been developed for several tens of seconds with normal hexyl acetate, rinsed for several tens of seconds with a 2-propanol rinse solution 102, and has a fine structure formed on the surface. Four pins provided in the high-pressure vessel 103 composed of 124 are installed through the holding guide hole 2. At this time, the rinsing liquid 102 made of 2-propanol soluble in liquid carbon dioxide 116 or supercritical carbon dioxide is on the entire surface of the substrate 101 with a thickness of several millimeters on the substrate 101, or the substrate 101 Is a state immersed in the rinse liquid 102.
(2) When the substrate 101 is installed in the sample holder 104 in the high-pressure processing vessel 103, the lid 105 is opened while the high-pressure processing vessel 103 is in a horizontal state, and the lid 105 is closed after installation to bring the high-pressure processing vessel 103 into an airtight state. To do. At this time, the valves 117, 110, and 107 are closed.
(3) When the valve 113 is opened, liquid carbon dioxide 116 is introduced into the high-pressure vessel 103. At this time, in order not to damage the fine structure formed on the substrate 101 by the pressure control device 123 and to minimize the turbidity of the rinsing liquid 102 and the liquid carbon dioxide, the steady pressure of the liquid carbon dioxide container 115 is about 5 MPa. Up to 1 MPa / several seconds. Liquid carbon dioxide introduced into the high-pressure processing vessel 103 passes through the filter 112 to remove impurities. After introducing the liquid carbon dioxide container 115 to a steady pressure, the pump 114 is operated to compress and deliver the liquid carbon dioxide 116 to a set pressure (about 7.5 to 13 MPa).
(4) FIG. 3 is a cross-sectional view of the microstructure drying apparatus showing a state in which the high-pressure processing vessel 103 is inclined. As shown in FIG. 3, by tilting the high-pressure processing vessel 103 in the tilting and rotating direction 125 by the tilting means, most of the 2-propanol rinsing liquid 102 placed on the substrate 101 is separated from the surface of the substrate 101 and enters the high-pressure vessel 103. The liquid carbon dioxide 116 in the liquid state is almost dissolved and mixed to become a turbid state. When the specific gravity difference with the rinsing liquid 102 is large, the turbid state stabilizes relatively quickly, so that it can be tilted quickly. Further, replacement and discharge can be effectively performed by applying a slow vibration 130 several times in the same direction as the tilt rotation direction 125 from the tilted state.
(5) When the temperature of the high-pressure vessel 103 is lowered by circulation of the heat medium and controlled to about 5 ° C., the specific gravity of liquid carbon dioxide becomes 0.95 g / ml, and the specific gravity of the rinse liquid 102 made of 2-propanol is 0.80 g. Since the specific gravity difference with respect to / ml is about 0.15 g / ml, as shown in FIG. 2, the rinsing liquid 102 collects in the upper portion of the inclined high-pressure processing vessel 103. The pressure increase to the set pressure (about 7.5 to 13 MPa) and the temperature decrease to 5 ° C. may be shifted simultaneously. At this time, in order for the rinsing liquid 102 to be quickly separated from the sample holder 104 and the substrate 101 through the inclined groove 1 described above, the entire surface of the sample holder 104 is subjected to a water-repellent treatment film or a mirror finishing process, and the flow is further improved. Therefore, the sample holder 104 is provided with the inclined groove 1 along the direction in which the high-pressure vessel is inclined as described above.
(6) When the pressure reaches a set pressure (about 7.5 to 13 MPa), in order to converge the turbid state of the rinsing liquid 102 composed of liquid carbon dioxide and 2-propanol, the liquid carbon dioxide 116 is pumped by the pump 114 for several tens of seconds. Is stopped so that the flow of the liquid carbon dioxide 116 does not occur in the high-pressure processing vessel 103. At the same time, in order to minimize the convection of the liquid carbon dioxide 122, the locally provided temperature regulator 106 in the sample holder 104 in the high-pressure processing vessel 103 is controlled to 5 ° C.
(7) When the turbidity of the 2-propanol rinse liquid 121 and the liquid carbon dioxide 122 collected in the upper part of the inclined high-pressure processing vessel 103 has converged, the pump 114 starts pumping the liquid carbon dioxide 116 again. When the valve 110 is opened, the 2-propanol rinse liquid 121 collected at the upper part in the inclined high-pressure processing vessel 103 is selectively discharged from the back pressure control valve 109 through the discharge port 119.
(8) At this time, as can be seen from FIG. 2, the 2-propanol rinse liquid 121 gathers at the top of the inclined high-pressure vessel 103 and can be discharged from the valve 110 and the back pressure control valve 109. In addition, it is difficult to efficiently separate the 2-propanol rinse solution 102 remaining between the sample holder 104 and the substrate 101. In order to separate and separate the remaining 2-propanol rinse solution 102 from between the substrate 101 and the sample holder 104, the high-pressure vessel 103 is moved in the same direction as the inclined rotation direction 125 while the high-pressure vessel 103 shown in FIG. By making the rotational vibration 130, it is possible to effectively separate from the inclined groove 1 provided in the sample holder 104. The separated 2-propanol of the rinsing liquid 102 is collected and discharged on the upper portion of the high-pressure vessel 103 as described above.
(9) The temperature adjusters 106 installed on the upper and lower portions of the sample holder 104 are sequentially controlled in the range of 5 to 60 ° C., so that the rinsing liquids 102 and 121 and the liquid carbon dioxide 122 remaining in the vicinity of the fine structure. It is possible to reduce the replacement time by controlling the temperature and generating a vortex or convection state change by changing the density of the rinsing liquids 102 and 121 and the liquid carbon dioxide 122 to promote the replacement of the liquid carbon dioxide 122 and the rinsing liquids 102 and 121. Useful.
(10) The pumping of the liquid carbon dioxide 116 by the pump 114 is stopped, and the temperature of the high-pressure vessel 103 is raised to 35 ° C. Although the pressure in the high-pressure vessel 103 is increased, when the set pressure (about 7.5 to 13 MPa) is exceeded, the pressure is discharged from the back pressure control valve 109 and the inside of the high-pressure vessel 103 is maintained at the set pressure (about 7.5 to 13 MPa). Be drunk. With this temperature change, the state of the liquid carbon dioxide in the high-pressure vessel 103 changes to a supercritical state. This change in state does not cause the surface tension of liquid carbon dioxide to act on the microstructure.
(11) The valves 113 and 110 are closed, the valve 117 is opened, and supercritical carbon dioxide is discharged from the pressure control valve 118 while maintaining the temperature at 35 ° C. When the pressure in the high-pressure vessel 103 becomes 7.38 MPa or less, the state of the carbon oxide changes into a gas supercritically filling the inside of the high-pressure vessel 103. Further, the discharge is continued with the pressure control valve 118, and the drying is finished when the pressure in the high-pressure vessel 103 becomes the atmospheric pressure.

  In this example, carbon dioxide that is in a supercritical state at a relatively low temperature and low pressure is used as the fluid used for drying the microstructure. For example, the critical pressure of carbon dioxide is 7.38 MPa. The critical temperature is 31 ° C. The density of liquid carbon dioxide can be changed from 0.65 to 0.95 g / ml by changing the temperature from 5 ° C. to 60 ° C. and the pressure from 3 MPa to 10 MPa. Is used as a rinsing liquid, a drying process capable of obtaining a uniform drying result in a short time can be achieved.

  As described above, according to this embodiment, there is no pattern collapse or sticking to a large-diameter substrate having a fine structure formed on the surface, and the substrate can be uniformly dried in a short time.

  Therefore, according to the present embodiment, the conventional critical point drying method can solve the disadvantage that the drying process time is long and a uniform drying result cannot be obtained for a large-diameter substrate. According to this embodiment, the pattern width of resist, etc. after exposure, development, and rinsing for manufacturing LSI or the like on a large scale is 100 nm or less, and further, the pattern width is 70 nm or less, particularly the pattern width (space width) is 30 nm or less. Since the drying process of a large-diameter substrate having a surface microstructure of 100 mm or more can be uniformly dried in a short time without pattern collapse, it has a processing speed that can be applied to a device manufacturing line.

  In the step (4) of the first embodiment, when the temperature of the high-pressure vessel 103 is controlled to about 28 ° C. by circulating the heat medium in the structure in which the heat medium can circulate in the side wall of the high-pressure vessel 103 itself. The specific gravity of liquid carbon dioxide is 0.70 g / ml, and the specific gravity difference from the specific gravity of 0.80 g / ml of 2-propanol, which is the rinsing liquid, is about 0.10. Collect in the lower part of the inclined high-pressure vessel 103. The sample holder 104 of this embodiment is exactly the same as that shown in FIG. 2, except that the holding guide hole 2 is opposite to that in FIG.

  The 2-propanol rinsing liquid collected at the bottom is collected at the outlet 120 by inclining in the same manner as in Example 1, and selectively operated from the outlet 120 in the same manner as in the step (5) and after in Example 1. After that, the pressure is reduced to atmospheric pressure through the same process as in Example 1 to finish drying. This embodiment also has the same effect as that of the first embodiment.

  In this example, a pattern having a fine structure is formed by hydrofluoric acid etching like a MEMS sample, and a drying process is performed after rinsing with pure water. However, the same process as in Example 1 or 2 is performed. Can do. In the pattern formation by hydrofluoric acid etching, the phenomenon that the movable part of the silicon three-dimensional structure sticks to the substrate (base part) due to the action of the surface tension as in the case of the resist pattern causes the device failure. This can prevent this phenomenon.

  First, since pure water as a rinsing liquid is hardly soluble in liquid or supercritical carbon dioxide, the substrate is previously immersed in a rinsing liquid soluble in carbon dioxide and replaced. The rinse liquid for the MEMS sample of this example is a mixture of HCFC-based cleaning agent and ethanol several to one. Since the used HCFC has a specific gravity of 1.55 g / ml, even if the specific gravity of carbon dioxide is controlled, the HCFC placed on the substrate cannot be collected on the upper side of the high-pressure vessel, but in this embodiment, the high-pressure vessel is inclined. The rinsing liquid placed on the substrate is collected in the lower part of the inclined high-pressure vessel and selectively discharged, and then the pressure is reduced to atmospheric pressure through the same process as in Example 1 to complete the drying in a short time and A uniform drying result can be obtained.

  The reason why the mixed liquid of HCFC and ethanol in this embodiment is used as a rinse liquid is to replace ethanol with water, and HCFC is used to replace carbon dioxide.

  As described above, according to the present embodiment, even a device such as a MEMS component can be uniformly dried in a short time without sticking a fine structure movable portion formed on a large-diameter substrate of 100 mm or more.

It is sectional drawing of the fine structure drying processing apparatus which shows an example of this invention. It is the top view and sectional drawing of the sample holder for fine structure drying processing apparatuses of this invention. It is sectional drawing of the fine structure drying processing apparatus after inclining the high-pressure container of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inclination groove, 2 ... Holding guide hole, 3 ... Heater escape groove, 4 ... Guide pin, 5 ... Coil spring, 6 ... Sliding groove, 7 ... Holding holder, 9 ... Flat part, 10 ... Board mounting part, DESCRIPTION OF SYMBOLS 11 ... Substrate presser, 12, 13 ... Bolt, 101 ... Substrate, 102, 121, 300 ... Rinse solution, 103 ... High pressure vessel, 104 ... Sample holder, 105 ... Lid, 106 ... Heater, 107, 110, 113, 117 ... Valves 108, 109 ... back pressure control valve, 112 ... filter, 114 ... pump, 115 ... liquid carbon dioxide container, 116, 122 ... liquid carbon dioxide, 118 ... back pressure control valve, 119, 120 ... discharge port, 123 ... Pressure control device, 124 ... lower container, 125 ... tilt rotation direction, 130 ... vibration.

Claims (17)

  A step of installing in a high-pressure vessel a sample holder equipped with a substrate having a fine structure immersed or wet in a rinsing liquid, and a fluid that is a gas at normal temperature and normal pressure and a liquid that is liquid under high pressure in the high-pressure vessel Or a step of introducing a set pressure in a supercritical state, and a step of inclining the high-pressure vessel and collecting the rinse liquid on the upper side or the lower side in the high-pressure vessel through a specific passage of the sample holder formed by the inclination. Discharging the collected rinse liquid from at least one discharge port provided on the upper side or the lower side in the inclined high-pressure vessel; and maintaining the pressure of the fluid at a critical pressure or higher The temperature of the fluid is increased to a critical temperature or higher, and the fluid is discharged sequentially while maintaining the temperature of the fluid at a critical temperature or higher. Fine structure dry processing method.   2. The microstructure according to claim 1, further comprising a step of collecting the rinsing liquid on an upper side or a lower side in the inclined high-pressure vessel by rotating and rotating the high-pressure vessel inclined in the inclined rotation direction. Drying method.   A step of installing in a high-pressure vessel a sample holder equipped with a substrate having a fine structure immersed or wet in a rinsing liquid, and a fluid that is a gas at normal temperature and normal pressure and a liquid that is liquid under high pressure in the high-pressure vessel Alternatively, the step of introducing a set pressure in a supercritical state, and the high-pressure vessel is inclined, and the rinse liquid on the substrate is collected on the upper side or the lower side in the inclined high-pressure vessel by the rotation vibration in the inclined rotation direction. A step of discharging the collected rinse liquid from at least one discharge port provided on the upper side or the lower side of the inclined high-pressure vessel, while maintaining the pressure of the fluid at a critical pressure or higher. A microstructure comprising a step of raising the temperature of the fluid to a critical temperature or higher and a step of discharging the fluid while maintaining the temperature of the fluid above the critical temperature.燥 processing method.   4. The method according to claim 1, further comprising: changing the specific gravity of the fluid by changing at least one of the temperature and the pressure of the fluid when collecting the rinse liquid on the upper side or the lower side in the high-pressure vessel. A fine structure drying method characterized by the above.   5. The fine structure drying treatment method according to claim 1, wherein the fluid is introduced from a lower portion of the sample holder while the high-pressure vessel is kept horizontal.   6. The eddy current according to any one of claims 1 to 5, wherein the temperature of the fluid is controlled between the step of discharging the rinse liquid and the step of bringing the fluid into a critical state. A method for drying a microstructure, characterized by generating convection and promoting replacement of the fluid and a rinsing liquid.   7. The microstructure drying process according to claim 1, wherein an inclination angle of the high-pressure vessel is set to 15 to 75 degrees in the step of collecting the rinse liquid on the upper side or the lower side in the high-pressure vessel. Method.   8. The fine structure drying treatment method according to claim 1, wherein a vibration angle in the vibration is performed in a range of ± 5 to ± 15 degrees.   9. The method for drying a microstructure according to claim 1, wherein the number of vibrations is 1 to 10 times.   10. The fine structure drying method according to claim 1, wherein the fluid is liquefied carbon dioxide, and the density thereof is changed to a predetermined density of 0.65 to 0.95 g / ml.   A high-pressure vessel in which a substrate having a fine structure immersed or wet in a rinsing solution is mounted on a sample holder, and a fluid that stores a gas that is a gas at normal temperature and normal pressure and a liquid under high pressure in a liquid or supercritical state A storage container, means for inclining the high-pressure container, means for vibrating the high-pressure container in the inclination direction, and the high-pressure container for discharging the rinse liquid collected on the upper side or the lower side in the inclined high-pressure container. A fine structure drying apparatus having a discharge port provided on at least one of the upper side and the lower side.   12. The microstructure drying apparatus according to claim 11, wherein the sample holder collects the rinse liquid on the upper side or the lower side of the high-pressure vessel through a groove provided on the mounting surface side of the substrate.   A high-pressure vessel in which a substrate having a fine structure immersed or wet in a rinsing solution is mounted on a sample holder, and a fluid that stores a gas that is a gas at normal temperature and normal pressure and a liquid under high pressure in a liquid or supercritical state A storage container, a means for inclining the high-pressure container, and a discharge port provided on at least one of the upper side or the lower side of the high-pressure container for discharging the rinse liquid collected on the upper side or the lower side in the inclined high-pressure container And the sample holder has an inclined groove provided outward from the mounting surface of the substrate, and the rinse liquid is collected on the upper side or the lower side of the high-pressure vessel through the inclined groove. Microstructure drying processing equipment.   14. The fine structure drying apparatus according to claim 11, further comprising a temperature or pressure adjusting means for changing at least one of a temperature and a pressure of the fluid in the high-pressure vessel to change a specific gravity of the fluid. .   The pump according to any one of claims 11 to 14, wherein the fluid is pumped to the high-pressure vessel, the temperature controller for controlling the temperature of the substrate on at least one of the upper side and the lower side of the sample holder, and the high pressure A fine structure drying apparatus comprising: a pressure control device that controls a pressure of a fluid introduced into a container; and a pressure increase speed control unit that controls a pressure increase speed in the high pressure container when the fluid is introduced into the high pressure container.   Microstructure drying in which a substrate having a fine structure immersed or wet in a rinsing liquid is installed in a high-pressure vessel, and the rinsing liquid is dried and removed by a fluid that is a gas at normal temperature and normal pressure and a liquid at high pressure. The processing apparatus sample holder includes an inclined groove having a predetermined width formed along a direction in which the high-pressure vessel is inclined from a predetermined position of the contact portion of the mounting portion of the substrate to the outside. Sample holder for fine structure drying processing equipment. The sample holder for a fine structure drying apparatus according to claim 16, wherein at least the inclined groove is subjected to a water-repellent treatment film or a mirror finish.

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