JP2008010638A - Method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor device having irregularities on the surface and a movable part without causing the fixing or damage to the irregularities and the movable part. <P>SOLUTION: The method comprises a step of processing irregularities and a movable part of a semiconductor device with a liquid, substituting the liquid with pure water, substituting the pure water with a solvent, involving a sublimable substance in the solvent, evaporating the solvent to deposit the sublimable substance on the semiconductor device surface, and sublimating the sublimable substance to remove it. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a semiconductor device having a concavo-convex portion or a movable portion on the surface, and in particular, can dry the semiconductor device without causing sticking or damage to the concavo-convex portion or operating portion of the surface. The present invention relates to a method for manufacturing a highly reliable semiconductor device.

  Conventionally, in a semiconductor device having a concavo-convex part or a movable part on its surface, a movable part and a fixed part, or a movable part and a movable part, called sticking at the time of drying, depending on the surface tension of a liquid such as pure water used in the manufacturing process. As a result, a sticking phenomenon with a portion occurs, which causes a reduction in the yield of the semiconductor device.

  This sticking phenomenon is observed in, for example, a schematic cross-sectional view when sticking occurs in the stencil mask of FIG. 1, an appearance photograph viewed from the front side of FIG. 2A, and this appearance photograph of FIG. It occurs in a state as shown in the schematic enlarged view of the fixed portion. As shown in FIG. 1, this stencil mask includes a single-crystal Si (100) layer 101 on the front surface side of the substrate, a buried silicon oxide film layer 102 as an intermediate layer, and a single-crystal Si (100) layer on the back surface side of the substrate. 103, a groove portion 122 formed by dry etching is provided in the single crystal Si (100) layer 101 on the front surface side, and an opening formed by etching in the single crystal Si (100) layer 103 on the back surface side. A portion 142 is provided. As shown in FIG. 1, in the stencil mask, a beam portion 161 for shaping the shape of the particle beam is fixed to an adjacent beam portion 161. Further, as can be seen from FIG. 2A, it can be confirmed that among the three beam portions, the second and third beam portions from the top of the photograph are fixed on the right side of the photograph. When the state of this fixation is enlarged and schematically shown, as shown in FIG. 2B, the second beam portion 161 and the third beam portion 161 are fixed.

  Although it is not a countermeasure against the sticking phenomenon as described above, for the purpose of reducing the amount of foreign matter adhering to the surface of the substrate, a solution of a sublimable substance is spin-coated on a semiconductor device having a concavo-convex part or a movable part on the surface, It is known to form a protective film (see, for example, Patent Document 1). In this case, when a solution of a sublimable substance is spin-coated on the semiconductor device in the manufacturing process, the rotation of the semiconductor device is started, and moisture attached to the uneven portion or the movable portion of the surface of the semiconductor device is shaken off by the centrifugal force due to the rotation. It will dry at this point. Therefore, the semiconductor device dries before the protective film made of a sublimation material is applied and formed on the part where the sticking may occur. ) May occur. Further, depending on the rotational speed in the case of spin coating, there is a possibility that the uneven portion and the movable portion on the surface of the semiconductor device are damaged by the generated centrifugal force.

  Further, by applying water or an organic solvent to a semiconductor device having a concavo-convex part or a movable part on the surface, freezing the applied droplet, and then sublimating the frozen substance under reduced pressure, by a freeze-drying method, the semiconductor device It is known that drying is performed without fixing uneven portions and movable portions on the surface (see, for example, Non-Patent Document 1). In this case, after freezing the organic solvent, it is necessary to maintain the conditions that the organic solvent does not dissolve and can be sublimated, so an expensive device for controlling the temperature and pressure is necessary and manufactured. This causes an increase in cost.

Furthermore, a semiconductor device having a concavo-convex part and a movable part on the surface is immersed in a melt of a sublimable substance to temporarily form a protective film made of a sublimable substance, and then the protective film is removed by sublimation, It is known to dry (see, for example, Patent Document 2). In this case, when a semiconductor device having a concavo-convex part or a movable part on the surface is immersed in the sublimable substance melt, the substrate is moved from the cleaning liquid tank to the sublimable substance melt tank in the air for a short time. There is a possibility that the substrate dries during this movement, and there is a possibility that the uneven portion or the movable portion of the semiconductor device is fixed. Further, since the temperature of the substrate rises when one end of the substrate comes into contact with the high-temperature melt of the sublimable substance, drying of the portion not in contact with the sublimable substance proceeds at this point. Therefore, there is a possibility that sticking may occur in the concavo-convex portion or the movable portion of the semiconductor device in a portion not in contact with the melt.
JP 63-41855 (Claims) ELECTROSTATIC PARALLELOGRAM ACTUATORS Transducers '91 (1991 International Conference on Solid-State Sensors and Actuators Digest of Technical Papers) pp. 63-66 JP-A-9-190996 (Claims, paragraphs 0023 and 0024)

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and a manufacturing method of a semiconductor device having an uneven portion or a movable portion on the surface, in particular, sticking or damage to the uneven portion or the movable portion on the surface. An object of the present invention is to provide an inexpensive and highly reliable manufacturing method of a semiconductor device that can dry the semiconductor device without any problem.

  A method for manufacturing a semiconductor device according to the present invention is a method for manufacturing a semiconductor device having an uneven portion or a movable portion on a surface thereof.

  (1) A step of replacing the liquid with pure water after treating the uneven part or the movable part with a liquid,

  (2) replacing pure water with a solvent;

  (3) The step of mixing and dissolving the sublimation substance in the substitution solvent, or the same type of solvent as the substitution solvent dissolving the sublimation substance or the solvent miscible with the substitution solvent dissolving the sublimation substance Mixing with solvent,

  (4) depositing the sublimable substance on the surface of the semiconductor device by evaporating the substitution solvent and a solvent miscible with the substitution solvent; and

  (5) A method for manufacturing a semiconductor device, comprising a step of removing the sublimable substance by sublimation.

  By including the steps (1) to (5), it is possible to prevent the uneven portion and the movable portion on the surface of the semiconductor device from being fixed due to the surface tension of the liquid in the drying step. In addition, since the solution of the sublimation substance is not spin-coated, it is not necessary to rotate the semiconductor device, so that the concave and convex portions and the movable portion on the surface of the semiconductor device are not damaged by the centrifugal force, and during the rotation There is no fear of drying. Furthermore, after the semiconductor device is treated with a liquid, the sublimation material is deposited on the irregularities and movable parts of the surface of the semiconductor device without being taken out into the atmosphere. It does not dry out and sticking occurs.

  It is preferable to use at least one selected from naphthalene, p-dichlorobenzene, tetrachlorodifluoroethane and camphor as the sublimable substance. By using such a sublimable substance, it becomes possible to sublime at room temperature and atmospheric pressure.

  Examples of the substitution solvent and a solvent miscible with the substitution solvent include isopropyl alcohol, methanol, ethanol, butanol, acetone, benzene, carbon disulfide, carbon tetrachloride, chloroform, hexane, decalin, tetralin, acetic acid, cyclohexanol, toluene and It is preferable to use at least one selected from ethers. By using such a solvent, it becomes easy to replace pure water with a solvent, and it becomes easy to mix and dissolve the sublimable substance in the solvent.

  According to the method for manufacturing a semiconductor device according to claim 1, after substituting moisture (pure water) with a solvent, the sublimable substance is dissolved without exposing the substrate on which the semiconductor device is formed to the atmosphere. It can be immersed in a solvent. Therefore, since the surface of the semiconductor device having a concavo-convex portion or a movable portion on the surface can be protected with a sublimation substance without drying the substrate, the concavo-convex portion on the surface of the semiconductor device due to the surface tension of the liquid generated during drying. And the effect of preventing sticking (sticking) of the movable part. In addition, since the solution of the sublimable substance is not spin-coated, the semiconductor device is not rotated, so that the concave and convex portions and the movable portion on the surface of the semiconductor device are not damaged by the centrifugal force.

  According to the method for manufacturing a semiconductor device according to claim 2, the sublimable substance is a substance that is solid at normal temperature and atmospheric pressure, such as naphthalene, p-dichlorobenzene, tetrachlorodifluoroethane, and camphor, and has sublimability. By using at least one selected from the above, it is possible to sublimate at room temperature and atmospheric pressure when this sublimable substance is deposited on the concavo-convex part or movable part of the surface of the semiconductor device.

  According to the method for manufacturing a semiconductor device according to claim 3, the solvent is isopropyl alcohol, methanol, ethanol, butanol, acetone, benzene, carbon disulfide, carbon tetrachloride, chloroform, hexane, decalin, tetralin, acetic acid, cyclohexane. By using at least one selected from hexanol, toluene, and ether, it becomes easy to replace pure water with a solvent, and it is possible to mix and dissolve the sublimable substance in the solvent. Play. Further, since these solvents evaporate at a temperature lower than that of the sublimable substance, there is an effect that the sublimable substance can be deposited on the concavo-convex part or the movable part of the surface of the semiconductor device.

In general, when manufacturing a semiconductor device having a concavo-convex part or a movable part on the surface, an etching process or a subsequent cleaning process is performed when the concavo-convex part or the movable part is formed. (e.g., such as, pure water, detergent, resist stripper (KOH, TMAH (TetraMethyl Ammonium Hydroxide , (CH 3) 4 NOH)) alkaline liquid and organic drugs, etc.) to remove liquid made of) drying It becomes necessary to do. Therefore, in the present invention, after the uneven part and the movable part are treated with the liquid, in order to remove the liquid and dry, the process of replacing the liquid with pure water, the process of replacing the pure water with a solvent. A step of mixing and dissolving a sublimable substance that is solid under normal temperature and normal pressure in the substitution solvent, or a solvent that dissolves a sublimable substance that is solid under normal temperature and normal pressure (which may be in the range of the solvent described above). Or a step of mixing a solvent capable of being mixed with the substitution solvent in which the sublimation substance is dissolved (which may be in the range of the above-mentioned solvent) into the substitution solvent, and evaporating these solvents The object is achieved by providing a method for manufacturing a semiconductor device including a step of depositing a sublimable substance on the surface and a step of removing the sublimable substance by sublimation. That is, in the drying process, the uneven portion and the movable portion on the surface of the semiconductor device are prevented from being fixed by the surface tension of the liquid, and the uneven portion and the movable portion on the surface of the semiconductor device are not damaged. In particular, the irregularities and the movable parts on the surface of the semiconductor device are not dried and sticking does not occur.

  As the substrate used in the method for manufacturing a semiconductor device of the present invention, any substrate that is normally used in a semiconductor device can be used. An SOI (Silicon On Insulator) substrate, a single crystal Si substrate, a single crystal Ge substrate, a single crystal GaAs substrate, a single crystal InSb substrate, etc. composed of three layers with a single crystal Si (100) layer on the back side be able to.

  According to one embodiment of the semiconductor device manufacturing method of the present invention, the surface side of the substrate composed of three layers of a front-side Si layer, a recon oxide film layer as an intermediate layer, and a back-side Si layer; A silicon oxide film is formed on both sides of the Si layer on the back surface side, a metal film is formed on the silicon oxide film on the front surface side of the substrate, and then an opening pattern is formed in the metal film using photolithography technology. Using this opening pattern as a mask, the Si layer on the surface side of the substrate is etched to form a groove, the metal film is etched away, and a silicon oxide film is formed on both sides of the substrate and the sidewall of the groove After that, an opening pattern is formed in the silicon oxide film on the back surface side of the substrate using a double-sided exposure technique to expose the Si layer on the back surface side, and then the back surface side of the exposed substrate using an alkaline etching solution Crystal Si is anisotropically etched to form openings, and the silicon oxide film formed on the front and back surfaces of the substrate and the silicon oxide film formed on the side walls of the groove are removed by etching. The pure water in which the substrate is immersed is replaced with a solvent, and after this solvent replacement, the sublimation substance is mixed and dissolved in the replacement solvent, or the same type as the replacement solvent in which the sublimation substance is dissolved. A solvent that is miscible with the substitution solvent in which the solvent or sublimation substance is dissolved is mixed with the substitution solvent, and the substitution solvent and the solvent that is miscible with the substitution solvent are evaporated. The semiconductor device can be manufactured by precipitating and removing the sublimable substance by sublimation, thereby achieving the intended purpose. The sublimable substance and the solvent in this case are as described above.

  According to another embodiment of the semiconductor device manufacturing method of the present invention, a first silicon oxide film, a silicon nitride film, and a second silicon oxide film serving as a sacrificial layer are sequentially formed on a substrate, and a photolithography technique is used. Then, an opening pattern is formed in the second silicon oxide film, a polycrystalline silicon film is formed on the substrate on which the opening pattern is formed, and then a movable portion and a beam portion are formed on the polycrystalline silicon film by using a photolithography technique. Then, the anchor part, the opening part and the electrode part are formed, then washed with pure water, the pure water in which the substrate is immersed is replaced with a solvent, and after substituting the solvent, the sublimation substance is mixed and dissolved in the substitution solvent. Or the solvent of the same type as the substitution solvent in which the sublimation substance is dissolved or the solvent miscible with the substitution solvent in which the sublimation substance is dissolved is mixed with the substitution solvent, and the substitution solvent, the substitution By evaporating a solvent that is miscible with the agent, a sublimable substance is deposited on the surface of the semiconductor device, and the sublimable substance is removed by sublimation, thereby producing a semiconductor device, thereby achieving the intended purpose. it can. The sublimable substance and the solvent in this case are as described above.

  In addition, by applying the semiconductor device manufacturing method of the present invention, when a liquid such as pure water or IPA is dried in a drying process after a cleaning process of a micromechanical switch, a vibration gyroscope, a semiconductor pressure detection element, a MEMS resonator, or the like. In addition, the thin film structure or the like constituting these semiconductor devices is a narrow gap portion formed between the substrate and the thin film structure and the substrate are prevented from adhering to each other due to the force caused by the surface tension of liquid such as pure water. be able to.

  For example, in the case of a micromechanical switch composed of a substrate and a beam formed on the substrate so as to be mechanically displaceable in a state of floating with a predetermined gap, the surface tension of the liquid when the substrate and the beam (beam) are dried. Since it is possible to prevent adhesion due to the force caused by this, it becomes possible to further reduce the distance between the substrate and the beam, so that the beam drive voltage applied to the drive electrode formed on the substrate can be reduced. It becomes possible.

  In the case of a vibrating gyroscope, a polycrystalline silicon thin film vibrator formed so as to be mechanically displaceable in a state of being floated from a substrate with a predetermined narrow gap may be separated from a substrate during drying after etching a sacrificial layer for forming a gap. It is possible to prevent the liquid crystal existing between the polycrystalline silicon thin film vibrators from being fixed to the substrate. Since this sticking phenomenon depends on the liquid surface tension and the mechanical strength of the thin film structure, the larger the area of the thin film structure, the lower the rigidity and the easier the sticking occurs. Although it was difficult to increase the mass of the vibrator by increasing the area of the child and improve the angular velocity detection sensitivity of the vibratory gyroscope, the substrate and the polycrystalline silicon thin film vibrator can be fixed when dried by using the present invention. Therefore, it is possible to use a larger vibrator, and it is therefore possible to improve the angular velocity detection sensitivity of the vibration gyro.

  Also, in the case of a vibration type semiconductor pressure detection element, it becomes possible to prevent the substrate and the vibrator from being fixed due to the surface tension of the liquid during drying after etching the sacrificial layer, thereby improving the manufacturing yield. It becomes possible.

  Further, in the case of the MEMS resonator, since it becomes possible to prevent the sticking generated in the sacrifice layer etching and the accompanying drying process, a large vibrator having low mechanical rigidity is formed close to the substrate. be able to. In other words, by using a large vibrator with low mechanical rigidity, it becomes possible to oscillate at a lower frequency and to reduce the distance between the vibrator and the substrate. Since the electrostatic force acting between them can be increased, the resonator can be driven with a low voltage.

  Hereinafter, the present invention will be described specifically by way of examples.

  In this example, a stencil mask was manufactured according to the manufacturing method of the present invention. This manufacturing process is shown in FIGS.

  An SOI (Silicon On Insulator) substrate 3 was used as the substrate (FIG. 3A). This SOI substrate 3 is composed of three layers of a single crystal Si (100) layer 301 on the front surface side, a buried silicon oxide film layer 302 as an intermediate layer, and a single crystal Si (100) layer 303 on the back surface side. Yes.

  Silicon oxide films 311a and 311b are respectively formed by thermal oxidation on both the front and back sides of the SOI substrate 3 having a multilayer structure, and a sputtering method is performed on the silicon oxide film 311a on the front side of the SOI substrate 3. A Cr film 312 was formed by vapor deposition or the like (FIG. 3B).

  Next, an opening pattern 321 was formed in the Cr film 312 by using a photolithography technique used for manufacturing a general semiconductor device such as an IC or LSI (FIG. 3C).

  Using the opening pattern 321 opened in the Cr film 312 as a mask, the Si layer 301 on the surface side of the SOI substrate 3 was dry-etched to form a groove 322 (FIG. 3D).

  After the Cr film 312 was removed by etching, a silicon oxide film 331 was formed by thermal oxidation on both sides of the SOI substrate 3 and the side walls of the groove 322 formed by dry etching (FIG. 3E). In this case, a new silicon oxide film 331 is formed on the side wall portion of the groove, and the silicon oxide film grows in a portion where the silicon oxide film has been previously formed, such as both sides of the substrate, and the silicon oxide film becomes thick. Instead of etching away only the Cr film 312, the Cr film 312 and the silicon oxide film 311a. After all of 311b is removed by etching, silicon oxide films 331 may be formed on both surfaces of the substrate 3 and the side walls of the grooves 322 by a thermal oxidation method.

  Next, using a double-sided exposure technique, an opening pattern 341 was formed in the silicon oxide film 311b on the back surface side of the SOI substrate 3 to expose the single crystal Si (100) layer 303 on the back surface side (FIG. 3F). .

  After the opening pattern 341 is formed, the single crystal Si (100) layer 303 on the back side of the SOI substrate 3 exposed by the opening pattern 341 is subjected to crystal anisotropic etching using an alkaline etching solution such as KOH or TMAH (FIG. 3 (g)). In this case, the single crystal Si (100) layer 301 and the groove 322 on the surface side of the SOI substrate 3 are not etched because they are protected by the silicon oxide films 311a and 331 having a low etching rate with an alkaline etchant. On the other hand, since the single crystal Si (100) layer 303 is exposed in the opening pattern 341 of the silicon oxide film of the single crystal Si (100) layer 303 on the back surface side, it is etched with an alkaline etching solution, and Si (111) is used. A configured opening 342 was formed.

  After the opening 342 is formed, silicon oxide films 311a (331) and 311b (331) respectively formed on the front and back surfaces of the SOI substrate 3, and silicon oxide formed on the side wall of the groove 322 formed by dry etching. The film 331 was removed by etching with a silicon oxide film etchant such as buffered hydrofluoric acid or diluted hydrofluoric acid.

  Then, it was washed with pure water. In cleaning the SOI substrate 3 with pure water, it is important to quickly transfer the SOI substrate 3 from the etching solution tank to the pure water tank so that the surface of the SOI substrate 3 is not dried. This water washing may be performed by replacing the etching solution with pure water by repeatedly diluting the etching solution with pure water while the SOI substrate 3 is immersed in the etching solution tank. In this case, it is possible to clean the SOI substrate 3 with pure water without exposing it to the atmosphere at all, and therefore no sticking occurs on the uneven portions and the movable portions on the surface of the semiconductor device.

  After washing with pure water, the pure water in which the SOI substrate 3 was immersed was replaced with IPA by repeatedly diluting with isopropyl alcohol (IPA). In addition, instead of IPA, methanol, ethanol, butanol, acetone, benzene, carbon disulfide, carbon tetrachloride, chloroform, hexane, decalin, tetralin, acetic acid, cyclohexanol, toluene or ether can be used as the solvent. .

  After IPA substitution of pure water, naphthalene as a sublimation substance was dissolved in this IPA. In this case, an IPA solution in which naphthalene is dissolved in IPA may be dropped and mixed. Of course, instead of naphthalene, p-dichlorobenzene, tetrachlorodifluoroethane, camphor can be used as a sublimable substance, and the above solvent can be used as a solvent instead of IPA.

  After the sublimation substance was added, IPA was evaporated and a naphthalene film 351 was deposited on the surface of the SOI substrate 3 (FIG. 3 (h)).

  After deposition of the naphthalene film, the naphthalene film 351 was sublimated in the atmosphere to manufacture a stencil mask having a beam portion 361 (FIG. 3 (i)). The beam portions 361 of the stencil mask thus obtained did not stick together.

  In this example, an acceleration sensor using surface micromachine technology was manufactured according to the manufacturing method of the present invention. This manufacturing process is shown in FIGS. 4A to 4G, and a plan view of the obtained acceleration sensor is shown in FIG.

  Using a Si substrate 401 as a substrate, a silicon oxide film 402 is formed on the substrate 401 by a thermal oxidation method, and then a silicon nitride film 403 and a silicon oxide film 404 as a sacrificial layer are formed by a CVD method (FIG. 4). (a)).

Next, an opening pattern 405 was formed in the silicon oxide film 404 by using a photolithography technique used for manufacturing a semiconductor device such as a general IC or LSI (FIG. 4B). As a method for etching the silicon oxide film 404, a wet etching technique using an etching solution such as buffered hydrofluoric acid or diluted hydrofluoric acid, a dry etching technique using plasma such as CF ₄ gas, or the like is appropriately selected and used. Can do.

  A polycrystalline silicon film 410 was formed by a CVD method on the Si substrate 401 on which the opening pattern 405 was formed (FIG. 4C).

Next, an opening 414 for shortening the time for etching the movable portion 411, the beam portion 412, the anchor portions 413a and 413b, and the sacrificial layer 404 under the movable portion 411 in the polycrystalline silicon film 410 by using a photolithography technique. A movable electrode portion 415 and a fixed electrode portion 421 were formed (FIGS. 4D and 5). As a method for etching the polycrystalline silicon film 410, a dry etching technique using plasma such as CF ₄ gas can be used as appropriate.

  The sacrificial silicon oxide film 404 was removed by etching with a silicon oxide film etchant such as buffered hydrofluoric acid or diluted hydrofluoric acid.

  Then, it was washed with pure water. When cleaning the Si substrate 401 with pure water, it is important to quickly transfer the Si substrate 401 from the etching solution tank to the pure water tank so that the surface of the Si substrate 401 is not dried. This washing with water may be performed by replacing the etching solution with pure water by repeatedly diluting the etching solution with pure water while the Si substrate 401 is immersed in the etching solution tank. In this case, it is possible to clean the Si substrate 401 with pure water without exposing it to the atmosphere. Therefore, the unevenness and the movable part on the surface of the semiconductor device are not fixed.

  After washing with pure water, the pure water in which the Si substrate 401 was immersed was replaced with IPA by repeatedly diluting with IPA. As the solvent, methanol, ethanol, butanol, acetone, benzene, carbon disulfide, carbon tetrachloride, chloroform, hexane, decalin, tetralin, acetic acid, cyclohexanol, toluene, or ether can be used instead of IPA. .

  After IPA substitution of pure water, naphthalene as a sublimation substance was dissolved in this IPA. In this case, an IPA solution in which naphthalene is dissolved in IPA may be dropped and mixed. Of course, instead of naphthalene, p-dichlorobenzene, tetrachlorodifluoroethane, camphor can be used as a sublimable substance, and the above solvent can be used as a solvent instead of IPA.

  After the sublimation substance was added, IPA was evaporated, and a naphthalene film 451a was deposited on the surface of the Si substrate 401 (FIG. 4E).

  After deposition of the naphthalene film 451a, the naphthalene film 451a was sublimated in the atmosphere (FIG. 4F) to manufacture an acceleration sensor. In the acceleration sensor thus obtained, the surface irregularities and the movable part were not fixed.

  As shown in FIG. 4 (g), in the process of evaporating IPA and depositing a naphthalene film, the irregularities and movable parts on the surface of the semiconductor device are mechanically strong, and vibrations and accelerations generated during handling. If there is no risk of breakage due to, for example, a thin naphthalene film 451b may be deposited on the surface of the Si substrate 401 for the purpose of preventing sticking. In this case, the thickness of the naphthalene film 451b is one molecular layer or more, preferably several molecular layers or more, and can have a thickness that can maintain an interval at which the concave and convex portions and the movable portion of the surface of the semiconductor device do not directly contact each other.

  According to the present invention, it is possible to prevent sticking (sticking) of uneven portions and movable parts of the surface of the semiconductor device due to the surface tension of the liquid generated during drying, and the uneven portions and movable parts of the surface of the semiconductor device are damaged. Therefore, the present invention can be used in the field of semiconductor devices having uneven portions and movable portions on the surface.

The schematic diagram of the cross section of the stencil mask which sticking generate | occur | produced. It is the photograph and sectional drawing for demonstrating generation | occurrence | production of sticking, (a) is an external appearance photograph seen from the surface side of the stencil mask which sticking generate | occur | produced, (b) is an expanded section which shows the state of fixation typically Figure. Manufacturing process drawing ((a)-(i)) explaining the manufacturing process of Example 1 using the schematic diagram of a board | substrate cross section. Manufacturing process figure ((a)-(g)) explaining the manufacturing process of Example 2 using the schematic diagram of a board | substrate cross section. FIG. 6 is a schematic plan view of an acceleration sensor obtained in Example 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Single crystal Si (100) layer on the surface side 102 Embedded silicon oxide layer 103 Single crystal Si (100) layer on the back surface 121 Opening pattern 142 Back surface opening 161 Beam portion 3 SOI substrate 301 Single crystal Si (100 on the front side) ) Layer 302 buried silicon oxide layer 303 single crystal Si (100) layers 311a and 311b on the back side silicon oxide film 312 Cr film 321 opening pattern 322 groove 331 groove side wall forming silicon oxide film 341 back side silicon oxide film opening pattern 342 back side opening Part 351 naphthalene film 361 beam part 401 Si substrate 402 silicon oxide film 403 silicon nitride film 404 silicon oxide film 405 opening pattern 410 polycrystalline silicon film 411 movable part 412 beam part 413a, 413b anchor part 414 opening part 415 movable electrode part 421 fixed electrode 451a, 451b Naphthalene film

Claims (3)

In the method of manufacturing a semiconductor device having a concavo-convex part or a movable part on the surface,
(1) A process of replacing the concavo-convex part or the movable part with a liquid and then replacing the liquid with pure water. (2) A process of replacing the pure water with a solvent.
(3) A step of mixing and dissolving a sublimable substance in the substitution solvent, or a solvent miscible with the substitution solvent in which a sublimation substance is dissolved, a solvent of the same type as the substitution solvent or a sublimation substance is dissolved. Mixing with the substitution solvent,
(4) depositing the sublimable substance on the surface of the semiconductor device by evaporating the substitution solvent and a solvent miscible with the substitution solvent; and
(5) A method for manufacturing a semiconductor device, comprising a step of removing the sublimable substance by sublimation. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the sublimable substance is at least one selected from naphthalene, p-dichlorobenzene, tetrachlorodifluoroethane, and camphor. The substitution solvent and a solvent miscible with the substitution solvent are isopropyl alcohol, methanol, ethanol, butanol, acetone, benzene, carbon disulfide, carbon tetrachloride, chloroform, hexane, decalin, tetralin, acetic acid, cyclohexanol, toluene and 3. The method of manufacturing a semiconductor device according to claim 1, wherein the semiconductor device is at least one selected from ethers.

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