TW201448022A - Processing method for inner wall surface of micro holes - Google Patents

Abstract

The invention provides a processing method for inner wall surface of micro holes which can still perform etching or cleaning even if the holes disposed on the processed substrate are narrow and deep. It comprise steps: decompressing the processing space disposed with a substrate (100) that capable of being decompressed, wherein the substrate includes a surface imposed with a processing liquid (106), and its interior having micro holes (104) in the opening (110) at the surface, and the aspect ratio (1/r) of the micro holes (104) is above 5 or the aspect ratio is under 5 while the V/S (V: the volume of the tiny holes; S: the area of the opening) is above 3; next introducing the processing liquid (106) into the decompressed processing space to process the inner wall surface of the micro holes (104).

Description

Inner wall surface treatment method for fine holes

The present invention relates to an inner wall surface treatment method for fine voids.

In the field of semiconductors, transistors which were one of the basic electronic active components (basic electronic components) have been highly integrated by miniaturization.

However, the exposure technology of one of its basic technologies has begun to stagnate, and it has been considered that the achievement of high integration by miniaturization has reached the limit. In addition, the miniaturization of basic electronic components poses a potential problem such as an increase in device temperature or electron leakage when an LSI (large scale integration) device is used. Recently, highly integrated technologies that do not rely on miniaturization have also begun to be developed. One of them is LSI 3D (3 Dimensional Integration) technology. One of the necessary technologies to implement this technology is the TSV (Through Silicon Via) technology.

The 3D integrated LSI device using this technology is different from the package level 3D integrated device using wire bonding technology, and the electrical interconnection characteristics between each device of the layer stack are also expected. There will be a dramatic upgrade, which is expected to be a high-generation device for the next generation.

The through holes required by TSV are tens of microns to hundreds of micrometers. A narrow, deep hole (high aspect ratio hole) with a meter and an aspect ratio of 10 or more. In order to form such a hole, it has been proposed to form a fine circuit pattern of 0.5 μm to 0.25 μm by a dry etching method recently employed and an oxygen plasma ashing method for resist removal. However, in such a dry etching method, a build-up polymer is generated in the peripheral portion of the formed hole due to dry etching gas, a resist, or the like, and remains in the inside of the hole and its peripheral portion, resulting in high resistance or electrical short circuit. , resulting in a decrease in yield. Further, in order to remove the residual polymer and the inside of the cleaned pores, it is necessary to use wet cleaning. Therefore, even if it relies on TSV, it will have higher requirements for past wet etching and cleaning projects.

However, after reviewing and experimenting with the team of the present invention, the following matters were found, and it was found that wet etching and washing were not sufficient if the method was conventionally known. That is to say, when the bottom of the high aspect ratio hole or the inside of the cleaning hole is etched, if the conventional treatment liquid is used, the processing liquid (etching liquid, cleaning liquid, etc.) may not be able to be formed because the hole is narrow and deep. Invade into the hole. Therefore, it may happen that etching or washing is not performed as expected. As a solution, the method which has been carried out in the past has been to incorporate a surfactant into the treatment liquid to improve the wettability with the inner wall of the pore to solve the previous problems.

However, in this proposal, it is ensured that the treatment liquid can fully function and the wettability is improved to achieve the object. However, in the current state, it is not suitable for the appropriate treatment liquid for etching and washing. Further, when the treatment liquid is to be supplied from the surface of the object to be treated into the pores, bubbles of the ambient gas may be formed in the pores, and the treatment liquid may be prevented from entering the pores. This phenomenon is clearly observed in the cylindrical hole.

Ultrasonic vibration to clean complex and multiple micropores In the case of a polycrystalline silicon for a solar cell, a technique of repeatedly performing decompression and pressurization has been proposed (see Patent Document 1). However, the technique disclosed in Patent Document 1 utilizes ultrasonic vibration, and for the hole pattern of a high aspect ratio such as TSV as the object in the present case, the wall thickness of the member is formed with respect to the wall surface forming the hole. The height of the wall is extremely high, so that the wall-constituting member may collapse due to ultrasonic vibration (the pattern collapses). This problem is more pronounced as the aspect ratio of the hole is higher or as the hole pattern is finer.

[Previous Technical Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2012-598

The present invention has been developed in view of the above problems, and an object of the present invention is to provide a method for treating an inner wall surface of a hole. Even if the hole provided in the substrate to be processed is a narrow and deep hole, the treatment liquid rapidly invades and fills. Inside the hole, it is possible to surely perform etching or cleaning without causing the hole pattern to collapse.

One aspect of the present invention is directed to a method for treating an inner wall surface of a fine void, characterized in that a treatment space provided with a substrate and decompressible is decompressed, wherein the substrate has a surface to which a treatment liquid is applied, and The inside has a fine void having an opening on the surface, and the micro-vacancy has an aspect ratio (l/r) of 5 or more, or an aspect ratio of less than 5 Further, V/S (V: volume of fine pores, area of S: opening) is 3 or more; and the treatment liquid is introduced into the treatment space to be depressurized to treat the inner wall surface of the fine pores.

According to the present invention, even in a narrow and deep hole, the treatment liquid quickly invades and fills the inside of the hole, whereby etching or washing can be surely performed.

100‧‧‧SOI substrate

101‧‧‧Si (矽) semiconductor substrate

102‧‧‧SiO2 (yttria) layer

103‧‧‧Si layer (103-1,103-2)

104‧‧‧ hole

105‧‧‧ bubbles

106‧‧‧Processing fluid

107‧‧‧ gas-liquid interface

108‧‧‧Inside wall surface (108-1,108-2)

109‧‧‧Inner wall

110‧‧‧ openings

200‧‧‧Processing system

201‧‧‧Decompression processing chamber (room)

202‧‧‧Processing body setting platform

202-1‧‧‧Rotating shaft body for the treatment body setting platform

203‧‧‧Processed body

204‧‧‧Environmental gas supply pipeline

205‧‧‧Processing (medicine) liquid supply pipeline

206‧‧‧Recovery cover

207‧‧‧Relief waste tank

208‧‧‧Atmosphere or N2 supply pipeline

209‧‧‧Draining line

210‧‧‧Recycling pipeline

211, 212‧‧‧ exhaust line

213‧‧‧Exhaust pump

214, 215, 216, 217, 218, 219, 220, 221 ‧ ‧ valves

222‧‧‧Variable nozzles for processing liquids

301‧‧‧Rotator

302‧‧‧Pharmaceuticals

303‧‧‧Aluminum frame

400‧‧‧Nitrogen pressure feeding method (medicine) liquid supply system

401‧‧‧ storage tank

402‧‧‧Processing liquid supply line

403, 411‧‧‧ stop valve

404‧‧‧Flow Regulator

405‧‧‧ flowmeter

406‧‧‧liquid mist trap

407, 408‧‧‧ nitrogen gas supply line

409‧‧‧Ventilation (exhaust) valve

410‧‧‧Swirl connector

412‧‧‧Regulator

413‧‧‧Connector

414, 415‧‧‧ Quick connectors

501‧‧‧Flange for draining

502‧‧‧Flange for decompression

503‧‧‧Flange for waste liquid introduction

504‧‧‧Flange for gas introduction

505‧‧‧ vacuum gauge

506‧‧‧ flowmeter

507‧‧‧ liquid level observation window

600‧‧‧Decompression chamber

601‧‧‧ chamber structure

602‧‧‧上盖

603‧‧‧The platform for the object to be processed

604‧‧‧Rotating shaft

605‧‧‧Magnetic fluid seals

606‧‧‧Special treatment (medicine) liquid supply line

607‧‧‧Ozone water supply pipeline

608‧‧‧Ultra pure water supply pipeline

609,610,611,618‧‧‧ flowmeter

612, 613, 614, 617, 621, 624‧ ‧ valves

615‧‧‧ gas introduction pipeline

619‧‧‧ gas discharge line

616, 620, 623‧‧ ‧ flange

622‧‧‧ Waste pipeline

625‧‧‧ observation window (625-1, 625-2)

626‧‧‧ Vacuum gauge

701‧‧‧ gas ejected inner wall tube

702‧‧‧ gas outlet

[Fig. 1] Fig. 1 is a model explanatory view for explaining a state in which bubbles are present in a narrow and deep hole (hole) provided on a SOI substrate, and the treatment liquid cannot penetrate to the bottom of the hole.

Fig. 2 is a view showing a model configuration diagram for explaining an example of a manufacturing system suitable for specifically exhibiting the present invention.

FIG. 3 is a partial model configuration diagram of the manufacturing line shown in FIG. 2. FIG.

FIG. 4 is a model explanatory diagram for explaining a suitable configuration of a treatment (medicine) liquid supply system provided inside the medicine cartridge 302.

FIG. 5 is a model configuration diagram of a vacuum waste liquid tank 207.

Fig. 6 is a view showing a model configuration of another suitable processing chamber.

Fig. 7 is a plan view showing the arrangement and discharge direction of a nitrogen gas (N ₂ ) gas discharge port provided on the inner wall surface of the processing chamber 501 of Fig. 6.

Fig. 8 is a schematic view showing a saturated vapor pressure curve of water.

Fig. 1 is a model explanatory view for explaining a state in which bubbles are present in a narrow and deep hole (hole) provided on the SOI substrate, and the treatment liquid cannot penetrate to the bottom of the hole.

As shown in FIG. 1, reference numeral 100 is an SOI substrate, 101 is a Si (yttrium) semiconductor substrate, 102 is a SiO ₂ (yttria) layer, 103 is a Si layer (103-1, 103-2), 104 is a hole, and 105 is The bubbles 106 are treatment liquids, 107 is a gas-liquid interface, 108 is an inner wall surface (108-1, 108-2), 109 is an inner bottom wall surface, and 110 is an opening.

When the treatment liquid is supplied to the surface of the SOI substrate 100 in a normal pressure environment, even if the wettability to the inner wall surface of the Si layer 103 is good, the inside of the pores 104 (micro space) may not be sufficiently treated. The situation of filling (Fig. 1 schematically discloses an example). Careful observation of the condition in which the untreated liquid is filled in the well 104 reveals that bubbles 105 are present in the pores 104. The bubble 105, when the SOI substrate 100 is maintained in a stationary state, resides in the hole 104 in a state of being blocked by the treatment liquid 106. When the bubble 105 is present, when the SOI substrate 100 is applied to the SOI substrate by ultrasonic vibration, gas-liquid exchange occurs in the hole 104, and the inside of the hole 104 is quickly filled with the treatment liquid. Alternatively, when ultrasonic vibration is applied to the SOI substrate and the processing liquid is supplied to the surface of the SOI substrate 100, bubble formation is prevented, and the bubble 104 tends to be difficult to form. However, if the vibration of the ultrasonic vibration is too large and too intense, for example, the pattern to be formed or formed is collapsed, so that ultrasonic vibration is not ideal in the present invention. Even if it is necessary to use it, it is preferable to perform ultrasonic vibration smoothly within a range that does not cause pattern collapse.

Assuming that the opening diameter of the hole 104 is "r" and the depth from the opening position of the hole 104 to the inner bottom wall surface 109 is "1", the so-called aspect ratio can be expressed by "l/r". The conditions for forming the bubble 105 in the hole 104 include the surface tension of the treatment liquid, the viscosity, the liquid component, the surface smoothness of the side wall surface 108, the wettability of the treatment liquid used, and the magnitude and depth of "r" and "l". Wide ratio, etc., many parameters, it is difficult to generalize.

The team of the present invention firstly determined the internal structure of the hole 104 as various kinds of holes of the cylinder, and used ultrapure water as a treatment liquid for the SOI substrate of the structural material shown in Fig. 1, to verify the tendency of the bubble formation. The internal structure of the hole 104 is not limited to a cylindrical shape, and various sizes are changed to have a wrap shape (the lower portion of the opening is expanded in a bag shape or a push-like shape), a rectangular shape (a square shape in which the opening is square, a rectangle, a rhombus, etc.), and a triangle. Shape, hexagonal shape, elliptical shape, super elliptical shape, star shape. As a result, it is found that, if the area of the opening 110 of the hole 104 is "S" and the internal volume is "V", the shape of the bubble is easily formed from the vicinity of "3" from the value of "V/S" regardless of the shape. There is a tendency to increase rapidly. Among them, the case where the inner side wall surface of the hole 104 is a curved surface (such as a cylinder or an ellipse) is compared with a case having a corner ridge (such as a rectangle), and it is also known that a bubble is more easily formed in the case of a curved surface. Although the reason is only speculative, it is considered that if the inner wall has a corner ridge, the bubble tends to become a sphere, so that the corner is hard to be occupied by the bubble, and the liquid passes through the corner to reach the inner bottom wall surface 109, and the result becomes It is easy to exchange gas and liquid, and the pore space will be filled with liquid.

Accordingly, hydrofluoric acid (HF) and buffered hydrofluoric acid (BHF) were used instead of ultrapure water, and the SiO ₂ layer 102 constituting the inner bottom wall surface 109 was etched. As a result, when hydrofluoric acid is used, even if the value of "V/S" is in the vicinity of "3", the bubble is not easily formed (the "V/S" value is "300" among the 300 holes. There are about 15 bubbles, and when buffered hydrofluoric acid is used, 80% (240) of the bubbles form bubbles, and etching is not sufficient. In view of this, in order to verify the above situation, the inventors of the present invention prepared a decompressible processing chamber under reduced pressure (30 Torr). As a result, any of a hydrofluoric acid aqueous solution (FH of 1 to 20%) and buffered hydrofluoric acid (ammonium fluoride: 20%, HF: 1 to 20%) was completely etched at a ratio of 100%. This decompression effect has a certain degree of correlation with the degree of decompression, but if the decompression is excessive, the boiling point of the treatment liquid will be exceeded under the pressure, so for the design of the device, the range is not exceeded. The pressure is better and ideal.

In the present invention, the internal space of the hole is hereinafter referred to as "micro-vacancy". In the present invention, when the fine pores are not a cylindrical structure (referred to as a "non-cylindrical"), the "r" value is a non-cylindrical shape by taking the fine pores at this time as a cylinder. "S" to find out. In this case, "l" is defined as the depth (maximum depth) from the opening position to the position of the innermost bottom wall surface at the deepest point of the fine hole. The pressure reduction effect in the present invention is 5 or more in the aspect ratio (l/r), or the aspect ratio is less than 5 and V/S (V: the volume of the fine pores, the area of the S: opening) is 3 The above is more significant. In particular, when the treatment liquid is buffered hydrofluoric acid and the object to be treated is an SOI matrix, a more remarkable effect can be obtained.

In the present invention, when the value of "l/r" is 5 or more, a significant decompression effect can be obtained regardless of the value of "V/S". When the value of "l/r" is less than 5, it is related to the value of "V/S". If "V/S" is <3, the decompression effect is hardly obtained, and the ratio of the pores of the internal residual bubbles increases. In the present invention, when the value of "l/r" is less than 5, the value of "V/S" is preferably 3.5 or more.

Fig. 2 is a view showing a model configuration of an example of a manufacturing system suitable for specifically exhibiting the present invention. Fig. 3 is a partial schematic structural view of the manufacturing line shown in Fig. 2. 2 and 3, 200 is a processing system, 201 is a reduced pressure processing chamber (chamber), 202 is a platform for the object to be processed, 202-1 is a rotating shaft body for setting a platform for the object to be processed, and 203 is processed. The body 204 is an ambient gas supply line, 205 is a treatment (medicine) liquid supply line, 206 is a recovery hood, 207 is a vacuum waste liquid tank, 208 is an atmospheric or N ₂ supply line, and 209 is a drain line. 210 is a recovery line, 211, 212 is an exhaust line, 213 is an exhaust pump, 214 to 221 are valves, 222 is a supply amount variable nozzle for processing liquid, 301 is a spinner, and 302 is a medicine.匣, and 303 are aluminum frames.

The processing system 200 includes a reduced pressure processing chamber (chamber) 201 and a reduced pressure waste liquid tank 207, and the inside thereof is configured to be depressurized to a predetermined value by the exhaust pump 213. In the pressure-reduction processing chamber (chamber) 201, an environmental gas such as N _{2 is} supplied to the ambient gas supply line 204 through a predetermined amount from the outside, and a treatment liquid is supplied through the processing liquid supply line 205. An on-off valve having a flow rate adjustment function is provided in the middle of the ambient gas supply line 204. In the reduced pressure processing chamber 201, the target object installation stage 202 is fixed to the rotating shaft body 201-1 for the object setting platform. The object to be processed 203 is set on the object setting platform 202. The ambient gas supplied into the decompression processing chamber 201 through the ambient gas supply line 204 passes through the recovery cover 206 as indicated by an arrow A, and passes through the treatment liquid supplied from the treatment liquid supply line 205, and passes through the recovery cover as indicated by an arrow B. 206 is recovered from the recovery line 210 into the reduced pressure waste tank 207, respectively. In the middle of the recovery line 210, an on-off valve 217 is provided.

In the vacuum waste tank 207, the supply line 208 and the exhaust line 211 are combined. Supply line 208 is a supply line for the atmosphere or N ₂ . The waste liquid 223 in the vacuum waste liquid tank 207 is discharged to the outside of the vacuum waste liquid tank 207 through the liquid discharge line 209. In the vacuum waste tank 207, the atmosphere or N _{2 may} be supplied from the supply line 208 as needed to recover an atmosphere. An on-off valve 215 is provided in the middle of the supply line 208. Further, an on-off valve 216 is provided in the middle of the drain line 209. The reduced pressure processing chamber 201 passes through the exhaust line 212 and the waste liquid tank 207 through the exhaust line 211, and is depressurized by the pump 213, respectively. Valves 218 and 219 are provided in the middle of the exhaust line 211, and valves 220 and 221 are provided in the middle of the exhaust line 212. The valves 219 and 221 are on-off valves having a variable flow rate mechanism. The exhaust pump 213 is a pump that is resistant to moisture, for example, a chemical dry vacuum pump of a diaphragm type, and specifically, DTC-120 (manufactured by ULVAC Co., Ltd.) can be preferably used.

The processing chamber 201 and the waste liquid tank 207 are attached to a frame 303 made of aluminum, for example, as shown in FIG. Also mounted on the frame 303 is a rotator 301 provided to rotate the rotating shaft body 202-1. In the treatment (medicine) liquid supply line 205 At the upstream end, a drug solution 302 for storing the treatment liquid is connected.

FIG. 4 is a model explanatory diagram for explaining a suitable configuration of a treatment (medicine) liquid supply system provided inside the medicine cartridge 302. As shown in FIG. 4, 400 is a nitrogen pressure feeding method (medicine) liquid supply system, 401 is a canister, 402 is a processing liquid supply line, 403, 411 is a stop valve, and 404 is a flow regulating valve. 405 is a flow meter, 406 is a mist trap, 407, 408 is a nitrogen gas supply line, 409 is a vent valve, 410 is a shunt joint, and 412 is a regulator. ), 413 is a joint, and 414, 415 is a quick connector.

The treatment (drug) liquid supply system 400 of the nitrogen pressure feed system is provided with a 3/8 inch line on the upstream side and a treatment liquid supply line 402 on the downstream side of the 1/4 line line in the storage tank 401. The joint 413 is connected through the quick joint 414; the 1/4 inch nitrogen gas supply line 407 is connected through the quick joint 415. In the middle of the processing liquid supply line 402, a stop valve 403, a flow rate adjusting valve 404, and a flow meter 405 are provided. Further, the downstream portion of the processing liquid supply line 402 on the side of the stop valve 403 is connected to the processing liquid supply line 205. A ventilation (exhaust) valve 409 and a shunt joint 410 are provided in the middle of the nitrogen gas supply line 407. The ventilation (exhaust) valve 409 is for exhausting the nitrogen gas in the inside of the storage tank 401 and the nitrogen gas supply line 407 to the outside. The downstream side of the nitrogen gas supply line 407 is inserted into the liquid mist trap 406. Nitrogen gas is introduced into the liquid mist trap 406 through the regulator 412, the stop valve 411, and the nitrogen gas supply line 408. The liquid mist trap 406 is arranged to prevent the treatment liquid from flowing upstream to the upstream side.

Fig. 5 is a view showing a model configuration of a vacuum waste liquid tank 207. As shown in Fig. 5, 501 is a flange for draining, 502 is a flange for pressure reduction, 503 is a flange for introducing waste liquid, 504 is a flange for gas introduction, 505 is a vacuum gauge, and 506 is a flow rate. The meter and 507 are liquid level observation windows.

In the vacuum waste liquid tank 207, the drain line 209 passes through the flange 501 for draining liquid, the drain line 211 passes through the flange 502 for pressure reduction, the recovery line 210 passes through the flange 503 for introducing the waste liquid, and the supply line 208 They are connected by flanges 504, respectively. The vacuum gauge 505 measures the pressure in the waste liquid tank 207. In the upper portion of the waste liquid tank 207, in order to observe the water level of the waste liquid in the waste liquid tank 207, a liquid level observation window 504 composed of a transparent member for waste liquid is provided.

Figure 6 is a diagram showing the construction of another suitable processing chamber. As shown in FIG. 6, 600 is a reduced pressure processing chamber, 601 is a chamber constituent body, 602 is an upper cover, 603 is a platform for a processed object, 604 is a rotating shaft body, 605 is a magnetic fluid seal, and 606 is special. The treatment (medicine) liquid supply line, 607 is an ozone water supply line, 608 is an ultrapure water supply line, 609, 610, 611, 618 is a flow meter, 612, 613, 614, 617, 621, 624 is a valve, 615 is The gas introduction line, 619 is a gas discharge line, 616, 620, 623 is a flange, 622 is a waste liquid line, 625 is an observation window (625-1, 625-2), and 626 is a vacuum gauge.

The reduced pressure processing chamber 600 shown in Fig. 6 differs from the reduced pressure processing chamber 201 shown in Fig. 2 in that it has a special treatment (medicine) liquid supply line 606, an ozone water supply line 607, and ultrapure water. Supply line 608 is the three supply lines. In addition, except for another difference, basically It is structurally identical to the reduced pressure processing chamber 201. Another difference is that a gas introduction line 615 and a gas discharge line 619 are installed in the pressure reduction processing chamber 600. The ambient gas in the reduced pressure processing chamber 600 is introduced through the gas introduction line 615. The gas introduction line 615 is attached to the reduced pressure processing chamber 600 by a flange 616. In the middle of the gas introduction line 615, a valve 617 for switching and a flow meter 618 are provided. The gas discharge line 619 is attached to the reduced pressure processing chamber 600 by a flange 620 for pressure reduction. A valve 621 for switching is provided in the middle of the gas discharge line 615. On the downstream side of the gas discharge line 615, a pump (not shown) identical to the vacuum pump 213 is connected. The reduced pressure processing chamber 600 is configured such that the inside of the chamber constituting body 601 and the upper cover 602 is maintained in a reduced pressure state. In the upper cover 602, two observation windows 625-1, 625-2 for observing the inside of the chamber 600 are provided. Inside the reduced-pressure processing chamber 600, a stage 603 for providing a target object to be processed by the object to be processed is provided. In the platform 603, the rotating shaft body 604 for rotating the platform 603 is fixedly disposed in a detachable state. The rotating shaft body 604 is sealed by the magnetic fluid seal 605 to be engaged with the rotating shaft body of the rotator provided outside the pressure reducing processing chamber 600. A flow meter 609 and a valve 612 are provided in the middle of the special treatment (medicine) liquid supply line 606. A flow meter 610 and a valve 613 are provided in the middle of the ozone water supply line 607. A flow meter 611 and a valve 614 are provided in the middle of the ultrapure water supply line 608. At the bottom of the reduced pressure processing chamber 600, the waste liquid line 622 is attached to the reduced pressure processing chamber 600 by the flange 623. In the middle of the waste liquid line 622, a valve 624 for switching is provided. On the side of the reduced pressure treatment chamber 600, a pressure reduction device is installed. A vacuum gauge 626 that processes the pressure within the chamber 600.

Fig. 7 is a plan view showing the arrangement and discharge direction of a nitrogen gas (N ₂ ) gas discharge port provided on the inner wall surface of the processing chamber 601 of Fig. 6. As shown in Fig. 7, 701 is a gas ejecting inner wall tube, and 702 is a gas ejection port.

The gas ejecting inner wall tube 701 combined with the gas introduction line 615 is attached to the inner wall of the decompression processing chamber 600. The gas ejecting inner wall tube 701 is provided with a predetermined number of gas ejection ports 702 that face in a direction in which the central axis of the inner space of the decompression processing chamber 600 is ejected. The discharge orifice diameter and the number of the gas discharge ports 702 are designed to have a predetermined gas discharge flow rate.

In the present invention, the flow rate of the gas ejected (bleeded) from the gas ejection port 702 is appropriately set in advance at the time of design so as not to cause a stirring action or a spoiler effect in the processing chamber due to the gas ejection, and more precisely, It is preferable to determine the optimum value in the preliminary experiment of gas ejection. The degree of agitation or turbulence caused by gas ejection is also related to the gas venting speed. In the present invention, it is preferably set to 0.1 to 5.0 m/sec, more preferably 0.5 to 3.0 m/sec. The best is ideal for around 2.0m/sec. For example, when the discharge port 702 having a diameter of 2 mm is provided on the half circumference as shown in the figure, it is preferable to flow N ₂ gas in an amount of 200 cc/min in the pressure reduction processing chamber 600. The flow rate of the N ₂ gas at this time was 2.0 m/sec. In the present invention, in order to increase the absorption force of the gas, it is preferred that the treatment liquid is sufficiently degassed in advance. Further, it is preferable to use a resin laminated tube (manufactured by NICHIAS Co., Ltd.) which is used for the supply of the treatment liquid. In the description so far, an example is given to use an N ₂ gas or an atmospheric gas as an ambient gas. However, if CO ₂ gas is used instead of these gases, the amount of the solution to be treated can be increased, which is preferable.

Figure 8 is a schematic diagram of the saturated vapor pressure curve of water. The horizontal axis represents temperature (° C.) and the vertical axis represents pressure (Torr). In the present invention, the treatment liquid is introduced into the treatment chamber under reduced pressure, but the degree of pressure reduction is preferably 30 Torr as the upper limit in order to avoid boiling of the treatment liquid. When the treatment liquid is supplied to the surface of the substrate to be treated under reduced pressure and then pressurized, even if bubbles remain in the pores, the volume of the bubbles is reduced by pressurization and is easily detached from the pores, which is preferable. For example, from a reduced pressure of 30 Torr to 760 Torr, the volume of the bubbles becomes about 1/25. Therefore, in a good aspect of the present invention, the treatment liquid is sufficiently decompressed and supplied, and then pressurized. Moreover, the decompression and pressurization can be repeated.

The present invention has been specifically described above, but the technology of the present invention is not limited to TSV, and any technology that requires high aspect ratio holes, such as MEMS, can be used.

100‧‧‧SOI substrate

101‧‧‧Si (矽) semiconductor substrate

102‧‧‧SiO2 (yttria) layer

103‧‧‧Si layer (103-1,103-2)

104‧‧‧ hole

105‧‧‧ bubbles

106‧‧‧Processing fluid

107‧‧‧ gas-liquid interface

108‧‧‧Inside wall surface (108-1,108-2)

109‧‧‧Inner wall

110‧‧‧ openings

Claims (1)

A method for treating an inner wall surface of a fine void, characterized in that a treatment space provided with a substrate and having a decompressible pressure is decompressed, wherein the substrate has a surface to which the treatment liquid is applied, and the inside has an opening on the surface Fine pores, and the aspect ratio (l/r) of the fine pores is 5 or more, or the aspect ratio is less than 5 and V/S (V: volume of fine pores, area of S: opening) is 3 or more; then, the treatment liquid is introduced into the decompressed treatment space to treat the inner wall surface of the fine pores.