JPH07297166A - Apparatus for drying substrate for manufacture of electronic device - Google Patents

Abstract

PURPOSE:To give a sufficient cleanliness degree to a substrate which has been finished so as to have a hydrophilic face by a method wherein a ventilation mechanism whose flow velocity is variable, a mechanism for removal of a contamination in the air, an air-heating mechanism and a filter by a ceramic filtration film are installed at a cleaned-air blowing mechanism. CONSTITUTION:A cleaned-air blowing mechanism is provided with a ventilation mechanism whose flow velocity is variable, with a mechanism for removal of a contamination in the air, with an air-heating mechanism and with a filter by a ceramic filtration film. For example, a fan 2 whose number of revolutions can be adjusted is enumerated as the ventilation mechanism whose flow velocity is variable. In addition, a mechanism which is provided with at least an activated-carbon filter 5 is required as the mechanism for removal of the contamination in the air. A double high-purity quartz glass tube 6 which does not generate a chemical contamination to the air and in which a heater has been built in an inner tube is enumerated as the air-heating mechanism. In addition, a filter which has a rated removal efficiency of 99% or higher with reference to fine particles of 0.01mum is used as the filter 7 by the ceramic filtration film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drying apparatus which is carried out after wet cleaning of an electronic device manufacturing substrate which requires an ultraclean surface.

[0002]

2. Description of the Related Art In a device manufacturing process, a substrate for manufacturing an electronic device such as a semiconductor wafer or a glass for a liquid crystal needs to sufficiently remove fine particles and chemical contaminants adhering to the surface thereof by washing. Moreover, the cleaning treatment with a liquid is most effective for removing fine particles. Therefore, in the substrate cleaning process, so-called wet cleaning is usually incorporated as an essential step.

The wet cleaning can also effectively remove chemical contaminants by using an appropriate chemical liquid as the cleaning liquid. Generally, in terms of productivity,
Dozens of substrates are held by the carrier for cleaning, and after this cleaning, so-called ultrapure water rinse that does not substantially produce a residue during evaporation is performed, and then the substrate is dried to perform cleaning. The cleaning process is complete.

Since the cleanliness of the substrate required in the electronic device manufacturing process is extremely high, the cleanliness must be sufficiently maintained even in the above drying process. For example, even ultrapure water contains impurities and fine particles although the amount is very small, and therefore ultrapure water adhered to the substrate by rinsing needs to be removed from the substrate by drying as quickly as possible. Further, the atmosphere required for drying also needs to be extremely clean.

As a drying method satisfying the above conditions, two methods have been mainly used in the past. One method is a centrifugal drying method in which a carrier holding the substrate is rotated at a high speed so that the substrate surface becomes a rotating surface, and the adhered water is blown off by a centrifugal force. This method is excellent in mass productivity and is desirable from the economical point of view, but has a troublesome problem that it is necessary to prevent scattered mist and redeposition and contamination of dust particles in the apparatus. Further, as the diameter of the substrate increases like a semiconductor wafer, a chip may occur around the wafer.

Another method is to put the substrate in saturated vapor of an organic solvent (usually isopropanol is used) which is hydrophilic and has a low latent heat of vaporization, and the condensed water on the substrate is condensed and dropped to displace the adhering water. The substrate is then dried by heating with solvent vapor to dry the substrate. This method
Since water is not removed by mechanical operation, it is advantageous in terms of recontamination and damage. However, it is economically disadvantageous in that a high-purity solvent must be used, and there is a problem in that there is a risk of ignition common to hydrophilic solvent vapors. Furthermore, it cannot be said that a surface having a high degree of cleanliness is necessarily obtained in that solvent molecules are adsorbed on the surface of the substrate.

As a method for improving the above-mentioned drawbacks of the conventional method, for example, a method is proposed in which a clean gas is caused to flow at a high speed substantially parallel to the substrate surface to form a very thin water film of adhering water, followed by continuous evaporation and drying. Has been done. As such a method, for example, there is a hot air drying method in which, as a clean gas, air dedusted by a HEPA filter is heated to about 100 ° C. and sprayed on a substrate for drying.

Further, Japanese Patent Publication No. 63-17224 discloses that
Conveying means for conveying the carrier holding the wafer from the rinse water tank to just below the HEPA filter on the clean bench, a drying fluid supplying means utilizing the HEPA filter structure, and a water drop absorbing means provided under the wafer in the carrier. There has been proposed a wafer rinsing / drying machine characterized by comprising: Also in this apparatus, the washed wafer is dried by blowing a gas, and it is desirable that the drying rate is high. Therefore, in the actual apparatus, the temperature of the rinse pure water is set to a high temperature (90 to 100 ° C.). ) And the wafer and carrier are maintained at an elevated temperature prior to drying.

[0009]

The method of removing water adhering to the material to be dried by spraying a gas, particularly by blowing hot air, proposed above is the most general method, and is a substrate to be dried. Is not damaged by mechanical shock,
Also, there is no problem in terms of safety. However, such a general method has heretofore been rarely adopted as a drying method after cleaning a semiconductor wafer for the purpose of high-level cleaning because a large amount of gas is directly applied to the wafer surface. This is because an extremely high degree of cleanliness is required for this gas and it has not been possible to meet such requirements in the past. For example, if the sprayed gas contains fine particles, an oily substance, or the like, these adhere to the surface of the wafer, resulting in a striped pattern.

By the way, in general, when the purity of the ultrapure water used for rinsing is sufficiently controlled and the spray drying is performed with the air filtered by the HEPA filter at a high speed, the above-mentioned conditions are used. It is said that such a striped pattern does not occur. Therefore, in the above-described wafer drying after rinsing with pure water at 90 to 100 ° C., the flow rate of the gas passing through the HEPA filter is set to 8 to 10 m / sec.

However, when applied to the above high-speed airflow, there is a problem in the reliability of the dust removal capacity of the HEPA filter. That is, the HEPA filter is originally made for a clean room, and the optimum flow velocity is about 0.5 m / sec. Therefore, if the HEPA filter, which is a folded structure of a thin fiber cloth, is used for a long period of time at a flow rate that is higher than the optimum flow rate by one digit or more, naturally, a problem arises in the reliability of its dust removal capacity.

Further, in the folded structure of the fiber cloth such as the HEPA filter, it is necessary to continuously use the fiber cloth at a constant speed because a leak may occur when the wind pressure changes rapidly. For example, assuming that the drying area is 30 cm × 30 cm when using a carrier for 25 6 ″ wafers and the air velocity at the filter outlet is 10 m / sec,
The required amount of drying gas per hour is 3000 m ^{3, which} is a very large amount. Therefore, it is difficult to use the high-purity inert gas that uses the liquefied gas as a raw material in terms of cost, and the blowing gas that is practically used is limited to the atmosphere. However, HE
Even in the air in a class 10 clean room equipped with a PA filter, TOC (total organic carbon) trapped in the water in the impinger for analysis is usually 10μ.
It is of the order of g / m ³ . Further, it is necessary to use a blower fan in order to increase the wind speed in the filter, but generally, this fan allows the mixing of oily substances.

Now the spacing between the 6 "wafers in the carrier is
Assuming 5.5 mm, the amount of air passing through the surface per one side of the wafer is about 4 liters / second when the wind speed is 10 m / second. Therefore, the air containing at least 2 × 10 ¹⁵ or more organic carbon particles passes through the wafer surface per second. In fact, RCA SC-1 cleaning solution (NH
₍₄ OH: H ₂ O ₂ : H ₂ O = 1 volume: 1 volume: 5 volumes) A carrier loaded with a wafer whose surface is sufficiently hydrophilicized is immersed in ultrapure water and then pulled up to 100 The above air heated to ℃ was blown at a speed of 10 m / sec, and the pure water accumulated underneath was sucked by a vacuum pump. It took more than 30 seconds for the carrier groove around the wafer to completely dry. Needed Therefore, the amount of organic carbon in the air passing through the wafer surface during this period is at least 3 × 10 ¹⁶ or more, and a considerable amount of this is adsorbed on the wafer surface.

Further, the cleaning effect of the HEPA filter is only dust removal and is extremely ineffective in removing organic molecules and the like. In fact, since hydrophilic wafers left in a clean room become hydrophobic in a short time, it is considered that most of these organic substances are oily. Therefore, if the wafer is dried by the air that has passed through the HEPA filter at high speed, harmful organic matter contamination is likely to occur even if it cannot be discerned by the naked eye. In the air in the clean room, in addition to organic molecules, SO _X , NO _X , HCl, H ₂ SO
_In addition to acid molecules such as ₄ , there are also alkali molecules such as NH ₃ ,
These concentrations can also reach levels close to TOC. That is, these acid molecules and alkali molecules, like organic substances, also cause wafer contamination in this drying method.

An oxide film of about 100 liters was formed on each of the already-released high-speed air-blasted dry wafer and the widely used centrifugally dried wafer, and an MDS diode was formed on the oxide film to compare the dielectric strength characteristics of both. High-speed air-blasted dry wafers often have poor yields. It is presumed that the oxide film has defects due to the above-mentioned contamination causes.

Further, it is advantageous to raise the temperature of pure water in the washing tank for rinsing with pure water in advance in terms of speeding up the drying. However, when immersing and rinsing a silicon wafer with heated pure water, ultrapure water is used. However, the present inventor has found that there is a problem that a slight amount of heavy metal present is easily adsorbed as compared with room temperature water immersion. For example, it is a radioisotope in ultrapure water
^{When 59} Fe of 0.1 ppb is added and the silicon wafer is immersed for 10 minutes, the adsorption on the wafer surface is about 3 × 10 ⁹ atoms / cm ² when the ultrapure water is 25 ° C. 70 ℃
When it is heated to, the adsorption amount reaches 3 × 10 ¹⁰ atoms / cm ² , which is a problem in the semiconductor process. The Fe concentration in ultrapure water can usually be controlled to 0.01 ppb or less,
The general purity standard for metal elements in ultrapure water control equipment is 0.1 ppb
Therefore, there is no guarantee that the Fe concentration will not deteriorate to about 0.1 ppb. Moreover, Cu, Al, Zn, etc. in ultrapure water tend to be adsorbed on the silicon surface to the same extent as Fe or more. From the above, the immersion rinse with high temperature pure water is not always more advantageous than room temperature water contamination in terms of chemical contamination.

Therefore, an object of the present invention is to provide an electronic device for a substrate which has been subjected to an ultrapure water immersion rinse at room temperature and whose surface is susceptible to striped stains and which has been subjected to a hydrophilic surface finish chemical treatment. Another object of the present invention is to provide a hot-air type drying device capable of obtaining sufficient cleanliness.

According to the present invention, there is provided an apparatus for drying a substrate for producing an electronic device rinsed with water, which substantially does not produce a residue upon evaporation, which is substantially parallel to the surface of the substrate supported substantially vertically. In a drying device that blows heated cleaning air to perform drying, the cleaning mechanism is composed of a chamber in which the cleaning air blowing mechanism is connected to the upper portion and an exhaust mechanism is connected to the lower portion, and the blowing mechanism is a blowing mechanism with a variable flow rate. And an air pollutant removal mechanism equipped with at least an activated carbon filter, an air heating mechanism which does not substantially cause chemical pollution to the air, and a ceramic having a rated removal efficiency of 99% or more for 0.01 μm fine particles. An electronic device having a filter with a filtering membrane, and a support mechanism for supporting the substrate so that the substrate surface is substantially vertical in the chamber. Vice of manufacturing apparatus for drying a substrate is provided.

In the present invention, the electronic device substrate to be dried is one that has been rinsed with water, which is the final step of wet cleaning. That is, since the drying apparatus of the present invention performs drying by blowing hot air of cleaning air from above onto the substrate to be dried (substrate for electronic device manufacturing) which is left standing substantially vertically, it is mechanically operated. A clean dry surface is obtained without impact and unless the rinse water leaves a residue on evaporation during drying. For example, when using a hydrophilic silicon wafer as the substrate, the rinse water drops downward from the top of the substrate along with the blowing of hot air, and the surface silanol groups are hydrated by hydrogen bonds. Almost all rinse water is released from the substrate surface in about 10 seconds, leaving the water film of the molecular layer. The temperature of the wafer, which is the substrate, rises from above due to the blowing of hot air, and when the temperature reaches 105 ° C. or higher, the hydrated water evaporates, leaving only silanol groups, and the wafer drying is completed. Similar drying is also performed when glass having a SiO ₂ film formed on the surface for liquid crystal is used as a substrate.

The purity of the rinse water that does not substantially produce evaporation residue is at the level of ultrapure water, for example, 18M which is commercially available.
Ultra pure water produced by Ω class pure water production equipment, 1986
It can be used as long as it has a purity that satisfies the SEMI Acceptable standard of the year. Also, if it is a high-purity acid for the electronics industry, it can be added to the rinse water as long as the amount is 500 ppm or less. For example, the amount of contamination from the water film of several molecular layers to the substrate is From the calculation, it can be confirmed that the level does not adversely affect the above (5 × 10 ⁹ atoms / cm ² or less for heavy metals).

Further, in the drying apparatus of the present invention, the cleaning air is blown from the upper part to the substrate supported almost vertically in the chamber from the cleaning air blowing mechanism provided in the upper part of the chamber. Be seen. The cleaning air blowing mechanism has a variable-flow-rate air blowing mechanism, an in-air contaminant removing mechanism, an air heating mechanism, and a filter with a ceramic filtration membrane. And it is possible to spray the purified air at an ideal wind speed.

In the above, as the variable flow velocity blowing mechanism, there is, for example, a fan capable of adjusting the number of revolutions, and in particular, a mechanism capable of setting the wind velocity on the substrate surface at 5 to 15 m / sec and 1 m / sec or less is preferably used. To be done. That is, the wind velocity of the hot air required for drying is ideally 5 to 15 m / sec, but if the blowing is always performed at this wind velocity, the amount of air is too large, which causes problems in economic efficiency and exhaust. . Therefore, it is preferable to set the wind speed to 5 to 15 m / sec only for several tens of seconds during drying, and to maintain the cleanliness at a wind velocity of 1 m / sec or less at other times.

Further, the mechanism for removing contaminants from the air needs to have at least an activated carbon filter. The activated carbon filter is a filter that is particularly effective for adsorbing and removing organic matter and NH ₃ , and for example, activated carbon particles are packed in a case, activated carbon fine particles are impregnated into a plastic woven fabric or the like to form pleats, or activated carbon fiber woven fabrics. There are things such as a pleated cloth.

Further, it is preferable to use a chemical filter for removing acid and alkali molecules in combination with an activated carbon filter. Known examples of the chemical filter include a case in which a chemical adsorbent such as KMnO ₄ is impregnated with activated alumina particles and case-filled, or a pleated ion exchange resin fiber woven cloth is used. Can also be used. When KMnO ₄ is used as a chemical adsorbent, NO ₂ and SO ₂ are oxidized to form acid ions such as NO ₃ ⁻ and SO ₄ ²⁻ , and at the same time, KOH, which is decomposed and produced, neutralizes them. Are captured by the filter. In the ion exchange resin fiber, both acid and alkali ions are captured by the resin. Also KM
A chemical adsorbent such as nO ₄ or iodine and an alkali which is attached to the activated carbon filter to integrate both adsorption functions can also be used in the present invention. The same reaction mechanism as in the case of using KMnO ₄ is also obtained in the case of impregnating iodine with alkali.

Further, in order to remove coarse particles in advance, a pre-filter for dust removal can be used together.
This pre-filter for dust removal is usually a single filter of a woven fabric of plastic fibers for removing large particles of, for example, 5 μm or more, and there are some that can be washed and regenerated. It is the same as that used for coolers.

The air heating mechanism is required to be a device which does not substantially cause chemical pollution to air,
For example, the material in the high temperature region that comes into contact with the drying air can be stainless steel, high-purity quartz, high-purity silicon carbide, high-purity silicon, etc., but high-purity quartz, high-purity silicon carbide, high-purity silicon can be used. Those that are configured are preferred. Specifically, a double high-purity quartz glass tube having a heater incorporated in the inner tube, a high-purity quartz glass tube having a high-purity silicon carbide heater, and the like are preferably used. With this air heating mechanism, the temperature required for hot air drying of the substrate,
For example, the boiling point of water is 100 ° C or higher, preferably 105
The drying air is heated in the range of 150 ° C. If the temperature of the drying air is higher than 150 ° C., the carrier for transporting the substrate to be dried may be deformed.

As a filter using a ceramic filtration membrane, a filter having a rated removal efficiency of 99% or more for 0.01 μm fine particles is used. For example, a thin tube made of porous ceramic such as porous alumina is used as a filter element. Used are those which are bundled in a large number and fixed in a suitable housing. This ceramic filter has the advantage of being extremely reliable against pressure changes. Further, even if hot air flows, the quality of the filter membrane (filter element) does not change, so that this filter and the above heating mechanism can be used integrally.

An example of hot air blowing of clean air by the above-mentioned blowing mechanism is shown in the flow chart of FIG. In the example of FIG. 1, the air first passes through the prefilter 1 for dust removal, and the blower 2 causes the chemical filter 3, the dryer 4, the activated carbon filter 5, and the heating unit 6 to be removed.
And the drying chamber 8 through the ceramic filter 7.
Supplied within.

That is, after the relatively large-sized particles are removed by the dust removal pre-filter 1, the chemical filter 3
The acid and alkali are removed by the dryer, dehydrated by the dryer 4, and the organic matter and NH ₃ by the activated carbon filter 5.
Etc. are adsorbed and removed. Next, the heating unit 6
Is heated to become hot air, fine particles are removed by the ceramic filter 7, and purified air is sprayed. Of course, the heating unit 6 and the ceramic filter 7 may be arranged in reverse, and the ceramic filter 7 may be provided with a heating mechanism.

FIG. 2 shows an example of the structure of the chamber 8, and FIG. 3 shows an example of a substrate transfer mechanism that is preferably used in the drying apparatus of the present invention together with the chamber.

In FIG. 2, the chamber 8 has a hot air blowing mechanism 9 in the upper part, and the lower part has the exhaust drain pipe 1 in the lower part.
It is provided on the chamber table 50 having 0. Further, carrier mounting tables 30, 30 are provided on the side wall of the chamber 8, and a substrate support 31 is provided which extends upward between the carrier mounting tables 30, 30 and has an upper end branched into a Y-shape. ing.

The hot air blowing mechanism 9 is provided with an air inlet 12 at the top and a nozzle 13 at the bottom. The nozzle 13 is preferably a high-purity silicon carbide nozzle, for example, and the air inlet 12 is connected to the cleaning mechanism shown in FIG. 1 described above. That is, the hot air purified through the ceramic filter 7 of FIG. 1 is blown into the chamber 8 from the nozzle 13 through the air inlet 12.

Further, the hot air blowing mechanism 9 includes a chamber 8
Plate 16 detachably joined to the upper flange 15 of the
It is fixed to. That is, in drying by blowing hot air, first, the support plate 16 is moved upward to open the upper part of the chamber 8, the substrate 20 to be dried is introduced into the chamber 8, and the support plate 16 is closed.

In FIG. 3 showing an example of the substrate transfer mechanism, the rinsed substrate 20 is transferred while being held in a transfer carrier 21 having openings formed in the top and bottom. As shown in FIG. 3, the lower opening of the carrier 21 for transport is small enough that the substrate 20 does not pass through the opening, while the upper opening is sized to allow the substrate 20 to pass through. is doing. The transport carrier 21 is sandwiched and transported by a pair of claws 23, 23 provided on a sandwiching function body 22 slidably held by rails, chains and the like. That is, when the carrier carrier 21 holding the substrate 20 is introduced into the chamber 8 and descends and is held by the carrier mounting table 30, the claws 23 open and the sandwiching function body 22 rises, so that the support plate 16 described above is lifted. Is closed. In this case, the substrate support 31 enters through the lower opening of the carrier 21 as the transport carrier 21 descends, and the substrate 20 is supported by the Y-shaped upper end portion thereof. Therefore, in the state where the carrier carrier 21 is held on the carrier mounting table 30, the substrate 20 is held almost vertically in a state where it jumps out of the carrier carrier 21 as shown in FIG. It is possible to efficiently perform drying by spraying.

It is desirable that an air inlet 32 is formed at the upper end of the substrate support 31 and the inlet 3
2 extends below the substrate support 31 and communicates with a suction pipe 33 provided on the wall of the chamber 8. That is, by connecting the suction pipe 33 to a decompression air-blowing mechanism (not shown) such as a vacuum pump and operating the mechanism, it is possible to suck and remove water drops that have fallen from the surface of the substrate 20 and accumulated in the lower portion.

Further, in the present invention, a rinse water injection pipe 41 having a nozzle 40 made of quartz glass or the like is provided above the inner wall of the chamber 8 so that the substrate 20 can be rinsed in the chamber 8. It is suitable. For example, when rinsing by immersing the substrate in pure water for each carrier,
Fine particles may remain in the water adhering to the substrate surface after the rinse is completed. Therefore, by spraying the rinse water from the rinse water spray pipe 41 immediately before drying, the fine particles can be effectively removed. Further, depending on the cleaning solution and the condition of rinsing, metal contamination of about 10 ¹⁰ to 10 ¹¹ atoms / cm ² may occur, but the rinsing water to be sprayed has a concentration of 500 ppm.
Such metal contamination can be prevented by adding the following HF and HNO ₃ or the like. However, 500
Addition of more than ppm may cause harmful adsorption of added acid molecules on the substrate.

After completion of the drying by the hot air blowing, the support 16 is moved again to open the upper part of the chamber 8, and the sandwiching function body 22 is moved to raise the carrier 21 for transportation.
The dried substrate 20 is housed in the carrier 21, carried out of the chamber 8, and the wafer is stored at a predetermined position. Then, the sandwiching function body 22 is returned to the pure water rinsing tank, and again conveyed to the chamber 8 and dried.

[0038]

[Example] In the hot air supply system of FIG. 1, the chemical filter 3 is an ESI filter (trade name: DPCC10).
73K, activated carbon with I and KOH impregnated) and 5 filters were used in combination, and a filter with 3 spun-woven fabrics of anion / cation exchange fibers was used in combination. As the activated carbon filter 5, a filter obtained by stacking five activated carbon fiber woven fabrics (trade name: Adol) manufactured by Osaka Gas Co., Ltd. was used. Further, the heating unit 6 is a ceramic heater with an attached temperature control function.
We used a heavy quartz glass tube structure that enables efficient and high-speed heating with a silicon carbide heater housed in the inner tube. Further, as the ceramic filter 7, a ceramic filter manufactured by Toshiba Ceramics Co., Ltd. (trade name: CE
PURE-TMHL) was used in parallel with ten heating mechanisms at 150 ° C.

The above hot air supply system is connected to the chamber 8, a quartz glass impinger is placed in the chamber 8 to operate the hot air supply system, and the impurities in the supplied air are absorbed by the ultrapure water. Analysis was performed using a TOC measuring device, an ion chromatograph, and a flameless atomic absorption spectrometer.

As a result, the supplied air is TOC 0.2
μg / m ³ or less, NO ₂ , NO ₃ , SO ₄ , Cl
It was confirmed that the cleaning was achieved chemically because both of F and F were 0.1 μg / m ³ or less, and all the metal elements were below the detection limit.

Next, when air dust in the chamber 8 was measured with a dust counter, it was confirmed that a cleanliness of class 10 or lower was obtained. In addition, all the elements of the filter had very little pressure, and even if the filter was composed of a large number of sheets, a flow velocity of 5 m / sec was sufficiently obtained.

Next, an 8-inch silicone wafer 2
The carrier 21 holding five sheets was moved from the ultrapure water tank into the chamber 8 by using the sandwiching function body 22. The chamber 8 and the claws 23 of the sandwiching function body 22 are made of quartz, and the carrier 2
1 is made of fluororesin (PFA), the carrier mounting table 30 and the substrate support 31 are made of fluororesin (PTFE), and the chamber table 50 is made of stainless steel.

At the same time as the depressurizing air-blowing mechanism connected to the suction pipe 33 is operated to absorb the water droplets accumulated in the lower part of the wafer, an exhaust pump is connected to the exhaust / drain pipe 10 of the chamber base 50 to operate the pump and hot air. The supply system was operated, and clean hot air was blown in at a wind speed of approximately 5 m ³ / sec.
An 8-inch silicone wafer cleaned with the SC-1 cleaning solution was dried in 40 seconds. The carrier is 50
Dry in seconds.

After the high-speed hot air blowing for a predetermined time, the flow velocity of the air was reduced to about 0.5 to 1 m / sec, and the reduced pressure blow from the suction pipe 33 was also stopped to complete the drying.

Before the reduced pressure air is blown from the suction pipe 33,
Cleaning was performed by spraying rinse water from the rinse water spray pipe 41. Depending on the cleaning process, the surface of the silicon wafer after the final ultrapure water rinse may have about 10 ¹¹ atoms / cm ² of Al.
Remained, but 100 ppm HF was added to the ultrapure water for spray rinsing, the mixture was heated to 50 ° C and sprayed for 2 minutes.
Was 10 ¹⁰ atoms / cm ² or less.

Further, the surface condition of the dried wafer is such that if the wafer is hydrophilic and fine particles are sufficiently removed in the final rinsing step, no visible stain such as a striped pattern is generated. I couldn't see it. In addition, the same lot of silicon wafers was used and compared with a widely used centrifugal dryer, but no significant difference was observed in the measurement of surface fine particle concentration.

[0047]

According to the drying apparatus of the present invention, since the substrate can be dried without giving a mechanical impact,
There is no risk of damaging the substrate like a centrifugal dryer. Also, there is no risk of adsorption of organic molecules as in steam cleaning. Furthermore, the heating air from which not only fine particles but also organic substances such as oily substances have been removed can be reliably and speed-varied from a high speed of 10 to 20 m / sec to a normal wind speed in a clean bench. Can be sprayed and dried separately from the carrier holding the. Therefore, it is possible to perform drying at a surface cleanliness that is extremely economical and has no problem in manufacturing electronic devices.

[Brief description of drawings]

FIG. 1 is a flowchart showing an example of a hot air blowing mechanism used in a drying device of the present invention.

FIG. 2 is a diagram showing an example of the structure of a drying device of the present invention.

FIG. 3 is a diagram showing an example of a transport mechanism for a substrate to be dried, which is preferably used in the drying apparatus of the present invention, together with a chamber.

[Explanation of symbols]

 1: Pre-filter for dust removal 2: Blower 3: Chemical filter 4: Dryer 5: Activated carbon filter 6: Heating unit 7: Ceramic filter 8: Drying chamber 8 9: Hot air blowing mechanism 9 13: Nozzle 13 20: Substrate 20 21 : Carrier for transport 22: Clamping function body 23: Claw 30: Carrier mounting table 31: Substrate support 41: Rinse injection pipe

 ─────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 000003078 Toshiba Corporation, 72 Horikawa-cho, Sachi-ku, Kawasaki-shi, Kanagawa (72) Inventor Noriyuki Saito, 3-7-1, Nishishinbashi, Minato-ku, Tokyo Toshiba Plant Construction Incorporated (72) Inventor Mitsunobu Masuda 1-32 Dojimahama, Kita-ku, Osaka City, Osaka Prefecture (72) Inventor Hideyasu Matsuo 30 Soya, Hadano City, Kanagawa Toshiba Ceramics Co., Ltd. (72) Inventor Hisashi Muraoka 3-15-2 Migaoka, Midori-ku, Yokohama-shi, Kanagawa

Claims (6)

[Claims] 1. An apparatus for drying a substrate for producing an electronic device, which is rinsed with water, which produces substantially no residue upon evaporation, and which is heated and cleaned substantially parallel to the surface of the substrate which is supported substantially vertically. In a drying device that blows dry air to dry the air, the clean air blow mechanism is connected to the upper part of the chamber, and the exhaust mechanism is connected to the lower part of the chamber, and the blow mechanism is a variable flow rate blowing mechanism and at least activated carbon. Air pollutant removal mechanism equipped with a filter, air heating mechanism that does not substantially cause chemical pollution to air, and filter with ceramic filtration membrane having a rated removal efficiency of 99% or more for 0.01 μm fine particles An apparatus for drying a substrate for manufacturing an electronic device, comprising: 2. The electronic device manufacturing substrate to be dried is:
The carrier is supported substantially vertically in a transfer carrier having openings in the upper and lower parts and is introduced into the chamber, and in the chamber, a support mechanism for supporting the transfer carrier and a separate support mechanism are provided. The drying device according to claim 1, further comprising: a substrate supporting member that supports the substrate. 3. The substrate supporting member extends upward through a lower opening of a carrier which is supported by the supporting mechanism, and has an upper end portion branched into a Y shape. 2. The drying device according to 2. 4. The drying apparatus according to claim 1, wherein the air blown onto the substrate is heated to a temperature of 105 ° C. to 150 ° C. by the air heating mechanism. 5. The drying apparatus according to claim 1, wherein the cleaning air is blown out by the air blowing mechanism through a silicon carbide nozzle. 6. The drying device according to claim 3, wherein the substrate support is provided with an air suction hole extending to an upper end.