JP5336894B2 - Photoresist removal device - Google Patents

Description

  The present invention relates to an apparatus for removing unnecessary photoresist on a substrate, and in particular, highly efficiently removes photoresist remaining on a substrate surface that has been subjected to dry etching processing or high current ion implantation processing in a semiconductor manufacturing process. And a photoresist removing apparatus capable of uniformly removing the photoresist.

Conventionally, in a semiconductor manufacturing process, in order to remove unnecessary photoresist remaining on the surface of a silicon substrate that has been subjected to dry etching processing or high current ion implantation processing, the surface of the silicon substrate supported on a rotating support base is removed. A remaining photoresist is dissolved and removed by discharging a solvent or chemicals from a cleaning nozzle.
However, this method generates a large amount of waste liquid containing solvents and chemicals, and these solvents and chemicals are generally subject to emission control. Therefore, special treatment facilities are required, and both the cost and the environment are heavy. It was.

For this reason, recently, a method has been studied in which ozone water having no emission restriction is supplied to the surface of a silicon substrate where unnecessary photoresist remains, and the remaining photoresist is removed by the oxidizing power of ozone (Patent Document). 1).
However, although ozone has been used in the past, for example, it has a strong oxidizing power compared to a mixed solution of sulfuric acid and hydrogen peroxide, ozone has a self-decomposing property, so the surface of the silicon substrate If the ozone contained in the ozone water is not supplied uniformly, there is a problem that the removal of the photoresist becomes non-uniform.

  That is, when ozone water is poured into the center of the silicon substrate surface where the photoresist remains, the substrate support base rotates at a high speed, so that the discharged ozone water is scattered radially and uniformly on the silicon substrate. In addition, the flow rate of ozone water per unit area of the surface of the substrate decreases in inverse proportion to the square of the radius of the substrate as it moves away from the center, so that the periphery of a large-diameter substrate such as 300 mmφ The removal of the photoresist on the part was uneven.

In addition, in order to increase the reaction efficiency of ozone water, a method of increasing the reactivity of ozone water by irradiating the surface of the silicon substrate where the photoresist remains with high energy rays such as excimer laser light and ultraviolet rays is also known. (See Patent Document 2).
However, even in this method, there is a large difference in the amount of ozone water flowing on the substrate surface between the central portion and the peripheral portion of the substrate, so that it is difficult to uniformly remove the remaining photoresist on the entire substrate.

JP 2006-295091 A JP 2008-3112561 A

As described above, in the conventional photoresist removal method using ozone water, ozone is uniformly contained in the surface of the silicon substrate simply by discharging ozone water to the substrate surface where unnecessary photoresist remains. Therefore, there is a problem that unnecessary photoresist is removed unevenly.
In addition, in the photoresist removal method using ozone water, the reaction product of the photoresist and ozone is deposited on the peripheral portion of the substrate, thereby obstructing the contact between the photoresist and ozone. This also removes the photoresist on the peripheral portion. It was the cause that made it difficult.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide a photoresist removing apparatus that uniformly removes unnecessary photoresist remaining on the surface of a silicon substrate.

  One embodiment of the photoresist removing apparatus of the present invention includes a support base that rotates while supporting a substrate to be cleaned, a cleaning nozzle disposed above the support base with a water injection port facing downward, A photoresist removal apparatus comprising a high-concentration ozone water supply device for supplying high-concentration ozone water to the cleaning nozzle, wherein the cleaning nozzle is a plurality of units arranged at predetermined intervals in the radial direction of the substrate Each of the unit cleaning nozzles is configured independently so as to reduce the difference in the amount of ozone supplied per unit area of the substrate.

  Further, in order to remove the reaction product of the photoresist and ozone deposited on the substrate, it is desirable to arrange an air knife extending in the radial direction of the substrate behind the rotation direction of the unit cleaning nozzle.

The high-concentration ozone water used in the present embodiment is, for example, GR-RB (gas flow rate 4 L / min (N)), GR-RC (gas flow rate 6 L / min (N)), GR-RD commercially available as the GR series. (Gas flow rate 8 L / min (N)), GR-RE (gas flow rate 10 L / min (N)), GR-RF (gas flow rate 12 L / min (N)), GR-RG (gas flow rate 14 L / min (N) )) [Each ozone gas generated by an ozonizer known as Sumitomo Seimitsu Kogyo Co., Ltd., product name, gas pressure 0.2 MPa], which is dissolved in ultrapure water at a predetermined concentration (for example, 140 ppm) can be used. .
Moreover, as a support stand used by this embodiment, 2000-6000r. p. A general-purpose rotation support that rotates at m can be used.

In the photoresist removing apparatus of the present invention, the cleaning nozzle is basically composed of a plurality of independent unit cleaning nozzles arranged at predetermined intervals in the radial direction of the substrate from the central portion side to the peripheral portion of the substrate. .
As a result, the amount of ozone water in the peripheral portion is reduced because it has been conventionally disposed only on the center portion side, and the non-uniformity of peeling caused by this is improved.
In order to further reduce the difference in the amount of ozone supplied per unit area of the substrate to be cleaned by using a plurality of unit cleaning nozzles arranged in the radial direction of the substrate, (1) it is arranged in the radial direction of the substrate. The number of unit cleaning nozzles to be installed is increased from the center side toward the peripheral side. (2) The flow rate of high-concentration ozone water discharged from the unit cleaning nozzles arranged in the radial direction of the substrate is (3) The ozone concentration of the high-concentration ozone water discharged from the unit cleaning nozzle disposed in the radial direction of the substrate is increased from the central side to the peripheral side. It is possible to adopt a method such as increasing the concentration toward the surface, or (4) combining these methods.

  In order to increase the number of unit cleaning nozzles in (1) from the center side toward the peripheral edge side, for example, the cleaning nozzle is divided into a plurality of sections in the radial direction of the substrate, and the annular (center) The unit cleaning nozzles are located in each area of the circle, with one at the center, two on the next concentric circle from the center, three on the next concentric circle, and so on. So that the number of. At this time, if the width of the annular region is made equal, the distance between the concentric circles in the circumferential direction becomes wider toward the peripheral portion, so that the width of the annular region is wider on the center side and narrower on the peripheral portion side. It is desirable to do. The method (2) is a method in which the flow rate of each unit cleaning nozzle is increased on the peripheral side instead of changing the nozzle interval. For example, the hole diameter of the unit cleaning nozzle is sequentially directed toward the peripheral side. This can be achieved by increasing the size. The method (3) is a method of increasing the ozone concentration on the peripheral edge side instead of increasing the number of cleaning nozzles on the peripheral edge side. The method (4) is a combination of these methods. For example, by combining the methods (1) and (2), the number of unit cleaning nozzles used (number of nozzle holes) can be reduced. .

Even if the amount of ozone water supplied per unit area of the substrate of ozone water is the same on the central side and the peripheral side, if the unit nozzles are arranged in the radial direction, the radius of the unit cleaning nozzle at the peripheral part Photoresist and ozone reaction products are deposited in the overlapping region.
In order to avoid this problem, it is desirable to arrange the plurality of unit cleaning nozzles arranged in the radial direction of the substrate so that the flow on the substrate does not overlap and the water flow is uniform.
When the cleaning nozzles are arranged in a row in the radial direction when the cleaning nozzles are arranged at predetermined intervals in the radial direction of the substrate, the cleaning nozzle row is formed in an open spiral shape in which the peripheral portion side is displaced in the rotation direction. Since the water discharged from the central cleaning nozzle does not overlap with the water discharged from the peripheral cleaning nozzle, it is possible to prevent the reaction product of the photoresist and ozone from being deposited on the peripheral edge of the substrate. .
The above is a method for increasing the discharge amount on the peripheral edge side of the substrate of ozone water in the photoresist removing apparatus using the rotating support, but instead of these methods or together with this method, the unit on the peripheral edge side. The ozone concentration of the ozone water discharged from the cleaning nozzle can be increased.

  Still another embodiment of the present invention includes a support base that supports a substrate to be cleaned, a cleaning nozzle disposed above the support base with a water injection port facing the support base, the support base, and the cleaning base. A photoresist removing apparatus comprising a drive mechanism for linearly moving the nozzle linearly on a plane and a high-concentration ozone water supply device for supplying high-concentration ozone water to the cleaning nozzle, wherein the cleaning nozzle includes a plurality of cleaning nozzles. The unit cleaning nozzle is arranged so as to cross the substrate supported by the support base when viewed from the moving direction.

In this method, when the moving speed is made constant, high-concentration ozone water is discharged uniformly over the entire surface of the substrate, so that peeling can be performed more uniformly.
However, also in this method, when the cleaning nozzle moves away from the ejected region, the water flow of the high-concentration ozone water becomes gentle, and the reaction product of the photoresist and ozone may be deposited on the substrate surface. .
Therefore, also in this embodiment, in order to prevent deposition of reaction products, an air knife is arranged over the diameter of the substrate behind the cleaning nozzles arranged in a row, and high-concentration ozone water is applied to the cleaned region. It is desirable to prevent inflow and remove deposited reaction products.

In the present invention, it is also possible to increase the ozone reactivity by irradiating the surface of the substrate on which the high-concentration ozone water is discharged with high energy rays such as ultraviolet rays and excimer laser light.
Furthermore, using a high concentration hot ozone water supplied from a high concentration high temperature ozone water production apparatus capable of maintaining a certain level of ozone concentration, for example, ozone water of 70 degrees or more, to increase the reaction rate with the photoresist. Is also possible.

  According to the present invention, the photoresist can be removed uniformly by increasing the reaction efficiency of ozone water per unit volume to the photoresist, and the removal of the photoresist without using chemicals can be realized.

It is a figure which shows schematically the structure of one Embodiment of this invention. It is a figure which expands and shows the principal part of FIG. It is a figure which shows notionally the principal part of other embodiment of this invention. It is a figure which shows notionally the principal part of other embodiment of this invention. It is a figure which shows notionally the principal part of other embodiment of this invention. It is a figure which shows schematically the structure of further another embodiment of this invention. It is a figure which shows notionally the principal part of FIG. It is a figure which shows schematically the structure of further another embodiment of this invention.

  The best mode for carrying out the photoresist removing apparatus according to the present invention will be described below with reference to the drawings based on the embodiments.

1 and 2 are diagrams for explaining an embodiment of the present invention.
As shown in FIG. 1, the photoresist removing apparatus 1 of this embodiment is driven by a motor 2 and runs 2000 to 6000 r. p. A support base 3 that rotates at m, a high-concentration ozone water supply device 4, and a cleaning nozzle 6 attached to a support arm 5 are provided.
The high-concentration ozone water supply device 4 dissolves ozone gas having a concentration of 210 g / m ³ from the ozone gas supply pipe 4a that supplies ozone gas generated by the ozonizer in ultrapure water supplied from the ultrapure water supply pipe 4b. A high-concentration ozone water having a concentration of 140 ppm is prepared, and this high-concentration ozone water is supplied to the cleaning nozzle 7 via the pipe 6.
The cleaning nozzle 7 is disposed at the lower end of the pipe 6 held by the support arm 5 and orthogonal to the moving direction of the support 3. In this cleaning nozzle 7, a large number of unit cleaning nozzles 7a, 7a,... Reference numeral 8 is an open / close valve for high-concentration ozone water supplied to the unit cleaning nozzle 7a for high-concentration ozone water, and 9 is a drain receiver.

Using the apparatus of this example, 70 ppm, 70 ° C. high-concentration ozone water was rotated at 3000 rpm for 30 seconds at 3000 rpm on a 300 mmφ silicon substrate 10 where unnecessary photoresist (novolak resin-based photoresist) remained. When discharged, the photoresist could be completely removed.
On the other hand, in the conventional photoresist removing apparatus in which the same amount of high-concentration ozone water is discharged from the cylindrical tube disposed at the center of the substrate 10, the cleaning of the photoresist on the peripheral portion of the substrate surface is performed for 30 seconds. An unpeeled part remained.

FIG. 3 shows an embodiment in which the cleaning nozzle 11 in which a large number of unit cleaning nozzles 11a are arranged downward is bent in an open spiral shape from the center side in the rotation direction of the support base 3 in the apparatus of the first embodiment. . In this example, the unit cleaning nozzles are arranged in an open spiral shape that is displaced in the rotational direction, and air knives 12 that eject high-pressure air downward in the rotational direction are disposed in the radial direction of the support base 3. This open spiral curve shows that the high-concentration ozone water discharged from each unit cleaning nozzle 11a comes into contact with the substrate, and the resultant force of the tangential force derived from the radial centrifugal force and the rotational force of the substrate. When scattered in the direction, the flow is such that the flows of the high-concentration ozone water discharged from each unit cleaning nozzle 11a do not overlap.
Therefore, according to the photoresist removing apparatus of this embodiment, the water flow of the high-concentration ozone water flowing in the peripheral portion becomes uniform, and the reaction product of the photoresist and ozone is hardly deposited on the peripheral portion.
Further, in this embodiment, an air knife 12 is arranged behind the cleaning nozzle 11 in the rotation direction, and before the high-concentration ozone water is discharged from each unit cleaning nozzle 11a, the photoresist and ozone deposited on the surface of the substrate. Since the reaction product is removed with high-pressure air, the photoresist remaining on the periphery can be completely removed.

  The cleaning nozzle 13 of this embodiment shown in FIG. 4 has a discharge port 13a of the cleaning nozzle of Embodiment 1 shown in FIG. 1, and the diameter increases from the center side A to the peripheral side B. Thus, the amount of contact with ozone per unit area of the substrate on the peripheral edge side of the substrate is increased. According to the photoresist removing apparatus of this embodiment, the amount of high-concentration ozone water flowing in the peripheral portion increases, and the reaction product of the photoresist and ozone becomes difficult to deposit on the peripheral portion.

  In the cleaning nozzle 14 of this embodiment shown in FIG. 5, the interval between the unit cleaning nozzles 14a formed on the support arm of the first embodiment shown in FIG. 1 becomes narrower from the central side A to the peripheral side B. As a result, the amount of contact with ozone per unit area of the substrate on the peripheral edge side of the substrate is increased. According to the photoresist removing apparatus of this embodiment, the amount of high-concentration ozone water flowing in the peripheral portion increases, and the reaction product of the photoresist and ozone becomes difficult to deposit on the peripheral portion.

In this embodiment shown in FIGS. 6 and 7, the support base 16 that supports the substrate 15 to be cleaned is configured to be linearly movable back and forth (perpendicular to the paper surface of FIG. 6). Reference numeral 17 is a wheel, and 18 is a guide rail. Portions common to FIG. 1 are denoted by the same reference numerals. In this embodiment, a cleaning nozzle 19 having a length over the entire width of the substrate 15 is disposed so as to be orthogonal to the moving direction of the support base 16, and unit cleaning nozzles 19 a are arranged at equal intervals downwardly toward the cleaning nozzle 19. It is arranged.
The cleaning nozzle 19 discharges high-concentration ozone water from each unit cleaning nozzle 19a when the support base 16 advances (advances) in one direction.
Further, an air knife 20 similar to that of the first embodiment is disposed behind the cleaning nozzle 19 in the forward direction F.
In this embodiment, after supporting the silicon substrate 15 on which unnecessary photoresist remains on the support base 16, the support base 16 is advanced (F), and high-concentration ozone water is discharged from the unit cleaning nozzle 19 a. High pressure air is ejected from 20.
According to the photoresist removing apparatus of this embodiment, high-concentration ozone water is directly jetted from the unit cleaning nozzle 19a to the entire region of the substrate 15 for the same time, and the compressed air of the air knife 20 is passed along with the passage of the unit cleaning nozzle 19a. By spraying the high concentration ozone water and preventing deposition of reaction products on the substrate surface after cleaning, more uniform photoresist removal is possible.

In the embodiment shown in FIG. 8, in the apparatus of Embodiment 1, high-concentration ozone water whose ozone concentration is increased in order from the center side to the peripheral side is supplied to a large number of unit cleaning nozzles 11a. Is.
8, reference numerals 40a, 40b, 40c,... Have the same structure as that of the high-concentration ozone water supply device 4 in FIG. 1, except that ozone gas having a concentration of 210 g / m ³ from the ozone gas supply pipe 41a and ultrapure. By changing the supply ratio of the water supply pipe 41b, the ozone concentration is made higher as it goes from the center side to the peripheral side. 1 denote the same items as those in FIG.
The high-concentration ozone water supplied from the high-concentration ozone water supply devices 40a, 40b, 40c,... Becomes more ozone from the unit cleaning nozzle 42a on the central side to the unit cleaning nozzle 42b. High-concentration ozone water having a high concentration is supplied.
Therefore, according to the photoresist removing apparatus of this embodiment, since the unit cleaning nozzle at the peripheral portion is supplied with high-concentration ozone water having a higher concentration, the reactivity of ozone at the peripheral portion of the substrate is enhanced, and the peripheral portion The reactivity of high-concentration ozone water at is improved.

  It should be noted that the present invention can be modified in various ways, for example, by appropriately combining a plurality of constituent elements shown in the above embodiments, or by deleting some constituent elements from all the constituent elements shown in the embodiments.

DESCRIPTION OF SYMBOLS 1 ... Photoresist removal apparatus 2 ... Motor 3 ... Rotating support stand 4 ... High concentration ozone water supply apparatus 5 ... Support arm 7, 11, 13, 14, 19 ... Cleaning nozzle 7a, 11a, 13a , 14a, 19a: Unit cleaning nozzle 8: Open / close valve 9: Drain receiver 10 , 15: Substrate 12, 20: Air knife

Claims (5)

A support base that rotates while supporting a substrate to be cleaned, a cleaning nozzle disposed above the support base with a water injection port facing downward, and high-concentration ozone that supplies high-concentration ozone water to the cleaning nozzle A photoresist removal device comprising a water supply device,
The cleaning nozzle includes a plurality of unit cleaning nozzles arranged at predetermined intervals in the radial direction of the substrate,
Each unit cleaning nozzle is configured independently so that the difference in the amount of ozone supplied per unit area of the substrate is reduced ,
The photoresist removal apparatus according to claim 1, wherein the ozone concentration of the high-concentration ozone water discharged from the plurality of unit cleaning nozzles increases as the distance from the central portion side to the peripheral portion side of the rotary support base increases .   The discharge amount of the plurality of unit cleaning nozzles is the same, and the number of cleaning nozzles to be installed is increased as the distance from the central part side to the peripheral part side of the rotation support base increases. Photoresist remover.   2. The photoresist removing apparatus according to claim 1, wherein the discharge amount of the plurality of unit cleaning nozzles increases as the distance from the central portion side to the peripheral portion side of the rotation support base increases. 4. The photoresist removing apparatus according to claim 1 , wherein an irradiation device for irradiating the substrate with high energy rays is disposed above the support base. 5. A support base for supporting a substrate to be cleaned, a cleaning nozzle disposed above the support base with a water injection port facing downward, and the support base and the cleaning nozzle are relatively moved in parallel on a plane. A photoresist removing apparatus comprising a drive mechanism and a high-concentration ozone water supply device that supplies high-concentration ozone water to the cleaning nozzle,
The cleaning nozzle is arranged so as to traverse the substrate when the plurality of unit cleaning nozzles are viewed from the moving direction.
Ozone concentration of the high concentration ozone water ejected from the plurality of unit cleaning nozzle, a photoresist removing apparatus characterized that you have been a high concentration with increasing distance to the periphery side from the support base center side.

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