JP6535493B2 - Substrate processing equipment - Google Patents

Description

  The present invention relates to a technology for supplying a processing liquid to a substrate to process the substrate.

  Conventionally, in the manufacture of devices, processing is performed by supplying various processing solutions to substrates for various uses such as semiconductor substrates and glass substrates. Since a very fine pattern is formed on the substrate, it is required to keep the surface of the substrate clean. In particular, thoroughly removing metal impurities such as metal particles and metal ions from the processing solution is important in improving the quality and reliability of devices obtained from a substrate.

  For example, in the semiconductor substrate cleaning apparatus disclosed in Patent Document 1, metal impurities are adsorbed by a filter.

Japanese Patent Application Laid-Open No. 8-8223

  When the semiconductor substrate is cleaned with a processing solution contaminated with metal impurities, the semiconductor substrate is contaminated with metal. Therefore, in order to remove metal particles and metal ions, a particle removal filter and an ion exchange membrane which is a metal removal filter are used. However, it has become clear that simply connecting these two filters in series may not sufficiently remove metal impurities and particles. In particular, when the processing solution which is an organic solvent is supplied from a container formed of stainless steel, it is not possible to effectively remove both iron impurities and particles.

  The present invention has been made in view of the above problems, and has an object to suppress iron and particles from remaining on a substrate after processing.

The invention according to claim 1 is a substrate processing apparatus, wherein a connection part to which a container formed of stainless steel for storing a processing liquid which is an organic solvent is connected, and the processing liquid is supplied to the substrate A processing unit that processes a substrate, a supply path that guides the processing liquid from the connection unit to the processing unit, a first particle removal filter provided on the supply path, the first particle removal filter, and the processing unit Between the metal removal filter and the processing unit, and a second particle removal provided between the metal removal filter and the processing unit. and a filter, the substrate processing apparatus further comprises another processing unit that performs processing on the substrate by supplying a processing liquid to a substrate, the supply channel extends from said connecting portion The first particle removal method includes a flow passage, a branch flow passage that guides the treatment liquid from the common flow passage to the processing unit, and another branch flow passage that guides the treatment liquid from the common flow passage to the other treatment unit The filter and the metal removal filter are provided in the common flow path, the second particle removal filter is provided in the branch flow path, and another second particle removal filter is provided in the other branch flow path, the substrate The processing apparatus further includes a buffer tank disposed on the supply path between the metal removal filter, the second particle removal filter, and the other second particle removal filter, and the buffer tank is made of resin or It is a container in which the resin layer was formed in the inner surface .

  The invention according to claim 2 is the substrate processing apparatus according to claim 1, wherein the processing liquid is isopropyl alcohol.

  The invention according to claim 3 is the substrate processing apparatus according to claim 2, wherein the processing with the processing liquid is a drying processing on the substrate.

The invention according to claim 4 is the substrate processing apparatus according to any one of claims 1 to 3, wherein an average pore diameter of the first particle removal filter is the second particle removal filter and the other of the second particle removal filter . 2 Larger than average pore size of particle removal filter .

  According to the present invention, iron and particles can be prevented from remaining on the processed substrate.

It is a figure which shows schematic structure of a substrate processing apparatus. It is a figure which compares and shows iron detected from IPA by combination of a filter. It is a figure which shows schematic structure of another substrate processing apparatus.

  FIG. 1 is a view showing a schematic configuration of a substrate processing apparatus 1 according to an embodiment of the present invention. The substrate processing apparatus 1 supplies various processing solutions to the substrate 9 to process the substrate 9. The process includes a drying process on the substrate 9. Specifically, the steps of supplying pure water to the substrate 9 for cleaning, and supplying IPA (isopropyl alcohol) to the substrate 9 to replace pure water with IPA to dry the substrate 9 are included. . FIG. 1 shows only the part related to the supply of IPA in the supply system of the processing liquid in the substrate processing apparatus 1. The actual substrate processing apparatus 1 is provided with a large number of pipes.

  The substrate processing apparatus 1 includes a processing unit 11 and a supply system 12 for leading a processing liquid to the processing unit 11. The processing unit 11 supplies a processing liquid to the substrate 9 to perform processing. The processing unit 11 includes a rotating unit 111 that rotates the substrate 9 in a horizontal posture, a supply unit 112 that supplies the processing liquid to the upper surface of the substrate 9, and a liquid receiving unit 113 that receives the processing liquid scattered from the substrate 9. . The treatment liquid received by the liquid receiver 113 is discarded. Another structure of the processing unit 11 may be employed. In the present embodiment, the processing unit 11 is a single wafer type, but may be a batch type.

  The supply system 12 includes a supply path 121, a first particle removal filter 122, a metal removal filter 123, a second particle removal filter 124, a valve 125, a connection portion 126, and a pump 127. The first particle removal filter 122 is provided on the supply path 121. The metal removal filter 123 is provided on the supply path 121 between the first particle removal filter 122 and the processing unit 11. The second particle removal filter 124 is provided on the supply path 121 between the metal removal filter 123 and the processing unit 11.

  The valve 125 is provided on the supply path 121 between the metal removal filter 123 and the second particle removal filter 124. One end of the supply path 121 is connected to the processing unit 11. The connection portion 126 is located at the other end of the supply path 121. The pump 127 is provided on the supply path 121 between the connection portion 126 and the first particle removal filter 122. A container 92 is connected to the connection portion 126. More precisely, a connection 922 provided at the end of the tube 921 attached to the container 92 is connected to the connection 126 of the supply system 12.

  The container 92 stores the IPA 91 in a sealed state. However, inflow of gas into the container 92 is permitted in order to take out the IPA 91. The container 92 is formed of stainless steel for explosion proofing. When the pump 127 is driven in a state where the valve 125 is open, the IPA 91 is sucked up from the container 92, and the IPA 91 is guided from the connection portion 126 to the processing portion 11 by the supply path 121. The IPA 91 passes through the first particle removal filter 122, the metal removal filter 123, and the second particle removal filter 124 in order.

  The first particle removal filter 122 and the second particle removal filter 124 remove particles contained in the IPA 91. The metal removal filter 123 is an ion exchange membrane in the present embodiment, and removes metal ions contained in the IPA 91. As described above, the IPA 91 is used during the drying process on the substrate 9. By removing the metal ions from the IPA 91, the metal is prevented from remaining on the substrate 9 after drying. In particular, the prevention of metal residue is effective in the case of the last step of the drying process at the processing unit 11.

  The average pore size of the first particle removal filter 122 is larger than the average pore size of the second particle removal filter 124. Thus, particles can be efficiently removed while using an inexpensive first particle removal filter 122.

  Next, the effect of arranging the three filters 122, 123 and 124 in this order will be described.

  FIG. 2 shows the level of iron detected from IPA after passing the filter, that is, iron, when particle removal filters or metal removal filters are arranged in various orders on the supply path in a device similar to the device of FIG. It is a figure which compares and shows the concentration of particle and iron ion. IPA also contains other metal ions, but since the container 92 is formed of stainless steel, it does contain a large amount of iron if it does not pass through the filter. Therefore, FIG. 2 shows only the result for iron.

  In the graph, "P" indicates that a particle removal filter is placed on the supply path. "M" indicates placing a metal removal filter on the supply path. “→” indicates the arrangement order of the filters, for example, “P → P” indicates that two particle removal filters are arranged in series from the upstream side toward the processing unit. “P → M” indicates that the particle removal filter and the metal removal filter are arranged in series in this order from the upstream side toward the processing unit.

  In FIG. 2, the detection level of iron is the lowest in the case of “P → P → M”, and subsequently the detection level of iron is low in the case of “P → M” and “P → M → P”. From this, it can be said that the detection level of iron can be lowered by disposing the metal removal filter on the downstream side of the particle removal filter. However, in reality, in the case of “P → P → M” and “P → M”, the detection level of particles increases. This is considered to be caused by the generation of particles other than metal from the metal removal filter.

  In the case of “P → M → P”, metal particles and particles other than metal are removed by the first particle removal filter, and metal ions are removed by the metal removal filter. Then, particles other than metal generated in the metal removal filter are removed by the last particle removal filter. That is, by arranging the particle removal filter, the metal removal filter and the particle removal filter in this order, it is possible to effectively remove all the metal particles, particles other than metal and metal ions.

  Therefore, in the substrate processing apparatus 1, the first particle removal filter 122, the metal removal filter 123, and the second particle removal filter 124 are disposed on the supply path 121 in this order. When IPA 91 flows from the container 92 formed of stainless steel through the supply path 121, generation of particles other than metal is suppressed while iron particles and iron ions contained in the IPA 91 are removed. As a result, iron and particles are prevented from remaining on the processed substrate 9.

  In addition, the first particle removal filter 122 is provided as a filter for removing particles contained in the processing liquid, and the second particle removal filter 124 is provided as a filter for removing particles generated from the metal removal filter 123. It is possible to use a filter matched to For example, in the case of the present embodiment, a filter suitable for removing metal particles and large particles is used as the first particle removal filter 122, and a filter suitable for removing non-metal particles and small particles is used as the second particle removal filter 124. Can be used.

  FIG. 3 is a view showing the substrate processing apparatus 1 in the case where a plurality of processing units 11 are provided. The configuration and operation of each processing unit 11 are the same. Further, in the substrate processing apparatus 1 of FIG. 3, the supply system 12 is provided with the buffer tank 133 and the pump 134. The other components are the same as those in FIG. 1 and denoted by the same reference numerals as in FIG.

  The supply path 121 includes a first supply path 131 from the connection portion 126 to the buffer tank 133 and a second supply path 132 from the buffer tank 133 to each processing unit 11. In other words, the buffer tank 133 is disposed on the supply path 121. In the first supply path 131, the pump 127, the first particle removal filter 122, and the metal removal filter 123 are disposed in order from the connection portion 126 toward the buffer tank 133.

  The second supply path 132 branches halfway and is connected to each processing unit 11. Hereinafter, in the supply path 121, a portion extending from the connection portion 126 to the branch position 135 is referred to as a "common flow path 141", and a portion from the branch position 135 to each processing unit 11 is referred to as a "support flow path 142". The first supply path 131 is included in the common flow path 141. The pump 134 is provided on the common flow path 141 between the buffer tank 133 and the branch position 135. In each of the branch flow paths 142, a valve 125 and a second particle removal filter 124 are provided in order from the branch position 135 toward the processing unit 11. When the pump 134 is driven, the IPA 91 is led to the processing unit 11 from the common flow channel 141 via the branch flow channel 142.

  As described above, the first particle removal filter 122 and the metal removal filter 123 are provided in the common flow channel 141. The plurality of second particle removal filters 124 are respectively provided in the plurality of branch channels 142. By providing the second particle removal filter 124 immediately before each processing unit 11, the IPA 91 from which particles are appropriately removed can be easily supplied to the substrate 9.

  In particular, when the buffer tank 133 is provided, the buffer tank 133 is preferably provided between the metal removal filter 123 and the second particle removal filter 124. Since the source of metal is mainly the container 92, by providing the metal removal filter 123 in front of the buffer tank 133, the IPA 91 from which the metal is removed can be stored in the buffer tank 133. Further, by providing the second particle removal filter 124 behind the buffer tank 133, the influence of various particle sources including the buffer tank 133 can be removed immediately before the processing.

  Since the buffer tank 133 is provided on the downstream side of the metal removal filter 123, the buffer tank 133 is preferably a container made of resin or having a resin layer formed on the inner surface.

  The substrate processing apparatus 1 can be variously modified.

  The processing liquid which is an organic solvent supplied in the container 92 formed of stainless steel is not limited to IPA. Also, the application of the treatment liquid is not limited to drying. The treatment liquid may be, for example, ketones (acetone, diethyl ketone etc.), ethers (methyl ether, ethyl ether etc.), polyhydric alcohols (ethylene glycol etc.).

  In FIG. 3, the buffer tank 133 may be omitted. Conversely, the substrate processing apparatus 1 of FIG. 1 may be provided with a buffer tank.

  The positional relationship between the valve 125 and the filter may be changed as appropriate. Also, a plurality of filters may be provided substantially in one filter device. For example, the first particle removal filter 122 and the metal removal filter 123 may be provided in the cover of one filter device. The metal removal filter 123 and the second particle removal filter 124 may be provided in the cover of one filter device. Furthermore, the first particle removal filter 122, the metal removal filter 123 and the second particle removal filter 124 may be provided in this order within the cover of one filter device.

  The first particle removal filter 122 and the second particle removal filter 124 may be the same filter. As the particle removal filter, a resin or other material may be used. The metal removal filter 123 may selectively remove iron ions. The metal removal filter 123 is only required to remove at least iron ions contained in the processing solution. The metal removal filter 123 may be a chelate resin.

  The substrate 9 is not limited to a semiconductor substrate or a glass substrate, and may be a substrate of another material. Also, the substrate 9 may be used for various applications.

  The configurations in the above embodiment and each modification may be combined as appropriate as long as no contradiction arises.

1 substrate processing apparatus 9 substrate 11 processing unit 91 IPA (processing liquid)
92 container 121 supply path 122 first particle removal filter 123 metal removal filter 124 second particle removal filter 126 connection portion 133 buffer tank 141 common flow path 142 branch flow path

Claims (4)

A substrate processing apparatus,
A connecting portion to which a container made of stainless steel for storing a processing solution which is an organic solvent is connected;
A processing unit that supplies a processing liquid to a substrate to process the substrate;
A supply path for introducing a processing liquid from the connection portion to the processing portion;
A first particle removal filter provided on the supply path;
A metal removal filter provided on the supply path between the first particle removal filter and the processing unit, which removes at least iron ions contained in the processing solution;
A second particle removal filter provided on the supply path between the metal removal filter and the processing unit;
Equipped with
The substrate processing apparatus
The substrate processing apparatus further includes another processing unit that supplies a processing liquid to the substrate to process the substrate,
The supply channel is
A common flow path extending from the connection;
A branch flow path for guiding the processing liquid from the common flow path to the processing unit;
Another branch flow path for guiding the processing solution from the common flow path to the other processing unit;
Including
The first particle removal filter and the metal removal filter are provided in the common flow path,
The second particle removal filter is provided in the branch flow path,
Another second particle removal filter is provided in the other branch flow path,
The substrate processing apparatus
A buffer tank disposed on the supply path between the metal removal filter and the second particle removal filter and the other second particle removal filter.
A substrate processing apparatus characterized in that the buffer tank is a container made of resin or having a resin layer formed on the inner surface . The substrate processing apparatus according to claim 1, wherein
The substrate processing apparatus, wherein the processing solution is isopropyl alcohol. The substrate processing apparatus according to claim 2,
A substrate processing apparatus, wherein the processing with the processing liquid is a drying processing on a substrate. The substrate processing apparatus according to any one of claims 1 to 3, wherein
A substrate processing apparatus, wherein an average pore diameter of the first particle removal filter is larger than an average pore diameter of the second particle removal filter and the other second particle removal filter .

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