JP2017069331A - Substrate processing apparatus and processing method thereof - Google Patents

Abstract

By devising the flow of processing liquid, etching performance can be improved while suppressing deterioration of particle performance of a substrate. A control unit 21 performs processing by immersing a substrate W in a processing liquid in a processing tank 1 after the temperature of the processing liquid is adjusted to a processing temperature by an in-line heater HE1 while the processing liquid is circulated by a pump CP. Over the entire time interval, the on-off valve BV of the bypass pipe 13 is opened to increase the flow rate of the processing liquid. Accordingly, the flow rate of the processing liquid in the processing tank 1 is also increased, and silicon that is etched by the processing liquid and eluted from the substrate W into the processing liquid can be prevented from staying around the substrate W and depositing on the substrate W. . As a result, since silicon deposition on the substrate W can be suppressed, the etching performance can be improved while suppressing the deterioration of the particle performance. [Selection] Figure 1

Description

  The present invention relates to a semiconductor wafer, a liquid crystal display substrate, a plasma display substrate, an organic EL substrate, an FED (Field Emission Display) substrate, an optical display substrate, a magnetic disk substrate, a magneto-optical disk substrate, and a photomask substrate. The present invention relates to a substrate processing apparatus and a processing method for processing a substrate and a solar cell substrate (hereinafter simply referred to as a substrate) with a processing solution containing phosphoric acid.

  Conventionally, this type of apparatus includes a processing tank, an overflow tank, a circulation pipe, a pump, an in-line heater, a filter, and a bypass pipe (see, for example, Patent Document 1). This apparatus, for example, etches a nitride film (SiN) formed on a substrate, for example, by heating a processing solution containing phosphoric acid to a processing temperature of about 160 ° C. and immersing the substrate in the processing solution. .

  The treatment tank stores a treatment liquid containing phosphoric acid and performs a treatment on the substrate by immersing the substrate in the treatment liquid. The overflow tank collects the processing liquid overflowing from the processing tank. The circulation pipe connects the treatment tank and the overflow tank in communication to circulate the treatment liquid. A pump is provided in circulation piping and distribute | circulates the process liquid in circulation piping. The filter is provided in the circulation pipe and filters particles in the processing liquid flowing through the circulation pipe. The bypass pipe communicates and connects the upstream side and the downstream side of the filter in the circulation pipe so as to bypass the filter. In the apparatus having such a configuration, when the temperature of the processing liquid is adjusted to the processing temperature, the temperature is raised to the processing temperature by an in-line heater while circulating the processing liquid.

  By the way, the process liquid used for a process contains phosphoric acid and has a high viscosity at normal temperature. For this reason, if the processing liquid before heating is circulated while being filtered through a filter, the pressure loss is large. Therefore, until the viscosity of the processing liquid decreases due to temperature rise, the bypass pipe is opened and the flow path of the processing liquid bypasses the filter. The processing liquid is circulated in parallel with the pipe. Then, after the temperature reaches the processing temperature, the substrate is processed while closing the bypass pipe and allowing the processing liquid to flow only to the filter side.

JP2013-21232A

However, the conventional example having such a configuration has the following problems.
That is, in the conventional apparatus, since the processing liquid is circulated through the filter, the flow rate of the processing liquid becomes slow, so that the etching performance may be insufficient. In addition, since the flow rate is slow, there is a problem that silicon that is etched and eluted from the substrate into the processing solution may stay around the substrate, precipitate on the substrate, and reattach.

  The present invention has been made in view of such circumstances, and by devising the flow of the processing solution, the deposition performance and etching performance are prevented while preventing the deposition and reattachment of silicon and suppressing the deterioration of the particles on the substrate. It is an object of the present invention to provide an improved substrate processing apparatus and a processing method thereof.

In order to achieve such an object, the present invention has the following configuration.
That is, in the substrate processing apparatus for processing a substrate with a processing liquid containing phosphoric acid, the invention according to claim 1 stores the processing liquid and immerses the processing liquid to perform processing on the substrate, and An overflow tank for recovering the processing liquid overflowing from the processing tank, a circulation pipe for connecting the overflow tank and the processing tank in communication, a pump provided in the circulation pipe for circulating the processing liquid, and a downstream side of the pump An in-line heater for adjusting the temperature of the processing liquid to the processing temperature, a filter for removing particles in the processing liquid provided on the circulation pipe on the downstream side of the pump, and an upstream side of the filter A bypass pipe that communicates with the circulation pipe on the downstream side, an on-off valve that opens and closes the bypass pipe, and the inline heater while circulating the processing liquid with the pump. The processing liquid is heated to the processing temperature with a filter, and then the on-off valve is opened for at least a certain time of the processing time in which the substrate is immersed in the processing liquid in the processing tank to perform processing. And a control means for speeding up the operation.

  [Operation / Effect] According to the invention described in claim 1, the control means adjusts the treatment liquid to the treatment temperature with the in-line heater while circulating the treatment liquid with the pump, and then attaches the substrate to the treatment liquid in the treatment tank. The on-off valve is opened to increase the flow rate of the processing liquid for at least a fixed time of the processing time for performing the immersion process. Accordingly, the flow rate of the treatment liquid in the treatment tank is also increased, and the etching rate can be improved, and silicon that is etched by the treatment liquid and eluted from the substrate into the treatment liquid stays around the substrate and is deposited on the substrate and re-applied. It can suppress adhering. As a result, silicon deposition on the substrate can be suppressed, and etching performance can be improved while suppressing deterioration in particle performance.

  Moreover, in this invention, it is preferable that the said control means opens the said on-off valve over the whole area of the said processing time (Claim 2).

  Since the flow rate of the processing solution is increased over the entire processing time for processing the substrate with the processing solution, it is possible to further suppress the deposition and reattachment of silicon to the substrate and further improve the etching performance.

  In the present invention, it is preferable that the control means opens the on-off valve in the first half and closes the on-off valve in the second half of all the processing time sections.

  In the first half of the processing time for processing the substrate with the processing solution, the flow rate of the processing solution is increased, and the deposition and reattachment of silicon to the substrate can be suppressed. On the other hand, in the second half, the flow rate of the processing liquid is slow, but particles in the processing liquid can be removed by a filter. Therefore, it can suppress that the particle in a process liquid adheres to the following board | substrate, and particle performance falls.

  In the present invention, it is preferable that the control means closes the on-off valve for a predetermined time after the processing time has elapsed.

  After the processing time has elapsed, the particles in the processing liquid can be removed with a filter by filtering the processing liquid for a certain period of time. Therefore, it can suppress that the particle in a process liquid adheres to the following board | substrate, and particle performance falls.

  The invention according to claim 5 is a substrate processing method for processing a substrate with a processing liquid containing phosphoric acid, wherein the processing tank stores the processing liquid and immerses the processing liquid to perform processing on the substrate; and A temperature control process for adjusting the temperature of the processing liquid to the processing temperature with an in-line heater while circulating the processing liquid with a pump through a circulation pipe communicating with an overflow tank for recovering the processing liquid overflowing from the processing tank, and the processing A filter provided in the circulation pipe for at least a fixed time of the processing time when the substrate is immersed in the processing solution of the tank and the processing process is performed in that order. The processing liquid is also circulated through the bypass pipe to be bypassed, and the flow rate of the processing liquid is increased.

  [Operation / Effect] According to the invention described in claim 5, when the temperature adjustment process and the treatment process are performed in this order, the filter provided in the circulation pipe for at least a fixed time of the treatment time. The processing liquid is also circulated through the bypass pipe that bypasses the flow rate to increase the flow rate of the processing liquid. Accordingly, the flow rate of the treatment liquid in the treatment tank is also increased, and the etching rate can be improved, and silicon that is etched by the treatment liquid and eluted from the substrate into the treatment liquid stays around the substrate and is deposited on the substrate and re-applied. It can suppress adhering. As a result, silicon deposition on the substrate can be suppressed, and etching performance can be improved while suppressing deterioration in particle performance.

  According to the substrate processing apparatus of the present invention, the control means adjusts the processing liquid to the processing temperature with an in-line heater while circulating the processing liquid with a pump, and then immerses the substrate in the processing liquid in the processing tank. During at least a certain time of the processing time to be performed, the on-off valve is opened to increase the flow rate of the processing liquid. Accordingly, the flow rate of the treatment liquid in the treatment tank is also increased, and the etching rate can be improved, and silicon that is etched by the treatment liquid and eluted from the substrate into the treatment liquid stays around the substrate and is deposited on the substrate and re-applied. It can suppress adhering. As a result, silicon deposition on the substrate can be suppressed, and etching performance can be improved while suppressing deterioration in particle performance.

It is a block diagram which shows schematic structure of the substrate processing apparatus which concerns on an Example. It is a time chart which shows the 1st operation example. It is a time chart which shows the 2nd example of operation.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram illustrating a schematic configuration of a substrate processing apparatus according to an embodiment.

  The substrate processing apparatus according to the embodiment is a batch type apparatus that collectively processes a plurality of substrates W with a processing liquid. This apparatus includes a processing tank 1 and an overflow tank 3. The processing tank 1 has a size that can accommodate a plurality of substrates W, stores the processing liquid, and processes the plurality of substrates W with the processing liquid. The overflow tank 3 is provided around the upper edge of the processing tank 1 and collects the processing liquid overflowing from the processing tank 1.

  The treatment tank 1 and the overflow tank 3 are connected in communication by a circulation pipe 5. One end side of the circulation pipe 5 is arranged from the upper part to the bottom part of the overflow tank 3, and the other end side is connected to the bottom part of the processing tank 1. In the circulation pipe 5, an on-off valve CV 1, a pump CP, an on-off valve CV 2, an in-line heater HE 1, and a filter 9 are arranged in that order from the overflow tank 3 side to the processing tank 1 side.

  The on-off valve CV1 controls the flow of the processing liquid from the overflow tank 3 to the circulation pipe 5. The pump CP pumps the processing liquid stored in the circulation pipe 5. The on-off valve CV <b> 2 controls the flow of the processing liquid in the circulation pipe 5. The in-line heater HE1 adjusts the temperature of the processing liquid flowing through the circulation pipe 5 to a processing temperature (for example, about 160 ° C.). The filter 9 filters and removes particles in the processing liquid flowing through the circulation pipe 5. When the pump CP is turned on, the processing liquid stored in the overflow tank 3 is sucked into the circulation pipe 5, the temperature is adjusted by the in-line heater HE 1, the filtration is performed by the filter 9, and sent to the processing tank 1.

  In the circulation pipe 5, one end side of the branch pipe 11 is connected in communication between the pump CP and the on-off valve CV2. The other end side of the branch pipe 11 is connected to a drainage processing unit (not shown). The branch pipe 11 includes an on-off valve EV. The on-off valve EV is opened only when the processing liquid in the circulation pipe 5 is drained. The circulation pipe 5 is provided with a bypass pipe 13 that communicates the upstream and downstream portions of the filter 9 described above. An open / close valve BV is attached to the bypass pipe 13. This on-off valve BV controls the flow of the processing liquid in the bypass pipe 13.

  The treatment tank 1 has a heater HE2 attached to the outer peripheral surface. The heater HE2 controls the temperature of the processing tank 1 so that the temperature of the processing liquid stored in the processing tank 1 does not decrease through the members of the processing tank 1. In the processing tank 1, one end side of the supply pipe 15 is arranged toward the bottom surface. The other end side of the supply pipe 15 is connected in communication with the processing liquid supply source 17. The processing liquid supply source stores a processing liquid containing phosphoric acid. An on-off valve SV is attached to the supply pipe 15. The on-off valve SV controls the supply of the processing liquid from the processing liquid supply source 17 to the processing tank 1.

  A lifter LF is disposed in the vicinity of the processing tank 1. The lifter LF includes a holding unit 19 that holds a plurality of substrates W in a standing posture at the bottom. The lifter LF has a “processing position” (indicated by a solid line in FIG. 1) where the holding unit 19 is located inside the processing tank 1 and a “standby position” (shown in FIG. 1) where the holding part 19 is located above the processing tank 1. And move up and down.

  The on-off valves CV1, CV2, EV, BV, SV, the pump CP, the in-line heater HE1, the heater HE2, and the lifter LF are comprehensively controlled by the control unit 21. The control unit 21 is configured by a CPU and a memory.

  The control unit 21 described above corresponds to the “control unit” in the present invention.

  Next, the operation of the substrate processing apparatus configured as described above will be described with reference to FIG. FIG. 2 is a time chart showing a first operation example. However, this time chart does not describe the on-off valve EV not related to processing.

  First, the control unit 21 opens the on-off valve SV in order to supply the processing liquid to the processing tank 1. Thereby, the processing liquid of the processing liquid supply source 17 is supplied (time t1). At this time, the control unit 21 positions the lifter LF at the standby position, turns off the pump CP, and opens the on-off valves CV1, CV2, and BV.

  Next, after the processing liquid is filled in the processing tank 1, the overflow tank 3, and the circulation pipe 5, the control unit 21 turns on the inline heater HE1 and the heater HE2 to start temperature control and turns on the pump CP. Thus, the treatment liquid stored in the treatment tank 1, the overflow tank 3, and the circulation pipe 5 is circulated (at time t2). Further, the control unit 21 closes the on-off valve SV and stops the supply of the processing liquid (at time t3). In addition, since the treatment liquid containing phosphoric acid has a high viscosity until the temperature is raised and the pressure loss in the filter 9 is large, the circulation flow rate in the treatment tank 1 cannot be obtained. However, since the on-off valve BV is opened and the processing liquid is also circulated through the bypass pipe 13 to form a flow path in parallel with the filter 9, the flow rate can be increased and the time required for temperature adjustment can be shortened. .

  The period from the time t2 to the time t3 corresponds to the “temperature adjustment process” in the present invention.

  After the temperature of the processing liquid reaches the processing temperature, the control unit 21 turns off the in-line heater HE1 and the heater HE2 and stops temperature control (at time t4). Note that the heater HE2 may be kept on to suppress the temperature drop of the processing liquid in the processing tank 1 due to the lifter LF and the substrate W being immersed in the processing tank 1.

  The control unit 21 lowers the lifter LF to the processing position (at time t4). The state is maintained only for the processing time Ts (from time t4 to time t6). The controller 21 keeps the on-off valve BV open during the entire section of the processing time Ts (from time t4 to time t6). Thereby, since a process liquid is distribute | circulated also to the bypass pipe 13 over the whole area of process time Ts, the flow velocity in the processing tank 1 can be made quick. Therefore, for example, the etching rate of the nitride film (SiN) on the surface of the substrate W can be improved, and silicon that is etched by the processing liquid and eluted from the substrate W stays around the substrate W for a long time. Reattachment to the substrate W can be suppressed. As a result, the deposition of silicon on the substrate W can be suppressed, and the etching performance can be improved while suppressing the deterioration of the particle performance of the substrate W.

  The period from the time t4 to the time t6 corresponds to the “processing process” in the present invention.

  The control unit 21 raises the lifter LF to the standby position when the processing time Ts has elapsed (time t6). Next, the control unit 21 closes the on-off valve BV after the lifter LF is raised to the standby position and the substrate W is unloaded from the processing tank 1 (at time t7). Then, this state is maintained for a predetermined time (from time t7 to time t8), and particles contained in the processing liquid are filtered and removed by the filter 9. Thereby, in the process with respect to the next board | substrate W, it can suppress that a particle adheres to the board | substrate W and particle performance falls.

  According to the present embodiment, the control unit 21 adjusts the processing liquid to the processing temperature with the in-line heater HE1 while circulating the processing liquid with the pump CP, and then immerses the substrate W in the processing liquid in the processing tank 1 to perform the processing. Over the entire section of the processing time Ts to be performed, the on-off valve BV of the bypass pipe 13 is opened to increase the flow rate of the processing liquid. Accordingly, the flow rate of the processing liquid in the processing tank 1 is also increased, the etching rate can be improved, and the silicon that is etched by the processing liquid and eluted from the substrate W stays around the substrate W and stays around the substrate W. It can suppress that it precipitates. As a result, since silicon deposition on the substrate W can be suppressed, the etching performance can be improved while suppressing the deterioration of the particle performance.

  The present invention is not limited to the above embodiment, and can be modified as follows.

  (1) In the embodiment described above, the control unit 21 opens the on-off valve BV in the entire section of the processing time Ts as shown in FIG. 2, but the present invention is not limited to such a form. For example, the filter 9 may be bypassed by opening the on-off valve BV for at least a fixed time of the processing time Ts for performing processing.

  Specifically, the processing may be performed by operating the on-off valve BV as shown in FIG. FIG. 3 is a time chart showing a second operation example.

  In this case, the on-off valve BV is opened during the time t4 to t5 in the first half of the processing time Ts from time t4 to t6. Then, the on-off valve BV is closed during the latter half of the period from t5 to t6 until the time t7 when the temperature control is resumed. By controlling the on-off valve BV in this way, the reattachment of silicon to the substrate W can be suppressed. On the other hand, in the latter half of the processing time Ts, the flow rate of the processing liquid is slow, but particles in the processing liquid can be removed by the filter 9. Therefore, it can suppress that the particle in a process liquid adheres to the following board | substrate W, and particle performance falls.

  As described above, the opening / closing is not divided into the first half and the second half of the processing time Ts. For example, the opening / closing valve is closed only for a certain period of the processing time Ts so that the opening / closing valve BV is closed by 10% of the processing time Ts. You may make it open | release BV.

  (2) In the above-described embodiment, the heater HE2 is also used to adjust the temperature of the processing liquid. However, the heater HE2 may be configured only by the inline heater HE1. Thereby, apparatus cost can be suppressed.

  (3) In the embodiment described above, only one bypass pipe 13 is provided. For example, two or more bypass pipes 13 may be provided. Thereby, the flow velocity in the processing tank 1 can be further increased.

W ... Substrate 1 ... Processing tank 3 ... Overflow tank 5 ... Circulation piping CV1, CV2, EV, BV, SV ... On-off valve HE1 ... Inline heater 9 ... Filter 11 ... Branch piping 13 ... Bypass pipe 15 ... Supply pipe LF ... Lifter 19 ... Holding part 21 ... Control part Ts ... Processing time

Claims (5)

In a substrate processing apparatus for processing a substrate with a processing solution containing phosphoric acid,
A treatment tank for storing the treatment liquid and immersing the treatment liquid to treat the substrate;
An overflow tank for recovering the processing liquid overflowing from the processing tank;
A circulation pipe connecting the overflow tank and the treatment tank in communication with each other;
A pump provided in the circulation pipe for circulating the treatment liquid;
An in-line heater that is provided in the circulation pipe on the downstream side of the pump and adjusts the temperature of the processing liquid to the processing temperature;
A filter that is provided in the circulation pipe on the downstream side of the pump and removes particles in the processing liquid;
A bypass pipe communicatingly connecting the circulation pipe corresponding to the upstream side and the downstream side of the filter;
An on-off valve for opening and closing the bypass pipe;
After adjusting the processing liquid to the processing temperature with the in-line heater while circulating the processing liquid with the pump, during at least a fixed time of the processing time for immersing the substrate in the processing liquid in the processing tank, Control means for opening the on-off valve to increase the flow rate of the processing liquid;
A substrate processing apparatus comprising: The substrate processing apparatus according to claim 1,
The substrate processing apparatus, wherein the control means opens the on-off valve over an entire interval of the processing time. The substrate processing apparatus according to claim 1,
The substrate processing apparatus, wherein the control means opens the on-off valve in the first half and closes the on-off valve in the second half of all the sections of the processing time. In the substrate processing apparatus according to claim 1,
The substrate processing apparatus, wherein the control means closes the on-off valve for a predetermined time after the processing time has elapsed. In a substrate processing method for processing a substrate with a processing solution containing phosphoric acid,
The processing liquid is stored in the processing tank, and the processing liquid is immersed in the processing liquid, and the processing liquid is circulated by a pump through a circulation pipe that communicates with the overflow tank that collects the processing liquid overflowing from the processing tank. While adjusting the temperature of the processing liquid to the processing temperature with an in-line heater,
A treatment process in which a substrate is immersed in a treatment liquid of the treatment tank and treatment is performed over a treatment time;
When carrying out in that order,
A substrate processing method, wherein a processing liquid is circulated through a bypass pipe that bypasses a filter provided in the circulation pipe for at least a fixed time of the processing time, thereby increasing a flow rate of the processing liquid.

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