WO2013164942A1

WO2013164942A1 - Etching method, etching device and storage medium

Info

Publication number: WO2013164942A1
Application number: PCT/JP2013/060903
Authority: WO
Inventors: 佐藤　秀明; 孝弘古川
Original assignee: 東京エレクトロン株式会社
Priority date: 2012-05-01
Filing date: 2013-04-11
Publication date: 2013-11-07
Also published as: JP6087063B2; JP2013232593A; TW201409558A

Abstract

[Problem] To precisely perform an etching process on a wafer, maintaining in a set constant range, the concentration of an elution component in an etching fluid eluted from the wafer. [Solution] An etching method is provided with: a process wherein the etching fluid (E), which is provided to the etching process after an etching process, is discharged from a discharging section (30) in a first set quantity; and a process wherein new etching fluid (E) is replenished from a replenishing section (11) in a second set quantity. The etching fluid discharging and the new etching fluid replenishing are performed by determining the first set quantity for discharging and the second set quantity for replenishing on the basis of: the elution component concentration of the wafer (W), said concentration being in the etching fluid (E) and being from an elution component measurement section (25); the etching fluid (E) concentration from a concentration measurement section (26); and the etching fluid temperature from a temperature measurement section (27).

Description

Etching method, etching apparatus and storage medium

The present invention relates to an etching method, an etching apparatus, and a storage medium, and more particularly, to an etching method, an etching apparatus, and a storage medium that perform an etching process on an object to be processed such as a semiconductor wafer with an etching solution.

Conventionally, in a wet etching method for an object to be processed such as a semiconductor wafer, phosphoric acid is used as an etchant to perform an etching process on a nitride film-oxide film. For example, an etching solution made of an aqueous phosphoric acid solution (H3PO4) or the like is stored in a processing tank and heated to a predetermined temperature, for example, 160 to 180 ° C., and is interposed in a circulation line and a circulation line connected to the processing tank. An object to be processed, for example, a semiconductor wafer (hereinafter referred to as a wafer) is etched while circulating and supplying an etching solution having a predetermined temperature via a circulation pump and a temperature controller (see Japanese Patent Publication No. 3-20895).

In the above etching method, when the etching process is repeated, the silicon (Si) content of the wafer elutes into the etching solution, and the silicon (Si) concentration in the etching solution increases, so that the semiconductor wafer is accurately etched. Processing cannot be performed. For this reason, conventionally, it has been necessary to periodically replace the etching solution in the processing tank.

Alternatively, it is also considered that the silicon concentration in the etching solution is measured and a new etching solution is replenished when the silicon concentration becomes high.

However, the properties of the etching solution are not determined only by the silicon concentration, and even if only the silicon concentration is measured and a new etching solution is replenished, the properties of the etching solution may not be controlled correctly. For example, when a new etching solution is replenished, the silicon concentration in the etching solution temporarily decreases, but the silicon concentration in the etching solution is not necessarily low, and the silicon concentration should be kept within a predetermined range. Thus, the semiconductor wafer can be accurately etched.

Japanese Patent Publication No. 3-20895 JP 2000-59812 A

The present invention has been made in consideration of such points, and by maintaining a constant concentration of the eluted component (silicon concentration) in the etching solution eluted from the semiconductor wafer, the semiconductor wafer is accurately etched. It is an object of the present invention to provide an etching method, an etching apparatus, and a storage medium that can perform the above.

The present invention relates to an etching method for performing an etching process using an etchant on an object to be processed housed in an etching process part, and supplying an etchant to the object to be processed in the etching process part. And a step of discharging the etching target solution subjected to the etching process by a first set amount, and a step of replenishing the etching solution discharged by the first set amount by a second set amount. In addition to measuring the elution component concentration, the concentration of the etching solution, and the temperature of the etching solution in the etching solution eluted from the processing body subjected to the etching process, the measured elution component concentration, the concentration of the etching solution and Based on the temperature of the etchant, the first set amount and the second set amount are obtained to discharge the etchant and An etching method characterized by charging takes place.

The present invention provides an etching apparatus that performs an etching process on an object to be processed using an etching solution, and discharges an etching process part that houses the object to be processed and an etching solution that has been used for the etching process by a first set amount. A discharge part, a replenishment part that replenishes a second set amount of a new etchant into the etchant that has been discharged by a first set amount, and an elution component in the etchant that is eluted from the processing body subjected to the etching process A control device comprising: an elution component measurement unit for measuring the concentration; a concentration measurement unit for measuring the concentration of the etching solution; a temperature measurement unit for measuring the temperature of the etching solution; and a control device for controlling the discharge unit and the replenishment unit. Is based on the elution component concentration from the elution component measurement unit, the concentration of the etching solution from the concentration measurement unit, and the temperature of the etching solution from the temperature measurement unit. An etching apparatus characterized by controlling the replenishment section and the discharge section seeking set amount.

The present invention relates to a storage medium storing a computer program for causing a computer to execute an etching method. The etching method includes an etching process for an object to be processed in an etching processing unit, and an etching process performed for the etching process. A process body provided for the etching process, comprising: a step of discharging the liquid by a first set amount; and a step of replenishing the etchant discharged by the first set amount by a second set amount of a new etchant. The elution component concentration, the etching solution concentration, and the etching solution temperature in the etching solution eluted from the first solution are measured. Based on the measured elution component concentration, the etching solution concentration, and the etching solution temperature, the first concentration is measured. The set amount and the second set amount are obtained and the etching solution is discharged and the new etching solution is replenished. A storage medium characterized.

As described above, according to the present invention, the concentration of the eluted component in the etching solution eluted from the object to be processed can be maintained within a predetermined range, and the object to be processed can be accurately etched. Can do.

FIG. 1 is a schematic view showing an etching apparatus according to a first embodiment of the present invention. FIG. 2 shows an etching method according to the present invention. FIG. 3 is a diagram showing an etching method of the present invention. FIG. 4 is a view showing a modification of the etching method of the present invention. FIG. 5A is a diagram showing a wafer before the etching process is performed, and FIG. 5B is a diagram showing the wafer after the etching process is performed. FIG. 6 is a schematic view showing an etching apparatus according to the second embodiment of the present invention.

First Embodiment Next, a first embodiment of the present invention will be described with reference to FIGS.

First, an object to be processed, such as a silicon wafer W, to be processed by the etching method according to the present invention will be described with reference to FIGS.

As shown in FIGS. 5A and 5B, first, a silicon oxide film 2 (SiO 2) and a silicon nitride film 3 (Si 4 N 3) as a base layer are formed on the surface of a silicon substrate 1 which is a base material of an object to be processed such as a wafer W. ) And a wafer W coated with a patterned resist film 4 on the surface of the silicon nitride film 3 is prepared (FIG. 5A). Next, etching is performed by immersing the wafer W in an etching solution such as phosphoric acid aqueous solution (H 3 PO 4) at a high temperature, for example, 160 to 180 ° C. (FIG. 5B). In this etching method, it is important to control the thickness of the silicon oxide film 2 underlying the silicon nitride film 3.

Next, an etching apparatus for performing the etching method according to the present invention will be described.

As shown in FIG. 1, the etching apparatus includes an inner tank 10a and an outer tank 10b. The etching apparatus accommodates a semiconductor wafer W (hereinafter referred to as a wafer W) as an object to be processed and an etching solution E (for example, phosphoric acid aqueous solution (for example) H3PO4)) is stored in the processing tank (etching processing unit) 10, the etching liquid E is extracted from the processing tank 10, and this etching liquid E is circulated and supplied to the processing tank 10, and the processing is connected to the circulation line 20. A discharge unit 30 that discharges the etching solution E in the tank 10 and a replenishment unit 11 that replenishes the new etching solution E in the processing tank 10 are provided.

In this case, the processing tank 10 accommodates the wafer W whose surface is vertically held by a wafer boat (not shown), and stores the etching liquid E in the quartz inner tank 10a and the etching liquid overflowing from the inner tank 10a. And an outer tank 10b made of quartz for receiving E. Panel heaters (not shown) are attached to the side and bottom of the inner tank 10a of the processing tank 10 configured as described above, and the etching solution E in the processing tank 10 is set to a predetermined temperature, for example, 100 to 180 ° C. It is configured as follows. Further, on the bottom side in the inner tank 11, a current plate (not shown) that guides the etching solution E circulated and supplied from the lower part uniformly to the wafer W is provided.

The circulation line 20 is connected to the outer tank 10b and the inner tank 10a of the treatment tank 10, and the circulation line 20 is provided with a circulation pump 21, a filter 23, and a temperature controller 22 in order from the upstream side. ing. Among these, the temperature controller 22 includes a heater for heating the etching solution E. A discharge line 31 is connected to the downstream side of the temperature controller 22 via a switching valve 29, and the discharge unit 30 described above is connected to the discharge line 31.

Further, a switching valve 32 is connected to the discharge line 31, and the silicon adjusting tank 14 is connected to the switching valve 32 via a communication line 33. The silicon adjusting tank 14 stores the etching solution E from which the silicon (Si) component after the etching process is eluted, and is necessary when the concentration of the silicon component in the etching solution E falls below a predetermined range. Accordingly, the silicon elution etchant is replenished into the etchant E in the outer tank 10b through the supply line 17.

The replenishment unit 11 includes an H3PO4 aqueous solution supply system 12 that supplies a phosphoric acid aqueous solution (H3PO4 aqueous solution) and a DIW supply system 13 that supplies pure water (DIW). The H3PO4 aqueous solution supply system 12 and the DIW supply system 13 are These are connected to the outer tank of the processing tank 10 via

supply lines

12a and 13a, respectively.

Further, a switching valve 18 is provided in the supply line 12 a from the H 3 PO 4 aqueous solution supply system 12, and the etching solution E from which the silicon component from the silicon adjustment tank 14 is eluted passes through the supply line 17 and the switching valve 18 to the outer tank 10 b. To be supplied.

By the way, on the downstream side of the temperature controller 22 of the circulation line 20, an elution composition measuring unit 25 that measures the concentration of the silicon elution component in the etching solution E subjected to the etching process using the refractive index of light, and the etching solution A concentration measuring unit 26 that measures the concentration of E, specifically, the concentration of H 3 PO 4 using the refractive index of light, and a temperature measuring unit 27 that measures the temperature of the etching solution E are arranged. Signals from the elution component measurement unit 25, the concentration measurement unit 26, and the temperature measurement unit 27 are sent to the control device 100, and the control device 100 supplies the H3PO4 aqueous solution supply amount and DIW supply from the H3PO4 aqueous solution supply system 12. The DIW supply amount from the system 13, the circulation pump 21 and the temperature controller 22 are driven and controlled. The control device 100 can be realized as a hard wafer by, for example, a general-purpose computer and a program (device control program, processing recipe, etc.) for operating the computer as software. The software is stored in a storage medium such as a hard disk drive fixedly provided in the computer, or is stored in a storage medium that is detachably set in the computer such as a CDROM, DVD, or flash memory. Such a storage medium is indicated by reference numeral 100a. The processor 100b calls a predetermined processing recipe from the storage medium 100a based on an instruction from a user interface (not shown) or the like as necessary, and causes each functional component of the etching apparatus to operate under the control of the control unit 3. Then, a predetermined process is performed.

In the above embodiment, the replenishment unit 11 includes the H3PO4 aqueous solution supply system 12 and the DIW supply system 13, and the H3PO4 aqueous solution from the H3PO4 aqueous solution supply system 12 and the DIW from the DIW supply system 13 are supplied to the respective supply lines. Although the example supplied to the outer tank 10b via 12a, 13a was shown, not only this but the H3PO4 aqueous solution from the H3PO4 aqueous solution supply system 12 and the DIW from the DIW supply system 13 are once mixed in the preparation tank 15. The aqueous solution in the blending tank 15 may be guided into the outer tank 10b (broken line in FIG. 1).

Next, an etching method using the etching apparatus will be described. An etching solution E (phosphoric acid aqueous solution (H 3 PO 4)) is supplied in advance to the inner tank 10 a and the outer tank 10 b of the processing tank 10 in the processing tank 10. Next, the circulation pump 21 is driven to circulate the etching solution E overflowed to the outer tank 11b so as to return to the inner tank 10a through the circulation line 20. Next, the etching liquid E is heated to a predetermined temperature (100 to 180 ° C.) by the temperature controller 22 and brought into a boiling state.

At this time, the H3PO4 concentration of the etching solution E is 60%, and the silicon concentration is 10 ppm.

After the temperature of the etchant E rises to a boiling state, the amount of heat given to the etchant E in the circulation line 20 is adjusted by the temperature controller 22, so that the etchant E in the inner tank 10a maintains the boiling state. Is maintained at a predetermined temperature.

Further, in order to perform etching at a desired etching rate, it is necessary to maintain the etching solution E at a predetermined concentration, and the temperature of the etching solution E is maintained at a boiling point specific to the etching solution E having the predetermined concentration.

In this state, the wafer W held vertically by a wafer boat (not shown) is accommodated in the inner tank 10a of the processing tank 10. The wafer W is immersed in the etching solution E in the inner tank 10a for a predetermined time and etched. Thereafter, the wafer W is taken out from the processing tank 10. The etching process is repeated.

The etching solution E is immersed in the etching solution E during the etching process (when the wafer W is immersed in the etching solution E in the inner tank 10a) and between the etching processes (the wafer W is immersed in the etching solution E in the inner tank 10a). In other words, the n-th etching process is completed, the wafer W for one processing unit is taken out from the inner tank 10a, and the wafer W for the next one processing unit is started to start the n + 1-th etching process. Until it is immersed in the inner tank 10a), it is continuously circulated through the circulation line 20.

By performing the etching process, silicon (Si) content is eluted from the wafer W into the etching solution E in the inner tank 10a.

When such an etching process is repeated, silicon (Si) content is eluted from the wafer W into the etching solution E, and if the silicon concentration becomes too high, the properties of the etching solution deteriorate.

In the present invention, in order to cope with such a case, first, when the silicon concentration in the etching solution E in the circulation line 20 exceeds a predetermined range, the etching solution E is discharged from the discharge unit 30. Next, the H3PO4 aqueous solution supply system 12 and the DIW supply system 13 of the replenishing unit 11 are supplied with the H3PO4 aqueous solution and DIW, respectively, into the outer tank 10b, and the H3PO4 aqueous solution is replenished into the etching solution E subjected to the etching process.

Specifically, as shown in FIGS. 2 and 3, when 50 wafers W are etched for 5 minutes, a large amount of silicon is eluted from the wafers W, and the silicon concentration in the etching solution E is reduced. For example, it rises from 10 ppm before treatment to 15 ppm in the determined range (FIG. 2 (a) and FIG. 3). Thereafter, the etching process is terminated.

During this time, with respect to the etching solution E in the circulation line 20, the elution component concentration is measured by the elution component measurement unit 25, the concentration of H3PO4 is measured by the concentration measurement unit 26, and the temperature is measured by the temperature measurement unit 27. Signals from the elution component measuring unit 25, the concentration measuring unit 26 and the temperature measuring unit 27 are sent to the control device 100.

Next, the control device 100 drives and controls the switching valve 29, the switching valve 32, and the discharge unit 30, and the first set amount is set so that the etching solution E in the circulation line 20 has a predetermined range of silicon concentration. It discharges | emits ((a) of FIG. 2 and FIG. 3).

Next, the control unit 100 controls the H3PO4 aqueous solution supply system 12 and the DIW supply system 13 of the replenishment unit 11 to supply the H3PO4 aqueous solution and DIW from the H3PO4 aqueous solution supply system and the DIW supply system 13 to the outer tank 10b, respectively, and etching. An H3PO4 aqueous solution having the determined H3PO4 component is replenished into the etching solution E subjected to the treatment.

In this case, for example, an H3PO4 aqueous solution having 85% of the H3PO4 component is supplied from the H3PO4 aqueous solution supply system 12, and this H3PO4 aqueous solution is diluted with DIW from the DIW supply system 13.

As a result, the etching solution E in the outer tub 11b is supplemented with a novel H3PO4 aqueous solution having 60% of the H3PO4 component (FIGS. 2A and 3).

In this case, an H3PO4 aqueous solution having 60% of H3PO4 component is replenished in the outer tank 11b by the second set amount so that the silicon concentration is within a predetermined range.

Thus, the silicon concentration in the etching solution E after the etching process is reduced to the concentration (10 ppm) before the etching process, and the silicon concentration in the etching solution can be adjusted with high accuracy. At the same time, the H3PO4 concentration in the etching solution E is also maintained at 60%.

During this time, the control device 100 determines the first set amount of the etching solution E discharged from the discharge unit 30 and the second set amount of the etching solution E replenished into the outer tub 10b as follows.

That is, the control device 100 first determines the first set amount of the etching liquid E discharged from the discharge unit 30 based on the elution component concentration of silicon from the elution component measurement unit 25.

Next, based on the first set amount thus determined, the H3PO4 concentration from the concentration measuring unit 26, and the temperature of the etching solution E from the temperature measuring unit 27, the etching solution replenished into the outer tank 10b. The second set amount is determined so that E becomes a silicon concentration within a predetermined range.

Thus, the silicon concentration in the etching solution E can be adjusted with high accuracy.

If the silicon concentration in the etching solution is too low, a part of the etching solution E after the etching process stored in the silicon adjustment tank 14 is supplied into the outer tank 10b, so that The silicon concentration can be increased and adjusted accurately.

Thus, a new etching process is performed in the same manner using the etching solution supplemented with the new etching solution (H3PO4 aqueous solution).

Next, a modification of the present invention will be described with reference to FIG.

In the above-described embodiment, the control device 100 operates the switching valve 29, the switching valve 32, and the discharge unit 30 after the etching process to discharge the etching solution E by the first set amount, and supplies the H3PO4 aqueous solution supply system 12 and the DIW supply. Although an example in which the system 13 is operated to replenish a new etching solution E into the outer tank 10b has been shown, the control unit 100 operates the switching valve 29, the switching valve 32, and the discharge unit 30 before the etching process to etch the etching solution. E may be discharged in advance by the first reserve amount, and the H3PO4 aqueous solution supply system 12 and DIW supply system 13 may be operated to replenish the outer tank 10b with a new etchant E in advance by a second reserve amount.

Thus, before the etching process, the etching solution E is discharged and the new etching solution E is replenished. For example, when the optimum silicon concentration of the etching solution E is 10 ppm, the silicon concentration is reduced to 10 throughout the entire etching process. % Can be maintained.

Note that the control device 100 includes a first reserve amount for discharging the etchant E so that the silicon concentration in the etchant E falls within a predetermined range, and a second reserve amount for replenishing the new etchant E, This is determined based on an etching processing recipe including a predetermined number of wafers W and processing time.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG.

In the second embodiment shown in FIG. 6, instead of using the processing tank 10 in which the etching solution E is stored as the etching processing section, the etching processing chamber 43 and the etching processing chamber 43 are provided to hold the wafer W. The etching processing unit 40 having a rotatable holding unit 41 and a nozzle (etching solution supply unit) 42 for supplying the etching solution E to the wafer W held by the holding unit 41 is used.

In the second embodiment shown in FIG. 6, the same parts as those in the first embodiment shown in FIG. 1 to FIG.

As shown in FIG. 6, the etching solution E supplied from the nozzle 42 to the wafer W in the etching processing chamber 43 is sent from the etching processing chamber 43 to the preparation tank 15A through the circulation line 20A.

Then, the etching solution E in the preparation tank 15A is circulated back to the nozzle 42 in the etching processing chamber 43 through the circulation line 20A. Further, a discharge unit 30 is provided in the circulation line 20A.

Further, the H3PO4 aqueous solution supply system 12 is supplied with the H3PO4 aqueous solution and the DIW supply system 13 is supplied with DIW, and the H3PO4 aqueous solution and DIW are prepared in the preparation tank 15A.

In FIG. 6, for example, an H3PO4 aqueous solution having 85% H3PO4 component is supplied from the H3PO4 aqueous solution supply system 12 into the preparation tank 15A, and diluted with DIW from the DIW supply system 13 in the preparation tank 15A to be 60% H3PO4 component. H3PO4 aqueous solution having

In this case, the replenishment unit 11 is configured by the preparation tank 15A, the H3PO4 aqueous solution supply system 12, and the DIW supply system 13.

Further, a tank circulation line 45 is connected to the blending tank 15A, and a circulation pump 21, a filter 23, and a temperature controller 22 are sequentially provided in the tank circulation line 45.

The tank circulation line 45 includes an elution component measurement unit 25 that measures the concentration of the elution component of silicon, a concentration measurement unit 26 that measures the concentration of H3PO4, and a temperature measurement unit 27 that measures the temperature of the etching solution E. Is provided.

In the circulation line 20A, a flow meter 28 is provided on the downstream side of the nozzle 42.

Next, an etching method using an etching apparatus having such a configuration will be described.

First, the wafer W is loaded into the etching processing chamber 43, and the wafer W is held on the holding unit 41 in the etching processing chamber 43.

The wafer W held by the holding unit 41 is then rotated by the holding unit 41, and the etching solution E is supplied from the nozzle 42 to the rotating wafer W. In this way, the etching process is performed on the wafer W by the etching solution E.

Etching solution E supplied from the nozzle 42 is then returned from the etching chamber 43 to the nozzle 42 through the circulation line 20A and the preparation tank 15A.

Next, the wafer W after the etching process is discharged from the etching process chamber 43 to the outside.

When such an etching process is sequentially performed on a plurality of wafers W, silicon (Si) content is eluted from the wafer W into the etchant E, and the properties of the etchant deteriorate.

In the present invention, in order to cope with such a case, the etching solution E in the circulation line 20A is first discharged from the discharge unit 30. Next, the H3PO4 aqueous solution supply system 12 and the DIW supply system 13 of the replenishing unit 11 respectively supply the H3PO4 aqueous solution and DIW into the preparation tank 15A, and the H3PO4 aqueous solution is replenished into the etching solution E subjected to the etching process.

Specifically, when a certain amount of wafer W is etched, a large amount of silicon is eluted from the wafer W, and the silicon concentration in the etching solution E is, for example, 15 ppm in a range determined from 10 ppm before the processing. To rise.

During this time, for the etching solution E in the circulation line 20A, the elution component concentration is measured by the elution component measurement unit 25, the concentration of H3PO4 is measured by the concentration measurement unit 26, and the temperature is measured by the temperature measurement unit 27. Signals from the elution component measuring unit 25, the concentration measuring unit 26 and the temperature measuring unit 27 are sent to the control device 100.

The control device 100 performs an etching process on a certain amount of wafers W, and stops the etching process when the properties of the etching solution E deteriorate. Next, the control device 100 drives and controls the discharge unit 30 to discharge the etching solution E in the circulation line 20A by the first set amount.

Next, the control unit 100 controls the H3PO4 aqueous solution supply system 12 and the DIW supply system 13 of the replenishment unit 11 to supply the H3PO4 aqueous solution and DIW from the H3PO4 aqueous solution supply system and the DIW supply system 13 to the blending tank 15A, respectively. The H3PO4 aqueous solution is replenished into the etching solution E subjected to the treatment.

In this case, an H3PO4 aqueous solution having 85% of the H3PO4 component is supplied from the H3PO4 aqueous solution supply system 12, and this H3PO4 aqueous solution is diluted with DIW from the DIW supply system 13.

As a result, the mixing tank 15A is supplemented with a new H3PO4 aqueous solution having 60% of the H3PO4 component.

In this case, the H3PO4 aqueous solution having 60% of the H3PO4 component is replenished to the blending tank 15A by the second set amount.

In this way, the silicon concentration in the etching solution E is lowered to the concentration before the etching process (10%), and the silicon concentration in the etching solution can be accurately adjusted. At the same time, the H3PO4 concentration in the etching solution E is also maintained at 60%.

During this time, the control device 100 determines the first set amount of the etching solution E discharged from the discharge unit 30 and the second set amount of the etching solution E replenished into the preparation tank 15A as follows.

That is, the control device 100 first determines the first set amount to be discharged from the discharge unit 30 based on the elution component concentration of silicon from the elution part measurement unit 25.

Next, based on the first set amount thus determined, the H3PO4 concentration from the concentration measuring unit 26, and the temperature of the etching solution E from the temperature measuring unit 27, the etching solution replenished into the outer tank 10b. A second set amount of E is determined.

Thus, a new etching process is performed on the next predetermined number of wafers W in the same manner using the etching solution supplemented with the new etching (H3PO4 aqueous solution).

Next, a modified example of the present invention will be described.

In the embodiment described above, after the etching process, the control device 100 operates the discharge unit 30 to discharge the etching solution E by the first set amount, and operates the H3PO4 aqueous solution supply system 12 and the DIW supply system 13 to perform a new process. Although the example which replenishes the etching liquid E in the preparation tank 15A was shown, the control part 100 act | operates the discharge | emission part 30 before an etching process, discharge | releases etching liquid E only 1st preliminary quantity beforehand, and H3PO4 aqueous solution supply system 12 Alternatively, the DIW supply system 13 may be operated to replenish the preparation tank 15A with a new etching solution E in advance by a second reserve amount.

Note that the control device 100 determines the first preliminary amount for discharging the etching solution E and the second preliminary amount for replenishing the new etching solution E based on an etching processing recipe including a predetermined processing time.

Further, in the above-described embodiment, the preparation tank 15A stores the etching solution E from which the silicon content after the etching process is eluted, similarly to the silicon adjustment tank 14 in FIG. A silicon adjustment tank (not shown) for replenishing the liquid E to the circulation line 20A or the preparation tank 15A may be provided.

W Semiconductor wafer (object to be processed)
E Etching solution 10 Treatment tank 11 Replenishment unit 12 H3PO4 aqueous solution supply system 13 DIW supply system 14 Silicon adjustment tank 15 Preparation tank 15A Preparation tank 20 Circulation line 20A Circulation line 21 Circulation pump 22 Temperature controller 23 Filter 25 Elution component measurement unit 26 Concentration Measuring unit 27 Temperature measuring unit 30 Discharging unit 31 Discharging line 33 Communication line 40 Etching processing unit 41 Holding unit 42 Nozzle 43 Etching processing chamber

Claims

In an etching method for performing an etching process using an etchant on an object to be processed housed in an etching processing unit,
A step of supplying an etching solution to the object to be processed in the etching processing unit and performing an etching process;
Discharging a first set amount of the etching solution used for the etching process;
Replenishing the etching solution discharged by the first set amount with a second set amount of the new etchant,
Measure the elution component concentration, etching solution concentration, and etching solution temperature in the etching solution eluted from the workpiece subjected to the etching process, and measure the elution component concentration, etching solution concentration and etching. An etching method, wherein the first set amount and the second set amount are obtained based on the temperature of the solution, and the etching solution is discharged and the new etching solution is replenished.
The first set amount for discharging the etching solution is determined by the concentration of the eluted component from the object to be processed,
2. The etching method according to claim 1, wherein the second set amount for replenishing the new etchant is determined by the determined first set amount, the concentration of the etchant and the temperature of the etchant.
The etching processing unit includes a processing tank in which an etching solution is stored, and the object to be processed is immersed in the etching solution in the processing tank to perform the etching process, and the etching solution used for the etching process in the processing tank is The etching method according to claim 1, wherein the etching method is discharged and a new etching solution is replenished into the processing tank.
The etching processing unit has a holding unit for storing and holding the object to be processed,
The etching solution is supplied from the etching solution supply unit to the object to be processed held in the holding unit, and the etching solution supplied from the etching solution supply unit to the object to be processed is returned to the etching solution supply unit again through the circulation line. ,
The etchant in the circulation line is discharged,
2. The etching method according to claim 1, wherein a new etching solution is replenished into the circulation line.
Before the etching process is performed on the object to be processed, the method further comprises a step of discharging the etching solution in advance by a first preliminary amount, and a step of replenishing a new etching solution in advance by a second preliminary amount thereafter. The etching method according to claim 1.
The first reserve amount for discharging the etchant and the second reserve amount for replenishing the new etchant are determined in advance according to the etching process recipe including the number of objects to be processed and the processing time during the etching process. The etching method according to claim 5.
In an etching apparatus that performs an etching process using an etchant on an object to be processed,
An etching processing section for storing the object to be processed;
A discharge unit for discharging the etching solution provided for the etching process by a first set amount;
A replenishment unit that replenishes the etching solution discharged by the first predetermined amount with a second set amount of the new etching solution;
An elution component measurement unit that measures the concentration of an elution component in an etching solution eluted from an object subjected to the etching process;
A concentration measuring unit for measuring the concentration of the etching solution;
A temperature measuring unit for measuring the temperature of the etching solution;
A control device for controlling the discharge unit and the replenishment unit, the control device is based on the elution component concentration from the elution component measurement unit, the concentration of the etching solution from the concentration measurement unit and the temperature of the etching solution from the temperature measurement unit, An etching apparatus characterized by controlling a discharge unit and a replenishment unit by obtaining a first set amount and a second set amount.
The control unit determines the first set amount for discharging the etching solution based on the concentration of the eluted component from the object to be processed, and the determined second set amount for replenishing the new etching solution, the determined first set amount, the concentration of the etching solution, and the etching 8. The etching apparatus according to claim 7, wherein the etching apparatus is determined by the temperature of the liquid.
The etching processing unit includes a processing tank in which an etching solution is stored, and the object to be processed is immersed in the etching solution in the processing tank to perform the etching process, and the etching solution used for the etching process in the processing tank is 8. The etching apparatus according to claim 7, wherein the etching apparatus is discharged by the discharge section, and a new etching solution is replenished into the processing tank by the replenishment section.
The etching processing unit has a holding unit for storing and holding the object to be processed,
An etching solution supply unit that supplies an etching solution to the object to be processed held by the holding unit is provided,
A circulation line is provided for returning the etchant supplied to the object to be processed from the etchant supply unit to the etchant supply unit again,
The etchant in the circulation line is discharged by the discharge part,
8. The etching apparatus according to claim 7, wherein a new etching solution is replenished into the circulation line by the replenishing unit.
The control unit discharges the etching solution in advance by the first preliminary amount by the discharge unit before performing the etching process on the object to be processed, and then replenishes the new etching solution in advance by the second preliminary amount by the replenishment unit. The etching apparatus according to claim 7, further comprising:
The control unit predetermines a first reserve amount for discharging the etchant and a second reserve amount for replenishing the new etchant according to the etching process recipe including the number of objects to be processed and the processing time during the etching process. The etching apparatus according to claim 11.
In a storage medium storing a computer program for causing a computer to execute an etching method,
Etching method
A step of supplying an etching solution to the object to be processed in the etching processing unit and performing an etching process;
Discharging a first set amount of the etching solution used for the etching process;
Replenishing the etching solution discharged by the first set amount with a second set amount of the new etchant,
Measure the elution component concentration, etching solution concentration, and etching solution temperature in the etching solution eluted from the workpiece subjected to the etching process, and measure the elution component concentration, etching solution concentration and etching. A storage medium characterized in that the first set amount and the second set amount are obtained based on the temperature of the solution, and the etching solution is discharged and the new etching solution is replenished.