JPH11233478A - Cleaning treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve cleaning ability and yield, by precisely measuring stained micro particles mixed in cleaning liquid, and cleaning based on data. SOLUTION: When cleaning, cleaning liquid L in a cleaning tank 20 storing cleaning liquid L into which a semiconductor wafer W is immersed is overflowed and is circularly supplied. It is filtered at the time of circular supply and the wafer W is cleaned. In such a case, the prescribed quantity of cleaning liquid L in the cleaning tank 20 is taken out from a part different from a circular supply part by an electric bellows pump 30, and a particle counter 50 detects particles mixed in cleaning liquid L. Cleaning, exchange of cleaning liquid and alarm display in an abnormal state are executed based on the number of detected particles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for cleaning an object to be processed such as a semiconductor wafer or a glass substrate for an LCD.

[0002]

2. Description of the Related Art Generally, in a manufacturing process of a semiconductor manufacturing apparatus, an object to be processed (hereinafter, referred to as a wafer) such as a semiconductor wafer or LCD glass is sequentially transferred to a cleaning tank in which a cleaning liquid such as a chemical solution or a rinsing liquid is stored. Cleaning apparatuses that perform processing such as cleaning are widely adopted.

As a cleaning apparatus for performing the above-described cleaning processing, a cleaning apparatus as shown in FIG. 11 is known. The cleaning apparatus includes a cleaning tank c including an inner tank a for storing a cleaning liquid L for immersing the wafer W and an outer tank b surrounding the upper end of the inner tank a. For example, an air bellows-type circulation pump g, a damper h, and a filter i are interposed in a circulation pipe f connecting a cleaning liquid supply nozzle d provided at a lower portion of the tank and a discharge port e provided at the bottom of the outer tank b. Has been established. According to this cleaning processing apparatus, the wafer W held by the wafer boat j is immersed in the cleaning liquid L stored in the inner tank a, and the cleaning liquid L supplied into the inner tank a from a cleaning supply source (not shown). The wafer W can be washed while overflowing into the outer tank b and circulating and filtering.

When the cleaning is performed repeatedly, contaminant fine particles such as particles adhering to the wafer W to be cleaned are mixed into the cleaning liquid. If a predetermined amount or more of particles or the like are mixed in the cleaning liquid, there is a problem that the wafer W to be subsequently cleaned is contaminated to lower the yield and cleaning performance.

Therefore, conventionally, as shown in FIG. 11, a branch pipe k for inspection is branched to the discharge side of the circulation pump g in the circulation pipe f, and a detecting means, for example, a particle counter m is connected to the branch pipe k. At the same time, the discharge side of the particle counter m is connected to the outer tank b. In this way, a part of the cleaning liquid L in the inner tank a is taken out through the circulation pipe f and the branch pipe k, the number of particles in the taken out cleaning liquid is detected, and a predetermined amount of the cleaning liquid L is taken out. The number of particles is monitored. In FIG. 11, reference numeral n denotes an on-off valve provided in a circulation line f, p denotes a drain pipe connected to a discharge port q provided in the bottom of the inner tank a, and r denotes a drain pipe q. Drain valve.

[0006]

However, since the circulation pump g is of the air bellows type, pulsation occurs and the detected flow rate of the cleaning liquid becomes unstable. Therefore, there is a problem that accurate measurement of particles cannot be performed, and the present invention in which the cleaning process based on the detected data cannot be performed sufficiently was performed in view of the above circumstances.
Provided is a cleaning method capable of accurately measuring contaminant particles such as particles mixed in a cleaning liquid and performing a cleaning process based on the detection data, thereby improving cleaning performance and yield. It is intended for.

[0007]

According to a first aspect of the present invention, a cleaning liquid in a cleaning tank for storing a cleaning liquid for immersion treatment of an object to be processed is overflowed, circulated and supplied, and circulated and supplied. In the cleaning processing method of cleaning the object to be processed, at least before or during the cleaning processing, while taking out a predetermined amount of the cleaning liquid in the cleaning tank from a location different from the circulating supply unit, The amount of contaminant particles mixed in the cleaning liquid is detected, and a detection signal within a predetermined amount or a predetermined amount or more is issued according to the detected amount of contaminant particles. in this case,
When the detected amount of the contaminating particles is a predetermined amount, a detection signal for cleaning solution exchange can be issued (Claim 2).
When the difference in the amount of contaminant particles mixed in the cleaning liquid during the cleaning process reaches a predetermined amount or more, a detection signal can be issued (claim 3). In addition, during the above-mentioned cleaning process, the object to be processed during the cleaning process can be recognized as an abnormal object by a detection signal generated when the amount of contaminant particles mixed into the cleaning liquid reaches a predetermined amount or more. It is also possible (claim 4).

According to the first aspect of the present invention, before or during the cleaning process, a predetermined amount of the cleaning solution in the cleaning tank is taken out of a location different from the circulating supply unit, and contamination mixed in the cleaning solution. Since the amount of fine particles is detected, contaminant fine particles mixed into the cleaning solution can be accurately measured, and a detection signal within a predetermined amount or a predetermined amount or more is issued according to the detected amount of contaminant fine particles, so that the operator can be cleaned. An improper state can be notified. Further, when the amount of the contaminating fine particles is less than the predetermined amount, it can be notified that the cleaning process is performed normally.

(2) According to a fifth aspect of the present invention, the cleaning liquid in the cleaning tank for storing the cleaning liquid for dipping the object to be processed is overflowed, circulated and supplied, and filtered during the circulating supply. In the cleaning method for cleaning an object to be processed, in the cleaning processing, a predetermined amount of the cleaning liquid in the cleaning tank is taken out from a location different from the circulating supply unit, and an amount of contaminant fine particles mixed in the cleaning liquid. Is detected, and after the detected amount of the contaminated fine particles has reached a predetermined amount or less suitable for cleaning, the object to be processed is cleaned.

According to the fifth aspect of the present invention, during the cleaning process, as in the first aspect of the present invention, a predetermined amount of the cleaning liquid in the cleaning tank is taken out from a location different from the circulating supply unit. Since the amount of contaminant particles mixed in the cleaning liquid is detected, the amount of contaminant particles mixed in the cleaning liquid can be accurately measured, and the amount of the detected contaminant particles reaches a predetermined amount or less suitable for cleaning. After that, by cleaning the object, the performance of the cleaning process and the yield can be improved.

(3) The invention according to claim 6 is to overflow the cleaning for storing the cleaning liquid for immersing the object to be processed, to circulate the cleaning liquid, and to filter during the circulating supply to filter the object to be processed. In the cleaning method for cleaning,
In the cleaning process, a predetermined amount of the cleaning liquid in the cleaning tank is taken out from a location different from the circulating supply unit, and the amount of the contaminant particles mixed in the cleaning liquid is detected. However, when the amount does not reach the predetermined amount or less within the predetermined time, the cleaning liquid is replaced.

According to the sixth aspect of the present invention, during the cleaning process, as in the first aspect of the present invention, a predetermined amount of the cleaning liquid in the cleaning tank is taken out from a location different from the circulating supply unit. Since the amount of contaminant particles mixed in the cleaning liquid is detected, the amount of contaminant particles mixed in the cleaning liquid can be accurately measured, and the amount of the detected contaminant particles is reduced to a predetermined amount or less within a predetermined time. If the cleaning liquid is not reached, the performance of the cleaning process and the yield can be improved by replacing the cleaning liquid.

(4) According to the present invention, the cleaning liquid in the cleaning tank for storing the cleaning liquid for immersing the object to be processed is overflowed, circulated and supplied, and filtered during the circulating supply. In the cleaning method for cleaning the object to be processed, a predetermined amount of the cleaning liquid in the cleaning tank is taken out from a location different from the circulating supply unit, and a step of detecting an amount of contaminant fine particles mixed in the cleaning liquid, Cleaning the object to be processed for a predetermined time based on the detected data, comprising: an amount of contaminating fine particles in the cleaning liquid before the first cleaning processing; and a cleaning liquid after the processing of cleaning the object to be processed. When the difference in the amount of contaminating particulates in the reaches a predetermined amount or more,
The cleaning liquid is replaced.

According to the seventh aspect of the present invention, similarly to the first and second aspects of the present invention, a predetermined amount of the cleaning liquid in the cleaning tank is taken out from a location different from the circulating supply unit and the cleaning liquid is taken out. It detects the amount of contaminant particles mixed in,
It is possible to accurately measure the contaminant particles mixed in the cleaning solution, and to determine the amount of the contaminant particles in the cleaning solution before the first cleaning process and the amount of the contaminant particles in the cleaning solution after the cleaning process of the object. When the difference reaches a predetermined amount or more, by replacing the cleaning liquid, the cleaning performance of the cleaning liquid can be improved, and the yield can be improved.

(5) In the invention according to claim 8, the cleaning liquid in the cleaning tank for storing the cleaning liquid for immersing the object to be processed is overflowed, circulated and supplied, and filtered during the circulating supply. In the cleaning method for cleaning the object to be processed, a predetermined amount of the cleaning liquid in the cleaning tank is taken out from a location different from the circulating supply unit, and a step of detecting an amount of contaminant fine particles mixed in the cleaning liquid, Cleaning the object to be processed for a predetermined time based on the detected data, the amount of contaminating particles in the cleaning liquid before the cleaning processing of the same object to be processed, and the cleaning liquid after the cleaning processing. When the difference between the lower limit values of the contaminated fine particles reaches a predetermined amount or more, the cleaning liquid is replaced.

According to the eighth aspect of the present invention, similarly to the first, second and seventh aspects of the present invention, a predetermined amount of the cleaning liquid in the cleaning tank is taken out from a location different from the circulating supply section. Since the amount of contaminant particles mixed in the cleaning liquid is detected, the amount of contaminant particles mixed in the cleaning liquid can be accurately measured, and the amount of contaminant particles in the cleaning liquid before the same object is cleaned. When the difference between the lower limit value of the contaminant fine particles in the cleaning liquid after the cleaning processing reaches a predetermined amount or more, the cleaning liquid is replaced, thereby improving the cleaning ability of the cleaning liquid and improving the yield. it can.

(6) According to a ninth aspect of the present invention, in the cleaning method according to the seventh or eighth aspect, the replacement of the cleaning liquid is performed together with a replacement time according to a set number of processing times or a replacement time according to a set time. It is characterized by having done.

According to the ninth aspect of the present invention, the replacement of the cleaning liquid can be performed properly by performing the replacement of the cleaning liquid together with the measurement value obtained by the detection and the predetermined number of times or the predetermined time based on the experimental value. In addition, the cleaning performance of the cleaning liquid can be improved, and the yield can be improved.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. In this embodiment, a case where the present invention is applied to a semiconductor wafer cleaning processing system will be described.

FIG. 1 is a schematic plan view showing an example of a cleaning system to which a cleaning apparatus according to the present invention is applied.

The cleaning system includes a loading / unloading unit 2 for loading and unloading a container, for example, a carrier 1 for horizontally storing a semiconductor wafer W (hereinafter, referred to as a wafer), which is a substrate to be processed, A processing unit 3 that performs a liquid processing such as a chemical solution and a cleaning liquid on the W and also performs a drying process; and an interface unit that is positioned between the loading / unloading unit 2 and the processing unit 3 to perform delivery, position adjustment, and posture conversion of the wafer W. 4 mainly.

The carry-in / carry-out unit 2 includes a carrier carry-in unit 5a and a carrier carry-out unit 5 at one end of the cleaning system.
b, and a wafer transfer unit 6 is provided. In this case, a transfer mechanism (not shown) is provided between the carrier carry-in section 5a and the wafer transfer section 6, and
The carrier 1 is moved by the carrier mechanism into the carrier loading section 5a.
Is transferred to the wafer transfer unit 6 from

A carrier lifter (not shown) is provided in each of the carrier unloading section 5b and the wafer transfer section 6, and the empty carrier 1 is provided above the loading / unloading section 2 by the carrier lifter. It is configured to be able to perform delivery to a standby unit (not shown) and reception from the carrier standby unit. In this case, a carrier transfer robot (not shown) movable in the horizontal direction (X and Y directions) and the vertical direction (Z direction) is provided in the carrier standby section, and the carrier transfer robot transfers the wafer. Empty carrier 1 transported from unit 6
And can be carried out to the carrier carrying-out section 5b. In addition, not only the empty carrier but also the carrier 1 containing the wafer W is stored in the carrier standby unit.
Can be kept waiting.

The wafer transfer section 6 has an opening in the interface section 4, and a lid opening / closing device 8 is provided in the opening. The lid (not shown) of the carrier 1 is opened or closed by the lid opening / closing device 8. Therefore, the lid of the carrier 1 that stores the unprocessed wafer W transferred to the wafer transfer unit 6 is removed by the lid opening / closing device 8 and the wafer W in the carrier 1 is removed.
Can be carried out, and after all the wafers W have been carried out, the lid can be closed again by the lid opening / closing device 8. Further, the lid of the empty carrier 1 transported from the carrier standby unit to the wafer transfer unit 6 is removed by the lid opening / closing device 8 so that the wafers W can be loaded into the carrier 1 and after all the wafers W have been loaded. Then, the lid 1 can be closed again by the lid opening / closing device 8. A mapping sensor 9 for detecting the number of wafers W stored in the carrier 1 is provided near the opening of the wafer transfer section 6.

The interface unit 4 holds a plurality of, for example, 25 wafers W in a horizontal state, and transfers the wafers W to and from the carrier 1 of the wafer transfer unit 6, for example, a horizontal transfer unit such as a wafer transfer arm 10. And a pitch changer (not shown) for holding a plurality of, for example, 50 wafers W in a vertical state at a predetermined interval, and a plurality of, for example, 25 wafers W positioned between the wafer transfer arm 10 and the pitch changer. Conversion means, for example, a posture conversion device 11 for converting the position into a horizontal state and a vertical state, and position detection means, for example, a notch aligner (not shown) for detecting a notch (not shown) provided on the wafer W whose posture has been converted to the vertical state. (Not shown). Further, the interface unit 4 is provided with a transfer path 12 that is continuous with the processing unit 3, and a wafer transfer unit, for example, a wafer transfer chuck 13 is movably disposed on the transfer path 1.

On the other hand, the processing section 3 includes a first processing unit 14 for removing particles and organic contaminants adhering to the wafer W, a second processing unit 15 for removing metal contaminants adhering to the wafer W, A cleaning / drying processing unit 16 and a chuck cleaning unit 17 for removing and drying a chemical oxide film attached to the wafer W are linearly arranged, and the first and second processing units 14 and 15 and the cleaning / drying are provided. The cleaning unit of the present invention is used for the processing unit 17. The wafer transfer chuck 13 that can rotate in the X and Y directions (horizontal direction), the Z direction (vertical direction), and rotate (θ) is disposed in a transfer path 12 provided at a position facing each of the units 14 to 17. Have been.

Next, the cleaning apparatus according to the present invention will be described in detail. As shown in FIG. 2, the cleaning treatment apparatus includes an inner tank 2 for storing a cleaning liquid L {for example, a diluting liquid (DHF) or a rinsing liquid (pure water) of hydrofluoric acid (HF)}.
1 and an outer tank 22 surrounding the upper opening of the inner tank 21 and receiving the washing liquid L overflowing from the inner tank 21, and a cleaning liquid supply nozzle 23 disposed below the inner tank 21. And a circulating pipe 24 connecting the cleaning liquid supply nozzle 23 and a discharge port 22 a provided at the bottom of the outer tank 22.
5, an air bellows type circulation pump 26, a damper 27 and a filter 28 are provided. A wafer boat 29 for holding a plurality of wafers W, for example, 50 wafers W is disposed in the inner tank 21 of the cleaning tank 20. Also, the inner tank 21
The drain port 21b provided at the bottom of the
Is connected to a drain pipe 21c.

In addition to a circulating pump 26 provided in the circulating line 24, a constant-pressure pumping means such as an electric bellows pump 30 (hereinafter referred to as a constant pump) is provided. Suction port 31 and inner tank 21
Are connected via a suction pipe 51, and the discharge port 32 of the metering pump 30 and the outer tub 22 are connected via a discharge pipe 52. In addition, a detection unit, for example, a particle counter 50 for detecting contaminant particles such as particles mixed in the cleaning liquid L sucked from the inner tank 21 by the metering pump 30 is provided in the suction pipe line 51. The particle counter 50 is configured to be operable at the time of suction driving of the constant-rate pump 30 by a control means such as a central processing unit 60 (CPU) so as to operate in synchronization with the constant-rate pump 30. That is, the CPU 60 detects the suction drive of the metering pump 30, transmits a drive signal to the particle counter 50 based on the detection signal, and mixes in the cleaning liquid L in the process of sucking a part of the cleaning liquid L in the inner tank 21. It is configured to be able to detect the amount of particles (particles / milliliter). When the particle counter 50 detects a number of particles equal to or more than a predetermined amount, a detection signal such as an alarm is displayed.

In this case, as shown in FIG. 3, the metering pump 30 includes a fixed end member 33 having a suction port 31 and a discharge port 32, and a movable end member 34 opposed to the fixed end member 33. A bellows 35 made of synthetic rubber having corrosion resistance and chemical resistance.
4 is provided with a ball screw mechanism 36 that moves forward and backward with respect to the fixed end member 33. That is, a nut 39 is screwed through a number of steel balls (not shown) to a screw shaft 38 rotated by a motor that can be rotated forward and backward, for example, a stepping motor 37, and the nut 39 and the movable end member 34 are connected to each other by a connecting member. 4
0, the bellows 35 expands and contracts with the driving of the stepping motor 37, and the inner tank 21
The cleaning liquid L inside is sucked in a fixed amount, for example, 0 to 40 ml, and the suctioned cleaning liquid L can be discharged to the outer tank 22. A check valve 4 is provided on the suction port side of the suction pipe 51 and on the discharge port side of the discharge pipe 52, respectively.
1, 42 are interposed.

As shown in FIG. 3, the particle counter 50 is provided in the whole or a part of the suction pipe 51 and connected to the transparent detection pipe 53, and is disposed on the side of the detection pipe 53. And a photoreceptor 5 disposed on the side opposite to the laser light emitter 54 with respect to the detection tube 53.
5 is comprised.

The metering pump 30 constructed as described above is driven to suck a part of the cleaning liquid L in the inner tank 21 and at the same time, the particle counter 50 is operated, that is, the inside of the detection tube 53 is moved from the laser light emitter 54. When the laser light is irradiated toward the flowing cleaning liquid L, the cleaning liquid L flowing in the detection tube 53 at a fixed amount of, for example, 40 ml (maximum) is irradiated with the laser light, and the laser light is contaminated by the contaminating particles such as particles mixed in the cleaning liquid L. The number of particles in a predetermined amount (particles / milliliter) can be detected by detecting that the light is bent or blocked by the photoreceptor 55. In this case, when the stepping motor 37 rotates at the same speed in the forward and reverse directions, the suction stroke and the discharge stroke become the same as shown in FIG. 4A, and the operation of the particle counter 50 stops at the time of discharge. And the ejection stroke is about several seconds, so that the influence on the detection of the number of particles is small. In order to increase the operation time of the particle counter 50 and shorten the stop time, as shown in FIG.
The rotational speed at the time of suction may be reduced and the rotational speed at the time of discharge may be increased.

In the above embodiment, the case where the particle counter 50 is provided on the suction side of the metering pump 30 has been described. However, the particle counter 50 does not necessarily need to be provided in the suction pipe 51 on the suction side of the metering pump 30. Instead, as shown in FIG. 5, it may be provided in the discharge pipe 52 on the discharge side of the metering pump 30. Thus, the metering pump 3
Since the particle counter 50 is disposed on the back pressure side of the metering pump 30 by disposing the particle counter 50 on the discharge side of 0, generation of air bubbles in the cleaning liquid L taken out from the inner tank 21 is prevented. be able to.

5 is the same as that shown in FIG. 3 except that the particle counter 50 is disposed on the discharge side of the metering pump 30. Omitted.

According to the cleaning apparatus configured as described above, the wafer W is immersed in the cleaning liquid L stored in the inner tank 21 of the cleaning tank 20, and the cleaning liquid L is supplied from a cleaning liquid supply source (not shown). At the same time, the cleaning liquid L overflowed from the inner tank 21 to the outer tank 22 is circulated while being filtered, whereby the wafer W can be cleaned. Then, during or before the cleaning process, the metering pump 30 is driven, and the particle counter 50 is operated to take out a certain amount of the cleaning solution L from the inner tank 21 separately from the circulating system and the like. The number of particles can be detected. The cleaning liquid L that has passed through the particle counter 50 and has been discharged from the discharge port 32 of the metering pump 30, or the cleaning liquid L that has passed through the particle counter 50 from the discharge port 32 of the metering pump 30, is returned to the cleaning tank 2.
0 is supplied to the outer tank 22 and is subjected to a cleaning process. Therefore, effective use of the cleaning liquid can be achieved. Note that the detected cleaning liquid may be discharged without being supplied to the outer tank 22.

Next, the cleaning treatment method of the present invention will be described.
This will be described with reference to FIGS. First, before the cleaning process or during the cleaning process, as described above, the metering pump 30 is driven to quantitatively take out the cleaning liquid L in the inner tank 21 from a location different from the circulating supply unit, and the particle counter 50. Is operated to detect the number of particles mixed in the cleaning liquid L (step A). When the detected number of particles is equal to or more than an upper limit value, for example, 20 particles / milliliter, a detection signal, for example, an alarm is displayed to notify an operator of an improper cleaning state (steps B and C; FIG. 6).
reference). By this alarm display, the cleaning liquid L in the cleaning tank 20 is discharged, and a new cleaning liquid L is supplied into the cleaning tank 20 to prepare for the next cleaning processing. Further, even when the number of detected particles does not reach the predetermined amount or less during the cleaning process, the cleaning liquid L is replaced to prepare for the next cleaning process.

If the detected number of particles is a predetermined amount, for example, the upper limit or less, and within a range of a proper cleaning value, the wafer W is put into the cleaning tank 20 (specifically, the inner tank 21).
The cleaning liquid L is supplied from a cleaning liquid supply source (not shown), circulated and supplied while overflowing, and filtered, and the wafer W is cleaned for a predetermined time, for example, 10 minutes (Steps D and E; see FIG. 6). Wafer W cleaned for a predetermined time
Is carried out of the cleaning tank 20. The cleaning liquid L in the cleaning tank 20 from which the wafer W has been carried out is circulated and filtered to remove particles mixed in the cleaning liquid L. When the number of particles mixed in the cleaning liquid L reaches a proper value or less, the next processing is performed. A plurality of wafers W, for example, 50 wafers W are loaded into the cleaning tank 20 and subjected to a cleaning process (see FIG. 7). During this cleaning process, a part of the cleaning liquid L in the inner tank 21 is taken out, and the number of particles is detected by the particle counter 50. During the cleaning process, the number of particles greatly exceeds an appropriate value. When the value is indicated, the operator is notified by an alarm display and the cleaning process is stopped (see FIG. 8). By this alarm display, for example, the number of particles in the cleaning liquid L before the first cleaning processing,
It is possible to know that the difference in the number of particles in the cleaning liquid L after the cleaning processing of the wafer W has reached a predetermined amount or more, and the cleaning liquid L can be replaced. Further, the alarm display allows the user to recognize that the wafer W being cleaned is an abnormal wafer, and treats the wafer recognized as an abnormal wafer as an abnormal wafer so that the wafer W can be separated from the normally processed wafer W. Can be.

As described above, the cleaning process is repeated a plurality of times for each lot of the wafer W. In the meantime, the number of particles mixed in the cleaning liquid L is also detected by the particle counter 50 during this period. Based on the data obtained, the difference (S1, S2, S3) between the number of particles in the previous cleaning step and the number of particles in the next cleaning step is monitored (compared), and when the difference is equal to or more than a predetermined amount (for example, S3), the cleaning liquid is used. Exchange of L is performed (steps F and G; see FIG. 9). Further, when the difference between the minimum value (lower limit value) of the number of particles in the same lot, for example, before the start of the n (integer) cleaning process and after the n-th cleaning process is equal to or more than a predetermined amount, the cleaning liquid L is replaced. The replacement of the cleaning liquid L can be performed at an optimum time by monitoring (monitoring) the replacement timing of the cleaning liquid L together with the replacement by a predetermined number of processes or the replacement by a set time, which is determined in advance by an experiment or the like. Can be.

In the above embodiment, the cleaning liquid L is DH
Although the description has been given of the case of F, other cleaning liquids such as an ammonia / hydrogen peroxide mixed liquid (APM) or a sulfuric acid / hydrogen peroxide mixed liquid (SPM) may also cause particles and the like mixed in the cleaning liquid. Contaminant particulates can be detected and monitored.

In the above embodiment, the case where the cleaning method of the present invention is applied to a semiconductor wafer cleaning processing system has been described. However, it is needless to say that the present invention can be applied to LCD glass substrates other than semiconductor wafers.

[0040]

As described above, according to the cleaning treatment method of the present invention, the following excellent effects can be obtained.

(1) According to the invention described in claims 1 to 4,
Before or during the cleaning process, a predetermined amount of the cleaning solution in the cleaning tank is taken out from a location different from the circulating supply unit, and the amount of contaminant particles mixed in the cleaning solution is detected. The contaminant particles can be accurately measured, and by issuing a detection signal within a predetermined amount or a predetermined amount or more according to the detected amount of the contaminant particles, an operator can be notified of an improper cleaning state. Therefore, the cleaning liquid can be managed in a proper cleaning state, so that the cleaning performance and the yield can be improved. Further, when the amount of the contaminating fine particles is less than the predetermined amount, it can be notified that the cleaning process is performed normally.

(2) According to the fifth aspect of the present invention, in the cleaning process, similarly to the first aspect of the present invention, a predetermined amount of the cleaning liquid in the cleaning tank is supplied from a location different from the circulating supply unit. As well as detecting the amount of contaminant particles mixed in the cleaning solution, the contaminant particles mixed in the cleaning solution can be accurately measured, and the amount of detected contaminant particles is
By cleaning the object after reaching a predetermined amount or less suitable for cleaning, the cleaning performance and the yield can be improved.

(3) According to the sixth aspect of the present invention, in the cleaning process, similarly to the first aspect of the present invention, a predetermined amount of the cleaning liquid in the cleaning tank is supplied from a location different from the circulating supply unit. As well as detecting the amount of contaminant particles mixed in the cleaning solution, the contaminant particles mixed in the cleaning solution can be accurately measured, and the amount of detected contaminant particles is
When the amount does not reach the predetermined amount or less within the predetermined time, the cleaning solution is replaced, thereby improving the performance of the cleaning process and the yield.

(4) According to the seventh aspect of the present invention, similarly to the first and second aspects of the present invention, a predetermined amount of the cleaning liquid in the cleaning tank is taken out from a location different from the circulating supply unit. Since the amount of contaminant particles mixed in the cleaning liquid is detected, the amount of contaminant particles mixed in the cleaning liquid can be accurately measured, and the amount of contaminant particles in the cleaning liquid before the first cleaning treatment is determined. When the difference in the amount of contaminant particles in the cleaning liquid after the cleaning processing of the object reaches a predetermined amount or more, the cleaning liquid is replaced to improve the cleaning ability of the cleaning liquid and improve the yield. it can.

(5) According to the eighth aspect of the present invention, similarly to the first, second and seventh aspects of the present invention, the predetermined amount of the cleaning liquid in the cleaning tank is supplied from a location different from the circulating supply section. At the same time, the amount of contaminant particles mixed in the cleaning solution is detected, so that the contaminant particles mixed in the cleaning solution can be accurately measured. When the difference between the amount of the fine particles and the lower limit of the contaminating fine particles in the cleaning solution after the cleaning process reaches a predetermined amount or more,
By exchanging the cleaning liquid, the cleaning ability of the cleaning liquid can be improved, and the yield can be improved.

(6) According to the ninth aspect of the present invention, the replacement of the cleaning liquid is performed appropriately by performing the replacement of the cleaning liquid in combination with the measurement value obtained by the detection and the predetermined number of times or the predetermined time based on the experimental value. The cleaning ability of the cleaning liquid can be improved, and the yield can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing an example of a cleaning system to which a cleaning apparatus according to the present invention is applied.

FIG. 2 is a schematic sectional view showing one embodiment of a cleaning apparatus according to the present invention.

FIG. 3 is a schematic sectional view showing a metering pump and a particle counter according to the present invention.

FIG. 4 is an explanatory diagram showing another embodiment of the suction stroke and the discharge stroke of the metering pump.

FIG. 5 is a schematic sectional view showing another embodiment of the cleaning apparatus according to the present invention.

FIG. 6 is a graph showing the relationship between the number of particles and time.

FIG. 7 is a graph showing the timing of a cleaning process.

FIG. 8 is a graph showing an abnormal state during a cleaning process.

FIG. 9 is a graph showing a change in a difference in the number of particles after filtration in a cleaning step.

FIG. 10 is a flowchart showing a cleaning process.

FIG. 11 is a schematic sectional view showing a conventional cleaning apparatus.

[Description of Signs] W Semiconductor wafer (object to be processed) L Cleaning liquid 20 Cleaning tank 21 Inner tank 22 Outer tank 23 Cleaning liquid supply nozzle 24 Circulation line 26 Circulation pump 28 Filter 30 Metering pump (motorized bellows pump; metering pump) 31 suction port 32 discharge port 35 bellows 50 particle counter (detection means) 60 CPU (control means)

Claims (9)

[Claims] 1. A cleaning method for cleaning an object to be processed, wherein the cleaning liquid in a cleaning tank storing a cleaning solution for immersion processing is overflowed, circulated and supplied, and filtered at the time of circulating supply to filter the object. In at least before or during the cleaning process, a predetermined amount of the cleaning solution in the cleaning tank is taken out from a location different from the circulating supply unit, and the amount of contaminant fine particles mixed into the cleaning solution is detected and detected. A cleaning method, wherein a detection signal within a predetermined amount or a predetermined amount or more is issued according to the amount of the contaminated fine particles. 2. The cleaning method according to claim 1, wherein when the detected amount of the contaminating fine particles is equal to or more than a predetermined amount, a signal for replacing the cleaning liquid is issued. 3. The cleaning method according to claim 1, wherein a difference between an amount of the contaminating particles mixed in the cleaning liquid before the cleaning processing and an amount of the contaminating particles mixed in the cleaning liquid during the cleaning processing is a predetermined amount. A cleaning processing method, wherein a detection signal is issued when the above is reached. 4. The cleaning method according to claim 1, wherein, during the cleaning processing, a detection signal is output when the amount of contaminant particles mixed into the cleaning liquid reaches a predetermined amount or more.
A cleaning processing method, wherein an object to be processed during cleaning processing can be recognized as an abnormal object to be processed. 5. A cleaning method in which a cleaning liquid in a cleaning tank for storing a cleaning liquid for immersion processing of an object to be processed is overflowed, circulated, supplied, and filtered at the time of circulating supply to wash the object. In the cleaning process, a predetermined amount of the cleaning liquid in the cleaning tank is taken out from a location different from the circulating supply unit, and the amount of the contaminant particles mixed in the cleaning liquid is detected. Cleaning the object to be processed after the amount of the liquid has reached a predetermined amount or less suitable for cleaning. 6. A cleaning method for cleaning an object to be processed in which a cleaning liquid in a cleaning tank for storing an object to be immersed is overflowed, circulated, and circulated and filtered at the time of circulating supply. In the cleaning process, a predetermined amount of the cleaning liquid in the cleaning tank is taken out from a location different from the circulating supply unit, and the amount of the contaminant particles mixed in the cleaning liquid is detected. The cleaning solution is replaced when the amount of the cleaning solution does not reach a predetermined amount or less within a predetermined time. 7. A cleaning processing method for cleaning and cleaning an object to be processed, wherein the cleaning liquid in a cleaning tank storing a cleaning liquid for immersion processing is overflowed, circulated and supplied at the time of circulating and filtered. A step of taking out a predetermined amount of the cleaning liquid in the cleaning tank from a location different from the circulating supply unit, and detecting the amount of contaminant fine particles mixed in the cleaning liquid; and Cleaning the processing object for a predetermined time, wherein the difference between the amount of the contaminating fine particles in the cleaning liquid before the first cleaning processing and the amount of the contaminating fine particles in the cleaning liquid after the cleaning processing of the object to be processed is determined. A cleaning method, wherein the cleaning liquid is replaced when the amount reaches a predetermined amount or more. 8. A cleaning method for cleaning the object to be processed, wherein the cleaning liquid in the cleaning tank for storing the object to be immersed is overflowed, circulated, and circulated and filtered during the circulated supply. A step of taking out a predetermined amount of the cleaning liquid in the cleaning tank from a location different from the circulating supply unit, and detecting the amount of contaminant fine particles mixed in the cleaning liquid; and Cleaning the processing object for a predetermined time, wherein the difference between the amount of the contaminating particles in the cleaning liquid before the cleaning processing of the same object to be processed and the lower limit value of the contaminating particles in the cleaning liquid after the cleaning processing is reduced. The cleaning solution is replaced when the amount reaches a predetermined amount or more. 9. The cleaning method according to claim 7, wherein the replacement of the cleaning liquid is performed together with a replacement time according to a set number of times or a replacement time according to a set time. Method.