JP3798712B2 - Cleaning device - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a semiconductor manufacturing apparatus, and more particularly to a cleaning apparatus for cleaning a semiconductor wafer using a cleaning liquid (chemical solution).
[0002]
[Prior art]
Conventionally, in order to remove a thin film such as a silicon oxide film or a silicon nitride film formed on a semiconductor wafer, or to remove a deposit (reaction by-product) remaining on a semiconductor wafer after dry etching (wet etching). In order to do this, a cleaning device is used.
The removal property of the deposit varies greatly depending on the process conditions of the dry etching, which is the previous step, and the device material such as a resist material. In order to cope with this change in removability, a conventional cleaning apparatus has prepared in advance a plurality of chemical solutions in which the mixing ratio is optimally adjusted for each process condition and device material. That is, even if the components of the chemical solution are approximately the same, cleaning is performed using any one of a plurality of chemical solutions having different preparation ratios.
[0003]
[Problems to be solved by the invention]
However, even when cleaning is performed using the chemical solution having the optimum blending ratio as described above, deposits may remain on the cleaned semiconductor wafer. For this reason, it was necessary to inspect the appearance of the deposits by the operator after the cleaning process. And when a deposit was discovered by this visual inspection, re-cleaning was performed in the cleaning device.
Therefore, conventionally, a visual appearance inspection is manually performed after the cleaning process, and when a deposit remaining in the deposit is found there, the cleaning apparatus performs re-cleaning. For this reason, since the start of the lot to the next process is delayed, there is a problem that time loss between processes becomes large.
[0004]
Moreover, in the said external appearance inspection, it was only judged simply whether the deposit remains, and the residual amount was not measured. Furthermore, when performing the re-cleaning, a chemical solution having the same composition as the chemical solution used in the first cleaning was used.
[0005]
However, since the state (amount and distribution) of the depot that is the object to be cleaned is different between the initial cleaning and the re-cleaning, when re-cleaning is performed using a chemical solution having the same composition as the first cleaning, There was a problem that it could not be cleaned accurately under the optimum conditions. For example, there is a problem that the removability of the chemical solution is increased in re-cleaning, and the selection ratio with the base cannot be taken. This problem of the selection ratio with the base is particularly important when the thin film is removed in a cleaning apparatus.
[0006]
The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a cleaning apparatus that performs cleaning under optimal conditions according to the state of an object to be cleaned.
[0007]
[Means for solving the problems]
A cleaning apparatus according to the present invention is a cleaning apparatus for removing a thin film formed on a substrate,
A film thickness measuring unit for measuring the film thickness of the thin film;
Based on the film thickness measured by the film thickness measurement unit, a preparation unit for preparing a chemical solution,
And a cleaning unit for cleaning the substrate by using the chemical solution formulated by the formulation unit,
The film thickness measurement unit further measures the film thickness of the thin film after the substrate is cleaned by the cleaning unit.
In order to remove the thin film remaining after the cleaning of the substrate, the blending unit remixes the chemical solution in consideration of the selection ratio of the remaining thin film to the base .
[0008]
Oite the cleaning equipment according to the present invention,
Further comprising a residual amount measuring unit for measuring a reaction by-product on the substrate;
The residual amount measuring unit further measures the residual amount of the reaction by-product after cleaning the substrate by the cleaning unit,
In order to remove the reaction byproduct remaining after cleaning the substrate, it is preferable that the blending unit remixes the chemical solution in consideration of the selection ratio with respect to the base .
[0009]
Oite the cleaning equipment according to the present invention,
The preparation unit, so that the time required for removing the thin film is within a predetermined range, it is preferable to set the even you formulate the drug solution.
[0010]
Oite the cleaning equipment according to the present invention,
The preparation unit is configured to formulate the drug solution, it is preferable to set the even that to adjust the temperature of the chemical solution.
[0011]
Oite the cleaning equipment according to the present invention,
The blending unit is
Multiple tanks that store each component of the chemical solution,
A blending valve for blending each component from the plurality of tanks in a desired ratio;
It is preferable that in the even that have a.
[0012]
A cleaning apparatus according to the present invention is a cleaning apparatus for removing reaction byproducts remaining on a substrate,
A residual amount measuring unit for measuring the residual amount of the reaction by-product;
Based on the residual amount measured by the residual amount measuring unit, a preparation unit for preparing a chemical solution,
A cleaning unit for cleaning the substrate using the chemical solution adjusted by the preparation unit;
It is characterized by comprising.
[0013]
Oite the cleaning equipment according to the present invention,
The residual amount measuring unit, it is preferable that the reaction by-products in a predetermined region of the substrate is to be you measure the area remaining.
[0014]
Oite the cleaning equipment according to the present invention,
The residual amount measuring unit, after cleaning the substrate by the cleaning unit, and than the even you further measuring the residual amount of reaction by-products,
In order to remove the reaction byproduct remaining after cleaning the substrate, it is preferable that the blending unit remixes the chemical solution in consideration of the selection ratio with respect to the base .
[0015]
Oite the cleaning equipment according to the present invention,
The preparation unit is configured so that the time required for removal of reaction by-products is within a predetermined range, it is preferable to set the even you formulate the drug solution.
[0016]
Oite the cleaning equipment according to the present invention,
The preparation unit is configured to formulate the drug solution, it is preferable to set the even that to adjust the temperature of the chemical solution.
[0017]
Oite the cleaning equipment according to the present invention,
The blending unit is
Multiple tanks that store each component of the chemical solution,
A blending valve for blending each component from the plurality of tanks in a desired ratio;
It is preferable that in the even that have a.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof may be simplified or omitted.
[0019]
Embodiment 1 FIG.
FIG. 1 is a schematic plan view for explaining a cleaning apparatus according to Embodiment 1 of the present invention.
In FIG. 1, reference numeral 1 is a carrier for housing a substrate, 2 is a semiconductor wafer as a substrate, 10 is a load / unload unit for loading and unloading the semiconductor wafer 2, and 3 is a semiconductor wafer 2. A transfer arm is shown. Reference numeral 4 indicates a film thickness measuring unit for measuring the film thickness of a thin film (for example, a silicon oxide film or a silicon nitride film) formed on the semiconductor wafer 2 using the film thickness measuring probe 41. Reference numeral 5 denotes a processing chamber for cleaning the semiconductor wafer 2 with a chemical solution (single-wafer spin cleaning), and 6 is provided in the processing chamber 5 to hold the semiconductor wafer 2 by clamping or vacuum suction and to rotate it. A rotary stage that rotates horizontally around an axis (described later), 7 is a chemical nozzle for injecting a chemical liquid prepared at a desired mixing ratio onto the semiconductor wafer 2 by a chemical liquid preparing unit 30 (details will be described later). Show. Reference numeral 8 denotes a residual amount measuring unit for measuring the residual amount of reaction by-products (deposited matter) remaining on the semiconductor wafer 2 using an image recognition probe as the residual amount measuring probe 81.
[0020]
Here, the film thickness measuring unit 4 is, for example, an optical film thickness meter, and measures the film thickness of the thin film at at least one point on the semiconductor wafer 2 determined in advance.
The remaining amount measuring unit 8 is an image recognition device, for example, and measures an area where deposits per unit area on the semiconductor wafer remain. The remaining amount measuring unit 8 determines the presence or absence of a deposit based on the difference between the optical deposit and the base film.
[0021]
Further, the cleaning apparatus according to the first embodiment grasps the state of the object to be cleaned based on the measurement result (film thickness) by the film thickness measurement unit 4 or the measurement result (residual amount) by the residual amount measurement unit 8, A control unit 20 that determines the mixing ratio of the chemical components and the optimum cleaning time according to the state is provided.
[0022]
FIG. 2 is a schematic diagram for explaining a chemical liquid preparation unit 30 for preparing a chemical liquid in the cleaning apparatus shown in FIG.
In FIG. 2, reference numerals 11a, 11b, and 11c are tanks for storing respective chemical components, 12a, 12b, and 12c are pipes for supplying the chemical components stored in the tanks 11a, 11b, and 11c, and 13 is a mixing valve ( (Mixing valve) 14 indicates piping.
[0023]
As shown in FIG. 2, in the cleaning apparatus according to the first embodiment, the chemical liquid preparation unit 30 has tanks 11a, 11b, and 11c for each chemical liquid component. A chemical component A is stored in the tank 11a, a chemical component B is stored in the tank 11b, and a chemical component C is stored in the tank 11c.
In addition, in this Embodiment 1, although the three tanks for storing a chemical | medical solution component are provided, you may change the number of tanks suitably according to the kind of chemical | medical solution component to mix | blend. For example, when an ammonium fluoride stripping solution is used as the chemical solution, ammonium fluoride that contributes to removability is contained in the tank 11a, and an organic solvent, water that adjusts dissociation is provided in the tanks 11b and 11c and tanks not shown. , PH adjusters, surfactants and the like are stored.
In addition, the compounding valve 13 prepares a chemical solution from each chemical solution component so as to achieve the compounding ratio determined by the control unit 20 described above, and supplies the prepared chemical solution to the chemical solution nozzle 7 via the pipe 14.
[0024]
FIG. 3 is a schematic view for explaining the vicinity of the chemical nozzle in the cleaning apparatus shown in FIG.
In FIG. 3, reference numeral 61 indicates a rotating shaft constituting the rotating stage 6. Further, the tip (injection port) of the chemical solution nozzle 7 is disposed in the vicinity of the semiconductor wafer 2.
As shown in FIG. 3, the semiconductor wafer 2 is held on the rotary stage 6, and the semiconductor wafer 2 rotates with the rotary stage 6 about the rotary shaft 61. Further, the chemical liquid prepared by the preparation valve 13 is sprayed from the chemical liquid nozzle 7 onto the semiconductor wafer 2.
[0025]
Next, the operation of the cleaning device will be described.
First, the first operation will be described. Here, the first operation is an operation of the cleaning device when the object to be cleaned is a thin film.
The carrier 1 is placed on the load / unload unit 10.
Next, the semiconductor wafer 2 is taken out from the carrier 1 by the transfer arm 3 and transferred to the film thickness measuring unit 4.
Then, in the film thickness measuring unit 4, the film thickness of the thin film formed on the semiconductor wafer 2 is measured using the film thickness measuring probe 41.
[0026]
After measuring the thickness of the thin film, the semiconductor wafer 2 is transferred onto the rotating stage 6 in the processing chamber 5 by the transfer arm 3. Then, while rotating the semiconductor wafer 2 together with the rotary stage 6, a chemical solution prepared at an optimal component ratio is sprayed onto the semiconductor wafer 2 from the chemical nozzle 7 to remove the thin film.
Here, the preparation of the chemical liquid in the chemical liquid preparation unit 30 will be described.
The control unit 20 determines the blending ratio of each chemical component according to the film thickness measured by the film thickness measuring unit 4, that is, according to the film thickness of the thin film that is the object to be cleaned. This determination is performed, for example, by providing a film thickness range such as 1 to 10 nm and 10 to 100 nm and calculating a blending ratio corresponding thereto. The blending valve 13 blends the chemical liquid from each chemical liquid component so that the blending ratio determined by the control unit 20 is obtained. Then, the prepared chemical solution is supplied to the chemical nozzle 7 through the pipe 14.
In addition, the control unit 20 determines the optimal mixing time as well as the mixing ratio.
[0027]
After cleaning for a time determined by the control unit 20, the semiconductor wafer 2 is transferred to the film thickness measuring unit 4 by the transfer arm 3, and the film thickness measuring unit 4 measures the film thickness of the thin film again.
Here, when the film thickness of the thin film is equal to or less than the desired film thickness, the semiconductor wafer 2 is returned to the carrier 1 by the transfer arm 3 and the cleaning process of the semiconductor wafer 2 is finished.
[0028]
On the other hand, when the film thickness of the thin film exceeds the desired film thickness, the semiconductor wafer 2 is transferred onto the rotating stage 6 in the processing chamber 5 by the transfer arm 3 and re-cleaning is performed. At this time, the control unit 20 determines the mixing ratio of each chemical component again according to the film thickness of the thin film, and also determines the optimum cleaning time. And the preparation valve | bulb 13 mixes a chemical | medical solution again so that it may become this determined preparation ratio.
After the re-cleaning, the film thickness measurement unit 4 measures the film thickness of the thin film again, and thereafter the same operation is performed.
[0029]
Next, the second operation will be described. Here, the second operation is an operation of the cleaning device when the object to be cleaned is a deposit.
First, the carrier 1 is placed on the load / unload unit 10 as in the first operation.
Next, the semiconductor wafer 2 is taken out from the carrier 1 by the transfer arm 3 and transferred to the remaining amount measuring unit 8.
Then, the remaining amount measuring unit 8 measures the remaining amount of deposits remaining on the semiconductor wafer 2 using the image recognition probe 81.
[0030]
After measuring the remaining amount of the deposit, the semiconductor wafer 2 is transferred onto the rotating stage 6 in the processing chamber 5 by the transfer arm 3. Then, while rotating the semiconductor wafer 2 together with the rotary stage 6, the chemical liquid prepared at the optimum component ratio is ejected from the chemical liquid nozzle 7 onto the semiconductor wafer 2 to remove the thin film.
Here, the preparation of the chemical liquid in the chemical liquid preparation unit 30 will be described.
The control unit 20 determines the preparation ratio of each chemical component according to the remaining amount measured by the remaining amount measuring unit 8, that is, according to the remaining amount of the deposit that is the object to be cleaned. The blending valve 13 blends the chemical liquid from each chemical liquid component so that the blending ratio determined by the control unit 20 is obtained. Then, the prepared chemical solution is supplied to the chemical nozzle 7 through the pipe 14.
In addition, the control unit 20 determines the optimal mixing time as well as the mixing ratio.
[0031]
After cleaning for a time determined by the control unit 20, the semiconductor wafer 2 is transferred to the remaining amount measuring unit 8 by the transfer arm 3. Then, the residual amount measuring unit 8 measures the residual amount of the deposit using the residual amount measuring probe 81 again.
If no deposit remains, the transfer arm 3 returns the semiconductor wafer 2 to the carrier 1 and the cleaning process for the semiconductor wafer 2 is completed.
[0032]
On the other hand, when the deposit remains, the transfer arm 3 transfers the semiconductor wafer 2 onto the rotating stage 6 in the processing chamber 5 and performs re-cleaning. At this time, the control unit 20 determines the mixing ratio of each chemical component anew and also determines the optimal cleaning time anew according to the remaining amount of the deposit. And the preparation valve | bulb 13 mixes a chemical | medical solution again so that it may become this determined preparation ratio.
After the re-washing, the remaining amount measuring unit 8 again measures the remaining amount of the deposit, and thereafter the same operation is performed.
[0033]
As described above, in the first embodiment, the state of the object to be cleaned is measured by the film thickness measuring unit 4 or the remaining amount measuring unit 8 before cleaning, and the composition of the chemical component optimal for the state is prepared. It was decided to determine the ratio and wash time. Therefore, it is possible to perform optimum cleaning according to the state of the object to be cleaned.
[0034]
In addition, the state of the object to be cleaned is measured again after cleaning to determine whether or not re-cleaning is necessary. Therefore, the appearance inspection process that has been performed manually after the conventional cleaning process becomes unnecessary. For this reason, the semiconductor manufacturing cost can be suppressed. Moreover, since it becomes possible to start a lot early in the next process, time loss between processes can be greatly reduced.
Furthermore, when re-cleaning is necessary, the optimum mixing ratio of chemical components and the cleaning time for the state of the object to be cleaned measured again are determined. Therefore, re-cleaning can be performed with high accuracy. This is particularly suitable in the case of thin film removal in which the selection ratio with the base is a problem.
[0035]
Although the cleaning apparatus according to the first embodiment includes both the film thickness measuring unit 4 and the remaining amount measuring unit 8, the present invention is not necessarily limited to this configuration. When only the thin film is removed, the film thickness measuring unit. In the case where only the removal of deposits is performed only for 4, the remaining amount measuring unit 8 only needs to be provided.
[0036]
A plurality of processing chambers 5 may be provided. Furthermore, a plurality of film thickness measuring units 4 and remaining amount measuring units 8 may be provided according to the number of processing chambers 5.
[0037]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the washing | cleaning apparatus which performs washing | cleaning on the optimal conditions according to the state of to-be-washed | cleaned object can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic plan view for explaining a cleaning device according to a first embodiment of the present invention.
FIG. 2 is a schematic view for explaining a chemical liquid preparation unit for preparing a chemical liquid in the cleaning apparatus shown in FIG. 1;
FIG. 3 is a schematic view for explaining the vicinity of a chemical liquid nozzle in the cleaning apparatus shown in FIG. 1;
[Explanation of symbols]
1 Carrier 2 Substrate (semiconductor wafer)
3 Transfer arm 4 Film thickness measuring part (optical film thickness meter)
5 Processing chamber 6 Rotating stage 7 Chemical solution nozzle 8 Remaining amount measuring unit (image recognition device)
10 Load / Unload parts 11a, 11b, 11c Tanks 12a, 12b, 12c Pipe 13 Mixing valve 14 Pipe 20 Control part 30 Chemical preparation part 41 Film thickness measurement probe 61 Rotating shaft 81 Residual amount measurement probe (image recognition probe)

Claims (11)

A cleaning apparatus for removing a thin film formed on a substrate,
A film thickness measuring unit for measuring the film thickness of the thin film;
Based on the film thickness measured by the film thickness measurement unit, a preparation unit for preparing a chemical solution,
And a cleaning unit for cleaning the substrate by using the chemical solution formulated by the formulation unit,
The film thickness measurement unit further measures the film thickness of the thin film after the substrate is cleaned by the cleaning unit.
The cleaning device is characterized in that, in order to remove the thin film remaining after the cleaning of the substrate, the chemical solution is re-mixed in consideration of the selection ratio of the remaining thin film to the base . The cleaning device according to claim 1,
Further comprising a residual amount measuring unit for measuring a reaction by-product on the substrate;
The residual amount measuring unit further measures the residual amount of the reaction by-product after cleaning the substrate by the cleaning unit,
The formulation unit, for removing the reaction by-products remaining after the cleaning of the substrate, in consideration of the selectivity to the underlying cleaning device according to claim der Rukoto which reconstitution of the drug solution. The cleaning apparatus according to claim 1 or 2,
The said mixing part prepares the said chemical | medical solution so that the time required for the removal of the said thin film may be in a predetermined range, The cleaning apparatus characterized by the above-mentioned. The cleaning apparatus according to any one of claims 1 to 3,
The said preparation part adjusts the temperature of the said chemical | medical solution while preparing the said chemical | medical solution, The washing | cleaning apparatus characterized by the above-mentioned. In the cleaning apparatus according to any one of claims 1 to 4,
The blending unit is
Multiple tanks that store each component of the chemical solution,
A blending valve for blending each component from the plurality of tanks in a desired ratio;
A cleaning apparatus comprising: A cleaning apparatus for removing reaction by-products remaining on a substrate,
A residual amount measuring unit for measuring the residual amount of the reaction by-product;
Based on the residual amount measured by the residual amount measuring unit, a preparation unit for preparing a chemical solution,
A cleaning unit for cleaning the substrate using the chemical solution adjusted by the preparation unit;
A cleaning apparatus comprising: The cleaning apparatus according to claim 6, wherein
The residual amount measuring unit measures an area where the reaction by-product remains in a predetermined region of the substrate. The cleaning apparatus according to claim 6 or 7,
The residual amount measuring unit further measures the residual amount of the reaction by-product after cleaning the substrate by the cleaning unit ,
The cleaning device is characterized in that, in order to remove reaction by-products remaining after cleaning the substrate, the preparation solution is re-prepared in consideration of the selection ratio with respect to the substrate. The cleaning apparatus according to any one of claims 6 to 8,
The said preparation part prepares the said chemical | medical solution so that the time required for the removal of the said reaction by-product may be in a predetermined range, The washing | cleaning apparatus characterized by the above-mentioned. The cleaning apparatus according to any one of claims 6 to 9,
The said preparation part adjusts the temperature of the said chemical | medical solution while preparing the said chemical | medical solution, The washing | cleaning apparatus characterized by the above-mentioned. The cleaning apparatus according to any one of claims 6 to 10,
The blending unit is
Multiple tanks that store each component of the chemical solution,
A blending valve for blending each component from the plurality of tanks in a desired ratio;
A cleaning apparatus comprising:

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