JP2001118762A - Method and device for manufacturing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and effectively manage various processes for processing a semiconductor wafer by a simple method and to facilitate detection and management by measuring every for defects in an unspecified wafer within a lot. SOLUTION: In at least one of the processes for various kinds of processings to the semiconductor wafer, the mass of the semiconductor wafer is measured after the processing of a unit process of before and after the processing, and the process is managed based on the measured mass.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a semiconductor device and an apparatus for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices, a process monitor for inspecting whether or not a substrate such as a semiconductor wafer processed in a unit process such as etching or film formation is normally processed is generally a semiconductor monitor. The management is performed based on the measurement of the dimensions of the pattern formed on the substrate of the wafer and the thickness of the film, and the management is not performed by measuring the mass of the substrate.

In a semiconductor device manufacturing apparatus, processing apparatuses dedicated to unit processes such as etching, film formation, and measurement are mainly used.

A conventional method of manufacturing a semiconductor device will be described below with reference to FIG.
The process will be described with reference to a schematic process flow diagram of the process.

[0005] As shown in FIG. 3, in the dry etching step, an acceptance inspection 32 is first performed on the semiconductor wafer that has been processed in the previous step 31. Next, dry etching 33 of the semiconductor wafer is performed using a dry etching apparatus. Here, the pre-process 31 is usually a photolithography process, and in the acceptance inspection 32, a lot check, a microscope inspection, and the like are performed on the semiconductor wafer on which the resist pattern is formed. Next, in an inspection 34 after the dry etching process 33, the semiconductor wafer is checked by a microscopic inspection to confirm whether the semiconductor wafer has been normally processed.
This is performed by measuring the remaining film after etching. Usually, the inspection of the etching residual film is performed by extracting about one or two semiconductor wafer lots using a film thickness measuring device. That is, the measurement is performed by measuring the film thickness of the residual film measurement pattern on the surface of the semiconductor wafer and comparing it with a management standard value. Those that pass these inspections are shipped to the post-process. Whether the processing by etching is normal is performed by measuring the processing dimensions of the pattern formed on the semiconductor wafer and observing the surface image using an electron microscope for length measurement (hereinafter referred to as a length measurement SEM).

A conventional semiconductor manufacturing apparatus will be described using a dry etching apparatus as an example with reference to FIG. 4 which is a conceptual diagram showing the configuration of the manufacturing apparatus.

As shown in FIG. 4, the dry etching apparatus includes a process chamber 41 for performing a dry etching process, a semiconductor wafer transfer unit 42, a driving system 43, and a control unit 44 including various measuring machines. . The transport section 42 includes a load lock 45. Numeral 46 indicates connection of information of the control unit.

[0008]

However, the conventional manufacturing method and the conventional manufacturing apparatus as described above have a problem that it is difficult to efficiently and effectively manage the process.

For example, in order to measure the thickness of a semiconductor wafer in a lot of semiconductor devices, it is necessary to identify a measurement pattern from a pattern on the semiconductor wafer, perform alignment, and then perform the measurement. Therefore, the inspection takes a relatively long time, and it is necessary to program these operations on a measuring machine and to make the measurement operator familiar with the operations. For this reason, there has been a problem that a large amount of labor and time are required for routine creation, maintenance, operation of an operator, and the like.

In addition, when a 100% inspection is performed to manage each semiconductor wafer, it takes a long time to perform the inspection, which causes a problem in manufacturing throughput. There was a problem that management was not possible. As a typical example in this regard,
In the process of forming a contact hole, which has been miniaturized in recent years, there is a problem that dry etching is stopped halfway and causes a failure due to a contact unopened.
This phenomenon is caused by the process chamber,
It is considered that due to subtle differences in the condition of the semiconductor wafer to be processed, polymer-based reaction products generated during etching are not completely removed at the bottom of the contact hole and remain. It is difficult to control the generation only by semiconductor wafer process management.
In addition, the occurrence of irregularities tends to be irregular, and occurs randomly for several wafers in a lot, or occurs only in a part of a series of semiconductor wafers. are doing.

[0011] Further, the defect of the unopened contact that has occurred is, for example, in the case of a contact hole having a diameter of 0.3 μm and a depth of 1.5 μm for contacting a semiconductor substrate, etching is performed leaving a film of about 100 nm at the bottom of the contact hole. When stopped halfway, there is a problem that it cannot be detected by the conventional techniques of length measurement SEM or residual film measurement. That is, the state of the bottom of the contact hole cannot be sufficiently observed in the image observation by the length measurement SEM, and the processed dimension has the same value as that of the normal product. Also, the residual film measurement
It is difficult to detect that there is no residual film, and it is impossible to measure a fine pattern such as a contact hole. In addition, the pattern for measurement has a large opening area, so that the phenomenon that the etching is stopped halfway does not occur.

As a conventional technique, it is possible to measure the depth and shape of a contact hole by AFM, but it requires much more labor and time than the length measuring SEM and the residual film measuring device in terms of operation, and is normal or defective. It is difficult to determine whether or not a defect occurs in a part of a lot in mass production. Defects can be found by observing the cross-sectional shape of the contact hole on the semiconductor wafer, which is a destructive inspection.However, because it is a destructive inspection, it is inevitably a sampling inspection and detects defects that occur in a part of a lot in mass production It is inappropriate to do so.

As described above, since the conventional method generally takes a long time for inspection, there is a problem that it is not easy to detect variations and differences between semiconductor wafers by inspection of all lots or the like. I was

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems. In various aspects of processing a semiconductor wafer, it is possible to efficiently and effectively manage a process by a simple method. It is an object of the present invention to provide a semiconductor device manufacturing method and a semiconductor device manufacturing apparatus capable of detecting a defect in which dry etching stops halfway and a contact is not opened by a simple method. It is another object of the present invention to provide a semiconductor device manufacturing method and a semiconductor device manufacturing apparatus capable of easily detecting variations between semiconductor wafers from a macro viewpoint.

[0015]

In order to achieve the above-mentioned object, a method of manufacturing a semiconductor device according to the present invention includes a method for manufacturing a semiconductor device such as a semiconductor wafer. Alternatively, the method is characterized in that the mass of the substrate is measured before and after the treatment, and the process is managed based on the measured mass.

According to this configuration, it is possible to efficiently and effectively manage various processes for processing the substrate by simple means. In addition, it is possible to easily detect the variation between the substrates from a macro viewpoint, and it becomes easy to manage each substrate by performing the total measurement.

Preferably, by comparing the measured mass of the processed substrate with a management standard value, whether or not the substrate has been processed normally is evaluated, and the process is managed based on the evaluation result.

The control standard value is determined in advance by an experiment.
It can be statistically determined using the mass of the processed substrate, the amount of change in the mass, and the like.

According to the semiconductor device manufacturing apparatus of the present invention, there is provided a processing unit for performing at least one type of processing on a substrate in a semiconductor device manufacturing process, a measuring unit for measuring the mass of the substrate,
A control unit that controls the operation of the processing unit based on the mass measured by the measurement unit.

In the above configuration, it is preferable to use a more specific configuration as described below. That is, a process chamber for processing the substrate, a transport unit for transporting the substrate, a control unit for controlling the process chamber and transport means, and a measuring unit having a mass meter for measuring the mass of the substrate And controlling at least one of the processing in the process chamber and the operation of the transfer unit based on the mass measured by the measurement unit.

Preferably, the transfer section includes a load lock and a front chamber of the process chamber, and a stage of a mass meter constituting a measuring section is provided in the front chamber of the process chamber.

[0022]

(Embodiment 1) A method of manufacturing a semiconductor device according to Embodiment 1 of the present invention will be described with reference to a schematic process flow diagram of the process in FIG. 1 taking a dry etching process as an example.

First, as shown in FIG. 1, in the dry etching step of the present embodiment, an acceptance inspection 12 is performed on the semiconductor wafer which has been processed in the previous step 11 in the same manner as in the conventional example.
Then, the mass measurement 13 of the semiconductor wafer is performed by the mass meter. Next, dry etching processing 14 of the semiconductor wafer is performed by using a dry etching apparatus, and mass measurement 15 of the semiconductor wafer is performed on the processed semiconductor wafer by a mass meter. Evaluation 1 for confirming whether or not the treatment was performed normally using the measured mass value
6 is compared with the management standard value. Next, sampling inspection 1 by microscopic inspection and measurement of the remaining etching film
7 is also performed as needed, and those that pass these inspections are shipped to the post-process 18.

The management standard value used in the evaluation 16 is statistically determined in advance by an experiment using the mass of the processed semiconductor wafer, the amount of change in the mass, and the like. For example, 0.3μm diameter and 1.5 depth for contacting semiconductor substrate
In the case of a μm contact hole, when the etching stops halfway while leaving a film of about 100 nm at the bottom of the contact hole, the mask aperture ratio of the contact hole is 2% in a 300 mmφ semiconductor wafer, and the density of the remaining film is 2.2 g. / cm ³
Calculated as a silicon oxide film, the weight of the remaining film is about 310 mg per semiconductor wafer if the entire surface remains uniformly. Therefore, if the etching of only one third of the total area of the semiconductor wafer is stopped halfway, the amount becomes about 103 mg. Judgment is performed by utilizing that these values become heavier than a semiconductor wafer that has been processed normally.

(Embodiment 2) Next, a semiconductor device manufacturing apparatus according to a second embodiment of the present invention will be described with reference to FIG. 2, which is a conceptual diagram showing the configuration of a semiconductor device manufacturing apparatus, using a dry etching apparatus as an example. explain. As shown in FIG. 2, the apparatus is the same as a conventional apparatus including a process chamber 21 for performing a dry etching process, a transfer unit 22 for a semiconductor wafer, a driving system 23, and a control unit 24 including various measuring devices. Including configuration. In addition to the above configuration,
A mass meter 25 capable of measuring the mass of the semiconductor wafer is incorporated in the semiconductor wafer transfer section 22. The transfer unit 22 includes a load lock 26 and a front chamber of the process chamber 21. In the front chamber of the process chamber 21, a stage (not shown) for positioning a semiconductor wafer and a stage of the mass meter 25 are provided. Numeral 27 indicates connection of information of the control unit.

Next, a dry etching process for a semiconductor wafer will be described by taking as an example the case where the dry etching apparatus is a single wafer type.

The semiconductor wafer to be loaded first passes through the load lock 26 and is placed in a vacuum in the front chamber of the process chamber 21. Next, it is conveyed to the stage of the mass meter 25 and the mass is measured. Next, it is conveyed to the positioning stage, and positioning is performed. Thereafter, the semiconductor wafer transferred to the process chamber 21 is processed under a predetermined etching condition. The etched semiconductor wafer is transferred to the stage of the mass meter 25 in the front chamber of the process chamber 21, and after the mass is measured, is unloaded via the load lock 26. The mass measured before and after the etching process is determined by a preset program of the control unit 24. For example, when an abnormality is detected, control according to the setting, such as taking an action to immediately stop the process, is performed. Done.

According to the above-described embodiment, dry etching of contact holes of unspecified semiconductor wafers in a lot stops halfway, and it is possible to easily and non-destructively detect a defect in which a contact is not opened. It becomes possible. In addition, since a single-wafer processing apparatus can promptly feed back a detection result, it is possible to prevent a series of failures due to a failure occurring during processing. In addition, mass measurement can be performed easily without troublesome operations such as alignment of measurement patterns, which reduces the work of measurement and maintenance personnel and shortens the time required for measurement. Process management for each wafer by 100% measurement is also facilitated.

In the above-described embodiment, the case of dry etching has been described as an example. However, in the processing of various semiconductor wafers such as film formation and CMP, the processing shape, film thickness, etc. are required in advance. The method for manufacturing a semiconductor device and the apparatus for manufacturing a semiconductor device according to the present invention can be applied so as to perform simple and effective management by taking a correlation between the parameter and the mass.

Further, the present invention is applicable not only to the manufacture of a semiconductor device using a substrate other than a semiconductor, such as a liquid crystal display device in which a thin film transistor or the like is formed on a glass substrate, but also to the semiconductor wafer described above. Can be applied.

[0031]

According to the method for manufacturing a semiconductor device and the apparatus for manufacturing a semiconductor device of the present invention, various processes for processing a semiconductor wafer can be efficiently managed by simple means.
And it can be performed effectively. In addition, it is possible to easily detect variations between semiconductor wafers from a macro viewpoint, and it becomes easy to manage each semiconductor wafer by measuring all the wafers, greatly contributing to more efficient and stable semiconductor device manufacturing. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic process flow chart of steps showing a method for manufacturing a semiconductor device according to a first embodiment of the present invention;

FIG. 2 is a conceptual diagram showing a configuration of a semiconductor device manufacturing apparatus according to a second embodiment of the present invention.

FIG. 3 is a schematic process flow diagram showing steps of a conventional method for manufacturing a semiconductor device.

FIG. 4 is a conceptual diagram showing a configuration of a conventional semiconductor device manufacturing apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 pre-process 12 acceptance inspection 13 mass measurement 14 dry etching treatment 15 mass measurement 21 process chamber 22 semiconductor wafer transfer unit 23 driving system 24 control unit 25 mass scale 26 load lock 27 connection of information of control unit

Claims (6)

[Claims] In at least a part of a step of performing various processes on a substrate, a mass of the substrate is measured before or after a unit process, and the process is managed based on the measured mass. Manufacturing method of a semiconductor device. 2. The method according to claim 2, wherein the mass measured for the processed substrate is compared with a control standard value to evaluate whether the substrate has been processed normally, and the process is managed based on the evaluation result. A method for manufacturing a semiconductor device according to claim 1. 3. The semiconductor device according to claim 2, wherein the management standard value is statistically determined in advance by an experiment using the mass of the processed substrate, the amount of change in the mass, and the like. Production method. 4. A processing unit for performing at least one type of processing on a substrate in a semiconductor device manufacturing process, a measuring unit for measuring a mass of the substrate, and the processing unit based on the mass measured by the measuring unit. And a control unit for controlling the operation of the semiconductor device. 5. A process chamber for processing a substrate, a transport unit for transporting the substrate, a control unit for controlling the process chamber and the transport unit, and a mass meter for measuring the mass of the substrate. And a measuring unit having at least one of a process in the process chamber and an operation of the transfer unit based on the mass measured by the measuring unit.
5. The semiconductor device manufacturing apparatus according to claim 1. 6. The transfer section includes a load lock and a front chamber of a process chamber, and a stage of a mass meter constituting the measuring section is provided in the front chamber of the process chamber. 6. The apparatus for manufacturing a semiconductor device according to item 5.