JP2005175122A - Semiconductor manufacturing apparatus and manufacturing method of semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor manufacturing apparatus and a manufacturing method of a semiconductor device capable of detecting insulation breakdown of a substrate support even during a film forming processing and forming a film with high reliability. <P>SOLUTION: A plasma CVD apparatus is provided with a current detecting unit 17 for measuring a current of a lower electrode 12 located in a control device DET. The current detecting unit 17 always monitors a current flowing through the lower electrode 12 during a plasma processing at all times to detect an overcurrent caused when insulation breakdown takes place. Thus, the current detecting unit 17 momentarily detects the occurrence of the insulation breakdown even when the insulation breakdown of the lower electrode 12 takes place during the processing of a semiconductor substrate WF wherein plasma is generated. Further, an insulation film is formed (coated) on the surface of the lower electrode 12 by a prescribed thickness in order to prevent the insulation breakdown of the lower electrode 12 or in order to recover the lower electrode 12 when the insulation breakdown takes place in the lower electrode 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a film forming process of a semiconductor substrate, and more particularly, to a semiconductor manufacturing apparatus and a semiconductor device manufacturing method that take measures against an insulation maintaining method of a single-wafer type plasma CVD apparatus.

  Plasma CVD (Chemical Vapor Deposition) is one of thin film forming methods, in which a reactive gas is placed in a plasma environment and a film is deposited on the surface of a semiconductor substrate. In LSI manufacturing, it is widely applied mainly to the formation of insulating films and has become an important technology. In order to improve the uniformity of film formation, the support mechanism of the semiconductor substrate is important. A support mechanism for a semiconductor substrate is required to have high adhesion to the substrate, temperature controllability of the substrate, durability against plasma, and the like.

  An electrostatic chuck has high adhesion performance, excellent thermal conductivity, and durability as a support mechanism for a semiconductor substrate. An electrostatic chuck is a DC voltage applied between an insulating layer on which a semiconductor substrate is placed and an electrode embedded in the insulating layer, and is applied between the insulating layer and the opposite substrate, and is attracted by Coulomb force and minute leakage current. Generate power. A ceramic material such as aluminum oxide is generally used as the insulating layer.

Ceramics are particularly excellent in thermal conductivity and plasma resistance. However, since the material is hard, it is difficult to adapt to the substrate. There is a risk that dielectric breakdown may also occur due to generation of scratches and other cracks related to substrate transportation, and there is a concern about gate element breakdown of the semiconductor substrate during processing. On the other hand, in order to reduce contact thermal resistance, a technique using a viscous fluid or a low hardness gel-like substance as an insulating layer of an electrostatic chuck is also disclosed (for example, see Patent Document 1).
JP 2002-60020 A (Page 5, FIG. 1)

  When dielectric breakdown occurs in the support portion of the semiconductor substrate, an overcurrent is generated in the substrate, causing breakdown of devices such as a gate insulating film. By using the support portion having the insulating layer disclosed in [Patent Document 1], it is possible that dielectric breakdown is less likely to occur, but it cannot be said that there is nothing at all. That is, the prior art cannot immediately detect the dielectric breakdown of the support portion of the semiconductor substrate. When a plurality of semiconductor substrates are processed without knowing the dielectric breakdown, there is a possibility that a product having a high possibility of including the device breakdown may be produced in large quantities.

  The present invention has been made in consideration of the above-described circumstances. A semiconductor manufacturing apparatus and a semiconductor capable of detecting a dielectric breakdown of a substrate support portion even during a film forming process and capable of forming a highly reliable film. It is an object of the present invention to provide a device manufacturing method.

  A semiconductor manufacturing apparatus according to the present invention includes a first electrode on which an object to be processed is placed and a second electrode facing the first electrode, and a high electric field is applied between the first and second electrodes and a reactive gas. Is supplied to generate a plasma of the reactive gas, and a control mechanism that monitors the current flowing through the first electrode and detects an abnormality.

  According to the semiconductor manufacturing apparatus of the present invention, the control mechanism monitors the current flowing through the first electrode and detects an abnormality. Specifically, an overcurrent is detected when the first electrode breaks down. Such detection is possible during the process in which plasma is generated, process abnormality can be detected in real time, and the influence on the object to be processed can be limited to the current process.

  The semiconductor manufacturing apparatus according to the present invention further includes a mechanism for forming an insulating film on the first electrode. Alternatively, a mechanism for forming an insulating film on the first electrode according to the control mechanism is further included. This contributes to prevention or repair of dielectric breakdown of the first electrode.

  In the semiconductor manufacturing apparatus according to the present invention, a first electrode on which a semiconductor substrate is supported, a second electrode facing the first electrode, and a reactive gas is supplied between the first electrode and the second electrode. A process chamber for generating a plasma of the reactive gas by a high electric field and forming an insulating film on at least the semiconductor substrate; and a detector for monitoring a current flowing through the first electrode and determining at least a dielectric breakdown; The insulating film is coated on the surface of the first electrode to prevent the dielectric breakdown.

  According to the semiconductor manufacturing apparatus of the present invention, the detector is always monitored for the presence or absence of dielectric breakdown of the first electrode during the plasma generation process. Processing abnormality can be detected in real time, and the influence on the semiconductor substrate can be limited to one currently being processed. In addition, an insulating film is coated on the surface of the first electrode to prevent breakdown, thereby improving reliability.

  In the semiconductor manufacturing apparatus according to the present invention, a first electrode on which a semiconductor substrate is supported, a second electrode facing the first electrode, and a reactive gas is supplied between the first electrode and the second electrode. A process chamber for generating a plasma of the reactive gas by a high electric field and forming an insulating film on at least the semiconductor substrate; and a detector for monitoring a current flowing through the first electrode and determining at least a dielectric breakdown, The insulating film is coated on the surface of the first electrode according to the determination result of the detector.

  According to the semiconductor manufacturing apparatus of the present invention, the detector is always monitored for the presence or absence of dielectric breakdown of the first electrode during the plasma generation process. Processing abnormality can be detected in real time, and the influence on the semiconductor substrate can be limited to one currently being processed. In addition, the first electrode has a dielectric breakdown repair function for coating the surface of the first electrode with an insulating film according to the determination result of the detector. Contributes to improved reliability.

  In the method for manufacturing a semiconductor device according to the present invention, a semiconductor substrate is placed on a first electrode in a processing chamber, a high electric field is applied between the opposing second electrode, and the plasma of the reactive gas is supplied by the supplied reactive gas. A plasma processing step of forming at least an insulating film on the semiconductor substrate, a current detection step of monitoring a current flowing through the first electrode during the plasma processing step, and placing the semiconductor substrate in the processing chamber Generating a plasma of the reactive gas in the processing chamber before carrying in, and forming at least the insulating film with a predetermined thickness on the first electrode.

  According to the semiconductor device manufacturing method of the present invention, the current flowing through the first electrode is monitored by the current detection step during the plasma processing step. Specifically, an overcurrent is detected when the first electrode breaks down. Processing abnormality can be detected in real time, and the influence on the semiconductor substrate can be limited to one currently being processed. In addition, before carrying the semiconductor substrate into the processing chamber, an insulating film having a predetermined thickness is formed on the first electrode by generating plasma of a reactive gas in the processing chamber in advance. This contributes to prevention of dielectric breakdown of the first electrode.

  In the method for manufacturing a semiconductor device according to the present invention, a semiconductor substrate is placed on a first electrode in a processing chamber, a high electric field is applied between the opposing second electrode, and the plasma of the reactive gas is supplied by the supplied reactive gas. A plasma processing step of forming at least an insulating film on the semiconductor substrate, a current detection step of monitoring a current flowing through the first electrode during the plasma processing step, and a dielectric breakdown by the current detection step When a corresponding abnormality is detected, before the next semiconductor substrate to be processed is carried into the processing chamber, plasma of the reactive gas is generated in the processing chamber, and at least the dielectric breakdown is eliminated on the first electrode. Forming the insulating film having a thickness to be formed.

  According to the semiconductor device manufacturing method of the present invention, the current flowing through the first electrode is monitored by the current detection step during the plasma processing step. Specifically, an overcurrent is detected when the first electrode breaks down. Processing abnormality can be detected in real time, and the influence on the semiconductor substrate can be limited to one currently being processed. In addition, when an abnormality corresponding to dielectric breakdown is detected by the current detection process, dielectric breakdown is caused on the first electrode by plasma generation of a reactive gas in the processing chamber before the semiconductor substrate to be processed next is carried into the processing chamber. An insulating film having a thickness that eliminates the above is formed. This contributes to the dielectric breakdown repair of the first electrode.

  Each of the semiconductor device manufacturing methods according to the present invention includes a plasma cleaning step of performing dry cleaning of the processing chamber in a stage before the step of forming the insulating film on the first electrode. It is useful to form an insulating film over the first electrode after cleaning the processing chamber.

BEST MODE FOR CARRYING OUT THE INVENTION

  1, FIG. 2 and FIG. 3 are schematic diagrams showing the main part of a plasma CVD apparatus, which is a semiconductor manufacturing apparatus according to the first embodiment of the present invention. The processing chamber 11 has an exhaust port 14 in which an upper electrode 13 is disposed so as to face the lower electrode 12 and the lower electrode 12 and is evacuated. Although not shown, the inner wall of the processing chamber 11, the lower electrode 12 and the upper electrode 13 are coated with an insulating film such as aluminum oxide. For example, a semiconductor substrate WF is placed on the lower electrode 12 as an object to be processed, and the semiconductor substrate is supported by an electrostatic chuck. The upper electrode 13 has a plurality of pinholes (not shown) and supplies the reaction gas into the processing chamber 11 in the form of a shower. The high frequency power supply 16 applies a high electric field between the upper electrode 13 and the lower electrode 12 via the matching circuit 15. Thereby, plasma of the reactive gas supplied into the processing chamber 11 is generated.

  Further, a current detector 17 for measuring the current of the lower electrode 12 is provided in the control mechanism DET. The current detector 17 constantly monitors the current flowing through the lower electrode 12 during plasma processing. In the current detector 17, an upper limit value of the current flowing through the lower electrode 12 is determined, and an overcurrent generated when the dielectric breakdown occurs is detected. Thereby, even if the dielectric breakdown of the lower electrode 12 occurs during the processing of the semiconductor substrate WF in which plasma is generated, the current detector 17 detects instantaneously. The control unit 18 receives at least an overcurrent detection from the current detector 17 and determines whether to stop the plasma processing, carry out the semiconductor substrate being processed at that time, or stop carrying in the semiconductor substrate to be processed next. To do.

  Further, as shown in FIG. 2, the plasma CVD apparatus has a mechanism for coating the surface of the lower electrode 12 with the insulating film 19. The coating of the insulating film 19 on the lower electrode 12 may be performed by the action of the control mechanism DET included in the control unit 18. The insulating film 19 is formed (coated) on the surface of the lower electrode 12 by a predetermined thickness for preventing the dielectric breakdown of the lower electrode 12 or for repairing when the lower electrode 12 has caused the dielectric breakdown. The The insulating film 19 conforms to the formation of the insulating film in this plasma CVD apparatus. For example, if this plasma CVD apparatus is used as an apparatus for forming a silicon oxide film, the surface of the lower electrode 12 is coated with a silicon oxide film. If it is a silicon oxide film, having a thickness of about 0.4 μm is effective for preventing dielectric breakdown of the lower electrode 12 or for repairing dielectric breakdown. If the thickness of the insulating film 19 is large, the useful life is extended, but there is a risk of cracking due to the influence of thermal contraction. For this reason, the thickness of the insulating film 19 needs an appropriate limit according to the member.

  FIG. 3 shows a form in which the semiconductor substrate WF is supported and plasma-processed on the lower electrode 12 coated with the insulating film 19 for preventing or repairing the breakdown of the lower electrode 12. The lower electrode 12 is less susceptible to dielectric breakdown than the uncoated insulating film 19. Further, since the current detector 17 is provided, the current flowing through the lower electrode 12 is constantly monitored during the plasma processing. Thereby, even if the lower electrode 12 breaks down, the current detector 17 can quickly detect it.

  According to the configuration of the above-described embodiment, the control mechanism DET has a form in which the presence or absence of dielectric breakdown of the lower electrode 12 is constantly monitored by the current detector 17 during the process of generating plasma in the processing chamber 11. That is, if the lower electrode 12 breaks down, an abnormality can be detected in real time due to the occurrence of overcurrent. Thereby, the influence on the semiconductor substrate WF can be limited to only one currently being processed. That is, a plurality of semiconductor substrates are not processed without knowing the dielectric breakdown of the lower electrode 12, and a product that is likely to include device breakdown inside the semiconductor substrate is not produced in large quantities.

  In addition, the reliability of the plasma treatment can be improved by having a mechanism for coating the surface of the lower electrode 12 with the insulating film 19 for preventing or repairing the breakdown of the lower electrode 12. Note that the insulating film 19 is not limited to a silicon oxide film, but is matched with an insulating film formed by a plasma CVD apparatus. Therefore, it can be a silicon nitride film or other insulating film.

  FIG. 4 is a flowchart showing the main part of the method of manufacturing a semiconductor device according to the second embodiment of the present invention in the order of steps. A description will be given with reference to any of FIGS. Regarding film formation processing of an insulating film (for example, silicon oxide film) in a plasma CVD apparatus, a pre-coating process is performed in a clean processing chamber 11 before a semiconductor substrate to be processed is loaded (processing S11). In this pre-coating process, plasma of a reactive gas for forming the insulating film (silicon oxide film) is generated in the processing chamber 11, and at least an insulating film is formed on the lower electrode 12 with a predetermined thickness (see FIG. 2). An insulating film 19).

  Next, the semiconductor substrate WF to be processed is loaded. The semiconductor substrate WF is placed on the lower electrode 12 coated with the precoat, that is, the insulating film 19, and supported by the electrostatic chuck (processing S12). Thereafter, plasma of a reactive gas for forming the insulating film (silicon oxide film) is generated in the processing chamber 11 (see FIG. 3), and at least an insulating film is formed on the semiconductor substrate WF with a predetermined thickness (processing). S13). For example, the same insulating film as the insulating film 19 is formed on the semiconductor substrate WF. During this plasma processing step, the current flowing through the lower electrode 12 is monitored by the operation of the control mechanism DET in FIG. 3 (processing S14).

  In the process S14 including the current detection process of the lower electrode 12, for example, when an abnormality (overcurrent) is determined, unique information of the semiconductor substrate WF that has been processed is stored and an abnormality determination count is added. If the continuous abnormality or abnormality frequency following the previously processed semiconductor substrate WF exceeds a specified value, measures such as processing stop are taken into consideration and the necessity for maintenance, parts replacement, etc. is taken into consideration.

  Next, the semiconductor substrate WF on which film formation has been completed is carried out of the processing chamber (processing S15). If it is a semiconductor substrate WF affected by the abnormality of the lower electrode 12, it can be considered to be handled as a defect or sent to a strict investigation. Next, dry cleaning is performed in the processing chamber 11 to clean it (processing S16). As the dry cleaning, for example, two stages of plasma cleaning with a dummy substrate (not shown) placed on the lower electrode 12 and plasma cleaning without a dummy substrate can be considered. For such plasma cleaning, it is conceivable to use a cleaning gas as required, such as fluorine-based, chlorine-based other reactive gas, inert gas, or the like. Thereafter, the process proceeds to a precoat process. That is, in this embodiment, even if no abnormality such as dielectric breakdown of the lower electrode 12 is recognized, a precoat process is performed before the next semiconductor substrate WF to be processed is loaded (processing S11).

  According to the method of the above-described embodiment, whether or not there is an abnormality (overcurrent) in the current flowing through the lower electrode 12 is constantly monitored by the current detection step during the plasma processing step. In addition, before the film formation process on the semiconductor substrate WF, an insulating film having a predetermined thickness is pre-coated on the lower electrode by generating plasma of a reactive gas in the processing chamber 11. Thereby, the dielectric breakdown of the lower electrode 12 hardly occurs, and high reliability can be obtained. Further, even if dielectric breakdown occurs in the lower electrode 12, it is possible to limit the influence on the semiconductor substrate WF to one currently being processed.

  FIG. 5 is a flowchart showing the main part of the method of manufacturing a semiconductor device according to the third embodiment of the present invention in the order of steps. A description will be given with reference to any of FIGS. A semiconductor substrate to be processed is carried into a film forming process of an insulating film (for example, a silicon oxide film) in a plasma CVD apparatus. That is, the semiconductor substrate WF is placed on the lower electrode 12 and supported by the electrostatic chuck (processing S21). Thereafter, plasma of a reactive gas for forming the insulating film (silicon oxide film) is generated in the processing chamber 11 (see FIG. 1), and at least an insulating film is formed on the semiconductor substrate WF with a predetermined thickness (processing). S22). During this plasma processing step, the current flowing through the lower electrode 12 is monitored by the action of the control mechanism DET in FIG. 3 (processing S23).

  In the process S23 including the current detection step of the lower electrode 12, for example, at the time of abnormality (overcurrent) determination, the unique information of the semiconductor substrate WF that has been processed is stored and the abnormality determination count is added. If the continuous abnormality or abnormality frequency following the previously processed semiconductor substrate WF exceeds a specified value, measures such as processing stop are taken into consideration and the necessity for maintenance, parts replacement, etc. is taken into consideration.

  Even if the abnormality determination of the lower electrode 12 is received, if it does not correspond to the above-mentioned continuous abnormality or abnormality of abnormality frequency, the processes after the process S34 are performed. That is, the semiconductor substrate WF that has been deposited is carried out of the processing chamber (processing S34). Since this is the semiconductor substrate WF affected by the abnormality of the lower electrode 12, it can be considered to be handled as a defect or to be strictly investigated. Next, dry cleaning is performed in the processing chamber 11 to clean it (processing S35). Next, a repair coating process is performed in the clean process chamber 11 (process S36). In this repair coating process, plasma of a reactive gas for forming the insulating film (silicon oxide film) is generated in the processing chamber 11 to form at least an insulating film on the lower electrode 12 with a predetermined thickness (FIG. 2). Reference: insulating film 19). After such a process, the process proceeds to a process for carrying in the semiconductor substrate WF to be processed next (process S21).

  On the other hand, when no abnormality (dielectric breakdown) is observed in the lower electrode 12, the process is performed after the process S24. That is, the semiconductor substrate WF that has been deposited is carried out of the processing chamber (processing S24). Next, dry cleaning is performed in the processing chamber 11 to clean it (processing S25). After such a process, the process proceeds to a process for carrying in the semiconductor substrate WF to be processed next (process S21).

  As for the dry cleaning in the processing chamber 11, the same conditions as the processing S16 in the second embodiment may be used for the processing S35. However, with regard to the processing S25, plasma cleaning is performed mainly by placing a dummy substrate (not shown) on the lower electrode 12. In addition, after the repair coating process of the process S36 is performed, it is conceivable that the execution of maintenance, parts replacement, and the like is performed as soon as the lot of semiconductor substrates being processed is completed. Or you may make it determine the time of maintenance, parts replacement, etc. in consideration of the implementation frequency of a restoration coating process.

  According to the method of the above-described embodiment, whether or not there is an abnormality (overcurrent) in the current flowing through the lower electrode 12 is constantly monitored by the current detection step during the plasma processing step. When an abnormality (dielectric breakdown) is observed in the lower electrode 12, an insulating film having a predetermined thickness is coated on the lower electrode 12 by generating a reactive gas plasma in the processing chamber 11. Thereby, the dielectric breakdown part of the lower electrode 12 is repaired, and the reliability of the subsequent film formation process can be maintained. Further, even if dielectric breakdown occurs in the lower electrode 12, it is possible to limit the influence on the semiconductor substrate WF to one currently being processed.

  As described above, according to the configuration and method of the present invention, the control mechanism including the current detector for the lower electrode is provided in the plasma CVD apparatus for forming the insulating film. Thereby, during the film forming process in which plasma is generated in the processing chamber, the current of the lower electrode is monitored, and the presence or absence of dielectric breakdown can be grasped in real time. This makes it possible to limit the influence on the semiconductor substrate WF to only one currently being processed. That is, a plurality of semiconductor substrates are not processed without knowing the dielectric breakdown of the lower electrode, and products that are likely to include device breakdown inside the semiconductor substrate are not produced in large quantities. In addition, it has a mechanism for pre-coating or coating an insulating film on the surface of the lower electrode for preventing breakdown of the lower electrode or repairing dielectric breakdown. That is, by incorporating a process for avoiding the dielectric breakdown of the lower electrode, the reliability of the plasma processing can be improved. As a result, it is possible to provide a semiconductor manufacturing apparatus and a semiconductor device manufacturing method capable of detecting a dielectric breakdown of the substrate support portion even during the film forming process and capable of highly reliable film formation.

The 1st schematic block diagram which shows the principal part of the semiconductor manufacturing apparatus which concerns on 1st Embodiment. The 2nd schematic block diagram which shows the principal part of the semiconductor manufacturing apparatus which concerns on 1st Embodiment. The 3rd schematic block diagram which shows the principal part of the semiconductor manufacturing apparatus which concerns on 1st Embodiment. 9 is a flowchart showing a main part of a method of manufacturing a semiconductor device according to a second embodiment in the order of steps. 9 is a flowchart showing a main part of a method for manufacturing a semiconductor device according to a third embodiment in the order of steps.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Processing chamber, 12 ... Lower electrode, 13 ... Upper electrode, 14 ... Exhaust port, 15 ... Matching circuit, 16 ... High frequency power supply, 17 ... Current detector, 18 ... Control part, 19 ... Insulating film, DET ... Control mechanism , WF... Semiconductor substrate, S11 to S16, S21 to S25, S34 to S36.

Claims (8)

A first electrode on which an object to be processed is placed and a second electrode facing the first electrode, a high electric field is applied between the first and second electrodes, and a reaction gas is supplied to the plasma of the reaction gas. A processing chamber in which is generated,
A control mechanism for monitoring the current flowing through the first electrode and detecting an abnormality;
A semiconductor manufacturing apparatus including: The semiconductor manufacturing apparatus according to claim 1, further comprising a mechanism for forming an insulating film on the first electrode. The semiconductor manufacturing apparatus according to claim 1, further comprising a mechanism for forming an insulating film on the first electrode in accordance with the control mechanism. A first electrode on which a semiconductor substrate is supported;
A second electrode facing the first electrode;
A processing chamber in which a reactive gas is supplied and a plasma of the reactive gas is generated by a high electric field applied between the first electrode and the second electrode, and at least an insulating film is formed on the semiconductor substrate;
A detector for monitoring the current flowing through the first electrode and determining at least a dielectric breakdown;
Including
A semiconductor manufacturing apparatus for coating the surface of the first electrode with the insulating film for preventing the dielectric breakdown. A first electrode on which a semiconductor substrate is supported;
A second electrode facing the first electrode;
A processing chamber in which a reactive gas is supplied and a plasma of the reactive gas is generated by a high electric field applied between the first electrode and the second electrode, and at least an insulating film is formed on the semiconductor substrate;
A detector for monitoring the current flowing through the first electrode and determining at least a dielectric breakdown;
Including
The semiconductor manufacturing apparatus which coats the said insulating film on the said 1st electrode surface according to the determination result of the said detector. In the processing chamber, a semiconductor substrate is placed on the first electrode, a high electric field is applied between the opposing second electrode, plasma of the reactive gas is generated by the supplied reactive gas, and at least on the semiconductor substrate A plasma treatment process for forming an insulating film;
A current detection step of monitoring a current flowing through the first electrode during the plasma treatment step;
Generating a plasma of the reaction gas in the processing chamber before carrying the semiconductor substrate into the processing chamber, and forming at least the insulating film on the first electrode to a predetermined thickness;
A method of manufacturing a semiconductor device including: In the processing chamber, a semiconductor substrate is placed on the first electrode, a high electric field is applied between the opposing second electrode, plasma of the reactive gas is generated by the supplied reactive gas, and at least on the semiconductor substrate A plasma treatment process for forming an insulating film;
A current detection step of monitoring a current flowing through the first electrode during the plasma treatment step;
When an abnormality corresponding to dielectric breakdown is detected by the current detection step, before the semiconductor substrate to be processed next is carried into the processing chamber, plasma of the reaction gas is generated in the processing chamber, and the first electrode is generated. Forming the insulating film having a thickness that eliminates at least the dielectric breakdown;
A method of manufacturing a semiconductor device including: 8. The method of manufacturing a semiconductor device according to claim 6, further comprising a plasma cleaning step of performing dry cleaning in the processing chamber before the step of forming the insulating film on the first electrode.

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