JP5016810B2 - Catalytic chemical vapor deposition apparatus, chemical vapor deposition method using this apparatus, and self-cleaning method for this apparatus - Google Patents

Description

  The present invention relates to a catalytic line chemical vapor deposition apparatus (hereinafter referred to as a catalytic CVD apparatus), a chemical vapor deposition method using this apparatus, and a self-cleaning method for this apparatus, and in particular, generates a potential difference between catalytic lines. The present invention relates to a catalytic CVD apparatus provided with an external power supply circuit, a chemical vapor deposition method using this apparatus, and a self-cleaning method for this apparatus.

  The conventional catalytic CVD apparatus uses a single catalyst wire and does not have an external power supply circuit other than an energizing power supply circuit for heating the catalyst wire, or is electrically insulated from the catalyst wire. Since a direct-current or high-frequency voltage is applied to the chamber from the outside, there is a problem of danger of arc discharge and damage to the substrate due to plasma.

For example, a direct-current voltage is applied between the catalyst line and the substrate to accelerate the deposition species (see, for example, Patent Document 1), or an RF voltage is applied between the catalyst line and the substrate to generate plasma. There is known a catalytic CVD apparatus (see Patent Document 2, for example). In the case of these devices, there is a risk that the substrate may be damaged.
JP 2000-223421 A (Claims etc.) JP 2003-347224 A (Claims and FIG. 1 etc.)

  An object of the present invention is to solve the above-described problems of the prior art. A potential difference is generated between a plurality of catalyst wires arranged on the upper part of the substrate, and the film formation speed is improved by using the potential difference. The present invention also provides a catalytic CVD apparatus capable of reducing damage to the substrate, a chemical vapor deposition method using this apparatus, and a self-cleaning method for this apparatus.

The catalytic CVD apparatus of the present invention includes a film forming chamber having a gas introduction system and an exhaust system, a plurality of catalyst wires arranged in the film forming chamber , a power supply for energizing each catalyst wire, and each catalyst wire. different voltage is applied to the difference potential difference of the applied voltage, characterized in that to obtain Bei an external power source circuit that generates between the catalyst line.

  The plurality of catalyst wires are arranged in parallel to the surface of the substrate placed in the film forming chamber.

  The plurality of catalyst wires are also concentric with a concentric circle shape or a concentric polygon shape with respect to the center of the substrate placed in the film forming chamber, and are arranged parallel to the substrate surface. Features. Thus, by making it a concentric shape, it is easy to make uniform the physical property and thickness distribution of the film | membrane to form.

  The plurality of catalyst wires are parallel to the surface of the substrate placed in the film forming chamber, and the catalyst wires are arranged so as to intersect with each other, and are arranged in a mesh shape. It is preferable.

  As described above, the intended purpose can be achieved by arranging a plurality of catalyst wires in a concentric shape and alternately generating a potential difference between the inner periphery and the outer periphery or from the inner side to the outer side. Moreover, the intended purpose can be achieved by arranging a plurality of catalyst wires in parallel as described above and alternately generating a potential difference between the parallel catalyst wires. Furthermore, the intended purpose can be achieved by generating a potential difference between the horizontally arranged and vertically arranged catalyst wires.

  The catalyst wire is preferably composed of at least one metal selected from W, Mo and Ta or an alloy containing at least one of these metals.

  The external power supply circuit is a power supply circuit composed of a power supply composed of a DC voltage power supply for external application, an AC voltage power supply for external application, or a combination of a DC voltage power supply for external application and an AC voltage power supply for external application. .

  The external power supply circuit is preferably connected between the catalyst wire and a power supply for energization, and further includes a power supply protection circuit.

  The catalytic CVD apparatus of the present invention is an apparatus that can be used for carrying out a method in which a raw material gas is brought into contact with each heated catalyst wire to be decomposed to form a thin film and can be self-cleaned. .

Chemical vapor deposition method of the present invention, allowed heating by passing a current from the current supply source to the catalytic wire of a plurality of catalytic wire disposed in the film-forming chamber of each catalytic wire to a predetermined temperature, the external power supply circuit A different voltage is applied to each catalyst line to generate a potential difference of the difference between the applied voltages between the catalyst lines, a film forming material is introduced into the film forming chamber, and brought into contact with the heated catalyst line. A film is formed on a substrate placed opposite to a plurality of catalyst wires.

  As the film forming raw material, a gas of at least one compound selected from silane, ammonia, hydrogen, nitric oxide, trimethylamine, trimethyldisilane, hexamethyldisilazane, and trisilylamine can be used.

The self-cleaning method of the catalytic CVD apparatus of the present invention is selected from nitrogen trifluoride, hydrogen fluoride, sulfur hexafluoride, carbon tetrafluoride and chlorine trifluoride as the self-cleaning gas in the film forming chamber. At least one halogen-containing gas is introduced, and a different voltage is applied to each catalyst line of the plurality of catalyst lines provided in the film formation chamber from the external power supply circuit, and a negative potential difference of the difference between the applied voltages Is generated between the catalyst wires to perform self-cleaning in the film formation chamber.

In the self-cleaning method, a different voltage is applied to each catalyst line of the plurality of catalyst lines provided in the film formation chamber from an external power supply circuit, and a negative potential difference of the applied voltage difference is applied between the catalyst lines. And at least one halogen-containing gas selected from nitrogen trifluoride, hydrogen fluoride, sulfur hexafluoride, carbon tetrafluoride and chlorine trifluoride as a self-cleaning gas in the film forming chamber. It may be introduced and self-cleaning in the film formation chamber may be performed.

  A halide gas containing the same metal as the catalyst component metal may be introduced instead of or together with the halogen-containing gas.

As described above, the negative potential difference of different voltages applied to the respective catalytic wire by generating between the catalytic wire, when performing self-cleaning, electronic exchange is performed between the catalytic wire, the catalytic wire Corrosion protection is possible.

  In the catalytic CVD apparatus of the present invention, the arrangement shape of the plurality of catalyst lines has a specific configuration, and an external power supply circuit that generates a potential difference between the catalyst lines is provided. In the film forming process using growth, the film forming speed can be improved, the substrate damage can be reduced, and the leakage current can be reduced.

  In addition, since the catalytic CVD apparatus of the present invention is configured as described above, by introducing a cleaning gas, self-cleaning in the film forming chamber is possible while preventing corrosion of the catalyst wire. There is an effect.

  In the catalytic CVD apparatus of the present invention, a plurality of catalyst wires are arranged in the film forming chamber, and an energizing power source is connected to each of the catalyst wires, and an external device connected between the catalyst wire and the energizing power source. Difference in voltage applied to each catalyst line by selected power supply circuit consisting of DC voltage power supply for application, AC voltage power supply for external application, and power supply that combines DC voltage power supply for external application and AC voltage power supply for external application The potential difference is generated between the catalyst wires.

  According to the present invention, since the external power supply circuit is provided as described above, the potential difference generated between the catalyst line and the catalyst line is used instead of the potential generated between the catalyst line and the chamber as in the prior art. There is provided a catalytic CVD apparatus capable of improving the deposition rate and reducing the damage to the substrate due to plasma or the like by generating a potential difference between the catalyst wires arranged on the upper part of the substrate. Can be provided.

  In the above apparatus, there is an advantage that any potential generated from a combination of direct current, alternating current, or direct current and alternating current can be used as a potential for generating a potential difference between the catalyst wires.

  In the catalytic CVD apparatus as described above, as long as a plurality of catalyst wires are configured so as to generate a potential difference between the catalysts as described above, the configuration is not limited, and the catalyst wires are arranged in any shape. For example, the following configurations are preferable.

  A process for forming a film using the catalytic CVD apparatus of the present invention will be briefly described below.

  A substrate is placed on a substrate stage in a film formation chamber of a catalytic CVD apparatus having a predetermined catalyst line arrangement shape, a direct current voltage of −200 to +200 V is applied to a plurality of catalyst lines arranged in the film formation chamber, −200 A voltage difference of a voltage difference applied to each catalyst wire is generated between the catalysts by applying an AC voltage of ~ + 200 V or a voltage obtained by combining a DC voltage of -200 to +200 and an AC voltage of -200 to +200 V, A gas is supplied into the film forming chamber, the source gas is brought into contact with a heated catalyst wire, the source gas is decomposed, and reacted on the substrate to form a desired thin film.

  The range of the applied voltage is preferably set for safety reasons when using the catalytic CVD apparatus of the present invention. That is, if a high voltage outside this range is applied, a discharge occurs in the device, and the possibility of a device failure increases. Within this applied voltage range, film formation suitable for the purpose can be performed in consideration of physical properties such as film formation speed, refractive index of the formed film, leakage current, and the like. This point will be specifically described below.

  As specifically shown in the following examples, as the applied voltage is sequentially changed from −200 V to +200 V, the film formation rate decreases sequentially, and within this range, about 23.6 to 13.7 nm / min. A film forming speed can be obtained. Therefore, the applied voltage can be selected as appropriate, and the film formation process can be performed in accordance with a desired film formation rate. For example, when the applied voltage is about −200 to +100 V, the film formation rate is 16 nm / min or more, and when the applied voltage is about −200 to +75 V, the film formation rate is 17 nm / min or more. In particular, the deposition rate can be improved by applying a negative voltage of 0 to -200 V to the catalyst wire.

  Further, the refractive index of the obtained film increases as the applied voltage is sequentially changed from −200 V to +200 V, and a refractive index of about 1.79 to 2.06 is obtained within this range. Accordingly, the applied voltage can be appropriately selected, and the film formation process can be performed so as to form a film having a desired refractive index. For example, if the applied voltage is about -20 to +200 V, the refractive index of the obtained film is 1.90 or more, and if the applied voltage is about +35 to +200 V, the refractive index of the film is 1.95 or more. . In particular, the refractive index of the obtained film can be improved by applying a positive voltage of 0 to +200 V to the catalyst wire.

  Further, as is apparent from the following examples, the leakage current increases when a negative voltage is applied, but the leakage current is suppressed when a positive voltage is applied. That is, when the voltage is 0 V or more, the leakage current is reduced, and preferably when a voltage of +20 V or more and +200 V or less is applied, more preferably +50 V or more and +200 V or less is applied, the leakage current is further reduced.

  In the chemical vapor deposition method of the present invention, it is possible to form a film having desired film characteristics by appropriately varying the voltage applied to the catalyst wire from the relationship between the refractive index, the film forming speed and the leakage current. Become. For example, in order to perform film formation that satisfies all three relationships of refractive index, film formation speed, and leakage current, the applied voltage is generally about 0 to +100 V, preferably about +20 to 100 V, and more preferably +50 to It is about +100.

  According to the present invention, by changing the voltage applied to each catalyst line, it becomes possible to control only the film formation speed and film quality of a predetermined portion on the substrate, so the film thickness distribution during film formation Can be controlled more accurately.

  Further, according to the present invention, the leakage current increases when a negative voltage is applied compared to when no voltage is applied to the catalyst wire from the outside, and the leakage current increases when a positive voltage is applied. It becomes possible to hold down the decrease. Therefore, according to the present invention, it is possible to reduce damage to the substrate due to thermoelectrons and obtain a desired thin film with higher quality.

Furthermore, the film that can be formed by the chemical vapor deposition method of the present invention is not particularly limited as long as it can be formed using a normal catalytic CVD apparatus. For example, a silicon nitride film (SiN _x film), amorphous A silicon film (a-Si film), a silicon oxide film (SiO _x film), a silicon oxynitride film (SiO _x N _y film), and the like can be given.

Generally, when a film is formed by a chemical vapor deposition reaction using a catalytic CVD apparatus, a film is also formed on the wall surface of the film forming chamber, the surface of the catalyst wire, or the surface of the component, and the efficiency of the catalyst wire is reduced. If it peels off, it causes the generation of particles. Therefore, it is necessary to clean the inside of the chamber at a constant cycle. However, according to the apparatus of the present invention, the self-cleaning in the film forming chamber can be easily performed by using the mechanism as it is without providing a new cleaning mechanism as in the case of a normal catalytic CVD apparatus. . Normally, in the case of a catalytic CVD apparatus, a cleaning gas such as NF ₃ is supplied to the energized catalyst line, and the film adhering to the wall surface is removed by self-cleaning without releasing the inside of the chamber to the atmosphere. Each time cleaning is performed, the catalyst wire itself is gradually scraped, and the thickness of the catalyst wire changes depending on the location, and the characteristics of the film to be formed change. Replacement is required. However, the apparatus of the present invention has an advantage that the problems of the prior art can be solved because the change in the catalyst itself can be suppressed by adjusting the potential difference generated between the catalyst lines and the self-cleaning can be performed.

Normally, during cleaning, a self-bias is generated (relative to the ground) depending on the type of atmospheric gas, and if a cleaning gas (for example, NF ₃ etc.) is present, the catalyst line potential is induced to the + side, so that the catalyst Corrosion such as scraping occurs. On the other hand, according to the self-cleaning method of the present invention, by applying a negative voltage of about −50 to −100 V to the catalyst line from the external power supply circuit at the time of self-cleaning, it is possible to prevent the catalyst line from being scraped. It becomes possible to prevent corrosion of the catalyst wire. As shown in the following examples, the amount of corrosion of the catalyst wire accompanying self-cleaning is higher when a positive potential difference is generated between the catalyst wires than when no voltage is applied from the outside. When a negative potential difference is generated, the amount of corrosion can be suppressed. Accordingly, a catalytic CVD apparatus provided with a plurality of catalysts having a specific catalyst line arrangement shape as in the present invention, and configured to generate a potential difference between the catalyst lines in the difference in voltage applied to each catalyst line from the external power supply circuit. In this case, corrosion of the catalyst wire due to the cleaning gas can be prevented during self-cleaning.

  In the self-cleaning method of the present invention, as described above, a halogen-containing gas such as nitrogen trifluoride and / or a halide gas containing the same metal as the catalyst component metal is introduced into the film forming chamber as the cleaning gas. Done. As the halide gas, for example, tungsten fluoride, molybdenum fluoride, tantalum fluoride, or the like can be used depending on the type of metal constituting the catalyst wire. Such halide gas is decomposed on the heated catalyst wire, and the liberated metal is combined with the catalyst wire metal.

  Hereinafter, examples of the arrangement shape of the catalyst wires arranged in the film forming chamber of the catalytic CVD apparatus of the present invention, as well as examples of the film forming method using this apparatus and the self-cleaning method of this apparatus will be described with reference to FIG. It demonstrates with reference to -14. 1 to 11, the same constituent elements are given the same reference numerals.

  The catalyst line arrangement shape shown in FIG. 1 is a set of different catalyst lines 2a and 2b connected to two heating power sources (catalyst line energization power source: constant current source) 1a and 1b, respectively. By applying a voltage from different externally applied DC voltage power supplies 3a and 3b, a device shape is generated that generates a potential difference of the difference between the voltages applied to the catalyst wires. In the figure, 4a and 4b are power supply protection circuits, and 5 is a substrate stage.

  The catalyst wire arrangement shape shown in FIG. 2 is a set of different catalyst wires 2a and 2b connected to two heating power sources (catalyst wire energization power source: constant current source) 1a and 1b, respectively. By applying a voltage from each of the different external application AC voltage power supplies 6a and 6b, a device shape is generated that generates a potential difference of the difference between the applied voltages between the catalyst wires. In the figure, 4a and 4b are power supply protection circuits, and 5 is a substrate stage.

  The catalyst line arrangement shape shown in FIG. 3 is between a pair of catalyst lines consisting of different catalyst lines 2a and 2b connected to two heating power sources (catalyst line energization power source: constant current source) 1a and 1b, respectively. By connecting an externally applied DC voltage power supply 3a, the apparatus is configured to generate a potential difference directly between the catalyst wires. In the figure, 4a and 4b are power supply protection circuits, and 5 is a substrate stage.

  The catalyst line arrangement shape shown in FIG. 4 is between a pair of catalyst lines composed of different catalyst lines 2a and 2b connected to two heating power sources (catalyst line energization power source: constant current source) 1a and 1b, respectively. By connecting an externally applied AC voltage power supply 6a, the apparatus is configured to generate a potential difference directly between the catalyst wires. In the figure, 4a and 4b are power supply protection circuits, and 5 is a substrate stage.

  The catalyst wire arrangement shape shown in FIG. 5 is a set of different catalyst wires 2a and 2b connected to two heating power sources (catalyst wire energization power source: constant current source) 1a and 1b, respectively. By applying a voltage from different external application DC voltage power supplies 3a and 3b, a potential difference of the difference between the voltages applied to the catalyst lines is generated, and further, an external application is applied to each of the catalyst lines 1a and 1b. It is the apparatus shape which applies a voltage from each of AC voltage power supply 6a and 6b. In the figure, 4a and 4b are power supply protection circuits, and 5 is a substrate stage.

  The catalyst wire arrangement shape shown in FIG. 6 is a set of different catalyst wires 2a and 2b connected to two heating power sources (catalyst wire energizing power source: constant current source) 1a and 1b, respectively. By applying a voltage from different AC voltage power supplies 3a and 3b for external application to each other, a potential difference of the difference between the voltages applied to the catalyst lines is generated, and further for external application to each of the catalyst lines 1a and 1b. This is a device shape in which a voltage is applied from each of the DC voltage power supplies 6a and 6b. In the figure, 4a and 4b are power supply protection circuits, and 5 is a substrate stage.

  The catalyst wire arrangement shape shown in FIG. 7 is between a pair of catalyst wires composed of different catalyst wires 2a and 2b connected to two heating power sources (catalyst wire energizing power source: constant current source) 1a and 1b, respectively. By connecting an external application DC voltage power supply 3a, a potential difference is directly generated between the catalyst wires, and an external application AC voltage power supply 6a is further applied to the voltage power supply 3a. In the figure, 4a and 4b are power supply protection circuits, and 5 is a substrate.

  The catalyst line arrangement shape shown in FIG. 8 is between a pair of catalyst lines consisting of different catalyst lines 2a and 2b connected to two heating power sources (catalyst line energization power source: constant current source) 1a and 1b, respectively. By connecting the external application AC voltage power supply 6a, a potential difference is directly generated between the catalyst wires, and the external application DC voltage power supply 3a is further applied to the voltage power supply 6a. In the figure, 4a and 4b are power supply protection circuits, and 5 is a substrate stage.

  FIG. 9 relates to the arrangement of the plurality of catalyst wires (1a and 1b in FIGS. 1 to 8) shown in Examples 1 to 8, and the inner periphery ( A configuration example of the catalyst wire arrangement shape arranged concentrically on 1a) and the outer periphery (1b in FIG. 9) is shown. Not only the arrangement of this shape but also a plurality of arrangements in a concentric circle shape with respect to the center of the substrate or a polygon shape having the same center may be employed. By disposing the potential difference between the inner periphery and the outer periphery or alternately from the inside to the outside, the intended purpose can be achieved.

  FIG. 10 shows a substrate on which two parallel catalyst wires are placed at the time of film formation with respect to the arrangement of the plurality of catalyst wires (1a and 1b in FIGS. 1 to 8) shown in Examples 1 to 8. An example of the configuration of the catalyst wire arrangement shape arranged at a predetermined distance from the surface of the substrate and parallel to the substrate surface is shown. This includes not only these two arrangements but also a state in which a larger number of catalyst wires are arranged in the same manner. By arranging in this way and alternately generating a potential difference between two catalyst wires or parallel catalyst wires, the intended purpose of uniformity of film thickness and membrane characteristics can be achieved.

  FIG. 11 shows the arrangement of a plurality of catalyst wires (1a and 1b in FIGS. 1 to 8) shown in Examples 1 to 8, and the two catalyst wires are placed at a predetermined distance from the surface of the substrate placed at the time of film formation. A configuration example of a catalyst line arrangement shape in which two catalyst lines are vertically separated from each other and separated is shown. Not only the arrangement of this shape but also a state in which a large number of catalyst wires are arranged in a mesh shape, and the intersecting state may be not perpendicular but intersected at a predetermined angle. By generating a potential difference between the catalyst lines arranged in this way (between the catalyst lines arranged in parallel or between the intersecting catalyst lines), the expected film thickness and membrane characteristics can be obtained. Can achieve the purpose.

Film formation was performed using a catalytic CVD apparatus provided with a plurality of catalyst wires configured to have the catalyst wire arrangement shape shown in FIG. A p-type Si substrate is placed on the substrate stage 5 as a substrate, SiH ₄ / NH ₃ / H ₂ is used as a source gas at a flow rate of 7/50/50 (sccm), and each catalyst wire composed of tungsten is used. A DC voltage of −200 to +200 V was applied in the same manner, and a SiN _x film was formed on the substrate under film forming process conditions: pressure 10 Pa, catalyst line temperature 1700 ° C., substrate temperature 300 ° C. FIG. 12 shows the influence of the film formation rate (nm / min) on the applied voltage and the refractive index of the obtained film.

  As is apparent from FIG. 12, when the applied voltage is sequentially changed within the range of −200 V to +200 V, the film formation rate decreases according to the change, and within this range, about 23.6 to 13.7 nm / min. A deposition rate was obtained. For example, if the applied voltage is about -200 to +100 V, the film forming rate is 16 nm / min or more, and if the applied voltage is about -200 to +75 V, the film forming speed is 17 nm / min or more and the applied voltage is -200 to 0 V. If it was set to about, a film formation rate of 19 nm / min or more was obtained. Therefore, the applied voltage can be selected as appropriate, and the film formation process can be performed in accordance with a desired film formation rate.

  Further, the refractive index of the obtained film increased as it was sequentially changed from −200 V to +200 V, and a refractive index of about 1.79 to 2.06 was obtained within this range. For example, when the applied voltage is about -20 to +200 V, a refractive index of 1.90 or more is obtained. When the applied voltage is about +35 to +200 V, a refractive index of 1.95 or more is obtained. Therefore, the applied voltage can be appropriately selected, and the film formation process can be performed so that a film having a desired refractive index can be obtained.

  The change in the deposition rate in FIG. 12 is the case where the same voltage is applied to each catalyst line. From this, it is possible to control only the film formation speed and film quality of a predetermined portion on the substrate by changing the voltage applied to each catalyst wire. The distribution can be controlled more precisely.

After performing the film formation process described in Example 12 using a catalytic CVD apparatus having a plurality of catalyst lines configured to have the catalyst line arrangement shape shown in FIG. The inside of the deposition chamber was self-cleaned, and the amount of catalyst wire scraped from tungsten was measured. This cleaning was performed using Ar gas and NF ₃ gas under conditions of a pressure of 60 Pa and a catalyst line temperature of 1900 ° C. In this case, for each catalyst line A and B (corresponding to 1a and 1b in FIG. 9), the catalyst line A when a voltage (DC) of ± 0 V is applied to the catalyst line A and +100 V is applied to the catalyst line B. And B, the amount of each of the catalyst lines A and B when a voltage of ± 0 V is applied to the catalyst line A and −50 V is applied to the catalyst line B, and the catalyst line A and B when no bias is applied. The amount of each B was measured.

  About the measurement result, the collapse amount (corrosion amount) of the tungsten (W) catalyst wire with respect to the cleaning time (0 to 20 minutes) is relatively compared and plotted in FIG. As is apparent from FIG. 13, the amount of corrosion of the catalyst wire due to self-cleaning is increased when a positive potential difference is generated between the catalyst wires, compared to the case where no voltage is applied from the outside. However, it is clear that the amount of corrosion is suppressed when a negative potential difference is generated.

  Therefore, by providing a plurality of catalyst wires having the catalyst wire arrangement shape as in the present invention, applying a voltage to each catalyst wire from the external power supply circuit and generating a potential difference between the applied voltages between the catalyst wires. It is possible to prevent the catalyst wire from being corroded during self-cleaning.

The film forming process described in Example 12 was performed using a catalytic CVD apparatus including a plurality of catalyst wires configured to have the catalyst wire arrangement shape shown in FIG. The voltage applied to the catalyst wire was −20 V, floating, ± 0 V, and +20 V, and a silicon nitride film was formed on the p-type Si substrate. For each applied voltage, the electric field was changed to around 0 to 10 mv / cm, and the current density (A / cm ² ) of the silicon nitride film was measured. The results are shown in FIG. 14 as current-voltage characteristics of the silicon nitride film.

Here, the floating (floating state) means a state in which a connection line for external application is not connected. Normally, when energized in a vacuum, ± 0 V and floating should be the same, but when a film forming gas such as SiH ₄ , NH ₃ , H ₂ or the like is flowed into the vacuum chamber, this gas and the catalyst Since electrons are exchanged with the line, even in a floating state, the state deviates from ± 0 V (for example, DC bias: about −2 V). This “deviation” is called self-bias. On the other hand, ± 0 V means a state where one of the terminals for energizing the catalyst wire is forcibly connected to the ground.

  As shown in FIG. 14, the leakage current increases when a negative voltage is applied compared to when no voltage is applied from the outside, but the leakage current can be suppressed when a positive voltage is applied. I understand that. That is, if the applied voltage is 0 V or more, the leakage current is reduced, and if the applied voltage is preferably +20 V or more, more preferably +50 V or more, the leakage current tends to be further reduced.

  Considering the experimental results regarding the film forming speed, refractive index and leakage current shown in the above examples, in the chemical vapor deposition method using the catalytic CVD apparatus of the present invention, the voltage applied to the catalyst wire is appropriately changed. It becomes possible to form a film having a desired refractive index at a desired film formation speed. For example, in order to perform film formation that satisfies all three relationships of refractive index, film formation speed, and leakage current, the applied voltage is generally about 0 to +100 V, preferably about +20 to 100 V, and more preferably +50 to It is about +100.

  As described above, according to the present invention, it is understood that it is possible to improve the deposition rate and reduce the damage to the substrate due to thermionic electrons, thereby obtaining a higher quality silicon nitride film.

  Since the catalytic CVD apparatus of the present invention has an arrangement of a plurality of catalyst lines in a specific shape and an external power supply circuit for generating a potential difference between the voltages applied to each catalyst line between the catalyst lines. In the film forming process using chemical vapor deposition using the apparatus, the film forming speed can be improved and the damage to the substrate can be reduced. In addition, the self-cleaning of the apparatus increases the cleaning rate, Corrosion of the catalyst wire can be prevented. Therefore, the apparatus, film forming method, and self-cleaning method of the present invention can be used for film forming technology in the semiconductor field.

Sectional drawing which shows typically 1st embodiment regarding the arrangement | positioning shape of the catalyst wire in the catalytic CVD apparatus of this invention. Sectional drawing which shows 2nd embodiment typically regarding the arrangement | positioning shape of the catalyst wire in the catalytic CVD apparatus of this invention. Sectional drawing which shows typically 3rd embodiment regarding the arrangement | positioning shape of the catalyst wire in the catalytic CVD apparatus of this invention. Sectional drawing which shows 4th Embodiment typically regarding the arrangement | positioning shape of the catalyst wire in the catalytic CVD apparatus of this invention. Sectional drawing which shows typically 5th embodiment regarding the arrangement | positioning shape of the catalyst wire in the catalytic CVD apparatus of this invention. Sectional drawing which shows typically 6th Embodiment regarding the arrangement | positioning shape of the catalyst wire in the catalytic CVD apparatus of this invention. Sectional drawing which shows typically 7th Embodiment regarding the arrangement | positioning shape of the catalyst wire in the catalytic CVD apparatus of this invention. Sectional drawing which shows typically 8th Embodiment regarding the arrangement | positioning shape of the catalyst wire in the catalytic CVD apparatus of this invention. The top view which shows typically one Embodiment of the arrangement | positioning shape seen from the upper surface regarding the arrangement | positioning shape of the catalyst wire in the catalytic CVD apparatus of this invention. The top view which shows typically another embodiment of the arrangement | positioning shape seen from the upper surface regarding the arrangement | positioning shape of the catalyst line in the catalytic CVD apparatus of this invention. The top view which shows typically another embodiment of the arrangement | positioning shape seen from the upper surface regarding the arrangement | positioning shape of the catalyst line in the catalytic CVD apparatus of this invention. The graph which shows the influence which it has on the refractive index of the film-forming speed | rate (nm / min) with respect to an applied voltage and the obtained film | membrane about the film | membrane obtained in Example 12. FIG. 14 is a graph in which the relative scraping amount of each catalyst wire by the applied voltage at the time of cleaning in Example 13 is plotted against the cleaning time. The current-voltage characteristic graph which shows the influence which it has on the tolerance of the film | membrane of the applied voltage at the time of forming a silicon nitride film on a board | substrate according to Example 14. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b Power supply for catalyst line energization 2a, 2b Catalyst line 3a, 3b DC voltage power supply for external application 4a, 4b Circuit for power supply protection 5 Substrate stage 6a, 6b AC voltage power supply for external application

Claims (15)

A deposition chamber having a gas introduction system and an exhaust system,
A plurality of catalytic wire disposed in said deposition chamber,
A power supply for energizing each catalyst wire;
Different voltages to each catalyst line is applied, the applied voltage catalytic wire chemical vapor deposition apparatus a potential difference of the differential, characterized in that to obtain Bei an external power source circuit that generates between the catalyst line.   2. The catalytic beam chemical vapor deposition apparatus according to claim 1, wherein the plurality of catalyst lines are arranged in parallel to a surface of a substrate placed in a film forming chamber. The plurality of catalyst wires are concentric with concentric circles or concentric polygons with respect to the center of the substrate placed in the film forming chamber, and are arranged in parallel with the substrate surface. The catalytic beam chemical vapor deposition apparatus according to claim 1 . Wherein the plurality of catalyst lines, a parallel to the surface of the substrate to be placed in the deposition chamber, and according to claim 1, a catalytic wire to each other, characterized in that it is arranged to cross Catalytic chemical vapor deposition system. It said catalyst lines, W, claim 1-4, characterized in that is obtained is composed of at least one kind of metal or alloy containing at least one of these metal selected from Mo and Ta 1 The catalytic wire chemical vapor deposition apparatus according to Item . The external power supply circuit is a power supply circuit including a DC voltage power source for external application, an AC voltage power source for external application, or a power source that combines a DC voltage power source for external application and an AC voltage power source for external application. The catalytic beam chemical vapor deposition apparatus according to any one of claims 1 to 5 . The external power supply circuit, a catalytic wire CVD apparatus according to any one of claims 1 to 6, characterized in that connected between the current supply source and said catalytic wire. The catalytic external chemical vapor deposition apparatus according to any one of claims 1 to 7 , wherein the external power supply circuit includes a power supply protection circuit. 9. The catalyst line chemical vapor deposition apparatus according to any one of claims 1 to 8 , wherein the catalyst line chemical vapor deposition apparatus is an apparatus for bringing a heated gas line into contact with a source gas to decompose and form a thin film. The catalytic line chemical vapor deposition apparatus described. The catalytic wire CVD apparatus, the catalytic wire CVD apparatus according to any one of claims 1 to 8, characterized in that an apparatus capable of performing a self-cleaning. By flowing a current from the current supply source to the catalytic wire of a plurality of catalytic wire disposed in the film-forming chamber allowed heat the catalytic wire to a predetermined temperature, by applying a different voltage from the external power supply circuit to each catalytic wire Then, a potential difference of the difference between the applied voltages is generated between the catalyst wires, the film forming raw material is introduced into the film forming chamber, brought into contact with the heated catalyst wires, and placed facing the plurality of catalyst wires. A chemical vapor deposition method characterized by forming a film on a formed substrate. A gas of at least one compound selected from silane, ammonia, hydrogen, nitric oxide, trimethylamine, trimethyldisilane, hexamethyldisilazane, and trisilylamine is used as the film forming material. Item 12. The chemical vapor deposition method according to Item 11 . A self-cleaning process of catalytic wire CVD apparatus, a film formation chamber, a self-cleaning gas, nitrogen trifluoride, hydrogen fluoride, sulfur hexafluoride, carbon tetrafluoride and chlorine trifluoride At least one kind of halogen-containing gas selected from the above is introduced, and a different voltage is applied to each catalyst line of the plurality of catalyst lines provided in the film forming chamber from the external power supply circuit, and the difference between the applied voltages The self-cleaning method is characterized in that a negative potential difference is generated between the catalyst wires to perform self-cleaning in the film forming chamber. A self-cleaning process of catalytic wire CVD apparatus, from the external power supply circuit, by applying different voltages to each catalytic wire of a plurality of catalytic wire provided in the deposition chamber, the difference of the applied voltage A negative potential difference between the catalyst lines and a self-cleaning gas in the deposition chamber selected from nitrogen trifluoride, hydrogen fluoride, sulfur hexafluoride, carbon tetrafluoride and chlorine trifluoride. A self-cleaning method comprising introducing at least one halogen-containing gas and performing self-cleaning in a film forming chamber. Self-cleaning process according to claim 13 or 14, characterized in that introducing the halide gas containing the same metal as the catalyst component metals with instead of or the halogen-containing gas in the halogen-containing gas.

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