JP2007063575A - Process gas feed mechanism, and plasma cvd film deposition apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process gas feed mechanism capable of ensuring the uniform ejection of a uniformly diffused process gas and allowing a gas ejection port to be hardly clogged, and a plasma CVD film deposition apparatus having the same. <P>SOLUTION: At least one of an outer pipe in which a plurality of gas ejection ports are formed in a barrel portion at a predetermined pitch along the longitudinal direction is arranged so as to surround an outer circumferential portion of an inner pipe in which a plurality of gas ejection ports are formed in a barrel portion at a predetermined pitch along the longitudinal direction. The opening positions of the gas ejection ports of the inner pipe and the outer pipe are set so that the gas introduced from a gas introduction unit at one end to the inner pipe is ejected outside from the gas ejection ports of the outer pipe via the gas ejection ports of the inner pipe, and the gas ejected from the gas ejection ports in the inner pipe does not reach the gas ejection ports of the outer pipe through a shortest path. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention diffuses uniformly in a vacuum chamber of a plasma CVD film forming apparatus used for forming a thin film on a substrate, particularly a plasma CVD film forming apparatus of a pass film forming method or a small stop film forming method. The present invention relates to a process gas supply mechanism and a plasma CVD film forming apparatus including the process gas supply mechanism, in which uniform discharge of the processed process gas can be ensured, and the gas outlet is hardly blocked.

  The plasma CVD method is excellent in high-speed film-forming properties, low-temperature film-forming properties, step coverage, adhesion, etc., and is used for the formation of various thin films in the manufacturing process of semiconductor elements, etc. It is widely used for the formation of a gate oxide film in the manufacturing process, as well as the formation of a gas barrier property-imparting film in the manufacturing process of a packaging material used for packaging foods, pharmaceuticals, chemicals and the like.

  FIG. 2 shows a schematic configuration of a parallel plate type plasma CVD film forming apparatus used for such film formation. This apparatus has an upper electrode 102 disposed substantially horizontally inside a vacuum chamber 101 and a lower electrode 103 disposed substantially in parallel to face the upper electrode 102.

  The upper electrode 102 has an internal space 104 in the vicinity of its tip, and a plurality of gas jets 105 for ejecting process gas are provided at the tip (bottom). Then, the process gas stored in the gas supply tank 107 is sent to the internal space 104 via the mass flow controller (mass flow rate controller) 106, and further ejected into the vacuum chamber 101 via the gas ejection port 105. It is like that. Further, an RF power source 108 is electrically connected to the upper electrode 102, and the lower electrode 103 is grounded.

  In order to form a film using the plasma CVD film forming apparatus having such a configuration, first, the inside of the vacuum chamber 101 is evacuated by a vacuum pump (not shown). Next, the process gas is caused to flow from the gas supply tank 107 into the internal space 104 of the upper electrode 102 while being controlled to a predetermined flow rate by the mass flow controller 106. Then, the process gas is ejected from the gas ejection port 105 into the vacuum chamber 101 and used for film formation.

  When the gas supply is started and the flow rate and the pressure in the vacuum chamber 101 are stabilized, a voltage is then applied between the upper electrode 102 and the lower electrode 103 connected to the RF power source 108 to generate plasma. Then, the ionized process gas atoms cause a chemical reaction in the reaction region on the substrate 109, and a thin film is formed on the substrate 109.

Generally, the electrode of a plasma CVD film forming apparatus used for forming such a thin film is a shower head electrode in which a plurality of gas outlets are arranged so that a process gas is uniformly jetted onto a substrate. . In the case of the shower head electrode, when the gas outlet is large, the process gas is not sufficiently diffused in the internal space of the electrode and is jetted out of the electrode. As a result, the film thickness distribution of the formed thin film becomes non-uniform. End up. Therefore, the gas outlet of the showerhead electrode must be sufficiently small. However, when the gas outlet is made small, the reaction product generated during the film formation immediately closes it. There has been a problem that non-uniform portions are generated in the thin film. In addition, attempts have been made to equalize the film thickness distribution by dividing the shower head into a plurality of blocks and individually ejecting gas by controlling the flow rate of gas ejected from the gas ejection ports of each block. The structure becomes complicated and the cost becomes high (for example, see Patent Document 1).
JP 2003-309075 A

  The present invention has been made in view of the above situation, and is a plasma CVD film forming apparatus used when a thin film is formed on a substrate, particularly a plasma CVD using a pass film forming method or a small stop film forming method. A process gas supply mechanism capable of ensuring uniform ejection of a process gas uniformly diffused in a film deposition apparatus and preventing the gas ejection port from being blocked, and a plasma CVD film deposition apparatus having the process gas supply mechanism It is to provide.

  In order to solve the problems as described above, the invention according to claim 1 is characterized in that at least one of the outer pipes in which a plurality of gas outlets are formed in the body portion at a predetermined pitch along the longitudinal direction. As described above, the gas outlets are arranged so as to surround the outer peripheral portion of the inner pipe formed in the body portion at a predetermined pitch along the longitudinal direction at a constant interval, and the gas introduction portion at one end The process gas introduced into the inner pipe from the outer pipe is ejected from the outer pipe gas outlet through the inner pipe gas outlet, and from the inner pipe gas outlet. The drilling position of the gas outlet of the inner pipe and the outer pipe is set so that the gas does not reach the gas outlet of the outer pipe in the shortest path Rosesugasu is a supply mechanism.

  According to a second aspect of the present invention, in the process gas supply mechanism of the first aspect, the outer pipe and the inner pipe have the same perforation pitch, and the outer pipe The gas ejection direction from the gas ejection port of the inner pipe is different from the gas ejection direction from the gas ejection port of the inner pipe by 180 degrees, and the relative position between the gas ejection port of the outer pipe and the gas ejection port of the inner pipe is shifted by a half pitch. The outer pipe is arranged on the outer peripheral portion of the inner pipe.

  Furthermore, the invention according to claim 3 is the process gas supply mechanism according to claim 1 or 2, wherein the opening of the gas outlet of the outer pipe is larger than the opening of the gas outlet of the inner pipe. Features.

  Furthermore, the invention according to claim 4 is the process gas supply mechanism according to any one of claims 1 to 3, characterized in that the opening shape of the outlet of the outer pipe is a slit shape.

   Furthermore, the invention according to claim 5 is the process gas supply mechanism according to any one of claims 1 to 4, wherein a tube joint is attached to at least one end face of the outer pipe, and the tube joint Thus, the outer pipe is fixed to the inner pipe.

   Furthermore, the invention described in claim 6 is an electrode in which the process gas supply mechanism according to any one of claims 1 to 5 is installed such that the gas injection direction therefrom is substantially horizontal in the vacuum chamber. It is arrange | positioned in a vacuum chamber so that it may spray in parallel toward the electrode center of this, The plasma CVD film-forming apparatus characterized by the above-mentioned.

According to the present invention, a process gas supply mechanism that can ensure uniform ejection of uniformly diffused process gas and that does not easily block the gas ejection port, and plasma that can be stably formed using the process gas supply mechanism. A CVD film forming apparatus can be provided.

  In addition, since the thin film formed by the plasma CVD film forming apparatus of the present invention has improved reliability and stability, the yield is improved, and further, downtime for cleaning is reduced, thereby reducing the cost of the product. Can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view showing the appearance of the process gas supply mechanism of the present invention. FIG. 3 is an explanatory view of a cross-sectional state showing the arrangement state of the inner pipe and the outer pipe in the process gas supply mechanism shown in FIG. 1 and the perforated state of the gas outlet formed in each pipe. Show.

  As shown in the figure, the main part of the process gas supply mechanism 2 includes a plurality of outer pipes 202 each having a plurality of gas outlets 206 formed at a predetermined pitch along the longitudinal direction. The outlet 204 is arranged so as to surround the outer peripheral portion of the inner pipe 201 formed in a plurality of holes in the body portion at a predetermined pitch along the longitudinal direction at a constant interval, and from the gas introduction portion 207 at one end. The process gas introduced into the inner pipe 201 is jetted from the gas jet port 206 of the outer pipe 201 toward the outside of the process gas supply mechanism 2 via the gas jet port 204 of the inner pipe 201. The gas ejected from the gas outlet 204 of the inner pipe 201 reaches the gas outlet 206 of the outer pipe 202 in the shortest path. Drilled position of the gas jetting port 204, 206 of the inner pipe 201 and outer pipe 202 are respectively set to not.

  In the process gas supply mechanism of the present invention, in addition to the configuration shown in FIG. 3, a plurality of outer pipes arranged so as to surround the outer peripheral portion of the outer pipe 202 at a constant interval are further arranged. It may be a multiple structure.

  One end of the inner pipe 201 is closed, and the other end is connected to the gas introduction part 207 of the gas supply line by, for example, a tube joint 203 (see FIG. 1). A process gas is introduced into the gas introduction unit 207 from a gas supply tank via a mass flow controller. Further, as described above, a plurality of gas outlets 204 drilled at a predetermined pitch along the longitudinal direction are provided in the body portion of the inner pipe 201 (see FIGS. 3 and 5). The opening degree of the gas ejection port 204 is set so that the flow rate of the gas ejected from the process gas at the required flow rate is almost equal at all the gas ejection ports, but is not particularly limited, but is usually less than 1 mm. Set as a degree of opening.

  On the other hand, one end of the outer pipe 202 is closed, and a bored through type bite joint 205 adapted to the diameter of the inner pipe 201 is attached to the other end (see FIG. 1). Then, the inner pipe 201 is inserted from the joint side of the outer pipe 202, and as shown in FIG. 4, the inner surface of the outer pipe 202 and the outer surface of the inner pipe 201 are in contact with each other, and the outer pipe 202 The joint is tightened in a state where the centers of the inner pipe 201 and the inner pipe 201 are coincident with each other, and a double structure is constructed. Here, one end of the outer pipe 202 is bitten and fastened by the joint 205 so that the outer pipe 202 can be detached from the inner pipe 201 so that, for example, particles entering the gap between the outer pipe 202 and the inner pipe 201 are cleaned. This is to make it easier.

As described above, a plurality of gas outlets 206 formed at a predetermined pitch along the longitudinal direction are formed in the body portion of the outer pipe 202. These gas outlets 206 may be formed larger than the gas outlet 204 formed in the inner pipe 201 so as not to be blocked by the reaction product of the process gas even if film formation is performed for a long time. preferable. Usually 1m
What is necessary is just to set so that it may become the opening more than m. The shape of the gas ejection port 206 is not particularly limited, and a circular or slit shape is applied. Of these, the slit-shaped gas outlet is particularly preferable because the jet in the longitudinal direction becomes more uniform.

  Further, when the outer pipe 202 is fixed to the inner pipe 201, for example, as shown in FIG. 5, the gas ejection direction (opening direction) of the gas ejection ports of the inner pipe 202 and the outer pipe 201 is set so as not to coincide. Thereby, the possibility that the jet port 204 of the inner pipe 201 is blocked by the reaction product during film formation can be eliminated. Further, when the distance until the process gas ejected from the gas ejection port 204 of the inner pipe 201 reaches the gas ejection port 206 of the outer pipe 202 is long, gas diffusion proceeds during that time, and as a result, the outer pipe 202 is diffused. This makes it possible to further promote the homogenization of the gas ejected from the gas ejection port 206. That is, by setting the drilling positions of the gas outlets of the inner pipe and the outer pipe so that the gas jetted from the gas outlet of the inner pipe does not reach the gas outlet of the outer pipe in the shortest path, Promotes gas diffusion.

  Further, the perforation pitch of the gas outlet 206 of the outer pipe 202 and the gas outlet 204 of the inner pipe 201 are the same, and the direction of gas emission from the gas outlet 206 of the outer pipe 202 and the gas outlet 204 of the inner pipe 201 are the same. The outer pipe 202 is arranged on the outer peripheral portion of the inner pipe 201 so that the gas jet directions of the outer pipe 202 are different by 180 degrees and the relative positions of the gas jet outlet 206 of the outer pipe 202 and the gas jet outlet 204 of the inner pipe 201 are shifted by a half pitch. By doing so, it is possible to further increase the distance until the gas that has come out from the gas outlet 204 of the inner pipe 201 reaches the gas outlet 206 of the outer pipe 202, and to further uniform the flow rate of the gas to be ejected. (See FIGS. 3 and 5).

  The process gas supply mechanism according to the present invention having such a configuration is disposed near the electrode in the vacuum chamber of the plasma CVD film forming apparatus. The setting method is not particularly limited as long as the process gas is evenly distributed between the electrodes. For example, as in the vapor deposition apparatus according to the present invention whose configuration is shown in FIG. The pipe portion of the process gas supply mechanism (that is, the body of the gas jet outlets at a predetermined pitch along the longitudinal direction so that the process gas is ejected toward the electrode center of the electrode that is installed substantially horizontally. At least one of the outer pipes perforated at a predetermined interval between the outer peripheral portions of the inner pipes at which the gas outlets are perforated at a predetermined pitch along the longitudinal direction at regular intervals. And the gas outlet 206 of the outer pipe 202 may be set so that the gas is ejected horizontally toward the center of the electrode.

  Also, if the film formation area is large, increase the number of pipe portions of the process gas supply mechanism as necessary, for example, arrange the pipe portions of the process gas supply mechanism on the four sides of the electrode, from each outer pipe The process gas to be ejected may be set so as to be ejected horizontally toward the center of the electrode. In addition, when depositing a large area or when further uniformity of the film thickness distribution is required, the pipe part of the process gas supply mechanism is arranged upstream of the electrode as a passing film forming method, and the center direction of the electrode What is necessary is just to set so that gas may spout toward (the advancing direction of a board | substrate).

  EXAMPLES Next, an Example is given and this invention is demonstrated further.

An outer pipe having 10 circular gas orifices having a circular opening (Φ1.2 mm) drilled in its body at a pitch of 30 mm along the longitudinal direction has a circular opening (Φ0.5 mm) The gas outlets are arranged so as to surround the outer peripheral portion of the inner pipe, which is formed in the body portion thereof at a pitch of 30 mm along the longitudinal direction, while maintaining an interval of 1 mm,
Gas introduced into the inner pipe from the gas introduction part at one end is ejected from the gas outlet of the outer pipe to the outside via the gas outlet of the inner pipe, and the gas injection of the outer pipe The outer pipe so that the gas ejection direction from the outlet and the gas ejection direction from the gas outlet of the inner pipe differ by 180 degrees, and the relative position between the gas outlet of the outer pipe and the gas outlet of the inner pipe is shifted by a half pitch. The gas flow direction from the process gas supply mechanism disposed on the outer peripheral portion of the inner pipe is directed toward the electrode center of the electrode installed substantially in parallel in the vacuum chamber of the plasma CVD film forming apparatus. Are arranged so as to be sprayed horizontally, using a plasma CVD method using a 1:10 mixed gas of HMDSO and oxygen. It was formed a thin film of SiO _X on the substrate. The film forming process was performed by repeating the process of forming the film for 2 hours, then opening the vacuum chamber to the atmosphere, and visually checking for clogging of the gas ejection port a total of 5 times. Table 1 shows the results of visual confirmation every 2 hours of the clogging at the gas outlet.

The SiO _x film was formed for 10 hours under the same conditions as in Example 1 except that the outer pipe had an opening shape with a slit width of 1 mm and a slit length of 270 mm. Table 1 shows the results of visual confirmation every 2 hours of the clogging at the gas outlet.

  Plasma CVD film formation comprising a shower head electrode having a pipe portion having 10 circularly-pierced gas outlets with a circular shape (Φ0.5 mm) in the longitudinal direction at a pitch of 30 mm along the longitudinal direction. Using a mixed gas of HMDSO and oxygen 1:10 by the apparatus, the film was formed for 2 hours, then the inside of the vacuum chamber was opened to the atmosphere, and the clogging of the gas outlet was visually confirmed 5 times in total. The film formation process was performed. Table 1 shows the results of visual confirmation every 2 hours of the clogging at the gas outlet.

表１に示すように、本発明のプロセスガス供給機構を用いた蒸着装置により成膜処理を行えば、ガス噴出口が詰まることなく長時間安定した成膜が行えた。

As shown in Table 1, when the film forming process was performed by the vapor deposition apparatus using the process gas supply mechanism of the present invention, the film could be stably formed for a long time without clogging the gas ejection port.

It is explanatory drawing which shows the external appearance of the process gas supply mechanism of this invention. It is explanatory drawing which shows the schematic structure of the conventional plasma CVD film-forming apparatus. FIG. 2 is a cross-sectional explanatory view showing an arrangement state of inner pipes and outer pipes in the process gas supply mechanism of the present invention shown in FIG. 1 and a gas outlet formed in each pipe. It is explanatory drawing which shows the cross-sectional structure in the A section of FIG. It is explanatory drawing which shows the cross-sectional structure in the B section of FIG. It is explanatory drawing which shows the schematic structure of the plasma CVD film-forming apparatus of this invention which comprises the process gas supply mechanism of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Plasma CVD film-forming apparatus 101 ... Vacuum chamber 102 ... Upper electrode 103 ... Lower electrode 104 ... Upper electrode internal space 105 ... Shower head jet 106 ... Mass flow controller 107 ... Gas supply tank 108 ... RF power supply 109 ... Substrate 2 ... Process gas supply mechanism 201 ... Inner pipe 202 ... Outer pipe 203 ... Tube joint 204 formed at one end of the inner pipe ... Gas outlet 205 of the inner pipe ... Biting joint 206 formed at one end of the outer pipe ... Outer pipe Pipe gas spout

Claims (6)

  At least one or more of the outer pipes in which a plurality of gas jets are perforated at a predetermined pitch along the longitudinal direction, and a plurality of gas jets are provided at the trunk at a predetermined pitch along the longitudinal direction. It is arranged so as to surround the outer peripheral part of the bored inner pipe at regular intervals, and the process gas introduced into the inner pipe from the gas introduction part at one end passes through the gas outlet of the inner pipe The outer pipe is designed to be ejected from the gas outlet of the outer pipe, and the inner pipe and the outer A process gas supply mechanism in which a drilling position of a gas outlet of a pipe is set.   The gas outlet of the outer pipe and the gas outlet of the inner pipe have the same drilling pitch, and the gas outlet direction from the gas outlet of the outer pipe and the gas outlet direction of the gas outlet of the inner pipe are the same. 2. The outer pipe is arranged at an outer peripheral portion of the inner pipe so that the relative positions of the gas outlet of the outer pipe and the gas outlet of the inner pipe are shifted by a half pitch so as to be different from each other by 180 degrees. The process gas supply mechanism described.   The process gas supply mechanism according to claim 1 or 2, wherein an opening of the gas outlet of the outer pipe is larger than an opening of the gas outlet of the inner pipe.   The process gas supply mechanism according to any one of claims 1 to 3, wherein an opening shape of a jet port of the outer pipe is a slit shape.   The process gas according to any one of claims 1 to 4, wherein a tube joint is attached to at least one end face of the outer pipe, and the outer pipe is fixed to the inner pipe by the tube joint. Supply mechanism.   The process gas supply mechanism according to any one of claims 1 to 5, wherein a gas injection direction from the process gas supply mechanism injects in parallel toward an electrode center of an electrode installed substantially horizontally in the vacuum chamber. A plasma CVD film forming apparatus, which is disposed in a vacuum chamber.

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