JP2007173848A - Processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma processing device, which can process the surface of a substrate with high uniformity, and is excellent in conservativeness, such as maintenance, without complicating the device structure. <P>SOLUTION: A first channel 30 is formed in the side of a first diffusion plate 21 which is on the side of a gas inlet tube 27 and a recess 32 is formed in the side which is on the side of an electrode plate 19. The first channel 30 and the recess 32 communicate with each other through a plurality of inlet ports 31. The first channel 30 and the inlet ports 31 form a gas flow passage L which leads to the recess 32 from the gas inlet tube 27. As a process gas supplied from the gas inlet tube 27 passes through the gas flow passage L, it is supplied and dispersed to a hollow portion formed between the recess 32 and the electrode plate 19. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a processing apparatus that performs a process such as a film forming process and an etching process on an object to be processed.

  In a manufacturing process of a semiconductor device, a liquid crystal display device or the like, a plasma processing apparatus that processes the surface of these substrates using plasma is used. Examples of the plasma processing apparatus include a plasma etching apparatus that performs etching on a substrate and a plasma CVD apparatus that performs chemical vapor deposition (CVD). Among them, the parallel plate type plasma processing apparatus is widely used because it is excellent in processing uniformity and the apparatus configuration is relatively simple.

  The parallel plate type plasma processing apparatus includes two plate electrodes which are vertically opposed to each other. Of the two electrodes, the substrate is placed on the lower electrode. The upper electrode includes an electrode plate having a large number of gas holes facing the lower electrode, and has a so-called shower head structure. The upper electrode is connected to a processing gas supply source, and at the time of processing, the processing gas is supplied between the two electrodes through the gas holes of the electrode plate. The processing gas supplied between the electrodes is turned into plasma by applying high-frequency power to the electrodes, and the surface of the substrate is processed by this plasma.

  In the plasma processing apparatus, in order to process the substrate surface with high uniformity, it is important to control the supply of the processing gas from each gas hole with high accuracy. For example, when the gas supply from the gas holes is non-uniform, the film thickness distribution on the surface of the substrate subjected to the film formation process is non-uniform.

  The upper electrode of the showerhead structure has a hollow diffusion part inside. The diffusion part is provided so as to cover one surface of the electrode plate, and the processing gas is diffused into a large number of gas holes by the diffusion part. In this configuration, in order to control the supply of the processing gas from the gas hole, it is important to control the diffusion of the processing gas in the diffusing section and guide it to the gas hole.

  In order to control the diffusion of the processing gas in the diffusion unit, for example, a structure has been developed in which the diffusion unit is divided into a plurality of regions and the processing gas is supplied to each region. According to this structure, it is possible to control the amount of the processing gas ejected from the gas hole communicating with each region by adjusting the amount of the processing gas supplied to each region. Thereby, a highly uniform process can be performed on the substrate surface.

  However, when the above structure is used, pipes connected to the plurality of diffusion regions are necessary. For this reason, the number of parts of the apparatus increases, the apparatus structure becomes complicated, the manufacturing cost increases, and maintainability such as maintenance decreases. As described above, there has been no plasma processing apparatus that can perform highly uniform processing on the substrate surface without complicating the apparatus structure.

In view of the above circumstances, an object of the present invention is to provide a processing apparatus capable of performing a highly uniform process on an object to be processed with a simple apparatus configuration.
It is another object of the present invention to provide a processing apparatus capable of supplying a processing gas to an object to be processed with good controllability with a simple apparatus configuration.

In order to achieve the above object, the processing apparatus of the present invention provides:
Chamber (2);
A supply plate (19) having a plurality of gas holes (22) and supplying a processing gas into the chamber (2) through the gas holes (22);
A first diffusion section for diffusing the gas in a substantially horizontal direction on the main surface of the supply plate (19);
A second diffusion part for guiding the gas diffused by the first diffusion part to the gas hole (22);
With
The second diffusion part is formed on one surface thereof, and is laminated on the supply plate (19) to form a hollow portion between the one surface and the groove (32, 57), and the groove (32, 57). And a through hole (31a, 54) provided in the inner surface and having a through hole (31a, 54) provided therein, and the gas from the first diffusion portion passes through the through hole (31a, 54) through the hollow part,
And a partition member (56) provided in the groove (57) constituting the second diffusion part and dividing the hollow part into a plurality of regions, wherein the first diffusion part transfers the gas to the plurality of regions. It is characterized by being distributed and supplied to the area.

  A processing apparatus according to an embodiment of the present invention will be described below with reference to the drawings. In the embodiment described below, a parallel plate type plasma processing apparatus that forms a silicon fluoride oxide (SiOF) film on a semiconductor wafer (hereinafter referred to as wafer W) by CVD (Chemical Vapor Deposition) will be described as an example.

(First embodiment)
FIG. 1 shows a cross-sectional view of a plasma processing apparatus 1 according to a first embodiment of the present invention.
As shown in FIG. 1, the plasma processing apparatus 1 has a substantially cylindrical chamber 2. The chamber 2 is made of a conductive material such as aluminum that has been anodized (anodized). The chamber 2 is grounded.

  An exhaust port 3 is provided at the bottom of the chamber 2. An exhaust device 4 composed of a turbo molecular pump or the like is connected to the exhaust port 3. The exhaust device 4 exhausts the inside of the chamber 2 to a predetermined pressure, for example, 0.01 Pa or less. A gate valve 5 that can be opened and closed in an airtight manner is provided on the side wall of the chamber 2. With the gate valve 5 opened, the wafer W is loaded and unloaded between the chamber 2 and a load lock chamber (not shown).

  A substantially cylindrical susceptor support base 6 stands up from the bottom of the chamber 2. A susceptor 8 is provided on the susceptor support 6. A wafer W is placed on the upper surface of the susceptor 8. The susceptor support 6 and the susceptor 8 are insulated by an insulator 7 made of ceramic or the like. Further, the susceptor support base 6 is connected to an elevating mechanism (not shown) via a shaft 9 so that the inside of the chamber 2 can be elevated. The wafer W loaded from the gate valve 5 is placed on the susceptor 8 at the lowered position. Further, plasma processing is performed on the wafer W at the raised position of the susceptor 8.

  A disc-shaped annular baffle plate 10 is attached to the susceptor support 6 or the inner wall of the chamber 2. The baffle plate 10 is provided slightly below the susceptor 8. The baffle plate 10 is made of a conductor such as aluminum. The baffle plate 10 has a slit (not shown). The slit blocks the passage of the plasma while allowing the gas to pass. As a result, the baffle plate 10 confines the plasma in the upper part of the chamber 2.

  The lower part of the susceptor support base 6 is covered with a bellows 11 made of, for example, stainless steel. An upper end and a lower end of the bellows 11 are screwed to the lower portion of the susceptor support base 6 and the bottom surface of the chamber 2, respectively. The bellows 11 expands and contracts as the susceptor support base 6 is raised and lowered to maintain the airtightness in the chamber 2.

  A lower refrigerant channel 12 is provided inside the susceptor support 6. A refrigerant circulates in the lower refrigerant flow path 12. The susceptor 8 and the wafer W are maintained at a desired temperature by the lower coolant channel 12.

  In the susceptor support base 6, lift pins 13 are provided so as to penetrate the insulator 7 and the susceptor 8. The lift pin 13 can be moved up and down by a cylinder or the like (not shown). As the lift pins 13 are moved up and down, the wafer W is transferred to and from a transfer arm (not shown).

  The susceptor 8 is composed of a disk-shaped member made of a conductor such as aluminum. On the susceptor 8, an electrostatic chuck (not shown) having the same shape as the wafer W is provided. A DC voltage is applied to the electrostatic chuck, and the wafer W is fixed on the susceptor 8.

  A focus ring 14 is provided on the periphery of the susceptor 8 so as to surround the susceptor 8. The focus ring 14 is made of, for example, ceramic. The focus ring 14 effectively causes plasma active species to be incident on the wafer W placed inside thereof.

  The susceptor 8 functions as a lower electrode. The susceptor 8 is supplied with high frequency power having a frequency in the range of 0.1 to 13 MHz from the first high frequency power supply 15 via the first matching unit 16.

  An upper electrode 17 is provided above the susceptor 8 so as to be parallel to and face the susceptor 8. The upper electrode 17 is installed on the upper portion of the chamber 2 via an insulating material 18. The upper electrode 17 includes an electrode plate 19, an electrode support 20, and a first diffusion plate 21.

  The electrode plate 19 is made of a conductive material such as aluminum. The electrode plate 19 has a number of gas holes 22 penetrating the electrode plate 19. In addition, a second high frequency power supply 24 is connected to the electrode plate 19 via a second matching unit 23. The second high frequency power supply 24 applies a high frequency power of 13 to 150 MHz to the electrode plate 19. By applying a high frequency electrode to the susceptor 8 (lower electrode) and the upper electrode 17, plasma is generated between them.

  A first diffusion plate 21 and an electrode plate 19 are held on the electrode support 20. An upper coolant channel 25 is provided inside the electrode support 20. A refrigerant circulates in the upper refrigerant flow path 25. The upper refrigerant channel 25 maintains the upper electrode 17 at a desired temperature.

A gas supply pipe 27 is connected to the electrode support 20 and is connected to a gas supply source 28. From the gas supply source 28, a processing gas used for forming the SiOF film is supplied. The processing gas is composed of, for example, a mixed gas of tetrafluorosilane (SiF ₄ ), silane (SiH ₄ ), oxygen (O ₂ ), and argon (Ar).

  Between the gas supply source 28 and the gas supply pipe 27, a flow rate control device 29 such as a mass flow controller (MFC) is provided. The flow rate is adjusted by the flow rate control device 29 from the gas supply source 28 and the processing gas is supplied into the chamber 2.

  The first diffusion plate 21 is composed of a disk-shaped member made of a conductive material such as aluminum. The first diffusion plate 21 is sandwiched between the electrode plate 19 and the electrode support 20 and has substantially the same diameter as the electrode plate 19. The first diffusion plate 21 diffuses the processing gas supplied from the gas supply pipe 27 to one surface of the electrode plate 19. The diffused processing gas is supplied to a number of gas holes 22 in the electrode plate 19. Thereby, the processing gas is supplied to the surface of the wafer W from all the gas holes 22 of the electrode plate 19.

  An exploded sectional view of the upper electrode 17 is shown in FIG. As shown in FIG. 2, the first diffusion plate 21 has a first channel 30 formed as a groove having a predetermined depth on one surface, and first and second conductions that penetrate the first diffusion plate 21. Mouth 31a, 31b and the 1st recessed part 32 formed in the other surface as a recessed part of predetermined depth are formed. The first channel 30, the first and second conduction ports 31a and 31b, and the first recess 32 can be easily formed by cutting, drilling, or the like. Inside the upper electrode 17, a gas flow path L composed of a first channel 30 and first and second conduction ports 31 a and 31 b is formed.

  The first channel 30 communicates with the gas supply pipe 27 and is arranged to receive the processing gas supplied from the gas supply source 28. The first and second conduction ports 31 a and 31 b connect the first channel 30 and the first recess 32. Accordingly, the processing gas supplied from the gas supply pipe 27 passes through the gas flow path L, is diffused in the horizontal direction as shown by the arrow in FIG.

  The diffused processing gas is supplied to a hollow portion formed by the electrode plate 19 and the first concave portion 32 of the first diffusion plate 21. The processing gas diffused and supplied to the hollow portion (first concave portion 32) is further diffused in the hollow portion, and is supplied to the many gas holes 22 of the electrode plate 19 with high uniformity with respect to pressure and the like. Accordingly, the processing gas is supplied almost uniformly over the entire surface of the wafer W from the large number of gas holes 22. As a result, a highly uniform process such as obtaining a good film thickness distribution is possible.

  Hereinafter, the configuration of the first diffusion plate 21 will be described in detail. In FIG. 3, the A arrow directional view of the 1st diffuser plate 21 is shown. As shown in FIG. 3, the first channel 30 formed on one surface of the first diffusion plate 21 is composed of four first grooves 30a, ..., 30a and one second groove 30b. Is done.

  The first grooves 30a, ..., 30a extend radially from substantially the center of the first diffusion plate 21 so as to be substantially perpendicular to each other. The first grooves 30a, ..., 30a have substantially the same length and are connected at the center. The second groove 30b is formed between the adjacent first grooves 30a and 30a. The second groove 30b has substantially the same length as the first grooves 30a, ..., 30a, and is connected to the first grooves 30a, ..., 30a at the center.

  In the first grooves 30a, ..., 30a, first conduction ports 31a are provided at equal distances from the center. A second conduction port 31b is provided at the center. The first and second conduction ports 31 a and 31 b are provided through both surfaces of the first diffusion plate 21.

  The second groove 30 b is provided at a position where the processing gas is supplied from the gas supply pipe 27. That is, for example, the second groove 30 b is disposed immediately below the position where the gas supply pipe 27 is connected to the electrode support 20. The processing gas supplied from the gas supply pipe 27 toward the first diffusion plate 21 is received in the second groove 30b. After that, the processing gas flows through the second groove 30b, flows to the other surface side through the second conduction port 31b, and flows almost uniformly dispersed in the four first grooves 30a. The processing gas flowing through the first groove 30a reaches the first conduction port 31a and is supplied to the first recess 32 on the other surface side through the first conduction port 31b.

  FIG. 4 shows a view of the first diffusion plate 21 as seen from the direction of arrow B. As shown in FIG. 4, a substantially circular first recess 32 is formed on the other surface of the first diffusion plate 21. The first recess 32 is formed at a predetermined depth on substantially the entire surface of the first diffusion plate 21. The first diffusion plate 21 and the electrode plate 19 are arranged so as to overlap each other, and a hollow portion is formed by the first recess 32.

  The processing gas supplied to one surface of the first diffusion plate 21 and diffused in the first channel 30 is hollow on the other surface via the first conduction ports 31a, ..., 31a and the second conduction ports 31b. Part (first recess 32). The processing gas is diffused in the hollow portion and supplied to the gas hole 22. Thus, the processing gas is supplied from the gas hole 22 to the surface of the wafer W with high uniformity.

  Hereinafter, the operation during the film forming process of the plasma processing apparatus 1 having the above configuration will be described with reference to the drawings. The operation described below is an example, and any operation may be used as long as a similar result can be obtained.

  First, the wafer W is loaded into the chamber 2. The wafer W is placed on the lift pins 13 that protrude from the surface of the susceptor 8 with the susceptor support base 6 in the lowered position. Next, the wafer W is placed on the susceptor 8 by the lowering of the lift pins 13 and fixed by an electrostatic chuck. Next, the gate valve 5 is closed, and the inside of the chamber 2 is exhausted to a predetermined degree of vacuum by the exhaust device 4. Thereafter, the susceptor support base 6 is raised to the processing position. In this state, the susceptor 8 is set to a predetermined temperature, for example, 50 ° C., and the inside of the chamber 2 is set to a high vacuum state, for example, 0.01 Pa by the exhaust device 4.

Thereafter, a processing gas composed of, for example, SiF ₄ , SiH ₄ , O ₂ , NF ₃ , NH ₃ gas and Ar gas is controlled from the processing gas supply source 28 to a predetermined flow rate by the flow rate control device 29, and the gas supply pipe 27. The mixed gas is sufficiently diffused by the diffusion plate 21 and ejected from the gas hole 22 of the electrode plate 19 toward the wafer W with high uniformity.

  Thereafter, the second high frequency power supply 24 applies, for example, high frequency power of 13 to 150 MHz to the upper electrode 17. As a result, a high-frequency electric field is generated between the upper electrode 17 and the susceptor 8 as the lower electrode, and plasma of the processing gas is generated. On the other hand, the first high frequency power supply 15 supplies high frequency power of, for example, 0.1 to 13 MHz to the lower susceptor 8. As a result, active species in the plasma are drawn to the susceptor 8 side, and the plasma density near the surface of the wafer W is increased. Due to the generated plasma, a chemical reaction proceeds on the surface of the wafer W, and a SiOF film is formed on the surface of the wafer W.

  After the film having a predetermined thickness is formed, the supply of the high frequency power is stopped and the supply of the processing gas is stopped. After returning the pressure in the chamber 2 to the original pressure, the wafer W is unloaded from the chamber 2 in the reverse order of loading the wafer W. Thus, the film formation process for the wafer W is completed.

  As described above, in the first embodiment, the upper electrode 17 includes the gas supply pipe 27, the electrode plate 19, and the first diffusion plate 21 provided therebetween. . The first diffusing plate 21 includes a first channel 30 composed of a plurality of grooves formed radially on one surface, and includes a first recess 32 formed almost entirely on the other surface. The processing gas supplied from the gas supply pipe 27 is diffused in the first channel 30 in a direction horizontal to the main surface of the electrode plate 19 and then supplied to the first recess 32 on the other surface side. The processing gas is further diffused in the first recess 32 and is supplied to the multiple gas holes 22 almost uniformly. Thereby, the processing gas is supplied to the wafer W from the gas hole 22 with high uniformity, and processing with good uniformity such as film thickness distribution can be performed.

  Moreover, the 1st diffuser plate 21 is comprised from the one plate-shaped member by which the groove | channel or the recessed part was formed in the both surfaces. Therefore, the 1st diffuser plate 21 can be easily produced, for example by performing processing, such as cutting, on both surfaces of one aluminum plate. Furthermore, a plurality of pipes are not required. Therefore, it is possible to easily diffuse the processing gas with high uniformity into the gas hole 22 without complicating the apparatus configuration. Thereby, it is possible to realize highly uniform processing while preventing an increase in manufacturing cost and a decrease in maintainability such as maintenance.

  In the first embodiment, four first channels 30a are provided in the first diffusion plate 21, and the processing gas is supplied from the four first conduction ports 31a to the hollow portion. However, the number of the first conduction ports 31a is not limited to this, and the number of the first channels 30a may be five or more, and the first conduction ports 31a may be provided in each first channel 30a. Further, two or more first conduction ports 31a may be formed in the first channel 30a. Even in this case, it is only necessary to increase the number of grooves or holes in the first diffusion plate 21, and the processing gas can be more evenly distributed without complicating the apparatus configuration.

(Second Embodiment)
The processing apparatus according to the second embodiment has the same configuration as the plasma processing apparatus 1 shown in FIG. FIG. 5 shows an exploded view of the upper electrode 17 according to the second embodiment. In order to facilitate understanding, the same reference numerals in FIG. 5 denote the same parts as in FIG. 2, and a description thereof will be omitted.

  In the second embodiment, the processing gas is supplied to the central portion and the end portion of the wafer W by independently controlling the flow rate. That is, as shown in FIG. 5, a center gas supply pipe 27a and an end gas supply pipe 27b are connected to the electrode support 20 and are connected to each other via flow control devices 29a and 29b, respectively. The gas supply source 28 is connected.

Process gas supplied from the central gas supply tube 27a and the end portion the gas supply pipe 27b, respectively, two independent central gas channel formed in the upper electrode 17 L _a and the end portion the gas flow path L _b It is diffused through and supplied to the center and end of the electrode plate 19. As a result, the processing gas is supplied to the central portion and the end portion of the wafer W at different flow rates through the gas holes 22 of the electrode plate 19.

In the upper electrode 17 of the second embodiment, a second diffusion plate 40 and a third diffusion plate 41 are provided between the electrode plate 19 and the electrode support 20. The 2nd and 3rd diffuser plates 40 and 41 are comprised from the disk-shaped member which consists of electroconductive materials, such as aluminum. The second and third diffusion plates 40 and 41 have substantially the same diameter as the electrode plate 19. Second and third diffusion plate 40 and 41, two independent central gas passage L _a and the end portion the gas flow path L _b, formed in the upper electrode 17.

  The second diffusion plate 40 is disposed so as to contact the electrode support 20. The second diffusion plate 40 includes a second channel 50 formed as a groove having a predetermined depth on one surface, and third and fourth conduction ports 51 and 52 penetrating the second diffusion plate 40. . The second channel 50 and the third and fourth conduction ports 51 and 52 can be easily formed by cutting, drilling, or the like.

  A C arrow view of the second diffusion plate 40 shown in FIG. 5 is shown in FIG. As shown in FIG. 6, a second channel 50 including four second grooves 50 a,..., 50 a is formed on one surface of the second diffusion plate 40. The second grooves 50a, ..., 50a are connected at substantially the center of the second diffusion plate 40 and extend radially from the center. The second grooves 50a, ..., 50a have substantially the same length and are formed so as to be substantially orthogonal to each other.

  A third conduction port 51 is formed in the second groove 30a at approximately the same distance from the center. The end gas supply pipe 27 b is provided so as to supply the processing gas to substantially the center of the second diffusion plate 40. As a result, the processing gas is supplied almost uniformly distributed to the four second grooves 50a,..., 50a from the center. The processing gas flows through the second groove 50 a and is supplied from the third conduction port 51 to the other surface side of the second diffusion plate 40.

  The fourth conduction port 52 is formed at a position that does not overlap the second groove 50a. The center gas supply pipe 27 a is arranged so as to be connected to the fourth conduction port 52. As a result, the processing gas supplied from the central gas supply pipe 27 a is supplied to the other surface side of the second diffusion plate 21 through the fourth conduction port 52.

  Returning to FIG. 5, the third diffusion plate 41 is disposed between the second diffusion plate 40 and the electrode plate 19. The third diffusion plate 41 includes a third channel 53 formed as a groove having a predetermined depth on a surface facing the second diffusion plate 40, and fifth and sixth channels penetrating the third diffusion plate 41. Conductive ports 54 and 55, and a second recess 56 formed as a recess having a predetermined depth on the surface facing the electrode plate 19. The third channel 50, the fifth and sixth conduction ports 54 and 55, and the second recess 56 can be easily formed by cutting, drilling, or the like.

  The hollow portion formed by the second recess 57 and the electrode plate 19 is divided into a center portion and an end portion by a partition member 56.

  FIG. 7 shows a view of the third diffusion plate 41 shown in FIG. As shown in the figure, on the one surface of the third diffusion plate 41, there are formed four third grooves 53a,..., 53a constituting one third channel 53 and one lead groove 53b. Has been. The third grooves 53a,..., 53a are connected substantially at the center of the third diffusion plate 41 and extend radially from the center. The third grooves 53a are substantially the same length and are formed so as to be substantially orthogonal to each other.

  In the third groove 53a, fifth conduction ports 54 are provided at approximately equal distances from the center. Here, the third groove 53a has a shorter length than the second groove 50a.

  The lead-out groove 53b is connected to the third grooves 53a, ..., 53a at the center. One end of the drawing groove 53 b is provided so as to overlap with the fourth conduction port 52 of the second diffusion plate 40. As a result, the processing gas supplied from the central gas supply pipe 27a and passing through the fourth conduction port 52 is received by the extraction groove 53b and flows toward the center. Thereafter, the processing gas is distributed almost evenly in the third grooves 53 a,..., 53 a and flows to the other surface side through the fifth conduction port 54.

  Four sixth conduction ports 55 are provided in the third diffusion plate 41. The sixth conduction port 55 is provided so as to overlap and communicate with the third conduction port 51 of the second diffusion plate 40. Thereby, the processing gas supplied from the end gas supply pipe 27 b and having passed through the third conduction port 51 passes through the sixth conduction port 55 and flows to the other surface side.

  FIG. 8 shows an E arrow view of the third diffusion plate 41 shown in FIG. As shown in the figure, the second concave portion 57 is formed in a substantially circular shape substantially concentric with the third diffusion plate 41 in almost the entire third diffusion plate 41. The second concave portion 57 is divided into a central region 57 a and an end region 57 b by an annular partition member 56. The partition member 56 is made of, for example, aluminum, and is made of a band-like member having a width substantially the same as the depth of the second recess 57. The annular partition member 56 has substantially the same center as the second recess 57. The partition member 56 divides a hollow portion (second recess 57) formed by the third diffusion member 41 and the electrode plate 19 into a center region 57a and an end region 57b.

  Here, the partition member 56 is provided so as to divide the plane of the second recess 57 shown in FIG. 8 into a predetermined area ratio between the center region 57a and the end region 57b. The diameter of the partition member 56 is configured such that, for example, the area of the central region 57a: the area of the end region 57b = 2: 1. The area referred to here is substantially a cross-sectional area viewed from a direction perpendicular to the main surface of the third diffusion plate 41.

  As described above, the third groove 53 a including the fifth conduction port 54 is formed shorter than the second groove 50 a including the third conduction port 51. As shown in FIG. 8, the fifth conduction port 54 is disposed inside the partition member 56. The sixth conduction port 55 that communicates with the third conduction port 51 is disposed outside the partition member 56. Thereby, the processing gas from the fifth conduction port 54 is supplied to the central region 57 a of the second recess 57, while the processing gas from the sixth conduction port 55 is supplied to the end region 57 b of the second recess 57. To be supplied.

In summary with reference to FIG. 5, in the upper electrode 17, the second and third diffusion plate 40, 41, and mutually independent center gas passage L _a and the end portion the gas flow path L _b formed Is done. Central processing gas supplied from the gas supply pipe 27a, as shown in the dashed-line arrow, is diffused in the horizontal direction to the principal surface of the diffusion plate 19 by passing through the center gas passage L _a, center The gas hole 22 communicating with the region 57a is ejected to the center of the wafer W. The processing gas supplied from the end gas supply tube 27b, as shown in the chain line arrow, is diffused by passing through the end portion gas passage L _b, the gas holes 22 in communication with the end regions 57b Jetted to the edge of the wafer W.

The a mutually independent center gas passage L _a and the end portion the gas flow path L _b, the flow control device 29a, the 29 b, the process gas is supplied flow rate is controlled. Therefore, the processing gas can be supplied to the central portion and the end portion of the wafer W by controlling the flow rate.

  In FIG. 9, the area ratio (cross-sectional area ratio) between the center region 57a and the end region 57b is set to 2: 1, and the supply amount ratio of the processing gas to the center region 57a and the end region 57b by the flow rate control devices 29a and 29b FIG. 5 shows the result of examining the uniformity of the film forming speed on the surface of the wafer W by changing the thickness.

  As can be seen from FIG. 9, when the gas supply amount ratio in the central region 57a and the end region 57b is 1: 1.2 to 1.6, the film formation rate shows good uniformity. Best around 1.4. The film formation rate uniformity indicates the degree of variation in the film formation rate on the surface of the wafer W, and the lower the value, the lower the variation and the film formation with high in-plane uniformity. Therefore, when the area ratio between the center region 57a and the end region 57b is 2: 1, the gas supply amount ratio with respect to the center region 57a and the end region 57b is about 1: 1.4. A highly uniform treatment with a good film thickness distribution is possible.

  Further, by adjusting the diameter of the partition member 56 disposed in the second recess 57, the gas supply can be controlled more favorably. FIG. 10 shows the results of examining the uniformity of the film forming rate when the area ratio of each of the regions 57a and 57b is changed while the gas supply amount ratio to the central region 57a and the end region 57b is constant.

  FIG. 10 shows the results when the area ratio is changed with the gas supply ratio being 1: 1.4, 1: 1.8, and 1: 2. FIG. 10 shows that the optimum area ratio when the gas supply amount ratio is 1: 1.4 is around 2: 1. Similarly, when the gas supply ratio is 1: 1.8, about 1.5: 1 is optimal, and when the gas supply ratio is 1: 2, about 1: 1 is optimal. Recognize. Thus, it can be seen that the area ratio and the supply amount ratio can be adjusted and optimized so as to obtain a desired result.

(Example)
For various films, the processing conditions with the best uniformity such as the deposition rate uniformity were examined. The results are shown in FIG. In FIG. 11, SiO ₂ , SiOF, SiC, SiN, SiCN, CF _x , SiCH, and SiCO are examined. The gas types are not limited to those shown in the figure, SiH ₄ is TEOS or the like, SiF ₄ is Si ₂ H ₂ F ₂ or the like, CH ₄ is C ₂ H ₆ or the like, and C ₆ F ₆ is CF _4. , N ₂ can be replaced with N ₂ O, NO, etc., O ₂ can be replaced with N ₂ O, CO _2, etc., and 3MS (trimethylsilane) can be replaced with methylsilane, dimethylsilane, or the like. Further, other alternative gases are shown in FIG.

  As shown in FIG. 11, the processing conditions can be optimized by appropriately changing the ratio between the center region and the end region in accordance with the film formation type.

As described above, in the second embodiment, the second recess 57 that communicates with the gas hole 22 is divided into the center region 57a and the end region 57b, and the center that communicates with the center region 57a and the end region 57b, respectively. a Department gas passage L _a and the end portion the gas flow path L _b are formed in the upper electrode 17. Process gas is diffused by passing through a central portion gas passage L _a and the end portion the gas flow path L _b, it is supplied are controlled independently to the central region 57a and the end region 57 b. The processing gas is further diffused in the central region 57 a and the end region 57 b and is ejected to the central portion and the end portion of the wafer W through the gas holes 22. As a result, the supply of the processing gas to the wafer W can be well controlled and highly uniform processing can be performed.

  Moreover, the said structure is formed of the two disk shaped members in which the groove | channel and the through-hole were formed. Therefore, the apparatus configuration is not complicated, and highly uniform processing is realized while preventing an increase in manufacturing cost and deterioration in maintainability such as maintenance.

  Furthermore, the boundary between the center region 57 a and the end region 57 b can be changed by changing the diameter of the partition member 56. As described above, the supply of the processing gas can be controlled with higher accuracy by changing the two regions.

In the second embodiment, the same gas type is caused to flow through the gas flow paths L _a and L _b that are independent of each other. However, another type of gas that is not desired to be mixed outside the processing space may flow through the gas flow paths L _a and L _b , respectively. Further, the number of gas flow paths is not limited to two, and three or more gas flow paths may be formed.

  In the second embodiment, four second channels 50a and three third channels 53a are formed. However, five or more of each may be provided to further diffuse the processing gas. In addition, gas is supplied from the four conduction ports 54 and 55 to the center region 57a and the end region 57b, respectively. However, the present invention is not limited to this, and may be 5 or more.

  In the second embodiment, the hollow portion 57 is divided into two regions by one partition member 56. However, a plurality of partition members having different inner diameters may be used to divide into three or more regions having different cross-sectional area ratios. The method of dividing the hollow portion 57 is not limited to this, and the hollow portion 57 may be divided by a plurality of plate-like members arranged on the diameter of the hollow portion 57, for example.

(Third embodiment)
The processing apparatus according to the third embodiment has the same configuration as the plasma processing apparatus 1 shown in FIG. FIG. 13 is an enlarged view of the upper electrode 17 according to the second embodiment. In order to facilitate understanding, the same reference numerals in FIG. 13 denote the same parts as in FIG. 2, and a description thereof will be omitted.

The plasma processing apparatus 1 according to the third embodiment has a configuration in which the processing gas and the carrier gas are diffused without being in contact with each other and ejected from the gas hole 22. That is, as shown in FIG. 14, the upper electrode 17 is provided with a processing gas supply pipe 27a and a carrier gas supply pipe 27b, and the processing gas supply source 28a is provided via the flow rate control devices 29a and 29b, respectively. And a carrier gas supply source 28b. Here, from the processing gas supply source 28a, various gases conventionally used for forming the SiOF film, for example, a mixed gas of SiF ₄ , SiH ₄ , O ₂ , NF ₃ , and NH ₃ are supplied, and the carrier Ar gas is supplied from the gas supply source 28b.

In the upper electrode 17, two gas flow paths L _c (solid line arrows) and L _d (broken line arrows) starting from the processing gas supply pipe 27 a and the carrier gas supply pipe 27 _b are formed. Yes. The gas flow paths L _c , L _d are formed independently of each other, and the processing gas and the carrier gas are diffused by passing through the gas flow paths L _c , L _{d, and} are almost uniform from the many gas holes 22 of the electrode plate 19. To the wafer W.

  An exploded view of the upper electrode 17 is shown in FIG. The upper electrode 17 has a configuration in which a disk-shaped diffusion plate 21 is sandwiched between a cylindrical electrode support 20 and an electrode plate 19.

  As shown in FIG. 14, two hollow portions 71 and 72 extending in the horizontal direction with respect to the main surface are formed in the electrode support 20. The two hollow portions 71 and 72 are arranged such that the distances from the main surface of the electrode support 20 are different from each other.

Of the two hollow portions 71 and 72, the seventh and eighth conduction ports 73a and 73b are connected to the first hollow portion 71 closer to the diffusion plate 21. The seventh conduction port 73a extends from the first hollow portion 71 in a direction (upward in the drawing) perpendicular to the main surface of the electrode support 20, and communicates with the processing gas supply pipe 27a. The eighth conduction port 73b extends from the first hollow portion 71 in a direction opposite to the seventh conduction port 73a (downward in the drawing) and communicates with the space on the lower surface side of the electrode support 20. Yes. Thus, the process gas supplied from the processing gas supply pipe 27a is a conduction port 73a of the seventh, and the first hollow portion 71, a hollow portion 73b of the eighth, the gas passage L _c comprised Flowing.

Ninth and tenth conduction ports 74 a and 74 b are connected to the second hollow portion 72 formed farther from the diffusion plate 21. The ninth conduction port 74a extends from the second hollow portion 72 in a direction perpendicular to the main surface of the electrode support 20 (upward in the drawing) and communicates with the carrier gas supply pipe 27b. The tenth conduction port 74b extends from the second hollow portion 72 in the direction opposite to the ninth conduction port 74a (downward in the drawing) and communicates with the space on the lower surface side of the electrode support 20. Yes. Thus, the carrier gas supplied from the carrier gas supply pipe 27b is a conductive port 74a of the ninth, and the second hollow portion 72, a hollow portion 74b of the first 10, a gas flow path L _d composed of Flowing.

  FIG. 15 shows a cross section taken along line A of the electrode support 20 shown in FIG. As shown in the figure, the second hollow portion 72 includes four first straight holes 72a, ..., 72a extending radially from the approximate center of the electrode support 20, and two adjacent first straight holes. The second straight hole 72b provided radially from the same center between 72a. The first straight holes 72a, ..., 72a are provided so as to be substantially orthogonal to each other. The first and second straight holes 72a and 72b are formed on substantially the same plane.

  Each first straight hole 72a is connected to the tenth conduction port 74b at a point substantially equidistant from the center. The second straight hole 72b communicates with the ninth conduction port 74a.

  The carrier gas supplied from the carrier gas supply source 27b flows to the second straight hole 72b through the ninth conduction port 74a. The carrier gas travels toward the center in the second straight hole 72b and is dispersed from the center to the four first straight holes 72a. Thereby, the carrier gas is diffused in the horizontal direction. The carrier gas that has passed through the first straight hole 72a flows from the tenth conduction port 74b to the diffusion plate 21 side.

  The seventh conduction port 73 a connected to the processing gas supply pipe 27 a is formed at a position that does not overlap the second hollow portion 72.

  FIG. 16 shows a cross section taken along line B of the upper electrode 17 shown in FIG. As shown in FIG. 16, the first hollow portion 71 is formed between the four third straight holes 71a,... 71a extending radially from the approximate center and two adjacent third straight holes 71a. And a fourth straight hole 71b extending radially from the same center. The third straight holes 71a, ..., 71a are formed on substantially the same plane so as to be substantially orthogonal to each other. The third and fourth straight holes 71a and 71b are provided at positions that do not overlap with the tenth conduction port 74b.

  Each third straight hole 71a is connected to the eighth conduction port 73b at a point substantially equidistant from the center and at the center. The fourth straight hole 71b communicates with the seventh conduction port 73a.

  The processing gas supplied from the processing gas supply pipe 27a flows to the fourth straight hole 71b through the seventh conduction port 73a. The processing gas travels toward the center in the fourth straight hole 71b and is dispersed from the center to the four third straight holes 71a. In this way, the processing gas is diffused in the horizontal direction. The processing gas that has passed through the third straight hole 71a flows from the eighth conduction port 73b to the diffusion plate 21 side.

  Here, the straight holes 71a, 71b, 72a, 72b constituting the first and second hollow portions 71, 72 are formed with holes of a predetermined depth from the side wall of the electrode support 20 toward the center, It is formed by sealing its end with a sealing member 75.

  For example, the straight hole is formed by drilling with a gun drill from the direction substantially perpendicular to the side wall of the electrode support 20 to the center thereof. Drilling with a gun drill is performed a plurality of times, for example, by rotating the electrode support 20 around its center. Thereby, a plurality of straight holes communicating with each other at the center are formed. Then, the hollow part is formed by sealing the edge part of the formed linear hole with the sealing member 75 which consists of the same material as the electrode support bodies 20, such as aluminum. Here, the 1st and 2nd hollow parts 71 and 72 can be easily formed by changing the relative position of a gun drill and the electrode support body 20, for example. The electrode support 20 having the above-described configuration can be formed by forming a hole (conduction port) from a direction perpendicular to the main surface of the electrode holding support 20 so as to reach the linear hole formed as described above.

  Returning to FIG. 14, a fourth channel 76 is formed on the surface of the diffusion plate 21 facing the electrode support 20. The fourth channel 76 includes a plurality of grooves, and forms a hollow portion in a state where the lower surface of the electrode support 20 is covered. The fourth channel 76 is provided so as to communicate with the tenth conduction port 74b and not to communicate with the eighth conduction port 73b. The fourth channel 76 is formed with a number of first through holes 77 that penetrate the diffusion plate 21, and the first through holes 77 are provided so as to communicate with the gas holes 22, respectively.

A fourth channel 76, a first through-hole 77, constitutes a gas flow path L _d of the carrier gas flow. The carrier gas supplied from the tenth conduction port 74 b to the diffusion plate 21 is diffused in the horizontal direction by the fourth channel 76, and is almost uniformly ejected from the numerous gas holes 22 through the first through-holes 77. The

  Further, the diffusion plate 21 is provided with a second through-hole 78 penetrating the diffusion plate 21 so as to communicate with the second conduction port 73b. A fifth channel 79 is provided on the surface of the diffusion plate 21 facing the electrode plate 19. The fifth channel 79 is composed of a plurality of grooves, and forms a hollow portion in a state where the upper surface of the electrode plate 19 is covered. The fifth channel 79 is provided so as to communicate with the second through-hole 78 and not to communicate with the first through-hole 77.

A second through hole 78, and the fifth channel 79, constitute a gas flow path L _c which process gas flows. The processing gas supplied from the eighth conduction port 73 b to the diffusion plate 21 passes through the second through-hole 77 and is diffused in the horizontal direction in the fifth channel 79. The fifth channel 79 communicates with a large number of gas holes 22, and the diffused processing gas is supplied from the gas holes 22 almost evenly.

Here, the same number of gas holes 22 of the diffusion plate 19 are connected to either the first through-hole 77 or the fifth channel 79, for example. As a result, the processing gas passing through the gas flow path L _c and the carrier gas passing through the gas flow path L _d are diffused in the horizontal direction without being in contact with each other, and are almost uniformly ejected from the gas holes 22. The processing gas and the carrier gas are mixed for the first time inside the chamber 2 and supplied onto the wafer W to become plasma.

  The upper electrode 17 of the third embodiment has the following advantages. That is, the diffusion region (the first and second hollow portions 71 and 72) for diffusing the gas used for the treatment is formed by punching the electrode support 20 using a gun drill or the like. Thus, by forming the diffusion region inside the electrode support 20, the gas supply from the gas holes 22 can be made uniform without increasing the number of parts and without complicating the device structure. Highly uniform processing can be performed.

  Further, since the number of parts does not increase, the interface existing in the upper electrode 17 (for example, the interface between the electrode support 20 and the diffusion plate 21) does not increase. Therefore, loss of high-frequency power due to an increase in the skin effect accompanying an increase in the interface can be prevented.

In the third embodiment, two independent gas flow paths L _c and L _d that do not communicate with each other are formed inside the upper electrode 17. However, if necessary, the number of gas flow paths in the upper electrode 17 may be three or more. In this case, for example, the number of hollow portions in the electrode support 20 may be changed by changing the distance from one surface of the electrode support 20 to form three or more layers of hollow portions.

In the third embodiment, flowing a process gas into the gas flow path L _c, was assumed to flow carrier gas into the gas flow path L _d. However, a gas that is not desirably mixed outside the chamber, for example, a combustible gas and a combustion-supporting gas, may be caused to flow through the gas flow paths L _c and L _d .

  In the said 3rd Embodiment, the 1st and 2nd hollow parts 71 and 72 of the electrode support body 20 shall each be comprised from four linear holes. However, the number of straight holes is not limited to this, and may be 5 or more in order to further diffuse the gas. Further, the method of forming the straight hole in the upper electrode 17 is not limited to the drilling by a gun drill, and the drilling may be performed by a laser or the like. Furthermore, although the straight hole is formed at a depth from the side wall to the center of the electrode support 20, it may be formed so as to penetrate the electrode support 20.

  In the first to third embodiments, the upper electrode 17 is made of aluminum. However, the material constituting the upper electrode 17 is not limited to this, and conductive materials other than those that adversely affect the processing, such as SUS, can be used.

In the first to third embodiments, the SiOF film is formed on the wafer using an inert gas such as SiF ₄ , SiH ₄ , O ₂ , NF ₃ , NH ₃ gas, Ar, and nitrogen. The gas used is not limited to this. Further, the film to be formed may be any film such as a SiO ₂ film, a SiC film, a SiN film, a SiOC film, and a CF film.

  In addition, the present invention is not limited to the plasma CVD process as long as the processing object is processed by supplying the processing gas from the side facing the main surface of the processing object through the shower head type plate-like member. The present invention can be applied to an apparatus for performing a thermal CVD process, and can be applied to an apparatus for performing various processes such as another film forming process, an etching process, and a heat treatment. Further, the object to be processed is not limited to a semiconductor wafer but may be a glass substrate for a liquid crystal display device.

(Industrial applicability)
The present invention can be suitably applied to a processing apparatus that performs a film forming process, an etching process, or the like on an object to be processed such as a semiconductor wafer.
The present invention is based on Japanese Patent Application No. 2001-13570 filed on January 22, 2001 and Japanese Patent Application No. 2001-14011 filed on January 23, 2001, the description, claims, and drawings thereof. And a summary. The disclosures in the above applications are incorporated herein by reference in their entirety.

FIG. 1 is a diagram showing the configuration of the plasma processing apparatus according to the first embodiment. FIG. 2 shows an enlarged view of the upper electrode shown in FIG. FIG. 3 shows a view of the upper electrode shown in FIG. FIG. 4 is a B arrow view of the upper electrode shown in FIG. FIG. 5 shows an exploded view of the upper electrode according to the second embodiment. 6 shows a C arrow view of the upper electrode shown in FIG. FIG. 7 shows a view of the upper electrode shown in FIG. FIG. 8 shows an E arrow view of the upper electrode shown in FIG. FIG. 9 is a graph showing the results of examining the supply ratio of the processing gas and the uniformity of the film formation rate. FIG. 10 is a graph showing the results of examining the uniformity of the deposition rate when the supply ratio of the processing gas and the area ratio are changed from each other. FIG. 11 shows examples of film forming conditions for various film forming types. FIG. 12 shows an alternative gas. FIG. 13 shows an enlarged view of the upper electrode according to the third embodiment. FIG. 14 shows an exploded view of the upper electrode shown in FIG. 15 shows a cross-sectional view of the upper electrode shown in FIG. 16 shows a cross-sectional view of the upper electrode shown in FIG.

Claims (1)

Chamber (2);
A supply plate (19) having a plurality of gas holes (22) and supplying a processing gas into the chamber (2) through the gas holes (22);
A first diffusion section for diffusing the gas in a substantially horizontal direction on the main surface of the supply plate (19);
A second diffusion part for guiding the gas diffused by the first diffusion part to the gas hole (22);
With
The second diffusion part is formed on one surface thereof, and is laminated on the supply plate (19) to form a hollow portion between the one surface and the groove (32, 57), and the groove (32, 57). And a through hole (31a, 54) provided in the inner surface and having a through hole (31a, 54) provided therein, and the gas from the first diffusion portion passes through the through hole (31a, 54) through the hollow part,
And a partition member (56) provided in the groove (57) constituting the second diffusion part and dividing the hollow part into a plurality of regions, wherein the first diffusion part transfers the gas to the plurality of regions. A processing apparatus (1), characterized by being distributed and supplied to the area.

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