JP2004152832A - Plasma generating method, plasma apparatus, and semiconductor manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma generating method and plasma apparatus capable of efficiently and surely generating plasma, and to provide a semiconductor manufacturing apparatus which is capable of efficiently and surely generating plasma and processing a work at high speed. <P>SOLUTION: The plasma generating method generates plasma in a processing chamber 5 by supplying generated high-frequency signals S into the processing chamber 5 through a matching device 4. A high-frequency wave generating unit 2 is controlled so as to generate high-frequency signals S having an electric power smaller than one capable of generating plasma and supply them into the processing chamber 5, reflectivity as the ratio of traveling waves Sf to reflected waves Sr is measured between the high-frequency wave generating unit 2 and the processing chamber 5, the matching device 4 is controlled on the basis of the measured reflectivity, and the matching condition of the matching device 4 under which reflectivity gets smaller than a specific value is designated as a preset matching condition. When plasma is generated in the processing chamber 5, the matching device 4 is controlled so as to satisfy the preset matching condition, then the high-frequency wave generating unit 2 is controlled to generate high-frequency signals S having an electric power high enough to generate plasma and supply them to the processing chamber 5. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a plasma generation method for generating a plasma by inputting a high-frequency signal to a processing chamber via an impedance matching device, a plasma apparatus for performing a predetermined process on an object to be processed using the generated plasma, and The present invention relates to a semiconductor manufacturing device.
[0002]
[Prior art]
As a plasma device of this type, the applicant has already developed a plasma device shown in FIG. The plasma apparatus 51 shown in FIG. 1 includes a high-frequency generator 2 that generates a high-frequency signal S, a directional coupler 3, and a plurality of matching elements (dielectrics such as slag and slab). The position of each matching element in the matching unit body 54, which performs processing such as thin film formation by generating plasma based on the high-frequency signal S, and the matching unit main unit 54 that matches impedance with the (chamber) 5 It has a moving mechanism 56 having a function of changing the impedance matching device together with the matching device main body 54, and an arithmetic control unit 57 for controlling the moving mechanism 56. In this case, the directional coupler 3 detects the traveling wave Sf and the reflected wave Sr of the high-frequency signal S at the input terminal of the matching device main body 54 and outputs the detected waves to the arithmetic control unit 57.
[0003]
Next, the operation of the plasma device 51 will be described. First, the high-frequency generator 2 generates a high-frequency signal S and supplies it to the processing chamber 5 via the directional coupler 3 and the matching device main body 54. In this case, in the processing chamber 5, processing such as thin film formation is performed by generating plasma based on the supplied high frequency signal S. On the other hand, based on the traveling wave Sf and the reflected wave Sr of the high-frequency signal S detected by the directional coupler 3, the arithmetic control unit 57 determines the ratio of the reflected wave Sr to the traveling wave Sf (hereinafter, also referred to as “reflectance”). ) Is calculated repeatedly. Further, the arithmetic and control unit 57 controls (changes) the position of each matching element of the matching device body 54 by controlling the moving mechanism 56 so that the calculated reflectance becomes equal to or less than a preset reference value. The impedance between the high-frequency generator 2 and the processing chamber 5 is matched. As the impedance matching progresses, the reflected wave Sr gradually decreases and the reflectivity also decreases. Therefore, the arithmetic and control unit 57 controls the position of the matching element of the matching device body 54 such that the reflectance is equal to or less than the reference value, thereby optimizing the impedance between the high-frequency generator 2 and the processing chamber 5. To match the condition. Thereby, plasma is generated stably in the processing chamber 5.
[0004]
Further, in the plasma apparatus 51, the input impedance of the processing chamber 5 is greatly different between a state where plasma is generated and a state before plasma is generated (a state before plasma is ignited). Therefore, in order to efficiently generate (ignite) the plasma, the position of each matching element of the matching device main body 54 is changed when the high-frequency signal S of the power capable of generating the plasma is supplied, so that the high-frequency generator It is necessary to match the impedance between 2 and the processing chamber 5. In this case, each position (matching position) of each matching element in the matching device main body 54 is generally determined by experiments and experiences.
[0005]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 9-26,096 (page 3-5, FIG. 1)
[0006]
[Problems to be solved by the invention]
However, the plasma device 51 developed by the applicant has the following problems to be improved. That is, in the plasma apparatus 51, when supplying the high-frequency signal S of power capable of generating plasma, each matching element of the matching device main body 54 is moved to a matching position determined in advance by experiment or experience, and the high-frequency generation unit 2 and the processing chamber 5 are matched in impedance. However, even if the structure of the processing chamber 5 itself is the same, the input impedance of the processing chamber 5 changes according to the type of the object to be processed in the processing chamber 5 and the like. Therefore, even if each matching element of the matching device main body 54 is moved to a matching position determined in advance through experiments and experiences, a situation may occur in which the high-frequency generator 2 and the processing chamber 5 cannot be accurately impedance-matched. In such a state, since the high-frequency signal S is not efficiently supplied to the processing chamber 5, the plasma may not be ignited. In addition, when the plasma is not ignited, it is difficult to quickly perform processing on the object to be processed. Therefore, it is preferable to improve this point.
[0007]
The present invention has been made in view of such points to be improved, and has as its main object to provide a plasma generation method and a plasma apparatus that can efficiently and reliably ignite plasma. Another object of the present invention is to provide a semiconductor manufacturing apparatus that can efficiently and reliably ignite plasma and quickly execute processing on an object to be processed.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a plasma generation method according to claim 1 controls a high-frequency generator to generate a high-frequency signal, and supplies the high-frequency signal to a processing chamber via an impedance matching device to process the plasma. A method for generating plasma in a room, wherein the method includes controlling the high-frequency generator to generate the high-frequency signal having a power smaller than the power generated by the plasma and supplying the generated high-frequency signal to the processing chamber. Measuring the reflectance as a ratio of the reflected wave to the traveling wave between the unit and the processing chamber, and controlling the impedance matching device based at least on the measured reflectance, and the reflectance becomes equal to or less than a specified value. The matching condition of the impedance matching device is defined as a preset matching condition, and when the plasma is generated in the processing chamber, the pre-matching condition is set. After controlling Tsu preparative matching condition wherein the impedance matching device to meet, supplied to the processing chamber wherein by controlling the high frequency generating unit to generate the high frequency signal of the power which the plasma is generated.
[0009]
According to another aspect of the present invention, there is provided a plasma apparatus, comprising: a high-frequency generator configured to generate a high-frequency signal; A processing chamber configured to be able to execute a predetermined process by the plasma, an impedance matching unit disposed between the high-frequency generation unit and the processing chamber to match impedance between the two, and the high-frequency generation unit; A measurement apparatus for measuring a reflectance as a ratio of a reflected wave to a traveling wave between the processing chamber, and a plasma device including a control unit for controlling the impedance matching device, wherein the impedance matching device includes: A cylindrical outer conductor, a columnar inner conductor disposed in the outer conductor so that their axes are aligned with each other, an inner surface of the outer conductor, and an outer surface of the inner conductor A dielectric disposed movably along the longitudinal direction of the internal conductor in a gap formed between the internal conductor, and a moving mechanism for moving the dielectric, the control unit includes: A high-frequency generation unit is controlled to generate the high-frequency signal having a power smaller than the power generated by the plasma, to supply the generated high-frequency signal to the processing chamber, and to control the moving mechanism based at least on the reflectance measured in that state. The position of the dielectric in the impedance matching device whose reflectance is equal to or less than a specified value is defined as a preset position, and when the plasma is generated in the processing chamber, the moving mechanism is controlled to control the preset. The dielectric is moved to a position.
[0010]
In order to achieve the above object, a semiconductor manufacturing apparatus according to a third aspect is a semiconductor manufacturing apparatus including the plasma apparatus according to the second aspect, wherein the plasma apparatus is provided with respect to the workpiece. A plasma CVD apparatus for forming a thin film by the plasma of a reactive gas is configured.
[0011]
Furthermore, in order to achieve the above object, a semiconductor manufacturing apparatus according to claim 4 is a semiconductor manufacturing apparatus including the plasma apparatus according to claim 2, wherein the plasma apparatus is provided with respect to the workpiece. A plasma etching apparatus for performing etching by a plasma of a reactive gas is configured.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of a plasma generation method, a plasma apparatus, and a semiconductor manufacturing apparatus according to the present invention will be described with reference to the accompanying drawings. As an example, an example in which a plasma apparatus is applied to a plasma CVD apparatus as a semiconductor manufacturing apparatus for forming a thin film on a workpiece such as a semiconductor wafer by plasma discharge decomposition of a reactive gas will be described. Also, the same components as those of the plasma device 51 are denoted by the same reference numerals, and redundant description will be omitted.
[0013]
A plasma CVD apparatus 1 shown in FIG. 1 includes a high-frequency generator 2, a directional coupler 3, a coaxial impedance matching device (hereinafter, also referred to as a "matching device") 4, and a processing chamber (a matching object in the present invention) 5. By supplying the high-frequency signal (for example, microwave) S generated by the high-frequency generator 2 to the processing chamber 5 via the directional coupler 3 and the matching device main body 11 in the matching device 4. A plasma is generated in the processing chamber 5 filled with gas, so that a thin film forming process can be performed on an object to be processed in the processing chamber 5.
[0014]
The high-frequency generator 2 generates a high-frequency signal (microwave of about 2.45 GHz, for example) S, and supplies the generated high-frequency signal S to the processing chamber 5. The high frequency generator 2 is configured to be able to control the power of the generated high frequency signal S based on the input power control signal Sp. The directional coupler 3 outputs a traveling wave Sf and a reflected wave Sr of the high frequency signal S. In this case, the traveling wave Sf and the reflected wave Sr have the same frequency and a different phase.
[0015]
As shown in FIG. 1, the matching device 4 includes a matching device main body 11, a moving mechanism 21, and an arithmetic control unit 31. In this case, as shown in FIG. 2, the matching device main body 11 includes a tubular (cylindrical) outer conductor 12, and a cylindrical inner conductor 13 disposed in the outer conductor 12 so that their axes are aligned with each other. And a coaxial impedance matching device (a so-called slug tuner) having, for example, two sets of dielectrics (slags) 14 and 15 disposed in a gap between the inner surface of the outer conductor 12 and the outer surface of the inner conductor 13. The directional coupler 3 is disposed between the directional coupler 3 and the processing chamber 5. Connectors (not shown) for connecting the matching device body 11 to the directional coupler 3 and the processing chamber 5 are attached to the input end 11a and the output end 11b of the matching device body 11, respectively. One slit SL is formed in the outer conductor 12 along the longitudinal direction.
[0016]
As shown in FIGS. 2 and 3, the slag 14 on the input end side includes slags 14 a and 14 b formed of a dielectric material, and a moving bracket 14 c that connects the slags 14 a and 14 b and is moved by the moving mechanism 21. It has. In this case, each of the slugs 14a and 14b is formed in a cylindrical shape having a thickness L1 equal to (or substantially equal to) λ / 4 (λ is the guide wavelength of the high-frequency signal S in the matching device main body 11). The slugs 14a and 14b are preset so that the distance L2 between the opposing surfaces is equal to (or substantially equal to) N × λ / 4 (N is an odd number). With this configuration, the amount of reflection of the entire slug 14 composed of the slugs 14a and 14b toward the input end 11a is sufficiently large as compared with a configuration in which only one of the slugs 14a and 14b exists. The moving bracket 14c is inserted into the slit SL, and its end (upper end in the drawing) protrudes from the slit SL to the outside of the external conductor 12. The slag 15 on the output end side is configured in the same manner as the slag 14, and as shown in FIGS. And a moving bracket 15c to be moved. In the embodiment of the present invention, as an example, distance L2 between slugs 14a and 14b and distance L2 between slugs 15a and 15b are defined as λ / 4.
[0017]
At the time of impedance matching using the matching device 4, the slugs 14, 15 are slid (moved). At this time, by adjusting the distance L3 between the center position O between the slugs 14 and 15 (see FIG. 3) and the output end (signal output side end) 11b of the matching device main body 11, both slugs 14 and 15 are adjusted. Adjusts the phases of the respective reflected signals respectively reflected. In this case, by adjusting the distance between the center position O between the two slugs 14 and 15 and the input end (signal input side end) 11a of the matching device main body 11, the light is reflected by the two slugs 14 and 15, respectively. The phase of each reflected signal can be similarly adjusted. Further, by adjusting the distance L4 (distance between opposing surfaces) between the end face of the output end 11b of the slag 14b of the slag 14 and the end face of the slag 15a on the input end 11a side, the input by the slag 15 is achieved. The amplitude of the reflected signal reflected to the end 11a is adjusted. Therefore, by appropriately adjusting the positions of the slugs 14a, 14b (slug 14) and the slugs 15a, 15b (slug 15) in the matching device main body 11 (that is, the positions of the dielectrics 14, 15 in the outer conductor). , The phase of the signal reflected by the slug 14 toward the input end 11a and the phase of the signal reflected by the slug 15 toward the input end 11a are mutually inverted, and the signal reflected by the slug 14 toward the input end 11a. And the amplitude of the signal reflected to the input end 11a side by the slug 15 are made equal to each other, so that the high-frequency generation unit 2 connected to the input end 11a and the processing chamber 5 connected to the output end 11b are separated. Impedance can be perfectly matched.
[0018]
As shown in FIG. 2, the moving mechanism 21 includes a moving mechanism 21a for moving the slag 14 and a moving mechanism 21b for moving the slag 15. The moving mechanism 21a includes a wire rope 22a wound between a pair of pulleys 23a and 24a disposed near the input end 11a and the output end 11b of the matching device body 11, and a motor 25a for rotating and driving the wire rope 22a. The bracket 14c for moving the slug 14 is connected to the wire rope 22a. With this configuration, when the wire rope 22a is rotationally driven by the motor 25a, the slug 14 slides inside the outer conductor 12 together with the moving bracket 14c. On the other hand, the moving mechanism 21b rotationally drives the wire rope 22b and the wire rope 22b that are stretched between a pair of pulleys 23b and 24b disposed near the input end 11a and the output end 11b of the matching device body 11, respectively. And a motor 25b, and a bracket 15c for moving the slug 15 is connected to the wire rope 22b. With this configuration, when the wire rope 22b is rotationally driven by the motor 25b, the slug 15 slides inside the outer conductor 12 together with the moving bracket 15c.
[0019]
The arithmetic control unit (control unit in the present invention) 31 measures the reflectance as a ratio of the reflected wave Sr to the traveling wave Sf at the input end 11a of the matching device main body 11 based on the input traveling wave Sf and reflected wave Sr. I do. Thereby, the arithmetic control unit 31 forms a measuring unit in the present invention together with the directional coupler 3. Further, the arithmetic and control unit 31 moves the slugs 14 and 15 by controlling the control amount Ss for the moving mechanism 21 so that the measured reflectance becomes equal to or less than a specified value stored in an internal memory (not shown). By doing so, the impedance between the directional coupler 3 and the processing chamber 5 is matched. Further, the arithmetic and control unit 31 controls the control amount Ss for the moving mechanism 21 to move each of the slugs 14 and 15 to a preset position stored in the internal memory or a predetermined position stored in advance. In this case, the specified position means a matching position for each of the slags 14 and 15 in each state after the ignition of the plasma, and is determined in advance by an experiment, for example. Further, the arithmetic control unit 31 controls the generated power of the high-frequency signal S by the high-frequency generation unit 2 by generating and outputting the power control signal Sp to the high-frequency generation unit 2.
[0020]
Although not shown, the processing chamber 5 is formed into a tubular outer shape using, for example, quartz, and a pump (not shown) that exhausts gas in the processing chamber 5 is provided at one end thereof. A gas inlet (not shown) for introducing a reaction gas into the processing chamber 5 is provided at the other end. Further, a stage (not shown) on which the object to be processed is placed is provided inside the processing chamber 5. When the plasma is ignited, the inside of the processing chamber 5 is filled with the reaction gas.
[0021]
Next, the operation of the plasma CVD apparatus 1 will be described with reference to FIGS.
[0022]
When the power is turned on, the plasma CVD apparatus 1 first executes a preset position defining process shown in FIG. 4, detects a matching state when the plasma is ignited, and stores it as a preset position (step 100). Specifically, as shown in FIG. 5, the arithmetic control unit 31 outputs a power control signal Sp to the high-frequency generation unit 2 so that the power is smaller than the power generated by the plasma (a small power that does not ignite the plasma). A high-frequency signal S of electric power is generated and supplied to the processing chamber 5 (step 101). Next, the arithmetic and control unit 31 measures the reflectance at the input end 11a of the matching device body 11 based on the traveling wave Sf and the reflected wave Sr, and determines whether or not the measured reflectance is equal to or less than a specified value. (Step 102). When determining that the measured reflectance exceeds the specified value, the arithmetic and control unit 31 controls the control amount Ss for the moving mechanism 21 to move each of the slugs 14 and 15 so that the reflectance decreases. (Step 103). The arithmetic control unit 31 gradually reduces the measured reflectance by repeatedly executing the above steps 102 and 103. On the other hand, when it is determined in step 102 that the measured reflectance is equal to or less than the specified value (that is, when it is determined that the impedance between the directional coupler 3 and the processing chamber 5 is matched), the arithmetic control is performed. The unit 31 detects (calculates) the current position of each of the slugs 14, 15 based on the control amount Ss for the moving mechanism 21. Further, the detected positions of the slugs 14 and 15 are defined as preset positions (preset matching conditions) and stored in the internal memory (step 104).
[0023]
Next, in the plasma CVD apparatus 1, as shown in FIG. 4, the arithmetic and control unit 31 executes an ignition process to ignite plasma in the processing chamber 5 (step 200). Specifically, as shown in FIG. 6, the arithmetic control unit 31 reads the preset position of each of the slugs 14 and 15 from the internal memory and controls the control amount Ss for the moving mechanism 21 so that the matching device main body 11 Each of the slugs 14 and 15 in is moved to a preset position (step 201). That is, the slugs 14 and 15 are moved so as to satisfy the preset matching condition. Next, the arithmetic control unit 31 outputs the power control signal Sp to cause the high-frequency generation unit 2 to generate the medium-power high-frequency signal S at which the plasma can be ignited and supply the generated high-frequency signal S to the processing chamber 5 (step 202). Next, the arithmetic control unit 31 measures the reflectance at the input end 11a of the matching device body 11 based on the traveling wave Sf and the reflected wave Sr, and determines whether the measured reflectance is equal to or less than a specified value (reflectance). Is determined (step 203). In this case, when the plasma is ignited in the processing chamber 5, the input impedance of the processing chamber 5 is greatly reduced as compared with that before the ignition, so that an impedance mismatch between the high-frequency generator 2 and the processing chamber 5 is caused. As a result, the measured reflectance increases. Therefore, when the measured reflectance is determined to be equal to or less than the specified value (when the reflectance is small), the arithmetic control unit 31 determines that the ignition of the plasma has failed, and performs the stop process (step 400). On the other hand, when determining that the measured reflectance exceeds the specified value (when the reflectance is large), the arithmetic and control unit 31 determines that the plasma has been ignited normally. At this time, the arithmetic and control unit 31 reads out the specified position after the above-described plasma ignition from the internal memory and controls the control amount Ss for the moving mechanism 21 so that the slugs 14 and 15 in the matching box main body 11 are controlled. Is moved to this specified position (step 204).
[0024]
Next, the arithmetic control unit 31 measures the reflectance at the input end 11a of the matching device body 11 (between the high-frequency generation unit 2 and the processing chamber 5), and determines whether the measured reflectance is equal to or less than a specified value. Is determined (step 205). In this case, in step 204, by moving each of the slags 14 and 15 to the specified position, the reflectance is reduced when the impedance between the high-frequency generator 2 and the processing chamber 5 is matched. Therefore, when it is determined that the measured reflectance is equal to or less than the specified value (the reflectance is small), the arithmetic control unit 31 determines that the impedance between the high-frequency generator 2 and the processing chamber 5 is matched in the ignition state. Then, this process ends, and thereafter, the process proceeds to the operation process shown in FIG. On the other hand, when it is determined that the measured reflectivity exceeds the specified value (when the reflectivity is large), the plasma once ignited is abnormal due to some cause such as movement of each of the slags 14 and 15. The state shifts to an ignition state (or a non-ignition state). As a result, it is determined that the state has shifted to an impedance mismatching state, and the processing shifts to a stop processing (step 400) shown in FIG.
[0025]
When the ignition process is completed normally, in the plasma CVD device 1, as shown in FIG. 4, the arithmetic and control unit 31 executes an operation process (step 300). In this process, a thin film is formed on an object to be processed in the processing chamber 5 by plasma discharge decomposition of a reactive gas. Specifically, as shown in FIG. 7, the arithmetic control unit 31 gradually increases the power of the high-frequency signal S generated by the high-frequency generation unit 2 by outputting the power control signal Sp, and The plasma intensity in 5 is increased to a target level (step 301).
[0026]
Next, the arithmetic and control unit 31 measures the reflectance at the input end 11a of the matching device main body 11, compares the measured reflectance with a specified value, and determines the degree (step 302). When the arithmetic control unit 31 determines that the measured reflectance is extremely large, it determines that the generation of plasma in the processing chamber 5 has stopped for some reason, and proceeds to the stop processing (step 400) shown in FIG. Transition. When it is determined that the measured reflectivity is slightly larger than the specified value (medium reflectivity), the arithmetic control unit 31 and the high-frequency generator 2 and the processing chamber in order to generate plasma more efficiently. In order to perform impedance matching between the slugs 5 and 5, the control amount Ss for the moving mechanism 21 is controlled to move each of the slugs 14 and 15 to reduce the reflectance (step 303). The arithmetic control unit 31 repeatedly executes steps 302 to 303. As a result, the reflectivity decreases. When it is determined in step 302 that the measured reflectivity is equal to or less than the specified value (the reflectivity is small), the power control signal Sp is further output to output the high-frequency signal S. APC (Automatic Power Control) is performed on the high frequency generator 2 so that the power of the RF power becomes constant (step 304). In this state, the impedance between the high-frequency generator 2 and the processing chamber 5 is in a matching state, plasma is efficiently generated, and the power of the high-frequency signal S is also controlled to a constant value. Therefore, the thin film forming process for the object to be processed in the processing chamber 5 is favorably performed. Thereafter, the arithmetic and control unit 31 stabilizes the plasma intensity in the processing chamber 5 at the target level during the thin film forming process on the object by repeatedly executing the above steps 302 to 304 and a step 305 described later. Let it. Note that the arithmetic and control unit 31 detects the presence or absence of the input of the stop instruction while performing the APC control (step 305), and shifts to the stop processing (step 400) when detecting the input of the stop instruction.
[0027]
When the operation processing is completed normally, as shown in FIG. 4, a stop processing (step 400) is executed (step 400). Specifically, the arithmetic control unit 31 outputs the power control signal Sp to gradually lower the power of the high-frequency signal S generated by the high-frequency generation unit 2 to stop the plasma generation in the processing chamber 5. Let it.
[0028]
As described above, according to the plasma CVD apparatus 1, the positions of the slugs 14, 15 for matching the impedance between the high-frequency generator 2 and the processing chamber 5 when the plasma is not ignited are detected and stored as preset positions. When the plasma is ignited, the moving mechanism 21 is controlled to move the slags 14 and 15 to the preset position and supply the high-frequency signal S. The plasma can be reliably generated in the inside of the fuel cell 5. Therefore, it is possible to reliably prevent the high-frequency signal S of excessive power from being supplied to the processing chamber 5 at the time of ignition, and to avoid abnormal discharge of plasma. As a result, it is possible to effectively prevent the object to be processed accommodated in the processing chamber 5 from being damaged by abnormal discharge of plasma. In addition, since plasma can be reliably generated, it is possible to shift to a thin film forming process and an etching process for an object to be processed using plasma of a reactive gas in a short time. Therefore, it is possible to sufficiently reduce the time required for these processes on the workpiece.
[0029]
Note that the present invention is not limited to the configuration described in the above embodiment. For example, in the embodiment of the present invention, the plasma apparatus according to the present invention is applied to a plasma CVD apparatus 1 as a semiconductor manufacturing apparatus for forming a thin film on a workpiece such as a semiconductor wafer by plasma discharge decomposition of a reactive gas. Although the above example has been described, the present invention can also be applied to a plasma etching apparatus that etches a thin film or the like formed on the surface of an object to be processed such as a semiconductor wafer entirely or partially by a predetermined thickness. As for the impedance matching method itself, various matching methods can be appropriately adopted. Further, a configuration may be adopted in which the arithmetic control unit 31 automatically performs impedance matching between the high-frequency generation unit 2 and the processing chamber 5 even after ignition.
[0030]
【The invention's effect】
As described above, according to the plasma generation method according to the present invention, the high-frequency generation unit is controlled to generate a high-frequency signal of power smaller than the power generated by the plasma, and supplies the generated high-frequency signal to the processing chamber. When controlling the impedance matching device based on at least the reflectance measured by the impedance matching device and defining the matching condition of the impedance matching device whose reflectance is equal to or less than a specified value as a preset matching condition, when generating plasma in the processing chamber, By supplying the high-frequency signal to the processing chamber after controlling the impedance matching device so as to satisfy the preset condition, it is possible to generate plasma in the processing chamber reliably and efficiently with the high-frequency signal of the minimum power.
[0031]
Further, according to the plasma device of the present invention, the high-frequency generator is controlled to generate a high-frequency signal of power smaller than the power generated by the plasma, and supplies the generated high-frequency signal to the processing chamber. When the impedance matching device is controlled based on at least the reflectance and the position of the dielectric in the impedance matching device where the reflectance is equal to or less than a specified value is defined as a preset position, and a plasma is generated in the processing chamber, the moving mechanism is used. Is controlled to supply the high-frequency signal to the processing chamber after the dielectric is moved to the preset position, whereby plasma can be reliably and efficiently generated in the processing chamber with the high-frequency signal of the minimum power.
[0032]
Further, according to the semiconductor manufacturing apparatus of the present invention, it is possible to reliably generate plasma in the processing chamber with a high-frequency signal of minimum power. Therefore, it is possible to prevent a high-frequency signal of excessive power from being supplied to the processing chamber, so that abnormal discharge of plasma can be avoided. As a result, breakage of the processing object in the processing chamber due to abnormal discharge of the plasma can be effectively prevented. In addition, since plasma can be reliably generated, it is possible to shift to a thin film forming process and an etching process for an object to be processed using plasma of a reactive gas in a short time. Therefore, it is possible to sufficiently reduce the time required for these processes on the workpiece.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a plasma CVD apparatus 1 configured by applying a plasma apparatus according to an embodiment of the present invention.
FIG. 2 is a side sectional view of a matching device main body 11 and a side view of a moving mechanism 21.
FIG. 3 is a conceptual diagram of a matching device main body 11;
FIG. 4 is a flowchart for explaining a film forming operation of the plasma CVD apparatus 1;
FIG. 5 is a flowchart illustrating a preset position defining process in FIG. 4;
FIG. 6 is a flowchart illustrating an ignition process in FIG. 4;
FIG. 7 is a flowchart for explaining operation processing in FIG. 4;
FIG. 8 is a configuration diagram of a conventional slag tuner 51.
[Explanation of symbols]
1 Plasma CVD equipment
2 High frequency generator
3 directional coupler
4. Matching device (coaxial impedance matching device)
5 Processing room
11 Matching device body
11a Input terminal
12 outer conductor
13 inner conductor
14,15 Slag (dielectric)
21 Moving mechanism
31 Operation control unit
S high frequency signal
Sf traveling wave
Sr reflected wave

Claims (4)

A plasma generation method for controlling a high-frequency generator to generate a high-frequency signal and supplying the high-frequency signal to a processing chamber via an impedance matching device to generate plasma in the processing chamber,
The high-frequency generator is controlled to generate the high-frequency signal having a power smaller than the power generated by the plasma, and supplies the generated high-frequency signal to the processing chamber. In this state, a traveling wave is generated between the high-frequency generator and the processing chamber. The impedance matching device is controlled based on at least the measured reflectance, and the matching condition of the impedance matching device whose reflectance is equal to or less than a specified value is set as a preset matching condition. When generating the plasma in the processing chamber, after controlling the impedance matching device so as to satisfy the preset matching conditions, the high-frequency power of the power generated by the plasma by controlling the high-frequency generation unit A plasma generation method for generating a signal and supplying the signal to the processing chamber. A high-frequency generation unit that generates a high-frequency signal, a processing chamber configured to be able to execute a predetermined process by the plasma with respect to an object to be processed, which is supplied with the high-frequency signal and generates plasma therein; An impedance matching unit disposed between the high-frequency generation unit and the processing chamber to match impedance between the two; and a reflection as a ratio of a reflected wave to a traveling wave between the high-frequency generation unit and the processing chamber. A measurement device for measuring the ratio, a plasma device comprising a control unit for controlling the impedance matching device,
The impedance matching device includes a cylindrical outer conductor, a columnar inner conductor disposed in the outer conductor so that their axes are aligned with each other, and a gap between an inner surface of the outer conductor and an outer surface of the inner conductor. A dielectric body movably disposed along the longitudinal direction of the internal conductor in the gap formed by, and a moving mechanism for moving the dielectric body,
The control unit controls the high-frequency generation unit to generate the high-frequency signal of power smaller than the power generated by the plasma and supply the generated high-frequency signal to the processing chamber, and at least based on the reflectance measured in that state. When the position of the dielectric in the impedance matching device whose reflectance is equal to or less than a specified value is controlled as a preset position, and the plasma is generated in the processing chamber, the moving mechanism is controlled. A plasma apparatus that moves the dielectric material to the preset position by controlling the dielectric material. 3. A semiconductor manufacturing apparatus comprising the plasma apparatus according to claim 2, wherein the plasma apparatus is a plasma CVD apparatus for forming a thin film on the object by plasma of a reactive gas. . A semiconductor manufacturing apparatus comprising the plasma apparatus according to claim 2, wherein the plasma apparatus is a plasma etching apparatus that performs etching on the object by using plasma of a reactive gas.

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