TW201014473A - Plasma control device - Google Patents

Abstract

Provided is a plasma control device which can suppress overshoot of Pf power and Vpp power supplied to a base and perform etching with a high etching rate. The plasma control device (10) includes: a power source unit (11) which supplies Pf power to a base (23); a control unit (13) which outputs a first control signal Pf1 equivalent to a power value of the Pf power which makes the Vpp voltage applied to the base (23) to be a voltage value substantially identical to a target voltage by supply of the Pf power; and a limiter (14). If the first control signal Pf1 outputted from the control unit (13) is not smaller than a second control signal PF2 equivalent to a first threshold value, the limiter (14) inputs the second control signal Pf2 to the power source unit (11). Otherwise, the limiter (14) inputs the first control signal Pf1 to the power source unit (11). The power source unit (11) outputs the Pf power corresponding to the first control signal Pf1 or the second control signal Pf2 which has been inputted.

Description

[Technical Field] The present invention relates to a plasma control device that supplies high-frequency electric power to an etching device that etches plasma. C. Background of the Invention It is known that the above-mentioned residual device includes a processing chamber that can fill an etching gas, an antenna that plasmas the gas that has been filled in the money chamber, and is disposed in the processing chamber. The base of the etched material is placed on the base of the etched material (Japan National Development Co., Ltd. 2007-12555). In the remnant device, the high-frequency power is supplied to the field and the abutment, and the etching gas filled in the surname chamber is plasmaized', and a potential difference is generated between the plasma and the base. When a potential difference is generated between the base and the base, the atomic group of the plasma is chemically reacted with the Mito that is placed on the base, and the ions of the plasma impact the material to be etched, and the material to be etched can be etched. The amount of exposure per unit time (hereinafter referred to as "etching rate")' of such a device is related to the potential difference between the plasma and the base. Since the plasma generated as described above has a substantially potential, the residual ratio can be controlled by controlling the potential difference between the base and the ground (hereinafter referred to as "application of high-frequency voltage" or "Vpp voltage"). The following two control methods can be cited as a control method for controlling the _ rate by controlling the VPP voltage, and the i-th control method is to open the high-frequency power supplied to the base station (hereinafter referred to as "Ke Electric Power". >) Maintaining the state of the 疋 power value' maintains the Vpp voltage at pf control that is approximately the same as the target voltage of 3 201014473 corresponding to the target etch rate. The second control method controls the Pf power to make the vpp voltage and the target voltage ginger smaller, thereby maintaining the Vpp voltage at a Vpp control which is substantially the same as the target voltage (Japanese Patent Laid-Open No. 2006-131954). I; SUMMARY OF THE INVENTION 3 SUMMARY OF THE INVENTION

The relationship between the Pf power and the Vpp voltage varies depending on the adhesion of the attachment to the device (e.g., the processing chamber, etc.) during etching. When the pf power is maintained at a constant value, the Vpp voltage decreases as the amount of such deposit increases. As a result, in the Pf control in which the Pf power is maintained at a constant power value, the adhering matter attached to the etching device from the start of etching increases with the elapse of time. Therefore, the Vpp voltage may decrease with the elapsed time. The rate will decrease with the passage of time. Further, the relationship between the 'Pf power and the Vpp voltage depends on the high-frequency power supplied to the antenna, the state of occurrence of the plasma, the integration of the impedance of the power supply unit and the plasma that supplies the power to the base, and the type of the etching gas. The plurals such as pressure will change accordingly. Shortly after the start of the etching to supply the high-frequency power to the antenna and the base, the occurrence of the plasma, the integration of the power supply unit that supplies the Pf power to the base, and the impedance of the plasma are unstable. Therefore, the pf power is The relationship of the Vpp voltage is in an easily changeable state. In general, the relationship between Pf power and Vpp voltage is a relationship in which the vpp electrical history increases as the pf power increases. However, shortly after the start of etching, the state of occurrence of the plasma or the like is unstable as described above, and therefore, when the power of the coke is increased and the Vpp voltage is decreased. As described above, the Vpp voltage generally increases as the Pf power increases. Therefore, in the Vpp control, the 201014473 reduces the power-on force in a state where the vpp voltage is larger than the target voltage. However, when the power is reduced, once the relationship between the Pf power and the Vpp voltage is changed to the relationship that the Vpp voltage decreases when the Pf power increases, the Vpp voltage increases and the Vpp voltage overshoots (〇versh〇〇t). Hey. Also shortly after the start of etching, the Vpp voltage is very small relative to the target voltage. In the Vpp control, when the Vpp voltage is very small relative to the target voltage, the power is greatly increased so that the Vpp voltage and the target voltage reach approximately the same voltage ❹ value. Therefore, there is a rush of Pf power overshoot. When the Vpp voltage or the Pf power is overshooted, the power supply unit or the like that supplies the Pf power may be damaged. In order to suppress such overshoot, a control (hereinafter referred to as "delay control") for gradually decreasing the difference between the Vpp voltage and the target voltage can be considered as the Vpp control so that the Vpp voltage gradually increases shortly after the start of etching. However, when the increase in the Vpp voltage becomes slow shortly after the start of etching, the rate of money is lowered shortly after the start of etching, and the problem that the overall etch rate is lowered. φ Therefore, the object of the present invention is to provide etching at a high etching rate and to suppress Pf power and Vpp voltage by suppressing a decrease in the etching rate with an elapsed time and a decrease in the etching rate immediately after the start of etching. Overshoot plasma control unit. The plasma control device provided by the present invention is a plasma control device for supplying high-frequency power to an etching device for remnant etching by plasma, wherein the device of the last name includes a base, and the base is electrically connected. A potential difference is generated between the slabs to etch the material to be etched, and the plasma control device includes a power supply unit that supplies high-frequency power to the base; and a control unit, 5 201014473

The first control signal is output, and the control signal corresponds to the supply of the high frequency voltage applied to the base station: the power value of the high frequency power of the same voltage value; and the limiter, The system starts from the monthly control _ ψ The first ice control signal is input to the power supply unit when the value corresponds to the first cabinet value, and the ith control signal output by the control unit is not When the full number is selected, the first control signal is inserted into the power supply unit, and the second control signal before: ==r is entered:

However, the power control indicates that the first control signal number corresponds to the Pf power value at which the 4 pp pp voltage is approximately the same as the target voltage by the supply of Pf power (10). Further, the term "substantially the same voltage value" means a voltage value in the range of 97.5% to 1% 2.5% with respect to the target voltage value. Limiter at

When the ith control signal outputted from the control unit corresponds to the second control signal phase of the second threshold value, (4) the second (fourth) (fourth) (fourth) input power _, (4) when the first control signal output from the control unit is less than the second control signal, The i-th control signal is input to the power supply unit. When the power supply unit receives the second control signal from the limiter, the Pf power corresponding to the second control signal (the first value) is output. In other words, the power supply unit is at the first! When the control signal (when the VPP voltage is the power value of the deduction power whose voltage value is substantially equal to the target voltage) is equal to or greater than the i-th value, the Pf control is performed to maintain the power value of the electric power corresponding to the % threshold. 6 201014473 In contrast, when the power supply unit receives the first control signal from the limiter, 'the output power corresponding to the first control signal is output. In other words, the power supply unit is at the first! When the control signal is less than the first value, Vpp control for controlling the pf power is performed to reach the power value corresponding to the first control signal. Fig. 1 (8) is a graph showing the relationship between the first control signal (the electric power value of the Pf electric power which makes Vpp electric power equal to the same voltage value as the target voltage) and the difference between the Vpp electric power and the target electric voltage. As shown in Fig. 4, when the difference becomes large, that is, when the VPP voltage becomes large, the first control signal becomes small. Shortly after the start of etching, the νΡΡ voltage was zero. Therefore, when the power value smaller than the difference between the VPP voltage and the voltage of 0 is set as the first value, the first control signal shortly after the start of the meal is equal to or greater than the first threshold Th1. Therefore, pf control was carried out shortly after the start of (4). When the Pf control is performed shortly after the start of the button, the Vpp voltage is sharply increased to the same extent as the case where the _ rate is controlled only by the Pf control. Therefore, the decrease in the side rate shortly after the start of the turn can be suppressed. The Pf power can be maintained at the first threshold Th1 by the Pf control shortly after the start of etching. The predetermined power value (hereinafter referred to as a value larger than the reference Pf power) included in (4) between the second control signal P0 and the reference Pf power corresponding to the difference of the Vpp voltage is set as the i-th threshold. Thi. The reference Pf power refers to the Pf power supplied to the base of the etching apparatus to which the attached material is not attached, when the Vpp voltage is substantially the same as the target voltage and is stable. Thus, when the value larger than the reference pf power is set as the first threshold value Thl, the pf power can be maintained at a value larger than the reference pf power by 7 201014473 by the pf control shortly after the start of etching. As shown in Fig. 1(b), the relationship between the Pf power and the Vpp voltage is usually a relationship in which the Vpp voltage increases as the Pf power increases. Therefore, the Pf power is maintained at a value greater than the reference Pf power (the i th threshold)

At Thl), the Vpp voltage becomes larger than the target voltage (refer to Figure 1(b)).

Vppl). When the Vpp voltage becomes larger than the target voltage, the difference between the Vpp voltage and the target voltage as shown in Fig. 1 (4) is larger than the difference (i.e., 0) when the vpp voltage is the target voltage (refer to Fig. 1 ( &) ¥1), the third control signal is smaller than the reference Pf power (refer to P1 of Fig. 1 (a)). As a result, when the value larger than the reference Pf power is set as the first threshold value Th1, the third control signal may be less than the first threshold value Th1. Therefore, when the value larger than the reference 卩 [the power is larger than the first threshold value Thl, the control method of the etching rate *pf control is switched to the Vpp control. The VPP control system controls the Vpp voltage to be approximately the same as the target voltage, so that the % voltage does not decrease even if the relationship between the Vpp voltage and the Pf power changes. Therefore, after switching from the Pf control to the Vpp control, as in the case of controlling the OFF rate only by the vpp control, it is possible to suppress the increase in the rate due to the adhesion of the attached device to the device (4). The lower the 0 level, the proposal has the following rhyme method. π, the etching process for etching the material to be etched and the table to be exposed (4) to be exposed by the extravagant engineering are alternately repeated at a short interval. However, in such a method, the short inter-gland switch 4 and the protective film form a guard, so that the time required for her (4) is short. In the etching process with a short time, the etching rate of the entire etching process is greatly reduced due to the decrease in the etching rate shortly after the start of the etching in 201014473. The plasma control device of the present invention can suppress the decrease in the etching rate shortly after the start of etching. Therefore, as described above, the plasma control apparatus of the present invention is suitable for a plasma control apparatus which supplies high-frequency electric power to an etching apparatus which performs an etching method for etching and etching a protective film forming process at a short interval. In other words, in the etching apparatus using the plasma control device of the present invention, the remaining etching of the button-engraved material and the formation of the protective film on the surface of the material to be etched exposed by the etching process are performed by the parent. The protective film is formed into a project, and it is better to engrave the aforementioned device for the engraving of the material. Moreover, the adhering matter adheres to the etching apparatus during the etching process. As a result, in the case where the etching process is repeated, the more the order is, the more the etching process is followed by the fact that a large amount of adhering matter adheres to the device of the surname. As described above, when the Pf power is maintained under a certain condition, the Vpp voltage is lowered as the adhering matter attached to the etching device increases. Therefore, in the subsequent etching apparatus, the Vpp voltage at the time of Pf control becomes small. As shown in Fig. 1(0), when the Vpp voltage becomes large, the first control signal becomes small. Therefore, the etching process after the order is higher, and the possibility that the i-th control signal does not become less than the first threshold value Th1 due to the Pf control shortly after the start of etching becomes high. Further, the possibility of controlling the etching rate from the Pf control to the Vpp control becomes high. In order to improve such a problem, it is sufficient to use a power value that is likely to be large as the first threshold value τμ in a range smaller than the second control signal P0 corresponding to the difference when the Vpp voltage is 〇. Thereby, even if the Vpp voltage is not too large, the possibility that the second control signal is less than the first threshold Th1 can be increased. In this way, the large value is set as the state of the first threshold TM of 201014473, and the control method of the axial rate (4) (4) can be controlled in the subsequent etching process. In a preferred embodiment, the plasma control device of the present invention includes an alarm unit that is configured such that when the high frequency power that is rotated by the power supply unit is equal to or less than the first threshold and the second threshold is equal to or longer than a predetermined time. , issued an alarm.

The Pf control system Pf power is maintained at the power value corresponding to the second threshold Thi. Therefore, the power of the Pf control is the same as the first cabinet value Thl. In contrast,

The Vpp control system causes the Vpp power to be pf power (corresponding to the first control signal) having substantially the same voltage value as the target voltage when the second threshold value Thi is not exceeded. The Vpp control system controls the Pf power to cause the Pf power to reach the first clamp signal. Therefore, the Pf power at the time of Vpp control is less than the i-th threshold Th1. When the adhesion to the contact device and the B-port is attached, the power required to maintain the Vpp voltage is constant. Therefore, when the adhesion of g to the etching device increases, the Pf power at the time of V卯 control becomes large. . As described above, when the plasma control device of the present invention has the above-described alarm portion, the amount of A deposit adheres to the environment of the device, and an alarm is issued only when the Vpp control is subscribed. Therefore, the plasma control device of the present invention has the above-described alarm unit, and can facilitate the operator to perform regular maintenance and repair of the surname device at a good timing (for example, (4) cleaning of the device, etc.). The present invention provides a plasma control device which can etch at a high etching rate and suppress Pf power by suppressing a decrease in the rate of time (4) and (4) after the start of the fourth time. And the overshoot of the Vpp voltage. 201014473 Brief description of the drawings Fig. 1 (4) and (b) are graphs showing the relationship between the first control signal and the Vpp voltage, and the relationship between the Pf power and the Vpp voltage. Figure 2 shows a schematic diagram of the plasma control device, the etching device, and the controller. Fig. 3 shows a specific example of a control circuit that can constitute a control unit and a limiter circuit that can constitute a limiter. Fig. 4 (a) to (f) are diagrams for explaining an etching method for etching a remnant material by performing an etching process and a protective film forming process in an interactive manner. Fig. 5 (a) to (7) show the magnitude of the application of the high-frequency voltage when performing the etching process by the plasma control device of the embodiment, the magnitude of the application of the high buccal voltage when the etching process is performed by Pf control, and the delay The conventional Vpp control controls a graph of the magnitude of the applied high frequency voltage during the etching process. Fig. 6 is a graph showing the amount of adhesion of the adhering matter attached to the etching apparatus and the magnitude of Pf power when the vpp voltage is maintained constant. [Implementation of the cold type] The second embodiment of the present invention is a plasma control apparatus 1 of the present embodiment, an etching apparatus 20 for supplying Pf power from the plasma control unit 10 of the present embodiment, and a control plasma. A schematic diagram of the control device 10, the controller 30 of the etching device 20, and the like. As shown in FIG. 2, the etching apparatus 20 includes a processing chamber 21, an antenna 22, a base 23, an exhaust gas exhaustor 24, and a gas supply device 25. The processing chamber 21 has an occlusive space on the inner side that can be filled with gas. This closed space is composed of an electropolymerization generating chamber 21a and an 11 201014473 reaction chamber 21b provided on the lower side of the plasma generating chamber 21a. The antenna 22 is formed in a coil shape and arranged to be wound around the upper portion of the processing chamber 2i. The day and the line 22 are connected to the source power supply unit 26 for supplying high frequency power to the antenna by the source integration unit 27. The source integration unit 27 integrates the impedance of the antenna 22 and the source power supply unit 26. When the high frequency power is supplied from the source power supply unit 26 to the antenna 22, a magnetic field is formed in the closed space processed to 21. The gas filled in the closed space of the processing chamber 21 is plasmad by the electric field induced by the formed magnetic field. ❹ The base 23 is placed in the closed space of the processing chamber 21, and the surnamed material 4 can be placed. A crucible is used as the material of the material to be etched 4. The exhaust unit 24 discharges gas from the closed space of the processing chamber 21, and decompresses the closed space of the processing chamber 21 by (4) exhaust. The exhaust unit 24 includes an exhaust pipe 24a that connects the side walls of the reaction chamber 211) of the processing chamber 21, a vacuum pump 24b that connects the exhaust pipe 24a, and a flow rate adjusting mechanism 24c that adjusts the flow rate of the gas flowing through the exhaust pipe 24& The amount of exhaust gas from the occlusion space of the processing chamber 21 is adjusted by the flow rate adjusting mechanism 24c. The gas supply device 25 supplies an etching gas and a protective film forming gas to the closed space of the processing chamber 21. The gas supply device 25 includes a supply pipe 25a that connects the ceiling portion of the plasma generating chamber 21a of the processing chamber 21, flow rate adjusting mechanisms 25b and 25c, and a high-pressure gas container 25d that is connected to the supply pipe 25&ample by the flow rate adjusting mechanism 25b. The local pressure gas damper 25e of the supply pipe 25a is connected by the flow rate adjustment mechanism 25c. The gas supply 12 supplied to the closed space of the processing chamber 21 by the high-pressure gas containers 25d and 25e is adjusted by the flow rate adjusting mechanisms 25b and 25c. The pressure gas container 25d is filled with an etching gas, and the high-pressure gas container 25e is filled with a protective film forming gas. . For example, SF6 gas can be used as the etching gas, and C, 8 gas can be used as the protective film forming gas. The plasma control device 10 includes a power supply unit n, an integration unit 12, a control unit 13, and a restriction unit 14. The power supply unit u supplies power to the base 23 of the etching apparatus 2A. The integration unit 12 connects the power supply unit 11 and the base 23, and integrates the impedance of the power supply unit η with the plasma generated in the closed space of the processing chamber 21. The control unit 13 outputs a first control signal Pf1 corresponding to the power value of the pf power, and the power value of the Pf power is applied to the Vpp of the base 23 by the pf power supplied from the power supply unit 丨丨 to the base 23 . The voltage is approximately the same as the target voltage. The Vpp voltage is the potential between the base 23 and the ground, and is measured by the integration unit 12. The actual voltage signal Vpp corresponding to the Vpp voltage is input from the integration unit π to the control unit 13. Further, the controller 3 inputs a target voltage signal vppsetpt corresponding to the target voltage to the control unit 13. The control unit 13 acquires the first control signal pfi based on the actual voltage signal Vpp input from the integration unit 12 and the target voltage signal Vppsetpt input from the controller 3. When the first control signal Pfl outputted from the control unit 13 is equal to or higher than the second control signal Pf2 corresponding to the first threshold, the limiter 14 inputs the second control signal Pf2 to the power supply unit 。. Further, when the first control signal Pfl outputted from the controller 13 is less than the second control signal Pf2, the limiter 14 inputs the first control signal Pfl to the power supply unit η. In the present embodiment, the first threshold value is set so that the Vpp voltage is substantially the same as the target voltage and is stable after the attachment of the attachment device 20 is removed by the cleaning device 20, and is stable. The measured value of the Pf power supplied to the base is a large value. By controller 3 〇 limit 13 201014473

The controller 14 inputs the second control signal pf2 corresponding to the first threshold. As shown in Fig. 3, the control unit 13a having the differential amplifier 13b and the control unit 13 can be configured to constitute the limiter 14 by the limiter circuit 14a. The measured voltage signal Vpp corresponding to the VPP voltage measured by the integrating unit 12 and the target voltage signal Vppsetpt corresponding to the target voltage are input to the differential amplifier 13b constituting the control circuit 13a. The i-th control signal Pfl corresponding to the power value of the Pf power which makes the Vpp voltage substantially the same as the target voltage is output from the differential amplifier 13b. On the other hand, the first control signal Pfl outputted from the differential amplifier 13b and the second control signal Pf2 corresponding to the first threshold are input to the limiter circuit 14a. When the first control signal Pfl is equal to or greater than the second control signal Pf2, the limiter circuit 14a outputs the second control signal Pf2 to the power supply unit 11, and outputs the second control signal Pf2 to the power supply unit 11 when the first control signal Pfl is less than the second control signal Pf2. The first control signal Pfl. The controller 30 includes a supply flow rate control unit 31, an exhaust gas flow rate control unit 32, a base power control unit 33, a coil power control unit 34, and a threshold value setting unit 35. The supply flow rate control unit 31 controls the flow rate adjustment mechanisms 25b and 25c of the gas supply device 25 to control the supply amount of the gas supplied from the high pressure gas containers 25d and 25e to the closed space of the processing chamber 21. The exhaust gas flow rate control unit 32 controls the flow rate adjusting mechanism 24c of the exhaust unit 24 to control the amount of exhaust gas of the gas discharged from the closed space of the processing chamber 21 by the vacuum pump 24b. The base power control unit 33 instructs the supply of the Pf power to the power supply unit of the plasma control device 10! And monitoring the power value of the Pf power. The coil power control unit 34 instructs the source power source unit 26 to supply high frequency power to the antenna 22, and monitors the power value of the pf power. The threshold setting unit 35 inputs the second control signal Pf2 corresponding to the first threshold value 14 201014473 to the limiter 14, and inputs the target voltage signal Vppsetpt corresponding to the target voltage to the control unit 13. The threshold setting unit 35 stores a function indicating the relationship between the second threshold and the second control signal Pf2. Further, the threshold setting unit 35 can convert, for example, the first threshold input by the operator using a keyboard or the like into the second control signal.乜 and enter the limiter 14. Similarly, the threshold setting unit 35 memorizes a function of the relationship between the target voltage and the target voltage signal Vppsetpt. Further, the threshold setting unit % can convert the target voltage input by the operator using a keyboard or the like into the target voltage signal Vppsetpt, for example, and input it to the controller 13. Next, etching of the material to be etched 4 placed on the base 23 of the etching apparatus 2 will be described. The etching method described here is a method of etching the etched material 4 by performing an etching process and a protective film forming process in an interactive manner. First, explain the whole method of money engraving. As shown in Fig. 4(a), a mask 41 is formed in a portion of the material to be etched 4 placed on the base 23 except for the portion to be etched. With respect to the material to be etched 4 in which the mask 41 has been formed, the protective film forming process is first performed. When the protective film forming process is performed, the supply flow rate control unit 31 of the controller 30 controls the flow rate adjusting mechanisms 25b and 25e to supply the protective film forming gas to the closed space of the processing chamber 21 from the pressurized gas container 25e filled with the protective film forming gas. When the protective film forming process is performed, the supply flow rate control unit 32 of the controller 3 is configured to control the flow rate adjusting mechanism 24c of the exhaust unit 24 by maintaining the closed space of the processing chamber 21 at a predetermined pressure. When the protective film forming process is performed, the coil power control unit 34 of the controller 30 instructs the source power supply unit 26 to supply the 焉 frequency power to the antenna 22. When the high frequency power is supplied to the antenna 22 by the source power supply unit 26 of 15 201014473, the protective film forming gas filled in the closed space of the process chamber 21 is plasma. As shown in FIG. 4ffl(b), in a state where the protective film forming gas is plasma-formed, a polymer can be generated from the atomic group of the protective film forming gas, and the polymer is deposited on the surface of the plate-removed material 4, and The deposition of the polymer forms a protective film 42 on the surface of the material to be etched 4. Once the protective film 42 is formed, a credit carving process is performed. When the surname process is performed, the supply flow rate control unit 31 of the controller 30 controls the flow rate adjustment mechanisms 25b and 25c to supply the engraved gas to the processing chamber from the high-pressure gas container 254 filled with the etching gas. When the etching process is performed, the exhaust gas flow control unit 32 of the controller 30 is configured to discharge the protective film from the occlusion space of the processing chamber 21 to form a gas, and to maintain the pressure of the etching gas in the occlusion space of the processing chamber 21 at a predetermined pressure value. And the flow rate adjusting mechanism 24c of the exhaust unit 24 is controlled. When the etching process is performed, the base power control unit 33 of the controller 30 instructs the power supply unit u of the plasma control unit to supply Pf power to the base 23. When electric power is supplied to the base 23, a potential difference is generated between the plasma and the base 23. When the potential difference is generated, the atomic group of the plasma reacts with the material to be etched, and the plasma ion impact protection film 42 and the surname 4 are. As shown in Fig. 4 (4), by the reaction of the atomic group with the material of the engraved material, the ion impact protection film 42 and the (4) engraved material 4 are removed from the unmasked portion of the (four) material 4. The film 42 and the material to be etched 4 can be etched. Once it is inscribed by Silver Rim 4, the secret degree is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ In the case of the shape, the etching process is carried out, and the portion which has been left as shown in Fig. 4(e) is further engraved. In the above description of the moon's meal engraving, the removal of the protective film 42 and the surname are performed at the bottom 43 of the hole where the ion irradiation amount is large. On the other hand, only the side surface portion 44 of the hole having a small amount of ion irradiation removes the protective film 42. This is used only for the bottom of the hole. In the case of the surname engraving of the surname engraving and the process of forming a protective film, M3 is not perpendicular to the direction of the digging direction (the left and right directions in Fig. 4(f)) Reaming, you can dig deep into the last name. In the following, the Vpp voltage at the time of the etching process described above, the Vpp voltage when the conventional Pf control is performed, and the conventional V using the delay control are performed by the plasma control device 10 of the present embodiment. The VPP voltage at the time of the control is compared, and the etching process performed by the plasma control device of the present embodiment will be described. Fig. 5 (a) and (d) show the VPP voltage at the time of etching operation by the conventional Pf control. Fig. 5 (b) and (e) show the Vpp voltage at the time of etching work performed by the conventional VPP control using the delay control ❹. Fig. 5 (c) and (f) show the Vpp voltage at the time of performing the etching process by the plasma control apparatus 1 of the present embodiment. Further, Fig. 5 (a), (b) and (c) show the vpp voltage when the etching process (corresponding to Fig. 4 (b)) performed immediately after the cleaning of the etching apparatus 2 is performed. Figs. 5(d), (e) and (f) show the Vpp voltage at the time of etching work in which the adhering matter adheres to the etching apparatus 20. Fig. 1(a) is a graph showing the relationship between the first control signal (the power value of the Pf power having the Vpp voltage which is substantially the same as the target voltage) and the difference between the Vpp voltage and the target voltage. As shown in Fig. 1(a), when the difference becomes 17 201014473, that is, when the Vpp voltage becomes larger, then the first! The control signal becomes smaller. In the present embodiment, the value is set to be larger than the reference pf power, that is, the first control signal P 对应 corresponding to the Vpp voltage and the difference of 0 is set, and the range between the reference pf power and the reference pf power is included. The predetermined power value is taken as the first threshold value Thl. Shortly after the start of the money, the Vpp voltage was zero. Therefore, the second control signal Pf1 shortly after the start of etching is equal to or higher than the second control signal pf2 corresponding to the first threshold Th1. Therefore, the second control signal Pf2 is inputted from the limiter to the power supply unit 11 shortly after the start of etching. When the second control signal Pf2 is input to the power supply unit 11, the Pf power corresponding to the second control signal Pf2 is output. In other words, when the i-th control number Pfl is equal to or greater than the first threshold, the power supply unit 控制 controls the Pf power to be maintained at the power value corresponding to the first threshold. In this way, since the Pf control is performed shortly after the start of etching, the Vpp voltage can be sharply increased by the same degree as the case where the etching rate is controlled by the Pf control only as shown in FIGS. 5(a) and (d). . Therefore, it is possible to suppress a decrease in the etching rate shortly after the start of etching. Thus, the plasma control apparatus 1 of the present embodiment can suppress the decrease in the etching rate shortly after the start of etching. @ By the Pf control shortly after the start of the remaining time, the Pf power can be maintained at a value which is larger than the reference Pf power set as the first threshold value Thl. As shown in Fig. 1(b), the relationship between the Pf power and the Vpp voltage is usually a relationship in which the Vpp voltage increases as the Pf power increases. When the Pf power is maintained at a value larger than the reference Pf power, the Vpp voltage becomes larger than the target voltage. When the Vpp voltage is larger than the target voltage, as shown in the first 圊(4), the difference between the Vpp voltage and the target voltage is larger than the difference (ie, 〇) when the Vpp voltage is the target voltage (refer to Figure 1 (^). 18, 201014473 VI) 'The first control signal pfi is smaller than the reference Pf power (refer to P1 of Fig. 1 (4)). When the first control signal Pfl becomes less than the second threshold Pf2, the power supply unit 11 is operated by the limiter 14. The first control signal pfl is input. When the first control signal pfl is input to the power supply unit 11, the Pf power corresponding to the first control signal 输出 is output. In other words, the power supply unit 11 is "not full" in the first control signal. At the time of one value, 'the Vpp control of the control pf* power is performed so that the first control signal is Pf power.

The Vpp control system controls the Vpp voltage to be approximately the same as the target voltage, so that even if the relationship between the Vpp voltage and the pf power is changed, the vpp voltage is not lowered. As shown in Fig. 5(d), the plasma control device 1 of the present embodiment can suppress the adhesion of the adhering matter attached to the etching device 20 with an lapse of time, so that the surname rate is accompanied by the elapsed time. Reduced situation. As described above, the plasma control apparatus 1 of the present embodiment can perform the engraving with a high surname rate by suppressing the decrease in the etching rate accompanying the elapsed time and the decrease in the etching rate shortly after the start of etching. And can suppress the overshoot of power and Vpp voltage. Further, each time an etching process is performed, the deposit adheres to the etching apparatus 2〇. As a result, in the case where the etching process is repeated, the etching process in the subsequent order is performed in an environment where a large amount of adhering matter adheres to the etching device 20. In the foregoing case, maintaining the Pf power at the timing, the Vpp voltage is lowered accompanying an increase in the attachment attached to the butterfly device. The VPP voltage at the time of Pf control in the subsequent (4) project is smaller due to the & As shown in Fig. 4 (4), when the difference is subtracted from the Vpp voltage (the Vpp voltage becomes large), the i-th control signal becomes small. Therefore, the more the order is, the higher the efficiency of the first threshold Thl is, the less the first control signal will become less than the Pf control shortly after 201014473. In order to improve such a problem, it is sufficient to use the largest possible power value as the first threshold value Th1 in a range where the first control signal is smaller than when the vpp voltage is zero. Thereby, even if the Vpp voltage is not too large, the possibility that the first control signal is less than the first threshold Th1 can be increased. In this way, the state in which the large value is set as the first threshold value Thl can be more reliably switched from the Pf control to the Vpp control in the subsequent sequential engraving process. Further, the plasma control device 1 of the present embodiment may include an alarm unit 15 that issues an alarm when the Pf power output from the power supply unit 11 is equal to or lower than the first threshold and the second threshold or more for a predetermined time or longer. The alarm unit 15 monitors the Pf power value output from the power supply unit 11. Further, the alarm unit 15 receives the third control signal ρβ corresponding to the second threshold value by the controller 3〇.

The Pf control system Pf power is maintained at a power value corresponding to the first threshold value Thl. Therefore, the Pf power at the time of 'Pf control is the same as the first threshold value Th1. On the other hand, the Vpp control system performs the power generation (corresponding to the first control signal) in which the Vpp voltage is substantially the same as the target voltage, when the i-th threshold Th1 is not exceeded. The Vpp control system controls the Pf power to cause the Pf power to reach the first control signal. Therefore, the Pf power at the time of vpp control is less than the first threshold Th1. When the deposit attached to the surname device 20 increases, the pf power necessary to maintain the Vpp voltage constant is increased. Therefore, when the adhering matter attached to the etching apparatus 2 is increased, the Pf power at the time of Vpp control becomes large. As described above, when the plasma control device 1 has the alarm portion 15, a large amount of deposits adhere to the environment of the etching device 2, and an alarm is issued only when the Vpp control is performed. Therefore, when the plasma control device 2 has the alarm portion 15, it is possible to facilitate the operator to perform etching at a good timing. 20 201014473 Periodic maintenance of the device 20 (for example, cleaning of the money engraving device 2, etc.). Further, the function of issuing an alarm can be possessed by, for example, the base station power control unit 33 of the controller 3. For example, when the pf power is equal to or less than the first threshold and the second threshold is equal to or longer than the second threshold for a predetermined time or longer, the soft body is introduced to the base power control unit 33, and the threshold setting unit 35 sets the jth threshold Th1 and the second threshold. The configuration of the base power control unit 33 is input. Thereby, the base power control unit 33 can have a function of issuing an alarm. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 (a) and (b) are graphs showing the relationship between the first control signal and the Vpp voltage, and a graph showing the relationship between the Pf power and the Vpp voltage. Figure 2 shows a schematic diagram of the plasma control device, etching device, and controller. The control circuit of the η 丹 取 屮 、 、 、 。 。 。 。 。 。 。 。 。 。 。 。 。 。 m ❹ Fig. 4 (4) ~ _ is used to illustrate the method of etched by the interaction and the process of forming a protective film. Fig. 5 (4) to _ show the magnitude of the application of the high-frequency voltage when the plasma control device of the embodiment is applied to the etching process, the magnitude of the applied high-frequency voltage when the Pf is controlled by the Pf control, and the delay from the private use. The conventional Vp control of the control performs a graph of the application of the high frequency core size. Figure 6 shows the maintenance of the Vpp voltage.

, + The graph of the adhesion amount of the adhering substance attached to the etching device S and the Pf power, 2 size. [Explanation of main component symbols] 4... Surnamed material n & Plasma control device 21 201014473 11... Power supply unit 12: Integration unit 13... Control unit 13a··· Control circuit 13b···Differential amplifier 14... Restriction unit 14a···limiter circuit 15...alarm unit 20...etching device 21...processing chamber 21a··plasma generating chamber 21b...reaction chamber 22...antenna 23...base 24...exhaust device 24a...exhaust pipe 24b...vacuum pump 24c...flow rate adjustment mechanism 25...gas supply device 25a...supply pipe 25b,25c...flow rate adjustment mechanism 25d,25e...high pressure gas container 26...source power supply unit 27...source integration unit 30...controller 31 ...supply flow rate control unit 32...exhaust flow rate control unit 33...base power control unit 34...coil power control unit 35...threshold value setting unit 41...mask 42...protective film 43...bottom of the hole 44···the side of the hole Part PO, Pfl...first control signal Pf2...second control signal Pf3...third control signal Vpp...measured voltage signal Vppsetpt...target voltage signal Thl".first threshold Th2...second threshold

twenty two

Claims (1)

201014473 VII. Patent Application Range 1. A plasma control device for supplying high frequency power to an etching device for etching by plasma, characterized in that the etching device includes a base, and the base is The plasma control device includes: a power supply unit that supplies high frequency power to the base station; and a control unit that outputs the first control signal. And the first control signal corresponds to a power value of the high-frequency power to which the applied high-frequency voltage applied to the base is substantially the same as the target voltage by the supply of the high-frequency power; and a limiter. When the first control signal outputted by the control unit is equal to or higher than the second control signal corresponding to the first threshold, the second control signal is input to the power supply unit, and the first control signal output by the control unit is not When the second control signal is full, the first control signal is input to the power supply unit, and the power supply unit output corresponds to the first control signal or the second control signal input by the limiter. The high frequency power. 2. The plasma control device according to claim 1, wherein the etching device etches the etching process of the material to be etched by alternately and repeatedly, and forms a surface of the material to be etched exposed by the etching process. The protective film forming process of the protective film etches the above-mentioned material to be etched. 3. The plasma control device according to claim 1 or 2, further comprising an alarm 23 201014473, wherein the high frequency electric power outputted by the power supply unit is equal to or lower than the first threshold and longer than a second threshold An alarm is issued when the time is above the scheduled time. twenty four