JP2005353812A - Device and method for plasma processing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make plasmatic a process gas in a process container by a high frequency power, and to optimize a plasma state when a board mounted on a mounting tray is subjected to a plasma process, whereby the board is subjected to the plasma process at a high in-plane uniformity. <P>SOLUTION: In this structure, the plasma process is performed in a state that a temperature difference is formed by a temperature adjusting mechanism so that the temperature at a ring provided so as to surround the periphery of the board is higher by 50°C or more than the temperature of the board on the mounting tray. Thus, as the density of the active seed of a plasma near the fringe of the board is apt to reduce, for example, even if the density of the active seed near the fringe of the board is increased by influences of an exhaust stream in the process container, the density difference of the active seed is suppressed small between a region near the fringe and the inside region. As a result, the board can be subjected to the plasma process at the high in-plane uniformity. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a plasma processing apparatus and a plasma processing method for performing a predetermined process such as an etching process on a substrate such as a semiconductor wafer using plasma.

  In the manufacturing process of semiconductor devices, for example, in order to separate capacitors and elements, or to form contact holes, dry etching or film formation processing by plasma is performed on a substrate such as a semiconductor wafer (hereinafter referred to as “wafer”). Has been done. As one of apparatuses for performing these processes, a single-wafer type parallel plate type plasma processing apparatus that generates plasma by applying a high-frequency voltage between an upper electrode and a lower electrode is used.

  FIG. 9 shows a schematic view of this type of plasma device. Briefly explaining the outline of the apparatus, an upper electrode 11 that also serves as a gas shower head and a lower electrode 12 that also serves as a substrate mounting table are provided vertically inside an airtight container 1 that forms a vacuum chamber. Further, a focus ring 13 made of quartz, for example, is provided so as to surround the periphery of the wafer 100 placed on the lower electrode (mounting table) 12. In the figure, reference numeral 14 denotes an electrostatic chuck for electrostatically adsorbing the wafer 100, and a foil-like electrode 15 to which a chuck voltage from a power source (not shown) is applied is provided inside the electrostatic chuck 14. . A predetermined processing gas selected according to the type of processing is injected from the gas shower head (upper electrode) 11 toward the wafer 100 and evacuated by the vacuum pump 16 so that the inside of the hermetic container 1 has a predetermined pressure. When a high-frequency voltage is applied between the upper electrode 11 and the lower electrode 12 by the high-frequency power source 17 in the state maintained in this state, a predetermined process such as etching is performed on the wafer 100 by converting the processing gas into plasma.

  Here, since the processing gas sprayed from the gas shower head (upper electrode) 11 and has reached the vicinity of the surface of the wafer 100 is exhausted from the periphery of the wafer 100 outward and downward, the periphery of the wafer 100 (near the periphery). The gas flow of the processing gas is different between the region near the center and the region near the center, so that the balance of the predetermined component ratio in the processing gas is lost at the peripheral portion of the wafer 100, and the region where the wafer 100 is placed The values of impedance component, conductance component, etc. between the plasma and the lower electrode 12 are different from the outside. Specifically, the dissociation degree of the processing gas is higher on the peripheral side of the wafer 100 near the exhaust space than the region near the center, and thus the plasma density in the vicinity of the peripheral portion is increased, resulting in the wafer. When viewed in the plane of 100, the etching rate at the peripheral edge portion may be larger than the etching rate at the central portion.

  On the other hand, in order to increase the utilization rate of the wafer 100, there is a strong demand for forming a device as close to the periphery of the wafer 100 as possible, and thus high in-plane uniformity is ensured with respect to the etching rate up to the vicinity of the periphery of the wafer 100. There is a need. For this reason, a focus ring 13 made of, for example, a conductor, a semiconductor, or a dielectric is disposed so as to surround the periphery of the wafer 100, and the plasma density above the peripheral edge of the wafer 100 is adjusted. Specifically, the material and optimum shape of the focus ring 13 are selected according to the type of processing gas and the material of the film to be etched, and the focus ring 13 suitable for the processing is installed.

  Further, in order to stabilize the plasma processing state between the wafers, a heating plate (heater) is coated on the protection plate corresponding to the focus ring 13, and a temperature sensor is attached to the temperature of the protection plate due to ion bombardment. A method is known in which the heating by the heating element is adjusted in response to the rise and the protective plate is kept at a constant temperature (see, for example, Patent Document 1).

JP 7-310187 A (the end of paragraph 0010 and FIG. 5)

  However, if the type of film to be etched is different, the type of processing gas is different, and further, in-plane uniformity of the in-plane processing of the wafer 100 may be required due to the recent progress of pattern miniaturization. Therefore, there is a concern that it is more difficult to determine conditions such as an optimal material and an optimal shape for controlling the plasma density in the vicinity of the peripheral edge of the wafer W by the focus ring 13. Therefore, further study is necessary to suppress the plasma density near the peripheral edge of the wafer 100 from becoming higher than that in the inner region.

  The present invention has been made under such circumstances, and an object of the present invention is to optimize the plasma state by adjusting the temperature difference between the substrate and the ring portion surrounding the substrate. An object of the present invention is to provide a plasma processing apparatus and a plasma processing method capable of performing plasma processing with high in-plane uniformity.

The plasma processing apparatus of the present invention is a plasma processing apparatus that converts a processing gas into a plasma with a high-frequency power in a processing container, and performs processing on the substrate placed on the mounting table with plasma.
A ring portion provided to surround the periphery of the substrate on the mounting table,
And a temperature adjustment mechanism for forming a temperature difference so that the temperature of the ring portion is higher than the substrate by 50 ° C. or more.

  For example, a gas that generates chlorine radicals may be used as the processing gas. Moreover, the structure which is at least one of the heating means which heats a ring part, and the cooling means which cools a mounting base may be sufficient as the said temperature adjustment mechanism.

A plasma processing apparatus according to another invention is a plasma processing apparatus that converts a processing gas into a plasma with high-frequency power in a processing container, and performs processing on the substrate mounted on the mounting table with plasma.
A ring portion provided to surround the periphery of the substrate on the mounting table,
A temperature adjustment mechanism for forming a temperature difference so that the temperature of the ring part is 50 ° C. or higher than that of the substrate;
Means for storing the temperature difference for each type of process processing and controlling the temperature adjusting mechanism so as to obtain a temperature difference corresponding to the selected process.

The plasma processing method of the present invention uses a plasma processing apparatus provided with a ring part so as to surround a mounting table in a processing container,
A step of placing the substrate on the mounting table;
Next, supplying a processing gas into the processing container, converting the processing gas into plasma with high-frequency power and processing the substrate with plasma,
And a step of forming a temperature difference between the ring portion and the substrate so that the ring portion is higher by 50 ° C. or more while the substrate is being processed by plasma. For example, a gas that generates chlorine radicals may be used as the processing gas.

The plasma processing method of another invention uses a plasma processing apparatus provided with a ring portion so as to surround a mounting table in a processing container,
A process that is performed on the product substrate so that the temperature of the ring portion is higher than that of the product substrate when the dummy substrate is placed on the mounting table and the product substrate is processed. A step of raising the temperature of the ring by generating plasma under more severe processing conditions;
Subsequently, a step of replacing the dummy substrate on the mounting table with a product substrate,
Then, a process gas is supplied into the process container, and the process gas is converted into plasma by high-frequency power and the substrate for the product is processed by plasma.

  According to the present invention, by setting the temperature of the ring portion to be higher than the temperature of the substrate, the density of active species of plasma in the vicinity of the peripheral portion of the substrate is higher than the density of active species in the inner region. Try to get smaller. For this reason, for example, even if the density of active species in the vicinity of the peripheral edge of the substrate becomes larger than the density of active species in the inner region due to the influence of the exhaust flow, the density difference is canceled by providing the temperature difference. Can be kept small. As a result, plasma processing with high in-plane uniformity can be performed on the substrate.

  Further, by setting the temperature difference according to the type of plasma processing, it is possible to perform processing with high in-plane uniformity on the substrate in each process processing. Furthermore, if the dummy substrate is used to generate plasma under severe conditions to raise the temperature of the ring portion and then the processing is performed on the product substrate, the temperature difference is provided. This eliminates the need for a dedicated temperature adjustment mechanism.

  An embodiment in which a plasma processing apparatus according to the present invention is applied to an etching apparatus will be described with reference to FIG. In the figure, 2 is a hermetically formed processing container made of a conductive member such as aluminum. An exhaust port 21 is provided at the bottom of the processing container 2, and the exhaust port 21 is connected to a vacuum pump 22 such as a vacuum molecular pump or a dry pump through an exhaust path 21 a. Further, a wafer transfer port 24 having a gate valve 23 that can be opened and closed is provided on the side wall of the processing chamber 2.

  An upper electrode 3 that also serves as a gas shower head, which is a gas supply unit for introducing a predetermined processing gas, for example, an etching gas, is provided inside the processing container 2. A large number of gas diffusion holes 31 are formed on the lower surface side of the upper electrode 3, and the processing gas sent from the processing gas supply source 32 through the supply path 33 is supplied to the wafer 100 located on the lower side. It is configured to be able to supply over the entire surface. Further, an insulating member 34 made of, for example, quartz is provided so as to surround the upper electrode 3, so that the upper electrode 3 is electrically insulated from the side wall of the processing vessel 2.

  Further, a substrate mounting table (mounting table) 4 is provided inside the processing container 2 so as to face the upper electrode 3. An insulating member 40 may be interposed between the substrate mounting table 4 and the processing container 2. The substrate mounting table 4 is provided with, for example, a columnar support portion 41 that also serves as a lower electrode made of a conductive member such as aluminum. A mounting plate 42 on which the wafer 100 is placed is placed on the upper end surface of the support portion 41. Is provided. The mounting plate 42 is formed as a dielectric plate made of a dielectric material such as ceramics such as aluminum nitride, and a foil-like electrode (electrostatic chuck electrode) 43 is provided on the upper surface side inside the mounting plate 42. On the side, a first temperature adjustment unit for adjusting the temperature of the wafer 100, for example, a mesh heater 44 as a heating means is provided.

  Furthermore, a first temperature detector 45 such as a fluorescent optical fiber thermometer for detecting the temperature of the wafer 100 placed on the surface of the mounting plate 42 is provided, for example, at the center. Yes. Reference numeral 46 in the figure denotes an exhaust ring having a large number of through holes formed on the surface thereof so that the processing gas is uniformly exhausted from the peripheral portion of the wafer 100 in the circumferential direction. Although illustration is omitted, substrate support pins that can be raised and lowered while supporting the wafer 100 from the back side are provided so as to be able to project and retract from the surface of the substrate mounting table 4, so that the wafer transfer entering from the outside of the apparatus can be carried out. The wafer 100 is transferred to the substrate mounting table 4 by the cooperative action of the mounting arm and the substrate support pins.

  For example, one end of a power supply rod 50a is connected to the support portion 41 which is the lower electrode, the other end of the power supply rod 50a is connected to the high frequency power source 5, and a matching circuit 51 is provided in the middle thereof. . Further, for example, one end of a power feeding rod 50b is connected to the electrostatic chuck electrode 43, the other end of the power feeding rod 50b is connected to a DC power source 52, and a switch 53 is provided in the middle thereof. That is, the electrostatic chuck electrode 43 and the upper dielectric portion constitute an electrostatic chuck for electrostatically attracting the wafer 100. Furthermore, the heater 44 is connected to the heater power source 55 via a conductive rod 54, for example.

  Plasma whose upper surface width is set to 55 mm, for example, made of an insulating member such as quartz, alumina, yttrium oxide so as to surround the entire circumference of the wafer 100 adsorbed and held on the surface of the mounting plate 42 described above. A ring member 6 called a focus ring which is a control ring portion is provided. Inside the ring member 6, for example, a heater 61 as a second temperature adjusting unit, for example, a heating unit is provided along the circumferential direction. The heater 61 is connected to the heater power source unit 63 through, for example, a conductive rod 62. Has been. Further, a second temperature detector 64 for detecting the surface temperature of the ring member 6 is provided on the surface of the ring member 6. In this example, the heater 61 creates a temperature difference between the wafer 100 and the ring member 6 so that the ring member 6 is higher than the wafer 100 by a predetermined temperature, for example, 50 ° C. or higher when the wafer 100 is processed. A temperature adjusting mechanism to be formed is configured.

  The ring member 6 is preferably provided as close to the outer peripheral edge of the wafer 100 as possible, and is provided within 1 mm from the outer peripheral edge of the wafer 100, for example. The surface of the ring member 6 is set at the same height as the surface of the wafer 100 or at a position higher by 2.5 to 7 mm, for example, than the surface of the wafer 100.

  Reference numeral 7 in the figure denotes a control unit. The control unit 7 has a function of controlling operations of the high-frequency power supply unit 5, the switch 53, the vacuum pump 55, a substrate support pin (not shown), the processing gas supply unit 32, the heater power supply units 63 and 55, and the like. Further, the control unit 6 includes a computer (not shown), for example, and includes a temperature detection value of the temperature detector 45 that detects the temperature of the wafer 100 and a temperature detection value of the temperature detector 64 that detects the temperature of the ring member 6. The temperature difference is monitored, and the ring member 6 is connected via, for example, the heater power source 63 so that the temperature detection value of the temperature detector 64 is higher than the temperature detection value of the temperature detector 45 to the predetermined temperature, for example, 50 ° C. or more. It has a function to control the temperature of.

Next, a method of etching the substrate, for example, the wafer 100 using, for example, a chlorine-based processing gas using the above-described etching apparatus will be described. FIG. 2 is a view showing how the metal layer (cap layer) 8 of the gate electrode is etched. 80a is a silicon layer, 80b is a gate insulating film made of, for example, an SiO ₂ film, 80c is a polysilicon layer that is a gate electrode layer, and the metal layer 8 is laminated on the upper surface of the polysilicon layer, for example, tungsten (W) or A tungsten silicide (WSi) layer is formed. Reference numeral 81 denotes a mask pattern made of, for example, a resist formed in a predetermined circuit pattern. As in this example, when plasma active species generated from a chlorine-based gas, for example, chlorine radicals are used as the main etchant (that is, when etching acceleration is controlled by the etching action of chlorine radicals), it is also apparent from the examples described later. As described above, the temperature difference between the wafer 100 and the ring member 6 is set to 50 ° C. or more, for example.

  Here, an example of generation of the gate electrode is given as an example of etching of the metal layer 8 formed of the W layer or the WSi layer. However, the present invention provides a metal layer interposed between the wiring layer and the interlayer insulating film. The present invention is also applied to the case where the W layer or WSi layer formed is etched. However, the etching object of the present invention is not limited to the W layer or the WSi layer, and can be applied to, for example, polysilicon etching.

  First, the gate valve 23 is opened, the wafer 100 is loaded into the processing container 2 from the load lock chamber (not shown) via the wafer transfer port 24, and heated to a predetermined temperature by the heater 44 via a substrate lift pin (not shown). The wafer 100 is mounted on the mounting plate 42. At this time, the ring member 6 is also heated by the heater 61. Thereafter, the switch 53 is turned on to apply a DC voltage, which is a chuck voltage, to the electrostatic chuck electrode 43, thereby electrostatically adsorbing the wafer 100 onto the surface of the mounting plate 42.

  Here, the heater 44 is controlled so as to heat the wafer 100 to such a temperature that a suitable plasma process can be performed on the wafer 100, for example, a temperature at which a predetermined etching rate can be obtained in the central portion of the wafer 100. This temperature set value is input from the plasma when the wafer 100 is exposed to the plasma, and the wafer 100 is heated by the heat input and the heat from the heater 44. It is determined by adjusting and obtaining an appropriate temperature of the wafer 100. On the other hand, the amount of heat generated by the heater 61 is controlled such that the temperature of the ring member 6 is higher than the temperature of the wafer 100 (the temperature of the wafer 100 has almost no distribution in the plane) by, for example, 50 ° C. or more.

Subsequently, after the gate valve 23 is closed to make the processing vessel 2 airtight, for example, chlorine (Cl ₂ ) gas and oxygen (O ₂ ) gas, which are processing gases, are included, and the flow rates thereof are set to 150 sccm and 10 sccm, for example. While etching gas set in each direction is sprayed toward the surface of the wafer 100 through the gas diffusion holes 31, the inside of the processing container 2 is evacuated by the vacuum pump 22, and the inside of the processing container 2 is, for example, 5 mTorr to 100 mTorr ( Maintain a vacuum of about 0.67 to 13.3 Pa). The gas forming the etchant in this example is chlorine gas, and the oxygen gas is an additive gas for promoting the formation of the sidewall protective film. The etching gas sprayed toward the wafer 100 through the gas diffusion holes 31 forms an airflow that flows radially outward along the surface of the wafer 100 and is dispersed using the ventilation resistance of the exhaust ring 46. Due to the action, air is exhausted uniformly from the periphery of the substrate mounting table 4 in the circumferential direction.

  Subsequently, when a high frequency voltage of 100 MHz, for example, is applied to the lower electrode 41 from the high frequency power source 5 through the matching circuit 51 and the power supply rod 50a at 250 to 500 W, for example, the upper electrode 3 and the wafer 100 on the mounting plate 42 are connected. A high-frequency voltage (high-frequency power) is applied between them to turn the etching gas into plasma, thereby generating active species of plasma as an etchant, such as chlorine radicals. At this time, since a temperature difference of, for example, 50 ° C. is formed between the wafer 100 and the ring member 6, a temperature difference corresponding to the temperature difference also occurs in the atmosphere in the vicinity of each surface (only Actually, the processing container 2 is evacuated to have a small heat transfer action and receives heat from the plasma, so the temperature difference in the atmosphere is different from 50 ° C.). That is, the atmosphere in the vicinity of the surface of the ring member 6 has a higher temperature than the atmosphere in the vicinity of the surface of the wafer 100, and as a result, the gas species near the surface of the ring member 6 become higher in the inner region. The density is smaller than. The active species in the plasma are incident on the surface of the wafer 100, and the metal film 8 is etched with a high selectivity with respect to the resist 81 (see FIG. 2B).

  Thereafter, for example, when a predetermined time elapses, the application of the high-frequency voltage from the high-frequency power source 5 and the introduction of the etching gas are stopped, and an inert gas such as nitrogen is introduced into the processing container 2 from, for example, an air supply means (not shown). At the same time, evacuation of the vacuum pump 22 is stopped. Thereafter, the switch 53 is switched to stop the application of the chucking voltage, and the wafer 100 is released from the suction state. Thereafter, the gate valve 23 is opened, and the wafer 100 is unloaded from the apparatus to complete the etching process.

  According to the above-described embodiment, since the surface temperature of the ring member 6 is set to be higher than the surface temperature of the wafer 100, the plasma in the vicinity of the surface of the ring member 6 (that is, in the vicinity of the peripheral portion of the wafer 100). The temperature of the atmosphere becomes higher than the temperature of the inner region, so that the density of the active species in the vicinity of the peripheral edge of the wafer 100 tends to be smaller than the density of the active species in the inner region. For this reason, for example, dissociation of gas species in the vicinity of the peripheral portion is promoted by the influence of the exhaust flow, and if the temperature difference is not controlled, the radical density in the vicinity of the peripheral portion is high as shown in FIG. However, this temperature difference is offset by controlling the density of the active species, and as shown in FIG. 3B, the radical density jumping up in the vicinity of the peripheral edge can be suppressed. Etching can be performed at an etching rate with high in-plane uniformity. In FIG. 3, for convenience of drawing, the electrode 44, the heaters 44 and 61, and the temperature detectors 45 and 64 are not shown.

  In the case where different types of processes are performed on the wafer 100 using different types of processing gases, the following configuration may be used. That is, the control unit 7 includes a computer 90 as shown in FIG. 4, for example, and a plurality of process recipes are stored in a storage unit 91 of the computer 90, for example, a memory. This process recipe includes, for example, process processing conditions corresponding to the type of film to be etched on the surface of the wafer 100, such as a temperature difference between the wafer 100 and the ring member 6, a process pressure, a temperature of the wafer 100, an etching gas Information on set values such as type, temperature and supply flow rate is stored. Reference numeral 92 denotes a recipe selection means for the operator to select a process recipe corresponding to the type of film to be etched, for example. Although the first process and the second process are shown for convenience, the process recipe may be prepared corresponding to the third process, the fourth process,... Conditions such as a set value of a temperature difference between the wafer 100 and the ring member 6 are determined for each process.

  Then, based on the information of the selected process recipe, a predetermined temperature difference is formed between the temperature detection value of the temperature detector 64 and the temperature detection value of the temperature detector 45, for example, via the heater power supply unit 63. To control the temperature of the ring member 6. The heater 44 that heats the mounting plate 42 sets the process temperature of the wafer 100. When the allowable range of the set value is wide, the heater 44 generates heat together with or in place of the heater 61. The temperature difference may be set by adjusting the amount. In the figure, 93 is a CPU and B is a bus. According to this example, each of a plurality of different types of processes can be processed with a suitable temperature difference, so that the finer density of active species can be controlled. That is, in each process processing, processing with high in-plane uniformity can be performed on the wafer 100.

  Next, an example in which a plasma apparatus according to another embodiment of the present invention is applied to an etching apparatus will be described with reference to FIG. The etching apparatus of this example does not include the heater 61 for heating the ring member 6, and performs a preheating described below to form a predetermined temperature difference between the wafer 100 and the ring member 6. Except for this, the same configuration as that of the apparatus shown in FIG. 1 is adopted (the same components are denoted by the same reference numerals and detailed description thereof is omitted).

  In the preheating, a dummy wafer which is a dummy substrate made of, for example, a bare wafer is prepared, and the dummy wafer is processed before the process wafer (wafer 100) which is a product substrate is processed. Thus, the temperature of the ring member 6 is adjusted to a predetermined temperature. Specifically, plasma is generated under conditions more severe than plasma processing performed on a process wafer that is a product substrate. For example, by applying a voltage higher than the high-frequency voltage applied during the actual process by the high-frequency power source 5 to generate plasma at a temperature higher than that in the actual process, the temperature of the member exposed to the plasma in the processing chamber 2 is increased. As a result, the temperature of the ring member 6 also rises.

  Thereafter, when the temperature of the ring member 6 is raised to a temperature at which a predetermined temperature difference is formed with respect to the temperature of the process wafer set during the actual process, that is, when applied to the above-described example, Since the temperature setting value of the wafer 100 is 76 ° C. and the temperature difference is 50 ° C. or more, for example, the temperature of the ring member 6 is increased so that the temperature of the ring member 6 is 126 ° C. or more. In addition to the dummy wafer, the process wafer is carried into the apparatus for processing. Even if it is such a structure, the effect similar to the above-mentioned embodiment can be acquired. Furthermore, according to this example, a dedicated temperature adjustment mechanism for providing the temperature difference is not necessary.

  Further, the present invention is not limited to the configuration in which the ring member 6 is heated to form a temperature difference. For example, a cooling means such as a Peltier element is provided in the mounting plate 42 in place of the heater 44, thereby W may be cooled to form a temperature difference. In this case, the ring member 6 is set to a predetermined temperature by the heater 61, or the predetermined temperature difference with respect to the ring member 6 whose temperature is increased by heat input from the plasma without being heated by the heater 61. The temperature of the wafer W is adjusted by the cooling means so as to be formed. Even if it is such a structure, the effect similar to the above-mentioned case can be acquired.

Next, examples performed to confirm the effects of the present invention will be described.
(Example 1)
In this example, a temperature difference of 50 ° C. is formed between the wafer 100 and the ring member 6 by performing the above-described preheating using the apparatus shown in FIG. Detailed process conditions are listed below. The film thickness of the wafer 100 before and after the etching process is measured at intervals along the X, Y, V, and W axes assigned equally from the center of the wafer W, and the etching rate at each measurement point is measured. FIG. 6 shows the result obtained by calculation.
Etching object: tungsten silicide Etching gas: Cl ₂ (150 sccm) and O ₂ (10 sccm)
・ Pressure: 5 mTorr
・ HF / LF power (for plasma generation / bias); 250W / 200W
・ Magnetic field strength: 56G
Temperature difference: 50 ° C. (ring member 6 = 126 ° C., wafer 100 = 76 ° C.)

(Comparative Example 1)
This example is a comparative example in which the same processing as in Example 1 was performed except that the temperature of the ring member 6 was set to 81 ° C. and a temperature difference of 5 ° C. was formed. The calculation result of the etching rate is shown in FIG.

(Comparative Example 2)
This example is a comparative example in which the same processing as in Example 1 was performed except that the temperature of the ring member 6 was set to 93 ° C. and a temperature difference of 17 ° C. was formed. The calculation result of the etching rate is shown in FIG.

(Results and discussion of Example 1, Comparative Example 1 and Comparative Example 2)
As is apparent from the results shown in FIGS. 6 to 8, in Example 1, the deviation of EE 3 mm was ± 27.38%, and the deviation of EE 30 mm was ± 13.5%. In contrast, in Comparative Example 1, the deviation of EE 3 mm is ± 46.39% and the deviation of EE 30 mm is ± 29.8%. In Comparative Example 2, the deviation of EE 3 mm is ± 32.88% and the deviation of EE 30 mm is ±±. It was 17.38%. Note that EE 3 mm means an average value of a measured value in a region extending from the edge portion of the wafer 100 to the inner side 3 mm, and EE 30 mm means an average value of a measured value in a region extending from the edge portion of the wafer 100 to the inner side 30 mm. That is, the jump of the etching rate of Comparative Example 1 in which the temperature difference between the wafer 100 and the ring member 6 is set to be small is the largest, and the jump of the etching rate of Example 1 in which the temperature difference between the wafer 100 and the ring member 6 is set to be large. Is the smallest. That is, the jumping is remarkably reduced at a temperature difference of 50 ° C.

  From the above results, it was confirmed that the formation of a temperature difference of 50 ° C. between the wafer 100 and the ring member 6 can suppress the jumping of the etching rate at the peripheral portion of the wafer 100. Further, since the jump of the etching rate tends to be reduced by increasing the set value of the temperature difference, it can be understood that the jump of the etching rate can be suppressed by setting the temperature difference to 50 ° C. or more.

It is a longitudinal cross-sectional view which shows the plasma processing apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the mode of the surface of the wafer etched using said plasma processing apparatus. It is explanatory drawing which shows typically distribution and temperature of the radical in the surface vicinity of a wafer. It is explanatory drawing which shows the other example of the control system which the said plasma processing apparatus has. It is a longitudinal cross-sectional view which shows the other example of the plasma processing apparatus which concerns on embodiment of this invention. It is a characteristic view which shows the result of the Example performed in order to confirm the effect of this invention. It is a characteristic view which shows the result of the Example performed in order to confirm the effect of this invention. It is a characteristic view which shows the result of the Example performed in order to confirm the effect of this invention. It is explanatory drawing which shows the conventional plasma processing apparatus.

Explanation of symbols

2 Processing Container 22 Vacuum Pump 3 Upper Electrode 4 Substrate Placement Table 42 Placement Plate 41 Lower Electrode 43 Electrostatic Chuck Electrode 44 Heater 45 First Temperature Detector 6 Ring Member 61 Heater 64 Second Temperature Detector 7 Control Unit

Claims (7)

In a plasma processing apparatus that converts a processing gas into plasma with high-frequency power in a processing container and performs processing on the substrate mounted on the mounting table with plasma,
A ring portion provided to surround the periphery of the substrate on the mounting table,
And a temperature adjusting mechanism for forming a temperature difference so that the temperature of the ring portion is 50 ° C. or more higher than that of the substrate.   The plasma processing apparatus according to claim 1, wherein the processing gas generates chlorine radicals.   The plasma processing apparatus according to claim 1, wherein the temperature adjusting mechanism is at least one of a heating unit that heats the ring portion and a cooling unit that cools the mounting table. In a plasma processing apparatus that converts a processing gas into plasma with high-frequency power in a processing container and performs processing on the substrate mounted on the mounting table with plasma,
A ring portion provided to surround the periphery of the substrate on the mounting table,
A temperature adjustment mechanism for forming a temperature difference so that the temperature of the ring part is 50 ° C. or higher than that of the substrate;
A plasma processing apparatus comprising: means for storing the temperature difference for each type of process processing, and controlling a temperature adjustment mechanism so as to obtain a temperature difference according to a selected process. Using a plasma processing apparatus in which a ring portion is provided so as to surround the mounting table in the processing container,
A step of placing the substrate on the mounting table;
Next, supplying a processing gas into the processing container, converting the processing gas into plasma with high-frequency power and processing the substrate with plasma,
And a step of forming a temperature difference between the ring portion and the substrate so that the ring portion is higher by 50 ° C. or more while the substrate is being processed with plasma. Processing method.   The plasma processing method according to claim 5, wherein the processing gas generates chlorine radicals. Using a plasma processing apparatus in which a ring portion is provided so as to surround the mounting table in the processing container,
A process that is performed on the product substrate so that the temperature of the ring portion is higher than that of the product substrate when the dummy substrate is placed on the mounting table and the product substrate is processed. A step of raising the temperature of the ring by generating plasma under more severe processing conditions;
Subsequently, a step of replacing the dummy substrate on the mounting table with a product substrate,
And a step of supplying a processing gas into the processing container, converting the processing gas into plasma with high-frequency power, and processing the substrate for the product with plasma.

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