JP2008181912A - Plasma treating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma treating apparatus capable of controlling conductance without exchanging a partition board. <P>SOLUTION: The plasma treating apparatus comprises: a treatment vessel, having a generation chamber for generating plasma and a treatment chamber where a substrate to be treated is arranged; and the partition board 111 that is installed so that it partitions the generation chamber from the treatment chamber and has a through hole for passing gas for treatment. The plasma treating apparatus also has a temperature adjustment means for adjusting the temperature of the partition board. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plasma processing apparatus that uses plasma to perform etching, ashing, film formation, modification, etc. on a substrate surface.

  In recent years, a semiconductor manufacturing process using plasma has been used in many processes such as etching, ashing, and CVD (Chemical Vapor Deposition). In these plasma processing apparatuses, a generation chamber for generating plasma and a processing chamber for processing a substrate by the plasma generated in the generation chamber are separated by a partition plate having a plurality of through holes. There is an apparatus, which is proposed in Patent Document 1, for example. In such an apparatus, a pressure difference is generated between the plasma generation chamber and the substrate processing chamber due to conductance based on the hole diameter, the hole length, and the number of holes of the through hole provided in the partition plate. By using this pressure difference, for example, in a CVD apparatus, a method has been proposed in which a source gas serving as a precursor introduced into the plasma processing chamber side is prevented from flowing into the plasma generation chamber side.

  In recent years, as a processing method for controlling the flux of active species reaching the substrate to be processed during plasma processing to an extremely small amount, upstream (or upflow) plasma processing in which the substrate to be processed is provided upstream of the gas flow from the plasma generation region. A so-called method is proposed in Patent Document 2. In the upflow plasma processing method, a method of using a partition plate in which a plurality of through holes are provided between a processing chamber in which a substrate is installed and a plasma generation chamber has been proposed as a method for further reducing the flux of active species. ing. By utilizing the pressure difference generated by the conductance of the partition plate, the back diffusion of the active species is reduced, and plasma processing with extremely low flux becomes possible.

Hereinafter, an example of the downflow plasma processing apparatus will be described with reference to FIG.
Here, 101 is a processing container, 102 is a plasma generation chamber, 103 is a processing chamber, 104 is a substrate to be processed, 105 is a support means, 107 is a gas introduction section, 108 is a gas exhaust section, 109 is a high-frequency power supply means, 110 Is a dielectric material through which high-frequency power is transmitted, and 111 is a partition plate.

  First, the inside of the processing vessel 101 of the plasma processing apparatus is sufficiently evacuated by the exhaust means (not shown) through the gas exhaust unit 108. Next, a gas having a predetermined flow rate is introduced into the generation chamber 102 through a gas introduction unit 107 by a gas introduction unit (not shown), and a desired pressure is obtained by a conductance valve (not shown) provided in the exhaust unit. Hold. Subsequently, high frequency power is radiated from the high frequency power supply means 109, and discharge is performed through the dielectric 110 to generate plasma in the generation chamber 102.

The partition plate 111 has a through-hole through which a gas passes, and active species such as ions and neutral radicals generated in the plasma generation region pass through the partition plate 111 together with the introduced gas, and enter the processing chamber 103. Flow into.
When the gas passes through the through hole formed in the partition plate, a pressure difference is generated between the generation chamber 102 and the processing chamber 103 due to the gas conductance of the partition plate. Using this pressure difference, for example, the amount of movement of neutral radicals between the generation chamber 102 and the processing chamber 103 can be controlled.
JP-A-7-263353 JP 2005-142234 A

By the way, the conductance of the partition plate is based on the number of through holes formed on the partition plate, the hole diameter, and the length of the hole. For this reason, when trying to obtain different conductances, it is necessary to replace with another partition plate having a different hole diameter, the number of holes, and the like, which causes a problem of reducing the operating rate of the apparatus.
Then, this invention aims at providing the plasma processing apparatus which has a partition plate which can control conductance, without replacing | exchanging a partition plate.

  In order to solve the above-described problems, a plasma processing apparatus of the present invention partitions a processing container including a generation chamber in which plasma is generated and a processing chamber in which a substrate to be processed is disposed, and the generation chamber and the processing chamber. And a partition plate having a through-hole through which a processing gas is passed, and having a temperature control means for adjusting the temperature of the partition plate.

  According to the present invention, the conductance of the partition plate can be controlled by adjusting the temperature of the partition plate. Therefore, the conductance can be controlled without replacing the partition plate.

  In the present invention, in the plasma processing apparatus having a partition plate for controlling the flow of gas between the plasma generation chamber and the substrate processing chamber, temperature control means for adjusting the temperature of the partition plate is provided. The conductance of the processing gas can be changed by heating or cooling the partition plate. That is, the gas conductance can be changed without replacing the partition plate.

In a preferred embodiment of the present invention, the temperature of the partition plate is selected from the range of -20 ° C to 600 ° C. As temperature control means, a heating element (heater) for heating is built in the partition plate. Alternatively, a cooling medium flow path is provided inside the partition plate. Alternatively, a means (cooling medium flow path) for cooling the processing container is provided in the vicinity of the portion of the processing container that supports the partition plate.
The temperature adjustment of the partition plate is preferably performed for each of a plurality of zones. The plurality of zones are, for example, divided into annular zones having concentricity.
The partition plate may be a flat plate having a plurality of through holes. The partition plate is preferably made of a material having a thermal conductivity of 30 W / m · K or more.

The present invention can be applied to any of the downflow processing and the upflow processing.
In the downflow process, the process gas is introduced into the plasma process from the side of the plasma generation chamber where the plasma is generated. The introduced process gas flows into the processing chamber in which the substrate to be processed is disposed after passing through the partition plate, and is exhausted outside the apparatus after processing the surface of the substrate to be processed. In the upflow process, the process gas is introduced into the plasma process from the process chamber side where the substrate to be processed is arranged. The introduced process gas is exhausted outside the apparatus after flowing into the plasma generation chamber where plasma generation is performed after passing through the partition plate.

  The plasma processing is, for example, processing for etching, ashing or modifying the surface of the substrate to be processed, or processing for depositing a thin film on the surface of the substrate to be processed. Here, the modifying treatment is a treatment for oxidizing or nitriding the surface of the substrate to be treated.

A microwave plasma processing apparatus according to a preferred embodiment of the present invention will be described in detail with reference to FIGS. In FIG. 1, 101 is a processing container, 102 is a plasma generation chamber, 103 is a processing chamber, 104 is a substrate to be processed, 105 is a support, 107 is a gas introduction section, and 108 is a gas exhaust section. 109 is a microwave supply means for supplying microwaves to the processing chamber, 110 is a dielectric material through which microwaves pass, 111 is a partition plate, and 112 is a cooling medium flow path. In FIG. 2, 202 is a through hole, 203 is a heater (heating means), and 204 is a medium flow path for temperature control. The heater 203 and the medium flow path 204 constitute a temperature adjusting means for adjusting the temperature of the partition plate 111.
That is, the apparatus shown in FIG. 1 is different from that shown in FIG. 8 in that the temperature adjusting mechanism including the temperature adjusting means (the heater 203 and the medium flow path 204) provided inside the partition plate 111 and the processing container 101 are cooled. A medium flow path 112 is provided.
In the drawings, common or corresponding parts are denoted by the same reference numerals.

  A microwave generation source (not shown) is made of, for example, a magnetron, and generates a microwave of 2.45 GHz, for example. However, in the present invention, the microwave frequency can be appropriately selected from the range of 0.8 GHz to 20 GHz. The microwave from the microwave generation source is then converted into TM, TE mode, etc. by a mode converter (not shown) and propagates through the waveguide. An isolator, an impedance matching device, and the like are provided in the microwave waveguide path. The isolator prevents the reflected microwave from returning to the microwave source and absorbs such reflected waves.

  The impedance matching unit functions to match the microwave generation source and the load side. This impedance matching device has a power meter that detects the intensity and phase of a traveling wave supplied from a microwave generation source to a load and a reflected wave reflected by the load and returning to the microwave generation source. Further, it is composed of a 4E tuner, an EH tuner, a stub tuner, and the like.

  The processing chamber 103 accommodates the substrate to be processed 104 and performs plasma processing on the substrate to be processed 104 in a vacuum or a reduced pressure environment. In FIG. 1, a gate valve for transferring the substrate 104 to be processed to and from a load lock chamber (not shown) is omitted.

The substrate to be processed 104 may be a semiconductor, a conductive one, or an electrically insulating one. Examples of the conductive substrate include metals such as Fe, Ni, Cr, Al, Mo, Au, Nb, Ta, V, Ti, Pt, and Pb, or alloys thereof, such as brass and stainless steel. Examples of the insulating substrate include SiO ₂ -based quartz and various glasses, Si ₃ N ₄ , NaCl, KCl, LiF, CaF ₂ , BaF ₂ , Al ₂ O ₃ , AlN, MgO, and other inorganic substances. Moreover, organic films such as polyethylene, polyester, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, and windows can be used.

  The substrate 104 to be processed is placed on the support 105. If necessary, the support 105 may be configured to be adjustable in height and temperature. The support 105 is housed in the processing chamber 103 and supports the substrate to be processed 104.

  The gas introduction unit 107 is provided on the wall surface of the plasma generation chamber 102 and supplies a plasma processing gas into the processing chamber. The gas introduction part 107 is a part of gas supply means. The gas supply means includes a gas supply source, a valve, a mass flow controller, and a gas introduction pipe connecting them, and supplies a processing gas and a discharge gas for obtaining a predetermined plasma when excited by microwaves. For rapid ignition of plasma, a rare gas such as Xe, Ar, or He may be added at least during ignition. Since the rare gas is not reactive, it does not adversely affect the substrate 104 to be processed and is easily ionized, so that the plasma ignition speed when the microwave is turned on can be increased.

As a gas used when forming a thin film on a substrate by a CVD method, generally known gases can be used.
A raw material for forming a Si-based semiconductor thin film such as a-Si, poly-Si, or SiC is a compound that is in a gas state at normal temperature and pressure or can be easily gasified. For example, inorganic silanes such as SiH ₄ and Si ₂ H ₆ , tetraethylsilane (TES), tetramethylsilane (TMS), dimethylsilane (DMS), dimethyldifluorosilane (DMDFS), dimethyldichlorosilane (DMDCS), etc. Organosilanes. Alternatively, halogens such as SiF ₄ , Si ₂ F ₆ , Si ₃ F ₈ , SiHF ₃ , SiH ₂ F ₂ , SiCl ₄ , Si ₂ Cl ₆ , SiHCl ₃ , SiH ₂ Cl ₂ , SiH ₃ Cl, SiCl ₂ F _2, etc. Silanes. In this case, H ₂ , He, Ne, Ar, Kr, Xe, and Rn are examples of additive gas or carrier gas that may be introduced by mixing with the Si source gas.

As a raw material for forming a Si compound-based thin film such as Si ₃ N ₄ or SiO ₂ , a compound that is in a gas state at normal temperature and pressure or can be easily gasified can be used. Examples of such a compound include inorganic silanes such as SiH ₄ and Si ₂ H ₆ . In addition, organic silanes such as tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), octamethylcyclotetrasilane (OMCTS), dimethyldifluorosilane (DMDFS), dimethyldichlorosilane (DMDCS), and the like can be given. Further, halogens such as SiF ₄ , Si ₂ F ₆ , Si ₃ F ₈ , SiHF ₃ , SiH ₂ F ₂ , SiCl ₄ , Si ₂ Cl ₆ , SiHCl ₃ , SiH ₂ Cl ₂ , SiH ₃ Cl, SiCl ₂ F _2, etc. Silanes. In this case, the nitrogen source gas or the oxygen source gas introduced at the same time includes N ₂ , NH ₃ , N ₂ H ₄ , hexamethyldisilazane (HMDS), O ₂ , O ₃ , H ₂ O, NO, N ₂ O, NO _{2 and the} like can be mentioned.

Examples of the raw material for forming a metal thin film such as Al, W, Mo, Ti, and Ta include the following organic metals and metal halides. Examples of the organic metal include trimethylaluminum (TMAl), triethylaluminum (TEAl), triisobutylaluminum (TIBAl), dimethylaluminum hydride (DMAlH), and tungsten carbonyl (W (CO) ₆ ). In addition, there are molybdenum carbonyl (Mo (CO) ₆ ), trimethyl gallium (TMGa), and triethyl gallium (TEGa). Examples of the metal halide include AlCl ₃ , WF ₆ , TiCl ₃ , and TaCl ₅ . In this case, H ₂ , He, Ne, Ar, Kr, Xe, and Rn are listed as additive gas or carrier gas that may be introduced by mixing with Si source gas.

As raw materials for forming a metal compound thin film such as Al ₂ O ₃ , AlN, Ta ₂ O ₅ , TiO ₂ , TiN, and WO ₃ , the following organic metals or metal halides can be exemplified. Examples of the organic metal include trimethylaluminum (TMAl), triethylaluminum (TEAl), triisobutylaluminum (TIBAl), dimethylaluminum hydride (DMAlH), and tungsten carbonyl (W (CO) ₆ ). In addition, there are molybdenum carbonyl (Mo (CO) ₆ ), trimethyl gallium (TMGa), and triethyl gallium (TEGa). Examples of the metal halide include AlCl ₃ , WF ₆ , TiCl ₃ , TaCl ₅ and the like. Further, in this case, oxygen source gas or nitrogen source gas to be introduced at the same time includes O ₂ , O ₃ , H ₂ O, NO, N ₂ O, NO ₂ , N ₂ , NH ₃ , N ₂ H ₄ , hexamethyl A disilazane (HMDS) etc. are mentioned.

As the etching gas for etching the substrate surface, F ₂ , CF ₄ , CH ₂ F ₂ , C ₂ F ₆ , C ₃ F ₈ , C ₄ F ₈ , CF ₂ Cl ₂ , SF ₆ , NF ₃ , Cl ₂ , CCl ₄ , CH ₂ Cl ₂ , C ₂ Cl _{6 and the} like can be mentioned.
Examples of the ashing gas used when ashing and removing organic components on the substrate surface such as a photoresist include O ₂ , O ₃ , H ₂ O, NO, N ₂ O, NO ₂ , N ₂ , and H ₂ .

  When the microwave plasma processing apparatus of the present invention is applied to the surface modification of the substrate to be processed 104, various processes can be performed by appropriately selecting the gas to be used. For example, by using Si, Al, Ti, Zn, Ta or the like as a substrate or a surface layer, oxidation treatment or nitridation treatment of these substrates or surface layers, doping treatment of B, As, P or the like can be performed. Furthermore, the film forming technique employed in the present invention can also be applied to a cleaning method. In that case, it can also be used for cleaning oxides, organic substances, heavy metals, and the like.

Examples of the oxidizing gas for oxidizing the surface of the substrate to be processed 104 include O ₂ , O ₃ , H ₂ O, NO, N ₂ O, and NO ₂ . Examples of the nitriding gas for nitriding the substrate to be processed 104 include N ₂ , NH ₃ , N ₂ H ₄ , hexamethyldisilazane (HMDS), and the like.

As cleaning / ashing gases for cleaning organic substances on the surface of the substrate or for ashing and removing organic components on the surface of the substrate to be processed 104 such as photoresist, O ₂ , O ₃ , H ₂ O, NO, N _{2 O,} such as NO 2, _{H 2} and the like. In addition, as a cleaning gas for cleaning the inorganic substance on the surface of the substrate, F ₂ , CF ₄ , CH ₂ F ₂ , C ₂ F ₆ , C ₄ F ₈ , CF ₂ Cl ₂ , SF ₆ , NF _{3 and the} like can be used. Can be mentioned.

  The gas exhaust unit 108 is provided on the gas downstream side of the processing chamber, and constitutes a pressure adjustment mechanism together with a pressure adjustment valve, a pressure gauge, a vacuum pump, and a control unit (not shown). That is, a control unit (not shown) adjusts the pressure in the processing chamber 103 by the degree of opening of the valve so that the pressure gauge for detecting the pressure in the processing chamber 103 becomes a predetermined value while operating the vacuum pump. Adjust by controlling. As the pressure adjustment valve, for example, a gate valve with a pressure adjustment function made by VAT or an exhaust slot valve made by MKS can be used. As a result, the internal pressure of the processing chamber 103 is controlled to a pressure suitable for processing through the exhaust unit 108. The pressure is preferably in the range of 13 mPa to 1330 Pa, more preferably in the range of 665 mPa to 665 Pa. The vacuum pump is composed of, for example, a dry pump, a turbo molecular pump (TMP) or the like, and is connected to the processing chamber 103 via a pressure adjustment valve such as a conductance valve (not shown).

  The partition plate 111 is disposed between the plasma generation chamber 102 and the processing chamber 103 and has a plurality of through holes 202. The diameters of the plurality of through holes may be the same or different. Further, the arrangement of the through holes may be, for example, a grid-like arrangement with an equal pitch, or may be arranged on the circumferences of different diameters having concentricity. Inside the partition plate 111, temperature adjusting means for adjusting the temperature of the partition plate is embedded.

  The temperature adjusting means is a part of a temperature adjusting mechanism including a heating means 203 and a flow path 204 through which a cooling medium flows. The temperature adjustment mechanism includes a thermometer (not shown) that measures the temperature of the partition plate 111, a power source that supplies power to the heating means 203, a circulator for a cooling medium, and a control unit. Further, the temperature adjusting means may be constituted only by the heating means 203.

The partition plate 111 is controlled to a predetermined temperature, for example, −20 ° C. or more and 600 ° C. or less by a temperature adjustment mechanism.
For the temperature control of the partition plate, for example, as shown in FIG. 3, the temperature may be divided into a plurality of sections (annular sections) 301, 302, and 303 having concentric annular zones, and the temperature may be adjusted independently.

The material of the partition plate 111 may be a semiconductor, a conductive material, or an electrically insulating material. Examples of the conductive material include metals such as Fe, Ni, Cr, Al, Mo, Au, Nb, Ta, V, Ti, Pt, and Pb, or alloys thereof, such as brass and stainless steel. Examples of the insulating material include SiO ₂ quartz and various glasses, inorganic materials such as Si ₃ N ₄ , NaCl, KCl, LiF, CaF ₂ , BaF ₂ , Al ₂ O ₃ , AlN, and MgO.

As a material of the partition plate 111, it is desirable that the thermal conductivity is 30 W / m · K or more. This is because when the partition plate is formed of a material having the above thermal conductivity, the heat generated by the temperature adjusting means is quickly conducted, and local temperature deviation is less likely to occur.
In the wall of the processing container 101 near the partition plate 111, a flow path 112 for circulating a cooling medium is provided to prevent the processing container 101 from being overheated by heat transmitted from the partition plate. Examples of the cooling medium include pure water, ethylene glycol, and fluorinate, and it is preferable to circulate a medium cooled to a constant temperature such as room temperature by an external refrigerator.

  The plasma treatment is performed as follows. First, the inside of the processing vessel 101 of the plasma processing apparatus is sufficiently evacuated by the exhaust means (not shown) through the gas exhaust unit 108. Next, a gas having a predetermined flow rate is introduced into the plasma generation chamber 102 through a gas introduction unit 107 by a gas introduction unit (not shown), and the processing chamber 103 is introduced by a conductance valve (not shown) provided in the exhaust unit. The inside is maintained at a desired pressure. Further, the temperature of the partition plate 111 is maintained at a desired temperature by the temperature adjusting means.

When the gas passes through the partition plate 111 heated by the heating means 203, the gas expands in volume because it receives heat from the partition plate. For this reason, the higher the temperature of the partition plate 111, the more difficult the gas flows and the conductance decreases. In addition, the pressure difference generated between the plasma generation chamber 102 and the processing chamber 103 becomes large.
As described above, in the conventional apparatus, in order to obtain a desired conductance, it is necessary to replace the partition plate with a different hole diameter and number of holes. In the present invention, it is desired to adjust the temperature of the partition plate 111. Can be obtained.

Hereinafter, the microwave plasma processing apparatus of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.
[Example 1]
FIG. 4 shows the individuality of the plasma processing apparatus according to the first embodiment of the present invention. 4, reference numeral 101 denotes a processing container, 102 denotes a plasma generation chamber, 103 denotes a processing chamber, 104 denotes a substrate to be processed (substrate), 105 denotes a support base (support), 106 denotes a heater, 107 denotes a gas introduction unit, and 108 denotes A gas exhaust unit, 111 is a partition plate, and 112 is a cooling medium flow path.

  The processing container 101 is made of an aluminum alloy and has an inner diameter of 350 mm. The partition plate 111 is made of aluminum having a thickness of 10 mm, and a heater is embedded therein. The partition plate 111 has 288 through holes with an opening diameter of 1.5 mm. In order to cool the processing vessel 101 in the medium flow path 112, water cooled and held at room temperature is circulated in a refrigerator (not shown) outside the apparatus.

First, the inside of the processing vessel 101 was evacuated through an exhaust system (not shown), and the pressure was reduced to a value of 10 ⁻² Pa. Subsequently, nitrogen gas was introduced into the generation chamber 102 through the gas introduction unit 107 at a flow rate of 1500 sccm. Next, a conductance valve (not shown) provided in the exhaust system (not shown) was adjusted, and the inside of the processing chamber 103 was held at 400 Pa.
Next, electric power was supplied to the heater built in the partition plate 111, and the temperature of the partition plate was heated from 20 degreeC to 300 degreeC.

At this time, the pressure in the generation chamber 102 was measured with a pressure gauge (not shown), and the pressure difference from the processing chamber 103 was examined. As a result, as shown in FIG. 5, the pressure difference between the generation chamber 102 and the processing chamber 103 increased as the temperature of the partition plate 111 increased. At this time, the conductance changes as shown in FIG. The conductance at the partition plate temperature of 300 ° C. was 0.06 m ³ / s, which is about half of the conductance at 20 ° C. This was a result almost equal to the conductance obtained when the number of through holes of the partition plate 111 was reduced to about half of 144 holes.

[Example 2]
Using the microwave plasma processing apparatus shown in FIG. 4, ashing of the photoresist was performed. Here, 109 is a slotted endless annular waveguide (microwave supply means), and 110 is a dielectric (or dielectric window).
The substrate 104 is a φ12 ″ P-type single crystal silicon substrate, and a surface is coated with a photoresist and further ion-implanted. The dielectric 110 is made of aluminum nitride.

First, after the silicon substrate 104 was placed on the base support 105, the inside of the processing chamber 103 was evacuated through an exhaust system (not shown), and the pressure was reduced to a value of 10 ⁻² Pa. Next, the heater 106 was energized to heat and hold the silicon substrate 104 at 280 ° C. Subsequently, electric power was supplied to the heater built in the partition plate 111, and the temperature of the partition plate was heated to 100 ° C. Further, oxygen gas was introduced into the generation chamber 102 through the gas introduction unit 107 at a flow rate of 1000 sccm. Next, a conductance valve (not shown) provided in the exhaust system (not shown) was adjusted, and the inside of the processing chamber 103 was held at 26 Pa. Next, 2 kW of power was supplied from a 2.45 GHz microwave power source (not shown) through the slotted endless annular waveguide 109 to generate surface wave plasma, and ashing was performed for 60 seconds.
When the ashing rate was measured from the film thickness change before and after ashing, it was 2.7 μm / min.

  Next, the same processing was performed on another substrate under the condition that the temperature of the partition plate 111 was set to 300 ° C. The ashing rate at this time was measured and found to be 2.1 μm / min.

[Example 3]
Using the microwave plasma processing apparatus shown in FIG. 4, the semiconductor substrate was oxidized and nitrided. The substrate 104 is a φ12 ″ P-type single crystal silicon substrate, which is obtained by removing the natural oxide film and heavy metal impurities on the surface by RCA cleaning. The material of the dielectric window 110 is made of quartz. The partition plate 111 is made of silicon with a thickness of 10 mm, and a heater is embedded therein, and the partition plate has 49 through holes with an opening diameter of 2 mm.

First, after the silicon substrate 104 was placed on the substrate support 105, the inside of the processing chamber 103 was evacuated through an exhaust system, and the pressure was reduced to a value of 10 ⁻² Pa. Subsequently, the heater 106 was energized to heat and hold the silicon substrate 104 at 280 ° C. Subsequently, electric power was supplied to the heater built in the partition plate 111, and the temperature of the partition plate was heated to 100 ° C. Further, oxygen gas was introduced into the generation chamber 102 through the gas introduction unit 107 at a flow rate of 500 sccm. Next, a conductance valve provided in the exhaust system was adjusted, and the inside of the processing chamber 103 was held at 133 Pa.

Next, 3 kW of electric power was supplied from a 2.45 GHz microwave power source via a slotted endless annular waveguide 109 to generate surface wave plasma, and an oxidation treatment was performed for 120 seconds. Next, the supply of microwaves and gas introduction were once stopped, the inside of the processing chamber 103 was evacuated, and the pressure was reduced to a value of 10 ⁻² Pa. Subsequently, nitrogen gas was introduced into the generation chamber 102 through the gas introduction unit 107 at a flow rate of 500 sccm. Next, the conductance valve was adjusted, and the inside of the processing chamber 103 was held at 133 Pa. Next, 3 kW of electric power was supplied from the 2.45 GHz microwave power source via the slotted endless annular waveguide 109 to generate surface wave plasma, and nitriding was performed for 60 seconds.

After the treatment, the thickness of the oxynitride film formed on the silicon substrate 104 and the surface density of nitrogen were measured by XPS. As a result, the film thickness was 2.4 nm, and the surface density of nitrogen was 8.2 × 10 ¹⁴ atoms / cm ² .

Next, the same process was performed on another substrate under the condition that the temperature of the partition plate 111 was set to 300 ° C. only during the nitriding process. After the treatment, the thickness of the oxynitride film formed on the silicon substrate 104 and the surface density of nitrogen were measured by XPS. As a result, the film thickness was 2.3 nm, and the surface density of nitrogen was 3.5 × 10 ¹⁴ atoms / cm ² .

[Example 4]
Using the microwave plasma processing apparatus shown in FIG. 7, the semiconductor substrate was oxidized. The substrate 104 is a φ12 ″ P-type single crystal silicon substrate, which is obtained by removing the natural oxide film and heavy metal impurities on the surface by RCA cleaning. The material of the dielectric window 110 is made of quartz. The partition plate 111 is made of silicon with a thickness of 10 mm, and a heater is embedded therein, and the partition plate has 49 through holes with an opening diameter of 2 mm, which is different from the apparatus shown in FIG. 4 indicates that the positions of the gas introduction part 107 and the gas exhaust part 108 in Fig. 4 are opposite to each other as in the gas introduction part 707 and the gas exhaust part 708 in Fig. 7. In contrast to the flow plasma process, the apparatus of FIG. 7 performs an up flow plasma process.

In the apparatus of FIG. 7, first, the silicon substrate 104 was placed on the base support 105, and then the inside of the processing chamber 103 was evacuated through an exhaust system, and the pressure was reduced to a value of 10 ⁻² Pa. Subsequently, the heater 106 was energized to heat and hold the silicon substrate 104 at 280 ° C. Subsequently, electric power was supplied to the heater built in the partition plate 111, and the temperature of the partition plate was heated to 100 ° C. Further, oxygen gas was introduced into the reaction chamber (processing chamber) 103 at a flow rate of 1000 sccm through the gas introduction unit 707.

Subsequently, the conductance valve provided in the exhaust system was adjusted to maintain the reaction chamber 103 at 400 Pa. Next, 3 kW of electric power was supplied from a 2.45 GHz microwave power source via a slotted endless annular waveguide 109 to generate surface wave plasma, and oxidation treatment was performed for 60 seconds.
After the treatment, the oxide film thickness formed on the silicon substrate 104 was measured with an ellipsometer. The average film thickness was 1.6 nm and the in-plane uniformity was ± 1.9%.

  Next, the same processing was performed on another substrate under the condition that the temperature of the partition plate 111 was set to 300 ° C. After the treatment, the oxide film thickness formed on the silicon substrate 104 was measured with an ellipsometer. The average film thickness was 1.0 nm and the in-plane uniformity was ± 2.2%.

It is a schematic sectional drawing of the plasma processing apparatus which uses the partition plate of this invention. It is a general | schematic partial enlarged view which shows the through-hole of a partition plate and temperature control means structure which the plasma processing apparatus shown in FIG. 1 uses. It is a general | schematic fragmentary enlarged view which shows arrangement | positioning of the through-hole of a partition plate and temperature control division which the plasma processing apparatus shown in FIG. 1 uses. It is a schematic sectional drawing which shows the example which the plasma processing apparatus shown in FIG. 1 uses a slotted endless annular waveguide as a microwave supply means. It is a figure which shows the change of the pressure difference between the production | generation chamber and the reaction chamber with respect to the temperature change of the partition plate used for the plasma processing apparatus shown in FIG. It is a figure which shows the change of the conductance with respect to the temperature change of the partition plate used for the plasma processing apparatus shown in FIG. FIG. 2 is a schematic cross-sectional view showing an example in which the plasma processing apparatus shown in FIG. 1 performs processing while introducing gas from a reaction chamber and exhausting it from a generation chamber. It is a schematic sectional drawing which shows the example of the plasma processing apparatus which uses the conventional partition plate.

Explanation of symbols

101 processing vessel 102 plasma generation chamber 103 processing chamber (reaction chamber)
104 Substrate (substrate to be processed)
107,707 Gas introduction part 108,708 Gas exhaust part 109 Endless annular waveguide (microwave supply means)
110 Dielectric (Dielectric Window)
111 Partition plate 112 Medium flow path for cooling 202 Through hole 203 Heater (heating means) constituting temperature control means
204 Cooling medium flow path 301, 302, 303 constituting temperature control means

Claims (13)

A processing container including a generation chamber in which plasma is generated and a processing chamber in which a substrate to be processed is disposed, and a through-hole that is disposed so as to partition the generation chamber and the processing chamber and allow a processing gas to pass therethrough A plasma processing apparatus having an opened partition plate,
A plasma processing apparatus comprising temperature control means for adjusting the temperature of the partition plate.   The plasma processing apparatus according to claim 1, wherein the temperature adjusting means adjusts the temperature of the partition plate to a temperature selected from a range of -20 ° C to 600 ° C.   3. The plasma processing apparatus according to claim 1, wherein the temperature adjustment unit includes a heating element that is built in the partition plate and heats the partition plate. 4.   The plasma processing apparatus according to any one of claims 1 to 3, wherein the temperature adjusting means includes means for cooling the partition plate in the vicinity of a portion of the processing container that supports the partition plate.   The plasma processing apparatus according to claim 1, wherein the partition plate includes a cooling medium flow path therein.   6. The plasma processing apparatus according to claim 1, wherein the temperature of the partition plate is adjusted for each of a plurality of zones.   The plasma processing apparatus according to claim 6, wherein the plurality of zones include annular zone-shaped sections having concentricity.   The plasma processing apparatus according to claim 1, wherein the partition plate is a flat plate having a plurality of through holes.   9. The plasma processing apparatus according to claim 1, wherein the partition plate is made of a material having a thermal conductivity of 30 W / m · K or more.   Means for introducing process gas from the generation chamber side; means for exhausting gas after passing through the partition plate and flowing into the processing chamber where the substrate to be processed is disposed and processing the surface of the substrate to be processed; The plasma processing apparatus according to claim 1, wherein the substrate to be processed is subjected to a downflow process.   A means for introducing a process gas from the side of the processing chamber where the substrate to be processed is disposed, and a means for exhausting the gas after passing through the partition plate and flowing into the plasma generation chamber; The plasma processing apparatus according to claim 1, wherein flow processing is performed.   The plasma treatment is a process of etching, ashing or modifying the surface of the substrate to be processed, or a process of depositing a thin film on the surface of the substrate to be processed. Plasma processing equipment.   The plasma processing apparatus according to claim 12, wherein the modifying process is a process of oxidizing or nitriding the surface of the substrate to be treated.

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