JP2012253209A - Device and method for dry etching - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and method for dry etching, simplifying a gas supply system and capable of improving the anisotropy of an etching shape.SOLUTION: A device for dry etching includes: a processing chamber 12 housing a substrate Sb having a silicon oxide film; a substrate electrode stage 20 to which high frequency power is fed, while being brought into contact with the substrate Sb via a dielectric; a carbon ring 26 arranged while being in direct contact with on the substrate electrode stage 20; a gas supply system 15 supplying etching gas comprising carbon tetrafluoride and inert gas into the processing chamber 12; and a high frequency antenna 30 and a high frequency power source 31 which change the etching gas into a plasma by inductive coupling.

Description

  The present invention relates to a dry etching apparatus and a dry etching method for processing a silicon oxide film.

Silicon oxide (SiO ₂ ) is used as a material for an insulating film that electrically insulates the wiring of semiconductor elements and the elements. As a gas for dry etching the silicon oxide film, a fluorocarbon gas such as C ₃ F ₈ , C ₄ F ₈ , C ₅ F ₈ , C ₄ F ₆ , or a fluorine gas such as CHF ₃ or CH ₂ F _{2 is used.} Methane-based gas is frequently used.

However, with only the gas described above, it is difficult to improve the anisotropy (perpendicularity) of the etching shape while maintaining a good selection ratio represented by the ratio between the etching rate of the insulating film and the etching rate of the resist mask. For this reason, at least one of C ₄ F ₆ and C ₅ F ₈ is mixed with at least one of a combination gas such as He, Ne, Ar, Xe, Kr, O ₂ , and CO, so that the selectivity and the etching shape are different. A method for achieving compatibility with the directivity has been proposed (see, for example, Patent Document 1).

JP 2011-044740 A

However, when three or more kinds of gases are mixed, the number of gas supply sources for supplying each gas to the processing chamber increases, and piping for introducing various gases to the processing chamber becomes complicated. Moreover, when using gases such as C ₅ F ₈ , C ₄ F ₆ , and CO, a leak detector is necessary from the viewpoint of danger or harm, and the cost is undeniable.

  The present invention has been made in view of the above problems, and an object thereof is to provide a dry etching apparatus and a dry etching method capable of simplifying a gas supply system and improving anisotropy of an etching shape. It is to provide.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
According to the first aspect of the present invention, there is provided a processing chamber for accommodating a substrate having a silicon oxide film, a substrate electrode to which high-frequency power is supplied and in contact with the substrate via a dielectric, and a direct contact on the substrate electrode. A carbon material arranged in an as-prepared state, a gas supply system for supplying an etching gas comprising carbon tetrafluoride and an inert gas to the processing chamber, and an inductively coupled plasma source for converting the etching gas into plasma by inductive coupling It is a summary to provide.

  According to a fifth aspect of the present invention, in the dry etching method for etching a silicon oxide film, a carbon material is provided in direct contact with the substrate electrode to which high-frequency power is supplied, and the silicon oxide film is formed on the substrate electrode. A substrate having a substrate is placed via a dielectric, an etching gas comprising carbon tetrafluoride and an inert gas is supplied to a processing chamber in which the substrate is accommodated, and the etching gas is turned into plasma by inductive coupling. This is the gist.

  According to the first and fifth aspects of the invention, since the etching gas composed of carbon tetrafluoride and an inert gas is used, the types of gases used for etching can be reduced as much as possible. Moreover, since there is no danger or harm, installation of a leak detector or the like is not necessary. Further, a carbon material is provided on the substrate electrode so that the substrate electrode and the carbon material are electrically connected, and the carbon material is etched at the same time when the silicon oxide film is etched. Therefore, the carbon-based polymer produced by etching the carbon material is deposited on the side surfaces of the holes and trenches formed in the silicon oxide film by etching, and functions as a protective film that suppresses isotropic etching. Can do. For this reason, even if it uses gas with few valences of carbon, such as carbon tetrafluoride, the anisotropy of an etching shape can be improved. In addition, since the carbon material is disposed on the substrate electrode in direct contact, the direction in which the positive ions in the plasma are drawn into the carbon material and the direction in which the positive ions are drawn into the substrate electrode may be substantially the same. it can. For this reason, by disposing the carbon material, it is possible to prevent adverse effects on the anisotropic etching of the silicon oxide film.

  The invention according to claim 2 is the dry etching apparatus according to claim 1, wherein the carbon material is formed in an annular shape and disposed on the substrate electrode so as to surround an outer periphery of the substrate. And

According to the second aspect of the present invention, the effect of increasing the anisotropy of the holes and trenches can be made uniform in the plane of the substrate by the carbon material surrounding the outer periphery of the substrate.
The invention according to claim 3 is the dry etching apparatus according to claim 2, wherein the carbon material is fixed to the substrate electrode by a fastening portion.

  According to the third aspect of the invention, since the carbon material is fixed to the substrate electrode by the fastening portion, the carbon material and the substrate electrode can be more closely attached. For this reason, the conduction state between the carbon material and the substrate electrode can be stabilized.

The invention according to claim 4 is the dry etching apparatus according to claim 1, wherein the carbon material is a tray on which the substrate is placed and carried into the processing chamber.
According to the fourth aspect of the present invention, since the carbon material also serves as a tray on which the substrate is placed, it is not necessary to separately provide the carbon material, and the number of members of the dry etching apparatus can be reduced.

1 is a schematic view of a dry etching apparatus according to a first embodiment. (A) is the board | substrate before an etching, (b) And (c) is an end elevation of the board | substrate with which the hole was formed. Schematic of the dry etching apparatus of 2nd Embodiment.

(First embodiment)
A first embodiment embodying the present invention will be described below with reference to FIGS.
As shown in FIG. 1, the dry etching apparatus has a vacuum chamber 11 formed in a substantially cylindrical shape. The vacuum chamber 11 is made of a metal such as aluminum and has a processing chamber 12 for accommodating the substrate Sb therein. The processing chamber 12 is a space in which etching gas plasma is generated, and its upper opening is sealed by a dielectric window 13 made of a dielectric such as quartz or sapphire.

  The vacuum chamber 11 is provided with a transfer port communicating with the processing chamber 12, and a gate valve is connected to the transfer port (all not shown). The substrate Sb to be etched is transferred from the adjacent chamber into the processing chamber 12 through the transfer port, and is transferred from the processing chamber 12 to another processing chamber. Further, the vacuum chamber 11 is provided with a discharge port 11a for exhausting an etching gas or a fluid such as the atmosphere in the vacuum chamber 11, and an exhaust device (not shown) is connected to the discharge port 11a. The vacuum chamber 11 is provided with a gas supply unit 14 that communicates with the processing chamber 12. A gas supply system 15 for supplying an etching gas to the processing chamber 12 is connected to the gas supply unit 14.

The gas supply system 15 includes a first gas supply source 16 that supplies CF ₄ (carbon tetrafluoride) and a second gas supply source 17 that supplies an inert gas made of Ar gas. CF ₄ and Ar gas are supplied from the first gas supply source 16 and the second gas supply source 17 to the vacuum chamber 11 while the flow rate is adjusted by each mass flow controller 19 and then supplied to the processing chamber 12 in a mixed state. Is done.

  A substrate electrode stage 20 is provided below the vacuum chamber 11. The substrate electrode stage 20 has a flat upper surface so that the substrate Sb can be placed thereon. The substrate electrode stage 20 is electrically connected to a bias high-frequency power source 22 via a matching box 21. The matching box 21 includes a matching circuit and a blocking capacitor for matching impedance between the plasma generation region in the processing chamber 12 and the transmission path from the bias high-frequency power source 22 to the substrate Sb.

  A plate-like insulating plate 23 is provided between the substrate electrode stage 20 and the bottom wall portion 11b of the vacuum chamber 11 so as to insulate the substrate electrode stage 20 and the bottom wall portion 11b of the vacuum chamber 11 from each other. Yes. A cylindrical insulating ring 24 is provided around the substrate electrode stage 20 to insulate the substrate electrode stage 20 and the like from the side surface of the vacuum chamber 11.

  Furthermore, an electrostatic chuck 25 that attracts the substrate Sb is provided on the substrate electrode stage 20. The electrostatic chuck 25 includes a pair of ESC electrodes 25a and 25b and an electrostatic chuck plate 25c made of a substantially disc-shaped dielectric. The ESC electrodes 25a and 25b are disposed in the electrostatic chuck plate 25c. These ESC electrodes 25a and 25b are connected to a power supply device (not shown). A predetermined positive voltage is applied to one ESC electrode 25a, and a predetermined negative voltage is applied to the other ESC electrode 25b. . When a predetermined voltage is applied from the power supply device to the ESC electrodes 25a and 25b, charges are induced on the surface of the electrostatic chuck plate 25c, and the substrate Sb is electrostatically attracted to the surface.

  In addition, a carbon ring 26 is provided on the substrate electrode stage 20 so as to be in direct contact with the surface of the substrate electrode stage 20, and is electrically connected to the substrate electrode stage 20. The carbon ring 26 is preferably a glassy carbon material. Further, the carbon ring 26 is formed in an annular shape, and has an accommodating portion 26a capable of accommodating the electrostatic chuck 25 inside thereof. Further, the carbon ring 26 is formed to have a thickness such that the upper surface thereof is substantially the same height as the upper surface of the substrate Sb attracted to the electrostatic chuck 25.

  On the other hand, the contact area between the carbon ring 26 and the substrate electrode stage 20 is small only by placing the carbon ring 26 on the substrate electrode stage 20. For this reason, the carbon ring 26 is closely attached to the substrate electrode stage 20 by being fixed to the substrate electrode stage 20 by fastening portions 27 such as bolts. As described above, the carbon ring 26 and the substrate electrode stage 20 are in close contact with each other, whereby the conduction state between the carbon ring 26 and the substrate electrode stage 20 can be stabilized. The carbon ring 26 fixed to the substrate electrode stage 20 in this way is insulated from the side surface of the vacuum chamber 11 by covering the end surface with the insulating ring 24.

  Above the dielectric window 13, high-frequency antennas 30 constituting an inductively coupled plasma source are stacked on different surfaces so as to circulate around the central axis of the vacuum chamber 11. In the present embodiment, the high frequency antenna 30 has a spiral shape in plan view. An input terminal (not shown) protruding from the high frequency antenna 30 is connected in parallel with a high frequency power source 31 and a matching box 32 constituting an inductively coupled plasma source via an input side capacitor 35.

  The high frequency power supply 31 outputs high frequency power for generating plasma in the processing chamber 12, for example, high frequency power of 13.56 MHz. The matching box 32 matches the impedance between the gas in the processing chamber 12 serving as a load and the transmission path from the high frequency power supply 31 including the high frequency antenna 30 to the vacuum chamber 11. The input-side capacitor 35 is a so-called variable capacitor whose capacitance can be changed, and arbitrarily changes the capacitance in the range of 10 pF to 100 pF, for example.

  Next, the operation of this embodiment will be described. As shown in FIG. 2A, the substrate Sb includes a base film Sb1 made of silicon (silicon), a silicon oxide film Sb2 stacked on the base film Sb1, and a resist mask Sb3 stacked on the silicon oxide film Sb2. And have. The resist mask Sb3 has an opening through which only a region to be etched, which is a region where a hole (or trench) is formed, is exposed.

  When an etching process is performed using the dry etching apparatus described above, the substrate Sb is first fixed to an arm (not shown). Further, the gate valve connected to the transfer port of the dry etching apparatus is opened, the arm is moved horizontally, and the substrate Sb is carried into the processing chamber 12 through the transfer port. Then, the arm is lowered, and the substrate Sb is placed on the electrostatic chuck plate 25 c and in the accommodating portion 26 a of the carbon ring 26. Further, the arm is pulled out from the processing chamber 12, and the gate valve is closed. Further, a predetermined voltage is applied to the ESC electrode 25b to induce charges on the electrostatic chuck plate 25c, whereby the substrate Sb is electrostatically attracted to the electrostatic chuck plate 25c.

Next, CF ₄ gas and Ar gas are supplied into the processing chamber 12 via the gas supply unit 14. Further, by driving the exhaust device connected to the discharge port 11a, the pressure in the vacuum chamber 11 is set according to the conditions of the plasma etching process. The supply of the etching gas and the evacuation in the vacuum chamber 11 by the evacuation device are continued during the plasma etching process.

  Further, high frequency power of 13.56 MHz, for example, is supplied from the high frequency power supply 31 to the high frequency antenna 30 via the matching box 32 and the input side capacitor 35. And the high frequency electric power output from the high frequency antenna 30 is propagated to the process chamber 12 through the dielectric window 13, and an induction electric field is produced | generated. And the plasma which uses etching gas as a raw material is produced | generated by the production | generation of this induction electric field.

When the bias high frequency power is supplied to the substrate electrode stage 20, a DC voltage is generated between the plasma generated in the processing chamber 12 and the substrate Sb. As a result, active ions such as positive ions such as CFx (x = 1 to 3), CFx radicals, and F radicals in the plasma existing in the processing chamber 12 reach the substrate Sb and etch the substrate Sb. The positive ions are attracted almost perpendicularly to the upper surface of the substrate Sb and mainly contribute to anisotropic etching. At this time, CFx in the plasma reacts with silicon oxide to produce volatile reaction products such as SiF ₄ and COF ₂ and carbon-based polymers such as CxHyFz (x, y, and z are natural numbers). . This carbon-based polymer is deposited on the side surface of the hole formed in the substrate Sb by etching, and the etching proceeds in a direction substantially perpendicular to the thickness direction of the substrate Sb. Functions as a membrane. Thus, the predetermined region of the substrate Sb is etched mainly along the vertical direction and the thickness direction.

  Further, since the carbon ring 26 is electrically connected to the substrate electrode stage 20, the carbon ring 26 is also etched by the active species in the plasma generated in the processing chamber 12. At this time, positive ions contributing to anisotropic etching are drawn perpendicular to the carbon ring 26. That is, the movement direction of positive ions with respect to the carbon ring 26 is substantially the same as the movement direction of positive ions drawn into the substrate Sb.

  On the other hand, the surface of the carbon material, which is provided at the position different from the present embodiment and along the side surface of the vacuum chamber 11 and is arranged toward the center side of the processing chamber 12, is the substrate Sb. When it is substantially orthogonal to the upper surface, a DC voltage is generated in a direction substantially orthogonal to the voltage generated between the substrate Sb and the substrate electrode stage 20. For this reason, the positive ions drawn perpendicularly to the substrate Sb are also affected by the DC voltage generated between the carbon material provided along the side surface of the vacuum chamber 11 and can deviate from the original moving direction. There is sex.

  On the other hand, since the carbon ring 26 of the present embodiment is fixed on the substrate electrode stage 20, as described above, the movement direction of the positive ions drawn into the carbon ring 26 is the positive ions drawn into the substrate Sb. The moving direction is substantially the same. For this reason, since the movement direction of the positive ions drawn into the substrate Sb is not adversely affected, it is possible to suppress a decrease in the verticality of the holes H formed in the substrate Sb due to the provision of the carbon ring 26.

  In addition, a carbon-based polymer is formed by the reaction between the active species such as CFx in the plasma and the carbon ring 26. Similar to the carbon-based polymer formed by etching the silicon oxide film Sb2, this carbon-based polymer is deposited on the side and bottom surfaces of the holes H formed in the silicon oxide film Sb2, as shown in FIG. A protective film F that suppresses isotropic etching is formed.

  Thus, by adding the carbon ring 26 made of solid to the supply source of the protective film F, the carbon-based polymer can be efficiently deposited on the side surface of the hole H. That is, when only the carbon-based gas in the etching gas is used as the supply source of the protective film F, the gas that is converted into plasma and reacts with the silicon oxide film Sb2 in the carbon-based gas is only a few percent of the total, so that the protective film F is finally protected. The carbon-based gas contributing to the formation of the film F is a small amount of the carbon-based gas supplied to the processing chamber 12, and the contribution rate for forming the protective film F is low. On the other hand, in the case of the carbon ring 26, the amount of the reaction between the carbon atoms in the carbon ring 26 and the active species in the plasma can contribute to the formation of the protective film F, so the contribution rate is high.

In addition, when one or a plurality of gases having a carbon valence higher than that of CF ₄ are used, carbon compounds in the plasma or carbon compounds generated by etching are deposited on the side wall of the vacuum chamber 11 or the like. However, in the present embodiment, the mixed gas filled in the processing chamber 12 has a composition containing only CF ₄ as the carbon-based gas, so the amount of deposits deposited on the side wall of the vacuum chamber 11 is reduced. can do. Further, since the carbon ring 26 is disposed only around the substrate, the amount of deposits can be minimized.

When performing such etching, the CF ₄ gas preferably has a flow rate of 1 sccm or more and 20 sccm or less. When it is less than 1 sccm, the etching rate and the selection ratio with respect to the resist mask Sb3 are reduced, and when it exceeds 20 sccm, the amount of the fluorocarbon compound deposited on the side surface of the hole H becomes excessive. The Ar gas is preferably 80 sccm or more and 100 sccm or less.

  In order to maintain a suitable etching rate and selectivity and improve the anisotropy of the etching shape, the pressure in the processing chamber 12 is preferably adjusted to 1.0 Pa or less, and the antenna power is 300W or more and 900W or less are preferable. Further, the bias high frequency power is preferably 200 W or more and 600 W or less.

  Then, as shown in FIG. 2C, when the hole H reaches the base film Sb1, the etching process is finished. Then, the protective film F formed on the side surface of the hole H is removed in the step of removing the resist mask Sb3.

[Example]
Next, the embodiment will be specifically described with reference to examples and comparative examples.
Etching was performed using the dry etching apparatus described above under the following conditions. A base film made of silicon (silicon) was formed on the base material, and a silicon oxide film was formed on the base film. Further, a resist mask made of OFPR800 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) was formed on the silicon oxide film. Then, the substrate Sb was etched under the following conditions to form a plurality of holes H.

Etching gas Ar: CF ₄
Etching gas flow ratio 87 sccm: 3 sccm
・ Pressure inside vacuum chamber 0.4Pa
・ Antenna power 450W
・ High frequency power for bias 300W
At this time, the etching rate of the silicon oxide film was 140 nm / min, and the selection ratio to the resist mask was 5. Further, when the taper angle θ (see FIG. 2C) formed by the side surface and the bottom surface of the hole H was measured, all the taper angles θ were in the range of 88 ° to 89 ° and were almost vertical.

[Comparative example]
Etching was performed under the same conditions as in Example 1 by using an apparatus in which the carbon ring 26 disposed around the substrate Sb was omitted from the dry etching apparatus described above, thereby forming a plurality of holes H. In addition, since the protective film F is hardly formed on the side surface of the hole H with only CF ₄ , the composition of the etching gas was configured as follows.

Etching gas Ar: C ₃ F ₈ : CH ₄
At this time, the etching rate of the silicon oxide film was 270 nm / min, and the selection ratio to the resist mask was 4. In addition, the taper angle θ of each hole H was in the range of 78 ° to 82 °, and the verticality of the hole H was lower than that of the example.

According to the above embodiment, the following effects can be obtained.
(1) Since an etching gas composed of carbon tetrafluoride and an inert gas is used when etching the substrate Sb having the silicon oxide film Sb2, the number of gas types used for etching is reduced as much as possible, and the number of gas supply sources Increase and complication of piping can be suppressed. Moreover, since the said etching gas does not have danger or harm, installation of a leak detector etc. is unnecessary. Further, the dry etching apparatus is configured such that the carbon ring 26 is provided on the substrate electrode stage 20, and the carbon ring 26 is etched at the same time when the silicon oxide film Sb2 is etched. Therefore, the carbon-based polymer produced by etching the carbon ring 26 can be deposited on the side surface of the hole H formed in the silicon oxide film Sb2 and function as the protective film F. For this reason, even if only a gas having a low carbon valence such as carbon tetrafluoride is used as the carbon-based gas, the carbon ring 26 is etched at the same time, so that a sufficient amount of carbon-based gas is formed on the side surface of the hole H Since the polymer can be deposited, the anisotropy of the etching shape can be improved. In addition, since the carbon ring 26 is arranged on the substrate electrode stage 20 in direct contact with the carbon ring 26 and is made conductive, positive ions in the plasma are drawn into the carbon ring 26 and positive ions are drawn into the substrate electrode stage 20. The direction can be made substantially the same. For this reason, by disposing the carbon ring 26, it is possible to prevent adverse effects on the anisotropic etching of the silicon oxide film Sb2.

  (2) In the above embodiment, the carbon ring 26 is formed in an annular shape and is disposed so as to surround the outer periphery of the substrate Sb. For this reason, the effect of increasing the anisotropy of the holes H formed in the substrate Sb can be made uniform in the plane of the substrate Sb.

  (3) In the above embodiment, since the carbon ring 26 is fixed to the substrate electrode stage 20 by the fastening portion 27, the carbon ring 26 and the substrate electrode stage 20 can be more closely attached. For this reason, the conduction state between the carbon ring 26 and the substrate electrode stage 20 can be stabilized, and the reproducibility of the etching shape and the like can be easily obtained.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. In addition, since 2nd Embodiment is a structure which only changed the carbon ring of 1st Embodiment, the detailed description is abbreviate | omitted about the same part.

  As shown in FIG. 3, the present embodiment is a batch type dry etching apparatus that collectively processes a plurality of substrates Sb. The dry etching apparatus includes a tray 40 on which a plurality of substrates Sb are placed. The tray 40 is made of a carbon material such as glassy carbon, and the tray 40 itself is electrostatically attracted to the electrostatic chuck plate 25c. The substrates Sb are arranged on the tray 40 at a predetermined interval, and are placed so that the four sides of the substrate Sb are surrounded by the tray 40 when the tray 40 on which the substrates Sb are arranged is viewed in plan view. That is, each board | substrate Sb is mounted so that the tray 40 may be exposed in the outer periphery of this board | substrate Sb.

  When carrying the substrate Sb into the processing chamber 12, the tray 40 on which the plurality of substrates Sb are placed is placed on an arm (not shown), the arm is moved horizontally, and the tray 40 is moved to the processing chamber 12 via the transfer port. Carry in. When the tray 40 is conveyed above the substrate electrode stage 20, the arm is lowered and the tray 40 is placed on the substrate electrode stage 20. Then, only the arm is moved horizontally to leave the processing chamber 12, and the gate valve is closed.

  When a plasma of an etching gas is generated in the processing chamber 12 and a bias voltage is applied to the substrate Sb, positive ions in the plasma are not only transmitted through the substrate Sb but also between the substrate Sb and the substrate Sb. The exposed tray 40 is also drawn. Since the tray 40 is overlapped with the substrate Sb, the moving direction of the active species is the same direction. For this reason, even if the tray 40 and the substrate electrode stage 20 are brought into conduction, the moving direction of the positive ions drawn into the substrate Sb is not adversely affected.

  The active species reaching the tray 40 reacts with carbon atoms to generate a carbon-based polymer. This carbon-based polymer is deposited on the side surface of the hole H formed in the substrate Sb, and functions as a protective film F (see FIG. 2C).

Therefore, according to the second embodiment, the following effects can be obtained in addition to the effects described in the first embodiment.
(4) In the second embodiment, the tray 40 on which the plurality of substrates Sb are placed and carried into the processing chamber 12 is formed from a carbon material. Therefore, even in a batch type dry etching apparatus that processes a plurality of substrates Sb, the carbon material can be disposed around the substrate Sb, so that the uniformity of the etching shape for each substrate can be improved. In addition, since it is not necessary to dispose a carbon material around each substrate Sb, the dry etching apparatus can be simplified.

In addition, you may change each said embodiment as follows.
In each of the above embodiments, the inert gas is Ar gas, but it may be He, Ne, Xe, Kr or the like.

In each of the above embodiments, the substrate Sb has a configuration in which the base film Sb1, the silicon oxide film Sb2, and the resist mask Sb3 are stacked, but other configurations may be used.
In the first embodiment, the carbon ring 26 is formed to have an annular shape surrounding the substrate Sb. However, the annular carbon ring 26 may be configured from a plurality of fan-shaped carbon materials.

  -In 1st Embodiment, although the volt | bolt was used as a fastening part which fixes the carbon ring 26 to the board | substrate electrode stage 20, you may fix with another fastening part. For example, the carbon ring 26 and the substrate electrode stage 20 may be provided with an uneven structure that fits together, and the carbon ring 26 may be fixed to the substrate electrode stage 20 by the uneven structure.

  In the second embodiment, the plurality of substrates Sb are placed on the flat tray 40, but the tray 40 may be provided with a recess for accommodating each substrate Sb. Then, the substrate Sb may be accommodated in the recess and carried into the processing chamber 12. In this case, the upper surface of the tray 40 and the upper surface of the substrate Sb can be the same surface.

  DESCRIPTION OF SYMBOLS 11 ... Vacuum chamber, 12 ... Processing chamber, 13 ... Dielectric window, 14 ... Gas supply part, 15 ... Gas supply system, 16 ... 1st gas supply source, 17 ... 2nd gas supply source, 18 ... Piping, 19 ... Mass flow controller, 20 ... substrate electrode stage, 21 ... matching box, 22 ... high frequency power supply for bias, 23 ... insulating plate, 24 ... insulating ring, 25 ... electrostatic chuck, 25a, 25b ... ESC electrode, 26 ... carbon ring, 27 DESCRIPTION OF SYMBOLS ... Fastening part, 30 ... High frequency antenna, 31 ... High frequency power supply, 32 ... Matching box, 35 ... Input side capacitor, Sb ... Substrate, Sb2 ... Silicon oxide film, 40 ... Tray.

Claims (5)

A processing chamber containing a substrate having a silicon oxide film;
A substrate electrode that is supplied with high-frequency power and is in contact with the substrate via a dielectric;
A carbon material disposed in direct contact with the substrate electrode;
A gas supply system for supplying an etching gas comprising carbon tetrafluoride and an inert gas to the processing chamber;
A dry etching apparatus comprising: an inductively coupled plasma source that converts the etching gas into plasma by inductive coupling.   The dry etching apparatus according to claim 1, wherein the carbon material is formed in an annular shape and disposed on the substrate electrode so as to surround an outer periphery of the substrate.   The dry etching apparatus according to claim 2, wherein the carbon material is fixed to the substrate electrode by a fastening portion.   The dry etching apparatus according to claim 1, wherein the carbon material is a tray on which the substrate is placed and carried into the processing chamber. In a dry etching method for etching a silicon oxide film,
A carbon material is provided in direct contact with the substrate electrode to which high-frequency power is supplied, and the substrate having the silicon oxide film is placed on the substrate electrode via a dielectric,
A dry etching method, wherein an etching gas comprising carbon tetrafluoride and an inert gas is supplied to a processing chamber in which the substrate is accommodated, and the etching gas is turned into plasma by inductive coupling.

Images