JP2009111397A - Method of etching deposition film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating element CVD method in which the life of the heating element is prolonged, a fixing method of the heating element is improved, and productivity is improved in a heating element CVD system which decomposes and/or activates material gas introduced in a processing vessel (vacuum chamber) by the heating element and deposits a thin film on a substrate arranged in the processing vessel (vacuum chamber). <P>SOLUTION: The heating element CVD system with a gas introduction mechanism 321 is used, in which a connection part 33 in which the heating element 3 is connected to a power supply mechanism and/or a support part 31 in which the heating element is supported by a support is covered with a cover without contacting the heating element by interposing a gap between the connection part 33 and the support part 31, and introduces the gas in the gap between the cover and the connection part 33, the support part 31, and purge gas is introduced at the end of the heating element 3 inserted into a heating element insertion port provided at the connection part 33. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

According to the present invention, a heating element maintained at a predetermined temperature is provided in a vacuum chamber (processing container), and an etching gas is decomposed and / or activated by the heating element to adhere to the inside of the vacuum chamber (processing container). The present invention relates to a method for etching a film.

In the manufacture of various semiconductor devices such as LSI (Large Scale Integrated Circuit) and LCD (Liquid Crystal Display), chemical vapor deposition (CVD) is one of processes for forming a predetermined thin film on a substrate.
The Deposition method is widely used.

The CVD method includes a plasma CVD method in which a source gas is decomposed and / or activated in discharge plasma to form a film, and a thermal CVD method in which a film is heated to cause a chemical reaction to form a film. In addition, there is a CVD method (hereinafter referred to as a heating element CVD method) in which a source gas is decomposed and / or activated by a heating element maintained at a predetermined high temperature to form a film.

A film forming apparatus (heating element CVD apparatus) that performs a heating element CVD method maintains a heating element made of a refractory metal such as tungsten provided in a processing chamber that can be evacuated at a high temperature of about 1000 to 2000 ° C. It is comprised so that source gas may be introduced. The introduced source gas is decomposed and activated when it passes through the surface of the heating element, and when they reach the substrate, a thin film of a material that is the final target is deposited on the surface of the substrate. Of these heating element CVD methods, those using wire-like heating elements are called hot wire (hot wire) CVD methods, and in the decomposition or activation of the source gas by the heating elements, What uses a catalytic reaction is called a catalytic CVD (or Cat-CVD: Catalytic-CVD) method.

In the heating element CVD method, since the decomposition and activation of the source gas occurs when passing through the surface of the heating element, there is an advantage that the temperature of the substrate can be lowered as compared with the thermal CVD method in which a reaction is caused only by the heat of the substrate. is there. Further, since plasma is not formed unlike the plasma CVD method, there is no concern from the problem of damage to the substrate due to plasma. For these reasons, the heating element CVD method is regarded as promising as a film forming method for next-generation semiconductor devices, display devices, and the like, which are becoming increasingly highly integrated and highly functional.

FIG. 8 shows a conceptual diagram of a conventional heating element CVD apparatus. In a processing container 1 in which a predetermined process of forming a thin film on a substrate (not shown) is performed, an exhaust system 11 that exhausts the inside of the processing container 1 to a vacuum, and a predetermined for forming a thin film in the processing container 1 A source gas supply system 21 that supplies source gas is connected.

A heating element 3 is disposed in the processing container 1 so that the source gas supplied into the processing container 1 passes through the surface, and the heating element 3 is required for the heating element CVD method. An electric power supply mechanism 30 that supplies electric power is connected so as to be heated and maintained at a predetermined high temperature (about 1600 to 2000 ° C.).

Further, a substrate holder that holds a substrate (not shown) on which a predetermined thin film is formed by a source gas decomposed and / or activated by the heating element 3 maintained at the predetermined high temperature in the processing container 1. 4 is provided.

In the form shown in FIG. 8, the source gas supply system 21 includes a cylinder filled with a source gas (not shown), a supply pressure regulator, a flow rate regulator, a supply / stop switching valve, and the like. The gas is supplied into the processing container 1 from the raw material gas supply system 21 through the gas supply device 2 disposed opposite to the heating element 3 in the processing container 1. In the process using two or more kinds of source gases, the source gas supply systems 21 are connected in parallel to the gas supply device 2 by the number of gas types used. The gas supply device 2 has a hollow structure, and a large number of gas blowing holes 210 are formed on the surface facing the substrate holder 4.

On the other hand, the exhaust system 11 is connected to the processing container 1 via a main valve 12 having an exhaust speed adjusting function, and the pressure in the processing container 1 is controlled by this adjusting function.

Further, a substrate (not shown), which is an object to be processed, which is subjected to a predetermined process of forming a thin film, is carried out / loaded into the processing container 1 through the gate valve 5, and the substrate (not shown) is placed in the substrate holder 4. ) Is heated to a predetermined temperature (not shown).

The heating element 3 is generally composed of a linear member, is bent in a sawtooth shape, and is held by a support 31 having at least a surface as an insulator. In addition, a power supply line 32 from the power supply mechanism 30 is connected by a connection terminal 33, and is supplied with power through the connection terminal 33, heated to a predetermined temperature required for the heating element CVD method, and at a predetermined temperature. Maintenance is planned.

For the power supply mechanism 30, a DC power supply or an AC power supply is usually used. The heating element 3 is supplied with electric power from a power source and is set to a predetermined temperature by energization heating. By heating the heating element at a high temperature, the source gas can be decomposed and / or activated to form a film efficiently.

The connection of the heating element 3 to the connection part at the connection part where the heating element 3 is connected to the power supply mechanism 30 is performed as shown in FIG. 10 in the connection terminal main body 331 (see FIG. 8) to which the power supply line 32 is connected. An end portion of the heating element 3 is inserted into a heating element insertion port 337 provided in the connection terminal 33) and is tightened with a screw 332.

In the case of forming a thin film by the heating element CVD apparatus shown in FIG. 8, taking as an example the case of producing a silicon film and the case of producing a silicon nitride film, when producing a silicon film, silane (SiH 4) is used as a source gas. A mixed gas of hydrogen (H 2) is used, and a mixed gas of silane and ammonia (NH 3) is used when forming a silicon nitride film. The pressure in the processing container 1 is about 0.1 to 100 Pa. In any film, the temperature of the heating element 3 is about 1600 to 2000 ° C., and the temperature of the substrate (not shown) held by the substrate holder 4 is 200 to 500 ° C. by a heating mechanism (not shown) in the substrate holder 4. To a degree.

When a silicon film or a silicon nitride film is formed under a predetermined film formation condition using the above-described conventional heating element CVD, a refractory metal used in the heating element, for example, the above-described tungsten wire is replaced with silane gas. It may react to produce a silicon compound (silicidation).

Such silicidation is shorter than the reaction in which the source gas denatures the heating element 3, such as in the vicinity of the connection terminal 33, which is a connection part of the power supply from the power supply mechanism 30, or in the vicinity of the connection part with the support 31. The raw material gas or its decomposition species cannot be instantaneously blown off from the surface of the heating element 3 by heat within the time, and proceeds from a slightly low temperature portion.

This silicidation changes the composition and diameter of the heating element and lowers the resistance value. As a result, the amount of heat generation is reduced, eventually causing deterioration of the entire heating element, and the film formation rate decreases as the usage time of the heating element becomes longer. Further, these reactants such as silicide generally have a high vapor pressure, which causes contamination of the deposited film. As the heating element deteriorates, the film quality of the silicon film or silicon nitride film to be formed is reduced. Deteriorate. Therefore, it is necessary to open the vacuum in the processing container 1 to the atmosphere and replace the heating element 3 at a certain point in time when the predetermined number of processing sheets is performed, which is a problem in productivity.

This silicidation phenomenon was observed at Materials Research held at Marriot Hotel and Argent Hotel in San Francisco, USA from April 24 to 28, 2000.
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As a control means for the deterioration of the heating element due to silicidation described above, Mahan et al. Touched on the means for extending the life of the heating element in the presentation, and heat the heating element in hydrogen or in vacuum after film formation. Propose that.

However, this means has a problem that productivity needs to be reduced because it is necessary to secure time for performing the processing between the respective films. Strictly speaking, since the silicidation of the heating element proceeds during film formation, that is, the heating element 3 such as the temperature of the heating element or the region of the heating element effective for decomposition and / or activation of the source gas. Therefore, when the deposition time is long, the film characteristics change (deteriorate) in the thickness direction.

FIG. 9 shows a part in which the heat generating body 3 is held on a support 31 by a wire 34 (usually molybdenum is used), thereby reducing the contact area, thereby reducing heat conduction and lowering the temperature of the heat generating body 3 slightly. The support 31 of the conventional example which tried to prevent silicidation proceeding from (a connection part where the heating element 3 is connected to the power supply mechanism 30 or a support part where the heating element 3 is supported by the support 31). This part will be explained. However, even in this method, the temperature of the heating element 3 at the point of contact with the wire 34 is lowered considerably, and silicidation occurs from that point depending on the film forming conditions such as high silane gas pressure in forming the silicon film.

Therefore, in the heating element CVD apparatus adopting the configuration shown in FIG. 9, it is necessary to release the vacuum in the processing container 1 to the atmosphere and replace the heating element 3 at a certain time after a predetermined number of processing has been performed. There was a problem in productivity.

On the other hand, when the film formation is repeatedly performed in the heating element CVD apparatus, the film adheres to the inside of the processing container, and eventually peels off to cause dust. The present inventor has proposed a removal method capable of efficiently removing the adhered film inside the processing vessel causing the dust, and further an in situ cleaning method for a heating element CVD apparatus (Japanese Patent Application No. 11-222087). issue). This is because a cleaning gas supply system having the same configuration as the source gas supply system 21 is provided in the gas supply unit 2 in the conventional heating element CVD apparatus as shown in FIG. Instead, the cleaning gas is introduced into the processing container 1 via the gas supply device 2. That is, after the inside of the processing container 1 is evacuated, the heating element 3 disposed therein is heated and held at 2000 ° C. or higher, and in this state, the activated species generated by being decomposed and / or activated by the heating element 3 However, the method is characterized in that a cleaning gas capable of reacting with an attached film and converting it into a gaseous substance is introduced into the processing container 1, and the produced gaseous substance is exhausted to remove the attached film. It is an invention. This invention is based on the knowledge that the heating element 3 itself is stable without causing a reaction with the cleaning gas by holding the heating element at 2000 ° C. or higher.

However, even after trying to hold the heating element 3 at 2000 ° C. or higher after the invention, the portions such as the vicinity of the connection terminal 33 and the vicinity of the contact portion with the support 31 that are the connection portions of the power supply from the power supply mechanism 30 are still in the temperature range. It was found that as the adhered film was removed, the portion was etched by the reaction with the cleaning gas and gradually thinned and eventually cut off. Therefore, similar to the problem of silicidation by the source gas, it is necessary to replace the heating element 3 at a certain point in time, which is a problem in productivity.

Further, as described above, in the conventional heating element CVD apparatus, the connection structure as shown in FIG. 10 is adopted in the connection portion where the heating element 3 is connected to the power supply mechanism 30. The tightening force of 332 is not constant by the manufacturer (operator). In addition to the fact that the force for tightening the screw 332 is not constant, the connection terminal main body 331 is heated by energizing the heating element 3, but in this thermal cycle, the screw 332 is loosened, and the heating element is generated by the screw 332. The fastening force to the connection terminal main body 331 of 3 may be reduced.

Usually, since the heating element 3 is heated to about 1600 to 2000 ° C. by energization heating, a refractory metal is used as a material, and generally, φ0.5 linear tungsten is used. However, once the tungsten wire is energized and heated at a high temperature of 1600 to 2000 ° C., the crystalline state changes, so that the tungsten wire changes to a brittle and easy-to-break property. Unlike the above-described silicidation, this change is not limited to the region where the heating element 3 and the power supply mechanism are connected, and is naturally used throughout the heating element 3 and particularly in the connection portion. As a problem of the method of fixing the tungsten wire, which has been changed to a brittle property instead of the above-described fixing by the screw, as well as prevention of silicidation of the heating element, in order to improve productivity, it is inherent to the heating element CVD apparatus. It was left as a problem to be solved.

It is an object of the present invention to use a heating element CVD apparatus to slightly heat the heating element at the connecting part between the heating element and the power supply mechanism, which is a heating member that generates heat when applying power when etching the adhesion film in the know container. An object of the present invention is to provide an etching method in which deterioration due to a chemical reaction with an etching gas or an active species originating from these at the time of film formation is improved in a portion where the temperature is low.

In order to achieve the above object, the method for etching an adhesion film of the present invention is configured as follows.

The present invention includes a step of preparing a processing container provided with a heat generating member that generates heat when power is applied, a step of exhausting the inside of the processing container, a step of supplying an etching gas into the processing container, and the heat generating member. Is connected to a power supply mechanism, power is supplied from the power supply mechanism to the heat generating member, and power is supplied to the heat generating member so that the heat generating member generates heat up to a temperature at which the etching gas is decomposed and / or activated. Thus, the step of etching the adhesion film, and the inside of the processing container toward the connection portion for applying the power from the power supply mechanism to the heat generating member, hydrogen, argon, helium, Step of introducing a gas containing neon, krypton, xenon, nitrogen or ammonia, or a mixed gas of these gases
A method for etching an adhesion film having

The heating element CVD apparatus used in the present invention is connected to the connection part in which the heating element is connected to the power supply mechanism and / or the support part in which the heating element is supported by the support in the above configuration. A cover is mounted without any contact with the heating element, and a gas is introduced into the gap between the cover and the connection part and the support part. For this purpose, a gas introduction system is provided.

In addition, in the connection part where the heating element is connected to the power supply mechanism and / or the support part where the heating element is supported by the support, the gap existing between the cover and the connection part and the support part is The cover is connected to the inner space of the processing container through a gap formed between the cover mounted without contacting the end of the heating element and the end of the heating element.

Therefore, the gas introduced from the gas introduction system for introducing the gas into the gap between the cover, the connection portion, and the support portion is a gap existing between the cover, the connection portion, and the support portion, and Then, it is introduced into the processing container through a gap formed between the cover and the end of the heating element.

As a result, when a gas is introduced from the gas introduction system into the gap between the cover and the connection portion and the support portion during film formation or adhesion film removal (cleaning), this results in the cover and the heating element end from the gap. It flows into the processing container through a gap formed between the two parts.

Therefore, at the time of film formation, the source gas such as silane gas penetrates into the gap between the cover and the connection part or the support part inside the cover, that is, the source gas contacts the part of the heating element having a slightly low temperature. Can be suppressed. In addition, when the attached film is removed (cleaning), the cleaning gas penetrates into the gap between the cover and the connection portion or the support portion inside the cover, that is, the cleaning gas is slightly lower in temperature of the heating element. It can suppress contacting a part.

Further, when the cover comes into contact with the heating element, the temperature of the heating element at the contact portion is lowered, and the portion where the temperature is lowered comes into contact with the raw material gas, the cleaning gas, and the active species originating from these, thereby silicidizing. However, as described above, the cover is attached to the connection part or the support part without coming into contact with the end of the heating element, that is, the cover and the heat generation. Since there is a gap between the end of the body, there is no such fear.

As a result, the part where the temperature of the heating element is slightly lowered, such as the connection part where the heating element is connected to the power supply mechanism and the support part where the heating element is supported by the support, Therefore, it is possible to prevent deterioration (silicidation) and reaction (etching) with the cleaning gas during removal of the attached film (cleaning).

As a result, it is possible to extend the life of the heating element and stabilize the film forming environment, and to provide a heating element CVD apparatus with good productivity by reducing the replacement frequency of the heating element due to the longer life of the heating element. it can.

In the above, the gas introduced from the gas introduction system into the gap between the cover and the connection portion or the support portion is any one of hydrogen, argon, helium, neon, krypton, xenon, nitrogen, ammonia, or these It can be set as the mixed gas which consists of 2 or more types.

Another heating element CVD apparatus used in the present invention is the heating element CVD apparatus of the basic form described above, wherein the end of the heating element is inserted / removed in the connection portion where the heating element is connected to the power supply mechanism. A heating element insertion port and an elastic body support that is slidably attached in a direction in which an end of the heating element is inserted into and removed from the heating element insertion port, and in the heating element insertion port, One side faces the end of the heating element inserted into the heating element insertion port, and the other side includes a metal or ceramic elastic body that is slidably supported by the elastic body support, and the elastic body By attaching the heating tool in the direction in which the end of the heating element is inserted into the heating element insertion port, the end of the heating element is pressed against the connecting portion by the elastic force of the elastic body, and the heating element is attached to the connecting portion. Is performed.

Here, as an elastic body made of metal or ceramic, it contacts with a heating element reaching a high temperature of 1600 to 2000 ° C. and may be heated to close to 600 ° C., so the elastic force is lost even at such temperature. It is desirable to employ a spring made of a metal such as nickel superalloy (Inconel: registered trademark) or a ceramic such as silicon nitride.

According to the heating element CVD apparatus having the above-described configuration, the contact area between the end of the heating element and the connection portion is maintained at a constant area given to the heating element insertion port, and the end of the heating element is connected. It can always be pressed against the part with almost constant force.

In addition, by adopting the above-described configuration, unlike the conventional fixing by the tightening force of the screw as shown in FIG. 10, an elastic body support (for example, a spring pressing metal fitting) is connected to the heating element insertion port of the connection portion. By sliding parallel to the insertion / removal direction of the end of the heating element, the connecting part at the end of the heating element is instantly fixed or released by the pressing force from the elastic body that exerts elasticity. Mounting and removal with can be realized.

Therefore, even if the heating element is once energized and heated and deteriorates and becomes brittle, the end of the heating element is fixed with a constant elastic force that is stable at high temperatures, and the end of the heating element is connected. Since the attachment and detachment at the unit can be performed easily and in a short time, the apparatus stop time due to the maintenance can be reduced, and a highly productive heating element CVD apparatus can be provided.

Still another heating element CVD apparatus used in the present invention is the heating element CVD apparatus of the basic form described above, wherein the end of the heating element is inserted / removed in the connection portion where the heating element is connected to the power supply mechanism. A heating element insertion port, and a metal coil spring disposed in the heating element insertion port, the metal block at the end of the heating element inserted into the heating element insertion port is inserted into the heating element insertion It is held by the elastic force of the metal coil spring in the mouth, and power is supplied from the power supply mechanism through the metal coil spring.

Also here, the metal coil spring is in contact with a heating element that reaches a high temperature of 1600 to 2000 ° C. and may be heated to close to 600 ° C. Therefore, the nickel coil spring is a material that does not lose its elastic force even at such a temperature. It is desirable to use a metal such as an alloy (Inconel: registered trademark) .

Even with such a configuration, the end of the heating element can be held by the metal coil spring at the connection portion with a substantially constant force at all times.

In addition, by inserting / removing the metal block at the end of the heating element into / from the heating element insertion slot, fixing by the pressing force from the metal coil spring that exerts elastic force or release of the force is instantaneously performed, and the heating element It is possible to easily attach and detach the end of the connector at a connecting portion in a short time, so that the apparatus stop time due to maintenance can be reduced, and a highly productive heating element CVD apparatus can be provided. it can.

Thus, with the above-described configuration, the temperature of the heating element is slightly higher, such as a connection part where the heating element is connected to the power supply mechanism and a support part where the heating element is supported by the support. It is possible to prevent the lowered portion from being deteriorated (silicidation) by the source gas during film formation and from reacting (etching) with the cleaning gas during removal of the attached film (cleaning), and the heating element is heated once. Even if it has deteriorated and becomes brittle, the end of the heating element continues to be fixed with a substantially constant elastic force even at high temperatures, and it is easy to attach and detach at the end of the heating element. And can be performed in a short time. That is, by combining with a longer life of the heating element by preventing silicidation and etching, it is possible to provide a highly productive heating element CVD apparatus capable of reducing apparatus downtime due to maintenance.

According to the present invention, the connecting portion where the heating element is connected to the power supply mechanism, and the supporting portion where the heating element is supported by the support, the gap between the connecting portion and the supporting portion exists, and In addition, a gas introduction mechanism is provided that does not contact the heating element, that is, covers the cover with a gap between the heating element and introduces gas into the gap between the cover, the connection portion, and the support portion. ing. Accordingly, hydrogen, argon, helium, neon, krypton, xenon, nitrogen, ammonia, or a mixed gas composed of two or more of these is introduced from the gas introduction mechanism into the gap between the cover, the connecting portion, and the supporting portion. Introduced into the substrate, the source gas such as silane gas and the active species originating therefrom are formed during the film formation, and the cleaning gas and the active species originating therefrom are removed between the cover and the connection portion and the support portion during the removal of the adhesion film. It can suppress that it intrudes into this clearance gap, and contacts the heat generating body part in which the temperature of a heat generating body near the connection part and the support part becomes somewhat low. Therefore, it is possible to effectively prevent silicidation that proceeds from a portion where the temperature of these heating elements becomes slightly low during film formation, or deterioration of the heating elements due to an etching phenomenon during cleaning.

In addition, attachment of the heating element end at the connection portion where the heating element is connected to the power supply mechanism, insertion of the heating element end into the heating element insertion port provided in the connection portion, and the inside of the heating element insertion port This is realized by pressing the end of the heating element against the connecting portion by a substantially constant elastic force by the elastic body made of metal or ceramic provided in the above. Therefore, even if the heating element becomes brittle when it is energized and heated, the end of the heating element can be kept fixed to the connecting portion with a substantially constant elastic force that is stable even at high temperatures. The attachment and detachment at the connection part of the part can be performed easily and in a short time.

Therefore, by combining with the extension of the lifetime of the heating element by preventing silicidation and etching, it is possible to provide a highly productive heating element CVD apparatus capable of reducing the apparatus stop time due to maintenance.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows the structure of a main part of a first embodiment of a heating element CVD apparatus used in the present invention , and forms of a processing vessel 1 and its internal structure, an exhaust system 11, a source gas introduction system 21, and the like. Since the structure is the same as that of the conventional heating element CVD apparatus shown in FIG. 8, the illustration is omitted. Further, the same members as those shown in FIG. 8 are denoted by the same reference numerals, and the description thereof is omitted.

In FIG. 1, a heating element 3, a support 31 that supports the heating element 3, a power supply line 32, and covers 301 and 302 are shown.

The covers 301 and 302 are respectively connected to the connection part side (connection terminal 33) where the heating element 3 is connected to the power supply line 32 and on the support part side (not shown) where the heating element 3 is supported by the support body 31. As shown in FIG. 5, there is a gap 311 a inside, that is, there is a gap 311 a between the connection part and the support part, and without contact with the heating element 3, that is, with the heating element 3. It is mounted with a gap 311b in between.

Furthermore, in order to introduce gas into the gap 311a inside the covers 301 and 302, a gas supply system 321 having the same configuration as the source gas introduction system 21 shown in FIG. 8 is schematically shown.

In the present embodiment, the connection part (connection terminal 33) in which the heating element 3 is connected to the power supply line 32 and the support part in which the heating element 3 is supported by the support 31 are covered by the covers 301 and 302. Therefore, it is indicated by a broken line.

The cover 301 covers one part where the heating element 3 is supported by the support 31 and two parts where the heating element 3 is connected to the connection terminal 33, and the cover 302 covers two parts where the heating element 3 is supported by the support 31. The parts are covered together.

Here, it goes without saying that the number of support portions and connection portions (connection terminals) covered with one cover is arbitrary depending on the shape of the heating element 3.

FIG. 2 shows the main structure of the second embodiment of the heating element CVD apparatus used in the present invention. The same members as those shown in FIGS. 1 and 8 are denoted by the same reference numerals. In the present embodiment, each of the portion where the heating element 3 is supported by the support 31 and the connection portion (connection terminal 33) where the heating element 3 is connected to the power supply line 32 are separated by individual covers 303 and 304. The cover 303 covers the support portions of the heating element 3 and the support 31, and the cover 304 covers the connection terminal 33.

FIG. 3 shows the structure of the main part of the third embodiment of the heating element CVD apparatus used in the present invention. The heating element CVD in which the heating element 3 is held by the support 34 shown in FIG. The present invention is applied to an apparatus. The same members as those shown in FIGS. 1, 2, and 9 are denoted by the same reference numerals. In the present embodiment, the portion where the heating element 3 is in contact with the wire 34 and the portion connected to the connection terminal 33 are covered with the covers 305 and 306. The cover 306 collectively covers the two portions where the heating element 3 is in contact with the wire 34. The cover 306 covers the two portions where the heating element 3 is in contact with the wire 34. Yes. Here, as with the description of the embodiment shown in FIG. 1, it goes without saying that the number of contact portions and connection terminal portions covered with one cover is arbitrary depending on the shape of the heating element 3.

FIG. 4 shows the main structure of the fourth embodiment of the heating element CVD apparatus used in the present invention. Members similar to those shown in FIGS. 1 to 3 and FIG. In the present embodiment, each of the portion where the heating element 3 is in contact with the wire 34 and the portion connected to the connection terminal 33 is covered with individual covers 307 and 308, and the cover 307 is connected to the wire 34. The contact portion including the wire 34 is covered, and the cover 308 covers the connection terminal 33 portion.

In the silicon film formation by the conventional heating element CVD apparatus shown in FIG. 8, silane gas and hydrogen gas are supplied from each source gas supply system 21 (only one system is shown in FIG. 8) through the gas supply device 2. It was introduced into the processing container 1.

On the other hand, in the embodiment of the present invention, preferably, only silane gas is introduced from the source gas supply system 21 into the processing container 1 via the gas supply device 2, and hydrogen gas is supplied from the gas supply system 321 to the cover 301. ˜308 can be introduced into the gap 311a.

In the heating element CVD apparatus used in the present invention, the covers 301 to 308 are arranged without contacting the heating element 3. That is, since the gap 311b is provided between the covers 301 to 308 and the heating element 3, the hydrogen gas introduced into the gap 311a in the covers 301 to 308 as described above is transferred from the covers 301 to 308 into the gap 311b. Is introduced into the processing container 1.

FIG. 5 shows a schematic view of a cross-section of the A part of the second embodiment of the present invention shown in FIG. Hydrogen gas is introduced from the gas supply system 321 into the gap 311a in the cover 304 in the direction of arrow 322, and is introduced into the processing container 1 from the gap 311b between the heating element 3 and the cover 304 as indicated by arrow 323.

The silane gas introduced into the processing container 1 from the gas supply device 2 by the flow of the hydrogen gas and the active species originating from the silane gas decomposed and / or activated on the surface of the uncovered heating element 3 are contained in the cover 304. Can be prevented from entering the gap 311a from the direction opposite to the arrow 323, and the heating element 3 in the vicinity of the connection portion (connection terminal) 33 where the heating element 3 is connected to the power supply line 32 from the power supply mechanism. It is possible to prevent these from coming into contact with a slightly low temperature portion of the end portion and silicidation and deterioration.

Further, in the part where the heating element 3 is supported by the support 31 (the part covered by the cover 303 of the second embodiment shown in FIG. 2), the structure (electric power) similar to the structure shown in FIG. The portion of the heating element 3 supported by the support 31 is adopted by adopting a difference from the structure shown in FIG. 5 only in that the power supply line 32 from the supply mechanism is not connected and the connection terminal 33 is not present. It is possible to prevent the silane gas or the like from coming into contact with silicidation and deterioration.

Such a deterioration prevention by silicidation of the heating element 3 is based on the same principle, and covers 301, 302, 305 to 308 in the first, third, and fourth embodiments shown in FIGS. Also realized in the department.

Here, the gas introduced into the covers 301 to 308 is not limited to hydrogen gas, and may be argon, helium, neon, krypton, xenon, or a mixed gas composed of two or more of these. Similarly, deterioration of the heating element 3 can be prevented.

When hydrogen gas is introduced simultaneously with these gases, hydrogen gas is introduced from the gas supply device 2 (FIG. 8), and other gases are introduced through the gaps in the covers 301 to 308. The gas may be mixed with other gas and introduced through the gaps in the covers 301 to 308. However, it is more efficient to introduce the mixture through the gaps in the covers 301 to 308.

In the silicon nitride film formation by the conventional heating element CVD apparatus shown in FIG. 8, silane gas and ammonia gas are supplied from the source gas supply system 21 (only one system is shown in FIG. 8) through the gas supply device 2. Was introduced into the processing container 1.

On the other hand, in the embodiment of the present invention, preferably, only the silane gas is introduced into the processing container 1 from the source gas supply system 21 via the gas supplier 2, and the ammonia gas is supplied from the gas supply system 321 to the cover 301. 308 to the gap 311a in the direction of the arrow 322, and the gap 311b between the heating element 3 and the cover 301 can be introduced into the processing container 1 as indicated by the arrow 323.

Thereby, as in the case of the silicon film formation, the active species derived from the silane gas introduced into the processing container 1 and the silane gas originating from the silane gas decomposed and / or activated on the surface of the uncovered heating element 3 are covered. 308 can be prevented from entering the gap 311a in the direction opposite to the arrow 323, and is supported by the vicinity of the portion where the heating element 3 is connected to the connection terminal 33 or the support 31 of the heating element 3. It is possible to prevent the heat generating element 3 from coming into contact with a part at a slightly low temperature, such as the vicinity of the part, to be silicided and deteriorated.

Here, the gas introduced through the gaps in the covers 301 to 308 is ammonia gas, hydrogen, argon, helium, neon, krypton, xenon, nitrogen, or a mixture of two or more of these. However, the deterioration of the heating element 3 can be similarly prevented by any of these.

In order to efficiently form the silicon nitride film, it is necessary to introduce ammonia gas. However, when ammonia gas is introduced simultaneously with these gases, the ammonia gas is introduced from the gas supply device 2 and other gases are covered with the cover 301. ˜308 may be introduced through a gap, or ammonia gas may be mixed with another gas and introduced through a gap in the covers 301 to 308. However, it is more efficient that it is introduced by mixing with other gases through the gaps in the covers 301 to 308.

The formation of the silicon film and the silicon nitride film according to the embodiment of the present invention is a film formation application example of the heating element CVD apparatus of the present invention, and can be applied to film formation other than these. Moreover, although silane gas is used in forming these films, the present invention can be applied to disilane (Si2H6), trisilane (Si3H8), tetraethoxysilane (TEOS), etc. other than silane gas.

In the embodiment of the present invention, when the film adhering to the inside of the processing container 1 is removed, the cleaning gas is supplied from the cleaning gas supply system (not shown) having the same configuration as the source gas supply system 21 to the gas supply device 2. Through the gas supply system 321 and a cover 301 to a mixed gas composed of hydrogen, argon, helium, neon, krypton, xenon, nitrogen, ammonia, or a mixture of two or more thereof. It introduces into the gap 311 a in 308.

As a result, the cleaning gas itself introduced into the processing container 1 or the active species originating from the cleaning gas decomposed and / or activated on the surface of the uncovered heating element 3 is opposite to the arrow 323 into the gap 311a in the cover. Can be prevented from entering, and the vicinity of the heating element 3 supported by the support 31 and the vicinity of the heating element 3 connected to the connection terminal 33 can be prevented from being etched and deteriorated. .

Here, the heating element CVD apparatus of the present invention includes fluorine (F2), chlorine (Cl2), nitrogen trifluoride (NF3), tetrafluoromethane (CF4), ethane hexafluoride (C2F6), and octafluoropropane ( C3F8), carbon tetrachloride (CCl4), trifluorochloromethane (CClF3), pentafluorochloroethane (C2ClF5), chlorine trifluoride (ClF3), and sulfur hexafluoride (SF6) Is applicable.

In the heating element CVD apparatus used in the present invention described above, a linear heating element is used as the heating element 3, but the heating element may be a foil or a linear heating element arranged in a coil or the like. May be. However, when a coiled heating element is used, the gap between the cover and the heating element is set narrow so as to effectively prevent the source gas and its active species, or the cleaning gas and its active species from entering the cover. In order to reduce the area of the gap, it is desirable to use a heating element in which at least the gap portion has a linear shape.

6 (a) and 6 (b) show a heating element 3 to a connection terminal main body 331 (corresponding to the connection terminal 33 in FIG. 5) which is a constituent member of the connection portion in the fifth embodiment of the present invention. This is a description of the attachment.

This embodiment is characterized in the structure for attaching the heating element at the connection portion where the heating element 3 is connected to the power supply line 32, which is represented by the symbol C in FIG. (B) represents a configuration in which a connection terminal main body 331 (corresponding to the connection terminal 33 in FIG. 5), which is a component of the connection portion, is directly fixed to the upper surface of the support 31 (not shown).

The connection terminal main body 331 (corresponding to the connection terminal 33 in FIG. 5) includes a heating element insertion port 337 into which an end of the heating element 3 is inserted and removed, and an end of the heating element 3 into the heating element insertion port 337. A spring retainer fitting 334 is provided as an elastic body support that is slidably attached in the insertion / removal direction (direction indicated by arrow 335 in FIG. 6A), and is made of metal or ceramics. An elastic body (in the embodiment shown in FIG. 6A, a spring 333) is provided in the heating element insertion port 337.

As shown in FIG. 6A, the spring 333 has one side (the left side in FIG. 6A) facing the end of the heating element 3 inserted into the heating element insertion port 337 and the other side. (Right side in FIG. 6A) is slidably supported by the spring retainer 334.

In the state shown in FIG. 6A, the spring retainer 334 does not push the spring 333. In this state, as shown in FIG. 6A, the end of the heating element 3 is inserted into the heating element insertion port 337, and then the spring retainer 334 is moved to the state shown in FIG. 3 is slid in the direction in which it is inserted into the heating element insertion port 337 (lower side in FIG. 6A), the spring 333 is pushed, and the end of the heating element 3 is pressed by the elastic force of the spring 333. Is pressed against the connection terminal body 331, and the heating element 3 is attached to the connection terminal body 331. Such attachment can be performed instantly and easily by the operation of sliding the spring retainer 334 downward in FIG. 6A.

Further, in the state shown in FIG. 6B in which the heating element 3 is attached to the connection terminal main body 331, the end of the heating element 3 is substantially constant due to the elastic force of the spring 333 supported by the spring retainer 334. It is pressed against the connection terminal main body 331 by force.

When the heating element 3 is replaced, if the spring holding metal 334 is slid upward in FIG. 6B and returned to the state shown in FIG. 6A, the spring 333 causes the end of the heating element 3 to move. Since the force pressed against the connection terminal main body 331 is released instantaneously, the end of the heating element 3 can be easily extracted.

In the embodiment of FIGS. 6A and 6B described above, as one measure for contributing to stable film formation, a plate of a refractory metal such as tungsten or molybdenum is attached to the end of the spring 333 and the heating element 3. The temperature of the spring 333 is less likely to be transmitted to the spring 333 by interposing it between the two parts (not shown) and preventing the change in the spring force due to the temperature increase of the spring 333. It is also possible to do.

As an elastic body that exerts an elastic force that presses the end of the heating element 3 against the connection terminal main body 331, a spring is conceivable. This spring is made of metal such as beryllium copper, stainless steel, or Inconel, or ceramic. Can be adopted. However, it is desirable to employ a nickel superalloy (Inconel: registered trademark) or a ceramic spring when it is in contact with a heating element reaching a high temperature of 1600 to 2000 ° C and heated to near 600 ° C.

In the heating element CVD apparatus according to the conventional basic form described with reference to FIGS. 8 and 9, the connecting portion where the heating element 3 is connected to the power supply mechanism is shown in the embodiment of FIGS. 6 (a) and 6 (b). With the structure described, the heating element CVD apparatus proposed by the present invention can be obtained. With such a configuration, even if the heating element is once energized and heated and deteriorates and becomes brittle, the end of the heating element 3 is fixed by a stable and almost constant elastic force of the spring 333 at a high temperature. In addition, attachment and removal at the connection portion 33 at the end of the heating element 3 can be easily performed.

Further, in the heating element CVD apparatus having the conventional basic form described with reference to FIGS. 8 and 9, the connecting portion in which the heating element 3 having the embodiment described with reference to FIGS. 1 to 5 is connected to the power supply line 32. And the structure of the support part by which the heat generating body 3 is supported by the support body 31 is employ | adopted, Furthermore, the connection part to which the heat generating body 3 is connected to the electric power supply mechanism is shown to Fig.6 (a), (b). With the structure described in the embodiment, the heating element CVD apparatus proposed by the present invention can be provided. With such a configuration, a portion where the temperature of the heating element 3 is slightly reduced is formed in the connection part of the heating element CVD apparatus, which is one of the important mechanism parts of the heating element CVD apparatus, mainly the heating element power supply mechanism. In addition to preventing deterioration (silicidation) due to the source gas and active species originating from it during film formation, and not reacting (etching) with the cleaning gas and active species originating therefrom during cleaning, It is possible to provide a heating element CVD apparatus in which the fixing method is improved and the problem of deterioration of the heating element at that location can be prevented.

FIGS. 7A and 7B show other implementations of the structure for attaching the heating element 3 to the connection terminal main body 331 (corresponding to the connection terminal 33 in FIG. 5) which is a component of the connection portion (connection terminal 33). The form will be described.

The connection terminal main body 331 (corresponding to the connection terminal 33 in FIG. 5) is a heating element insertion port 337 into which the end of the heating element 3 is inserted and removed, and a metal made in the heating element insertion port 337. A coil spring 340 is provided.

On the other hand, the heating element 3 is provided with a metal block in the form of a boss 338 at its end, and the boss 338 inserted into the heating element insertion port 337 is elastic of the metal coil spring 340 in the heating element insertion port 337. The heating element 3 is held by the connection terminal body 331 by force, and the heating element 3 is attached to the connection terminal body 331, and power is supplied to the heating element 3 through the metal coil spring 340.

When the boss 338 provided at the end of the heating element 3 is inserted into the heating element insertion port 337, the boss 338 is held in the connection terminal body 331 instantly and easily by the elastic force of the metal coil spring 340. In addition, electrical contact for supplying power to the heating element 3 through the metal coil spring 340 can be made.

Further, in the state shown in FIG. 7A in which the heating element 3 is attached to the connection terminal body 331, the heating element 3 is held by the connection terminal body 331 with a substantially constant force due to the elastic force of the metal coil spring 340. Has been.

When the heating element 3 is replaced, the boss 338 of the heating element 3 can be easily extracted simply by extracting the boss 338 from the heating element insertion port 337 against the elastic force of the metal coil spring 340.

In the heating element CVD apparatus according to the conventional basic form described with reference to FIGS. 8 and 9, the connection part where the heating element 3 is connected to the power supply mechanism is shown in the embodiment of FIGS. 7 (a) and 7 (b). With the structure described, the heating element CVD apparatus proposed by the present invention can be obtained. With such a configuration, even if the heating element is once energized and heated and deteriorates and becomes brittle, the end of the heating element 3 is caused by a stable and almost constant elastic force of the metal coil spring 340 at a high temperature. In addition, the attachment and detachment at the connection portion 33 at the end of the heating element 3 can be easily performed.

The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to such embodiments, but within the technical scope grasped from the description of the claims. It can be changed into various forms.

For example, the forms of the covers 301 to 308, the fixing method to the support 31, the power and hydrogen gas introduction positions to the covers 301 to 308, etc. are not limited to those illustrated in the attached drawings.

It is a conceptual diagram which shows the principal part structural example of 1st Embodiment of the heat generating body CVD apparatus used by this invention. It is a conceptual diagram which shows the principal part structural example of 2nd Embodiment of the heat generating body CVD apparatus used by this invention. It is a conceptual diagram which shows the principal part structural example of 3rd Embodiment of the heat generating body CVD apparatus used by this invention. It is a conceptual diagram which shows the principal part structural example of 4th Embodiment of the heat generating body CVD apparatus used by this invention. It is a conceptual diagram which shows the A section cross section of 2nd Embodiment of the heat generating body CVD apparatus used by this invention. It is a conceptual diagram which shows the principal part structural example of 5th Embodiment of the heat generating body CVD apparatus used by this invention, (a) is a figure explaining the state by which the heat generating body is not pressed by the spring, (b) Is a diagram illustrating a state in which the heating element is pressed by a spring, (A) The conceptual diagram which shows the principal part structural example of 6th Embodiment of the heat generating body CVD apparatus used by this invention, (b) is the schematic of the coil spring employ | adopted as embodiment of Fig.7 (a). It is a conceptual diagram which shows the structural example of the conventional heat generating body CVD apparatus. It is a conceptual diagram which shows the principal part structure of another structural example of the conventional heat generating body CVD apparatus. The figure explaining the attachment part of the heat generating body in the conventional heat generating CVD apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing container 2 Gas supply device 3 Heat generating body 4 Substrate holder 11 Exhaust system 21 Raw material gas supply system 30 Power supply mechanism 31 Support body 33 Connection terminal 301-308 Cover 311a, 311b Gap 321 Gas supply system 331 Connection terminal main body 333 Spring 334 Spring clamp 337 Heating element insertion port 338 Boss 340 Coil spring

Claims (3)

A step of preparing a processing container provided with a heat generating member that generates heat by applying power;
Exhausting the interior of the processing vessel;
Supplying an etching gas into the processing vessel;
Connecting the heat generating member to a power supply mechanism, supplying power from the power supply mechanism to the heat generating member, and generating the heat so that the heat generating member generates heat up to a temperature at which the etching gas is decomposed and / or activated. Applying power to the member, thereby etching the deposited film; and
A gas having hydrogen, argon, helium, neon, krypton, xenon, nitrogen, or ammonia, toward the connection for applying power from the power supply mechanism to the heating member inside the processing container, or Step of introducing a mixed gas of these gases
A method for etching an adhesion film, characterized by comprising:
2. The adhesion film etching method according to claim 1, wherein the heat generating member includes a tungsten wire.
The etching gas is fluorine (F ₂ ), Chlorine (Cl ₂ ), Nitrogen trifluoride (NF) ₃ ), Tetrafluoromethane (CF ₄ ), Hexafluoroethane (C ₂ F ₆ ), Octafluoropropane (C ₃ F ₈ ), Carbon tetrachloride (CCl ₄ ), Trifluorochloromethane (CCIF) ₃ ), Pentafluorochloride ethane (C ₂ ClF ₅ ) Or chlorine trifluoride (ClF) ₃ ), Sulfur hexafluoride (SF) ₆ The method of etching an adhesion film, characterized by comprising a gas