WO2004021425A1 - Method of etching and etching apparatus - Google Patents

Abstract

A thin film formed on a substrate is etched with an etching gas containing a β-diketone, thereby exposing substrate surface.

Description

 Description Etching method and etching equipment

 The present invention relates to an etching method and an etching apparatus. Background art

In recent years, the development of a gate insulating film that can lower the gate voltage of a MOS (Metal Oxide-Semiconductor) transistor and obtain an excellent dielectric strength has become an important issue. As a means to solve such problems, the Gut insulating film be shape ¾¾ a high dielectric constant insulating film such as H f 0 ₂ film has been attracting attention.

 However, if a high-k insulating film is used for the gate insulating film, the drain current during operation of the MOS transistor may be reduced. It is preferable to suppress such a decrease in the drain current, since this causes a hindrance to an increase in the speed of the device. For this reason, a Si-containing film such as a Si ON film is formed between the high-dielectric-constant insulating film and the Si substrate to suppress a decrease in drain current.

 Incidentally, in order to form the high dielectric constant insulating film and the Si-containing film formed on the Si substrate into predetermined shapes, it is necessary to perform etching. At present, an HF solution is used for etching a high dielectric constant insulating film and a Si-containing film.

However, when the high dielectric constant insulating film and the Si-containing film are etched using the HF solution, there is a problem that the field oxide film below the Si-containing film is locally damaged. Disclosure of the invention

 The present invention has been made to solve the above problems. That is, an object of the present invention is to provide an etching method and an etching apparatus capable of reducing damage to a substrate.

 The etching method of the present invention includes a substrate preparing step of preparing a substrate on which a thin film is formed, and etching of the thin film formed on the substrate with an etching gas containing 3_ diketone, whereby the surface of the substrate is etched. It is characterized by comprising an etching step for exposing. Since the etching method of the present invention includes an etching step, damage to the substrate can be reduced.

 The above-mentioned J3-diketone is preferably hexafluoroacetylacetone. By using hexafluoroacetyl / racetone as the 3-diketone, the damage to the substrate can be further reduced.

 The etching gas containing β-diketone preferably contains at least one of water and alcohol. The etching rate can be increased by including such a gas in the etching gas containing a 3-ketone.

 The etching step may be performed while alternately supplying an etching gas containing β-diketone and a gas containing at least one of water and alcohol. By supplying these gases alternately, accurate etching can be performed.

 The etching step is preferably performed in a state where the temperature of the substrate is maintained at 300 ° C. or higher, preferably 450 ° C. or higher. By performing etching in such a state, the etch rate can be further increased.

The etching gas containing β-diketon is preferably supplied so that the etching gas containing β-diketon flows along the surface of the thin film. No. By supplying an etching gas containing] -diketone in this manner, the etch rate can be increased.

 The thin film may be composed of at least one of a metal film and a metal oxide film. ] An etching gas containing three diketones is particularly effective for etching a metal film and a metal oxide film.

 At least one of the metal film and the metal oxide film may include at least one of Al, Zr, Hf, Y, La, Ce, and Pr. Even when at least one of the metal film and the metal oxide film contains any of these, damage to the substrate can be reliably reduced.

 The surface of the substrate is preferably made of a Si-containing film. By forming the surface of the substrate with the Si-containing film, the etching of the thin film can be stopped on the surface of the Si-containing film.

 The above etching method may further include a Si-containing film etching step of etching the Si-containing film. The Si-containing film etching step is preferably a step of etching the Si-containing film with an etching gas containing a fluorine-containing gas or an etching solution containing a hydrogen fluoride solution. By etching the Si-containing film by such a method, the etch rate in etching the Si-containing film can be improved.

 The etching gas containing the fluorine-containing gas preferably contains at least one of water and alcohol. By including such an etching gas in an etching gas containing a fluorine-containing gas, the etch rate in etching the Si-containing film can be further increased.

The Si-containing film etching step may be performed while alternately supplying an etching gas containing a fluorine-containing gas and a gas containing at least one of water and alcohol. By supplying these gases alternately, Accurate etching of the Si-containing film can be performed.

 The Si-containing film etching step is preferably performed in a state where the temperature of the substrate is kept at 10 ° C. or lower. By etching the Si-containing film in such a state, the etch rate in etching the Si-containing film can be reliably increased.

An etching apparatus according to the present invention includes: a reactor accommodating a substrate having a first thin film and a second thin film formed below the first thin film; and an etching apparatus for etching the first thin film in the reactor. a supply system for supplying an etching gas containing β-diketone, and a supply system for supplying an etching gas containing a fluorine-containing gas or an etching solution containing a hydrogen fluoride solution for etching the second thin film into the reactor. It is characterized by having. Since the etching apparatus of the present invention includes the Hhfac-containing etching gas supply system, damage to the substrate can be reduced. Further, the first thin film and the second thin film can be continuously etched. Further, the etching of the first thin film and the etching of the second thin film can be performed by one apparatus. Another etching apparatus of the present invention includes a first reactor containing a substrate having a first thin film and a second thin film formed under the first thin film, and a first reactor containing the first thin film and a second thin film formed under the first thin film. A supply system for supplying an etching gas containing a ketone for etching the first thin film, a second reactor containing the substrate on which the first thin film has been etched, and a second reactor in the second reactor. A supply system for supplying an etching gas containing a fluorine-containing gas or an etching solution containing a hydrogen fluoride solution for etching a thin film of the substrate, and a substrate transfer for transferring the substrate to the first reactor and the second reactor. And a system is provided. Since the etching apparatus of the present invention includes the Hh Hac-containing etching gas supply system, damage to the substrate can be reduced. Further, the first thin film and the second thin film can be continuously etched. The diketone is preferably hexafluoroacetylacetone. By using hexafluoroacetylacetone as the / 3-diketone, damage to the substrate can be further reduced. BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is a schematic vertical sectional view of the etching apparatus according to the first embodiment.

 FIG. 2 is a schematic horizontal sectional view of the etching apparatus according to the first embodiment.

 FIG. 3 is a diagram schematically showing a wafer before etching according to the first embodiment.

 FIG. 4 is a flowchart showing a flow of etching performed by the etching apparatus according to the first embodiment.

5 _c Figure 7 A first is a figure _c 6 is a diagram schematically showing the etching according to the first embodiment showing the etching according to the first embodiment schematically FIG. 7B is a diagram schematically illustrating the chemical structure of H hfac used in the first embodiment, and FIG. 7B is a diagram schematically illustrating the chemical structure of the H f complex generated in the first embodiment. It is.

Figure 8 A is a diagram schematically showing a wafer after etching of H f 0 ₂ film according to the first embodiment, FIG. 8 B is etched S i ON film according to the first embodiment It is the figure which showed the later wafer typically.

Figure 9 is a graph showing the relationship between the etch rate of the temperature and H f 0 ₂ film wafer according to Example 2 and Reference Example.

Figure 1 0 is a graph showing the relationship between the temperature and A 1 ₂ O ₃ film of E Tsuchireto the wafer according to Example 3 and Reference Example.

Figure 1 1 is the pressure in the internal chamber of the fourth embodiment and Reference Examples and H f O ₂ 5 is a graph showing a relationship with a film etch rate.

 FIG. 12 is a graph showing a relationship between Hhfac and an etch rate according to the fifth embodiment.

Figure 1 3 is a graph showing the relationship between the etch rate of the flow rate and H f O ₂ film of O ₂ according to Example 6 and Reference Examples.

Figure 1 4 is a graph showing the relationship between the etching rate of the flow rate and A 1 ₂ O ₃ film of O ₂ according to Example 7及Pi Reference Example.

Figure 1 5 is a graph showing the relationship between Etsu Chireto concentration and H f 0 ₂ film of H ₂ 0 according to Example 8 and Reference Examples.

Figure 1 6 is a graph showing the relationship between Etsu Chireto of Example 9 and according to the reference example H ₂ 0 concentration and A 1 ₂ 0 ₃ film.

FIG. 17 is a graph showing the relationship between the concentration of C ₂ H ₅ OH and the etch rate according to Example 10.

 FIGS. 18A and 18B are flowcharts showing a flow of etching performed by the etching apparatus according to the second embodiment.

 FIG. 19 is a schematic vertical sectional view of the etching apparatus according to the third embodiment.

 FIG. 20 is a flowchart showing a flow of etching performed by the etching apparatus according to the third embodiment.

 FIG. 21 is a diagram schematically showing etching according to the third embodiment.

 FIG. 22 is a schematic vertical sectional view of the etching apparatus according to the fourth embodiment.

 FIG. 23 is a schematic configuration diagram of an etching apparatus according to the fifth embodiment.

FIG. 24 is a schematic vertical view of the first etching unit according to the fifth embodiment. It is sectional drawing.

 FIG. 25 is a schematic vertical cross-sectional view of a second etching unit according to the fifth embodiment.

 FIGS. 26A and 26B are flowcharts showing the flow of etching performed by the etching apparatus according to the fifth embodiment. BEST MODE FOR CARRYING OUT THE INVENTION

 (First Embodiment)

 Hereinafter, the etching apparatus according to the first embodiment of the present invention will be described. FIG. 1 is a schematic vertical cross-sectional view of the etching apparatus according to the present embodiment, FIG. 2 is a schematic horizontal cross-sectional view of the etching apparatus according to the present embodiment, and FIG. FIG. 4 is a view schematically showing such a wafer before etching.

 As shown in FIGS. 1 and 2, the etching apparatus 10 includes a chamber 20 for accommodating a semiconductor wafer W (hereinafter, simply referred to as “wafer”). The chamber 20 includes an external chamber 30 and an internal chamber 40 disposed in the external chamber 30.

The outer chamber 30 is formed of, for example, A1. In addition, it is not limited to A 1, and may be formed of hastelloy or the like. Further, the inner wall surface of the outer chamber 30 may be subjected to a surface treatment such as a PTFE (polytetrafluoroethylene) coating or an alumite treatment. On the side of the outer chamber 30, a step 31 protruding inward is formed. Openings 32, 33, and 34 are formed at predetermined locations in the outer chamber 30. At the edge of the opening 32, a gate valve 50 for separating a space inside the external chamber 30 from a space outside the external chamber 30 is attached. At the edge of the opening 33, an exhaust pipe 60 for exhausting the interior chamber 40 Are connected at one end. The other end of the exhaust pipe 60 is connected to a pressure reducing pump 70. When the decompression pump 70 operates, the inside of the internal chamber 40 is exhausted through the opening 33. An automatic pressure controller 80 for controlling the pressure in the internal chamber 40 is interposed in the exhaust pipe 60. By adjusting the conductance by the auto-pressure controller 80, the pressure in the internal chamber 40 is controlled to a predetermined pressure. One end of an exhaust pipe 90 for exhausting a space between the outer chamber 30 and the inner chamber 40 is connected to an edge of the opening 34. The other end of the exhaust pipe 90 is connected to a pressure reducing pump 100. When the decompression pump 100 is operated, the space between the outer chamber 30 and the inner chamber 40 is exhausted through the opening 34, so that heat is hardly transmitted from the inner chamber 40 to the outer chamber 30. Become. The exhaust pipe 90 has an auto-pressure controller 110 for controlling the pressure in the space between the outer chamber 30 and the inner chamber 40. By adjusting the conductance by the auto-pressure controller 110, the pressure in the space between the external chamber 30 and the internal chamber 40 is controlled to a predetermined pressure.

A disk-shaped susceptor 120 on which the wafer W is placed is provided in the outer chamber 30. The susceptor 120 is formed of, for example, ceramics such as A 1 N and Al ₂ O ₃ . Here, the wafer W mounted on the susceptor 120 will be described.

As shown in FIG. 3, the wafer W includes a P-type Si substrate 1, and an N-type diffusion layer 2 is formed in a predetermined region of the P-type Si substrate 1. It should be noted that the present invention is not limited to the P-type S1 substrate 1, but may be an N-type Si substrate. On the upper part of the P-type Si substrate 1, an SiO ₂ film 3 functioning as a field oxide film is formed. The SiO ₂ film 3 is formed with a thickness of about 100A.

Functions as a good insulation film on P-type Si substrate 1 and SiO ₂ film 3 And S i ON film 4 and H f 0 ₂ film 5 is formed. Specifically, H f O ₂ film 5 on S i ON film 4 is formed. Further, S i ON film 4 is formed in about 1 0 A thickness less than, H f 0 ₂ film 5 is formed to a thickness of about 2 0 to 4 0 A. In addition, not only the SiO ON film 4 but also other Si-containing films may be used. Is in such a S i containing film, for example, S i 0 ₂ film include S i N film. Further, not limited to H f 0 ₂ film 5 may be used and other high dielectric constant insulating film. Is in such a high-dielectric-constant insulating film, A 1 ₂ 0 ₃ film, Z r 0 ₂ film, L a ₂ 0 ₃ film, Y ₂ 0 ₃ film, C e 0 ₂ film, C e ₂ 0 ₃ film, P r ₂ 0 ₃ film, P r ₆ O film, and P r 0 ₂ metal oxides such as film. On the HίO ₂ film 5, a W film 6 functioning as a gate electrode formed in a predetermined pattern is formed. In addition, not only the W film 6 but also another metal film or a polysilicon film may be used. Examples of the metal film include a Ti film, a Mo film, and a Ta film. On the W film 6, an SiO ₂ film 7 functioning as a side wall film is formed so as to cover the W film 6. In addition, not only the SiO ₂ film 7 but also other Si-containing films may be used. Examples of such a Si-containing film include a Si ₃ N ₄ film.

 Holes 121 for placing the wafer W on the susceptor 120 and separating the wafer W from the susceptor 120 are formed in three places on the susceptor 120 in the vertical direction.

The susceptor 120 is supported by a ring-shaped support member 130 formed of, for example, ceramics. An air cylinder 140 is fixed to the support member 130. When the rod 140 of the air cylinder 140 expands and contracts by driving the air cylinder 140, the susceptor 120 moves up and down. The susceptor 120 stops at a transfer position for transferring the wafer W and an etching position for etching the wafer W. A portion of the rod 141 outside the outer chamber 30 is covered with a telescopic bellows 150. By covering the rod 14 1 with the bellows 150, the airtightness in the external chamber 30 is maintained.

 Below the hole 122 of the susceptor 120, wafer elevating pins 160 that can be inserted into the hole 121 are respectively disposed. The wafer elevating pins 160 are fixed to a ring-shaped wafer elevating pin support 170 such that the wafer elevating pins 160 stand upright.

 An air cylinder 180 is fixed to the wafer elevating pin support 170. While the wafer W is supported by the wafer lifting pins 160, the rod 1801 of the air cylinder 180 is retracted, so that the wafer lifting pins 160 are pulled out of the holes 121. The wafer W is placed on the susceptor 120. Also, when the rod 18 1 of the air cylinder 180 is extended while the wafer W is placed on the susceptor 120, the wafer elevating pins 16 0 are inserted into the holes 12 1, The wafer W is separated from the susceptor by about 120. A portion of the rod 181, which is outside the outer chamber 30, is covered with a stretchable bellows 190. By covering the rod 181 with the bellows 190, the airtightness in the external champer 30 is maintained.

The susceptor 120 and the support member 130 are surrounded by a cylindrical member 200 formed in a cylindrical shape. The cylindrical member 200 is made of, for example, quartz. At an upper portion of the cylindrical member 200, a flange portion 201 protruding inward is formed. The flange portion 201 is formed so that the inner diameter is smaller than the outer diameter of the support member 130 and is larger than the diameter of the susceptor 120. By forming such a flange portion 201, the susceptor 120 stops at the etching position. A space communicating with the opening 33 is formed between the cylindrical member 200 and the external chamber 30. Below the susceptor 120, it is made of, for example, quartz, which allows heat rays to pass through. A heat transmission window 210 is provided. The heat ray transmission window 210 is fixed by being fitted into the external chamber 30. A heating chamber 220 is provided below the heat ray transmission window 210 so as to surround the heat ray transmission window 210.

 In the heating chamber 220, a heating lamp 230 for heating the susceptor 120 is provided. When the heating lamp 230 is turned on, a heating wire is emitted from the heating lamp 230, so that the heating wire passes through the heat ray transmission window 210. Thereby, the susceptor 120 located above the heat ray transmission window 210 is heated. In addition, not only the heating lamp 230 but also other heating mechanisms may be used. Examples of the heating mechanism other than the heating lamp 230 include a resistance heating element.

 The motor 240 for rotating the heating lamp 230 is connected to the heating lamp 230. The rotation of the rotation shaft 241 of the motor 240 rotates the heating lamp 230 to uniformly heat the wafer W.

 The inner chamber 40 is disposed on the step 31 of the outer chamber 30. The internal chamber 40 is made of, for example, quartz. At the bottom of the internal chamber 40, an opening 41 for accommodating the wafer W and an exhaust port 42 for exhausting the internal chamber 40 are formed. The exhaust port 42 is formed at a position communicating with the space between the external chamber 30 and the cylindrical member 200. By forming the exhaust port 42 at such a position, the inside of the internal chamber 40 is exhausted by the operation of the pressure reducing pump 70.

A nozzle 250 for supplying Hhfac-containing etching gas or the like to the internal chamber 40 is provided in the internal chamber 40. It is disposed at a position facing the exhaust port 42 with the wafer W interposed therebetween. The nozzle 250 is provided near the bottom of the internal chamber 40. By disposing the nozzle 250 at such a position, the Hhfac-containing etch Ing gas or the like can flow along the surface of the wafer W. A gas supply pipe 260 whose tip is divided into five directions is connected to the nozzle 250. One end of the gas supply pipe 260 is connected to a H hfac supply source 270 containing hexafluoroacetylacetone (CF ₃ CO CH ₂ CO CF ₃ : H hfac). Not only Hh fac but also other β-diketones can be used. Such J3- diketone, For example, Te tetramethyl heptane-dione _{((CH 3) 3 CCOCH 2} COC (CH 3) a: H thd), Asechiruase tons _{(CH 3 COCH 2 CO CH 3} ) or the like include Can be An open / close valve 280 for supplying H hfac and a mass flow controller 290 for adjusting the flow rate of H hfac are interposed in the gas supply pipe 260. By opening the on-off valve 280 with the mass flow controller 290 adjusted, Hhfac is supplied into the internal chamber 40 from the Hhfac supply source 270 at a predetermined flow rate.

 The other end of the gas supply pipe 260 is connected to an HF supply source 300 containing anhydrous HF. An on-off valve 310 for supplying HF and a mass flow controller 320 for adjusting the flow rate of HF are interposed in the gas supply pipe 260. By opening the on-off valve 310 while the mass flow controller 32 is adjusted, HF is supplied from the HF supply source 300 into the internal champer 40 at a predetermined flow rate.

The other end of the gas supply pipe 2 6 0 0 ₂ 0 ₂ source 3 3 0 containing the are connected. The gas supply pipe 2 6 0 is in massflow controller 3 5 0 force S intervening to regulate the flow rate of the opening and closing valves 3 4 0 and 0 ₂ for supplying O _2. In a state in which the mass flow controller 35 0 is adjusted, by opening and closing the valve 3 4 0 is opened, O ₂ is supplied into the chamber 4 in 0 O ₂ source 3 3 0 at a predetermined flow rate . The other end of the gas supply pipe 2 6 0, H ₂ 0 source 3 6 0 containing the H ₂ 0 is connected. It is also possible to use alcohol in place of H ₂ 0. Such alcohols include, for example, ethanol (C ₂ H ₅ OH). The gas supply pipe 2 6 0 massflow controller 3 8 0 for adjusting the flow rate of the opening and closing valve 3 7 0 and H ₂ O order to supply the H ₂ 0 is interposed. In a state in which the mass flow con preparative roller 3 8 0 is adjusted, by opening and closing valve 3 7 0 is opened, H ₂ O is supplied into the chamber 4 in 0 H ₂ 0 source 3 6 0 at a predetermined flow rate You.

The other end of the gas supply pipe 2 6 0, N ₂ supply source 3 9 0 containing the N ₂ is connected. The gas supply pipe 2 6 0 is in mass flow con preparative roller 4 1 0 force S intervening to regulate the flow rate of the closing bar Dzu 4 0 0 and N ₂ for supplying N _2. In a state in which the mass flow controller 4 1 0 is adjusted, by opening and closing the valve 4 0 0 is opened, N ₂ is supplied into the chamber 4 in 0 from N ₂ supply source 3 9 0 at a predetermined flow rate .

Hereinafter, the etching performed by the etching apparatus 10 will be described with reference to FIGS. FIG. 4 is a flowchart showing the flow of etching performed by the etching apparatus 10 according to the present embodiment, and FIGS. 5 and 6 are diagrams schematically showing the etching according to the present embodiment. . FIG. 7A is a diagram schematically illustrating the chemical structure of H hfac used in the present embodiment, and FIG. 7B is a schematic diagram illustrating the chemical structure of the H complex formed in the present embodiment. FIG. FIG. 8A is a diagram schematically showing the height W after the etching of the HfO ₂ film 5 according to the present embodiment, and FIG. 8B is a diagram showing the Si ON film 4 according to the present embodiment. FIG. 3 is a view schematically showing a wafer W after etching ₍ first, a vacuum pump 70 is operated to evacuate the internal chamber 4 °; and a vacuum pump 100 is operated, The space between the outer chamber 30 and the inner chamber 40 is evacuated (step 1A). Thereafter, the heating lamp 230 is turned on, and the susceptor 120 is heated (step 2A). The pressure inside the chamber 4 within 0 is reduced to ^{9. 3 1 X 1 0 3 ~} 1. 3 3 X 1 0 4 P a, and after rising on than at temperature 3 0 0 susceptor 1 2 0, The gate valve 50 is opened, the transfer arm (not shown) holding the wafer W is extended, and the wafer W is loaded into the external chamber 30 (Step 3A).

 Thereafter, the transfer arm is retracted, and the wafer W is supported by the wafer elevating pins 160. After the wafer W is supported by the wafer elevating pins 160, the wafer elevating pins 160 are lowered by the driving of the air cylinder 180, and the wafer W is placed on the susceptor 120 (step 4). A) After the wafer W is placed on the susceptor 120, the susceptor 120 is raised by driving the air cylinder 140, and the wafer W is carried into the internal chamber 40 (Step 5A).

After the wafer W is heated and the temperature of the wafer W is maintained at 300 ° C. or higher, preferably 450 ° C. or higher, the on-off valves 280, 340, 370, 400 are opened. When opened, the Hhfac-containing etching gas is supplied from the nozzle 250 into the internal chamber 40 as shown in FIG. 5 (step 6A). The H hfac-containing etching gas is mainly composed of H hfac, O ₂ , H ₂₀ , and N ₂ . Hh fac, O ₂ , and N ₂ are supplied into the internal chamber 40 at flow rates of 320-380 sccm, 50-250 sccm, 100-300 sccm, respectively. Moreover, H ₂ 0 is fed to a concentration of about 2 0 0 0 ppm or less (including O ppm.) Becomes by Uni interior chamber 4 within 0. The Hhfac-containing etching gas supplied from the nozzle 250 flows in a laminar flow along the surface of the wafer W. When the H hfac containing Etsuchingugasu contacts the H f O ₂ film 5, H h ί ac and H f O ₂ film 5 and reacts, S i O ₂ film 7 as a mask H f O ₂ film 5 Is Etsu Be chilled. The reaction mechanism is as follows. Hh fac has tautomerism. Therefore, H hfac can have two structures, Structure I and Structure II, as shown in FIG. 7A. In structure II, the 0_H bond is easily broken because the shared electron is delocalized between the C = 〇 bond and the C—C bond. When the O—H bond is broken, Hh fac coordinates with H f of the H f O ₂ film 5 to form an H f complex as shown in FIG. 7B. The generated H f complex is vaporized and separated from the surface of the H f O ₂ film 5. H f 0 ₂ film 5 is etched by H hfac In this Yo I Do reaction mechanism. The Hί complex separated from the surface of the HfO ₂ film 5 is exhausted to the outside of the external chamber 30 via the exhaust pipe 60 by exhaust.

Advances etching of H f 0 ₂ film 5, after the exposed surface of the S i ON film 4 as shown in FIG. 8 A, the opening and closing valve 2 8 0, 3 4 0, 3 7 0 closes et al is in, The supply of the etching gas containing H hfac is stopped. Further, the lighting of the heating lamp 230 is stopped, and the heating of the susceptor 120 is stopped. Thus, the etching of the HfO ₂ film 5 is completed. Since the opening and closing valves 4 0 0 is open, only N ₂ is supplied into the interior chamber 4 0 continue. Thus, the wafer W is cooled (Step 7A). In the present exemplary embodiment to cool the wafer W with N _2, is not limited to N _2, it may be used other inert gas. Also, the susceptor 120 may be provided with a cooling mechanism such as a Veltier element and a water-cooled jacket to cool the wafer W.

After the wafer W is cooled and the temperature of the wafer W is maintained at about 100 ° C. or less, preferably 10 to 50 ° C., the opening / closing valves 310, 370 are opened, and FIG. As shown in the figure, an etching gas containing HF is supplied from the nozzle 250 into the internal chamber 40 (step 8A). HF-containing etching gas is mainly, HF, H ₂ 0, and a及Pi ^ _[2. Nozzle 2 5 0 The HF-containing etching gas supplied from flows laminarly along the surface of W. When the HF-containing etching gas comes into contact with the SiO 2 film 4, the HF reacts with the SiO ₂ film 4, and the SiO ₂ film 4 is etched using the SiO ₂ film 7 as a mask. .

After the etching of the SiO ON film 4 progresses and the surfaces of the P-type Si substrate 1 and SiO ₂ film 3 are exposed as shown in FIG. 8B, the opening / closing valves 3 1 0, 3 7 0, 4 0 0 is closed, and the supply of the HF-containing etching gas is stopped (Step 9A). Thus, the etching of the SiON film 4 is completed. After the supply of the HF-containing etching gas is stopped, the susceptor 120 is lowered by driving the air cylinder 140, and the wafer W is carried out from the internal chamber 40 (Step 10A).

 Thereafter, the wafer lifting pins 16 are raised by driving the air cylinder 180, and the wafer W is separated from the susceptor 120 (step 11A). Further, the gate valve 50 is opened, the transfer arm (not shown) extends, and the transfer arm holds the wafer W. Finally, the transfer arm is retracted, and the wafer W is unloaded from the external chamber 30 (Step 12A).

In the present embodiment, since the H ₂ O ₂ film 5 formed on the SiO ₂ film 4 is etched by the H hfac-containing etching gas, damage to the SiO ₂ film 3 can be reduced. That is, it is considered that the reason that the field oxide film is damaged by the HF solution is a large difference in etching between the portion that is easily etched and the portion that is hardly etched. In the present embodiment, the etching is stopped at the surface of the SiON film 4 by using H hfac having a high selectivity in the etching of the H ₂ O ₂ film 5 formed on the SiON film 4. be able to. As a result, even when the SiON film 4 is subsequently etched with an HF-containing etching gas, the difference in etching between the easily etched portion and the hardly etched portion is reduced. Is done. Therefore, damage to the SiO ₂ film 3 can be reduced.

In this embodiment, since the Mase contains a 〇 _2, H ₂ 0 to Hh fac-containing etching gas, the etching rate in the etching of H f O ₂ film 5 can highly Mel possible. Further, since the etching apparatus 1 0 is a H hfac source 2 7 0 and HF supply 3 0 0, be etched with H f 〇 ₂ film 5 and the S i ON film 4 in one And throughput can be improved.

In this embodiment, since I urchin Hh fac containing Etsu Chingugasu and HF-containing etchant gas flows H hfac containing Etsuchin Gugasu and HF-containing etching gas along the surface of the wafer W is supplied, H f O ₂ film 5 In addition, the etch rate in etching the SiON film 4 can be increased.

 In this embodiment, since the Hhfac-containing etching gas and the HF-containing etching gas are supplied into the internal chamber 40, the corrosion of the internal chamber 40 can be reduced. That is, when the HF solution is used, it is difficult to remove the HF solution attached to the chamber or the like. On the other hand, in this embodiment, since the Hhfac-containing etching gas or the like is used, the Hhfac-containing etching gas or the like can be easily removed from the inside of the internal chamber 40 by exhausting. Therefore, corrosion of the internal chamber 40 can be reduced.

In the present embodiment, the internal chamber 40 is formed of quartz and the susceptor 120 is formed of ceramic. However, the internal chamber 40 is formed of SiC, and the gas of the susceptor 120 and the like is formed. The member that comes into contact with the metal may be made of quartz, metal coated with PTFE (polytetrafluoroethylene), Hastelloy, or titanium. In this case, corrosion in the internal chamber 40 can be further reduced. (Example 1)

Hereinafter, Example 1 will be described. In this embodiment, H f 0 ₂ film and _{A 1 2 O 3 H f 0} 2 film when film was etched, respectively, and A 1 ₂ 0 ₃ film condition, and H f O ₂ film and A 1 ₂ 0 ₃ The state of the SiON film formed under the film was observed.

The measurement conditions will be described. In this embodiment, using Etsu quenching apparatus of the first embodiment, the H f 0 ₂ film and A 1 ₂ O ₃ film formed on the wafer was etched. The H f 0 ₂ film and A 1 ₂ 0 ₃ film was used which was formed by heating the wafer to about 3 0 0 ° C. As the etching gas, a gas composed of H hίac and O ₂ was used. The flow rates of Hhfac and O ₂ were 375 sccm and 100 sccm, respectively. The concentration of H ₂ 0 in E Tsu Chingugasu was 0 ppm. The pressure in the inner chamber was about ^{1. 1 3 X 1 0 4 P} a. While maintaining this state was etched H f 0 ₂ film and A 1 ₂ 0 ₃ film. In order to compare with the present embodiment, the observation state of the H f O ₂ film and A 1 ₂ 0 ₃ film is also attached to the case of etching, as well as the state of S i ON film by HF solution as a comparative example.

The measurement result will be described. H f 0 ₂ film and A 1 ₂ 0 ₃ of the Examples and Comparative Examples are both etched and removed from the S i ON film. On the other hand, while the SiON film of the comparative example was etched, the SiON film of the present example was hardly etched.

From the above results, that when using the etching gas of this embodiment can stop the Etsuchingu at the surface of S i ON film it is possible to etch the H f O ₂ film and A 1 ₂ 0 _{3 T} (Example 2)

Hereinafter, a second embodiment will be described. In this embodiment, Etsu a H f O ₂ film The optimum temperature of the wafer at the time of chucking was examined.

The measurement conditions will be described. In this embodiment, using Etsu quenching apparatus of the first embodiment, etching the H f 0 ₂ film formed on the wafer. The H f 0 ₂ film was used for was also deposited by heating the wafer to about 3 0 0 ° C. As the etching gas, it was used those composed of H hfac, 0 _2. The flow rates of H hfac and O ₂ were 375 sccm and 100 sccm, respectively. The concentration of H ₂₀ in the etching gas was O ppm. The pressure in the internal chamber was about 1.13 × 10 ⁴ Pa. The varying Ete H f O ₂ film the temperature of the wafer while maintaining the good UNA state was etched. As a reference example, for the 1 5 0 ° C in film was H f O ₂ film was etched ring the H f 0 ₂ film by changing the temperature of the wafer. Here, the H f O ₂ film formed at 300 ° C. is denser than the H ₂ O ₂ film formed at 150 ° C.

The measurement result will be described. Figure 9 is a graph showing the relationship between the etching rate of the temperature and H f 0 ₂ film © E c according to the Examples and Reference Examples. As can be seen from the graph of FIG. 9, in the etching of the HfO ₂ film of the present example, a high etch rate was obtained when the temperature of the wafer was 400 ° C. or higher. On the other hand, in the etching of the HfO ₂ film of the reference example, a high etch rate was obtained when the wafer temperature was 350 ° C. or higher.

From the above results, it is considered that it is preferable to maintain the temperature of the wafer at 400 ° C. or higher when etching the HfO ₂ film of this example. Note that in the case of etching of H f O ₂ film of Reference Example, it is considered preferable to maintain the temperature of © E c to 3 5 0 ° or more C.

 (Example 3)

Hereinafter, a third embodiment will be described. In this embodiment, it was examined for the optimum temperature of the wafer at the time of Etsu quenching the A 1 ₂ 0 ₃ film. The measurement conditions will be described. In this embodiment, using Etsu quenching apparatus of the first embodiment, to etch the A 1 ₂ 0 ₃ film formed on the wafer. The A 1 ₂ O ₃ film was used for was also deposited by heating the wafer to about 3 0 0 ° C. As the etching gas, it was used those composed of H hfac, 0 _2. Hh fac, 0 ₂ flow rate were respectively 3 7 5 sccm, 1 0 0 sccm. The concentration of H ₂ O in the etching gas was 0 ppm. Further, - the pressure in the internal Chiyanba was about ^{1. 1 3 X 1 0 4 P} a. The varying Ete H f O ₂ film the temperature of the wafer while維特such conditions was etched. As a reference example, for the 1 5 0 ° C in film was A 1 ₂ O ₃ film was market shares Tsuchingu the A 1 ₂ 0 ₃ film by changing the temperature of the wafer.

The measurement result will be described. Figure 1 0, Ru graph der showing the relationship between the etching rate of this example and the temperature and A 1 ₂ 0 ₃ film © E c according to a reference example. As can be seen from the graph of FIG. 1 0, in the etching ring of A 1 ₂ O ₃ film of this example, high Etchire bets if the temperature of the wafer 4 0 0 ° C or higher was obtained. On the other hand, in the etching of the A 1 ₂ O ₃ film of Reference Example, the temperature of © E c is 3 5 0 ° higher in the case of more than C Etsuchireto was obtained.

From the above results, in the case of Etsuchingu the A 1 ₂ 0 ₃ film of this example, it is thought that it is preferable to maintain the temperature of the wafer 4 0 0 ° or more C. In the case of etching of the A 1 ₂ O ₃ film of Reference Example, it is considered preferable to maintain the temperature of © E c to 3 5 0 ° or more C.

 (Example 4)

 Hereinafter, a fourth embodiment will be described. In this example, the optimum pressure in the internal chamber was examined.

The measurement conditions will be described. In this embodiment, etched using Etsu quenching apparatus of the first embodiment, the H f 0 ₂ film formed on the wafer did. Is a H f 0 ₂ film was used for was also deposited by heating the wafer to about 3 0 0 ° C. An etching gas composed of Hhίac and O ₂ was used. The flow rates of H hfac and O ₂ were 375 sccm and 100 sccm, respectively. The concentration of H ₂₀ in the etching gas was O ppm. The temperature of the wafer was 450 ° C. While maintaining such a state, the HfO ₂ film was etched by changing the pressure in the internal chamber. Incidentally, as a reference example, for the 1 5 0 ° was formed with C H f 0 ₂ film was Etsuchin grayed the H f 0 ₂ film by changing the pressure in the internal chamber.

The measurement result will be described. FIG. 11 is a graph showing the relationship between the pressure in the internal chamber and the etch rate of the HfO ₂ film according to the present embodiment and the reference example. As can be seen from the graph of FIG. 1 1, in the etching of H f O ₂ film of this example, the pressure in the internal chamber of ^{1. 0 6 Χ 1 0 4 ~} 1 · 2 0 X 1 0 4 P a High etch rates were obtained in some cases. On the other hand, in the etching of H f O ₂ film of Reference Example, the pressure inside the chamber內is 0.9

5 X 10 ⁴ : High etch rate was obtained in the case of L 2 0 X 10 ⁴ Pa. From the above results, when etching the H f 0 ₂ film of this embodiment, the internal chamber It is considered preferable to maintain the internal pressure at 1.06 × 10 ⁴ to: 1.2 × 10 ⁴ Pa. In the case of E Tsuchingu of H f 〇 ₂ film of Reference Example, and it is preferable to maintain the pressure within the internal chamber ^{0. 9 5 X 1 0 4 ~} 1. to 2 0 X 1 0 ⁴ P a Conceivable.

 (Example 5)

 Hereinafter, a fifth embodiment will be described. In this example, the optimum flow rate of H hi ac was examined.

The measurement conditions will be described. In this embodiment, etched using Etsu quenching apparatus of the first embodiment, the H f 0 ₂ film formed on the wafer did. The Etsuchingugasu, were used as _{H hfac, 0 2, N 2} , and is configured H ₂ 0 or al.

Were supplied at a ratio of 15: 2: 8, respectively, and the concentration of H ₂ O in the etching gas was 100 ppm. The pressure in the inner chamber was about 6.65 × 10 ³ Pa, and the temperature of the wafer was about 400 ° C. Etching the H f 0 ₂ film by changing the flow rate of H hfac while maintaining this state. The measurement result will be described. FIG. 12 is a graph showing the relationship between Hh ί ac and the etch rate according to the present embodiment. As can be seen from the graph of FIG. 12, when the flow rate of Hh fac was in the range of 320 to 380 sccm, a high etchate was obtained.

From the above results, in the case where the H f 0 ₂ film E Tsuchingu using an etching gas of this embodiment, it is considered preferable to flow the H hfac at a flow rate of 3 2 0~ 3 8 0 sccm.

 (Example 6)

Hereinafter, a sixth embodiment will be described. In this embodiment, it was examined for the optimal concentration of O ₂ at the time of Etsu quenching the H f 〇 ₂ film.

The measurement conditions will be described. In this example, the HfO ₂ film formed on the wafer was etched using the etching apparatus of the first embodiment. The H f 0 ₂ film was used for was also deposited by heating the wafer to about 3 0 0 ° C. As the etching gas, a gas composed of Hh fac, O ₂ , and H ₂₀ was used. The flow rate of H h ί ac was 375 sccm, and the concentration of H ₂ O was 700 ppm. The pressure內部chamber is about ^{9. 3 1 X 1 0 3 P} a, the temperature of the wafer is approximately 4 5 0 ° C Der ivy. The H f 0 ₂ film market shares Tsuchingu by changing the 0 ₂ flow rate while maintaining this state. Incidentally, as a reference example, even with the H f O ₂ film formed in 1 5 0 ° C, it was etched H f 0 ₂ film by changing the 0 ₂ flow. The measurement result will be described. FIG. 13 is a graph showing the relationship between the flow rate of O ₂ and the etch rate of the HfO ₂ film according to the present example and the reference example. As can be seen from the graph of FIG. 1 3, Oite the etching of H f O ₂ film of this example, 0 _second flow has a higher Etchire bets in the case of 5 0 to 2 5 0 sccm obtained. On the other hand, in the etching of H f O ₂ film of Reference Example, 0 _second flow has a higher Etsuchire bets in the case of 5 0 to 2 5 0 sccm obtained. From the above results, it is considered that it is preferable to maintain the flow rate of O ₂ at 50 to 250 sccm when etching the HfO ₂ film of the present example and the reference example.

 (Example 7)

Hereinafter, a seventh embodiment will be described. In this embodiment, it was examined for the optimal concentration of O ₂ at the time of Etsu quenching the A 1 ₂ 0 ₃ film.

The measurement conditions will be described. In this embodiment, using Etsu quenching apparatus of the first embodiment, to etch the A 1 ₂ 〇 ₃ film formed on the wafer. The A 1 ₂ ◦ ₃ film was used for was also deposited by heating the wafer to about 3 0 0 ° C. As the etching gas, a gas composed of H hfac, O ₂ , and H ₂₀ was used. The flow rate of H hfac was 375 sccm and the concentration of H ₂₀ was 700 ppm. The pressure within the internal chamber is about ^{9. 3 1 X 1 0 3 P} a, the temperature of the wafer is approximately 4 5 0 ° C Der ivy. It was etched A 1 ₂ 0 ₃ film by changing the flow rate of O ₂ while maintaining such a state. As a reference example, for the _{1 5 0 ° A 1 2 0} 3 film formed in C, and was etched A l ₂ 0 ₃ film by changing the 0 ₂ flow.

The measurement result will be described. Figure 1 4 is a graph showing the relationship between the etching rate of this example and the O ₂ according to the reference example flow rate and A 1 ₂ 0 ₃ film. As can be seen from the graph of FIG. 1 4, in the etching of the A 1 ₂ O ₃ film of this example, the flow rate of O ₂ is higher in the case of 5 0~ 2 5 0 sccm Etchire I got one. On the other hand, in the etching of the A 1 ₂ 0 ₃ film of Reference Example, the flow rate of 〇 ₂ is higher etch rate in the case of 5 0 to 2 5 0 sccm obtained.

From the above results, in the case of etching the A 1 ₂ 〇 ₃ film of this example and Reference Examples, it is believed that good preferable to maintain the flow rate of O ₂ to 5 0~ 2 5 0 sccm.

 (Example 8)

Hereinafter, Example 8 will be described. In this embodiment, it was examined for the optimal concentration of H ₂ 0 at the time of Etsu quenching the H f 0 ₂ film.

The measurement conditions will be described. In this embodiment, using Etsu quenching apparatus of the first embodiment, etching the H f 0 ₂ film formed on the wafer. Η The ί 0 ₂ film was used for was also deposited by heating the wafer to about 3 0 0 ° C. As an etching gas, a gas composed of Hhfac, O ₂ , and H ₂₀ was used. The flow rates of Hh fac and O ₂ were 375 sccm and 50 sccm, respectively. The pressure in the internal chamber was about 9.31 × 10 ³ Pa, and the temperature of the wafer was about 450 ° C. Was Etsu quenching the H f 0 ₂ film by changing the concentration of H ₂ O while maintaining this state. Incidentally, as a reference example, even have One in H f O ₂ film formed in 1 5 0 ° C, was etched H f O ₂ film by changing the concentration of H ₂ O.

The measurement result will be described. Figure 1 5 is a graph showing the relationship between the etching rate of this example and the concentration of H ₂ 0 according to the reference example and H f 0 ₂ film. As can be seen from the graph of FIG. 1 5, in the etching of H f 0 ₂ film of this example, the concentration of H ₂ 0 was obtained a high Etsuchire over preparative if: 1 0 0 0 ppm. On the other hand, in the etching of H f 0 ₂ film of Reference Example, high etch rate when the concentration of H ₂ 0 is less than 1 0 0 0 ppm was obtained. In both cases of this example and the reference example, the concentration of H ₂₀ was Even at 0 ppm, high etch rates were obtained.

From the above results, in the case of etching the H f 0 ₂ film in this Example and Reference Examples, it may be preferable to maintain the concentration of H ₂ 0 (including. A O ppm) l OOO p pm or less Can be

 (Example 9)

Hereinafter, a ninth embodiment will be described. In this embodiment, it was examined for the optimum concentration of of H ₂ O when E Tsu quenching the A 1 ₂ 0 ₃ film.

The measurement conditions will be described. In this embodiment, using Etsu quenching apparatus of the first embodiment, to etch the A 1 ₂ 0 ₃ film formed on the wafer. The Alpha 1 ₂ Omicron ₃ film was used for was also deposited by heating the wafer to about 3 0 0 ° C. As the etching gas, a gas composed of H hfac, O ₂ , and H ₂₀ was used. The flow rates of Hh fac and O ₂ were 375 sccm and 50 sccm, respectively. The pressure in the internal chamber was about 9.31 × 10 ³ Pa, and the temperature of the wafer was about 450 ° C. Was Etsu quenching the A 1 ₂ 0 ₃ film by changing the concentration of H ₂ 0 while keeping such a state. Incidentally, as a reference example, even have One to A 1 ₂ 0 ₃ film formed in 1 5 0 ° C, was etched A 1 ₂ 0 ₃ film by changing the concentration of H ₂ 0.

The measurement result will be described. Figure 1 6 is a graph showing the relationship between the etching rate of this example and the concentration of H ₂ 0 according to the reference example and A 1 ₂ 0 ₃ film. As can be seen from the graph of FIG. 1 6, in the etching of the A 1 ₂ 0 ₃ film of this example, the concentration of H ₂ O were obtained high Etsuchire over preparative if: 1 0 0 0 ppm. On the other hand, in the etching of the A 1 ₂ 0 ₃ film of Reference Example, high etch rate when the concentration of H ₂ 0 is less than 1 0 0 0 ppm was obtained. In both cases of this example and the reference example, a high etch rate was obtained even when the concentration of H ₂ O was O ppm.

From the above results, the field of etching the A 1 ₂ 0 ₃ film in this Example and Reference Examples In such a case, it is preferable to maintain the concentration of H ₂₀ at 100 ppm or less (including O ppm or less).

 (Example 10)

Hereinafter, Example 10 will be described. In this example, the optimum concentration of C ₂ H ₅ OH was examined.

The measurement conditions will be described. In this embodiment, using Etsu quenching apparatus of the first embodiment, etching the H f 0 ₂ film formed on the wafer. As the etching gas, a gas composed of H hfac, 〇 ₂ , N ₂ , and C ₂ H ₅ OH was used. The flow rates of H hfac, O ₂ , and N ₂ were 375 sccm, 50 sccm, and 200 sccm, respectively. The pressure in the internal chamber was about 6.65 × 10 ³ Pa, and the temperature of the wafer was about 400 ° C. While maintaining such a state, the H ₂ O ₅ film was etched by changing the concentration of C ₂ H ₅ OH.

The measurement result will be described. Figure 1 7 is a graph showing the relationship between the concentration and Etchire DOO C ₂ Η ₅ 0 Η according to the present embodiment. As can be seen from the graph of FIG. 17, a high etch rate was obtained when the concentration of C ₂ H ₅ OH was from 50,000 to: LOOO ppm.

From the above results, in the case of E Tsuchingu the H f 0 ₂ film using an etching gas of this embodiment, it is preferred to maintain the concentration of C ₂ H ₅ OH in 5 0 0~ 1 0 0 0 ppm it is conceivable that.

 (Second embodiment)

Hereinafter, a second embodiment of the present invention will be described. In the following description, among the embodiments after this embodiment, the description of the same contents as those of the preceding embodiment may be omitted. In this embodiment, alternately supplying a Hh fac-containing organic etching gas and H ₂ O-containing gas, and an example will be described for supplying a HF-containing E Tsuchingugasu and H ₂ 0 containing gas alternately. FIG. 18A and FIG. 18B are flowcharts showing the flow of etching performed by etching apparatus 10 according to the present embodiment.

First, the decompression pump 70 operates to evacuate the internal chamber 40. Further, the decompression pump 100 is operated to evacuate the space between the outer chamber 30 and the inner chamber 40 (step 1B). Thereafter, the heating lamp 230 is turned on, and the susceptor 120 is heated (step 2B). The pressure inside the chamber 4 within 0 is reduced to ^{9. 3 1 X 1 0 3 ~} 1. 3 3 X 1 0 4 P a, and after the temperature of the susceptor 1 2 0 rises to a predetermined temperature, the gate valve 5 0 is opened, the transfer arm (not shown) holding the wafer W extends, and the wafer W is loaded into the external chamber 30 (step 3B).

 Thereafter, the transfer arm is retracted, and the wafer W is supported by the wafer elevating pins 160. After the wafer W is supported by the wafer elevating pins 160, the wafer elevating pins 160 are lowered by the driving of the air cylinder 180, and the wafer W is placed on the susceptor 120 (step 4). B) After the wafer W is placed on the susceptor 120, the susceptor 120 is raised by driving the air cylinder 140, and the wafer W is loaded into the internal chamber 40 (Step 5B;).

After the wafer W is heated, the opening / closing valves 280, 340, and 400 are opened, and the Hhfac-containing etching gas is supplied into the internal chamber 40 (step 6B). H hfac containing etching gas is composed of _{Hh fac, 0 2, N 2} . If the supplied H hfac containing etch gas reaches the surface of the H f O ₂ film 5, H hfac like are adsorbed on the surface of the H f O ₂ film 5. Those other than those adsorbed on the surface of the HfO ₂ film 5 are exhausted from the internal chamber 40 by exhaust.

After a lapse of a predetermined time, the on-off valves 280 and 340 are closed, and Hh fa The supply of the _c- containing etching gas is stopped. Since the on-off valve 400 is open, only N ₂ is continuously supplied into the internal chamber 40. Thus, the internal chamber 4 within 0 is purged with N _2, extra H hfac other than H hfac adsorbed on the surface of the H f 0 ₂ film 5 is reliably discharged from the internal Chiya Nba 4 0內( Step 7 B).

After a lapse of a predetermined time, the opening / closing valve 370 is opened, and the H ₂ O-containing gas is supplied into the internal chamber 40 (step 8B). H ₂ 0 containing gas is composed of H ₂ 0, N _2. If the supplied H ₂ 0 containing gas reaches the surface of the H ί O ₂ film 5, the reaction of the H hfac and H f O ₂ film 5 which is adsorbed on the surface of the H f 〇 ₂ film 5 is promoted, after _c predetermined time elapses H f O ₂ film 5 is etched, closing pulp 3 7 0 is closed, the supply of H ₂ O-containing gas is stopped. Thus, the etching of the H HO ₂ film 5 is stopped. Since the opening / closing valve 400 is open, only N ₂ is continuously supplied into the internal chamber 40. As a result, the inside of the internal chamber 40 is purged with N ₂ , and the excess H ₂₀ remaining in the internal chamber 40 is discharged from the internal chamber 40 (step 9B).

Thereafter, assuming that the steps 6B to 9B are one cycle, the central controller (not shown) determines whether or not the etching of the HfO ₂ film 5 has been performed for a predetermined cycle (step 10B). ). If it is determined that the etching of the HfO ₂ film 5 has not been performed in the predetermined cycle, the processes of Step 6B to Step 9B are performed again.

The etching of H f 0 ₂ film 5 is determined to have been performed for a predetermined cycle, the heating of the susceptor 1 2 0 is stopped. Further, N ₂ is supplied into the internal chamber 40 for a predetermined time, and the wafer W is cooled (Step 11B). Note that the etching of H f O ₂ film 5 is performed a predetermined cycle, to expose the surface of the S i ON film 4. After the wafer W is cooled, the opening / closing valve 310 is opened, and the HF-containing etching gas is supplied into the internal chamber 40 (Step 12B). HF-containing etching gas is mainly composed HF, a N _2. When the supplied HF-containing etching gas reaches the surface of the SiON film 4, HF is adsorbed on the surface of the SiON film 5. Except for those adsorbed on the surface of the SiON film 4, they are exhausted from the internal chamber 40 by exhaust. After a lapse of a predetermined time, the on-off valve 310 is closed, and the supply of the HF-containing etching gas is stopped. Since the opening / closing valve 400 is open, only N ₂ is continuously supplied into the internal chamber 40. As a result, the inside of the internal chamber 40 is purged with N ₂ , and HF other than the HF adsorbed on the surface of the SiON film 4 is discharged from the internal chamber 40 (step 13B).

After a predetermined time, the switch valve 3 7 0 is opened, H ₂ 0 containing gas is supplied into the chamber 4 in 0 (Step 1 4 B). When the supplied H ₂ O-containing gas reaches the surface of the SiON film 4, the reaction between the HF adsorbed on the surface of the SiON film 4 and the SiON film 4 is promoted, and the SiON film 4 is promoted. The membrane 4 is etched.

After a lapse of a predetermined time, the on-off valve 370 is closed, and the supply of the H ₂ O-containing gas is stopped. As a result, the etching of the SiON film 4 is stopped. Since the opening / closing valve 400 is open, only N ₂ is continuously supplied into the internal chamber 40. As a result, the inside of the internal chamber 40 is purged with N ₂ , and excess H ₂₀ remaining in the internal chamber 40 is discharged from the internal chamber 40 (step 15B).

Thereafter, with the process of Steps 12B to 15B as one cycle, the central controller (not shown) determines whether or not the etching of the SiON film 4 has been performed in a predetermined cycle (Step 16B). Et of S i ON film 4 If it is determined that the cycle is not performed in the predetermined cycle, the processes of Steps 12B to 15B are performed again.

When it is determined that the etching of the SiON film 4 has been performed for a predetermined cycle, the susceptor 120 is lowered by driving the air cylinder 140, and the wafer W is carried out from the internal chamber 40 (Step 1). 7 B). When the etching of the SiO ON film 4 is performed for a predetermined cycle, the surfaces of the P-type Si substrate 1 and the SiO ₂ film 3 are exposed.

 Then, the wafer lifting pins 16 are raised by driving the air cylinder 180, and the wafer W is separated from the susceptor 120 (step 18B). Finally, the gate valve 50 is opened, and the wafer W is unloaded from the external chamber 30 (Step 19B).

In this embodiment, since the supply alternating with H hfac containing etching gas and H ₂ 0 containing gas, H f 0 ₂ film 5 can exactly the child etching.

Further, since the supplied alternating with HF containing etching gas and H ₂ 0 containing gas, it is possible to accurately etch the S i ON film 4.

 (Third embodiment)

 Hereinafter, a third embodiment of the present invention will be described. In this embodiment, an example in which a SiON film is etched using F radicals will be described. FIG. 19 is a schematic vertical sectional view of the etching apparatus according to the present embodiment.

As shown in FIG. 1 9, the gas supply pipe 2 6 0 F ₂ sources 5 1 0 containing the F ₂ instead of HF supply source 3 0 0 is connected. Further, a dent is formed in the outer chamber 30 near the nozzle 250, and an ultraviolet lamp 520 for generating ultraviolet light is provided in this dent. When the ultraviolet lamp 520 is turned on, it is generated from the ultraviolet lamp 520. The ultraviolet light is supplied into the internal chamber 40 through the bottom of the internal chamber 40.

 Hereinafter, the etching performed by the etching apparatus 10 will be described with reference to FIGS. FIG. 20 is a flowchart showing a flow of etching performed by the etching apparatus 10 according to the present embodiment, and FIG. 21 is a diagram schematically showing etching according to the present embodiment.

First, the decompression pump 70 operates to evacuate the internal chamber 40. Further, the decompression pump 100 is operated to evacuate the space between the outer chamber 30 and the inner chamber 40 (step 1C). Thereafter, the heating lamp 230 is turned on to heat the susceptor 12 ° (step 2C). The pressure inside the chamber 4 within 0 is reduced to ^{9. 3 1 X 1 0 3 ~} 1. 3 3 X 1 0 4 P a, and after rising to a temperature of the susceptor 1 2 0 3 0 0 ° C or more on Then, the gate valve 50 is opened, the transfer arm (not shown) holding the wafer W is extended, and the wafer W is loaded into the external chamber 30 (Step 3C).

 Thereafter, the transfer arm is retracted, and the wafer W is supported by the wafer elevating pins 160. After the wafer W is supported by the wafer elevating pins 160, the wafer elevating pins 160 are lowered by driving the air cylinder 180, and the wafer W is placed on the susceptor 120 (step 4C). ). After the wafer W is placed on the susceptor 120, the susceptor 120 is raised by driving the air cylinder 140, and the wafer W is loaded into the internal chamber 40 (step 5C).

After the wafer W is heated and the temperature of the wafer W is maintained at 300 ° C. or higher, preferably 450 ° C. or higher, the opening / closing valves 280, 340, 370, and 400 are turned on. When opened, the etching gas containing Hhίac is supplied into the inner chamber 40 (Step 6C). Thereby, the etching of the HfO ₂ film 5 is performed. Is started.

Advances etching of H f O ₂ film 5, after the exposed surface of the S i ON film 4, in a state where the opening and closing valve 4 0 0 is opened, the opening and closing valve 2 8 0, 3 4 0, 3 7 0 closes Then, the supply of the etching gas containing H hfac is stopped. In addition, the lighting of the heating lamp 230 is stopped, and the heating of the susceptor 120 is stopped. Thus, the etching of the HfO ₂ film 5 is completed. Further, the wafer W is cooled by N ₂ (Step 7C).

After the wafer W is cooled and the temperature of the wafer W is stabilized at about 100 ° C. or less, preferably 10 to 50 ° C., the opening / closing valves 310 and 370 are opened to contain F _2. An etching gas is supplied into the internal chamber 40. Further, the ultraviolet lamp 520 is turned on, and ultraviolet rays are supplied into the internal chamber 40 as shown in FIG. 21 (Step 8C). F ₂ containing etch gas is mainly composed of _{F 2, N 2, H 2} O. When the F ₂ -containing etching gas is supplied into the internal chamber 40, F ₂ is excited by ultraviolet rays to generate F radicals. Then, the generated F radical reacts with the SiON film 4, and the SiON film 4 is etched.

After the etching of the S i ON film 4 progresses and the surfaces of the P-type S i substrate 1 and the S i 0 ₂ film 3 are exposed, the opening / closing valves 310, 370, 400 are closed, and F ₂ The supply of the containing etching gas is stopped. Also, the ultraviolet lamp 520 is turned off to stop generating ultraviolet light (step 9C). Thus, the etching of the SiON film 4 is completed. After the supply of the F ₂ containing Etsuchin Gugasu is stopped, Eashiri Sunda 1 4 0 susceptor motor 1 2 0 by driving the lowered, the wafer W is unloaded from the chamber interior 4 0 (scan Tetsupu 1 0 C).

Thereafter, the wafer lifting pins 16 are raised by driving the air cylinder 180, and the wafer W is separated from the susceptor 120 (step 11C). Most Later, the gate valve 50 is opened, and the wafer W is carried out of the external chamber 30 (Step 12C).

 (Fourth embodiment)

 Hereinafter, a fourth embodiment of the present invention will be described. In this embodiment, an example in which an Hhfac-containing etching gas or the like is supplied from a shower head will be described. FIG. 22 is a schematic vertical sectional view of the etching apparatus according to the present embodiment.

 As shown in FIG. 22, the etching apparatus 10 includes a chamber 610 formed of, for example, A1. In addition, it is not limited to A 1, and may be formed of SiC, hastelloy, or the like. In addition, the inner wall surface of the chamber 610 may be subjected to a surface treatment such as a PTF E (polytetrafluoroethylene / rhothene ethylene) coating or an anoremate treatment. Openings 611 and 612 are formed at predetermined positions of the chamber 610.

 A gate valve 50 is attached to an edge of the opening 611, and an exhaust pipe 60 is connected to an edge of the opening 611. Inside the chamber 610, a cylindrical reflector 620 that reflects light emitted from the heating lamp 230 is provided. The reflector 620 is formed of, for example, A1 or the like. A support member 630 for supporting the susceptor 120 is fixed to the upper part of the reflector 620. The support member 630 is formed of, for example, quartz or the like.

In the upper part of the chamber 6100, a shading head 6400 for supplying an etching gas containing Hhfac or the like toward the susceptor 120 is fitted. The gas supply unit 641 for supplying H hfac and HF and the gas supply unit 642 for supplying O ₂ , H ₂₀ , and N ₂ are separated. A number of gas supply holes for discharging gas such as Hhfac are formed in the gas supply units 641 and 642, respectively. The gas supply section 6 41 is connected to a gas supply pipe 6 50 whose tip is divided in two directions, and the gas supply section 6 4 2 is connected to a gas supply pipe 6 60 whose tip is divided in three directions. It is connected. The tip of the gas supply pipe 6 5 0 is connected to the H hfac source 2 7 0 and HF sources 3 0 0, the tip of the gas supply pipe 6 6 0 O ₂ source 3 3 ◦, ^ € ₂ 0 source 3 6 0, and N ₂ is connected to a supply source 3 9 0.

 (Fifth embodiment)

Hereinafter, a fifth embodiment of the present invention will be described. In this embodiment, an example of performing the etching of the S i ON film H f 〇 ₂ film in a separate Chiya Nba be described. FIG. 23 is a schematic configuration diagram of the etching apparatus according to the present embodiment. FIG. 24 is a schematic vertical cross-sectional view of the first etching unit according to the present embodiment. FIG. 3 is a schematic vertical sectional view of a second etching part according to the present embodiment.

As shown in FIGS. 23 to 25, the etching apparatus 10 mainly performs the first etching section 10A for etching the HfO ₂ film 5 and the etching for the SiON film 4. The second etching unit 10B includes a transfer system 11 for transferring the wafer W.

The first etching section 10A has substantially the same configuration as the etching apparatus 10 shown in FIG. However, the first etching unit 100A is not provided with an HF supply source 300 or the like. The second etching section 10B has substantially the same configuration as the etching apparatus 10 shown in FIG. However, the second etching section 10B is not provided with the heating lamp 230, the H hfac supply source 270, the O ₂ supply source 330, and the like.

The transfer system 11 includes a transfer chamber 12 connected to gate valves 50A and 50B. In the transfer chamber 12, a transfer arm 13 for transferring the wafer W to the first etching unit 10A or the like is provided. In transfer room 1 2 The port lock chamber 14 into which a carrier cassette containing about 25 wafers W is loaded is connected via a gate valve 15.

 Hereinafter, the etching performed by the etching apparatus 10 will be described with reference to FIGS. 26A and 26B. FIG. 26A and FIG. 26B are flow charts showing the flow of etching performed by etching apparatus 10 according to the present embodiment.

 First, the decompression pumps 70A and 70B operate to evacuate the internal chambers 4OA and 40B. In addition, the decompression pumps 100 A and 100 B operate to evacuate the space between the external chamber 30 A and the internal chamber 40 A, and to evacuate the space between the external chamber 30 B and the internal chamber 40 B. The space between them is evacuated (Step 1D).

Thereafter, the heating lamp 23 OA is turned on, and the susceptor 120 A is heated (step 2D). The pressure inside the chamber 4 0 A, 4 0 in B is ^{9. 3 1 X 1 0 3 ~1} . 3 3 X 1 0 4 P dropped to a, and the susceptor 1 2 0 temperature of A 3 0 0 ° C After ascending above, the gate valve 15 is opened, and the transport arm 13 takes out the wafer W from the carrier cassette force in the load lock chamber 14. Next, the gate valve 50A is opened, the transfer arm 13 is extended, and the wafer W is loaded into the external chamber 30A (Step 3D).

Thereafter, the transfer arm 13 is retracted, and the wafer W is supported by the wafer elevating pins 160A. After the wafer W is supported by the wafer lifting pins 16 OA, the air cylinder 180 A is driven to lower the wafer lifting pins 16 OA, and the wafer W is placed on the susceptor 120 A (step 4D). After the wafer W is placed on the susceptor 120 A, the susceptor 120 A rises by driving the air cylinder 140 A, and the wafer W is carried into the internal chamber 40 A. (Step 5D). After the wafer W is heated and the temperature of the wafer W is maintained at 300 ° C. or higher, preferably 450 ° C. or higher, the opening / closing valves 280 A, 340 A, 370 A, 4 00 A is opened, and the Hh fac-containing etching gas is supplied into the inner chamber 4 OA (step 6D). Thus, the etching of the HfO ₂ film 5 is started.

Advances etching of H f O ₂ film 5, S after the surfaces of the i ON film 4 is exposed, and the opening and closing valve 2 8 0 A, 3 4 0 A, 3 7 0 A, 4 0 OA is closed, H hfac The supply of the contained etching gas is stopped (Step 7D). Thus, the etching of the H ₂ O ₂ film 5 is completed.

 After the supply of the etching gas containing Hhfac is stopped, the susceptor 12OA is lowered by driving the air cylinder 140A, and the wafer W is carried out from the internal chamber 40A (step 8D). Thereafter, the wafer elevating pins 160 A are raised by driving the air cylinder 180 A, and the wafer W is separated from the susceptor 12 O A (step 9D).

 After the wafer W leaves the susceptor 120A, the gate valve 5OA is opened, and the wafer W is carried out of the external chamber 30A (step 10D). Subsequently, the gate valve 50B is opened, the transfer arm 13 is extended, and the wafer W is loaded into the external chamber 30B (Step 11D). Thereafter, the transfer arm 13 is retracted, and the wafer W is supported by the wafer lifting pins 160B. After the wafer W is supported by the wafer lifting pins 160B, the wafer lifting pins 160B are lowered by driving the air cylinder 180B. The wafer W is placed on the susceptor 120B. (Step 1 2D). After the wafer W is placed on the susceptor 120B, the susceptor 120B is raised by driving the air cylinder 140B, and the wafer W is carried into the internal chamber 40B (step). 1 3D).

After wafer W is loaded into internal chamber 40 B, open / close valve 3 1 0 B, 370B, and 40OB are opened, and the HF-containing etching gas is supplied to the internal chamber 40 內 (step 14D). Thus, the etching of the SiO ON film 4 is started.

Advances etching of S i ON film 4, after the exposed surface of the P-type S i substrate 1 and S i 0 ₂ film 3, opening and closing valve 3 1.0 B, 3 7 0 B , 4 0 0 B is closed, The supply of the HF-containing etching gas is stopped (Step 15D) _c. Thereby, the etching of the SiON film 4 is completed.

 After the supply of the HF-containing etching gas is stopped, the susceptor 120B is lowered by driving the air cylinder 140B, and the wafer W is carried out from the internal chamber 40B (Step 16D). Then, the wafer lifting pins 1660B are raised by driving the air cylinder 180B, and the wafer W is separated from the susceptor 120B (step 17D).

 After the wafer W is separated from the susceptor 120B, the gate valve 50B is opened, and the wafer W is unloaded from the external chamber 30B by the transfer arm 13 (step 18D).

The present invention is not limited to the description of the above embodiment, and the structure, the material, the arrangement of each member, and the like can be appropriately changed without departing from the gist of the present invention. In the first to fifth embodiments, although etching the H f O ₂ film 5 by H hfac containing E Tsuchingugasu, the metal film may be etched by H hfac containing etching gas. Examples of such a metal film include at least one of A 1, Z r, H f, Y, La, Ce, and P r. Further, a force s using the wafer W and a glass substrate may be used.

Although the HF-containing etching gas is used in the first, second, fourth, and fifth embodiments, an etching solution such as a HF solution may be used instead of the HF-containing etching gas. The first, third to the fifth embodiment mainly Hh fac, O _2, H ₂ O, and using H hfac containing Etsuchingugasu constructed from及Pi ^^ _2, a second embodiment Uses an H hfac -containing etching gas mainly composed of H hfac, O ₂ , and N _2, but other than H hfac -containing etching gas may be removed from the H hfac -containing etching gas.

The first, fourth, and fifth embodiments mainly use an HF-containing etching gas composed of HF, H ₂₀ , and N ₂ , and the second embodiment mainly uses an HF-containing etching gas. Although an HF-containing etching gas composed of N ₂ and N ₂ is used, a gas other than HF may be removed from the HF-containing etching gas. Further, in the third embodiment mainly, F _2, H ₂ 0, and it uses the F ₂ containing etching gas composed of N _2, removing those from the HF-containing E Tsuchingugasu other than F ₂ You may. Industrial applicability

 The etching method and the etching apparatus according to the present invention can be used in the semiconductor manufacturing industry.

Claims

The scope of the claims

1. a substrate preparing step of preparing a substrate on which a thin film is formed;

 an etching step of etching a thin film formed on the substrate with an etching gas containing β-diketone to expose a surface of the substrate.

 2. The etching method according to claim 1, wherein the 3-diketone is hexafluoroacetylacetone.

 3. The etching method according to claim 1, wherein the etching gas containing the [3-diketone] contains at least one of water and alcohol.

 4. The etching method according to claim 1, wherein the etching step is performed while alternately supplying an etching gas containing the β-diketone and a gas containing at least one of water and alcohol.

 5. The etching method according to claim 1, wherein the etching step is performed while maintaining the temperature of the substrate at 300 ° C. or higher.

6. The etching method according to claim 5, wherein the etching step is performed while maintaining the temperature of the substrate at 450 ° C. or higher.

7. The etching method according to claim 1, wherein the etching gas containing one diketone is supplied so that the etching gas containing one diketone flows along the surface of the thin film.

 8. The etching method according to claim 1, wherein the thin film is composed of at least one of a metal film and a metal oxide film.

9. At least one of the metal film and the metal oxide film has a feature including at least one of Al, Zr, Hf, Y, La, Ce, and Pr. An etching method according to claim 8.

10. The etching method according to claim 8, wherein the surface of the substrate is formed of a Si-containing film.

 11. The etching method according to claim 10, further comprising an Si-containing film etching step of etching the Si-containing film.

12. The Si-containing film etching step is a step of etching the Si-containing film with an etching gas containing a fluorine-containing gas or an etching solution containing a hydrogen fluoride solution. Ching method.

 13. The etching method according to claim 12, wherein the etching gas containing the fluorine-containing gas contains at least one of water and alcohol.

 14. The claim, characterized in that the Si-containing film etching step is performed while alternately supplying the etching gas containing the fluorine-containing gas and the gas containing at least one of water and alcohol. The described etching method.

 15. The etching method according to claim 11, wherein the step of etching the Si-containing film is performed while maintaining the temperature of the substrate at 100 ° C. or lower.

 16. A reactor containing a substrate having a first thin film and a second thin film formed below the first thin film;

 A supply system for supplying an etching gas containing 3-diketone for etching the first thin film into the reactor;

 A supply system for supplying an etching gas containing a fluorine-containing gas or an etching solution containing a hydrogen fluoride solution for etching the second thin film into the reactor;

An etching apparatus comprising:

17. The etching apparatus according to claim 16, wherein the 3-diketone is hexafluoroacetylacetone.

 18. A first reactor containing a substrate having a first thin film and a second thin film formed under the first thin film;

 A supply system for supplying an etching gas containing / 3-diketone for etching the first thin film into the first reactor;

 A second reactor accommodating the substrate on which the first thin film has been etched; and an etching gas or a hydrogen fluoride solution containing a fluorine-containing gas for etching the second thin film in the second reactor. A supply system for supplying an etching solution containing

 A substrate transport system that transports the substrate to the first reactor and the second reactor,

 An etching apparatus comprising:

 19. The etching apparatus according to claim 18, wherein the 3-diketone is hexafluoroacetylacetone.