JP2006049607A - Method and apparatus for plasma treatment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently remove chlorine from a metal wire on a substrate having been etched with efficiency without damaging the substrate. <P>SOLUTION: A plasma treatment method is disclosed for removing Cl components remaining in a metal layer 42 on the substrate 12. The substrate 12 is arranged in a vacuum container 16. Then vapor or hydrogen-containing gas is introduced in the vacuum container 16, and the substrate 12 is held for a predetermined 1st time T1 while heated above at least room temperature. Further, oxygen-containing gas or mixed gas of oxygen-containing gas and fluorine-containing gas is introduced in the vacuum container 16, and the substrate is held for a predetermined 2nd time T2 while plasma is produced in the vacuum container 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a plasma processing method and a plasma processing apparatus for removing a Cl component from a metal layer of a substrate.

  It is widely known that a workpiece is processed by dry etching using plasma in various processes such as a semiconductor device manufacturing process (see, for example, Patent Document 1 and Patent Document 2). It is also known to remove (ash) a resist for dry etching using plasma (see, for example, Patent Document 3).

  When the Cl component contained in the etching gas remains in the metal layer such as the metal wiring of the semiconductor device, corrosion occurs. It is known that the treatment for preventing corrosion (corrosion prevention treatment) is performed during the ashing treatment.

  An example of a conventional anticorrosion process will be described with reference to FIG. 11. After the etching (step S11-1) is completed, the substrate as the workpiece is transferred to an ashing vacuum vessel. Next, a hydrogen-containing gas is introduced into the vacuum container to generate plasma (steps S11-2 and S11-3), and this state is maintained for a certain time (step S11-4). Thereafter, an oxygen-containing gas or a mixed gas of an oxygen-containing gas and a fluorine-containing gas is supplied into the vacuum vessel to generate plasma again (steps S11-5 and S11-6), and this state is maintained for a predetermined time.

  FIG. 12 shows an example of the workpiece at the end of etching (step S11-1 in FIG. 11). A metal layer 2 made of Al or an Al alloy, another metal layer 3 and a resist layer 4 are formed on the substrate 1. The metal layer 2 becomes a metal wiring when the device is completed. Since the metal layer 2 has a terrace shape and the upper surface is widely exposed, a large amount of the Cl component 5 contained in the etching gas remains. In addition to what is adsorbed on the surface of the metal layer 2, the Cl component 5 includes one that is bonded to Al on the surface of the metal layer 2. Further, a part of the Cl component 5 penetrates to the inside (near the surface) of the metal layer 2.

  When the processing shown in FIG. 11 is performed on the workpiece shown in FIG. 12, the Cl component 5 remaining in the metal layer 2 is removed by combining with the plasma H (steps S11-2 to S11-4), and further plasma is obtained. By combining with the oxidized O, the organic material constituting the resist layer 4 is decomposed and removed.

  However, even if the processing shown in FIG. 11 is performed on the workpiece shown in FIG. 12, the Cl component 5 remaining in the metal layer 2 made of Al or Al alloy cannot be efficiently removed. The reason for this is that even if the Cl component 5 and H are combined by converting the hydrogen-containing gas into plasma, thereby removing the Cl component 5 from the surface of the metal layer 2 (steps S11-2 to S11-4), It is speculated that the removal efficiency of Cl component 5 bonded to Al on the surface of metal layer 2 is very low because the bonding force of Al and Cl of metal layer 2 is stronger than that of H and Cl. The Therefore, in the anticorrosion treatment of FIG. 11, the irradiation time of the H plasma (step S11-4) requires about 300 to 600 seconds (5 to 10 minutes), and is usually about 60 seconds (1 minute). When combined with the irradiation time (steps S11-5 to S11-6), plasma irradiation of at least about 360 seconds (6 minutes) is required. This long-time plasma irradiation will damage the workpiece. Usually, in the manufacturing process of a semiconductor device or the like, etching is performed many times, and corrosion prevention and ashing are also performed many times correspondingly. Therefore, it is necessary to shorten the plasma irradiation time for one anticorrosion and ashing as much as possible.

JP 2001-110777 A JP 2001-320053 A JP 2004-193536 A

  An object of the present invention is to provide an anticorrosion treatment in which Cl remaining in a metal layer of a substrate after etching is efficiently removed in a short time and damage to the substrate is greatly reduced.

  A first aspect of the present invention is a plasma processing method for removing a chlorine component remaining in a metal layer on a substrate, wherein the substrate is disposed in a vacuum vessel, and the vacuum vessel contains water vapor or hydrogen. A gas is introduced and the substrate is heated to at least a temperature higher than room temperature for a first predetermined time, and an oxygen-containing gas or a mixed gas of oxygen-containing gas and fluorine-containing gas is placed in the vacuum vessel. A plasma processing method for introducing and maintaining a predetermined second time in a state where plasma is generated in the vacuum vessel.

  In the plasma processing method of the present invention, the oxygen-containing gas or the oxygen-containing gas and the fluorine-containing gas are mixed by introducing and holding water vapor or a hydrogen-containing gas in the vacuum vessel while the substrate is heated to a temperature higher than room temperature. When plasma is generated by introducing a gas, the chlorine component remaining in the metal layer can be efficiently removed, so that the plasma irradiation time or the time for maintaining the plasma generation state (second time) is increased. Significantly shortened. For example, when the metal layer is made of Al or an Al alloy, the first time that is the time for introducing the water vapor or hydrogen-containing gas is set to about 60 to 300 seconds (1 to 5 minutes). Even for a short time of about 30 to 60 seconds (0.5 to 1 minute), the chlorine component can be sufficiently removed from the metal layer. As a result, it is possible to prevent the metal layer from being corroded by the chlorine component while greatly suppressing damage to the substrate. The total of the first time and the second time is about 90 to 360 (1.5 to 6 minutes), and the total time required for the processing can be shortened.

  The metal layer is made of, for example, Al or an Al alloy. Examples of the Al alloy include an Al—Cu alloy, an Al—Nd alloy, an Al—Si alloy, and an Al—Si—Cu alloy. However, the metal layer is not limited to Al or an Al alloy, and may be another metal having corrosiveness to the Cl component or an alloy thereof.

Examples of the hydrogen-containing gas include H ₂ gas. The oxygen-containing gas includes, for example, O ₂ gas. Furthermore, the mixed gas of the oxygen-containing gas and the fluorine-containing gas includes, for example, a mixed gas of O 2 gas and CF ₄ gas.

  The heating temperature is preferably 200 ° C. or higher.

  According to a second aspect of the present invention, a vacuum vessel in which a substrate (12) is disposed, a heating mechanism for heating the substrate in the vacuum vessel, and water vapor or a hydrogen-containing gas are contained in the vacuum vessel. A first gas supply source capable of supplying; a second gas supply source capable of supplying an oxygen-containing gas or a mixed gas of an oxygen-containing gas and a fluorine-containing gas into the vacuum vessel; and plasma in the vacuum vessel. The plasma generation source to be generated and a state in which the first gas supply source supplies the water vapor or the hydrogen-containing gas into the vacuum vessel while the heating mechanism heats the substrate at a temperature higher than at least room temperature are predetermined. After the first time has elapsed, the second gas supply source supplies the oxygen-containing gas or a mixed gas of oxygen-containing gas and fluorine-containing gas into the vacuum vessel, and the plasma generation source is the vacuum vessel. Within And a controller for controlling the heating mechanism, the first and second gas supply sources, and the plasma generation source so that the state in which the plasma is generated continues for a predetermined second time. A plasma processing apparatus is provided.

  According to the plasma processing method and apparatus of the present invention, an oxygen-containing gas or an oxygen-containing gas can be obtained by introducing and holding water vapor or a hydrogen-containing gas in a vacuum vessel while the substrate is heated to a temperature higher than at least room temperature. When plasma is generated by introducing a mixed gas of fluorine-containing gas, chlorine remaining in the metal layer can be efficiently removed. As a result, the time for maintaining the state in which plasma is generated in the vacuum vessel, that is, the plasma irradiation time for the substrate is greatly shortened, so that the metal layer is corroded by the chlorine component while greatly suppressing the substrate damage. Can be prevented. Also, the total time required for processing can be shortened.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  1 to 3 show an ashing device 11 which is an example of a plasma processing apparatus for performing the plasma processing method of the present invention. As will be described in detail later, the ashing device 11 performs anticorrosion treatment together with ashing. FIG. 4 shows an example of dry etching equipment provided with this ashing device 11. In addition to the ashing device 11, the dry etching facility includes a substrate supply unit 13 that accommodates a substrate 12 that is a workpiece, a load lock chamber 14, and an etching device 15. The substrate 12 supplied from the substrate supply unit 13 to the load lock chamber 14 is first transported to the etching apparatus 15 and subjected to dry etching. The substrate 12 that has been etched is transferred from the etching device 15 to the ashing device 11 through the load lock chamber 14.

  Referring to FIG. 1, the ashing device 11 includes a vacuum container 16. The vacuum container 16 includes a container main body 17 having an upper opening, and a lid 18 that seals the opening of the container main body 17 so that the opening can be opened and closed.

  The lid 18 includes a grid frame 19 and a dielectric plate 20 disposed on the grid frame 19. Referring also to FIG. 2, the lattice frame 19 includes a plurality of openings or windows 19 a, and the dielectric plate 20 faces the inside 21 of the vacuum vessel 16 through the windows 19 a. The lattice frame 19 is provided with a gas flow path 19b which is a closed flow path. On the lower surface of the lattice frame 19, there are provided a plurality of gas jets 19 c that allow the gas flow paths 19 b and the interior 21 of the vacuum vessel 16 to communicate with each other. These gas outlets 19c are evenly arranged with respect to the inside 21 of the vacuum vessel 16 in plan view so that gas can be supplied uniformly to the surface of the substrate 12 on the stage 30 described later. . The dielectric substrate 12 is made of, for example, quartz.

The inlet 19d of the gas flow path 19b of the lattice frame 19 has a first gas supply source 24 for supplying water vapor (H ₂ 0) or H-containing gas, and O-containing gas or O-containing gas and F-containing. A second gas supply source 25 for supplying a gas mixture is connected. The first and second gas supply sources 25 include an MFC (mass flow controller) and the like, and can supply gas to the gas flow path 19b at a desired flow rate. The gas supplied from the first and second gas supply sources 25 is supplied from the gas flow path 19b to the inside 21 of the vacuum vessel 16 through the gas jet port 19c.

  An ICP coil (inductively coupled plasma coil) 26 that is a plasma generation source is disposed on the dielectric plate 20. Referring also to FIG. 3, the ICP coil 26 is formed by arranging a plurality of strip-shaped conductors 27 in a spiral shape. One end of each conductor 27 is electrically connected to a high frequency power supply 29 via a matching circuit 28 for impedance adjustment, and the other end is grounded.

  On the bottom side of the inside 21 of the vacuum vessel 16, a stage 30 functioning as a lower electrode is disposed. The substrate 12 is detachably held on the stage 30. A heater 31 as a heating mechanism is built in the stage 30. Instead of the heater 31, a heating mechanism that circulates the heat medium inside the stage 30 may be adopted. The stage 30 is simply grounded. The stage 30 may be connected to a high frequency power supply 32 for applying a bias voltage.

  An exhaust port 17 a is provided in the container body 17 of the vacuum container 16. A vacuum exhaust device 34 including a valve, a TMP (turbo molecular pump), a vacuum pump (for example, a rotary pump or a dry pump) and the like is connected to the exhaust port 17a.

  The controller 35 shown in FIG. 1 controls the operations of the first and second gas supply sources 24 and 25, the high frequency power sources 29 and 32, the matching circuit 28, the heater 31, and the vacuum exhaust device 34.

  Next, the plasma processing performed by the ashing apparatus 11 of FIG. 1 will be described with reference to FIG. Further, in the following description, as shown in FIG. 6A, the substrate 12 includes a substrate body 41, a metal layer 43 made of Al or an Al alloy formed on the substrate body 41, and a non-Al formed on the metal layer 43. It is assumed that another metal layer 44 of the system and a resist layer 44 made of an organic material are provided. Examples of the Al alloy constituting the metal layer 43 include an Al—Cu alloy, an Al—Nd alloy, an Al—Si alloy, and an Al—Si—Cu alloy. The metal layer 44 is made of, for example, W or Mo.

First, in step S5-1, etching is performed on the substrate 12 in the etching apparatus 15. As the etching gas, for example, a Cl-containing gas such as a mixed gas of BF ₃ Cl and Cl ₂ is used, and plasma is irradiated in the etching apparatus 15. As a result, as shown in FIG. 6A, the metal layer 43 is etched at a portion not covered with the resist layer 44, and the metal layer 42 is exposed in a terrace shape. Further, the Cl component 45 remains in the metal layer 42. In addition to what is adsorbed on the surface of the metal layer 42, the Cl component 45 includes one that is bonded to Al on the surface of the metal layer 42. A part of the Cl component 45 penetrates into the metal layer 42 (near the surface). After completion of the etching, the substrate 12 is transferred to the ashing device 11 through the load lock chamber 14. Specifically, the etched substrate 12 is transported to the inside 21 of the vacuum vessel 16 and held on the stage 30.

  Next, in step S5-2, the substrate 12 is heated to a temperature higher than at least room temperature by the heater 30. As will be described later, the substrate 12 is preferably heated to 200 ° C. or higher.

Subsequently, in step S <b> 5-3, water vapor or a hydrogen-containing gas is introduced from the first gas supply source 24 into the interior 21 of the vacuum vessel 16. Specifically, water vapor or H-containing gas is jetted from the first gas supply source 24 into the interior 21 of the vacuum vessel 16 through the gas flow path 19b. Further, the vacuum exhaust device 34 is operated to hold the inside 21 of the vacuum vessel 16 at a predetermined pressure. The flow rate of water vapor or H-containing gas is set to about 500 to 2000 sccm, and the pressure in the vacuum vessel 16 is set to about 20 to 100 Pa. An example of the H-containing gas is H ₂ gas.

  As shown in step S5-4, the state of introducing the water vapor or H-containing gas is maintained for a predetermined time (first time T1). As will be described in detail later, the first time T1 is set to about 60 to 300 seconds (1 to 5 minutes).

  During the introduction of water vapor or H-containing gas (steps S5-2 to S5-4), the ICP coil 26 is maintained in a non-energized state, and plasma is not generated in the interior 21 of the vacuum vessel 16. Therefore, during this time, the substrate 12 is not damaged due to the plasma irradiation.

Next, after elapse of the first time T1, in step S5-5, an O-containing gas or a mixed gas of an O-containing gas and an F-containing gas is introduced from the second gas supply source 25 into the interior 21 of the vacuum vessel 16. Further, the vacuum exhaust device 34 is operated to hold the inside 21 of the vacuum vessel 16 at a predetermined pressure. Further, in step S5-6, high frequency power is applied from the high frequency power supply 28 to the ICP coil 26 via the matching circuit 28, and plasma is generated in the interior 21 of the vacuum vessel 16. At this time, a bias voltage is applied from the high frequency power supply 30 to the stage 30. The total flow rate of the O-containing gas or the mixed gas of the O-containing gas and the F-containing gas is set to about 500 to 200 sccm, the pressure in the vacuum vessel 16 is set to about 20 to 100 Pa, and the high-frequency power applied to the ICP coil 26 is set to 2000 to 5000 W. . An example of the O-containing gas is O ₂ gas. Moreover, as a mixed gas of O-containing gas and F-containing gas, there is a mixed gas of O 2 gas and CF ₄ gas.

  As shown in step S5-7, the state in which the plasma is generated by introducing the O-containing gas or the mixed gas of the O-containing gas and the F-containing gas is maintained for a predetermined time (second time T2). By this plasma irradiation, the Cl component 45 remaining in the metal layer 2 is removed as will be described later. Moreover, the organic material which comprises the resist layer 44 is decomposed | disassembled and removed by couple | bonding with O made into plasma. The second time T2 is set to about 30 to 60 seconds (0.5 to 1 minute).

  In the conventional method described with reference to FIG. 11, the H plasma irradiation time (step S11-4) is about 300 to 3000 seconds (5 to 10 minutes), and the O plasma irradiation time (steps S11-5 to S11-). 6) is about 60 seconds (1 minute), and plasma irradiation of at least about 360 seconds (6 minutes) is required. On the other hand, in this embodiment, the plasma irradiation time (second time T2) is about 30 to 60 seconds (0.5 to 1 minute), and the plasma irradiation time is greatly shortened. In other words, the Cl component 45 remaining in the metal layer 42 can be efficiently removed by the method of the present embodiment. Due to the significant shortening of the plasma irradiation time, damage to the substrate 12 is greatly suppressed.

  As for the total time required for processing, the method of FIG. 11 requires about 360 seconds (6 minutes) as described above. On the other hand, in the present embodiment, the introduction time (first time T1) of water vapor or H gas under heating is about 60 to 300 seconds (1 to 5 minutes), and the plasma irradiation time (second time) The time T2) is about 30 to 60 seconds (0.5 to 1 minute), and the total is about 90 to 360 seconds (1.5 to 6 minutes). Therefore, the total time required for processing can be shortened.

It is inferred that the mechanism by which the Cl component 45 is efficiently removed by the method of the present embodiment is as follows. In the following description, FIGS. 6A to 6D are referred to. Further, it is assumed that water vapor (H ₂ O) is introduced from the first gas supply source 24 and a mixed gas of O ₂ gas and CF ₄ is supplied from the second gas supply source 25.

At the end of etching, as shown in FIG. 6A, the Cl component 45 contained in the etching gas remains in the metal layer 42 exposed in a terrace shape (step S5-1 in FIG. 5). Next, when water vapor is introduced into the vacuum vessel 16 while heating the substrate 12 (steps S5-2 to S5-3 in FIG. 5), as shown in FIG. 6B, H ₂ O is formed on the surface of the metal layer 42. Layer 46 is formed. The presence of the _{H 2} 0 layer 46, the surface of the metal layer 46 and the _{H 2} O molecules, H is adsorbed.

When plasma is generated by introducing a mixed gas of O ₂ gas and CF ₄ into the vacuum vessel 16 (steps S5-5 to S5-7), an H ₂ O layer 46 is formed on the surface of the metal layer 42. Therefore, the Cl component 45 is efficiently bonded to the H ₂ O molecule, the H component, and the H radical and removed from the metal layer 42. Further, since the bonding force between F and Al is larger than the bonding force between Al in the Cl component 45 and the bonding force between O and Al is almost the same as the bonding force between Al in the Cl component 45, the surface of the metal layer 42 and the vicinity thereof. The bond between Al and Cl is broken and is replaced with Al-F or Al-O. Then, the Cl component 45 from which the bond with Al is broken is bonded to the H ₂ O molecule, the H component, and the H radical and removed from the metal layer 42.

  Experiments were conducted to confirm the effects of the present invention.

  First, the sample was subjected to plasma treatment under the conditions of Experimental Examples 1 and 2 and Comparative Examples 1 and 2 shown in Table 1. As a sample, a substrate 12 that had been etched using an etching gas containing a Cl component shown in FIG. 6A was used. Therefore, the Cl component 45 remains in the metal layer 42 exposed in a terrace shape.

Experimental Examples 1 and 2 are both examples of the plasma processing method according to the present invention. In Table 1, the first step of Experimental Examples 1 and ₂ corresponds to steps S5-1 to S5-4 (step of introducing water vapor (H ₂ 0) under heating) in FIG. 5, and the second step is illustrated in FIG. 5 corresponds to steps S5-5 to S5-7 (step of generating plasma by introducing O ₂ gas and CF ₄ gas). In Experimental Example 1, the time of the first step (first time T1) is 180 seconds (3 minutes), whereas in Experimental Example 2, the time of the first step is 300 seconds (5 minutes). For both the first and second steps, the other conditions (gas type, gas flow rate, pressure in the vacuum vessel, power supplied to the ICP coil, and stage temperature) are the same in Experimental Example 1 and Experimental Example 2. It is.

Comparative Examples 1 and 2 are both examples of the conventional plasma processing method described with reference to FIG. In Table 1, the first step of Comparative Examples 1 and 2 corresponds to steps S11-2 to S11-3 (step of generating plasma by introducing H-containing gas) in FIG. 11, and the second step is shown in FIG. Steps S11-5 to S11-7 (a step of generating plasma by introducing O ₂ gas and CF ₄ gas). In Comparative Example 1, the other conditions (gas type, gas flow rate, pressure in the vacuum vessel, stage temperature, and each step except for the point that plasma is generated by supplying 4000 W power to the ICP coil in the first step. Is the same as in Experiment Example 1. Also, Comparative Example 2 is the same as Experimental Example 2 except that plasma is generated by supplying 4000 W of power to the ICP coil in the first step. In Comparative Example 1, the time for the first step is 180 seconds (3 minutes), whereas in Comparative Example 2, the time for the first step is 300 seconds (5 minutes).

  For Experimental Examples 1 and 2 and Comparative Examples 1 and 2, the surface of the sample after the second step (specifically, the surface of the metal layer 42) was observed with an electron microscope. The electron micrographs of Experimental Examples 1 and 2 are shown in FIG. An electron micrograph of Comparative Example 1 is shown in FIG. 8A, and an electron micrograph of Comparative Example 2 is shown in FIG. 8B.

  In Comparative Example 2 (FIG. 8B) in which the irradiation time of the plasma generated using the H-containing gas in the first step is 300 seconds, no corrosion was observed on the Al surface 50. However, in Comparative Example 2 (FIG. 8A) in which the plasma irradiation time in the first step is 180 seconds, a lump-like corrosion 51 was observed on the Al surface 50. In contrast, in Experimental Example 1 (water vapor introduction time of 180 seconds) and Experimental Example 2 (water vapor introduction time of 300 seconds), no corrosion was observed on the Al surface 50 as shown in FIG. . In Comparative Example 2, the sample is irradiated with plasma for a total of 360 seconds in the first step and the second step. On the other hand, in both Experimental Examples 1 and 2, the time for which the sample is irradiated with plasma is only 60 seconds of the time of the second step (second time T2). From this, it can be confirmed that in the plasma processing method of the present invention, the plasma irradiation time for the substrate is greatly shortened, and the damage to the substrate due to the plasma irradiation can be greatly reduced.

For Experimental Examples 1 and 2, the inside of the vacuum vessel 16 was evacuated by the exhaust device 34 (see FIG. 1) after completion of the first step, and then the second step was performed. There was a difference in effect. That is, when the degree of vacuum was 1.0 Pa, no corrosion was observed as in the case where no evacuation was performed, but when the degree of vacuum was 1.0 × 10 ⁻³ Pa, the anticorrosion effect tended to decrease. It was. Therefore, as described with reference to FIGS. 6A to 6B, the Cl component 45 can be efficiently removed by the method of the present invention because the H ₂ O layer 46 is formed on the surface of the metal layer 42. This is presumed to be due to this. In other words, in order to efficiently remove the Cl component 45, it is necessary to perform the second step (plasma irradiation) while the H ₂ O is sufficiently adsorbed on the surface of the second step metal layer 42. . Furthermore, it is presumed from this that it is preferable that the time interval from the end of the first step to the start of the second step is short.

  Next, an experiment for examining the influence of the stage temperature in the first step was performed. Specifically, the sample was processed under the conditions of Experimental Examples 3 and 4 shown in Table 2. Experimental Examples 3 and 4 are all examples of the processing method of the present invention. In Experimental Example 3, the stage temperature in the first step is 200 ° C., whereas in Experimental Example 4, the stage temperature in the first step is 300 ° C. It is. The other conditions (gas type, gas flow rate, pressure in the vacuum vessel, power supplied to the ICP coil in the second step, time of the first and second steps) are the same between the experimental examples 3 and 4. .

  In Experimental Example 4 where the stage temperature in the first step was 300 ° C., no corrosion was observed on the Al surface 50 as shown in FIG. 9B. In Experimental Example 3 where the stage temperature in the first step was 200 ° C., granular corrosion 52 was observed on the Al surface 50 as shown in FIG. 9A. According to the experimental results and the inventor's considerations, as shown in FIG. 10, when the stage temperature of the first step is 200 ° C., the Cl component removal effect is drastically improved. It is presumed that a component removal effect can be obtained.

1 is a schematic cross-sectional view showing an ashing apparatus that is an example of a plasma processing apparatus according to the present invention. The bottom view which shows a grid | lattice-like frame. The schematic perspective view which shows an ICP coil, a high frequency power supply, and a matching circuit. The schematic block diagram of the dry etching apparatus provided with the ashing apparatus of FIG. The flowchart for demonstrating the anticorrosion process which is embodiment of the plasma processing method which concerns on this invention. The partial expansion schematic cross section which shows the state of the substrate surface immediately after an etching. The partial expansion schematic cross section which shows the state of the substrate surface at the time of water vapor | steam introduction | transduction under heating. The partial expanded schematic cross section which shows the state of the substrate surface at the time of completion | finish of water vapor | steam introduction under heating. The partial expanded sectional view which shows the state of the substrate surface at the time of plasma irradiation. The electron micrograph of the Al surface after completion | finish of the anticorrosion process of Experimental example 1. FIG. The electron micrograph of the Al surface after completion | finish of the anticorrosion process of the comparative example 1. The electron micrograph of the Al surface after the anticorrosion process of the comparative example 2 completion | finish. The electron micrograph of the Al surface after completion | finish of the anticorrosion process of Experimental example 3. The electron micrograph of the Al surface after completion | finish of the anticorrosion process of Experimental example 4. The conceptual diagram which shows the relationship between the stage temperature and Cl removal effect of a 1st process. It is a flowchart for demonstrating the conventional anti-corrosion process. The partial expansion schematic cross section which shows the state of a substrate surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Ashing apparatus 12 Substrate 13 Substrate supply part 14 Load lock chamber 15 Etching apparatus 16 Vacuum container 17 Container body 18 Lid body 19 Lattice frame body 19a Window part 19b Gas flow path 19c Gas outlet 19d Inlet 20 Dielectric plate 21 Inside 24, 25 Gas supply source 26 ICP coil 27 Conductor 28 Matching circuit 29, 32 High frequency power supply 30 Lower electrode 31 Heater 34 Evacuation device 35 Controller 41 Substrate body 42 Metal layer 43 Metal layer 44 Resist layer 45 Cl component 46 H ₂ 0 layer

Claims (3)

A plasma processing method for removing a chlorine component remaining in a metal layer (42) on a substrate (12),
Placing the substrate in a vacuum vessel (16);
Introducing water vapor or hydrogen-containing gas into the vacuum vessel, and holding the substrate at a predetermined first time in a state of being heated to a temperature higher than at least room temperature,
A plasma processing method in which an oxygen-containing gas or a mixed gas of an oxygen-containing gas and a fluorine-containing gas is introduced into the vacuum container, and the plasma is generated in the vacuum container and held for a predetermined second time.   The plasma processing method according to claim 1, wherein the metal layer is made of aluminum or an aluminum alloy. A vacuum vessel (16) in which a substrate (12) is disposed;
A heating mechanism (31) for heating the substrate in the vacuum vessel;
A first gas supply source (24) capable of supplying water vapor or hydrogen-containing gas into the vacuum vessel;
A second gas supply source (25) capable of supplying an oxygen-containing gas or a mixed gas of an oxygen-containing gas and a fluorine-containing gas into the vacuum vessel;
A plasma generation source (26) for generating plasma in the vacuum vessel;
The state in which the first gas supply source supplies the water vapor or the hydrogen-containing gas into the vacuum container is continued for a predetermined first time while the heating mechanism heats the substrate to at least a temperature higher than room temperature. Thereafter, the second gas supply source supplies the oxygen-containing gas or a mixed gas of oxygen-containing gas and fluorine-containing gas into the vacuum container, and the plasma generation source generates plasma in the vacuum container. A control device (35) for controlling the heating mechanism, the first and second gas supply sources, and the plasma generation source so as to continue the state for a predetermined second time, Plasma processing equipment.