JP3384705B2 - Semiconductor device manufacturing method, plasma processing apparatus, and plasma processing apparatus for flattening process - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor element including a step of flattening a stepped shape of a semiconductor element substrate, and a processing apparatus for performing the flattening. In particular, a method for manufacturing a semiconductor device including a step of flattening an insulating film having an uneven shape formed on a stepped structure such as a circuit conductor layer or a memory cell, and a processing apparatus for flattening an insulating film having an uneven shape Regarding

[0002]

2. Description of the Related Art In recent years, as semiconductor elements have been highly integrated, the elements have been multi-layered and wirings have been miniaturized. A fine resist pattern needs to be formed in order to miniaturize a wiring or the like, but the resist pattern can be miniaturized by increasing resolution during exposure in a photolithography process. However, on the other hand, the depth of focus becomes shallower as the resolution is increased. Therefore,
In a semiconductor device having a multilayer structure, it is required to flatten the steps formed in the interlayer insulating film in order to ensure the accuracy of the resist pattern. Further, it is necessary to flatten the step in order to prevent the stepping of the upper wiring layer.

In the flattening of the insulating film in such a semiconductor element manufacturing process, the unevenness of about 1 μm is
The shaving allowance is about 1 μm, and planarization is required in a more severe situation than Si wafer polishing.

As this flattening means, for example, CMP
(Chemical Mechanical Poli
shing; chemical mechanical polishing). This is a method of pressing the substrate against the polishing pad attached to the surface plate while supplying a polishing liquid containing an abrasive, and rotating the surface plate while applying a load to the substrate to selectively polish the convex portions of the substrate. In addition to the mechanical polishing effect of the polishing agent and the polishing pad, there is also the chemical polishing effect of the polishing liquid. This CMP has a very high flatness over a wide area, but on the other hand, since it is a so-called wet polishing technique that uses a polishing liquid, it cannot be used for an insulating film of a material having a high water absorption. There are problems such as high cost of consumables for the polishing agent and polishing pad, and a large amount of particles generated.

Therefore, it is desirable to perform planarization by dry etching such as plasma etching or RlE (reactive ion etching). In the case of dry etching, it does not matter whether the insulating film absorbs water or not, and the amount of particles generated is much smaller than that in the wet polishing technique. Further, since there is no mechanical wear, the cost of consumables can be suppressed.

[0006] For example, in plasma etching, plasma is generated based on a reaction gas that chemically reacts with an object to be etched, and etching is performed by causing the plasma to react with the object to be etched. It is a different etching method. Therefore, the surface after etching is free from polishing scratches.

As a flattening means using dry etching, there is a resist etch back method. An example of this is shown in FIG.
Will be explained. FIG. 21 is a schematic view showing a cross section of the semiconductor element substrate in the logic LSI manufacturing process. The first insulating film 28 is formed on the substrate 27, and the metal wiring 29 is formed thereon. Due to the uneven shape of the metal wiring 29, the surface of the second insulating film 30 serving as an interlayer insulating film in the multilayer structure also has the uneven shape (FIG. 21A). Next, a resist 3 is formed on the insulating film 30.
Apply 1. The resist 31 has good fluidity, and the surface after application becomes a flat surface (FIG. 21B). This is dry-etched under the condition that the resist 31 and the second insulating film 30 are uniformly etched to obtain a flat surface (FIG. 21C). This is a commonly used planarization method, but substantial planarization is performed by applying the resist 31 rather than dry etching in the resist etch back method.

[0008]

However, as described above, the flattening of the insulating film by the resist etch back method requires the steps of coating and baking the resist, resulting in an increase in manufacturing cost. . Therefore, it is desired that the dry etching itself be a processing method having selectivity with respect to the uneven shape of the insulating film. However, dry etching generally used at present is isotropic processing, and the spatial resolution of the processing is poor,
Sufficient selectivity for uneven shapes cannot be obtained. Therefore,
The surface cannot be flattened unless a sufficient cutting allowance is taken.
As a result, it can be said that dry etching does not have a substantial planarizing ability in the planarizing step in semiconductor device manufacturing.

Further, in the conventional dry etching, a substrate is placed in a reaction vessel, the inside of the reaction vessel is evacuated once, and a desired gas has a relatively low density (about 1 mTorr to 1 Torr).
To generate plasma. Therefore, it is necessary to maintain the vacuum of the reaction container, the processing apparatus becomes expensive, and its operation is complicated.

The present invention has been made in view of the above circumstances, and an object thereof is to (1) flatten the surface of an insulating film only by a dry etching step without adding steps such as resist coating and baking. By simplifying, the steps required for planarization are simplified, and (2) problems caused by water absorption of the insulating film and generation of particles are reduced,
(3) The cost of consumables required for the flattening process is suppressed, and quick flattening is realized. As a result, (4) Manufacturing of a semiconductor element capable of manufacturing a high-performance semiconductor element at low cost A method and a manufacturing apparatus are provided.

[0011]

A plasma processing apparatus of the present invention comprises a stage for holding a substrate, a gas supply means for supplying a high density gas, a gas exhaust means for exhausting the high density gas, and a high frequency wave. A plasma generating means having a power source and a pair of electrodes arranged to face each other; and a transfer means for transferring radicals of the generated plasma that chemically react with the substrate surface in a direction along the substrate surface. The transfer means is a cylindrical rotating body that rotates about an axis parallel to the surface of the substrate, and the cylindrical rotating body also serves as one electrode of the plasma generating means. The other electrode of the generating means is arranged separately from the stage so that the plasma is generated at a position apart from the substrate by the one electrode, and the other electrode is generated by the pair of electrodes. The radicals in the plasma is that,
By the rotation of the cylindrical rotary member, the radicals are transferred to the substrate on the stage, and further, the radicals are transferred in the direction along the substrate surface by the rotation of the cylindrical rotary member.

Further, the plasma processing apparatus of the present invention is a plasma processing apparatus for a flattening step used in a step of flattening an insulating film formed on a substrate, the apparatus including a stage for holding the substrate. A plasma generating means having a gas supplying means for supplying a high density gas, a gas exhausting means for exhausting the high density gas, a high frequency power supply, and a pair of electrodes arranged to face each other, And a transfer means for transferring radicals chemically reacting with the surface of the substrate in a direction along the surface of the substrate, the transfer means being a cylindrical type rotating about an axis parallel to the surface of the substrate. In the rotating body, the cylindrical rotating body also serves as one electrode of the plasma generating means, and the other electrode of the plasma generating means is separated from the substrate by the one electrode. The The radicals in the plasma, which are arranged separately from the stage so that a zuma is generated, in the plasma generated by the pair of electrodes are transferred to the substrate on the stage by the rotation of the cylindrical rotor. And the radicals are transferred by the rotation of the cylindrical rotor.
Transferred in a direction along the surface of the substrate.

Further, the plasma processing apparatus of the present invention includes a stage for holding the substrate, a gas supply means for supplying a high density gas, and a gas exhaust means for exhausting the high density gas.
Plasma generating means having a high-frequency power source and a pair of electrodes arranged to face each other; transfer means for transferring radicals of the generated plasma that chemically react with the substrate surface in a direction along the substrate surface. The transfer means is a cylindrical rotating body that rotates about an axis parallel to the substrate surface, and has a hollow cylindrical shape having a large number of holes in its cylindrical surface, and The mold rotating body also serves as one electrode of the plasma generating means, and the other electrode of the plasma generating means is arranged outside the cylindrical rotating body so as to face its cylindrical surface, A gas having a density is guided to the outside from the inside of the cylindrical rotor through the holes of the cylindrical surface, and the plasma is generated between the pair of electrodes in a region where the gas is introduced outside the cylindrical rotor. Generated, rotation of the cylindrical rotor Thus, the radicals in the plasma is transported in the direction along the substrate surface.

Further, the plasma processing apparatus of the present invention is a plasma processing apparatus for a flattening step used in a step of flattening an insulating film formed on a substrate, the apparatus including a stage for holding the substrate. A plasma generating means having a gas supplying means for supplying a high density gas, a gas exhausting means for exhausting the high density gas, a high frequency power supply, and a pair of electrodes arranged to face each other, And a transfer means for transferring radicals chemically reacting with the surface of the substrate in a direction along the surface of the substrate, the transfer means being a cylindrical type rotating about an axis parallel to the surface of the substrate. The rotating body has a hollow cylindrical shape having a large number of holes on its cylindrical surface, and the cylindrical rotating body also serves as one electrode of the plasma generating means, and the other of the plasma generating means is The electrode is The cylinder-shaped rotating body is disposed outside the cylindrical rotating body so as to face the cylindrical surface, and the high-density gas is guided from the inside of the cylindrical rotating body to the outside through the holes of the cylindrical surface, and the cylindrical rotating body is rotated. The plasma is generated between the pair of electrodes in the region where the gas is introduced outside the body, and the radicals in the plasma are transferred in the direction along the substrate surface by the rotation of the cylindrical rotating body. It

Further, the plasma processing apparatus of the present invention comprises a stage for holding the substrate, a gas supply means for supplying a high density gas, and a gas exhaust means for exhausting the high density gas.
Plasma generating means having a high-frequency power source and a pair of electrodes arranged to face each other; transfer means for transferring radicals of the generated plasma that chemically react with the substrate surface in a direction along the substrate surface. The transfer means is a cylindrical rotating body that rotates about an axis parallel to the substrate surface, and has a hollow cylindrical shape having a large number of holes in its cylindrical surface, and The mold rotating body also serves as one electrode of the plasma generating means, and the other electrode of the plasma generating means is an internal cylindrical body disposed inside the cylindrical rotating body and coaxial with the cylindrical rotating body. And the radicals in the plasma generated by the pair of electrodes of the plasma generating means are guided to the outside through a hole formed in the cylindrical surface of the cylindrical rotating body to rotate the cylindrical rotating body. Due to the rotation of the body Te, the radical is transferred in the direction along the substrate surface.

Further, the plasma processing apparatus of the present invention is a plasma processing apparatus for a flattening step used in a step of flattening an insulating film formed on a substrate, and the apparatus includes a stage for holding the substrate. A plasma generating means having a gas supplying means for supplying a high density gas, a gas exhausting means for exhausting the high density gas, a high frequency power supply, and a pair of electrodes arranged to face each other, And a transfer means for transferring radicals chemically reacting with the surface of the substrate in a direction along the surface of the substrate, the transfer means being a cylindrical type rotating about an axis parallel to the surface of the substrate. The rotating body has a hollow cylindrical shape having a large number of holes on its cylindrical surface, and the cylindrical rotating body also serves as one electrode of the plasma generating means, and the other of the plasma generating means is The electrode is Inside the cylindrical rotary member, the internal cylindrical member is disposed coaxially with the cylindrical rotary member, and the radicals in the plasma generated by the pair of electrodes of the plasma generating means are The radicals are guided to the outside through a hole formed in the cylindrical surface of the cylindrical rotating body, and the radicals are transferred in a direction along the surface of the substrate by the rotation of the cylindrical rotating body.

Further, the plasma processing apparatus of the present invention comprises a stage for holding the substrate, gas supply means for supplying a high density gas, and gas exhaust means for exhausting the high density gas.
Plasma generating means having a high-frequency power source and a pair of electrodes arranged to face each other; transfer means for transferring radicals of the generated plasma that chemically react with the substrate surface in a direction along the substrate surface. The transfer means also serves as one electrode of the plasma generation means, and rotates relative to the substrate surface and the other electrode of the plasma generation means about an axis perpendicular to the substrate surface. Which is a disc-shaped rotating body, wherein the other electrode of the plasma generating means is
The radicals in the plasma generated by the pair of electrodes are arranged separately from the stage so that the plasma is generated by the one electrode at a position distant from the substrate. Transferred to the substrate on the stage by relative rotation of the mold rotating body,
The radicals are transferred in the direction along the surface of the substrate by the relative rotation of the disk-shaped rotating body.

Further, the plasma processing apparatus of the present invention is a plasma processing apparatus for a flattening step used in a step of flattening an insulating film formed on a substrate, the apparatus including a stage for holding a substrate. A plasma generating means having a gas supplying means for supplying a high density gas, a gas exhausting means for exhausting the high density gas, a high frequency power supply, and a pair of electrodes arranged to face each other, And a transfer means for transferring radicals of the plasma that chemically react with the substrate surface in a direction along the substrate surface, the transfer means also serving as one electrode of the plasma generation means, and the substrate surface. A disk-shaped rotating body that rotates relative to the surface of the substrate and the other electrode of the plasma generating means about an axis perpendicular to, and the other electrode of the plasma generating means is
The stage is arranged separately from the stage so that the plasma is generated at a position away from the substrate by the one electrode, and the radicals in the plasma generated by the pair of electrodes are By the relative rotation of the disk-shaped rotating body, it is transferred to the substrate on the stage, and further, the radicals are transferred in the direction along the surface of the substrate by the relative rotation of the disk-shaped rotating body. The cylindrical rotating body is a ground electrode. The disk-shaped rotating body is a ground electrode.

Further, the plasma processing apparatus of the present invention comprises a stage for holding the substrate, gas supply means for supplying a high density gas, and gas exhaust means for exhausting the high density gas.
Plasma generating means having a high-frequency power source and a pair of electrodes arranged to face each other; transfer means for transferring radicals of the generated plasma that chemically react with the substrate surface in a direction along the substrate surface. The transfer means also serves as one electrode of the plasma generation means, and rotates relative to the substrate surface and the other electrode of the plasma generation means about an axis perpendicular to the substrate surface. Then, the radicals in the plasma generated by the pair of electrodes of the plasma generating means are transferred in a direction along the surface of the substrate, and at least one of the pair of electrodes is
The distance between the pair of electrodes in a portion where the relative speed between the pair of electrodes is high is larger than the distance between the pair of electrodes in a portion where the relative speed is low.

Further, the plasma processing apparatus of the present invention is a plasma processing apparatus for a flattening step used in a step of flattening an insulating film formed on a substrate, the apparatus including a stage for holding the substrate. A plasma generating means having a gas supplying means for supplying a high density gas, a gas exhausting means for exhausting the high density gas, a high frequency power supply, and a pair of electrodes arranged to face each other, And a transfer means for transferring radicals of the plasma that chemically react with the substrate surface in a direction along the substrate surface, the transfer means also serving as one electrode of the plasma generation means, and the substrate surface. Relative to the surface of the substrate and the other electrode of the plasma generating means about an axis perpendicular to, and the radio wave in the plasma generated by the pair of electrodes of the plasma generating means. Is transferred in a direction along the surface of the substrate, and in at least one of the pair of electrodes, the distance between the pair of electrodes in a portion where the relative speed between the pair of electrodes is large is small. It has a taper shape that is larger than the distance between the pair of electrodes in the portion.

[0021]

[0022]

Further, the plasma processing apparatus of the present invention includes a stage for holding the substrate, gas supply means for supplying a high density gas, and gas exhaust means for exhausting the high density gas.
Plasma generating means having a high-frequency power source and a pair of electrodes arranged to face each other; transfer means for transferring radicals of the generated plasma that chemically react with the substrate surface in a direction along the substrate surface. One of the pair of electrodes of the plasma generation means is a rotating body that rotates about an axis parallel to the substrate surface, and the one of the gas supply port of the gas supply means and the gas exhaust means of the gas supply means. The gas exhaust port sandwiches the rotating body and is in the rotation direction of the rotating body.
One is arranged so that gas flows in a direction along the substrate surface, and the transfer means is configured by the cooperation of the rotating body, the gas supply port and the gas exhaust port, and The radicals are transferred along the direction.

Further, the plasma processing apparatus of the present invention is a plasma processing apparatus for a flattening step used in a step of flattening an insulating film formed on a substrate, the apparatus including a stage for holding the substrate. A plasma generating means having a gas supplying means for supplying a high density gas, a gas exhausting means for exhausting the high density gas, a high frequency power supply, and a pair of electrodes arranged to face each other, And a transfer means for transferring radicals of the plasma that chemically react with the substrate surface in a direction along the substrate surface, and one of the pair of electrodes of the plasma generation means is parallel to the substrate surface. A rotating body that rotates about an axis, wherein the gas supply port of the gas supply unit and the gas exhaust port of the gas exhaust unit sandwich the rotating unit and are in the rotating direction of the rotating unit.
And is arranged so that gas parallel to the substrate surface flows , and the rotor, the gas supply port and the gas exhaust port .
The transfer means is configured by the cooperation of the above , and the radicals are transferred in the direction along the surface of the substrate.

Further, the plasma processing apparatus of the present invention is a plasma processing apparatus for a flattening step used in a step of flattening an insulating film formed on a substrate, the apparatus including a stage for holding a substrate. A gas supply unit for supplying a high-density gas, a gas exhaust unit for exhausting the high-density gas, a high-frequency power source, and a plasma generation unit having a pair of electrodes arranged to face each other, The pair of electrodes of the plasma generating means generate an electric field in a direction parallel to the substrate surface.
In a direction parallel to the surface of the substrate above the substrate.
In opposite, the pair of electrodes at least one of, of the pair
To generate a spatially non-uniform electric field between the electrodes, it has a sharp shape toward the other opposing electrode ,
The pair of electrodes generate a non-uniform electric field parallel to the surface of the substrate, thereby generating a spatially localized plasma due to the non-uniform electric field.

Further, the plasma processing apparatus of the present invention is a plasma processing apparatus for a flattening process used in a step of flattening an insulating film formed on a substrate, which has a stage for holding the substrate and a high density. The stage is provided with a gas supply unit for supplying gas, a gas exhaust unit for exhausting the high-density gas, a high-frequency power source, and a plasma generation unit having a pair of electrodes arranged to face each other. One of the pair of electrodes of the plasma generating means constitutes one of the electrodes, and the other electrode is arranged so as to face the stage, and at least one of the pair of electrodes is flattened with a region on the substrate to be flattened. It has a concavo-convex shape that matches the arrangement with the region where no light is applied. The stage is an electrode having the concavo-convex shape of the pair of electrodes, and the other electrode is a cylindrical rotating body that rotates about an axis parallel to the substrate surface. The stage is an electrode having the concavo-convex shape among the pair of electrodes, and the other electrode is a disk-shaped rotating body that rotates around an axis perpendicular to the substrate surface.

A method of manufacturing a semiconductor element according to the present invention is a method of manufacturing a semiconductor element, which has a step of flattening an insulating film formed so as to cover a step portion formed on a substrate,
The insulating film is produced by generating a plasma by a high-frequency electric field in a high-density gas atmosphere by the plasma processing apparatus for planarization process according to any one of claims 2, 4, 6, 8, 12 , 14, and 16. Performing a step of generating radicals that chemically react with the substrate, and a step of transporting the radicals by a gas flow parallel to the substrate surface, thereby selectively supplying the radicals to the convex portions of the insulating film. .

A method of manufacturing a semiconductor device according to the present invention is a method of manufacturing a semiconductor device, which comprises a step of flattening an insulating film formed so as to cover a step portion formed on a substrate,
The step of supplying a high-density gas in the vicinity of the surface of the substrate in a concentrated manner by the plasma processing apparatus for the planarization step according to claim 14 , and the radicals which generate plasma by a high frequency electric field and chemically react with the insulating film. The step of generating, the step of flattening by supplying the radical to the insulating film, and the step of exhausting and recovering the reaction product generated on the substrate surface from the substrate surface are carried out in an atmosphere open system.

[0029]

[0030]

[0031]

The step of flattening the insulating film is performed at about 100 MHz in a high density gas atmosphere of about 1 atm or more.
This is performed by applying the above high-frequency electric field to generate plasma.

[0033]

(Operation) The operation of the present invention will be described below.

According to the present invention, in the step of flattening the insulating film, plasma is generated by a high frequency electric field in a high-density gas atmosphere to generate radicals that chemically react with the insulating film, and the radicals parallel to the substrate surface are generated. Flattening is performed by transporting the radicals by a simple gas flow and thereby selectively supplying the radicals to the convex portions of the insulating film. Alternatively, a high-frequency electric field that is spatially non-uniform in a high-density gas atmosphere is generated, and plasma is locally generated by the high-frequency electric field to generate radicals that chemically react with the insulating film. Planarization is performed by selectively acting the radicals on the convex portions of the film.

Further, these flattening steps are steps performed in an atmosphere open system, in which a high density gas is concentratedly supplied near the surface of the substrate and plasma is generated by a high frequency electric field to generate the insulating film. Radicals that chemically react with are generated, and the radicals are supplied to the insulating film for planarization, and the reaction products generated on the substrate surface are exhausted and collected from the substrate surface. Further, a temperature gradient is given to the high-density gas atmosphere so that the temperature of the surface of the substrate becomes higher than the temperature of the high-density gas atmosphere in the direction perpendicular to the surface of the substrate, thereby flattening.

Alternatively, these flattening steps are performed at a pressure of about 100 MH in a high density gas atmosphere of about 1 atm or more.
It is performed by applying a high frequency electric field of z or more to generate plasma.

As the high density gas, a mixed gas of a rare gas and a reaction gas for chemically reacting with the insulating film is used. Furthermore, the reaction gas is any one of sulfur hexafluoride, tetrafluoromethane, trifluoromethane, hexafluoroethane, octafluoropropane, octafluorobutene, butane dodecafluoride, or a mixture of two or more kinds. Including gas. The rare gas is preferably helium gas or argon gas.

As a plasma processing apparatus for a flattening process which realizes this, a stage for holding a substrate, a gas supply means for supplying a high density gas, a gas exhaust means for exhausting the high density gas, and a high frequency A plasma generating means having a power source and a pair of electrodes arranged so as to face each other; and a transfer means for relatively transferring, to the substrate surface, radicals that chemically react with the substrate surface in the generated plasma, Equipped with. The transfer means transfers the radical in a direction along the surface of the substrate.

As a first structural example thereof, the transfer means is a cylindrical rotating body, and rotates about an axis parallel to the substrate surface.

Further, the cylindrical rotary member of the transfer means has a hollow cylindrical shape having a large number of holes on the cylindrical surface, and also serves as one of the pair of electrodes of the plasma generating means. The other electrode of the plasma generating means is arranged outside the cylindrical rotating body so as to face the cylindrical surface thereof.
The high-density gas is guided from the inside of the cylindrical rotating body to the outside through the holes of the cylindrical surface, and the plasma is generated between the pair of electrodes in a region where the gas is introduced outside the cylindrical body. To be done. Alternatively, the cylindrical rotating body of the transfer means is a hollow cylindrical shape having a large number of holes in a cylindrical surface, and an inner cylinder arranged coaxially with the cylindrical rotating body inside the cylindrical rotating body. A body is provided, and the cylindrical rotating body and the inner cylindrical body form a pair of electrodes of the plasma generating means.

As a second configuration example, the transfer means is a disk type rotating body which is arranged so as to face the substrate surface and rotates about an axis perpendicular to the substrate surface. further,
The cylindrical or disk-shaped rotating body of the transfer means also serves as one of the pair of electrodes of the plasma generating means.

In the first and second configuration examples, the stage constitutes the other electrode of the plasma generating means,
The plasma generating means forms plasma in at least a region facing the substrate surface. In the first and second configuration examples, the cylindrical or disc type rotating body is configured as a ground electrode.

As a third configuration example, the stage is rotatable about an axis vertical to the substrate and also serves as the transfer means.

The pair of electrodes of the plasma generating means are arranged between electrodes in a portion where a relative speed between the electrodes is large when at least one of the pair of electrodes rotates about an axis perpendicular to the substrate. At least one of them has a tapered shape so that the distance becomes larger than the inter-electrode distance of the portion where the relative speed is small.

As a fourth configuration example, the gas supply port of the gas supply unit and the gas exhaust port of the gas exhaust unit are arranged so as to form a gas flow parallel to the substrate surface. The gas supply port and the gas exhaust port constitute the transfer means.

Alternatively, one of the electrodes of the plasma generating means is a cylindrical rotating body that rotates about an axis parallel to the surface of the substrate, and a cylindrical rotating body having minute projections arranged on the surface of the cylindrical surface, and A disc type rotating body that rotates about an axis perpendicular to the substrate surface, in which microscopic protrusions are arranged on a surface facing the substrate, and the stage is configured to generate the plasma. It constitutes the other electrode of the means.

Alternatively, the plasma processing apparatus for the flattening step for flattening the substrate includes a stage for holding the substrate, a gas supply means for supplying a high density gas, and a gas exhaust means for exhausting the high density gas. And a plasma generating means having a high frequency power source and a pair of electrodes arranged to face each other, at least one of the pair of electrodes having a shape for generating a non-uniform electric field. is doing.

As one configuration example thereof, the pair of electrodes of the plasma generating means are disposed above the substrate, and at least one of the pair of electrodes has a sharp shape toward the other electrode facing the other. And thereby generate a spatially localized plasma due to the non-uniform electric field.

Alternatively, in the plasma processing apparatus for the flattening step, the stage for holding the substrate used in the step of flattening the insulating film formed on the substrate and the high frequency power source are opposed to each other in the atmosphere open system. Plasma generating means having a pair of electrodes that are arranged in a pair. further,
A gas supply means for intensively supplying a high-density gas near the surface of the substrate and a gas exhaust means for intensively exhausting the atmosphere and reaction products near the surface of the substrate are provided near the surface of the substrate. As a result, plasma is generated in the atmosphere to perform flattening.

Alternatively, a stage for holding the substrate, a gas supply means for supplying a high-density gas, a gas exhaust means for exhausting the high-density gas, a high-frequency power source, and a pair of gas supply means arranged to face each other. Plasma generating means having an electrode. The stage constitutes one of the pair of electrodes of the plasma generating means, the other electrode is arranged to face the stage, and at least one of the pair of electrodes is an area for planarizing the substrate. And has a concavo-convex shape according to the arrangement of the non-planarized region.

As one configuration example thereof, the stage is an electrode having the uneven shape among the pair of electrodes, and the other electrode is a cylindrical rotating body which rotates about an axis parallel to the substrate surface. is there.

As another configuration example, the stage is an electrode having the uneven shape of the pair of electrodes, and the other electrode is a disk-shaped rotating body that rotates about an axis perpendicular to the substrate surface. is there.

The present invention is, for example, a logic LSI or a DR.
In a semiconductor device having a multi-layer structure such as AM, a method of manufacturing a semiconductor device, including a step of flattening an interlayer insulating film,
It is also suitable as a processing device for flattening the interlayer insulating film.

[0055]

BEST MODE FOR CARRYING OUT THE INVENTION The flattening step in the method of manufacturing a semiconductor device according to the present invention uses plasma etching in which plasma is generated based on a reaction gas and etching is performed by causing the plasma to interact with a workpiece. . By this etching process, the workpiece having an uneven shape is flattened. Further, this flattening step is executed by using the plasma etching processing apparatus of the present invention.
Hereinafter, the present invention will be described with reference to the drawings by the embodiments.

First, a plasma etching process was used.
The principle of the flattening process of a work such as an insulating film will be described.
To the plasma etching itself, it is possible to impart a flattening ability to selectively etch only the convex and concave portions by locally arranging generated plasma in a region to be selectively etched. That is, by localizing the plasma, radicals or charged particles that chemically react with the workpiece become localized. Therefore, as shown in FIG. 1, by localizing the plasma 1 at least on the upper surface of the work piece 2 and selectively causing the plasma 1 to act on the uneven projections 2 a of the work piece 2,
The convex portion 2a is selectively etched, and a flat surface can be obtained.

It is possible to generate a localized plasma by forming a high frequency electric field in a high density gas atmosphere. For example, an apparatus for generating localized plasma by using a high-frequency electric field in a high-density gas atmosphere and performing chemical processing is disclosed in Japanese Patent Laid-Open No. 4-128393 and Journal of Precision Engineering 57/1/1991 (P.36). ), Etc., and an example of planar processing of Si is also shown.

When plasma is generated by a high frequency electric field (eg, about 100 MHz or more) in a high density gas atmosphere, charged particles in the plasma can be captured in a minute area. Plasma is maintained by ionization due to collision between charged particles and other particles, or by excitation,
By trapping the charged particles in a minute area, a spatially localized plasma area can be formed. The radicals generated by the plasma are electrically neutral and can diffuse out of the plasma region, but when the density of the gas atmosphere is high, the diffused radicals immediately collide with other particles to lose energy and become inactive. Therefore,
The region where radicals exist is also localized near the plasma region. Note that, under a constant temperature and volume, the high density of the gas atmosphere is equivalent to the high pressure.

Further, when processing is performed by plasma etching, it is necessary to supply a reaction gas such as a halogen gas, which easily causes a chemical reaction with the object to be processed, and generate plasma based on this reaction gas. However, under the high-density gas atmosphere as described above, it is difficult to generate and maintain plasma by supplying only the reaction gas. For this reason, the reactive gas and the rare gas, which is relatively easy to stably maintain the plasma, are mixed and used. In addition, by introducing only the rare gas, the plasma based on the rare gas is generated and maintained, and then the reaction gas is introduced to generate the plasma based on the reaction gas. Can be stably generated and maintained.

The above is the method for localizing the plasma,
And its principle. If the localized plasma region generated in this way is used, the etching process itself has a flattening ability to selectively process only the convex and concave portions of the unevenness of the workpiece while belonging to the so-called dry etching technique. It is possible to give.

Further, since the charged particles in the plasma are oscillating by the high frequency electric field, the charged particles may damage the work piece due to collision with the work piece. For a work piece in which such damage is a problem, the plasma area and the work piece are treated so that the radial force that diffuses from the trapped area of the charged particles mainly acts without collision of the charged particles. It is also possible to set the distance.

However, a minute step (for example, in the manufacturing process of a semiconductor element, which is an application of the present invention,
In order to planarize a circuit conductor layer or an insulating film formed on a memory cell), it is required to have a planarization ability higher than that of the polishing of a Si wafer, which is capable of planarization in a situation where the machining allowance is small. It

Therefore, in the present invention, not only the localized plasma is generated, but also the radicals are transferred by the gas flow parallel to the surface of the semiconductor element substrate and selectively to the convex portion of the workpiece such as the insulating film. Planarization is performed by supplying radicals. Alternatively, by generating a high-frequency electric field spatially non-uniformly, plasma is localized in a finer area with respect to the work piece, and radicals that chemically react with the localized work piece are generated. Flattening is performed by selectively acting on the convex portions of the work piece.

When there is no gas flow, radicals generated by localized plasma are isotropically diffused, but by using a gas flow parallel to the semiconductor element substrate surface,
Radicals are mainly transported in the direction of gas flow. When the radicals are transported only in the direction along the surface of the substrate, the radicals selectively act on the uneven convex portions on the surface of the substrate.
Thus, by transporting radicals in the direction parallel to the semiconductor substrate surface, the planarization ability can be further improved.

Further, conventionally, in plasma etching in a semiconductor element manufacturing process, it is important to uniformly process the entire substrate surface (or wafer). Therefore,
In the conventional plasma etching process, it was important to generate a uniform plasma under a uniform electric field. As described above, conventionally, no plasma etching itself has been provided with a planarizing ability. However, as in the intended use of the present invention, in the case of flattening a minute step of a semiconductor element by plasma etching,
The plasma needs to be localized. In order to further improve the flattening ability, a non-uniform electric field is generated in the present invention. In a non-uniform electric field, plasma is selectively generated only in a portion having a strong electric field strength. Therefore, by controlling the electric field distribution, more specifically, by optimizing the electrode shape with respect to the workpiece, the plasma can be more localized. In this way, it is possible to further improve the flattening ability of the plasma etching itself in the step of flattening the semiconductor element.

As conditions for generating plasma,
Conditions that can trap the charged particles in a minute region and prevent undesired diffusion of radicals are desirable.
The former is possible by increasing the frequency of the high-frequency electric field, and the latter is possible by increasing the pressure (that is, gas density) at the time of plasma generation in order to increase the probability of collision of radicals with other particles. Desirable conditions are firstly that the high frequency electric field is a high frequency electric field of 100 MHz or higher, and secondly that the gas atmosphere is approximately 1 atm or higher. Since the gas atmosphere is set to approximately 1 atm, the plasma processing apparatus used in the manufacturing method according to the present invention does not require the function of maintaining the vacuum, which is required in the conventional dry etching apparatus, and thus the plasma processing apparatus is inexpensive. Can be realized. Also, a semiconductor element manufactured by using the device can be manufactured at low cost.

The object to be processed in the present invention is an insulating film,
More specifically, it is made of SiO ₂ and similar materials. Therefore, as reaction gas that easily causes a chemical reaction with the workpiece, sulfur hexafluoride, tetrafluoromethane, trifluoride methane, hexafluoroethane, octafluoropropane, octafluorobutene, butane dodecafluoride are used. Processing is possible by including any one or a mixed gas of two or more kinds. Also,
As the rare gas mixed with the reaction gas, for example, a rare gas such as helium gas that can easily generate plasma may be used.

As a method for preventing undesired diffusion of radicals and controlling the radical region, a rare gas having a large atomic radius, for example, an argon gas is used, and a predetermined temperature gradient is given to the radical diffusion region. Is also effective. That is, the use of argon gas having a large atomic radius as the rare gas increases the probability that the radicals collide with the rare gas, and prevents the radicals from undesirably diffusing. Also, for example, raising the substrate temperature,
Alternatively, a temperature gradient can be applied to the radical diffusion region by lowering the ambient temperature. This causes the particles near the substrate surface to diffuse. That is, thermal diffusion occurs. This is the opposite diffusion of radicals from the plasma region to the substrate. Therefore, the diffusion of radicals toward the substrate is suppressed in the vicinity of the substrate, and the radical region can be more localized in a predetermined region between the plasma region and the substrate surface.

Further, when performing plasma processing in a system open to the atmosphere, the function of maintaining a vacuum is not required and a reaction vessel is not required, so that mounting or moving of the semiconductor element substrate on the stage is easy. Therefore, the operation of the plasma processing apparatus becomes simple. However, in an open air system, the atmosphere is easily mixed into a high-density gas atmosphere, and it is difficult to stably generate plasma. There is also a problem that the reaction product is diffused into the atmosphere and the working environment is polluted. Therefore, according to the present invention, when introducing a high-density gas in the atmosphere, a gas supply means for intensively supplying the high-density gas near the substrate surface and the atmosphere and the reaction products near the substrate surface are concentrated. And a gas exhaust means for exhausting the gas. With these gas supply / exhaust means, the gas necessary for generating plasma can be sufficiently introduced near the substrate surface, and the reaction products can be exhausted, so that the planarization process can be easily performed in the atmosphere. Become.

The plasma processing apparatus for the flattening step, which realizes the flattening of the semiconductor element by the above plasma etching process, will be described below.

The plasma processing apparatus for flattening process according to the present invention has, as its basic constitution, a stage for holding a semiconductor element substrate which is a workpiece and a high-density gas supply / supply stage.
It is provided with a gas supply unit for exhausting gas and a gas exhaust unit, a plasma generation unit, and a transfer unit for transferring radicals generated by plasma. The plasma generating means is
It has a high-frequency power source and a pair of electrodes arranged to face each other, and the transfer means is configured to transfer radicals in a direction along the substrate surface.

[0072]

【Example】

(Embodiment 1) FIG. 2 schematically shows the configuration of a plasma processing apparatus 100 for a flattening process in the first embodiment. As shown in FIG. 2, the plasma processing apparatus 100 includes a stage 4 that holds the substrate 3, a cylindrical rotating body 5 that is disposed so as to face the substrate 3 and that rotates about an axis parallel to the substrate surface. And an electrode 7 arranged so as to face the cylindrical surface of the cylindrical rotating body 5. And
The cylindrical rotating body 5 and the electrode 7 form a pair of electrodes 40 of the plasma generating means. The electrodes are connected to the high frequency power supply 41. The high frequency power supply 41 is, for example, 100 MH
Supply high frequency power of z or higher.

Then, the electrode 40 (cylindrical rotary member 5) is provided by the gas supply means and the gas exhaust means (both not shown).
And a high-density gas atmosphere is formed between the electrodes 7).
A plasma 6 is generated by applying a high frequency electric field between the electrodes 40 by the high frequency power supply 41. When the plasma processing apparatus 100 is arranged in a reaction container (not shown), the gas supply means and the gas exhaust means
A high-density gas atmosphere may be formed throughout the reaction vessel.

By rotating the cylindrical rotary member 5 by a rotary drive system (not shown), the cylindrical rotary member 5 is rotated in the vicinity of the outer peripheral surface of the cylindrical rotary member 5 along the circumferential direction of rotation (indicated by the arrow 42 in FIG. 2). A gas stream is formed. This gas flow is in the direction along the substrate surface near the substrate surface. The radicals in the plasma generation region 6 are transferred to the vicinity of the substrate surface by this gas flow, and the transfer direction is in the vicinity of the substrate surface and along the substrate surface. That is, the cylindrical rotating body 5 is also a transfer unit that transfers radicals generated between the electrodes 40.

Then, the distance between the cylindrical rotary member 5 and the substrate 3 is kept at a predetermined preferable distance so that the transferred radicals act on the convex portions of the insulating film on the substrate 3, and the substrate 3 is subjected to the plasma etching process. By doing so, the insulating film is flattened.

Further, while the cylindrical rotating body 5 is rotating around the fixed rotation axis, the stage 4 holds the substrate 3 and moves in a direction parallel to the substrate surface as indicated by an arrow 8. The entire surface of the substrate 3 can be flattened. It is also possible to flatten the entire surface of the substrate 3 by fixing the stage 4 and scanning the cylindrical rotating body 5 and the electrode 7 in the direction parallel to the substrate surface in the opposite direction. is there.

In this structure, the generation region of the plasma 6 can be arranged at a position distant from the substrate 3, so that the number of charged particles reaching the substrate 3 is extremely small, and radicals are mainly generated in the substrate 3.
Can be a reactive species that acts on. For this reason,
It is possible to perform a plasma etching process that causes less damage to the substrate surface due to collision of charged particles. In addition, by controlling the rotation speed of the cylindrical rotating body 5, that is, by controlling the gas flow velocity,
The amount of radial force transferred to the substrate surface can be controlled. Also,
If the radius of the cylindrical rotating body 5 is set large, a gas flow parallel to the substrate 3 can be stably formed correspondingly. In this way, by optimizing the conditions of the rotational speed and radius of the cylindrical rotary body 5, the characteristics of the gas flow can be optimized to the shape of the insulating film to be flattened.

Further, since the cylindrical rotary member 5 is arranged, the pressure between the cylindrical rotary member 5 and the substrate 3 is increased by the fluid lubrication action of the gas, and radicals can be concentrated and transferred. The density of radicals that act on the insulating film on the surface of the substrate 3 is increased, and the planarization processing speed is improved. In addition, it is desirable that the radicals parallel to the surface of the substrate 3 be acted on the surface of the substrate 3 at a speed as high as possible from the viewpoints of the planarization ability and the planarization processing speed. On the other hand, among the radicals transferred by the cylindrical rotary body 5, the radical having the highest speed is the radical near the outer peripheral surface of the cylindrical rotary body 5, and in order to increase the contribution of this fast radical, It is preferable to narrow the gap between 3 and the cylindrical rotor 5.

According to this structure, since the generation region of the plasma 6 can be arranged at a position distant from the substrate 3, even if the space between the cylindrical rotating body 5 and the substrate 3 is set to be extremely narrow, It is not damaged by charged particles. That is,
In this configuration, it is possible to set the interval between the cylindrical rotary body 5 and the substrate 3 to be extremely narrow, and thereby radicals near the outer peripheral surface of the cylindrical rotary body 5 can act on the substrate 3. This further improves the flattening ability and the flattening processing speed. Further, the effect of the gas flow near the surface of the substrate 3 can effectively eliminate the reaction products due to the plasma etching, and thus the problem that particles adhere to the substrate surface can be reduced.

In the present embodiment, in the electrode 40, either the cylindrical rotating body 5 or the electrode 7 may be the ground electrode, but if the cylindrical rotating body 5 is the ground electrode, the rotating portion is There is an advantage that it is not necessary to supply high frequency power and the device configuration can be simplified.

Example 2 FIGS. 3A and 3B are
FIG. 3 is an apparatus cross-sectional view and a perspective view schematically showing the configuration of a plasma processing apparatus 200 for flattening process in a second embodiment, respectively. This embodiment is different from the first embodiment in that
A structure of a cylindrical rotating body and a gas supply method. Since other configurations are common to those of the plasma processing apparatus 100 in the first embodiment, common parts are denoted by the same reference numerals and detailed description thereof will be omitted.

As shown in FIGS. 3A and 3B, in the plasma processing apparatus 200, facing the substrate 3,
A cylindrical rotating body 5a having a function of rotating about an axis parallel to the substrate surface is arranged. The cylindrical rotating body 5a has a hollow cylindrical shape and has a large number of holes 5b on the cylindrical surface.
Further, the electrode 7 is arranged so as to face the cylindrical surface of the cylindrical rotating body 5a. The electrode 7 and the cylindrical rotor 5a form a pair of electrodes 40a of the plasma generating means. Further, inside the cylindrical rotary member 5a, the electrode 40a (the cylindrical rotary member 5a
A gas introducing passage 9 is formed so as to face the electrode 7 so that the gas is effectively introduced between a and the electrode 7).

A high-density gas is introduced from a gas supply device (not shown) through the gas introduction passage 9 into the electrode 40a (cylindrical rotor 5a and electrode 7) to form a high-frequency electric field between the high-frequency power source 41 and the electrode 40a. By applying, plasma 6 is generated in the region between the electrodes 40a.

In this configuration, the high-density gas is introduced between the electrodes 40a by the gas introduction passage 9 through the cylindrical rotary member 5.
Since it can be effectively performed from the inside of a, radicals can be efficiently generated. In the present embodiment, the gas introduction path 9 is formed facing the electrode 7 so as to introduce the high density gas into the space where the plasma 6 is generated. However, the gas is introduced from the entire cylindrical surface of the cylindrical rotary member 5a. The same effect can be obtained even with the supplied structure.

(Embodiment 3) FIG. 4 schematically shows the structure of a plasma processing apparatus 300 for a flattening process according to a third embodiment. In this embodiment, the stage 4 in the first embodiment also serves as one of the electrodes 40c of the plasma generator instead of the electrode 7. That is, in the plasma processing apparatus 300, the stage 4 and the cylindrical rotating body 5 form a pair of electrodes 40c. Since other configurations are common to those of the plasma processing apparatus 100 in the first embodiment, common parts are denoted by the same reference numerals and detailed description thereof will be omitted.

In this structure, the plasma 6 is generated between the stage 4 holding the substrate 3 and the cylindrical rotary member 5, so that the plasma 6 exists near the substrate 3. Therefore, in this embodiment, the number of radicals reaching the substrate surface is large, and efficient planarization processing can be performed. If the damage on the substrate surface does not affect the semiconductor device characteristics, the space between the cylindrical rotor 5 and the substrate 3 is narrowed, and the plasma 6 is removed.
The trapped region of the charged particles may be set so as to act on the convex portion of the insulating film on the substrate. If damage to the substrate 3 due to collision of charged particles poses a problem, the distance between the cylindrical rotating body 5 and the substrate 3 is appropriately set so that damage does not occur. In the configuration according to the present embodiment, the stage 4 also serves as an electrode, so that the number of constituent elements can be reduced as compared with the first embodiment.

Example 4 FIGS. 5 (a) and 5 (b) show
14A and 14B are a sectional view and a perspective view, respectively, schematically showing the configuration of a plasma processing apparatus 400 for a flattening process in a fourth example. In the plasma processing apparatus 400, the substrate 3
A cylindrical rotary body 5a having a function of rotating about an axis parallel to the substrate surface is arranged facing the. The cylindrical rotating body 5a has a hollow cylindrical shape and has a large number of holes 5b on the cylindrical surface. Further, the inner cylindrical body 10 is arranged inside the cylindrical rotating body 5a so as to be coaxial with the cylindrical rotating body 5a. The cylindrical rotating body 5a and the internal cylindrical body 10 arranged inside the cylindrical rotating body 5a constitute the electrode 40d of the plasma generating means.

Then, the electrode 40d (cylindrical rotary member 5) is provided by gas supply means and gas exhaust means (both not shown).
a high-density gas is introduced between a and the inner cylindrical body 10),
Plasma 6 is generated by applying a high-frequency electric field from the high-frequency power source 41 to the electrode 40d. The charged particles in the plasma 6 are trapped between the electrodes, but the neutral radicals are diffused from the cylindrical surface of the cylindrical rotor 5a to the outside through the holes 5b. Then, as the cylindrical rotary member 5a rotates, a gas flow is formed in the circumferential direction of rotation, and the gas flow is in the direction along the substrate surface near the substrate surface. Due to this gas flow, radicals are transferred in the direction along the substrate surface in the vicinity of the substrate surface. That is, the cylindrical rotating body 5
“A” is an electrode and also a transfer means for transferring radicals generated between the electrodes.

Then, the radius and the rotation speed of the cylindrical rotary member 5a are set so that the radicals act on the convex portions of the insulating film on the substrate 3, and the space between the cylindrical rotary member 5a and the substrate 3 is desired. The insulating film is flattened by controlling the value of.

Further, while the cylindrical rotating body 5a rotates about the fixed axis and the inner cylindrical body 10 is fixed, the stage 4 holds the substrate 3 and moves it to the substrate surface as indicated by an arrow 8. By moving in the parallel direction, the entire surface of the substrate 3 can be flattened. It should be noted that the stage 4 is fixed, and conversely, by scanning the cylindrical rotating body 5a and the internal cylindrical body 10 in the direction parallel to the substrate surface with respect to the substrate surface, flattening over the entire surface of the substrate 3 is similarly performed. It is possible.

In this structure, the plasma 6 is formed inside the cylindrical rotating body 5a, and the charged particles are trapped between the electrodes 40d (ie, the cylindrical rotating body 5a and the inner cylindrical body 10). Even if the distance between the substrate 5a and the substrate 3 is extremely small, the substrate 3 is provided outside the cylindrical rotary member 5a.
Most of the reactive species that act on are radicals. Therefore, according to the plasma processing apparatus 400 of the present embodiment, although the plasma processing causes very little damage to the substrate surface,
Further, the flattening ability and the flattening processing speed are improved.

(Embodiment 5) FIGS. 6A and 6B show
Plasma processing apparatus 5 for flattening process in the fifth embodiment
00 schematically shows the configuration of 00. As shown in FIGS. 6A and 6B, in the plasma processing apparatus 500,
A disk-shaped rotating body 11 having a function of rotating about an axis 50 perpendicular to the substrate surface is arranged facing the substrate 3. Further, a conductive block 12 facing the disk-shaped rotating body 11 is arranged side by side with the stage 4 holding the substrate 3, and the conductive block 12 and the disk-shaped rotating body 11 constitute an electrode 40e of the plasma generating means. Plasma processing device 50
At 0, as shown in FIG. 6B, the substrate 3 of the stage 4 is rotated around the rotation axis 50 of the disk-shaped rotating body 11.
And the conductive blocks 12 are alternately arranged.

Then, the electrode 40e (conductive block 1) is provided by gas supply means and gas exhaust means (both not shown).
Plasma 6 is generated by forming a high-density gas atmosphere between the rotor 2 and the disk-shaped rotor 11) and applying a high-frequency electric field from the high-frequency power source 41 to the electrode 40e. That is, the plasma 6 is formed between the disk-shaped rotating body 11 and each conductive block 12 arranged therebelow.

When the plasma processing apparatus 500 is arranged in a reaction container (not shown), a high-density gas atmosphere may be formed in the entire reaction container by the gas supply means and the gas exhaust means. .

Then, the disk type rotating body 11 rotates about the rotating shaft 50, so that a gas flow in the circumferential direction along the rotating surface of the disk rotating body 11 is generated. Therefore, the gas flow is along the substrate surface. By this gas flow, radicals are transferred from the plasma generation region between the disk-shaped rotating body 11 and each conductive block 12 to the vicinity of the surface of the substrate 3 on the stage 4. The transferred direction is along the substrate surface. In this way, the disk-shaped rotating body 11
Is also a transfer means for transferring radicals generated between the electrodes 40e.

Then, the rotational speed of the disk-shaped rotating body 11 and the distance from the substrate 3 are set so that the radicals selectively act on the convex portions of the insulating film on the substrate 3 to flatten the insulating film. .

In this embodiment, one electrode of the plasma generating means is the disc type rotating body 11. In the case of this structure, a plurality of the substrates 3 and the conductive blocks 12 arranged to face the disk-shaped rotating body 11 can be alternately arranged in the circumferential direction of rotation of the disk-shaped rotating body 11. Therefore, a large number of substrates 3 can be collectively processed, and the planarization process can be performed more efficiently. In the present embodiment, in the electrode 40e, either the disc type rotating body 11 or the conductive block 12 may be used as the ground electrode, but if the disc type rotating body 11 is used as the ground electrode, high frequency power is supplied to the rotating portion. There is an advantage that the device configuration can be simplified because it is not necessary to supply.

(Embodiment 6) FIG. 7 schematically shows the structure of a plasma processing apparatus 600 for a flattening process in a sixth embodiment. In the present embodiment, the stage 4 also serves as one electrode of the plasma generating means instead of the conductive block 12 without separately providing the conductive block 12 in the fifth embodiment. The other structure is the same as that of the plasma processing apparatus 500 according to the fifth embodiment, and common constituent elements are designated by the same reference numerals and detailed description thereof will be omitted.

As shown in FIG. 7, in the stage 4, the portion 4a for holding the substrate 3 projects toward the disc-shaped rotating body 11, and the distance from the disc-shaped rotating body 11 becomes small in this portion. There is. Therefore, in this configuration, when a high-frequency electric field is applied between the stage 4 and the disc rotating body 11, the portion 4a of the stage 4 that holds the substrate 3 is held.
Then, the plasma 6 is generated between the disk-shaped rotating body 11 and the plasma 6, and the plasma 6 exists near the substrate 3. Therefore, in this embodiment, the number of radicals reaching the substrate surface is large, and efficient planarization processing can be performed. As the disk rotating body 11 rotates, a gas flow in the direction parallel to the substrate surface exists near the surface of the substrate 3, and the radicals are also transferred in the direction parallel to the substrate surface by this gas flow. . Further, in FIG. 7, only one protrusion 4 a holding the substrate 3 is shown, but a plurality of protrusions 4 a are provided.
Is provided, it is possible to process a plurality of substrates 3 at a time as in the fifth embodiment.

Further, according to the structure of this embodiment, the number of constituent elements of the plasma processing apparatus can be reduced as compared with the structure of the fifth embodiment.

Incidentally, without providing the projecting portion 4a on the stage 4,
The configuration may be such that plasma is generated in the entire area between the disk-shaped rotating body 11 and the stage 4. Also in this case, as in the above case, a large number of substrates 3 are placed on the stage 4.
Can be arranged.

(Embodiment 7) FIG. 8 shows the configuration of a plasma processing apparatus 700 for a flattening process in a seventh embodiment.
As shown in FIG. 8, in the plasma processing apparatus 700, the disk 13 is arranged so as to face the substrate 3. The stage 4 holding the substrate 3 has a function of rotating about an axis 50 perpendicular to the substrate surface, and is provided with a region 4b having a small distance from the disk 13 in a region other than the substrate position. The disk 13 and the stage 4 form an electrode in the plasma generating means.

Then, a high-density gas atmosphere is formed between the electrodes (disk 13 and stage 4) by means of gas supply means and gas exhaust means (both not shown), and
By applying a high frequency electric field from the high frequency power source 41 between the electrodes, plasma 6 is generated between the disk 13 and the region 4b of the stage 4. Then, as the stage 4 rotates, a gas flow is formed on the substrate 3 in a direction along the substrate surface. That is, when viewed from the coordinate system fixed to the substrate 3, the radicals are transferred from the plasma generation region to the vicinity of the substrate surface by the flow of the gas, and the transfer direction is along the substrate surface. That is, the stage 4 is also a transfer unit that transfers radicals generated between the electrodes.

The rotation speed of the stage 4 and the gap between the disk 13 and the substrate 3 are appropriately set so that the radicals act on the convex portions of the insulation film on the substrate 3, thereby flattening the insulation film.

In this embodiment, one electrode of the plasma generating means is a disk type (disk 13). Therefore, in the case of this structure, since a plurality of substrates 3 can be arranged on the stage 4 along the circumferential direction of the disk 13, a large number of substrates 3 can be collectively processed. More preferably, the substrates 3 and the regions 4b are arranged alternately.

Further, in this embodiment, the disk 13 is fixed, and the rotating stage 4 serves as a transfer means for transferring radicals to the substrate 3. Alternatively, further, stage 4
Not only that, the disk 13 may be rotated about the axis 50 perpendicular to the substrate surface in the direction opposite to the rotation direction of the stage 4. By imparting the rotary motion to the disk 13 in this manner, the relative gas flow velocity in the direction along the substrate surface can be increased with respect to the substrate 3. This makes it possible to further improve the flattening ability by the rotational movement of the disk 13 and the stage 4.

(Embodiment 8) FIG. 9 shows a structure of a plasma processing apparatus 710 for a flattening process in an eighth embodiment.
In this embodiment, the plasma processing apparatus 700 of the seventh embodiment is used.
In the stage 4, the region 4b ′ in which the space between the disk 13 and the stage 4 is narrow includes the substrate holding region. That is, the substrate 3 is arranged in the region 4b '.

The other structure is the same as that of the plasma processing apparatus 700 according to the seventh embodiment, and the common constituent elements are designated by the same reference numerals and the detailed description thereof will be omitted.

In this structure, the plasma 6 exists in the space area facing the substrate 3. Therefore, in this embodiment, the number of radicals reaching the substrate surface is large, and efficient planarization processing can be performed. Moreover, as in Examples 5 to 7,
A region 4b 'for holding the substrate 3 and having a short distance from the disc 13
A plurality of can be provided on the stage 4. In this case, it is possible to process a plurality of substrates 3 at once.
It should be noted that the disc 13 is not provided on the stage 4 without the protrusion 4 b ′.
The plasma may be generated in the entire area between the stage 4 and the stage 4.

(Embodiment 9) FIG. 10 schematically shows the structure of a plasma processing apparatus 800 for a flattening process according to a ninth embodiment. In the plasma processing apparatus 800, the conductive block 14 is arranged so as to face the substrate 3. Also,
The stage 4 holding the substrate 3 has a function of rotating about an axis 50 perpendicular to the substrate surface. The conductive block 14 has a taper shape along the radial direction of the rotational movement of the stage 4. In this tapered shape, the distance between the conductive block 14 and the stage 4 is small in the central portion of the stage 4 (near the rotation axis 50), and the distance gradually increases toward the outer peripheral portion of the stage 4. Then, the stage 4 and the conductive block 14 form an electrode in the plasma generating means. The stage 4 also has a function of holding a plurality of substrates 3.

Then, a high-density gas atmosphere is formed between the electrodes (conductive block 14 and stage 4) by a gas supply means and a gas exhaust means (both not shown), and a high-frequency electric field is applied between the high-frequency power source 41 and the electrodes. By doing so, plasma 6 is generated between the electrodes. Then, by rotating the stage 4, the plasma 6 can be made to act on the entire surfaces of the plurality of substrates 3.

Planarization is performed with the space between the conductive block 14 and the substrate 3 maintained so that the plasma 6 acts on the convex portions of the insulating film on the substrate 3. At this time, the relative speed between the conductive block 14 and the substrate 3 is larger toward the outer periphery of the rotary motion of the stage 4.

The plasma processing apparatus 800 according to the present embodiment is constructed so that the distance between the electrodes increases as the outer circumference of the rotational movement of the stage 4 is approached. Therefore, on the outer peripheral side, the peripheral speed is high but the distance between the electrodes is large, and on the inner peripheral side, the peripheral speed is low but the distance between the electrodes is small. The faster the peripheral speed is or the smaller the distance between the electrodes is, the more radicals act on the convex portions of the insulating film on the substrate 3. Therefore, by tapering the conductive block 14, it becomes possible to make the number of radicals acting on the convex portion of the insulating film on the substrate surface uniform along the radial direction of the rotational movement of the stage 14.

Although the conductive block is tapered in this embodiment, at least one of the electrodes has a large relative velocity so that the distance between the electrodes is larger than that of the portion with a small relative velocity. It is sufficient that the electrodes have a tapered shape. Therefore, the stage 4 may be tapered instead of the conductive block 14. Further, the conductive block 14 may be a rotating body having a function of rotating about an axis 50 perpendicular to the substrate surface.

Further, in the present embodiment, when the conductive block 14 is a tapered cylindrical rotary member having a function of rotating about the axis 51 parallel to the substrate surface, the conductive block 14 is parallel to the substrate surface with respect to the substrate 3. It is possible to further increase the flow of various gases and improve the flattening ability.

The amount of change in the distance between the electrodes (that is, the distance between the stage 4 and the conductive block 14), that is, the taper angle of the electrode is determined by the rotational speed of the stage 4 and the conductive block 14.
Set according to the shape (and rotation speed) of. For example,
First, using an electrode without a taper, measure the machining speed distribution in the rotational motion radial direction using the distance between the electrodes as a parameter, and refer to the measurement result to make the machining speed constant along the radial direction. The distance between the electrodes may be set to.

(Embodiment 10) FIG. 11 schematically shows the structure of a plasma processing apparatus 810 for planarization process according to a tenth embodiment. In the plasma processing apparatus 810, a cylindrical rotating body 5 having a function of rotating about an axis 50 parallel to the substrate surface is arranged so as to face the substrate 3, and the stage 4 for holding the substrate 3 and the cylindrical type rotating body 5 are arranged. The rotating body 5 constitutes an electrode in the plasma generating means. Further, the gas supply port 15 is provided so that the gas flows in the rotation direction of the cylindrical rotary member 5.
The gas exhaust port 16 is arranged so as to sandwich the cylindrical rotating body 5 and to form a gas flow parallel to the substrate surface.

Then, from the gas supply means and the gas exhaust means (both not shown), a high density gas is introduced between the electrodes (stage 4 and cylindrical rotor 5) through the gas supply port 15 and the gas exhaust port 16. A plasma 6 is generated by applying a high frequency electric field between the electrodes. And
Due to the supply and exhaust of the gas and the rotation of the cylindrical rotary member 5, the gas flows near the substrate surface in the direction along the substrate surface. Due to this gas flow, radicals are transferred in the direction along the substrate surface in the vicinity of the substrate surface.

As described above, in the plasma processing apparatus 810, the cylindrical rotating body 5 is sandwiched between the plasma generating regions.
Gas supply port 15 and gas exhaust port 16 which are arranged so that gas flows in the direction of rotation of
And form a cooperative transfer means for transferring radicals generated between the electrodes.

Then, so that the plasma 6 selectively acts on the convex portions of the insulating film on the substrate 3, the arrangement and rotation speed of the cylindrical rotor 5, the gas supply port 15 and the gas exhaust port 16 or the gas flow rate. Controlling the flow rate, etc., the cylindrical rotor 5 and the substrate 3
The insulating film is flattened by performing the plasma treatment while keeping the distance between and at a desired value.

Further, in this state, the stage 4 holds the substrate 3 and moves in a direction parallel to the substrate surface as indicated by an arrow 8, whereby the entire surface of the substrate 3 can be flattened. On the contrary, the entire surface of the substrate 3 can be flattened by scanning the entire cylindrical rotor 5, the gas supply port 15, and the gas exhaust rod 16 in the direction parallel to the substrate surface with respect to the substrate surface.

In this embodiment, the cylindrical body which is one of the electrodes of the plasma generating means is the rotating body.
Even if the electrode is not a rotating body, the gas supply port and the gas exhaust port may be arranged so that the gas flow is in the direction along the substrate surface with the plasma generation region interposed therebetween. In this case, the function of rotating the electrode at a high speed is not required, so that the number of components of the plasma processing apparatus can be reduced.
Alternatively, only one of the gas supply port and the gas exhaust port may be arranged.

Further, according to this embodiment, the gas supply port 15
Since the gas exhaust port 16 and the gas exhaust port 16 are arranged in the immediate vicinity of the substrate surface, the high-density gas can be concentratedly supplied near the substrate surface. At the same time, the gas in the vicinity of the substrate surface can be exhausted in a concentrated manner. Therefore, according to the present embodiment, the invention can be applied to an atmosphere open system without using the reaction vessel.

Next, in the following embodiments, a plasma processing apparatus for a flattening process for generating a non-uniform high frequency electric field will be described. In the following examples, the plasma processing apparatus for a flattening process of the present invention includes a stage for holding a substrate, a gas supply unit and a gas exhaust unit for supplying and exhausting a high density gas, and a high frequency power source facing each other. And a plasma generating means including a pair of electrodes arranged, at least one of the electrodes having a shape for generating a nonuniform electric field.

(Embodiment 11) FIG. 12 schematically shows the structure of a plasma processing apparatus 900 for flattening process in this embodiment. The plasma processing apparatus 900 includes an electrode (hereinafter referred to as a processing electrode 17a) to which high frequency power is supplied and a stage 4 that holds the substrate 3. The processing electrode 17 a is arranged so as to face the substrate 3, and its shape has a sharp shape toward the substrate 3. The processing electrode 17a constitutes one electrode of the plasma generating means in the plasma processing apparatus 900. The stage 4 is grounded and constitutes the other electrode of the plasma generating means.

Then, a high-density gas atmosphere is formed between the electrodes by a gas supply means and a gas exhaust means (both not shown), and a high-frequency electric field is applied from the high-frequency power source 41 to the electrodes so that plasma is generated between the electrodes. It occurs locally near the sharpened part. The plasma processing apparatus 90
When 0 is placed in a reaction container (not shown), a high-density gas atmosphere may be formed in the entire reaction container by the gas supply unit and the gas exhaust unit.

Arrangement of the processing electrode 17a and the processing electrode 1 so that the radicals in the plasma localized in the sharpened portion selectively act on the convex portions of the insulating film on the substrate 3.
By appropriately setting the distance between 7a and the substrate 3,
The insulating film is flattened.

In this state, the arrow 8
By scanning the processing electrode 17a in the direction parallel to the substrate surface as described above, the entire surface of the substrate 3 can be flattened. Conversely, even if the stage 4 holds the substrate 3 and moves in a direction parallel to the substrate surface, the entire surface of the substrate 3 can be flattened. Further, even if at least one of the stage 4 and the processing electrode 17a is rotated about an axis perpendicular to the substrate surface, the entire surface of the substrate 3 can be flattened similarly.

Further, in the present embodiment, the processing electrode 1
7a has a sharp shape. Therefore, for example, when the processing electrode 17a scans in the direction of the arrow 8 in the direction parallel to the substrate surface, the surrounding gas is entrained by the shape in which the space is narrowed toward the electrode tip portion, and the sharpened portion (plasma generation region) is reached. A high-density gas can be supplied effectively. Further, even when the gas supplied to the tip portion of the electrode is exhausted, the reaction product can be effectively exhausted from the vicinity of the substrate surface because the space is opened. This effect can be similarly obtained even when the stage 4 holds the substrate 3 and moves in a direction parallel to the substrate surface.

Further, as in the case of the above-mentioned seventh to ninth embodiments, the stage 4 is provided with a function of rotating about the axis perpendicular to the substrate surface, and a plurality of stages are provided in the circumferential direction of the rotary motion of the stage 4. By adding the function of holding the substrate 3, the stage 4 rotates to allow the plurality of substrates 3 to rotate.
It is also possible to collectively flatten. Of course,
Instead of rotating the stage 4, the processing electrode 17a
May be rotated about an axis perpendicular to the surface of the substrate so as to cover the entire area of the plurality of opposed substrates 3.

Example 12 FIGS. 13A and 13B
FIG. 14B schematically shows the configuration of the plasma processing apparatus 910 for the flattening process in the twelfth embodiment. In the plasma processing apparatus 910, as shown in FIG. 13A, the processing electrode 17b is arranged to face the substrate 3,
Moreover, it has a cylindrical shape having a function of rotating around an axis parallel to the substrate surface. Further, as shown in FIG. 13B, a plurality of minute projections 53 are arranged on the cylindrical surface of the processing electrode 17b. The processing electrode 17b constitutes one electrode of plasma generation means in the plasma processing apparatus 910. The other electrode of the plasma generating means is grounded by the stage 4 holding the substrate 3.

A high-density gas atmosphere is formed between the electrodes by a gas supply means and a gas exhaust means (both not shown), and a high-frequency electric field is applied from the high-frequency power source 41 to the electrodes, so that the plasma 6 acts as an electrode. It occurs locally in the vicinity of the microprojection portion 53.

The insulating film is flattened by maintaining the distance between the processing electrode 17b and the substrate 3 so that the localized plasma 6 selectively acts on the convex portion of the insulating film on the substrate 3. I do.

Further, in this state, by scanning the substrate surface with the processing electrode 17b in the direction parallel to the substrate surface as indicated by the arrow 8, the entire surface of the substrate 3 can be flattened. Conversely, even when the stage 4 holds the substrate 3 and moves in a direction parallel to the substrate surface, the entire surface of the substrate 3 can be planarized.

In the plasma processing apparatus 910 according to the present embodiment, the effect of the gas flow parallel to the substrate surface, which is formed by rotating the processing electrode 17b (the same effect as the third embodiment (FIG. 4)), and , The effect of localization of the plasma 6 due to the non-uniform electric field generated by the processing electrode 17b,
Contributes to flattening. Therefore, the plasma processing apparatus 910
Has a configuration excellent in flattening ability.

(Embodiment 13) FIG. 14 schematically shows the structure of a plasma processing apparatus 920 for planarization process according to a 13th embodiment. In the plasma processing apparatus 920,
The processing electrode 17c is arranged so as to face the substrate 3 and has a disk shape having a function of rotating around an axis perpendicular to the substrate surface. Of the disk of the processing electrode 17c,
A plurality of minute protrusions (not shown) are arranged on the surface facing the substrate 3. The processing electrode 17c constitutes one electrode of plasma generation means in the plasma processing apparatus 920. The other grounded electrode in the plasma generating means is the stage 4 that holds the substrate 3.

Then, a high-density gas atmosphere is formed between the electrodes by a gas supply means and a gas exhaust means (both not shown), and a high-frequency electric field is applied from the high-frequency power source 41 to the electrodes, so that the plasma 6 is discharged to the electrodes. It occurs in the vicinity of the microprojection site.

The plasma etching process is performed while maintaining the distance between the processing electrode 17c and the substrate 3 so that the localized plasma 6 selectively acts on the convex portion of the insulating film on the substrate 3. The film is flattened.

In the plasma processing apparatus 920 according to the present embodiment, the radical transport effect in the direction parallel to the substrate surface by the gas flow formed by the rotation of the processing electrode 17c (of the sixth embodiment (FIG. 7)). Effect) and the localization effect of the plasma 6 due to the non-uniform electric field generated by the processing electrode 17c contribute to the flattening, so that the plasma processing apparatus 920 has an apparatus configuration excellent in flattening ability. ing. Furthermore, for the rotation interlocking of the processing electrode 17c,
By arranging the plurality of substrates 3 on the stage 4 along the circumferential direction, it is possible to collectively process the plurality of substrates 3.

(Embodiment 14) FIG. 15 schematically shows the structure of a plasma processing apparatus 930 for a flattening process according to a fourteenth embodiment. In the plasma processing apparatus 930,
The processing electrode 17d is arranged parallel to the substrate surface and has a wire shape. The processing electrode 17d constitutes one electrode of plasma generation means in the plasma processing apparatus 930. The other grounded electrode in the plasma generating means is the stage 4 that holds the substrate 3.

A high-density gas atmosphere is formed between the electrodes by a gas supply means and a gas exhaust means (both not shown), and a high-frequency electric field is applied between the high-frequency power source 41 and the electrodes, so that the plasma 6 has a wire shape. It is generated locally near the processing electrode 17d.

The insulating film can be flattened by maintaining the distance between the processing electrode 17d and the substrate 3 so that the plasma 6 selectively acts on the convex portions of the insulating film on the substrate 3. .

In this state, if the processing electrode 17d is scanned on the substrate surface in the direction parallel to the substrate surface, the substrate 3
Flattening over the entire surface is possible. Further, if the processing electrode 17d is composed of a plurality of wire-shaped electrodes arranged in parallel so as to face the substrate surface, the distance for scanning the processing electrode 17d is reduced, and the planarization process can be performed in a short time. You can do it. Contrary to the above, the stage 4 is the substrate 3
Even if the substrate surface 3 is moved in the direction parallel to the substrate surface while holding
The entire surface can be flattened.

By adopting a wire shape for the processing electrode 17d as in this embodiment, an electrode for generating a non-uniform electric field can be easily manufactured and an inexpensive plasma processing apparatus can be realized.

(Embodiment 15) FIG. 16 schematically shows the structure of a plasma processing apparatus 940 for a planarization process according to a 15th embodiment. In the plasma processing apparatus 940, the electrode 17e and the electrode 18 are arranged above the substrate surface so as to face each other in a direction parallel to the substrate surface. And
Each of the electrode 17e and the electrode 18 has a sharp shape toward the other electrode. In this embodiment, the electrode 17e and the electrode 18 form a pair of electrodes of the plasma generating means.

A high-density gas atmosphere is formed between the pair of electrodes by a gas supply means and a gas exhaust means (both not shown), and a high-frequency electric field is applied between the high-frequency power source 41 and the electrodes to generate plasma 6. , Occurs locally near the sharpened portions of the electrodes 17e and the electrodes 18.

Then, the arrangement and relative distances of the electrodes 17e and 18 are appropriately set so that the radicals selectively act on the convex portions of the insulating film on the substrate, and the distance between the pair of electrodes and the substrate 3 is set. By keeping it, the insulating film is flattened.

In this state, if the pair of electrodes are scanned in the direction parallel to the substrate surface as indicated by the arrow 8 while keeping their relative positions, the entire surface of the substrate 3 can be flattened. . Further, even if the stage 4 moves, it can be flattened similarly.

According to the structure of the plasma processing apparatus 940 of this embodiment, the direction of the electric field is mainly the direction along the substrate surface (component parallel to the substrate surface). Therefore, since the charged particles moving along the electric field have the main component in the direction along the substrate surface, the radicals generated by the collision with the charged particles also have a large velocity component moving in the direction along the substrate surface. As a result, radicals have the effect of selectively acting on the convex and concave portions of the substrate surface, and the planarization ability can be improved for treatment.

(Embodiment 16) FIG. 17 schematically shows a plasma processing apparatus 950 for flattening process according to a sixteenth embodiment. The plasma processing apparatus 950 has a stage 4 for holding the substrate 3, a plasma generation means having a high frequency power supply 41 and a pair of electrodes 19 and 20 arranged to face each other, and a high-density gas concentrated in the vicinity of the substrate surface. And a gas exhausting means 22 for exhausting the atmosphere and reaction products near the substrate surface in a concentrated manner. Plasma is generated in the atmosphere to flatten the substrate 3.

As shown in FIG. 17, in the plasma processing apparatus 950 for the flattening process in this embodiment, the electrode 19 and the electrode 20 facing the electrode 19 are arranged above the substrate surface. Further, a gas supply port 21 for intensively supplying a high-density gas near the substrate surface and a gas exhaust port 22 for exhausting the atmosphere and reaction products intensively from near the substrate surface form a pair. It is located immediately above the electrodes 19 and 20.

Then, in a system open to the atmosphere, a high-density gas is introduced between the electrodes 19 and 20 from the gas supply means and the gas exhaust means (both not shown) through the gas supply port 21 and the gas exhaust port 22. Then, by applying a high frequency electric field from the high frequency power source 41 between the electrodes 19 and 20, plasma 6 is generated.

Then, the pair of electrodes 19 and 2 are arranged so that the plasma 6 selectively acts on the convex portions of the insulating film on the substrate 3.
By setting the arrangement of 0, the relative distance, etc., the pair of electrodes 19
The insulating film is flattened by performing a plasma etching process while keeping the distance between the substrate 20 and the substrate 3.

Further, in this state, if the pair of electrodes 19 and 20 are scanned in the direction parallel to the substrate surface while keeping the relative positions, it is possible to flatten the entire surface of the substrate 3. is there. Conversely, the same applies when the stage is scanned.

In this embodiment, the gas supply port 21 and the gas exhaust port 2 are provided in the immediate vicinity of the pair of electrodes 19 and 20.
2 are arranged. As a result, a high-density gas containing a rare gas for stably generating the plasma 6 can be sufficiently supplied between the electrodes 19 and 20, and an atmosphere which is not necessary for the stable generation of the plasma 6 can be obtained. The reaction products generated near the substrate surface can be exhausted intensively. Therefore, the plasma 6 can be stably maintained even in the atmosphere, and the diffusion of reaction products into the atmosphere can be suppressed. Further, since the plasma processing is performed in the atmosphere, a vacuum device for maintaining a vacuum is not necessary, and the substrate 3 can be easily attached and moved, and the operation of the plasma processing device can be simplified.

(Embodiment 17) This embodiment will be described by using a more specific application example to a semiconductor element. When the semiconductor element is a DRAM, the cause of forming the step shape in the insulating film is the memory cell formed under the insulating film. Figure 1
8 schematically shows a cross section of the semiconductor element substrate 960 in the DRAM manufacturing process. The semiconductor device substrate 960 is roughly divided into a memory cell region in which the memory cells 23 are formed on the substrate 24 and a peripheral circuit region. Therefore, the surface of the insulating film 25 has a shape in which the memory cell region is entirely high and the peripheral circuit region is generally low, and undulations are formed, and the unevenness 23 a by the individual memory cells 23 is provided thereon. . When flattening such a wavy insulating film,
It is required to selectively flatten only the memory cell region and not process the peripheral circuit region at all.

FIG. 19 schematically shows the structure of the plasma processing apparatus 970 for the flattening process according to this embodiment. The plasma processing apparatus 970 includes a stage 4 that holds the substrate 3.
A gas supply means and a gas exhaust means (not shown) for supplying and exhausting a high density gas, and a plasma generation means having a high frequency power supply 41 and a pair of electrodes 26 and 4 arranged to face each other. I have it. Stage 4 is
Of the pair of electrodes, it also serves as a ground electrode. One of the pair of electrodes has a concavo-convex shape that matches the region on the substrate 3 where the planarization is performed and the region where the planarization is not performed.

As shown in FIG. 19, in the plasma processing apparatus 970 for the flattening process, the disk body 26 is arranged so as to face the substrate 3. In the disk body 26, a flattening region, that is, a region opposite to the memory cell region is flattened in a convex shape (a convex region 26a) in accordance with a flattening region and a non-flattening region of the substrate 3. Area that does not
It has an uneven shape in which a region facing the peripheral circuit region is formed in a concave shape. Further, the stage 4 holding the substrate 3 and the disk body 26 form a pair of electrodes in the plasma generating means.

Then, a high-density gas atmosphere is formed between the electrodes (the disk body 26 and the stage 4) by means of the gas supply means and the gas exhaust means (both not shown), and a high-frequency electric field from the high-frequency power source 41 is applied between the electrodes. Apply. As a result, the plasma 6 can be selectively generated only in the space between the disc body 26 and the stage 4 and facing the convex region 26 a of the disc body 26. This is because the electric field strength increases in the region where the distance between the electrodes is narrow.

By properly maintaining the distance between the disk body 26 and the substrate 3, the radicals are selectively made to act only on the desired region to be flattened.

As a result, according to the structure of the plasma processing apparatus 970 of this embodiment, radicals can be made to reach the substrate region (for example, the memory cell region) to be planarized in a concentrated manner, so that the undulation of the insulating film is caused. The ingredients can be reduced.

(Embodiment 18) FIG. 20 schematically shows a structure of a plasma processing apparatus 980 for a flattening process according to an 18th embodiment. In the plasma processing apparatus 980, a cylindrical rotating body 5 that faces the substrate 3 and has a function of rotating about an axis parallel to the substrate surface is arranged. Then, the stage 4 that holds the substrate 3 has a convex (convex portion) region that should be flattened, that is, a region corresponding to the memory cell region, in accordance with a region that should be flattened and a region that is not flattened. The region 4c) has a concavo-convex shape in which a region that is not flattened is formed in a concave shape. Further, the stage 4 holding the substrate 3 and the cylindrical rotating body 5 constitute a pair of electrodes of the plasma generating means. Therefore, when the stage 4 is scanned parallel to the substrate surface (scanning in the direction of arrow 8 in the figure),
The distance between the electrodes of the pair of electrodes is small when the cylindrical rotating body 5 faces the convex region 4c, and the distance between the electrodes becomes large when the cylindrical rotating body 5 faces the other concave portions.

A gas supply means and a gas exhaust means (both not shown) form a high-density gas atmosphere between the electrodes (cylindrical rotor 5 and stage 4), and a high-frequency electric field between the high-frequency power source 41 and the electrodes. Is applied, and
The stage 4 is scanned in the direction of arrow 8. As a result, the plasma 6 can be selectively generated only in the space between the cylindrical rotating body 5 and the substrate 3 and facing the convex region 4c of the stage 4. As a result,
Radicals intensively reach the substrate region to be planarized. As a result, for example, when the semiconductor element substrate 960 is flattened as in the case of the seventeenth embodiment, it is possible to reduce the waviness component between the memory cell region and the peripheral circuit region. In addition, in the case where the cylindrical rotating body 5 faces the convex portion region 4c by the scanning of the stage 4, the third embodiment
Similarly to (FIG. 4), the surface of the substrate 3 facing this can be flattened by the rotational movement of the cylindrical rotating body 5. For example, the unevenness 23a of the insulating film on the memory cell region of FIG. 18 can be flattened.

The cylindrical rotor 5 is so arranged that the radicals selectively act on the region of the substrate 3 where the insulating film should be flattened.
The insulating film is flattened by appropriately setting the arrangement and rotation speed of the above and the distance between the cylindrical rotating body 5 and the substrate 3.

Contrary to the above, even if the cylindrical rotary member 5 is scanned in the direction parallel to the substrate surface, it is possible to flatten the entire surface of the substrate 3 in the same manner as above.

In the configuration of the plasma processing apparatus 980 according to this embodiment, since the electrode having the uneven shape is the stage 4 for holding the substrate 3, the cylindrical rotating body 5 which is the other electrode facing the stage 4 is used. Even if the rotating motion is performed, the generated plasma region is limited to the space facing the region on the substrate 3 to be planarized. For this reason, radicals mainly reach the substrate area to be flattened in a concentrated manner, and the undulation component can be reduced, and further, due to the rotational movement of the cylindrical rotary member 5, a gas flow parallel to the substrate surface is generated. It becomes possible to form a plasma etching process having a higher planarization ability, that is, capable of global planarization.

When the stage 4 holding the substrate 3 is an electrode having an uneven shape, either the stage 4 or the other electrode facing the stage, or both of them move in the direction along the substrate surface. As a result, even if a gas flow parallel to the surface of the substrate is formed, the plasma 6 can be generated only in the space facing the flattening region on the substrate, and the above effect can be obtained. further,
When the other electrode facing the stage 4 is a disk-shaped rotating body having a function of rotating about an axis perpendicular to the substrate surface, a plurality of electrodes are provided as in the fifth embodiment (FIG. 6B). It is possible to collectively process a plurality of substrates 3 by arranging the substrates 3 on the stage 4 along the circumferential direction of rotation of the disk-shaped rotating body.

[0168]

As described above, the semiconductor device according to the present invention
According to the manufacturing method of
Capable semiconductor element at low cost.

[Brief description of drawings]

FIG. 1 is a diagram illustrating performing planarization by utilizing a localized plasma region.

FIG. 2 is a diagram illustrating a configuration of a plasma processing apparatus in which a radical transfer device is a cylindrical rotating body in the present invention.

FIG. 3A is a diagram illustrating a configuration of a plasma processing apparatus in which a radical transfer device is a cylindrical rotating body and gas is supplied from the inside of the cylindrical rotating body in the present invention;
(B) is an apparatus perspective view of the plasma processing apparatus shown in (a).

FIG. 4 is a diagram illustrating a configuration of a plasma treatment device in which a radical transfer device is a cylindrical rotating body and plasma is generated in a region facing a substrate in the present invention.

FIG. 5A is a diagram illustrating a configuration of a plasma processing apparatus in which a radical transfer device is a cylindrical rotating body and radicals are supplied from the inside of the cylindrical rotating body in the present invention; 8A is a device perspective view of the plasma processing device shown in FIG.

FIG. 6 (a) is a diagram for explaining the configuration of a plasma processing apparatus in which the radical transfer device is a disk-shaped rotating body in the present invention, and FIG. 6 (b) is a diagram illustrating the plasma processing apparatus shown in (a). It is the figure seen from the upper part.

FIG. 7 is a diagram illustrating a configuration of a plasma treatment device in which a radical transfer device is a disk-shaped rotating body and plasma is generated in a region facing a substrate in the present invention.

FIG. 8 is a diagram illustrating a configuration of a plasma processing apparatus in which a radical transfer device is a stage for holding a substrate in the present invention.

FIG. 9 is a diagram illustrating a configuration of a plasma treatment device in which a radical transfer device is a stage for holding a substrate and plasma is generated in a region facing the substrate in the present invention.

FIG. 10 is a diagram illustrating a configuration of a plasma processing apparatus in which one electrode has a function of rotating in a plane parallel to a substrate surface and the distance between the electrodes increases as the outer peripheral surface increases in the present invention. .

FIG. 11 is a diagram illustrating a configuration of a plasma processing apparatus in which a radical transfer device is a cylindrical rotor, and a gas supply port and a gas exhaust port in the present invention.

FIG. 12 is a diagram illustrating a configuration of a plasma processing apparatus in which an electrode for generating a nonuniform electric field has a sharp shape toward a substrate in the present invention.

FIG. 13 (a) shows a configuration of a plasma processing apparatus according to the present invention, in which an electrode for generating a non-uniform electric field is a cylindrical rotating body and fine protrusions are arranged on the cylindrical surface. It is a figure explaining, and (b) is a figure explaining in detail the electrode surface vicinity in the plasma processing apparatus shown to (a).

FIG. 14 is a diagram illustrating a configuration of a plasma processing apparatus according to the present invention in which an electrode for generating a non-uniform electric field has a disk shape and fine projections are arranged on the surface of the disk.

FIG. 15 is a diagram illustrating a configuration of a plasma processing apparatus in which an electrode for generating a nonuniform electric field has a wire shape in the present invention.

FIG. 16 illustrates a structure of a plasma processing apparatus in which a pair of electrodes for generating a non-uniform electric field are arranged so as to face a substrate, and each electrode has a sharp shape toward the other electrode in the present invention. FIG.

FIG. 17 is a diagram illustrating the configuration of a plasma processing apparatus that has an introducing device for introducing a high-density gas into the vicinity of the substrate surface and a removing device for removing particles from the vicinity of the substrate surface in the present invention, and that can be processed in the atmosphere. It is a figure.

FIG. 18 is a diagram illustrating that undulations are formed in the insulating film of the semiconductor element substrate in the DRAM manufacturing process.

FIG. 19 is a diagram illustrating a configuration of a plasma processing apparatus in which one electrode has a concavo-convex shape in accordance with a substrate region in which one electrode is planarized and a substrate region in which one electrode is not planarized.

FIG. 20. In the present invention, an electrode having a concavo-convex shape corresponding to a substrate region to be flattened and a substrate region not to be flattened is a stage for holding a substrate, and the other electrode is a cylindrical rotating body. It is a figure explaining the structure of a certain plasma processing apparatus.

FIG. 21 is a diagram illustrating that planarization is performed by resist etch back.

[Explanation of symbols]

1 Localized plasma region 2 Flattened workpiece 3 substrates 4 stages 5 Cylindrical rotating body 6 plasma 7 Conductive plate 9 gas introduction path 10 Internal cylinder 11 Disk type rotating body 12 Conductive block 15 Gas supply 16 gas exhaust port 17a to 17e Processing electrode 23 memory cells 25 insulating film

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isamu Mori ▲ Kura, 8-16-19 Private City, Katano City, Osaka Prefecture (56) References JP-A-8-222548 (JP, A) JP-A-9- 31670 (JP, A) JP 7-74146 (JP, A) JP 6-85059 (JP, A) JP 8-323699 (JP, A) JP 6-251894 (JP, A) JP-A-7-106311 (JP, A) JP-A-11-176808 (JP, A) Actual Kaihei 6-79143 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/3065 H01L 21/3205

Claims (21)

(57) [Claims] 1. A stage for holding a substrate, a gas supply means for supplying a high density gas, a gas exhaust means for exhausting the high density gas, a high frequency power source, and a pair of gas supply means arranged to face each other. And a transfer means for transferring radicals of the generated plasma that chemically react with the surface of the substrate in a direction along the surface of the substrate. Is a cylindrical rotating body that rotates about an axis parallel to, the cylindrical rotating body also serves as one electrode of the plasma generating means, and the other electrode of the plasma generating means is the one electrode. Are arranged separately from the stage so that the plasma is generated at a position distant from the substrate, and the radicals in the plasma generated by the pair of electrodes are A plasma processing apparatus, which is transferred to the substrate on the stage by rotation of a rotating body, and further, the radicals are transferred in a direction along the surface of the substrate by rotation of the cylindrical rotating body. 2. A plasma processing apparatus for a flattening process used in a step of flattening an insulating film formed on a substrate, which comprises a stage for holding the substrate and a high-density gas supply. Plasma generating means having a gas supply means, a gas exhausting means for exhausting the high-density gas, a high-frequency power source, and a pair of electrodes arranged to face each other, and among the generated plasma, the substrate surface Transporting means for transporting radicals that chemically react with the substrate in a direction along the surface of the substrate, the transporting means being a cylindrical rotating body that rotates about an axis parallel to the surface of the substrate. The mold rotating body also serves as one electrode of the plasma generating means, and the other electrode of the plasma generating means generates the plasma at a position apart from the substrate by the one electrode. The Stage are arranged separately from the,
The radicals in the plasma generated by the pair of electrodes are transferred to the substrate on the stage by the rotation of the cylindrical rotor, and the radicals are further rotated by the rotation of the cylindrical rotor. A plasma processing apparatus for a flattening step, which is transferred in a direction along the surface of the substrate. 3. A stage for holding a substrate, a gas supply means for supplying a high density gas, a gas exhaust means for exhausting the high density gas, a high frequency power supply, and a pair of gas supply means arranged to face each other. And a transfer means for transferring radicals of the generated plasma that chemically react with the surface of the substrate in a direction along the surface of the substrate. A cylindrical rotary member that rotates about an axis parallel to the hollow cylindrical member having a large number of holes in its cylindrical surface, and the cylindrical rotary member has one electrode of the plasma generating means. Also, the other electrode of the plasma generating means is arranged outside the cylindrical rotary member so as to face the cylindrical surface thereof, and the high-density gas is supplied from the inside of the cylindrical rotary member. To the outside through the hole in the cylindrical surface The plasma is generated between the pair of electrodes in the region where the gas is introduced outside the cylindrical rotor, and the plasma is generated in the direction along the substrate surface by the rotation of the cylindrical rotor. A plasma processing apparatus in which the radicals are transferred. 4. A plasma processing apparatus for a flattening process used in a step of flattening an insulating film formed on a substrate, which comprises a stage for holding the substrate and a high-density gas supply. Plasma generating means having a gas supply means, a gas exhausting means for exhausting the high-density gas, a high-frequency power source, and a pair of electrodes arranged to face each other, and among the generated plasma, the substrate surface Transporting means for transporting radicals chemically reacting with the substrate surface in a direction along the surface of the substrate, the transporting means being a cylindrical rotating body that rotates about an axis parallel to the surface of the substrate. It has a hollow cylindrical shape having a large number of holes on its surface, and the cylindrical rotor also serves as one electrode of the plasma generating means, and the other electrode of the plasma generating means is the cylindrical rotor. Outside the circle A region where the high-density gas is arranged so as to face the surface, is guided from the inside of the cylindrical rotary member to the outside through the hole of the cylindrical surface, and the gas is introduced outside the cylindrical rotary member. Among these, the plasma is generated between the pair of electrodes, and the radicals in the plasma are transferred in a direction along the surface of the substrate by the rotation of the cylindrical rotating body. . 5. A stage for holding a substrate, a gas supply means for supplying a high density gas, a gas exhaust means for exhausting the high density gas, a high frequency power supply, and a pair of gas supply means arranged to face each other. And a transfer means for transferring radicals of the generated plasma that chemically react with the surface of the substrate in a direction along the surface of the substrate. A cylindrical rotary member that rotates about an axis parallel to the hollow cylindrical member having a large number of holes in its cylindrical surface, and the cylindrical rotary member has one electrode of the plasma generating means. The other electrode of the plasma generating means is also constituted by an internal cylindrical body that is arranged coaxially with the cylindrical rotating body inside the cylindrical rotating body. Depending on the electrode The radicals in the generated plasma are guided to the outside through holes formed in the cylindrical surface of the cylindrical rotating body, and the radicals are transferred in a direction along the substrate surface by the rotation of the cylindrical rotating body. The plasma processing apparatus. 6. A plasma processing apparatus for a flattening step used in a step of flattening an insulating film formed on a substrate, which comprises a stage for holding the substrate and a high-density gas supply. Plasma generating means having a gas supply means, a gas exhausting means for exhausting the high-density gas, a high-frequency power source, and a pair of electrodes arranged to face each other, and among the generated plasma, the substrate surface Transporting means for transporting radicals chemically reacting with the substrate surface in a direction along the surface of the substrate, the transporting means being a cylindrical rotating body that rotates about an axis parallel to the surface of the substrate. It has a hollow cylindrical shape having a large number of holes on its surface, and the cylindrical rotor also serves as one electrode of the plasma generating means, and the other electrode of the plasma generating means is the cylindrical rotor. Inside the cylinder The radicals in the plasma generated by the pair of electrodes of the plasma generating means are formed on the cylindrical surface of the cylindrical rotating body. A plasma processing apparatus for a flattening step, which is guided to the outside through a hole, and the radical is transferred in a direction along the surface of the substrate by the rotation of the cylindrical rotating body. 7. A stage for holding a substrate, a gas supply means for supplying a high density gas, a gas exhaust means for exhausting the high density gas, a high frequency power source, and a pair of gas supply means arranged to face each other. The plasma generation means having an electrode; and the transfer means for transferring radicals of the generated plasma that chemically react with the substrate surface in a direction along the substrate surface. A disk-shaped rotating body which also serves as one electrode of the means and rotates relative to the substrate surface and the other electrode of the plasma generating means about an axis perpendicular to the substrate surface. The other electrode of the stage is arranged separately from the stage so that the plasma is generated by the one electrode at a position distant from the substrate, and the other electrode is generated by the pair of electrodes. The radicals in the plasma are transferred to the substrate on the stage by the relative rotation of the disk-shaped rotating body, and the radicals are further rotated by the relative rotation of the disk-shaped rotating body. Plasma processing apparatus transferred in the direction along the. 8. A plasma processing apparatus for a flattening step used in a step of flattening an insulating film formed on a substrate, which comprises a stage for holding the substrate and a high-density gas supply. Plasma generating means having a gas supply means, a gas exhausting means for exhausting the high-density gas, a high-frequency power source, and a pair of electrodes arranged to face each other, and among the generated plasma, the substrate surface A transfer means for transferring radicals that chemically react with the substrate in a direction along the surface of the substrate, the transfer means also serving as one electrode of the plasma generation means, and centering on an axis perpendicular to the surface of the substrate. A disk-shaped rotating body that rotates relative to the substrate surface and the other electrode of the plasma generating means, wherein the other electrode of the plasma generating means is separated from the substrate by the one electrode. To As the plasma is generated already there is arranged separately from the stage,
The radicals in the plasma generated by the pair of electrodes are transferred to the substrate on the stage by the relative rotation of the disk-shaped rotating body, and further, the radicals are
A plasma processing apparatus for a flattening step, which is transferred in a direction along the substrate surface by relative rotation of the disk-shaped rotating body. 9. The cylindrical rotary member is a ground electrode,
The plasma processing apparatus according to claim 1. 10. The plasma processing apparatus according to claim 7, wherein the disk-shaped rotating body is a ground electrode. 11. A stage for holding a substrate, a gas supply means for supplying a high density gas, a gas exhaust means for exhausting the high density gas, a high frequency power supply, and a pair of gas supply means arranged to face each other. The plasma generation means having an electrode; and the transfer means for transferring radicals of the generated plasma that chemically react with the substrate surface in a direction along the substrate surface. The electrode also serves as one electrode of the means, and is rotated relative to the substrate surface and the other electrode of the plasma generation means about an axis perpendicular to the substrate surface, and by the pair of electrodes of the plasma generation means. The radicals in the generated plasma are transferred in the direction along the surface of the substrate, and at least one of the pair of electrodes is located in a portion where the relative velocity between the pair of electrodes is large. The distance between the pair of electrodes has a tapered shape which is larger than the distance between the pair of electrodes in a portion where the relative speed is small,
Plasma processing equipment. 12. A plasma processing apparatus for a flattening step used in a step of flattening an insulating film formed on a substrate, which comprises a stage for holding the substrate and a high-density gas supply. Plasma generating means having a gas supply means, a gas exhausting means for exhausting the high-density gas, a high-frequency power source, and a pair of electrodes arranged to face each other, and among the generated plasma, the substrate surface A transfer means for transferring radicals that chemically react with the substrate in a direction along the surface of the substrate, the transfer means also serving as one electrode of the plasma generation means, and centering on an axis perpendicular to the surface of the substrate. Rotating relative to the surface of the substrate and the other electrode of the plasma generating means, the radicals in the plasma generated by the pair of electrodes of the plasma generating means are transferred in a direction along the surface of the substrate. At least one of the pair of electrodes has a distance between the pair of electrodes in a portion where the relative speed between the pair of electrodes is high, and a distance between the pair of electrodes in a portion where the relative speed is low. It has a tapered shape that is larger than the distance,
Plasma processing equipment for flattening process. 13. A stage for holding a substrate, a gas supply means for supplying a high density gas, a gas exhaust means for exhausting the high density gas, a high frequency power source, and a pair of gas supply means arranged to face each other. A plasma generating means having an electrode; and a transfer means for transferring, in the generated plasma, radicals that chemically react with the substrate surface in a direction along the substrate surface. One of the electrodes is a rotating body that rotates about an axis parallel to the surface of the substrate, and the gas supply port of the gas supply means and the gas exhaust port of the gas exhausting means sandwich the rotating body to rotate the rotor. In the direction of body rotation
And the gas flows in the direction along the substrate surface.
Is disposed, cooperating with said rotating body, and the gas supply port and the gas exhaust port
A plasma processing apparatus in which the transfer means is configured to transfer the radicals in a direction along the surface of the substrate. 14. A plasma processing apparatus for a flattening step used in a step of flattening an insulating film formed on a substrate, which comprises a stage for holding the substrate and a high-density gas supply. Plasma generating means having a gas supply means, a gas exhausting means for exhausting the high-density gas, a high-frequency power source, and a pair of electrodes arranged to face each other, and among the generated plasma, the substrate surface And a transfer means for transferring radicals that chemically react with the substrate in a direction along the surface of the substrate, wherein one of the pair of electrodes of the plasma generation means rotates about an axis parallel to the surface of the substrate. The gas supply port of the gas supply unit and the gas exhaust port of the gas exhaust unit sandwich the rotating body in the rotation direction of the rotating body.
And is arranged so that gas parallel to the surface of the substrate flows , and the rotor and the gas supply port and the gas exhaust port cooperate with each other.
The plasma processing apparatus for the flattening step , wherein the transfer means is constituted by the transfer means , and the radicals are transferred in a direction along the surface of the substrate. 15. A plasma processing apparatus for a flattening process used in a step of flattening an insulating film formed on a substrate, which comprises a stage for holding the substrate and a high-density gas supply. Gas supply means, gas exhaust means for exhausting the high-density gas, high-frequency power supply, and plasma generating means having a pair of electrodes arranged so as to face each other, and the pair of plasma generating means. The electrodes are flat on the substrate surface.
The substrate is above the substrate so that an electric field in the direction of travel is generated.
The pair of electrodes face each other in a direction parallel to the plate surface, and at least one of the pair of electrodes is vacant between the pair of electrodes.
In order to generate a non-uniform electric field between the electrodes, it has a sharp shape toward the other opposing electrode , and the pair of electrodes creates a non-uniform electric field parallel to the substrate surface. Generated, thereby generating a spatially localized plasma due to the non-uniform electric field,
Plasma processing equipment for flattening process. 16. A plasma processing apparatus for a flattening step used in a step of flattening an insulating film formed on a substrate, comprising: a stage for holding the substrate; and a gas supply means for supplying a high density gas. A plasma generating means having a gas exhausting means for exhausting the high-density gas, a high-frequency power source, and a pair of electrodes arranged to face each other, and the stage includes the pair of electrodes of the plasma generating means. And the other electrode is arranged so as to face the stage, and at least one of the pair of electrodes is arranged in a region on the substrate to be planarized and a region not to be planarized. A plasma processing apparatus for a flattening process, which has a combined uneven shape. 17. the stage is an electrode having a concave-convex shape of the pair of electrodes, the other electrode is a cylindrical rotating body which rotates about an axis parallel to the substrate surface, according to claim 16 The plasma processing apparatus for the flattening step according to. 18. the stage is an electrode having a concave-convex shape of the pair of electrodes, the other electrode is a disk-shaped rotary body rotating about an axis perpendicular to the substrate surface, according to claim 17 The plasma processing apparatus for the flattening step according to. 19. A method of manufacturing a semiconductor device, which comprises a step of flattening an insulating film formed so as to cover a step portion formed on a substrate, the method comprising the steps of: 2, 4, 6, 8, 12. , 14 or 16 for generating a radical that chemically reacts with the insulating film by generating plasma by a high-frequency electric field in a high-density gas atmosphere by the plasma processing apparatus for planarization process according to any one of A method of manufacturing a semiconductor device, comprising the step of: transporting the radicals by a gas flow parallel to the substrate surface, thereby selectively supplying the radicals to the convex portions of the insulating film. 20. A method of manufacturing a semiconductor device, comprising a step of flattening an insulating film formed so as to cover a step portion formed on a substrate, wherein the plasma for the flattening step according to claim 14. A step of intensively supplying a high density gas near the surface of the substrate by a processing device; a step of generating plasma by a high frequency electric field to generate radicals that chemically react with the insulating film; And a step of performing planarization by supplying the same to the substrate surface and a step of exhausting and recovering a reaction product generated on the substrate surface from the substrate surface in an atmosphere open system. 21. The step of planarizing the insulating film comprises about 1
Approximately 100M in a high density gas atmosphere above atmospheric pressure
21. The method of manufacturing a semiconductor device according to claim 19 , which is performed by applying a high frequency electric field of Hz or more to generate plasma.