JP2003059918A - Method and apparatus for plasma treatment and manufacturing method for semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for plasma treatment wherein anisotropic film formation characteristics and anisotropic etching characteristics are improved. SOLUTION: The plasma treatment equipment includes at least an evacuated reaction chamber (1, 2); a substrate holder (4a, 4b, 4c, 4d) placed in the reaction chamber, on which a substrate 5 is to be placed, an evacuating pipe 13 connected to the reaction chamber and for reducing the pressure in the reaction chamber, a plurality of first nozzles 801, etc., 807, etc., directed diagonally upward, a plurality of second nozzles 901, etc., 905, etc., directed in the horizontal direction, and a high-frequency electric field applying means (3, 6) for producing plasma in the reaction chamber. Through the first nozzles, a first gas is fed which is a material for producing first ionic species required for the surface reaction of substrates 5. Through the second nozzles, a second gas is fed which is a material for producing second ionic species higher in sputtering efficiency than the first ionic species.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing method for forming a thin film on a substrate using plasma, a plasma processing apparatus, and a semiconductor device manufacturing method using the same, and more particularly to an inductive coupling type (ICP type). ), Helicon wave excitation type (H
WP type), electron cyclotron resonance type (ECR type), magnetron discharge type, surface wave excitation type, etc.

[0002]

2. Description of the Related Art In a semiconductor device, an insulating film for electrically isolating element wiring is used. Conventionally, as the insulating film, a silicon oxide film (SiO ₂ film) formed by oxidizing a silicon substrate by a thermal oxidation method, or a gas such as monosilane (SiH ₄ ) or tetraethoxysilane (TEOS) is used as a raw material. A SiO ₂ film formed by chemical vapor deposition (CVD) is mainly used. However, in these film forming methods, high-temperature heat treatment at 600 ° C. or higher is indispensable, and there is a problem that it is difficult to process the substrate to be processed after depositing the low melting point metal. As a method for solving this problem, a silicon oxidation method using a plasma reaction and a plasma CVD method, which can be processed at a low temperature, have been developed.
However, the oxide film obtained by these treatment methods has a lower density, a lower electrical breakdown voltage, and a higher dielectric constant than the oxide film obtained by the thermal oxidation method. is there.

Further, in recent high-speed logic devices, memory devices, etc., there is an increasing demand for finer wiring widths, multi-layered wirings, etc. due to the complexity of circuits. One of the characteristics required for the method of forming the interlayer insulating film in the multilayer wiring is the burying performance. This is because it is necessary to fill the trenches for element isolation and the spaces between the wirings, which have become narrower with the miniaturization of the elements, with an insulating film. A CVD method using high-density plasma has been attracting attention as one that satisfies these requirements. The high-density plasma CVD method is characterized by performing plasma discharge at a pressure of about 1 Pa, and there are ICP type, HWP type, ECR type, magnetron discharge type, surface wave excited plasma type and the like depending on the plasma generation method. In the high-density plasma CVD, since the discharge is performed under a low pressure, the density of the ion species accounts for several% of the neutral particles, and the film formation using the ion species is realized. Therefore, by applying a bias voltage to the susceptor, ionic species are drawn into the substrate to achieve directional deposition, and by adding a rare gas such as argon (Ar), the opening of the groove where the electric field is concentrated By selectively sputter-etching the edge part of, the high aspect groove can be filled.

An ICP type high density plasma processing apparatus will be described as an example of a conventional example. FIG. 8 shows a schematic view of an ICP type high density plasma processing apparatus. This high-density plasma processing apparatus includes a container substrate 1 used for plasma generation,
Dielectric container 2, RF coil 3 and R for plasma generation
F power supply device 6, substrate 5, substrate holders (4a, 4b, 4c, 4d) for holding substrate 5, RF power source 7 for attracting ions by bias voltage, vacuum exhaust system (not shown), It is composed of a plurality of horizontal nozzles 910 and 911 connected to a plurality of source gas supply systems (not shown) and a top nozzle 921. In the plasma chamber composed of the plasma container 1 and the dielectric container 2, a raw material gas is supplied from a plurality of horizontal nozzles 910 and 911 and a top nozzle 921 which are respectively connected to a plurality of raw material gas supply systems (not shown). The inside of the chamber is maintained at about 1 Pa by exhausting from the vacuum exhaust system. A high frequency electric field of about 3 kW is applied to the RF coil 3 by the RF power supply device 6 to generate plasma in the chamber.
Further, the RF power source 7 applies a bias voltage to the substrate 5 (the temperature control means is not shown) held on the substrate holder upper portion 4a to draw the ion species from the plasma to the substrate 5. As shown in FIG. 8, the horizontal nozzles 910 and 911 and the top nozzle 921 are connected to the holding substrate holders (4a, 4b, 4c, 4).
d) Above the substrate 5, which is arranged parallel to the substrate 5, monosilane (SiH ₄ ) / Ar gas and O ₂ gas are supplied from the horizontal nozzles 910 and 911 and the top nozzle 921. A SiO ₂ film is deposited on the substrate 5 by the neutral radical species and ionic species generated by the plasma.

[0005]

Here, the problems of plasma CVD will be examined by taking the formation of a silicon oxide film (SiO ₂ film) as an example. The first problem in a plasma processing apparatus that actively uses ion species, such as a plasma apparatus for a SiO ₂ film, especially a high-density plasma processing apparatus, is a problem of insufficient Si source ion species density. This is because in the formation of the SiO ₂ film,
There is a problem of deterioration of the burying characteristic (limit of burying characteristic) due to progress of miniaturization of wiring width and trench for element isolation. Explaining with an example of high density plasma CVD, a film formation site (Si (s) -OH) formed on the surface by ion irradiation.
Si source (neutral radical species Si source (SiH ₃ , SiH ₂ ,
SiH, Si, SiO, etc.) and ionic species Si source (Si
H ₃ ⁺ , SiH ₂ ⁺ , SiH ⁺ , Si ^+, etc.) is supplied, and the formation of the SiO ₂ film proceeds, but even under high-density plasma conditions of about 1 Pa, the flux of neutral radical species on the surface is 5 to 10 times more than the flux of ionic species.
As a result, the anisotropic film forming characteristics are impaired and the groove filling characteristics are limited. That is, in the conventional method of forming a SiO ₂ film by high-density plasma CVD, the filling characteristic limit occurs due to insufficient Si source ion species density, a space remains between wirings, and a step after the insulating film is filled (wet cleaning treatment, etc.)
Yield is significantly reduced and the reliability of the device is reduced.

The second problem is that the material to be deposited (Si
There is a deterioration in the embedding shape due to the sputtering due to the non-Si source ion species for the O ₂ film. The ionic species (Ar ⁺ ) generated from the Ar gas and the ionic species (O ⁺ , O ₂ ⁺ ) generated from the O ₂ gas are compared with the Si source ionic species to form a film (SiO 2). _The "sputtering efficiency" for ₂ films is large. If the energy or the flux of the ion species to the substrate 5 is too large, as shown in FIG. 3B, the film formation 61 occurs due to the sputter species knocked out from the inclined portion of the SiO ₂ film 59 on the adjacent wiring. . Especially the width l of the opening
_{When 2} is narrower than the width l ₁ (l ₁ >> l ₂ ), that is, when the trench width l ₂ is further miniaturized, an overhang 62 is generated during the buried film formation, and even if the deposition is further continued thereafter. Cavities and cavities are formed inside the groove (FIG. 3A is a schematic diagram showing a case where energy and flux of ion species to the substrate 5 are small). As a result, the filling characteristics in the trench having the narrow trench width l ₂ are deteriorated depending on the kind and energy of the ion species.

The third problem is that the film thickness uniformity is deteriorated due to the plasma density distribution and the supplied gas density distribution. This is the gas nozzles 911, 912, 921.
It becomes particularly noticeable in an ICP type high-density plasma processing apparatus in which a raw material gas is introduced using a gas supply pipe such as. The raw material gas is introduced from outside the plasma or from a portion with low plasma density by using a nozzle or the like to prevent the consumption of the member by the plasma, and the raw material gas density distribution is inevitably generated in the plasma portion. It leads to deterioration of distribution uniformity.

In the above description, the case of embedding a SiO ₂ film was explained, but reactive ion etching (RI
The same applies to the case where plasma etching or doping such as E) is included. Alternatively, tungsten (W),
The same applies when a metal such as molybdenum (Mo) is embedded in a fine contact hole or via hole of 100 nm level. As described above, in the process of positively using the ionic species, there are problems of insufficient density of the ionic species and improvement of the in-plane distribution of the ionic species.

In view of the above problems, the present invention provides a plasma processing method and a plasma processing apparatus capable of increasing the density of ion species (ion species density) required for surface reaction of a substrate as compared with neutral radical species. Is to provide. Specifically, at the film formation site or etching site on the substrate surface, the flux of ionic species can be increased compared to the flux of neutral radical species, which improves anisotropic film formation characteristics and anisotropic etching characteristics. Another object of the present invention is to provide a plasma processing method and a plasma processing apparatus.

Another object of the present invention is to provide a plasma processing method and a plasma processing apparatus which have good characteristics of plasma reaction such as burying and etching even when miniaturization of wiring width and trenches for element isolation has progressed to the level of 100 nm. Is to provide.

Still another object of the present invention is a plasma treatment method which suppresses sputtering due to a second ion species whose presence excessively inhibits surface reaction, thereby improving anisotropic film forming characteristics and anisotropic etching characteristics. And a plasma processing apparatus.

Still another object of the present invention is to provide a plasma processing method and a plasma processing in which the in-plane distribution of the plasma density and the in-plane distribution of the ion species density are made uniform to improve the film thickness uniformity and the etching depth uniformity. It is to provide a device.

Still another object of the present invention is to provide a method for manufacturing a semiconductor device in which a good thin film can be buried without leaving a space between wirings or trenches for element isolation, and the manufacturing yield in subsequent steps can be significantly improved. Is to provide.

[0014]

In order to achieve the above object, a first feature of the present invention is to arrange a substrate in a reaction chamber, and between the top of the reaction chamber and the substrate, an ion transport region adjacent to the substrate. A first low density plasma formation region adjacent to the ion transit region, a high density plasma formation region adjacent to the first low density plasma formation region, and a first low density plasma formation region sandwiched between the high density plasma formation region and the top of the reaction chamber. The present invention relates to a method of forming a low density plasma formation region, and forming a film on the substrate or etching the substrate by a surface reaction of the substrate using plasma in the high density plasma formation region. That is, the first aspect of the present invention
In the plasma processing method according to the feature (1), a step of placing a substrate in the reaction chamber, (b) a step of reducing the pressure in the reaction chamber, and (c) a side wall portion of the reaction chamber are provided. Using a nozzle having a root portion in the plasma formation region and a tip portion directed toward the high-density plasma formation region, in the elevation angle direction of the substrate surface, only the compound gas that generates the first ion species necessary for the surface reaction is substantially used. At the same time as the step of injecting the first gas and the step of (d) injecting the first gas, a film is formed or etched in the first low-density plasma formation region in a direction parallel to the surface of the substrate. Injecting a second gas that produces a second ionic species having a sputtering efficiency higher than that of the first ionic species, and (e) high-density plasma formation region, first and second low-density plasma formation A high-frequency electric field is applied to the region to generate high-density plasma in which the first ion species are generated in high density in the high-density plasma formation region, and low-density plasma is generated in the first and second low-density plasma formation regions. Generate and first
The step of causing the ionic species to reach the surface of the substrate via the ion transit region and causing a surface reaction by the first ionic species. The "sputtering efficiency for a substance to be deposited" means the sputtering efficiency by ions for a deposition (deposited film) material in the case of deposition such as CVD and epitaxial growth. Further, the "sputtering efficiency for the substance to be etched" is the sputtering efficiency by the ions for the substrate material when the substrate itself is etched, and the portion to be etched of a material different from the substrate is formed on the substrate. In this case, it means the sputtering efficiency by the ions for the material to be etched. The "sputtering efficiency" is measured by an experiment using an ion gun in combination with various ion species and various materials to be sputtered. The experimental result of "sputtering efficiency" is described in the literature as basic data, and therefore it may be used. According to the experiment of the inventor,
“Only the compound gas that produces the first ionic species is“ substantially ”
In consideration of the components of the first gas, the gas other than this is contained in the flow rate ratio of 20% or less with respect to the “compound gas that generates the first ionic species necessary for the surface reaction”. If so, it can be construed as "being" substantially "only."

According to the plasma processing method of the first aspect of the present invention, the ion species density of the first ion species required for the surface reaction of the substrate can be increased as compared with the neutral radical species. That is, at the film formation site on the substrate surface, the flux of the first ionic species can be increased as compared with the flux of the neutral radical species to the surface. Therefore, the anisotropic film forming characteristics are improved, and the filling characteristics in the groove are improved. As a result, in plasma CVD, the burying characteristics can be improved even when the miniaturization of the wiring width and the trench for element isolation has progressed to the level of 100 nm. As a result, a good insulating film can be embedded without leaving a space between the wirings, and the subsequent steps (wet cleaning processing, etc.)
Yield is significantly improved, and the reliability of the semiconductor device is improved. As described above, Ar ⁺ , O ⁺ , O ₂ ^{+ and the} like as the second ionic species have a higher sputtering efficiency for the substance to be deposited or etched as compared with the first ionic species necessary for the surface reaction. According to the plasma processing method of the first feature, the sputtering due to the second ionic species, whose excessive presence hinders the surface reaction, is suppressed, so that the burying property in plasma CVD is improved. Since excess energy and excess flux of the second ion species to the substrate can be controlled, in plasma CVD, abnormal film formation due to sputter species knocked out from the inclined portion of the film formation on the adjacent wiring is suppressed. It is possible to avoid the occurrence of overhang shape. As a result, the filling characteristics between the narrow trenches at the 100 nm level are extremely excellent. or,
Since the in-plane distribution of the plasma density and the in-plane distribution of the ion species density are made uniform, the film thickness uniformity and the etching depth uniformity are improved.

In the first aspect of the present invention, the first gas is a metal hydrogen compound gas, a metal halogen compound gas, a metal organic compound gas, a semiconductor hydrogen compound gas,
It is possible to select from the group consisting of a semiconductor halogen compound gas and a semiconductor organic compound gas. On the other hand, the second gas can be selected from the group consisting of rare gas, hydrogen gas, nitrogen gas, nitrogen compound gas, oxygen gas, and oxygen compound gas. For example, in the first aspect of the present invention, the first gas is a silicon hydride gas,
If the second gas is oxygen gas or oxygen compound gas, plasma CVD of silicon oxide can be realized.
In the first aspect of the present invention, the density ratio of the first ionic species to the neutral radical species generated from the first gas is:
It can be 0.01 to 0.045.

The second feature of the present invention is to arrange the substrate in the reaction chamber and to adjoin the substrate between the top of the reaction chamber and the substrate, as in the plasma processing method according to the first feature of the present invention. The ion transit region, the first low density plasma formation region adjacent to the ion transit region, the high density plasma formation region adjacent to the first low density plasma formation region, and the high density plasma formation region and the top of the reaction chamber. The present invention relates to a method for arranging the second low-density plasma formation region, and forming a film on the substrate or etching the substrate by the surface reaction of the substrate using the plasma in the high-density plasma formation region. That is, in the plasma processing method according to the second aspect of the present invention, (a) arranging the substrate in the reaction chamber, (b) depressurizing the reaction chamber, and (c) a side wall of the reaction chamber. A compound which is provided and has a root portion in the first low-density plasma formation region and uses a nozzle whose tip is directed toward the high-density plasma formation region to generate ion species necessary for surface reaction in the elevation direction of the substrate surface. Simultaneously with the step of injecting the first gas consisting essentially of only the gas and (d) the step of injecting the first gas, in the first low-density plasma formation region, in a direction parallel to the surface of the substrate, Injecting a second gas, which is a raw material for generating radical species necessary for the surface reaction of the substrate, and (e) applying a high-frequency electric field to the high-density plasma formation region and the first and second low-density plasma formation regions. To do To generate high-density plasma in which the ion species are generated in high density in the high-density plasma formation region, and to generate low-density plasma in the first and second low-density plasma formation regions, and to generate ion species in the ion transit region. The step of reaching the surface of the substrate through the surface of the substrate and causing a surface reaction by ionic species and radical species. here,
"Ionic species" are reactive species (chemical species) that have a charge, and "radical species" are reactive species (chemical species) that do not have a charge.
Is. As described in the first feature, "being" substantially "from only a compound gas that produces an ionic species""meansthat" an ionic species necessary for surface reaction is produced as a component of the first gas. With respect to the "compound gas", it is intended to allow mixing of another gas at a flow rate ratio of 20% or less.

In the second aspect of the present invention, the raw material is a raw material for generating ion species necessary for the surface reaction of the substrate along the direction inclined from the side wall of the reaction chamber toward the high-density plasma formation region. By injecting the first gas and injecting the second gas, which is a raw material for generating the radical species necessary for the surface reaction of the substrate, in the direction parallel to the surface of the substrate,
It is possible to improve the decomposition efficiency of the first gas and increase the density of deficient ionic species. That is, it becomes easy to control the ion species density and neutral radical species density required when forming trenches, contact holes, via holes, etc. having a large aspect ratio. In the high aspect ratio trench etching reaction, neutral radical species are used for reactive layer formation at the etching surface and for sidewall protection that appears during etching. Conventionally, in the etching reaction of a trench having a large aspect ratio, it has been generally difficult to form a trench having a large aspect ratio due to insufficient ion species density. However, according to the second feature of the present invention,
Since the ion species density can be made sufficiently high, the formation of trenches and holes having a large aspect ratio can be performed easily and with high precision.

In the second aspect of the present invention, for example, the first gas is an alkyl halide gas and the second gas is
It can be a gas of perfluorocarbon.

A third feature of the present invention relates to an apparatus for forming a film on a substrate or etching the substrate by a surface reaction using plasma. That is, the plasma processing apparatus according to the third aspect of the present invention includes (a) a reaction chamber capable of being evacuated,
(B) A substrate holder for arranging the substrate, and (c) a root portion is arranged on the side wall portion of the reaction chamber, and an injection direction is set from the side wall portion to the top of the reaction chamber. A plurality of first nozzles for introducing into the reaction chamber a first gas substantially consisting of a compound gas that generates the first ionic species necessary for the surface reaction; and (d) a root portion of the first nozzle. They are arranged at substantially the same horizontal level or at a horizontal position closer to the substrate than the root of the first nozzle, have a jetting direction parallel to the surface of the substrate, and the number of nozzles is smaller than that of the first nozzle, and film formation or etching For introducing into the reaction chamber a second gas, which is a raw material for generating a second ionic species having a sputtering efficiency higher than that of the first ionic species or a raw material for generating a radical species necessary for the surface reaction of the substrate. A second nozzle, (E) A high-frequency electric field applying means for generating a high-density plasma in which the first ion species are generated at a high density is included in a space between the position where the first nozzle is arranged and the top of the reaction chamber. And

According to the plasma processing apparatus of the third aspect of the present invention, by using the plurality of first nozzles, the ion species density of the first ion species necessary for the surface reaction of the substrate is changed to the neutral radical species. In comparison, it can be increased. That is, at the reaction site on the substrate surface, the flux of the first ionic species can be increased as compared with the flux of the neutral radical species to the surface. Therefore, the anisotropic film forming characteristics and the anisotropic etching characteristics are improved.

A fourth aspect of the present invention corresponds to a method of manufacturing a semiconductor device including a step of depositing a silicon oxide film on a semiconductor substrate by using the plasma processing method according to the first aspect of the present invention. Therefore, similarly to the plasma processing method according to the first aspect of the present invention, the semiconductor substrate is arranged in the reaction chamber, and the ion traveling region adjacent to the semiconductor substrate is provided between the top of the reaction chamber and the semiconductor substrate. A first low density plasma formation region adjacent to the region, a high density plasma formation region adjacent to the first low density plasma formation region, and a second low density plasma sandwiched between the high density plasma formation region and the top of the reaction chamber Positioning the formation region and depositing a silicon oxide film on the semiconductor substrate by the surface reaction of the semiconductor substrate using the plasma of the high density plasma formation region. That is, in the method for manufacturing a semiconductor device according to the fourth aspect of the present invention, (a) the width of the opening is 95n on the surface of the semiconductor substrate.
a step of providing a groove of m to 130 nm, (b) placing a semiconductor substrate in the reaction chamber, (c) reducing the pressure in the reaction chamber, and (d) being provided on the side wall of the reaction chamber. Having a root in the low-density plasma formation region,
At the same time as the step of injecting a hydrogen compound gas of silicon and (e) the step of injecting a hydrogen compound gas of silicon in the elevation angle direction of the substrate surface using a nozzle whose tip portion is directed toward the high-density plasma formation region, In the low-density plasma formation region, a step of injecting an oxygen gas or an oxygen compound gas in a direction parallel to the surface of the substrate, and (f) a high-frequency electric field is applied to the high-density plasma formation region. The high density plasma in which the seeds are generated in high density is generated, the low density plasma is generated in the first and second low density plasma formation regions, and the silicon oxide film is deposited by the surface reaction via the Si source ion species. And embedding the groove.

According to the semiconductor device manufacturing method of the fourth aspect of the present invention, the Si source ion species necessary for the surface reaction of the trench (trench), that is, SiH _x ⁺ (SiH ₃ ⁺ , SiH ₂ ⁺ ,
The density of SiH ⁺ , Si ⁺ ) is the Si source neutral radical species, namely SiH _x (SiH ₃ , SiH ₂ , SiH, Si, SiO)
The density can be increased compared to the density. That is, at the reaction site on the substrate surface, the flux of the Si source ion species can be increased as compared with the flux of the Si source neutral radical species. Therefore, the anisotropic film forming characteristics for the fine groove portion (trench) are improved, and the burying characteristics of the silicon oxide film are improved. Therefore, even when the aspect ratio is about 5 and the miniaturization of the groove width of the trench progresses from 95 nm to 130 nm, excellent filling characteristics can be exhibited. As a result, the silicon oxide film can be satisfactorily embedded without leaving a space between the wirings, so that the yield in the subsequent steps (wet cleaning processing, etc.) is significantly improved and the reliability of the semiconductor device is improved. Further, according to the method of manufacturing a semiconductor device having the fourth characteristic, excessive Ar ⁺ , O ⁺ , O ₂ ⁺
Since the spattering due to the above is suppressed, the filling characteristics in plasma CVD are improved. Since it is possible to control excess energy and excess flux of Ar ⁺ , O ⁺ , O ₂ ^+, etc., in plasma CVD of a silicon oxide film, a sputter species knocked out from a sloped portion of a film formed on an adjacent wiring is used. It is possible to suppress the abnormal film formation due to it and avoid the occurrence of overhang shapes and the like. Further, since the in-plane distribution of the plasma density and the in-plane distribution of the ion species density are made uniform, the film thickness is excellent and the manufacturing yield of the semiconductor device is high.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Next, first to third embodiments of the present invention will be described with reference to the drawings. The present invention is an ICP
, HWP type, ECR type, magnetron discharge type, surface wave excitation type, etc., it is applicable to a method and apparatus for treating a substrate (substrate to be treated) using various high density plasmas.
In the following first to third embodiments, an ICP type high density plasma processing apparatus will be exemplarily described. or,
In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and the relationship between the thickness and the plane dimension, the ratio of the thickness of each layer, and the like are different from the actual ones.
Therefore, the specific thickness and dimensions should be determined in consideration of the following description. Also, it is needless to say that the drawings include portions having different dimensional relationships and ratios.

(First Embodiment) As shown in FIG. 1, a plasma processing apparatus according to a first embodiment of the present invention comprises a reaction chamber (1, 2) which can be evacuated, and this reaction chamber. (1,
2) The substrate holders (4a, 4b, 4c, 4d) for arranging the substrate 5 and the reaction chambers (1, 2) connected to the reaction chambers (1, 2) are decompressed. Vacuum exhaust pipe 13 and a plurality of first nozzles 8 facing diagonally upward
, 807, ..., and a plurality of second nozzles 901 ,. 2) is an ICP-type high-density plasma processing apparatus having at least high-frequency electric field applying means (3, 6) for generating plasma. The reaction chambers (1, 2) are container bases (bases) 1 made of corrosion-resistant metal such as stainless steel.
And a dielectric container 2 connected to the upper flange of the container base 1 in a hermetically sealed structure. The dielectric container 2 is made of, for example, semitransparent quartz (SiO ₂ ) or opaque alumina (Al ₂ O ₃ ). Substrate holder (4a,
4b, 4c, 4d) are metal embedded electrodes 4d,
The embedded electrode 4d is surrounded by a substrate holder upper portion 4a and a substrate holder lower portion 4b made of an insulating material, and further fixed to the container base 1 by a substrate holder supporting portion 4c. The embedded electrode 4d has, for example, 13.5.
A 6 MHz RF bias power supply 7 is connected via a blocking capacitor (not shown). In addition to the bias power supply 7, a DC power supply for an electrostatic chuck may be connected to the embedded electrode 4d. Further, although not shown in the drawing, a gas cooling means for controlling the substrate temperature is provided on the substrate holder (4
a, 4b, 4c, 4d). The plurality of first nozzles 801, ..., 807, .. have root portions arranged on the side wall portions of the reaction chambers (1, 2), and the reaction chambers (1, 2) extend from the side wall portions. The injection direction is set to the top direction of. From the first nozzles 801, ..., 807, ..., a first gas substantially composed of only a compound gas that produces the first ion species necessary for the surface reaction of the substrate 5 is produced. Gas is introduced into the reaction chamber (1,2). Further, from the top nozzle 921 provided at the center of the top of the dielectric container 2,
Gas is introduced into the reaction chamber (1, 2). First nozzle 801, ..., 807, ... And top nozzle 921
Is provided with an orifice having a diameter of about 0.1 mm to 0.8 mm, and the first nozzle 801 ,.
7 ... and in front of the top nozzle 921 are supersonic regions,
Alternatively, a subsonic region is generated. First nozzle 801, ...
, 807, ... are connected to gas pipes 81, and an introduced gas control valve such as a mass flow controller for controlling the introduction amount of the first gas (not shown) is connected to the gas pipes 81. It is provided. Although not shown, the top nozzle 921 is also connected to a gas pipe having a control means for controlling the introduction amount of the first gas.

On the other hand, the second nozzles 901, ..., 90
5, ... are the first nozzles 801, ..., 807, ...
・ The root part is arranged at substantially the same horizontal level as that of the root part, or on the side wall part at a horizontal position closer to the substrate 5 than the root part of the first nozzles 801, ..., 807 ,. Has been done. That is, the roots of the second nozzles 901, ..., 905, ... Are lower than the roots of the first nozzles 801 ,. May be. Second nozzle 901,
From 905, ..., the second gas, which is a raw material for generating the second ionic species having a high sputtering efficiency for the substance deposited or etched by the first ionic species, is used as the reaction chamber. It is introduced in (1, 2). Second nozzle 901, ...
.., 905, ... The first nozzle 801, ...
., 807, ..., 0.1 mm to 0.8 m in diameter
An orifice of about m is provided, and a supersonic region or a subsonic region is generated in front of the nozzle. Gas pipes (not shown) are connected to the second nozzles 901, ..., 905, .. The gas pipes include a mass flow controller or the like for controlling the introduction amount of the 21st gas. The introduction gas control valve is provided for the first nozzle 801, ...
, 807, ... The first nozzle 80
1, ..., 807, ..., Top nozzle 921 and second
The orifice diameter of the nozzles 901, ..., 905, ... is 0.2 mm to facilitate the arrival and mixing of gas.
More preferably, it is about 0.6 mm.

In order to ensure excellent reaction uniformity,
First nozzle 801, which determines the distribution of the first ion species, ...
It is important that there are a large number of ..., 807, .... This is because when the total number of nozzles increases, interference occurs between the gas jets discharged from the nozzles, and the gas escapes toward the substrate 5 due to this interference, resulting in deterioration of the film thickness distribution. Therefore, as shown in FIG.
Second nozzle 901 for horizontally introducing the above gas
The first nozzles 801, 8 for introducing the first gas substantially composed of only the compound gas for generating the first ionic species necessary for the surface reaction are small in number of 902, ..., 906.
It is necessary to increase the number of 02, ..., 812 (a cross-sectional view taken along the line AA of FIG. 2 corresponds to FIG. 1). In FIG. 2, the second nozzles 901, 902,
The number of 906 is 6, the first nozzles 801, 80
An example in which the number of 2, ..., 812 is 12 is shown, but it goes without saying that the number is not limited to this number. In short,
If the number of the second nozzles 901, 902, ..., 906 is less than the number of the first nozzles 801, 802, .., 812, depending on the target plasma reaction type and characteristics, The number of nozzles can be appropriately selected.

Although not shown, a predetermined pressure measuring device such as a diaphragm type pressure gauge or other vacuum gauge is arranged on the container base 1, and the reaction chamber ( The pressure in 1, 2) can be controlled. Although not shown, a pressure control valve for feeding back and controlling a signal from the pressure measuring device is connected to the vacuum exhaust pipe 13, and the pressure control valve further has a chemical exhaust rate of about 2 to 8 m ³ / s. A vacuum exhaust system such as a type turbo molecular pump, a diffusion pump, a cryopump, or a mechanical booster pump is connected.

The high frequency electric field applying means (3, 6) includes an RF coil 3 provided near the top of the dielectric container 2 and the R coil.
Supplying high frequency power to the F coil 3, for example 13.56
And an RF power supply 6 of MHz. RF power supply 6
The high frequency output from the RF coil 3 is supplied to the RF coil 3 via a matching box (not shown). The high frequency electric field applying means (3, 6) includes second nozzles 901, ..., 90.
Plasma is generated in the space between the position where 5, ... Is arranged and the top of the reaction chamber (1, 2). Generally, there is a distribution in the plasma generation part in the reaction chambers (1, 2), and there are a high-density plasma formation region 11 in which the RF electric field is concentrated and low-density plasma formation regions (12a, 12b) around it. In 1, the “high density plasma region” 11,
It is abbreviated as "low density plasma region" (12a, 12b). ). The distribution becomes particularly remarkable in high-density plasma processing apparatuses such as ICP type and surface wave excited plasma type.
In the case of the type high-density plasma processing apparatus, a high-density plasma forming region 11 (a region where the ion species density and the electron density in plasma are high) is provided in the vicinity of the dielectric container 2 in which the coil 3 is installed and above the substrate 5. There are low density plasma forming regions (12a, 12b) around them.

In FIG. 1, in the reaction chamber (1, 2), in the direction normal to the surface of the substrate 5, the ion transit region 10 adjacent to the substrate 5 and the first ion transit region 10 adjacent to the ion transit region 10 are sequentially arranged. Low-density plasma formation region (in FIG. 1, “first
A low density plasma region ") a and a high density plasma formation region adjacent to the first low density plasma formation region 12a (abbreviated as" high density plasma region "in FIG. 1) 1
1 and a second low density plasma formation region (abbreviated as “second low density plasma region” in FIG. 1) 12b adjacent to the high density plasma formation region 11 are generated. The first low density plasma forming region 12a and the second low density plasma forming region 12b are continuous with each other in the vicinity of the side wall portion of the dielectric container 2 so as to surround the high density plasma forming region 11.

In FIG. 1, the first nozzle 801, ...
The nozzle length L ₁ of 807, ...
a, 4b, 4c) and the container base 1, and the elevation angle (upward angle) θ _{1 of} the first nozzles 801, ..., 807 ,. 1 inside diameter 2
R, the following equation determined by the radius r of the substrate 5 is preferable: R-r ≧ L ₁ · cos θ ₁ ≧ 0.9L (1). First nozzle 801,
The height (hereinafter, referred to as “nozzle root height”) H ₁ of the wall surface of the container base 1 of the container base 1 from the substrate 5 is 2R, the inner diameter of the container base 1 is 2R, If the radius r of the substrate 5 and the height H ₂ of the central ceiling (top part) of the reaction chambers (1, 2) from the substrate 5 are satisfied, then from the nozzle length L ₁ and the elevation angle θ ₁ , H = R−r−L ₁・ Cos θ ₁ (2) is defined, and using this H, H ₂ −L ₁ · sin θ ₁ − (R−L ₁ · cos θ ₁ ) · tan θ ₁ ≧ H ₁ ≧ H · tan ( It is preferable that the range is 50-θ ₁ ) -L ₁ · sin θ ₁ (3).

Further, the first nozzles 801, ..., 807, ...
The elevation angle θ _{1 with} respect to the substrate 5 is the height H ₂ from the substrate 5 of the central ceiling (top part) of the reaction chamber (1, 2), the container substrate 1
From the inner diameter 2R of the nozzle and the height H _{1 of the} root of the nozzle, the angle θ obtained by the relationship of H ₂ −H ₁ −L ₁ · sin θ ₂ = (R−L ₁ · cos θ ₂ ) tan θ ₂ (4) ₂ and H ₁ + L ₁ · sin θ ₃ = (R−r−L ₁ · cos θ ₃ ) · tan (50−θ ₃ ) · (5), the angle θ ₃ is defined, and these angles θ ₂ And the angle θ ₃ are used, and it is preferable that θ ₂ ≧ θ ₁ ≧ θ ₃ (6).

The inner diameter of the container substrate 1 is 2R = 380 mm, the height of the central ceiling (top) of the reaction chambers (1, 2) from the substrate H ₂ = 140 mm, and the substrate holders (4a, 4b, 4c, 4).
In the case where the gap length L between the d) and the container base is 50 mm and the radius r of the substrate 5 is 100 mm (8 inch wafer), as described later, it is the first due to the filling characteristics and the in-plane film thickness uniformity.
The elevation angle θ ₁ of the nozzles 801, ..., 807, ... Is 8 °
The range of from 30 ° is preferred.

Considering equations (1) to (6), for example, the elevation angle θ of the first nozzles 801, ..., 807 ,.
_{When 1} = 8 °, 91 mm ≧ L ₁ ≧ 45 mm, elevation angle θ ₁
= 30 °, a nozzle length in the range of 103 mm ≧ L ₁ ≧ 52 mm is preferable. Further, for example, the nozzle length L ₁ = 55
mm, 113 mm ≧ H when the elevation angle θ ₁ = 8 °
_{When 1} ≧ 24 mm and elevation angle θ ₁ = 30 °, 35 mm ≧ H
A range of the nozzle root height H ₁ of ₁ ≧ −12 mm is preferable. Here, the “minus” nozzle base height H1 is
It literally means “below the surface of the substrate 5”.

Further, the inner diameter of the container base 1 is 2R = 500 m.
m, from the substrate 5 on the central ceiling (top) of the reaction chambers (1, 2)
Height H_Two= 160 mm, substrate holder (4a, 4b, 4
c, 4d) and the gap length between the container base and L = 60 m
m, radius of substrate 5 r = 150 mm (12 inch wafer)
In the case of, when considering equations (1) to (6), for example,
Elevation angle θ of one nozzle 801, ..., 807 ,.₁= 8
In case of °, 101mm ≧ L ₁≧ 54 mm, θ₁= 30 °
In case of, 115mm ≧ L₁Nozzle length in the range of ≧ 62 mm
Is preferred. Further, for example, the nozzle length L₁= 55 mm
Then, the elevation angle θ₁= 8 °, 140mm ≧ H₁≧ 45
mm, elevation angle θ₁= 30 °, 0 ≧ H₁≧ -14 mm
Nozzle root height H₁Is preferred.

More specifically, a silicon oxide film (SiO ₂
Explaining the case of CVD of a film, a compound gas containing silicon (Si) may be used as the first gas. For example, using SiH ₄ gas as the first gas, the first nozzle 801, which has a nozzle length L ₁ = 50 mm and a nozzle root height H ₁ = 40 mm facing the high-density plasma formation region 11, is ...
Introduced from 807, ... at a flow rate of 50 sccm. On the other hand, as the _second gas, O ₂ gas having a flow rate of 100 sccm or a mixed gas of O ₂ gas and a rare gas such as Ar can be used. This second gas is used as an 8-inch wafer (substrate)
Nozzle length L ^* ₁ = 5 parallel to the substrate surface
It may be introduced from the second nozzles 901, ..., 905, ... Of 20 mm and the height H ^* _{1 of} the nozzle root is 40 mm.
Then, a high frequency electric field for plasma generation of about 3 kW is applied from the RF power source 6, and at the same time, the bias power source 7 is used to
Plasma is generated by applying a bias high-frequency electric field of about 2 kW. As shown in FIG. 1, since the first nozzles 801, ..., 807, ... Introducing SiH ₄ are directed upward, Si in the high density plasma formation region 11 is
The H ₄ gas concentration becomes high. As a result, the first ion species (S
iH ₃ ⁺ , SiH ₂ ⁺ , SiH ⁺ , Si ⁺ ) reaches the surface of the substrate 5 via the ion transit region 10, and the first ion species (SiH ₃ ⁺ , SiH ₂ ⁺ , SiH) are formed on the surface of the substrate 5. ⁺ ,
The surface reaction via Si ⁺ is promoted, and Si on the substrate 5
An O ₂ film is deposited.

The reaction of depositing the silicon oxide film (SiO ₂ film) on the substrate 5 by the high density plasma using SiH ₄ / Ar / O ₂ gas system will be described in detail below.
In the following description, the subscripts (s), (g), and (d) represent the surface, gas, and deposited film state, respectively. That is, the following five main reactions occur in the plasma CVD of the SiO ₂ film.

[0038] (a) oxidation of the surface (OH group _{created): Si (s) -H p} + oxidizing agent → Si _(s) -OH _q + byproducts ..... (7) where, p = 1,2,3, q = 1,2,3, the oxidizer is O, O *, OH, and the byproducts are OH and H ₂ O.

(B) Desorption of H by excitation of ion species (film formation surface site Si _(s) -OH generation): Si _(s) -OH _q + ion species X ⁺ → Si _(s) -OH + by-product + X (8) Here, q = 1, 2, 3, and the ion species X ⁺ is Ar ⁺ , O ⁺ ,
O ₂ ⁺ , Si _x H _y ⁺ , and by-products are H ₂ and H ₂ O.

(C) Si source supply (film formation reaction at the film formation site on the surface): Si _(s) -OH + Si source Neutral radical species SiH _x → SiO _{2 (d)} + Si _(s) -H _{x + 1} (9) Si _(s) -OH + Si source ion species SiH _x ⁺ + e → SiO _{2 (d)} + Si _(s) -H _{x + 1} (10) where Si source Neutral radical species SiH _x is SiH ₃ , Si
H ₂ , SiH, Si and SiO, and Si _(s) -H _{x + 1} is S
_{i (s) -H, Si (} s) are _{-H 2, Si (s) -H} 3, Si source ionic species SiH _x ⁺ is ^{_{SiH 3 +, SiH 2 +,}} SiH +, Si +
Is.

(D) Sputter etching: ionic species X ⁺ + SiO _{2 (d)} → SiO _{2 (g)} + X (11) Here, the ionic species X ⁺ is Ar ⁺ , O ⁺ , O ₂ ^+. , Si _x H _y ⁺ .

[0042] (e) direct deposition (sputtering species of re-adhesion, film formation) of _{SiO 2: SiO 2 (g)} → SiO 2 (d) ····· (12) of the groove embedded characteristic of the formula ( 8), improved by the ionic reaction shown in formula (10), and formula (9), formula (12)
It is exacerbated by the reaction shown in. According to the present invention, the Si source ionic species Si which is the first ionic species necessary for the surface reaction
H _x ⁺ (SiH ₃ ⁺ , SiH ₂ ⁺ , SiH ⁺ , Si ⁺ ) is increased, and Si source neutral radical species SiH _x (SiH ₃ , SiH ₂ ,
(SiH, Si, SiO) density is reduced, and further non-Si source ion species (Ar ⁺ , O ⁺ , O ₂ ^+, etc.) which is the second ion species.
In order to reduce the density, the ionic reaction shown in formula (10) is promoted, and the reaction of the neutral radical species shown in formula (9) and the reaction of formula (12) (formula (11) are suppressed. The sputtering reaction with respect to the SiO ₂ film represented by () is suppressed. Therefore, it becomes possible to fill the narrow wirings with the SiO ₂ film, which cannot be filled by the conventional method.

FIG. 4 shows the RF power dependence of the Si source ion species density and the RF of the Si source ion species relative density defined by (Si source ion species density / Si source neutral radical species density).
Shows power dependence. Figure 4 shows the Journal of Vacuum Science End Technology (J.Vac.Sc
i.Technol.), Vol. A16, No. 2, 1998, which is a result of a reaction simulation using a reaction model of Ellen Meeks et al. This reaction simulation was calculated using a complete mixing tank (PSR) and Chemkin Aurora, which is an application for analyzing a tank row model. As shown in FIG. 4, when the RF power is 1 kW or higher, the Si source neutral radical species density ([SiH _x ] = [S
iH ₃ ] + [SiH ₂ ] + [SiH] + [Si] + [SiO]) does not change much, while the Si source ion species density ([SiH _x
⁺ ] = [SiH ₃ ⁺ ] + [SiH ₂ ⁺ ] + [SiH ⁺ ] + [S
It can be seen that i ⁺ ]) continues to increase. As a result, as shown in FIG. 4, it can be seen that the relative density of Si source ion species (= Si source ion species density / Si source neutral radical species density) increases up to 8 kW.

[0044] Figure 5 shows the SiH ₄ gas concentration dependency of the Si source ion species density in the RF power 3 kW, and the SiH ₄ gas concentration dependency of the Si source ionic species relative density. Si
The H ₄ gas concentration is [SiH ₄ ] / ([SiH ₄ ] + [O ₂ ] + [A
r]). As shown in FIG. 5, as the SiH ₄ gas concentration increases, the Si source neutral radical species (SiH _x )
Both the density and the Si source ion species (SiH _x ⁺ ) density increase, but since the Si source neutral radical species density becomes saturated, the Si source ion species relative density rapidly increases at a SiH ₄ gas concentration of 0.4 or more. Increase. That is, since the first nozzles 801, ..., 807, ... for ejecting SiH ₄ are directed obliquely upward, the SiH ₄ gas concentration in the high density plasma formation region 11 is increased. I understand. As a result, the density ratio of the first ion species (SiH _x ⁺ ) that controls the reaction rate (growth rate) of the surface reaction on the Si substrate 5 to the neutral radical species (SiH _x ) is 0.015 to 0. 0
25, the relative density of the Si source ion species (first ionic species) to the neutral radical species is high.

[0045] Figure 6 shows the SiH ₄ gas concentration dependency of the Si source ion species density in the RF power 7 kW, and the SiH ₄ gas concentration dependency of the Si source ionic species relative density. Figure 6
As shown in, with increasing SiH ₄ gas concentration, Si source neutral radicals (SiH _x) atom density, Si source ion species (S
iH _x ⁺ ) density increases, but Si source neutral radical density becomes saturated, so SiH ₄ gas concentration is 0.4
As described above, the relative density of the Si source ion species rapidly increases. As a result, the density ratio of “first ionic species (SiH _x ⁺ ) generated from the first gas” to “neutral radical species (SiH _x ) generated from the first gas” is 0.
It is 025 to 0.045, and it can be seen that the relative density of the Si source ion species (first ion species) to the neutral radical species is extremely high. As can be seen from the results shown in FIGS. 5 and 6, the relative density of Si source ion species is increased and the embedding limit is greatly improved by the synergistic effect of increasing the RF power applied to the gas and the effect of increasing the SiH ₄ gas concentration. I understand.

Actual fluxes of Si source neutral radical species and Si source ion species to the substrate Γ (SiH _x ), Γ (SiH
_x +) is Γ (SiH _x ) = (1/4) · [SiH _x ] · v (SiH _x ) (13) Γ (SiH _x ⁺ ) = 0.6 · [SiH _x ⁺ ] · V (SiH _x ⁺ ) (14) v (SiH _x ⁺ ) = (2 · q · V _dc / m _i ) ^1/2 (15) Where q is the elementary charge, x is the ionization number,
m _i is the ion mass, V _dc is the self-bias voltage, and v (S
iH _x ) is the heat velocity of neutral radicals, and v (SiH _x ⁺ ) is the substrate incident velocity of ionic species. Taking a typical example, V _dc
= 85V, temperature T (gas) = 700 [K], v (SiH ₂ ) =
660 [m / s], v (SiH ₂ ⁺ ) = 22000 [m / s], and the flux ratio is about 80 times the relative density of Si source ion species.

FIG. 7 shows the improvement of the embedding limit in the first embodiment by using the first nozzles 801, ..., 807 ,.
Shown as the nozzle angle (elevation angle) θ ₁ dependency of ... Figure 7
As shown in the drawing, when the aspect ratio is about 5, the embedding limit is about 140 nm in the conventional example (θ ₁ = 0 °), but the first nozzles 801, ..., 807, ... -By only facing upward, the filling property in the groove is greatly improved, and at least in the range of 8 ° ≤ θ ₁ ≤ 40 °, the groove depth is about 400 nm to 800 nm, and the groove width up to about 110 nm is easy. It can be seen that it can be embedded in. Although illustration is omitted, if the conditions are further optimized, it is possible to embed up to a groove width of 95 nm at a groove depth of 400 nm to 800 nm. For optimizing the conditions, Ar ⁺ shown in equations (11) and (12) is used.
In order to prevent sputtering, re-deposition and film formation (reaction) due to ions, it is effective to reduce the Ar gas flow rate or not flow Ar gas at all.

On the other hand, as shown in FIG. 7, the uniformity of the film thickness is obtained by directing the first nozzles 801, ..., 807 ,. Since the source is reduced and the growth rate of the CVD film is reduced in the peripheral portion of the substrate 5, the film thickness uniformity is greatly changed. If the condition that the uniformity is ± 8% or less is required as a practical level, the angle is 8 ° ≦ θ ₁ ≦ 30 °.
Is preferred. These are 3 sccm ≦ SiH ₄ flow rate / one nozzle ≦ 7 sccm, 10 sccm ≦ O ₂ flow rate / one nozzle ≦ 26 sccm, 0 sccm ≦ Ar flow rate /
It is effective within the range of 1 nozzle ≦ 10 sccm. CVD
In order to prevent the growth rate of the film from decreasing and to ensure the insulating property of the SiO ₂ film, the O ₂ gas or the O ₂ / Ar mixed gas is used as the second nozzles 901, ...・ ・ ・
.... From low density plasma formation region (12a, 12b)
Is supplied to.

[0049] SiH ₄ as long as a small amount of a 20% or less of the flow rate of the gas, as the carrier gas, noble gases such as Ar is also the first nozzle 801, ....., 807, SiH ₄ from ----- You may mix in. That is, in the present invention, the first gas is mixed with another gas such as a carrier gas having a flow rate ratio of 20% or less with respect to the “compound gas that generates the ionic species necessary for the surface reaction”. Can also be interpreted as "become" substantially "only from the compound gas that produces the ionic species."
In any case, in order to achieve both excellent groove filling characteristics and excellent film thickness uniformity, it is effective for these nozzle arrangements to have an angle range of 8 ° ≦ θ ₁ ≦ 30 °.

As already described using the equations (1) to (6), in order to improve the filling property in the groove portion while ensuring the uniformity, the first nozzles 801 ,. 80
7, nozzle length L ₁ , nozzle root height H ₁ , angle θ ₁ , substrate 5 size (radius r), plasma space size, that is, reaction chamber (1, 2) size (Radius R), height H ₂ from the ceiling of the dielectric container 2 to the surface of the substrate 5, between the substrate holders (4a, 4b, 4c, 4d) and the side walls (body) of the reaction chambers (1, 2). It is important to optimize the relationship with the gap length L of. First nozzle 801, ..., 807, ...
The elevation angle θ _{1 of} ... Is defined by the dielectric container 2 defined by the equation (4).
If it becomes larger than the angle θ ₂ directed to the center of the ceiling, the supply of Si source to the peripheral portion of the substrate 5 is greatly reduced, and it becomes impossible to secure the film thickness uniformity. On the contrary, when the elevation angle θ ₁ is small and the gas jet flow spreads in the direction of directly hitting the substrate 5, the filling property in the groove portion in the peripheral portion of the substrate 5 is deteriorated and
The film thickness locally increases and the uniformity deteriorates. Similar restrictions are applied to the upper limit of the nozzle root height H ₁ .
Further, when the nozzle length L ₁ is shortened, the gas is pulled toward the exhaust side, and the raw material efficiency is greatly deteriorated. If the nozzle length L ₁ is too long, it becomes difficult to secure the film thickness uniformity in the peripheral portion of the substrate 5,
The problem of nozzle deterioration due to high-density plasma also occurs.

When the first nozzles 801, ..., 807, ... According to the first embodiment of the present invention are used, fine particles are generated between processes, for example, when the substrate 5 is transferred. May enter through the nozzle hole, resulting in deterioration of stability in a later film forming process. In order to ensure long-term stability, it is necessary to flow a rare gas or an inert gas such as N _{2 at} a time other than when the raw material gas is flowing during film formation.

In the above description, SiO₂Membrane plasma C
Generates the first ionic species required for surface reaction in VD
SiH as compound gas_FourAlthough gas was used as an example, S
iH_FourOther than gas, disilane (Si₂H₆) Si such as gas
Hydride, silicon tetrachloride (SiCl_Four), Trichlorosila
(SiHCl_Three), Dichlorosilane (SiH_TwoC
l _Two) Etc., or tetraethyl silicate
An organic source such as TEOS is supplied to the first nozzle 801, ...
・ ・ ・, 807, ...₂Gas, CO₂, N₂O
Second nozzle 90 that horizontally directs a gas containing oxygen such as
1, ..., 905, ...
SiO with excellent filling characteristics and film thickness uniformity₂The membrane
It is possible to form a film.

(Second Embodiment) The ICP type plasma CVD was explained in the first embodiment, but the plasma etching is explained in the second embodiment. The configuration of the plasma processing apparatus used for the plasma etching according to the second embodiment is substantially the same as the configuration shown in FIGS. 1 and 2. However, the gas to be introduced is different from that of plasma CVD, and particularly, the second nozzles 901, ...
5, the main difference is that the second gas, which is a raw material for generating radical species necessary for the surface reaction of the substrate 5, is injected. Further, the plasma C according to the first embodiment
In the VD apparatus, it has been described that the gas cooling means (not shown) is housed inside the substrate holders (4a, 4b, 4c, 4d), but in the plasma etching apparatus according to the second embodiment, the substrate 5 It is different in that a water cooling pipe for cooling is provided. Regarding the method of cooling the upper portion 4a of the substrate holder serving as the wafer stage, liquid nitrogen, liquid helium or fluorocarbon may be used as the coolant. Others are the ICP type plasma C according to the first embodiment.
Since it is substantially the same as the VD apparatus, duplicate description of the structure of the plasma processing apparatus will be omitted.

Here, the ICP type plasma CVD apparatus shown in FIGS. 1 and 2 will be described as a plasma etching apparatus. That is, in the plasma processing apparatus shown in FIGS. 1 and 2, in the direction inclined from the side wall portion adjacent to the first low density plasma formation region 12a of the reaction chamber (1, 2) toward the high density plasma formation region 11 direction. Along with this, a compound gas that generates an ionic species (corresponding to the “first ionic species” in the first embodiment) that is necessary for the surface reaction of the substrate 5 or that controls the reaction rate (etching rate) of the surface reaction. Injecting a first gas consisting essentially of only the first gas
At the same time as the step of injecting the gas of
From the side wall portion adjacent to the first low-density plasma formation region 12a of the second gas as a raw material for generating radical species necessary for the surface reaction (etching reaction) of the substrate 5 in the direction parallel to the surface of the substrate 5. By injecting, the plasma etching according to the second embodiment can be performed. And
By applying a high-frequency electric field to the high-density plasma formation region 11, the first low-density plasma formation region 12a, and the second low-density plasma formation region 12b, high-density ion species were generated in the high-density plasma formation region 11. High-density plasma is generated, and low-density plasma is generated in the first low-density plasma formation region 12a and the second low-density plasma formation region 12b. Then, the generated ionic species and radical species reach the surface of the substrate 5 via the ion transit region 10, and plasma etching is promoted on the surface of the substrate 5 by a surface reaction via the ionic species and radical species.

In RIE, etching is advanced in the depth direction by using anisotropy of ionic species, but in order to open a trench, a contact hole or a via hole having a large aspect ratio, ionic species and neutrality are required. It is important to control the density of radical species. The neutral radical species are used for reaction layer formation on the etching surface and for sidewall protection that appears during etching. In general, insufficient production of ionic species occurs.

Specifically, as the first gas substantially composed of only the compound gas which produces the ionic species controlling the etching rate, for example, an alkyl halide gas which easily produces CH ₃ ⁺ ions, For example, methyl iodide (CH ₃ I) gas, methyl chloride (CH ₃ Cl) gas, or methyl fluoride (CH ₃ F) gas is used. on the other hand,
As the second gas, a perfluorocarbon gas that easily generates CF ₂ radicals, for example, tetrafluoroethylene (C ₂ F ₄ ) gas or perfluorosoncrobutane (C ₄ F ₈ ) gas is used. Although the ion species density is increased by using an alkyl halide such as CH ₃ I gas, the deficiency still remains. In the plasma etching apparatus according to the second embodiment, the alkyl halide gas is introduced from the first nozzles 801, ..., 807 ,. By introducing from the facing second nozzles 901, ..., 905, ..., It becomes possible to increase the decomposition efficiency of the alkyl halide and increase the ionic species insufficient for the surface reaction. . As a result, a trench having a large aspect ratio, a contact hole, a via hole, etc. can be etched with high accuracy and good reproducibility at an opening width of 100 nm level.

In addition to the alkyl halide / perfluorocarbon system, a gas for producing ionic species is introduced from the first nozzles 801, ..., 807 ,. The second nozzle 901, which horizontally orients the target gas or a gas other than the ion target generation gas,
..., 905, ...
Etching of trenches, contact holes, via holes, etc. with a large aspect ratio is possible with high precision and reproducibility.

(Third Embodiment) By optimizing the elevation angle θ ₁ of the nozzle, it becomes possible to control the increasing ion amount and radical amount. For example, plasma CVD
, The first nozzles 801, ..., 807, .. are used in the portions that require strict filling characteristics in the groove, and the elevation angle θ ₁ is reduced in the process that prioritizes deposition. A high-speed process can be achieved by introducing SiH ₄ gas or the like from the second nozzles 901, ..., 905, ... Even in one film forming process, the elevation angle θ ₁ is changed to a small value after the embedding, or the second nozzles 901, ...
It is also possible to increase the film formation rate by using .., 905, ..

In etching, the etching rate and anisotropic shape (etching shape) can be controlled.

The angle adjusting mechanism includes the first nozzles 801, ...
.., 807 ... There are mechanisms that are adjusted at the same time as a whole and mechanisms that are individually adjusted. In the case of individual control mechanisms, fine adjustment is possible to improve the film thickness distribution and to correct individual nozzle differences.

(Other Embodiments) As described above, the present invention has been described by the first to third embodiments. However, the description and drawings forming a part of this disclosure limit the present invention. Should not be understood to be. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

In the first embodiment, the plasma CVD of the SiO ₂ film has been described as an example, but the gas flowing from the second nozzles 901, ..., 905, ... Is replaced with a compound gas containing nitrogen such as nitrogen (N ₂ ) gas or ammonia (NH ₃ ) gas, or hydrogen (H ₂ ) gas, a silicon nitride film having excellent filling characteristics in the groove and excellent film thickness uniformity (Si ₃ N ₄ film) or amorphous silicon a
-SiH film can be formed using plasma reaction.
Also, together with the SiH ₄ gas, the first nozzles 801, ..., 8
07, ... from which monogermane (GeH ₄ ) gas and germanium fluoride (GeF ₄ ) gas are supplied to the second nozzle 901 ,.
Gases such as methane (CH ₄ ) gas, ethane (C ₂ H ₆ ) gas, ethylene (C ₂ H ₄ ) gas, acetylene (C ₂ H ₂ ) gas are introduced from ・ ・ ・, 905, ・ ・ ・. As a result, a-SiC and a-Si which are excellent in the filling property in the groove and the film thickness uniformity
A Ge: H film can also be formed.

Further, tungsten hexafluoride (WF ₆ ) is used as the first gas, which is a “compound gas for generating the ionic species (first ionic species) necessary for the surface reaction”, and the first nozzle 80.
1, ..., 807, ... Injecting, SiH ₄ gas or H ₂ gas as the second gas, the second nozzle 901,
.., 905, ....., a tungsten (W) film can be deposited. Similarly, titanium tetrachloride (TiCl ₄ ) gas is used as the first gas for the first nozzles 801, ...
-, 807, injected from · · · · ·, NH ₃ as a second gas
Gas, H ₂ gas, or N ₂ gas to the second nozzle 901,
......, 905, ...
iN) film can be deposited. By doing this, the W,
By improving the burying property of a metal film such as a TiN film, it is possible to form a metal wiring having excellent electrical conductivity properties, reliability, and film thickness uniformity. In this way, the gas for the purpose of ionization is introduced from the first nozzles 801, ..., 807 ,. .....
Various metal films, diamond films, ceramic films, and compound semiconductor films can be deposited by introducing 905, ...

In the above description of the first to third embodiments, the system of plasma CVD and plasma etching has been described. However, even in the case of ashing or the like other than this, a gas which needs ionization is used. It is possible to increase the ion species density by introducing it into the high-density plasma part and introducing another source gas into the low-density plasma region.

A vacuum preliminary chamber may be arranged in front of and behind the container base 1 via a substrate transfer gate valve.
In this way, when the substrate 5 is transferred, the substrate 5 is first set in the vacuum preliminary chamber (load lock chamber), the vacuum preliminary chamber is evacuated, the substrate transfer gate valve is opened, and the set substrate 5 is loaded by the loader robot. It is transferred into the container base 1 by the arm. Then, the substrate 5 is set on the substrate holder upper portion 4a by moving the substrate 5 onto a pin for delivering the substrate arranged around the upper portion 4a of the substrate holder, and applying a predetermined electrostatic chuck voltage to the embedded electrode. Alternatively, the substrate 5 may be clamped by an electrostatic chuck.

By using the plasma processing apparatus as shown in FIG. 1, a semiconductor device can be manufactured by the following steps.

(A) First, the surface of the semiconductor substrate (Si substrate) 5 is thermally oxidized to form an oxide film of 300 nm to 800 nm. Then, a photoresist film is spin-coated on the surface of the oxide film. Then, the photoresist film is patterned by the photolithography technique. Then, using this photoresist film as a mask, the oxide film is etched by RIE or the like. After etching the oxide film, the photoresist film is removed. Then, using the patterned oxide film as a mask, a groove having an opening width l ₂ of 95 nm to 130 nm and a depth of 400 nm to 800 nm is provided on the surface of the semiconductor substrate 5, as shown in FIG. After forming the groove, the oxide film used as the etching mask is removed.

(B) Next, a groove portion is provided inside a vacuum preliminary chamber (not shown) provided on the side wall of the container substrate 1 of the plasma processing apparatus shown in FIG. 1 via a substrate transfer gate valve (not shown). The semiconductor substrate 5 provided with is arranged. Then, after the vacuum preliminary chamber is evacuated, the substrate transfer gate valve is opened, and the semiconductor substrate 5 set in the vacuum preliminary chamber is transferred into the container substrate 1 by the loader robot arm. Next, the semiconductor substrate 5 is set on the substrate holder upper portion 4a by moving it to a substrate delivery pin arranged around the substrate holder upper portion 4a, and by lowering this pin, a predetermined electrostatic chuck voltage is applied to the embedded electrode. Then, the semiconductor substrate 5 is clamped by the electrostatic chuck. Then, the loader robot arm is returned and the substrate transfer gate valve is closed. As a result,
The semiconductor substrate 5 is arranged inside the reaction chamber (1, 2).

(C) Next, the main gate valve (not shown) connected to the vacuum exhaust pipe 13 of the plasma processing apparatus shown in FIG. 1 is opened, and the pressure in the reaction chambers (1, 2) is adjusted to the container substrate 1 10 ^-3 P while monitoring with a pressure measuring device installed in
Evacuate until a predetermined pressure of about a to 10 ^-7 Pa is reached. At this time, a vacuum exhaust pump such as a chemical type turbo-molecular pump connected to the vacuum exhaust pipe 13 via a main gate valve is used.

(D) When the predetermined pressure is reached, the cooling of the semiconductor substrate 5 is started by using the gas cooling means for controlling the substrate temperature. Further, as shown in FIG. 1, the reaction chamber (1, 2)
Provided on the side wall of the first low density plasma forming region 12
a has a root portion and a tip portion has a high-density plasma formation region 1
First nozzles 801, 802, ..., 8 heading in one direction
12, a silicon hydrogen compound (SiH ₄ ) gas is injected in the elevation angle θ ₁ direction of the substrate surface. At this time, the introduction gas control valve such as a mass flow controller provided in a part of the gas pipe 81 connected to the first nozzles 801, 802, ..., 812 controls the flow rate of the hydrogen compound gas of silicon. To do. Further, the CVD pressure is controlled by using a pressure control valve connected to the vacuum exhaust pipe 13.

(E) Simultaneously with the step of injecting the hydrogen compound gas of silicon, the second nozzles 901, ..., Provided in the first low density plasma forming region 12a shown in FIG.
905, ... Is used to inject oxygen gas or oxygen compound gas in a direction parallel to the surface of the semiconductor substrate 5. At this time, the second nozzles 901, ..., 905, ...
The flow rate of oxygen gas or oxygen compound gas is controlled by the introduction gas control valve provided in a part of the gas pipe connected to. Further, the CVD pressure is controlled by using a pressure control valve connected to the vacuum exhaust pipe 13.

(F) From the RF power source 6, for example, 13.5
By supplying a high frequency electric field of 6 MHz to the RF coil 3 and applying a high frequency electric field, the high density plasma forming region 1
A high density plasma in which the Si source ion species is generated at a high density is generated at 1, and a low density plasma is generated at the first low density plasma formation region 12a and the second low density plasma formation region 12b. At this time, the embedded electrode 4d shown in FIG.
The RF bias power supply 7 is used to apply an RF bias of 13.56 MHz, for example. As a result, the silicon oxide film 59 is deposited on the surface of the semiconductor substrate 5 by the surface reaction via the Si source ion species, and the groove is filled as shown in FIG. FIG. 3A is a schematic diagram of a stage in the middle of filling, but deposition is continued until the groove portion having a depth of 400 nm to 800 nm is completely filled.

(G) When the groove is completely filled, the RF power source 6
, The RF bias power source 7 is turned off, and the first nozzles 801, 802, ..., 812 and the second nozzle 9
The gas supply from 01, ..., 905 ,. Then, a main gate valve (not shown) connected to the vacuum exhaust pipe 13 of the plasma processing apparatus shown in FIG. 1 is closed, and a vacuum is supplied through a substrate transfer gate valve (not shown) provided on the side wall of the container substrate 1. The semiconductor substrate 5 in the preliminary chamber (not shown) is returned. Then, after closing the substrate transfer gate valve, the window of the vacuum preliminary chamber is opened and the semiconductor substrate 5 is taken out into the atmosphere.

(H) Thereafter, the surface of the silicon oxide film 59 is flattened by chemical mechanical polishing (CMP) or the like, if necessary. Since the subsequent process is a well-known semiconductor manufacturing process such as selective ion implantation making full use of the photolithography technique, description thereof will be omitted.

As described above, it goes without saying that the present invention includes various embodiments and the like not described here. Therefore, the technical scope of the present invention is defined only by the matters specifying the invention according to the scope of claims appropriate from the above description.

[0076]

According to the present invention, the burying property and etching property in a fine groove of 100 nm level are greatly improved, and the film thickness uniformity is also improved.

As a result, trenches, contact holes (via holes) and STI between fine wirings of 100 nm level are formed.
The trenches can be filled and etched, and an ultra-high speed and low power consumption semiconductor device or a giga-scale ultra-high density semiconductor integrated circuit (GSI) can be manufactured.

[Brief description of drawings]

FIG. 1 is a sectional view showing an outline of a plasma processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a top view schematically showing the arrangement of gas nozzles of the plasma processing apparatus according to the first embodiment of the present invention.

FIG. 3 (a) is a schematic cross-sectional view showing a characteristic of burying an oxide film in a groove when Ar ion flux is low and FIG. 3 (b) is high Ar ion flux. is there.

FIG. 4 is a diagram showing a relationship between RF power and Si source neutral radical species density, and a relationship between RF power and Si source ion species relative density.

FIG. 5 is a diagram showing the relationship between the SiH ₄ gas concentration and the Si source neutral radical species density and the relationship between the SiH ₄ gas concentration and the Si source ion species relative density at an RF power of 3 kW.

FIG. 6 is a diagram showing the relationship between the SiH ₄ gas concentration and the Si source neutral radical species density and the relationship between the SiH ₄ gas concentration and the Si source ion species relative density at an RF power of 7 kW.

FIG. 7 is a diagram showing a relationship between nozzle angle and film thickness uniformity, and a relationship between nozzle angle and embedding limit width.

FIG. 8 is a sectional view showing an outline of a conventional plasma CVD apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Container base (base) 2 Dielectric container 3 RF coil 4a Substrate holder upper part 4b Substrate holder lower part 4c Substrate holder support part 4d Embedded electrode 5 Substrate 6 RF power supply 7 Bias power supply 10 Ion transit area 11 High density plasma formation area (high density) Plasma region) 12a First low-density plasma formation region (first low-density plasma region) 12b Second low-density plasma formation region (second low-density plasma region) 13 Vacuum exhaust pipe 59 Silicon oxide film (SiO ₂ film) 61 Sputtering Deposition by seed 62 Overhang 81 Gas pipe 801, ..., 807, ... First nozzle 901, ..., 905, ... Second nozzle 921 Top nozzle

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hirotaka Ogiwara             8th Shinsugita Town, Isogo Ward, Yokohama City, Kanagawa Prefecture             Ceremony company Toshiba Yokohama office F-term (reference) 4K030 AA02 AA05 AA06 AA09 AA11                       AA13 AA14 AA16 AA17 AA18                       BA44 CA04 EA05 EA06 FA01                       FA02 FA04 KA20 LA15                 5F004 AA01 AA05 BA13 BA14 BB13                       BB20 BB22 BB25 BB28 BB29                       CA02 DA00 DA16                 5F045 AA08 AB01 AB03 AB32 AB33                       AC01 AC05 AC07 AC11 AC12                       AC14 DP03 DP04 EF09 EH11                       EH16 EH17 EJ03

Claims (8)

[Claims] 1. A substrate is disposed in a reaction chamber, an ion transit region adjacent to the substrate, a first low-density plasma formation region adjacent to the ion transit region, is provided between the top of the reaction chamber and the substrate. A high-density plasma forming area adjacent to the first low-density plasma forming area and a second low-density plasma forming area sandwiched between the high-density plasma forming area and the top of the reaction chamber are located, A method of forming a film on the substrate or etching the substrate by the surface reaction of the substrate using the plasma of, comprising placing the substrate in the reaction chamber, and reducing the pressure in the reaction chamber. A nozzle provided on a side wall of the reaction chamber, having a root portion in the first low-density plasma formation region, and having a tip portion directed toward the high-density plasma formation region, At the same time as the step of injecting a first gas substantially consisting only of a compound gas that generates the first ionic species necessary for the surface reaction in the elevation direction of the substrate surface, the step of injecting the first gas , The first
In the low-density plasma formation region, a second gas is generated in a direction parallel to the surface of the substrate, the second gas generating a second ionic species having a higher sputtering efficiency for the substance to be deposited or etched than the first ionic species. And a high frequency electric field is applied to the high-density plasma formation region and the first and second low-density plasma formation regions to generate the first ion species at high density in the high-density plasma formation region. High-density plasma is generated, low-density plasma is generated in the first and second low-density plasma formation regions, and the first ion species is allowed to reach the surface of the substrate via the ion transit region, And a step of causing the surface reaction with a first ionic species. 2. A substrate is disposed in a reaction chamber, an ion transit region adjacent to the substrate, a first low-density plasma formation region adjacent to the ion transit region, is provided between the top of the reaction chamber and the substrate. A high-density plasma forming area adjacent to the first low-density plasma forming area and a second low-density plasma forming area sandwiched between the high-density plasma forming area and the top of the reaction chamber are located, A method of forming a film on the substrate or etching the substrate by the surface reaction of the substrate using the plasma of, comprising placing the substrate in the reaction chamber, and reducing the pressure in the reaction chamber. A nozzle provided on a side wall of the reaction chamber, having a root portion in the first low-density plasma formation region, and having a tip portion directed toward the high-density plasma formation region, At the same time as the step of injecting a first gas substantially consisting of a compound gas that generates an ionic species necessary for the surface reaction in the elevation direction of the substrate surface, and at the same time as the step of injecting the first gas, First
In the low-density plasma formation region, injecting a second gas, which is a raw material for generating radical species necessary for the surface reaction of the substrate, in a direction parallel to the surface of the substrate; A high-frequency electric field is applied to the first and second low-density plasma formation regions to generate high-density plasma in which the ion species are generated at high density in the high-density plasma formation region, Generating low-density plasma in the low-density plasma formation region of No. 2 and allowing the ion species to reach the surface of the substrate through the ion transit region, and causing the surface reaction by the ion species and radical species. A plasma processing method comprising: 3. The group consisting of a metal hydrogen compound gas, a metal halogen compound gas, a metal organic compound gas, a semiconductor hydrogen compound gas, a semiconductor halogen compound gas, and a semiconductor organic compound gas. Wherein the second gas is a gas selected from the group consisting of a rare gas, a hydrogen gas, a nitrogen gas, a nitrogen compound gas, an oxygen gas and an oxygen compound gas. Item 3. The plasma processing method according to Item 1 or 2. 4. The plasma processing method according to claim 1, wherein the first gas is a hydrogen compound gas of silicon, and the second gas is an oxygen gas or a compound gas of oxygen. 5. The plasma processing method according to claim 2, wherein the first gas is an alkyl halide gas and the second gas is a perfluorocarbon gas. 6. The density ratio of the first ionic species to the neutral radical species generated from the first gas is 0.0.
It is 1-0.045, The plasma processing method of any one of Claims 1-5 characterized by the above-mentioned. 7. An apparatus for forming a film on a substrate or etching a substrate by a surface reaction using plasma, comprising: a reaction chamber capable of being evacuated; and a reaction chamber disposed in the reaction chamber for arranging the substrate. A substrate holder, a root portion is arranged on a side wall of the reaction chamber, and an injection direction is set from the side wall to a top direction of the reaction chamber, and a compound gas for generating a first ionic species necessary for the surface reaction. A plurality of first nozzles for introducing a first gas substantially consisting of only the first gas into the reaction chamber, a horizontal level substantially the same as the root of the first nozzle, or the root of the first nozzle It is arranged at a horizontal position closer to the substrate, has a jetting direction parallel to the surface of the substrate, has a smaller number of nozzles than the first nozzles, and has a sputtering efficiency with respect to the substance to be formed or etched. A second nozzle for introducing into the reaction chamber a second gas that is a raw material that generates a second ionic species higher than the first ionic species or a raw material that generates a radical species necessary for the surface reaction of the substrate; A high-frequency electric field applying unit for generating a high-density plasma in which the first ion species are generated in a high density, in a space between a position where the first nozzle is arranged and a top of the reaction chamber. A plasma processing apparatus characterized by the above. 8. A semiconductor substrate is disposed in a reaction chamber, an ion transit region adjacent to the semiconductor substrate and a first low density plasma formation adjacent to the ion transit region are provided between the top of the reaction chamber and the semiconductor substrate. A region, a high-density plasma formation region adjacent to the first low-density plasma formation region, and a second region sandwiched between the high-density plasma formation region and the top of the reaction chamber.
A method of manufacturing a semiconductor device, comprising: positioning a low-density plasma formation region and depositing a silicon oxide film on the semiconductor substrate by a surface reaction of the semiconductor substrate using plasma in the high-density plasma formation region. The opening has a width of 95 nm to 130 on the surface of the semiconductor substrate.
nm groove, arranging the semiconductor substrate in the reaction chamber, depressurizing the reaction chamber, and providing a side wall of the reaction chamber in the first low-density plasma formation region. Using a nozzle having a root portion and a tip portion directed toward the high-density plasma formation region, injecting a hydrogen compound gas of silicon in the elevation direction of the substrate surface; and injecting a hydrogen compound gas of the silicon. Simultaneously with the step, in the first low density plasma formation region, injecting oxygen gas or oxygen compound gas in a direction parallel to the surface of the substrate, and applying a high frequency electric field to the high density plasma The high-density plasma in which the Si source ion species is generated at a high density is generated in the formation region, and the first and second low-density plasma formation is performed. The method of manufacturing a semiconductor device for generating a low-density plasma to pass, the deposited silicon oxide film by the surface reaction via the Si source ionic species, characterized in that it comprises the step of filling the groove.