JP4255563B2 - Semiconductor manufacturing method and semiconductor manufacturing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a semiconductor, and more particularly to a method for forming a gate insulating film in a MIS type semiconductor device.
[0002]
[Prior art]
Recently, with the miniaturization of MIS type semiconductor devices, an extremely thin gate insulating film of about 4 nm or less is required. Conventionally, as a gate insulating film material, a silicon oxide film (SiO 2) obtained by direct oxidation of a silicon substrate using a high temperature heating furnace of about 850 ° C. to 1000 ° C. ₂ Membranes) have been used industrially.
[0003]
However, SiO ₂ If the film is thinned to 4 nm or less, a leakage current (gate leakage current) flowing through the gate insulating film increases, and problems such as an increase in power consumption and acceleration of device characteristic deterioration occur.
[0004]
In addition, when the gate electrode is formed, boron contained in the gate is SiO. ₂ There is also a problem that the semiconductor device characteristics are deteriorated by penetrating the film and reaching the silicon substrate. As one method for solving such problems, a nitride film (SiN film) has been studied as a gate insulating film material.
[0005]
When this SiN film is formed by the CVD method, a large number of incomplete bonds (dangling bonds) are generated at the interface with the silicon substrate, thereby deteriorating device characteristics.
For this reason, a method of directly nitriding a silicon substrate using plasma is considered promising in forming the SiN film. The reason for performing direct nitriding is to obtain a high-quality gate insulating film with few interface states.
[0006]
The reason for using plasma is to form the SiN film at a low temperature. When the SiN film is nitrided by heating, a high temperature of 1000 ° C. or higher is required, and the device characteristics deteriorate due to differential diffusion of the dopant implanted into the silicon substrate by this thermal process. Such a method is disclosed in Japanese Patent Laid-Open Nos. 55-134937 and 59-4059.
[0007]
However, when the SiN film is formed using plasma, ions in the plasma are accelerated by the plasma sheath potential and incident on the silicon substrate with high energy, so that so-called plasma damage occurs on the silicon substrate interface or the silicon substrate, The problem of device characteristics has been pointed out.
[0008]
In response to this problem, a microwave plasma apparatus including a planar antenna having a large number of slits having a low electron temperature and a small plasma damage has been reported.
[0009]
(Ultra Clean technology Vol.10 Supplement 1, p.32,1998, Published by Ultra Clean Society).
[0010]
When this plasma apparatus is used, since the electron temperature is about 1 eV or less and the plasma sheath voltage is also several volts or less, plasma damage can be greatly reduced compared to conventional plasma having a plasma sheath voltage of about 50V.
[0011]
However, even when silicon nitridation is performed using this plasma apparatus, in the case of forming a SiN film by direct nitridation, in order to obtain a high-quality interface with few bonding defects by unevenly distributing oxygen only at the silicon substrate interface. However, there is a problem that it is difficult to control the film quality at the interface with the silicon substrate.
[0012]
Further, when this plasma apparatus is used, since nitriding proceeds by diffusion of nitrogen atoms into the silicon substrate, the nitriding rate is slow, the time for performing predetermined treatment on the object to be processed is long, and the object to be processed per unit time There is a problem that the number of processed bodies is small and cannot be used industrially. For example, in the case of forming a 4 nm SiN film, it takes about 5 minutes or more even if various plasma conditions such as pressure and microwave power are adjusted, and throughput required from the point of mass production, for example, 1 minute per object to be processed This is significantly below the target processing time.
[0013]
[Problems to be solved by the invention]
The present invention has been made to solve the above conventional problems. That is, an object of the present invention is to provide a semiconductor manufacturing method and manufacturing apparatus capable of successfully controlling film quality at the interface between a silicon substrate and a SiN film.
[0014]
Another object of the present invention is to provide a semiconductor manufacturing method and manufacturing apparatus capable of forming a high-quality SiN film in a short time.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, a semiconductor manufacturing method of the present invention irradiates a substrate to be processed mainly composed of silicon with a microwave through a planar antenna member having a plurality of slits in a processing gas atmosphere. Ar, Contains oxygen or nitrogen or oxygen and nitrogen Of the process gas A plasma is formed, and the surface of the substrate to be processed is directly oxidized, nitrided, or oxynitrided using the plasma, and the equivalent film thickness of the oxide film is 1 nm or less. Forming a first insulating film; and forming a second insulating film on the first insulating film by a CVD method. It is characterized by that.
[0016]
In the semiconductor manufacturing method of the present invention, since the insulating film thickness is 1 nm or less, the nitridation of the silicon substrate is not diffusion but the step of reacting nitrogen atoms or oxygen atoms or nitrogen atoms and oxygen atoms generated by plasma with the silicon substrate surface. The nitriding rate can be performed in a short time of about 30 seconds.
[0017]
When the remaining insulating film is formed by CVD on this directly nitrided or oxidized or oxynitrided thin film insulating film, a film forming speed of 3 nm / min or more can be achieved relatively easily, so that the insulation with a total film thickness of 4 nm is achieved. Even a film can be formed within 2 minutes.
[0018]
Furthermore, in the semiconductor manufacturing method of the present invention, the step of forming a high-quality insulating film at the interface with the silicon substrate by direct nitridation, oxidation, or oxynitriding and the step of forming the remaining insulating film thereon by CVD are performed independently. Therefore, the quality controllability at the interface of the silicon substrate is improved as compared with a method of forming an insulating film by direct nitridation or CVD, and a higher quality insulating film can be formed.
[0019]
In this semiconductor manufacturing method, the processing gas is, for example, N. ₂ Or N ₂ O or NO or NH _Three The gas containing is mentioned. This processing gas may contain a rare gas such as argon.
[0021]
In the semiconductor manufacturing method, examples of the second insulating film include an insulating film made of silicon nitride.
[0023]
The second insulating film is formed by, for example, N ₂ Or NH _Three And a method of forming by supplying plasma containing monosilane, dichlorosilane, or trichlorosilane.
[0024]
According to the semiconductor manufacturing method of the present invention, a so-called RLSA (Radial Line Slot) is used in which a substrate to be processed mainly composed of silicon is irradiated with microwaves through a planar antenna member having a plurality of slits in a processing gas atmosphere. Antenna) Since the SiN insulating film is formed by supplying plasma directly onto the silicon substrate by using an antenna, the film quality at the interface between the silicon substrate and the SiN insulating film formed on the surface of the silicon substrate can be controlled successfully. .
[0025]
Furthermore, according to another semiconductor manufacturing method of the present invention, the first insulating film is formed by a method using a so-called RLSA antenna, and the second insulating film is formed by low-damage plasma irradiation. A SiN film can be formed. In particular, when the second insulating film is formed by the CVD method, the film can be formed in a short time, and a high-quality SiN film can be formed in a short time.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
One embodiment of the present invention will be described below.
[0027]
First, an example of the structure of a semiconductor device manufactured by the semiconductor manufacturing method of the present invention will be described with reference to FIG. 1 taking a semiconductor device having a gate insulating film as an insulating film as an example.
[0028]
In the figure, 1 is a silicon substrate, 11 is a field oxide film, 2 is a gate insulating film, and 13 is a gate electrode. The present invention is characterized by the gate insulating film 2, which is made of a high-quality insulating film formed at the interface with the silicon substrate 1, as shown in FIG. 1B, for example, about 1 nm. Of the first insulating film 21 and the second film 22 formed on the upper surface of the first insulating film 21 and having a thickness of about 3 nm, for example.
[0029]
In this example, the high-quality first film 21 is formed by irradiating a substrate to be processed mainly composed of silicon with microwaves through a planar antenna member having a plurality of slits in a processing gas atmosphere. Alternatively, a first silicon oxynitride film formed by forming nitrogen or a plasma containing oxygen and nitrogen and directly oxidizing, nitriding, or oxynitriding the surface of the substrate to be processed using the plasma ( (Hereinafter referred to as “SiON film”).
[0030]
The second film 22 having a higher deposition rate than the first film 21 is formed by a step of forming a second insulating film on the first insulating film.
[0031]
Next, a method for forming such a gate insulating film 2 will be described.
[0032]
FIG. 2 is a schematic diagram showing the overall configuration of a semiconductor manufacturing apparatus 30 for carrying out the semiconductor manufacturing method of the present invention.
[0033]
As shown in FIG. 2, a transfer chamber 31 is disposed almost at the center of the semiconductor manufacturing apparatus 30. A plasma processing unit 32, a CVD processing unit 33, and two load locks are provided so as to surround the transfer chamber 31. Units 34 and 35 and a heating unit 36 are provided.
[0034]
A pre-cooling unit 45 and a cooling unit 46 are disposed beside the load lock units 34 and 35, respectively.
[0035]
Transfer arms 37 and 38 are disposed inside the transfer chamber 31, and transfer wafers W to and from the units 32 to 36.
[0036]
Loader arms 41 and 42 are disposed on the front side of the load lock units 34 and 35 in the drawing. These loader arms 41 and 42 further move wafers W in and out of four cassettes 44 set on a cassette stage 43 disposed on the front side thereof.
[0037]
The CVD processing unit 33 in FIG. 2 can be replaced with a plasma processing unit of the same type as the plasma processing unit 32, and two plasma processing units may be set.
[0038]
Further, both the plasma processing unit 32 and the CVD processing unit 33 can be replaced with a single chamber type plasma / CVD processing unit, and one or two single chamber types are provided at the position of the plasma processing unit 32 or the CVD processing unit 33. It is also possible to set a plasma / CVD processing unit. In the case of two plasma treatments, a SiON film is directly formed by the processing unit 32, and then a plasma SiN film is CVD-processed by the processing unit 33; May be performed. Alternatively, after the SiON film is directly formed in parallel by the processing units 32 and 33, the SiN CVD film can be formed by another apparatus.
[0039]
FIG. 3 is a vertical sectional view of the plasma processing unit 32 used for forming the gate greening film 2.
[0040]
Reference numeral 50 denotes a vacuum vessel made of, for example, aluminum. An opening 51 larger than the substrate, for example, the wafer W, is formed on the upper surface of the vacuum vessel 50, and a flat cylindrical gas made of a dielectric such as aluminum nitride so as to close the opening 51 is formed. A supply chamber 54 is provided. A large number of gas supply holes 55 are formed in the lower surface of the gas supply chamber 54, and the gas introduced into the gas supply chamber 54 is supplied into the vacuum container 50 through the gas supply holes 55 in a shower shape. It is like that.
[0041]
Outside the gas supply chamber 54, for example, a high-frequency power source is formed via a radial line slot antenna (hereinafter abbreviated as “RLSA”) 60 formed of a copper plate, for example, generating 2.45 GHz microwaves. A waveguide 63 connected to the microwave power source 61 is provided. The waveguide 63 includes a flat circular waveguide 63A having a lower edge connected to the RLSA 60, a cylindrical waveguide 63B having one end connected to the upper surface of the circular waveguide 63A, and the cylindrical waveguide. A coaxial waveguide converter 63C connected to the upper surface of 63B, and a rectangular waveguide 63D having one end connected at right angles to the side surface of the coaxial waveguide converter 63C and the other end connected to the microwave power source 61. Are combined.
[0042]
Here, in the present invention, UHF and microwaves are referred to as a high-frequency region, and high-frequency power supplied from a high-frequency power supply unit is 300 MHz to 2500 MHz including 300 MHz or more UHF or 1 GHz or more microwaves. The plasma generated by these high frequency powers is called high frequency plasma.
Inside the cylindrical waveguide 63B, one end side of the shaft portion 62 made of a conductive material is connected to substantially the center of the upper surface of the RLSA 60, and the other end side is connected to the upper surface of the cylindrical waveguide 63B. Thus, the waveguide 63B is configured as a coaxial waveguide.
[0043]
For example, gas supply pipes 72 are provided at 16 positions arranged uniformly along the circumferential direction of the upper side wall of the vacuum vessel 50, and a gas containing a rare gas and N is supplied from the gas supply pipe 72. Are supplied evenly in the vicinity of the plasma region P of the vacuum vessel 50 without unevenness.
[0044]
A mounting table 52 for the wafer W is provided in the vacuum container 50 so as to face the gas supply chamber 54. The mounting table 52 incorporates a temperature control unit (not shown) so that the mounting table 52 functions as a heat plate. Further, one end side of the exhaust pipe 53 is connected to the bottom of the vacuum vessel 50, and the other end side of the exhaust pipe 53 is connected to the vacuum pump 55.
[0045]
FIG. 4 is a plan view of the RLSA 60 used in the semiconductor manufacturing apparatus of the present invention.
[0046]
As shown in FIG. 4, in the RLSA 60, a plurality of slots 60a, 60a,... Are concentrically formed on the surface. Each slot 60a is a substantially rectangular through groove, and adjacent slots are arranged so as to be orthogonal to each other to form the letter “T” of the alphabet. The length and arrangement interval of the slots 60 a are determined according to the wavelength of the microwave generated from the microwave power supply unit 61.
FIG. 5 is a vertical sectional view schematically showing a CVD processing unit 33 used in the semiconductor manufacturing apparatus of the present invention.
[0047]
As shown in FIG. 5, the processing chamber 82 of the CVD processing unit 33 is formed in an airtight structure with aluminum or the like, for example. Although omitted in FIG. 5, the processing chamber 82 includes a heating mechanism and a cooling mechanism.
[0048]
A gas introduction pipe 83 for introducing a gas is connected to the processing chamber 82 at the upper center, and the inside of the processing chamber 82 and the inside of the gas introduction pipe 83 are communicated with each other. The gas introduction pipe 83 is connected to a gas supply source 84. A gas is supplied from the gas supply source 84 to the gas introduction pipe 83, and the gas is introduced into the processing chamber 82 via the gas introduction pipe 83. As this gas, various gases used as raw materials for thin film formation are used, and an inert gas is used as a carrier gas when necessary.
[0049]
A gas exhaust pipe 85 for exhausting the gas in the processing chamber 82 is connected to the lower part of the processing chamber 82, and the gas exhaust pipe 85 is connected to an exhaust means (not shown) such as a vacuum pump. Then, the gas in the processing chamber 82 is exhausted from the gas exhaust pipe 85 by this exhaust means, and the processing chamber 82 is set to a desired pressure.
[0050]
In addition, a mounting table 87 on which the wafer W is mounted is disposed below the processing chamber 82.
[0051]
In the present embodiment, the wafer W is mounted on the mounting table 87 by an electrostatic chuck (not shown) having the same diameter as that of the wafer W. The mounting table 87 is provided with a heat source means (not shown), and has a structure capable of adjusting the processing surface of the wafer W mounted on the mounting table 87 to a desired temperature.
[0052]
The size of the mounting table 87 is such that a large-diameter wafer W having a diameter of 300 mm can be mounted, and the mechanism allows the mounted wafer W to rotate as necessary.
[0053]
By incorporating the large mounting table 87 in this manner, a 300 mm large-diameter wafer W can be processed, and a high yield and the resulting low manufacturing cost can be realized.
[0054]
In FIG. 5, an opening 82a for taking in and out the wafer W is provided on the wall surface of the processing chamber 82 on the right side of the mounting table 87. The opening and closing of the opening 82a moves the gate valve 98 in the vertical direction in the drawing. Is done. In FIG. 5, a transfer arm (not shown) for transferring the wafer W is provided adjacent to the right side of the gate valve 98, and the transfer arm enters and exits the processing chamber 82 through the opening 82a. The wafer W is placed on the wafer W and the processed wafer W is unloaded from the processing chamber 82. A shower head 88 as a shower member is disposed above the mounting table 87. The shower head 88 is formed so as to partition a space between the mounting table 87 and the gas introduction pipe 83, and is made of, for example, aluminum.
[0055]
The shower head 88 is formed so that the gas outlet 83a of the gas introduction pipe 83 is located at the upper center of the shower head 88, and the gas introduced into the processing chamber 82 is directly placed in the shower head 88 disposed in the processing chamber 82. Has been introduced.
[0056]
Next, a method for forming an insulating film made of the gate insulating film 2 on the wafer W using the above-described apparatus will be described.
[0057]
FIG. 6 is a flowchart showing the flow of each step of the method of the present invention.
[0058]
First, the field oxide film 11 is formed on the surface of the wafer W in the previous step.
[0059]
Next, a gate valve (not shown) provided on the side wall of the vacuum container 50 is opened, and the wafer W having the field oxide film 11 formed on the surface of the silicon substrate 1 is placed on the mounting table 52 by the transfer arms 37 and 38. .
[0060]
Subsequently, after closing the gate valve and sealing the inside, the internal atmosphere is evacuated by the vacuum pump 55 through the exhaust pipe 53 and evacuated to a predetermined degree of vacuum, and maintained at a predetermined pressure. On the other hand, for example, 2.45 GHz (3 kW microwave is generated from the microwave power supply unit 56, and the microwave is guided from the waveguide 51 and introduced into the vacuum vessel 50 through the RLSA 60 and the gas supply chamber 54. High-frequency plasma is generated in the upper plasma region P in the vacuum vessel 50.
[0061]
Here, the microwave is transmitted through the rectangular waveguide 63D in the rectangular mode, converted from the rectangular mode to the circular mode by the coaxial waveguide converter 63C, and transmitted through the cylindrical coaxial waveguide 63B in the circular mode. The signal is transmitted in a state of being expanded by the circular waveguide 63A, is radiated from the slot 60a of the RLSA 60, passes through the gas supply chamber 54, and is introduced into the vacuum vessel 50. At this time, since microwaves are used, high-density plasma is generated, and since microwaves are radiated from many slots 60a of the RLSA 60, the plasma becomes high-density.
[0062]
Then, while adjusting the temperature of the mounting table 52 and heating the wafer W to 400 ° C., for example, the Xe gas as the first gas from the gas supply pipe 72 and N ₂ Gas and H ₂ Gas and O ₂ Gas is introduced at a flow rate of 500 sccm, 25 sccm, 15 sccm, and 1.0 sccm, respectively, and the first step is performed.
[0063]
In this step, the introduced gas is activated (plasmaized) by the plasma flow generated in the vacuum vessel 3, and the surface of the silicon substrate 1 is oxynitrided by this plasma as shown in FIG. A first insulating film (SiON film) 21 is formed. Thus, this nitriding treatment is performed for 30 seconds, for example, to form a first insulating film (SiON film) 21 having a thickness of 1 nm.
[0064]
Next, the gate valve is opened, the transfer arms 37 and 38 are moved into the vacuum vessel 50, and the wafer W on the mounting table 52 is received. The transfer arms 37 and 38 take out the wafer W from the plasma processing unit 32 and then set it on the mounting table 87 in the adjacent CVD processing unit 33.
[0065]
Next, a CVD process is performed on the wafer W in the CVD processing unit 33, and a second insulating film is formed on the previously formed first insulating film.
[0066]
That is, in the vacuum vessel 3, the second step is performed by introducing the second gas into the vessel 82 in a state where the wafer temperature is 400 ° C. and the process pressure is 50 mTorr to 1 Torr, for example.
That is, a gas containing Si from the gas supply source 84, for example, SiH _Four The gas is introduced at a flow rate of 15 sccm, for example, and Xe gas and N are introduced from the gas introduction pipe 83. ₂ The gas is introduced at a flow rate of 500 sccm and 20 sccm, respectively.
[0067]
In this step, the introduced second gas is deposited on the wafer W, and the film thickness increases in a relatively short time. Thus, as shown in FIG. 7B, a second insulating film (SiN film) 22 is formed on the surface of the first insulating film (SiON film) 21. Since the SiN film 22 has a film forming speed of, for example, 4 nm / min, this film forming process is performed for, for example, 30 seconds to form a second insulating film (SiN film) 22 having a thickness of 2 nm. In this way, the gate insulating film 2 having a thickness of 4 nm is formed in a total of 30 seconds.
[0068]
In the first step described above, when forming the first insulating film, a microwave is passed through a planar antenna member (RLSA) having a plurality of slits on a wafer W containing silicon as a main component in a processing gas atmosphere. To form a plasma containing oxygen or nitrogen, or oxygen and nitrogen, and using this plasma, the surface of the substrate to be treated is directly oxidized, nitrided, or oxynitrided to form an insulating film. Therefore, the quality is high and the film quality can be controlled successfully.
[0069]
That is, the quality of the first insulating film is high as shown in FIG.
[0070]
As shown in FIG. 8, by using the semiconductor manufacturing method of the present invention, it is possible to secure a low interface level at the same level as the thermal oxide film, and to reduce the pressure resistance of the gate insulating film and the penetration of boron in the gate electrode. Became possible.
[0071]
On the other hand, in the SiN film formed by direct nitridation and CVD, the interface state increased compared to the thermal oxide film. In this case, carrier dispersion at the interface increases, and the drive current of the transistor decreases.
[0072]
The reason why the quality of the first insulating film formed by the above-described method is high is considered as follows.
[0073]
That is, in the semiconductor manufacturing method of the present invention, both nitrogen atoms and oxygen atoms efficiently terminate the bonding of silicon atoms at the silicon substrate interface, and dangling bonds are reduced. In addition, the CVD-SiN film effectively acts on the pressure resistance of the gate insulating film and the penetration of boron. As a result, the advantages of the direct oxynitride SiON film and the CVD-SiN film can be successfully used in the semiconductor manufacturing method of the present invention.
[0074]
On the other hand, when the interface is formed of only SiN, it is considered that the termination of dangling bonds is incomplete, which increases the interface state.
[0075]
In addition, by performing the second step, the second insulating film formed on the first insulating film can be formed in a short time. As a result, the entire insulating film 2 can be formed in a short time as shown below.
[0076]
For example, for the formation of the first insulating film SiON, the pressure is 100 mTorr, Xe, N using RLSA plasma. ₂ , H ₂ , O ₂ As shown in FIG. 9, a 1 nm SiON film can be formed in about 30 seconds by forming the gas flow rates of 500 sccm, 25 sccm, 15 sccm and 1 sccm at 400 ° C., respectively.
[0077]
However, it took 245 seconds to form a 3 nm SiON film under the same conditions. At this deposition rate, O ₂ Even when the flow rate was zero, there was almost no change. On the other hand, in CVD, Xe, SiH _Four , N ₂ A film formation rate of about 4.5 nm / min was achieved at a gas flow rate of 500 sccm, 15 sccm, 20 sccm and a temperature of 400 ° C., respectively. Therefore, it was formed within about 30 seconds with a film thickness of 2 nm. As a result, the semiconductor manufacturing method of the present invention can form an insulating film having a thickness of 3 nm within a total of about 60 seconds, so that the deposition rate can be greatly improved compared to the direct nitriding method.
[0078]
Further, it can be seen that the film thickness change due to the direct oxynitridation film formation by the RLSA plasma is proportional to the time up to about 1 nm as shown in FIG. However, if it exceeds this, it becomes diffusion-controlled and the film-forming speed | rate falls gradually. Therefore, in the semiconductor manufacturing method of the present invention, a 1 nm SiON film was formed by direct oxynitridation, and then a SiN film was formed by CVD.
[0079]
(Example)
Examples are shown below.
[0080]
By the semiconductor manufacturing method of the present invention, a 2 nm SiON film is formed on the n-type silicon substrate on which element isolation has been formed by using the processing unit shown in FIG. 2 using RLSA plasma using the apparatus shown in FIG. did. The total insulating film thickness is 3 nm (equivalent oxide film thickness). For SiON film formation conditions, Xe / N ₂ / H ₂ / O ₂ The flow rate was 500 sccm / 25 sccm / 15 sccm / 1 sccm, the pressure was 100 mTorr, the microwave power was 2.0 KW, and the temperature was 400 ° C.
[0081]
Regarding the formation conditions of the CVD-SiN film, Xe / SiH _Four / N ₂ The flow rate was 500 sccm / 15 sccm / 20 sccm, the pressure was 100 mTorr, the microwave was 25 KW, and the temperature was 400 ° C. The film formation time was 62 seconds, the throughput was 40 sheets / h, and it was confirmed that it was a level that could be applied industrially.
[0082]
The film thickness uniformity was 3% with 3 sigma, and good results were obtained.
[0083]
Subsequent to the formation of the gate insulating film, a p-type poly-Si-gate was formed and the gate leakage current and the interface state were measured. As a result, the gate leakage is 1.3 × 10 5 with respect to the applied electric field of 75 mV / cm. ^-6 A / cm ² The interface state is 6.5 × 10 ^Ten / Cm ² Good results were obtained with / eV. Further, when a p-MOSFET (L / W = 0.25 / 10 μm) was formed and the on-current was measured, a value equal to or higher than that of the oxide film (5.5 × 10 5). ^-Four A / μm) was obtained.
[0084]
As described above, a high-quality gate insulating film of about 3 nm can be formed at an industrially sufficient film formation rate by the semiconductor manufacturing method of the present invention.
[0085]
【The invention's effect】
According to the present invention, in a process gas atmosphere, a substrate using silicon as a main component is irradiated with microwaves via a planar antenna member having a plurality of slits, and a method using a so-called RLSA antenna is used. Since the plasma is directly supplied to the SiN insulating film, the film quality at the interface between the silicon substrate and the SiN insulating film formed on the surface of the silicon substrate can be successfully controlled.
[0086]
Furthermore, according to another semiconductor manufacturing method of the present invention, since a second insulating film is formed on a first insulating film formed by a method using a so-called RLSA antenna, a high-quality SiN film is formed. Can do. In particular, when the second insulating film is formed by the CVD method, the film can be formed in a short time, and a high-quality SiN film can be formed in a short time.
[Brief description of the drawings]
FIG. 1 is a vertical sectional view of a semiconductor device manufactured by a semiconductor manufacturing method of the present invention.
FIG. 2 is a schematic view of a semiconductor manufacturing apparatus for carrying out the semiconductor manufacturing method of the present invention.
FIG. 3 is a vertical sectional view of an RLSA plasma processing unit used in the semiconductor manufacturing method of the present invention.
FIG. 4 is a plan view of RLSA used in the semiconductor manufacturing apparatus of the present invention.
FIG. 5 is a schematic vertical sectional view of a CVD processing unit used in the semiconductor manufacturing method of the present invention.
FIG. 6 is a flowchart of a gate insulating film forming step in the method of the present invention.
FIG. 7 is a detailed view of forming a gate insulating film by the method of the present invention.
FIG. 8 is a diagram comparing various film forming conditions and quality characteristics of a gate insulating film obtained under the film forming conditions.
FIG. 9 is a diagram showing a relationship between a film formation time and a film thickness in various film formation methods.
FIG. 10 is a graph showing the relationship between film formation time and film thickness in the semiconductor manufacturing method of the present invention.
[Explanation of symbols]
W: Wafer (substrate to be processed)
60 ... RLSA (planar antenna member)
21: First insulating film
22 ... Second insulating film
32 ... Plasma processing unit (process chamber)
33 ... CVD processing unit (process chamber)

Claims (6)

In a processing gas atmosphere, Ar and oxygen or nitrogen or oxygen and nitrogen are included by irradiating a substrate to be processed mainly composed of silicon through a planar antenna member having a plurality of slits. A plasma of the processing gas is formed, and the plasma is used to directly oxidize, nitride, or oxynitride the surface of the substrate to be processed to form a first insulating film having an equivalent oxide thickness of 1 nm or less . Process,
Forming a second insulating film on the first insulating film by a CVD method;
A semiconductor manufacturing method comprising : The semiconductor manufacturing method according to claim 1, wherein the processing gas contains N _2, N ₂ O, NO, or NH ₃ . A semiconductor manufacturing method according to claim 1 or 2 ,
It said second insulating film, a semiconductor manufacturing method which is a silicon nitride. A semiconductor manufacturing apparatus for carrying out the semiconductor manufacturing method according to claim 1,
One or more process chambers having an evacuation mechanism for reducing the internal pressure to 1 Torr or less and oxidizing, nitriding, or oxynitriding;
A planar antenna member disposed at an upper portion of the process chamber and having a plurality of slits;
A microwave power source connected to the planar antenna member;
A temperature raising mechanism for placing a substrate to be processed in the process chamber and maintaining the temperature of the object to be processed at 400 ° C. or higher;
A gas supply mechanism for supplying a processing gas into the chamber;
A transport system for vacuum transporting the substrate to be processed;
A semiconductor manufacturing apparatus comprising: The semiconductor manufacturing apparatus according to claim 4 ,
Two or more process chambers are disposed so that gate insulating films can be formed in parallel. A semiconductor manufacturing apparatus according to claim 4 or 5 ,
The semiconductor manufacturing apparatus characterized by further comprising a CVD Chang bar.

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