JP5130589B2 - Semiconductor device manufacturing method and oxidation treatment apparatus - Google Patents

Description

  The present invention relates to a semiconductor device manufacturing method and an oxidation processing apparatus, and more particularly to a semiconductor device manufacturing method and an oxidation processing apparatus including a step of performing an oxidation process.

In order to improve the degree of integration and processing speed of semiconductor devices, it is essential to increase the electric capacity of the gate insulating film. For this reason, the SiO ₂ film as the gate insulating film has been thinned while improving its insulating characteristics. As a result, the thickness of the SiO ₂ film has been reduced to, for example, several atomic layers. For example, in a logic device, an oxide film having both a thickness of about 1.0 to 1.5 nm and high reliability is required. It is difficult to form such an oxide film by a conventional thermal oxidation method as described in, for example, literature: BE Deal and AS Grove, J. Appl. Phys. 36, 3770 (1965) (Non-Patent Document 1). It has become to.

  As a method of thinning the oxide film to increase the capacitance of the gate insulating film, in addition to the method of reducing the physical thickness while maintaining the reliability of the oxide film as described above, the dielectric constant is considered. There is also a method for reducing the equivalent oxide thickness (EOT). Since a high dielectric constant film (High-K film) such as an HfSiO film used in this case is likely to cause mutual diffusion with the Si substrate, it is formed on the Si substrate via a highly reliable oxide film as a barrier film. It is formed. Therefore, even when a high dielectric constant film is applied, a new technique for thinning an oxide film having high reliability is desired.

  In addition, it is required to form such a highly reliable oxide film at a lower temperature. For example, logic devices and SRAMs (Static Random Access Memory) are required to lower the oxide film formation temperature from the viewpoint of reducing the thermal budget for preventing re-diffusion of conductive impurities. Further, when a glass substrate is used as in, for example, an LTPS-TFT (Low Temperature Poly-Si Thin Film Transistor) device, the heat-resistant temperature of the substrate is about 400 to 500 ° C. A method for forming an oxide film accompanied by a high temperature is difficult to apply, and a reduction in the formation temperature of a highly reliable oxide film is required. Furthermore, when a flexible substrate is used as in the case of a sheet computer required in the ubiquitous network society, the heat-resistant temperature of the substrate is about 250 to 300 ° C., so the formation temperature of the highly reliable oxide film is further lowered. is necessary. Thus, in various product fields, it is required to lower the temperature for forming a highly reliable oxide film.

  For this reason, for example, according to the oxide film forming method disclosed in Japanese Patent Application Laid-Open No. 2008-53561 (Patent Document 1), the substrate is irradiated with light in the ultraviolet region, and the source gas made of organic silicon is applied to the substrate. And ozone gas. According to this publication, it is described that an oxide film having excellent electrical characteristics can be formed by a process of 200 ° C. or lower. Moreover, it is described that the reaction shown in the following formulas (1) and (2) occurs by the irradiation of the light.

O ₃ + hν (λ <410 nm) → O ₂ ( ³ Σ) + O ( ¹ D) (1)
_{O 3 + hν (λ <310nm} ) → O 2 (3 Δ g) + O (1 D) ··· (2)
In recent years, power devices using SiC substrates (SiC power devices) have been developed. When an oxide film is formed by thermal oxidation of a SiC substrate, a carrier-derived defect, that is, an increase in current loss may occur due to a C-derived defect caused by C remaining in the substrate. In addition, in order to form a thick gate insulating film of about 20 to 100 nm suitable for power devices by thermal oxidation, it is necessary to perform thermal oxidation to a deeper portion on the substrate. A high temperature is required. For this reason, methods other than the thermal oxidation method for forming a highly reliable oxide film are required.

For this reason, for example, according to Japanese Patent Application Laid-Open No. 2008-243919 (Patent Document 2), a deposition process for depositing a SiO ₂ film on a SiC substrate is first performed, and then an oxidation process using oxygen radicals is performed. Specific examples of the method for generating oxygen radicals include a method using plasma, a method using UV (Ultraviolet) irradiation, and a method using thermal decomposition of ozone. According to this publication, it is described that an interface between an SiO ₂ film and SiC with few C-derived defects is obtained, and the SiO ₂ film is densified by oxygen radicals.

JP 2008-53561 A JP 2008-243919A

B. E. Deal and A. S. Grove, "General Relationship for the Thermal Oxidation of Silicon", J. Appl. Phys. 36, 3770 (1965)

  According to the technique disclosed in Japanese Patent Application Laid-Open No. 2008-53561 (Patent Document 1), light having a wavelength of 410 nm or less, that is, light having a high energy of 3.02 eV or more is used as shown in Equation (1). It is easy to damage the substrate on which the oxide film is formed. For example, when light having an energy of 3.02 eV or more is irradiated onto the Si substrate as described above, since the Si—Si bond energy is 2.3 eV, defects such as dangling bonds can easily occur. Therefore, for example, when the oxide film is a gate insulating film, a defect is generated in the channel, so that the characteristics of the transistor can be deteriorated. Thus, the method using ultraviolet light tends to increase the damage to the substrate.

  Further, according to the technique disclosed in Japanese Patent Application Laid-Open No. 2008-243919 (Patent Document 2), plasma is used. Since plasma generally generates a large amount of charged particles such as ions and electrons having high kinetic energy, damage to the substrate is likely to increase as described above.

  As described above, according to the technique described above, damage to the substrate is likely to increase, and there is a problem in that the characteristics of the semiconductor device obtained by using this method are deteriorated.

  The present invention has been made in view of the above problems, and one object of the present invention is to provide a semiconductor device manufacturing method and an oxidation process capable of suppressing performance deterioration due to damage to a substrate accompanying the formation of an oxide film. Is to provide a device.

A method for manufacturing a semiconductor device according to one aspect of the present invention includes the following steps.
An oxidation process is performed on one surface of the semiconductor substrate. When the oxidation treatment is performed, O ( ³ P) radicals are generated, and O ( ¹ D) radicals are generated by exciting the O ( ³ P) radicals. The step of generating O ( ³ P) radicals includes a step of supplying O ₃ gas onto one surface of the semiconductor substrate and a step of thermally decomposing the O ₃ gas.
A method for manufacturing a semiconductor device according to another aspect of the present invention includes the following steps.
An oxidation process is performed on one surface of the semiconductor substrate. When the oxidation treatment is performed, O ( ³ P) radicals are generated, and O ( ¹ D) radicals are generated by exciting the O ( ³ P) radicals . OH radicals are generated by reacting O ( ¹ D) radicals with H ₂ O.

The oxidation processing apparatus of the present invention is for performing an oxidation process on one surface of a semiconductor substrate, and includes a container, a stage, an introduction unit, a heating unit, and a light source. The stage is for supporting the semiconductor substrate in the container. The introduction part is for introducing O ₃ gas into the container. The heating unit is for heating the semiconductor substrate. The light source is for emitting red-orange light having a wavelength of 590 nm or more and 630 nm or less toward the semiconductor substrate.

According to the method for manufacturing a semiconductor device of the present invention, O ( ¹ D) radicals for performing an oxidation treatment are generated by excitation of O ( ³ P) radicals. Thus, O ( ¹ D) radicals are generated with lower energy than when O ( ¹ D) radicals are generated directly from O ₃ . As a result, damage to the substrate due to the formation of the oxide film is suppressed, so that deterioration of the performance of the semiconductor device due to this damage can be suppressed.

According to the oxidizing apparatus of the present invention, O ₃ gas to generate O ⁽³ P) radical by heating, and irradiating the O ⁽³ P) light having a wavelength of 590nm or more 630nm following radicals Thus, O ( ¹ D) radicals are generated. Therefore, damage to the substrate due to the formation of the oxide film is suppressed as compared with the case where light having a shorter wavelength, that is, light having higher energy is used.

It is sectional drawing which shows schematically the structure of the oxidation processing apparatus in Embodiment 1 of this invention. The process of generating O ⁽¹ D) radicals in a first embodiment of the present invention is a diagram schematically showing. 1 is a cross sectional view schematically showing a configuration of a semiconductor device in a first embodiment of the present invention. It is sectional drawing which shows schematically the 1st process of the manufacturing method of the semiconductor device in Embodiment 1 of this invention. It is sectional drawing which shows schematically the 2nd process of the manufacturing method of the semiconductor device in Embodiment 1 of this invention. It is sectional drawing which shows schematically the 1st process of the manufacturing method of the semiconductor device in the modification of Embodiment 1 of this invention. It is sectional drawing which shows schematically the 2nd process of the manufacturing method of the semiconductor device in the modification of Embodiment 1 of this invention. It is sectional drawing which shows schematically the structure of the oxidation processing apparatus in Embodiment 2 of this invention. The process of generating O ⁽¹ D) radicals in the second embodiment of the present invention is a diagram schematically showing. It is sectional drawing which shows schematically the structure of the oxidation treatment apparatus in Embodiment 3 of this invention. The process of generating O ⁽¹ D) radicals in the third embodiment of the present invention is a diagram schematically showing. It is sectional drawing which shows schematically the structure of the semiconductor device in Embodiment 3 of this invention. It is sectional drawing which shows roughly the 1st process of the manufacturing method of the semiconductor device in Embodiment 3 of this invention. It is sectional drawing which shows schematically the 2nd process of the manufacturing method of the semiconductor device in Embodiment 3 of this invention. It is sectional drawing which shows roughly the 1st process of the manufacturing method of the semiconductor device in the 1st modification of Embodiment 3 of this invention. It is sectional drawing which shows schematically the 2nd process of the manufacturing method of the semiconductor device in the 1st modification of Embodiment 3 of this invention. It is sectional drawing which shows roughly 1 process of the manufacturing method of the semiconductor device in the 2nd modification of Embodiment 3 of this invention. It is sectional drawing which shows roughly the structure of the oxidation processing apparatus in Embodiment 4 of this invention. The process of generating O ⁽¹ D) radicals and OH radicals in the fourth embodiment of the present invention is a diagram schematically showing. It is sectional drawing which shows schematically the structure of the oxidation processing apparatus in Embodiment 5 of this invention. The process of generating O ⁽¹ D) radicals and OH radicals in the fifth embodiment of the present invention is a diagram schematically showing. It is sectional drawing which shows schematically the structure of the oxidation processing apparatus in Embodiment 6 of this invention. The process of generating O ⁽¹ D) radicals and OH radicals in the sixth embodiment of the present invention is a diagram schematically showing. O in the thermal decomposition of O ₃ is ⁽³ P) graph showing the temperature dependency of the generation efficiency of a radical. According to O ₂ is a graph showing the temperature dependency of the oxidation rate of the Si.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
(Embodiment 1)
First, the configuration of the oxidation processing apparatus of the present embodiment will be described.

  Referring to FIG. 1, an oxidation processing apparatus 51a of the present embodiment is for performing an oxidation process on a main surface (one surface) of a substrate 6a to be processed. The oxidation processing apparatus 51a includes a processing chamber 10, a sample stage 7, a gas introduction pipe 3a (introduction part), an exhaust pipe 23, a heating IR (Infrared) light source 2 (heating part), a support part 22, It has a lower window 9, a current plate 1a, and an excitation red-orange light source 4a (light source).

The sample stage 7 is for supporting the substrate 6 a to be processed in the processing chamber 10.
The gas introduction pipe 3 a is for introducing O ₃ gas into the processing chamber 10.

  The heating IR light source 2 is supported by a support portion 22 outside the processing chamber 10, and IR light 25 is applied to a surface opposite to the main surface of the substrate 6 a to be processed through a lower window 9 attached to the processing chamber 10. Irradiation. The heating IR light source 2 has an output capable of heating the substrate 6a to be processed to a temperature of 280 ° C. or more and 620 ° C. or less, and the temperature of the substrate 6a to be processed is an arbitrary value of 280 ° C. or more and 620 ° C. or less This output can be controlled so as to be maintained at a temperature.

The rectifying plate 1a is for making the flow of the introduced O ₃ gas a down flow that is uniformly supplied to the main surface of the substrate 6a to be processed, as indicated by arrows in the figure.

  The red-orange light source 4a for excitation emits red-orange light 5a having a wavelength of 590 nm or more and 630 nm or less toward the substrate 6a. That is, the red-orange light 5a is incident on the substrate 6a to be processed from the main surface of the substrate 6a. The red-orange light source 4a for excitation has a plurality of light emitting portions. Each light emitting part is attached to the lower end of the current plate 1a so as to be disposed between the main surface of the substrate 6a to be processed and the current plate 1a. With this configuration, the excitation red-orange light source 4a can uniformly irradiate the main surface of the substrate 6a with the red-orange light 5a. Preferably, each light emission part has LED. Thereby, each light emission part can be easily attached to the baffle plate 1a.

  Preferably, the oxidation processing apparatus 51a has a cooling mechanism for maintaining the temperature of the inner wall of the processing chamber 10 and the gas introduction pipe 3a at room temperature or higher and 100 ° C. or lower.

Next, a method for using the oxidation treatment apparatus 51a will be described.
With reference to FIGS. 1 and 2, first, a substrate 6a to be processed is prepared. Next, the substrate 6 a to be processed is placed on the sample stage 7 in the processing chamber 10. Next, an oxidation process is performed on the main surface of the substrate 6a to be processed as follows.

  First, when the heating IR light source 2 is turned on, the IR light 25 is irradiated through the lower window 9 onto the surface opposite to the main surface of the substrate 6a to be processed. By controlling the output of the IR light source 2 for heating, the temperature of the main surface of the substrate 6a to be processed is maintained at a predetermined temperature of 280 ° C. or higher and 620 ° C. or lower.

Next, O ₃ gas is caused to flow through the gas introduction pipe 3a. As a result, O ₃ gas is introduced into the processing chamber 10 from above the processing chamber 10. The introduced O ₃ gas is supplied to the main surface of the substrate 6a to be processed as a uniform down flow by being guided to the current plate 1a. The supplied O ₃ gas is thermally decomposed by being heated by the main surface of the substrate to be processed 6a maintained at a predetermined temperature of 280 ° C. or more and 620 ° C. or less. By this thermal decomposition, O ( ³ P) radicals are generated on the main surface of the substrate 6a. That is, the reaction shown in the following formula (3) occurs.

O ₃ + heat → O ₂ + O ( ³ P) (3)
O ( ³ P) radicals generated on the substrate 6a to be processed are excited by the red-orange light 5a from the red-orange light source 4a for excitation as shown in the following formula (4).

O ( ³ P) + hν (590 <λ <630 nm) → O ( ¹ D) (4)
As a result, O ( ¹ D) radicals are uniformly generated on the main surface of the substrate 6a. Oxidation is performed on the main surface of the substrate 6a to be processed by the oxidizing action of the O ( ¹ D) radical.

Next, a method for manufacturing the semiconductor device of the present embodiment will be described.
Referring to FIG. 3, the semiconductor device of the present embodiment includes a semiconductor substrate (substrate to be processed) 6a, a gate insulating film 30g, a gate electrode 33, and source / drain regions 34 and 35. A method for manufacturing this semiconductor device will be described below.

With reference to FIGS. 4 and 5, a substrate 6a to be processed having a main surface P is prepared. The substrate 6a to be processed is, for example, a Si substrate. Next, the oxidation treatment is performed on main surface P by performing the above-described oxidation treatment using oxidation treatment apparatus 51a. As a result, the main surface P is oxidized, whereby an oxide film 30a is formed on the substrate 6a. When the substrate 6a to be processed is a Si substrate, the oxide film 30a is a SiO ₂ film.

  Referring again to FIG. 3, formation of gate electrode 33, formation of gate insulating film 30g by patterning of oxide film 30a, and formation of source / drain regions 34 and 35 are performed. Thereby, the semiconductor device of the present embodiment is obtained.

Next, a method for manufacturing a semiconductor device in a modification of the present embodiment will be described.
Referring to FIG. 6, oxide film 30p is deposited on substrate 6a to be processed. The thickness of the oxide film 30p is arbitrary, and may be, for example, about 20 to 100 nm, that is, a thickness suitable for a gate insulating film of a power device. Specifically, as the oxide film 30p, a SiO ₂ film is formed by, for example, a CVD (Chemical Vapor Deposition) method. An oxide film formed by CVD has a relatively low density and poor insulating properties.

  Referring to FIGS. 6 and 7, the oxidation treatment is performed by performing the above-described oxidation treatment using oxidation treatment apparatus 51a. Thereby, oxide film 30p is modified to oxide film 30i. Specifically, for example, density and insulation characteristics are improved. As a result, an oxide film 30i is formed on the substrate 6a to be processed.

  Next, the gate electrode 33 (FIG. 3) is formed, the gate insulating film 30g (FIG. 3) is formed by patterning the oxide film 30i, and the source / drain regions 34 and 35 (FIG. 3) are formed. Thereby, a semiconductor device (FIG. 3) is obtained.

According to the present embodiment, O ( ¹ D) radicals for performing the oxidation treatment are generated by excitation of O ( ³ P) radicals. Thus, O ( ¹ D) radicals are generated with lower energy than when O ( ¹ D) radicals are generated directly from O ₃ . That is, since O ( ³ P) radicals can be generated using red-orange light 5a having a wavelength of 590 nm or more and 630 nm or less, it is not necessary to use UV light. Thereby, the damage to the to-be-processed substrate 6a accompanying formation of the oxide film 30a (FIG. 5) or 30i (FIG. 7) is suppressed. Therefore, performance degradation of the semiconductor device due to this damage can be suppressed.

Also, it is not necessary to use plasma in order to generate O ( ¹ D) radicals. Therefore, there is no damage to the substrate 6a to be treated by charged particles such as ions and electrons having high kinetic energy.

  For example, even if a special plasma such as microwave-excited low electron temperature plasma using RLSA (Radial Line Slot Antenna) is used, it is difficult to completely prevent plasma damage. In addition, since a large-scale facility is required to generate plasma uniformly over a wide area, if the substrate area is relatively large, such as LTPS-TFT, the manufacturing cost is greatly increased.

In addition, since the O ( ¹ D) radical is generated on the main surface of the substrate 6a to be processed by the red-orange light 5a, the initial period of an extremely short lifetime of about 10 ⁻⁷ seconds of the O ( ¹ D) radical is sufficient. Thus, the oxidation treatment on the main surface of the substrate 6a to be processed can be performed.

If the O ( ¹ D) radical generated at a position away from the target substrate 6a is transferred onto the target substrate 6a, the O ( ¹ D) radical moves on the order of several hundred μm on average. Since it changes to a ground state and changes to an O ( ³ P) radical at that time, it is difficult to efficiently supply the O ( ¹ D) radical to the substrate 6a to be processed.

Further, during the oxidation treatment, the substrate 6a to be processed is held at a temperature of 280 ° C. or higher. In general, O ₃ is said to thermally decompose at 200 ° C. or higher, but in order to obtain a sufficiently high production efficiency of about 10 ⁻¹⁸ (molecules / s), as shown in FIG. Preference is given to pyrolysis at temperature. In this embodiment, since O ₃ can be heated to a temperature of 280 ° C. or higher by the substrate 6a to be processed, O ( ³ P) radicals can be generated on the substrate 6a with sufficiently high generation efficiency. Therefore, O ( ¹ D) radicals can be efficiently generated on the surface, and oxidation by O ( ¹ D) radicals can be performed efficiently.

Further, during the oxidation treatment, the substrate 6a to be processed is held at a temperature of 620 ° C. or lower. Thereby, the rate at which Si of the substrate 6a to be processed is oxidized by O ₂ can be set to 1 nm / hr or less, which is a practically small value, as shown in FIG. Therefore, thermal oxidation of Si of the substrate 6a to be processed by O ₂ generated together with O ( ³ P) radicals during O ₃ thermal decomposition (formula (3)) can be suppressed.

Note that thermal oxidation with O ₂ has weaker oxidizing power than oxidation with radicals (radical oxidation). For this reason, when thermal oxidation due to O ₂ occurs excessively, defects are likely to remain in the oxide film 30a (FIG. 5). When the substrate 6a to be processed is a SiC substrate, C is not sufficiently oxidized and tends to remain on the substrate 6a to be processed. Further, thermal oxidation by O ₂ cannot contribute to the modification of the oxide film 30p (FIG. 6).

Further, the temperature of the inner wall of the processing chamber 10 and the gas introduction pipe 3a is set to 100 ° C. or less, that is, a temperature sufficiently lower than 200 ° C., which is generally said to be a temperature at which O ₃ begins to decompose, so that the O ₃ gas is covered. It is possible to suppress decomposition before reaching the processing substrate 6a.

  Further, by using radical oxidation, the crystal orientation dependence of the oxidation rate is suppressed as compared with the case where thermal oxidation is used. As a result, the interface between the oxide film 30a and the substrate 6a to be processed becomes flatter, so that, for example, an increase in mobility and a reduction in leakage current are expected in the semiconductor device (FIG. 3). Further, it is very advantageous for formation of STI (Shallow Trench Isolation) and three-dimensional structures such as tri-gate transistors. In addition, when an oxide film is formed on polysilicon having crystal grains having various crystal orientations, such as an interpoly film of a flash memory, it is possible to suppress an increase in roughness. For devices such as ultra-high-integrated 3D LSIs and sheet computers, radical oxidation is required because not only crystalline-Si (c-Si) but also oxide film formation on polycrystalline-Si (p-Si) is required. It is thought that the construction method by will increase in importance.

Further, O ( ³ P) radicals are uniformly generated on the target substrate 6a by the O ₃ gas uniformly supplied to the main surface of the heated target substrate 6a. By reddish-orange light 5a is uniformly irradiated with O ⁽³ P) radicals uniformly generated on the target substrate 6a, O ⁽¹ D) radicals are uniformly generated on the substrate to be processed 6a . For this reason, it is possible to suppress variations in the in-plane distribution of the oxidation treatment on the main surface of the substrate 6a. Therefore, for example, in-plane variation in oxidation treatment can be particularly reduced in a substrate having a large area such as a 300 mm wafer or a substrate for LTPS-TFT.

  Further, according to the modification of the present embodiment, an oxide film 30p (FIG. 6) having an arbitrary thickness can be formed by using, for example, a CVD method, and the oxide film 30p (FIG. 7) is formed by oxidation treatment. High reliability can be ensured by reforming to). That is, it is possible to easily form the oxide film 30i having a larger film thickness and higher reliability than the thickness of the oxide film 30a which can be easily formed by radical oxidation. This method of forming the oxide film 30i is suitable when the CVD method is desired from the viewpoint of mass productivity, such as the formation of an oxide film on the surface of the poly-Si layer in a three-dimensional LSI or a sheet computer.

  In addition, since an oxide film 30i having an arbitrary film thickness and an excellent insulating property can be formed on an arbitrary ground at an arbitrary temperature, it can be applied to all structures of all devices and can be applied to all structures. It is expected that the cost can be significantly reduced by unifying the processing devices.

  The oxide film 30p (FIG. 6) is formed not by oxidation of the substrate 6a to be processed but by deposition of an oxide film on the substrate 6a to be processed. Therefore, the oxide film 30p not containing C can be formed by, for example, a CVD method using an inorganic gas source. By modifying the oxide film 30p, even if the substrate 6a to be processed is a SiC substrate containing C, it is possible to obtain the oxide film 30i having a high density and no C residue.

(Embodiment 2)
Referring to FIG. 8, the oxidation treatment device 52a of the present embodiment includes an excitation red-orange light source 4b (light source), an upper window 8, and a rectifying plate 1b.

  The current plate 1b has substantially the same shape and arrangement as the current plate 1a (FIG. 1). The rectifying plate 1b is made of a material that easily transmits light having a wavelength of 590 nm or more and 630 nm or less, such as quartz glass.

  The upper window 8 is disposed in the processing chamber 10 so that the current plate 1b is sandwiched between the upper window 8 and the main surface of the substrate 6a.

  The red-orange light source 4b for excitation emits red-orange light 5b having a wavelength of 590 nm or more and 630 nm or less, and is, for example, an LED or a lamp. The excitation red-orange light source 4b is disposed outside the processing chamber 10 so as to sandwich the rectifying plate 1b and the upper window 8 between the main surface of the substrate 6a to be processed. As a result, the red-orange light 5b passes through the upper window 8 and enters the processing chamber 10, and further passes through the rectifying plate 1b and enters the processing substrate 6a from the main surface of the processing substrate 6a.

As shown in FIG. 9, the generation process of the O ( ¹ D) radical is almost the same as that of the first embodiment (FIG. 2).

  Since the configuration other than the above is substantially the same as the configuration of the first embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof will not be repeated.

  Also in the present embodiment, the same effect as in the first embodiment can be obtained. Further, since the excitation red-orange light source 4b is provided outside the processing chamber 10, the excitation red-orange light source 4b can be easily installed, and the shape and size of the excitation red-orange light source 4b are also limited.

(Embodiment 3)
First, the configuration of the oxidation processing apparatus of the present embodiment will be described.

  Referring to FIG. 10, an oxidation processing apparatus 53a according to the present embodiment is for performing an oxidation process on a main surface (one surface) of a substrate 6b to be processed, and an excitation red-orange light source 4c ( Light source).

  The substrate 6b to be processed is made of a material that transmits at least part of the red-orange light 5c from the excitation red-orange light source 4c, and preferably made of a material that easily transmits light having a wavelength of 590 nm to 630 nm. For example, the substrate 6b to be processed is a glass substrate or a SiC substrate.

  The excitation red-orange light source 4 c is supported by the support portion 22 together with the heating IR light source 2. Therefore, the red-orange light source 4c for excitation faces the surface opposite to the main surface (one surface) of the substrate 6b to be processed through the lower window 9. Accordingly, the red-orange light source 4c for excitation can emit red-orange light 5c having a wavelength of 590 nm or more and 630 nm or less toward the substrate 6b to be processed through the lower window 9. In the present embodiment, the lower window 9 is made of a material that easily transmits not only IR but also light having a wavelength of 590 nm to 630 nm, for example, quartz glass.

  Since the configuration other than the above is substantially the same as the configuration of the first embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof will not be repeated.

Next, a method for using the oxidation treatment apparatus 51a will be described.
Referring to FIG. 11, O ( ³ P) radicals are generated on the main surface (upper surface in the drawing) of substrate to be processed 6b by the same method as in the first embodiment (FIG. 2). Next, red-orange light 5c from the excitation red-orange light source 4c is incident on the main surface of the substrate 6b through the substrate 6b. Thereby, as shown in the above formula (4), O ( ¹ D) radicals are generated. Oxidation is performed on the main surface of the substrate 6a to be processed by the oxidizing action of the O ( ¹ D) radical.

Next, a method for manufacturing the semiconductor device of the present embodiment will be described.
Referring to FIG. 12, the semiconductor device of the present embodiment includes a semiconductor substrate (substrate to be processed) 6b, a gate insulating film 30g, a gate electrode 33, and source / drain regions 34 and 35. A method for manufacturing this semiconductor device will be described below.

  Referring to FIGS. 13 and 14, a substrate 6b to be processed having a main surface P is prepared. The substrate 6b to be processed is, for example, a SiC substrate. Next, the oxidation treatment is performed on main surface P by performing the above-described oxidation treatment using oxidation treatment apparatus 53a. As a result, the main surface P is oxidized, whereby an oxide film 30b is formed on the substrate 6b.

  Referring again to FIG. 3, formation of gate electrode 33, formation of gate insulating film 30g by patterning of oxide film 30b, and formation of source / drain regions 34 and 35 are performed. Thereby, the semiconductor device of the present embodiment is obtained.

Next, a method for manufacturing a semiconductor device according to a first modification of the present embodiment will be described.
Referring to FIG. 15, oxide film 30p is deposited on substrate 6b. The thickness of the oxide film 30p is arbitrary, and may be, for example, about 20 to 100 nm, that is, a thickness suitable for a gate insulating film of a power device. Specifically, as the oxide film 30p, a SiO ₂ film is formed by, for example, a CVD (Chemical Vapor Deposition) method. An oxide film formed by CVD has a relatively low density and poor insulating properties.

  Further, referring to FIG. 16, the oxidation treatment is performed by performing the above-described oxidation treatment using oxidation treatment apparatus 53a. Thereby, oxide film 30p is modified to oxide film 30i. Specifically, for example, density and insulation characteristics are improved. As a result, an oxide film 30i is formed on the substrate 6b.

  Next, formation of the gate electrode 33 (FIG. 12), formation of the gate insulating film 30g (FIG. 12) by patterning of the oxide film 30i, and formation of the source / drain regions 34 and 35 (FIG. 12) are performed. Thereby, a semiconductor device (FIG. 12) is obtained.

  As shown in FIG. 17, a substrate to be processed 6 c having a glass substrate 61 and a semiconductor layer 62 formed on the glass substrate 61 may be used instead of the substrate to be processed 6 b.

  Also in the present embodiment, the same effect as in the first embodiment can be obtained. Further, unlike the first embodiment, since the excitation red-orange light source 4c is provided outside the processing chamber 10, the excitation red-orange light source 4c can be easily installed, and the shape and size of the excitation red-orange light source 4c are restricted. Is also small. Unlike the second embodiment, the light red-orange light 5c from the excitation red-orange light source 4c is not blocked by the rectifying plate 1a, so that the red-orange light 5c is not reflected, absorbed or scattered by the rectifying plate 1a. Therefore, since the main surface of the substrate 6b can be irradiated with the red-orange light 5c uniformly, the in-plane variation of the oxidation process can be suppressed.

  Further, according to the modification of the present embodiment, the oxide film 30i is formed by modifying the oxide film 30p deposited on the substrate 6a to be processed, and therefore it is necessary to directly oxidize the substrate 6b to be processed. Absent. Therefore, it is possible to prevent residual C which is a concern when the substrate 6b to be processed is directly oxidized.

(Embodiment 4)
First, the configuration of the oxidation processing apparatus of the present embodiment will be described.

Referring to FIG. 18, the oxidation treatment apparatus 51b of the present embodiment has a gas introduction pipe 3b. The gas introduction pipe 3 b is for introducing O ₃ gas containing H ₂ O into the processing chamber 10. That is, the gas introduction pipe 3b is for introducing O ₃ gas and H ₂ O gas.

  Since the configuration other than the above is substantially the same as the configuration of the above-described first embodiment (FIG. 1), the same or corresponding elements are denoted by the same reference numerals, and description thereof will not be repeated.

Next, a method for using the oxidation treatment apparatus 51b will be described.
Referring to FIG. 19, first, O ( ¹ D) radicals are uniformly generated on the main surface of substrate 6a to be processed by the same method as in the first embodiment (FIG. 2). This O ( ¹ D) radical reacts with H ₂ O supplied together with O ₃ gas on the main surface of the substrate 6a to be processed. That is, OH radicals are generated by the reaction shown in the following formula (5).

O ( ¹ D) + H ₂ O → 2OH (5)
Oxidation is performed on the main surface of the substrate 6a to be processed by the oxidizing action of the O ( ¹ D) radical and the OH radical.

O ( ³ P), unlike O ( ¹ D), cannot react with H ₂ O as shown in Formula (5).

According to the present embodiment, the same effect as in the first embodiment can be obtained.
Furthermore, according to the present embodiment, not only O ( ¹ D) radicals but also OH radicals contribute to the oxidation treatment. Since OH radicals are extremely reactive, a higher oxidation rate or higher reforming efficiency can be obtained by using OH radicals.

Moreover, OH radicals have the property of being easily deactivated in a short time due to collisions between OH radicals. In the present embodiment, the OH radicals are O ( ¹ D) radicals uniformly supplied on the main surface of the substrate 6a to be processed, and H ₂ O uniformly supplied on the main surface of the substrate 6a to be processed. It is produced by the reaction. Thereby, the oxidation process on the main surface of the substrate 6a to be processed can be efficiently performed by fully utilizing the initial period of the lifetime of the OH radical. In addition, since OH radicals are uniformly generated on the main surface of the substrate 6a to be processed, in-plane variations in the oxidation treatment can be suppressed.

(Embodiment 5)
Referring to FIG. 20, an oxidation treatment apparatus 52b of the present embodiment has a gas introduction pipe 3b similar to that of the fourth embodiment (FIG. 18).

  Since the configuration other than the above is substantially the same as the configuration of the above-described second embodiment (FIG. 8), the same or corresponding elements are denoted by the same reference numerals, and description thereof is not repeated.

Further, as shown in FIG. 21, the generation process of O ( ¹ D) radicals and OH radicals is almost the same as in the fourth embodiment (FIG. 19).

According to the present embodiment, the same effect as in the second embodiment can be obtained.
Furthermore, according to the present embodiment, a higher oxidation rate or higher reforming efficiency can be obtained for the same reason as in the fourth embodiment, and in-plane variation of the oxidation treatment can be suppressed.

(Embodiment 6)
Referring to FIG. 22, oxidation treatment apparatus 53b of the present embodiment has gas introduction pipe 3b similar to that of the fourth embodiment (FIG. 18).

  Since the configuration other than the above is substantially the same as the configuration of the above-described third embodiment (FIG. 10), the same or corresponding elements are denoted by the same reference numerals, and the description thereof will not be repeated.

Further, as shown in FIG. 23, the generation process of O ( ¹ D) radicals is almost the same as that in Embodiment 3 (FIG. 11), and the generation process of OH radicals is almost the same as that in Embodiment 4 (FIG. 19). It is.

According to the present embodiment, the same effect as in the third embodiment can be obtained.
Furthermore, according to the present embodiment, a higher oxidation rate or higher reforming efficiency can be obtained for the same reason as in the fourth embodiment, and in-plane variation of the oxidation treatment can be suppressed.

  Each embodiment disclosed this time must be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention can be applied particularly advantageously to a semiconductor device manufacturing method and an oxidation processing apparatus including a step of performing an oxidation process.

  1a, 1b Rectifier plate, 2 IR light source for heating (heating part), 3a, 3b Gas introduction pipe (introduction part), 4a-4c Red-orange light source (light source) for excitation, 5a-5c Light red-orange light, 6a, 6b Substrate, 7 Sample stage, 8 Upper window, 9 Lower window, 10 Processing chamber, 22 Support, 23 Exhaust piping, 25 IR light, 30 g Gate insulating film, 30a, 30b, 30i, 30p Oxide film, 33 Gate electrode, 34 Source / drain region, 51a, 51b, 52a, 52b, 53a, 53b Oxidation processing apparatus.

Claims (9)

A method of manufacturing a semiconductor device comprising a step of performing an oxidation treatment on one surface of a semiconductor substrate,
Wherein the step of performing the oxidation process comprises the steps of generating O ⁽³ P) radical, it saw including a step of generating O ⁽¹ D) radicals by exciting the O ⁽³ P) radical,
Step of generating the O ⁽³ P) radicals, semiconductors said a process of supplying the O ₃ gas on one surface of the semiconductor substrate, the O ₃ gas, wherein the free Mukoto and pyrolyzing Device manufacturing method. A method of manufacturing a semiconductor device comprising a step of performing an oxidation treatment on one surface of a semiconductor substrate,
Wherein the step of performing the oxidation process comprises the steps of generating O ⁽³ P) radical, it saw including a step of generating O ⁽¹ D) radicals by exciting the O ⁽³ P) radical,
A method of manufacturing a semiconductor device, further comprising a step of generating OH radicals by reacting the O ( ¹ D) radicals with H ₂ O. Wherein the step of performing the oxidation process is characterized by a step of forming an oxide film on one surface of the semiconductor substrate, a manufacturing method of a semiconductor device according to claim 1 or 2. Before the step of performing the oxidation treatment, further comprising a step of forming an oxide film on one surface of the semiconductor substrate;
3. The method of manufacturing a semiconductor device according to claim 1, wherein the step of performing the oxidation treatment is a step of modifying the oxide film already formed on one surface of the semiconductor substrate. Method. Step of generating the O ⁽¹ D) radicals, characterized in that it comprises a step for exciting by irradiating light to the O ⁽³ P) radical, a semiconductor according to any one of claims 1-4 Device manufacturing method. 6. The method of manufacturing a semiconductor device according to claim 5 , wherein the light is red-orange light having a wavelength of 590 nm to 630 nm. An oxidation processing apparatus for performing an oxidation process on one surface of a semiconductor substrate,
A container,
A stage for supporting the semiconductor substrate in the container;
An introduction part for introducing O ₃ gas into the container;
A heating unit for heating the semiconductor substrate;
An oxidation processing apparatus comprising: a light source that emits red-orange light having a wavelength of 590 nm to 630 nm toward the semiconductor substrate. The oxidation processing apparatus according to claim 7 , further comprising a current plate for controlling the flow of the O ₃ gas. The light source is characterized by having a plurality of light emitting portions, the oxidation processing apparatus according to claim 7 or 8.

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