JP2000091331A - Formation of insulation film and manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which a thin insulating film having low defect density can be formed at a low temperature, and a method with which a semiconductor device can be manufactured through the use of the method. SOLUTION: An oxide film 12 is formed on the surface of a silicon substrate 11 by emitting an ionized gas G1, containing oxygen atoms upon the surface. Then the oxide film 12 is irradiated with an excimer laser beam E. Consequently, the defect densities in the oxide film 12 and at the boundary between the film 12 and the substrate 11 decrease, and an insulating film having low defect density is obtained. Since only the temperature at the surface of the substrate 11 rises instantaneously, but that of the periphery does not rise, when the film film 12 is irradiated with the laser beam E. Even such a substrate that is made of a low heat-resistant material, such as borosilicate glass, etc., can be used. The oxide film 12 may also be irradiated with the laser beam E over a coating film formed on the film 12. Accordingly, occurrence of new defects by the irradiation of the excimer laser beam E can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing an insulating film for forming an oxide film, a nitride film or an oxynitride film on the surface of a base portion, and a method for manufacturing a semiconductor device using the same.

[0002]

2. Description of the Related Art Some semiconductor devices, such as a field effect transistor or a memory, have an insulating film such as an oxide film, a nitride film or an oxynitride film formed on a base portion made of a semiconductor. Conventionally, these insulating films have been produced by, for example, a chemical vapor deposition (CVD) method or a sputtering method. In particular, when an oxide film is formed on the surface of an underlying portion made of silicon (Si), it has been manufactured by heating the underlying portion at a high temperature (about 1000 ° C.) in an oxygen or water vapor atmosphere.

[0003]

However, in the chemical vapor deposition method or the sputtering method, it is difficult to form a thin insulating film with good controllability, and the defect density at the interface between the insulating film and the underlayer is 10 ¹² cm. ^-2 eV ^-1 which is high. Therefore, in these methods, the thickness of the insulating film could not be reduced to several nm, and the area could not be reduced. Therefore, it has not been possible to cope with recent miniaturization of semiconductor devices.

On the other hand, according to a method of heating a base portion made of silicon in an atmosphere of oxygen or water vapor, a thin insulating film having a thickness of several nm can be formed with good controllability. The density can be as low as about 10 ¹⁰ cm ^-2 eV ^-1, but there is a problem that the base must be heated at a high temperature of about 1000 ° C., and an insulating film cannot be formed at a low temperature. . Therefore, it is not possible to use a substrate provided with a base portion made of a semiconductor on a base substrate made of a low heat-resistant material such as silicate glass, borosilicate glass, or plastic, and to form a semiconductor device having a large area. Could not. In addition, when each semiconductor element is miniaturized like a field-effect transistor in a next-generation LSI (Large-Scale Integration), processing at a high temperature is not preferable in order to avoid redistribution of impurities and distortion of a formation layer. This method could not cope.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method of manufacturing an insulating film capable of forming an insulating film having a small thickness and a low defect density at a low temperature and using the same. An object of the present invention is to provide a method for manufacturing a semiconductor device.

[0006]

According to the method of manufacturing an insulating film of the present invention, a surface of a base portion made of a semiconductor is exposed to an ionized gas containing at least one of oxygen atoms and nitrogen atoms to form a surface of the base portion. The method includes a step of forming an insulating film made of an oxide film, a nitride film, or an oxynitride film, and a step of heating a surface of a base portion on which the insulating film is formed.

In the method of manufacturing a semiconductor device according to the present invention, an oxide film, a nitride film, or The method includes a step of forming an insulating film made of an oxynitride film and a step of heating a surface of a base portion on which the insulating film is formed.

Another method of manufacturing a semiconductor device according to the present invention is for manufacturing a semiconductor device having a transistor in which an insulating film is formed on a base portion made of a semiconductor constituting a conductive layer. Exposing the surface to an ionizing gas containing at least one of oxygen atoms and nitrogen atoms to form an insulating film made of an oxide film, a nitride film or an oxynitride film on the surface of the underlying portion; And heating the surface of the part.

According to still another method of manufacturing a semiconductor device according to the present invention, there is provided a method of manufacturing a semiconductor device comprising: a memory in which an insulating film is formed on a base made of a semiconductor constituting a conductive layer; For manufacturing a semiconductor device having a memory with an insulating film formed thereon or a memory with an insulating film formed on a base portion constituting an electrode of a capacitor, wherein the surface of the base portion is formed of oxygen atoms and nitrogen atoms. Forming an insulating film made of an oxide film, a nitride film, or an oxynitride film on the surface of the underlying portion by exposing to an ionized gas containing at least one of the above; and heating the surface of the underlying portion on which the insulating film is formed. Is included.

[0010] Still another method of manufacturing a semiconductor device according to the present invention is to manufacture a semiconductor device having a diode in which an insulating film is formed on a base portion made of a semiconductor constituting an electrode. Exposing the surface to an ionizing gas containing at least one of oxygen atoms and nitrogen atoms to form an insulating film made of an oxide film, a nitride film or an oxynitride film on the surface of the underlying portion; And heating the surface of the part.

[0011] Still another method of manufacturing a semiconductor device according to the present invention is to manufacture a semiconductor device having a single-electron transistor in which an insulating film is formed on a base portion made of a semiconductor constituting a conductive layer. Forming an insulating film made of an oxide film, a nitride film or an oxynitride film on the surface of the base by exposing the surface of the base to an ionizing gas containing at least one of oxygen atoms and nitrogen atoms; And heating the surface of the underlayer on which the surface is formed.

Still another method of manufacturing a semiconductor device according to the present invention is to manufacture a semiconductor device having a single-electron memory in which an insulating film is formed on a base portion made of a semiconductor constituting a conductive layer. Forming an insulating film made of an oxide film, a nitride film or an oxynitride film on the surface of the base by exposing the surface of the base to an ionizing gas containing at least one of oxygen atoms and nitrogen atoms; And heating the surface of the underlayer on which the surface is formed.

In the method of manufacturing an insulating film and the method of manufacturing a semiconductor device according to the present invention, first, the surface of a base portion made of a semiconductor is exposed to an ionized gas containing at least one of oxygen atoms and nitrogen atoms, and the surface is exposed to the ionized gas. An oxide film, a nitride film or an oxynitride film is formed. Next, the surface is heated to reduce defects in the oxide film, nitride film or oxynitride film formed on the surface.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention.
3A to 3C show a method of manufacturing an insulating film according to the first embodiment in the order of steps. First, for example, as shown in FIG.
A substrate 11 is prepared as an underlayer made of silicon, and the surface thereof is washed with an aqueous solution of nitric acid (HNO ₃ ). Next, the substrate is washed with an aqueous solution of ammonium hydroxide (NH ₄ OH) and hydrogen peroxide (H ₂ O ₂ ), and further washed with water.

[0016] Subsequently, as shown in FIG. 1 (B), the ionized gas G ₁ is irradiated containing oxygen atoms (O) to the surface of the substrate 11, the surface of the substrate 11 in an atmosphere of ionized gas G ₁ Expose.
At this time, for example, a gas containing at least one of oxygen (O ₂ ) and ozone (O ₃ ) is ionized in a vacuum device to generate an ionized gas containing oxygen atoms. The condition at that time is, for example, an atmosphere of 0.6 To
rr, supply gas flow rate 400 sccm, temperature 1
The power is set to 50 ° C. and the power is set to 350 W. Thereby, the substrate 11
An oxide film 12 as an insulating film is formed on the surface of the substrate. The oxide film 12 has many defects, and the oxide film 12 and the substrate 1
Many defects also exist at the interface with No. 1.

After the oxide film 12 is formed, as shown in FIG. 1C, for example, the surface thereof is irradiated with an energy beam E absorbed by the substrate 11, so that the surface of the substrate 11 and the oxide film 12 are removed. Heat. As the energy beam, any of an excimer laser beam and an electron beam beam may be used, but an excimer laser beam is particularly preferable. As the wavelength of the excimer laser beam, for example, any wavelength such as 308 nm for XeCl, 248 nm for KrF, or 193 nm for ArF may be used.

The irradiation time of the energy beam is set to a short time, for example, about 100 nsec, so that the temperature of the surface of the substrate 11 becomes higher than the temperature when the oxide film 12 is formed. Therefore, in this heating, only the temperature near the surface of the substrate 11 instantaneously increases, and the temperature of the entire substrate 11 does not increase. Thereby, defects of oxide film 12 are reduced, and defects at the interface between oxide film 12 and substrate 11 are also reduced.
That is, a good oxide film 12 is thereby obtained.

The oxide film 12 thus formed is
Was measured by an ellipsometry method. FIG. 2 shows the relationship between the film thickness and the time during which the substrate 11 was exposed to ionized gas containing oxygen atoms. As shown in FIG. 2, according to this method, a thin oxide film 12 having a thickness of about several nm can be formed.

As described above, according to the method of manufacturing an insulating film according to the present embodiment, after exposing the surface of substrate 11 to an atmosphere of ionized gas containing oxygen atoms, the surface of substrate 11 is heated at a higher temperature. Is heated, the oxide film 12 having a small thickness and a low defect density can be easily formed. Therefore, when a semiconductor device is formed using this method, the size of the semiconductor device can be reduced.

Further, since only the surface of the substrate 11 is heated, a good oxide film 12 can be formed at a low temperature without increasing the temperature of the entire substrate 11. Therefore, instead of the substrate 11, a substrate in which a silicon layer is formed as a base portion on a base substrate made of a low heat-resistant material such as silicate glass, borosilicate glass, or plastic can also be used. Therefore, when a semiconductor device is formed using this method, a large-area semiconductor device can be obtained. Further, distribution of impurities and distortion of a formed layer can be prevented, so that the semiconductor device can be miniaturized. In addition, since the surface of the substrate 11 is heated by irradiating the energy beam, only the vicinity of the surface of the substrate 11 can be easily heated.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
3A to 3C show a method of manufacturing an insulating film according to the first embodiment in the order of steps. In this embodiment, a case where an oxynitride film 13 is formed as an insulating film over a substrate 11 which is a base portion, instead of the oxide film 12 in the first embodiment, will be described. This method has the same configuration as that of the first embodiment except that the type of ionized gas is different. Therefore, here, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. In addition,
The oxynitride film 13 refers to a compound containing oxygen and nitrogen.

First, as shown in FIG. 3A, similarly to the first embodiment, a substrate 11 is prepared as a base portion made of, for example, silicon, and its surface is cleaned. Then, as shown in FIG. 3 (B), the ionized gas G ₂ was irradiated containing an oxygen atom and a nitrogen atom (N) on the surface of the substrate 11, exposing the surface of the substrate 11 in an atmosphere of ionized gas G ₂ .
At this time, for example, a gas containing dinitrogen monoxide (N ₂ O) is ionized in a vacuum device to generate an ionized gas containing oxygen atoms and nitrogen atoms. The conditions at that time are, for example, an atmosphere of 0.1 Torr, a supply gas flow rate of 250 sccm, a temperature of 400 ° C., and an electric power of
W. Thereby, the oxynitride film 1 is formed on the surface of the substrate 11.
3 is formed. This oxynitride film 13 has many defects, and many defects also exist at the interface between the oxynitride film 13 and the substrate 11.

After the formation of the oxynitride film 13, FIG.
As shown in (C), similarly to the first embodiment, for example, the surface is irradiated with the energy beam E absorbed by the substrate 11 and heated. Thereby, similarly to the first embodiment, defects in the oxynitride film 13 are reduced, and defects at the interface between the oxynitride film 13 and the substrate 11 are also reduced. That is, thereby, a favorable oxynitride film 13 is obtained.

The thickness of the oxynitride film 13 thus formed was measured by an ellipsometry method. FIG. 4 shows the relationship between the film thickness and the time during which the substrate 11 was exposed to an ionized gas containing oxygen atoms and nitrogen atoms. As shown in FIG. 4, according to this method, a thin oxynitride film 13 having a thickness of about several nm can be formed.

As described above, according to the method of manufacturing an insulating film according to the present embodiment, after exposing the surface of substrate 11 to an atmosphere of an ionized gas containing oxygen atoms and nitrogen atoms, the substrate is heated at a higher temperature than that. Since the surface of 11 is heated, the oxynitride film 13 having a small thickness and a low defect density can be easily formed as in the first embodiment. In addition, as in the first embodiment, only the surface of the substrate 11 is heated by the irradiation of the energy beam, so that the same effect as that described in the first embodiment is obtained. That is, a good oxynitride film 1 at a low temperature
3 can be easily formed.

In this embodiment, a case has been described in which a gas containing dinitrogen monoxide is ionized to generate an ionized gas containing oxygen atoms and nitrogen atoms. May be ionized with a gas containing at least one of ammonia (NH ₃ ) and nitrogen (N ₂ ) to generate an ionized gas containing oxygen atoms and nitrogen atoms. In addition, a gas containing nitrous oxide may be ionized to generate an ionized gas containing oxygen atoms and nitrogen atoms.

(Third Embodiment) FIG. 5 shows a third embodiment of the present invention.
3A to 3C show a method of manufacturing an insulating film according to the first embodiment in the order of steps. In this embodiment, a case will be described in which a nitride film 14 is formed as an insulating film on a substrate 11, which is a base, instead of the oxide film 12 in the first embodiment. This method, except that the type of ionized gas is different,
It has the same configuration as the first embodiment. Therefore,
Here, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

First, as shown in FIG. 5A, as in the first embodiment, a substrate 11 is prepared as a base portion made of, for example, silicon, and its surface is cleaned. Then, as shown in FIG. 5 (B), the ionized gas G ₃ containing nitrogen atoms by irradiating the surface of the substrate 11, exposing the surface of the substrate 11 in an atmosphere of ionized gas G _3. At that time, for example, a gas containing at least one of ammonia and nitrogen is ionized in a vacuum device to generate an ionized gas containing nitrogen atoms. The conditions at this time are, for example, an atmosphere of 600 Torr, a temperature of 150 ° C., and an electric power of 340.
W. Thereby, a nitride film 14 is formed on the surface of the substrate 11. This nitride film 14 has many defects,
Many defects also exist at the interface between the nitride film 14 and the substrate 11.

After the nitride film 14 is formed, as shown in FIG. 5C, for example, the energy beam E absorbed on the surface by the substrate 11 is formed in the same manner as in the first embodiment.
And heat it. Thereby, similarly to the first embodiment, defects in the nitride film 14 are reduced, and defects at the interface between the nitride film 14 and the substrate 11 are also reduced. That is, thereby, a good nitride film 14 is obtained.

As described above, according to the method of manufacturing an insulating film according to the present embodiment, after exposing the surface of substrate 11 to an atmosphere of an ionized gas containing nitrogen atoms, the surface of substrate 11 is heated at a higher temperature. Is heated, so that the nitride film 1 having a small thickness and a low defect density is formed similarly to the first embodiment.
4 can be easily formed. Further, as in the first embodiment, only the surface of the substrate 11 is heated by irradiating the energy beam, so that the same effect as that described in the first embodiment is obtained. That is, a good nitride film 14 can be easily formed at a low temperature.

(Fourth Embodiment) FIG. 6 shows a fourth embodiment of the present invention.
3A to 3C show a method of manufacturing an insulating film according to the first embodiment in the order of steps. This method has the same configuration as that of the first embodiment except that the method further includes a step of forming a coating film 15 on the oxide film 12. Therefore, here, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

First, as in the first embodiment, a substrate 11 is prepared as a base portion made of, for example, silicon, and its surface is cleaned (see FIG. 1A). Then
As in the first embodiment, the ionized gas G containing oxygen atoms
The surface of the substrate 11 is exposed to the atmosphere of ₁ to form an oxide film 12 which is an insulating film (see FIG. 1B).

Subsequently, as shown in FIG. 6A, a coating film 15 made of a semiconductor or a metal is formed on the oxide film 12 by, for example, a CVD method or a vacuum evaporation method. The coating film 15 covers at least a part of the oxide film 12 and indirectly heats the surface of the substrate 11, thereby suppressing generation of new defects due to irradiation with an energy beam. It is. As a material for forming the coating film 15, for example, a semiconductor such as silicon, germanium (Ge) or silicon germanium (SiGe), or tungsten (W), titanium (T
i), a metal containing at least one kind of high melting point metal such as molybdenum (Mo), tantalum (Ta) and nickel (Ni), or an alloy containing these semiconductors and a metal is preferable. This is because if the coating film 15 is formed by these, the melting point becomes high, and the surface of the substrate 11 can be heated at a high temperature.

After the coating film 15 is formed, as shown in FIG.
Is irradiated. Thereby, the surface of the substrate 11 and the oxide film 12 are indirectly heated, and the generation of new defects due to the irradiation of the energy beam E is suppressed. Therefore, defects in oxide film 12 are reduced more effectively than in the first embodiment, and defects at the interface between oxide film 12 and substrate 11 are also reduced. That is, a good oxide film 12 is thereby obtained.

The method for manufacturing an insulating film according to the present embodiment can be applied to a method for manufacturing a semiconductor device having a diode as it is. FIG. 7 illustrates a method for manufacturing a semiconductor device using the method for manufacturing an insulating film according to the present embodiment in the order of steps.

First, in the same manner as the method of manufacturing an insulating film according to the present embodiment, a substrate 11 is prepared as a base portion made of, for example, silicon, and the surface thereof is cleaned. Then
As shown in FIG. 7A, for example, a metal layer 16 made of a metal such as aluminum is deposited on one surface of the substrate 11,
By performing heat treatment at 400 ° C. for 1 minute, they are made to form an ohmic junction. Thereby, the substrate 11 and the metal layer 16 are
Is formed. Subsequently, FIG.
As shown in (B), for example, the surface of the substrate 11 is exposed to an atmosphere of an ionizing gas containing oxygen atoms in the same manner as in the method for manufacturing an insulating film according to this embodiment, so that an oxide film serving as an insulating film is formed. 12 is formed.

After the oxide film 12 is formed, as shown in FIG. 7C, for example, a metal such as aluminum is formed on the oxide film 12 in the same manner as in the method of manufacturing the insulating film according to the present embodiment. A second electrode 18 is deposited. Note that the second electrode 18 also functions as a coating film in this manufacturing method. After that, as shown in FIG. 7D, for example, the energy beam E is irradiated from above the second electrode 18 as a coating film in the same manner as in the method for manufacturing the insulating film according to the present embodiment. I do. As a result, a diode having the second electrode is formed on the substrate 11 constituting the first electrode 17 with the oxide film 12 interposed therebetween.

In order to examine the characteristics of the oxide film 12 formed by using the method according to the present embodiment, a diode is manufactured by this method, and a voltage is applied between the first electrode 17 and the second electrode 18. The voltage was applied and the current-voltage characteristics were measured. At that time, the ionized gas G ₁ with those obtained by ionizing the oxygen gas, the energy beam was irradiated at the intensity of 300 mJ / cm ² using a XeCl excimer laser beam. FIG. 8 shows the result.

As Comparative Example 1, a diode was fabricated in the same manner as in the present embodiment except that the heat treatment of the oxide film 12 was not performed, and the current-voltage characteristics were examined in the same manner. Further, as Comparative Example 2, the metal layer 1
6 and the second electrode 18 were formed, and the current-voltage characteristics were examined in the same manner. The results are also shown in FIG. In FIG. 8, the dotted line is the current-voltage characteristic of the diode manufactured by the method according to the present embodiment, the broken line is the current-voltage characteristic of Comparative Example 1, and the solid line is the current-voltage characteristic of Comparative Example 2.

As shown in FIG. 8, Comparative Examples 2 and 1
The current value decreases in the order of the diodes manufactured by the method according to the present embodiment. That is, according to the method according to the present embodiment, it can be seen that the film quality of oxide film 12 can be improved and the current value of the diode can be reduced.

As described above, according to the manufacturing method of the insulating film according to the present embodiment, after forming the coating film 15 on the oxide film 12, the coating film 15 is irradiated with an energy beam. Is heated, it is possible to prevent new defects from being generated by the irradiation of the energy beam, and it is possible to further reduce the defect density of the oxide film 12. Therefore, when a semiconductor device having a diode is formed by using this method, a current value can be reduced and characteristics can be improved.

Note that the method of manufacturing the insulating film according to the present embodiment is not limited to the case where the oxide film 12 is formed, and the method of manufacturing the insulating film is not limited to the case where the oxide film 12 is formed.
And the case of forming the nitride film 14 described in the third embodiment can be similarly applied.

FIG. 9 shows that the substrate is exposed to ionizing gas in the same manner as in the second embodiment, then a second electrode is formed in the same manner as in this embodiment, and a heat treatment is performed to form an oxynitride film. 4 shows current-voltage characteristics of a diode formed with. When producing the diode, a gas obtained by ionizing nitrous oxide as the ionized gas G ₂ was used, and the energy beam E was XeCl 2.
Irradiation was performed at an intensity of 300 mJ / cm ² using an excimer laser beam.

Further, the current-voltage characteristics of a diode manufactured in the same manner as the method according to the present embodiment except that the heat treatment of the oxynitride film was not performed were used as a comparative example 3 for the substrate 11.
FIG. 9 shows current-voltage characteristics of Comparative Example 4 in which a metal layer 16 and a second electrode 18 were formed. In FIG. 9, the dotted line indicates the current-voltage characteristics of the diode having the oxynitride film manufactured by the method according to the present embodiment, the broken line indicates the current-voltage characteristics of Comparative Example 3, and the solid line indicates the current-voltage characteristics of Comparative Example 4. It is a voltage characteristic.

As shown in FIG. 9, also in this case, the current value decreases in the order of Comparative Examples 4, 4 and the diodes manufactured by the method according to the present embodiment. That is, according to the method of the present embodiment, it can be seen that the film quality of the oxynitride film can be similarly improved, and the current value of the diode can be reduced.

(Fifth Embodiment) FIGS. 10 to 12 show a method of manufacturing a semiconductor device according to a fifth embodiment of the present invention in the order of steps. In this method, a semiconductor device having a thin-film field-effect transistor is manufactured by using the method for manufacturing an insulating film according to the fourth embodiment.

First, as shown in FIG. 10A, an undersubstrate 21 made of quartz glass, silicate glass, borosilicate glass, or the like is prepared, and a carbon dioxide is formed thereon by, for example, a CVD method or a sputtering method. An insulating layer 22 made of silicon (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ) is formed. Next, as shown in FIG. 10B, a semiconductor layer 23 as a base portion made of amorphous silicon (amorphous silicon) is formed on the insulating layer 22 by, for example, a CVD method.

Subsequently, as shown in FIG. 10C, for example, the semiconductor layer 23 is etched by using an ionized gas of a mixed gas of carbon tetrafluoride (CF ₄ ) and hydrogen (H ₂ ).
Is selectively removed to form a conductive layer 23a. Conductive layer 2
After 3a was formed, as shown in FIG. 10 (D), in the same manner as in the first embodiment, exposing the surface of the conductive layer 23a in an atmosphere of ionized gas G ₁ containing an oxygen atom, the surface Then, an oxide film 24 as an insulating film is formed.

After forming the oxide film 24, FIG.
As shown in (1), a gate electrode 25 made of amorphous silicon is selectively formed on a part of the gate electrode 25 by, for example, a CVD method. The gate electrode 25 functions as a coating film in this manufacturing process. After forming the gate electrode 25, as shown in FIG. 11B, for example, a phosphorus atom (P) or a boron atom (B) is implanted by ion implantation, and the gate electrode 25 and the gate of the conductive layer 23a are formed. Impurities are introduced into regions not covered by the electrodes 25, respectively. Thereby, an impurity is added to the gate electrode 25, and the source region 23b and the drain region 23c are formed with the gate electrode 25 interposed therebetween.

After the impurities are introduced, as shown in FIG. 11C, the energy beam E is irradiated from above the gate electrode 25 as a coating film in the same manner as in the fourth embodiment. After irradiation with the energy beam E, FIG.
As shown in FIG. 5, the oxide film 24 is etched by using an ionized gas of a mixed gas of carbon tetrafluoride and hydrogen.
Out of the region not covered by the gate electrode 25 is selectively removed. Thereafter, a source electrode 26 made of a metal such as aluminum is selectively formed corresponding to the source region 23b by, for example, a vacuum deposition method, and a drain electrode 27 made of a metal such as aluminum is formed corresponding to the drain region 23c. Are formed selectively. As a result, a thin film field effect transistor having the gate electrode 25 on the conductive layer 23a with the oxide film 24 interposed therebetween is formed.

After the gate electrode 25 is formed, a thin film field effect transistor may be formed as follows. FIG. 13 shows another method of manufacturing the semiconductor device according to the fifth embodiment in the order of steps.

That is, after the gate electrode 25 is formed as shown in FIG. 11A, as shown in FIG. 13A, for example, an ionized gas of a mixed gas of carbon tetrafluoride and hydrogen is discharged. Then, etching is performed to selectively remove a region of the oxide film 24 that is not covered with the gate electrode 25.
After that, for example, by irradiating ionizing gas G ₄ of phosphine (PH ₃₎ or diborane (B ₂ H _6), the gate electrode 2
Impurities are introduced into regions 5 and conductive layer 23a not covered by gate electrode 25, respectively. Thereby, an impurity is added to the gate electrode 25, and the source region 23b and the drain region 2
3c are formed.

After the impurities are introduced, as shown in FIG. 13B, the energy beam E is irradiated from above the gate electrode 25 as a coating film in the same manner as in the fourth embodiment. After irradiation with the energy beam E, the source electrode 26 and the drain electrode 27 are selectively formed in the same manner as described above (see FIG. 12). Thereby, a thin film field effect transistor is formed.

As described above, according to the method of manufacturing a semiconductor device according to the present embodiment, the surface of conductive layer 23a is exposed to the atmosphere of ionized gas containing oxygen atoms, and then the surface is heated. The oxide film 24 having a small thickness and a low defect density can be formed at a low temperature. Therefore, the semiconductor device can be miniaturized and quartz glass,
A base substrate 21 made of silicate glass, borosilicate glass, or the like can be used, and a large-area semiconductor device can be formed.

After the gate electrode 25 is formed on the oxide film 24, heat treatment is performed using the gate electrode 25 as a coating film, so that the defect density of the oxide film 24 can be further reduced. .

In the method of manufacturing a semiconductor device according to the present embodiment, the oxide film 24 as an insulating film is formed on the conductive layer 23a.
Is similarly applied to the case where the oxynitride film described in the second embodiment is formed as the insulating film and the case where the nitride film described in the third embodiment is formed as the insulating film. be able to.

In this embodiment, a method for manufacturing a semiconductor device having a transistor has been described.
A semiconductor device having a memory made up of a capacitor having a second electrode formed on a base part made of a semiconductor constituting a first electrode via an insulating film, and a base part made of a semiconductor constituting the first electrode A semiconductor device having a diode on which a second electrode is formed via an insulating film is also provided.
It can be manufactured in the same manner as in the present embodiment.

(Sixth Embodiment) FIGS. 14 to 16 show a method of manufacturing a semiconductor device according to a sixth embodiment of the present invention in the order of steps. In this method, a semiconductor device having a memory is manufactured by using the method for manufacturing an insulating film according to the fourth embodiment. Note that here, the fifth
Since the steps are partially the same as those in the method of manufacturing the semiconductor device according to the embodiment, the same steps are referred to the previous drawings, and the same components are denoted by the same reference numerals, and detailed description thereof will be omitted. Description is omitted.

First, as in the fifth embodiment, a base substrate 21 made of quartz glass, silicate glass, borosilicate glass, or the like is prepared, and an insulating layer 22 is formed thereon.
Is formed (see FIG. 10A). Next, as in the fifth embodiment, a semiconductor layer 23 as a base portion made of amorphous silicon is formed on the insulating layer 22 and is selectively removed to form a conductive layer 23a ( FIG. 10 (B)
(C)). After that, as in the fifth embodiment,
Conductive layer 23a in an atmosphere of ionized gas G ₁ containing an oxygen atom
Is exposed, and an oxide film 24 as an insulating film is formed on the surface (see FIG. 10D).

After forming oxide film 24, FIG.
As shown in FIG. 1, amorphous silicon, amorphous germanium (G
e) or forming a charge storage portion 31 made of silicon nitride. Note that the charge storage section 31 does not need to be a two-dimensional film, and may have a structure separated into a plurality of islands.
After forming the charge storage section 31, as shown in FIG. 14 (B), the charge storage section 31 and a base portion, in the same manner as in the first embodiment, the atmosphere of ionized gas G ₁ containing an oxygen atom The surface of the charge storage portion 31 is exposed inside, and an oxide film 32 as an insulating film is formed on the surface. The oxide film 32 may be formed by a CVD method or a sputtering method.

After forming the oxide film 32, FIG.
As shown in (1), a gate electrode 33 made of amorphous silicon is selectively formed corresponding to a part of the conductive layer 23a by, for example, a CVD method. After the gate electrode 33 is formed, etching is performed using, for example, an ionized gas of a mixed gas of carbon tetrafluoride and hydrogen, and the oxide film 32, the charge storage portion 31, and the oxide in a region not covered by the gate electrode 33 are formed. The film 24 is selectively removed. After that, as shown in FIG. 15B, for example, an ionizing gas G ₄ of phosphine or diborane is irradiated to form the gate electrode 33 and the conductive layer 23.
Impurities are respectively introduced into the regions a not covered by the gate electrode 33. Thereby, the gate electrode 33
, And a source region 23b and a drain region 23c are respectively formed.

After the impurity is introduced, as shown in FIG. 16A, the gate electrode 33 is used as a coating film, and the energy beam E is irradiated thereon from the same as in the fourth embodiment. Thereby, defects of the oxide films 24 and 33 are reduced. After irradiation with the energy beam E, FIG.
As shown in (B), the source electrode 34 and the drain electrode 35 are selectively formed by, for example, a vacuum evaporation method. Thereby, oxide film 2 is formed on conductive layer 23a.
4, a memory having a charge storage layer 31 and a gate electrode 33 on the charge storage layer 31 via an oxide film 32 is formed.

As described above, according to the method of manufacturing the semiconductor device according to the present embodiment, the conductive layer 23a or the charge storage layer 3
After exposing the surface 1 to an atmosphere of an ionized gas containing oxygen atoms, the surface is heated, so that the oxide films 24 and 32 having a small thickness and a low defect density can be formed at a low temperature. . Accordingly, the semiconductor device can be miniaturized, and the base substrate 21 made of quartz glass, silicate glass, borosilicate glass, or the like can be used, and a large-area semiconductor device can be formed.

After the charge storage portions 31 and the like are formed on the oxide film 24, heat treatment is performed using them as a coating film, or the gate electrode 33 is formed on the oxide film 32. Thereafter, the heat treatment is performed using the film as the peritoneum, so that the defect density of the oxide films 24 and 32 can be further reduced.

The method of manufacturing a semiconductor device according to the present embodiment is not limited to the case where the oxide films 24 and 33 are formed as insulating films, but also the case where the oxynitride film described in the second embodiment is used as the insulating film. The same applies to the case of manufacturing and the case of manufacturing the nitride film described in the third embodiment.

The semiconductor device according to the present embodiment also provides a single-electron memory capable of obtaining a remarkable single-electron effect by reducing the capacitance between the charge storage portion and the gate electrode to about 1 aF. Can be manufactured in exactly the same manner as in the method of manufacturing.

(Seventh Embodiment) FIGS. 17 to 20 show a method of manufacturing a semiconductor device according to a seventh embodiment of the present invention in the order of steps. 17 to 20 show a plan view and a sectional view thereof, respectively.

The method for manufacturing a semiconductor device according to the present embodiment uses a single electron transistor (Single Charge Tunneling, Ple) using the method for manufacturing an insulating film according to the fourth embodiment.
numPress, edited by H. Grabert and MHDevoret). In addition,
This method has the same configuration as the method of manufacturing the semiconductor device according to the fifth embodiment except that the step of forming the conductive layer 43a is different. Therefore, here, the same components as those in the fifth embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

First, as shown in FIG. 17, a base substrate 21 made of, for example, quartz glass, silicate glass or borosilicate glass is prepared, and an insulating layer 22 is formed thereon. Next, a semiconductor layer as a base portion made of amorphous silicon is formed thereon, and the semiconductor layer is selectively removed to form a conductive layer 41. At this time, the width of the central portion 41a of the conductive layer 41 is made narrower than the end portions 41b and 41c.

[0071] Then, as shown in FIG. 18, in an atmosphere of ionized gas G ₁ containing oxygen atoms exposed to the surface of the conductive layer 41, to form an oxide film 24 as an insulating film on the surface thereof.
Here, since the width of the central portion 41a of the conductive layer 41 is smaller than that of the end portions 41b and 41c, a tunnel junction is formed at the boundary between the central portion 41a and the end portions 41b and 41c by shape-dependent oxidation. Parts 41d and 41e are respectively formed.

After the oxide film 24 is formed, as shown in FIG. 19, the gate electrode 25 is selectively formed so as to cover a part of the central portion 41a of the conductive layer 41. After the gate electrode 25 is formed, for example, phosphorus atoms or boron atoms are implanted, and impurities are introduced into regions of the gate electrode 25 and the conductive layer 41 that are not covered by the gate electrode 25, respectively. And a source region 42 and a drain region 43 are formed. After that, the energy beam E is irradiated from above the gate electrode 25 as a coating film.

After irradiating the energy beam E, FIG.
As shown at 0, the oxide film 24 is selectively removed, exposing the source region 42 and the drain region 43. After that, the source electrode 26 and the drain electrode 27 are selectively formed. Thus, a single-electron transistor having gate electrode 25 on conductive layer 41 with oxide film 24 interposed therebetween is formed.

As described above, according to the method of manufacturing a semiconductor device according to the present embodiment, after exposing the surface of conductive layer 41 to the atmosphere of ionized gas containing oxygen atoms, gate electrode 25 is formed thereon. Since heat treatment is performed using this as a coating film, the oxide film 24 having a small thickness and a low defect density can be formed at a low temperature, similarly to the fifth embodiment. Therefore, a semiconductor device can be miniaturized and a large-area semiconductor device can be formed.

In the method of manufacturing a semiconductor device according to the present embodiment, not only the case where the oxide film 24 is formed as the insulating film, but also the oxynitride film described in the second embodiment is formed as the insulating film. The same can be applied to the case and the case of manufacturing the nitride film described in the third embodiment.

Although the present invention has been described with reference to the embodiments, the present invention is not limited to these embodiments and can be variously modified. For example, in each of the above embodiments, the surface of the underlying portion is heated by irradiating the energy beam, but the surface of the underlying portion may be heated by another method.

In each of the above embodiments, the case where the base portion is formed of silicon has been specifically described. However, in the present invention, the base portion may be formed of germanium or silicon germanium. Or
The base may be formed of a compound semiconductor such as gallium arsenide (GaAs).

Further, in each of the fourth to seventh embodiments, a specific method of manufacturing a semiconductor device has been described. However, if the method of manufacturing an insulating film of the present invention is included, any other method may be used. Steps may be included.

In addition, in each of the fifth to seventh embodiments, the case where the base substrate 21 made of quartz glass, silicate glass, borosilicate glass, or the like is used has been specifically described. Alternatively, a substrate made of a material having a lower melting point, such as plastic, can be used.

Further, in each of the fifth to seventh embodiments, the insulating layer 22 made of silicon dioxide or silicon nitride is formed on the base substrate 21. However, the insulating layer 22 is made of silicon oxynitride. (Ie, a compound of oxygen, nitrogen and silicon). Also,
The insulating layer 22 having a multilayer structure of a silicon nitride film and a silicon dioxide film may be formed.

In addition, in the fourth embodiment,
A method for manufacturing a semiconductor device having a diode has been described. For example, an insulating film is formed by exposing the surface of a substrate 11 to ionizing gas, and after heat treatment, a thin semiconductor layer of, for example, 10 nm or less is formed on the insulating film. Then, a thin insulating film and a thin semiconductor layer are repeatedly formed such that an insulating film is formed by exposing the surface to an ionizing gas, a heat treatment is performed, and then a semiconductor layer is formed on the insulating film. By doing so, a semiconductor device having a resonant tunnel diode provided with multiple tunnel barriers can be formed.

[0082]

As described above, according to the method for manufacturing an insulating film according to any one of claims 1 to 8, after exposing the surface of the underlying portion to the ionized gas to form the insulating film,
Since the surface is heated, there is an effect that an insulating film having a small thickness and a low defect density can be easily formed at a low temperature.

In particular, according to the method of manufacturing an insulating film according to claim 4 or 5, since the surface of the underlying portion is heated by irradiating the energy beam, only the vicinity of the surface of the underlying portion is heated. The effect of being able to heat easily and to prevent the surrounding temperature from rising is produced.

According to the method of manufacturing an insulating film according to the sixth or seventh aspect, after forming the insulating film, a coating film is formed thereon and irradiated with an energy beam, thereby forming an underlayer. Since the surface of the portion is heated, it is possible to prevent new defects from being generated by the irradiation of the energy beam, and to further lower the defect density of the insulating film.

Further, according to the method of manufacturing a semiconductor device according to any one of the ninth to twenty-first aspects, the surface of the underlying portion is exposed to ionized gas to form an insulating film, and then the surface is heated. Thus, an insulating film having a small thickness and a low defect density can be easily formed at a low temperature. Therefore, the semiconductor device can be miniaturized, and, for example, the base portion can be formed on a base substrate made of a low heat-resistant material, which has an effect that a large-area semiconductor device can be formed. Play.

In addition, according to the method of manufacturing a semiconductor device according to the twelfth aspect or the thirteenth aspect, the surface of the underlying portion is heated by irradiating the energy beam. Can be easily heated, and an increase in ambient temperature can be prevented. Therefore, for example, the base portion can be formed on a base substrate made of a low heat-resistant material, which has an effect that a large-area semiconductor device can be formed. In addition, the distribution of impurities and the distortion of the formed layer can be prevented, and the semiconductor device can be miniaturized.

Further, according to the method of manufacturing a semiconductor device according to the fourteenth or fifteenth aspect, after forming an insulating film, a covering film is formed thereon and irradiated with an energy beam. Since the surface of the base portion is heated, it is possible to prevent new defects from being generated by the irradiation of the energy beam, and to further reduce the defect density of the insulating film. Therefore, there is an effect that the characteristics of the semiconductor device can be improved and the device can be miniaturized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a method for manufacturing an insulating film according to a first embodiment of the present invention in the order of steps.

FIG. 2 is a characteristic diagram showing a relationship between a thickness of an oxide film formed by the method shown in FIG. 1 and a time of exposing a substrate to an ionized gas containing oxygen atoms.

FIG. 3 is a cross-sectional view illustrating a method of manufacturing an insulating film according to a second embodiment of the present invention in the order of steps.

FIG. 4 is a characteristic diagram showing a relationship between a film thickness of an oxynitride film manufactured by the method shown in FIG. 3 and a time of exposing a substrate to an ionized gas containing oxygen atoms and nitrogen atoms.

FIG. 5 is a cross-sectional view illustrating a method of manufacturing an insulating film according to a third embodiment of the present invention in the order of steps.

FIG. 6 is a sectional view illustrating a method of manufacturing an insulating film according to a fourth embodiment of the present invention in the order of steps.

7 is a cross-sectional view illustrating a method of manufacturing a diode using the method illustrated in FIG. 6 in the order of steps.

8 is a characteristic diagram showing current-voltage characteristics of a diode manufactured by the method shown in FIG.

FIG. 9 is a characteristic diagram illustrating current-voltage characteristics of another diode manufactured using the method according to the fourth embodiment.

FIG. 10 is a sectional view illustrating a method of manufacturing a semiconductor device according to a fifth embodiment of the present invention in the order of steps.

FIG. 11 is a sectional view illustrating each step following FIG. 10;

FIG. 12 is a sectional view illustrating each step following FIG. 11;

FIG. 13 is a sectional view illustrating another method of manufacturing the semiconductor device according to the fifth embodiment of the present invention in the order of steps.

FIG. 14 is a sectional view illustrating a method of manufacturing a semiconductor device according to a sixth embodiment of the present invention in the order of steps.

FIG. 15 is a sectional view illustrating each step following FIG. 14;

FIG. 16 is a sectional view illustrating each step following FIG. 15;

FIG. 17 is a plan view illustrating one step of a method for manufacturing a semiconductor device according to a seventh embodiment of the present invention, and a cross-sectional view taken along the line II.

FIG. 18 is a plan view showing a step following FIG.
FIG. 2 is a sectional view taken along the line I-II.

FIG. 19 is a plan view showing a step following FIG.
FIG. 3 is a sectional view taken along line II-III.

20 is a plan view showing a step following the step shown in FIG. 19, and FIG.
It is sectional drawing along the V-IV line.

[Explanation of symbols]

11 ... substrate, 12, 24, 32 ... oxide film, 13 ... oxynitride film, 14 ... nitride film, 15 ... coating film, 16 ... metal layer, 1
7: first electrode, 18: second electrode, 21: base substrate,
22 insulating film, 23 semiconductor layer, 23a, 41 conductive layer, 23b, 42 source region, 23c, 43 drain region, 25, 33 gate electrode, 26, 34 source electrode, 27, 35 drain Electrode, 31 ... Charge storage layer, 41a ... Center, 41b, 41c ... End, 41d,
41e ... tunnel _{junction, G 1, G 2, G} 3 ... ionized gas, E ... energy beam

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01L 21/336 H01L 29/78 617U 21/329 618C 622 29/91 A (72) Inventor Setsuo Usui Kita, Shinagawa-ku, Tokyo Shinagawa 6-chome 7-35 Sony Corporation F-term (reference) BH04 BJ01 BJ04 5F083 EP18 FZ01 HA02 JA02 JA05 JA19 PR21 PR33

Claims (21)

[Claims] An oxide film is formed on the surface of the base by exposing the surface of the base made of a semiconductor to an ionizing gas containing at least one of oxygen atoms (O) and nitrogen atoms (N).
A method for manufacturing an insulating film, comprising: a step of forming an insulating film made of a nitride film or an oxynitride film; and a step of heating a surface of a base portion on which the insulating film is formed. 2. The method according to claim 1, wherein the surface of the base is heated at a temperature higher than the temperature at which the insulating film is formed.
A method for manufacturing the insulating film according to the above. 3. Oxygen by ionizing at least one of oxygen (O ₂ ), ozone (O ₃ ), dinitrogen monoxide (N ₂ O), ammonia (NH ₃ ) and nitrogen (N ₂ ). 2. The method according to claim 1, wherein at least one of atoms and nitrogen atoms is generated. 4. The method according to claim 1, wherein the surface of the base portion is heated by irradiating an energy beam. 5. The method according to claim 4, wherein an excimer laser beam is irradiated as an energy beam. 6. The method according to claim 6, further comprising the step of forming a coating film so as to cover at least a part of the insulating film before heating after forming the insulating film on the surface of the base portion. 2. The method according to claim 1, wherein the surface of the underlying portion is heated by irradiating the substrate. 7. Silicon (Si), germanium (G)
e) forming a coating film containing at least one of tungsten (W), titanium (Ti), molybdenum (Mo), tantalum (Ta), nickel (Ni) and aluminum (Al); 7. An excimer laser beam is radiated.
A method for manufacturing the insulating film according to the above. 8. The method according to claim 1, wherein the underlayer is formed of silicon. 9. An oxide film on the surface of the base portion by exposing the surface of the base portion made of a semiconductor to an ionizing gas containing at least one of oxygen atoms (O) and nitrogen atoms (N).
A method for manufacturing a semiconductor device, comprising: a step of forming an insulating film made of a nitride film or an oxynitride film; and a step of heating a surface of a base portion on which the insulating film is formed. 10. The method of manufacturing a semiconductor device according to claim 9, wherein the surface of the underlying portion is heated at a temperature higher than the temperature at which the insulating film is formed. 11. The method according to claim 9, wherein at least one of an oxygen atom and a nitrogen atom is generated by ionizing at least one of oxygen, ozone, nitrous oxide, ammonia and nitrogen. Of manufacturing a semiconductor device. 12. The method for manufacturing a semiconductor device according to claim 9, wherein the surface of the underlying portion is heated by irradiating an energy beam. 13. The method for manufacturing a semiconductor device according to claim 12, wherein an excimer laser beam is irradiated as an energy beam. 14. The method according to claim 14, further comprising the step of forming a coating film so as to cover at least a part of the insulating film before heating after forming the insulating film on the surface of the base portion. The method for manufacturing a semiconductor device according to claim 9, wherein the surface of the underlying portion is heated by irradiating the substrate. 15. A method of forming a coating film containing at least one of silicon, germanium, tungsten, titanium, molybdenum, tantalum, nickel and aluminum, and irradiating an excimer laser beam as an energy beam. A method for manufacturing a semiconductor device according to claim 14. 16. The method of manufacturing a semiconductor device according to claim 9, wherein the base portion is formed of silicon. 17. A method for manufacturing a semiconductor device having a transistor in which an insulating film is formed on a base portion made of a semiconductor constituting a conductive layer, wherein the surface of the base portion is formed by at least one of oxygen atoms and nitrogen atoms. Forming an insulating film made of an oxide film, a nitride film, or an oxynitride film on the surface of the underlying portion by exposing it to an ionizing gas containing one of the two; and heating the surface of the underlying portion on which the insulating film is formed. A method for manufacturing a semiconductor device, comprising: 18. A memory in which an insulating film is formed on a base portion made of a semiconductor constituting a conductive layer and a memory or a capacitor in which an insulating film is formed on a base portion made of a semiconductor forming a charge storage portion. A method for manufacturing a semiconductor device having a memory in which an insulating film is formed on a base portion constituting an electrode, comprising exposing a surface of the base portion to an ionized gas containing at least one of oxygen atoms and nitrogen atoms. A method of manufacturing a semiconductor device, comprising: a step of forming an insulating film made of an oxide film, a nitride film, or an oxynitride film on a surface of a base portion; and a step of heating the surface of the base portion on which the insulating film is formed. . 19. A method for manufacturing a semiconductor device having a diode in which an insulating film is formed on a base part made of a semiconductor constituting an electrode, wherein the surface of the base part is formed by at least one of oxygen atoms and nitrogen atoms. Forming an insulating film made of an oxide film, a nitride film, or an oxynitride film on the surface of the underlying portion by exposing it to an ionizing gas containing, and heating the surface of the underlying portion on which the insulating film is formed. A method for manufacturing a semiconductor device. 20. A method of manufacturing a semiconductor device having a single-electron transistor in which an insulating film is formed on a base portion made of a semiconductor constituting a conductive layer, wherein the surface of the base portion is formed of oxygen atoms and nitrogen atoms. Forming an insulating film made of an oxide film, a nitride film, or an oxynitride film on the surface of the underlying portion by exposing it to an ionized gas containing at least one of the above; and heating the surface of the underlying portion on which the insulating film is formed. A method for manufacturing a semiconductor device, comprising: 21. A method of manufacturing a semiconductor device having a single-electron memory in which an insulating film is formed on a base portion made of a semiconductor constituting a conductive layer, wherein the surface of the base portion is formed of oxygen atoms and nitrogen atoms. Forming an insulating film made of an oxide film, a nitride film, or an oxynitride film on the surface of the underlying portion by exposing it to an ionized gas containing at least one of the above; and heating the surface of the underlying portion on which the insulating film is formed. A method for manufacturing a semiconductor device, comprising: