JP2856307B2 - Thin film formation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma-enhanced chemical vapor deposition for forming a thin film on a sample surface such as a semiconductor substrate.
The present invention relates to a method of forming a thin film using a hanced CVD method.

[0002]

2. Description of the Related Art Conventionally, in order to form a thin film on a sample surface such as a semiconductor substrate, a high frequency of a certain frequency is applied to a source gas introduced into a reaction vessel to generate plasma, and the source gas is activated. Promotes chemical reactions,
A plasma-enhanced chemical vapor deposition (hereinafter, referred to as PECVD) method of depositing a generated reaction product on a sample surface is widely used.

In particular, when forming an interlayer insulating film or a wiring protection film (passivation film) between wirings made of Al or an Al alloy, hillocks in the wiring (Al) are formed.
It is highly preferred to use a sufficiently low forming temperature so that formation of the lock can be prevented. Therefore, PE capable of forming an insulating film or a protective film at a low temperature of about 400 ° C.
CVD is widely used to date and is increasingly being used in the future.

In this PECVD, for example, a SiH ₄ / N ₂ O-based gas or a tetraethoxysilane (TEOS) / O ₂ -based gas is used as a source gas in order to deposit an SiO ₂ film on the surface of a semiconductor substrate. I have been.

[0005]

In recent years, with the demand for higher integration of a large-scale integrated circuit (LSI), PEC
In the case of VD as well, the development of submicron-scale miniaturization technology has become extremely important. From such a viewpoint, the inventor tried experimental verification of the shape of a thin film formed by the conventional PECVD method. Hereinafter, the experimental results by the present inventors will be described.

FIGS. 5 (a) to 5 (f) show 13.56 of tetraethoxysilane (TEOS) / O ₂ -based gas introduced between opposed electrodes provided in a reaction vessel of a PECVD apparatus.
Experimental results when plasma was generated by applying high-frequency power such as MHz, and the reaction product SiO ₂ thin film was coated on the SiO ₂ film on the semiconductor substrate surface and the Al wiring formed on the surface. FIG. FIG. 5 shows a micrograph traced.

[0007] According to the experimental results, FIG.
When the space between the wirings has a margin as shown in (c), the covering shape of the SiO ₂ thin film in that space is a good shape close to a forward taper, but FIGS. 5D to 5F.
In the formation of a thin film for a pattern in which the distance between the wirings is narrow, the coating shape tends to have an inverse taper according to the submicron rule, and a gap such as a groove is formed between the wirings. Then, the SiO ₂ thin films on the adjacent wirings were connected at the head, and a cavity, that is, a void was formed.

[0008] In the vicinity of a place where the wiring pattern runs in parallel at a right angle or a curve, the distance between the wirings is large, so that the thin films are not connected at the head, and the void tends to form an opening like a nest. was there. Therefore, it is difficult to completely bury the voids, gaps, and openings with the liquid leveling material applied by the SOG (spin-on-glass) method. It was also difficult to completely remove the liquid component by adding cures such as cure and high vacuum cure.

There is a similar problem in the case of flattening by the TEOS / O ₃ system. This residual liquid component not only deteriorates the moisture resistance of the SiO ₂ thin film, but also causes poor contact in contact holes between multilayer wirings formed later on the interlayer insulating film and disconnection of wiring due to electromigration. Was. Further, in the conventional SiO ₂ thin film forming technology using PECVD,
By using the SiH ₄ / N ₂ O system, a SiO ₂ thin film having good film properties (excellent in moisture resistance) can be formed, but the coating shape is inferior, so that the LSI is highly integrated and miniaturized. Therefore, its application has become difficult. In recent years, the formation of SiO ₂ thin film is requested by good coverage shape TEOS / O ₂ system obtained currently, SiH ₄
It has been widely applied to highly integrated LSIs instead of the / N ₂ O system. However, Si using TEOS / O ₂ system
The O ₂ thin film contains a large amount of moisture in the film, and this moisture sometimes causes various defects, and thus has a problem that the reliability of the device is reduced.

The present invention has been made in view of the problems of the conventional PECVD method, and an object of the present invention is to provide a method for forming a thin film capable of coping with higher integration and higher reliability. It is in.

[0011]

According to the present invention, the above-mentioned object is achieved by applying a high-frequency power to a mixed gas comprising an organic silane compound and a nitrogen oxide in a reaction vessel for accommodating a substrate. And a step of exciting the mixed gas with the plasma discharge energy to deposit a reaction product on the substrate.

[0012]

According to the thin film forming method of the present invention, a plasma is generated by applying high frequency power to a mixed gas comprising an organic silane compound and nitrogen oxide in a reaction vessel, and the mixed gas is generated by the plasma discharge energy. To excite chemical bonds and break down chemical bonds, depositing reaction products based on these active particles on the substrate as atomic or molecular radicals.

According to the knowledge of the present inventors, in a SiO ₂ thin film formed by the PECVD method, the supply gas system is made of Si.
Compared to the case of H ₄ system, the organic silane compound (TEOS
Etc.), the organic silane compound originally has a SiO bond, so that a good coating shape can be obtained based on its reactivity. In addition, when the supply gas system is an organic silane-based compound / nitrogen oxide system as compared with the case where the supply gas system is an organic silane-based compound / O ₂ system, due to the effect of nitrogen oxides,
Advantageously, a coated shape is obtained during the planarization step.

In the prior art, when an organic silane-based compound containing a large amount of hydrogen is simply used as a supply gas, if the temperature for forming the thin film is further lowered, a certain amount of SiO ₂ thin film is formed in the formed SiO ₂ thin film. The incorporation of hydrogen could not be prevented.

On the other hand, in the present invention, by using nitrogen oxide as an oxidizing agent supplied simultaneously with the organic silane compound and suppressing the oxidation reaction and accelerating the nitridation reaction, hydrogen is converted into SiOH bonds. Instead, it can be incorporated into the SiO ₂ thin film in the form of SiNH bonds.

Thus, in the present invention, defects caused by moisture in the SiO ₂ thin film can be eliminated, and nitrogen is taken into the SiO ₂ thin film (the SiN thin film is used as a protective film for LSI). As in the case of application, the function of preventing the penetration of impurities (water, Na ⁺ ions) can be provided to the SiO ₂ thin film.

Therefore, it is considered that a good interlayer insulating film or a protective film can be provided even in a large-scale integrated circuit (LSI) having a fine structure with high integration.

According to the knowledge of the present invention, in the present invention, in a SiO ₂ thin film formed on a substrate, a nitrogen atom is bonded only to silicon and is not directly bonded to oxygen.
It is considered that a molecular structure of (SiO ₃ ) ₃一部 is partially formed. Therefore, it is considered that by increasing the nitrogen content in the SiO ₂ thin film, the moisture in the film is reduced and a denser film quality structure is obtained, and as a result, the moisture resistance of the film is improved.

Hereinafter, the present invention will be described in detail.

In the present invention, "organic silane compound" refers to a silane compound having an organic group. It is preferable to use a compound having the following structural formula (Formula 1) as the organic silane-based compound in the present invention.

(R ₁ ) _m Si (OR ₂ ) _n (1) wherein R ₁ represents an alkyl, aryl or alkenyl group, R ₂ represents an alkyl group, and m and n represent , M + n = 4. More specifically, in the present invention, R ₁ is preferably a C ₁ -C ₆ alkyl, aryl, or alkenyl group, and R ₂ is a C ₁ -C ₄ lower alkyl group. Is preferred.

The organic silane compound is Si (OC
_{2 H 5) 4, (C} 2 H 5) Si (OC 2 H 5) 3, C 5
H ₁₁ Si (OC ₂ H ₅ ) ₃ , CH ₂ CHSi (OC ₂ H
_{5) 3, C 6 H 5} Si (OC 2 H 5) 3, (CH 3) 2
Si (OC ₂ H ₅ ) ₂ , Si (OCH ₃ ) ₄ , Si ₄ C
_{8 H 24 O 4, Si 4} C 4 H 16 O 4, Si 1 C 12 H
₂₄ O ₆ , Si ₂ C ₆ H ₁₈ O ₁ , and (C ₂ H ₅ ) ₂ S
It preferably contains at least one kind of gas selected from iH _2, and among these organosilane compounds, TEOS is particularly preferably used from the viewpoint of reactivity.

Further, as the nitrogen oxides in the present invention, N _x O _y [x and y represent the natural number] is preferred to use a compound having a structural formula comprising, nitrogen oxides, N ₂ O, NO And at least one gas selected from NO ₂ . Among them, N ₂ O is preferable from the viewpoint of reactivity and coating shape of the film.

In the present invention, when the flow rate (relative ratio) of the organosilane compound constituting the mixed gas is set to 10, the flow rate of nitrogen oxide is about 10 to 40 (further, 20 to 40).
30), but can be adjusted appropriately so as to obtain the “preferred nitrogen content” in the thin film described below.

The nitrogen content in the thin film (oxide film) formed by the method of the present invention is set at 0.1 from the viewpoint of the moisture resistance of the thin film.
About 1 to 5% by weight is preferable. In addition to this moisture resistance, when considering the step coverage shape of the thin film, the film formation rate, the in-plane uniformity, the film stress, and the like, the nitrogen content is 0.1 to
About 1% is preferable. Such a nitrogen content can be measured, for example, by X-ray photoelectron spectroscopy (XPS).

The thickness of the thin film formed by the method of the present invention is usually about 0.1 to 1.0 μm (further, 0.2 to 1.0 μm).
(About 0.3 μm). When the film thickness is small, it is preferable that the above-mentioned nitrogen content is large from the viewpoint of moisture resistance.

In the present invention, a carrier gas may be used, if necessary, to introduce the organosilane compound or nitrogen oxide into the reaction vessel. As the carrier gas, for example, an inert gas such as Ar or He can be preferably used. When the flow rate (relative ratio) of the organic silane compound is 10, the flow rate of the carrier gas is preferably about 5 to 50 (more preferably about 10 to 30).

The mixed gas used in the present invention contains at least the above-mentioned organic silane compound and nitrogen oxide. The mixed gas may further contain a nitrogen compound, if necessary. In the present invention, the "nitrogen compound" is a compound containing N atom (including single N _2), refers to those which do not contain O atoms.

From the viewpoint of facilitating the control of the nitrogen content in the SiO ₂ thin film, it is preferable to add a nitrogen compound such as N ₂ or NH ₃ .

[0030] Furthermore, the SiO ₂ thin film the ratio of nitrogen to total active particles present in the plasma increases {N
The molecular structure of (SiO ₃ ) ₃ ｝ can be increased, and the moisture in the film can be further reduced.

The "nitrogen compound" can be used as the carrier gas, if necessary. In the embodiment in which the mixed gas contains the nitrogen compound, the uniformity of the film thickness can be further improved by the stability of the plasma discharge.

The mixed gas (containing at least the organic silane compound and the nitrogen oxide) may further contain an oxygen compound, if necessary. In the present invention,
This “oxygen compound” is a compound containing an O atom (simple O 2
₂ and O ₃ ) which do not contain N atoms.

As the "oxygen compound", O ₂ , O _{3 and the} like are preferably used, but O ₂ is preferable from the viewpoint of reactivity.

In the embodiment in which the mixed gas contains the oxygen compound, the molecular structure of {N (SiO ₃ ) ₃ } in the SiO ₂ thin film can be reduced, so that the nitrogen content can be appropriately controlled. it can. Therefore, when the amount of nitrogen contained in the formed SiO ₂ thin film is excessively increased and the stress is increased, or when the access speed of the device is decreased due to an increase in the dielectric constant, an oxygen compound is appropriately added. Thereby, these can be easily prevented.

In the present invention, as the reaction conditions other than those described above, for example, the following conditions can be preferably used.

Pressure: 2 [Torr] to 10 [Torr
r] High frequency: 13.56 [MHz] High frequency power: 200 [W] to 600
[W] Substrate temperature: 350 [° C] to 450 [° C] Distance between electrodes: 100 [Mils] to 400
[Mils] Flow rate: 1000 [SCCM] to 3000 [SC
CM] A reaction apparatus that can be used in the thin film forming method of the present invention includes a reaction vessel for accommodating a substrate, and an introduction system capable of introducing a mixed gas containing at least an organic silane compound and nitrogen oxide into the reaction vessel. The reactor is not particularly limited as long as it is a reactor having an electrode for applying a high frequency to the mixed gas. For example, PECVD as shown in FIG.
An apparatus is preferably used.

Hereinafter, a schematic configuration of the PECVD apparatus will be described with reference to FIG. Referring to FIG. 1, opposed electrodes 3 and 4 are accommodated in a reaction vessel 2 for realizing a reaction chamber 1 sealed from the outside air. One electrode 4 is held at the ground potential, and a semiconductor substrate 5 for forming a thin film is placed on the opposing surface, and the other electrode 3 receives high-frequency power output from a high-frequency oscillation source 8 for plasma generation. The voltage is applied via an impedance matching circuit 9. In addition, a reaction gas is introduced into the reaction chamber 1 from above the electrode 3 via the pipe 6 and exhausted from the exhaust port of the reaction vessel 2. A heater 7 for controlling temperature is provided on the electrode 4 side.

Hereinafter, the present invention will be described more specifically based on examples.

Using a PECVD apparatus having the structure shown in FIG .
The conditions for the gas used are shown in Table 1 below.
Thus, a SiO ₂ thin film was formed. Here, it is preferable to heat the semiconductor substrate 5 to 400 ° C. in advance by a halogen lamp before placing it in the reaction vessel 2 from the viewpoint of improving the reproducibility of the growth characteristics of the SiO ₂ thin film. .

Examples 2 to 20 A SiO ₂ thin film was formed in the same manner as in Example 1 except that the PECVD apparatus having the structure shown in FIG. 1 was used and the conditions for the gases used were as shown in Table 1 below. did. Other conditions are based on Example 1.

[0041]

[Table 1]

The growth rate of the SiO ₂ thin film obtained under the above conditions was about 0.5 μm / min. The refractive index of the SiO ₂ thin film obtained in Example 10 was 1.49,
In another embodiment, the refractive index of the thin film is between 1.46 and
1.52.

Here, it is preferable that the semiconductor substrate 5 be heated to 400 ° C. in advance by a halogen lamp before being placed in the reaction vessel 2.

Example 21 The nitrogen content in the SiO ₂ thin film formed under the conditions of Example 1 was examined by infrared absorption spectrum. As a result, a peak related to nitrogen (NH) was observed at a wave number of about 3400 cm ⁻¹ . It was confirmed that nitrogen was contained in the film.

With respect to the moisture resistance, the preferred range of the nitrogen content in the SiO ₂ thin film was 0.1% or more and 5% or less. Considering other characteristics such as coating shape, growth rate, in-plane uniformity, and film stress, the nitrogen content is 1% or more 2
% Or less was preferred.

Example 22 The elemental composition and bonding state in the depth direction of the SiO ₂ thin film formed under the conditions of Example 1 were measured by XPS (X-ray Photoel).
ectron Spectroscopy). As a result, nitrogen does not form isolated grains such as Si ₃ N ₄ , and is uniformly dispersed in the SiO ₂ thin film on the order of atoms, and is bonded only to silicon, and is not directly bonded to oxygen. N
(SiO ₃ ) ₃ ｝ (see the following structural formula (Chem. 2)).

[0047]

Embedded image

Example 23 For example, under the thin film forming conditions of Example 10, an SiO ₂ thin film for insulating coating was further formed on the SiO ₂ film on the surface of the semiconductor substrate and on the Al wiring formed on the surface. .
FIGS. 2A to 2F show longitudinal sectional shapes of the formed thin film. The figure is a cross-sectional view in which a contour portion of a micrograph of a vertical cross-sectional shape is traced, and the vertical and horizontal lengths are as indicated by a unit scale (0.5 μm) in the figure.

In this embodiment, FIGS. 2E and 2F
Even when the widths and relative intervals of the Al wirings are in the submicron range as described above, no connection was made at the head of the wiring due to the thinning of the wiring side wall. And T
PECVD of the present invention using a mixed gas composed of an organic silane-based gas such as EOS and a nitrogen oxide such as N ₂ O
The SiO ₂ thin film formed by the method contains nitrogen as described above and removes moisture in the film, so that the moisture resistance is improved, and the SiO ₂ thin film is formed from a mixed gas of an organic silane-based gas and O _2. As compared with the SiO ₂ thin film to be obtained, the same or higher moisture resistance was obtained even when the film thickness was reduced. Therefore, even if a high degree of integration required in the design of a sub-micron rule, the SiO ₂ thin film quality to be formed on the wiring is superior in moisture resistance, even as a thin film than the conventional SiO ₂ film request Was satisfied, and a design was made so that the SiO ₂ thin film would not be connected at the adjacent Al wiring head. That is, the margin (degree of freedom) in device design in forming the SiO ₂ thin film has been widened.

In this embodiment, the nitrogen content in the SiO ₂ thin film is appropriately changed according to the amount of the nitrogen compound or the oxygen compound added to the mixed gas composed of the organosilane gas and the nitrogen oxide. As a result, a thin film having a thin film composition which meets the requirements of highly integrated large-scale integrated circuits (LSI) such as an access speed depending on film stress and dielectric constant could be provided as appropriate.

Comparative Example 1 Mixed gas used in Example 1 (TEOS / nitrogen oxide system)
Instead, a SiO ₂ thin film was formed in the same manner as in Example 1 except that the following TEOS / O ₂ -based mixed gas was used.

TEOS: 500 SCCM O ₂ : 500 SCCM He: 500 SCCM The thus formed SiO ₂ thin film (Comparative Example 1)
For the SiO ₂ thin film formed in Example 1, was compared with the infrared absorption spectrum, as compared to the SiO ₂ thin film formed by PECVD method using a mixed gas of TEOS / O ₂ system (Comparative Example 1), In the thin film of Example 1, it was confirmed that the peak near the wave number of 3670 cm ^-1 indicating the absorption related to water (OH) was reduced. As a result, it was found that the SiO ₂ thin film formed in Example 1 contained nitrogen, and as a result, moisture was reduced and moisture resistance was improved.

Embodiment 24 The TEOS / N ₂ O-based or TEOS / O
For each of the SiO ₂ thin films obtained by the _two systems,
A Pressure Cooker Test was performed to determine moisture resistance. In this pressure cooker test, for example, a PSG (phos
pho-silicate glass) was formed to a thickness of 1 μm, and an SiO ₂ thin film to be further evaluated was formed thereon. The sample was left for a predetermined time under a humidified condition of a pressure of 2 atm, a steam atmosphere, and an atmospheric temperature of 121 ° C.

When PSG absorbs moisture, the P = O bond in the PSG changes to a P-OH bond. This behavior can be measured by an infrared absorption spectrum. That is,
When PSG absorbs moisture, the absorption peak of the P ＝ O bond on the infrared absorption spectrum decreases, and the absorption peak of the P-OH bond increases.

Utilizing such a phenomenon, the height of the peak in the absorption spectrum of the P = O bond before leaving under the above conditions was set to 100% (that is, the moisture resistance was set to 100%). Based on this value, the absorption peak of the P = O bond was converted.

FIG. 3 shows the result of a pressure cooker test when a SiO ₂ thin film was formed to a thickness of 0.2 μm, and FIG.
The results of the pressure cooker test when the O ₂ thin film was formed at 0.1 μm were shown.

As a result, when the SiO ₂ thin film was formed to have a thickness of 0.2 μm (FIG. 3), the TEOS / N ₂ O-based film obtained a good 98% moisture resistance even after performing the pressure cooker test for 60 hours. On the other hand, in the TEOS / O ₂ system, after performing this for 40 hours, the moisture resistance is reduced to 85%,
In 60 hours, it has dropped to 78%.

When the SiO ₂ thin film was formed to a thickness of 0.1 μm (FIG. 4), in the case of the TEOS / N ₂ O system, the pressure was reduced to 89% after the pressure cooker test was performed for 60 hours. On the other hand, in the case of the SiH ₄ / N ₂ O system, after performing the above test for 40 hours, it was almost the same as that of the TEOS / O ₂ system, but after 40 hours, it decreased to 68%. Conventionally, a SiO ₂ thin film formed of a SiH ₄ / N ₂ O system has been considered to be excellent in moisture resistance.
The moisture resistance of the thin film formed by the / N ₂ O system was better than this.

According to these results, TEOS / N ₂ O
The system was found to be more excellent in moisture resistance than the TEOS / O ₂ system or the SiH ₄ / N ₂ O system. In practice, it is preferable that the TEOS / N ₂ O-based thin film has a thickness of at least 0.2 μm.

[0060]

As described above, according to the thin film forming method of the present invention, high frequency power is applied to a mixed gas comprising an organic silane compound and nitrogen oxide in a reaction vessel to generate plasma. Since the gas mixture is excited by the plasma discharge energy to deposit a reaction product on the substrate, nitrogen atoms are bonded only to silicon in the SiO ₂ thin film formed based on the reactivity of the organosilane compound, and oxygen And a molecular structure of {N (SiO ₃ ) ₃ } which is not directly bonded to at least a part thereof. Therefore,
According to the present invention, the nitrogen content in the film can be increased, and at the same time, the water content in the film is reduced.
The iO ₂ thin film can have a denser composition, and can also be a thin film having excellent moisture resistance because it blocks external moisture and does not allow moisture to permeate.
Even if the iO ₂ thin film is thinned so as not to generate voids, moisture resistance can be maintained.

In the present invention, the nitrogen content in the formed SiO ₂ thin film can be more easily controlled by adding a nitrogen compound or an oxygen compound to the above mixed gas as required. As a result, SiO that can be used for a large-scale integrated circuit (LSI) with high integration and high reliability can be used.
_Two thin films can be formed.

[Brief description of the drawings]

FIG. 1 shows a PEC capable of performing a thin film forming method according to the present invention.
FIG. 2 is an explanatory diagram illustrating a schematic configuration of one embodiment of a VD device.

FIG. 2 shows SiO ₂ formed in Example 5 of the present invention.
It is a longitudinal cross-sectional view which shows the shape of a thin film.

FIG. 3 is a graph comparing moisture resistance by a pressure cooker test when a SiO ₂ thin film is formed to a thickness of 0.2 μm in Example 6.

FIG. 4 is a graph comparing moisture resistance by a pressure cooker test when forming a SiO ₂ thin film of 0.1 μm in Example 6.

FIG. 5 shows SiO formed by a conventional thin film forming method.
FIG. ₂ is a longitudinal sectional view showing the shape of _two thin films.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reaction chamber, 2 ... Reaction container, 3/4 ... Counter electrode, 5 ... Semiconductor substrate, 6 ... Piping, 7 ... Heater, 8 ... High frequency power supply, 9
... Impedance matching circuit.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Naoyuki Iwasaki 14-3 Shinizumi, Narita City, Chiba Pref. Nogedaira Industrial Estate Inside Applied Materials Japan Co., Ltd. (72) Inventor Naoaki Kobayashi 14-3 Shinizumi, Narita City, Chiba Prefecture Applied Materials Japan Co., Ltd. (72) Inventor Kazuo Urata 14-3 Shinsen, Narita-shi, Chiba Applied Materials Japan Co., Ltd. (72) Inventor Tatsuya Sato Chiba Prefecture Applied Materials Japan Co., Ltd. in 14-3 Shinzumi, Narita City Nogedaira Industrial Park (56) References JP-A-5-175132 (JP, A) JP-A-64-48425 (JP, A) -502065 (JP, A) Thin Solid Films No. 69 (1980) 39-5 2 pages

Claims (6)

(57) [Claims] 1. A high-frequency power is applied to a mixed gas comprising an organic silane-based compound, a nitrogen oxide, and an oxygen compound and containing substantially no water vapor in a reaction vessel containing a substrate. Silane compounds, nitrogen oxides ,
And generating a plasma based on an oxygen compound, and exciting the mixed gas with the plasma discharge energy to deposit a reaction product on the substrate. 2. The method according to claim 1, wherein the mixed gas further contains a nitrogen compound. 3. The method according to claim 1, wherein the organic silane compound is Si (OC
_{2 H 5) 4, (C} 2 H 5) Si (OC 2 H 5) 3, C 5 H 11 Si
(OC ₂ H ₅ ) ₃ , CH ₂ CHSi (OC ₂ H ₅ ) ₃ , C ₆ H ₅
Si (OC ₂ H ₅ ) ₃ , (CH ₃ ) ₂ Si (OC ₂ H ₅ ) ₂ , S
i (OCH ₃ ) ₄ , Si ₄ C ₈ H ₂₄ O ₄ , Si ₄ C ₄ H
A gas containing at least one gas selected from ₁₆ O ₄ , Si ₁ C ₁₂ H ₂₄ O ₆ , Si ₂ C ₆ H ₁₈ O ₁ , and (C ₂ H ₅ ) ₂ SiH _2. 3. The method for forming a thin film according to 1 or 2 . Wherein said nitrogen oxides, N ₂ O, NO, and a thin film forming method according to any one of claims 1 to 3, characterized in that it comprises at least one kind of gas selected from NO ₂ . 5. The method according to claim ₂ , wherein the nitrogen compound contains at least one kind of gas selected from N ₂ and NH ₃ . Wherein said oxygen compound thin film forming method according to claim 1, characterized in that it comprises at least one kind of gas selected from O ₂ and O _3.