JP2781299B2 - Thin film manufacturing method and thin film manufacturing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a thin film in a semiconductor device, for example, a method for forming a flat film on a substrate having a large unevenness such as an interlayer insulating film of a highly integrated DRAM having a three-dimensional structure. About.

[0002]

2. Description of the Related Art For forming a thin film, for example, a CVD method or an SOG method is used. In the CVD method, for example,
With the substrate kept at 400 ° C., the Si
By chemically reacting H ₄ and O ₂ gas, SiO ₂
It forms a film.

SiH ₄ + O ₂ → SiO ₂ + 2H ₂ (1) On the other hand, in the SOG method, for example, a liquid containing a sol-form Si—O polymer is applied on a substrate by a spin method, and the substrate is coated with a liquid.
Baking is performed at 00 ° C. to form a SiO ₂ film.

[0004]

However, as shown in FIG. 6, a thin film formed by the CVD method has a problem that a conformal film with the underlayer is obtained and unevenness of the underlayer remains.

On the other hand, in the thin film formed by the SOG method, as shown in FIG.
Although the underlayer is flattened, the film quality is not good. That is, evaporation of the solvent in the liquid by baking proceeds from the upper part of the film, and formation of SiO ₂ by polymerization proceeds from the upper surface. For this reason, a large amount of unreacted groups remain inside the film, and when baking is advanced, there is a problem that cracks occur due to an increase in stress.

The present invention has been made to solve these problems, and an object of the present invention is to provide a method of manufacturing a thin film which realizes planarization of an interlayer insulating film and realizes high quality of the film. .

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the thin film manufacturing method of the present invention uses a mist liquid on a substrate .
And depositing liquid fine particles containing film constituent elements .
Ri, a first step of forming a thin film having a thickness of 50-500, after its first step, by subjecting the thin film to an ozone or plasma or active oxygen atom, to promote the oxidation of the thin film The second step is repeated until a desired film thickness is obtained. Further, the thin film manufacturing apparatus of the present invention is a thin film manufacturing apparatus used in the above thin film manufacturing method, and supplies the above mist liquid.
A first reaction chamber for performing the first step, a second reaction chamber for performing the second step, and a partition between the first reaction chamber and the second reaction chamber; The above substrate passes
A partition having a size space of possible, said substrate said first
Between the first reaction chamber and the second reaction chamber via the space
And a moving means for moving freely . The thickness of the film deposited on the substrate is preferably about 100 °.

[0008]

The film thickness can be reduced to 50 to 5 by using the mist liquid.
00 °. Making such a film thickness
Can make the oxidation uniform and cause cracks.
The surface can be flattened without using. In addition, since each thin coating amount is exposed to ozone, plasma, or active oxygen atoms, evaporation of the solvent contained in the liquid and evaporation of by-products accompanying polymerization are completely performed,
The formation of a SiO ₂ film in the applied film is promoted.

[0009]

FIG. 1 is a schematic diagram of an apparatus used in an embodiment of the present invention, and FIG. 2 is a configuration diagram of the apparatus. Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the apparatus used in the embodiment of the present invention is provided with a coating chamber 1 in which a step of attaching liquid fine particles containing film constituent elements, that is, a liquid source, onto a wafer 4 is performed. Further, a film improvement chamber 2 is provided in which a step of promoting the film to SiO ₂ by exposing the wafer 4 having a predetermined thickness in the coating chamber 1 to oxygen plasma is performed. The film improvement chamber 2 is provided with a parallel plate electrode 6 for generating oxygen plasma, and a voltage is applied to the parallel plate electrode 6 by an RF power source to perform discharge. The whole apparatus is in a cylindrical shape, and a partition wall 5 for partitioning the above-mentioned chambers is formed in the center thereof. The provision of the partition walls 5 prevents gas from being mixed between these two chambers. For example, when oxygen plasma enters the coating chamber 1, the cause of generation of dust due to conversion of the atomized liquid into SiO ₂ is eliminated. can do.

Further, an introduction portion (not shown) of a reaction gas to be used is provided in the periphery, and an exhaust mechanism 11 for exhausting exhaust gas generated by the reaction is provided in a central portion. The wafer 4 on which the above-described steps are performed is mounted on the rotatable susceptor 3. The susceptor 3 is provided with a heater (not shown) for heating the susceptor 3 and a cooling mechanism (not shown) for cooling with a cooling medium.

Next, a description will be given of an embodiment of the present invention which is performed using the apparatus having the above-described configuration. First, in the coating chamber 1, SOG generally used for the SOG method is used.
The liquid or TEOS is atomized to fill the atomized SOG liquid or TEOS. The wafer 4 is placed on the susceptor 3 in the coating chamber 1 filled with the gas, and the mist is deposited on the wafer 4. When the amount of the adhering liquid reaches a film thickness of 50 to 500 °, the adhering is interrupted, and the susceptor 3 is rotated to rotate the wafer 4 on which the atomized liquid is adhering.
Is moved to the membrane improvement chamber 2. Further, by exposing the wafer 4 to oxygen plasma generated by discharging the parallel plate electrode 6, the film is promoted to become SiO ₂ .
To generate this oxygen plasma, a reduced pressure of 10 Torr or less is required.

Thereafter, by repeating these steps, a thin film having a desired film thickness can be formed. FIG. 3 is a configuration diagram of an apparatus for implementing another embodiment of the present invention.

Here, in the embodiment described above, the S
While the conversion to iO ₂ is performed by oxygen plasma, another embodiment is characterized in that ozone is used. Film thickness 50-50
The wafer 4 on which the film of the mist of 0 ° is formed, the susceptor 3
While being placed on the upper side, it moves to the film improvement chamber 2. The membrane improvement chamber 2 is in a state filled with ozone introduced from the inlet 12. Then, exposing the wafer 4 to the ozone promotes the formation of the film into SiO ₂ . This method has the advantage that a film can be formed at or near atmospheric pressure, and does not require an exhaust step.

By repeating the above steps in the same manner as in the previous embodiment, a thin film having a desired film thickness can be obtained. Also,
FIG. 4 is a block diagram of an apparatus for carrying out another embodiment of the present invention.

The feature here is that active oxygen atoms are used to convert the film into SiO ₂ . That is, the active oxygen atoms are generated by introducing ozone gas or oxygen gas into the film improvement chamber 2 and irradiating the gas introduced by the UV lamp 7 through the quartz window 6 with UV. However, it is configured to promote the formation of SiO ₂ in the film. Also in this embodiment, the wafer 4 on which the mist liquid film having a film thickness of 50 to 500 ° is formed is moved to the film improvement chamber 2 while being placed on the susceptor 3. The film improvement chamber 2 is in a state of being filled with oxygen atoms irradiated with UV. And
By exposing the wafer 4 to its oxygen atoms, the Si
Promotes O ₂ formation.

By repeating the above steps in the same manner as in the previous embodiment, a thin film having a desired thickness can be formed. FIG. 5 shows a schematic cross-sectional view of a film formed by the method according to the embodiment described above.

The metal wiring 9 is formed on the substrate S, and the SiO ₂ film 8 formed by the method according to the embodiment of the present invention is formed on the metal wiring 9 and the substrate S. The SiO ₂ film 8 has a shape in which the unevenness of the metal wiring 9 is flattened.

In each of the embodiments, the example in which the susceptor moves the wafer by rotation has been described. However, the susceptor may be moved by reciprocating motion.

[0019]

As described above, the thin film of the present invention
According to the fabrication method, the film constituent elements are formed on the substrate by using a mist liquid.
By depositing liquid fine particles containing
A first step of forming a thin film having a thickness of Å,
After that, a second step of promoting oxidation of the thin film is desired.
It was repeated until the film thickness of
The film thickness formed each time can be reduced. This
Oxidation can be made uniform by setting
First, the surface can be flattened without cracks.
Wear. In addition, ozone or
Exposure to plasma or active oxygen atoms
Of by-products from evaporation and polymerization of solvents contained in
Evaporation can be performed completely, and it is the second step
In the film improvement process, low-temperature processes that do not use heat energy
Can be realized. As a result, the flatness of the film is reproduced
High quality and highly reliable membrane
Can be provided. Further, according to the thin film manufacturing apparatus of the present invention,
A first reaction chamber having a liquid source for supplying a liquid,
The second reaction chamber is partitioned from the first reaction chamber and the second reaction chamber.
A partition having a space large enough to allow a substrate to pass through;
The plate is interposed between the first reaction chamber and the second reaction chamber through the space.
With moving means to move freely.
Therefore, the first reaction chamber is based on the nebulized liquid from the liquid source.
Can be deposited on the plate to a small thickness of 50-500 °
And a low-temperature process in the film improvement process performed in the second reaction chamber.
Process can be realized. As a result, as described above
In addition, the film can be flattened and high quality can be realized.
You.

As a result, the film can be flattened with good reproducibility, and a high quality and highly reliable film can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an apparatus used in an embodiment of the present invention.

FIG. 2 is a configuration diagram of an apparatus used in an embodiment of the present invention.

FIG. 3 is a configuration diagram of an apparatus used in another embodiment of the present invention.

FIG. 4 is a configuration diagram of an apparatus used in another embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view of a film formed according to an embodiment of the present invention.

FIG. 6 is a schematic cross-sectional view of a film formed by a conventional method.

FIG. 7 is a schematic sectional view of a film formed by a conventional method.

[Explanation of symbols]

1 ··· Coating room 2 ··· Film improvement room 3 ··· Susceptor 4 ··· Wafer 5 ··· Partition wall 6 ··· Parallel plate electrode 7 ··· UV lamp 8 · ... SiO ₂ film 11 ... Exhaust mechanism S ... Substrate

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 21/314-21/3213 H01L 21/768

Claims (2)

(57) [Claims] A liquid fine particle containing a film constituent element is deposited on a substrate by using an atomized liquid , so that 50 to 500 °
A first step of forming a film thickness of the thin film, after the first step, by subjecting the thin film to an ozone or plasma or active oxygen atom, and a second step of accelerating the oxidation of the thin film Is repeated until a desired film thickness is obtained. 2. A thin film manufacturing apparatus used in the thin film manufacturing method according to claim 1 , wherein the liquid saw supplies the atomized liquid.
A first reaction chamber for performing the first step, a second reaction chamber for performing the second step, and a partition between the first reaction chamber and the second reaction chamber. Large enough for substrate to pass
A partition having a space of size and the substrate are subjected to the first reaction
Between the reaction chamber and the second reaction chamber via the space
A thin film manufacturing apparatus, comprising: a moving means for moving.