JP3172307B2 - Method for manufacturing semiconductor device - 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 semiconductor device, and more particularly to an improvement in the quality of a plasma oxide film.

In a recent miniaturized semiconductor device manufactured by a submicron process, the thickness of an insulating film formed in a manufacturing process of the semiconductor device must be reduced, so that requirements for film quality are strict, and the film quality is poor. In such a case, the variation in transistor characteristics is adversely affected.

[0005] Under the circumstances described above, there is a demand for a method of manufacturing a semiconductor device capable of forming an insulating film capable of coping with miniaturization of the semiconductor device.

[0004]

2. Description of the Related Art A conventional method for manufacturing a semiconductor device will be described in detail with reference to FIG. FIG. 3 is a side sectional view showing a conventional method of manufacturing a semiconductor device in the order of steps.

First, as shown in FIG. 3A, an aluminum wiring layer 12 is formed on the surface of a semiconductor substrate 11, and a plasma oxide film 13 having a thickness of about 3,000 mm covering the semiconductor substrate 11 and the aluminum wiring layer 12. Is formed by a plasma method, and an SOG film 14 is applied on the surface of the plasma oxide film 13 to form the same.

[0006] Next, as shown in FIG.
12 until the plasma oxide film 13 formed on the surface of
Etchback for removing the OG film 14 is performed. Then Figure 3
A PSG film 15 is formed on the entire surface as shown in FIG.

Thereafter, these plasma oxide films 13 and SO
The insulating film composed of the G film 14 and the PSG film 15 is coated at a flow rate of 7,500 sccm.
Annealing is performed at 450 degrees Celsius for 30 minutes in a mixed gas atmosphere of nitrogen gas and hydrogen gas at a flow rate of 7,500 sccm.

[0008]

In the above-described conventional method of manufacturing a semiconductor device, after an SOG film or a PSG film is formed on the surface of a plasma oxide film, it is placed in a mixed gas atmosphere of nitrogen gas and hydrogen gas. , The moisture contained in the plasma oxide film or the SOG film cannot be completely removed, which has a problem that the transistor characteristics of the completed semiconductor device are adversely affected. .

In view of the above, the present invention provides a method of manufacturing a semiconductor device capable of forming an insulating film that does not transmit moisture in a miniaturized semiconductor device by improving a process that can be performed easily and easily. It is intended for.

[0010]

According to a method of manufacturing a semiconductor device of the present invention, a wiring layer is formed on a semiconductor substrate, and a plasma oxide film is formed on the wiring layer and the surface of the semiconductor substrate. Step 1, annealing in a mixed gas atmosphere of hydrogen gas and oxygen gas, and forming a plasma oxide film made of tetra-ethyl-ortho-silicate on the surface of the plasma oxide film It is configured to include a third step and a fourth step of applying and forming an insulating film for flattening the surface of the plasma oxide film made of tetra-ethyl-ortho-silicate.

In the second step, hydrogen gas and oxygen gas are mixed.
Instead of the mixed gas atmosphere, it is also possible to perform the treatment in an oxygen gas atmosphere or a mixed gas atmosphere of nitrogen gas and hydrogen gas.

[0012]

According to the present invention, a plasma oxide film is deposited on a wiring layer formed on a semiconductor substrate and a surface of the semiconductor substrate, and then a mixed gas atmosphere of hydrogen gas and oxygen gas, an oxygen gas atmosphere, or After annealing in a mixed gas atmosphere of gas and hydrogen gas, a plasma oxide film made of tetra-ethyl-ortho-silicate is deposited and formed, and the surface of the plasma oxide film made of tetra-ethyl-ortho-silicate is formed. Since the insulating film to be flattened is formed, the plasma oxide film can be directly and reliably annealed, and deterioration of transistor characteristics of the completed semiconductor device can be prevented.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG.

FIG. 1 is a side sectional view showing an embodiment according to the present invention in the order of steps, and FIG. 2 is a view showing the degree of deterioration of the moisture resistance of an RF plasma oxide film processed by the processing method of the embodiment according to the present invention.

In one embodiment of the present invention, FIG.
1A, an aluminum wiring layer 2 having a thickness of about 1 μm is formed on the surface of a semiconductor substrate 1, and the aluminum wiring layer 2 and the entire surface of the semiconductor substrate 1 are subjected to a film thickness of 3,000 using a parallel plate type plasma apparatus. The plasma oxide film 3 of Å is formed.

Next, the semiconductor substrate 1 in this state is placed in an annealing furnace, and hydrogen gas at a flow rate of 7,500 sccm and flow rate of 5,000 sc
30 at 450 degrees Celsius in a mixed gas atmosphere of oxygen gas of sccm
Minute annealing process.

Then, as shown in FIG. 1B, a plasma oxide film 4 (hereinafter referred to as TE) made of tetra-ethyl-ortho-silicate is formed on the surface of the plasma oxide film 3 which has been subjected to this treatment.
OS plasma oxide film 4).

Thereafter, as shown in FIG.
An insulating film for flattening the surface of the S plasma oxide film 4, for example, an SOG film 5 is formed by applying using a spinner. In the present embodiment, the annealing was performed in a mixed gas atmosphere of hydrogen gas and oxygen gas, but only oxygen gas at a flow rate of 5,000 sccm or nitrogen gas at a flow rate of 7,500 sccm and a flow rate of 7,500 sccm were used.
The same temperature in a mixed gas atmosphere of hydrogen gas of sccm,
It is also possible to perform annealing for the same time.

When the pressure-cooker test is performed on the semiconductor device on which the insulating film is formed in a container at a pressure of 2 atm and a temperature of 121 ° C., the degree of deterioration of each semiconductor device with respect to the pressure-cooker test time is shown in FIG. As shown in FIG.

The vertical axis in FIG. 2 shows the degree of deterioration in comparison of the infrared absorption peak areas. In the case where no annealing treatment is performed, as shown in the figure, "no treatment" is shown, the deterioration completely occurs in about 70 hours, but in the case of annealing treatment in a mixed gas atmosphere of nitrogen gas and hydrogen gas, "N ₂ + H ₂ " As shown, it deteriorates completely in about 200 hours. Those annealed in an oxygen gas only atmosphere of completely deteriorated in about 250 hours as shown as "O _2". Those annealed in a mixed gas atmosphere of hydrogen gas and oxygen gas are maintained even after the lapse of 250 hours as shown as "H ₂ + O _2", it noted a degree deterioration degree 0.8.

As described above, since the plasma oxide film 3 is annealed immediately after the plasma oxide film 3 is first formed, the insulating film having good moisture resistance can block the invasion of moisture from the outside by this process. A film can be formed.

[0022]

As is apparent from the above description, according to the present invention, there is an advantage that the film quality of the insulating film of the semiconductor device can be improved by a very simple process change.
It is possible to provide a method of manufacturing a semiconductor device which can be expected to be significantly economical and to have an effect of improving reliability.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an embodiment according to the present invention in the order of steps;

FIG. 2 is a diagram showing the degree of deterioration of moisture resistance of an RF plasma oxide film processed by the processing method according to one embodiment of the present invention;

FIG. 3 is a side sectional view showing a conventional method of manufacturing a semiconductor device in the order of steps;

[Explanation of symbols]

1 is a semiconductor substrate, 2 is an aluminum wiring layer, 3 is a plasma oxide film, 4 is a TEOS plasma oxide film, 5 is an SOG film,

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-118927 (JP, A) JP-A-5-343542 (JP, A) JP-A-6-163521 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H01L 21/316 H01L 21/768

Claims (3)

(57) [Claims] A first step of forming a wiring layer on a semiconductor substrate and applying a plasma oxide film on the wiring layer and the surface of the semiconductor substrate to form a mixed gas atmosphere of hydrogen gas and oxygen gas; A second step of annealing in the inside, and tetra-ethyl-ortho.
A third step of depositing and forming a plasma oxide film of silicate; and a fourth step of depositing and forming an insulating film for flattening the surface of the plasma oxide film of tetra-ethyl-ortho-silicate. A method for manufacturing a semiconductor device, comprising: 2. A wiring layer is formed on a semiconductor substrate.
Depositing a plasma oxide film on the surface of the layer and the semiconductor substrate
A first step of forming by plasma etching , a second step of annealing in an oxygen gas atmosphere, and a step of forming a tetra-ethyl-ortho-
Deposition by forming a plasma oxide film made of silicate
A third step, and a step of preparing the tetra-ethyl-ortho-silicate
Deposits an insulating film to flatten the surface of the zuma oxide film.
The method of manufacturing a semiconductor device comprising: the fourth step, characterized in that it comprises that. 3. A wiring layer is formed on a semiconductor substrate.
Depositing a plasma oxide film on the surface of the layer and the semiconductor substrate
A second step of annealing in a mixed gas atmosphere of nitrogen gas and hydrogen gas, and a step of forming a tetra-ethyl-ortho-
Deposition by forming a plasma oxide film made of silicate
A third step, and a step of preparing the tetra-ethyl-ortho-silicate
Deposits an insulating film to flatten the surface of the zuma oxide film.
The method of manufacturing a semiconductor device comprising: the fourth step, characterized in that it comprises that.