JPH11162969A - Manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve adhesiveness between lower SOG and upper SOG in a process for applying multiple SOG film layers. SOLUTION: A wiring film is sputtered and patterned and wiring layers 103 and formed on a semiconductor substrate. Then, a CVD oxide film layer 102 whose film thickness is about 5000 Å is formed on the whole face. Then, an SOG film 104 of the lower layer is formed and a surface is prcessed by plasma 106 using Ar gas as inert gas which does not positively react to Si-OR and Si-H in the SOG film. Then, the SOG film 105 of the upper layer is formed. Consequently, danger of deterioration of the SOG film owing to crack (micro crack) of the SOG film and peeling-off is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an SO
The present invention relates to a G application step and a surface treatment method in a state where an SOG layer is exposed.

[0002]

2. Description of the Related Art In the prior art, various flattening techniques have been used in accordance with miniaturization and high integration of semiconductor devices.
As one of them, there is a flattening method of applying SOG. Such a flattening method is generally performed by the following steps.

First, after a lower wiring is formed on a desired semiconductor device substrate, a first CVD oxide film layer is formed. Next, a desired planarizing film layer is formed by applying SOG one or more times, and then a second CVD oxide film layer is formed to form a planarized interlayer insulating film on the lower wiring. doing. In this case, in order to increase the adhesion between the lower SOG coating layer and the upper SOG coating layer, the lower SOG coating (the application of SOG and the baking immediately after the coating are continuously performed) and the upper SOG coating are performed.
O ₂ plasma treatment, O ₃ treatment, annealing at 350 ° C. or more, or the like was performed as a surface treatment during coating. However, in the case of O ₂ plasma or O ₃ treatment, not only the organic components on the SOG surface but also the organic components (Si—OR, Si—H, Si—CH _3, etc.) remaining in the SOG film and O ₂ , O ₃ is the SOG film to be sublimated by reaction causing deterioration of the film quality is degraded. In the case of annealing, unreacted, Si-OR, easily remaining Si-CH ₃ and the like surface, turned and upper SOG applied layer, causing poor adhesion to the second CVD oxide film layer I was

Further, the interlayer insulating film having a multi-layer structure formed in such a state is not affected by the film stress at the time of forming a wiring layer later or the film stress due to the formation of a protective film layer of a semiconductor substrate. Peeling or SOG between upper SOG film layers
There was a problem that microcracks were generated due to poor adhesion between the layer and the second CVD oxide film layer.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is capable of applying SOG a plurality of times by performing a surface treatment without deteriorating the film quality of an underlying SOG film layer. A lower SOG film layer and an upper SOG film layer,
It is an object of the present invention to provide a method for manufacturing a semiconductor device capable of improving adhesion to an insulating film layer formed after formation of a planarization layer by SOG.

[0006]

SUMMARY OF THE INVENTION The present invention provides a method of applying a plasma between a lower SOG coating and an upper SOG coating in order to apply SOG a plurality of times without deteriorating the lower SOG film layer in the prior art. And a method for manufacturing a semiconductor device characterized by performing a surface treatment by the method.

The invention according to claim 2 is performed using a reaction gas containing at least one kind of gas selected from the group consisting of argon gas, krypton gas, neon gas, xenon gas, nitrogen gas, and helium gas. A method of manufacturing a semiconductor device according to claim 1 is provided.

[0008]

According to the manufacturing method of the present invention described above, the SO
By performing surface treatment by plasma irradiation with the gas after the application of the lower SOG film in the G application process, Si-OR and Si- of organic components remaining in the lower SOG film are applied.
H, Si—CH ₃ etc. without affecting lower layer SOG
Si-OR on the surface of the membrane layer, Si-H, Si-CH 3
Therefore, the adhesion between the lower SOG film layer and the upper SOG film layer can be ensured.

According to a second aspect of the present invention, there is provided a method for manufacturing a semiconductor device, comprising: a reaction including at least one gas selected from the group consisting of argon gas, krypton gas, neon gas, xenon gas, nitrogen gas, and helium gas. By performing the plasma irradiation using a gas, the lower layer SO
Organic components Si-OR, Si-H, S remaining in the G film
Si-OR in no surface of the lower SOG layer to affect the i-CH ₃ and the like, Si-H, in order to decompose the Si-CH _3, efficiently upper SOG layer and the second CVD oxide film layer And an improvement in the adhesion to the substrate.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a part of the manufacturing process of the semiconductor device according to the present invention. In the step shown in FIG. 1A, the semiconductor substrate 101 on which desired processing has been performed is performed.
On top, a wiring film is sputtered and patterned to form a wiring layer 103. Subsequently, the film thickness is 5000 on the entire surface.
A CVD oxide film layer 102 of about Å is formed.

In the step shown in FIG. 1B, SOG is spin-coated on the CVD oxide film 102 formed in the step shown in FIG. Form a film layer. The flattening by SOG coating is the crack resistance of SOG (hereinafter, the crack limit is about 1500 ° in the case of inorganic SOG, and 2500 ° in the case of organic SOG, which shows various values depending on the material).
A predetermined flatness is ensured by applying the film thickness from once to a plurality of times. In particular, when a desired flatness is obtained by applying SOG a plurality of times, and when the surface treatment is not performed between the lower SOG film 104 and the upper SOG film 105, the surface of the lower SOG film 104 is coated with Si. -OR group or S
Since there is an i-H group and Si-CH ₃ , the underlying SOG film 1
04 and the SOG film 105 of the upper layer are not secured.
OG coating becomes impossible, or even if coating can be performed, the film may be peeled off during baking after application (work to promote polymerization of the SOG film with heat of 400 ° C. or more to secure film quality as an insulating film). O ₂ plasma treatment or O ₃ treatment is performed as a surface treatment to decompose the Si—OR group or Si—H group on the surface of the lower layer SOG 104 and stabilize it into a Si—O group or the like. The adhesion of the SOG applied to the upper layer was ensured.

However, in the case of this method, the lower layer SO
The SOG film partially reacts because the O ₂ radicals and O ₃ that have entered the film in addition to the reaction on the outermost surface of the G film 104 cause the above-described decomposition and sublimation reactions, and the film is cracked (micro crack). Also, there were side effects that caused peeling.

Therefore, the Si-OR, S in the SOG film
By performing surface treatment using plasma using Ar gas, which is an inert gas that does not actively react with i-H, adhesion can be ensured.

Since Ar plasma is an inert gas and is hardly radicalized and is almost ionized,
Physical energy is given to the surface of the SOG film by ion bombardment due to Ar ions, and a bake effect due to heat generation, and a bond of Si-OR group or SI-H group on the outermost surface of the SOG film is broken by bombardment. The same effects as those obtained by performing O ₂ plasma treatment or O ₃ treatment can be obtained, and a reaction effect on the outermost surface can be obtained.

Further, even if Ar gas is radicalized, it is an inert gas and does not directly react with the above-mentioned one in the SOG film, so there is no fear of deterioration of the film.

This effect can also be obtained by using a reaction gas containing at least one gas selected from the group consisting of argon gas, krypton gas, neon gas, xenon gas, nitrogen gas and helium gas in addition to Ar gas. However, Ar is superior from the viewpoint of economical efficiency in production and availability. Also, Ar gas plasma requires 1.5 to 2 kilowatts of high-frequency power to obtain discharge stability at low pressure, but has very strong ionicity. Since the heat generation is large, temperature control of the wafer becomes a problem.

In particular, as in this case, in the case of surface treatment of SOG used between AL wiring layers, when the reaction between AL and Si is accelerated to 400 ° C. or more, it only affects AL and the contact resistance of the semiconductor substrate. No, A in the semiconductor substrate
In order to cause leakage due to diffusion of L, shortening of processing time to prevent excessive temperature rise of wafer temperature by plasma processing, shortening from 1 minute processing to 15 seconds, improvement of thermal conductivity from the back side of wafer, low power To stabilize the discharge of Si-OR group and SI-H group on the outermost surface of SOG, and to reduce the temperature of the wafer, which is most suitable for promoting polymerization, from about 250 ° C to 350 ° C. I needed to control.

[0018]

According to the manufacturing method of the present invention described above, the surface treatment by plasma irradiation is performed in the multi-layer coating process of SOG, so that the remaining organic components Si-OR and Si- H, Si-O on the surface of no lower SOG layer affecting the Si-CH _3, etc.
Lower SOG to decompose R, Si-H, the Si-CH ₃
Adhesion between the film layer and the upper SOG film layer can be ensured.

Further, according to the method of manufacturing a semiconductor device according to the second aspect, the reaction including at least one gas selected from the group consisting of argon gas, krypton gas, neon gas, xenon gas, nitrogen gas, and helium gas. By performing the plasma irradiation using a gas, the lower layer SO
Organic components Si-OR, Si-H, S remaining in the G film
Si-OR in no surface of the lower SOG layer to affect the i-CH ₃ and the like, Si-H, in order to decompose the Si-CH _3, efficiently upper SOG layer and the second CVD oxide film layer It is possible to prevent SOG peeling and cracking from occurring by improving the adhesion to the SOG.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a part of a manufacturing process of a semiconductor device according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 101 semiconductor substrate 102 first CVD oxide film layer 103 wiring 104 lower SOG film layer 105 upper SOG film layer 106 plasma irradiation 107 second CVD oxide film layer

Claims (2)

[Claims] In an SOG coating process of a semiconductor device,
A step of continuously applying SOG from one to a plurality of times;
A method for manufacturing a semiconductor device, comprising a step of performing a surface treatment by plasma irradiation between application of OG and application of an upper layer SOG. 2. The method according to claim 1, wherein the plasma irradiation is performed using a reaction gas containing at least one gas selected from the group consisting of argon gas, krypton gas, neon gas, xenon gas, nitrogen gas, and helium gas. The method for manufacturing a semiconductor device according to claim 1.