JPH06112191A - Semiconductor device - Google Patents

Abstract

(57) [Summary] [Object] Regarding improvement of an interlayer insulating film between conductive layers of a semiconductor device or a flattening film of the surface of the conductive layer, an interlayer insulation which does not increase tensile stress and damages a wiring layer. An object is to provide a semiconductor device having a film or a planarization film. [Composition] An interlayer insulating film between the conductive layers or a flattening film on the surface of the conductive layer is formed of a silicon compound material having a silazane bond in the skeleton, which is baked in an atmosphere having an oxygen content of 30% or more. It is configured to include an insulating film having a reductive film stress.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an interlayer insulating film between conductive layers of a semiconductor device or a flattening film on the surface of a conductive layer.

With the recent miniaturization and multi-layer structure of semiconductor devices, there has been an increasing demand for a technique for embedding an insulating film in a step having a high aspect ratio formed on a semiconductor substrate and flattening it. The silicon-on-glass film (hereinafter abbreviated as SOG film) that has been used as a planarizing material tends to have a large film thickness in order to promote planarization.

However, when the underlying wiring layers are filled with the SOG film to make it flat, the SOG film is thicker in the portion where the spacing between the wiring layers is narrow. The stress of the SOG film conventionally used is tensile stress. Tensile stress is three times or more in the thick portion of the SOG film compared to the thin portion on the wiring layer. Has become.

Generally, when the stress of the interlayer insulating film is compressive or weak tensile, it is said that the damage to the wiring layer is small.
Since all the conventional insulating films formed by the D method have tensile stress, the combination of the conventional atmospheric pressure CVD film formed by the atmospheric pressure CVD method and the conventional SOG film results in the interlayer having strong tensile stress. Since it becomes an insulating film, it seriously damages the wiring layer.

Under the circumstances as described above, there is a demand for a semiconductor device having an interlayer insulating film which does not damage the wiring layer.

[0006]

2. Description of the Related Art A conventional semiconductor device will be described in detail with reference to FIGS. FIG. 3 is a side sectional view showing a conventional semiconductor device, and FIG. 4 is a diagram showing a structural formula of SOG used for an interlayer insulating film of the conventional semiconductor device.

The SOG generally used for flattening layers between layers of a conventional semiconductor device is an alkoxysilane produced by a sol-gel method having a structural formula as shown in FIG. 4, and a firing atmosphere is a nitrogen atmosphere. In the case of, the atmosphere having an oxygen content of 30% or less and the atmosphere of an oxygen content of 30% or more also have a tensile stress of about 1 × 10 ⁹ (dyne / cm ² ). ing.

When such an SOG film is used to fill the space between the underlying wiring layers to make it flat, the wiring layer 12 is formed on the surface of the semiconductor substrate 11 as shown in FIG. After forming the protrusion prevention film 13 for preventing the protrusion (hillock) generated on the surface, the SOG film 14 and the atmospheric pressure CVD film 15 are laminated to form the interlayer insulating film. Since the SOG film 14 becomes thicker in the portion where the space between them is narrower and the tensile stress is increased, the SO on the upper surface of the wiring layer 12 is
It is difficult to make the G film 14 thick.

[0009]

In the conventional semiconductor device described above, the SOG film having a large tensile stress is used for the interlayer insulating film and the flattening film. It is difficult to form a film, and if the tensile stress increases, there is a problem that tensile stress may be applied to the wiring layer that is formed in close contact with the interlayer insulating film and the planarization film, resulting in disconnection. It was

Under the circumstances described above, the present invention has an object to provide a semiconductor device having an interlayer insulating film or a flattening film which does not increase the tensile stress and does not damage the wiring layer.

[0011]

The semiconductor device of the present invention comprises:
A compressive film made of a silicon compound material having a silazane bond in the skeleton, which is baked in an atmosphere having an oxygen content of 30% or more, as an interlayer insulating film between conductive layers or a flattening film on the surface of the conductive layer. It is configured to include an insulating film having stress.

[0012]

In the present invention, since SOG having a silazane bond in the skeleton, which has a structural formula as shown in FIG. 2, is used as a material having a compressive membrane stress, hydrogen (H) at the polymer end is used. Oxidation causes the membrane to swell and compressive membrane stress occurs.

When the SOG film having a silazane bond of the present invention is fired in various atmospheres, as shown in Table 1 below, it is 0.9 × 10 ⁹ in a nitrogen atmosphere or an atmosphere having an oxygen content of 30% or less. It has a tensile stress value of (dyne / cm ² ), but it is −0 in an atmosphere having an oxygen content of 30% or more.
It has a compressive stress value of 5 × 10 ⁹ (dyne / cm ² ).

[0014]

[Table 1]

When an SOG film made of such SOG film having a silazane bond is used as an interlayer insulating film between the conductive layers or a flattening film on the surface of the conductive layer, the stress value seems to have a negative compressive stress value. Therefore, it becomes possible to increase the thickness of the SOG film, and it is possible to prevent disconnection due to tensile stress applied to the wiring layer.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIG. 1 is a side sectional view showing a semiconductor device according to an embodiment of the present invention, and FIG. 2 is an SO having a silazane bond used for an interlayer insulating film of the semiconductor device according to an embodiment of the present invention.
It is a figure which shows the structural formula of G.

The material used for planarizing the layers of the semiconductor device of one embodiment according to the present invention is SOG having a silazane bond having a structural formula as shown in FIG. Conventional SOG in a nitrogen atmosphere and in an atmosphere with an oxygen content of 30% or less
It has a tensile stress of about 0.9 × 10 ⁹ (dyne / cm ² ) similar to the above, but minus 0.5 × 10 ⁹ (dyne / cm ² ) in an atmosphere with an oxygen content of 30% or more. To have a compressive stress value of.

When the SOG film having such a silazane bond is used to fill the space between the underlying wiring layers 2 to make it flat, the wiring layer 2 is formed on the surface of the semiconductor substrate 1 as shown in FIG. After forming the protrusion prevention film 3 on the entire surface, SOG
The film 4 and the atmospheric pressure CVD film 5 are laminated to form an interlayer insulating film. However, since the SOG film 4 has a compressive stress value, the thickness of the SOG film 4 is increased as a whole. Therefore, even if the thickness of the SOG film 4 is increased in the portion where the distance between the wiring layers 2 is narrow, the tensile stress does not increase, and the tensile stress is not applied to the wiring layer formed in close contact with the interlayer insulating film or the flattening film. The sill stress is applied and the wire will not break.

[0019]

As is apparent from the above description, according to the present invention, it is possible to manufacture a semiconductor device having an interlayer insulating film having a compressive stress value by selecting an extremely simple material. Therefore, it is possible to provide a semiconductor device which can be expected to have a remarkable economic effect and reliability improvement effect.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a structural formula of an SOG having a silazane bond used for an interlayer insulating film of a semiconductor device according to an embodiment of the present invention.

FIG. 3 is a side sectional view showing a conventional semiconductor device.

FIG. 4 SO used for an interlayer insulating film of a conventional semiconductor device
Diagram showing the structural formula of G

[Explanation of symbols]

1 is a semiconductor substrate, 2 is a wiring layer, 3 is a protrusion prevention film, 4 is S
OG film, 5 is a normal pressure CVD film,

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01L 21/90 P 7514-4M

Claims (1)

[Claims] 1. A silicon compound material having a silazane bond in the skeleton, which is fired in an atmosphere having an oxygen content of 30% or more, as an interlayer insulating film between conductive layers or a flattening film on the surface of the conductive layers. A semiconductor device comprising an insulating film having a compressive film stress.