JPH05335300A - Semiconductor device - Google Patents

Abstract

PURPOSE:To eliminate the deterioration of film characteristics and device characteristics owing to moisture absorption of an applied insulating film in a semiconductor device wherein the applied insulating film is formed on a underlying primary coat and a semiconductor protective film is formed on the applied insulating film by coating an exposed end of the applied insulating film with the semiconductor protective film CONSTITUTION:A device isolating thick oxide film 2 is formed on a semiconductor substrate. Then, an insulating film 3 is deposited on the thick oxide film 2. Then, an interlayer insulating film 4 is formed holding an applied insulating film 5 therebetween. Thereafter, a semiconductor protective film 6 is formed, oversized, from a scribe line 7 so as to cover a scribe section formed before the formation of the semiconductor protective film Hereby, the scribe cross section from which the applied insulating film 5 is exposed is coated with the semiconductor protective film 6 to interrupt moisture absorption by the applied insulating film 5 and hence eliminate capacitance variations.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly, it is suitable for a semiconductor device such as a semiconductor device having a multi-layer wiring, in which unevenness is formed on a base surface and a coating insulating film is formed for planarization. Is used for.

[0002]

2. Description of the Related Art Conventionally, there is a semiconductor device in which a metal wiring is formed in a multi-layered structure, in which a coating insulating film is used to flatten a base surface.

5, 6, and 7 are partial cross-sectional views showing the structure of such a semiconductor device. 5 to 7,
1 is a semiconductor substrate, 2 is a thick oxide film for element isolation, 3 is an insulating film such as a BPSG film formed on the thick oxide film 4, 4 is an interlayer insulating film, 5 is a coating insulating film, 6 is semiconductor protection Membrane, 7
Is a scribe line. 5 shows the case where the coating insulating film 5 is provided on the insulating film 3, FIG. 6 shows the case where the coating insulating film is provided in the interlayer insulating film 4, and FIG. 7 shows the case where the coating insulating film is provided on the interlayer insulating film 4. It shows the case. As shown in FIGS. 5 to 7, BPS is formed on the scribe end surface of the semiconductor device.
The insulating film 3 such as a G film, the interlayer insulating film 4, the coating insulating film 5, and the semiconductor protective film 6 are exposed.

The coating insulating film 5 used here is used for flattening, has a very high hygroscopic property, and even if it is sufficiently baked after coating the liquid insulating film, it is left in the air when left in the air. Due to the absorption of water, the film characteristics may be deteriorated and further the element characteristics may be deteriorated.

[0005]

In the above conventional semiconductor device, since the coating insulating film on the scribe end face is exposed in the air, the above-mentioned properties of the coating insulating film cause
The following problems have occurred. (1) Since the coated insulating film has a high hygroscopic property, the capacitance of the capacitors having metal electrodes above and below the coated insulating film varies due to absorption of water by the coated insulating film. Therefore, the high speed performance of the device is significantly deteriorated. (2) Since the coating insulating film has a high hygroscopic property, moisture is not absorbed from the coating insulating film at the time of patterning forming a via hole that connects the first wiring and the second wiring (provided via the interlayer insulating film and the coating insulating film). 1st which is emitted and exists in the via hole
A high-resistance layer is formed on the wiring, and ohmic contact between the first wiring and the second wiring cannot be made at all.

It is an object of the present invention to provide a semiconductor device capable of eliminating the deterioration of film characteristics and element characteristics due to moisture absorption of the coated insulating film.

[0007]

According to the present invention, in a semiconductor device in which a coating insulating film is formed on a base surface and a semiconductor protective film is formed on the coating insulating film, the exposed end portion of the coating insulating film is It is characterized by being covered with a semiconductor protective film.

Here, the coated insulating film is an inorganic insulating film formed by coating and baking a liquid solution. For example, in a semiconductor element manufacturing process using Si, silanol or the like is used as an organic solvent. An example is a SiO ₂ film formed by applying and baking a dissolved solution. Forming the semiconductor protective film on the coated insulating film means not only the case where the semiconductor protective film is directly formed on the coated insulating film, but also the semiconductor protective film formed on the coated insulating film through a layer such as an interlayer insulating layer or a wiring layer. Including the case of forming.

[0009]

According to the present invention, an end portion (for example, a scribe end surface) where the coated insulating film is exposed is covered with a semiconductor protective film,
By blocking the moisture absorption path of the coating insulating film, deterioration of element characteristics is suppressed.

In the present invention, in order to improve the step coverage of the semiconductor protective film, an interlayer insulating film is formed on the insulating film, and the coating insulating film is formed on the upper or lower part of the interlayer insulating film or inside thereof. In the case of forming the film, it is preferable that the interlayer insulating film and / or the insulating film is formed undersize than the scribe line.

In addition, in the present invention, in order to improve the step coverage of the semiconductor protective film, it is desirable to form the semiconductor protective film in an oversize rather than the scribe line.

[0012]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a partial sectional view of a first embodiment of a semiconductor device of the present invention. As shown in FIG. 1, a thick oxide film 2 for element isolation is formed on a semiconductor substrate 1. At this time, the scribe line separating the chip and the chip on the semiconductor substrate 1 is defined by 7 in the figure. In this embodiment, the thickness of the thick oxide film 2 is about 4000 to 8000Å.
An insulating film 3 formed directly under the first electrode (not shown) is deposited on the thick oxide film 2. This insulating film 3 was a BPSG film, and the film thickness was deposited from 4000 to 8000Å. Next, the interlayer insulating film 4 was formed by sandwiching the coating insulating film 5. It is needless to say that the present invention can be used in the case where the coating insulating film 5 is formed below or above the interlayer insulating film 4 shown in FIGS.

The thickness of the interlayer insulating film 4 below the coating insulating film 5 is 3
000-6000Å, the thickness of the coating insulating film 5 is 1000-
3000Å, the interlayer insulating film 4 on the coating insulating film 5 is 3000
~ 6000Å formed. After that, the semiconductor protective film 6 is formed so as to cover the scribe end face formed before the semiconductor protective film is formed. In the present embodiment, the semiconductor protective film 6 is oversized from the scribe line 7 to the oversizes 1 to 8.
μm. The oversize distance (d in the figure) from the scribe line of the semiconductor protective film 6 is the distance from the scribe line 7 to the dicing line 8 (in the figure,
It is set to be sufficiently shorter than L). At this time, a P-SiN film 6000 to the semiconductor protective film 6 is used.
About 12,000Å was deposited.

At this time, FIG. 2 shows how the capacitance variation of the interlayer insulating film 4 + the coated insulating film 5 occurs depending on whether the scribe end surface is covered with the semiconductor protective film 6 or not. is there. As shown in FIG. 2, the scribe end surface of the interlayer insulating film 4 + the coating insulating film 5 is covered with the semiconductor protective film 6
If not covered (white circle in Fig. 2), the humidity is 85%,
When left for 110 hours in an atmosphere with a temperature of 85 ° C,
A capacity increase of around 30% is observed.

On the other hand, when the scribe end face is covered with the semiconductor protective film 6, there is almost no capacitance variation (black circle in FIG. 2). Therefore, as shown in FIG. 1, the scribe end surface where the coating insulating film 5 is exposed is covered with the semiconductor protective film 6
By coating with, it is possible to block the moisture absorption of the coated insulating film, and it becomes possible to eliminate the capacitance fluctuation that influences the characteristics of the IC as shown in FIG.

Next, a second embodiment of the semiconductor device of the present invention will be described with reference to FIG.

FIG. 3 is a partial sectional view of a second embodiment of the semiconductor device of the present invention. The same components as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

As shown in the figure, in this embodiment,
When the scribe end face is covered with the semiconductor protective film 6, in order to further improve the step coverage (step coverage) of the semiconductor protective film 6, a first wiring and a second wiring (interlayer insulating film and coating) not shown are provided. The scribe line of the mask for forming a via hole is formed to be undersized than the normal scribe line during the patterning of forming a via hole for connecting (providing via an insulating film). Further, when patterning a part of the semiconductor protective film 6 for the pad opening, the scribe line of the mask was formed to be oversized as compared with the normal scribe line. As a result, the step coverage with which the semiconductor protective film 6 covers the scribe end surface is further improved. At this time, the undersize amount of the via hole forming mask was 1 to 8 μm, and the oversize amount of the pad opening mask of the semiconductor protective film 6 was 1 to 8 μm. Also in the present embodiment, it is possible to suppress the capacity fluctuation as in the first embodiment.

Next, a third embodiment of the semiconductor device of the present invention will be described with reference to FIG.

FIG. 4 is a partial sectional view of a third embodiment of the semiconductor device of the present invention. The same components as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

Also in the case of this embodiment, like the second embodiment, it is carried out to improve the step coverage in the vicinity of the scribe of the semiconductor protective film 6. As shown in FIG. 4, in this example, a mask for forming a contact hole was formed under the size of d _CNT from the scribe line 7, and a mask for forming a via hole was formed under the size of d _via from the scribe line. At this time, the relationship between d _CNT and d _via is d _CNT <d _via , and here 1 μm <d _CNT <6 μm, 2 μm <d _via
<8 μm. As a result, the step coverage of the semiconductor protective film 6 could be improved without changing the scribe line pattern. Also, in the case of this example, as in the first example, almost no capacity fluctuation was observed.

As described above, by adopting a structure in which the exposed scribe end surface is covered with the semiconductor protective film, it is possible to eliminate capacitance variation and increase in resistance of the via hole.

In this embodiment, the semiconductor protective film is made of PS.
An organic film such as iN, P-SiO, PSG, or polyimide is used, and P-SiO, PSG, NSG is used as the interlayer insulating film.
Etc. can be used. In any case, the above semiconductor device characteristics were obtained.

[0025]

As described above in detail, according to the present invention, (1) by covering the scribe end surface where the coated insulating film is exposed with a semiconductor protective film, the absorption of moisture by the coated insulating film is completely completed. It can be eliminated, and it is possible to completely prevent an increase in capacitance of the capacitor having the first wiring and the second wiring (provided via the interlayer insulating film and the coating insulating film) as electrodes. This has the effect of completely preventing the deterioration of the response speed of the semiconductor element. (2) By covering the scribe end surface where the coated insulating film is exposed with the semiconductor protective film, the high resistance layer is not formed on the first wiring at all during the via hole formation patterning, and the yield of the semiconductor element is improved. There is. (3) By covering the scribe end surface where the coating insulating film is exposed with a semiconductor protective film, it is possible to completely eliminate the absorption of moisture from the coating insulating film, and there is an effect that the reliability of the semiconductor element is improved. ..

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view near a scribe of a first embodiment of a semiconductor device of the present invention.

FIG. 2 is a characteristic diagram showing a capacitance variation between a semiconductor device implementing the present invention and a conventional semiconductor device.

FIG. 3 is a partial cross-sectional view near a scribe of a second embodiment of the semiconductor device of the present invention.

FIG. 4 is a partial cross-sectional view near a scribe of a third embodiment of the semiconductor device of the present invention.

FIG. 5 is a cross-sectional view of a conventional semiconductor device near a scribe.

FIG. 6 is a cross-sectional view of a conventional semiconductor device near a scribe.

FIG. 7 is a cross-sectional view of a conventional semiconductor device near a scribe.

[Explanation of symbols]

 1 semiconductor substrate 2 thick silicon oxide film 3 BPSG film 4 interlayer insulating film 5 coating insulating film 6 semiconductor protective film 7 scribe line 8 dicing line

Claims (6)

[Claims] 1. A semiconductor device in which a coating insulating film is formed on a lower ground and a semiconductor protective film is formed on the coating insulating film, wherein an exposed end portion of the coating insulating film is covered with the semiconductor protective film. Characteristic semiconductor device. 2. The semiconductor device according to claim 1, wherein an exposed end portion of the coating insulating film is a scribe end surface, and the scribe end surface is covered with the semiconductor protective film. 3. The semiconductor device according to claim 2, wherein the semiconductor protective film is formed to be oversized as compared with a scribe line. 4. The semiconductor device according to claim 2, wherein an interlayer insulating film is formed on the insulating film, and the coating insulating film is formed on or under the interlayer insulating film or inside the insulating film. Alternatively, the semiconductor device is characterized in that the interlayer insulating film is formed undersize than the scribe line. 5. The semiconductor device according to claim 2, wherein an interlayer insulating film is formed on the insulating film, and the coating insulating film is formed on or under the interlayer insulating film or inside the insulating film. And a semiconductor device in which the interlayer insulating film is formed undersize than the scribe line. 6. The semiconductor device according to claim 3, wherein an oversize distance of the semiconductor protective film from a scribe line is sufficiently shorter than a distance from the scribe line to the dicing line.