JPH08186109A - Semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE: To eliminate the spoilage of the reliability of a semiconductor device even when thermal impact is applied at the time of sealing mold resin or even when heating is applied at the time of operating a circuit in the mold resin sealed device. CONSTITUTION: A wiring layer 3 and an electrode 4 formed on a semiconductor substrate 1 and an insulating film 2, and a surface protective film 5 covering the entire surface of a semiconductor element including the layer 3 are formed, and a conductor layer 6 formed thereon. The substrate 1, the film 5, etc., are sealed by mold resin. The layer 6 is formed at a boundary to the resin on the surface of the film 5, and hence can deal with heating at the time of thermal impact or operating a circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device encapsulated in a mold resin, and has a semiconductor structure having a semiconductor structure which withstands stress such as thermal shock and which enhances heat dissipation during circuit operation and maintains high reliability. The present invention relates to a circuit device.

[0002]

2. Description of the Related Art Conventionally, in a resin-sealed semiconductor device, deterioration of characteristics of the semiconductor device is protected from stress such as thermal shock applied during resin sealing or heat generation during circuit operation.
A semiconductor integrated circuit device having a semiconductor structure in consideration of reliability improvement is disclosed in, for example, JP-A-62-150859.
Japanese Patent Laid-Open No. 1-268150 has been proposed.

This prior art is shown in FIGS. 7 and 8. FIG. 7 shows a surface protection film that covers a wiring layer and is provided with an uneven surface directly. An insulating film (1) is formed on a semiconductor substrate (11).
2), the electrode (14) and the protective film (15) are formed, and the unevenness (17) is directly provided on the protective film (15). In addition, FIG. 8 shows a semiconductor substrate (1
1) An inorganic material film (12), an electrode (14), and a protective film (15) are formed on the first material, and the peripheral region (1) of the semiconductor device is formed.
The adhesive layer (18) is provided in 3).

[0004]

The structure of the conventional semiconductor device described above has the following problems. (A) For example, in JP-A-62-150859,
In the structure where the uneven surface is directly provided on the polyimide film as the surface protection film that covers the wiring layer, the recesses are formed by partially deleting the surface protection film, and the uniformity of the film thickness is intentionally eliminated. As a result, the wiring layer is more likely to be subjected to stress, and there is a drawback in that deterioration of insulation between wirings as well as between wiring layers and defective connection characteristics are likely to occur. Further, this structure has a problem that it does not radiate heat generated during circuit operation.

(B) For example, in Japanese Unexamined Patent Publication No. 1-261850, a structure is provided in which a bonding layer made of metal or the like having a high adhesiveness with a sealing resin is provided in the peripheral region of a semiconductor device. In this structure, the adhesion between the sealing resin and the surface protective film is effective at the peripheral portion of the semiconductor device, but does not improve the adhesion to the entire surface of the semiconductor device. Cracks (voids) are generated by the thermal shock applied at the time,
There is a problem that the phenomenon that the moisture resistance of the semiconductor device is impaired cannot be completely avoided. Further, there is also a problem that internal heat generation during circuit operation cannot be solved by this structure.

According to the present invention, in the structure of the surface protective film of the semiconductor device sealed with the mold resin, the semiconductor device is damaged by thermal shock when the mold resin is sealed and heat generated when the circuit is operated. Therefore, it is an object of the present invention to provide a semiconductor integrated circuit device having a semiconductor structure in which the reliability is not impaired.

[0007]

In order to achieve the above object, in a semiconductor integrated circuit device of the present invention, a conductor layer is formed and present on the surface of a surface protective film which covers the surface of a semiconductor element and a wiring layer. It is a thing. The present invention provides a semiconductor device including a semiconductor substrate, a surface protective film that covers a semiconductor element and a wiring layer formed on the semiconductor substrate, and a mold resin body that seals the semiconductor substrate and the surface protective film. 2. In the semiconductor integrated circuit device, the conductor layer is formed on the surface of the surface protective film at the boundary with the mold resin body.

Further, the present invention is the semiconductor integrated circuit device, wherein the conductor layer is formed with a surface having irregularities. Further, the present invention is, the conductor layer,
The semiconductor integrated circuit device is characterized in that it is formed in a continuously connected state on the surface of a dummy electrode directly installed on the semiconductor substrate without an insulating film.
Further, the present invention is the semiconductor integrated circuit device, wherein the conductor layer is a high melting point metal or a nitride or compound of a high melting point metal. Further, the present invention is the semiconductor integrated circuit device, wherein the conductor layer is formed of a laminated film made of a combination of refractory metals or nitrides or compounds of refractory metals.

Further, the present invention is the semiconductor integrated circuit device, wherein the uneven surface formed on the conductor layer is constituted by the presence or absence of the conductor layer. Also, the present invention
In the semiconductor integrated circuit device, the concavo-convex surface formed on the conductor layer is formed by a partial lack of one metal layer of a laminated film forming the conductor layer. Further, the present invention is the semiconductor integrated circuit device, wherein the dummy electrode is provided in at least a corner portion of the semiconductor substrate. Further, the dummy electrode directly installed on the semiconductor substrate without an insulating film is an electrode that is not electrically connected to the semiconductor element. Further, it is more effective that the dummy electrodes are provided with an arbitrary size at least at the corners of the semiconductor substrate, or that there are several dummy electrodes on at least one side.

[0010]

In the present invention, as described above, a conductor layer is formed and present on the surface of the surface protective film that covers the surface of the semiconductor element and the wiring layer. Since the surface protective film is provided with an uneven shape, the surface area of the surface is increased and the adhesion strength with the mold resin to be sealed is increased. Further, if the material of the conductor layer is formed by selecting a refractory metal or the like having high adhesiveness between the mold resin and the surface protective film, it is effective to further improve the adhesive strength.

This prevents cracks (voids) from being generated against thermal shock when the mold resin is sealed, and maintains high reliability with respect to moisture resistance. In addition, since the conductor layer is formed by adhering to the dummy electrode directly installed on the semiconductor substrate without an insulating film, the presence of the conductor layer on the surface protective film causes Internal heat generated during circuit operation is efficiently dissipated, which serves to further reduce damage to the semiconductor device.

[0012]

Embodiments of the present invention will be described with reference to the drawings. [Embodiment 1] One embodiment of the present invention is shown in FIGS.
FIG. 1 described in (b) is a partial cross-sectional view of an electrode portion of a semiconductor device according to an embodiment of the present invention.
(A) (b) is a process sequence diagram which shows the manufacturing method of a semiconductor device. According to this embodiment, the semiconductor device of the present invention is mainly composed of a semiconductor substrate (silicon) (1) and an Al film formed on the insulating film (2) of the semiconductor substrate (1) or Al. , The wiring layer (3) made of an alloy film containing, for example, Cu, and the electrode (4) (in the following description, simply referred to as A
l wiring layer, called Al electrode) and this Al wiring layer (3)
A structure including a surface protection film (5) covering the entire surface of the semiconductor element including and a conductor layer (6) formed on the surface protection film (5) is formed.

As a method of forming a surface protective film as a protective film on the surface of a semiconductor element including a wiring layer, first, C
It is more common to form a SiN film or PSG film as a passivation film by the VD method, and then form an organic polymer material film such as polyimide as a semiconductor protective film on the film to form a laminated structure. In this example and the following description, it is treated as one surface protective film.

In forming the conductor layer (6), a conventional semiconductor device manufacturing method is used. That is, as shown in FIG. 2A, the insulating film (2) of the semiconductor substrate (1)
An Al wiring layer (3), an Al electrode (4), and a surface protective film (5) are formed on top of this, and Cu, for example, as a refractory metal is attached to this surface by electron beam evaporation as shown in FIG. Let Then, the Cu film on the Al electrode (4) is removed by etching using a photolithography technique, and the exposed surface protective film (5) on the Al electrode (4) is removed to obtain the desired structure shown in FIG. To be When removing by etching,
If the plasma etching method is used, the selection ratio can be appropriately selected, and the pattern of FIG. 1 can be constructed at once.

When the surface protection film on the Al electrode (4) has a laminated structure of a passivation film and a polyimide film, the selection ratio of the passivation film to the photoresist film used for patterning is set to 1: 1 in advance. CV
It is desirable to perform etching by the D method. This is because more accurate patterning can be formed with respect to the unevenness of the manufacturing process.

In the description of the above embodiments, the case where a single layer of Cu is used as the refractory metal in forming the conductor layer has been described. However, including the compound of the refractory metal, for example, Mo, Ni, Cr, Similar effects can be obtained by using a single layer of Ti, W, TiN, TiW, or the like, or a laminate including Cu and a combination thereof. Here, Mo, N
Each of the metal films of i, Cr, and Ti is formed by electron beam evaporation
i and TiW are ordinary sputtering methods targeting each metal, and TiN is N ₂ targeting a Ti plate.
It can be deposited by a sputtering method in which a gas is introduced. The W film is generally C using a mixed gas of WF ₆ and H ₂ as a reaction gas.
It is deposited by the VD method. As long as the above metal is used,
Even if it is directly deposited on the Al film as the dummy electrode, there is no problem because the thermal diffusion phenomenon to the Al film does not occur in the heat treatment process.
This point Au is not suitable as a single layer, and requires a barrier metal.

[Second Embodiment] Next, a second embodiment of the present invention is shown in FIG. FIG. 3 is a partial cross-sectional view of the electrode portion of the semiconductor device of the second embodiment. The semiconductor device according to this embodiment has the same configuration as that of the above-described first embodiment. The difference in this configuration is the structure of the conductor layer (6), and the conductor layer (6) on the surface of the surface protective film (5) is formed in a shape such as a mesh, spots or stripes to form an uneven shape. To do. In forming the uneven shape, A in FIG. 2A described in the first embodiment is used.
A photoresist mark corresponding to a mesh, spots, or stripe shape may be used by a photolithography technique for removing the Cu film on the 1-electrode (4) by etching.

In this case, the unevenness of the conductor layer (6) is formed by the presence or absence of Cu metal, the portion where the metal layer is present is the convex portion (7), and the non-existing portion is the concave portion (8). become. At this time, for example, the polyimide film of the surface protective film (5) is exposed in the recess (8). In the second embodiment, the unevenness of the conductor layer (6) is formed by Cu.
However, Cu can be directly attached to the surface of the surface protective film (5) by an evaporation method using a desired pattern mask. This is effective when the etching condition is a metal which is difficult even by the wet method or the plasma CVD method. In this manufacturing method in which the conductor layer (6) is directly attached, the Al electrode (4)
The upper surface protective film (5) can be removed in advance. This is because the vapor deposition mask should take this point into consideration.

In the second embodiment, the conductor layer has been described as a single layer of Cu. However, similar to the first embodiment, other refractory metals or the like may be used or a combination of the refractory metals or the like may be used. It can also be laminated. When this stack is used, for example, the combination of Ti—TiN is excellent not only in the adhesion of the adhered film but also in the film formation. TiN
Since the film can be formed by using Ti as a sputtering target and a mixed gas of argon and nitrogen as a discharge gas, it can be deposited with the same sputtering apparatus as that for forming the Ti film and without breaking the vacuum degree of the sputtering chamber. Productivity efficiency is good.

[Embodiment 3] Next, a third embodiment of the present invention is shown in FIG. In the third embodiment, the conductor layer (6) has a structure having an uneven surface. As shown in FIG. 4, the semiconductor device of this embodiment has the same structure as that of the above-mentioned second embodiment, and the difference in structure is that the conductor layer (6) is a laminated film and the metal part corresponding to the upper layer is partially present. There is a point that the uneven shape is formed by the lack. In this case, the lower layer metal is exposed in the recess (8). The method of forming the conductor layer having this structure can be freely selected by a combination of the metal film deposition method, the etching removal method and the photolithography technique using a desired pattern. As one of the methods, a target conductor layer pattern can be formed by using a so-called replica method other than the method shown in the above embodiment. In this case, a photoresist film for patterning can be formed to have a higher convex surface by thickly using a photoresist having a high viscosity. It is necessary to consider that the conductor layer does not adhere to the Al electrode due to the mask pattern.

[Fourth Embodiment] Next, a fourth embodiment of the present invention will be described with reference to FIGS. 5 and 6A and 6B. The fourth embodiment has a structure in which the conductor layer (6) is formed when the dummy electrode (9) directly formed on the semiconductor substrate (1) is present. As seen in Figure 5,
In the semiconductor device of Example 4, a dummy Al electrode (9) formed directly on the semiconductor substrate (1) and an internal semiconductor element (not shown) on the insulating film (2) are connected to each other.
l electrode (4), a surface protective film (5) covering the entire surface of the semiconductor element, and a dummy Al electrode (9) formed on the surface protective film (5) and connected and covered. A structure including a conductor layer (6) is formed. The structure is different from the structure of the above embodiment in the presence or absence of the dummy Al electrode (9).

In the fourth embodiment, in order to form a desired conductor layer (6), a dummy Al electrode (9) and an insulating film (2) are formed on a semiconductor substrate (1) as shown in FIG. 6 (a). ) On A
The l wiring (3) and the Al electrode (4) are formed, and the surface protection film (5) is formed while leaving the dummy Al electrode (9). On this surface, as shown in FIG. 6 (b), as refractory metal,
For example, Cu is attached by an electron beam evaporation method or the like. Then, the conductor layer (6) and the surface protective film (5) on the Al electrode (4) are removed by the same method as in Example 1 to obtain a desired structure as shown in FIG.

In the fourth embodiment, the case where the conductor layer (6) is a single layer and is a uniform film having no uneven shape has been described. However, the metal of the conductor layer (6) is selected or The forming method can be the same as described above. It is effective to form an uneven surface on the conductor layer (6) in this example, and the uneven surface can be formed by the same method as described above. In consideration of heat dissipation during circuit operation of the semiconductor element, when the uneven surface of the conductor layer (6) is formed by partially removing only the upper layer metal having the conductor layer as a laminated metal, It is desirable that further efficiency can be obtained.

In the fourth embodiment, the structure in which the dummy Al electrode (9) is directly formed on the semiconductor substrate (1) has been described, but the semiconductor substrate (4) is connected to the semiconductor substrate (1) similarly to the Al electrode (4) connected to the semiconductor internal element. It may be formed on the insulating film (2) of 1), and this effect is not lost at all. In addition,
In the formation of the dummy Al electrode (9), the material and the formation time thereof have been described as the same metal and the same process as the circuit electrode (Al electrode in the embodiment). It can also be composed of the same metal as the layer. In this case, it can be formed by removing Al in the corresponding portion when forming the Al electrode (4).

The number and setting positions of the dummy electrodes are as follows.
Although it depends on the circuit arrangement of the semiconductor device, it is more effective to set the Al electrode at least at the four corners of the semiconductor circuit board as large as possible within the range that can be secured, regardless of the size of the Al electrode. Furthermore, within the range permitted by the circuit design for the four sides on the same side where the Al electrode is set, A
It is desirable to provide this dummy electrode without being particular about the size of the l electrode.

In each of the above examples, the case where the conductor layer (6) is formed by using a refractory metal or the like is shown.
It can be the same as the metal used for the internal wiring and electrodes. In the embodiment, the metal of the wiring and the electrode is A
Although the description has been made by using the 1 film or the Al alloy film, the effect of the present invention is not lost even if the metal of the conductor layer is formed by using the evaporated film of Al or Al alloy, the sputtered film, or the CVD film.

Further, the surface protective film for covering the semiconductor element is made to exist up to the outer peripheral edge portion of the semiconductor circuit board including both side surfaces of the Al electrode to increase the adhesion area of the conductor layer adhered on the surface. Is desirable. In each of the embodiments described above, the semiconductor device having the single wiring layer has been described, but the same can be applied to the case where the semiconductor device has two or more wiring layers.

[0028]

Since the present invention is constructed as described above, it has the following effects. A conductor layer made of a refractory metal or the like is allowed to exist at the interface between the mold resin body to be sealed and the surface protection film of the semiconductor element, and the selection of a material having excellent adhesion of the conductor layer as an interposition of both substances, unevenness Due to the increase in the adhesive surface area due to having the shape, the adhesive strength with the mold resin body in the resin sealing of the semiconductor device forms a stronger state. As a result, cracks and the like do not occur between the surface protective film and the molded resin body even with a thermal shock generated during resin sealing, and the semiconductor device can maintain high moisture resistance and high reliability. it can.

Further, since the conductor layer is connected to the dummy electrode formed directly on the semiconductor substrate, the conductor layer is formed on the surface protective film, and this occurs during the circuit operation of the semiconductor device. Internal heat is dispersed on the front surface and the back surface of the semiconductor device, and the presence of this conductor layer promotes heat dissipation, and the damage due to heat generation of the semiconductor element is further reduced, so that a highly reliable semiconductor device can be provided.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of an electrode portion of a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a process flow chart showing a method for manufacturing a semiconductor device according to an embodiment of the present invention.

FIG. 3 is a partial sectional view of an electrode portion according to a second embodiment of the present invention.

FIG. 4 is a partial sectional view of an electrode portion according to a third embodiment of the present invention.

FIG. 5 is a partial sectional view of an electrode portion according to a fourth embodiment of the present invention.

FIG. 6 is a process flow chart showing one of the manufacturing methods of the electrode part of the fourth embodiment of the present invention.

FIG. 7 is a partial cross-sectional view of an electrode portion of a conventional semiconductor device.

FIG. 8 is a partial cross-sectional view of an electrode portion of a conventional semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 2 Insulating film 3 Al wiring 4 Al electrode 5 Surface protective film 6 Conductor layer 7 Convex portion 8 Recessed portion 9 Dummy Al electrode

Claims (8)

[Claims] 1. A semiconductor substrate, and a surface protective film for covering a semiconductor element and a wiring layer formed on the semiconductor substrate,
In a semiconductor device including a semiconductor substrate and a mold resin body that seals the surface protection film, a conductor layer is formed on a surface of the surface protection film at a boundary with the mold resin body. A characteristic semiconductor integrated circuit device. 2. The semiconductor integrated circuit device according to claim 1, wherein the conductor layer is formed to have an uneven surface. 3. The conductor layer is formed so as to be continuously connected to the surface of a dummy electrode directly installed on the semiconductor substrate without an insulating film interposed therebetween. Semiconductor integrated circuit device. 4. The semiconductor integrated circuit device according to claim 1, wherein the conductor layer is a refractory metal or a nitride or compound of a refractory metal. 5. The semiconductor integrated device according to claim 1, wherein the conductor layer is formed of a laminated film made of a combination of refractory metals or nitrides or compounds of refractory metals. Circuit device. 6. The uneven surface formed on the conductor layer is constituted by the presence or absence of the conductor layer.
5. The semiconductor integrated circuit device according to 3 or 4. 7. The uneven surface formed on the conductor layer is formed by a partial lack of one metal layer of a laminated film forming the conductor layer. The semiconductor integrated circuit device according to 1. 8. The dummy electrode is provided in at least a corner portion of the semiconductor substrate.
8. The semiconductor integrated circuit device according to any one of 7 to 7.