JPS6149452A - Semiconductor element - Google Patents

Abstract

PURPOSE:To form a sufficiently thick protective film without generating cracks by dividing a bonding pad into the plural. CONSTITUTION:Al or an Al alloy is used as the principal ingredient. Conductor layers 1 consisting of the alloy, etc. form one electrode sections on four divided surfaces. A continuous contact area between a conductor metal constituting the electrode and an insulating film is quartered approximately by forming the electrode section in such structure. Accordingly, no crack is generated even when the insulating film consisting of SiO2 or PSG through a CVD method in thickness such as 2.0-2.5mum is grown.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to semiconductor devices such as ICs and LSIs, and particularly relates to their electrode structures.

Conventional configuration and its problems The semiconductor element is a transistor on the surface of a semiconductor substrate.

After forming circuit elements such as resistors and diodes and interconnecting them with a conductive layer such as Al to form the desired circuit, the entire surface is covered with an insulating film, and then a part of the insulating film is removed to form the desired circuit. A portion of the conductor layer is exposed in the opening and serves as an element-side electrode (bonding pad) for electrically connecting the element to an external circuit or lead in a later step.

This top layer insulating film is called a surface protection film, and protects the device from external forces unexpectedly applied in subsequent processes. This is to prevent it from reaching the main parts of the circuit and damaging its function. The first reaction method and material for growing this insulating film are C
Yorosilicon nitride, 8102 for VD (P-CVD) method
゜Comparing the two, the former P-CVD film has a dense film quality and good step coverage (step adhesion), and even a relatively thin film shows excellent mechanical strength and moisture resistance. The growth rate is slow and the process is batch-based, making it difficult to mass-produce.

On the other hand, the latter CvD method K Yoru S z 02-! ! Taha P
SG or a film made from a combination of these is excellent in mass production, but the film made by the P-CVD method is not dense and has poor step coverage, so in order to achieve sufficient mechanical strength and moisture resistance, it is necessary to use P-CVD. In the case of a film formed by the CVD method, a large film thickness is also required.

According to experience, for example, with a thickness of 0.8 to 1.0 μm,
In order to obtain the same moisture resistance as a film made by the fP-CVD method, a film using S z 02 and PSG must have a thickness of 1.6 μm.
As described above, a film thickness of preferably 2.0 μm or more was required.

However, such a thick insulating film is prone to cracking because of the large stress generated from the difference in thermal expansion coefficient with the underlying layer during growth. In particular, cracks are likely to occur in areas where they come into contact with conductive layers such as Al, which have a coefficient of thermal expansion significantly different from that of the insulating film, and the larger the continuous contact area, the more likely they are to occur. In actual devices, this phenomenon is most likely to occur on sides of 90~
This is an element electrode portion (bonding band) provided in a rectangular shape of 120 μm. The first example is the typical crack condition in the gap.
and FIG. 2 (cross-sectional view). Cracks appear in the surface insulating film 2 at the periphery of the element electrode portion 1 made of Al or the like, and the cracks also propagate toward the periphery from several locations. Although most of the surface insulating film on the electrode part (area surrounded by broken line 6) is removed in a later process, the cracks that extend around the electrode remain as they are, allowing moisture and impurities to easily penetrate, which poses a significant problem in terms of reliability. It becomes a problem. For the above reasons, it has been difficult to provide a sufficiently thick insulating film using the CVD method in the conventional structure.

OBJECTS OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art and to provide a semiconductor element in which a sufficiently thick surface protective film can be provided without causing cracks.

Structure of the Invention The present invention is a semiconductor element having a conductor layer forming a wiring pattern including a bonding pad and an insulating film formed immediately above the semiconductor element, wherein the bonding pad is divided into a plurality of parts. This makes it possible to prevent cracks from forming in the insulating film during growth of the insulating film in which the continuous contact area between the conductor forming the bonding pad and the insulating film is small.

DESCRIPTION OF EMBODIMENTS The present invention will now be described in detail with reference to the drawings. Third
FIG. 4 is a plan view and a cross-sectional view showing the electrode structure of a semiconductor device according to the present invention.

- A rectangular conductor layer 1 made of Al or an alloy containing Al as a main component and having sides of 40 to 60 μm forms one electrode portion with four divided planes. A suitable distance between them is 5 to 16 μm. This structure is equivalent to a conventional electrode part divided by two 6-15 μm wide grooves that intersect near the center, and the manufacturing process requires slight changes to the mask for forming the conductor wiring pattern. This can be easily carried out by the method, and no new device processing steps are required.

By making the electrode part have such a structure, the continuous contact area between the conductive metal such as Al constituting the electrode and the insulating film such as S x 02 or PSG becomes approximately -.

By this, for example, a CV with a thickness of 2.0 to 2.5 μm
Even when an insulating film made of Sio2 or PSG was grown using the D method, no cracks were generated.

Note that when an opening is made in the surface insulating film in the groove part, the base is exposed, but the area is small compared to the entire electrode part, and as in the past, for example, a thin wire of Au or A/= is exposed. If ball bonding is carried out, a bond as shown in Fig. 5 will be made, and most of the bonding surfaces will be made of thin wire material.
There is no problem electrically or mechanically because the bond is between u or Al and Al or Al alloy which is the electrode material.

Effects of the Invention As described above, according to the present invention, Si
It is possible to provide an insulating film such as O or PSG thicker than in the past, and a highly reliable semiconductor element that is highly mass-producible can be realized.

[Brief explanation of drawings]

1 and 2 are main part plan views and cross-sectional views showing the state of the electrode portion and the surface insulating film around the electrode portion in a conventional semiconductor device, and FIG. 3 and 4 are electrodes of a semiconductor device according to the present invention. FIG. 5 is a plan view and a cross-sectional view of a main part showing the structure and state of a surface insulating film, and FIG. 5 is a cross-sectional view of a main part showing a state in which thin metal wires are connected to electrode parts of a semiconductor element according to the present invention by pole bonding. 1...Element electrode part (bonding pad), 2
...Surface insulating film, 3...Crack, 4...
... Base, 6 ... Insulating film opening, 6 ...
...Thin metal wire end. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4

Claims (5)

[Claims] (1) A semiconductor element having a conductor layer forming a wiring pattern including a bonding pad and an insulating film formed directly above a portion of the conductor layer, characterized in that the bonding pad is divided into a plurality of parts. semiconductor element. (2) The bonding pads intersect near the center 2
The semiconductor device according to claim 1, which is divided into four parts by a book groove. (3) The semiconductor device according to claim 1 or 2, wherein the conductor layer is made of Al or an alloy containing Al as a main component. (4) The insulating film is SiO_2, PSG (Phosphos)
2. The semiconductor device according to claim 1, which is selected from the group consisting of ilicate glass. (5) The semiconductor device according to claim 4, wherein the insulating film has a thickness of 2 μm or more.