JPS6224950B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to semiconductor devices, and particularly to measures to prevent electrostatic damage in integrated circuits (ICs).

Destruction of an IC due to static electricity means that static electricity charged on things around the IC, such as jigs during the IC chip mounting process, carriers for transportation, inspection jigs, or the human body, may approach or come in contact with the IC between the terminals of the IC. This is a phenomenon that causes a discharge to occur through the battery, leading to destruction of internal elements. The development of ICs and LSIs (Large-Scale Integrated Circuits) has been remarkable, with only a few advances since the invention of the transistor.
Over the past 30 years, it has continued to rapidly spread across all consumer and industrial fields. One of the major reasons for this widespread use is that the introduction of ICs has reduced the number of components and connection terminals installed in electronic devices and systems, contributing to a significant improvement in the reliability of devices and systems. It will be done. On the other hand, with the introduction of ICs, the reliability of devices and systems has come to greatly depend on the reliability of the ICs, and the demands for improving the reliability of ICs are becoming increasingly severe. There are various failure mechanisms for ICs, such as deterioration due to moisture intrusion, disconnection at wire connections, and increased leakage current due to defects in the diffusion process, but thanks to the efforts of IC manufacturers, many problems can be solved. has been solved to a level where there are almost no practical problems.

One of the major problems is damage caused by static electricity. There are two reasons why damage caused by static electricity has become a focus of attention. One is
This is because LSIs have become more highly integrated. Inevitably, higher density is required, and LSI patterns have become extremely fine. This tendency is not necessarily desirable from the standpoint of damage caused by static electricity. Another reason is the diversification of the environments in which ICs are used.
As ICs have begun to be used in all fields, especially in portable electronic devices, and petrochemical products have increased in our daily lives, the opportunities for static electricity to interact with ICs have increased significantly. It is.

In order to prevent the IC from being destroyed by this static electricity,
Diodes as shown in Special Publication No. 43-455,
Various protection elements using MOSFETs, punch-through elements, etc. have been considered, and ICs that are quite resistant to static electricity have been obtained. However, as the input/output wiring becomes finer as described above in order to improve the degree of integration and performance of ICs, even if the protection element itself has a structure that is sufficiently strong against electrostatic energy, the input wiring itself However, it has come to have the disadvantage that it melts due to static electricity energy and the input terminal becomes open.

An object of the present invention is to provide a high-quality IC that is less likely to be damaged by static electricity without impairing the degree of integration or performance of the device.

The present invention is characterized in that among the metal wiring connecting the input/output terminal bonding pad and the input/output element, the wiring width between the bonding pad and the electrostatic discharge protection element is thicker than the remaining input/output wiring width. It is said that

Hereinafter, the present invention will be explained in detail with reference to the drawings.

Figure 1 is a plan view of a device using an electrostatic discharge protection element that has been commonly used. It is connected to the circuit area 8. In addition, the input wiring is input to the electrostatic damage protection element 2 from the middle, and the protection element 2 passes through the wiring 6,
It is connected to the power supply pad 5 of the device. As the protection element 2, various known elements such as a diode, MOSFET, punch-through element, etc. can be used. In the drawing, 7 indicates the edge of the chip. In this structure, the charge discharged to the input terminal enters the pad 1, passes through the wiring 3, is absorbed by the protection element 2, and is finally absorbed by the power supply of the device through the wiring 6 and the pad 5. At this time, a part of the discharged charge flows into the internal region 8 of the device, but this amount is very small and does not destroy the device. However, in FIG. 1, the input wirings 3 and 4 are designed to be very thin considering the performance of the device, and have the same width. Therefore, in this device, although the protective element 2 itself has a structure that is strong against static electricity, the wiring 3, which is the discharge path of the electric charge, can be melted and disconnected by the Joule heat generated when the electric charge flows. Occasionally,
There were times when the input of the device became open.
Generally, when there was no protection element 2, there were many failures such as shorting of input elements in the internal circuit 8, but since the protection element 2 was included, open failures became a new problem.

FIG. 2 is a plan view showing a preferred embodiment of the present invention. The difference from FIG. 1 is that the wiring 3' from the input pad 1' to the protection element 2' is
Another point is that the wiring 6' extending from the protection element 2' to the power supply pad 5' is wider than the input wiring 4' extending to the internal circuit area 8'. In the structure of the embodiment of the present invention, the width of the wirings 3' and 6' is 12 μm so as to be able to sufficiently withstand the Joule heat generated by charge discharge.
m or more, and this device has no open defects caused by static electricity.

The important points of the embodiments of the present invention are the high density of the device,
In order not to damage the finer wiring pattern that is recently required for higher performance, the protective element is placed close to the bonding pad 1', and after the input wiring is input to the protective element 2', The point is that the required narrow wiring width has been achieved.

As described above using the embodiments of the present invention, if the configuration of the present invention is used, a semiconductor device having high quality against static electricity can be obtained without impairing the degree of integration or performance of the device.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a device having a conventional electrostatic discharge protection element, and FIG. 2 is a plan view showing a preferred embodiment of the present invention. In the figure, 1...bonding pad for input/output terminals, 2...electrostatic damage protection element, 3, 4,
6... Internal wiring, 5... Bonding pad for power supply terminal, 7... Chip edge, 8... Internal circuit area.

Claims (1)

[Claims] 1. Bonding pads for a plurality of input/output terminals;
A circuit area connected to the input/output terminal bonding pad via a first metal wiring, a power supply electrode that receives a power supply potential applied to the circuit element area from the outside, and a predetermined one of the first metal wiring. a protection element that prevents the circuit area connected to the circuit area via a second metal wiring from being damaged by electrostatic discharge, and a current path between the protection element and the power supply electrode, the first metal wiring and The wiring width of a portion of the second metal wiring that serves as a current path between the input/output terminal bonding pad and the protection element is made wider than other portions, and between the protection element and the power supply electrode. A semiconductor device characterized in that the current capacity of the current path is increased. 2. The semiconductor device according to claim 1, wherein a portion of the first and second metal wiring that becomes the current path has a wiring width of 12 μm or more. 3. The current path between the protection element and the power supply electrode is a third metal wiring, and the third metal wiring is thicker than a portion of the first metal wiring other than the portion that becomes the current path. A semiconductor device according to claim 1, characterized in that: 4. The distance between the third metal wiring and the portion of the first and second metal wiring that becomes the current path is 12μ.
4. The semiconductor device according to claim 3, having a wiring width of m or more.