JPH0110937Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a semiconductor device, in particular a semiconductor resistor, one end of which is directly connected to an external terminal without intervening other elements, and furthermore, the semiconductor layer on which this resistor element is formed is connected to a predetermined area. The present invention relates to a semiconductor integrated circuit device having a structure in which it is directly connected to an external potential terminal without using other elements.

A resistive element in a semiconductor integrated circuit device is generally composed of a P-type region formed in an N-type epitaxial layer, but in order to electrically isolate these regions, the epitaxial layer is usually kept at a high potential (for example, at a power supply voltage). )It is connected to the. However, the part that connects this epitaxial layer to a high potential (hereinafter this part will be referred to as C1) is directly connected to an external terminal (hereinafter this external terminal will be referred to as T1), and furthermore, this epitaxial layer If one end of the contact portion of the P-type diffused resistance region arranged in the layer is directly connected to the external terminal (hereinafter, this contact portion will be referred to as C2 and the external terminal as T2), T1 is positive and T2 is It may be destroyed by negative polarity static electricity. A problem arises when the level of static electricity damage is lower than the level of static electricity from the surrounding environment and the human body that is encountered during the manufacturing process at the manufacturer, shipping as a product, and the mounting process at the user.

Therefore, in order to improve the level of electrostatic damage, conventional measures have been taken by providing a sufficient distance between the junction of the epitaxial layer and the P-type diffused resistor and the contact of the P-type diffused resistor. However, if there is a P-type diffused resistor that has taken such measures and a resistor that requires relative accuracy due to circuit characteristics, the contact part of the resistor that requires this relative accuracy must also take the above measures. If the number of pellets is large, the pellet area may increase and the pattern design becomes complicated.

An object of the present invention is to provide a semiconductor device having a resistive element that is resistant to electrostatic damage while minimizing the pellet area.

According to the present invention, a region of the same conductivity type as the resistor region is provided in the semiconductor layer between the contact portion of the semiconductor resistor and the contact portion of the semiconductor layer in which this resistor is formed, and the contact portion provided in this region is further provided. A semiconductor device is obtained in which the contact portion of the resistance region and the contact portion of the resistance region are short-circuited. According to this structure, due to the existence of a region other than the resistance region, static electricity is directly applied to the PN of the resistance region.
Since no voltage is applied to the junction, the electrostatic breakdown strength can be improved without increasing the distance between the junction of the resistor region and the contact of the resistor.
Naturally, it is assumed that the electrostatic breakdown strength of the region provided between the two is sufficiently large. Further, this region may be made of any conductivity type that is the same as that of the resistance region such as the diffused resistor or the insulation isolation region, but the effect is greater if the concentration is higher than that of the diffused resistor.

The present invention will be explained in more detail below using the drawings.

FIG. 1 is a cross-sectional view and a plan view showing an example of the vicinity of a P-type diffused resistor of a conventional semiconductor integrated circuit device.
A P-type diffused resistor 3 is disposed in an N-type epitaxial layer 2 grown on a P-type substrate 1, and an N ⁺ buried layer 4 is disposed below it. A part of the silicon oxide film 5 on the P-type diffused resistor 3 is removed to form a contact 6.
is provided and connected to an external terminal via metal wiring 7 and bonding wire 8 thereon. Further, a high concentration N diffusion layer 9 is formed in the epitaxial layer 2, and a contact 10 is provided by removing a portion of the silicon oxide film 5 thereon, and a metal wiring 11 thereon is formed.
and is connected to an external terminal via a bonding wire 12.

In the semiconductor integrated circuit device having the above structure, when static electricity is applied with a polarity such that the contact 10 is positive and the contact 6 on the external terminal side of the P-type diffused resistor 3 is negative, the static electricity will be as shown in 13 or 14. Exit by route. Normally, static electricity is easily applied in the 13 directions because the layer resistance of the N ⁺ buried layer 4 is low.
If the electrostatic breakdown strength in the 13th direction is stronger than the electrostatic breakdown strength in the 14th direction, the breakdown in the 14th direction becomes a problem, and in order to increase the strength, the contact 6 is There were cases where the distance A was made longer. In this case, the region where the contact 6 is provided also contributes as a resistor, and a resistor that needs to have a precisely controlled resistance ratio with this region also needs to be formed in the same way.

FIG. 2 is a sectional view and a plan view showing an embodiment of the present invention, and the same numbers as in FIG. 1 indicate the same functions. As can be seen from this figure, a P-type diffused layer 1 is located between the P-type diffused resistor 3 and the high concentration N diffused layer 9.
Further, a part of the silicon oxide film 5 on this P type diffusion layer 15 is removed to form a contact 1.
6 is provided and short-circuited to the contact 6 by a metal wiring 7. Therefore, the contact 10 is
When static electricity with a negative polarity is applied to the contact 6 on the external terminal side of the P-type diffused resistor 3, the electrostatic breakdown paths are in directions 13 and 17. 14 directions and 1
When comparing seven directions, the series resistance from contact 10 to contact 16 is smaller than the series resistance from contact 10 to contact 16, so 14
Almost no static electricity is applied in this direction. Therefore,
N-type epitaxial layer 2 from the contact 6 part
It is no longer necessary to increase the distance A between the P-type diffused resistor and the junction. Naturally, the P-type diffusion layer 15 provided in between should have a sufficient contact area, and the distance from the junction between the P-type diffusion layer 15 and the N-type epitaxial layer to the contact 16 of the P-type diffusion layer 15 should be sufficient. It shall have sufficient electrostatic breakdown strength by considering the following. Then,
Even if there are a large number of resistors that require relative precision to the P-type diffused resistor 3, it is possible to design the contact portions without special consideration.

In this way, in the present invention, the part that connects the epitaxial layer to a high potential is directly connected to the external terminal, and the epitaxial layer includes a P-type diffused resistor, and the contact part at one end of the resistor is also connected to the external terminal. In the case of direct connection, a P-type diffusion layer is further provided between the contact part of the P-type diffused resistor and the part connecting the epitaxial layer to a high potential, and the P-type diffusion layer and the P-type diffusion Although the feature is that the contact portion of the resistor is short-circuited, the P-type diffusion layer interposed therebetween may be any P-type material such as a P-type diffused resistor or an insulating P layer. The effect of the higher concentration than that of P-type diffused resistance is large. Further, its position may be designed to surround the contact portion as shown at 15' in the plan view of FIG.

[Brief explanation of the drawing]

FIG. 1a is a sectional view of a conventional semiconductor integrated circuit device near a diffused resistor, FIG. 1b is a plan view thereof, FIG. 2a is a sectional view showing an embodiment of the present invention, and FIG. FIG. 1...P type substrate (substrate), 2...N
type epitaxial layer, 3...P type diffused resistor, 4...
...N ⁺ buried layer, 5... silicon oxide film, 6, 10,
16...Contact, 7,11...Metal wiring,
8, 12... Bonding line, 9... High concentration N diffusion layer, 13, 14, 17... Static electricity breakdown path, 1
5,15'...P type diffusion layer.

Claims (1)

[Scope of utility model registration request] In a semiconductor device having a resistive region of a different conductive type formed in a semiconductor layer of one conductive type, and contacts for supplying voltage to the semiconductor layer and the resistive layer, respectively, these two contacts are connected to each other. A semiconductor device characterized in that a semiconductor region of a different conductivity type is provided in between, and a contact between the semiconductor region and the resistor region is short-circuited.