KR19980058382A - Electrostatic Discharge Semiconductor Device and Manufacturing Method Thereof - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention provides a static discharge semiconductor device and a method of manufacturing the same, which can prevent accumulation of charge by plasma during wiring formation by using a separate conductive film pattern having a polarity opposite to that of an electrostatic discharge impurity region. The electrostatic discharge semiconductor device according to the present invention includes a first conductivity type semiconductor substrate having a field oxide film formed thereon; A transistor having a gate insulating film formed on a substrate on one side of the field oxide film, a gate, and a second conductivity type source / drain region formed on the substrate on both sides of the gate; A first conductivity type electrostatic discharge impurity region formed on the substrate on the other side of the field oxide film; A first insulating film formed over the substrate and having first and second contact holes formed on the gate and impurity regions, and having a trench having a predetermined depth formed on the field oxide film; A second conductive type electrostatic discharge conductive film pattern embedded in the trench; A second insulating film formed on the first insulating film and the conductive film pattern and sharing the first and second contact holes, and having a third contact hole formed on the conductive film pattern; And first and second wiring layers in contact with the gate through the first to third contact holes, the impurity regions and the conductive layer patterns, and insulated from each other on the second insulating layer.

Description

Electrostatic Discharge Semiconductor Device and Manufacturing Method Thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method for manufacturing the same, and more particularly, to a static discharge semiconductor device capable of preventing the accumulation of static charges by plasma and a method for manufacturing the same.

Recently, as the manufacturing technology of semiconductor devices is improved, high integration and high speed are rapidly progressing. Accordingly, studies on wiring technologies that can freely design wiring and allow setting of wiring resistance and current capacity, etc., are being actively conducted.

As a general wiring forming method, a method of patterning wirings by dry etching using plasma by a combination of halogen gas such as Cl ₂ , BCl ₃ , SF ₆ , and HBr using a predetermined photoresist pattern as an etching mask is mainly used. However, electrostatic charges continue to accumulate due to the electrostatic charge generated by the plasma, which in turn stresses the gate oxide film under the gate electrode connected to the wiring, thereby deteriorating the characteristics of the gate oxide film and improving reliability of the device. Lowers.

Therefore, a separate discharge device must be provided for discharging the above-mentioned static charge.

1 is a cross-sectional view showing a static discharge semiconductor device.

As shown in Fig. 1, the conventional electrostatic discharge semiconductor device includes a semiconductor substrate 1 of a first conductivity type, field oxide films 2a, 2b and 2c formed on the substrate 1, and a field oxide film 2b. The gate oxide film 3 and the gate 4 formed on the substrate on one side, the second conductive source / drain regions 5 and 6 and the field oxide film 2b formed on the substrate 1 on both sides of the gate 4. An insulating film 8 having a first conductivity type electrostatic discharge impurity region 7 formed on the substrate 1 on the other side, a gate 4 and a contact hole formed on the impurity region 7, and the contact The first and second wirings 9a and 9b are in contact with the gate 4 and the impurity region 7 through the holes.

That is, as the interconnection of the impurity region 7 and the wiring is contacted, the static charge by dry etching by the plasma is discharged to the impurity region 7 at the time of formation of the wiring, so that accumulation of the static charge can be prevented.

However, the above-described conventional electrostatic discharge semiconductor device has the following problems depending on the polarity of the electrostatic charge.

That is, when the first conductivity type is n-type, when negative charge is generated during dry etching by plasma for wiring formation, the negative charge is discharged to the substrate 1 through the second wiring 9b and the impurity region 7, When positive charges are generated, charges induced in the second wiring 9b are accumulated without being discharged. In contrast, when the first conductivity type is p-type, positive charges are discharged and negative charges are accumulated. As a result, a strong electric field is formed by the accumulated electrostatic charge, which stresses the gate oxide film 3, resulting in lowering the reliability of the device.

Accordingly, the present invention was created in view of the above-described problems, and an electrostatic charge capable of preventing charge accumulation by plasma during wiring formation by using a separate conductive film pattern having a polarity opposite to that of an electrostatic charge impurity region. An object thereof is to provide a low discharge semiconductor device and a method of manufacturing the same.

1 is a cross-sectional view showing a conventional electrostatic discharge semiconductor device.

2A to 2D are sequential process cross-sectional views illustrating a method of manufacturing a static discharge semiconductor device according to an embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

DESCRIPTION OF SYMBOLS 11 First conductivity type semiconductor substrate, 12 Field oxide film, 13 Gate oxide film, 14 Gate, 15/16 Second conductivity type source / drain region, 100 Transistor, 17 First conductivity type electrostatic discharge impurity Region, 18: first oxide film, 19: trench, 20: second conductive conductive film pattern, 21: second oxide film, 22: contact hole, 23a, 23b: first and second wiring layers

Electrostatic discharge semiconductor device according to the present invention for achieving the above object is a first conductivity type semiconductor substrate having a field oxide film formed thereon; A transistor having a gate insulating film, a gate formed on the substrate on one side of the field oxide film, and a second conductive source / drain region formed on the substrate on both sides of the gate; A first conductivity type electrostatic discharge impurity region formed on a substrate on the other side of the field oxide film; A first insulating film formed on the entire surface of the substrate and having first and second contact holes formed on the gate and the impurity region, and having a trench having a predetermined depth formed on the field oxide film; A second conductive type electrostatic discharge conductive film pattern embedded in the trench; A second insulating film formed on the first insulating film and the conductive film pattern and sharing the first and second contact holes, and having a third contact hole formed on the conductive film pattern; And first and second wiring layers which are in contact with the gate, the impurity region and the conductive layer pattern, respectively and insulated from each other on the second insulating layer through the first to third contact holes.

In addition, a method of manufacturing an electrostatic discharge semiconductor device according to the present invention for achieving the above object comprises the steps of forming a field oxide film on the first conductivity type semiconductor substrate; Forming a gate insulating film and a gate on the substrate on one side of the field oxide layer, and forming a second conductive source / drain region on the substrate on both sides of the gate to form a transistor; Forming a first conductivity type electrostatic discharge impurity region on a substrate on the other side of the field oxide film; Forming a first insulating film on the entire surface of the substrate; Etching the first insulating film on the field oxide film to a predetermined depth to form a trench; Forming a second conductive electrostatic discharge conductive film pattern embedded in the trench; Forming a second insulating film on the conductive film pattern and the first insulating film; Forming first to third contact holes, respectively, by exposing the gate and impurity regions and the conductive layer pattern to a predetermined portion; And forming first and second wiring layers to contact the gate, the impurity region, and the conductive layer pattern through the first to third contact holes, and to be insulated from each other on the second insulating layer. It is characterized by.

The forming of the conductive film pattern may include forming a second conductive conductive film on the first insulating film to fill the trench; And etching back the conductive film so that the first insulating film is exposed.

The second wiring layer is formed so that the conductive film pattern and the impurity region are connected to each other.

The first conductivity type is n-type, the second conductivity type is p-type, the first conductivity type is p-type, and the second conductivity type is n-type.

According to the present invention having the above structure, by forming a separate conductive film pattern for electrostatic discharge through the trench formed in the same pattern as the field oxide film in the first insulating film on the field oxide film, it is generated during etching by plasma at the time of wiring formation The positive and negative charges are discharged through the impurity regions for the electrostatic discharge and the conductive film pattern having different polarities.

EXAMPLE

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention.

2D is a cross-sectional view illustrating a static discharge semiconductor device according to an embodiment of the present invention, in which the first conductive semiconductor substrate having the field oxide films 12a, 12b, and 12c formed thereon is formed. 11 and a second conductive source / drain formed in the gate insulating film 13 formed on the substrate 11 on one side of the field oxide film 12b, the gate 14 and the substrate 11 on both sides of the gate 14. A transistor 100 having regions 15 and 16, a first conductivity type electrostatic discharge impurity region 17 formed on the substrate 11 on the other side of the field oxide film 12b, and a gate formed on the entire surface of the substrate. A first oxide film 18 having first and second contact holes formed on the impurity region 17 and a trench having a predetermined depth formed on the field oxide film, and a trench embedded in the trench. On the conductive film pattern 20 for the 2-conducting electrostatic discharge, on the first oxide film 18 and the conductive film pattern 20 A second oxide layer 21 having a third contact hole formed on the conductive layer pattern 20 and sharing the first and second contact holes, and a gate formed through the first to third contact holes. And the first and second wiring layers 23a and 23b which are in contact with the impurity region 17 and the conductive film pattern 20, and insulated from each other on the second oxide film 21.

Next, a method of manufacturing a static discharge semiconductor device according to an embodiment of the present invention will be described with reference to FIGS. 2A to 2D.

First, as shown in FIG. 2A, field oxide films 12a, 12b, and 12c are formed on the first conductivity type semiconductor substrate 11 using LOCOS (LOCal Oxidation of Silicon) technology. Subsequently, the gate oxide film 13 and the gate 14 are formed on the substrate 11 on one side of the field oxide film 12b, and both sides of the gate 14 inject the second conductivity type impurity ions into the substrate 11. The second conductive source / drain regions 15 and 16 are formed to form the transistor 100 of the device.

Then, the first conductivity type impurity ions are implanted into the other side substrate 11 of the field oxide film 12b in which the transistor 100 is not formed to form the first conductivity type impurity region 17 for electrostatic discharge. Then, the first oxide film 18 formed of one of the TEOS oxide film, the BPSG film, or the composite film is formed on the entire surface of the substrate, and the first oxide film 18 on the field oxide films 12a, 12b, 12c is formed. The trench 19 is etched to a depth, preferably 1,000 to 5,000 kPa, to form the trench 19 having the same pattern as the field oxide films 12a, 12b, and 12c.

As shown in FIG. 2B, a trench 19 is formed on the structure of FIG. 2A with a conductive film containing a second conductivity type impurity of opposite polarity to the impurity region 17 for electrostatic discharge, for example, a polysilicon film or an amorphous silicon film. The conductive film is etched back so that the first oxide film 18 is exposed to form a first conductive electrostatic discharge conductive film pattern 20.

As shown in FIG. 2C, a second oxide film 21 is formed with a TEOS oxide film or a BPSG film on the structure of FIG. 2B to a thickness of about 500 to 2,000 micrometers. The first to third contact holes 22a to 22c are formed by exposing predetermined portions of the gate 14, the impurity region 17, and the conductive layer pattern 20 by photolithography and etching processes.

As shown in FIG. 2D, a metal layer is deposited on the structure of FIG. 2C and patterned by photolithography and etching processes to contact the gate 14 through the first to third contact holes 21a to 22c. The second wiring 23b is formed in contact with the first wiring 23a, the impurity region 17 and the conductive film pattern 20 at the same time.

According to the above embodiment, by forming a separate conductive film pattern for electrostatic discharge through the trench formed in the same pattern as the field oxide film in the first insulating film on the field oxide film, the positive charge and the negative charge generated at the time of the plasma formation when the wiring is formed The electrostatic charges of are discharged through the impurity region for electrostatic discharge and the conductive film pattern having different polarities. Accordingly, it is possible to prevent the accumulation of electric charges and to improve the reliability of the device.

In addition, this invention is not limited to the said Example, It can variously deform and implement within the range which does not deviate from the technical summary of this invention.

Claims (24)

A first conductivity type semiconductor substrate having a field oxide film formed thereon; A transistor having a gate insulating film, a gate formed on the substrate on one side of the field oxide film, and a second conductive source / drain region formed on the substrate on both sides of the gate; A first conductivity type electrostatic discharge impurity region formed on the substrate on the other side of the field oxide film; A first insulating film formed on the entire surface of the substrate and having first and second contact holes formed on the gate and the impurity region, and having a trench having a predetermined depth formed on the field oxide film; A second conductive type electrostatic discharge conductive film pattern embedded in the trench; A second insulating film formed on the first insulating film and the conductive film pattern and sharing the first and second contact holes, and having a third contact hole formed on the conductive film pattern; And And a first and a second wiring layer contacting the gate, the impurity region, and the conductive layer pattern through the first to third contact holes, and insulated from each other on the second insulating layer. Semiconductor device. The electrostatic discharge semiconductor device of claim 1, wherein the trench has a depth of 1,000 to 5,000 microns. The electrostatic discharge semiconductor device according to claim 1, wherein the trench has the same pattern as the field oxide film. The electrostatic discharge semiconductor device according to claim 1, wherein the conductive film is a polysilicon film. The electrostatic discharge semiconductor device of claim 1, wherein the conductive film is an amorphous silicon film. The electrostatic discharge semiconductor device according to claim 1, wherein the conductive film pattern is electrically connected to the impurity region through the second wiring layer. The electrostatic discharge semiconductor device according to claim 1, wherein the first insulating film is a film selected from a TEOS film or a BPSG film or a composite film of a TEOS film and a BPSG film. The electrostatic discharge semiconductor device according to claim 1, wherein the second insulating film has a thickness of 500 to 2,000 kPa. The electrostatic discharge semiconductor device according to claim 8, wherein the second insulating film is a film selected from among a TEOS film and a BPSG film. 2. The electrostatic discharge semiconductor device of claim 1, wherein the first conductivity type is n-type and the second conductivity type is p-type. The electrostatic discharge semiconductor device according to claim 1, wherein the first conductivity type is p-type and the second conductivity type is n-type. Forming a field oxide film on the first conductivity type semiconductor substrate; Forming a gate insulating film and a gate on the substrate on one side of the field oxide layer, and forming a second conductive source / drain region on the substrate on both sides of the gate to form a transistor; Forming a first conductivity type electrostatic discharge impurity region on a substrate on the other side of the field oxide film; Forming a first insulating film on the entire surface of the substrate; Etching a first insulating film on the field oxide film to a predetermined depth to form a trench; Forming a second conductive electrostatic discharge conductive film pattern embedded in the trench; Forming a second insulating film on the conductive film pattern and the first insulating film; Forming first to third contact holes, respectively, by exposing the gate and impurity regions and the conductive layer pattern to a predetermined portion; And, Forming first and second wiring layers to contact the gate, the impurity region, and the conductive layer pattern through the first to third contact holes, and to be insulated from each other on the second insulating layer. A method of manufacturing an electrostatic discharge semiconductor device. 13. The method of claim 12, wherein the first insulating film is a film selected from among a TEOS film or a BPSG film or a composite film of a TEOS film and a BPSG film. The method of claim 12, wherein the trench is formed to a depth of 1,000 to 5,000 Å. 13. The method of claim 12, wherein the trench is formed in the same pattern as the field oxide film. The method of claim 12, wherein the forming of the conductive layer pattern is performed. Forming a second conductivity type conductive film on the first insulating film so as to fill the trench; And, And etching back the conductive film so that the first insulating film is exposed. The method of manufacturing a static discharge semiconductor device according to claim 16, wherein the conductive film is a polysilicon film. 17. The method of claim 16, wherein the conductive film is an amorphous silicon film. 17. The method of claim 16, wherein the etch back is performed by a chemical mechanical polishing technique. 13. The method of claim 12, wherein the second insulating film has a thickness of 500 to 2,000 mW. 21. The method of claim 20, wherein the second insulating film is a film selected from among a TEOS film and a BPSG film. The method of claim 12, wherein the second wiring layer is formed so that the conductive film pattern and the impurity region are connected to each other. 13. The method of claim 12, wherein the first conductivity type is n-type and the second conductivity type is p-type. 13. The method of claim 12, wherein the first conductivity type is p-type and the second conductivity type is n-type.