KR19990005526A - Semiconductor device and manufacturing method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method of manufacturing the same for improving device reliability by suppressing degradation of isolation characteristics and generation of leakage current even in a contact hole forming process without contact margin.

A semiconductor device and a method of manufacturing the same according to an embodiment of the present invention form an isolation layer in an isolation region of a substrate, form a transistor having an impurity region in an active region of the substrate, and have a contact hole in an impurity region adjacent to the isolation layer and etch the isolation layer. And forming an insulating film having a different selectivity on the entire surface.

Description

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 semiconductor device for improving the reliability of a device and a method for manufacturing the same.

In the conventional semiconductor device, as shown in FIG. 1, an active region and an isolation region are defined and have a p-type semiconductor substrate 11, a field oxide film 12 formed on a surface of the semiconductor substrate 11 of the isolation region, and the active region. A gate electrode 14 formed on the semiconductor substrate 11 with a gate oxide film 13 and a cap gate oxide film 15 formed therein, and a first electrode formed in the surface of the semiconductor substrate 11 on both sides of the gate electrode 14. Fourth oxide film sidewalls 18 formed on the semiconductor substrate 11 on both sides of the first and second n-type impurity regions 16 and 17, the gate oxide film 13, the gate electrode 14, and the cap gate oxide film 15. ) And a fifth oxide film 19 formed on the entire surface of the fourth oxide film sidewall 18 and a predetermined area on the field oxide film 12 having a contact hole for exposing the semiconductor substrate 11. do.

In the method of manufacturing a semiconductor device according to the related art, as shown in FIG. 2A, a first oxide film, a first nitride film, and a first photosensitive film are sequentially formed on a semiconductor substrate 11 in which an isolation region is defined, and then the first photosensitive film is formed. Is selectively exposed and developed so as to be removed only above the isolation region, and then the first nitride film and the first oxide film are selectively etched using the selectively exposed and developed first photoresist film as a mask, and the first photoresist film is removed. do.

Since the first nitride film is used as a mask, heat is applied to the entire surface, so that the field oxide film 12 is grown on the surface of the semiconductor substrate 11 in the isolation region, and then the first oxide film formed on the semiconductor substrate 11 is formed. And the first nitride film is removed.

As shown in FIG. 2B, a second oxide film, a first polycrystalline silicon, a third oxide film, and a second photosensitive film are sequentially formed on the entire surface including the field oxide film 12, and then the second photosensitive film is formed only at a portion where the gate electrode is to be formed. After selectively exposing and developing to remain, the third oxide film, the first polycrystalline silicon, and the second oxide film are selectively etched using the selectively exposed and developed second photosensitive film as a mask to form a gate oxide film 13 and a gate electrode 14. And a cap gate oxide film 15 is formed to remove the second photoresist film.

As shown in FIG. 2C, the first and second n-type impurity regions 16 and 17 are formed by implanting and driving-in diffusion of n-type impurity ions onto the front surface using the gate electrode 14 as a mask. After the fourth oxide film is formed in the substrate, the fourth oxide film sidewalls 18 are formed on both sides of the gate oxide film 13, the gate electrode 14, and the cap gate oxide film 15.

As shown in FIG. 2D, the fifth oxide film 19 and the third photoresist film are sequentially formed on the entire surface, and then the third photoresist film is removed so that only a portion where the contact hole is to be formed on the second n-type impurity region 17 is removed. After selectively exposing and developing, the fifth oxide film 19 is selectively etched using the selectively exposed and developed third photoresist film to form a contact hole on the second n-type impurity region 17, and The third photosensitive film is removed. Since the gap between the fourth oxide film sidewall 18 and the field oxide film 12 is narrow, there is no contact margin, and thus the semiconductor substrate 11 is exposed because the field oxide film 12 is selectively etched during the contact hole forming process.

However, in the conventional semiconductor device and its manufacturing method, when the contact margin is not formed due to the integration of the device in the contact hole forming process, the field oxide film is etched to deteriorate the isolation property of the device and also expose the semiconductor substrate, so that leakage current is generated. There was a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a semiconductor device and a method of manufacturing the same, which improves device reliability by suppressing degradation of isolation characteristics and generation of leakage current even in a contact hole forming process without contact margin. There is a purpose.

1 is a cross-sectional view showing a conventional semiconductor device

2A to 2D are cross-sectional views illustrating a method of manufacturing a semiconductor device according to the prior art.

3 is a cross-sectional view illustrating a semiconductor device in accordance with an embodiment of the present invention.

4A through 4D are cross-sectional views illustrating a method of manufacturing a semiconductor device in accordance with an embodiment of the present invention.

Explanation of symbols for the main parts of the drawings

31 semiconductor substrate 32 field oxide film

33: gate oxide film 34: gate electrode

35: cap gate oxide film 36: first n-type impurity region

37: second n-type impurity region 38: fourth oxide film sidewall

39: second nitride film 40: fifth oxide film

The semiconductor device of the present invention has an isolation selectivity formed in an isolation region of a substrate, a transistor formed having an impurity region in an active region of the substrate, and an etching selectivity with an isolation ratio formed on the entire surface with a contact hole in an impurity region adjacent to the isolation layer. It is characterized by including the other insulating film.

In the method of manufacturing a semiconductor device of the present invention, the method may further include forming an isolation layer in an isolation region of a substrate, forming a transistor having an impurity region in an active region of the substrate, and selecting the isolation layer and an etch on the entire surface including the transistor. Forming a first insulating film having a different ratio, forming a second insulating film on the first insulating film, and selectively etching a second insulating film on the first insulating film to form a contact hole on an impurity region adjacent to the isolation film Characterized in that it comprises a step.

When described in detail with reference to the accompanying drawings a preferred embodiment of a semiconductor device and a method for manufacturing the same according to the present invention as follows.

In the semiconductor device according to the embodiment of the present invention, as shown in FIG. 3, an active region and an isolation region are defined and a p-type semiconductor substrate 31 and a field oxide layer 32 formed on a surface of the semiconductor substrate 31 in the isolation region. And a gate electrode 34 formed on a predetermined region on the semiconductor substrate 31 in the active region and having a gate oxide film 35 and a cap gate oxide film 35, and the semiconductor substrate 31 on both sides of the gate electrode 34. First and second n-type impurity regions 36 and 37 formed in the surface, the gate oxide film 33, the gate electrode 34 and the cap gate oxide film 35 formed on the semiconductor substrate 31 on both sides. A fourth nitride film sidewall 38, a second nitride film 39 and a fifth oxide film 40 having contact holes at predetermined portions on the second n-type impurity region 37 and sequentially formed on the entire surface thereof.

In the method of manufacturing a semiconductor device according to an embodiment of the present invention, as shown in FIG. 4A, a first oxide film, a first nitride film, and a first photoresist film are sequentially formed on a semiconductor substrate 31 having an isolation region defined therein, and then the And selectively exposing and developing the photoresist film so as to be removed only above the isolation region, and selectively etching the first nitride film and the first oxide film by using the selectively exposed and developed first photoresist film as a mask and Remove it.

Since the first nitride film is used as a mask, heat is applied to the entire surface, so that the field oxide film 32 is grown on the surface of the semiconductor substrate 31 in the isolation region, and then the first oxide film formed on the semiconductor substrate 31. And the first nitride film is removed.

As shown in FIG. 4B, a second oxide film, a first polycrystalline silicon, a third oxide film, and a second photosensitive film are sequentially formed on the entire surface including the field oxide film 32, and then the second photosensitive film is formed only at a portion where the gate electrode is to be formed. After selectively exposing and developing to remain, the third oxide film, the first polycrystalline silicon and the second oxide film are selectively etched using the selectively exposed and developed second photosensitive film as a mask to form a gate oxide film 33 and a gate electrode 34. ) And a cap gate oxide film 35 is formed to remove the second photosensitive film.

As shown in FIG. 4C, first and second n-type impurity regions 36 and 37 are formed by implanting and driving-in diffusion of n-type impurity ions onto the front surface using the gate electrode 34 as a mask. After forming the fourth oxide film on the substrate, the fourth oxide film sidewalls 38 are formed on both sides of the gate oxide film 33, the gate electrode 34, and the cap gate oxide film 35.

As shown in FIG. 4D, the second nitride film 39, the fifth oxide film 40, and the third photoresist film are sequentially formed on the entire surface, and then the third photoresist film is formed on the second n-type impurity region 37. After selectively exposing and developing only a portion to be formed, the second nitride film 39 and the fifth oxide film 40 are selectively etched using the selectively exposed and developed third photoresist film as a mask to form a second n n. A contact hole is formed on the type impurity region 36 and the third photoresist film is removed. Since the contact hole forming process is performed after the second nitride film 39 is formed, the distance between the second oxide film sidewall 38 and the field oxide film 32 is narrow so that the field oxide film is formed during the contact hole forming process even if there is no contact margin. Since the 32 is not etched, the semiconductor substrate 31 is not exposed.

In the semiconductor device of the present invention and a method of manufacturing the same, a nitride film and an oxide film are sequentially formed in a contact hole forming process without a contact margin, and then the contact hole forming process is performed to prevent the field oxide film from being etched. There is an effect of suppressing the generation of current to improve the reliability of the device.

Claims (2)

An isolation film formed in the isolation region of the substrate; A transistor having an impurity region in an active region of the substrate; And an insulating layer having a contact hole in an impurity region adjacent to the isolation layer and having an etch selectivity different from that of the isolation layer formed on the front surface. Selectively forming an isolation layer in an isolation region of the substrate; Forming a transistor having an impurity region in an active region of the substrate; Forming a first insulating layer having an etch selectivity different from that of the isolation layer on the entire surface including the transistor; Forming a second insulating film on the first insulating film; And selectively etching the second insulating film on the first insulating film to form a contact hole on an impurity region adjacent to the isolation film.