KR20000066131A - Semiconductor device and method for manufacturing the same - Google Patents

Abstract

PURPOSE: A method for manufacturing a semiconductor device is provided to simplify a manufacturing process by not using a separate process for forming a contact hole, and to prevent a misalignment between contact holes from being generated by forming the contact hole only once. CONSTITUTION: A first impurity region is formed by injecting impurity ions of a second conductivity type in a predetermined region of a semiconductor substrate(31) of a first conductivity type, and nitrogen ions are injected into the surface of the first impurity region. An insulating layer is formed which is thicker in a region where the nitrogen ions are not injected than in a region where the nitrogen ions are injected. The insulating layer is etched to sufficiently eliminate the insulating layer in the nitrogen ion injection region. A gate electrode(34) is patterned on the gate insulating layer, directly connected to the first impurity region through the portion in which the insulating layer is eliminated. A sidewall(35) is formed on both side surfaces of the gate electrode. Impurity ions of a second conductivity type are injected into the substrate on both sides of the sidewall to form a second impurity region symmetrical to the first impurity region. An interlayer dielectric(38) is formed on the entire surface of the substrate including the gate electrode, and a contact hole is formed to expose the second impurity region. A conductive plug(40) is formed in the contact hole. Metal(41) electrically connected to the plug is formed.

Description

Semiconductor device and its manufacturing method {SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly, to a semiconductor device suitable for directly connecting a gate and an active region using a process of implanting nitrogen ions prior to gate formation, and a method of manufacturing the same.

Hereinafter, a semiconductor device manufacturing method according to the prior art will be described with reference to the accompanying drawings.

1A to 1J are cross-sectional views illustrating a method of manufacturing a conventional semiconductor device.

As shown in Fig. 1A, a gate electrode 22 is formed on the semiconductor substrate 1 in the active region.

After the insulating film is deposited on the entire surface including the gate electrode 2, the sidewalls 3 are formed on both sides of the gate electrode 2 by etching back.

In this case, polysilicon is applied to the material of the gate electrode 2.

Subsequently, source / drain regions 4 and 5 are formed in both substrates of the gate electrode 2 through ion implantation, and a conventional method is formed on the upper surface of the gate electrode 2 and the semiconductor substrate 1. The silicide layer 6 is formed.

After forming the first ILD layer 7 on the entire surface including the silicide layer 6, the first ILD layer 7 is planarized by a chemical mechanical polishing (CMP) process.

As shown in FIG. 1B, the silicide layer of the drain region 5 and the first contact hole 7a where the silicide of the source region 4 and the silicide layer 6 on the gate electrode 2 are simultaneously exposed. A second contact hole 7b through which 7) is exposed is formed.

The contact hole may be formed through a photolithography process, and may be connected to the first interconnect hole 7a through which the silicide layer 6 on the source region 4 and the gate electrode 2 is simultaneously exposed. Local Interconnection), hereinafter referred to as local interconnection.

As shown in Fig. 1C, the first tungsten 8 is deposited on the entire surface including the local interconnection 7a and the second contact hole 7b.

1D, the first tungsten 8 is planarized until the first ILD layer 7 is exposed to remove the local interconnection 7a and the second contact hole 7b. 1 is embedded in tungsten (8).

As shown in FIG. 1E, after the second ILD layer 9 is formed on the embedded first tungsten 8 and the first ILD layer 7, the photoresist (2) is formed on the second ILD layer 9. 10) Apply.

The first tungsten buried in the second contact hole 7b by an etching process using the patterned photoresist 10 as a mask, as shown in FIG. 1F. The second ILD layer 9 is selectively removed so that the 8 is exposed to form the third contact hole 9a.

As shown in FIG. 1G, after the photoresist 10 is removed, the second tungsten 8a is deposited, and as shown in FIG. 1H, the second tungsten 8a is planarized by the CMP process to make the second A second tungsten 8a electrically connected to the first tungsten 8 is embedded in the third contact hole 9a.

Thereafter, as illustrated in FIG. 1I, the barrier metal 11 is deposited on the entire surface including the second tungsten 8a and the second ILD layer 9.

After the photoresist 10a is applied onto the barrier metal 11, the photoresist 10a is patterned by an exposure and development process.

As shown in Fig. 1J, only on the upper and adjacent second ILD layer 9 of the second tungsten 8a embedded in the third contact hole 9a using the patterned photoresist 10a as a mask. When the barrier metal 11 is etched to remain, the semiconductor device manufacturing process according to the prior art is completed.

However, the conventional semiconductor device manufacturing method as described above has the following problems.

First, since the contact hole is formed again after forming the local interconnection, the process is complicated because the processes of photo, etch, barrier metal deposition, tungsten deposition, and tungsten planarization are performed twice.

Second, since contact holes are formed in different layers, misalignment between contact holes

align).

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to provide a semiconductor device and a method of manufacturing the same, which can simplify the process and solve the problem of misalignment between contact holes.

1A to 1J are cross-sectional views illustrating a method of manufacturing a semiconductor device according to the related art.

2 is a structural cross-sectional view of a semiconductor device according to the present invention.

3A to 3F are cross-sectional views illustrating a method of manufacturing a semiconductor device in accordance with the present invention.

Explanation of symbols for main parts of the drawings

31 semiconductor substrate of first conductivity type 33 oxide film

34 gate electrode 35 side wall

36,36a: source and drain impurity region 37: silicide layer

38: interlayer insulating film 39: contact hole

40: plug 41: metal

The semiconductor device of the present invention for achieving the above object comprises a first conductive semiconductor substrate, a first impurity region and a second impurity region of a second conductivity type formed at predetermined intervals in the surface of the substrate, A portion of which is directly connected to the first impurity region, the other portion of which is formed on a substrate between the first impurity region and the second impurity region with an insulating film therebetween, and a gate electrode having sidewalls on both sides thereof; The semiconductor of the present invention comprises an interlayer insulating film formed on the entire surface including the gate electrode and having a contact hole to expose a second impurity region, a plug embedded in the contact hole, and a metal electrically connected to the plug. In the device manufacturing method, a first impurity region is formed by implanting impurity ions of a second conductivity type into a predetermined region of a semiconductor substrate of a first conductivity type. Implanting nitrogen ions into the surface, forming an insulating film on the substrate to have a thicker thickness in the region where the nitrogen ions are not implanted, and in the region where the nitrogen ions are implanted Etching the insulating film so that the insulating film can be sufficiently removed, and directly connecting the first impurity region through the portion where the insulating film is removed, and using the portion where the insulating film is not removed as the gate insulating film. Patterning a gate electrode on the film, forming sidewalls on both sides of the gate electrode, and implanting second conductive impurity ions into the substrate on both sides of the sidewall to symmetrical with the first impurity region; Forming an interlayer insulating film over the substrate including the gate electrode; And forming a contact hole to expose the second impurity region, forming a conductive plug in the contact hole, and forming a metal electrically connected to the plug.

Hereinafter, a semiconductor device and a method of manufacturing the same will be described with reference to the accompanying drawings.

2 is a structural cross-sectional view of a semiconductor device according to the present invention.

As shown in FIG. 2, the first conductive semiconductor substrate 31, the second conductive source impurity region 36 and the drain impurity region 36a formed at predetermined intervals in the substrate 31, The gate electrode 34 is partially connected to the source impurity region 36 and the remaining portion is insulated from the substrate 31 by the insulating layer 33, and sidewalls formed on both sides of the gate electrode 34. 35, a silicide layer 37 formed on the source impurity region 36 and the drain impurity region 36a on both sides of the gate electrode 35 and the sidewall 35, and an entire surface including the silicide layer 37. A conductive layer electrically connected to the silicide layer 37 corresponding to the drain impurity region 36a that is not connected to the gate electrode 34 through the interlayer insulating layer 38 formed on the interlayer insulating layer 38 and the interlayer insulating layer 38. Plug 40 and the plug 40 It is configured to include a metal 41 is connected to the enemy.

Referring to the accompanying drawings, a semiconductor device manufacturing method of the present invention configured as described above is as follows.

3A to 3F are cross-sectional views illustrating a method of manufacturing a semiconductor device of the present invention.

As shown in Fig. 3A, a second conductive type source / drain impurity ion implantation is performed on the first conductive semiconductor substrate 31 using the photoresist 32 as a mask.

Nitrogen ions are implanted only into the surface of the substrate.

As shown in FIG. 3B, after the photoresist 32 is removed, an oxide film 33 is grown on a substrate including a portion into which nitrogen ions and source / drain impurity ions are implanted.

At this time, since the growth rate of the oxide film is slow compared to the portion where the nitrogen ion is not implanted, the portion where the nitrogen ion is implanted and the portion where the nitrogen ion is not implanted have a step.

In this case, an SPM process using sulfuric acid is used to remove the photoresist 32.

Thereafter, as illustrated in FIG. 3C, the oxide film 33 in the portion where the nitrogen ions are not implanted in the state where the mask is not used is etched to a thickness sufficient to serve as a gate insulating film.

Therefore, the oxide film in the portion where the nitrogen ions are implanted is completely removed to expose the surface of the substrate 31.

That is, the substrate 31 is divided into portions in which the oxide film 33 is formed and portions in which the substrate 31 is exposed without being formed.

Thereafter, as illustrated in FIG. 3D, a conductive material such as polysilicon is deposited on the entire surface, and then patterned to form a gate electrode 34, and the oxide layer 33 on both sides of the gate electrode 34 is removed.

In this case, the gate electrode 34 is formed on the exposed substrate 31 and the oxide film 33 at the same time, so that a part of the gate electrode 34 is directly connected to the substrate 31.

In addition, the oxide layer 33 formed under a portion of the gate electrode 34 serves as a gate insulating layer.

As shown in FIG. 3E, the sidewalls 35 are formed on both sides of the gate electrode 34 using a conventional method.

Thereafter, after ion implantation of the impurity of the second conductivity type, source and drain impurity regions 36 and 36a are formed in the substrate 31 on both sides of the gate electrode 34 through diffusion.

Thereafter, the silicide layer 37 is formed on the surfaces of the gate electrode 34 and the substrate 31 by a conventional method.

The ILD layer is formed by the interlayer insulating film 38 on the entire surface of the substrate 31 including the silicide layer 37.

After the photoresist 32a is coated on the interlayer insulating layer 38, the photoresist 32a is patterned, and an etching process using the patterned photoresist 3 as a mask is performed. The substrate 31 is not connected to the gate electrode 34. The contact hole 39 is formed by etching the interlayer insulating film 38 to expose the (silicide layer 37 on the substrate).

Subsequently, as shown in FIG. 3F, a conductive material such as tungsten is deposited on the entire surface of the substrate 31 including the contact hole 39, and then planarized to form a plug 40 embedded in the contact hole 39. do.

Subsequently, after depositing the metal 41 on the plug 40 and the interlayer insulating film 38, and patterning and electrically connecting the plug 41 to the plug 40, the semiconductor device manufacturing process according to the present invention is completed.

As described above, the semiconductor device of the present invention and its manufacturing method have the following effects.

First, since the gate electrode and the source impurity region are directly connected, a separate contact hole forming process for electrically connecting the gate electrode and the source impurity region is not necessary, thereby simplifying the process.

Second, since contact holes are formed only once, there is no fear of misalignment between contact holes.

Claims (7)

A semiconductor substrate of a first conductivity type; First impurity regions and second impurity regions of a second conductivity type formed at predetermined intervals in the surface of the substrate; A gate electrode having a portion directly connected to the first impurity region, the remaining portion being formed on a substrate between the first impurity region and the second impurity region with an insulating film interposed therebetween, the gate electrode having sidewalls on both sides thereof; An interlayer insulating film formed on an entire surface including the gate electrode and having a contact hole to expose the second impurity region; A plug embedded in the contact hole; A semiconductor device comprising a metal electrically connected to the plug. The semiconductor device of claim 1, further comprising a silicide layer on upper portions of the first and second impurity regions on both sides of the sidewall and an upper surface of the gate electrode. The semiconductor device according to claim 1, wherein the insulating film is an oxide film. Implanting impurity ions of the second conductivity type into a predetermined region of the semiconductor substrate of the first conductivity type to form a first impurity region, and implanting nitrogen ions into the surface thereof; Forming an insulating film on the substrate to have a thickness thicker in a region where the nitrogen ions are not implanted than in a region where the nitrogen ions are implanted; Etching the insulating film to sufficiently remove the insulating film in the region where the nitrogen ions are implanted; Patterning a gate electrode on the gate insulating film using a portion which is directly connected to the first impurity region through a portion where the insulating film is removed, and wherein the insulating film is not removed, as a gate insulating film; Forming sidewalls on both sides of the gate electrode; Implanting impurity ions of a second conductivity type into the substrate on both sides of the sidewall to form a second impurity region symmetric to the first impurity region; Forming an interlayer insulating film over the entire substrate including the gate electrode and forming a contact hole to expose the second impurity region; Forming a conductive plug in the contact hole; A method of manufacturing a semiconductor device, comprising the step of forming a metal electrically connected to the plug. The method of claim 4, further comprising performing a silicide process after forming the sidewalls. The method of claim 4, wherein the insulating film is formed by growing an oxide film in an oxygen atmosphere. 7. The method of claim 6, wherein the oxide film grows thinner in a region where nitrogen ions are not implanted in a region where nitrogen ions are implanted.