KR19980075043A - Manufacturing method of semiconductor device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for fabricating a semiconductor device designed to reduce a reverse short channel effect (RSCE), comprising the steps of: preparing a semiconductor substrate defined by an active region and a field region; And forming a gate electrode sequentially, forming an LDD region in a surface of the semiconductor substrate on both sides of the gate electrode, forming an insulating film on the entire surface of the semiconductor substrate including the gate electrode, and insulating films on both sides of the gate electrode. And forming a sidewall space in the gate electrode and a source / drain impurity region connected to the LDD region in a surface of the semiconductor substrate on both sides of the gate electrode and the sidewall space.

Description

Manufacturing method of semiconductor device

The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a method for manufacturing a semiconductor device to reduce the reverse short channel effect (RSCE).

In general, in the MOS (Metal Oxide Semiconducter) device, LDD (Lightly Doped Drain) structure is formed to form a low-concentration junction under the gate sidewall in order to prevent high concentration and electric field concentration to drain due to the reduction of the gate width. have.

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

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

First, as shown in FIG. 1A, a gate insulating film 12 and a polysilicon 13 for a gate electrode are sequentially formed in an active region on a semiconductor substrate 11 defined as an active region and a field region.

Subsequently, after the photoresist 14 is applied onto the polysilicon 13, the photoresist 14 is patterned by an exposure and development process.

As shown in FIG. 1B, the polysilicon 13 and the gate insulating layer 12 are selectively removed using the patterned photoresist 14 as a mask to form a gate electrode 13a.

The photoresist 14 is removed, and low concentration impurity ions are implanted into the entire surface using the gate electrode 13a as a mask, so that the LDD region 15 is formed in the surface of the semiconductor substrate 11 on both sides of the gate electrode 13a. To form.

Next, as shown in FIG. 1C, an insulating film 16 is formed on the entire surface of the semiconductor substrate 11 including the gate electrode 13a.

In this case, the insulating film 16 is formed at a high temperature of 700 ° C. or higher in order to improve the interface characteristics with the semiconductor substrate 11.

As illustrated in FIG. 1D, an etch back process is performed on the entire surface of the insulating film 16 to form insulating film sidewalls 16a on both sides of the gate electrode 13a.

Subsequently, a high concentration impurity ion implantation is performed using the gate electrode 13a and the insulating film sidewall 16a as a mask to connect the LDD region 15 to the surface of the semiconductor substrate 11 on both sides of the gate electrode 13a. Drain impurity region 17 is formed.

At this time, the interstitial generated during the implantation of the impurity ions to form the source / drain impurity region 20 is diffused toward the channel by the thermal process after the ion implantation, thereby causing dopant dispersion, thereby causing RSCE. Is generated, and punch-through impurity is reduced.

In order to reduce the RSCE, a separate Rapid Thermal Annealing (RTA) process is performed after impurity ion implantation.

However, such a conventional method of manufacturing a semiconductor device has the following problems.

First, the RTA process is performed to reduce RSCE, making the process complicated and warping of the substrate.

Second, since the insulating film forming process for forming the insulating film sidewall is performed at a high temperature, the diffusion of the channel dopant is increased to generate RSCE.

An object of the present invention is to provide a method of manufacturing a semiconductor device to simplify the process by preventing the occurrence of RSCE to solve the above problems.

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

2A through 2D are cross-sectional views illustrating a method of manufacturing a semiconductor device in accordance with a first embodiment of the present invention.

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

Explanation of symbols for the main parts of the drawings

21,31 semiconductor substrate 22,32 gate insulating film

23,33: polysilicon 23a, 33a: gate electrode

24,34 photoresist 25,38 LDD region

26,35 insulating film 27,36 polysilicon sidewall

28,37: source / drain impurity region

The semiconductor device manufacturing method of the present invention for achieving the above object comprises the steps of preparing a semiconductor substrate defined by an active region and a field region, and then in turn a gate insulating film and a gate electrode in a predetermined portion of the active region on the semiconductor substrate Forming a film, forming an LDD region in a surface of the semiconductor substrate on both sides of the gate electrode, forming an insulating film on the entire surface of the semiconductor substrate including the gate electrode, and forming sidewall spaces on the insulating film on both sides of the gate electrode. And forming a source / drain impurity region connected to the LDD region in a surface of the semiconductor substrate on both sides of the gate electrode and the sidewall space.

In another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, the method including: preparing a semiconductor substrate defined by an active region and a field region; Forming a film in turn, forming an insulating film on the entire surface of the semiconductor substrate including the gate electrode, forming a sidewall space in the insulating film on both sides of the gate electrode, and a semiconductor substrate surface on both sides of the gate electrode and the sidewall space. Forming a source / drain impurity region in the semiconductor substrate; and removing the sidewall space and the insulating layer, and forming an LDD region in the surface of the semiconductor substrate on both sides of the gate electrode.

Hereinafter, a method of manufacturing a semiconductor device according to the present invention will be described in detail with reference to the accompanying drawings.

2A to 2D are cross-sectional views illustrating a method of manufacturing a semiconductor device in accordance with a first embodiment of the present invention.

First, as shown in FIG. 2A, the gate insulating film 22 and the gate electrode polysilicon 23 are sequentially formed in the active region on the semiconductor substrate 21 defined as the active region and the field region.

Subsequently, a photoresist 24 is applied onto the polysilicon 23, and then the photoresist 24 is patterned by an exposure and development process.

As shown in FIG. 2B, the polysilicon 23 and the gate insulating film 22 are selectively removed using the patterned photoresist 24 as a mask to form a gate electrode 23a.

The photoresist 24 is removed, and low concentration impurity ions are implanted into the entire surface using the gate electrode 23a as a mask, so that the LDD region 25 is formed in the surface of the semiconductor substrate 21 on both sides of the gate electrode 23a. To form.

As shown in FIG. 2C, the insulating film 26, which is an oxide film or a nitride film, is formed on the entire surface of the semiconductor substrate 21 including the gate electrode 23a by a plasma CVD process. Form.

Next, polysilicon is formed on the insulating layer 26, and an etchback process is performed on the entire surface to form the polysilicon sidewall 27 on the insulating layer 26 on both sides of the gate electrode 23a.

As shown in FIG. 2D, a high concentration of impurity ions are implanted by using the polysilicon sidewall 27 and the gate electrode 23a as a mask, so that the semiconductor substrate 21 on both sides of the gate electrode 23 and the polysilicon sidewall 27 is formed. The source / drain impurity region 28 connected to the LDD region 25 is formed on the surface thereof.

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

First, as shown in FIG. 3A, a gate insulating film 32 and a polysilicon 33 for a gate electrode are sequentially formed in an active region on a semiconductor substrate 31 defined as an active region and a field region.

Subsequently, after the photoresist 34 is applied onto the polysilicon 33, the photoresist 34 is patterned by an exposure and development process.

As shown in FIG. 3B, the polysilicon 33 and the gate insulating layer 32 are selectively removed using the patterned photoresist 34 as a mask to form a gate electrode 33a.

Then, the photoresist 34 is removed, and the insulating film 35, which is an oxide film or a nitride film, is formed on the entire surface of the semiconductor substrate 31 including the gate electrode 33a by a plasma chemical vapor deposition (CVD) process. It is formed to have a thickness of.

Subsequently, polysilicon is formed on the insulating layer 35 and an etchback process is performed on the entire surface to form the polysilicon sidewall 36 on the insulating layer 35 on both sides of the gate electrode 33a.

High concentration impurity ions are implanted using the polysilicon sidewall 36 and the gate electrode 33a as a mask so that source / drain is formed in the surface of the semiconductor substrate 31 on both sides of the gate electrode 33a and the polysilicon sidewall 36. The impurity region 37 is formed.

As shown in FIG. 3C, the polysilicon sidewall 36 and the insulating layer 35 are removed, and low concentration impurity ions are implanted into the entire surface of the semiconductor substrate 31 using the gate electrode 33a as a mask to form the gate. The LDD region 38 is formed in the surface of the semiconductor substrate 31 on both sides of the electrode 33a.

As described above, the gap between the source / drain impurity region and the channel must be removed to reduce the gap diffusion toward the channel. However, the method of manufacturing a semiconductor device according to the present invention has the following effects.

That is, in order to remove the gap between the source / drain impurity region and the channel, the formation temperature of the sidewall spacer is lowered to reduce the gap at the interface with the semiconductor substrate, thereby reducing the RSCE without additional processes such as RTA, and channel dopant. Can reduce the diffusion of

Claims (5)

Preparing a semiconductor substrate defined by an active region and a field region, Sequentially forming a gate insulating film and a gate electrode in a predetermined portion of the active region on the semiconductor substrate; Forming an LDD region in the surface of the semiconductor substrate on both sides of the gate electrode; Forming an insulating film on the entire surface of the semiconductor substrate including the gate electrode; Forming sidewall spaces in the insulating films on both sides of the gate electrode; And forming a source / drain impurity region connected to the LDD region in a surface of the semiconductor substrate on both sides of the gate electrode and the sidewall space. The method of claim 1, The insulating film is a method of manufacturing a semiconductor device, characterized in that formed by a CVD process of 500 ℃ or less. The method of claim 1, The insulating film is a semiconductor device manufacturing method, characterized in that formed to a thickness of 100 ~ 500 ~. The method of claim 1, And the sidewall space forms polysilicon. Preparing a semiconductor substrate defined by an active region and a field region, Sequentially forming a gate insulating film and a gate electrode in a predetermined portion of the active region on the semiconductor substrate; Forming an insulating film on the entire surface of the semiconductor substrate including the gate electrode; Forming sidewall spaces in the insulating films on both sides of the gate electrode; Forming a source / drain impurity region in a surface of the semiconductor substrate on both sides of the gate electrode and the sidewall space; And removing the sidewall space and the insulating film to form an LDD region in the surface of the semiconductor substrate on both sides of the gate electrode.