JPS627165A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a diffused layer having a low resistance and a shallow junction by selectively coating a diffused layer region with a high melting point metal film, then accumulating arsenic thereon, and implanting silicon to form a metal silicide in a self-aligning manner. CONSTITUTION:A gate oxide film 3 and a gate electrode 4 are formed on an active region partitioned by a field insulating film 2, a silicon dioxide film is accumulated, the entire semiconductor substrate 1 is etched, a silicon dioxide film 5 remains on the side wall on the electrode 4, with the film 5 as a mask an impurity to form a reverse conductive impurity to the substrate 1 is implanted to form a diffused layer region 6. A tungsten film 7 is selectively coated by a CVD method on the region 6, and an amorphous or polycrystalline silicon film 8 is coated thereon. Then, silicon ions are implanted from above to react the film 8 with the film 7, and heat treated at 650 deg.C to form a tungsten silicide film 9. The remaining film 8 is removed to allow the film 9 to remain only on the region 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method for manufacturing a semiconductor device, and particularly to a method for forming a metal silicide film.

[Background of the invention]

A conventional method of forming a metal silicide on a gate electrode or a diffusion layer electrode by self-manufacturing is described, for example, in Japanese Patent Application Laid-Open No. 59-9.
As described in No. 9774, a metal film 7 is formed on the entire surface of the semiconductor substrate.
(FIG. 3(a)), a reaction is caused only on the surface where the metal film and the silicon substrate are in contact by heat treatment etc. to form the metal silicide film 9.
(Fig. 3(b)), but since the silicon necessary for forming the metal silicide film is obtained from the semiconductor substrate 1, the formed metal silicide film 9 is as shown in Fig. 3(c). It is difficult to form a diffusion layer region that penetrates into the semiconductor substrate 1 side and has a shallow junction depth and low resistance under the metal silicide film.

[Purpose of the invention]

An object of the present invention is to provide a diffusion layer with low resistance and a shallow junction depth by forming a metal silicide film in a self-aligned manner on the diffusion layer with little silicon corrosion in the diffusion layer in the semiconductor substrate. It's about doing.

[Summary of the invention]

In order to achieve the above object, the present invention first forms a high separation point metal film on the diffusion layer region by chemical vapor deposition so that the metal silicide film can be formed on the diffusion layer region in a self-aligned manner with less erosion of the semiconductor substrate. After selectively depositing it by a method, amorphous or polycrystalline silicon is then deposited on top of it by a chemical vapor deposition method, etc., and then silicon, etc. is implanted by ion implantation to form a high separation point metal film and a polycrystalline silicon film. It is characterized by reacting silicon and then removing excess polycrystalline silicon.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

A first embodiment of the present invention is shown in FIG.
As shown in a), a gate oxide film 3 is formed by thermal oxidation in the active region defined by the field insulating film 2, and a gate electrode material is deposited (after that, a gate electrode 4 is formed by patterning, and then chemically After depositing a silicon dioxide film by vapor phase deposition (CVD), reactive ion etching (
Etching the entire surface of the semiconductor substrate 1 using RIE),
A silicon dioxide film 5 was left on the side wall of the gate electrode 4, and using this as a mask, an impurity was implanted to form an impurity of a conductivity type opposite to that of the semiconductor substrate 1, thereby forming a diffusion layer region 6. In addition, as shown in FIG. 1(b), CV is applied onto the diffusion layer region 6.
A tungsten film 7 is selectively deposited to a thickness of about 40 nm using the D method, and then an amorphous or polycrystalline silicon film 8 is deposited thereon to a thickness of l by CVD or sputtering at a temperature of about 600°C.
oonm adheres. Then, as shown in FIG. 1(C),
Accelerating silicon from above the polycrystalline silicon 8 at a voltage of 100 to 1
50 keV, injection dose I x 10" to I x 10'
After the polycrystalline silicon film 8 and the tungsten film 7 are implanted by ion implantation to react with each other, a heat treatment is performed at a temperature of about 650° C. to form a tungsten silicide film 9.

Next, the polycrystalline silicon film 8 remaining on the insulating films 2 and 5 is removed using a hydrazine solution, leaving the tungsten silicide film 9 only on the diffusion layer region 6 as shown in No. 111(d).

This is an example in which a tungsten silicide film 9 is formed after forming a diffusion layer region 6, and then using FIG.
A second embodiment will be described in which the diffusion layer region 6 is formed after the tungsten silicide film 9 is formed.

In FIG. 2(a), a gate oxide film 3 is formed by thermal oxidation in an active region defined by a field insulating film 2, a gate electrode material is deposited, and then a gate electrode 4 is formed by patterning.
A cross-sectional view of a MOS type semiconductor device in which a silicon dioxide film is deposited by a CVD method, and a silicon dioxide film 5 is left only on the sidewalls of an eratin bleed gate electrode 4 over the entire surface of the semiconductor substrate 1 by RIE. It is. Next, Figure 2 (
As shown in b), a tungsten film 7 is selectively deposited to a thickness of about 400 mm by CVD only on the exposed region of the semiconductor substrate 1 where a diffusion layer is to be formed, and then a polycrystalline silicon film is deposited on top of it. 8 is deposited to a thickness of 1000 by CVD in a cutting atmosphere at a temperature of about 600°C. Then, as shown in FIG.
00~150keV, injection dose x X 10111~I
Implanted by ion implantation to the extent of X I O”/ffl,
After reacting the polycrystalline silicon film 8 and the tungsten film 7, heat treatment is performed at a temperature of about 650°C to form the tungsten silicide film 9.
6 Next, the polycrystalline silicon fi18 remaining on the insulating films 2 and 5 was removed using a hydrazine solution, and as shown in FIG.
As shown in d), the tungsten silicide film 9 is left only in the exposed region of the semiconductor substrate 1 where the diffusion layer is to be formed.

Here, instead of implanting silicon by ion implantation in FIG. 2(,), As is used as the ion species in the case of an n-channel MOS type semiconductor device, and B F z is used in the case of the p-channel MOS type semiconductor device. You can also do it.

Next, as shown in FIG. 2(e), an impurity having a conductivity type opposite to that of the semiconductor substrate 1 is implanted into the tungsten silicide film 9 by ion implantation, and a diffusion layer is formed by heat treatment at a temperature of about 950°C. Create area 6.

FIG. 4 is a sectional view of a complementary MOS type semiconductor device formed using the first embodiment or the second embodiment.

In this embodiment, the metal is limited to tungsten, but it is also possible to use metals such as molybdenum and titanium instead of tungsten.

〔Effect of the invention〕

According to the present invention, the sheet resistance of the diffusion layer electrode can be made approximately 10Ω/hole, and the junction depth of the diffusion layer can be made 0.15 μm or less from the interface between the gate oxide film and the semiconductor substrate. Fine MOS that requires shallow diffusion layer formation
It is always useful in realizing transistors and large scale integrated circuits using them.

[Brief explanation of drawings]

Fig. 1 is a process diagram showing a first embodiment of the present invention, Fig. 2 is a process diagram showing a second embodiment of the invention, Fig. 3 is a process diagram showing a conventional manufacturing method, and Fig. 4 is a process diagram showing a conventional manufacturing method. 1 is a diagram showing an example of a cross-sectional structure of a complementary MQS type semiconductor device formed according to the present invention. DESCRIPTION OF SYMBOLS 1... Semiconductor substrate, 2... Field insulating film, 3...
... Gate oxide film, 4... Gate electrode, 5... Silicon dioxide film, 6... N4'' type region, 7... Tungsten film, 8... Polycrystalline silicon film, 9... Tungsten silicide film, 10...P0 1 Figure 2Z Figure

Claims (1)

[Claims] 1. A gate electrode provided with at least a gate insulating film and a sidewall insulating film is formed at a predetermined position of an active region partitioned by a field insulating film, and the gate electrode is masked. A step of forming a diffusion layer of a conductivity type opposite to that of the semiconductor substrate, selectively depositing a high-resolution metal film on the diffusion region, and depositing amorphous or polycrystalline silicon on the high-resolution metal film. a step of depositing silicon on the amorphous or polycrystalline silicon film, a step of implanting silicon into the amorphous or polycrystalline silicon film by ion implantation, reacting with the metal film, and forming a metal silicide film by heat treatment; A method for manufacturing a semiconductor device, comprising a step of removing polycrystalline silicon. 2. In a method for manufacturing a MOS type semiconductor device, at a predetermined position of an active region partitioned by a field insulating film,
A step of forming a gate electrode provided with at least a gate insulating film and a sidewall insulating film, and selectively depositing a high barrier point metal film only in the region where the diffusion layer of the active region is to be formed; A step of depositing amorphous or polycrystalline silicon on the retardation point metal, implanting silicon by ion implantation, reacting with the retardation point metal, and performing heat treatment to form a metal silicide film;
A step of removing the amorphous or polycrystalline silicon film on the insulating film, and then implanting an impurity into the metal silicide film to form a diffusion layer of a conductivity type opposite to that of the semiconductor substrate, and heat treatment to remove the impurity from the semiconductor substrate side. A method of manufacturing a semiconductor device, the method comprising forming a diffusion layer.