JPH06204161A - Method for forming source/drain on semiconductor element - Google Patents

Abstract

PURPOSE: To form a source and a drain of a shallow bond by a method wherein after impurity ions for forming the source and the drain are implanted in a semiconductor substrate, Ar<+> ions are implanted under an impurity ion implanted layer to form an amorphous layer and thereafter, a heat treatment is performed. CONSTITUTION: Impurity B11 or BF12 ions for forming a P<+> source and a P<+> drain are implanted in a semiconductor substrate and thereafter, Ar<+> ions are implanted under this P<+> impurity non implanted layer. An amorphous layer is formed and a heat treatment is performed to obtain the source and the drain of a shallow bond. If the Ar<+> ions are implanted in such a way and the amorphous layer is formed, holes are abundantly formed in this layer and the degree of diffusion of boron within the substrate during the heat treatment is reduced. Thereby, the source and the drain of the shallow bond are formed. That is, the diffusion of the boron within the substrate is prevented by the armorphous layer formed by the implantation of the Ar<+> ions and the source and the drain of the shallow bond are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an argon ion (A
A method of forming a shallow junction source / drain in a semiconductor device by implantation of r ⁺ ).

[0002]

2. Description of the Related Art Generally, in a semiconductor device in which a process is performed in a size of a micron or less, a vertical size must be formed in balance according to a size of a side surface. The depth of the / drain junction must also be shallow.

As shown in FIG. 1, the conventional source / drain formation of a semiconductor device is a deep junction (deep junction) by heat treatment after implantation of impurity B ₁₁ ions or BF ₂ ions.
Since n) is formed, it is difficult to apply it to a micron-class or smaller device that requires a shallow junction. That is, when implanting the above B ₁₁ ions, 20 KeV is required to form a shallow junction.
B ₁₁ ions must be implanted at a low energy below, but when such a high-concentration impurity of 10 ¹⁵ atoms / cm ² or more is implanted, due to problems such as low energy beam current setting of 30 KeV or less, the energy is actually low. Therefore, it is impossible to implant high-concentration impurities.
Further, in the case of implanting BF ₂ ions, it is used to complement the disadvantages of the above B ₁₁ ions, and a junction is formed by having a shallow penetration depth immediately after the implantation of BF ₂ ions. However, in this case, there was a limit to forming a shallow junction of about 0.15 to 0.18 μm after heat treatment.

Further, as shown in FIG.
After the s, Si, and Ge ions are implanted in advance to form the amorphous layer on the single crystal layer, p ⁺ is added to the amorphous layer as shown in FIG.
There is a method of implanting B ₁₁ or BF ₂ ions for forming a mold source / drain and then performing heat treatment to form a source / drain.

However, this method also makes it difficult to control the depth of penetration into the substrate when implanting B ₁₁ and BF ₂ ions into a preformed amorphous layer, and the implantation was performed as shown in the graph of FIG. During the heat treatment of boron ions, a deep bond is formed after the heat treatment due to the difference in boron diffusion between the amorphous layer and the single crystal layer. In this case, since boron has a higher diffusivity in the interstitial than that in the vacancy, the diffusion becomes smaller in the amorphous layer rich in the vacancy, and the rich interstitial is generated. In the single crystal layer, the diffusion becomes large, resulting in the formation of a deep junction. Furthermore, As (group 5), Si (group 4), G
There is a problem that the physical properties of the substrate itself are changed by implanting e (group 4) ions.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention is directed to argon ion (A
By adding r ⁺ ) to control the thickness of the layer rich in vacancy, a shallow junction can be realized even after the heat treatment by post-amorphize by implantation of argon ions (Ar ⁺ ). ) Method of forming shallow coupled source / drain by the method.

[0007]

In order to achieve the above-mentioned object, the present invention achieves the above object by implanting impurity ions for forming source / drain into a semiconductor substrate, and then forming A under the impurity ion-implanted layer.
Provided is a method for forming a source / drain of a semiconductor device, which comprises implanting r ⁺ ions to form an amorphous layer and then performing heat treatment.

[0008]

Embodiments of the present invention will be described in detail below with reference to FIG.

After implanting impurities B ₁₁ or BF ₂ ions for forming P ⁺ type source / drain into the semiconductor substrate, the p ⁺
Ar ⁺ ions are implanted below the type impurity ion-implanted layer to form an amorphous layer, and heat treatment is performed to obtain a shallow junction. When the amorphous layer is formed by implanting Ar ⁺ ions in this manner, vacancy is abundantly formed in this layer, and the degree of diffusion of boron into the substrate during the heat treatment is reduced. A shallow junction is formed. That is, the amorphous layer formed by the implantation of Ar ⁺ ions prevents boron diffusion into the substrate and forms a shallow bond.

In the above-described embodiments of the present invention, the p ⁺ type was mainly described, but a shallow junction can be obtained by the same steps in forming the n ⁺ type source / drain.

[0011]

As described above, in the method of forming the source / drain of the shallow junction according to the present invention, since the high temperature heat treatment can be applied to the heat treatment for activating boron, the damage of the substrate due to the impurity implantation is compensated. It is possible to reduce the leakage current required for a device of micron class or less.

[Brief description of drawings]

FIG. 1 is a diagram showing a conventional p ⁺ type source / drain forming method.

FIG. 2 is a diagram showing a first step of another p ⁺ type source / drain forming method according to the prior art.

FIG. 3 is a second method of forming the p ⁺ type source / drain.
The figure which shows a process.

FIG. 4 is a diagram showing a p ⁺ type source / drain formation method according to the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor San Ki Hong Republic of Korea Kyung Kydo Kyung Kun Buvalub Amy Risan 136-1 (72) Inventor Yun Arm Yang South Korea Seoul Sung Pak Bangui Don Olympic Sancheon Apartment 107-903 (72) Inventor Yae Wankok Republic of Korea Kyungkidonnam-Shyeonwonk Yunhaen 1 Dong Hyundai Apartment 101-907 (72) Inventor Ilsung Hyun Korea Seoul Kangdong Sangyil Dong Yukon Apartment 301-405

Claims (2)

[Claims] 1. A method of implanting impurity ions for forming a source / drain into a semiconductor substrate, implanting Ar ⁺ ions under the impurity ion-implanted layer to form an amorphous layer, and then performing heat treatment. And method for forming source / drain of semiconductor device. 2. The method of forming a source / drain according to claim 1, wherein the impurity ions forming the source / drain are either B ₁₁ ions or BF ₂ ions.