KR19990002649A - Manufacturing Method of Semiconductor Device - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a method for depositing a tungsten silicide layer.

2. The technical problem to be solved by the invention

When depositing tungsten silicide layer by DCS process, Cl ions of dichlorosilance (SiH ₂ Cl ₂ ) gas, which is used as reducing agent, is exposed to air outside the equipment and reacts with hydrogen components such as moisture in the air. This causes milky haze, making it difficult to follow the photo process or changing the properties of the tungsten silicide layer.

3. Summary of Solution to Invention

When depositing tungsten silicide layer by DCS process, it is treated with monosilane and hydrogen compound to remove chlorine (Cl) component which is a source of haze.

4. Important uses of the invention

Tungsten silicide layer formation process in semiconductor devices.

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 forming a tungsten silicide layer of a semiconductor device.

The tungsten silicide layer (WSi _x ) is used to replace polysilicon to improve the resistance of the device. In general, the tungsten silicide layer is deposited by reducing the monosilane (SiH ₄ ) to tungsten fl (WF ₆ ) and dichlorosilance (SiH ₂ Cl ₂ ) to tungsten flor. Deposited by a DCS process. However, since all of these processes use tungsten fl as the reducing gas of the silicon-source gas, the deposited tungsten silicide layer is 10 ¹⁶ to 10 ¹⁷ ions / cm 3 for the DCS process and 10 ¹⁹ to 10 ²⁰ ions / for the MS process. Fluorine (F) is contained at a concentration of cm 3. Therefore, DCS process with low fluorine content and good step coverage has been favored in the recent device applications.

However, in depositing tungsten silicide layer by DCS process, dichloroxylene gas, which is used as reducing agent, is exposed to the outside of equipment after completion of deposition process and reacts with hydrogen components such as moisture in air in clean room to make milky color. Causes haze. The occurrence of such haze makes it difficult to make subsequent photo processes or to change its own characteristics of the tungsten silicide layer. Meanwhile, deionized water rinsing and scrubbing are performed in order to remove such haze. However, there is a disadvantage in that process cost and time increase.

Accordingly, the present invention is to suppress the haze phenomenon caused by the exposure of dichloroxylene used as a reducing agent in the air in the deposition of tungsten silicide layer by the DCS process in the semiconductor manufacturing process to ensure that the subsequent process proceeds well have.

In the method of manufacturing a semiconductor device according to the present invention for achieving the above object, in the process of depositing a tungsten silicide layer on the underlayer by a DCS process, chlorine ions and fluorine inside the tungsten silicide layer by flowing monosilylene gas Removing ions and depositing silicon decomposed in the monosilylene gas on the tungsten silicide layer.

1 (a) and 1 (b) are cross-sectional views sequentially shown for explaining the method of manufacturing a semiconductor device according to the present invention.

Explanation of symbols for the main parts of the drawings

11 silicon substrate 12 polysilicon layer

13 tungsten silicide layer 14 silicon layer

The present invention will be described in detail with reference to the accompanying drawings.

1 (a) and 1 (b) are cross-sectional views sequentially shown to explain a method of manufacturing a semiconductor device according to the present invention.

FIG. 1A is a cross-sectional view of sequentially depositing a polysilicon layer 12 and a tungsten silicide layer 13 having a tungsten polyside structure on the silicon substrate 11. The tungsten silicide layer 13 is deposited by a DCS process. When the chlorine component of the dichloroxylene gas used as the source gas is exposed to air, the tungsten silicide layer 13 reacts with the hydrogen component to generate a haze phenomenon.

During the deposition of the tungsten silicide layer 13, when a monosilylene gas containing hydrogen is flowed, the monosilylene gas is decomposed into hydrogen and silicon in a CVD reaction chamber of 550 ° C. or higher. The hydrogen component of is reacted with the chlorine component of the tungsten silicide layer 13 to form HCl to remove the chlorine component of the tungsten silicide layer 13. In addition, the silicon component of the decomposed monosilicon is partially deposited on the tungsten silicide layer 13 or formed of SiF ₄ by reacting with the fluorine component of the tungsten silicide layer 13 to form a fluorine component of the tungsten silicide layer 13. Remove Therefore, the electrical properties of the gate oxide film can be improved by reducing the diffusion of fluorine when applied to the gate, and the deposited silicon layer 14 is a buffer layer against stress change of the tungsten silicide layer 13. Can play a role and contribute to thermal stability.

FIG. 1B is a cross-sectional view of the silicon layer 14 laminated on the tungsten silicide layer 13. In this process, even if a hydrogen compound gas is used instead of monosilylene gas, the chlorine component of the tungsten silicide layer 13, which is a source of haze, can be removed.

Therefore, when the monosilene and hydrogen compound gas are flowed two or three times and the deposition process of the tungsten silicide layer 13 is carried out, not only the chlorine component but also the fluorine component of the tungsten silicide layer 13 which causes haze is removed. Therefore, when applied to the gate can improve the characteristics of the gate.

As described above, according to the present invention, by flowing a gas of a hydrogen compound, chlorine ions present in the tungsten silicide layer are removed to prevent haze, and the fluorine component is removed and the silicon layer is deposited to improve the electrical characteristics of the device and thermal stability. Can contribute to

Claims (5)

In the process of depositing a tungsten silicide layer on the underlayer by a DCS process, flowing a monosilylene gas to remove chlorine ions and fluorine ions in the tungsten silicide layer, And depositing silicon decomposed in the monostyrene gas on the tungsten silicide layer. The method of claim 1, The DCS process is a method for manufacturing a semiconductor device, characterized in that carried out at a reaction temperature of 550 ℃ or more. The method of claim 1, The chlorine ion is removed in the form of HCl by reacting with the hydrogen component of the monostyrene gas. The method of claim 1, The fluorine ion is removed in the form of SiF _{4 by} reacting with the silicon component of the monostyrene gas. The method of claim 1, A method of manufacturing a semiconductor device, characterized in that chlorine ions in the tungsten silicide layer are removed using a hydrogen compound gas instead of the monosilylene gas.