KR100210897B1 - Process for forming barrier metal layer in semiconductor device - Google Patents

Abstract

The present invention forms a TiN _x O _y layer using an N ₂ O plasma to prevent an increase in contact resistance due to excessive oxygen filling, and to prevent junction breakage caused by the interdiffusion of aluminum and silicon. Disclosed is a method of forming a metal diffusion barrier layer of a semiconductor device capable of improving productivity and increasing productivity by omitting a subsequent heat treatment step using a reactor or RTP equipment.

Description

Method for forming metal diffusion barrier layer of semiconductor device

1 (a) to 1 (c) are cross-sectional views of a device for explaining a method for forming a metal diffusion barrier layer of a semiconductor device according to the present invention.

* Explanation of symbols for main parts of the drawings

1 silicon substrate 2 junction region

3: insulating film 4A: Ti film

4B: TiN film 5: TiN _x O _y layer

6: aluminum metal layer 7: contact hole

The present invention relates to a method for forming a metal diffusion barrier layer of a semiconductor device, and more particularly to a method for forming a metal diffusion barrier layer of a semiconductor device to form a TiN _x O _y layer using N ₂ O plasma.

In general, in forming a metal layer of a semiconductor device, a Ti film and a TiN film are deposited and used as a diffusion barrier layer in order to prevent a junction spiking phenomenon caused by mutual diffusion of aluminum and silicon. In addition, after the TiN film is deposited to enhance the barrier properties, the barrier properties due to oxygen filling are improved by performing heat treatment using a reactor or a rapid heat treatment apparatus. When heat treatment by the above method 450 700 The barrier effect is improved by oxygen filling by performing heat treatment in between. However, during oxygen filling, not only oxygen penetration into the thin film inside the TiN film but also resistance due to oxygen penetration into the bonding region and oxidation of the Ti film due to diffusion of oxygen Controlling the amount of oxygen is very important when filling the oxygen as it leads to an increase. For this reason, as the device is highly integrated, as the two-step metal deposition and remelting methods introduced to improve the metal layer covering are introduced, more excellent barrier characteristics are required. Due to a poor layer covering of the TiN film due to a decrease in contact size and an increase in step ratio, there are disadvantages of deterioration of barrier properties and productivity.

Therefore, in order to solve the above-mentioned disadvantages, the present invention deposits Ti and TiN films, and then fills oxygen inside the TiN film, and continuously forms the TiN film surface using nitrogen and oxygen groups using N ₂ O plasma at low temperature. _It is an object of the present invention to provide a method for forming a diffusion barrier layer of a semiconductor device capable of forming a _x O _y layer.

The present invention for achieving the above object is formed by etching a selected region of the insulating film formed on the silicon substrate to form a contact hole for exposing the junction region formed on the silicon substrate, and over the entire structure including the contact hole Sequentially depositing a Ti film and a TiN film, and forming a TiN _x O _y layer by using an N ₂ O plasma over the entire structure, and then forming an aluminum metal layer.

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

1 (a) to 1 (c) are cross-sectional views of a device for explaining a method for forming a diffusion barrier layer of a semiconductor device according to the present invention.

Referring to FIG. 1A, after the N ⁺ or P ⁺ ions are implanted into the silicon substrate 1 to form the junction region 2, the insulating film 3 is deposited. An etching process using a contact mask is performed on the entire structure to form a contact hole 7. A Ti film 4A and a TiN film 4B, which are diffusion preventing layers, are deposited on the entire structure including the contact hole 7. Ti film 4A and TiN film 4B are deposited by a reactive sputtering method.

Referring to FIG. 1 (b), an N ₂ O plasma is generated using RF power continuously in the same chamber or another chamber as the Ti film and the TiN film deposition chamber, thereby forming a TiN _x O _y layer 5 over the entire structure. Is formed. Here, the total RF power applied is 1 1.5 kW, and a dual RF frequency is used to facilitate the decomposition of the N ₂ O gas. At this time, the high frequency is 13.56MHz RF frequency is used, power is 300W 1 kW is used. Low frequency is 300 RF frequency of 400kHz is used, power is 300W 800 W is used. In addition, the ratio of low frequency to total power is 50% or more. And the temperature of the reaction chamber is 100 450 Shall be. When the reaction occurs under the above conditions, decomposition occurs by N ₂ O gas or RF power, and the plasma state. At this time, the generated oxygen group is excellent in reactivity, and thus it is possible to form the TiN _x O _y layer 5 _by reacting with the TiN film 4B even at a low temperature.

FIG. 1C is a cross-sectional view of the aluminum metal layer 6 formed on the entire structure.

As described above, according to the present invention, it is possible to prevent the increase of contact resistance due to excessive oxygen filling by forming a TiN _x O _y layer by using an N ₂ O plasma, and to prevent the bonding failure caused by the mutual diffusion of aluminum and silicon. In this way, the reliability of the metal wiring can be improved, and productivity can be increased by omitting a subsequent heat treatment step using a reactor or RTP equipment.

Claims (6)

Etching a selected region of the insulating film formed on the silicon substrate to form a contact hole exposing a junction region formed on the silicon substrate, and sequentially depositing a Ti film and a TiN film over the entire structure including the contact hole And forming a TiN _x O _y layer by using an N ₂ O plasma on the entire structure, and then forming an aluminum metal layer. The method of claim 1, wherein the TiN _x O _y layer is formed by applying RF power of 1 to 1.5 kW. The method of claim 1, wherein the TiN _x O _y layer is formed by applying a high frequency of 13.56 MHz through RF power of 300 W to 1 kW. 2. The method of claim 1, wherein the TiN _x O _y layer is formed by applying a low frequency of 300 to 400 kHz through an RF power of 300 W to 800 W. 3. The method of claim 2, wherein the ratio of the low frequency to the total RF power is 50% or more. The method of claim 1, wherein the TiN _x O _y layer is 100 to 450 The metal diffusion barrier layer forming method of a semiconductor device, characterized in that formed at a temperature of.