KR100668738B1 - Forming method of titanium nitride layer and deposition apparatus of titanium nitride layer - Google Patents

Abstract

The present invention relates to a method for forming a titanium nitride film and an apparatus for depositing a titanium nitride film using an atomic layer deposition method, and a method of forming a titanium nitride film that can significantly improve the deposition rate of a titanium nitride film, and to form a titanium nitride film through such a method. It relates to a deposition apparatus of a titanium nitride film to enable.

The method of forming a titanium nitride film according to the present invention may include forming titanium trichloride (TiCl ₃ ) or titanium hexachloride gas through a reduction reaction with titanium tetrachloride (TiCl ₄ ) gas, and forming the titanium on a predetermined region of the wafer substrate. Supplying a trichloride or titanium hexachloride gas, and reacting the titanium trichloride or titanium hexachloride gas supplied to a predetermined region of the wafer substrate with ammonia gas to form a titanium nitride film.

Titanium nitride film, atomic side deposition method, titanium trichloride, titanium hexachloride

Description

 Formation method of titanium nitride film and deposition apparatus of titanium nitride film TECHNICAL FIELD             

1 is a schematic diagram showing a schematic configuration of a titanium nitride film deposition apparatus according to an embodiment of the present invention.

Brief description of the symbols in the drawing

100 titanium nitride film deposition apparatus 102 first supply pipe

104: opening and closing means of the first supply pipe 106: second supply pipe

108: second supply pipe opening and closing means 110: shower head

The present invention relates to a method for forming a titanium nitride film and an apparatus for depositing a titanium nitride film using an atomic layer deposition method, and a method of forming a titanium nitride film that can significantly improve the deposition rate of a titanium nitride film, and to form a titanium nitride film through such a method. It relates to a deposition apparatus of a titanium nitride film to enable.

As the integration and ultra miniaturization of semiconductor devices progress, the use of titanium nitride films is increasing.

First, the titanium nitride film has traditionally been used as a diffusion barrier layer or a capping film in the case of using aluminum as a wiring material, and has been used as a glue film to increase the adhesive force of the CVD tungsten film. In recent years, the titanium nitride film has been used as a metal electrode in a metal-insulator-metal (MIM) structure introduced to improve the performance of a capacitor in DRAM.

Due to the various uses of the titanium nitride film, a method of depositing and forming such a titanium nitride film may also be divided into various ways. In the case where the titanium nitride film is used together with the aluminum wiring, physical vapor deposition (PVD) is mainly performed. In general, the deposition process is performed through a chemical vapor deposition (CVD) method in consideration of step coverage characteristics when used as a contact hole or a capacitor electrode.

However, in recent years, semiconductor devices have become more highly integrated, and in particular, as the actual size of semiconductor devices has been reduced to 100 nm or less, for example, the aspect ratio of contact holes in which a titanium nitride film is to be deposited has sharply increased. Therefore, when the titanium nitride film is deposited using a general chemical vapor deposition method, sufficient uniformity or step coverage characteristics cannot be secured.

For this reason, conventionally, a method of forming a titanium nitride film through atomic layer deposition (ALD) has been considered. Conventionally, titanium tetrachloride (TiCl ₄ ) gas and ammonia (NH ₃ ) gas are respectively used as raw materials. Using as a gas, a titanium nitride film was formed by the atomic layer deposition method.

In more detail, the conventional titanium nitride film formation process by the atomic layer deposition method, first, by supplying titanium tetrachloride gas for a short time to adsorb these gas molecules to a predetermined region of the wafer substrate, and then to ammonia gas A short time supply is made to react with the adsorbed titanium tetrachloride to form a titanium nitride film. Then, a purge may be performed to remove by-products and the like by the reaction, and a titanium nitride film having a predetermined thickness may be formed by continuously repeating this process.

When the titanium nitride film is formed by the atomic layer deposition method as described above, a titanium nitride film having a substantially improved uniformity can be obtained as compared with the previous physical or chemical vapor deposition method, and in particular, the concentration of chlorine-based impurities in the titanium nitride film can be effectively reduced.

However, according to the conventional method, when the titanium nitride film is formed by the atomic layer deposition method, the deposition rate of the titanium nitride film is too slow as compared with the general physical or chemical vapor deposition method, which is very unsuitable for the semiconductor manufacturing process of the mass production system. It has a fatal drawback.

For this reason, in the formation method of the titanium nitride film using the atomic layer deposition method, the development of the technology which can significantly improve the deposition rate of a titanium nitride film is urgently required.

Accordingly, the present invention is to provide a method of forming a titanium nitride film that can significantly improve the deposition rate of the titanium nitride film in the method of forming a titanium nitride film using the atomic layer deposition method.

In addition, another object of the present invention is to provide an apparatus for depositing a titanium nitride film, which enables the formation of a titanium nitride film through the method of forming a titanium nitride film according to the present invention.

In order to achieve this object, the present invention is to form a titanium trichloride or titanium hexachloride gas through a reduction reaction to the titanium tetrachloride gas, supplying the titanium trichloride or titanium hexachloride gas to a predetermined region of the wafer substrate And reacting the titanium trichloride or titanium hexachloride gas supplied to a predetermined region of the wafer substrate with ammonia gas to form a titanium nitride film.

That is, in the method of forming the titanium nitride film according to the present invention, in the process of forming the titanium nitride film by atomic layer deposition, instead of the conventional titanium tetrachloride gas, titanium trichloride or titanium hexachloride gas produced by reduction thereof is used. It is supplied to a wafer substrate as a raw material gas. However, since the reactivity of the raw material gas of the present invention with the ammonia gas is significantly greater than that of the titanium tetrachloride gas, according to the present invention, the reaction rate between the raw material gases for forming the titanium nitride film is remarkably faster, and eventually, the titanium nitride film. Can significantly improve the deposition rate.

In the method of forming the titanium nitride film according to the present invention, the forming of the titanium trichloride or titanium hexachloride gas may be performed by reacting the titanium tetrachloride gas with titanium.

In the method for forming a titanium nitride film according to the present invention, in the titanium nitride film deposition apparatus for forming a titanium nitride film, the titanium tetrachloride gas is preferably supplied through a titanium metal supply pipe.

In the method of forming the titanium nitride film, the forming of the titanium trichloride or titanium hexachloride gas and the forming of the titanium nitride film are preferably performed at a temperature of 200-500 ° C.

On the other hand, in order to achieve the other object of the present invention, the present invention is made of a titanium metal material and titanium tetrachloride gas flows through the first supply pipe, the gas supply from the first supply pipe to the lower wafer substrate to control Provided is a vapor deposition apparatus of a titanium nitride film including a first supply pipe opening and closing means, a second supply pipe through which ammonia gas flows, and second supply pipe opening and closing means for controlling gas supply from the second supply pipe to a lower wafer substrate. .

That is, by using the titanium nitride film deposition apparatus, it is possible to form a titanium nitride film according to the formation method according to the present invention, it is possible to significantly improve the deposition rate of the titanium nitride film by the atomic layer deposition method.

In the deposition apparatus of the titanium nitride film according to the present invention, the first supply pipe is preferably maintained at a temperature of 200-500 ℃.

In the deposition apparatus of the titanium nitride film, the first supply pipe and the second supply pipe are preferably spaced apart from each other.

Hereinafter, a method of forming a titanium nitride film according to an exemplary embodiment of the present invention will be described in detail. However, this is presented as an example and thereby does not limit the scope of the present invention.

In forming the titanium nitride film according to an embodiment of the present invention, first, titanium trichloride or titanium hexachloride gas is formed by performing a reduction reaction on the titanium tetrachloride gas. This reduction reaction can be carried out by reacting all generally used reducing agents with titanium tetrachloride gas, but preferably by reacting titanium metal with the titanium tetrachloride gas as the reducing agent. In addition, the titanium metal may be separately added and reacted with the titanium tetrachloride gas, but in the titanium nitride film deposition apparatus for forming a titanium nitride film, the titanium tetrachloride gas supply pipe itself is made of a titanium metal material, and thus the titanium tetrachloride Preferably, gas is allowed to react with the titanium metal while passing through the feed duct. This eliminates the need for a separate reaction time, a separate reactant, and the like, thereby improving productivity and yield of the process. As a result of this reduction reaction, titanium trichloride or titanium hexachloride gas is produced by the reaction process shown in Scheme 1 below.

Scheme 1

TiCl ₄ (g) + 1/3 Ti (s)-> 4 / 3TiCl ₃ (g) ΔG (400 ° C) = 6kJ

TiCl ₄ (g) + 1/3 Ti (s)-> 2 / 3Ti ₂ Cl ₆ (g) ΔG (400 ° C.) = -40 kJ

In the reaction of Scheme 1, Gibb's free energy (ΔG) has a small positive value or a negative value, and by this reaction, a certain amount or more of titanium tetrachloride gas is easily reduced, thereby reducing titanium trichloride or titanium hexa. Chloride gas may be produced.

In addition, the reaction is more likely to occur at higher temperatures, so that a greater amount of titanium tetrachloride gas can be reduced to titanium trichloride or titanium hexachloride gas. However, as will be described in more detail below, the titanium trichloride or titanium hexachloride gas has a significantly greater reactivity with the ammonia gas than the titanium tetrachloride gas, so that the titanium nitride film at a faster rate through the reaction with the ammonia gas Since it is possible to form and deposit, the reduction reaction of the titanium tetrachloride gas is more advantageous at higher temperatures. That is, as the reduction occurs at a higher temperature, a raw material gas containing a higher content of highly reactive titanium trichloride or titanium hexachloride gas is supplied onto the wafer substrate, and the reaction rate with the ammonia gas is increased at a higher speed. A titanium nitride film can be deposited. However, when the reduction reaction is carried out at an excessively high temperature, since a hot gas is applied on the wafer substrate, there is a risk of damaging the device or the like on the wafer substrate. Thus, the reduction reaction is preferably performed at a temperature of 200-500 ° C. Do.

Meanwhile, after the titanium trichloride or titanium hexachloride gas is formed through the reduction reaction, the titanium trichloride or titanium hexachloride gas is supplied to a predetermined region of the wafer substrate, that is, the region where the titanium nitride film is to be formed. At this time, if all of the titanium tetrachloride gas was reduced and formed into titanium trichloride or titanium hexachloride gas in the previous reduction process, only such titanium trichloride or titanium hexachloride gas was supplied as raw material gas, but remained partially unreduced. If unreacted titanium tetrachloride gas is present, such titanium tetrachloride gas is fed together in a mixed state with the titanium trichloride or titanium hexachloride gas. However, the higher the content of the titanium trichloride or titanium hexachloride gas in the supply step of the raw material gas is advantageous in terms of the deposition rate of the titanium nitride film as already salping.

Such a raw material gas supply process can be performed similarly to the process of supplying the titanium tetrachloride gas in the prior art except the kind of the gas to be supplied. That is, a source gas such as titanium trichloride or titanium hexachloride gas is supplied for a short time so that each gas molecule in the source gas is adsorbed to a predetermined region of the wafer substrate. Since the specific conditions of the process can be easily determined by those skilled in the art in consideration of various factors, a detailed description thereof will be omitted.

On the other hand, after supplying a raw material gas such as titanium trichloride or titanium hexachloride gas, the titanium trichloride or titanium hexachloride gas is reacted with ammonia gas to form a titanium nitride film on a predetermined region of the wafer substrate. In this process, the titanium trichloride or titanium hexachloride adsorbed to a predetermined region of the wafer substrate reacts with ammonia gas as shown in Scheme 2 below, whereby a titanium nitride film is formed in the region.

Scheme 2

TiCl ₃ (g) + NH ₃ (g)-> TiN (s) + 3HCl (g) ΔG (400 ° C) = -72kJ

Ti ₂ Cl ₆ (g) + 2NH ₃ (g)-> 2TiN (s) + 6HCl (g) ΔG (400 ° C.) = -79 kJ

On the other hand, in order to contrast with the reaction scheme 2, when the titanium tetrachloride gas of the prior art is reacted with ammonia gas to examine the reaction process to form a titanium nitride film as shown in the following scheme 3.

Scheme 3

TiCl ₄ (g) + 8 / 6NH ₃ (g)-> TiN (s) + 4HCl (g) + 1 / 6N ₂ (g) ΔG (400 ° C) = -3kJ

That is, considering that the smaller the Gibbs free energy at the same temperature, the greater the reactivity, the titanium trichloride or titanium hexachloride gas as compared to the titanium tetrachloride gas of the prior art, as clearly shown in Schemes 2 and 3 The reactivity with ammonia gas is so high that it is possible to form a titanium nitride film at a high speed.

On the other hand, the reaction shown in Scheme 2 may also occur as the temperature increases, the formation process of the titanium nitride film is also advantageous as the progress at a high temperature. That is, as the reaction process proceeds at a high temperature, the titanium nitride film may be deposited at a faster rate by increasing the reactivity between the titanium trichloride or titanium hexachloride gas and the ammonia gas.

However, the fact that the titanium trichloride or titanium hexachloride gas is already supplied at a relatively high temperature of about 200-500 ° C. in the previous reduction process, and that higher temperatures may cause damage to the device on the wafer substrate, etc. Considering the facts, it is preferable that the formation process of the titanium nitride film proceed at a temperature of about 200-500 ° C. as in the reduction process.

After the titanium nitride film is formed, a purge may be performed to remove by-products and the like by the reaction process as in the prior art, and the titanium nitride film having a predetermined thickness may be formed by repeatedly repeating the process.

That is, according to the method of forming the titanium nitride film according to the present invention, by using the titanium trichloride or titanium hexachloride gas having a high reactivity with ammonia gas as a raw material gas, the atomic layer deposition on the titanium nitride film is carried out, the prior art Compared to the above, the titanium nitride film can be formed on a predetermined region of the wafer substrate at a considerably faster speed.

Next, the configuration of the titanium deposition apparatus according to an embodiment of the present invention with reference to the accompanying drawings will be described in detail.

1 is a schematic diagram showing a schematic configuration of a titanium nitride film deposition apparatus according to an embodiment of the present invention.

The titanium nitride film deposition apparatus 100 (hereinafter, abbreviated as "deposition apparatus") firstly includes a first supply pipe 102 connected through an upper surface of the deposition apparatus 100. The first supply pipe 102 is made of a titanium metal material and titanium tetrachloride gas flows inside.

Inside this first feed canal 102, the titanium tetrachloride gas reacts with the titanium metal forming the first feed canal 102, thereby reducing the titanium tetrachloride gas to titanium trichloride or titanium hexachloride gas. do. In addition, the titanium trichloride or titanium hexachloride gas may be supplied onto the lower wafer substrate through the first supply pipe 102 during the deposition process of the titanium nitride film.

On the other hand, the first supply pipe 102 is preferably maintained at a temperature of 200-500 ℃ so that the reduction process of the titanium tetrachloride gas can be carried out at a temperature of 200-500 ℃.

In addition, the deposition apparatus 100 includes a first supply pipe opening and closing means 104 for controlling gas supply from the first supply pipe 102 to the lower wafer substrate. The first supply pipe opening and closing means 104 is formed on the outlet side of the first supply pipe 102 inside the deposition apparatus 100 to control the opening and closing of the first supply pipe 102 and thus the first supply pipe 102. Gas supply to the lower wafer substrate is controlled.

The vapor deposition apparatus 100 separates the ammonia gas from the first supply pipe 102 and the first supply pipe opening / closing means 104 for supplying the titanium trichloride or titanium hexachloride gas and the like on the wafer substrate. And a second supply pipe 106 and a second supply pipe opening and closing means 108 for supplying the gas.

The second supply pipe 106 also has an ammonia gas flowing therein, and is formed to penetrate the upper surface of the deposition apparatus 100. In addition, the gas supply from the second supply pipe 106 to the lower wafer substrate is controlled by the second supply pipe opening and closing means 108 that is formed at the outlet side of the second supply pipe 106 and opens and closes it.

Meanwhile, in the titanium nitride film deposition apparatus 100, the first supply pipe 102 and the second supply pipe 106 are preferably spaced apart from each other. That is, since the first supply pipe 102 and the second supply pipe 106 are spaced apart in this manner, the ammonia gas and the titanium trichloride or titanium hexachloride gas can be prevented from reacting before reaching the wafer substrate.

In addition, the deposition apparatus 100 according to the present embodiment may separately include a shower head 110 connected to the first supply pipe 102 and the second supply pipe 106. Such a showerhead 110, for example, when the first supply pipe opening and closing means 104 is opened to flow the titanium trichloride or titanium hexachloride gas from the first supply pipe 102 to the lower wafer substrate It can be supplied evenly over a predetermined region of.

That is, by using the vapor deposition apparatus having the above-described configuration, titanium trichloride or titanium hexachloride gas and ammonia gas are respectively supplied on the wafer substrate as a raw material gas, and the titanium nitride film at high speed according to the titanium nitride film forming method of the present invention. Can be deposited.

According to the present invention, since the deposition rate of the titanium nitride film by the atomic layer deposition method can be significantly improved, it is possible to take advantage of the atomic layer deposition method and to make it suitable for mass production systems of semiconductor devices.

Therefore, excellent productivity can be obtained while maintaining the advantages of the atomic layer deposition method such as the excellent uniformity of the titanium nitride film in the mass production of the semiconductor device, which can greatly contribute to the high integration of the semiconductor device.

Claims (7)

Reacting titanium tetrachloride gas with titanium to form titanium trichloride or titanium hexachloride gas, Supplying said titanium trichloride or titanium hexachloride gas to a predetermined region of a wafer substrate, and And reacting titanium trichloride or titanium hexachloride gas supplied to a predetermined region of the wafer substrate with ammonia gas to form a titanium nitride film. delete The method of claim 2, In the titanium nitride film deposition apparatus for forming a titanium nitride film, the titanium tetrachloride gas is supplied through a supply pipe made of titanium metal material. The method according to claim 1 or 2, The forming of the titanium trichloride or titanium hexachloride gas and the forming of the titanium nitride film may be performed at a temperature of 200-500 ° C. A first feed pipe made of titanium metal and having titanium tetrachloride gas therein; First supply pipe opening and closing means for controlling gas supply from the first supply pipe to a lower wafer substrate, A second supply pipe through which ammonia gas flows, and And a second supply pipe opening / closing means for controlling gas supply from the second supply pipe to the lower wafer substrate. The method of claim 5, The first supply pipe is a deposition apparatus of a titanium nitride film is maintained at a temperature of 200-500 ℃. The method of claim 5, The first supply pipe and the second supply pipe is a vapor deposition apparatus of the titanium nitride film is installed spaced apart.

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