KR20050109036A - Method of manufacturing a metal silicate layer using atomic layer deposition technique - Google Patents

Abstract

Provided are methods for forming metal silicate films using atomic layer deposition techniques. These methods perform at least one metal silicate film formation cycle to form the metal silicate film of a desired thickness. The metal silicate film forming cycle includes repeating the metal oxide film forming cycle K times and repeating the silicon oxide film forming cycle Q times. K and Q are each an integer of 1 or more and 10 or less. The metal oxide film forming cycle includes injecting a metal raw material gas, purging the metal raw material gas remaining in the reactor to purify the inside of the reactor, injecting oxidizing gas into the reactor, and purifying the inside of the reactor. . The silicon oxide film forming cycle includes injecting a silicon raw material gas, purging the silicon raw material gas remaining in the reactor to purify the inside of the reactor, injecting oxidizing gas into the reactor, and purifying the inside of the reactor. .

Description

Method of manufacturing a metal silicate layer using atomic layer deposition technique

The present invention relates to a method for forming a thin film of a semiconductor device, and more particularly to a method for forming a metal silicate film using atomic layer deposition technology.

As the semiconductor device needs to be highly integrated, its components, transistors and capacitors, should be miniaturized as much as possible. The transistor and the capacitor have a dielectric film. There are various difficulties faced by reducing the size and thickness of the dielectric film.

For example, when the thickness of the gate dielectric layer, which is a component of the transistor, is made thin, the insulating property of the gate dielectric layer is reduced. As the film forming material of the gate dielectric film, a silicon oxide film is widely used. The silicon oxide film has been reported to rapidly increase the leakage current by direct tunneling (gate tunneling) at the gate electrode when the thickness is reduced to less than 15Å. As a method of overcoming such a problem, researches on high-k dielectric films having a larger dielectric constant and less leakage current than the silicon oxide films have been actively conducted.

Recently, a metal silicate film, such as a hafnium silicate (HfSiO _X ) film, has been proposed as the high dielectric film. The metal silicate film has excellent carrier mobility compared to other high dielectric films when applied to a transistor. .

Conventional methods for forming the metal silicate film include physical vapor deposition (PVD) and chemical vapor deposition (CVD). As is well known, the physical vapor deposition method has a disadvantage of poor step coverage and poor interface characteristics with a silicon substrate. The chemical vapor deposition method has a high thin film formation temperature, there is a limit to precisely control the thickness by several Å units, and difficult to control the composition ratio in the thin film, which is not suitable for the highly integrated device.

Atomic layer deposition (ALD) technology has been studied as a method of forming the metal silicate film which overcomes the limitations of the physical vapor deposition method and the chemical vapor deposition method and has a small thickness in atomic layer units. The atomic layer deposition technology is a method of time-dividing and supplying an independent pulse form without simultaneously supplying source gases for forming a thin film. The supply of the gases is performed by opening and closing the valves provided in the respective gas pipes at a time difference, so that the respective gases are supplied into the reactor at a time difference without mixing. When the gases are time-divided and supplied at a predetermined flow rate, it is common to supply a purge gas every time the gases are supplied to remove the remaining gas from the reactor without reacting. The atomic layer deposition technique has an excellent step coverage, can form a thin film of uniform thickness on a large area substrate, and finely control the thickness of the thin film by controlling the number of repetitions. have.

The method for forming a metal silicide film using the atomic layer deposition technique is described in US Patent Publication No. 2003-0031793, which describes a method for depositing a film having a relative high dielectric constant on a substrate. SUBSTRATE), as disclosed by Cheng et al.

According to the U.S. Patent Publication No. 2003-0031793, an aluminum oxide film (Al ₂ O ₃ ), a tantalum oxide film (Ta ₂ O ₅ ), a hafnium oxide film (HfO ₂ ), or a metal silicate film, zirconium, which is a metal oxide film, is disposed on a semiconductor substrate. A silicate film (SiZrO ₄ ), a hafnium silicate film (SiHfO ₄ ), and the like are formed. More specifically, the semiconductor substrate is loaded into the reactor. The first precursor is supplied to the entire surface of the substrate and then purged. Oxidizing gases such as oxygen, water vapor, and nitrous oxide (N ₂ O) are used to oxidize the first precursor adsorbed on the entire surface of the substrate. The process is carried out repeatedly until an appropriate thickness is formed. The second precursor is supplied to the entire surface of the substrate and then purged. An oxidizing gas such as oxygen, water vapor or nitrous oxide (N ₂ O) is used to oxidize the second precursor adsorbed on the entire surface of the substrate. The process is repeated until a metal silicate film of appropriate thickness is formed.

Another method of forming the metal silicide film has been disclosed in Japanese Patent Laid-Open No. 2003-347298 entitled "Method of Manufacturing Semiconductor Device and Substrate Processing Apparatus".

According to Japanese Laid-Open Patent Publication No. 2003-347298, high-k dielectric films including a hafnium silicate film (SiHfO ₄ ) are prepared. More specifically, the first film forming raw material is supplied to the upper portion of the semiconductor substrate and then purged. RPO (Oxidation by Remote-Plasma) process of supplying oxygen radicals on a substrate is performed. The above steps are repeatedly performed any number of times. After supplying a second source gas to the entire surface of the resultant, film formation is performed. RPO (Oxidation by Remote-Plasma) process of supplying oxygen radicals on a substrate is performed. The above process is repeatedly performed any number of times to form a thin film.

When forming the metal silicate film by the method disclosed in the above-mentioned US Patent Publication No. 2003-0031793 and Japanese Patent Laid-Open No. 2003-347298, the silicon oxide gas is supplied after repeating the metal oxide film forming step any number of times. The steps are taken. Generally, the silicon source gas has a chemically stable structure with respect to the metal oxide film. Accordingly, a technique for converting the metal oxide film into a metal silicate film using the silicon source gas is subject to a number of constraints. For example, if the silicon source gas is supplied after the metal oxide film forming step is repeated 10 times or more, the metal oxide film is very difficult to be converted into a metal silicate film. That is, the silicon oxide film is separated and laminated on the metal oxide film, or the silicon oxide film forming reaction does not occur on the metal oxide film.

SUMMARY OF THE INVENTION The present invention has been made in an effort to improve the above-described problems of the prior art, and to provide a metal silicate film forming method capable of controlling the thickness slightly and adjusting the composition ratio of metal and silicon.

Another technical problem to be achieved by the present invention is to provide a method for forming a hafnium silicate film which can control the thickness slightly and adjust the composition ratio of hafnium and silicon.

In order to achieve the above technical problem, the present invention provides methods for forming a metal silicate film using an atomic layer deposition technique. These methods include loading a substrate into a reactor and injecting a metal source gas into the reactor with the substrate to form a chemisorption layer containing the metal on the substrate. An oxidizing gas is injected into the reactor to react with the chemisorption layer containing the metal to form a metal oxide film on the substrate. Injecting the metal raw material gas to forming the metal oxide film is repeated K times. A silicon source gas is injected into the reactor to form a chemisorption layer containing the silicon on the substrate having the metal oxide film. An oxidizing gas is injected into the reactor to react with the metal oxide film and the chemical adsorption layer containing the silicon to form a metal silicate film. Injecting the silicon source gas to forming the metal silicate film is repeated Q times. Injecting the metal raw material gas to forming the metal silicate film at least once to form a metal silicate film having a desired thickness.

In some embodiments, the method may further include purifying the reactor after injecting the gases. Specifically, after the chemical adsorption layer containing the metal is formed, the metal source gas remaining in the reactor may be discharged to purify the inside of the reactor. After the metal oxide film is formed, the inside of the reactor may be purified by discharging the oxidizing gas and the reaction byproduct remaining in the reactor. After forming the chemical adsorption layer containing the silicon, the silicon source gas remaining in the reactor may be discharged to purify the inside of the reactor. After the metal silicate film is formed, the inside of the reactor may be purified by discharging the oxidizing gas and the reaction byproduct remaining in the reactor. A purge gas may be injected into the reactor to discharge the gases and the reaction byproducts. As the purge gas, an inert gas such as argon (Ar), helium (He), or nitrogen (N ₂ ) is generally used.

Preferably, the K times and the Q times are each one selected from one to ten times. For example, K may be 2 or more and 5 or less and Q may be 1. When the K times is 10 or more times, the metal oxide film formed in the metal oxide film forming step has a stable chemical state. The metal oxide film having the stable chemical state makes it difficult to form the metal silicate film. In addition, when the Q cycle is performed 10 times or more, the chemical adsorption layer containing the silicon is not formed on the metal silicate film even when the silicon raw material gas is supplied. In other words, the metal silicate film is no longer formed even if the Q is performed 10 times or more. The metal silicate film may be represented by the formula M _x Si _1-x O ₂ . Here, M may be one selected from the group consisting of Hf, Zr, and Ti, wherein "x" represents a composition ratio of the metal material. By combining the K times and the Q times, the "x" may be adjusted to be 0.10 to 0.95. More preferably, the "x" may be adjusted to be 0.65 to 0.85. That is, the metal silicate film having a desired composition ratio may be formed on the substrate by adjusting the K times and the Q times.

The present invention also provides methods for forming a hafnium silicate film using an atomic layer deposition technique. The hafnium silicate film forming methods include loading a substrate into a reactor, and adding TEMAH {tetrakis (ethylmethylamino) hafnium into the reactor having the substrate; Injecting Hf [N (CH₃) C₂H ₅ ] 주입} gas to form a chemisorption layer containing hafnium (Hf) on the substrate. An oxidizing gas is injected into the reactor to react with a chemisorption layer containing hafnium (Hf) to form a hafnium (Hf) oxide film on the substrate. Injecting the TEMAH gas to forming the hafnium (Hf) oxide film is repeated K times. HCD (hexachlorodisilane; Si ₂ Cl ₆ ) gas is injected into the reactor to form a chemisorption layer containing silicon on a substrate having the hafnium (Hf) oxide film. An oxidizing gas is injected into the reactor to react with the hafnium (Hf) oxide film and the chemical adsorption layer containing the silicon to form a hafnium silicate (Hf _x Si _1-x O ₂ ) film. Injecting the HCD gas to forming the hafnium silicate film is repeated Q times. Injecting the TEMAH gas to forming the hafnium silicate film at least once to form a hafnium silicate film of a desired thickness.

In some embodiments, the method may further include purifying the reactor after injecting the gases. Specifically, after forming the chemisorption layer containing the hafnium (Hf), it is possible to purify the inside of the reactor by discharging the TEMAH gas remaining in the reactor. After forming the hafnium (Hf) oxide film, the inside of the reactor may be purified by discharging the oxidizing gas and the reaction by-products remaining in the reactor. After forming the chemical adsorption layer containing the silicon, the HCD gas remaining in the reactor may be discharged to purify the inside of the reactor. After the hafnium silicate film is formed, the inside of the reactor may be purified by discharging the oxidizing gas and the reaction by-products remaining in the reactor.

Preferably, the K times and the Q times are each one selected from one to ten times. For example, K may be 2 or more and 5 or less and Q may be 1. When the K times is 10 or more times, as described above, the hafnium oxide film formed in the hafnium oxide film forming step has a stable chemical state. The hafnium oxide film having the stable chemical state makes it difficult to form the hafnium silicate film. In addition, when the Q cycle is performed 10 times or more, even if the HCD (hexachlorodisilane; Si ₂ Cl ₆ ) gas is supplied on the hafnium silicate film, the chemical adsorption layer containing the silicon is not formed. In other words, the hafnium silicate film is no longer formed even if the Q is performed 10 times or more. The hafnium silicate film may be represented by the formula Hf _x Si _1-x O ₂ . Here, "x" represents the composition ratio of the hafnium (Hf) element. By combining the K times and the Q times, the "x" may be adjusted to be 0.10 to 0.95. More preferably, the "x" may be adjusted to be 0.65 to 0.85. That is, the hafnium silicate (Hf _x Si _1-x O ₂ ) having a desired composition ratio on the substrate by adjusting the K times and the Q times. A film can be formed.

In addition, the present invention provides other methods of forming the hafnium silicate film. The other methods load a substrate into a reactor and include TEMAH {tetrakis (ethylmethylamino) hafnium in a reactor with the substrate; Injecting Hf [N (CH₃) C₂H ₅ ] 주입} gas to form a chemisorption layer containing hafnium (Hf) on the substrate. An oxidizing gas is injected into the reactor to react with a chemisorption layer containing hafnium (Hf) to form a hafnium (Hf) oxide film on the substrate. Injecting the TEMAH gas to forming the hafnium (Hf) oxide film is repeated K times. TDMAS {tris (dimethylamino) silane; [(CH ₃ ) ₂ N] ₃ SiH} gas is injected to form a chemisorption layer containing silicon on the substrate having the hafnium (Hf) oxide film. An oxidizing gas is injected into the reactor to react with the hafnium (Hf) oxide film and the chemical adsorption layer containing the silicon to form a hafnium silicate (Hf _x Si _1-x O ₂ ) film. The TDMAS {tris (dimethylamino) silane; Injecting [(CH ₃ ) ₂ N] ₃ SiH} gas to forming the hafnium silicate film is repeated Q times. Injecting the TEMAH gas to forming the hafnium silicate film at least once to form a hafnium silicate film of a desired thickness.

In some embodiments, the method may further include purifying the reactor after injecting the gases. Specifically, after forming the chemisorption layer containing the hafnium (Hf), it is possible to purify the inside of the reactor by discharging the TEMAH gas remaining in the reactor. After forming the hafnium (Hf) oxide film, the inside of the reactor may be purified by discharging the oxidizing gas and the reaction by-products remaining in the reactor. After forming the chemisorbent layer containing the silicon, the TDMAS {tris (dimethylamino) silane remaining in the reactor; [(CH ₃ ) ₂ N] ₃ SiH} gas may be discharged to purify the inside of the reactor. After the hafnium silicate film is formed, the inside of the reactor may be purified by discharging the oxidizing gas and the reaction by-products remaining in the reactor.

Preferably, the K times and the Q times are each one selected from one to ten times. For example, K may be 1 or more and 3 or less and Q may be 1. When the K times is 10 or more times, as described above, the hafnium oxide film formed in the hafnium oxide film forming step has a stable chemical state. The hafnium oxide film having the stable chemical state makes it difficult to form the hafnium silicate film. In addition, when the Q cycle is performed 10 times or more, the TDMAS {tris (dimethylamino) silane; Even when the [(CH ₃ ) ₂ N] ₃ SiH} gas is supplied, the chemisorption layer containing the silicon is not formed. In other words, the hafnium silicate film is no longer formed even if the Q is performed 10 times or more. The hafnium silicate film may be represented by the formula Hf _x Si _1-x O ₂ . Here, "x" represents the composition ratio of the hafnium (Hf) element. By combining the K times and the Q times, the "x" may be adjusted to be 0.10 to 0.95. More preferably, the "x" may be adjusted to be 0.65 to 0.85. That is, the hafnium silicate (Hf _x Si _1-x O ₂ ) having a desired composition ratio on the substrate by adjusting the K times and the Q times. A film can be formed.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed contents are thorough and complete, and that the spirit of the present invention to those skilled in the art will fully convey.

1 is a process flow chart showing a method for forming a metal silicate film by an atomic layer deposition technique according to the present invention, Figure 2 is a block diagram showing a deposition cycle of the metal silicate film forming method using an atomic layer deposition technique according to the present invention. .

1 and 2, a method for forming a metal silicate film according to embodiments of the present invention includes loading a substrate into a reactor of an atomic layer deposition apparatus (step 5 of FIG. 1).

The reactor may be single or batch. The substrate may be a semiconductor substrate such as a silicon substrate, and an isolation layer may be formed on the substrate. In addition, a three-dimensional structure such as a lower electrode of a cylindrical capacitor may be formed on the substrate.

The reactor interior is heated to a temperature suitable for the process. For example, a suitable temperature for the process can be 250 ℃ to 600 ℃.

The metal oxide film forming cycle 10 is repeated K times on the substrate to form a metal oxide film having a desired thickness. The metal oxide film forming cycle 10 injects a metal source gas (step 11 of FIG. 1), discharges the metal source gas remaining in the reactor to purify the inside of the reactor (step 13 of FIG. 1), and the reactor Injecting an oxidizing gas (step 15 of FIG. 1), and purifying the inside of the reactor (step 17 of FIG. 1).

Specifically, the metal source gas is injected into the reactor loaded with the substrate (step 11 of FIG. 1). The metal source gas is a material having an MX ₄ structure, wherein M is one selected from the group consisting of Hf, Zr, and Ti, and X may be one selected from the group consisting of F, Cl, Br, and I. In addition, the metal source gas is a material having a M (NRR ') ₄ structure, M is one selected from the group consisting of Hf, Zr and Ti, R is in the group consisting of H, Me, Et and ⁱ Pr The R 'may be one selected from the group consisting of H, Me, Et, and ⁱ Pr. In addition, the metal raw material gas is TEMAH {Tetrakis (ethylmethylamino) hafnium; Hf [N (CH₃) C₂H ₅ ] ₄}. For example, when the TEMAH is injected, the pulse time for supplying the metal source gas may be 0.2 to 2 seconds. As a result, a chemisorption layer containing the metal is formed on the surface of the substrate. After the chemisorbent layer containing the metal is formed, the metal source gas remaining in the reactor is discharged to purify the inside of the reactor (step 13 of FIG. 1). In order to discharge the metal source gas, a purge gas may be injected into the reactor. As the purge gas, an inert gas such as argon (Ar), helium (He), or nitrogen (N ₂ ) is generally used. The oxidizing gas is then injected into the reactor (step 15 of FIG. 1). The oxidizing gas may be at least one selected from the group consisting of oxygen (O ₂ ), ozone (O ₃ ), water (H ₂ O), and hydrogen peroxide (H ₂ O ₂ ). As a result, the chemisorption layer and the oxidizing gas react to form the metal oxide film on the substrate. Next, the oxidizing gas remaining in the reactor and by-products generated by the reaction between the chemisorption layer and the oxidizing gas are discharged to purify the inside of the reactor (step 17 of FIG. 1). A purge gas may be injected into the reactor to discharge the oxidizing gas and the reaction byproduct. As the purge gas, an inert gas such as argon (Ar), helium (He), or nitrogen (N ₂ ) is generally used. Check that the metal oxide film of the desired thickness is formed. The metal oxide film forming cycle 10 is repeated K times until the metal oxide film having a desired thickness is formed on the substrate (step 19 of FIG. 1). Here, said K is an integer of 1 or more and 10 or less. That is, it is preferable that said K times are 1 time or more and 10 times or less.

The silicon oxide film forming cycle 20 is repeated Q times on the substrate having the metal oxide film to form a metal silicate film. The silicon oxide film forming cycle 20 injects a silicon source gas (step 21 of FIG. 1), discharges the silicon source gas remaining in the reactor to purify the inside of the reactor (step 23 of FIG. 1), and the reactor Injecting an oxidizing gas (step 25 of FIG. 1), and purifying the inside of the reactor (step 27 of FIG. 1).

Specifically, the silicon source gas is injected into the reactor (step 21 of FIG. 1). The silicon source gas is a material having a structure of Si _n X ′ _{2n + 2} , wherein n = 1 to 4, and X ′ represents NCO, F, Cl, Br. And I may be one selected from the group consisting of. In addition, the silicon source gas is a material having a structure of Si _n X ' _{2n + 2} O _n-1 , wherein n = 2 ~ 5, X' is NCO, F, Cl, Br And I may be one selected from the group consisting of. In addition, the silicon source gas is a material having a SiX ″ _n (NRR ′) _4-n structure, wherein n = 0 to 3 and X ″ is H, F, Cl, Br. And one selected from the group consisting of I, R is one selected from the group consisting of H, Me, Et and ⁱ Pr, the R 'may be one selected from the group consisting of H, Me, Et and ⁱ Pr. . In another embodiment, the silicon source gas is a material having a structure of NH _n (SiR ″ ₃ ) _3-n , wherein n = 0 to 2, R ″ is H, F, Cl, Br, I, Me, It may be one selected from the group consisting of Et and ⁱ Pr. In another embodiment, the silicon source gas is a material having a SiSX ₂ structure, wherein X may be one selected from the group consisting of F, Cl, Br, and I. In another embodiment, the silicon source gas may be HCD (Hexachlorodisilane; Si ₂ Cl ₆ ). In another embodiment, the silicon source gas is TDMAS {tris (dimethylamino) silane; [(CH ₃ ) ₂ N] ₃ SiH}. As a result, a chemisorption layer containing silicon is formed on the substrate having the metal oxide film. After the chemical adsorption layer containing the silicon is formed, the silicon source gas remaining in the reactor is discharged to purify the inside of the reactor (step 23 of FIG. 1). In order to discharge the silicon source gas, a purge gas may be injected into the reactor. As the purge gas, an inert gas such as argon (Ar), helium (He), or nitrogen (N ₂ ) is generally used. The oxidizing gas is then injected into the reactor (step 25 of FIG. 1). The oxidizing gas may be at least one selected from the group consisting of oxygen (O ₂ ), ozone (O ₃ ), water (H ₂ O), and hydrogen peroxide (H ₂ O ₂ ). For example, when the silicon source gas is the HCD, the oxidizing gas may use H ₂ O. When the silicon source gas is the TDMAS, the oxidizing gas may use ozone (O ₃ ). As a result, the chemisorption layer and the oxidizing gas react to form a silicon oxide film on the substrate. At the same time, the metal oxide film and the silicon oxide film react with each other to form the metal silicate film. Next, the oxidant gas remaining in the reactor and by-products generated by the reaction between the chemisorption layer and the oxidizing gas are discharged to purify the inside of the reactor (step 27 of FIG. 1). A purge gas may be injected into the reactor to discharge the oxidizing gas and the reaction byproduct. As the purge gas, an inert gas such as argon (Ar), helium (He), or nitrogen (N ₂ ) is generally used. It is confirmed whether the metal silicate film having a desired composition ratio is formed. The silicon oxide film formation cycle 20 is repeated Q times until the metal silicate film having the desired composition ratio is formed on the substrate (step 29 in FIG. 1). Here, Q is an integer of 1 or more and 10 or less. That is, it is preferable that the said Q times are 1 time or more and 10 times or less.

In the method for forming the metal silicate film according to the embodiments of the present invention, it is very important that the K times and the Q times do not exceed 10 times, respectively. For example, K may be 2 or more and 5 or less and Q may be 1. More preferably, K is 3 and Q may be 1. When the K times is 10 or more times, the metal oxide film formed in the metal oxide film forming cycle 10 has a stable chemical state. The metal oxide film having the stable chemical state makes it difficult to form the metal silicate film in the silicon oxide film forming cycle 20. That is, the silicon oxide film may be separated and laminated on the metal oxide film having the stable chemical state, or the silicon oxide film forming reaction may not occur due to the metal oxide film having the stable chemical state. In addition, when the Q cycle is performed 10 times or more, the chemical adsorption layer containing the silicon is not formed on the metal silicate film even when the silicon raw material gas is supplied. In other words, the metal silicate film is no longer formed even if the Q is performed 10 times or more. The metal silicate film may be represented by the formula M _x Si _1-x O ₂ . Here, M may be one selected from the group consisting of Hf, Zr, and Ti, wherein "x" represents a composition ratio of the metal material. By combining the K times and the Q times, the "x" may be adjusted to be 0.10 to 0.95. More preferably, the "x" may be adjusted to be 0.65 to 0.85. That is, the metal silicate film having a desired composition ratio may be formed on the substrate by adjusting the K times and the Q times.

As a result, the metal silicate film forming cycle includes repeating the metal oxide film forming cycle 10 times and repeating the silicon oxide film forming cycle 20 times. Subsequently, the thickness of the metal silicate film is checked (step 39 of FIG. 1). The metal silicate film forming cycle is performed at least once until the metal silicate film having a desired thickness is formed on the substrate. That is, the step of repeating the metal oxide film forming cycle 10 times and the step of repeating the silicon oxide film forming cycle 20 times at least once until the metal silicate film having a desired thickness is formed on the substrate. Conduct.

According to some embodiments of the present invention, a hafnium silicate (Hf _x Si _1-x O ₂ ) film may be formed. Referring to FIGS. 1 and 2 again, a method of forming the hafnium silicate (Hf _x Si _1-x O ₂ ) film according to some embodiments of the present invention will be described.

The hafnium silicate film forming method includes loading a substrate into a reactor of an atomic layer deposition apparatus (step 5 of FIG. 1).

The reactor interior is heated to a temperature suitable for the process. For example, a suitable temperature for the process can be 250 ℃ to 600 ℃.

The hafnium (Hf) oxide film formation cycle 10 is repeated K times on the substrate to form a hafnium (Hf) oxide film having a desired thickness. The hafnium (Hf) oxide film forming cycle 10 injects a hafnium (Hf) source gas (step 11 of FIG. 1), discharges the hafnium (Hf) source gas remaining in the reactor, and purifies the inside of the reactor ( Step 13 of FIG. 1 may include injecting oxidizing gas into the reactor (step 15 of FIG. 1) and purifying the inside of the reactor (step 17 of FIG. 1).

Specifically, the hafnium (Hf) source gas is injected into the reactor loaded with the substrate (step 11 of FIG. 1). The hafnium (Hf) source gas is a material having a HfX ₄ structure, wherein X may be one selected from the group consisting of F, Cl, Br, and I. In addition, the hafnium (Hf) source gas is a material having a structure Hf (NRR ') ₄ , wherein R is one selected from the group consisting of H, Me, Et and ⁱ Pr, wherein R' is H, Me, Et And it may be one selected from the group consisting of ⁱ Pr. In addition, the hafnium (Hf) source gas is TEMAH {tetrakis (ethylmethylamino) hafnium; Hf [N (CH₃) C₂H ₅ ] ₄}. For example, when injecting the TEMAH, the pulse time for supplying the TEMAH gas may be 0.2 ~ 2 seconds. As a result, a chemisorption layer containing hafnium (Hf) is formed on the surface of the substrate. After the chemisorption layer containing hafnium (Hf) is formed, the hafnium (Hf) source gas remaining in the reactor is discharged to purify the inside of the reactor (step 13 of FIG. 1). A purge gas may be injected into the reactor to discharge the hafnium (Hf) source gas. As the purge gas, an inert gas such as argon (Ar), helium (He), or nitrogen (N ₂ ) is generally used. The oxidizing gas is then injected into the reactor (step 15 of FIG. 1). The oxidizing gas may be at least one selected from the group consisting of oxygen (O ₂ ), ozone (O ₃ ), water (H ₂ O), and hydrogen peroxide (H ₂ O ₂ ). When TEMAH is used as the hafnium (Hf) source gas, ozone (O ₃ ) may be used as the oxidizing gas. The ozone has a high oxidation power with impurities attached to hafnium. That is, the ozone has an effect of removing impurities attached to hafnium. As a result, the chemistry adsorption layer and the oxidizing gas react to form the hafnium (Hf) oxide film on the substrate. Next, the oxidizing gas remaining in the reactor and by-products generated by the reaction between the chemisorption layer and the oxidizing gas are discharged to purify the inside of the reactor (step 17 of FIG. 1). A purge gas may be injected into the reactor to discharge the oxidizing gas and the reaction byproduct. As the purge gas, an inert gas such as argon (Ar), helium (He), or nitrogen (N ₂ ) is generally used. Check that the hafnium (Hf) oxide film having a desired thickness is formed. The hafnium (Hf) oxide film formation cycle 10 is repeated K times until the hafnium (Hf) oxide film having a desired thickness is formed on the substrate (step 19 in FIG. 1). Here, said K is an integer of 1 or more and 10 or less. That is, it is preferable that said K times are 1 time or more and 10 times or less.

The silicon oxide film formation cycle 20 is repeated Q times on the substrate having the hafnium (Hf) oxide film to form a hafnium silicate film. The silicon oxide film forming cycle 20 injects a silicon source gas (step 21 of FIG. 1), discharges the silicon source gas remaining in the reactor to purify the inside of the reactor (step 23 of FIG. 1), and the reactor Injecting an oxidizing gas (step 25 of FIG. 1), and purifying the inside of the reactor (step 27 of FIG. 1).

Specifically, in the embodiments of the present invention, the hafnium silicate film may be formed by the same method as described with reference to FIGS. 1 and 2. For example, the silicon source gas may use HCD (Hexachlorodisilane; Si ₂ Cl ₆ ). When the silicon source gas is the HCD, the oxidizing gas may use H ₂ O. As a result, the hafnium (Hf) oxide film and the silicon oxide film react with each other to form the hafnium silicate film. It is confirmed whether the hafnium silicate film having a desired composition ratio is formed. The silicon oxide film formation cycle 20 is repeated Q times until the hafnium silicate film having a desired composition ratio is formed on the substrate (step 29 in FIG. 1). Here, Q is an integer of 1 or more and 10 or less. That is, it is preferable that the said Q times are 1 time or more and 10 times or less.

In the hafnium silicate film forming method according to some embodiments of the present invention, it is very important that the K times and the Q times do not exceed 10 times, respectively. For example, K may be 2 or more and 5 or less and Q may be 1. More preferably, K is 3 and Q may be 1. When the K times is 10 or more times, as described above, the hafnium oxide film formed in the hafnium oxide film forming cycle 10 has a stable chemical state. The hafnium oxide film having the stable chemical state makes it difficult to form the hafnium silicate film in the silicon oxide film forming cycle 20. That is, the silicon oxide film may be separated and laminated on the hafnium oxide film having the stable chemical state, or the silicon oxide film forming reaction may not occur due to the hafnium oxide film having the stable chemical state. In addition, when the Q cycle is performed 10 times or more, even if the HCD (hexachlorodisilane; Si ₂ Cl ₆ ) gas is supplied on the hafnium silicate film, the chemical adsorption layer containing the silicon is not formed. In other words, the hafnium silicate film is no longer formed even if the Q is performed 10 times or more. The hafnium silicate film may be represented by the formula Hf _x Si _1-x O ₂ . Here, "x" represents the composition ratio of the hafnium (Hf) element. By combining the K times and the Q times, the "x" may be adjusted to be 0.10 to 0.95. More preferably, the "x" may be adjusted to be 0.65 to 0.85. That is, the hafnium silicate (Hf _x Si _1-x O ₂ ) having a desired composition ratio on the substrate by adjusting the K times and the Q times. A film can be formed.

As described in the metal silicate film formation cycle, the hafnium silicate film formation cycle comprises repeating the hafnium oxide film formation cycle 10 times and repeating the silicon oxide film formation cycle 20 times. . Subsequently, the thickness of the hafnium silicate film is checked (step 39 of FIG. 1). The hafnium silicate film formation cycle is performed at least once until the hafnium silicate film having a desired thickness is formed on the substrate. That is, repeating the hafnium oxide film formation cycle 10 times and repeating the silicon oxide film formation cycle 20 times at least once until the hafnium silicate film having a desired thickness is formed on the substrate. Conduct.

In addition, the present invention provides other methods of forming the hafnium silicate (Hf _x Si _1-x O ₂ ) film. Now, another method will be described with reference to FIGS. 1 and 2 again.

Other methods of forming the hafnium silicate film include loading a substrate into a reactor of an atomic layer deposition apparatus (step 5 of FIG. 1).

The reactor interior is heated to a temperature suitable for the process. For example, a suitable temperature for the process can be 250 ℃ to 600 ℃.

The hafnium (Hf) oxide film formation cycle 10 is repeated K times on the substrate to form a hafnium (Hf) oxide film having a desired thickness. The hafnium (Hf) oxide film forming cycle 10 injects a hafnium (Hf) source gas (step 11 of FIG. 1), discharges the hafnium (Hf) source gas remaining in the reactor, and purifies the inside of the reactor ( Step 13 of FIG. 1 may include injecting oxidizing gas into the reactor (step 15 of FIG. 1) and purifying the inside of the reactor (step 17 of FIG. 1).

Specifically, the hafnium (Hf) source gas is injected into the reactor loaded with the substrate (step 11 of FIG. 1). The hafnium (Hf) source gas is a material having a HfX ₄ structure, wherein X may be one selected from the group consisting of F, Cl, Br, and I. In addition, the hafnium (Hf) source gas is a material having a structure Hf (NRR ') ₄ , wherein R is one selected from the group consisting of H, Me, Et and ⁱ Pr, wherein R' is H, Me, Et And it may be one selected from the group consisting of ⁱ Pr. In addition, the hafnium (Hf) source gas is TEMAH {tetrakis (ethylmethylamino) hafnium; Hf [N (CH₃) C₂H ₅ ] ₄}. For example, when injecting the TEMAH, the pulse time for supplying the TEMAH gas may be 0.2 ~ 2 seconds. As a result, a chemisorption layer containing hafnium (Hf) is formed on the surface of the substrate. After the chemisorption layer containing hafnium (Hf) is formed, the hafnium (Hf) source gas remaining in the reactor is discharged to purify the inside of the reactor (step 13 of FIG. 1). A purge gas may be injected into the reactor to discharge the hafnium (Hf) source gas. As the purge gas, an inert gas such as argon (Ar), helium (He), or nitrogen (N ₂ ) is generally used. The oxidizing gas is then injected into the reactor (step 15 of FIG. 1). The oxidizing gas may be at least one selected from the group consisting of oxygen (O ₂ ), ozone (O ₃ ), water (H ₂ O), and hydrogen peroxide (H ₂ O ₂ ). When TEMAH is used as the hafnium (Hf) source gas, ozone (O ₃ ) may be used as the oxidizing gas. The ozone has a high oxidation power with impurities attached to hafnium. That is, the ozone has an effect of removing impurities attached to hafnium. As a result, the chemistry adsorption layer and the oxidizing gas react to form the hafnium (Hf) oxide film on the substrate. Next, the oxidizing gas remaining in the reactor and by-products generated by the reaction between the chemisorption layer and the oxidizing gas are discharged to purify the inside of the reactor (step 17 of FIG. 1). A purge gas may be injected into the reactor to discharge the oxidizing gas and the reaction byproduct. As the purge gas, an inert gas such as argon (Ar), helium (He), or nitrogen (N ₂ ) is generally used. Check that the hafnium (Hf) oxide film having a desired thickness is formed. The hafnium (Hf) oxide film formation cycle 10 is repeated K times until the hafnium (Hf) oxide film having a desired thickness is formed on the substrate (step 19 in FIG. 1). Here, said K is an integer of 1 or more and 10 or less. That is, it is preferable that said K times are 1 time or more and 10 times or less.

The silicon oxide film formation cycle 20 is repeated Q times on the substrate having the hafnium (Hf) oxide film to form a hafnium silicate film. The silicon oxide film forming cycle 20 injects a silicon source gas (step 21 of FIG. 1), discharges the silicon source gas remaining in the reactor to purify the inside of the reactor (step 23 of FIG. 1), and the reactor Injecting an oxidizing gas (step 25 of FIG. 1), and purifying the inside of the reactor (step 27 of FIG. 1).

Specifically, in the embodiments of the present invention, the hafnium silicate film may be formed by the same method as described with reference to FIGS. 1 and 2. For example, the silicon source gas may include TDMAS {tris (dimethylamino) silane; [(CH ₃ ) ₂ N] ₃ SiH} can be used. When the silicon source gas is the TDMAS, the oxidizing gas may use ozone (O ₃ ). As a result, the hafnium (Hf) oxide film and the silicon oxide film react with each other to form the hafnium silicate film. It is confirmed whether the hafnium silicate film having a desired composition ratio is formed. The silicon oxide film formation cycle 20 is repeated Q times until the hafnium silicate film having a desired composition ratio is formed on the substrate (step 29 in FIG. 1). Here, Q is an integer of 1 or more and 10 or less. That is, it is preferable that the said Q times are 1 time or more and 10 times or less.

In the hafnium silicate film forming method according to some embodiments of the present invention, it is very important that the K times and the Q times do not exceed 10 times, respectively. For example, K may be 1 or more and 3 or less and Q may be 1. More preferably, K is 3 and Q may be 1. When the K times is 10 or more times, as described above, the hafnium oxide film formed in the hafnium oxide film forming cycle 10 has a stable chemical state. The hafnium oxide film having the stable chemical state makes it difficult to form the hafnium silicate film in the silicon oxide film forming cycle 20. That is, the silicon oxide film may be separated and laminated on the hafnium oxide film having the stable chemical state, or the silicon oxide film forming reaction may not occur due to the hafnium oxide film having the stable chemical state. In addition, when the Q cycle is performed 10 times or more, the TDMAS {tris (dimethylamino) silane; Even when the [(CH ₃ ) ₂ N] ₃ SiH} gas is supplied, the chemisorption layer containing the silicon is not formed. In other words, the hafnium silicate film is no longer formed even if the Q is performed 10 times or more. The hafnium silicate film may be represented by the formula Hf _x Si _1-x O ₂ . Here, "x" represents the composition ratio of the hafnium (Hf) element. By combining the K times and the Q times, the "x" may be adjusted to be 0.10 to 0.95. More preferably, the "x" may be adjusted to be 0.65 to 0.85. That is, the hafnium silicate (Hf _x Si _1-x O ₂ ) having a desired composition ratio on the substrate by adjusting the K times and the Q times. A film can be formed.

As described in the metal silicate film formation cycle, the hafnium silicate film formation cycle comprises repeating the hafnium oxide film formation cycle 10 times and repeating the silicon oxide film formation cycle 20 times. . Subsequently, the thickness of the hafnium silicate film is checked (step 39 of FIG. 1). The hafnium silicate film formation cycle is performed at least once until the hafnium silicate film having a desired thickness is formed on the substrate. That is, repeating the hafnium oxide film formation cycle 10 times and repeating the silicon oxide film formation cycle 20 times at least once until the hafnium silicate film having a desired thickness is formed on the substrate. Conduct.

Experimental Examples

3 is a graph measuring the thickness of a hafnium silicate film formed on a semiconductor substrate according to an embodiment of the present invention. In the graph of FIG. 3, the horizontal axis P represents a measurement position on the semiconductor substrate and is disposed at a distance of 7 mm from the center of the semiconductor substrate to the bottom. In the graph of FIG. 3, the vertical axis T represents the measured thickness, and the unit of scale is Å. In the experimental examples illustrated in FIG. 3, the reactor temperature was set to 320 ° C. and the deposition pressure was 0.2 tortor in the process conditions for forming the hafnium silicate film. In addition, the pulse time to which a hafnium source gas is supplied was made the same at 0.2 second.

Referring to FIG. 3, curve A shows the result of repeating the hafnium silicate film formation cycle 40 times in the method described with reference to FIGS. 1 and 2, where K is 1 Q is set to 3. At this time, in the hafnium (Hf) oxide film formation cycle 10, the hafnium source gas used TEMAH, and the oxidizing gas used ozone. In the silicon oxide film formation cycle 20, HCD was used as the silicon source gas and H ₂ O was used as the oxidizing gas. As a result, as shown in curve A, a hafnium silicate film (Hf _x Si _1-x O ₂ ) was formed to a thickness of 50 kHz.

Curve B is set to only 40 in the method described with reference to FIGS. 1 and 2, that is, the thickness of the hafnium oxide film HfO ₂ formed after only 40 hafnium (Hf) oxide formation cycles 10 has been performed. One result. In this case, the hafnium source gas was TEMAH, and the oxidizing gas was ozone. In this case, a hafnium oxide film (HfO ₂ ) was formed to have a thickness of 38 kHz as shown in curve B. FIG.

Curve C is continuous after setting K to 40 in the method described with reference to FIGS. 1 and 2, that is, going through the hafnium (Hf) oxide formation cycle 10 for 40 times to form hafnium oxide (HfO ₂ ). As a result, the thickness of the thin film formed by setting Q to 40 on the semiconductor substrate having the hafnium oxide film HfO ₂ , that is, performing the silicon oxide film forming cycle 20 additionally 40 times is measured. At this time, in the hafnium (Hf) oxide film formation cycle 10, the hafnium source gas used TEMAH, and the oxidizing gas used ozone. In the silicon oxide film formation cycle 20, HCD was used as the silicon source gas and H ₂ O was used as the oxidizing gas. As a result, as shown in curve C, no further thin film was formed on the hafnium oxide film (HfO ₂ ) having the thickness of 38 kPa. That is, when the K times is 40 times, as described above, even if the silicon oxide film forming cycle 20 is further performed, the hafnium silicate film is not formed.

According to the experimental examples shown in FIG. 3, it can be seen that a hafnium silicate film having a predetermined thickness can be formed by appropriately adjusting the K times and the Q times each 10 times or less.

4 to 6 is a graph comparing the thickness of the metal silicate film formed according to the metal raw material gas injection time of the present invention. In the graphs of FIGS. 4 to 6, the horizontal axis P represents a measurement position on the semiconductor substrate, and is disposed at a distance of 7 mm from the center of the semiconductor substrate to the bottom. In the graphs of FIGS. 4 to 6, the vertical axis T represents measured thickness, and the unit of scale is Å. At this time, the hafnium silicate film according to the embodiments of the present invention was formed, the reactor temperature and pressure of the deposition conditions are all the same conditions of 320 ℃ and 0.2torr, respectively, and only the injection time of the metal raw material gas was different. As described above, the hafnium silicate film forming cycle includes repeating the hafnium (Hf) oxide film forming cycle 10 times and repeating the silicon oxide film forming cycle 20 times. In the hafnium (Hf) oxide film formation cycle 10, the hafnium source gas used TEMAH, and the oxidized gas used ozone. In the silicon oxide film formation cycle 20, HCD was used as the silicon source gas and H ₂ O was used as the oxidizing gas.

4 is a graph showing the thickness distribution of the hafnium silicate film formed when the pulse time for supplying the TEMAH is 0.2 seconds. Referring to FIG. 4, the thickness of the hafnium silicate film was uniformly about 46 kV at the center and the bottom of the semiconductor substrate.

FIG. 5 is a graph showing a pulse time for supplying the TEMAH at 0.1 second. Unlike the result of FIG. 4, the thickness of the hafnium silicate film is almost constant at the center of the semiconductor substrate, whereas the bottom of the semiconductor substrate is lower. Decreases to). In particular, the thickness (E) of the hafnium silicate film rapidly decreases from a distance of 70 mm from the center of the semiconductor substrate.

FIG. 6 is a graph in which the pulse time for supplying the TEMAH is performed at 0.05 seconds. The thickness of the hafnium silicate film is substantially constant at the center of the semiconductor substrate, and decreases further toward the bottom of the semiconductor substrate. In particular, the thickness (E) of the hafnium silicate film decreases rapidly from the point of 42 mm from the center of the semiconductor substrate. This is presumably because the pulse time for supplying the TEMAH is so short that the TEMAH is not sufficiently supplied to the bottom portion of the semiconductor substrate.

As can be seen from the results of Figs. 4 to 6, the pulse time for supplying the TEMAH is preferably set to 0.2 seconds or more. For example, the pulse time for supplying the TEMAH may be set to 0.2 to 2 seconds.

7 is a graph illustrating deposition thicknesses according to injection amounts of a metal source gas and a silicon source gas when the metal silicate film is formed according to the present invention. In the graph of FIG. 7, the horizontal axis F represents the injection amount of source gas, and in the graph of FIG. 7, the vertical axis T represents the deposition thickness.

Referring to FIG. 7, as the injection amount of the source gases increases, the thickness of the metal silicate film changes as shown by curve S. FIG. Specifically, the curve S has a section in which the thickness of the metal silicate film deposited on the substrate increases as the injection amount of the source gases increases, that is, an unsaturated region. Further, the curve S has a section in which the injection amount of the source gases is sufficient so that the thickness increase of the metal silicate film deposited on the substrate no longer occurs, that is, a saturated region. Therefore, by appropriately adjusting the supply amount of the source gas in the unsaturated region, it is possible to control the deposition thickness, thereby adjusting the composition ratio in the metal silicate film.

For example, in order to form a metal silicate film having a high composition ratio of metal elements, the supply amount of the metal source gas may be supplied as much as the saturated region, and the supply amount of the silicon source gas may be supplied in the range corresponding to the unsaturated region. have. On the contrary, in order to form a metal silicate film having a high composition ratio of silicon element, the supply amount of the metal source gas may be supplied as much as the unsaturated region, and the supply amount of the silicon source gas may be supplied in the range corresponding to the saturation region. .

8 to 11 are graphs showing the results of X-ray photoelectron spectroscopy (XPS) analysis of a hafnium silicate film (Hf _x Si _1-x O ₂ ) deposited according to the present invention. 8 to 11, the horizontal axis M represents the sputter time of the XPS, and the scale unit is minutes, the vertical axis A is an atomic concentration ratio, and the unit is%.

Reactor temperature and pressure in the deposition conditions of the hafnium silicate film was set to the same conditions of 320 ℃ and 0.2torr, respectively. In the hafnium (Hf) oxide film formation cycle 10, the hafnium source gas used TEMAH, and the oxidized gas used ozone. In the silicon oxide film formation cycle 20, HCD was used as the silicon source gas and H ₂ O was used as the oxidizing gas. The hafnium silicate film formation cycle was performed 80 times in each of FIGS. 8 to 11. As described above, the hafnium silicate film forming cycle includes repeating the hafnium (Hf) oxide film forming cycle 10 times and repeating the silicon oxide film forming cycle 20 times. In FIGS. 8 to 11, the K times and the Q times are set differently.

In order to exclude the possibility of surface contamination of the specimen which may occur during the X-ray photoelectron spectroscopy (XPS) analysis, the hafnium silicate film was formed using the interval measurement result between 2 and 14 minutes after the start of the sputter as the effective period (D) It was used for the composition ratio analysis of (Hf _x Si _1-x O ₂ ). As shown in FIGS. 8 to 11 in the effective period (D), the composition ratios of carbon (C) and chlorine (Cl) were all 0.5% or less.

Referring to FIG. 8, FIG. 8 is an XPS analysis result of a hafnium silicate film (Hf _x Si _1-x O ₂ ) formed with K = 1 and Q = 3. Analyzing the effective period (D), it can be seen that the hafnium silicate film (Hf _x Si _1-x O ₂ ) is composed of Hf = 17.8, Si = 17.9, and O = 63.8. At this time, the composition ratio "x" of hafnium to silicon was found to be 0.50 ㅁ 0.03.

Referring to FIG. 9, FIG. 9 is an XPS analysis result of a hafnium silicate film (Hf _x Si _1-x O ₂ ) formed by K = 1 and Q = 1. Analyzing the effective period (D), it can be seen that the hafnium silicate film (Hf _x Si _1-x O ₂ ) is composed of Hf = 21.9, Si = 14.3, and O = 62.2. At this time, the composition ratio "x" of hafnium to silicon was found to be 0.61 ㅁ 0.04.

Referring to FIG. 10, FIG. 10 is an XPS analysis result of a hafnium silicate film (Hf _x Si _1-x O ₂ ) formed when K = 3 and Q = 1. Analyzing the effective period D, it can be seen that the hafnium silicate film (Hf _x Si _1-x O ₂ ) is composed of Hf = 29.2, Si = 9.8, and O = 58.7. At this time, the composition ratio "x" of hafnium to silicon was 0.75 ㅁ 0.03.

Referring to FIG. 11, FIG. 11 is an XPS analysis result of a hafnium silicate film (Hf _x Si _1-x O ₂ ) formed when K = 5 and Q = 1. Analyzing the effective period (D), it can be seen that the hafnium silicate film (Hf _x Si _1-x O ₂ ) is composed of Hf = 30.7, Si = 8.0, and O = 60.3. At this time, the composition ratio "x" of hafnium to silicon was 0.80 ㅁ 0.05.

Referring to the XPS analysis result, it can be seen that the composition ratio of hafnium and silicon in the hafnium silicate film can be controlled by appropriately adjusting K and Q in the hafnium silicate film forming cycles of FIGS. 1 and 2. At this time, when the composition ratio of the hafnium (Hf), the metal element, is high, the dielectric constant is increased while the mobility of the carrier is reduced. The decrease in mobility has a problem of lowering the switching characteristics of the transistor. On the contrary, when the composition ratio of hafnium (Hf) is lower than that of the silicon element, the mobility (mobility) is improved while the dielectric constant is low, so that the K and Q must be properly adjusted.

12 is a graph showing an increase in thickness according to the hafnium silicate film formation cycle repetition of the present invention. In the graph of FIG. 12, the horizontal axis C represents the number of cycles of the hafnium silicate film formation cycle, and the vertical axis T represents the measured thickness. In the hafnium (Hf) oxide film formation cycle 10, the hafnium source gas used TEMAH, the oxidized gas used ozone, and K = 1. In addition, in the silicon oxide film forming cycle 20, the silicon source gas used HCD, and the oxidized gas used H ₂ O, and Q = 3.

Referring to FIG. 12, the thickness of the hafnium silicate film linearly increased with increasing number of repetitions of the hafnium silicate film formation cycle, and the equation of the straight line was Y = 4.635 + 1.01797X. That is, the thickness of the hafnium silicate film can be minutely adjusted by controlling the repetition frequency of the hafnium silicate film formation cycle.

13 is a drain current degradation characteristic diagram obtained when a hafnium silicate film formed in accordance with the present invention is applied to a MOS transistor. In the graph of FIG. 13, the horizontal axis S represents a stress time applied to the MOS transistor, and the unit of the scale is seconds. In the graph of FIG. 13, the vertical axis ΔI _d represents a drain current deterioration rate and a unit of scale is a percentage (%). The drain current degradation rate may be expressed as the ratio of the drain saturation current difference after the stress time has elapsed with respect to the initial drain saturation current.

The MOS transistors used in the experimental examples were all fabricated using a width (W) 10 um and a length (L) 0.13 um pattern. In addition, all of the gate dielectric layers of the MOS transistors are formed of hafnium silicate layers having a thickness of 30 Å. As described with reference to FIGS. 1 and 2, the hafnium silicate film formation cycle may include repeating the hafnium oxide film formation cycle 10 times and repeating the silicon oxide film formation cycle 20 times. Equipped. In the hafnium (Hf) oxide film formation cycle 10, the hafnium source gas used TEMAH, and the oxidized gas used ozone. In the silicon oxide film formation cycle 20, HCD was used as the silicon source gas and H ₂ O was used as the oxidizing gas. The K and Q were adjusted differently.

In the present experimental examples, the bias conditions applied to the MOS transistors were equalized with the gate voltage Vg 3.0V and the drain potential difference Vd 3.0V, respectively.

Referring to FIG. 13, the curve HS31 is a drain current degradation characteristic of the hafnium silicate film formed by K = 3 and Q = 1, and the curve HS51 is a drain current degradation characteristic of the hafnium silicate film formed by K = 5 and Q = 1. Curve HS11 is a drain current deterioration characteristic of the hafnium silicate film formed by K = 1 and Q = 1, and curve HS13 is a drain current deterioration characteristic curve of the hafnium silicate film formed by K = 1 and Q = 3.

As shown in FIG. 13, all of the experimental examples according to the present invention were excellent in the drain current degradation characteristics. In particular, the drain current deterioration characteristic of the hafnium silicate film formed by the curve HS31, that is, K = 3 and Q = 1, was found to be the best as compared with the other curves. Referring to the XPS analysis result of FIG. 10, the hafnium silicate film (Hf _x Si _1-x O ₂ ) formed by K = 3 and Q = 1 has a composition ratio “x” of hafnium to silicon of 0.75 W 0.03 Has a value. In other words, the hafnium silicate film (Hf _x Si _1-x O ₂ ) having a composition ratio "x" of 0.75 wh 0.03 exhibits a relatively excellent drain current degradation characteristic compared to the hafnium silicate film having a different composition ratio. have.

Fig. 14 is a diagram showing the transconductance (Gm) and threshold voltage (Vth) degradation characteristics obtained when the hafnium silicate film formed according to the present invention is applied to a MOS transistor. In the graph of FIG. 13, the horizontal axis KQ represents the K and Q set in the hafnium silicate film formation cycle. For example, point 5: 1 of the horizontal axis KQ means K = 5 and Q = 1. In the graph of FIG. 14, the first vertical axis ΔGm / Gm represents the mutual conductance deterioration rate and the unit of scale is percent (%). The mutual conductance deterioration rate may be expressed as a ratio of the mutual conductance difference after 1000 seconds of a stress time with respect to the initial mutual conductance. The transconductance (Gm) has a linear proportionality with the mobility of a carrier. In the graph of FIG. 14, the second vertical axis ΔVth represents a threshold voltage difference and the unit of the scale is V. In FIG. The threshold voltage difference may be expressed as a difference between an initial threshold voltage and a threshold voltage measured after 1000 seconds of a stress time.

Morse transistors used in the present experimental examples were manufactured under substantially the same process conditions as the experimental examples of FIG. 13. In addition, in the present experimental examples, the bias conditions applied to the MOS transistors were equal to the gate voltage Vg 3.0V drain potential difference Vd 3.0V, respectively.

Curve G in Fig. 14 shows the cross-conductance deterioration characteristics. Referring to the intersections between the points of the curve G and the horizontal axis KQ, it can be seen that the interconductivity deterioration characteristics of the hafnium silicate film formed by the above K = 5 and Q = 1 are superior to other conditions.

Curve V in Fig. 14 shows the threshold voltage degradation characteristics. Referring to the intersection between the points of the curve V and the horizontal axis KQ, it can be seen that the threshold voltage deterioration characteristics of the hafnium silicate film formed with K = 3 and Q = 1 are superior to other conditions.

15 is a diagram illustrating a hot carrier injection (HCI) lifetime obtained when a hafnium silicate film formed according to the present invention is applied to a MOS transistor. In the graph of FIG. 15, the horizontal axis 1 / Vd represents an inverse of the drain potential difference of the MOS transistor. In the graph of FIG. 15, the vertical axis L represents a lifetime and the unit of the scale is seconds.

Morse transistors used in the present experimental examples were manufactured under substantially the same process conditions as the experimental examples of FIG. 13. In addition, in the present experimental examples, the gate voltage Vg applied to the MOS transistors was equal to 3.0V.

Referring to FIG. 15, curve HS31 is a hot carrier injection (HCI) lifetime characteristic of the hafnium silicate film formed by K = 3 and Q = 1, and curve HS51 is K = 5 and Q. Hot carrier injection (HCI) lifetime characteristics of the hafnium silicate film formed by = 1, and curve HS11 is a hot carrier injection of the hafnium silicate film formed by K = 1 and Q = 1. ; HCI) Lifetime characteristics.

As shown in FIG. 15, all of the experimental examples according to the present invention were excellent in the hot carrier injection (HCI) lifetime characteristics. In particular, the hot carrier injection (HCI) lifetime characteristics of the hafnium silicate film formed by the curve HS31, that is, K = 3 and Q = 1, were found to be the best as compared with the other curves. Referring to the XPS analysis result of FIG. 10, the hafnium silicate film (Hf _x Si _1-x O ₂ ) formed by K = 3 and Q = 1 has a composition ratio “x” of hafnium to silicon of 0.75 W 0.03 Has a value. In other words, the hafnium silicate film (Hf _x Si _1-x O ₂ ) having a composition ratio "x" of 0.75 wh 0.03 is relatively superior to the hafnium silicate film having a different composition ratio. HCI) shows the lifetime characteristics.

FIG. 16 is a diagram of a positive bias temperature instability (PBTI) lifetime obtained when a hafnium silicate film formed according to the present invention is applied to an nMOS transistor. In the graph of FIG. 16, the horizontal axis Vg represents the gate voltage of the nMOS transistor, and the scale unit is V. FIG. In the graph of FIG. 16, the vertical axis L represents a lifetime and the unit of the scale is seconds.

The nMOS transistors used in the experimental examples were all fabricated using a width of 10 μm and a length of 1 μm of length L. In addition, the gate dielectric layers of the nMOS transistors are all formed of hafnium silicate layers having a thickness of 30 占 퐉. As described with reference to FIGS. 1 and 2, the hafnium silicate film formation cycle may include repeating the hafnium oxide film formation cycle 10 times and repeating the silicon oxide film formation cycle 20 times. Equipped. In the hafnium (Hf) oxide film formation cycle 10, the hafnium source gas used TEMAH, and the oxidized gas used ozone. In the silicon oxide film formation cycle 20, HCD was used as the silicon source gas and H ₂ O was used as the oxidizing gas. The K and Q were adjusted differently.

In the present experimental examples, the drain potential difference Vd applied to the nMOS transistors was equal to 50mV. In addition, the temperature in the positive bias temperature instability (PBTI) conditions was 125 ℃.

Referring to FIG. 16, curve HS31 is a positive bias temperature instability (PBTI) lifetime characteristic of a hafnium silicate film formed by K = 3 and Q = 1, and curve HS51 is K = 5 and Q. PBITI (positive bias temperature instability) of the hafnium silicate film formed by = 1, and the curve HS11 is a positive bias temperature instability of the hafnium silicate film formed by K = 1 and Q = 1. (PBTI) lifetime lifetime, and curve HS13 is a positive bias temperature instability (PBTI) lifetime lifetime of the hafnium silicate film formed by K = 1 and Q = 3.

As shown in FIG. 16, all of the experimental examples according to the present invention were found to be excellent in the PBTI lifetime characteristics. In particular, the positive bias temperature instability (PBTI) lifetime of the hafnium silicate film formed by the curve HS31, i.e., K = 3 and Q = 1, was found to be superior to other curves. Referring to the XPS analysis result of FIG. 10, the hafnium silicate film (Hf _x Si _1-x O ₂ ) formed by K = 3 and Q = 1 has a composition ratio “x” of hafnium to silicon of 0.75 W 0.03 Has a value. In other words, the hafnium silicate film (Hf _x Si _1-x O ₂ ) having a composition ratio of "x" of 0.75 0.0 0.03 has a relatively excellent positive bias temperature instability compared to the hafnium silicate film having a different composition ratio; PBTI) shows a lifetime characteristic.

As described above, according to the present invention, the metal silicate film forming cycle includes repeating the metal oxide film forming cycle K times and repeating the silicon oxide film forming cycle Q times. K and Q are each an integer of 1 or more and 10 or less. By appropriately adjusting the K and Q in the metal silicate film formation cycle, the composition ratio of metal and silicon in the metal silicate film can be adjusted. In addition, the thickness of the metal silicate film may be minutely adjusted by controlling the number of times the metal silicate film forming cycle is repeated. Therefore, a metal silicate film having an excellent composition ratio and uniform thickness can be formed by using an atomic layer deposition technique.

1 is a process flow chart showing a method for forming a metal silicate film by atomic layer deposition according to the present invention.

2 is a block diagram showing a deposition cycle of a method for forming a metal silicate film using an atomic layer deposition technique according to the present invention.

3 is a graph measuring the thickness of a hafnium silicate film formed on a semiconductor substrate according to an embodiment of the present invention.

4 to 6 is a graph comparing the thickness of the metal silicate film formed according to the metal raw material gas injection time of the present invention.

7 is a graph illustrating deposition thicknesses according to injection amounts of a metal source gas and a silicon source gas when the metal silicate film is formed according to the present invention.

8 to 11 are graphs showing the results of X-ray photoelectron spectroscopy (XPS) analysis of a hafnium silicate film (Hf _x Si _1-x O ₂ ) deposited according to the present invention.

12 is a graph showing an increase in thickness according to the hafnium silicate film formation cycle repetition of the present invention.

13 is a view illustrating drain current deterioration characteristics according to experimental examples of the present invention.

14 is a diagram illustrating deterioration of transconductance (Gm) and threshold voltage (Vth) according to experimental examples of the present invention.

FIG. 15 is a diagram illustrating a hot carrier injection (HCI) lifetime characteristic according to experimental examples of the present invention. FIG.

FIG. 16 is a diagram of a positive bias temperature instability (PBTI) lifetime characteristic according to experimental examples of the present invention.

Claims (38)

Load the substrate into the reactor, Injecting a metal raw material gas into the reactor having the substrate to form a chemisorption layer containing the metal on the substrate, Injecting an oxidizing gas into the reactor and reacting with a chemical adsorption layer containing the metal to form a metal oxide film on the substrate, Injecting the metal raw material gas to forming the metal oxide film K times; Injecting a silicon raw material gas into the reactor to form a chemical adsorption layer containing the silicon on a substrate having the metal oxide film, Injecting an oxidizing gas into the reactor to react with the metal oxide film and the chemical adsorption layer containing the silicon to form a metal silicate film, Injecting the silicon source gas to forming the metal silicate film Q times; And injecting the metal source gas to forming the metal silicate film at least once to form a metal silicate film having a desired thickness. The method of claim 1, After the chemical adsorption layer containing the metal is formed, the metal source gas remaining in the reactor is discharged to purify the inside of the reactor, After forming the metal oxide film, the oxidizing gas and reaction by-products remaining in the reactor are discharged to purify the inside of the reactor, After the chemical adsorption layer containing the silicon is formed, the silicon source gas remaining in the reactor is discharged to purify the inside of the reactor, And forming the metal silicate film, and then purifying the inside of the reactor by discharging the oxidizing gas and the reaction by-products remaining in the reactor. The method of claim 1, The method of forming a metal silicate film using atomic layer deposition technology, wherein K or Q is 1 or more and 10 or less. The method of claim 1, Wherein K is 2 or more and 5 or less and Q is 1 Method for forming a metal silicate film using an atomic layer deposition technique. The method of claim 1, Wherein K is 3 and Q is 1 characterized in that the metal silicate film forming method using atomic layer deposition technology. The method of claim 1, The temperature of the reactor is 250 ℃ to 600 ℃ metal silicate film forming method using the atomic layer deposition technology, characterized in that. The method of claim 1, The metal raw material gas is a material having an MX ₄ structure, wherein M is one selected from the group consisting of Hf, Zr, and Ti, and X is one selected from the group consisting of F, Cl, Br, and I. Metal silicate film formation method using atomic layer deposition technology. The method of claim 1, The metal source gas is a material having a M (NRR ') ₄ structure, M is one selected from the group consisting of Hf, Zr and Ti, R is one selected from the group consisting of H, Me, Et and ⁱ Pr And wherein R 'is one selected from the group consisting of H, Me, Et and ⁱ Pr. The method of claim 1, The metal raw material gas is TEMAH {tetrakis (ethylmethylamino) hafnium; Hf [N (CH₃) C₂H ₅ ] ₄}. A method for forming a metal silicate film using atomic layer deposition technology. The method of claim 9, The pulse time for supplying the metal raw material gas is 0.2 to 2 seconds, characterized in that the metal silicate film forming method using an atomic layer deposition technique. The method of claim 1, The oxidizing gas is at least one selected from the group consisting of H ₂ O, O ₃ , O ₂ and H ₂ O ₂ A metal silicate film forming method using an atomic layer deposition technique. The method of claim 1, The silicon source gas is a material having a structure of Si _n X ′ _{2n + 2} , wherein n = 1 to 4, and X ′ represents NCO, F, Cl, Br. And I selected from the group consisting of I. A method for forming a metal silicate film using an atomic layer deposition technique. The method of claim 1, The silicon source gas is a material having a structure of Si _n X ′ _{2n + 2} O _n-1 , wherein n = 2 to 5 and X ′ represents NCO, F, Cl, Br. And I selected from the group consisting of I. A method for forming a metal silicate film using an atomic layer deposition technique. The method of claim 1, The silicon source gas is a material having a structure of SiX ″ _n (NRR ′) _4-n , wherein n = 0 to 3 and X ″ is H, F, Cl, Br. And one selected from the group consisting of I, R is one selected from the group consisting of H, Me, Et and ⁱ Pr, wherein R 'is one selected from the group consisting of H, Me, Et and ⁱ Pr Metal silicate film formation method using the atomic layer deposition technique. The method of claim 1, The silicon source gas is a material having a structure of NH _n (SiR ″ ₃ ) _3-n , wherein n = 0 to 2, and R ″ is composed of H, F, Cl, Br, I, Me, Et, and ⁱ Pr. Method for forming a metal silicate film using an atomic layer deposition technique, characterized in that one selected from the group. The method of claim 1, The silicon source gas is a material having a SiSX ₂ structure, wherein X is one selected from the group consisting of F, Cl, Br and I, the metal silicate film forming method using atomic layer deposition technology. The method of claim 1, The silicon source gas may be HCD (hexachlorodisilane; Si ₂ Cl ₆ ) or TDMAS {tris (dimethylamino) silane; [(CH ₃ ) ₂ N] ₃ SiH} A method for forming a metal silicate film using an atomic layer deposition technique. The method of claim 1, The metal silicate film forming method using atomic layer deposition technology, characterized in that the composition ratio x of the metal element in the metal silicate film (M _x Si _1-x O ₂ ) is 0.10 to 0.95. The method of claim 1, The metal silicate film forming method using atomic layer deposition technology, characterized in that the composition ratio x of the metal element in the metal silicate film (M _x Si _1-x O ₂ ) is 0.65 to 0.85. Load the substrate into the reactor, TEMAH {tetrakis (ethylmethylamino) hafnium in a reactor having the substrate; Hf [N (CH₃) C₂H ₅ ] ₄} gas is injected to form a chemisorption layer containing hafnium (Hf) on the substrate, Injecting an oxidizing gas into the reactor to react with the chemisorption layer containing hafnium (Hf) to form a hafnium (Hf) oxide film on the substrate, Injecting the TEMAH gas to forming the hafnium (Hf) oxide film K times; Injecting a hexachlorodisilane (Si ₂ Cl ₆ ) gas into the reactor to form a chemisorption layer containing silicon on the substrate having the hafnium (Hf) oxide film, Injecting an oxidizing gas into the reactor to react with the hafnium (Hf) oxide film and the chemical adsorption layer containing the silicon to form a hafnium silicate (Hf _x Si _1-x O ₂ ) film, Injecting the HCD gas to forming the hafnium silicate film Q times, And injecting the TEMAH gas to forming the hafnium silicate film at least once to form a hafnium silicate film having a desired thickness. The method of claim 20, After forming the chemisorption layer containing the hafnium (Hf), the TEMAH gas remaining in the reactor is discharged to purify the inside of the reactor, After forming the hafnium (Hf) oxide film, the oxidizing gas and reaction by-products remaining in the reactor are discharged to purify the inside of the reactor, After the chemical adsorption layer containing the silicon is formed, the HCD gas remaining in the reactor is discharged to purify the inside of the reactor, After forming the hafnium silicate film, the method for forming a hafnium silicate film using an atomic layer deposition technique further comprises purifying the inside of the reactor by discharging the oxidizing gas and reaction by-products remaining in the reactor. The method of claim 20, The method of forming a hafnium silicate film using atomic layer deposition technology, wherein K or Q is 1 or more and 10 or less. The method of claim 20, The method of forming a hafnium silicate film using atomic layer deposition technology, wherein K is 2 or more and 5 or less and Q is 1. The method of claim 20, Wherein K is 3 and Q is 1 hafnium silicate film forming method using atomic layer deposition technology. The method of claim 20, Method for forming a hafnium silicate film using the atomic layer deposition technique, characterized in that the temperature of the reactor is 250 ℃ to 600 ℃. The method of claim 20, The pulse time for supplying the TEMAH gas is 0.2 ~ 2 seconds, characterized in that the hafnium silicate film forming method using atomic layer deposition technology. The method of claim 20, The oxidizing gas is at least one selected from the group consisting of H ₂ O, O ₃ , O ₂ and H ₂ O ₂ Hafnium silicate film forming method using an atomic layer deposition technology. The method of claim 20, The hafnium silicate (Hf _x Si _1-x O ₂ ) film in the hafnium (Hf) element composition ratio x is 0.10 ~ 0.95 characterized in that the hafnium silicate film forming method using an atomic layer deposition technique. The method of claim 20, The composition ratio x of the hafnium (Hf) element in the hafnium silicate (Hf _x Si _1-x O ₂ ) film is 0.65 ~ 0.85 characterized in that the hafnium silicate film forming method using an atomic layer deposition technique. Load the substrate into the reactor, TEMAH {tetrakis (ethylmethylamino) hafnium in a reactor having the substrate; Hf [N (CH₃) C₂H ₅ ] ₄} gas is injected to form a chemisorption layer containing hafnium (Hf) on the substrate, Injecting an oxidizing gas into the reactor to react with the chemisorption layer containing hafnium (Hf) to form a hafnium (Hf) oxide film on the substrate, Injecting the TEMAH gas to forming the hafnium (Hf) oxide film K times; TDMAS {tris (dimethylamino) silane; Injecting a [(CH ₃ ) ₂ N] ₃ SiH} gas to form a chemisorption layer containing silicon on the substrate having the hafnium (Hf) oxide film, Injecting an oxidizing gas into the reactor to react with the hafnium (Hf) oxide film and the chemical adsorption layer containing the silicon to form a hafnium silicate (Hf _x Si _1-x O ₂ ) film, Injecting the TDMAS gas to forming the hafnium silicate film Q times; And injecting the TEMAH gas to forming the hafnium silicate film at least once to form a hafnium silicate film having a desired thickness. The method of claim 30, After forming the chemisorption layer containing the hafnium (Hf), the TEMAH gas remaining in the reactor is discharged to purify the inside of the reactor, After forming the hafnium (Hf) oxide film, the oxidizing gas and reaction by-products remaining in the reactor are discharged to purify the inside of the reactor, After the chemical adsorption layer containing the silicon is formed, the TDMAS gas remaining in the reactor is discharged to purify the inside of the reactor, After forming the hafnium silicate film, the method for forming a hafnium silicate film using an atomic layer deposition technique further comprises purifying the inside of the reactor by discharging the oxidizing gas and reaction by-products remaining in the reactor. The method of claim 30, The method of forming a hafnium silicate film using atomic layer deposition technology, wherein K or Q is 1 or more and 10 or less. The method of claim 30, The method of forming a hafnium silicate film using atomic layer deposition technology, wherein K is 1 or more and 3 or less and Q is 1. The method of claim 30, Method for forming a hafnium silicate film using the atomic layer deposition technique, characterized in that the temperature of the reactor is 250 ℃ to 600 ℃. The method of claim 30, The pulse time for supplying the TEMAH gas is 0.2 ~ 2 seconds, characterized in that the hafnium silicate film forming method using atomic layer deposition technology. The method of claim 30, The oxidizing gas is at least one selected from the group consisting of H ₂ O, O ₃ , O ₂ and H ₂ O ₂ Hafnium silicate film forming method using an atomic layer deposition technology. The method of claim 30, The hafnium silicate (Hf _x Si _1-x O ₂ ) film in the hafnium (Hf) element composition ratio x is 0.10 ~ 0.95 characterized in that the hafnium silicate film forming method using an atomic layer deposition technique. The method of claim 30, The composition ratio x of the hafnium (Hf) element in the hafnium silicate (Hf _x Si _1-x O ₂ ) film is 0.65 ~ 0.85 characterized in that the hafnium silicate film forming method using an atomic layer deposition technique.