CN103668108A - Atomic layer deposition method of oxide medium - Google Patents

Abstract

The invention discloses an atomic layer deposition method of an oxide medium. The method uses an atomic layer deposition system to prepare an oxide medium, comprising: step 1: setting the growth parameters of the atomic layer deposition system; Pass the metal precursor source pulse into the reaction chamber of the deposition system, followed by cleaning with high-purity nitrogen gas to wash away the reaction by-products and residual metal precursor source; Step 3: Pass water pulses into the reaction chamber of the atomic layer deposition system , followed by cleaning with high-purity nitrogen to wash away the reaction by-products and residual water; Step 4: Introduce pulses of in-situ processing gas into the reaction chamber of the atomic layer deposition system, followed by cleaning with high-purity nitrogen to wash away the reaction By-products and residual in-situ processing gas; step 5: repeat step 2, step 3 and step 4 in sequence to obtain a high dielectric constant oxide dielectric film. The atomic layer deposition method of oxide medium provided by the invention can be applied to the growth of CMOS technology gate medium.

Description

A kind of atomic layer deposition method of oxide medium

technical field

The invention relates to a preparation method of an oxide dielectric, in particular to an atomic layer deposition method of an oxide dielectric, and belongs to the technical field of semiconductor integration.

Background technique

As the core and foundation of the information industry, semiconductor technology is an important symbol to measure a country's scientific and technological progress and comprehensive national strength. In the past 40 years, silicon-based integration technology has followed Moore's law to increase the working speed of devices, increase integration and reduce costs by reducing the feature size of devices. The feature size of silicon-based CMOS devices has been reduced from micrometers to nanometers. However, when the gate length of MOS devices shrinks below 90 nanometers, the traditional silicon-based CMOS integration technology begins to face challenges from both physical and technical aspects. Silicon dioxide can no longer meet the dielectric requirements of current semiconductor devices, and high dielectric constant oxides have been used more and more in CMOS integration technology as gate dielectric materials.

The use of high-mobility channel materials to replace traditional silicon materials will be an important development direction of semiconductor integration technology in the "post-Moore era". Among them, germanium and III-V compound semiconductor materials are most likely to achieve large-scale applications. High dielectric constant oxides of III-V compound semiconductor materials have also become a recent research hotspot at home and abroad.

The method of atomic layer deposition has the advantages of high uniformity, good surface coverage, self-limiting surface adsorption reaction and precise controllable growth rate, etc., and has been applied in the growth process of current CMOS technology gate dielectric. Based on the method of atomic layer deposition, the development of high performance and high dielectric constant oxide dielectric deposition method has important application prospects.

Contents of the invention

(1) Technical problems to be solved

The main purpose of the present invention is to provide an atomic layer deposition method of an oxide medium to optimize the growth conditions of the atomic layer deposition of an oxide medium with a high dielectric constant.

(2) Technical solutions

In order to achieve the above object, the present invention provides an atomic layer deposition method of an oxide medium, the method is to utilize an atomic layer deposition system to prepare an oxide medium, comprising:

Step 1: Set the growth parameters of the atomic layer deposition system;

Step 2: Introduce pulses of metal precursor sources into the reaction chamber of the atomic layer deposition system, followed by cleaning with high-purity nitrogen to wash away reaction by-products and residual metal precursor sources;

Step 3: Pass water pulses into the reaction chamber of the atomic layer deposition system, followed by cleaning with high-purity nitrogen gas to wash away reaction by-products and residual water;

Step 4: Pass in-situ processing gas pulses into the reaction chamber of the atomic layer deposition system, followed by cleaning with high-purity nitrogen to wash away reaction by-products and residual in-situ processing gas;

Step 5: Repeat step 2, step 3 and step 4 in sequence to obtain a high dielectric constant oxide dielectric film.

In the above scheme, in the step 1, the temperature of the reaction chamber of the atomic layer deposition system is 20°C-500°C, and the pressure of the reaction chamber is 0.5mbar-10mbar.

In the above scheme, in the step 2, the metal precursor source is trimethylaluminum (Al(CH ₃ ) ₃ ), tetrakis(ethylmethylamino) hafnium (Hf[N(CH ₃ )(C ₂ H ₅ )] ₄ ), tetrakis(diethylamino)hafnium (Hf[N(CH ₃ ) ₂ ] ₄ ), tetrakis(diethylamino)hafnium (Hf[N(C ₂ H ₅ ) ₂ ] ₄ ) , hafnium tetra-tert-butoxide (Hf[OC(CH ₃ ) ₃ ] ₄ ), tris(N,N'-diisopropyl-amd)yttrium (Y( ⁱ Pr ₂ amd) ₃ ), tris(N,N '-Diisopropylformamidine) lanthanum (La( ⁱ Pr ₂ fmd) ₃ ) and dimethyl beryllium (Be(CH ₃ ) ₂ ), titanium tetrachloride (TiCl ₄ ), diethylzinc ((C ₂ H ₅ ) ₂ Zn) one or more.

In the above scheme, in the step 2, the temperature of the metal precursor source is 15 degrees Celsius to 300 degrees Celsius, the pulse time of the metal precursor source is 1 millisecond to 60 seconds, and the purity of the high-purity nitrogen gas is 99.999 % and above, the flow rate of the high-purity nitrogen gas is 10 sccm-1000 sccm, and the cleaning time of the high-purity nitrogen gas is 10 milliseconds-120 seconds.

In the above scheme, in the step 3, the pulse time of the water pulse is 1 millisecond-60 seconds; the purity of the high-purity nitrogen gas is 99.999% and above, and the flow rate of the high-purity nitrogen gas is 10 sccm-1000 sccm, so The cleaning time of the high-purity nitrogen gas is 10 milliseconds to 120 seconds.

In the above solution, in the step 4, the flow rate of the in-situ processing gas is between 0 sccm-1000 sccm, and the pulse time of the in-situ processing gas pulse is 1 millisecond-10 minutes.

In the above solution, in step 4, the flow rate of the high-purity nitrogen gas is 10 sccm-1000 sccm, and the cleaning time of the high-purity nitrogen gas is 10 milliseconds-120 seconds.

In the above solution, in the step 4, the in-situ treatment gas is one or more mixed gases of oxygen, nitrogen, ammonia, hydrogen, and laughing gas.

In the above solution, in the step 5, the oxide medium is one or more combinations of aluminum oxide, hafnium oxide, lanthanum oxide, yttrium oxide, beryllium oxide, titanium dioxide, and zinc oxide.

(3) Beneficial effects

The atomic layer deposition method of the oxide medium provided by the invention can be applied to the preparation of gate dielectrics of silicon-based, germanium-based and compound semiconductor-based MOS devices. This atomic layer deposition method increases the two reaction precursor sources in the traditional atomic layer deposition method to three reaction precursor sources, and uses water as the precursor source to ensure that the reaction grows at a low temperature and the carbon impurity content in the reaction product is low. After the gas pulse is passed into the reaction chamber after the water pulse is completed, the defects such as oxygen vacancies in the oxide medium can be effectively reduced, and the vacancies caused by the steric effect can be filled, thereby improving the electrical characteristics of the oxide medium and reducing the gate size. Dielectric leakage and increase gate dielectric breakdown voltage. These characteristics indicate that the present invention has broad application prospects and market prospects in gate dielectric deposition of CMOS integration technology in the post-Moore era.

Description of drawings

FIG. 1 is a flowchart of a method for atomic layer deposition of aluminum oxide according to an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

The invention provides an atomic layer deposition method of an oxide medium. The method uses an atomic layer deposition system to prepare an oxide medium, comprising the following steps:

Step 1: Set the growth parameters of the atomic layer deposition system; wherein, the temperature of the reaction chamber of the atomic layer deposition system is 20 degrees Celsius to 500 degrees Celsius, and the pressure of the reaction chamber is 0.5 millibar to 10 millibars.

Step 2: Introduce pulses of metal precursor sources into the reaction chamber of the atomic layer deposition system, followed by cleaning with high-purity nitrogen to wash away reaction by-products and residual metal precursor sources;

Wherein, the metal precursor source is trimethylaluminum (Al(CH ₃ ) ₃ ), tetrakis(ethylmethylamino)hafnium (Hf[N(CH ₃ )(C ₂ H ₅ )] ₄ ), tetrakis (Diethylamino)hafnium (Hf[N(CH ₃ ) ₂ ] ₄ ), tetrakis(diethylamino)hafnium (Hf[N(C ₂ H ₅ ) ₂ ] ₄ ), hafnium tetra-tert-butoxide (Hf [OC(CH ₃ ) ₃ ] ₄ ), Tris(N,N'-diisopropyl-amd)yttrium (Y( ⁱ Pr ₂ amd) ₃ ), Tris(N,N'-diisopropylformamidine ) lanthanum (La( ⁱ Pr ₂ fmd) ₃ ) and dimethyl beryllium (Be(CH ₃ ) ₂ ), titanium tetrachloride (TiCl ₄ ), diethyl zinc ((C ₂ H ₅ ) ₂ Zn) one or more of. The temperature of the metal precursor source is 15 degrees Celsius to 300 degrees Celsius, the pulse time of the metal precursor source is 1 millisecond to 60 seconds, the purity of the high-purity nitrogen is 99.999% and above, and the high-purity nitrogen is The flow rate is 10 sccm-1000 sccm, and the cleaning time of the high-purity nitrogen gas is 10 milliseconds-120 seconds.

Step 3: Pass water pulses into the reaction chamber of the atomic layer deposition system, followed by cleaning with high-purity nitrogen gas to wash away reaction by-products and residual water;

Wherein, the pulse time of the water pulse is 1 millisecond-60 seconds; the purity of the high-purity nitrogen is 99.999% and above, the flow rate of the high-purity nitrogen is 10sccm-1000sccm, and the cleaning time of the high-purity nitrogen is 10 milliseconds - 120 seconds.

Step 4: Pass in-situ processing gas pulses into the reaction chamber of the atomic layer deposition system, followed by cleaning with high-purity nitrogen to wash away reaction by-products and residual in-situ processing gas;

Wherein, the flow rate of the in-situ processing gas is between 0 sccm-1000 sccm, and the pulse time of the in-situ processing gas pulse is 1 millisecond-10 minutes. The flow rate of the high-purity nitrogen gas is 10 sccm-1000 sccm, and the cleaning time of the high-purity nitrogen gas is 10 milliseconds-120 seconds. The in-situ treatment gas is one or more mixed gases of oxygen, nitrogen, ammonia, hydrogen and laughing gas.

Step 5: Repeat step 2, step 3 and step 4 in sequence to obtain an oxide dielectric film with a high dielectric constant; wherein, the oxide dielectric is aluminum oxide, hafnium oxide, dilanthanum oxide, trioxide One or more combinations of diyttrium, beryllium oxide, titanium dioxide, and zinc oxide.

The following examples specifically describe an atomic layer deposition method of an oxide medium aluminum oxide (Al ₂ O ₃ ) provided by the present invention.

As shown in Figure 1, Figure 1 is a flow chart of a method for atomic layer deposition of aluminum oxide according to an embodiment of the present invention, the method includes the following steps:

Step 101: As shown in Figure 1, the parameters of the atomic layer deposition system are set, the temperature of the reaction chamber is 250 degrees Celsius, and the pressure of the reaction chamber is 1.5 mbar;

Step 102: Introduce a metal precursor source Al(CH ₃ ) ₃ pulse into the reaction chamber of the atomic layer deposition system. The temperature of the Al(CH ₃ ) ₃ source is 20 degrees Celsius, and the pulse time is 100 milliseconds. For nitrogen cleaning, the purity of high-purity nitrogen is 99.999%, the flow rate of high-purity nitrogen is 300 sccm, and the cleaning time is 3 seconds.

Step 103: Pass water pulses into the reaction chamber of the atomic layer deposition system. The temperature of the water source is 20 degrees Celsius, and the pulse time is 100 milliseconds, followed by cleaning with high-purity nitrogen. The purity of high-purity nitrogen is 99.999%. The flow rate is 300 sccm, and the cleaning time is 3 seconds.

Step 104: Pass oxygen pulses into the reaction chamber of the atomic layer deposition system. The oxygen pulses have a purity of 99.9999%, the flow rate of oxygen is 500 sccm, and the pulse time of oxygen is 5 seconds, followed by cleaning with high-purity nitrogen. It is 99.999%, the flow rate of high-purity nitrogen gas is 300 sccm, and the cleaning time is 4 seconds.

Step 102, step 103 and step 104 form a growth cycle of Al2O3, the thickness of each growth cycle is 0.1 nanometer, repeat Step 102, Step 103 and Step 104 in sequence for 100 cycles, and grow Al2O3 with a thickness of 10nm film.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (9)

1. an atomic layer deposition method of oxide medium, it is characterized in that, the method utilizes atomic layer deposition system to carry out the preparation of oxide medium, comprising: Step 1: Set the growth parameters of the atomic layer deposition system; Step 2: Introduce pulses of metal precursor sources into the reaction chamber of the atomic layer deposition system, followed by cleaning with high-purity nitrogen to wash away reaction by-products and residual metal precursor sources; Step 3: Pass water pulses into the reaction chamber of the atomic layer deposition system, followed by cleaning with high-purity nitrogen gas to wash away reaction by-products and residual water; Step 4: Pass in-situ processing gas pulses into the reaction chamber of the atomic layer deposition system, followed by cleaning with high-purity nitrogen to wash away reaction by-products and residual in-situ processing gas; Step 5: Repeat step 2, step 3 and step 4 in sequence to obtain a high dielectric constant oxide dielectric film. 2. The atomic layer deposition method for oxide media according to claim 1, characterized in that, in the step 1, the temperature of the reaction chamber of the atomic layer deposition system is 20 degrees Celsius to 500 degrees Celsius, and the pressure of the reaction chamber is 0.5 millibar - 10 millibar. 3. The atomic layer deposition method of the oxide medium according to claim 1, characterized in that, in the step 2, the metal precursor source is trimethylaluminum (Al(CH ₃ ) ₃ ), tetra( Ethylmethylamino) hafnium (Hf[N(CH ₃ )(C ₂ H ₅ )] ₄ ), tetrakis(diethylamino)hafnium (Hf[N(CH ₃ ) ₂ ] ₄ ), tetrakis(diethyl Amino) hafnium (Hf[N(C ₂ H ₅ ) ₂ ] ₄ ), hafnium tetra-tert-butoxide (Hf[OC(CH ₃ ) ₃ ] ₄ ), tris(N,N'-diisopropyl-amd ) yttrium (Y( ⁱ Pr ₂ amd) ₃ ), tris(N,N'-diisopropylformamidine) lanthanum (La( ⁱ Pr ₂ fmd) ₃ ) and dimethyl beryllium (Be(CH ₃ ) ₂ ), titanium tetrachloride (TiCl ₄ ), and diethylzinc ((C ₂ H ₅ ) ₂ Zn). 4. The atomic layer deposition method of oxide medium according to claim 1, characterized in that, in the step 2, the temperature of the metal precursor source is 15 degrees Celsius-300 degrees Celsius, and the temperature of the metal precursor source is The pulse time is 1 millisecond-60 seconds, the purity of the high-purity nitrogen gas is 99.999% or above, the flow rate of the high-purity nitrogen gas is 10 sccm-1000 sccm, and the cleaning time of the high-purity nitrogen gas is 10 milliseconds-120 seconds. 5. the preparation method of high dielectric constant oxide according to claim 1 is characterized in that, in described step 3, the pulse time of described water pulse is 1 millisecond-60 second; The purity of described high-purity nitrogen 99.999% and above, the flow rate of the high-purity nitrogen gas is 10 sccm-1000 sccm, and the cleaning time of the high-purity nitrogen gas is 10 milliseconds-120 seconds. 6. The atomic layer deposition method of oxide medium according to claim 1, characterized in that, in the step 4, the flow rate of the in-situ processing gas is between 0sccm-1000sccm, and the in-situ processing gas pulse The pulse time is from 1 millisecond to 10 minutes. 7. the atomic layer deposition method of oxide medium according to claim 1, is characterized in that, in described step 4, the flow rate of described high-purity nitrogen gas is 10sccm-1000sccm, and the cleaning time of described high-purity nitrogen gas is 10sccm. milliseconds - 120 seconds. 8. The atomic layer deposition method of oxide medium according to claim 1, characterized in that, in the step 4, the in-situ treatment gas is one of oxygen, nitrogen, ammonia, hydrogen, laughing gas or a mixture of gases. 9. The atomic layer deposition method of oxide medium according to claim 1, characterized in that, in the step 5, the oxide medium is aluminum oxide, hafnium oxide, dilanthanum oxide, trioxide One or more combinations of diyttrium, beryllium oxide, titanium dioxide, and zinc oxide.

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