Titanium nitride film atomic layer deposition method and atomic layer deposition equipment

Abstract

The invention discloses a titanium nitride film atomic layer deposition method and atomic layer deposition equipment, and relates to the technical field of semiconductors. The method for depositing the titanium nitride thin film on the atomic layer comprises the steps that S100, a semiconductor substrate is placed in a reaction cavity of atomic layer deposition equipment; s200, the temperature of the reaction cavity is increased to a preset temperature, and the pressure of the reaction cavity is adjusted to a preset pressure; s300, C8H24N4Ti serving as a precursor source is conveyed into the reaction cavity, Ti (N (CH3) 2) x is generated on the surface of the semiconductor substrate, and x is larger than or equal to 1 and smaller than or equal to 2; s400, nitrogen plasma is provided to serve as active nitrogen free radicals to be conveyed into the reaction cavity, the active nitrogen free radicals react with Ti (N (CH3) 2) x, TiNy is generated on the surface of the semiconductor substrate through deposition, and y is larger than or equal to 0.75 and smaller than or equal to 0.85; and S500, hydrogen plasma serves as a reducing agent to be conveyed into the reaction cavity, TiNy is subjected to a reduction reaction through the hydrogen plasma, and the TiN film is deposited and generated on the surface of the semiconductor substrate. Compared with the prior art, C8H24N4Ti serves as a precursor source, the problem of Cl residue is solved, and the electrical property of the TiN film is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to an atomic layer deposition method for titanium nitride thin films and an atomic layer deposition device. Background Art

[0002] Currently, growing TiN (titanium nitride) using ALD (atomic layer deposition) requires temperatures of 350°C or higher, resulting in damage to devices during extended experiments. Furthermore, the reaction typically uses a precursor source, TiCl4 (titanium tetrachloride), which can leave residual Cl in the resulting TiN film, affecting its electrical properties and stability, leading to high resistivity. Summary of the Invention

[0003] The object of the present invention is to provide a method for atomic layer deposition of titanium nitride thin film and an atomic layer deposition device. The atomic layer deposition method of titanium nitride thin film provided by the present invention is used to improve the electrical properties of the film and reduce the resistivity.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] In a first aspect, the present invention provides a method for atomic layer deposition of titanium nitride thin films, using an atomic layer deposition device, the method comprising:

[0006] S100, providing a semiconductor substrate, wherein the semiconductor substrate is placed in a reaction chamber of the atomic layer deposition device;

[0007] S200, heating the temperature of the reaction chamber to a preset temperature, and adjusting the pressure of the reaction chamber to a preset pressure;

[0008] S300, offering C8H 24 N4Ti is transported into the reaction chamber as a precursor source to generate Ti(N(CH3)2) on the surface of the semiconductor substrate. x , where 1≤x≤2;

[0009] S400, providing nitrogen plasma as active nitrogen free radicals to be transported into the reaction chamber, and the active nitrogen free radicals react with the Ti(N(CH3)2) x Reacts to deposit TiN on the surface of the semiconductor substrate y , where 0.75≤y≤0.85;

[0010] S500, providing hydrogen plasma as a reducing agent and delivering it into the reaction chamber, and reducing the TiN y A reduction reaction is performed to deposit and generate a TiN film on the surface of the semiconductor substrate.

[0011] Optionally, in the above-mentioned atomic layer deposition method for titanium nitride thin film, the C8H 24 The concentration of N4Ti is greater than 99.99%.

[0012] Optionally, in the above-mentioned atomic layer deposition method for titanium nitride thin film, the C8H 24 The pulse processing time of N4Ti is 0.7s-0.9s.

[0013] Optionally, in the above-mentioned atomic layer deposition method for titanium nitride thin film, the preset temperature is 240° C.-260° C., and the preset pressure is 0.2 torr-0.4 torr.

[0014] Optionally, in the above-mentioned atomic layer deposition method for titanium nitride thin film, providing nitrogen plasma as active nitrogen radicals to be transported into the reaction chamber includes:

[0015] Pulsing a mixture of nitrogen and ammonia through a radio frequency coil to generate the nitrogen plasma;

[0016] The nitrogen plasma is delivered into the reaction chamber as active nitrogen radicals.

[0017] Optionally, in the above-mentioned atomic layer deposition method of titanium nitride film, the active nitrogen radicals react with the Ti(N(CH3)2) x The reaction time is 3s-5s.

[0018] Optionally, in the above-mentioned atomic layer deposition method for titanium nitride thin film, providing hydrogen plasma as a reducing agent and delivering it into the reaction chamber comprises:

[0019] Providing a mixed gas of hydrogen and argon through a pulse process of a radio frequency coil to generate the hydrogen plasma;

[0020] The hydrogen plasma is delivered into the reaction chamber as a reducing agent.

[0021] Optionally, in the above-mentioned atomic layer deposition method of titanium nitride film, the hydrogen plasma y The reduction reaction takes 1s to 3s.

[0022] Optionally, in the above-mentioned atomic layer deposition titanium nitride film method, Ti(N(CH3)2) is generated on the surface of the semiconductor substrate. x Afterwards, before providing nitrogen plasma as active nitrogen radicals to be transported into the reaction chamber, the atomic layer deposition titanium nitride film method further includes:

[0023] S310 , providing diethylamine as an inhibitor and delivering it into the reaction chamber to inhibit deposition in the raised area on the semiconductor substrate.

[0024] Optionally, in the above-mentioned atomic layer deposition method for titanium nitride thin film, the concentration of diethylamine is 0.5 vol%-1.8 vol%; and / or, the inhibition reaction time of diethylamine as an inhibitor is 0.4 s-0.6 s.

[0025] Optionally, in the above-mentioned atomic layer deposition method for titanium nitride film, after step S500, steps S300, S400, and S500 are repeated at least once until the thickness of the TiN film on the surface of the semiconductor substrate reaches a preset thickness.

[0026] Optionally, in the above-mentioned atomic layer deposition titanium nitride film method, it is characterized in that, after step S300 and before step S400, the atomic layer deposition titanium nitride film method further includes: introducing a purge gas into the reaction chamber to remove residual gas and reaction by-products.

[0027] The present invention provides an atomic layer deposition method for titanium nitride thin film. After the semiconductor is placed in the reaction chamber of the atomic layer deposition equipment, the temperature of the reaction chamber is adjusted to a preset temperature, and the pressure of the reaction chamber is adjusted to a preset pressure, and then C8H 24 N4Ti (tetrakis(dimethylamino)titanium) is transported into the reaction chamber and generates Ti(N(CH3)2) on the surface of the semiconductor substrate under the action of pulse treatment. x , Ti(N(CH3)2) is generated on the surface of the semiconductor substrate x Then, nitrogen plasma is introduced into the reaction chamber, and the ions act as active nitrogen free radicals and react with Ti(N(CH3)2) x Reacts to generate TiN on the surface of the semiconductor substrate y Finally, hydrogen plasma is transported into the reaction chamber as a reducing agent, and hydrogen plasma acts on TiN y The reduction reaction is carried out, and finally a TiN film is deposited on the surface of the semiconductor substrate. Compared with the prior art, the atomic layer deposition titanium nitride film method provided by the present invention has a C8H 24 N4Ti replaced TiCl4 as the precursor source in the existing technology, and used atomic layer deposition equipment to prepare TiN film, which solved the problem of residual Cl in TiN film, reduced the resistivity of TiN film, improved the breakdown strength of TiN film, and then significantly improved the electrical properties of TiN film.

[0028] In a second aspect, the present invention provides an atomic layer deposition apparatus for use in any of the above methods for atomic layer deposition of titanium nitride thin films, the atomic layer deposition apparatus comprising:

[0029] A reaction chamber for performing atomic layer deposition reaction;

[0030] Gas source bottle, used to hold C8H 24 N4Ti gas, the gas source bottle is connected to the reaction chamber through a first pipe;

[0031] a heating plate, arranged in the reaction chamber, and heating is performed by the heating plate;

[0032] a plasma generating mechanism comprising a plasma generating chamber and a radio frequency coil, wherein the plasma generating chamber is in communication with the reaction chamber, and is in communication with a mixture of hydrogen and argon through a second pipe, and is in communication with a mixture of nitrogen and ammonia through a third pipe, and the radio frequency coil is wound around an outer wall of the plasma generating chamber;

[0033] A vacuum pump is connected to the reaction chamber, and the reaction chamber is evacuated by the vacuum pump.

[0034] Optionally, in the above-mentioned atomic layer deposition equipment, the atomic layer deposition equipment further includes a gas flow meter for detecting the gas flow rate, and the first pipeline, the second pipeline and the third pipeline are all provided with the gas flow meter.

[0035] The atomic layer deposition device provided by the present invention is used for the above-mentioned atomic layer deposition method of titanium nitride thin film, and therefore has all the technical effects of the above-mentioned atomic layer deposition method of titanium nitride thin film, which will not be described in detail herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0037] Figure 1 A schematic diagram of the process of atomic layer deposition of titanium nitride thin films disclosed in an embodiment of the present invention;

[0038] Figure 2 A schematic flow chart of a method for atomic layer deposition of titanium nitride thin films according to another embodiment of the present invention;

[0039] Figure 3 This is a schematic structural diagram of the atomic layer deposition equipment disclosed in an embodiment of the present invention.

[0040] Reference numerals:

[0041] 10 is a reaction chamber, 20 is a gas source bottle, 30 is a heating plate, 40 is a plasma generating mechanism, 41 is a plasma generating chamber, 42 is a radio frequency coil, 50 is a vacuum pump, 61 is a first pipeline, 62 is a second pipeline, 63 is a third pipeline, 64 is a fourth pipeline, and 70 is a gas flow meter. DETAILED DESCRIPTION

[0042] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0043] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined. "Several" means one or more, unless otherwise specifically defined.

[0045] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0046] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and may encompass internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0047] like Figure 1As shown, an embodiment of the present invention discloses a method for atomic layer deposition of titanium nitride thin film, wherein the titanium nitride thin film is prepared by an atomic layer deposition device. The method for atomic layer deposition of titanium nitride thin film disclosed in the embodiment of the present invention includes:

[0048] Step S100: providing a semiconductor substrate, and placing the semiconductor in a reaction chamber of an atomic layer deposition device;

[0049] The size of the semiconductor substrate can be adjusted according to actual needs. The polishing treatment on both sides of the semiconductor substrate reduces the roughness and needs to be kept clean to prepare for subsequent coating and other processes, ensuring that the subsequent processes have high forming quality.

[0050] Step S200, heating the reaction chamber to a preset temperature and adjusting the pressure of the reaction chamber to a preset pressure;

[0051] The reaction chamber is heated by a heating device so that the temperature of the reaction chamber reaches a preset temperature, and the pressure of the reaction chamber is adjusted to a preset pressure value, thereby providing good reaction conditions for subsequent reactions in each stage and improving the efficiency of the chemical reaction.

[0052] Step S300, providing C8H 24 N4Ti is delivered into the reaction chamber as a precursor source to generate Ti(N(CH3)2) on the surface of the semiconductor substrate. x , where 1≤x≤2;

[0053] When the temperature in the reaction chamber reaches the preset temperature, the reaction chamber is evacuated to avoid interference of air on the subsequent reaction gas and to prevent contamination by dust or other particles in the air. The pressure of the reaction chamber is controlled within the preset pressure range, and then the precursor source C8H is delivered to the reaction chamber. 24 N4Ti (tetrakis(dimethylamino)titanium), tetrakis(dimethylamino)titanium generates Ti(N(CH3)2) on the surface of the semiconductor substrate through thermal decomposition reaction x , where 1≤x≤2, i.e., a dimethylamino complex of titanium, and tetrakis(dimethylamino)titanium is delivered to the reaction chamber in a periodic pulse manner during delivery to adapt to the pyrolysis reaction process of tetrakis(dimethylamino)titanium in the reaction chamber, thereby avoiding delivery of excessive tetrakis(dimethylamino)titanium, which would not react and would result in waste.

[0054] Step S400: nitrogen plasma is provided as active nitrogen free radicals to be transported into the reaction chamber. The active nitrogen free radicals react with Ti(N(CH3)2) x Reacts and deposits TiN on the surface of the semiconductor substrate y , where 0.75≤y≤0.85;

[0055] Ti(N(CH3)2) is generated on the surface of the semiconductor substrate x After that, the supply of tetrakis(dimethylamino)titanium to the reaction chamber is stopped, and nitrogen plasma is introduced into the reaction chamber. Nitrogen plasma acts as an active nitrogen free radical and reacts with Ti(N(CH3)2) x Reacts and then deposits TiN on the surface of the semiconductor substrate y , that is, non-stoichiometric titanium nitride.

[0056] Step S500: hydrogen plasma is provided as a reducing agent and transported into the reaction chamber to reduce the TiN y Performing a reduction reaction to deposit a TiN film on the surface of the semiconductor substrate;

[0057] TiN is generated on the surface of the semiconductor substrate y After that, the nitrogen plasma is stopped and hydrogen plasma is supplied to the reaction chamber. The hydrogen plasma is a reducing agent for TiN y A reduction reaction is carried out, and finally a TiN film is deposited on the surface of the semiconductor substrate.

[0058] The atomic layer deposition method of titanium nitride film provided in this embodiment, C8H 24 N4Ti is used as a precursor source to prepare TiN film through atomic layer deposition equipment. There is no Cl residue in the TiN film, so that the resistivity of the TiN film is reduced to 85μΩ·cm, and the breakdown electric field strength is ≥8MV / cm, which reduces the resistivity of the TiN film. In addition, the step coverage of the structure with an aspect ratio of 70:1 is >95%, and the uniform hole bottom / hole mouth film thickness ratio is ≥0.93, which improves the coverage of the deposited film on the surface of the three-dimensional structure with a large aspect ratio. At the same time, the deposition rate is increased by 2.3 times that of the existing technology, which improves the deposition rate, the precursor utilization rate is >40% (the average precursor utilization rate in the existing technology is 15%), which improves the precursor utilization rate, can be compatible with the film thickness of 28nm-3nm, and increases the thickness range of the deposited film.

[0059] In a specific embodiment, the concentration of tetrakis(dimethylamino)titanium as a precursor source is greater than 99.99%, and specifically a concentration of 99.999% can be used. The higher the purity of the precursor, the lower the impurity content of the film, the higher the purity of the titanium nitride film, the lower the impurities such as carbon and oxygen, and the enhanced electrical properties of the titanium nitride film.

[0060] In a specific embodiment, the thermal decomposition reaction time of tetrakis(dimethylamino)titanium in the reaction chamber is 0.7s-0.9s, specifically 0.7s, 0.8s or 0.9s, which is the Ti(N(CH3)2) deposited on the surface of the semiconductor substrate during the thermal decomposition process of tetrakis(dimethylamino)titanium. xProvide sufficient time to generate sufficient Ti(N(CH3)2) while ensuring the efficiency of preparing titanium nitride film x , which makes tetrakis(dimethylamino)titanium have a higher conversion rate and utilization rate.

[0061] In a specific embodiment, the preset temperature range of the reaction chamber is 240° C.-260° C., specifically 240° C., 245° C., 250° C. or 260° C., and the preset pressure of the reaction chamber is 0.2 torr-0.4 torr, specifically 0.2 torr, 0.25 torr, 0.3 torr or 0.4 torr. By setting the temperature and pressure within the preset range, the thermal decomposition of the precursor is controlled, and the impurity deposition caused by high temperature is avoided, thereby improving the generation of Ti(N(CH3)2). x quality purity.

[0062] In a specific embodiment, in step S400, nitrogen plasma is introduced into the reaction chamber as active nitrogen free radicals, including pulse treatment of a mixture of nitrogen and ammonia through a radio frequency coil to generate nitrogen plasma; that is, radio frequency pulses are emitted to the mixture of nitrogen and ammonia through the radio frequency coil to obtain nitrogen plasma, and the nitrogen plasma is transported into the reaction chamber as active nitrogen free radicals. Compared with directly using pure nitrogen, the use of a mixture of nitrogen and ammonia can reduce the generation of chloride residual reaction byproducts, which is beneficial to improving the purity of the titanium nitride film, thereby improving the performance of the titanium nitride film. In addition, during the radio frequency pulse process, the hydrogen plasma produced by the ammonia gas has a great effect on the Ti-N intermediate (Ti(N(CH3)2) x ) is subjected to reduction treatment to increase the deposition amount of titanium nitride film on the surface of the semiconductor substrate and improve the conversion rate of Ti-N intermediates.

[0063] In a specific embodiment, in step S400, nitrogen plasma is introduced into the reaction chamber as active nitrogen radicals to react with Ti(N(CH3)2) x The reaction time is 3s-5s, specifically 3s, 4s, 4.5s or 5s, which ensures that the atomic layer deposition method of titanium nitride film provided by this embodiment has a high titanium nitride film deposition efficiency while also ensuring that the nitrogen plasma and Ti(N(CH3)2) x With sufficient reaction time, more Ti(N(CH3)2) x TiN is deposited on the surface of the semiconductor substrate y .

[0064] In a specific embodiment, providing hydrogen plasma as a reducing agent for delivery into the reaction chamber in step 500 includes: providing a mixture of hydrogen and argon gases and subjecting the mixture to pulses through a radio frequency coil to generate the hydrogen plasma; in this case, the radio frequency coil applies radio frequency pulses to the mixture of hydrogen and argon gases to generate hydrogen plasma, thereby enabling the delivery of the hydrogen plasma as a reducing agent into the reaction chamber. Compared to using pure hydrogen directly, using a mixture of hydrogen and argon gases has a lower breakdown voltage during plasma generation, thereby improving ionization efficiency. However, pure hydrogen leads to insufficient hydrogen radical density, resulting in inadequate reduction of the Ti-N intermediate. Furthermore, pure hydrogen is highly explosive and dangerous, and may also produce hydrogen embrittlement, posing a risk of cracking in the stainless steel reaction chamber. Alternatively, nitrogen-hydrogen or helium-hydrogen may be used to generate hydrogen ions through radio frequency pulses from a radio frequency coil, but these are not listed here.

[0065] In a specific embodiment, in step 500, hydrogen plasma is provided as a reducing agent and delivered into the reaction chamber. y The time range for the reduction reaction is 1s-3s. The specific reaction time can be set to 1s, 2s or 3s to provide sufficient time for the reduction reaction so that TiN y A larger amount of TiN is converted and deposited on the surface of the semiconductor substrate to form a TiN film. Of course, those skilled in the art can set the reaction time according to actual needs, as long as the reaction time is within the range.

[0066] like Figure 2 As shown, in another specific embodiment, in step S300, C8H 24 N4Ti thermally decomposes to generate Ti(N(CH3)2) on the surface of the semiconductor substrate x Afterwards, and before introducing nitrogen plasma into the reaction chamber in step S400, the method for atomic layer deposition of titanium nitride thin film provided in this embodiment further includes:

[0067] Step S310 , providing diethylamine as an inhibitor and delivering it into the reaction chamber to inhibit deposition in the raised area;

[0068] After diethylamine (DEA) is introduced into the reaction chamber, it preferentially adsorbs onto raised areas (such as trench tops) of the semiconductor substrate, effectively suppressing subsequent deposition and thereby improving step coverage in high-aspect-ratio structures. Compared to step coverages <60% in the prior art, the step coverage of the atomic layer deposition titanium nitride thin film method provided in this embodiment is >95%. This demonstrates that the atomic layer deposition titanium nitride thin film method provided by the present invention also improves the coverage of deposited thin films on the surfaces of three-dimensional structures with large aspect ratios. Furthermore, during the delivery of DEA into the reaction chamber, argon can be used as a carrier gas to carry DEA. The resulting mixture of argon and diethylamine diffuses more thoroughly than pure diethylamine, thereby enhancing the adsorption of diethylamine.

[0069] In the atomic layer deposition method provided in this embodiment, when diethylamine is used as an inhibitor to preferentially adsorb on the raised areas of the semiconductor substrate, the diethylamine concentration range is 0.5 vol%-1.8 vol%, specifically 0.5 vol%, 0.7 vol%, 1.5 vol% or 1.8 vol%, and the diethylamine adsorption reaction time ranges from 0.4 s to 0.6 s, specifically 0.4 s, 0.5 s or 0.6 s, so that the diethylamine has a good adsorption effect on the raised areas of the semiconductor substrate. If the diethylamine concentration used is lower than this range or the adsorption reaction time is lower than this range, the adsorption effect of diethylamine on the raised areas of the semiconductor substrate will be poor, and the inhibitory ability on the raised areas will be insufficient. If the diethylamine concentration is higher than this range or the adsorption reaction time is longer than this range, the inhibitory effect of diethylamine may be greater, which is not conducive to the subsequent deposition and formation of the titanium nitride film.

[0070] In a specific embodiment, after the TiN film is deposited on the surface of the semiconductor substrate once in step S500, if the thickness of the TiN film does not reach the preset thickness, then steps S300, S400 and S500 are repeated, that is, the precursor source C8H is supplied to the reaction chamber again. 24 N4Ti, Ti(N(CH3)2) is generated on the surface of the semiconductor substrate x , nitrogen plasma and Ti(N(CH3)2) are delivered to the reaction chamber x Reacts and deposits TiN on the surface of the semiconductor substrate y , hydrogen plasma is delivered to the reaction chamber, and the hydrogen plasma is used to y A reduction reaction is performed to deposit a TiN film on the surface of the semiconductor substrate again, and this process is repeated until the thickness of the TiN film on the surface of the semiconductor substrate reaches a preset thickness.

[0071] In a specific embodiment, the method for atomic layer deposition of titanium nitride film provided in this embodiment further includes a purge process. In step S300C8H24 After N4Ti is delivered as a precursor source into the reaction chamber for pyrolysis reaction, and before delivering nitrogen plasma to the reaction chamber in step S400, the delivery of tetrakis(dimethylamino)titanium to the reaction chamber is stopped, and a purge gas is introduced into the reaction chamber to remove the unreacted C8H 24 N4Ti, and the reaction byproducts produced in the reaction process are purged and cleaned out in time to avoid affecting the subsequent chemical reaction process. In addition, when diethylamine is needed to suppress the deposition in the raised area, that is, when step S310 is performed after step S300, after completing step S300, before performing step S310, it is also necessary to pass a purge gas into the reaction chamber to remove residual gas and reaction byproducts, thereby ensuring that diethylamine has a good inhibitory effect on the deposition in the raised area of ​​the semiconductor substrate. After step S310, the deposition inhibition in the raised area is completed, and after stopping to continue to transport diethylamine to the reaction chamber, before step S400, a purge gas is passed into the reaction chamber to clean out the diethylamine remaining in the reaction chamber, and then step S400 is continued to pass nitrogen plasma into the reaction chamber. In a specific embodiment, argon gas can be used as the purge gas to purge the reaction chamber, and the purge amount of the argon gas can be adjusted according to actual needs.

[0072] like Figure 3 As shown, the embodiment of the present invention also discloses an atomic layer deposition device, which is used for the above-mentioned atomic layer deposition method of titanium nitride thin film. The atomic layer deposition device provided by the embodiment of the present invention includes a reaction chamber 10, a gas source bottle 20, a heating plate 30, a plasma generating mechanism 40 and a vacuum pump 50. Among them, the reaction chamber 10 has a space for holding gas. The various stages of the atomic layer deposition reaction are carried out in the reaction chamber 10, which is used to hold C8H 24 The gas source bottle 20 of N4Ti gas is connected to the reaction chamber 10 through the first pipe 61, and the first pipe 61 is provided with a switch control valve, which controls the C8H 24The flow of N4Ti gas in the first pipe 61 is controlled and cut off, and the diethylamine used to selectively suppress the deposition in the raised area is connected to the reaction chamber 10 through the fourth pipe 64. Similarly, the fourth pipe 64 is provided with a switch control valve, so that diethylamine can be delivered to the reaction chamber 10 according to actual needs during the atomic layer deposition reaction process. The heating disk 30 is located in the reaction chamber 10 and heats the reaction chamber 10 by the heating disk 30 so that the temperature in the reaction chamber 10 reaches a preset temperature. The plasma generating mechanism 40 includes a plasma generating chamber 41 and a radio frequency coil 42. The plasma generating chamber 41 is connected to the reaction chamber 10. A mixture of hydrogen and argon is delivered to the plasma generating chamber 41 through a second pipe 62, and a mixture of nitrogen and ammonia is delivered to the plasma generating chamber 41 through a third pipe 63. The radio frequency coil 42 is wound around the outer cavity wall of the plasma generating chamber 41. Therefore, after the mixture of hydrogen and argon or the mixture of nitrogen and ammonia is delivered to the plasma generating chamber 41, a current is passed through the radio frequency coil 42 to generate radio frequency pulses in the plasma generating chamber 41, thereby generating hydrogen plasma or nitrogen plasma. The hydrogen plasma or nitrogen plasma is then delivered to the reaction chamber 10. The vacuum pump 50 is connected to the reaction chamber 10 through a pipe and is used to evacuate the reaction chamber 10.

[0073] In another specific embodiment, the atomic layer deposition equipment provided in this embodiment is provided with a gas flow meter 70, and the first pipeline 61, the second pipeline 62, the third pipeline 63, and the fourth pipeline 64 are all provided with a gas flow meter 70, and then the gas delivery amount is controlled and monitored by the gas flow meter 70 to control the amount of gas entering the reaction chamber 10 and the plasma generation chamber 41.

[0074] In a specific embodiment, the method for atomic layer deposition of titanium nitride thin film provided in this embodiment uses the above-mentioned atomic layer deposition equipment to perform atomic layer deposition of titanium nitride thin film. The specific process is as follows:

[0075] S100, providing a semiconductor substrate, and placing the semiconductor in a reaction chamber 10;

[0076] S200, the temperature of the reaction chamber 10 is heated to 250 degrees by the heating plate 30, and the precursor source gas bottle 20 is heated to 75 degrees, and the reaction chamber 10 is evacuated by the vacuum pump 50 and the pressure of the reaction chamber 10 is controlled to be maintained at 0.3 torr;

[0077] S300, open the upper switch control valve of the first pipeline 61, and control the flow rate of argon gas through the gas flow meter 70, open the precursor source gas bottle 20, and use argon as the carrier gas at 50 sccm to transfer C8H 24 N4Ti is transported into the reaction chamber 10, C8H 24The pyrolysis reaction time of N4Ti in the reaction chamber 10 is 0.8s, and Ti(N(CH3)2) is generated on the surface of the semiconductor substrate. x After the reaction is completed, the precursor gas source bottle 20 is closed and the supply of C8H2 to the reaction chamber 10 is stopped. 24 N4Ti, and the flow rate of argon was increased to 200 sccm for purging, and the purging time was controlled to be 12 s;

[0078] S310, a mixture of argon and diethylamine is delivered to the reaction chamber 10 through the fourth pipe 64. The diethylamine inhibits the reaction of the raised areas of the semiconductor substrate for 0.5 seconds. Then, the delivery of the mixture of argon and diethylamine to the reaction chamber 10 is stopped, and the flow rate of the argon is adjusted to 150 sccm and the purge is continued for 5 seconds.

[0079] At step S400, a mixture of nitrogen and ammonia is delivered to the plasma generation chamber 41 through the third pipe 63, wherein the delivery rate of nitrogen is 100 sccm and the delivery rate of ammonia is 40 sccm. The RF power supply is turned on and the power is set to 800 W (13.56 MHz). Under the action of the RF coil 42 on the outer wall of the plasma generation chamber 41, nitrogen plasma is generated in the plasma generation chamber 41. The nitrogen plasma is then delivered to the reaction chamber 10 and reacts with the Ti(N(CH3)2) x The reaction time is controlled to 4s, and TiN is deposited on the surface of the semiconductor substrate. y , then stop supplying nitrogen and ammonia to the reaction chamber 10;

[0080] S500, a mixture of hydrogen and argon is delivered to the plasma generation chamber 41 through the second pipe 62, wherein the concentration of the mixture of hydrogen and argon is 5 vol%, and the input amount of the mixture of hydrogen and argon is 50 sccm. Then, the RF power supply is turned on, and the power is set to 800 W (13.56 MHz). Under the action of the RF coil 42 on the outer cavity wall of the plasma generation chamber 41, hydrogen plasma is generated in the plasma generation chamber 41, and the hydrogen plasma is delivered to the reaction chamber 10 to react with the TiN y A reduction reaction is performed for 2 seconds to deposit a TiN thin film on the surface of the semiconductor substrate. The supply of the hydrogen and argon mixture to the reaction chamber 10 is then stopped, and argon purge at 300 sccm is continued for 21 seconds, completing a single cycle of the TiN thin film reaction. If the thickness of the TiN thin film deposited on the surface of the semiconductor substrate does not reach a predetermined thickness, steps S300, S400, and S500 are repeated until the thickness of the TiN thin film on the surface of the semiconductor substrate reaches a predetermined thickness.

[0081] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0082] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for atomic layer deposition of titanium nitride thin film, characterized in that: Using atomic layer deposition equipment, the atomic layer deposition method of titanium nitride film includes: S100, providing a semiconductor substrate, wherein the semiconductor substrate is placed in a reaction chamber of the atomic layer deposition device; S200, heating the temperature of the reaction chamber to a preset temperature, and adjusting the pressure of the reaction chamber to a preset pressure; S300, offering C8H 24 N4Ti is transported into the reaction chamber as a precursor source to generate Ti(N(CH3)2) on the surface of the semiconductor substrate. x , where 1≤x≤2; S400, providing nitrogen plasma as active nitrogen free radicals to be transported into the reaction chamber, and the active nitrogen free radicals react with the Ti(N(CH3)2) x The reaction occurs and TiN is deposited on the surface of the semiconductor substrate. y , where 0.75≤y≤0.85; S500, providing hydrogen plasma as a reducing agent and delivering it into the reaction chamber, and reducing the TiN y A reduction reaction is performed to deposit and generate a TiN film on the surface of the semiconductor substrate.

2. The method for atomic layer deposition of titanium nitride thin film according to claim 1, characterized in that: The C8H 24 The concentration of N4Ti is greater than 99.99%.

3. The method for atomic layer deposition of titanium nitride thin film according to claim 1, wherein the C8H 24 The reaction time of N4Ti in the reaction chamber is 0.7s-0.9s.

4. The method for atomic layer deposition of titanium nitride thin film according to claim 1, wherein: The preset temperature is 240° C.-260° C., and the preset pressure is 0.2 torr-0.4 torr.

5. The method for atomic layer deposition of titanium nitride thin film according to claim 1, characterized in that: The providing of nitrogen plasma as active nitrogen radicals to be transported into the reaction chamber comprises: Pulsing a mixture of nitrogen and ammonia through a radio frequency coil to generate the nitrogen plasma; The nitrogen plasma is delivered into the reaction chamber as active nitrogen radicals.

6. The method for atomic layer deposition of titanium nitride thin film according to claim 1, characterized in that: The active nitrogen radical and the Ti(N(CH3)2) x The reaction time is 3s-5s.

7. The method for atomic layer deposition of titanium nitride thin film according to claim 1, characterized in that: The providing hydrogen plasma as a reducing agent and delivering it into the reaction chamber comprises: Providing a mixed gas of hydrogen and argon through a pulse process of a radio frequency coil to generate the hydrogen plasma; The hydrogen plasma is delivered into the reaction chamber as a reducing agent.

8. The method for atomic layer deposition of titanium nitride thin film according to claim 1, characterized in that: The hydrogen plasma acts on the TiN y The reduction reaction takes 1s to 3s.

9. The method for atomic layer deposition of titanium nitride thin film according to claim 1, characterized in that: Ti(N(CH3)2) is generated on the surface of the semiconductor substrate x Afterwards, before providing nitrogen plasma as active nitrogen radicals to be transported into the reaction chamber, the atomic layer deposition titanium nitride film method further includes: S310 , providing diethylamine as an inhibitor and delivering it into the reaction chamber to inhibit deposition in the raised area on the semiconductor substrate.

10. The method for atomic layer deposition of titanium nitride thin film according to claim 9, characterized in that: The concentration of the diethylamine is 0.5 vol%-1.8 vol%; and / or the inhibition reaction time of the diethylamine as an inhibitor is 0.4s-0.6s.

11. The method for atomic layer deposition of titanium nitride thin film according to claim 1, characterized in that: After step S500 , steps S300 , S400 , and S500 are repeated at least once until the thickness of the TiN film on the surface of the semiconductor substrate reaches a preset thickness.

12. The method for atomic layer deposition of titanium nitride thin film according to any one of claims 1 to 11, characterized in that: After step S300 and before step S400 , the atomic layer deposition titanium nitride thin film method further includes: introducing a purge gas into the reaction chamber to remove residual gas and reaction by-products.

13. An atomic layer deposition device, characterized in that: The method for atomic layer deposition of titanium nitride thin film according to any one of claims 1 to 12, wherein the atomic layer deposition equipment comprises: A reaction chamber for performing atomic layer deposition reaction; Gas source bottle, used to hold C8H 24 N4Ti gas, the gas source bottle is connected to the reaction chamber through a first pipe; a heating plate, arranged in the reaction chamber, and heating is performed by the heating plate; a plasma generating mechanism comprising a plasma generating chamber and a radio frequency coil, wherein the plasma generating chamber is in communication with the reaction chamber, and is in communication with a mixture of hydrogen and argon through a second pipe, and is in communication with a mixture of nitrogen and ammonia through a third pipe, and the radio frequency coil is wound around an outer wall of the plasma generating chamber; A vacuum pump is connected to the reaction chamber, and the reaction chamber is evacuated by the vacuum pump.

14. The atomic layer deposition apparatus according to claim 13, wherein: The atomic layer deposition equipment further includes a gas flow meter for detecting gas flow rate, and the gas flow meter is provided on the first pipeline, the second pipeline and the third pipeline.

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