CN119121175A

CN119121175A - Tantalum ring and preparation method thereof

Info

Publication number: CN119121175A
Application number: CN202411044440.7A
Authority: CN
Inventors: 徐雷; 岳晓聪; 黄宇彬; 蔡新志; 童培云
Original assignee: Leading Film Materials Jiangsu Co ltd
Current assignee: Leading Film Materials Jiangsu Co ltd
Priority date: 2024-07-31
Filing date: 2024-07-31
Publication date: 2024-12-13

Abstract

The application belongs to the field of metal processing, and discloses a preparation method of a tantalum ring, which comprises the steps of firstly cleaning and drying a steel ring; then, the steel ring is filled with a titanium source and reducing gas in a vacuum environment, heated, and titanium is deposited on the surface of the steel ring through chemical vapor deposition to obtain the titanium ring; finally, the tantalum ring is put into a tantalum source and a reducing gas in a vacuum environment, heated, tantalum is deposited on the surface of the titanium ring by chemical vapor deposition to obtain the tantalum ring, the proposal utilizes a vapor deposition method, the application further discloses the tantalum ring prepared by the method.

Description

Tantalum ring and preparation method thereof

Technical Field

The invention relates to the field of metal processing, in particular to a tantalum ring and a preparation method thereof.

Background

Currently, sputtering is commonly used to form electrode films on the surface of semiconductor structures. Sputtering is a Physical Vapor Deposition (PVD) coating method, which is a process of bombarding a target with charged particles, causing surface atoms of the target to collide and transfer energy and momentum, and escaping the target atoms from the surface and depositing on a substrate. However, the direction of the charged particles bombarding the target is uncertain, so that the directionality of target atoms escaping from the target surface is poor, that is, the target atoms can be separated from the target surface from various angles and then reach the substrate surface along a straight line, so that the coverage capability of the target atoms on the bottom and the side wall of a contact hole or a through hole in the substrate surface and the coverage capability of the target atoms on the side wall of a step are poor, and in order to obtain a good coverage effect on the bottom and the side wall of the contact hole or the through hole and the side wall of the step, collimation sputtering is generally adopted. The collimated sputtering typically places a ring structure in the sputtering apparatus to constrain the motion trajectories of the sputtered particles, that is, the ring structure acts to focus the high energy particles during the sputtering process.

Meanwhile, in the sputtering process, high-energy particles continuously bombard the surface of the target, so that the temperature of the surface of the target is increased, and thermal stress is easily generated, so that the target is broken or deformed. The high melting point and excellent corrosion resistance of the tantalum ring can enable the tantalum ring to bear high temperature and high energy particle bombardment, and the target material is effectively protected from being damaged. In addition, the high heat-conducting property of the tantalum ring is also beneficial to quickly conducting heat to the periphery of the target, the rise of the surface temperature of the target is reduced, the risk of damage to the target is further reduced, and the tantalum ring can improve the sputtering efficiency. In the sputtering process, the tantalum ring can absorb part of the sputtered material to form a tantalum compound, so that the loss of the sputtered material is reduced, and the sputtering efficiency is improved. In addition, the tantalum ring has higher surface smoothness and precision, is favorable for improving the stability and uniformity in the sputtering process, ensures the thickness and component uniformity of the film, has good chemical stability and corrosion resistance, can keep stable performance under various sputtering conditions, and is not easy to be influenced by factors such as gas, sputtering materials and the like. The tantalum ring can maintain high-efficiency performance for a long time in the sputtering process, the production efficiency is improved, and in addition, the service life of the target material can be prolonged. The target is a core material in the sputtering process, and the quality and stability of the target directly influence the quality and performance of the film. The protection effect and high-efficiency sputtering of the tantalum ring can prolong the service life of the target, reduce the times of changing the target, reduce the production cost, and the importance of the tantalum ring in the sputtering process is not ignored in general. The method not only can protect the target material and improve the sputtering efficiency, but also can improve the quality and performance of the film, and plays a vital role in the stability and reliability of the sputtering process. Therefore, in performing the sputtering process, it is important to select an appropriate tantalum ring material and a good-quality tantalum ring manufacturer to ensure smooth progress of the sputtering process and improvement of film quality

Tantalum rings are required to be used in sputtering of tantalum targets, tantalum is a rare strategic resource, and high purity tantalum is expensive, so a tantalum ring preparation method for reducing the tantalum metal consumption needs to be explored.

The chinese patent application 201910128675.7 discloses a method for preparing a high-purity tantalum sputtering target by chemical vapor deposition. In the scheme, tantalum pentafluoride is used as a raw material, and tantalum is deposited on the surface of a substrate material through chemical deposition with reducing gas to form a layer of tantalum film. In the scheme, the tantalum target material is prepared by adopting a one-step method, so that the quality of the tantalum target material product is guaranteed, and the production cost is high due to secondary processing pollution is avoided.

The Chinese patent application 202211316953.X discloses a preparation method of a material for forming a tantalum/tantalum-iron gradient layer on the surface of carbon steel, which comprises the steps of putting a target material into a vacuum chamber, introducing inert gas, applying voltage and heating to perform bombardment pretreatment, then alternately changing and adjusting the voltage and current of the tantalum target material and a carbon steel substrate by utilizing a double glow cross-linking discharge phenomenon, raising the temperature gradient of the carbon steel substrate to a preset temperature to perform activation, raising the temperature to the preset temperature and uniformly diffusing tantalum element on the surface of the substrate at constant temperature, and finally raising the voltage of the tantalum target material to ensure that the sputtering rate of the tantalum element is larger than the reverse sputtering rate and rapidly depositing a layer of tantalum/tantalum-iron gradient film on the surface of the carbon steel substrate. In the scheme, the modification treatment of the surface of the metal substrate is realized by utilizing a double glow plasma surface metallurgy technology, and the prepared base material has better performance but more complicated process.

The scheme solves the problem of how to provide a preparation method of a tantalum ring with low cost.

Disclosure of Invention

The invention aims to provide a preparation method of a tantalum ring, which comprises the steps of carrying out primary deposition on the surface of a steel ring by utilizing titanium tetrafluoride and reducing gas to form a layer of titanium film, and then carrying out secondary deposition on tantalum pentafluoride and reducing gas on the basis of the titanium film to form a tantalum film, thereby obtaining the tantalum ring with a two-layer film structure.

In order to achieve the above purpose, the application discloses a preparation method of a tantalum ring, which comprises the following steps:

Step 1, cleaning a steel ring and drying;

step 2, depositing titanium on the surface of the steel ring prepared in the step 1 in a vacuum environment to obtain a titanium ring;

step 3, depositing tantalum on the surface of the titanium ring prepared in the step 2 in a vacuum environment to obtain a tantalum ring;

In the step 2, the thickness of titanium deposited on the surface of the steel ring is 100-200 nm;

in the step 3, the thickness of tantalum deposited on the surface of the titanium ring is 450-550 nm.

Preferably, the deposition method of the step 2 is any one of physical vapor deposition, chemical vapor deposition, low-pressure chemical vapor deposition and plasma enhanced chemical vapor deposition;

The deposition method in the step 3 is any one of physical vapor deposition, chemical vapor deposition, low-pressure chemical vapor deposition and plasma enhanced chemical vapor deposition.

Preferably, the deposition method of the step 2 is chemical vapor deposition, and the step 2 specifically comprises the steps of introducing a titanium source and a reducing gas into the steel ring prepared in the step 1 in a vacuum environment, heating, and depositing titanium on the surface of the steel ring through chemical vapor deposition to obtain a titanium ring;

the deposition method of the step 3 is chemical vapor deposition, and the step 3 specifically comprises the steps of introducing a tantalum source and a reducing gas into the titanium ring prepared in the step 2 in a vacuum environment, heating, and depositing tantalum on the surface of the titanium ring through chemical vapor deposition to obtain the tantalum ring.

Preferably, the cleaning process in the step 1 is to sequentially carry out ultrasonic cleaning, acid cleaning, water cleaning and ethanol cleaning on the steel ring to obtain the cleaned steel ring.

Preferably, the titanium source in step 2 is at least one of TiCl ₄、Ti(OMe)₄、Ti(OEt)₄.

Preferably, the tantalum source in step 3 is at least one of TaCl ₅、TaF₅、TaBr₅.

Preferably, the total thickness of titanium deposited on the surface of the steel ring and tantalum deposited on the surface of the titanium ring is 650.+ -.50 nm.

Preferably, the heating temperature in the step 2 is 600-700 ℃;

The heating temperature in the step 3 is 900-1000 ℃.

In addition, the application also discloses a tantalum ring which is prepared by the preparation method of the tantalum ring.

The beneficial effects of the invention are as follows:

The invention provides a preparation method of a tantalum ring, which comprises the steps of carrying out primary deposition on the surface of a steel ring by utilizing titanium tetrafluoride and reducing gas to form a layer of titanium film, and then carrying out secondary deposition on tantalum pentafluoride and reducing gas on the basis of the titanium film to form a tantalum film, thereby obtaining the tantalum ring with a two-layer film structure. The combination of the titanium film and the tantalum film is used for replacing a pure tantalum film structure, so that the purpose of reducing the use of rare metal tantalum is achieved, the cost is further reduced, and the resource is saved.

Detailed Description

In the description of the present invention, it is to be noted that the specific conditions are not specified in the examples, and the description is performed under the conventional conditions or the conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.

Example 1

Step 1, firstly, ultrasonically cleaning a steel ring for 3min, then pickling for 3min, then washing with pure water for 3min, finally washing with absolute alcohol for 3min, and drying with clean nitrogen;

Step 2, introducing TiCl ₄ and H ₂ into the steel ring prepared in the step 1 in a vacuum environment, heating to 650 ℃, and depositing titanium on the surface of the steel ring through chemical vapor deposition to obtain a titanium ring, wherein the thickness of the titanium film is 150nm;

And 3, introducing TaCl ₅ and H ₂ into the titanium ring prepared in the step 2 in a vacuum environment, heating to 950 ℃, and depositing tantalum on the surface of the titanium ring through chemical vapor deposition to obtain the tantalum ring, wherein the thickness of the tantalum film is 500nm.

Example 2

Step 2, introducing TiCl ₄ and H ₂ into the steel ring prepared in the step 1 in a vacuum environment, heating to 700 ℃, and depositing titanium on the surface of the steel ring through chemical vapor deposition to obtain a titanium ring, wherein the thickness of the titanium film is 200nm;

And 3, introducing TaCl ₅ and H ₂ into the titanium ring prepared in the step 2 in a vacuum environment, heating to 900 ℃, and depositing tantalum on the surface of the titanium ring through chemical vapor deposition to obtain a tantalum ring, wherein the thickness of the tantalum film is 450nm.

Example 3

Step 2, introducing TiCl ₄ and H ₂ into the steel ring prepared in the step 1 in a vacuum environment, heating to 600 ℃, and depositing titanium on the surface of the steel ring through chemical vapor deposition to obtain a titanium ring, wherein the thickness of the titanium film is 100nm;

And 3, introducing TaCl ₅ and H ₂ into the titanium ring prepared in the step 2 in a vacuum environment, heating to 1000 ℃, and depositing tantalum on the surface of the titanium ring through chemical vapor deposition to obtain a tantalum ring, wherein the thickness of the tantalum film is 550nm.

Example 4

Step 2, introducing TiCl ₄ and H ₂ into the steel ring prepared in the step 1 in a vacuum environment, heating to 650 ℃, and depositing titanium on the surface of the steel ring through chemical vapor deposition to obtain a titanium ring, wherein the thickness of the titanium film is 250nm;

And 3, introducing TaCl ₅ and H ₂ into the titanium ring prepared in the step 2 in a vacuum environment, heating to 950 ℃, and depositing tantalum on the surface of the titanium ring through chemical vapor deposition to obtain a tantalum ring, wherein the thickness of the tantalum film is 400nm.

Example 5

Step 2, introducing TiCl ₄ and H ₂ into the steel ring prepared in the step 1 in a vacuum environment, heating to 650 ℃, and depositing titanium on the surface of the steel ring through chemical vapor deposition to obtain a titanium ring, wherein the thickness of the titanium film is 50nm;

And 3, introducing TaCl ₅ and H ₂ into the titanium ring prepared in the step 2 in a vacuum environment, heating to 950 ℃, and depositing tantalum on the surface of the titanium ring through chemical vapor deposition to obtain a tantalum ring, wherein the thickness of the tantalum film is 600nm.

Example 6

Step 2, introducing TiCl ₄ and H ₂ into the steel ring prepared in the step 1 in a vacuum environment, heating to 650 ℃, and depositing titanium on the surface of the steel ring through chemical vapor deposition to obtain a titanium ring, wherein the thickness of the titanium film is 200nm;

And 3, introducing TaCl ₅ and H ₂ into the titanium ring prepared in the step 2 in a vacuum environment, heating to 950 ℃, and depositing tantalum on the surface of the titanium ring through chemical vapor deposition to obtain a tantalum ring, wherein the thickness of the tantalum film is 50nm.

Example 7

Comparative example 1

And 2, introducing TaCl ₅ and H ₂ into the steel ring prepared in the step 1 in a vacuum environment, heating to 950 ℃, and depositing tantalum on the surface of the steel ring through chemical vapor deposition to obtain a tantalum ring, wherein the thickness of the tantalum film is 650nm.

Comparative example 2

Step 2, introducing TiCl ₄ and H ₂ into the steel ring prepared in the step 1 in a vacuum environment, heating to 650 ℃, and depositing titanium on the surface of the steel ring through chemical vapor deposition to obtain a titanium ring, wherein the thickness of the titanium film is 650nm;

Comparative example 3

Step 2, introducing hafnium tetrachloride and H ₂ into the steel ring in the step1 in a vacuum environment, heating to 650 ℃, and depositing hafnium on the surface of the steel ring through chemical vapor deposition to obtain a hafnium ring, wherein the thickness of the hafnium film is 150nm;

and 3, introducing TaCl ₅ and H ₂ into the titanium ring obtained in the step 2 in a vacuum environment, heating to 950 ℃, and depositing tantalum on the surface of the titanium ring by chemical vapor deposition to obtain the tantalum ring, wherein the thickness of the tantalum film is 500nm.

Comparative example 4

As a comparative example, a pure tantalum ring of the same size as in example 1 was used, and it should be noted that the pure tantalum ring refers to a pure tantalum ring composed of tantalum metal only.

Performance testing

Film adhesion-adhesion to 100 grid areas using 3M tape, number of unpeeled areas/100. The higher the number of unpeels, the stronger the film adhesion.

The tantalum ring performance test results in examples 1-7 and comparative examples 1-4 are shown in Table 1:

TABLE 1

Analysis of results

1. As can be seen from examples 1 to 4 and comparative example 1, the thickness of the titanium film in the tantalum ring of example 1 was 150nm, and the thickness of the tantalum film was 500nm;

example 2 the thickness of the titanium film in the tantalum ring was 200nm and the thickness of the tantalum film was 450nm;

example 3 the thickness of the titanium film in the tantalum ring was 100nm and the thickness of the tantalum film was 550nm;

Example 4 the thickness of the titanium film in the tantalum ring was 250nm, the thickness of the tantalum film was 400nm, and experimental data are shown in table 2:

TABLE 2

From experimental data, when the thickness of the titanium film in the tantalum ring is increased from 100nm to 200nm, the adhesion between the titanium film and the film layer of the steel ring is continuously enhanced, but when the thickness of the titanium film is increased from 200nm to 250nm, the adhesion between the titanium film and the film layer is also enhanced to a certain extent, but the adhesion is very small.

When the thickness of the tantalum film in the tantalum ring is increased from 400nm to 550nm, the reflectivity of the sputtering particles in the whole life cycle of the tantalum ring is continuously reduced, which means that the thickness of the tantalum film is favorable for improving the reflectivity of the sputtering particles in the whole life cycle of the tantalum ring, but the material cost is gradually increased along with the increase of the thickness of the tantalum film due to higher cost of tantalum metal.

2. As can be seen from examples 5 to 7, the thickness of the titanium film in the tantalum ring of example 5 was 50nm, and the thickness of the tantalum film was 600nm;

Example 6 the thickness of the titanium film in the tantalum ring was 200nm and the thickness of the tantalum film was 50nm;

example 7 the thickness of the titanium film in the tantalum ring was 50nm, the thickness of the tantalum film was 50nm, and experimental data of the above tantalum ring are shown in table 3:

TABLE 3 Table 3

From experimental data, when the thickness of the titanium film is less than 100nm, the film adhesion between the titanium film and the steel ring is greatly reduced, and when the thickness of the titanium film is only 50nm, the film adhesion is only 66%.

And when the thickness of the tantalum film in the tantalum ring is too thin, the reflectivity of sputtering particles in the whole life cycle of the tantalum ring can be easily fallen off along with the too thin tantalum film in the sputtering process, so that the reflectivity is extremely high.

3. Meanwhile, as can be seen from the example 1 and the comparative examples 1-2, in the example 1, the film layer of the steel ring consists of a titanium film and a tantalum film;

the film layer of the steel ring in comparative example 1 consists of a tantalum film;

The film layer of the steel ring in comparative example 2 was composed of a titanium film, and experimental data of the tantalum ring or the titanium ring prepared above are shown in table 4:

TABLE 4 Table 4

From experimental data, it is known that when the tantalum ring is entirely formed of a tantalum film, the reflectivity of the tantalum ring should be <1% according to the rule that the thicker the tantalum film is, the higher the reflectivity of the sputtering particles in the whole life cycle is, but the reflectivity of the sputtering particles in the whole life cycle of comparative example 1 is more than 30%, because the tantalum ring is not easily detached during use due to the poor adhesion of the tantalum film to the tantalum ring provided by the titanium film, and the reflectivity thereof is only >30%.

When the film layer of the tantalum ring is entirely formed of a titanium film, the film layer adhesiveness thereof is excellent, but the titanium film cannot provide sputtering performance of the tantalum film like the tantalum film, so the full life cycle sputtered particle reflectivity is >60%.

As can be seen from example 1 and comparative example 1, the cost of the tantalum ring made by combining the titanium film and the tantalum film is reduced by 740 yuan per sheet compared with the cost of the tantalum ring made by single tantalum film.

4. As can be seen from example 1 and comparative example 3, in comparative example 3, the titanium element was replaced with hafnium element, which is a same group as titanium element, to form a hafnium film and form a double coating with a tantalum film, and a tantalum ring was produced, but the film adhesion was only 54%, which is far less than that provided by the titanium film.

And because the adhesion provided by the hafnium film is smaller, the hafnium film can not firmly adsorb the tantalum film like a titanium film, so that the tantalum film is easy to fall off in the use process, and the reflectivity of sputtering particles in the whole life cycle is more than 20%.

The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principle of the present invention should be made in the equivalent manner, and the embodiments are included in the protection scope of the present invention.

Claims

1. A method for preparing a tantalum ring, characterized in that it comprises the following steps:

Step 1: Clean and dry the steel ring;

Step 2: Under a vacuum environment, titanium is deposited on the surface of the steel ring obtained in step 1 to obtain a titanium ring;

Step 3: Under a vacuum environment, tantalum is deposited on the surface of the titanium ring obtained in step 2 to obtain a tantalum ring;

And in step 2, the thickness of titanium deposited on the surface of the steel ring is 100 to 200 nm;

In step 3, the thickness of the tantalum deposited on the surface of the titanium ring is 450-550 nm.

2. The method for preparing a tantalum ring according to claim 1, characterized in that the deposition method in step 2 is any one of physical vapor deposition, chemical vapor deposition, low pressure chemical vapor deposition, and plasma enhanced chemical vapor deposition;

The deposition method in step 3 is any one of physical vapor deposition, chemical vapor deposition, low pressure chemical vapor deposition, and plasma enhanced chemical vapor deposition.

3. The method for preparing a tantalum ring according to claim 1, characterized in that the deposition method in step 2 is chemical vapor deposition, and step 2 specifically comprises: introducing a titanium source and a reducing gas into the steel ring obtained in step 1 under a vacuum environment, heating the steel ring, and depositing titanium on the surface of the steel ring by chemical vapor deposition to obtain a titanium ring;

The deposition method of step 3 is chemical vapor deposition, and step 3 specifically includes: introducing a tantalum source and a reducing gas into the titanium ring obtained in step 2 under a vacuum environment, heating, and depositing tantalum on the surface of the titanium ring through chemical vapor deposition to obtain a tantalum ring.

4. The method for preparing a tantalum ring according to claim 1 is characterized in that the cleaning process in step 1 is: the steel ring is sequentially subjected to ultrasonic cleaning, acid cleaning, water washing, and ethanol washing to obtain a cleaned steel ring.

5 . The method for preparing a tantalum ring according to claim 1 , wherein the titanium source in step 2 is at least one of TiCl ₄ , Ti(OMe) ₄ , and Ti(OEt) ₄ .

6 . The method for preparing a tantalum ring according to claim 1 , wherein the tantalum source in step 3 is at least one of TaCl ₅ , TaF ₅ , and TaBr ₅ .

7. The method for preparing a tantalum ring according to claim 1, characterized in that the total thickness of the titanium deposited on the surface of the steel ring and the tantalum deposited on the surface of the titanium ring is 650±50 nm.

8. The method for preparing a tantalum ring according to claim 1, characterized in that the heating temperature in step 2 is 600-700°C;

The heating temperature in step 3 is 900-1000°C.

9. A tantalum ring made by the method for making a tantalum ring according to any one of claims 1 to 8.