CN102409293A - Preparation method of aluminum oxide film - Google Patents

Abstract

The invention relates to a method for preparing an aluminum oxide film, and belongs to the field of surface engineering technology. The method comprises the following steps: placing a flexible polymer film substrate in a vacuum chamber, evacuating the vacuum chamber to a pressure of ≤2.0×10 ^-3 Pa in the vacuum chamber; using an ion source to bombard the substrate with argon ions to improve the adhesion of the plated film layer; wherein the argon gas flow rate is 15 sccm, the ion beam discharge voltage is 280V, and the ion beam current is 1A; and using oxygen ion beam assisted pulse reactive magnetron sputtering technology to deposit the aluminum oxide film, the target source is an aluminum target. During the preparation process, the substrate is kept at room temperature to avoid damage to the flexible polymer film substrate by high temperature. Rapid deposition of high-quality aluminum oxide film can be achieved on a flexible polymer substrate.

Description

A kind of preparation method of aluminum oxide thin film

technical field

The invention relates to a method for preparing an aluminum oxide film, which belongs to the technical field of surface engineering.

Background technique

Al ₂ O ₃ film is an important functional film material, due to its high dielectric constant, high thermal conductivity, strong resistance to radiation damage, strong resistance to alkali ion penetration and transparency in a wide range of wavelengths, etc. Many excellent physical and chemical properties make it widely used in many fields such as microelectronic devices, electroluminescent devices, optical waveguide devices and anti-corrosion coatings.

There are many methods for preparing Al ₂ O ₃ thin films, such as: magnetron sputtering, ion beam assisted deposition (IBAD), pulsed laser deposition (PLD), electron beam physical vapor deposition, chemical vapor deposition (CVD), atomic layer deposition (ALD) and sol-gel (Sol-Gel), etc. Pulse reactive magnetron sputtering has become a research hotspot because it can maintain the uniformity of the film in a large area and can effectively solve the discharge effect when preparing dielectric films such as Al ₂ O ₃ films. However, the preparation of Al ₂ O ₃ thin films by pulse reactive magnetron sputtering is affected by hysteresis. When the substrate is not heated and the target is in a metallic state, it is impossible to obtain a completely stoichiometric Al ₂ O ₃ thin film. Using substrate heating (above 500°C) or plating pure Al ₂ O ₃ thin films under the condition of target poisoning cannot achieve low-temperature and rapid deposition of thin films, which limits the preparation and application of compound thin films on flexible polymer substrates. Ion beam assisted deposition technology can synthesize compound thin films at low substrate temperature. The prepared thin films have the characteristics of high film-base bonding strength and high film density. They are widely used in the preparation of structural thin film materials and functional thin film materials. In the traditional IBAD method, the oxide thin film is generally prepared by Ar ion-assisted electron beam evaporation deposition method. The deposition rate of this method is low and the film composition is difficult to control. Therefore, it is urgent to develop a new preparation method to reduce the deposition temperature and increase the deposition rate.

Contents of the invention

The purpose of the present invention is to provide a low-temperature and rapid preparation method for high-quality aluminum oxide film to overcome the problems of high deposition temperature of aluminum oxide film and low deposition rate caused by metal target poisoning in the prior art. The substrate can be popularized and applied to flexible polymer films, greatly expanding the application range of aluminum oxide films.

A method for preparing an aluminum oxide film, said method comprising the following steps:

(1) Place the flexible polymer film substrate in a vacuum chamber, and evacuate the vacuum chamber until the pressure in the vacuum chamber is ≤2.0×10 ^-3 Pa;

(2) Carry out argon ion bombardment treatment to substrate with ion source, improve the adhesive force of plating film layer; Wherein argon gas flow rate is 15sccm, ion beam discharge voltage is 280V, and ion beam current is 1A;

(3) The alumina film was deposited by oxygen ion beam assisted pulse reaction magnetron sputtering technology, the target source was aluminum target, and the process parameters were as follows:

The working gas flow rate of argon is 8~15sccm;

The volume fraction of oxygen in the ion source is 86% to 89%;

Working pressure 0.3～0.5Pa;

Ion source voltage 300～500V;

Ion beam current 0.85～1A;

Al target sputtering power 400～600W;

Sputtering pulse frequency 20～25KHz;

Wherein, the argon and oxygen are high-purity gases with a purity of 99.99%.

Preferably, the substrate is a polyimide film with a film thickness of 25-125 microns.

Beneficial effect

The present invention uses oxygen ion beam-assisted pulse-response magnetron sputtering technology, which can reduce the deposition temperature by utilizing the high chemical activity of oxygen ions and the enhancement of the kinetic energy of ions to surface adsorption, dissociation and diffusion, and at the same time solve the phenomenon of target poisoning and improve the deposition rate. speed, and then achieve low-temperature and rapid preparation of aluminum oxide thin films. During the deposition process, the substrate is kept at room temperature, which avoids the damage of high temperature to the flexible polymer film substrate. Rapid deposition of high-quality aluminum oxide films can be achieved on flexible polymer substrates, and with corresponding flexible substrate winding equipment, large-area continuous deposition can be achieved.

Detailed ways

The technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

Example

A method for preparing an aluminum oxide film, said method comprising the following steps:

(1) Place a 50 μm thick polyimide film substrate in a vacuum chamber, and evacuate the vacuum chamber until the pressure in the vacuum chamber is 2.0×10 ^-3 Pa;

(2) Carry out argon ion bombardment treatment to substrate with ion source, improve the adhesive force of plating film layer; Wherein argon gas flow rate is 15sccm, ion beam discharge voltage is 280V, and ion beam current is 1A;

(3) The aluminum oxide thin film was deposited by oxygen ion beam assisted pulse reactive magnetron sputtering technology, the process and process parameters are as follows:

The purity of the metal aluminum target used for sputtering is 99.99%. The target is long and the area is 560mm×80mm. The distance between the target and the substrate is 100mm. The sputtering working gas is argon and oxygen with a purity of 99.99%. Accounting for 86% to 89%, the sputtering power supply is a pulse power supply produced by AE Company in the United States, and the output power is up to 5kW. The oxygen-argon mixed gas is passed into the ion source, and the oxygen ions generated oxidize the sputtered aluminum on the substrate to prepare an aluminum oxide film.

The working gas argon for metal aluminum target sputtering passes through the aluminum tube to the surface of the magnetron target, adjust the flow rate of argon gas to 8-15 sccm with a mass flow meter, turn on the pulse sputtering power supply, and apply the voltage between the metal Al target and the vacuum chamber . The mixed gas of oxygen and argon fed into the ion source is controlled by a mass flow meter. Oxygen ions oxidize the sputtered metal particles, and the bombardment of the film by argon ions is used to further improve the quality of the film, improve its performance, and achieve high-quality aluminum oxide films. of plating. During the film deposition process, the substrate is in a state of natural temperature rise without additional heating.

The conditions of a preferred processing technology in this step are as follows: ion source voltage 300V, ion beam current 0.85A, ion source oxygen content 86%, magnetron target sputtering power 600V, working pressure 0.45Pa. Other pulse reaction magnetron sputtering parameters are: argon gas flow rate 15 sccm, pulse frequency 25 kHz, positive pulse amplitude 300 V, positive pulse width 1 μs. After 30 minutes of deposition, the prepared thin film has a dense structure and conforms to the stoichiometric ratio, and the deposition rate reaches 72.4nm/min.

To sum up, the above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of 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 (2)

1. the preparation method of an aluminum oxide film is characterized in that: said method comprising the steps of:

(1) the flexible polymer film substrate is placed in the Vakuumkammer, Vakuumkammer is evacuated to pressure in the Vakuumkammer≤2.0 * 10 ^-3Pa;

(2) with ion source argon ion bombardment being carried out in substrate handles; Wherein argon flow amount is 15sccm, and the ionic fluid sparking voltage is 280V, and ion beam current is 1A;

(3) adopt oxygen ion beam satellite pulse reaction magnetocontrol sputtering deposition techniques aluminum oxide film, the target source is the aluminium target, and processing parameter is following:

The working gas argon flow amount is 8～15sccm;

Ion source carrier of oxygen integration amount is 86%～89%;

Operating air pressure 0.3～0.5Pa;

Ion source voltage 300～500V;

Ion beam current 0.85～1A;

Al target sputtering power 400～600W;

Sputter pulse-repetition 20～25KHz;

Wherein, said argon gas and oxygen are that purity is 99.99% high-purity gas.

2. the preparation method of a kind of aluminum oxide film according to claim 1, it is characterized in that: said substrate is that thickness is 25～125 microns a polyimide film.