CN116240493A - Method for preparing amorphous La-Mn-O film by direct-current magnetron sputtering - Google Patents

Abstract

The invention relates to a method for preparing an amorphous La-Mn-O film by direct current magnetron sputtering, which uses lanthanum-manganese alloy as a target material, puts the alloy target material and a substrate into a magnetron sputtering growth chamber, carries out magnetron sputtering under vacuum condition to obtain a deposited film, carries out post annealing treatment on the deposited film, and obtains the amorphous La-Mn-O film by regulating annealing temperature.

Description

Method for preparing amorphous La-Mn-O film by direct-current magnetron sputtering

Technical Field

The invention belongs to the field of magnetron sputtering and perovskite oxide film preparation, and particularly relates to a method for preparing an amorphous La-Mn-O film by direct current magnetron sputtering.

Technical Field

Functional oxide films as unique electronic materials exhibit excellent properties and several unusual characteristics such as large linear strain gradients, high efficiency catalysts, photovoltaic effects, and photovoltaic properties that can be utilized in combination in future microelectronic devices. Lanthanum-based perovskite is particularly promising in practical applications due to the high abundance of lanthanum. LaMnO ₃ Is a typical lanthanum perovskite oxide, laMnO ₃ Films have unique electrical, magnetic and transmission properties and are used for infrared detection, sensors and other applications. Polycrystalline LaMnO ₃ Films have proven useful as temperature sensors, negative temperature coefficient thermistors, due to their good electrical conductivity and electrochemical stability.

At present, a magnetron sputtering method is often adopted to prepare a large quantity of monocrystalline or polycrystalline perovskite oxide films with high crystallization quality, and the application of the crystalline perovskite oxide films to modern industrial technology has obvious defects, for example, in order to ensure that polycrystalline film materials have fewer defects, a higher annealing temperature and a longer heat preservation time are required to be adjusted, so that the energy consumption is increased. The crystalline film crystal atomic arrangement has periodicity, and the defects of uniformity, poor crystallinity and the like inevitably exist in the preparation process, so that the performance of the crystalline film crystal atomic arrangement is influenced. The amorphous material atomic arrangement does not have periodicity and long-range order, so that the preparation cost and the performance uniformity are low, and many metal oxides have excellent performance in an amorphous state. Amorphous materials are a ubiquitous and critical aspect of modern and emerging semiconductor devices, such as amorphous silicon (a-Si) photovoltaic solar cells, gate dielectrics, thermoelectric devices, and the like.

Disclosure of Invention

The invention aims to provide a method for preparing an amorphous La-Mn-O film by direct-current magnetron sputtering, which utilizes a direct-current magnetron sputtering La: mn (1:1) alloy target to form a deposited metal film, carries out post-annealing treatment on the deposited film, and adopts a lower annealing temperature to prepare the amorphous metal oxide film. The preparation method of the amorphous La-Mn-O film has the advantages of simple process, low cost and the like, and the prepared amorphous oxide film has uniform components, low surface roughness and negative temperature coefficient characteristics and can be used as a substrate material of electronic elements such as NTC film thermistors and the like.

The invention relates to a method for preparing an amorphous La-Mn-O film by direct current magnetron sputtering, which is characterized by comprising the following steps: lanthanum-manganese alloy is used as a target material, monocrystalline silicon is used as a substrate, and the specific operation is carried out according to the following steps:

a. sequentially placing the monocrystalline silicon substrate in acetone, deionized water and absolute ethyl alcohol, performing ultrasonic cleaning for 30min, and then placing the monocrystalline silicon substrate in an ultraviolet ozone cleaning machine for cleaning for 10min;

b. placing the substrate cleaned in the step a in a substrate tray in a magnetron sputtering deposition device, placing a lanthanum-manganese alloy target on a target position of the magnetron sputtering deposition device according to an atomic ratio lanthanum: manganese=1:1, and vacuumizing, wherein the pressure is 1.5-2.0x10 ^-3 Pa, introducing inert gas argon to keep the pressure in the magnetron sputtering chamber at 1Pa, wherein the temperature of the substrate is 100-300 ℃, the power of the direct current power supply is 20-50w, and the magnetron sputtering deposition time is 20-40min to obtain a deposition state film;

c. and c, placing the deposited film in the step b into a tube furnace, and carrying out annealing treatment at the temperature of 500-700 ℃ in an air atmosphere for 60-120min to obtain the amorphous La-Mn-O film with the thickness of 100-300 nm.

The method for preparing the amorphous La-Mn-O film by direct current magnetron sputtering is hopeful to be applied to the substrate raw materials of electronic devices such as NTC film thermistors and the like.

Aiming at the requirements of the temperature sensor field on an amorphous oxide film, the invention provides a method for preparing the amorphous La-Mn-O film by direct-current magnetron sputtering, which has the advantages of simple process, low cost, energy conservation, high efficiency, uniform components, low surface roughness, good negative temperature coefficient characteristic and the like.

Compared with the prior art, the amorphous film has the unique points in the process of preparing the amorphous film:

compared with the preparation method of the polycrystalline La-Mn-O film, the annealing temperature of the amorphous film is relatively low, the annealing process time is short, the energy is saved, and the cost is reduced;

the prepared amorphous film has uniform components and low surface roughness;

the prepared amorphous film has obvious negative temperature coefficient characteristic.

Drawings

FIG. 1 is an XRD spectrum of an amorphous La-Mn-O thin film prepared according to the present invention, showing an amorphous phase pattern;

FIG. 2 is a scanning electron microscope picture of an amorphous La-Mn-O film prepared by the invention, and an illustration is a scanning electron microscope picture of a film section;

FIG. 3 is a graph showing the resistance-temperature relationship of amorphous La-Mn-O thin films prepared according to the present invention.

Detailed Description

Example 1

a. Sequentially placing the monocrystalline silicon substrate in acetone, deionized water and absolute ethyl alcohol, performing ultrasonic cleaning for 30min, and then placing the monocrystalline silicon substrate in an ultraviolet ozone cleaning machine for cleaning for 10min;

b. placing the substrate cleaned in the step a in a substrate tray in a magnetron sputtering deposition device, placing a lanthanum-manganese alloy target on a target position of the magnetron sputtering deposition device according to an atomic ratio lanthanum: manganese=1:1, and vacuumizing, wherein the pressure is 1.5x10 ^-3 Pa, introducing inert gas argon with purity of 99.999%, controlling the flow of the argon to be 99sccm, keeping the pressure in a magnetron sputtering chamber at 1Pa, the temperature of a substrate at 100 ℃, the power of a direct current power supply at 20w, and the magnetron sputtering deposition time at 40min to obtain a deposition state film;

c. and c, placing the deposited film in the step b into a tube furnace, and carrying out annealing treatment at the temperature of 500 ℃ in an air atmosphere for 60 minutes to obtain the amorphous La-Mn-O film with the thickness of 100 nm.

The obtained film is an amorphous film (figure 1), the thickness of the film is 230nm (figure 2), interdigital electrodes are sputtered on the surface of the film by using a magnetron sputtering device, and the film is subjected to resistance-temperature performance test, and the test result shows that the amorphous La-Mn-O film has negative temperature coefficient characteristics (figure 3).

Example 2

a. Sequentially placing the monocrystalline silicon substrate in acetone, deionized water and absolute ethyl alcohol, performing ultrasonic cleaning for 30min, and then placing the monocrystalline silicon substrate in an ultraviolet ozone cleaning machine for cleaning for 10min;

b. placing the substrate cleaned in the step a in a substrate tray in a magnetron sputtering deposition device, placing a lanthanum-manganese alloy target on a target position of the magnetron sputtering deposition device according to an atomic ratio lanthanum: manganese=1:1, and vacuumizing, wherein the pressure is 1.5x10 ^-3 Pa, introducing inert gas argon with purity of 99.999%, controlling the flow of the argon to be 99sccm, keeping the pressure in a magnetron sputtering chamber at 1Pa, keeping the temperature of a substrate at 200 ℃, keeping the power of a direct current power supply at 40w, and keeping the magnetron sputtering deposition time at 30min to obtain a deposition state film;

c. and c, placing the deposited film in the step b into a tube furnace, and carrying out annealing treatment at the temperature of 600 ℃ in an air atmosphere for 90min to obtain the amorphous La-Mn-O film with the thickness of 255 nm.

Example 3

a. Sequentially placing the monocrystalline silicon substrate in acetone, deionized water and absolute ethyl alcohol, performing ultrasonic cleaning for 30min, and then placing the monocrystalline silicon substrate in an ultraviolet ozone cleaning machine for cleaning for 10min;

b. placing the substrate cleaned in the step a in a substrate tray in a magnetron sputtering deposition device, placing a lanthanum-manganese alloy target on a target position of the magnetron sputtering deposition device according to an atomic ratio lanthanum: manganese=1:1, and vacuumizing, wherein the pressure is 1.5-2.0x10 ^-3 Pa, introducing inert gas argon with purity of 99.999%, and controlling the flow of the argon to be 99sccm to ensure the pressure in the magnetron sputtering chamberThe high temperature is kept at 1Pa, the substrate temperature is 300 ℃, the power of a direct current power supply is 50w, and the magnetron sputtering deposition time is 40min, so that a deposition state film is obtained;

c. and c, placing the deposited film in the step b into a tube furnace, and carrying out annealing treatment at the temperature of 700 ℃ in an air atmosphere for 120min to obtain the amorphous La-Mn-O film with the thickness of 300 nm.

Claims (1)

1. A method for preparing an amorphous La-Mn-O film by direct current magnetron sputtering is characterized in that: lanthanum-manganese alloy is used as a target material, monocrystalline silicon is used as a substrate, and the specific operation is carried out according to the following steps:

a. sequentially placing the monocrystalline silicon substrate in acetone, deionized water and absolute ethyl alcohol, performing ultrasonic cleaning for 30min, and then placing the monocrystalline silicon substrate in an ultraviolet ozone cleaning machine for cleaning for 10min;

b. placing the substrate cleaned in the step a in a substrate tray in a magnetron sputtering deposition device, placing a lanthanum-manganese alloy target on a target position of the magnetron sputtering deposition device according to an atomic ratio lanthanum: manganese=1:1, and vacuumizing, wherein the pressure is 1.5-2.0x10 ^-3 Pa, introducing inert gas argon to keep the pressure in the magnetron sputtering chamber at 1Pa, wherein the temperature of the substrate is 100-300 ℃, the power of the direct current power supply is 20-50w, and the magnetron sputtering deposition time is 20-40min to obtain a deposition state film;

c. and c, placing the deposited film in the step b into a tube furnace, and carrying out annealing treatment at the temperature of 500-700 ℃ in an air atmosphere for 60-120min to obtain the amorphous La-Mn-O film with the thickness of 100-300 nm.

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