CN108682739A - A kind of metal quantum point enhancing ZnO resistive memories and preparation method thereof - Google Patents

Abstract

The invention discloses a kind of metal quantum points to enhance ZnO resistive memories, the metal quantum point enhancing ZnO resistive memories include substrate, it is disposed with Pt films, the first ZnO layer, the second ZnO layer and electrode on the substrate, metal quantum point is interspersed in second ZnO layer.The metal quantum point enhancing ZnO resistives memory of the present invention has metal quantum point by interting deposition in ZnO layer, the thickness of the ZnO layer is small, the cost of preparation and the size of device are significantly reduced, the stability of the respective rate and device of ZnO resistive memories is improved；Metal quantum point can play the role of mask, be conducive to the crystal quality for improving ZnO film, assign the good operation stability of resistive memory.

Description

A metal quantum dot enhanced ZnO resistive memory and its preparation method

technical field

The invention belongs to the field of sensor technology, and in particular relates to a metal quantum dot reinforced ZnO resistive memory and a preparation method thereof.

Background technique

Memory is a memory device used to save information in modern information technology, and its main function is to store various data and programs. The development of technologies such as big data, cloud computing, and the Internet of Things has led to an explosive growth in the demand for storage and analysis information. In the integrated circuit industry, semiconductor memory is quite important, and it is widely used in information, security, national defense and other fields. Therefore, Continuously improving the performance of memory has become one of the keys to the development of information technology.

ZnO is a wide band gap metal oxide with a hexagonal wurtzite structure. Its raw materials are cheap and easy to obtain, and its preparation process is simple. It has excellent photoelectric properties and excellent piezoelectricity, gas sensitivity, pressure sensitivity and humidity sensitivity. It is an excellent semiconductor material. The current common ZnO resistive memory mainly enhances the performance of the device by doping and introducing a metal insertion layer, but this has certain disadvantages, such as the thickness of the metal insertion layer is too large, resulting in a larger device volume; The corresponding speed of the device is low, and the stability of the device is poor.

Therefore, there is a need for a metal quantum dot-enhanced ZnO resistive memory with high response rate and good stability.

Contents of the invention

The purpose of the present invention is to provide a metal quantum dot reinforced ZnO resistive memory with high response rate and good stability and a preparation method thereof.

The technical solution adopted in the present invention is: a metal quantum dot enhanced ZnO resistive memory, including a substrate, on which a Pt thin film, a first ZnO layer, a second ZnO layer and an electrode are sequentially arranged, and the Metal quantum dots are interspersed in the second ZnO layer.

Preferably, the volume of the metal quantum dots accounts for 10-60% of the volume of the second ZnO layer.

Preferably, the thickness of the Pt thin film is 30-200nm. More preferably, the thickness of the Pt thin film is 30nm.

Preferably, the thickness of the first ZnO layer is 10-30 nm. More preferably, the thickness of the first ZnO layer is 30nm.

Preferably, the metal quantum dots are Au quantum dots, Ag quantum dots, Pt quantum dots, Cu quantum dots, Al quantum dots or Fe quantum dots.

Preferably, the metal quantum dots have a diameter of 2-250nm.

Preferably, the thickness of the second ZnO layer is 30-50 nm; the electrode is a Pt electrode or an Al electrode, and the thickness of the electrode is 30-200 nm. More preferably, the thickness of the second ZnO layer is 50 nm, and the thickness of the electrode is 50 nm.

The present invention also provides a method for preparing a metal quantum dot enhanced ZnO resistive memory, comprising the following steps:

1) preparing a Pt thin film on a substrate;

2) preparing the first ZnO layer on the Pt film;

3) Deposit a metal thin film on the first ZnO layer, then rapidly raise the temperature to 500-600°C, and anneal for 30-240s to obtain metal quantum dots;

4) preparing the second ZnO layer at the metal quantum dot;

5) Repeat steps 3) and 4) 3-7 times to prepare metal quantum dots and the second ZnO layer;

6) Prepare electrodes on the third ZnO layer to obtain metal quantum dot-enhanced ZnO resistive memory.

Preferably, in step 1), magnetron sputtering is used to prepare the Pt thin film, and the conditions for controlling the magnetron sputtering process are: the vacuum is 1×10 ^-3 -1×10 ^-6 Pa, and the sputtering temperature is 300-600°C , the sputtering power is 300-550W, and the pressure of Ar gas is 0.01-10Pa.

Preferably, in step 2), the first ZnO layer is prepared by magnetron sputtering, and the conditions for controlling the magnetron sputtering process are: the vacuum is 1×10 ^-3 -1×10 ^-6 Pa, and the sputtering temperature is 400- 600°C, the sputtering power is 350-550W, and the pressure of Ar gas is 0.01-10Pa.

Preferably, in step 3), a metal film with a thickness of 8-20nm is deposited by magnetron sputtering, and the conditions for controlling the magnetron sputtering process are: the vacuum is 1×10 ^-3 -1×10 ^-6 Pa, and the sputtering power It is 300-550W, and the pressure of Ar gas is 0.01-10Pa.

Preferably, in step 4), the second ZnO layer is prepared by magnetron sputtering, and the conditions for controlling the magnetron sputtering process are: the vacuum is 1×10 ^-3 -1×10 ^-6 Pa, and the sputtering temperature is 400- 600°C, the sputtering power is 350-550W, and the pressure of Ar gas is 0.01-10Pa.

Preferably, in step 6), magnetron sputtering is used to prepare electrodes, and the conditions for controlling the magnetron sputtering process are: the vacuum is 1×10 ^-3 -1×10 ^-6 Pa, the sputtering temperature is 300-600°C, The sputtering power is 300-550W, and the pressure of Ar gas is 0.01-10Pa.

The beneficial effect of the present invention is: metal quantum dots of the present invention strengthens ZnO resistive change memory by interspersing and depositing metal quantum dots in the ZnO layer, the thickness of this ZnO layer is small, effectively reduces the cost of preparation and the size of the device , improve the corresponding speed of the ZnO resistive memory and the stability of the device; the metal quantum dots can play the role of a mask, which is conducive to improving the crystal quality of the ZnO thin film, and endows the resistive memory with good operational stability.

Description of drawings

Fig. 1 is the structural representation of metal quantum dot enhanced ZnO resistive variable memory, wherein, 11 is substrate, 12 is Pt film, 13 is the first ZnO layer, 14 is metal quantum dot, 15 is the second ZnO layer, 16 is the electrode.

FIG. 2 is a photomicrograph of Pt quantum dots prepared in Example 1.

Detailed ways

The invention provides a metal quantum dot enhanced ZnO resistive memory, comprising a substrate, on which a Pt thin film, a first ZnO layer, a second ZnO layer and an electrode are sequentially arranged, and the second ZnO layer Metal quantum dots are interspersed inside.

The present invention also provides a method for preparing a metal quantum dot enhanced ZnO resistive memory, comprising the following steps:

1) Prepare a Pt film on the substrate by magnetron sputtering;

2) preparing the first ZnO layer on the Pt film by magnetron sputtering;

3) On the first ZnO layer, magnetron sputtering is used to deposit a metal film, and then the temperature is rapidly raised to 500-600°C, and annealed for 30-240s to obtain metal quantum dots;

4) Prepare the second ZnO layer by magnetron sputtering on the metal quantum dots;

5) Repeat steps 3) and 4) 3-7 times to prepare metal quantum dots and the second ZnO layer;

6) Electrodes are prepared on the third ZnO layer by magnetron sputtering to obtain metal quantum dot-enhanced ZnO resistive memory.

The structural representation of the ZnO resistive switchable storage device enhanced by metal quantum dots prepared by the present invention is shown in Figure 1, wherein, 11 is a substrate, 12 is a Pt film, 13 is the first ZnO layer, 14 is a metal quantum dot, and 15 is a The second ZnO layer, 16 is an electrode.

Example 1

A method for preparing a metal quantum dot reinforced ZnO resistive memory, comprising the following steps:

1) A Pt film with a thickness of 30nm was prepared on the substrate by magnetron sputtering, and the conditions for the control of the magnetron sputtering process were: the vacuum was 1×10 ^-3 Pa, the sputtering temperature was 300°C, and the sputtering power was 300W, the pressure of Ar gas is 0.01Pa;

2) Prepare the first ZnO layer with a thickness of 10-30nm on the Pt film by magnetron sputtering, wherein the control conditions of the magnetron sputtering process are: the vacuum is 1×10 ^-3 Pa, and the sputtering temperature is 400°C , the sputtering power is 350W, and the pressure of Ar gas is 0.01Pa;

3) On the first ZnO layer, use magnetron sputtering to deposit a metal film with a thickness of 8nm, then rapidly raise the temperature to 500°C, anneal for 30s, and obtain metal quantum dots with a diameter of 200nm, wherein the conditions of the magnetron sputtering process control It is: the vacuum is 1×10 ^-3 Pa, the sputtering power is 300W, and the pressure of Ar gas is 0.01Pa;

4) The second ZnO layer with a thickness of 30nm was prepared on the metal quantum dots by magnetron sputtering, wherein the conditions for the control of the magnetron sputtering process were: the vacuum was 1×10 ^-3 Pa, the sputtering temperature was 400°C, and the sputtering temperature was 400°C. The radiation power is 350W, and the pressure of Ar gas is 0.01Pa;

5) repeat operation steps 3) and 4) 3 times, to insert metal quantum dots in the second ZnO layer;

6) Prepare a Pt electrode with a thickness of 30nm on the third ZnO layer by magnetron sputtering to obtain a ZnO resistive memory enhanced by metal quantum dots, wherein the control condition of the magnetron sputtering process is: the vacuum is 1×10 ^{- 3} Pa, the sputtering temperature is 300°C, the sputtering power is 300W, and the pressure of Ar gas is 0.01Pa.

Wherein, in step 3), a micrograph of metal quantum dots with a diameter of 200 nm is obtained as shown in FIG. 2 .

Example 2

A method for preparing a metal quantum dot reinforced ZnO resistive memory, comprising the following steps:

1) A Pt film with a thickness of 80nm was prepared on the substrate by magnetron sputtering, and the conditions for the control of the magnetron sputtering process were: the vacuum was 5×10 ^-3 Pa, the sputtering temperature was 400°C, and the sputtering power was 350W, the pressure of Ar gas is 0.1Pa;

2) The first ZnO layer with a thickness of 15nm was prepared on the Pt film by magnetron sputtering, wherein the control conditions of the magnetron sputtering process were: the vacuum was 1×10 ^-4 Pa, the sputtering temperature was 450°C, and the sputtering temperature was 450°C. The radiation power is 400W, and the pressure of Ar gas is 0.1Pa;

3) On the first ZnO layer, use magnetron sputtering to deposit a metal film with a thickness of 10nm, then rapidly raise the temperature to 520°C, and anneal for 60s to obtain metal quantum dots with a diameter of 5nm. It is: the vacuum is 1×10 ^{- 4} Pa, the sputtering power is 400W, and the pressure of Ar gas is 1Pa;

4) The second ZnO layer with a thickness of 35nm was prepared on the metal quantum dots by magnetron sputtering, wherein the conditions for the control of the magnetron sputtering process were: the vacuum was 1×10 ^-4 Pa, the sputtering temperature was 450°C, and the sputtering temperature was 450°C. The radiation power is 400W, and the pressure of Ar gas is 0.1Pa;

5) repeat operation steps 3) and 4) 4 times, to insert metal quantum dots in the second ZnO layer;

6) Prepare a Pt electrode with a thickness of 60nm on the third ZnO layer by magnetron sputtering to obtain a ZnO resistive memory enhanced by metal quantum dots, wherein the control condition of the magnetron sputtering process is: the vacuum is 5×10 ^{- 3} Pa, the sputtering temperature is 400°C, the sputtering power is 350W, and the pressure of Ar gas is 0.1Pa.

Example 3

A method for preparing a metal quantum dot reinforced ZnO resistive memory, comprising the following steps:

1) A Pt film with a thickness of 30nm was prepared on the substrate by magnetron sputtering, and the conditions for the control of the magnetron sputtering process were: the vacuum was 1×10 ^-4 Pa, the sputtering temperature was 450°C, and the sputtering power was 550W, the pressure of Ar gas is 0.01Pa;

2) The first ZnO layer with a thickness of 10nm was prepared on the Pt film by magnetron sputtering, wherein the control conditions of the magnetron sputtering process were: the vacuum was 1×10 ^-4 Pa, the sputtering temperature was 450°C, and the sputtering temperature was 450°C. The radiation power is 500W, and the pressure of Ar gas is 0.01Pa;

3) On the first ZnO layer, magnetron sputtering is used to deposit a metal film with a thickness of 10nm, and then the temperature is rapidly raised to 600°C and annealed for 60s to obtain metal quantum dots with a diameter of 8nm, wherein the conditions of the magnetron sputtering process control It is: the vacuum is 1×10 ^{- 3} Pa, the sputtering power is 400W, and the pressure of Ar gas is 0.01Pa;

4) Prepare the second ZnO layer with a thickness of 50nm on the metal quantum dots by magnetron sputtering, wherein the conditions for the control of the magnetron sputtering process are: the vacuum is 1×10 ^-4 Pa, the sputtering temperature is 450°C, and the sputtering temperature is 450°C. The radiation power is 500W, and the pressure of Ar gas is 0.01Pa;

5) repeat operation steps 3) and 4) 5 times, to insert metal quantum dots in the second ZnO layer;

6) Prepare an Al electrode with a thickness of 50nm on the third ZnO layer by magnetron sputtering to obtain a ZnO resistive memory device enhanced by metal quantum dots, wherein the control condition of the magnetron sputtering process is: the vacuum is 1×10 ^{- 4} Pa, the sputtering temperature is 450°C, the sputtering power is 550W, and the pressure of Ar gas is 0.01Pa.

Example 4

A method for preparing a metal quantum dot reinforced ZnO resistive memory, comprising the following steps:

1) A Pt film with a thickness of 100nm was prepared on the substrate by magnetron sputtering, and the conditions for the control of the magnetron sputtering process were: the vacuum was 1×10 ^-5 Pa, the sputtering temperature was 520°C, and the sputtering power was 500W, the pressure of Ar gas is 8Pa;

2) The first ZnO layer with a thickness of 20nm was prepared on the Pt film by magnetron sputtering, wherein the control conditions of the magnetron sputtering process were: the vacuum was 1×10 ^-4 Pa, the sputtering temperature was 500°C, and the sputtering temperature was 500°C. The radiation power is 450W, and the pressure of Ar gas is 6Pa;

3) On the first ZnO layer, use magnetron sputtering to deposit a metal film with a thickness of 12nm, then rapidly raise the temperature to 550°C, and anneal for 120s to obtain metal quantum dots with a diameter of 20nm. It is: the vacuum is 1×10 ^-5 Pa, the sputtering power is 500W, and the pressure of Ar gas is 3Pa;

4) Prepare the second ZnO layer with a thickness of 40nm on the metal quantum dots by magnetron sputtering, wherein the conditions for the control of the magnetron sputtering process are: the vacuum is 1×10 ^-4 Pa, the sputtering temperature is 50°C, and the sputtering temperature is 50°C. The radiation power is 450W, and the pressure of Ar gas is 6Pa;

5) repeat operation steps 3) and 4) 6 times, to insert metal quantum dots in the second ZnO layer;

6) Prepare a Pt electrode with a thickness of 100nm on the third ZnO layer by magnetron sputtering to obtain a ZnO resistive memory enhanced by metal quantum dots, wherein the control condition of the magnetron sputtering process is: the vacuum is 1×10 ^{- 4} Pa, the sputtering temperature is 500°C, the sputtering power is 450W, and the pressure of Ar gas is 6Pa.

Example 5

A method for preparing a metal quantum dot reinforced ZnO resistive memory, comprising the following steps:

1) A Pt film with a thickness of 200nm was prepared on the substrate by magnetron sputtering. The control conditions of the magnetron sputtering process were as follows: the vacuum was 1×10 ^-6 Pa, the sputtering temperature was 600°C, and the sputtering power was 550W, the pressure of Ar gas is 10Pa;

2) The first ZnO layer with a thickness of 30nm was prepared on the Pt film by magnetron sputtering, wherein the control conditions of the magnetron sputtering process were: vacuum 11×10 ^-6 Pa, sputtering temperature 600°C, sputtering The radiation power is 550W, and the pressure of Ar gas is 10Pa;

3) On the first ZnO layer, magnetron sputtering is used to deposit a metal film with a thickness of 18nm, and then the temperature is rapidly raised to 600°C and annealed for 240s to obtain metal quantum dots with a diameter of 25nm, wherein the conditions of the magnetron sputtering process control It is: the vacuum is 1×10 ^-6 Pa, the sputtering power is 550W, and the pressure of Ar gas is 10Pa;

4) The second ZnO layer with a thickness of 50nm was prepared on the metal quantum dots by magnetron sputtering, wherein the conditions for controlling the magnetron sputtering process were: the vacuum was 1×10 ^-6 Pa, the sputtering temperature was 600°C, and the sputtering temperature was 600°C. The radiation power is 550W, and the pressure of Ar gas is 10Pa;

5) repeat operation steps 3) and 4) 7 times, to insert metal quantum dots in the second ZnO layer;

6) Prepare an Al electrode with a thickness of 200nm on the third ZnO layer by magnetron sputtering to obtain a metal quantum dot-enhanced ZnO resistive memory, wherein the control condition of the magnetron sputtering process is: the vacuum is 1×10 ^{- 6} Pa, the sputtering temperature is 600°C, the sputtering power is 550W, and the pressure of Ar gas is 10Pa.

Claims (10)

1. a kind of metal quantum point enhances ZnO resistive memories, which is characterized in that the metal quantum point enhancing ZnO resistives are deposited Storage includes substrate, and Pt films, the first ZnO layer, the second ZnO layer and electrode, the 2nd ZnO are disposed on the substrate It is interspersed with metal quantum point in layer.

2. metal quantum point according to claim 1 enhances ZnO resistive memories, which is characterized in that the Pt films Thickness is 30-200nm.

3. metal quantum point according to claim 1 enhances ZnO resistive memories, which is characterized in that first ZnO layer Thickness be 10-30nm.

4. metal quantum point according to claim 1 enhances ZnO resistive memories, which is characterized in that the metal quantum Point is Au quantum dots, Ag quantum dots, Pt quantum dots, Cu quantum dots, Al quantum dots or Fe quantum dots.

5. metal quantum point according to claim 1 enhances ZnO resistive memories, which is characterized in that the metal quantum A diameter of 2-250nm of point.

6. metal quantum point according to claim 1 enhances ZnO resistive memories, which is characterized in that second ZnO layer Thickness be 30-50nm；The electrode is Pt electrodes or Al electrodes, and the thickness of electrode is 30-200nm.

7. the preparation method of the metal quantum point enhancing ZnO resistive memories described in any one of claim 1-6, feature exist In including the following steps：

1) Pt films are prepared on substrate；

2) the first ZnO layer is prepared on Pt films；

3) in the first ZnO layer, then deposited metal film is rapidly heated to 500-600 DEG C, and anneal 30-240s, obtains metal Quantum dot；

4) the second ZnO layer is prepared in metal quantum point；

5) repetitive operation step 3) and 4) 3-7 time, preparation metal quantum point and the second ZnO layer；

6) electrode is prepared in third ZnO layer, obtains metal quantum point enhancing ZnO resistive memories.

8. preparation method according to claim 7, which is characterized in that in step 1), Pt films are prepared using magnetron sputtering, Magnetron sputtering process control condition be：Vacuum is 1 × 10^-3-1×10^-6Pa, sputter temperature are 300-600 DEG C, sputtering power Air pressure for 300-550W, Ar gas is 0.01-10Pa.

9. preparation method according to claim 7, which is characterized in that in step 2), the first ZnO is prepared using magnetron sputtering Layer, the condition that magnetron sputtering process controls are：Vacuum is 1 × 10^-3-1×10^-6Pa, sputter temperature are 400-600 DEG C, sputter work( Rate is 350-550W, and the air pressure of Ar gas is 0.01-10Pa.

10. preparation method according to claim 7, which is characterized in that in step 3), using magnetron sputtering deposition 8-20nm Thick metallic film, the condition that magnetron sputtering process controls are：Vacuum is 1 × 10^-3-1×10^-6Pa, sputtering power 300- The air pressure of 550W, Ar gas is 0.01-10Pa.