Nano composite stacked phase-change film and preparation method and application thereof

A nano-composite and thin-film technology, applied in the field of microelectronics, can solve the problems that the thermal stability of the thin film is not very high and the thermal stability needs to be improved, and achieve the effects of improving thermal stability, high thermal stability and improving signal-to-noise ratio.

Inactive Publication Date: 2016-04-20

TONGJI UNIV

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AI-Extracted Technical Summary

Problems solved by technology

Although there are not too many shortcomings, there are many places to be improved and improved (Seo, Jae-Hee, etc., Journal of Applied Physics, 108, 064515, 2010)

For example, Ge 2 Sb 2 Te 5 The film has only two resistance states, high and low, corresponding to logical "0" and "1", and there is room for improvement in storag...

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Method used

[0074] Fig. 1 shows the resistance of the Ge2Sb2Te5/ZnSb nanocomposite stacked phase change film of the present invention as a function of temperature, and the heating rate in the test is 10°C/min. It can be seen from Figure 1 that both single-layer Ge2Sb2Te5 (GST) and ZnSb films have only two resistance states, high and low, while in multilayer composite phase change films [Ge2Sb2Te5(15nm)/ZnSb(35nm)]1, [Ge2Sb2Te5(25nm) /ZnSb(25nm)]1 and [Ge2Sb2Te5(35nm)/ZnSb(15nm)]1 were observed in three resistance states of high, medium and low, indicating that it can be used as a multi-level storage phase change material. Moreover, compared with the single-layer Ge2Sb2Te5 thin film material, the crystallization temperature of the Ge2Sb2Te5/ZnSb stacked thin film is greatly improved by compounding with ZnSb, so that the thin film has better thermal stability.

[0075] Fig. 2 is a corresponding relationship curve between the failure time and the reciprocal of...

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Abstract

The invention relates to a nano composite stacked phase-change film and a preparation method and an application thereof. Ge2Sb2Te5 films and ZnSb films are arranged alternately into a stacked film unit, wherein each Ge2Sb2Te5 film is 15-35nm thick, and each ZnSb film is 15-35nm thick. The stacked film unit formed by alternate arrangement is of a one-layer structure, and can be applied to a phase-change memory with multistage storage characteristic. Compared with the prior art, the nano composite stacked phase-change film has two stable phase change processes and three storage modes, and the storage density of PCRAM can be greatly improved; and the crystallization temperature and the ten-year data holding temperature are high, and the thermal stability of PCRAM can be greatly improved.

Application Domain

Material nanotechnologyElectrical apparatus

Technology Topic

EngineeringPhase-change memory +3

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Examples

Experimental program(4)
Comparison scheme(2)

Example Embodiment

[0031] Example 1

[0032] Ge prepared in this example 2 Sb 2 Te 5 /ZnSb nanocomposite stacked phase change film with a total thickness of 50nm and a general structural formula of [Ge 2 Sb 2 Te 5 (a)/ZnSb(b)]x, the specific structure is [Ge 2 Sb 2 Te 5 (15nm)/ZnSb(35nm)] 1 、[Ge 2 Sb 2 Te 5 (25nm)/ZnSb(25nm)] 1 、[Ge 2 Sb 2 Te 5 (35nm)/ZnSb(15nm)] 1.

[0033] 1. Clean SiO2 2 //Si(100) substrate surface and back, remove dust particles, organic and inorganic impurities:

[0034] (a) Place the substrate in an ethanol solution, and clean it ultrasonically for 15 minutes to remove dust particles and inorganic impurities on the surface of the substrate;

[0035] (b) The substrate is placed in an acetone solution, and ultrasonically cleaned for 15 minutes to remove organic impurities on the surface of the substrate;

[0036] (c) Place the substrate in deionized water, clean it ultrasonically for 15 minutes, and clean the surface again;

[0037] (d) Take out the substrate, dry it with pure Ar gas, and set it aside.

[0038] 2. Prepared by sputtering method [Ge 2 Sb 2 Te 5 (a)/ZnSb(b)]x film preparation

[0039] (a) put Ge 2 Sb 2 Te 5 and ZnSb alloy target, install the substrate, and then seal the vacuum chamber

[0040] (b) Turn on the gas flow meter for 5 minutes, then put it in the valve control state, turn on the mechanical pump to vacuum, when the vacuum reaches 5Pa or below, start the molecular pump, and vacuum to 2x10 -4 Below Pa.

[0041] (c) Set the RF power to 20W.

[0042] (d) High-purity Ar gas is used as the sputtering gas, the gas flow rate is 30SCCM, and the sputtering pressure is 0.2Pa.

[0043] 3. Coating with the coating monitoring program, the required sputtering thickness can be changed by the sputtering time, where Ge 2 Sb 2 Te 5 The sputtering speed of the target is 0.25nm/s, and the sputtering speed of the ZnSb target is 0.21nm/s

[0044] (a) Rotate the substrate to Ge 2 Sb 2 Te 5 Target, open Ge 2 Sb 2 Te 5 The RF power supply starts sputtering Ge 2 Sb 2 Te 5 film, [Ge 2 Sb 2 Te 5 (15nm)/ZnSb(35nm)] 1 、[Ge 2 Sb 2 Te 5 (25nm)/ZnSb(25nm)] 1 、[Ge 2 Sb 2 Te 5 (35nm)/ZnSb(15nm)] 1 The durations are 75s, 120s and 175s respectively, Ge 2 Sb 2 Te 5 After the thin film sputtering is completed, turn off the Ge 2 Sb 2 Te 5 RF power supply.

[0045] (b) Rotate the substrate to the ZnSb target position, turn on the RF power of ZnSb, start sputtering ZnSb thin film, [Ge 2 Sb 2 Te 5 (15nm)/ZnSb(35nm)] 1 、[Ge 2 Sb 2 Te 5 (25nm)/ZnSb(25nm)] 1 、[Ge 2 Sb 2 Te 5 (35nm)/ZnSb(15nm)] 1 The durations were 167s, 119s, and 71s, respectively. After the ZnSb thin film sputtering was completed, the RF power of ZnSb was turned off.

Example Embodiment

[0078] Example 2

[0079] Nanocomposite stacked phase-change films made of Ge 2 Sb 2 Te 5 Thin films and ZnSb thin films are arranged alternately to form stacked thin film units, Ge 2 Sb 2 Te 5 The thickness of the thin film is 25nm, the thickness of the ZnSb thin film is 25nm, and they are alternately arranged to form a layer structure of stacked thin film units, and the thickness of the unit is 50nm.

[0080] The preparation method of the nanocomposite stacked phase change film adopts the following steps:

[0081] (1) cleaning SiO2 2 /Si(100) substrate surface and back, remove dust particles, organic and inorganic impurities;

[0082] (2) Install the sputtering target, set the RF power, gas flow and sputtering pressure;

[0083] (3) Prepare Ge by room temperature magnetron sputtering method 2 Sb 2 Te 5 /ZnSb nanocomposite stacked phase change film, specifically adopt the following steps:

[0084] (3-1) Rotate the substrate to Ge 2 Sb 2 Te 5 Target, open Ge 2 Sb 2 Te 5 RF power supply, using Ar gas as the sputtering gas to sputter Ge 2 Sb 2 Te 5 Target, Ge 2 Sb 2 Te 5 After the thin film sputtering is completed, turn off the Ge 2 Sb 2 Te 5 RF power supply;

[0085] (3-2) Rotate the substrate to the ZnSb target position, turn on the RF power supply of ZnSb, use Ar gas as the sputtering gas, sputter the ZnSb target material, and turn off the RF power supply of ZnSb after the sputtering of the ZnSb thin film is completed.

[0086] The above Ge 2 Sb 2 Te 5 The purity of the /ZnSb target is above 99.999% atomic percent, and the background vacuum is not greater than 2x10 -4 Pa, the purity of Ar gas is more than 99.999% by volume. Ge 2 Sb 2 Te 5 Both ZnSb and ZnSb targets are sputtered by RF power supply, the sputtering power is 15W, the gas flow rate of Ar gas used is 25SCCM, the sputtering pressure is 0.15Pa, and the single-layer Ge 2 Sb 2 Te 5 Thicknesses of thin films and single-layer ZnSb films are tuned by sputtering time, Ge 2 Sb 2 Te 5 The sputtering time of ZnSb is 250s, and the sputtering speed of ZnSb is 238s. The prepared nano-composite stacked phase-change film can be applied in phase-change memory with multi-level storage characteristics.

Example Embodiment

[0087] Example 3

[0088] Nanocomposite stacked phase-change films made of Ge 2 Sb 2 Te 5 Thin films and ZnSb thin films are arranged alternately to form stacked thin film units, Ge 2 Sb 2 Te 5 The thickness of the thin film is 35nm, and the thickness of the ZnSb thin film is 35nm, which are alternately arranged to form a stacked thin film unit as a layer structure. The thickness of the stacked thin film unit is 50 nm.

[0089] The preparation method of the nanocomposite stacked phase change film adopts the following steps:

[0090] (1) cleaning SiO2 2 /Si(100) substrate surface and back, remove dust particles, organic and inorganic impurities;

[0091] (2) Install the sputtering target, set the RF power, gas flow and sputtering pressure;

[0092] (3) Prepare Ge by room temperature magnetron sputtering method 2 Sb 2 Te 5 /ZnSb nanocomposite stacked phase change film, specifically adopt the following steps:

[0093] (3-1) Rotate the substrate to Ge 2 Sb 2 Te 5 Target, open Ge 2 Sb 2 Te 5 RF power supply, using Ar gas as the sputtering gas to sputter Ge 2 Sb 2 Te 5 Target, Ge 2 Sb 2 Te 5 After the thin film sputtering is completed, turn off the Ge 2 Sb 2 Te 5 RF power supply;

[0094] (3-2) Rotate the substrate to the ZnSb target position, turn on the RF power supply of ZnSb, use Ar gas as the sputtering gas, sputter the ZnSb target material, and turn off the RF power supply of ZnSb after the sputtering of the ZnSb thin film is completed.

[0095] The above Ge 2 Sb 2 Te 5 The purity of the /ZnSb target is above 99.999% atomic percent, and the background vacuum is not greater than 2x10 -4 Pa, the purity of Ar gas is more than 99.999% by volume. Ge 2 Sb 2 Te 5 The sputtering of ZnSb and ZnSb targets adopts radio frequency power supply, the sputtering power is 20W, the gas flow rate of Ar gas used is 30SCCM, the sputtering pressure is 0.25Pa, and the single layer Ge 2 Sb 2 Te 5 Thicknesses of thin films and single-layer ZnSb films are tuned by sputtering time, Ge 2 Sb 2 Te 5 The sputtering time of ZnSb is 250s, and the sputtering speed of ZnSb is 238s. The prepared nano-composite stacked phase-change film can be applied in phase-change memory with multi-level storage characteristics.

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PUM

Property	Measurement	Unit
Thickness	15.0 ~ 35.0	nm
Thickness	25.0 ~ 35.0	nm
Thickness	50.0 ~ 70.0	nm
tensile		MPa
Particle size		Pa
strength	10

Description & Claims & Application Information

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Classification and recommendation of technical efficacy words

Improve thermal stability
Improve storage density

Methods of forming polycrystalline diamond cutting elements, cutting elements, and earth-boring tools carrying cutting elements

ActiveUS20110036641A1Improve thermal stabilityPigmenting treatmentDrill bitsPolycrystalline diamondDrill bit

Owner:BAKER HUGHES INC

Nano composite stacked phase-change film and preparation method and application thereof

AI-Extracted Technical Summary

Problems solved by technology

Method used

Abstract

Image

Examples

Example Embodiment

Example Embodiment

Example Embodiment

PUM

Description & Claims & Application Information

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