CN104361908A - Method for extracting carrier transport channel of metal oxide-based resistive random access memory - Google Patents

Abstract

The invention discloses a method for extracting a carrier transport channel of a metal oxide-based resistive random access memory, which comprises the following steps: measuring an I-V curve of the metal oxide-based resistive random access memory, and determining a low-resistance current value and a high-resistance current value of the resistive random access memory according to the I-V curve; calculating the average activation energy of the transition of the current carrier in the conductive filament under the low resistance state and the high resistance state; calculating the average activation energy of a channel when a current carrier transits in the conductive filament; determining the defect energy level of carrier transport and extracting a channel of carrier transport. The method has simple operation and accurate result, and can be widely applied to extracting the carrier transport channel of the resistive random access memory with different materials and metal oxide bases with different device thicknesses, such as HfO₂、ZrO₂、WO₃The RRAM has the advantages that the RRAM is equal to the RRAM, so that a new physical method is provided for researching the microscopic physical mechanism of different types of RRAMs, and theoretical guidance is provided for researching the microscopic physical mechanism of the RRAM.

Description

A kind of method extracting metal oxide based resistance-variable storing device carrier transport passage

Technical field

The present invention relates to semiconductor memory technical field, especially a kind of method extracting metal oxide based resistance-variable storing device carrier transport passage.

Background technology

Storer is one of the most basic in integrated circuit, most important parts, is also the important indicator of microelectric technique level.The silica-based floating-gate memory of current main flow is along with technology is after entering 22nm process node, due to complex process, the many factors limiting unit sizes such as the leakage effect that in super thin oxide layer, Direct Tunneling Effect, stress cause, Punchthrough effect and ortho position serious interference reduce further, and reducing of memory cell dimensions is faced with huge difficulty.This makes the resistor-type nonvolatile RAM device (Resistive Random AccessMemory is called for short RRAM) of carrying out data storage based on resistance variations be paid close attention to widely.

RRAM is as a kind of new non-volatility memorizer, and having the advantages such as structure is simple, operating rate is fast, low in energy consumption, information maintenance is stable, is one of contenders of non-volatility memorizer of future generation.But unintelligible due to RRAM microphysics mechanism, seriously hinders its development.From the microphysics mechanism of the most basic microcosmic point research RRAM, the storage characteristics for control and raising device has important directive function.In metal oxide based RRAM, the generation of resistive phenomenon is considered to usually because the formation of conductive filament is formed with vanishing, and the seepage channel that various types of defect is formed is given the credit in the formation of conductive filament usually.Therefore, the key that the transport property of charge carrier in conductive filament is the microphysics mechanism being well understood to RRAM is studied.At present, random telegraph signal (RTN) method is the method for defect level in a kind of comparatively conventional probing semiconductor material, but owing to there is a large amount of defects in RRAM device, people want to be had by the defect of carrier transport in RTN method detection RRAM huge because of difficulty.

Therefore, develop the defect in a kind of effective method detection RRAM device, and then in extraction device, the passage of carrier transport is very important, simultaneously, for the fundamental characteristics understanding RRAM device, instruct the designing and making of device all tool be of great significance.

Summary of the invention

(1) technical matters that will solve

In view of this, the present invention is according to the analysis to Related Research Domain present situation, based on transition theory and the first-principles calculations method of charge carrier, propose a kind of method extracting metal oxide based resistance-variable storing device carrier transport passage, the method is simple to operate, can be widely used in the extraction of the different metal oxide based resistance-variable storing device transfer passages of various materials and structures.

(2) technical scheme

For achieving the above object, the present invention is according to the analysis to Related Research Domain present situation, the I-V curve that the theoretical also Binding experiment of transition based on charge carrier records, propose a kind of method extracting metal oxide based resistance-variable storing device carrier transport passage, the method comprises:

Step 1: the I-V curve measuring metal oxide based resistance-variable storing device, and according to the low resistance state current value of this I-V curve determination resistance-variable storing device and high-impedance state current value;

Step 2: the average activation energy calculating the transition in conductive filament at low resistance state and high-impedance state download stream;

Step 3: calculate charge carrier average activation energy of passage during transition in conductive filament;

Step 4: determine the defect level of carrier transport and extract the passage of carrier transport.

In such scheme, described metal oxide based resistance-variable storing device is the HfO utilizing the method for ald to prepare ₂, ZrO ₂or WO ₃the resistance-variable storing device device of material, thickness of detector is 5-30nm, and the bottom electrode of device is Pt/Ti metal level, and Pt thickness is 40nm, Ti thickness is 10nm; Power on very W/Ti metal level, and W thickness is 30nm, Ti thickness is 5nm.

In such scheme, described in step 1, measure the I-V curve of metal oxide based resistance-variable storing device, adopt KEITHLEY4200-SCS type characteristic of semiconductor analytic system to carry out.

In such scheme, according to the low resistance state current value of this I-V curve determination resistance-variable storing device and high-impedance state current value described in step 1, comprise: adopt the voltage of reading of 0.1V from the I-V curve recorded, read this two current values reading under voltage, larger value in these two current values is decided to be the current value of low resistance state, and less value is decided to be the current value of high-impedance state.

In such scheme, described step 2 comprises:

Step 21: calculate the electric current in resistance-variable storing device conductive filament under low resistance state and high-impedance state;

Wherein, the electric current under low resistance state in resistance-variable storing device conductive filament is obtained by following formula:

$I={\mathrm{\σ}}_{\mathrm{LRS}}{F}_{2}S={\mathrm{\σ}}_0\mathrm{Sexp}(-2\mathrm{\α}{R}_{\mathrm{ij}}-q{E}_{a\left(a\right)}^L/k_{B}T)V/L---\left(1\right)$

F in formula ₂the electric field of conductive filament under expression low resistance state, σ _lRSrepresent conductivity, σ ₀represent the prefactor of conductance, α represents the inverse of localized modes length, R _ijrepresent the length of carrier transition, q represents electron charge, represent the activation energy of low resistance state download stream motion, k _brepresent Boltzmann constant, T represents the temperature of device, and V represents impressed voltage, and L represents the thickness of device, and S represents the cross-sectional area of conductive filament;

Under high-impedance state, due to the effect of space charge limited current, for the part of resistance-variable storing device conductive filament conducting, electric field meets Poisson's law, namely

dF(x)/dx＝-nq/ε (2)

In formula, n represents carrier concentration, and ε represents the specific inductive capacity of material, and F (x) represents electric field intensity;

Under high-impedance state, the electric current of resistance-variable storing device conductive filament turning part is expressed as:

$I_{\mathrm{hopping}}=\mathrm{nq}{\mathrm{\μ}}_0\exp (-2\mathrm{\α}{R}_{\mathrm{ij}}-q{E}_{a\left(a\right)}^H/k_{B}T)F\left(x\right)S---\left(3\right)$

μ in formula ₀represent the prefactor of carrier mobility, represent the activation energy of high-impedance state carrier moving;

Meanwhile, launch theoretical according to Fowler-Nordheim, under high-impedance state, the electric current of resistance-variable storing device conductive filament breaking part is represented by following formula:

$I_{\mathrm{tunneling}}=q^3{F_1}^{2}S/\left(8\mathrm{\πh}{\mathrm{\φ}}_B\right)\exp [-8\mathrm{\π}\sqrt{2m}{{\mathrm{\φ}}_B}^{\frac{3}{2}}/\left(3\mathrm{hq}{F}_1\right)]---\left(4\right)$

F in formula ₁represent conduction carefully than the electric field of break up location, h represents Planck constant, φ _brepresent barrier height, m represents the quality of free electron;

Step 22: the extra electric field of conductive filament under calculating resistance-variable storing device high-impedance state:

$V=V_{\mathrm{hopping}}+V_{\mathrm{tunneling}}={\∫}_0^{L_1}F\left(x\right)\mathrm{dx}+F_1(L-L_1)---\left(5\right)$

L in formula ₁represent the length of filament turning part, V _hoppingrepresent the voltage of conductive filament turning part, V _tunnelingrepresent the voltage of conductive filament breaking part;

Step 23: calculate the average activation energy under low resistance state and high-impedance state in resistance-variable storing device conductive filament: the average activation energy calculating the sub-transition of high low resistance state download stream in conjunction with above-mentioned formula (2)-(5).

In such scheme, described step 3 comprises:

Step 31: the activation energy calculating individual defect in metal oxide based resistance-variable storing device;

Step 32: by carrying out permutation and combination to the activation energy of individual defect, calculates charge carrier average activation energy of all possible passage during transition in conductive filament;

Conductive filament is regarded as the passage be in series by different defects, therefore, resistance total in conductive filament is:

R _tot＝R ₁+...+R _i+...+R _n， (6)

In formula, subscript i represents i-th transition of charge carrier, R _irepresent resistance during charge carrier i-th transition, R in formula _tot=σ ₀ ^-1exp (qE _{a (path)}/ k _bt), R _i=σ ₀ ^-1exp (2 α R _{ij (i)}+ qE _{a (i)}/ k _bt), the prefactor of conductance is represented, E _{a (path)}represent the average activation energy of each transfer passages, E _{a (i)}represent the activation energy of charge carrier i-th transition, then, formula (6) can be expressed as:

$e^{\frac{q{E}_{a\left(\mathrm{path}\right)}}{k_{B}T}}=e^{2\mathrm{\α}{R}_{\mathrm{ij}\left(1\right)}+\frac{q{E}_{a\left(1\right)}}{k_{B}T}}...+e^{2\mathrm{\α}{R}_{\mathrm{ij}\left(i\right)}+\frac{q{E}_{a\left(i\right)}}{k_{B}T}}...+e^{2\mathrm{\α}{R}_{\mathrm{ij}\left(n\right)}+\frac{q{E}_{a\left(n\right)}}{k_{B}T}},---\left(7\right)$

Step 33: by formula (7), according to the combination of different defects, can obtain charge carrier average activation energy of different passage during transition in conductive filament.

In such scheme, calculating the activation energy of individual defect in metal oxide based resistance-variable storing device described in step 31, is use the density functional theory (DFT) of the method for ultra-soft pseudo potential and plane wave expansion to calculate based on passing through; When calculating, the HfO of monocline ₂crystal unit cell parameters is: a axle is 0.5079nm, b axle is 0.5177nm, and c-axis is 0.5250nm, α and γ angle is 90.0 °, and β angle is 99.240 °; HfO ₂the occupancy of each atom adopts the No.43-1017 data in JCPDS file.

In such scheme, described step 4 comprises: by the acquisition charge carrier in the average activation energy of carrier transition obtained in step 2 and step 3 in conductive filament during transition the average activation energy of passage compare, when both errors are less than 5%, then represent that the average activation energy of carrier transition is identical with the average activation energy of passage, finally, the defect composition forming the average activation energy of passage is then expressed as the passage of conductive filament.

(3) beneficial effect

As can be seen from technique scheme, the present invention has following beneficial effect:

1, according to the analysis to Related Research Domain present situation, the I-V curve that the theoretical also Binding experiment of transition based on charge carrier records, the present invention proposes a kind of method extracting metal oxide based resistance-variable storing device carrier transport passage, the method is simple to operate, result is accurate, can be widely used in extracting the carrier transport passage with the different metal oxide based resistance-variable storing device of different materials, thickness of detector, as HfO ₂, ZrO ₂, WO ₃deng resistance-variable storing device, thus provide a kind of new physical method for the microphysics studying dissimilar RRAM is machine-processed.

2, utilize the present invention, the passage of the carrier transport of resistance-variable storing device can be extracted by simple method, for the microphysics mechanism studying resistance-variable storing device provides theoretical direction.

3, utilize the present invention, the carrier transport passage of extraction can be directly used in the electrology characteristic analyzing resistance-variable storing device, thus goes out resistance-variable storing device device prepared by optimum material by simple method choice.

Accompanying drawing explanation

figure1 is the method flow of extraction provided by the invention metal oxide based resistance-variable storing device carrier transport passage figure.

figure2 (a) is by calculating the I-V curve obtained and the signal of testing the I-V curve recorded figure.

figure2 (b) is the transfer passages of the charge carrier extracted, and wherein (1), (2), (3) and (4) correspond respectively to figurefour kinds in 2 (a) different states.

Embodiment

For making the object, technical solutions and advantages of the present invention clearly understand, below in conjunction with specific embodiment, and with reference to attached figure, the present invention is described in more detail.

The present invention is according to the analysis to Related Research Domain present situation, and the I-V curve that the theoretical also Binding experiment of the transition based on charge carrier records, proposes a kind of method extracting metal oxide based resistance-variable storing device carrier transport passage, as figureshown in 1, the method comprises the following steps:

Step 1: the I-V curve measuring metal oxide based resistance-variable storing device, and according to the low resistance state current value of this I-V curve determination resistance-variable storing device and high-impedance state current value;

Wherein, the I-V curve of the metal oxide based resistance-variable storing device of described measurement, adopts KEITHLEY4200-SCS type characteristic of semiconductor analytic system to carry out.The described low resistance state current value according to this I-V curve determination resistance-variable storing device and high-impedance state current value, comprise: adopt the voltage of reading of 0.1V from the I-V curve recorded, read this two current values reading under voltage, larger value in these two current values is decided to be the current value of low resistance state, and less value is decided to be the current value of high-impedance state.

Step 2: the average activation energy calculating the transition in conductive filament at low resistance state and high-impedance state download stream; This step specifically comprises the following steps:

Step 21: calculate the electric current in resistance-variable storing device conductive filament under low resistance state and high-impedance state;

Wherein, the electric current under low resistance state in resistance-variable storing device conductive filament is obtained by following formula:

$I={\mathrm{\σ}}_{\mathrm{LRS}}{F}_{2}S={\mathrm{\σ}}_0\mathrm{Sexp}(-2\mathrm{\α}{R}_{\mathrm{ij}}-q{E}_{a\left(a\right)}^L/k_{B}T)V/L---\left(1\right)$

F in formula ₂the electric field of conductive filament under expression low resistance state, σ _lRSrepresent conductivity, σ ₀represent the prefactor of conductance, α represents the inverse of localized modes length, R _ijrepresent the length of carrier transition, q represents electron charge, represent the activation energy of low resistance state download stream motion, k _brepresent Boltzmann constant, T represents the temperature of device, and V represents impressed voltage, and L represents the thickness of device, and S represents the cross-sectional area of conductive filament;

Under high-impedance state, due to the effect of space charge limited current, for the part of resistance-variable storing device conductive filament conducting, electric field meets Poisson's law, namely

dF(x)/dx＝-nq/ε (2)

In formula, n represents carrier concentration, and ε represents the specific inductive capacity of material, and F (x) represents electric field intensity;

Under high-impedance state, the electric current of resistance-variable storing device conductive filament turning part is expressed as:

$I_{\mathrm{hopping}}=\mathrm{nq}{\mathrm{\μ}}_0\exp (-2\mathrm{\α}{R}_{\mathrm{ij}}-q{E}_{a\left(a\right)}^H/k_{B}T)F\left(x\right)S---\left(3\right)$

μ in formula ₀represent the prefactor of carrier mobility, represent the activation energy of high-impedance state carrier moving;

Meanwhile, launch theoretical according to Fowler-Nordheim, under high-impedance state, the electric current of resistance-variable storing device conductive filament breaking part is represented by following formula:

$I_{\mathrm{tunneling}}=q^3{F_1}^{2}S/\left(8\mathrm{\πh}{\mathrm{\φ}}_B\right)\exp [-8\mathrm{\π}\sqrt{2m}{{\mathrm{\φ}}_B}^{\frac{3}{2}}/\left(3\mathrm{hq}{F}_1\right)]---\left(4\right)$

F in formula ₁represent conduction carefully than the electric field of break up location, h represents Planck constant, φ _brepresent barrier height, m represents the quality of free electron;

Step 22: the extra electric field of conductive filament under calculating resistance-variable storing device high-impedance state:

$V=V_{\mathrm{hopping}}+V_{\mathrm{tunneling}}={\∫}_0^{L_1}F\left(x\right)\mathrm{dx}+F_1(L-L_1)---\left(5\right)$

L in formula ₁represent the length of filament turning part, V _hoppingrepresent the voltage of conductive filament turning part, V _tunnelingrepresent the voltage of conductive filament breaking part;

Step 23: calculate the average activation energy under low resistance state and high-impedance state in resistance-variable storing device conductive filament: the average activation energy calculating the sub-transition of high low resistance state download stream in conjunction with above-mentioned formula (2)-(5).

Step 3: calculate charge carrier average activation energy of passage during transition in conductive filament; This step specifically comprises the following steps:

Step 31: the activation energy calculating individual defect in metal oxide based resistance-variable storing device; The activation energy of individual defect in the metal oxide based resistance-variable storing device of wherein said calculating uses the density functional theory (DFT) of the method for ultra-soft pseudo potential and plane wave expansion to calculate based on passing through; When calculating, the HfO of monocline ₂crystal unit cell parameters is: a axle is 0.5079nm, b axle is 0.5177nm, and c-axis is 0.5250nm, α and γ angle is 90.0 °, and β angle is 99.240 °; HfO ₂the occupancy of each atom adopts the No.43-1017 data in JCPDS file;

Step 32: by carrying out permutation and combination to the activation energy of individual defect, calculates charge carrier average activation energy of all possible passage during transition in conductive filament;

Conductive filament is regarded as the passage be in series by different defects, therefore, resistance total in conductive filament is:

R _tot＝R ₁+...+R _i+...+R _n， (6)

In formula, subscript i represents i-th transition of charge carrier, R _irepresent resistance during charge carrier i-th transition, R in formula _tot=σ ₀ ^-1exp (qE _{a (path)}/ k _bt), R _i=σ ₀ ^-1exp (2 α R _{ij (i)}+ qE _{a (i)}/ k _bt), the prefactor of conductance is represented, E _{a (path)}represent the average activation energy of each transfer passages, E _{a (i)}represent the activation energy of charge carrier i-th transition, then, formula (6) can be expressed as:

$e^{\frac{q{E}_{a\left(\mathrm{path}\right)}}{k_{B}T}}=e^{2\mathrm{\α}{R}_{\mathrm{ij}\left(1\right)}+\frac{q{E}_{a\left(1\right)}}{k_{B}T}}...+e^{2\mathrm{\α}{R}_{\mathrm{ij}\left(i\right)}+\frac{q{E}_{a\left(i\right)}}{k_{B}T}}...+e^{2\mathrm{\α}{R}_{\mathrm{ij}\left(n\right)}+\frac{q{E}_{a\left(n\right)}}{k_{B}T}},---\left(7\right)$

Step 33: by formula (7), according to the combination of different defects, can obtain charge carrier average activation energy of different passage during transition in conductive filament.

Step 4: determine the defect level of carrier transport and extract the passage of carrier transport;

This step specifically comprises: by the acquisition charge carrier in the average activation energy of carrier transition obtained in step 2 and step 3 in conductive filament during transition the average activation energy of passage compare, when both errors are less than 5%, then represent that the average activation energy of carrier transition is identical with the average activation energy of passage, finally, the defect composition forming the average activation energy of passage is then expressed as the passage of conductive filament.

Wherein, described metal oxide based resistance-variable storing device is the HfO utilizing the method for ald to prepare ₂, ZrO ₂or WO ₃the resistance-variable storing device device of material, thickness of detector is 5-30nm, and the bottom electrode of device is Pt/Ti metal level, and Pt thickness is 40nm, Ti thickness is 10nm; Power on very W/Ti metal level, and W thickness is 30nm, Ti thickness is 5nm.

Measure the I-V curve of metal oxide based resistance-variable storing device described in step 1, adopt KEITHLEY4200-SCS type characteristic of semiconductor analytic system to carry out.The described low resistance state current value according to this I-V curve determination resistance-variable storing device and high-impedance state current value, comprise: adopt the voltage of reading of 0.1V from the I-V curve recorded, read this two current values reading under voltage, larger value in these two current values is decided to be the current value of low resistance state, and less value is decided to be the current value of high-impedance state.

Embodiment

With W/Ti/HfO ₂/ Pt device, as an embodiment, first measures the I-V characteristic obtained under HRS and LRS state by electrical method, read voltage then by 0.1V, and the current value obtained when this reads voltage under low resistance state is 1.97 × 10 ^-4a, the current value 1.14 × 10 under high-impedance state ^-5a, by 1.97 × 10 ^-4a calculates in formula (1), obtains the activation energy of the sub-transition of low resistance state download stream; By 1.14 × 10 ^-5a substitutes into formula (3) and (4), then calculates the average activation energy of the sub-transition of high-impedance state download stream in conjunction with formula (2)-(5); In addition, the HfO of monocline can be calculated by CASTEP module ₂there is the size of two kinds of different defects and the charge carrier activation energy when these two kinds different defect transition: 0.891eV and 1.101eV respectively in crystal.Utilize the calculation flow chart shown in Fig. 1, the final W/Ti/HfO obtained ₂the passage of carrier transport in/Pt device, result as shown in Figure 2.In calculating, parameter used is: temperature is T=300K, V=0.1V, σ ₀=10 ¹³s/m, α ^-1=1.5nm, R _ij=0.385nm, ε=23, μ ₀=450m ²/ Vs, L=5nm, φ _b=2eV.

Above-described specific embodiment; object of the present invention, technical scheme and beneficial effect are further described; be understood that; the foregoing is only specific embodiments of the invention; be not limited to the present invention; within the spirit and principles in the present invention all, any amendment made, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (8)

1. extract a method for metal oxide based resistance-variable storing device carrier transport passage, it is characterized in that, the method comprises:

Step 1: the I-V curve measuring metal oxide based resistance-variable storing device, and according to the low resistance state current value of this I-V curve determination resistance-variable storing device and high-impedance state current value;

Step 2: the average activation energy calculating the transition in conductive filament at low resistance state and high-impedance state download stream;

Step 3: calculate charge carrier average activation energy of passage during transition in conductive filament;

Step 4: determine the defect level of carrier transport and extract the passage of carrier transport.

2. the method for extraction according to claim 1 metal oxide based resistance-variable storing device carrier transport passage, is characterized in that, described metal oxide based resistance-variable storing device is the HfO utilizing the method for ald to prepare ₂, ZrO ₂or WO ₃the resistance-variable storing device device of material, thickness of detector is 5-30nm, and the bottom electrode of device is Pt/Ti metal level, and Pt thickness is 40nm, Ti thickness is 10nm; Power on very W/Ti metal level, and W thickness is 30nm, Ti thickness is 5nm.

3. the method for extraction according to claim 1 metal oxide based resistance-variable storing device carrier transport passage, it is characterized in that, measure the I-V curve of metal oxide based resistance-variable storing device described in step 1, adopt KEITHLEY4200-SCS type characteristic of semiconductor analytic system to carry out.

4. the method for extraction according to claim 1 metal oxide based resistance-variable storing device carrier transport passage, is characterized in that, according to the low resistance state current value of this I-V curve determination resistance-variable storing device and high-impedance state current value described in step 1, comprising:

Adopt the voltage of reading of 0.1V from the I-V curve recorded, read this two current values reading under voltage, larger value in these two current values is decided to be the current value of low resistance state, and less value is decided to be the current value of high-impedance state.

5. the method for extraction according to claim 1 metal oxide based resistance-variable storing device carrier transport passage, is characterized in that, described step 2 comprises:

Step 21: calculate the electric current in resistance-variable storing device conductive filament under low resistance state and high-impedance state;

Wherein, the electric current under low resistance state in resistance-variable storing device conductive filament is obtained by following formula:

$I={\mathrm{\σ}}_{\mathrm{LRS}}{F}_{2}S={\mathrm{\σ}}_0\mathrm{Sexp}(-2\mathrm{\α}{R}_{\mathrm{ij}}-q{E}_{a\left(a\right)}^L/k_{B}T)V/L---\left(1\right)$

F in formula ₂the electric field of conductive filament under expression low resistance state, σ _lRSrepresent conductivity, σ ₀represent the prefactor of conductance, α represents the inverse of localized modes length, R _ijrepresent the length of carrier transition, q represents electron charge, represent the activation energy of low resistance state download stream motion, k _brepresent Boltzmann constant, T represents the temperature of device, and V represents impressed voltage, and L represents the thickness of device, and S represents the cross-sectional area of conductive filament;

Under high-impedance state, due to the effect of space charge limited current, for the part of resistance-variable storing device conductive filament conducting, electric field meets Poisson's law, namely

dF(x)/dx＝-nq/ε (2)

In formula, n represents carrier concentration, and ε represents the specific inductive capacity of material, and F (x) represents electric field intensity;

Under high-impedance state, the electric current of resistance-variable storing device conductive filament turning part is expressed as:

$I_{\mathrm{hopping}}=\mathrm{nq}{\mathrm{\μ}}_0\exp (-2\mathrm{\α}{R}_{\mathrm{ij}}-q{E}_{a\left(a\right)}^H/k_{B}T)F\left(x\right)S---\left(3\right)$

μ in formula ₀represent the prefactor of carrier mobility, represent the activation energy of high-impedance state carrier moving;

Meanwhile, launch theoretical according to Fowler-Nordheim, under high-impedance state, the electric current of resistance-variable storing device conductive filament breaking part is represented by following formula:

$I_{\mathrm{tunneling}}=q^3{F_1}^{2}S/\left(8\mathrm{\πh}{\mathrm{\φ}}_B\right)\exp [-8\mathrm{\π}\sqrt{2m}{{\mathrm{\φ}}_B}^{\frac{3}{2}}/\left(3\mathrm{hq}{F}_1\right)]---\left(4\right)$

F in formula ₁represent conduction carefully than the electric field of break up location, h represents Planck constant, φ _brepresent barrier height, m represents the quality of free electron;

Step 22: the extra electric field of conductive filament under calculating resistance-variable storing device high-impedance state:

$V=V_{\mathrm{hopping}}+V_{\mathrm{tunneling}}={\∫}_0^{L_1}F\left(x\right)\mathrm{dx}+F_1(L-L_1)---\left(5\right)$

L in formula ₁represent the length of filament turning part, V _hoppingrepresent the voltage of conductive filament turning part, V _tunnelingrepresent the voltage of conductive filament breaking part;

Step 23: calculate the average activation energy under low resistance state and high-impedance state in resistance-variable storing device conductive filament: the average activation energy calculating the sub-transition of high low resistance state download stream in conjunction with above-mentioned formula (2)-(5).

6. the method for extraction according to claim 1 metal oxide based resistance-variable storing device carrier transport passage, is characterized in that, described step 3 comprises:

Step 31: the activation energy calculating individual defect in metal oxide based resistance-variable storing device;

Step 32: by carrying out permutation and combination to the activation energy of individual defect, calculates charge carrier average activation energy of all possible passage during transition in conductive filament;

Conductive filament is regarded as the passage be in series by different defects, therefore, resistance total in conductive filament is:

R _tot＝R ₁+...+R _i+...+R _n， (6)

In formula, subscript i represents i-th transition of charge carrier, R _irepresent resistance during charge carrier i-th transition, R in formula _tot=σ ₀ ^-1exp (qE _{a (path)}/ k _bt), R _i=σ ₀ ^-1exp (2 α R _{ij (i)}+ qE _{a (i)}/ k _bt), the prefactor of conductance is represented, E _{a (path)}represent the average activation energy of each transfer passages, E _{a (i)}represent the activation energy of charge carrier i-th transition, then, formula (6) can be expressed as:

$e^{\frac{q{E}_{a\left(\mathrm{path}\right)}}{k_{B}T}}=e^{2\mathrm{\α}{R}_{\mathrm{ij}\left(1\right)}+\frac{q{E}_{a\left(1\right)}}{k_{B}T}}...e^{2\mathrm{\α}{R}_{\mathrm{ij}\left(i\right)}+\frac{q{E}_{a\left(i\right)}}{k_{B}T}}...+e^{2\mathrm{\α}{R}_{\mathrm{ij}\left(n\right)}+\frac{q{E}_{a\left(n\right)}}{k_{B}T}},---\left(7\right)$

Step 33: by formula (7), according to the combination of different defects, can obtain charge carrier average activation energy of different passage during transition in conductive filament.

7. the method for extraction according to claim 6 metal oxide based resistance-variable storing device carrier transport passage, it is characterized in that, calculating the activation energy of individual defect in metal oxide based resistance-variable storing device described in step 31, is use the density functional theory (DFT) of the method for ultra-soft pseudo potential and plane wave expansion to calculate based on passing through; When calculating, the HfO of monocline ₂crystal unit cell parameters is: a axle is 0.5079nm, b axle is 0.5177nm, and c-axis is 0.5250nm, α and γ angle is 90.0 °, and β angle is 99.240 °; HfO ₂the occupancy of each atom adopts the No.43-1017 data in JCPDS file.

8. the method for extraction according to claim 1 metal oxide based resistance-variable storing device carrier transport passage, is characterized in that, described step 4 comprises:

By the acquisition charge carrier in the average activation energy of carrier transition obtained in step 2 and step 3 in conductive filament during transition the average activation energy of passage compare, when both errors are less than 5%, then represent that the average activation energy of carrier transition is identical with the average activation energy of passage, finally, the defect composition forming the average activation energy of passage is then expressed as the passage of conductive filament.