Method for measuring ferroelectric hysteresis loop between any two points of ferroelectric material without plating electrode

Abstract

The invention discloses a method for measuring a ferroelectric hysteresis loop between any two points of an electrode-plating-free ferroelectric material, and the method comprises the steps: fixing the ferroelectric material on a probe table, pressing two probes at two positions of the ferroelectric material, measuring the capacitance between the two points under different bias voltages through a semiconductor parameter analyzer, and obtaining a CV curve, and then separating the capacitance signal into a leakage conductance signal, a linear polarization capacitance and a ferroelectric polarization capacitance by a CV curve, and obtaining a ferroelectric polarization capacitance-bias voltage curve between any two points of the ferroelectric film through processing, namely a ferroelectric hysteresis loop. According to the method, electrode preparation and soaking in silicone oil are not needed, so that the measurement process is greatly simplified; the method can measure the ferroelectric hysteresis loop between any two points on the surface of a ferroelectric film to obtain polarization information in the horizontal direction, can also measure the ferroelectric hysteresis loop of a ferroelectric nano material, can also apply external fields such as illumination and stress to perform in-situ measurement while measuring, and greatly expands the ferroelectric material ferroelectric hysteresis loop measuring range.

Description

technical field

[0001] The invention belongs to the field of G01R measuring electric variables, and specifically relates to a method for measuring hysteresis loops between arbitrary ferroelectric points through a probe and a semiconductor parameter analyzer without the need for plated electrodes. Background technique

[0002] Ferroelectric materials will generate spontaneous polarization within a certain temperature range. Since the positive and negative charge centers in the ferroelectric lattice do not coincide, electric dipole moments can be generated even without an external electric field, and its spontaneous polarization can be Under the action of an external electric field, the direction is changed to produce an electric hysteresis loop, which has unique spontaneous polarization reversibility, electro-optical effect, piezoelectric effect, pyroelectric effect, nonlinear optical effect, photorefractive effect, etc., in ferroelectric Memory, ferroelectric field effect tr...

Examples

Embodiment 1

[0041] Step 1. Fix an epitaxial bismuth ferrite thin film with a size of 0.5 mm×0.5 mm grown on a strontium titanate substrate on a probe station, and press two probes on the thin film.

[0042]Step 2. Apply a scanning bias voltage from 10V to -10V and then to -10V through the semiconductor parameter analyzer, and then add an AC voltage signal with an amplitude of 25mV and a frequency of 1MHz to the bias voltage to scan the CV curve. The curve is as follows image 3 shown.

[0043] Step 3, draw the obtained CV curve, perform mathematical processing on the curve, eliminate the influence of leakage conduction, and obtain C act ~ V curve, and then take the average value to get the static capacitance C s , subtract the static capacitance from the measured capacitance to obtain the ferroelectric polarization capacitance C f ~ V curve, such as Figure 4 shown.

Embodiment 2

[0045] Step 1. Fix an epitaxial bismuth ferrite thin film with a size of 0.5 mm×0.5 mm grown on a strontium titanate substrate on a probe station, and press two probes on the thin film.

[0046] Step 2. Apply a 10V to -10V and then to -10V scanning bias through the semiconductor parameter analyzer, respectively add 405nm LED purple light in the dark, and then add a 25mV amplitude and a frequency of 1MHz to the bias voltage. AC voltage signal for CV curve scanning.

[0047] Step 3. Draw the obtained CV curve and perform mathematical processing on the curve to obtain C under dark and light conditions. act ~ V curve such as Figure 5 As shown in (a), then get the ferroelectric polarization capacitance C f ~V curve, the ferroelectric polarization capacitance is multiplied by the amplitude of the applied AC bias voltage of 25mV, then divided by the probe diameter of 0.52mm and film thickness of 10 microns to obtain the ferroelectric polarization intensity, and then the polarizati...

Embodiment 3

[0049] Step 1. Fix the PVDF ferroelectric fiber prepared by electrospinning on the PET substrate on a probe station, and add probes to both ends of a fiber on a microscope.

[0050] Step 2. Apply a 20V to -20V and then to -20V scanning bias through the semiconductor parameter analyzer, and at the same time apply bending deformation to the PET substrate to generate bending strain on the PVDF fiber, and then add an amplitude of 25mV to the bias , the AC voltage signal with a frequency of 1kHz is used to scan the CV curve.

[0051] Step 3. Draw the obtained CV curve, perform mathematical processing on the curve, and measure the leakage conductance under light, linear polarization capacitance, ferroelectric polarization charge, coercive voltage; and Q-V hysteresis loop and P-E hysteresis loop .

technical field

[0001] The invention belongs to the field of G01R measuring electric variables, and specifically relates to a method for measuring hysteresis loops between arbitrary ferroelectric points through a probe and a semiconductor parameter analyzer without the need for plated electrodes. Background technique

[0002] Ferroelectric materials will generate spontaneous polarization within a certain temperature range. Since the positive and negative charge centers in the ferroelectric lattice do not coincide, electric dipole moments can be generated even without an external electric field, and its spontaneous polarization can be Under the action of an external electric field, the direction is changed to produce an electric hysteresis loop, which has unique spontaneous polarization reversibility, electro-optical effect, piezoelectric effect, pyroelectric effect, nonlinear optical effect, photorefractive effect, etc., in ferroelectric Memory, ferroelectric field effect tr...

Examples

Embodiment 1

[0041] Step 1. Fix an epitaxial bismuth ferrite thin film with a size of 0.5 mm×0.5 mm grown on a strontium titanate substrate on a probe station, and press two probes on the thin film.

[0042]Step 2. Apply a scanning bias voltage from 10V to -10V and then to -10V through the semiconductor parameter analyzer, and then add an AC voltage signal with an amplitude of 25mV and a frequency of 1MHz to the bias voltage to scan the CV curve. The curve is as follows image 3 shown.

[0043] Step 3, draw the obtained CV curve, perform mathematical processing on the curve, eliminate the influence of leakage conduction, and obtain C act ~ V curve, and then take the average value to get the static capacitance C s , subtract the static capacitance from the measured capacitance to obtain the ferroelectric polarization capacitance C f ~ V curve, such as Figure 4 shown.

Embodiment 2

[0045] Step 1. Fix an epitaxial bismuth ferrite thin film with a size of 0.5 mm×0.5 mm grown on a strontium titanate substrate on a probe station, and press two probes on the thin film.

[0046] Step 2. Apply a 10V to -10V and then to -10V scanning bias through the semiconductor parameter analyzer, respectively add 405nm LED purple light in the dark, and then add a 25mV amplitude and a frequency of 1MHz to the bias voltage. AC voltage signal for CV curve scanning.

[0047] Step 3. Draw the obtained CV curve and perform mathematical processing on the curve to obtain C under dark and light conditions. act ~ V curve such as Figure 5 As shown in (a), then get the ferroelectric polarization capacitance C f ~V curve, the ferroelectric polarization capacitance is multiplied by the amplitude of the applied AC bias voltage of 25mV, then divided by the probe diameter of 0.52mm and film thickness of 10 microns to obtain the ferroelectric polarization intensity, and then the polarizati...

Embodiment 3

[0049] Step 1. Fix the PVDF ferroelectric fiber prepared by electrospinning on the PET substrate on a probe station, and add probes to both ends of a fiber on a microscope.

[0050] Step 2. Apply a 20V to -20V and then to -20V scanning bias through the semiconductor parameter analyzer, and at the same time apply bending deformation to the PET substrate to generate bending strain on the PVDF fiber, and then add an amplitude of 25mV to the bias , the AC voltage signal with a frequency of 1kHz is used to scan the CV curve.

[0051] Step 3. Draw the obtained CV curve, perform mathematical processing on the curve, and measure the leakage conductance under light, linear polarization capacitance, ferroelectric polarization charge, coercive voltage; and Q-V hysteresis loop and P-E hysteresis loop .

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