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CN-115295720-B - Terahertz ferroelectric nerve synapse device and preparation method thereof

CN115295720BCN 115295720 BCN115295720 BCN 115295720BCN-115295720-B

Abstract

The invention discloses a terahertz ferroelectric nerve synapse device and a preparation method thereof. The terahertz ferroelectric nerve synapse device comprises a substrate, a hafnium-based ferroelectric functional layer formed on the substrate and in a strip shape, and electrodes formed on two sides of the strip-shaped hafnium-based ferroelectric functional layer, wherein the electrodes comprise a test area and a contact area, the contact area is in contact with the ferroelectric functional layer, the contact area is in a T shape, the extending direction of a flat top of the contact area is perpendicular to the extending direction of the ferroelectric functional layer, terahertz excitation is applied to one side of the electrodes, high-speed electric domain polarization inversion is achieved, and a controllable conductivity modulation state is obtained and is used for nerve morphology calculation.

Inventors

  • MENG JIALIN
  • WANG TIANYU
  • HE ZHENYU
  • CHEN LIN
  • SUN QINGQING
  • ZHANG WEI

Assignees

  • 复旦大学

Dates

Publication Date
20260508
Application Date
20220531

Claims (7)

  1. 1. A terahertz ferroelectric nerve synapse device is characterized in that, Comprising the following steps: A substrate; a hafnium-based ferroelectric functional layer formed on the substrate and having a long strip shape; The electrodes are formed on two sides of the long hafnium-based ferroelectric functional layer, the electrodes comprise a test area and a contact area, the contact area is in contact with the ferroelectric functional layer, the contact area is in a T shape, the extending direction of a flat top part of the contact area is perpendicular to the extending direction of the ferroelectric functional layer, Terahertz excitation is applied to one side electrode to realize high-speed electric domain polarization inversion, obtain a controllable conductivity modulation state for nerve morphology calculation, The distance between flat tops of contact areas of the electrodes at two sides is 10 nm-70 nm.
  2. 2. The terahertz ferroelectric synapse device according to claim 1, characterized in that, The hafnium-based ferroelectric functional layer is Hf 0.5 Zr 0.5 O 2 ,HfAlO x or HfSiO x .
  3. 3. The terahertz ferroelectric synapse device according to claim 1, characterized in that, The length of the hafnium-based ferroelectric functional layer is 50-200 mu m, and the width is 10-80 mu m.
  4. 4. A preparation method of a terahertz ferroelectric nerve synapse device is characterized in that, The method comprises the following steps: Forming a strip hafnium-based ferroelectric functional layer on a substrate; Electrodes are formed on two sides of the strip-shaped hafnium-based ferroelectric functional layer, the electrodes comprise a test area and a contact area, the contact area is in contact with the ferroelectric functional layer, the contact area is in a T shape, the extending direction of a flat top part of the contact area is perpendicular to the extending direction of the ferroelectric functional layer, Terahertz excitation is applied to one side electrode to realize high-speed electric domain polarization inversion, obtain a controllable conductivity modulation state for nerve morphology calculation, The distance between flat tops of contact areas of the electrodes at two sides is 10 nm-70 nm.
  5. 5. The method for fabricating a terahertz ferroelectric synapse device according to claim 4, The step of forming a long hafnium-based ferroelectric functional layer specifically includes: spin-coating photoresist as a barrier layer, wherein the rotation speed is 2000-4000 revolutions per minute, the rotation time is 20-120 s, baking is carried out for 30-120 s at 90-150 ℃, and then ultraviolet exposure is carried out for defining a growth area of the ferroelectric functional layer; growing a hafnium-based ferroelectric film with the thickness of 10-25 nm on a substrate by using a physical vapor deposition method; Removing the photoresist to obtain a strip-shaped hafnium-based ferroelectric functional layer; and then adopting a rapid thermal annealing process to anneal for 30-120 s at 400-600 ℃ in a nitrogen atmosphere.
  6. 6. The method for fabricating a terahertz ferroelectric synapse device according to claim 4, The hafnium-based ferroelectric functional layer is Hf 0.5 Zr 0.5 O 2 ,HfAlO x or HfSiO x .
  7. 7. The method for fabricating a terahertz ferroelectric synapse device according to claim 4, The length of the hafnium-based ferroelectric functional layer is 50-200 mu m, and the width is 10-80 mu m.

Description

Terahertz ferroelectric nerve synapse device and preparation method thereof Technical Field The invention belongs to the technical field of semiconductors, and particularly relates to a terahertz ferroelectric nerve synapse device and a preparation method thereof. Background The response time of the nerve synapse in the organism is 10ms, and the response frequency is 100HZ, so that various nerve calculation and storage functions can be efficiently realized. At present, the existing electronic nerve synapse device can also reach the response frequency of 100HZ, and the nerve synapse plasticity function simulation is completed. In order to further improve the computational efficiency, it is not easy to develop a biomimetic neural synaptic device with a high-speed response. Recently, terahertz devices have been widely focused and rapidly developed due to the advantages of high signal-to-noise ratio of time-domain spectrum, high instantaneous bandwidth, matching with vibration and rotation energy levels of biomacromolecules, and the like. Particularly, the characteristic of high frequency is of great significance to the improvement of the response of the electronic device. Development of a neurosynaptic device with terahertz response will greatly improve the response sensitivity of the device, maximizing the computational efficiency. Ferroelectric memories have important applications in the field of integrated circuits as a potential non-volatile memory device. Although the possibility for neural synapse simulation has been demonstrated by the conventional ferroelectric materials such as BiFeO 3、PbTiO3, the development is limited by the problems of CMOS process compatibility and low response frequency. The preparation of the doped hafnium-based ferroelectric film by using the physical vapor deposition method breaks the limitations, and has potential of being applied to the terahertz ferroelectric nerve synapse compatible with the CMOS process. Disclosure of Invention The invention discloses a terahertz ferroelectric nerve synapse device which comprises a substrate, a hafnium-based ferroelectric functional layer and electrodes, wherein the hafnium-based ferroelectric functional layer is formed on the substrate and is in a strip shape, the electrodes are formed on two sides of the strip-shaped hafnium-based ferroelectric functional layer, each electrode comprises a test area and a contact area, each contact area is in contact with the ferroelectric functional layer, each contact area is in a T shape, the extending direction of a flat top of each contact area is perpendicular to the extending direction of the ferroelectric functional layer, terahertz excitation is applied to one side of each electrode, and a high-speed electric domain polarization overturning state is achieved to obtain a controllable electric conduction modulation state and used for nerve morphology calculation. In the terahertz ferroelectric nerve synapse device, the distance between flat tops of contact areas of two side electrodes is preferably 10 nm-70 nm. In the terahertz ferroelectric nerve synapse device of the present invention, the hafnium-based ferroelectric functional layer is preferably Hf 0.5Zr0.5O2,HfAlOx,HfSiOx. In the terahertz ferroelectric nerve synapse device of the present invention, the length of the hafnium-based ferroelectric functional layer is preferably 50 μm to 200 μm, and the width is preferably 10 μm to 80 μm. The invention also discloses a preparation method of the terahertz ferroelectric nerve synapse device, which comprises the following steps of forming a strip-shaped hafnium-based ferroelectric functional layer on the substrate, forming electrodes on two sides of the strip-shaped hafnium-based ferroelectric functional layer, wherein the electrodes comprise a test area and a contact area, the contact area is in contact with the ferroelectric functional layer, the contact area is in a T shape, the extending direction of a flat top of the contact area is perpendicular to the extending direction of the ferroelectric functional layer, and applying terahertz excitation on one side of the electrodes to realize high-speed electric domain polarization inversion so as to obtain a controllable conductivity modulation state for nerve morphology calculation. The preparation method of the terahertz ferroelectric nerve synapse device comprises the steps of forming a strip-shaped hafnium-based ferroelectric functional layer, specifically comprising the steps of spin-coating photoresist serving as a barrier layer, rotating at 2000-4000 rpm for 20-120 s, baking at 90-150 ℃ for 30-120 s, then performing ultraviolet exposure to define a growth area of the ferroelectric layer, growing a hafnium-based ferroelectric film with the thickness of 10-25 nm on a substrate by a physical vapor deposition method, removing the photoresist to obtain the strip-shaped hafnium-based ferroelectric film, and then annealing at 400-600 ℃ for 30-120 s in