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CN-121985561-A - Ferroelectric thin film transistor based on aluminum scandium nitride, aluminum nitride and aluminum scandium nitride multilayer structure and preparation method thereof

CN121985561ACN 121985561 ACN121985561 ACN 121985561ACN-121985561-A

Abstract

The invention discloses a ferroelectric thin film transistor based on a multilayer structure of aluminum scandium nitride, aluminum nitride and aluminum scandium nitride and a preparation method thereof, and relates to the field of semiconductor devices and ferroelectric memories. The ferroelectric thin film transistor based on the multilayer structure of aluminum scandium nitride, aluminum nitride and aluminum scandium nitride comprises a multilayer ferroelectric gate stack structure and a channel layer matched with the multilayer ferroelectric gate stack structure, wherein the multilayer ferroelectric gate stack structure is a symmetrical laminated structure of aluminum scandium nitride/aluminum scandium nitride. The ferroelectric thin film transistor based on the aluminum scandium nitride, aluminum nitride and aluminum scandium nitride multilayer structure provides a basis for decoupling residual polarization and coercive field and relieving negative effects brought by depolarization field from the structural layer through the level matching of a laminated structure, is compatible with the assembly logic of a conventional semiconductor device, and reserves structural space for subsequent performance optimization and material replacement.

Inventors

  • ZHAO CHUN
  • ZHANG JINWEI

Assignees

  • 深圳市华芯邦科技有限公司

Dates

Publication Date
20260505
Application Date
20260403

Claims (10)

  1. 1. The ferroelectric thin film transistor based on the multilayer structure of aluminum scandium nitride, aluminum nitride and aluminum scandium nitride is characterized by comprising a multilayer ferroelectric gate stack structure and a channel layer matched with the multilayer ferroelectric gate stack structure, wherein the multilayer ferroelectric gate stack structure is a symmetrical laminated structure of aluminum scandium nitride/aluminum scandium nitride, a bottom electrode and a top electrode are arranged in the laminated structure, and the bottom electrode, the symmetrical laminated structure of aluminum scandium nitride/aluminum scandium nitride and the top electrode are sequentially laminated.
  2. 2. The ferroelectric thin film transistor based on the multilayer structure of aluminum scandium nitride, aluminum nitride and aluminum scandium nitride according to claim 1, wherein the symmetrical stacked structure of aluminum scandium nitride/aluminum scandium nitride comprises a lower aluminum scandium nitride ferroelectric layer, an aluminum nitride dielectric layer and an upper aluminum scandium nitride ferroelectric layer, which are sequentially stacked between the bottom electrode and the top electrode from bottom to top.
  3. 3. The ferroelectric thin film transistor based on a multilayer structure of aluminum scandium nitride, aluminum nitride and aluminum scandium nitride according to claim 2, wherein the mole fraction of Sc in the lower and upper layers of aluminum scandium nitride is 0.2-0.3 and the thickness of both layers is 5-15nm independently.
  4. 4. A ferroelectric thin film transistor based on a multilayer structure of aluminum scandium nitride, aluminum nitride, and aluminum scandium nitride according to claim 2, wherein the dielectric layer of aluminum nitride has a dielectric constant of 10.1 and a thickness of 0-30nm.
  5. 5. The ferroelectric thin film transistor based on the aluminum scandium nitride, the aluminum nitride and the aluminum scandium nitride multilayer structure according to claim 1 is characterized in that the bottom electrode is HfN 0 . 4 , the top electrode is TiN, the channel layer is made of an oxide semiconductor material, the thickness is 10-30nm, and the oxide semiconductor material is amorphous indium gallium zinc oxide.
  6. 6. A ferroelectric thin film transistor based on a multilayer structure of aluminum scandium nitride, aluminum nitride, and scandium aluminum nitride according to claim 2, wherein said aluminum nitride dielectric layer is provided as a low dielectric constant ferroelectric or dielectric material having interfacial compatibility with scandium aluminum nitride, said low dielectric constant ferroelectric or dielectric material being HfO 2 or ZrO 2 .
  7. 7. Ferroelectric thin film transistor based on a multilayer structure of aluminum scandium nitride, aluminum scandium nitride according to claim 2, characterized in that the lower and upper aluminum scandium nitride ferroelectric layers can be provided as wurtzite structured ferroelectric material, which is ZnO or GaN, and adapted to adjust Sc doping concentration to maintain ferroelectricity.
  8. 8. A ferroelectric thin film transistor based on a multilayer structure of aluminum scandium nitride, aluminum nitride, scandium aluminum nitride according to claim 1, wherein the bottom and top electrodes are arranged as metal nitride materials having a matching lattice constant with aluminum scandium nitride and good conductivity, said metal nitride materials being TaN or WN.
  9. 9. The method for preparing a ferroelectric thin film transistor according to any one of claims 1 to 8, wherein each layer structure is formed by continuous deposition at room temperature by using a radio frequency magnetron sputtering technology, vacuum is not broken in the deposition process, mixed gas of Ar and N 2 is introduced during deposition, the deposition pressure is controlled to be 2-20mTorr, and the sputtering power is controlled to be 200-400W.
  10. 10. The method for fabricating a ferroelectric thin film transistor according to claim 9, wherein the total thickness of the multi-layered ferroelectric gate stack structure is 20-40nm, the thickness of the aluminum nitride dielectric layer is 10nm or 20nm when the total thickness is 40nm, and the thickness of the aluminum nitride dielectric layer is 15nm when the total thickness is 20 nm; The preparation method specifically comprises the following steps: S1, depositing a corresponding material on a substrate to form the bottom electrode; S2, sequentially depositing a lower aluminum scandium nitride ferroelectric layer, an aluminum nitride dielectric layer and an upper aluminum scandium nitride ferroelectric layer on the surface of the bottom electrode; and S3, depositing a corresponding material on the surface of the upper aluminum scandium nitride ferroelectric layer to form the top electrode, and simultaneously depositing an oxide semiconductor material at a corresponding position to form the channel layer.

Description

Ferroelectric thin film transistor based on aluminum scandium nitride, aluminum nitride and aluminum scandium nitride multilayer structure and preparation method thereof Technical Field The invention relates to the field of semiconductor devices and ferroelectric memories, in particular to a ferroelectric thin film transistor based on a multilayer structure of aluminum scandium nitride, aluminum nitride and aluminum scandium nitride and a preparation method thereof. Background Ferroelectric field effect transistors are widely used as core devices in the fields of semiconductor devices and ferroelectric memories in hardware platforms such as nonvolatile memories and neuromorphic computing devices, and the material properties of gate dielectric layers directly determine the overall working effect of the devices. In the prior art, a single-layer aluminum scandium nitride film is mostly adopted as a gate dielectric layer of the ferroelectric field effect transistor, but the material has the characteristic of high coercive field, but the high residual polarization of the material can cause strong depolarization field, the problem directly causes a large accumulation of device interface charges, so that the retention characteristic of the ferroelectric field effect transistor is obviously degraded, the performance attenuation problem is particularly prominent in a high-temperature working environment, the practical application of the ferroelectric field effect transistor in the scenes of high-temperature storage, industrial computing and the like is seriously restricted, and the material becomes a core technical problem to be solved in the field. Disclosure of Invention The invention aims to provide a ferroelectric thin film transistor based on a multilayer structure of aluminum scandium nitride, aluminum nitride and aluminum scandium nitride and a preparation method thereof, so as to solve the problems in the prior art. In order to achieve the above purpose, the invention provides a ferroelectric thin film transistor based on an aluminum scandium nitride, aluminum nitride and aluminum scandium nitride multilayer structure, which comprises a multilayer ferroelectric gate stack structure and a channel layer matched with the multilayer ferroelectric gate stack structure, wherein the multilayer ferroelectric gate stack structure is a symmetrical laminated structure of aluminum scandium nitride/aluminum scandium nitride, a bottom electrode and a top electrode are arranged in the laminated structure, and the bottom electrode, the symmetrical laminated structure of aluminum scandium nitride/aluminum scandium nitride and the top electrode are sequentially laminated. Preferably, the symmetrical stacked structure of aluminum scandium nitride/aluminum scandium nitride comprises a lower aluminum scandium nitride ferroelectric layer, an aluminum nitride dielectric layer and an upper aluminum scandium nitride ferroelectric layer, wherein the lower aluminum scandium nitride ferroelectric layer, the aluminum nitride dielectric layer and the upper aluminum scandium nitride ferroelectric layer are sequentially stacked between the bottom electrode and the top electrode from bottom to top. Preferably, the mole fraction of Sc in the lower aluminum scandium nitride ferroelectric layer and the upper aluminum scandium nitride ferroelectric layer is 0.2-0.3, and the thicknesses of the lower aluminum scandium nitride ferroelectric layer and the upper aluminum scandium nitride ferroelectric layer are 5-15nm independently. Preferably, the dielectric constant of the aluminum nitride dielectric layer is 10.1, and the thickness is 0-30nm. Preferably, the bottom electrode is HfN 0.4, the top electrode is TiN, the channel layer is made of an oxide semiconductor material with the thickness of 10-30nm, and the oxide semiconductor material is amorphous indium gallium zinc oxide. Preferably, the aluminum nitride dielectric layer may be provided as a low dielectric constant ferroelectric or dielectric material having interfacial compatibility with aluminum scandium nitride, and the low dielectric constant ferroelectric or dielectric material is HfO 2 or ZrO 2. Preferably, the lower aluminum scandium nitride ferroelectric layer and the upper aluminum scandium nitride ferroelectric layer may be made of wurtzite structure ferroelectric material, and Sc doping concentration is adapted to be adjusted to maintain ferroelectricity, wherein the wurtzite structure ferroelectric material is ZnO or GaN. Preferably, the bottom electrode and the top electrode may be provided as a metal nitride material having a lattice constant matching with scandium aluminum nitride and good conductivity, and the metal nitride material is TaN or WN. A method for preparing ferroelectric thin film transistor includes using radio frequency magnetron sputtering technique to deposit each layer continuously at room temperature, applying Ar and N 2 mixed gas to deposit at pressure of