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CN-122028442-A - Hafnium oxide-based ferroelectric capacitor

CN122028442ACN 122028442 ACN122028442 ACN 122028442ACN-122028442-A

Abstract

The invention provides a hafnium oxide-based ferroelectric capacitor, which is provided with an aluminum oxide top interface layer between a ferroelectric layer and a top electrode, and the stress inside the ferroelectric layer is regulated and controlled by introducing the aluminum oxide top interface layer so as to reduce the coercive electric field of the hafnium oxide-based ferroelectric layer material, thereby reducing the working voltage required for reaching the polarization intensity of 10 mu C/cm 2 . In addition, the invention can effectively regulate the out-of-plane O phase content in the hafnium oxide-based ferroelectric layer, thereby improving the polarization intensity and dielectric constant under the same voltage, and can effectively inhibit the leakage current of the hafnium oxide-based ferroelectric capacitor and improve the cycle performance of the capacitor by utilizing the higher forbidden bandwidth of the aluminum oxide.

Inventors

  • CHEN DANYANG
  • LI XIUYAN
  • Si Mengwei
  • GAO QIANG

Assignees

  • 上海交通大学

Dates

Publication Date
20260512
Application Date
20241112

Claims (10)

  1. 1. A hafnium oxide-based ferroelectric capacitor is characterized in that an aluminum oxide top interface layer is arranged between a ferroelectric layer and a top electrode, and the aluminum oxide top interface layer is used for adjusting the internal stress of a ferroelectric layer film, adjusting and controlling the content of out-of-plane polarized O phase in an annealing process and improving the cycle performance of the capacitor.
  2. 2. The hafnium oxide based ferroelectric capacitor of claim 1, wherein the thickness of the aluminum oxide top interface layer is 0.1-10 nm.
  3. 3. The hafnium oxide based ferroelectric capacitor according to claim 1, wherein the thickness of the ferroelectric layer is 0.1 to 30nm.
  4. 4. The hafnium oxide based ferroelectric capacitor according to claim 1, wherein the total thickness of the capacitor is 0.2-40 nm.
  5. 5. The hafnium oxide-based ferroelectric capacitor according to claim 1, wherein said ferroelectric layer is a hafnium oxide ferroelectric thin film doped with any one of Zr, si, ge, la and Al elements.
  6. 6. The hafnium oxide based ferroelectric capacitor according to claim 1, wherein the top electrode is a single layer structure formed of any one of TiN, W, al, ru, mo, ti and RuO 2 , or a stacked layer structure formed of at least two of TiN, W, al, ru, mo, ti and RuO 2 .
  7. 7. The hafnium oxide based ferroelectric capacitor of claim 1, wherein the ferroelectric layer further comprises a substrate layer and a bottom electrode below the substrate layer, the substrate layer being located below the bottom electrode.
  8. 8. The hafnium oxide based ferroelectric capacitor according to claim 7, wherein the bottom electrode is a single layer structure formed of any one of TiN, W, al, ru, mo, ti and RuO 2 , or a stacked layer structure formed of at least two of TiN, W, al, ru, mo, ti and RuO 2 .
  9. 9. The hafnium oxide based ferroelectric capacitor of claim 7, wherein said substrate layer is a semiconductor substrate or an oxide substrate.
  10. 10. Hafnium oxide-based ferroelectric capacitor according to any one of claims 1 to 9, characterized in that the capacitor is annealed by a rapid annealing process, whereby the ferroelectric properties of the ferroelectric layer are achieved.

Description

Hafnium oxide-based ferroelectric capacitor Technical Field The invention relates to the technical field of integrated circuit devices, in particular to a hafnium oxide-based ferroelectric capacitor. Background In the big data age driven by artificial intelligence and the internet of things technology, explosive growth of data volume puts higher demands on the computing and storage capacities of integrated circuits. Among them, problems such as slow read/write speed, high operation voltage, limited number of cycles, and size scaling limit are major problems faced by the current advanced nonvolatile memory device. Therefore, there is a need for a new technology that is characterized by new materials, new principles, new architecture, and that achieves higher speed, lower power consumption, higher density, and new functions such as memory integration. At present, several novel memory technology routes have been proposed by academic and industry, including Resistive Random Access Memory (RRAM), phase change memory (PCRAM), spin-electron memory (STT-MRAM), and various ferroelectric memory devices, etc. The ferroelectric memory device including ferroelectric transistor (FeFET), ferroelectric memory (FeRAM) and Ferroelectric Tunnel Junction (FTJ) has the advantages of high memory density, high read-write speed, low memory energy consumption, etc. The early development of the device is mainly based on perovskite structures such as ferroelectric materials including PZT, BTO and the like. However, the traditional perovskite ferroelectric material has the problems of incompatibility with the CMOS process, poor micro performance, environmental pollution and the like. Whereas the novel doped hafnium oxide based ferroelectric material discovered in germany NamLab in 2011 is compatible with existing CMOS processes and exhibits ferroelectric properties on the nanometer scale (< 30 nm), with excellent scaling characteristics. Therefore, hafnium oxide-based ferroelectric memory devices are a new generation of nonvolatile semiconductor memory with great development potential. Among them, hafnium oxide-based ferroelectric transistors have great potential for development in terms of miniaturization performance and 3D integration, and thus have been attracting attention. But its coercive electric field E C is typically an order of magnitude higher than that of conventional ferroelectric materials, which results in an increase in its power consumption and a decrease in reliability. The coercive electric field of the material itself needs to be tailored to reduce its operating voltage. Meanwhile, performance indexes such as polarization intensity, leakage current, cycle performance, dielectric constant and the like also need synchronous regulation and optimization. The invention discloses an antiferroelectric capacitor and a preparation method thereof, wherein the antiferroelectric capacitor comprises a substrate, a first functional layer, a lower electrode layer, a dielectric layer, a second functional layer and an upper electrode layer, the first functional layer is arranged on the substrate, the lower electrode layer is arranged on the first functional layer, the dielectric layer is arranged on the lower electrode layer, the second functional layer is arranged on the dielectric layer, the upper electrode layer is arranged on the second functional layer, the first functional layer is made of aluminum oxide, and the second functional layer is made of aluminum oxide, zirconium oxide or hafnium oxide. The antiferroelectric capacitor improves the storage performance and flexibility of the antiferroelectric capacitor, so that the energy storage density and the working efficiency of the antiferroelectric capacitor are greatly improved. However, the energy storage device in the patent has different requirements on the performance of the whole device from the data storage device, the energy storage device actually needs to regulate and control the antiferroelectric P-E curve shape, the data storage device needs to regulate and control the coercive electric field to realize lower working voltage, and the patent does not realize the regulation and control on the performance such as the working voltage of the device. There is no clear means to optimize all the above properties at the same time, and for this reason, a new hafnium oxide-based ferroelectric capacitor is needed to solve the above technical problems. Disclosure of Invention Aiming at the defects in the prior art, the invention aims to provide a hafnium oxide-based ferroelectric capacitor, which can reduce the operating voltage of the hafnium oxide-based ferroelectric capacitor, improve the polarization intensity, reduce the leakage current, improve the cycle performance and improve the dielectric constant. The invention is realized by the following technical scheme: The invention provides a hafnium oxide-based ferroelectric capacitor, which is provided with an aluminum oxide t