Shanghai IC R&D Center Co. Ltd. Obtains US Patent for Phase Change Memory Unit and Preparation Method

Strategic Insights -

Scientists at Shanghai IC R&D Center Co. Ltd. have developed a novel phase change memory unit and a method for its preparation, as revealed in a recently published patent. The inventive phase change memory unit features a distinct electrical conductivity between the crystalline and amorphous states of a chalcogenide material, enabling the storage of data. The invention addresses the shortcomings of traditional phase change memory units, aiming to improve device performance and reliability.

Key Takeaways:

  • The patented phase change memory unit comprises a bottom electrode, a phase change cell, a heating electrode, and a top electrode, formed on a substrate.
  • The phase change cell consists of a columnar phase change material layer, a hollow columnar heat dissipation layer, and a hollow columnar switch layer.
  • The inventive phase change memory unit overcomes defects in prior art devices by offering improved device performance and reliability.
  • The claimed phase change memory unit has various combinations of cross-sectional shapes, including circles, ellipses, rectangles, rhombuses, and polygons.
  • The phase change material layer can comprise GeTe-Sb2Te3, GeTe-SnTe, Sb2Te5, In3SbTe2, or Sb-based materials, doped with Sc, Ag, In2, Al, In, C, S, Se, N, Cu, W, or other elements.
  • The heating electrode can be connected to a contact surface of the phase change material layer or longitudinally arranged on the top surface of the phase change material layer.
  • The inventive phase change memory unit features enhanced thermal conductivity of the material of the heat dissipation layer, exceeding 100 W/mK.
  • The switch formed by the switch layer can be a two-dimensional material transistor, an ovonic threshold switch, or a metal oxide thin film resistance switch.
  • The inventive method for preparing the phase change memory unit consists of several steps, including substrate preparation, electrode formation, and phase change material layer deposition.
  • The phase change material layer can be removed on the second dielectric layer by chemical mechanical polishing to form a phase change cell.

Statistics:

  • Patented phase change memory unit features a novel structure with a phase change cell, heating electrode, and top electrode.
  • The inventive phase change memory unit consists of a bottom electrode, a phase change cell, a heating electrode, and a top electrode.
  • The phase change material layer is comprised of GeTe-Sb2Te3, GeTe-SnTe, Sb2Te5, In3SbTe2, or Sb-based materials, doped with various elements.
  • The heat dissipation layer has a thermal conductivity of over 100 W/mK.
  • The inventive phase change memory unit has a cross-sectional shape consisting of one or more combinations of a circle, an ellipse, a rectangle, a rhombus, and a polygon.

Sources:

  • Feng, Gaoming. Phase change memory unit and preparation method therefor. U.S. Patent Number 12446478, filed December 24, 2021, and published online on October 14, 2025.
  • Feng, Gaoming. Phase change memory unit and preparation method therefor. URL and more information: https://ppubs.uspto.gov/pubwebapp/external.html?q=(12446478)&db=USPAT&type=ids