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CN-122003103-A - High-stability large-window all-optical phase-change brain-like computing material and device

CN122003103ACN 122003103 ACN122003103 ACN 122003103ACN-122003103-A

Abstract

The invention discloses an all-optical phase-change brain calculation material with a high stability and a large window and a device, wherein the device structure sequentially comprises a substrate, an optical waveguide layer, a dielectric layer, a phase-change layer and a top oxidation prevention layer from bottom to top, the phase-change layer of the device is a germanium-enriched germanium-antimony-tellurium phase-change material, and the chemical formula is Ge x Sb y Te z , wherein x is more than or equal to 25 and less than or equal to 50,15, y is more than or equal to 25, and z is more than or equal to 30 and less than or equal to 50. The phase change material has high crystallization temperature, good amorphous thermal stability, large optical property difference between amorphous phase and crystalline phase, large switching ratio of the device and excellent cycle stability.

Inventors

  • WANG JIANGJING
  • DU YUXIN
  • ZHANG WEI

Assignees

  • 西安交通大学

Dates

Publication Date
20260508
Application Date
20260126

Claims (7)

  1. 1. The full-optical phase-change brain-like computing material with the high stability and the large window is characterized in that the material is germanium-enriched germanium-antimony-tellurium phase-change material, the chemical formula is Ge x Sb y Te z , wherein x is more than or equal to 25 and less than or equal to 50,15, y is more than or equal to 30 and less than or equal to 50, z is more than or equal to 30 and less than or equal to 50, x+y+z=100, and x, y and z are atomic percentages of elements; The amorphous phase of the germanium-enriched germanium-antimony-tellurium phase change material is bonded by covalent bonds, the crystalline phase is bonded by metal covalent bonds, and the two-phase structure is mainly in an octahedral configuration.
  2. 2. The high-stability large-window all-optical phase-change brain-like computing material is characterized in that the germanium-enriched germanium-antimony-tellurium phase-change material is strongest in modulation capacity of an optical communication C wave band of 1530-1565 nm commonly used in optical fiber communication, and the refractive index difference delta n between an amorphous phase and a crystalline phase is more than or equal to 1.7 and the extinction coefficient difference delta k is more than or equal to 0.8 at a center wavelength of 1550 nm.
  3. 3. An all-optical phase-change brain computing device based on germanium-enriched germanium-antimony-tellurium phase-change material is characterized by comprising a substrate, an optical waveguide layer, a phase-change layer and a top oxidation-resistant layer from bottom to top along the Z-axis direction; The phase-change layer is the germanium-enriched germanium-antimony-tellurium phase-change material as claimed in claim 1 or 2; the optical waveguide layer comprises a square structure below and a ridge type central bulge positioned on the surface of the square structure, wherein the ridge type central bulge is arranged along the X-axis center of the surface of the square structure, and the length of the ridge type central bulge is the same as that of the square structure; The upper surface of the ridge-type central bulge is provided with a phase change layer, and the width of the phase change layer is the same as that of the ridge-type central bulge; The widths of the optical waveguide layer and the substrate are 2-10 mu m; The thickness range of the phase change layer is 5-50 nm; The thickness range of the top oxidation preventing layer is 5-50 nm; the length w of the phase-change layer and the top oxidation prevention layer ranges from 40 to 80 mu m, the length of the optical waveguide layer ranges from 200 to 500 mu m, the width of the square structure ranges from 300 to 800 nm, and the thickness ranges from 150 to 500 nm.
  4. 4. The device of claim 3, wherein the substrate material is silicon dioxide, the optical waveguide layer material is one of silicon and silicon nitride material, and the top oxidation preventing layer is Indium Tin Oxide (ITO).
  5. 5. The all-optical phase-change brain-like computing device based on germanium-enriched germanium-antimony-tellurium phase-change material according to claim 3, wherein the preparation process of the germanium-enriched germanium-antimony-tellurium phase-change material is one of magnetron sputtering, electron beam evaporation, chemical vapor deposition, laser pulse deposition and atomic layer deposition.
  6. 6. The all-optical phase-change brain-like computing device based on germanium-enriched germanium-antimony-tellurium phase-change materials according to claim 3, wherein 1550nm pumping laser is used for applying single-step write pulse and double-step erase pulse to the device, phase states of the phase-change materials are switched, the applied photocurrent ranges from 50 mA to 600 mA, the write pulse width ranges from 50 ns to 300 ns, the erase pulse width ranges from 800 ns to 2000 ns, and 1540 nm detection laser is synchronously used for detecting signal values of the device after the pulse is applied.
  7. 7. The application of the all-optical phase-change brain-like computing device based on the germanium-enriched germanium-antimony-tellurium phase-change material according to any one of claims 3-6, wherein the brain-like device is specifically applied to a high-precision analog synaptic system, a physical reserve pool in pool calculation, a multi-value photon memory in high-bandwidth cache and a photoelectric mixed memory internal computing unit.

Description

High-stability large-window all-optical phase-change brain-like computing material and device Technical Field The invention relates to the technical field of phase change materials and nerve morphology memory computation, in particular to an all-optical phase change brain computation material and device with high stability and large window. Background The all-optical storage and brain-like computing chip based on the phase change material is one of the most potential leading directions in the current information field, and a brand new physical carrier is provided for breaking through the traditional electronic computing 'von Neumann bottleneck' and 'storage wall' by combining the advantages of the phase change material such as non-volatility, ultra-high speed, high bandwidth and low crosstalk of photonics. The phase change material can be quickly and reversibly converted between amorphous phase and crystalline phase, has the characteristic of non-volatility, namely, the state of the phase change material can be stably maintained after the phase change of external stimulus (light pulse), continuous power supply is not needed, and the ultra-low static power consumption operation can be supported. In addition, the phase change material has obvious difference in optical properties between amorphous phase and crystalline phase, has extremely strong optical modulation capability, and can realize larger optical contrast ratio under the volume of nanometer scale. The excellent stability and optical modulation capability of the optical fiber provide a physical basis for high-density data storage and high-precision analog computation. At present, the high temperature process after the manufacture of the embedded chip and the service temperature (-40-165 ℃) of edge calculation present a plurality of severe requirements on phase change materials, such as high thermal stability, large extinction ratio, long service life, stable circulation and the like, in the actual high-precision multistage calculation application. However, the crystallization temperature of the germanium antimony tellurium phase change material used in the current commercial chip is low (150 ℃), the amorphous thermal stability is poor, and the possibility of thermally induced crystallization in the preparation process or in use cannot be avoided. In addition, the extinction ratio of germanium antimony tellurium in the prior report is only about 0.5 dB, and only 100 cycles can be maintained, the cycle stability is poor, and precise and stable modulation of a plurality of intermediate states is difficult to realize in practical application. Therefore, development of a novel all-optical phase change material with high thermal stability, large optical window and long cycle life is needed to meet the practical application requirements of processing and edge computing of embedded chips. Disclosure of Invention In order to overcome the defects in the prior art, the invention provides the all-optical phase-change brain-like computing material and device with high stability and large window, the germanium-enriched germanium-antimony-tellurium phase-change material is based, the enriched germanium element increases the proportion of strong covalent bonds in an amorphous structure to a certain extent, the amorphous thermal stability of the material is improved, meanwhile, the chemical bonding and structural difference between amorphous and crystalline phases are increased, the difference of the optical properties of amorphous phases and crystalline phases is increased, and the all-optical brain-like computing device based on the material has the advantages of high thermal stability, large switching ratio and good cycle stability. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: The material is a germanium-enriched germanium-antimony-tellurium phase-change material, and has a chemical formula of Ge xSbyTez, wherein x is more than or equal to 25 and less than or equal to 50,15 and less than or equal to 25, z is more than or equal to 30 and less than or equal to 50, x+y+z=100, and x, y and z are atomic percentages of elements; the thickness range of the phase change layer formed by the germanium-enriched germanium-antimony-tellurium phase change material is 5-50 nm; The amorphous phase of the germanium-enriched germanium-antimony-tellurium phase change material is bonded by covalent bonds, the crystalline phase is bonded by metal covalent bonds, and the two-phase structure is mainly in an octahedral configuration. The doping of germanium element increases the tetrahedral configuration proportion in the amorphous phase, so that the chemical bonding and the structural difference between the two phases are more obvious, the optical property difference is more obvious, and the optical contrast is larger. The germanium-enriched germanium-antimony-tellurium phase change material has the strongest modulation capability i