OxRAM Memory Point Fabrication via Ion Implantation

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Solution Overview

Problem

The industrialization of OxRAM technology is hindered by strong dispersion of electrical properties in the High Resistance State (HRS) due to variations in bandgap values across different sub-stoichiometric phases of HfOx in HfO2, leading to challenges in reliably distinguishing between programmed and reset states.

Innovation Solution

A method involving ion implantation of Ti in a HfO2 layer using Xe, Kr, or Ar, with a recoil effect to form Hf1-yTiyO2 phases, which homogenizes bandgap energies and reduces behavioral dispersions, allowing for easier discrimination between programmed and reset states with reduced potential differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ion implantation is performed to form conductive filaments in HfO2, then programming capability is achieved, but strong dispersion of electrical properties in HRS occurs due to variations in bandgap values across different sub-stoichiometric phases

Engineering Contradiction:
Improvereliability of state discriminationVSAvoiddispersion of electrical properties
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by modifying the bandgap energy parameter through controlled ion implantation. By implanting ions at specific doses and energies, the sub-stoichiometric phases of HfOx are transformed to have homogeneous bandgap values, directly addressing the dispersion issue while maintaining programming capability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent achieves homogeneity by reducing the dispersion of bandgap values across different sub-stoichiometric phases. The ion implantation process creates a uniform distribution of oxygen vacancies and modifies the phases to exhibit similar electrical properties, enabling reliable state discrimination with reduced behavioral dispersions

Inventive Principle:
Principle #33Homogeneity

2Ease of manufacture

If multiple sub-stoichiometric phases of HfOx are present, then conductive filament formation is enabled, but behavioral dispersions increase making state discrimination difficult

Engineering Contradiction:
Improveconductive filament formationVSAvoidstate discrimination reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the electrical parameters of multiple sub-stoichiometric phases by controlling ion implantation conditions. This transforms the phases to have uniform bandgap energies, allowing conductive filament formation to proceed while eliminating the behavioral dispersions that would otherwise prevent reliable state discrimination

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent substitutes the natural formation process of sub-stoichiometric phases with a controlled ion implantation process. This replaces the uncontrolled mechanical/chemical phase development with a precisely controlled physical process that achieves both filament formation and phase homogenization

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach significantly reduces behavioral dispersions and enhances thermodynamic stability, ensuring reliable switching between states while maintaining good insulation properties, thus facilitating the industrialization of OxRAM technology.

Implementation Method 1

A method involving ion implantation of Ti in a HfO2 layer using Xe, Kr, or Ar

Methodology Applied
Scientific EffectIon implantation: Ion Implantation

Implementation Method 2

with a recoil effect to form Hf1-yTiyO2 phases

Methodology Applied
Scientific EffectRecoil effect:

Data Source

PatentEP3496168B1Method of fabricating a point memory of the oxram type to limit the variations of characteristics and corresponding memory
Publication Date: 2020.06.10 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP3496168B1 patent drawingFigure 1~3
  • EP3496168B1 patent drawingFigure 4~5
  • EP3496168B1 patent drawingFigure 6~8

AI summary

The invention relates to a method for manufacturing an OxRAM type memory point, comprising the steps of: -providing a stack (1) comprising a superposition of: -a first layer (102) including a first material in Ti with more than 30% by mole fraction; -a second layer (101) in HfO2 disposed under the first layer; -by an ionic implantation of a second material (2) chosen from Xe, Kr or Ar in the first layer (102), carrying out an implantation of the first material in the second layer (101) by collision with recoil effect in the first layer (102).