The tunable amorphous-crystalline transition temperature by indium-doping on GeTe thin films

Area of Science:

• Materials Science
• Solid State Physics
• Nanotechnology

Background:

• Germanium telluride (GeTe) is a promising material for phase-change memory applications.
• Controlling the amorphous-crystalline transition temperature is crucial for device performance.
• Doping is a common strategy to tune material properties.

Purpose of the Study:

• To investigate the effect of indium doping on the properties of amorphous GeTe thin films.
• To explore the potential of solution doping for tuning the transition temperature.
• To assess the impact of doping on the electronic structure and phase transition behavior.

Main Methods:

• Fabrication of amorphous GeTe thin films via RF sputtering.
• Solution doping of GeTe films using Indium(III) chloride (InCl3) solutions.
• Annealing treatments to induce amorphous-crystalline transitions.
• Characterization using I-T measurements, X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and Density of States (DOS) calculations.

Main Results:

• Indium doping significantly lowers the amorphous-crystalline transition temperature of GeTe films.
• Annealing at 280°C results in the formation of a rock salt structure.
• XPS analysis confirms the presence of In-Te bonds, suggesting In2Te3 formation.
• DOS calculations show changes in electronic states around the Fermi level with increasing indium content.

Conclusions:

• Solution process doping with indium effectively tunes the transition temperature of GeTe thin films.
• The observed reduction in transition temperature holds potential for decreasing the set current in devices.
• This study demonstrates a viable method for optimizing GeTe properties for memory applications.