Transparent Flash Memory Using Single Ta₂O₅ Layer for Both Charge-Trapping and Tunneling Dielectrics

Area of Science:

• Materials Science
• Electrical Engineering
• Solid-State Physics

Background:

• Conventional flash memory cells utilize distinct dielectric layers for charge trapping and tunneling.
• The fabrication of advanced flash memory devices often involves complex multi-layer dielectric structures.
• There is a need for simplified and efficient memory cell designs.

Purpose of the Study:

• To demonstrate reproducible multibit transparent flash memory using a single dielectric layer.
• To investigate the feasibility of using tantalum pentoxide (Ta2O5) as a dual-function layer.
• To evaluate the memory characteristics, reliability, and fabrication simplicity of the proposed device.

Main Methods:

• Fabrication of transparent flash memory devices employing a single solution-derived Ta2O5 layer.
• Optimization of programming and erasing operations for the memory device.
• Characterization of memory window, data retention, and endurance performance.

Main Results:

• Achieved reproducible multibit transparent flash memory with a single Ta2O5 layer acting as both charge-trapping and tunneling dielectric.
• Demonstrated a maximum memory window of approximately 10.7 V under optimized operations.
• Exhibited stable 2-bit memory performance with data retention exceeding 10^4 s and endurance over 100 cycles.

Conclusions:

• A single Ta2O5 layer can effectively serve as both charge-trapping and tunneling layers in transparent flash memory.
• The simplified fabrication process using a common dielectric layer facilitates the development of advanced flash memories.
• The reported memory device shows promising characteristics for future electronic applications.