Low Voltage Operating 2D MoS₂ Ferroelectric Memory Transistor with Hf_1-xZr_xO₂ Gate Structure

Area of Science:

• Materials Science
• Electrical Engineering
• Nanotechnology

Background:

• Ferroelectric Field-Effect Transistors (FeFETs) offer high speed and endurance for non-volatile memory.
• High programming voltages in traditional FeFETs increase power consumption.
• Developing low-voltage FeFETs is crucial for energy-efficient memory applications.

Purpose of the Study:

• To develop a CMOS-compatible FeFET with a significantly reduced operating voltage.
• To engineer ferroelectric materials for enhanced memory performance.
• To explore novel device architectures for scalable non-volatile memory.

Main Methods:

• Fabrication of a FeFET using ferroelectric Hf_1-xZr_xO₂ (HZO) as negative capacitance (NC) gate dielectrics.
• Integration of HZO with few-layered molybdenum disulfide (MoS₂) channel.
• Characterization of device performance, including operating voltage, on/off current ratio, memory window, endurance, and retention.

Main Results:

• Achieved a low operating voltage FeFET with a counterclockwise hysteresis loop.
• Demonstrated a high on/off current ratio exceeding 10⁷.
• Observed a memory window of 0.1 V at a programming/erase voltage of 3 V, with robust endurance (10³ cycles) and retention (10⁴ s).

Conclusions:

• The engineered HZO/MoS₂ FeFET enables low-voltage operation, addressing power consumption challenges.
• The negative capacitance effect in HZO facilitates switching with reduced voltage requirements.
• This technology presents new opportunities for size- and voltage-scalable non-volatile memory applications.