Nonvolatile Transistor Memory with Self-Assembled Semiconducting Polymer Nanodomain Floating Gates

Area of Science:

• Materials Science
• Organic Electronics
• Nanotechnology

Background:

• Organic field effect transistor nonvolatile memory (OFET-NVM) typically uses metallic floating gates.
• Semiconducting nanofloating gates offer advantages in charge storage control due to their energetic structure.
• Self-assembled semiconducting polymer nanodomains within dielectric tunneling layers present a promising approach for integrated OFET-NVM.

Purpose of the Study:

• To investigate the use of crystalline p-type semiconducting polymer nanodomains as nanofloating gates in OFET-NVMs.
• To evaluate the memory performance, including memory window, endurance, and retention time.
• To explore the potential for multilevel operation by incorporating n-type semiconductors.

Main Methods:

• Fabrication of OFET-NVM devices utilizing self-assembled crystalline polymer nanodomains within a tunneling dielectric layer.
• Characterization of the polymer nanodomain dimensions (approx. 20 nm width, few hundred nm length).
• Testing of device performance, including memory window, programming/erasing cycles, retention time, and multilevel operation via semiconductor mixing.

Main Results:

• OFET-NVM with crystalline nanofloating gates achieved a large memory window of 10 V.
• Demonstrated programming/erasing switching endurance exceeding 500 cycles and a retention time of 5000 s.
• Comixing with an n-type semiconductor enabled solution-processed p- and n-type double floating gates for multilevel operation, achieving four reliable levels (two bits per cell).

Conclusions:

• Semiconducting polymer nanofloating gates are effective for high-performance OFET-NVMs.
• The developed OFET-NVM exhibits excellent memory characteristics and endurance.
• The integration of p- and n-type semiconductors facilitates reliable multilevel storage, paving the way for advanced memory applications.