Negative Capacitance Oxide TFT on Glass

(a) Transfer characteristics of reference TFT and NC-TFT with inset showing gate leakage.

(b) Extracted SS values of reference TFT and NC-TFT.

Invention Summary:

Scaling down operating voltage and reducing power consumption remain a significant challenge in the evolution of integrated circuits (IC). Negative capacitance field effect transistor (NC-FET) is designed to reduce operation voltage and power consumption by reducing the subthreshold swing (SS) value through the use of ferroelectric materials.  However, improvements have been limited due to high temperature fabrication process, performance, stability and cost issues.

Rutgers researchers have developed a novel negative capacitance oxide thin film transistor (NC-TFT) built on glass using multifunctional metal oxide materials. This NC-TFT integrates the semiconductor channel with the ferroelectric-oxide stacking gate dielectric structure using a multifunctional material system. The minimum subthreshold swing (SS) value has been shown to be reduced to below 60 mV/decade, the thermionic limit of SS value at room temperature.  The capability of employing low-temperature fabrication process allows for glass- and flexible substrate-based applications.

Market Applications:

• Ultralow power logic devices, e.g., RFID, IoT, sensors
• Large-area electronics, e.g., displays, solar panels
• Low-thermal budget flexible devices, e.g., wearable electronics

Advantages:

• Normally-off
• Low power consumption, with subthreshold swing below 60 mV/decade
• Low-temperature processing, suitable for applications on glass and flexible substrates
• No cross-contamination (use of multifunctional metal oxide for both the channel and ferroelectric layers)
• Low cost (substrates and TFT materials, processing, equipment, etc.)

Intellectual Property & Development Status:

Patent pending. Available for licensing and/or collaboration.