Performance Improvement of a Nonvolatile UV TD Sensor Using SAHAOS with a High Temperature Annealed, Partially...

Area of Science:

• Materials Science
• Semiconductor Devices
• Radiation Sensing

Background:

• Nonvolatile sensors are crucial for detecting cumulative radiation doses.
• Existing sensors face challenges with performance degradation and charge retention.

Purpose of the Study:

• To investigate the performance of a novel capacitor device for nonvolatile ultraviolet radiation total dose (UV TD) sensing.
• To evaluate the impact of a partially-nanocrystallized hafnium aluminum oxide layer on sensor characteristics.

Main Methods:

• Fabrication of silicon-aluminum oxide-hafnium aluminum oxide-silicon oxide-silicon (PNC-SAHAOS) capacitor devices.
• High-temperature pre-metal anneal treatment to induce partial nanocrystallization in hafnium aluminum oxide.
• Testing under ultraviolet radiation total dose (UV TD) irradiation to measure threshold voltage shift and charge density.
• Evaluating charge retention at elevated temperatures (85 °C) over extended periods.

Main Results:

• The PNC-SAHAOS device demonstrated a significant UV-induced threshold voltage (V_T) shift of 10 V after 100 mW·s/cm² UV TD irradiation.
• UV-induced charge density was approximately eight times higher compared to amorphous silicon-aluminum oxide-silicon nitride-silicon dioxide-silicon (SANOS) devices.
• Excellent charge retention was observed, with a fading rate below 10% for ten-year retention even at 85 °C.
• The charge fading rate at 85 °C was nearly half that of amorphous SANOS devices over a ten-year period.

Conclusions:

• Partially-nanocrystallized hafnium aluminum oxide significantly enhances the performance of nonvolatile UV TD sensors.
• PNC-SAHAOS devices offer superior UV sensitivity and long-term charge stability compared to conventional SANOS.
• These findings position PNC-SAHAOS as a highly promising candidate for advanced nonvolatile UV TD sensor technology.