Ultrafast Measurements and Physical Modeling of NBTI Stress and Recovery in RMG FinFETs Under Diverse DC-AC Experimental Conditions

• Published in: IEEE transactions on electron devices Vol. 65; no. 1; pp. 23 - 30
• Main Authors: Parihar, Narendra, Sharma, Uma, Southwick, Richard G., Wang, Miaomiao, Stathis, James H., Mahapatra, Souvik
• Format: Journal Article
• Language: English
• Published: IEEE 01.01.2018
• Subjects: AC stress; Data models; dc stress; high-k metal gate (HKMG); hole trapping; interface and bulk trap generation; Kinetic theory; Logic gates; Negative bias temperature instability; negative-bias temperature instability (NBTI); reaction–diffusion (RD) model; recovery after stress; replacement metal gate (RMG) FinFETs; Stress; Stress measurement; Thermal variables control
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2017.2773122

Threshold voltage shift (<inline-formula> <tex-math notation="LaTeX">\Delta {\text V}_{\text T} </tex-math></inline-formula>) due to negative-bias temperature instability (NBTI) in p-FinFETs with replacement metal gate-based high-k metal gate process is measured using an ultrafast method. A comprehensive modeling framework involving uncorrelated contributions from the generation of interface traps (<inline-formula> <tex-math notation="LaTeX">\Delta {\text V}_{\text {IT}} </tex-math></inline-formula>), hole trapping in preexisting (<inline-formula> <tex-math notation="LaTeX">\Delta {\text V}_{\text {HT}} </tex-math></inline-formula>), and generation of new (<inline-formula> <tex-math notation="LaTeX">\Delta {\text V}_{\text {OT}} </tex-math></inline-formula>) bulk insulator traps is used to quantify measured data. The model can explain dc stress and recovery data over an extended temperature range (−40 °C to 150 °C), for different stress and recovery biases. It can explain ac stress and recovery data for different bias, temperature, frequency, and duty cycle. The differences in time kinetics and temperature activation of <inline-formula> <tex-math notation="LaTeX">\Delta {\text V}_{\text {IT}} </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">\Delta {\text V}_{\text {HT}} </tex-math></inline-formula>, and <inline-formula> <tex-math notation="LaTeX">\Delta {\text V}_{\text {OT}} </tex-math></inline-formula>, and their relative dominance at various experimental conditions are shown. End-of-life NBTI for dc and ac stress is estimated by using the model and compared to prediction from conventional analytical methods.