Demonstration of Wide Bandgap AlGaN/GaN Negative‐Capacitance High‐Electron‐Mobility Transistors (NC‐HEMTs) Using Barium Titanate Ferroelectric Gates. (12th July 2020)

• Record Type: Journal Article
• Authors: Chandrasekar, Hareesh; Razzak, Towhidur; Wang, Caiyu; Reyes, Zeltzin; Majumdar, Kausik; Rajan, Siddharth
• Is Part Of: Advanced Electronic Materials. Volume 6:Number 8(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-07-12
• Subjects: BaTiO 3, ferroelectric bandgaps -- GaN -- HEMT -- negative capacitances semiconductors -- subthreshold slopes; Materials -- Electric properties -- Periodicals; Materials science -- Periodicals; Magnetic materials -- Periodicals; Electronic apparatus and appliances -- Periodicals; 537
• DOI: 10.1002/aelm.202000074
• Languages: English
• ISSNs: 2199-160X

Abstract

Abstract: A negative‐capacitance high electron mobility transistor (NC‐HEMT) with low hysteresis in the subthreshold region is demonstrated in the wide bandgap AlGaN/GaN material system using sputtered BaTiO3 as a "weak" ferroelectric gate in conjunction with a conventional SiN x dielectric. An enhancement in the capacitance for BaTiO3 /SiN x gate stacks is observed in comparison to control structures with SiN x gate dielectrics directly indicating the negative capacitance contribution of the ferroelectric BaTiO3 layer. A significant reduction in the minimum subthreshold slope for the NC‐HEMTs is obtained in contrast to standard metal‐insulator‐semiconductor HEMTs with SiN x gate dielectrics—97.1 mV dec −1 versus 145.6 mV dec −1 —with almost no hysteresis in the I D – V G transfer curves. These results are promising for the integration of ferroelectric perovskite oxides with III‐Nitride devices toward NC‐field‐effect transistor switches with reduced power consumption. Abstract : A negative capacitance metal–insulator semiconductor high electron mobility transistor is fabricated in the wide bandgap AlGaN/GaN material system using a thin sputtered BaTiO3 layer as the ferroelectric gate. Gate capacitance enhancement and voltage amplification are observed for these devices as well as a sharp reduction in subthreshold slopes, with minimal hysteresis, as compared to control samples.