Analysis of TID process, geometry, and bias condition dependence in 14-nm FinFETs and implications for RF and SRAM performance

Journal Article · Wed Dec 07 00:00:00 EST 2016 · IEEE Transactions on Nuclear Science

DOI:https://doi.org/10.1109/tns.2016.2634538· OSTI ID:1338310

King, M. P.  ^[1]; Wu, X. ^[2]; Eller, Manfred ^[2]; Samavedam, Srikanth ^[2]; Shaneyfelt, M. R. ^[1]; Silva, A. I. ^[1]; Draper, B. L. ^[1]; Rice, W. C. ^[1]; Meisenheimer, T. L. ^[1]; Felix, J. A. ^[1]; Shetler, K. J.  ^[3]; Zhang, E. X.  ^[3]; Haeffner, T. D. ^[3]; Ball, D. R. ^[3]; Alles, M. L. ^[3]; Kauppila, J. S. ^[3]; Massengill, L. W. ^[3]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2. GLOBALFOUNDRIES, Malta, NY (United States)
3. Vanderbilt Univ., Nashville, TN (United States)

Here, total ionizing dose results are provided, showing the effects of different threshold adjust implant processes and irradiation bias conditions of 14-nm FinFETs. Minimal radiation-induced threshold voltage shift across a variety of transistor types is observed. Off-state leakage current of nMOSFET transistors exhibits a strong gate bias dependence, indicating electrostatic gate control of the sub-fin region and the corresponding parasitic conduction path are the largest concern for radiation hardness in FinFET technology. The high-Vth transistors exhibit the best irradiation performance across all bias conditions, showing a reasonably small change in off-state leakage current and Vth, while the low-Vth transistors exhibit a larger change in off-state leakage current. The “worst-case” bias condition during irradiation for both pull-down and pass-gate nMOSFETs in static random access memory is determined to be the on-state (Vgs = Vdd). We find the nMOSFET pull-down and pass-gate transistors of the SRAM bit-cell show less radiation-induced degradation due to transistor geometry and channel doping differences than the low-Vth transistor. Near-threshold operation is presented as a methodology for reducing radiation-induced increases in off-state device leakage current. In a 14-nm FinFET technology, the modeling indicates devices with high channel stop doping show the most robust response to TID allowing stable operation of ring oscillators and the SRAM bit-cell with minimal shift in critical operating characteristics.

• Research Organization: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC04-94AL85000
• OSTI ID: 1338310
• Report Number(s): SAND-2016-6554J; 644863; TRN: US1701170
• Journal Information: IEEE Transactions on Nuclear Science, Journal Name: IEEE Transactions on Nuclear Science; ISSN 0018-9499
• Publisher: Institute of Electrical and Electronics Engineers (IEEE)
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
leakage current
FinFET
total ionizing dose
threshold voltage shift