A Three-Dimensional Physical Model for V-th Variations Considering the Combined Effect of NBTI and RDF

作者：Panagopoulos Georgios D^*; Roy Kaushik

来源：IEEE Transactions on Electron Devices, 2011, 58(8): 2337-2346.

DOI：10.1109/TED.2011.2148720

• Aging
• negative bias temperature instability (NBTI)
• random dopant fluctuations (RDFs)
• stochastic differential equation (SDE)
• temporal degradation
• three dimensional (3-D) physical model
• threshold voltage variations

Aggressive transistor scaling affects the threshold voltage V-th in two ways: space and time. Transistors on the same die can have different V-th due to random dopant fluctuations (RDFs). On the other hand, V-th of a specific transistor can randomly shift in time due to random position of dangling bonds and random motion of atomic H or H-2 molecules in the oxide [negative bias temperature instability (NBTI)]. These two random effects are not totally independent because the dissociation rate of Si-H bonds at the silicon-oxide interface depends on the nonuniform electric field. In this paper, we describe the combined effect of RDF and NBTI on V-th using stochastic differential equation. In this paper, we are able to examine the effect of RDF on critical NBTI parameters such as k(f), k(r), and temperature and the correlation among these parameters. The efficacy of the proposed model is evaluated by performing Monte Carlo simulations on various transistors under different direct-current stress and obtained distributions for N-IT and V-th

• 出版日期2011-8