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EIT4. Ballisticity of the Linear response Transport in Nanometric Silicon Devices. C. Jungemann Institute for Electronics Bundeswehr University Neubiberg, Germany. Outline. Introduction Theory Results for 40nm N + NN + structure High bias Zero bias Conclusions. Introduction.
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EIT4 Ballisticity of the Linear response Transport in Nanometric Silicon Devices C. Jungemann Institute for Electronics Bundeswehr UniversityNeubiberg, Germany
Outline • Introduction • Theory • Results for 40nm N+NN+ structure • High bias • Zero bias • Conclusions
Introduction 1D 40nm N+NN+ structure • Macroscopic models (DD, HD) fail for strong nonequilibrium due toBallistic transport! • Macroscopic models also fail near equilibrium in nanometric devices!Why?
Theory • Boltzmann and Poisson equations • Deterministic solver based on an nth-order Spherical harmonics expansion • Newton-Raphson method to solve the nonlinear system of equations • Modena electron model (analytical band structure)
Results 1D 40nm silicon N+NN+ structure Transport is in x-direction
Results Biased at 0.5V Velocity overshoot is a sign of (quasi-)ballistic transport
Results Scattering dominated Biased at 0.5V Quasi-ballistic
Results Distribution function at 0.5V
Results Distribution function at 0.5V
Results Scattering dominated Linear response without zero order Quasi-ballistic
Results Differential distribution function at equilibrium
Conclusions • Ballistic transport occurs in nanometric devices at high bias • The linear response of the distribution function shows ballistic peaks at zero bias in regions with large built-in fields • The ballistic peaks of the linear response can be negative • Linear response in nanometric devices with large built-in fields is fundamentally different from the bulk case