Title :
Scaling properties and short-channel effects in submicrometer AlGaAs/GaAs MODFET´s: A Monte Carlo study
Author :
Kizilyalli, Isik C. ; Artaki, Michael ; Shah, Nitin J. ; Chandra, Amitabash
Author_Institution :
AT&T Bell Labs., Allentown, PA, USA
fDate :
2/1/1993 12:00:00 AM
Abstract :
Scaling properties of n+-AlxGa1-xAs/GaAs MODFETs with submicrometer gate lengths (LG=0.50 to 0.05 μm) are examined, using Monte Carlo methods. High-frequency performance of MODFETs can be improved by scaling the gate lengths, but various studies suggest that there exists a lower limit for the gate after which no improvement should be expected. The lower limit is determined here to be ≈0.10 μm. Devices with smaller gate lengths than 0.1 μm exhibit degraded transconductance (gm), large shift in threshold voltage due to poor charge control in the channel, and a sharp reduction in output resistance (Ro). It is shown that the drain current saturation in MODFETs is not caused by the velocity saturation effect, but by channel pitch-off. Electron velocities calculated from Monte Carlo simulations and extracted from gm and ft measurements are reconciled
Keywords :
III-V semiconductors; Monte Carlo methods; aluminium compounds; carrier mobility; gallium arsenide; high electron mobility transistors; semiconductor device models; solid-state microwave devices; 0.05 to 0.5 micron; AlxGa1-xAs-GaAs; MODFETs; Monte Carlo simulations; channel charge control; channel pitch-off; degraded transconductance; drain current saturation; electron velocity; high frequency performance; output resistance; scaling; short-channel effects; submicrometer gate lengths; threshold voltage shift; Capacitance; Degradation; Electrons; Epitaxial layers; FETs; Gallium arsenide; HEMTs; MODFET circuits; Monte Carlo methods; Transconductance;
Journal_Title :
Electron Devices, IEEE Transactions on
