Temporal and spatial current stability of smart field emission arrays

Emission current stability and the spatial uniformity of field emission devices are improved when a lightly doped drain MOSFET (LD-MOSFET) is integrated with a field emission array (FEA). At comparable current levels, the emission noise (/spl Delta/I/I) decreased from 16.9% to 1.8%. Emission current fluctuation was reduced in the integrated device compared to the FEA device even in the presence of gases. Spatial current uniformity was achieved in the integrated MOSFET/FEA devices at different wafer positions and for different array sizes. The results are explained by a two-step field emission process, which consists of an electron supply step determined by the MOSFET inversion layer and an electron transmission step determined by the field emission barrier width. The device structure also results in low voltage control of emission current.