Narrow-base diode: The source and drain regions of a MOSFET in a modern [(3 are one-sided junctions with the more heavily doped side being very...

Narrow-base diode: The source and drain regions of a MOSFET in a modern IC are one-sided junctions with the more heavily doped side being very narrow. Care is taken during the manufacturing process to ensure that the silicide (metallic) contact to the heavily doped source/drain is not too close to the metallurgical junction, i.e. to ensure that the heavily doped side is not too narrow, to avoid significant reverse diode current. (The drain junction is reverse-biased when the transistor is turned off, and ideally no junction current should flow in this state.) Consider a pn+ Si step junction maintained at 300K with NA = 2×1017 cm-3 and ND = 1019 cm-3 . The p-type side is wide (WP >> Ln) while the n-type side is narrow (WN = 50 nm). The minority carrier lifetime on the ptype side is 10-7 s. a) Find the diode saturation current density, J0 = I0/A. Is the current in this diode dominated by injection/collection of minority carriers on the n-type side or on the p-type side? Explain why. b) Find the current density (A/cm2 ) for an applied bias VA = -1.0 V. c) Fin the current density (A/cm2 ) for an applied bias VA = 0.6 V. Sketch the electron and hole current density components as a function of distance on both sides of the junction.