摘要 |
An insulated-gate field-effect transistor (100, 100V, 140, 150, 150V, 160, 170, 170V, 180, 180V, 190, 210, 210W, 220, 220U, 220V, 220W, 380, or 480) is fabricated so as to have a hypoabrupt vertical dopant profile below one (104 or 264) of its source/drain zones for reducing the parasitic capacitance along the pn junction between that source/drain zone, normally serving as the drain, and adjoining body material (108 or 268). In particular, the concentration of semiconductor dopant which defines the conductivity type of the body material increases by at least a factor of 10 in moving from that source/drain zone down to an underlying body-material location no more than 10 times deeper below the upper semiconductor surface than that source/drain zone. The body material is preferably provided with a more heavily doped pocket portion (120 or 280) situated along the other source/drain zone (102 or 262) normally serving as the source.
|