Insulated-gate field-effect transistors (“IGFETs”), both symmetric and asymmetric, suitable for a semiconductor fabrication platform that provides IGFETs for analog and digital applications, including mixed-signal applications, utilize empty-well regions in achieving high performance. A relatively small amount of semiconductor well dopant is near the top of each empty well. Each IGFET (100, 102, 112, 114, 124, or 126) has a pair of source/drain zones laterally separated by a channel zone of body material of the empty well (180, 182, 192, 194, 204, or 206). A gate electrode overlies a gate dielectric layer above the channel zone. Each source/drain zone (240, 242, 280, 282, 520, 522, 550, 552, 720, 722, 752, or 752) has a main portion (240M, 242M, 280M, 282M, 520M, 522M, 550M, 552M, 720M, 722M, 752M, or 752M) and a more lightly doped lateral extension (240E, 242E, 280E, 282E, 520E, 522E, 550E, 552E, 720E, 722E, 752E, or 752E). Alternatively or additionally, a more heavily doped pocket portion (250 or 290) of the body material extends along one of the source/drain zones. When present, the pocket portion typically causes the IGFET to be an asymmetric device.