Abstract:
A semiconductor device includes a semiconductor substrate, an insulating layer on a top surface of the substrate, and a first semiconductor transistor on the insulating layer, the transistor including an active region with a source region, a drain region, a channel region between the source and drain regions and a gate structure over the channel region, the gate structure extending beyond the transistor to an adjacent area. An outer well is included in the substrate, an inner well of an opposite type as the outer well situated within the outer well and under the active region and adjacent area, and a contact for the inner well in the adjacent area, the contact surrounding the gate structure. Operating the device includes applying a variable voltage at the contact for the inner well, a threshold voltage for the first transistor being altered by the variable voltage. The inner well and gate may be exposed and contacts created therefor together.
Abstract:
In one aspect there is set forth herein a semiconductor device having a first field effect transistor formed in a substrate structure, and a second field effect transistor formed in the substrate structure. The first field effect transistor can include a first substrate structure doping, a first gate stack, and a first threshold voltage. The second field effect transistor can include the first substrate structure doping, a second gate stack different from the first gate stack, and a second threshold voltage different from the first threshold voltage.
Abstract:
In one aspect there is set forth herein an integrated circuit having a first plurality of field effect transistors and a second plurality of field effect transistor, wherein field effect transistors of the first plurality of field effect transistors each have a first gate stack and wherein field effect transistors of the second plurality of field effect transistors each have a second gate stack, the second gate stack being different from the first gate stack by having a metal layer common to the first gate stack and the second gate stack that includes a first thickness at the first gate stack and a second thickness at the second gate stack.