Method for the Construction of a Body-Contacted finFET by Utilizing Thru-Si Vias
Original Publication Date: 2009-Apr-16
Included in the Prior Art Database: 2009-Apr-16
Described is a method for constructing a body-contacted finFET by creating a landing pad which is connected to the body beneath the surface of the finFET on which to land a thru-Si via.
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Due to the 3D nature of the device, the channel and body is nearly surrounded by the gate metal in one dimension and by the source and drain in the perpendicular dimension. This causes great difficulty in contacting the body. Solutions have been devised which create a gap in the gate metal at the top of the fin. However, this changes the current characteristics of the device.
This invention leaves the body-contacted finFET virtually indiscernible from its non-body-contacted counterpart, at least from the view above. The idea is to create a landing pad which is connected to the body beneath the surface of the fin on which to land a thru-Si via. The gate metal remains undisturbed and the size of the body-contacted device is virtually the same as that of the floating-body device.
The figure shows how the device can be fabricated. The fabrication steps that are shown are only those used to create the body-contact. The remaining fabrication follows the standard finFET device fabrication process.
The landing pad that is created can also be enlarged such that many body-contacted finFETs could be created and attached above it. This then creates a common connection, oftentimes ground or Vdd, between body-contacted neighbors.
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