Selective single diffusion/electrical barrier
Presented are structures and methods for forming such structures that allow for electrical or diffusion breaks between transistors of one level of a stacked transistor device, without necessarily requiring that a like electrical or diffusion break exists in another level of the stacked transistor device. Also presented, an electrical break between transistor devices may be formed by providing a channel of a first polarity with a false gate comprising a work-function metal of an opposite polarity.
1. A transistor device comprising:
at least two layers of transistors; and
a hybrid gate/electrical break,
wherein a first layer of the at least two layers comprises a plurality of active NFET transistor devices and wherein a second, vertically aligned layer, of the at least two layers comprises a plurality of active PFET transistor devices, and
wherein the hybrid gate/electrical break is an electrical break between adjacent active transistor devices of either the first or second layer, and wherein the hybrid gate/electrical break is a gate between source and drain regions of an active transistor device in the other of the first or second layer.
2. The device of claim 1 , wherein
the hybrid gate/electrical break comprises an N-work function metal (nWFM) layer, wherein the hybrid gate/electrical break is an electrical break between two adjacent active PFET transistor devices in the second layer, and wherein the hybrid gate/electrical break is the gate between the source and drain regions of an active NFET transistor device in the first layer.
3. The device of claim 2 , wherein the nWFM layer comprises one or more of: TiAl, TiAlC, ZrAl, WAl, TaAl, HfAl, La, Sr, Ba, Lu, Y, and polysilicon.
4. The device of claim 3 , wherein the nWFM layer comprises one or more of La, Sr, Ba, Lu, or Y, the La, Sr, Ba, Lu, or Y is at least partially oxidized, and the at least partially oxidized La, Sr, Ba, Lu, or Y serves in a dipole engineering layer.
5. The device of claim 1 , wherein
the hybrid gate/electrical break comprises a P-work function metal (pWFM) layer, wherein the hybrid gate/electrical break is an electrical break between two adjacent active NFET transistor devices in the first layer, and wherein the hybrid gate/electrical break is the gate between the source and drain regions of an active PFET transistor device in the second layer.
6. The device of claim 5 , wherein the pWFM layer comprises one or more of: Ni, Pd, Pt, Be, Ir, Te, Re, Ru, Rh, W, Mo, WN, RuN, MON, TIN, TaN, WC, TaC, TiC, TiAIN, TaAIN, Al, Ta, Zr, Ti, Hf, Sc, and polysilicon.
7. The device of claim 6 , wherein the pWFM layer comprises one or more of Al, Ta, Zr, Hf, Sc, or Ti, the Al, Ta, Zr, Hf, Sc, or Ti that is at least partially oxidized, and the at least partially oxidized Al, Ta, Zr, Hf, Sc, or Ti serves in a dipole engineering layer.
8. The device of claim 1 , wherein,
two adjacent transistor devices of a layer of the at least two layers are isolated by a dielectric between two transistors of one layer of the at least two layers, and a gate region, vertically adjacent to the dielectric in the other layer, comprises a work function metal layer.