Top metal contact for vertical transistor structures
A vertical transistor includes a source layer arranged on a substrate; a channel extending vertically from the source layer; a drain arranged on a distal end of the channel that opposes the source layer, the drain including an epitaxial growth; and a drain contact wrapped around exposed areas of the drain and filling a cavity having a liner layer disposed sidewalls of the drain contact.
1. A vertical transistor, comprising:
a source layer arranged on a substrate;
a channel extending vertically from the source layer;
a drain arranged on a distal end of the channel that opposes the source layer, the drain comprising an epitaxial growth; and
a drain contact comprising a metal wrapped around all exposed areas of the drain, the metal being disposed on and around the drain such that the metal contacts all exposed sidewalls of the drain; and
a liner layer disposed directly on sidewalls of the metal of the drain contact, the liner layer comprising an insulating material.
2. The vertical transistor of claim 1 , further comprising a gate surrounding and in contact with the channel, wherein the liner layer is also disposed on the gate.
3. The vertical transistor of claim 2 , further comprising a gate contact extending from a surface of an ILD and through the liner layer to the gate.
4. The vertical transistor of claim 1 , wherein the liner layer has a thickness in a range from about 2 to about 50 nm.
5. The vertical transistor of claim 1 , wherein the liner layer is a dielectric nitride, a dielectric oxide, a dielectric oxynitride, or a combination thereof.