Four terminal stacked complementary junction field effect transistors
A semiconductor device that is composed of an epitaxial semiconductor material stacked structure that includes a first epitaxial channel for a first junction field effect transistor (JFET) atop a supporting substrate and a second epitaxial channel region for a second junction field effect transistor (JFET). A commonly electrically contacted source/drain region for each of the first JFET and the second JFET is positioned at an interface of the first and second epitaxial channel region. A channel length for each of the first and second is substantially perpendicular to an upper surface of the supporting substrate. An epitaxial semiconductor gate conductor in direct contact with each of said first epitaxial channel region and the second epitaxial channel region.
1. A method of forming a semiconductor device comprising:
forming a trench through a multi-layered stack including a semiconductor material layer at a base of the trench;
epitaxially forming a semiconductor stacked structure in the trench, the semiconductor stacked structure including a first intrinsic channel on the semiconductor material layer, a first conductivity doped source/drain region on the first intrinsic channel, a second conductivity doped source/drain region on the first conductivity doped source/drain region, and a second intrinsic channel;
recessing the multi-layered stack to expose at least the first intrinsic channel;
forming a first gate conductor in direct contact with the first intrinsic channel to provide a first JFET device; and
forming a second gate conductor in direct contact with the second intrinsic channel to provide a second JFET device.
2. The method of claim 1 , wherein the semiconductor material layer at the base of the trench is doped to provide a first conductivity type.
3. The method of claim 2 , further comprising forming an epitaxial semiconductor material doped of a second conductivity type on a second end of the second intrinsic channel that is opposite a first end of the second intrinsic channel that is contact with the second conductivity doped source/drain region.
4. The method of claim 3 , wherein the first conductivity type for the first JFET is n-type, and the second conductivity type for the second JFET is p-type.
5. The method of claim 4 , further comprising forming a strapped contact in simultaneous electrical contact to the first conductivity doped source/drain region and the second conductivity doped source/drain region and a output node.
6. The method of claim 5 , wherein the first JFET is a four terminal device, and the method further comprises forming a ground contact from the semiconductor material layer that provides a source region at the base of the trench to ground, a first voltage input contact to a first side of the first gate conductor, and a second voltage input contact to a second side of the first gate conductor.
7. The method of claim 5 , wherein the second JFET is a four terminal device, and the method further comprises forming a power contact from the epitaxial semiconductor material doped of the second conductivity type on the second end of the second intrinsic channel to the power supply, a first voltage input contact to a first side of the second gate conductor, and a second voltage input contact to a second side of the second gate conductor.
8. The method of claim 1 , wherein said forming the first gate conductor in direct contact with the first intrinsic channel to provide a first JFET device comprises epitaxial growth of a doped semiconductor gate conductor.
9. The method of claim 1 , wherein said forming the second gate conductor in direct contact with the second intrinsic channel to provide a second JFET device comprises epitaxial growth of a doped semiconductor gate conductor.