Transistors with monocrystalline metal chalcogenide channel materials
Transistor structures with monocrystalline metal chalcogenide channel materials are formed from a plurality of template regions patterned over a substrate. A crystal of metal chalcogenide may be preferentially grown from a template region and the metal chalcogenide crystals then patterned into the channel region of a transistor. The template regions may be formed by nanometer-dimensioned patterning of a metal precursor, a growth promoter, a growth inhibitor, or a defected region. A metal precursor may be a metal oxide suitable, which is chalcogenated when exposed to a chalcogen precursor at elevated temperature, for example in a chemical vapor deposition process.
1. An integrated circuit (IC), comprising:
a plurality of transistor structures, wherein individual ones of the transistor structures occupy an area over a substrate, and wherein within the area, each of the transistor structures comprises:
a channel region, wherein the channel region comprises a monocrystalline metal chalcogenide;
a template region comprising a metal and oxygen, wherein the template region comprises a sidewall in direct contact with the channel region, wherein the template region has a chemical composition distinct from the channel region;
and
a source terminal, a drain terminal, and a gate terminal electrically coupled to the channel region.
2. The IC of claim 1 , wherein the metal in the template region is also present in the metal chalcogenide.
3. The IC of claim 1 , wherein the template region comprises WOx, W, Mo, or Cu.
4. The IC of claim 1 , wherein the channel region comprises Mo, W, Zn, Cu, Cd, Ni, Co, Pd, Pt, Ti, Cr, V, Al, Sn, Ga, or In.
5. The IC of claim 1 , wherein a plurality of template regions corresponding to the plurality of transistors has a pitch over the substrate that is substantially equal to a pitch of at least one of the channel region, the source terminal, the drain terminal, or the gate terminal of the plurality of transistors.
6. The IC of claim 1 , wherein the source terminal or the drain terminal is electrically coupled to the channel region through only the template region.
7. The IC of claim 1 , wherein the template region is in direct contact with an amorphous material layer of the substrate and at least a portion of the channel region is over, and in direct contact with, the amorphous material layer.
8. The IC of claim 1 , wherein an in-plane crystal orientation of the metal chalcogenide varies across the plurality of transistor structures.
9. The IC of claim 1 , wherein the metal chalcogenide has a thickness less than 10 nm, and the source terminal is separated from a drain terminal by a channel length that exceeds the thickness.
10. An integrated circuit (IC), comprising:
a plurality of complementary metal-oxide-semiconductor (CMOS) field effect transistor (FET) structures, wherein individual ones of the CMOS FET structures comprise a Group IV semiconductor material; and
a plurality of back-end transistor structures over the CMOS FET structures, with one or more levels of interconnect metallization therebetween, wherein individual ones of the back- end transistor structures comprise the transistor structure of claim 1 .
11. The IC of claim 1 , wherein the template region is electrically conductive.
12. The IC of claim 1 , wherein the source terminal or the drain terminal is in direct contact with the template region.