BOTTOM-GATE TRANSISTOR FORMED IN SURFACE RECESS
A bottom-gate transistor has a channel in a recess of a substrate surface. A gate electrode is disposed in and in contact with the recess. A dielectric material layer contacts the gate electrode in the recess. A semiconductor material contacts the dielectric material in the recess and extends over the top surface of the substrate outside of the recess. A source electrode and a drain electrode contact the semiconductor material on opposite sides of the narrow dimension of the recess such that at least a portion of the channel of the transistor is in the recess.
1 . A bottom-gate transistor having a channel in a surface recess, comprising:
a substrate surface having a recess, the recess having a narrow dimension;
a gate electrode disposed in and in contact with the recess;
a dielectric material in contact with the gate electrode in the recess;
a semiconductor material in contact with the dielectric material in the recess and extending over the top surface of the substrate outside of the recess; and
a source electrode and a drain electrode in contact with the semiconductor material on opposite sides of the narrow dimension of the recess over the top surface of the substrate outside of the recess such that at least a portion of the channel of the transistor is in the recess.
2 . The bottom-gate transistor of claim 1 , wherein the dielectric material is a conformal thin-film inorganic dielectric material.
3 . The bottom-gate transistor of claim 2 , wherein the thin-film inorganic dielectric material includes SiO 2 , HfO, ZrO, Si x N y or Al 2 O 3 .
4 . The bottom-gate transistor of claim 1 , wherein the semiconductor material is a conformal thin-film inorganic semiconductor material.
5 . The bottom-gate transistor of claim 4 , wherein the thin-film inorganic semiconductor material is a zinc oxide-based semiconductor material.
6 . The bottom-gate transistor of claim 1 , wherein the source electrode and the drain electrode are regions of a thin-film inorganic conductive material.
7 . The bottom-gate transistor of claim 1 , wherein the source electrode and the drain electrode are over the semiconductor material.
8 . The bottom-gate transistor of claim 1 , wherein the source electrode and the drain electrode are over the dielectric material and under the semiconductor material.
9 . The bottom-gate transistor of claim 1 , wherein the gate electrode is a conformal thin-film inorganic conductive material.
10 . The bottom-gate transistor of claim 1 , wherein the gate electrode includes multiple layers of conductive materials.
11 . The bottom-gate transistor of claim 10 , wherein the multiple layers of conductive materials include a non-conformal conductive material layer and a conformal thin-film inorganic conductive material layer.
12 . The bottom-gate transistor of claim 1 , wherein the gate electrode extends beyond the recess over the substrate surface.
13 . The bottom-gate transistor of claim 1 , wherein a channel length of the channel is defined by the narrow dimension of the recess.