Multi-channel transistor structure and method of making thereof
View Patent ↗A method of forming an electronic device includes, forming a first channel coupled to a first current electrode and a second current electrode and forming a second channel coupled to the first current electrode and the second current electrode. The method also includes the second channel being substantially parallel to the first channel within a first plane, wherein the first plane is parallel to a major surface of a substrate over which the first channel lies. A gate electrode is formed surrounding the first channel and the second channel in a second plane, wherein the second plane is perpendicular to the major surface of the substrate. The resulting semiconductor device has a plurality of locations with a plurality of channels at each location. At small dimensions the channels form quantum wires connecting the source and drain.
1. A method of making an electronic device comprising:
forming a first channel coupled to a first current electrode and a second current electrode;
forming a second channel coupled to the first current electrode and the second current electrode, wherein the second channel is substantially parallel to the first channel within a first plane, wherein the first plane is parallel to a major surface of a substrate over which the first channel lies;
forming a gate electrode surrounding the first channel in a second plane, wherein the second plane is perpendicular to the major surface; and
forming a gate electrode surrounding the second channel in the second plane.
2. The method of claim 1 , further comprising:
forming a third channel coupled to the first current electrode and the second current electrode, wherein the third channel is substantially parallel to the first channel in a third plane, wherein the third plane is perpendicular to the major surface;
forming a fourth channel coupled to the first current electrode and the second current electrode, wherein the fourth channel is substantially parallel to the third channel within a fourth plane, wherein the fourth plane is parallel to the major surface; wherein
forming the gate electrode further comprises forming the gate electrode surrounding the third channel in the second plane; and
forming the gate electrode surrounding the fourth channel in the second plane.
3. The method of claim 1 , wherein forming the first and second channels further comprises masking the first and second current electrodes during an etch process that shapes of the first and second channel.
4. The method of claim 1 , further comprising:
forming a stack comprising a plurality of layers, wherein a composition of a first layer of the stack includes a semiconductor material and the first layer abuts an overlying layer and an underlying layer within the stack, wherein the overlying layer comprises a first composition and the underlying layer comprises a second composition; and
etching the first layer to define a dimension of the first channel and a dimension of the second channel.
5. The method of claim 4 , wherein forming the first and second channels further comprises:
removing the overlying layer and the underlying layer abutting the first and second channel.
6. The method of claim 4 , wherein the first current electrode and first channel are formed from the same layer of the stack.
7. The method of claim 4 , wherein the first composition and the second composition are the same.
8. The method of claim 7 , wherein the first composition is a different than the composition of the first layer.
9. The method of claim 4 , wherein the first composition and the second composition are different.
10. The method of claim 4 , wherein the composition of the first layer, the first composition, and the second composition each include silicon.
11. The method of claim 4 , further comprising:
forming a first opening in a layer overlying the stack; and
forming a sidewall spacer within the opening and abutting the layer to form a second opening overlying the stack.
12. The method of claim 11 , wherein etching the first layer further comprises:
etching the first layer of the stack underlying the second opening.
13. The method of claim 12 , further comprising:
selectively removing portions of the overlying and underlying layer that abut the first and second channel and leaving the first and second channel.
14. The method of claim 4 , wherein forming the stack further comprises:
the first layer being formed from the group consisting of silicon, germanium, silicon germanium and silicon germanium carbon;
the overlying layer being formed from the group consisting of silicon, germanium, silicon germanium and silicon germanium carbon; and
wherein the material comprising the first layer and the material comprising the overlying layer have different compositions.
15. A method of making an electronic device comprising:
forming a stack of semiconductor materials comprising a plurality of at least three adjacent layers of semiconductor material, wherein at least one layer of the plurality of adjacent layers is comprised of a semiconductor material different than an abutting layer overlying the at least one layer and underlying adjacent layer;
etching the stack of semiconductor materials to form a first current electrode location;
etching the stack of semiconductor materials to form a second current electrode location;
masking the stack, including the first and second current electrode locations;
etching to form a first opening in a mask overlying a channel region of the stack of semiconductor materials;
forming a dielectric spacer in the first opening to define a second opening;
removing a vertical portion of the stack of semiconductor materials defined by the second opening;
etching a layer of semiconductor material in the stack of semiconductor materials after removing the vertical portion of the stack of semiconductor materials, to define a first and second channel; and
forming a gate electrode surrounding the first and second channel and between the first current electrode location and the second current electrode location.
16. The method of claim 15 , wherein the method further comprises:
forming a dielectric layer over the stack of semiconductor materials;
forming an oxide layer over the stack of semiconductor materials, the dielectric layer and the substrate;
planarizing the oxide layer and exposing the dielectric layer;
etching the dielectric layer to expose the stack of semiconductor layers; and
depositing a dielectric spacer over the stack of semiconductor layers defining an opening over the stack of semiconductor layers.
17. The method of claim 15 , wherein etching a layer of semiconductor material in the stack comprises:
etching portions of a layer of semiconductor material anisotropically.
18. The method of claim 15 , wherein forming a stack of semiconductor material comprises:
forming a first layer comprising silicon;
forming a second layer, overlying the first layer comprising silicon germanium; and
forming a third layer, overlying the second layer comprising silicon.