Doped and strained flexible thin-film transistors
AssigneeWisconsin Alumni Research Foundation
InventorsZhenqiang Ma, Jung-Hun Seo, Max G. Lagally
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Abstract
Semiconductor trilayer structures that are doped and strained are provided. Also provided are mechanically flexible transistors, including radiofrequency transistors, incorporating the trilayer structures and methods for fabricating the trilayer structures and transistors. The trilayer structures comprise a first layer of single-crystalline semiconductor material, a second layer of single-crystalline semiconductor material and a third layer of single-crystalline semiconductor material. In the structures, the second layer is in contact with and sandwiched between the first and third layers and the first layer is selectively doped to provide one or more doped regions in the layer.
Claims14
A doped and strained semiconductor trilayer structure comprising:
- a first layer of single-crystalline semiconductor material, wherein the first layer is selectively doped to provide one or more doped regions extending through the first layer;
- a second layer of single-crystalline semiconductor material;
- and
- a third layer of single-crystalline semiconductor material;
- wherein the second layer is in contact with and sandwiched between the first and third layers, wherein the semiconductor material of the first and third layers is the same material and the thicknesses of the first and third layers are substantially equal, and further wherein the trilayer structure is not attached to a substrate with which it has an epitaxial relationship, such that the trilayered structure has self-sustained strain that is shared between the three layers.
A method of fabricating a doped, strained trilayer structure, the method comprising:
- selectively doping a layer of single-crystalline semiconductor material to form one or more doped regions, wherein the layer of single-crystalline material is attached to a sacrificial substrate;
- annealing the doped layer of single-crystalline semiconductor material, whereby damage to the single-crystalline structure caused by the doping is repaired;
- thinning the doped and annealed layer of single-crystalline semiconductor material;
- growing a second layer of single-crystalline semiconductor material on the thinned first layer, wherein the second layer is a strained layer;
- growing a third layer of single-crystalline semiconductor material on the second layer of single-crystalline semiconductor material, wherein the semiconductor material of the first and third layers is the same material and the thicknesses of the first and third layers are substantially equal;
- and
- releasing the trilayer structure from the sacrificial substrate, whereby the released trilayer structure has self-sustained strain that is shared between the three layers.
Dependencies are inferred from the claim text.