III-N based material structures, methods, devices and circuit modules based on strain management
AssigneeThe Regents of the University of California
InventorsUmesh K. Mishra, Stacia Keller, Elaheh Ahmadi, Chirag Gupta, Yusuke Tsukada
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Abstract
The disclosure describes the use of strain to enhance the properties of p- and n-materials so as to improve the performance of III-N electronic and optoelectronic devices. In one example, transistor devices include a channel aligned along uniaxially strained or relaxed directions of the III-nitride material in the channel. Strain is introduced using buffer layers or source and drain regions of different composition
Claims20
A device, comprising:
- a ridge or fin structure comprising III-nitride material that is at least partially biaxially relaxed or strained along a first direction of the ridge or the fin structure and at least partially relaxed along a second direction perpendicular to the first direction, wherein the III-nitride material in the ridge or the fin structure comprises a III-nitride layer on a porous III-nitride layer.
A device comprising a field effect transistor (FET), comprising:
- a stripe comprising III-nitride material, wherein:
- the III-nitride material includes a channel layer on a layer;
- a source contact comprising a first metal on the stripe making ohmic contact to the channel layer;
- a drain contact comprising second metal on the stripe making ohmic contact to the channel layer;
- a gate contact on the stripe between the source contact and the drain contact, the gate contact controlling flow of current along a direction of a long axis or a short axis of the stripe through the channel layer and between the source contact and the drain contact,
- the source contact and the drain contact are positioned for the flow of current along the long axis when the layer has a smaller lattice constant than the channel layer so that the channel layer is strained along a first direction comprising a long axis of the stripe and at least partially relaxed along a second direction comprising a direction (short axis) perpendicular to the long axis;
- and
- the source contact and the drain contact are positioned for the flow of the current along the short axis when the channel layer has a smaller lattice constant than the layer.
A device comprising a field effect transistor, comprising:
- a stripe comprising III-nitride material, wherein the III-nitride material includes a channel layer;
- a source region, and a drain region,
- the source region is in physical contact with the channel layer between the source contact and the channel layer,
- the drain region is in physical contact with the channel layer between the drain contact and the channel layer, and
- the source region and the drain region have a lattice constant different than a lattice constant of channel layer so as to induce strain in the channel layer along a long axis of the stripe.
Dependencies are inferred from the claim text.