Methods of fabricating printable compound semiconductor devices on release layers

A method of fabricating transferable semiconductor devices, the method comprising;

• providing a release layer comprising indium aluminum phosphide on a substrate;
• providing a support layer on the release layer, the support layer and the substrate comprising respective materials such that the release layer has an etching selectivity relative to the support layer and the substrate;
• providing at least one device layer on the support layer;
• and
• selectively etching the release layer without substantially etching the support layer and the substrate,
• wherein selectively etching comprises selectively laterally etching the release layer using an etching solution comprising hydrochloric acid, and wherein the etching solution further comprises ethanol.

A method of fabricating transferable semiconductor devices, the method comprising:

• providing a release layer comprising indium aluminum phosphide on a substrate;
• providing a support layer on the release layer, the support layer and the substrate comprising respective materials such that the release layer has an etching selectivity relative to the support layer and the substrate;
• providing at least one device layer on the support layer;
• selectively etching the release layer without substantially etching the support layer and the substrate;
• forming an encapsulation layer on the at least one device layer prior to selectively etching the release layer, wherein the encapsulation layer comprises a photoresist material;
• and
• baking the photoresist material prior to selectively etching the release layer.

A method of fabricating transferable semiconductor devices, the method comprising:

• providing a release layer comprising indium aluminum phosphide on a substrate;
• providing a support layer on the release layer, the support layer and the substrate comprising respective materials such that the release layer has an etching selectivity relative to the support layer and the substrate;
• providing at least one device layer on the support layer;
• selectively etching the release layer without substantially etching the support layer and the substrate;
• forming an encapsulation layer on the at least one device layer prior to selectively etching the release layer;
• and
• forming anchoring and/or tethering structures in the encapsulation layer, wherein the anchoring and/or tethering structures are configured to maintain spatial orientation of the semiconductor devices during and after the selective etching.

A method of fabricating transferable semiconductor devices, the method comprising:

• providing a release layer comprising indium aluminum phosphide on a substrate;
• providing a support layer on the release layer, the support layer and the substrate comprising respective materials such that the release layer has an etching selectivity relative to the support layer and the substrate;
• providing at least one device layer on the support layer;
• selectively etching the release layer without substantially etching the support layer and the substrate;
• and
• forming an encapsulation layer on the at least one device layer prior to selectively etching the release layer,
• wherein the at least one device layer comprises an active layer of a photovoltaic cell, and further comprising the following prior to forming the encapsulation layer:
• providing an indium aluminum phosphide window layer on the active layer;
• and
• providing a dielectric anti-reflective coating on the window layer.

A method of preparing a releasable printable device, comprising:

• epitaxially growing on a gallium arsenide substrate an indium aluminum phosphide release layer, an arsenide-based layer adjacent to the release layer, and device layers, thereby forming an epi-stack;
• partially or fully forming functional devices on the epi-stack and exposing some portion of the release layer by microfabrication techniques;
• and
• selectively laterally etching the release layer in a mixture of hydrochloric acid and ethanol, thereby releasing the devices.