Systems and methods for controlling release of transferable semiconductor structures
First Claim
1. A method of fabricating a plurality of transferable micro objects, comprising:
- forming a sacrificial layer comprising sacrificial material on a process side of a source substrate;
forming a plurality of releasable micro objects at least in part on the sacrificial layer, so that the sacrificial material is disposed between the releasable micro objects and the source substrate;
applying a polymer layer over the plurality of releasable micro objects and at least a portion of the source substrate, wherein the polymer layer encapsulates the plurality of releasable micro objects;
treating the polymer layer to form;
(i) a plurality of anchor structures on the source substrate for the plurality of releasable micro objects,(ii) at least one tether between each releasable micro object and a pre-determined anchor structure of the plurality of anchor structures, and(iii) for each of the releasable micro objects, a port of ingress in the polymer layer to a portion of the sacrificial layer underneath a respective releasable micro object; and
removing at least a portion of the sacrificial layer between the plurality of releasable micro objects and the source substrate, to at least partially release the releasable micro objects from the source substrate.
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Accused Products
Abstract
The disclosed technology relates generally to methods and systems for controlling the release of micro devices. Prior to transferring micro devices to a destination substrate, a native substrate is formed with micro devices thereon. The micro devices can be distributed over the native substrate and spatially separated from each other by an anchor structure. The anchors are physically connected/secured to the native substrate. Tethers physically secure each micro device to one or more anchors, thereby suspending the micro device above the native substrate. In certain embodiments, single tether designs are used to control the relaxation of built-in stress in releasable structures on a substrate, such as Si (1 1 1). Single tether designs offer, among other things, the added benefit of easier break upon retrieval from native substrate in micro assembly processes. In certain embodiments, narrow tether designs are used to avoid pinning of the undercut etch front.
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Citations
21 Claims
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1. A method of fabricating a plurality of transferable micro objects, comprising:
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forming a sacrificial layer comprising sacrificial material on a process side of a source substrate; forming a plurality of releasable micro objects at least in part on the sacrificial layer, so that the sacrificial material is disposed between the releasable micro objects and the source substrate; applying a polymer layer over the plurality of releasable micro objects and at least a portion of the source substrate, wherein the polymer layer encapsulates the plurality of releasable micro objects; treating the polymer layer to form; (i) a plurality of anchor structures on the source substrate for the plurality of releasable micro objects, (ii) at least one tether between each releasable micro object and a pre-determined anchor structure of the plurality of anchor structures, and (iii) for each of the releasable micro objects, a port of ingress in the polymer layer to a portion of the sacrificial layer underneath a respective releasable micro object; and removing at least a portion of the sacrificial layer between the plurality of releasable micro objects and the source substrate, to at least partially release the releasable micro objects from the source substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A source substrate and plurality of releasable micro objects, comprising:
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a source substrate having a process side; a sacrificial layer comprising sacrificial material on the process side of the source substrate; a plurality of releasable micro objects formed at least in part on the sacrificial layer, so that the sacrificial material is disposed between the releasable micro objects and the source substrate; a polymer layer applied over the plurality of releasable micro objects and at least a portion of the source substrate, wherein the polymer layer encapsulates the plurality of releasable micro objects, wherein the polymer layer has been treated such that the polymer layer comprises; (i) a plurality of anchor structures on the source substrate for the plurality of releasable micro objects, (ii) at least one tether between each releasable micro object and a pre-determined anchor structure of the plurality of anchor structures, and (iii) for each of the releasable micro objects, a port of ingress in the polymer layer to a portion of the sacrificial layer underneath a respective releasable micro object. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A source substrate and plurality of releasable micro objects, comprising:
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a source substrate having a process side; a sacrificial layer comprising sacrificial material on the process side of the source substrate; a plurality of releasable micro objects formed at least in part on the sacrificial layer; a polymer layer applied over the plurality of releasable micro objects and at least a portion of the source substrate, wherein the polymer layer encapsulates the plurality of releasable micro objects, wherein the polymer layer has been treated such that the polymer layer comprises; (i) a plurality of anchor structures on the source substrate for the plurality of releasable micro objects, (ii) at least one tether between each releasable micro object and a pre-determined anchor structure of the plurality of anchor structures, and (iii) for each of the releasable micro objects, a port of ingress in the polymer layer to a portion of the sacrificial layer underneath a respective releasable micro object, wherein the sacrificial layer has an anisotropic crystal structure.
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Specification