Systems and methods for controlling release of transferable semiconductor structures
First Claim
1. An array of micro devices, the array comprising:
- a silicon (111) source substrate having a plurality of anchor portions in the silicon (111) source substrate that are laterally separated by etched portions in the silicon (111) source substrate;
a plurality of releasable micro objects, each located over an etched portion; and
a plurality of tethers, wherein each tether of the plurality of tethers connects a releasable micro object to an anchor portion, wherein the anchor portion to which the tether connects laterally separates adjacent releasable micro objects,wherein the releasable micro objects are formed at least in part on the source substrate.
3 Assignments
0 Petitions
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
23 Claims
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1. An array of micro devices, the array comprising:
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a silicon (111) source substrate having a plurality of anchor portions in the silicon (111) source substrate that are laterally separated by etched portions in the silicon (111) source substrate; a plurality of releasable micro objects, each located over an etched portion; and a plurality of tethers, wherein each tether of the plurality of tethers connects a releasable micro object to an anchor portion, wherein the anchor portion to which the tether connects laterally separates adjacent releasable micro objects, wherein the releasable micro objects are formed at least in part on the source substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of making thin and low-cost wafer-packaged micro-scale devices suitable for micro transfer printing using a (111) silicon system, the method comprising:
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providing a plurality of micro-scale devices; assembling the micro-scale devices onto a carrier wafer using micro-assembly techniques, wherein the carrier wafer comprises silicon (111) and a first dielectric layer; embedding the assembled micro-scale devices within a second layer of dielectric; patterning the first and second dielectric layers to define a perimeter of each of the micro-scale devices with anchors and tethers that preserve the spatial configuration of the micro-scale devices with respect to the carrier wafer when the micro-scale devices are moved with respect to the carrier wafer, thereby providing a wafer-level thin wafer package having micro-scale devices suitable for micro transfer printing to other substrates. - View Dependent Claims (14, 15)
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16. A method of fabricating a printable component array, the method comprising:
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providing a source substrate having a sacrificial layer comprising sacrificial material; forming a plurality of releasable micro objects at least in part on the sacrificial layer; forming an anchor structure on the source substrate that remains rigidly attached to the source substrate in the absence of the sacrificial material; forming a plurality of tethers, wherein each tether of the plurality of tethers connects a releasable micro object of the plurality of releasable micro objects to one of the anchor structures, each tether of the plurality of tethers is located on an off-center, anchor-facing edge of the respective releasable micro object of the plurality of releasable micro objects, and each tether is shaped to fracture in response to movement of the releasable micro object, so that in the absence of the sacrificial material; the releasable micro objects move with respect to the anchor structures; the tethers deform and are mechanically stressed; and each tether of the plurality of tethers remains rigidly attached to both a respective anchor and a respective releasable micro object of the plurality of micro objects, thereby preserving the spatial configuration of the plurality of releasable micro objects with respect to the source substrate; and removing at least a portion of the sacrificial material underneath the plurality of releasable micro objects so that the releasable micro objects move with respect to the anchor structures and the tethers deform and are mechanically stressed, wherein; the portion of the anchor to which the tether connects laterally separates adjacent releasable micro objects, the source substrate is a growth substrate made of a substrate material on or over which the micro objects are formed and the tethers are made of a tether material, either the tether material is the same material as the substrate material or the tether material is not disposed between the releasable micro objects and the source substrate, and the tethers are shaped to fracture in response to pressure. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
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Specification