Printable Inorganic Semiconductor Structures

摘要

The present invention provides structures and methods that enable the construction of micro-LED chiplets formed on a sapphire substrate that can be micro-transfer printed. Such printed structures enable low-cost, high-performance arrays of electrically connected micro-LEDs useful, for example, in display systems. Furthermore, in an embodiment, the electrical contacts for printed LEDs are electrically interconnected in a single set of process steps. In certain embodiments, formation of the printable micro devices begins while the semiconductor structure remains on a substrate. After partially forming the printable micro devices, a handle substrate is attached to the system opposite the substrate such that the system is secured to the handle substrate. The substrate may then be removed and formation of the semiconductor structures is completed. Upon completion, the printable micro devices may be micro transfer printed to a destination substrate.

主权项

1. A method of making an inorganic semiconductor structure suitable for micro-transfer printing, comprising:
providing a source substrate; forming a semiconductor layer on the source substrate, wherein the semiconductor layer has a first side and a second side opposite the first side and adjacent to the substrate; forming a first electrical contact on the first side of the semiconductor layer opposite the source substrate; removing a portion of the semiconductor layer surrounding the first electrical contact to form a trench surrounding a semiconductor element made from the semiconductor layer, the semiconductor element having a substrate side in contact with the source substrate and a handle side opposite the substrate side; providing a sacrificial layer covering the first electrical contact and covering at least a portion of the handle side of the semiconductor element and filling a portion of the trench; providing an interlayer over the sacrificial layer, the interlayer having different chemical selectivity than the sacrificial layer, wherein a portion of the interlayer contacts the source substrate at the base of the trench to form an anchor; adhering the interlayer to a handle substrate; removing the source substrate to expose the substrate side of the semiconductor element; forming a second electrical contact on the exposed substrate side of the semiconductor element; optionally forming a tether bridging the exposed substrate side of the semiconductor element to the anchor; and removing the sacrificial layer, thereby forming a printable semiconductor structure partially released from the handle substrate and physically secured to the anchor by the tether.