Micro-led structure and micro-led chip including the same

Abstract

To provide a micro-LED structure improved in light emission efficiency.SOLUTION: A micro-LED structure 1000 includes: a first type conductive layer 101; a second type conductive layer 102 stacked on the first type conductive layer; and a light emitting layer 103 formed between the first type conductive layer and the second type conductive layer. The light emitting layer extends along a horizontal level away from a top edge 101a of the first type conductive layer and a bottom edge 102a of the second type conductive layer, such that an edge of the light emitting layer does not contact the top edge of the first type conductive layer and the bottom edge of the second type conductive layer. The bottom edge of the second type conductive layer is aligned with the top edge of the first type conductive layer.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Application No. 63 / 131,128, filed December 28, 2020, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to micro LED structures and micro LED chips including the micro LED structures. [Background technology]

[0003] Micro Light Emitting Diodes (Micro LEDs) are devices that emit light using electrical signals and have a size on the order of a micrometer or smaller. Micro LEDs can be driven at low voltages so that they can be widely implemented in small optical elements. In recent years, Micro LEDs have been developed as illumination sources due to their high efficiency. Summary of the Invention

[0004] According to one aspect of an embodiment of the present disclosure, a micro LED structure includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer extends along a horizontal level away from a top edge of the first type of conductive layer and a bottom edge of the second type of conductive layer such that an edge of the light emitting layer does not contact either the top edge of the first type of conductive layer or the bottom edge of the second type of conductive layer. The bottom edge of the second type of conductive layer is aligned with the top edge of the first type of conductive layer.

[0005] According to another aspect of an embodiment of the present disclosure, a micro LED structure includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer projects along a horizontal level away from a top edge of the first type of conductive layer and a bottom edge of the second type of conductive layer such that an edge of the light emitting layer does not contact either the top edge of the first type of conductive layer or the bottom edge of the second type of conductive layer. The contour of the second type of conductive layer projected vertically onto the top surface of the first type of conductive layer is surrounded by the top edge of the first type of conductive layer.

[0006] According to another aspect of an embodiment of the present disclosure, a micro LED structure includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer extends along a horizontal level away from a top edge of the first type of conductive layer and a bottom edge of the second type of conductive layer such that an edge of the light emitting layer does not contact either the top edge of the first type of conductive layer or the bottom edge of the second type of conductive layer. The outline of the first type of conductive layer projected vertically onto a bottom surface of the second type of conductive layer is surrounded by the bottom edge of the second type of conductive layer.

[0007] According to another aspect of an embodiment of the present disclosure, a micro LED structure includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer extends along a horizontal level from an edge of the first type of conductive layer. The edge of the light emitting layer is aligned with an edge of the second type of conductive layer. The edge of the second type of conductive layer extends along a horizontal level away from an edge of the first type of conductive layer.

[0008] According to another aspect of an embodiment of the present disclosure, a micro LED structure includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer extends along a horizontal level from an edge of the second type of conductive layer. The edge of the light emitting layer is aligned with an edge of the first type of conductive layer. The edge of the first type of conductive layer extends along a horizontal level away from an edge of the second type of conductive layer.

[0009] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one of which includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer, the light emitting layer being continuously formed over the entire micro LED chip, and the plurality of micro LEDs share the light emitting layer.

[0010] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs. At least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the entire micro LED chip, and the plurality of micro LEDs share the light emitting layer. An isolation structure is formed between adjacent micro LEDs, and at least a portion of the isolation structure is formed in the light emitting layer.

[0011] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs. At least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed across the chip, and the plurality of micro LEDs share the light emitting layer. An isolation structure is formed between adjacent micro LEDs, and at least a portion of the isolation structure is formed in the light emitting layer. A top surface of the isolation structure is aligned with a top of the light emitting layer, and a bottom surface of the isolation structure is below the light emitting layer.

[0012] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the micro LED chip, and the plurality of micro LEDs share the light emitting layer. The micro LED chip further includes a top spacer formed on a top surface of the light emitting layer, a bottom spacer formed on a bottom surface of the light emitting layer, an edge of the top spacer being aligned with an edge of the light emitting layer, and an edge of the bottom spacer being aligned with an edge of the light emitting layer, and an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed in the light emitting layer, an upper surface of the isolation structure being aligned with an upper portion of the light emitting layer, and a bottom surface of the isolation structure being above the bottom surface of the bottom spacer and below the light emitting layer.

[0013] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs. At least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed across the chip, and the plurality of micro LEDs share the light emitting layer. The micro LED chip further includes a top spacer formed on a top surface of the light emitting layer, a bottom spacer formed on a bottom surface of the light emitting layer, an edge of the top spacer being aligned with an edge of the light emitting layer, and an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed within the light emitting layer, an upper surface of the isolation structure being aligned with an upper portion of the light emitting layer, and a bottom surface below the bottom spacer.

[0014] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one of which includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the micro LED chip, and the plurality of micro LEDs share the light emitting layer. The micro LED chip further includes a top spacer formed on a top surface of the light emitting layer, a bottom spacer formed on a bottom surface of the light emitting layer, an edge of the top spacer being aligned with an edge of the light emitting layer, and an edge of the bottom spacer being aligned with an edge of the light emitting layer, and an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed in the light emitting layer, an upper surface of the isolation structure being aligned with an upper portion of the light emitting layer, and a bottom surface of the isolation structure being aligned with a bottom surface of the bottom spacer.

[0015] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs. At least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the entire micro LED chip, and the plurality of micro LEDs share the light emitting layer. The micro LED further includes an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed in the light emitting layer. A top surface of the isolation structure is above the light emitting layer. A bottom surface of the isolation structure is aligned with a bottom of the light emitting layer.

[0016] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one of which includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the micro LED chip, and the plurality of micro LEDs share the light emitting layer. The micro LED chip further includes a top spacer formed on a top surface of the light emitting layer, a bottom spacer formed on a bottom surface of the light emitting layer, an edge of the top spacer being aligned with an edge of the light emitting layer, and an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed in the light emitting layer, a bottom surface of the isolation structure being aligned with a bottom surface of the light emitting layer, and a top surface of the isolation structure being above the light emitting layer and below a top surface of the top spacer.

[0017] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one of which includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the micro LED chip, and the plurality of micro LEDs share the light emitting layer. The micro LED chip further includes a top spacer formed on a top surface of the light emitting layer, a bottom spacer formed on a bottom surface of the light emitting layer, an edge of the top spacer being aligned with an edge of the light emitting layer, an edge of the bottom spacer being aligned with an edge of the light emitting layer, and an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed in the light emitting layer, a bottom surface of the isolation structure being aligned with a bottom surface of the light emitting layer, and an upper surface of the isolation structure being aligned with an upper surface of the top spacer.

[0018] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the micro LED chip, and the plurality of micro LEDs share the light emitting layer. The micro LED chip further includes a top spacer formed on a top surface of the light emitting layer, a bottom spacer formed on a bottom surface of the light emitting layer, an edge of the top spacer being aligned with an edge of the light emitting layer, an edge of the bottom spacer being aligned with an edge of the light emitting layer, and an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed in the light emitting layer, a bottom surface of the isolation structure being aligned with a bottom surface of the light emitting layer, and a top surface of the isolation structure being above the top spacer.

[0019] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs. At least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the entire micro LED chip, and the plurality of micro LEDs share the light emitting layer. An isolation structure is formed between adjacent micro LEDs, and at least a portion of the isolation structure is formed in the light emitting layer. A top surface of the isolation structure is above the light emitting layer, and a bottom surface of the isolation structure is below the light emitting layer.

[0020] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the micro LED chip, and the plurality of micro LEDs share the light emitting layer. The micro LED chip further includes a top spacer formed on a top surface of the light emitting layer, a bottom spacer formed on a bottom surface of the light emitting layer, an edge of the top spacer being aligned with an edge of the light emitting layer, and an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed in the light emitting layer, a top surface of the isolation structure being above the light emitting layer and below a top surface of the top spacer, and a bottom surface of the isolation structure being below a bottom of the light emitting layer.

[0021] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one of which includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the micro LED chip, and the plurality of micro LEDs share the light emitting layer. The micro LED chip further includes a top spacer formed on a top surface of the light emitting layer, a bottom spacer formed on a bottom surface of the light emitting layer, an edge of the top spacer being aligned with an edge of the light emitting layer, and an edge of the bottom spacer being aligned with an edge of the light emitting layer, and an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed in the light emitting layer, a top surface of the isolation structure being above the light emitting layer and below a top surface of the top spacer, and a bottom surface of the isolation structure being below a bottom of the light emitting layer and above a bottom surface of the bottom spacer.

[0022] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the micro LED chip, and the plurality of micro LEDs share the light emitting layer. The micro LED chip further includes a top spacer formed on a top surface of the light emitting layer, a bottom spacer formed on a bottom surface of the light emitting layer, an edge of the top spacer being aligned with an edge of the light emitting layer, and an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed in the light emitting layer, a top surface of the isolation structure being above the light emitting layer and below a top surface of the top spacer, and a bottom surface of the isolation structure being aligned with a bottom surface of the bottom spacer.

[0023] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the micro LED chip, and the plurality of micro LEDs share the light emitting layer. The micro LED chip further includes a top spacer formed on a top surface of the light emitting layer, a bottom spacer formed on a bottom surface of the light emitting layer, an edge of the top spacer being aligned with an edge of the light emitting layer, and an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed in the light emitting layer, a top surface of the isolation structure being above the light emitting layer and below a top surface of the top spacer, and a bottom surface of the isolation structure being below the bottom spacer.

[0024] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one of which includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the micro LED chip, and the plurality of micro LEDs share the light emitting layer. The micro LED chip further includes a top spacer formed on a top surface of the light emitting layer, a bottom spacer formed on a bottom surface of the light emitting layer, an edge of the top spacer being aligned with an edge of the light emitting layer, an edge of the bottom spacer being aligned with an edge of the light emitting layer, and an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed in the light emitting layer, a bottom surface of the isolation structure being below the light emitting layer and above a bottom surface of the bottom spacer, and a top surface of the isolation structure being aligned with a top surface of the top spacer.

[0025] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one of which includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the micro LED chip, and the plurality of micro LEDs share the light emitting layer. The micro LED chip further includes a top spacer formed on a top surface of the light emitting layer, a bottom spacer formed on a bottom surface of the light emitting layer, an edge of the top spacer being aligned with an edge of the light emitting layer, and an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed in the light emitting layer, a bottom surface of the isolation structure being below the light emitting layer and above a bottom surface of the bottom spacer, and a top surface of the isolation structure being above the top spacer.

[0026] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs. At least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the entire micro LED chip, and the plurality of micro LEDs share the light emitting layer. An isolation structure is formed between adjacent micro LEDs, and at least a portion of the isolation structure is formed in the light emitting layer. A bottom surface of the isolation structure is aligned with a bottom of the light emitting layer, and a top surface of the isolation structure is aligned with a top surface of the light emitting layer.

[0027] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one of which includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the micro LED chip, and the plurality of micro LEDs share the light emitting layer. The micro LED chip further includes a top spacer formed on a top surface of the light emitting layer, a bottom spacer formed on a bottom surface of the light emitting layer, an edge of the top spacer being aligned with an edge of the light emitting layer, an edge of the bottom spacer being aligned with an edge of the light emitting layer, and an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed in the light emitting layer, a bottom surface of the isolation structure being aligned with a bottom surface of the bottom spacer, and a top surface of the isolation structure being aligned with a top surface of the top spacer.

[0028] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one of which includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the micro LED chip, and the plurality of micro LEDs share the light emitting layer. The micro LED chip further includes a top spacer formed on a top surface of the light emitting layer, a bottom spacer formed on a bottom surface of the light emitting layer, an edge of the top spacer being aligned with an edge of the light emitting layer, and an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed in the light emitting layer, an upper surface of the isolation structure being aligned with an upper surface of the top spacer, and a bottom surface of the isolation structure being below the bottom spacer.

[0029] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the micro LED chip, and the plurality of micro LEDs share the light emitting layer. The micro LED chip further includes a top spacer formed on a top surface of the light emitting layer, a bottom spacer formed on a bottom surface of the light emitting layer, an edge of the top spacer being aligned with an edge of the light emitting layer, an edge of the bottom spacer being aligned with an edge of the light emitting layer, and an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed in the light emitting layer, a bottom surface of the isolation structure being aligned with a bottom surface of the bottom spacer, and a top surface of the isolation structure being above the top spacer.

[0030] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the micro LED chip, and the plurality of micro LEDs share the light emitting layer. The micro LED chip further includes a top spacer formed on a top surface of the light emitting layer, a bottom spacer formed on a bottom surface of the light emitting layer, an edge of the top spacer being aligned with an edge of the light emitting layer, and an isolation structure formed between adjacent micro LEDs, at least a portion of the isolation structure being formed in the light emitting layer, a bottom surface of the isolation structure being below the bottom spacer, and a top surface of the isolation structure being above the top spacer.

[0031] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs. At least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the entire micro LED chip, and the plurality of micro LEDs share the light emitting layer. A bottom edge of the second type of conductive layer is aligned with a top edge of the first type of conductive layer.

[0032] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs. At least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the entire micro LED chip, and the plurality of micro LEDs share the light emitting layer. The outline of the second type of conductive layer vertically projected onto the top surface of the first type of conductive layer is surrounded by the edge of the first type of conductive layer.

[0033] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs. At least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer is continuously formed over the entire micro LED chip, and the plurality of micro LEDs share the light emitting layer. The outline of the first type of conductive layer vertically projected onto a bottom surface of the second type of conductive layer is surrounded by an edge of the second type of conductive layer.

[0034] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs, at least one of which includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer, with at least a portion of the light emitting layer being formed between adjacent micro LEDs, and the micro LED chip further includes a metal layer formed on the light emitting layer between adjacent micro LEDs.

[0035] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs. At least one micro LED structure includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer extends along a horizontal level from a top edge of the first type of conductive layer and a bottom edge of the second type of conductive layer such that an edge of the light emitting layer does not contact either a top edge of the first type of conductive layer or a bottom edge of the second type of conductive layer, and the bottom edge of the second type of conductive layer is aligned with the top edge of the first type of conductive layer. The micro LED chip further includes a metal layer formed on the light emitting layer between adjacent micro LEDs.

[0036] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs. At least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer extends along a horizontal level from an upper edge of the first type of conductive layer and a bottom edge of the second type of conductive layer such that an edge of the light emitting layer does not contact an upper edge of the first type of conductive layer or a bottom edge of the second type of conductive layer, and an outline of the second type of conductive layer vertically projected onto an upper surface of the first type of conductive layer is surrounded by an edge of the first type of conductive layer. The micro LED chip further includes a metal layer formed on a portion of the light emitting layer extending from an upper edge of the first type of conductive layer.

[0037] According to another aspect of an embodiment of the present disclosure, a micro LED chip includes a plurality of micro LEDs. At least one micro LED of the plurality of micro LEDs includes a first type of conductive layer, a second type of conductive layer stacked on the first type of conductive layer, and a light emitting layer formed between the first type of conductive layer and the second type of conductive layer. The light emitting layer extends along a horizontal level from a top edge of the first type of conductive layer and a bottom edge of the second type of conductive layer such that an edge of the light emitting layer does not contact either the top edge of the first type of conductive layer or the bottom edge of the second type of conductive layer. The contour of the first type of conductive layer projected vertically onto a bottom surface of the second type of conductive layer is surrounded by the bottom edge of the second type of conductive layer. The micro LED chip further includes a metal layer formed on a portion of the light emitting layer extending from the second type of conductive layer. [Brief description of the drawings]

[0038] [Figure 1A] FIG. 2 is a cross-sectional view of a micro LED structure according to a first embodiment of the present disclosure. [Figure 1B] FIG. 2 is a cross-sectional view of a micro LED structure according to a first variant of the first embodiment of the present disclosure. [Figure 1C] FIG. 2 is a cross-sectional view of a micro LED structure according to a second variant of the first embodiment of the present disclosure. [Figure 1D] FIG. 13 is a cross-sectional view of a micro LED structure according to a third variant of the first embodiment of the present disclosure. [Figure 2A] FIG. 2 is a cross-sectional view of a micro LED structure according to a second embodiment of the present disclosure. [Figure 2B] FIG. 13 is a cross-sectional view of a micro LED structure according to a first variant of the second embodiment of the present disclosure. [Figure 2C] FIG. 13 is a cross-sectional view of a micro LED structure according to a second variant of the second embodiment of the present disclosure. [Figure 2D] FIG. 13 is a cross-sectional view of a micro LED structure according to a third variant of the second embodiment of the present disclosure. [Figure 3A]FIG. 13 is a cross-sectional view of a micro LED structure according to a third embodiment of the present disclosure. [Figure 3B] FIG. 13 is a cross-sectional view of a micro LED structure according to a first variant of the third embodiment of the present disclosure. [Figure 3C] FIG. 13 is a cross-sectional view of a micro LED structure according to a second variant of the third embodiment of the present disclosure. [Figure 3D] FIG. 13 is a cross-sectional view of a micro LED structure according to a third variant of the third embodiment of the present disclosure. [Figure 4A] FIG. 11 is a cross-sectional view of a micro LED structure according to a fourth embodiment of the present disclosure. [Figure 4B] FIG. 13 is a cross-sectional view of a micro LED structure according to a first variant of the fourth embodiment of the present disclosure. [Figure 4C] FIG. 13 is a cross-sectional view of a micro LED structure according to a second variant of the fourth embodiment of the present disclosure. [Figure 4D] FIG. 13 is a cross-sectional view of a micro LED structure according to a third variant of the fourth embodiment of the present disclosure. [Figure 5A] FIG. 13 is a cross-sectional view of a micro LED structure according to a fifth embodiment of the present disclosure. [Figure 5B] FIG. 13 is a cross-sectional view of a micro LED structure according to a first variant of the fifth embodiment of the present disclosure. [Figure 5C] FIG. 13 is a cross-sectional view of a micro LED structure according to a second variant of the fifth embodiment of the present disclosure. [Figure 5D] FIG. 13 is a cross-sectional view of a micro LED structure according to a third variant of the fifth embodiment of the present disclosure. [Figure 6A] FIG. 13 is a cross-sectional view of a micro LED chip according to a sixth embodiment of the present disclosure. [Figure 6B] FIG. 13 is a cross-sectional view of a micro LED chip according to a first variant of the sixth embodiment of the present disclosure. [Figure 6C] FIG. 13 is a cross-sectional view of a micro LED chip according to a second variant of the sixth embodiment of the present disclosure. [Figure 6D]FIG. 13 is a cross-sectional view of a micro LED chip according to a third variant of the sixth embodiment of the present disclosure. [Figure 6E] FIG. 13 is a cross-sectional view of a micro LED chip according to a fourth variant of the sixth embodiment of the present disclosure. [Figure 6F] FIG. 13 is a cross-sectional view of a micro LED chip according to a fifth variant of the sixth embodiment of the present disclosure. [Figure 7] FIG. 13 is a cross-sectional view of a micro LED chip according to a seventh embodiment of the present disclosure. [Figure 8A] FIG. 13 is a cross-sectional view of a micro LED chip according to an eighth embodiment of the present disclosure. [Figure 8B] FIG. 13 is a cross-sectional view of a micro LED chip according to a first variant of the eighth embodiment of the present disclosure. [Figure 8C] FIG. 13 is a cross-sectional view of a micro LED chip according to a second variant of the eighth embodiment of the present disclosure. [Figure 9A] FIG. 13 is a cross-sectional view of a micro LED chip according to a ninth embodiment of the present disclosure. [Figure 9B] FIG. 13 is a cross-sectional view of a micro LED chip according to a first variant of the ninth embodiment of the present disclosure. [Figure 9C] FIG. 13 is a cross-sectional view of a micro LED chip according to a second variant of the seventh embodiment of the present disclosure. [Figure 10A] FIG. 16 is a cross-sectional view of a micro LED chip according to a tenth embodiment of the present disclosure. [Figure 10B] FIG. 23 is a cross-sectional view of a micro LED chip according to a first variant of the tenth embodiment of the present disclosure. [Figure 10C] FIG. 23 is a cross-sectional view of a micro LED chip according to a second variant of the tenth embodiment of the present disclosure. [Figure 11A] FIG. 23 is a cross-sectional view of a micro LED chip according to an eleventh embodiment of the present disclosure. [Figure 11B] FIG. 23 is a cross-sectional view of a micro LED chip according to a first variant of the eleventh embodiment of the present disclosure. [Figure 11C] FIG. 23 is a cross-sectional view of a micro LED chip according to a second variant of the eleventh embodiment of the present disclosure. [Figure 11D] FIG. 23 is a cross-sectional view of a micro LED chip according to a third variant of the eleventh embodiment of the present disclosure. [Figure 12A] FIG. 23 is a cross-sectional view of a micro LED chip according to a twelfth embodiment of the present disclosure. [Figure 12B] FIG. 23 is a cross-sectional view of a micro LED chip according to a first variant of the twelfth embodiment of the present disclosure. [Figure 12C] FIG. 23 is a cross-sectional view of a micro LED chip according to a second variant of the twelfth embodiment of the present disclosure. [Figure 12D] FIG. 23 is a cross-sectional view of a micro LED chip according to a third variant of the twelfth embodiment of the present disclosure. [Figure 13A] FIG. 23 is a cross-sectional view of a micro LED chip according to a thirteenth embodiment of the present disclosure. [Figure 13B] FIG. 23 is a cross-sectional view of a micro LED chip according to a variation of the thirteenth embodiment of the present disclosure. [Figure 14A] FIG. 23 is a cross-sectional view of a micro LED chip according to a fourteenth embodiment of the present disclosure. [Figure 14B] FIG. 23 is a cross-sectional view of a micro LED chip according to a modified example of the fourteenth embodiment of the present disclosure. [Figure 15A] FIG. 23 is a cross-sectional view of a micro LED chip according to a fifteenth embodiment of the present disclosure. [Figure 15B] FIG. 23 is a cross-sectional view of a micro LED chip according to a modified example of the fifteenth embodiment of the present disclosure. [Figure 16A] FIG. 23 is a cross-sectional view of a micro LED chip according to a sixteenth embodiment of the present disclosure. [Figure 16B] FIG. 23 is a cross-sectional view of a micro LED chip according to a variation of the sixteenth embodiment of the present disclosure. [Figure 17A] FIG. 23 is a cross-sectional view of a micro LED chip according to a seventeenth embodiment of the present disclosure. [Figure 17B] FIG. 23 is a cross-sectional view of a micro LED chip according to a variation of the seventeenth embodiment of the present disclosure. [Figure 18] FIG. 2 is a cross-sectional view of a micro LED structure according to a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] The following text provides a detailed description of the present disclosure in conjunction with specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present disclosure. The scope of protection for the present disclosure encompasses modifications made by those skilled in the art to structures, methods, or functions based on these embodiments.

[0040] To facilitate the presentation of the figures in this disclosure, the size of certain structures or parts may be exaggerated relative to other structures or parts. Thus, the figures in this application are intended only to illustrate the basic structures of the subject matter of this application. The same numbers in different figures represent the same or similar elements unless otherwise indicated.

[0041] Furthermore, terms in the documents indicating relative spatial positions, such as "front", "back", "upper", "lower", "above", "below", etc., are used for descriptive purposes in describing the relationship between a unit or feature depicted in a drawing and another unit or feature in the drawing. Terms indicating relative spatial positions may refer to positions other than those depicted in the drawings when the device is in use or operation. For example, if a device shown in a drawing is turned over, a unit described as being positioned "below" or "above" another unit or feature would be located "above" that other unit or feature. Thus, the exemplary term "below" can include both upper and lower positions. The device may be oriented in other ways (rotated 90 degrees or oriented in a different direction) and the spatially related descriptive terms appearing in the documents should be interpreted accordingly. When a component or layer is said to be "on" or "connected to" another component or layer, it may be directly on or connected to the other component or layer, or there may be intermediate components or layers.

[0042] First embodiment 1A is a cross-sectional view of a micro light emitting diode (micro LED) structure 1000 according to a first embodiment of the present disclosure. As shown in FIG. 1A, the micro LED structure 1000 includes a first type of conductive layer 101, a second type of conductive layer 102 stacked on the first type of conductive layer 101, and a light emitting layer 103 formed between the first type of conductive layer 101 and the second type of conductive layer 102. The light emitting layer 103 extends along a horizontal level away from the top edge 101a of the first type of conductive layer 101 and the bottom edge 102a of the second type of conductive layer 102 such that the edge 103a of the light emitting layer 103 does not contact either the top edge 101a of the first type of conductive layer 101 or the bottom edge 102a of the second type of conductive layer 102. The bottom edge 102a of the second type of conductive layer 102 is aligned with the top edge 101a of the first type of conductive layer 101.

[0043] The first type of conductive layer 101 and the second type of conductive layer 102 may be any type of conductive layer. In one embodiment, the first type of conductive layer 101 may be an n-type conductive semiconductor containing one or more n-type dopants, and the second type of conductive layer 102 may be a p-type conductive semiconductor layer containing one or more p-type dopants. In another embodiment, the first type of conductive layer 101 may be a p-type conductive semiconductor, and the second type of conductive layer 102 may be an n-type conductive semiconductor layer. As shown in FIG. 1A, the top area of ​​the first type of conductive layer 101 is larger than the bottom area of ​​the first type of conductive layer 101. The top area of ​​the second type of conductive layer 102 is smaller than the bottom area of ​​the second type of conductive layer 102.

[0044] The light emitting layer 103 may have a quantum well structure in which quantum well layers and barrier layers are alternately stacked. In one embodiment, the light emitting layer 103 may include a pair of quantum well layers and a barrier layer interposed between the quantum well layers. In another embodiment, the light emitting layer 103 may include multiple pairs of quantum well layers and a barrier layer interposed between adjacent quantum well layers. The quantum well layers are made of, for example, GaAs, AlGaAs, InGaAs, GaAsP, AlGaInP, GaInAsP, GaInP, AlInP, GaP, InP, etc. The barrier layers are made of, for example, GaAs, AlGaAs, InGaAs, GaAsP, AlGaInP, GaInAsP, GaInP, AlInP, GaP, InP, etc.

[0045] As shown in FIG. 1A, the micro LED structure 1000 also includes a top spacer 107 formed on the top surface 103b of the light emitting layer 103 and a bottom spacer 108 formed on the bottom surface 103c of the light emitting layer 103. The top spacer 107 and the bottom spacer 108 can be made of GaAs, AlGaAs, InGaAs, GaAsP, AlGaInP, GaInAsP, GaInP, AlInP, GaP, InP, etc. The top spacer 107 and the bottom spacer 108 are configured to control the carrier injection efficiency to improve the performance and reliability of the micro LED. The edge 107a of the top spacer 107 and the edge 108a of the bottom spacer 108 are aligned with the edge 103a of the light emitting layer 103. The thickness of the top spacer 107 is greater than the thickness of the light emitting layer 103. The thickness of the bottom spacer 108 is greater than the thickness of the light emitting layer 103.

[0046] In the embodiment shown in FIG. 1A, the micro LED structure 1000 further includes a reflective structure 104 surrounding the first type conductive layer 101. The reflective structure 104 is attached to the sidewall surface 101b of the first type conductive layer 101. The reflective structure 104 on the sidewall of the first type conductive layer 101 is inclined with respect to the surface 110a of the substrate 110. The inclination angle of the reflective structure 104 is about 30° to about 75° with respect to the surface 110a of the substrate 110. The reflective structure 104 on the sidewall surface 101b of the first type conductive layer 101 is made of an ODR (Omnidirectional Reflector) structure or a DBR (Distributed Bragg Reflector) structure. The reflective structure 104 is configured to focus light on the second type conductive layer 102.

[0047] In the embodiment shown in Figure 1A, the micro LED structure 1000 further includes a bottom connection structure 105 formed under and electrically connected to the first type of conductive layer 101. The bottom connection structure 105 may be formed of a conductive material, such as a metal. The bottom connection structure 105 may be reflective.

[0048] As shown in FIG. 1A, the micro LED structure 1000 further includes a substrate 110 below the first type conductive layer 101 and electrically connected to the bottom connection structure 105 by connection pads 106 in the substrate 110. In some embodiments, the substrate 110 may be made of one of a plurality of materials from the III-V group, such as GaN. In some other embodiments, the substrate 110 may include IC circuitry. The connection pads 106 may be made of a conductive material, such as Cu.

[0049] 1A, the micro LED structure 1000 further includes an isolation layer 109 surrounding the first type conductive layer 101 and underlying the light emitting layer 103. The isolation layer 109 may be made of a light absorbing material including, for example, impurity doped SiO2 or Si3N4.

[0050] 1A, the micro LED structure 1000 further includes a micro lens 111 formed on the second type conductive layer 102 and the top surface 107b of the top spacer 107. The micro lens 111 is configured to focus the light emitted by the light emitting layer 103.

[0051] First Modification of the First Embodiment Figure 1B is a cross-sectional view of a micro LED structure 1001 according to a first variant of the first embodiment of the present disclosure. The embodiment shown in Figure 1B differs from the embodiment shown in Figure 1A in that the sidewall surface 101b of the first type of conductive layer 101 is curved and a reflective structure 1041 is formed on the sidewall surface 101b of the first type of conductive layer 101, having a curved surface 104a. Except for the reflective structure 1041, the components of the micro LED structure 1001 shown in Figure 1B are the same as the components of the micro LED structure 1000 shown in Figure 1A, and therefore a detailed description of these components will not be repeated.

[0052] Second Modification of the First Embodiment FIG. 1C is a cross-sectional view of a micro LED structure 1002 according to a second variant of the first embodiment of the present disclosure. The embodiment shown in FIG. 1C differs from the embodiment shown in FIG. 1A in that a reflective structure 1042 is attached to the bottom surface 101c of the first type of conductive layer 101. The reflective structure 1042 is electrically conductive. The bottom connection structure 105 is formed on the bottom of the reflective structure 1042 and is electrically connected to the reflective structure 1042. The reflective structure 1042 on the bottom surface 101c of the first type of conductive layer 101 may be made of metal. Except for the reflective structure 1042, the components of the micro LED structure 1002 shown in FIG. 1C are the same as the components of the micro LED structure 1000 shown in FIG. 1A, and therefore a detailed description of these components will not be repeated.

[0053] Third Modification of the First Embodiment FIG. 1D is a cross-sectional view of a micro LED structure 1003 according to a third variant of the first embodiment of the present disclosure. The embodiment shown in FIG. 1D differs from the embodiment shown in FIG. 1A in that a reflective structure 1043 is attached to both the sidewall surface 101b and the bottom surface 101c of the first type conductive layer 101. The reflective structure 1043 is electrically conductive. The bottom connection structure 105 is formed on the bottom of the reflective structure 1043 and is electrically connected with the reflective structure 1043. Except for the reflective structure 1043, the components of the micro LED structure 1003 shown in FIG. 1D are the same as those of the micro LED structure 1000 shown in FIG. 1A, and therefore the detailed description of these components will not be repeated.

[0054] Second embodiment 2A is a cross-sectional view of a micro LED structure 2000 according to a second embodiment of the present disclosure. The second embodiment shown in FIG. 2A differs from the first embodiment shown in FIG. 1A in that the bottom edge 102a of the second type of conductive layer 102 is not aligned with the top edge 101a of the first type of conductive layer 101. Instead, the contour of the second type of conductive layer 102 projected vertically onto the top surface 101d of the first type of conductive layer 101 is surrounded by the top edge 101a of the first type of conductive layer 101. The components of the micro LED structure 2000 of the second embodiment shown in FIG. 2A are the same as the components of the micro LED structure 1000 of the first embodiment shown in FIG. 1A, and therefore a detailed description of these components will not be repeated.

[0055] First modification of the second embodiment Figure 2B is a cross-sectional view of a micro LED structure 2001 according to a first variant of the second embodiment of the present disclosure. The embodiment shown in Figure 2B differs from the embodiment shown in Figure 2A in that the sidewall surface 101b of the first type of conductive layer 101 is curved and a reflective structure 1041 is formed on the sidewall surface 101b of the first type of conductive layer 101, having a curved surface 104a. Except for the reflective structure 1041, the components of the micro LED structure 2001 shown in Figure 2B are the same as the components of the micro LED structure 2000 shown in Figure 2A, and therefore a detailed description of these components will not be repeated.

[0056] Second modification of the second embodiment FIG. 2C is a cross-sectional view of a micro LED structure 2002 according to a second variant of the second embodiment of the present disclosure. The embodiment shown in FIG. 2C differs from the embodiment shown in FIG. 2A in that a reflective structure 1042 is attached to the bottom surface 101c of the first type of conductive layer 101. The reflective structure 1042 is electrically conductive. The bottom connection structure 105 is formed on the bottom of the reflective structure 1042 and is electrically connected to the bottom of the reflective structure 1042. The reflective structure 1042 on the bottom surface 101c of the first type of conductive layer 101 may be made of metal. Except for the reflective structure 1042, the components of the micro LED structure 2002 shown in FIG. 2C are the same as the components of the micro LED structure 2000 shown in FIG. 2A, and therefore a detailed description of these components will not be repeated.

[0057] Third modification of the second embodiment FIG. 2D is a cross-sectional view of a micro LED structure 2003 according to a third variant of the second embodiment of the present disclosure. The embodiment shown in FIG. 2D differs from the embodiment shown in FIG. 2A in that a reflective structure 1043 is attached to both the sidewall surface 101b and the bottom surface 101c of the first type conductive layer 101. The reflective structure 1043 is electrically conductive. The bottom connection structure 105 is formed on the bottom of the reflective structure 1043 and is electrically connected with the reflective structure 1043. Except for the reflective structure 1043, the components of the micro LED structure 2003 shown in FIG. 2D are the same as those of the micro LED structure 2000 shown in FIG. 2A, and therefore the detailed description of these components will not be repeated.

[0058] Third embodiment 3A is a cross-sectional view of a micro LED structure 3000 according to a third embodiment of the present disclosure. The third embodiment shown in FIG. 3A differs from the first embodiment shown in FIG. 1A in that the bottom edge 102a of the second type of conductive layer 102 is not aligned with the top edge 101a of the first type of conductive layer 101. Instead, the contour of the first type of conductive layer 101 projected vertically onto the bottom surface 102b of the second type of conductive layer 102 is surrounded by the bottom edge 102a of the second type of conductive layer 102. The components of the micro LED structure 3000 of the third embodiment shown in FIG. 3A are the same as the components of the micro LED structure 1000 of the first embodiment shown in FIG. 1A, and therefore a detailed description of these components will not be repeated.

[0059] First modification of the third embodiment Figure 3B is a cross-sectional view of a micro LED structure 3001 according to a first variant of the third embodiment of the present disclosure. The embodiment shown in Figure 3B differs from the embodiment shown in Figure 3A in that the sidewall surface 101b of the first type of conductive layer 101 is curved and a reflective structure 1041 is formed on the sidewall surface 101b of the first type of conductive layer 101, having a curved surface 104a. Except for the reflective structure 104, the components of the micro LED structure 3001 shown in Figure 3B are the same as the components of the micro LED structure 3000 shown in Figure 3A, and therefore a detailed description of these components will not be repeated.

[0060] Second modification of the third embodiment 3C is a cross-sectional view of a micro LED structure 3002 according to a second variant of the third embodiment of the present disclosure. The embodiment shown in FIG. 3C differs from the embodiment shown in FIG. 3A in that a reflective structure 1042 is attached to the bottom surface 101c of the first type conductive layer 101. The reflective structure 1042 is electrically conductive. The bottom connection structure 105 is formed on the bottom of the reflective structure 1042 and is electrically connected to the bottom of the reflective structure 1042. The reflective structure 1042 on the bottom surface 101c of the first type conductive layer 101 may be made of metal. Except for the reflective structure 1042, the components of the micro LED structure 3002 shown in FIG. 3C are the same as the components of the micro LED structure 3000 shown in FIG. 3A, and therefore a detailed description of these components will not be repeated.

[0061] Third modification of the third embodiment 3D is a cross-sectional view of a micro LED structure 3003 according to a third variant of the third embodiment of the present disclosure. The embodiment shown in FIG. 3D differs from the embodiment shown in FIG. 3A in that a reflective structure 1043 is attached to both the sidewall surface 101b and the bottom surface 101c of the first type conductive layer 101. The reflective structure 1043 is electrically conductive. The bottom connection structure 105 is formed on the bottom of the reflective structure 1043 and is electrically connected with the reflective structure 1043. Except for the reflective structure 1042, the components of the micro LED structure 3003 shown in FIG. 3D are the same as those of the micro LED structure 3000 shown in FIG. 3A, and therefore the detailed description of these components will not be repeated.

[0062] Fourth embodiment FIG. 4A is a cross-sectional view of a micro LED structure 4000 according to a fourth embodiment of the present disclosure. The fourth embodiment shown in FIG. 4A differs from the third embodiment shown in FIG. 3A in that the light emitting layer 103 extends horizontally away from the top edge 101a of the first type conductive layer 101, and the edge 103a of the light emitting layer 103 is aligned with the bottom edge 102a of the second type conductive layer 102. Furthermore, the micro LED structure 4000 further includes an upper isolation layer 114 surrounding the light emitting layer 103. The upper isolation layer 114 may be made of one or more electrically insulating dielectric materials, such as, for example, SiO2, Si3N4, Al2O3, TiO2, HfO2, AlN, and the like. The upper isolation layer 114 is configured to isolate the micro LED structure 4000 from adjacent micro LED structures (not shown). A microlens 111 is formed on the second type conductive layer 102 and the top surface 114a of the isolation layer 114. The components of the fourth embodiment micro LED structure 4000 shown in FIG. 4A are the same as the components of the first embodiment micro LED structure 3000 shown in FIG. 3A, and therefore detailed descriptions of these components will not be repeated.

[0063] First modification of the fourth embodiment Figure 4B is a cross-sectional view of a micro LED structure 4001 according to a first variant of the fourth embodiment of the present disclosure. The embodiment shown in Figure 4B differs from the embodiment shown in Figure 4A in that the sidewall surface 101b of the first type of conductive layer 101 is curved and a reflective structure 1041 is formed on the sidewall surface 101b of the first type of conductive layer 101, having a curved surface 104a. Except for the reflective structure 1041, the components of the micro LED structure 4001 shown in Figure 4B are the same as the components of the micro LED structure 4000 shown in Figure 4A, and therefore a detailed description of these components will not be repeated.

[0064] Second modification of the fourth embodiment FIG. 4C is a cross-sectional view of a micro LED structure 4002 according to a second variant of the fourth embodiment of the present disclosure. The embodiment shown in FIG. 4C differs from the embodiment shown in FIG. 4A in that a reflective structure 1042 is attached to the bottom surface 101c of the first type conductive layer 101. The reflective structure 1042 is electrically conductive. The bottom connection structure 105 is formed on the bottom of the reflective structure 1042 and is electrically connected to the bottom of the reflective structure 1042. The reflective structure 1042 on the bottom surface 101c of the first type conductive layer 101 may be made of metal. Except for the reflective structure 1042, the components of the micro LED structure 4002 shown in FIG. 4C are the same as the components of the micro LED structure 4000 shown in FIG. 4A, and therefore a detailed description of these components will not be repeated.

[0065] Third modification of the fourth embodiment FIG. 4D is a cross-sectional view of a micro LED structure 4003 according to a third variant of the fourth embodiment of the present disclosure. The embodiment shown in FIG. 4D differs from the embodiment shown in FIG. 4A in that a reflective structure 1043 is attached to both the sidewall surface 101b and the bottom surface 101c of the first type conductive layer 101. The reflective structure 1043 is electrically conductive. The bottom connection structure 105 is formed on the bottom of the reflective structure 1043 and is electrically connected with the reflective structure 1043. Except for the reflective structure 1042, the components of the micro LED structure 4003 shown in FIG. 4D are the same as those of the micro LED structure 4000 shown in FIG. 4A, and therefore the detailed description of these components will not be repeated.

[0066] Fifth embodiment FIG. 5A is a cross-sectional view of a micro LED structure 5000 according to a fifth embodiment of the present disclosure. The fifth embodiment shown in FIG. 5A differs from the second embodiment shown in FIG. 2A in that the light emitting layer 103 extends along a horizontal direction from the bottom edge 102a of the second type conductive layer 102, and the edge 103a of the light emitting layer 103 is aligned with the top edge 101a of the first type conductive layer 101. In addition, the micro LED structure 4000 further includes an upper isolation layer 114 surrounding the light emitting layer 103. The microlenses 111 are formed on the upper surface 114a of the second type conductive layer 102 and the isolation layer 114. The components of the micro LED structure 5000 of the fourth embodiment shown in FIG. 5A are the same as the components of the micro LED structure 2000 of the second embodiment shown in FIG. 2A, and therefore the detailed description of these components will not be repeated.

[0067] First modification of the fifth embodiment Figure 5B is a cross-sectional view of a micro LED structure 5001 according to a first variant of the fifth embodiment of the present disclosure. The embodiment shown in Figure 5B differs from the embodiment shown in Figure 5A in that the sidewall surface 101b of the first type of conductive layer 101 is curved and a reflective structure 1041 is formed on the sidewall surface 101b of the first type of conductive layer 101, having a curved surface 104a. Except for the reflective structure 1041, the components of the micro LED structure 5001 shown in Figure 5B are the same as the components of the micro LED structure 5000 shown in Figure 5A, and therefore a detailed description of these components will not be repeated.

[0068] Second modification of the fifth embodiment 5C is a cross-sectional view of a micro LED structure 5002 according to a second variant of the fifth embodiment of the present disclosure. The embodiment shown in FIG. 5C differs from the embodiment shown in FIG. 5A in that a reflective structure 1042 is attached to the bottom surface 101c of the first type of conductive layer 101. The reflective structure 1042 is electrically conductive. The bottom connection structure 105 is formed on the bottom of the reflective structure 1042 and is electrically connected to the bottom of the reflective structure 1042. The reflective structure 1042 on the bottom surface 101c of the first type of conductive layer 101 is made of metal. Except for the reflective structure 1042, the components of the micro LED structure 5002 shown in FIG. 5C are the same as the components of the micro LED structure 5000 shown in FIG. 5A, and therefore a detailed description of these components will not be repeated.

[0069] Third modification of the fifth embodiment 5D is a cross-sectional view of a micro LED structure 5003 according to a third variant of the fifth embodiment of the present disclosure. The embodiment shown in FIG. 5D differs from the embodiment shown in FIG. 5A in that a reflective structure 1043 is attached to both the sidewall surface 101b and the bottom surface 101c of the first type conductive layer 101. The reflective structure 1043 is electrically conductive. The bottom connection structure 105 is formed on the bottom of the reflective structure 1043 and is electrically connected with the reflective structure 1043. Except for the reflective structure 1042, the components of the micro LED structure 5003 shown in FIG. 5D are the same as those of the micro LED structure 5000 shown in FIG. 5A, and therefore the detailed description of these components will not be repeated.

[0070] Sixth embodiment 6A is a cross-sectional view of a micro LED chip 6000 according to a sixth embodiment of the present disclosure. The micro LED chip 6000 may include a plurality of micro LEDs. At least one of the micro LEDs included in the micro LED chip 6000 may have any one of the micro LED structures 1000, 1001, ..., 3003 described above.

[0071] In the embodiment shown in Figure 6A, the micro LED chip 6000 includes two micro LEDs 610 and 620. Each of the micro LEDs 610 and 620 includes the micro LED structure 1000 described in the first embodiment shown in Figure 1A. In the following description and in Figure 6A, the micro LEDs 610 and 620 in Figure 6A are also referred to as micro LEDs 610(1000) and 620(1000).

[0072] As shown in FIG. 6A , each of the micro LEDs 610 (1000) and 620 (1000) includes a first type of conductive layer 101, a second type of conductive layer 102 stacked on the first type of conductive layer 101, and a light emitting layer 103 formed between the first type of conductive layer 101 and the second type of conductive layer 102. The light emitting layer 103 is continuously formed over the entire micro LED chip 6000. The first and second micro LEDs 610 (1000) and 620 (1000) share the light emitting layer 103. The light-emitting layer 103 extends along a horizontal level away from the top edge 101a of the first type of conductive layer 101 and the bottom edge 102a of the second type of conductive layer 102 such that the edge 103a of the light-emitting layer 103 does not contact either the top edge 101a of the first type of conductive layer 101 or the bottom edge 102a of the second type of conductive layer 102. The bottom edge 102a of the second type of conductive layer 102 is aligned with the top edge 101a of the first type of conductive layer 101.

[0073] As shown in FIG. 6A, each of the micro LEDs 610 (1000) and 620 (1000) also includes a top spacer 107 formed on the top surface 103b of the light emitting layer 103 and a bottom spacer 108 formed on the bottom surface 103c of the light emitting layer 103. Both the top spacer 107 and the bottom spacer 108 are continuously formed over the entire micro LED chip 6000 and are shared by the first and second micro LEDs 610 (1000) and 620 (1000). The edge 107a of the top spacer 107 is aligned with the edge 103a of the light emitting layer 103. The edge 108a of the bottom spacer 108 is aligned with the edge 103a of the light emitting layer 103.

[0074] As shown in FIG. 6A , each of the micro-LEDs 610 (1000) and 620 (1000) also includes a reflective structure 104 surrounding the first type of conductive layer 101, a bottom connection structure 105 formed below the first type of conductive layer 101, connection pads 106 formed in the substrate 110, an isolation layer 109 surrounding the first type of conductive layer 101 and below the light-emitting layer 103, a substrate 110 below the first type of conductive layer 101 and electrically connected to the bottom connection structure 105 by the connection pads 106, and a microlens 111 formed on the second type of conductive layer 102 and the upper surface 107b of the upper spacer 107.

[0075] The components of the first and second micro LEDs 610 (1000) and 620 (1000) of the sixth embodiment shown in Figure 6A are the same as those of the micro LED structure 1000 of the first embodiment shown in Figure 1A, except for the light emitting layer 103, the top spacer 107, and the bottom spacer 108, which are continuously formed over the micro LED chip 6000 and shared by the first and second micro LEDs 610 (1000) and 620 (1000). Therefore, detailed descriptions of these components will not be repeated.

[0076] First modification of the sixth embodiment Figure 6B is a cross-sectional view of a micro LED chip 6001 according to a first variant of the sixth embodiment of the present disclosure. The first variant of the sixth embodiment shown in Figure 6B differs from the sixth embodiment shown in Figure 6A in that each of the micro LEDs 610 and 620 in the micro LED chip 6001 includes the micro LED structure 1001 described in the first variant of the first embodiment shown in Figure 1B. Thus, the micro LEDs 610 and 620 in Figure 6B are also referred to as micro LEDs 610(1001) and 620(1001).

[0077] More specifically, as shown in Figure 6B, the sidewall surface 101b of the first type conductive layer 101 is curved, and the reflective structure 1041 formed on the sidewall surface 101b of the first type conductive layer 101 has a curved surface 104a. Except for the reflective structure 1041, the components of the micro LED chip 6001 shown in Figure 6B are the same as the components of the micro LED chip 6000 shown in Figure 6A, and therefore detailed descriptions of these components will not be repeated.

[0078] Second modification of the sixth embodiment Figure 6C is a cross-sectional view of a micro LED chip 6002 according to a second variant of the sixth embodiment of the present disclosure. The second variant of the sixth embodiment shown in Figure 6C differs from the sixth embodiment shown in Figure 6A in that each of the micro LEDs 610 and 620 in the micro LED chip 6002 includes the micro LED structure 1002 described in the second variant of the first embodiment shown in Figure 1C. Thus, the micro LEDs 610 and 620 in Figure 6C are referred to as micro LEDs 610 (1002) and 620 (1002).

[0079] More specifically, as shown in FIG. 6C, the reflective structure 1042 is attached to the bottom surface 101c of the first type conductive layer 101. The reflective structure 1042 is conductive. The bottom connection structure 105 is formed on the bottom of the reflective structure 1042 and is electrically connected to the bottom of the reflective structure 1042. The reflective structure 1042 on the bottom surface 101c of the first type conductive layer 01 may be made of metal. Except for the reflective structure 1042, the components of the micro LED chip 6002 shown in FIG. 6C are the same as the components of the micro LED chip 6000 shown in FIG. 6A, and therefore the detailed description of these components will not be repeated.

[0080] Third modification of the sixth embodiment Figure 6D is a cross-sectional view of a micro LED chip 6003 according to a third variant of the sixth embodiment of the present disclosure. The embodiment shown in Figure 6D differs from the embodiment shown in Figure 6A in that each of the micro LEDs 610 and 620 in the micro LED chip 6003 includes a micro LED structure 1003 as described in the third variant of the first embodiment shown in Figure 1D. Thus, the micro LEDs 610 and 620 in Figure 6C are referred to as micro LEDs 610 (1003) and 620 (1003).

[0081] More specifically, as shown in Fig. 6D, the reflective structure 1043 is attached to both the sidewall surface 101b and the bottom surface 101c of the first type conductive layer 101. The reflective structure 1043 is electrically conductive. The bottom connection structure 105 is formed on the bottom of the reflective structure 1043 and is electrically connected with the reflective structure 1043. Except for the reflective structure 1043, the components of the micro LED chip 6003 shown in Fig. 6D are the same as the components of the micro LED chip 6000 shown in Fig. 6A, and therefore the detailed description of these components will not be repeated.

[0082] Fourth modification of the sixth embodiment Figure 6E is a cross-sectional view of a micro LED chip 6004 according to a fourth variant of the sixth embodiment of the present disclosure. The embodiment shown in Figure 6E differs from the embodiment shown in Figure 6A in that each of the micro LEDs 610 and 620 in the micro LED chip 6004 includes the micro LED structure 2000 described in the second embodiment shown in Figure 2A. Thus, the micro LEDs 610 and 620 in Figure 6E are referred to as micro LEDs 610(2000) and 620(2000).

[0083] More specifically, as shown in Figure 6E, the bottom edge 102a of the second type of conductive layer 102 is not aligned with the top edge 101a of the first type of conductive layer 101. Instead, the contour of the second type of conductive layer 102 vertically projected onto the top surface 101d of the first type of conductive layer 101 is surrounded by the top edge 101a of the first type of conductive layer 101. The components of the micro LED chip 6004 of the embodiment shown in Figure 6E are the same as the components of the micro LED chip 6000 of the embodiment shown in Figure 6A, and therefore a detailed description of these components will not be repeated.

[0084] In the embodiment shown in Figure 6E, each of the micro LEDs 610 and 620 in the micro LED chip 6004 includes a micro LED structure 2000 as described in the second embodiment shown in Figure 2A. Alternatively, in other embodiments, each of the micro LEDs 610 and 620 in the micro LED chip 6004 may include a micro LED structure 2001, 2002, or 2003 as described in the first, second, or third variant of the second embodiment shown in Figure 2B, Figure 2C, or Figure 2D, respectively.

[0085] Fifth modification of the sixth embodiment Figure 6F is a cross-sectional view of a micro LED chip 6005 according to a fifth variant of the sixth embodiment of the present disclosure. The embodiment shown in Figure 6F differs from the embodiment shown in Figure 6A in that each of the micro LEDs 610 and 620 in the micro LED chip 6005 includes a micro LED structure 3000 as described in the second embodiment shown in Figure 3A. Thus, the micro LEDs 610 and 620 in Figure 6F are referred to as micro LEDs 610 (3000) and 620 (3000).

[0086] More specifically, as shown in Figure 6F, the bottom edge 102a of the second type conductive layer 102 is not aligned with the top edge 101a of the first type conductive layer 101. Instead, the contour of the first type conductive layer 101 projected vertically onto the bottom surface 102b of the second type conductive layer 102 is surrounded by the bottom edge 102a of the second type conductive layer 102. The components of the micro LED chip 6005 of the embodiment shown in Figure 6F are the same as the components of the micro LED chip 6000 of the embodiment shown in Figure 6A, and therefore a detailed description of these components will not be repeated.

[0087] In the embodiment shown in Figure 6F, each of the micro LEDs 610 and 620 in the micro LED chip 6005 includes a micro LED structure 3000 as described in the third embodiment shown in Figure 3 A. Alternatively, in other embodiments, each of the micro LEDs 610 and 620 in the micro LED chip 6005 may include a micro LED structure 3001, 3002, or 3003 as described in the first, second, or third variant of the third embodiment shown in Figure 3B, Figure 3C, or Figure 3D, respectively.

[0088] Seventh embodiment 7 is a cross-sectional view of a micro LED chip 7000 according to a seventh embodiment of the present disclosure. The micro LED chip 7000 may include a plurality of micro LEDs. At least one of the micro LEDs included in the micro LED chip 7000 may have any one of the micro LED structures 1000, 1001, ..., 3003 described above.

[0089] The micro LED chip 7000 shown in FIG. 7 differs from the micro LED chip 6000 shown in FIG. 6A in that the micro LED chip 7000 further includes an isolation structure 112 formed between adjacent micro LEDs 610 (1000) and 620 (1000). The isolation structure 112 may be made of a light absorbing material, which may be a dielectric material, for example, including impurity-doped SiO2 or Si3N4. In other embodiments, the isolation structure 112 may be made of a reflective material, for example, a metal. The isolation structure 112 is configured to electrically isolate adjacent micro LEDs 610 (1000) and 620 (1000) from each other.

[0090] At least a portion of the isolation structure 112 is formed in the light emitting layer 103. In the embodiment shown in FIG. 7, the top surface 112a of the isolation structure 112 is aligned with the top surface 103b of the light emitting layer 103, and the bottom surface 112b of the isolation structure 112 is aligned with the bottom surface 103c of the light emitting layer 103. The isolation structure 112 may be formed to surround at least one of the micro-LEDs 610 (1000) and 620 (1000). Additionally or alternatively, at least a portion of the isolation structure 112 may be formed in the top spacer 107 or the bottom spacer 108.

[0091] Except for the separation structure, the components of the micro LED chip 7000 of the embodiment shown in FIG. 7 are the same as the components of the micro LED chip 6000 of the embodiment shown in FIG. 6A, and therefore detailed descriptions of these components will not be repeated.

[0092] Eighth embodiment 8A is a cross-sectional view of a micro LED chip 8000 according to an eighth embodiment of the present disclosure. The micro LED chip 8000 shown in FIG. 8A differs from the micro LED chip 7000 shown in FIG. 7 in that the bottom surface 112b of the isolation structure 112 is below the light emitting layer 103. More specifically, as shown in FIG. 8A, the bottom surface 112b of the isolation structure 112 is below the bottom surface 103c of the light emitting layer 103 and above the bottom surface 108b of the bottom spacer 108. Except for the isolation structure 112, the components of the micro LED chip 8000 shown in FIG. 8A are the same as the components of the micro LED chip 7000 shown in FIG. 7, and therefore the detailed description of these components will not be repeated.

[0093] First modification of the eighth embodiment Figure 8B is a cross-sectional view of a micro LED chip 8001 according to a first variant of the eighth embodiment of the present disclosure. The micro LED chip 8001 shown in Figure 8B differs from the micro LED chip 8000 shown in Figure 8A in that the bottom surface 112b of the isolation structure 112 is aligned with the bottom surface 108b of the bottom spacer 108. Except for the isolation structure 112, the components of the micro LED chip 8001 shown in Figure 8B are the same as the components of the micro LED chip 8000 shown in Figure 8A, and therefore detailed descriptions of these components will not be repeated.

[0094] Second modification of the eighth embodiment Figure 8C is a cross-sectional view of a micro LED chip 8002 according to a second variant of the eighth embodiment of the present disclosure. The micro LED chip 8002 shown in Figure 8C differs from the micro LED chip 8000 shown in Figure 8A in that the bottom surface 112b of the isolation structure 112 is below the bottom surface 108b of the bottom spacer 108 and is disposed on the isolation layer 109. Except for the isolation structure 112, the components of the micro LED chip 8002 shown in Figure 8C are the same as the components of the micro LED chip 8000 shown in Figure 8A, and therefore detailed descriptions of these components will not be repeated.

[0095] 8A-8C, the area of ​​the top surface 112a of the isolation structure 112 is equal to the area of ​​the bottom surface 112b of the isolation structure 112. Alternatively, in other embodiments, the area of ​​the top surface 112a of the isolation structure 112 may be greater than or less than the area of ​​the bottom surface 112b of the isolation structure 112. Further alternatively, in some embodiments, the cross-sectional area of ​​the isolation structure 112 at the interface between the light-emitting layer 103 and the bottom spacer 108, or at the bottom surface 108b of the bottom spacer 108, may be greater than the area of ​​the bottom surface 112b of the isolation structure 112.

[0096] Ninth embodiment 9A is a cross-sectional view of a micro LED chip 9000 according to a ninth embodiment of the present disclosure. The micro LED chip 9000 shown in FIG. 9A differs from the micro LED chip 7000 shown in FIG. 7 in that the top surface 112a of the isolation structure 112 is above the light emitting layer 103. More specifically, as shown in FIG. 9A, the top surface 112a of the isolation structure 112 is above the top surface 103b of the light emitting layer 103 and below the top surface 107b of the upper spacer 107. Except for the isolation structure 112, the components of the micro LED chip 9000 shown in FIG. 9A are the same as the components of the micro LED chip 7000 shown in FIG. 7, and therefore detailed descriptions of these components will not be repeated.

[0097] First modification of the ninth embodiment Figure 9B is a cross-sectional view of a micro LED chip 9001 according to a first variant of the ninth embodiment of the present disclosure. The micro LED chip 9001 shown in Figure 9B differs from the micro LED chip 9000 shown in Figure 9A in that the top surface 112a of the isolation structure 112 is aligned with the top surface 107b of the upper spacer 107. Except for the isolation structure 112, the components of the micro LED chip 9001 shown in Figure 9B are the same as the components of the micro LED chip 9000 shown in Figure 9A, and therefore detailed descriptions of these components will not be repeated.

[0098] Second modification of the ninth embodiment Figure 9C is a cross-sectional view of a micro LED chip 9002 according to a second variant of the ninth embodiment of the present disclosure. The micro LED chip 9002 shown in Figure 9C differs from the micro LED chip 9000 shown in Figure 9A in that the top surface 112a of the isolation structure 112 is above the top surface 107b of the upper spacer 107 and between adjacent second type conductive layers 102. Except for the isolation structure 112, the components of the micro LED chip 9002 shown in Figure 9C are the same as the components of the micro LED chip 9000 shown in Figure 9A, and therefore detailed descriptions of these components will not be repeated.

[0099] 9A-9C, the area of ​​the top surface 112a of the isolation structure 112 is equal to the area of ​​the bottom surface 112b of the isolation structure 112. Alternatively, in other embodiments, the area of ​​the top surface 112a of the isolation structure 112 may be greater than or less than the area of ​​the bottom surface 112b of the isolation structure 112. Further alternatively, in some embodiments, the cross-sectional area of ​​the isolation structure 112 at the top surface 103b of the light-emitting layer 103 or at the top surface 107b of the upper spacer 107 may be greater than the area of ​​the bottom surface 112b of the isolation structure 112.

[0100] Tenth embodiment 10A is a cross-sectional view of a micro LED chip 10000 according to a tenth embodiment of the present disclosure. The micro LED chip 10000 shown in FIG. 10A differs from the micro LED chip 7000 shown in FIG. 7 in that the top surface 112a of the isolation structure 112 is above the light emitting layer 103, and the bottom surface 112b of the isolation structure 112 is below the light emitting layer 103. More specifically, as shown in FIG. 10A, the top surface 112a of the isolation structure 112 is above the top surface 103b of the light emitting layer 103 and below the top surface 107b of the top spacer 107, and the bottom surface 112b of the isolation structure 112 is below the bottom surface 103c of the light emitting layer 103 and above the bottom surface 108b of the bottom spacer 108. Except for the isolation structure 112, the components of the micro LED chip 10000 shown in FIG. 10A are the same as the components of the micro LED chip 7000 shown in FIG. 7, and therefore detailed descriptions of these components will not be repeated.

[0101] First modification of the tenth embodiment Figure 10B is a cross-sectional view of a micro LED chip 10001 according to a first variant of the tenth embodiment of the present disclosure. The micro LED chip 10001 shown in Figure 10B differs from the micro LED chip 10000 shown in Figure 10A in that the bottom surface 112b of the isolation structure 112 is aligned with the bottom surface 108b of the bottom spacer 108. Except for the isolation structure 112, the components of the micro LED chip 10001 shown in Figure 10B are the same as the components of the micro LED chip 10000 shown in Figure 10A, and therefore detailed descriptions of these components will not be repeated.

[0102] Second modification of the tenth embodiment Figure 10C is a cross-sectional view of a micro LED chip 10002 according to a second variant of the tenth embodiment of the present disclosure. The micro LED chip 10002 shown in Figure 10C differs from the micro LED chip 10000 shown in Figure 10A in that the bottom surface 112b of the isolation structure 112 is below the bottom surface 108b of the bottom spacer 108 and is disposed on the isolation layer 109. Except for the isolation structure 112, the components of the micro LED chip 10002 shown in Figure 10C are the same as the components of the micro LED chip 10000 shown in Figure 10A, and therefore detailed descriptions of these components will not be repeated.

[0103] 10A-10C, the area of ​​the top surface 112a of the isolation structure 112 is equal to the area of ​​the bottom surface 112b of the isolation structure 112. Alternatively, in other embodiments, the area of ​​the top surface 112a of the isolation structure 112 may be greater than or less than the area of ​​the bottom surface 112b of the isolation structure 112. Further alternatively, in some embodiments, the cross-sectional area of ​​the isolation structure 112 at the bottom surface 103c of the light-emitting layer 103 or at the bottom surface 108b of the bottom spacer 108 may be greater than the area of ​​the bottom surface 112b of the isolation structure 112.

[0104] Eleventh embodiment 11A is a cross-sectional view of a micro LED chip 11000 according to an eleventh embodiment of the present disclosure. The micro LED chip 11000 shown in FIG. 11A differs from the micro LED chip 7000 shown in FIG. 7 in that the top surface 112a of the isolation structure 112 is aligned with the top surface 107b of the top spacer 107, and the bottom surface 112b of the isolation structure 112 is below the light emitting layer 103. More specifically, in the embodiment shown in FIG. 11A, the bottom surface 112b of the isolation structure 112 is below the bottom surface 103c of the light emitting layer 103 and above the bottom surface 108b of the bottom spacer 108. Except for the isolation structure 112, the components of the micro LED chip 11000 shown in FIG. 11A are the same as the components of the micro LED chip 7000 shown in FIG. 7, and therefore detailed descriptions of these components will not be repeated.

[0105] First modification of the eleventh embodiment Figure 11B is a cross-sectional view of a micro LED chip 11001 according to a first variant of the eleventh embodiment of the present disclosure. The micro LED chip 11001 shown in Figure 11B differs from the micro LED chip 11000 shown in Figure 11A in that the bottom surface 112b of the isolation structure 112 is aligned with the bottom surface 108b of the bottom spacer 108. Except for the isolation structure 112, the components of the micro LED chip 11001 shown in Figure 11A are the same as the components of the micro LED chip 11000 shown in Figure 11A, and therefore detailed descriptions of these components will not be repeated.

[0106] Second modification of the eleventh embodiment 11C is a cross-sectional view of a micro LED chip 11002 according to a second variant of the eleventh embodiment of the present disclosure. The micro LED chip 11002 shown in FIG. 11C differs from the micro LED chip 11000 shown in FIG. 11A in that the bottom surface 112b of the isolation structure 112 is below the bottom surface 108b of the bottom spacer 108 and is disposed on the isolation layer 109. Except for the isolation structure 112, the components of the micro LED chip 11002 shown in FIG. 11C are the same as the components of the micro LED chip 11000 shown in FIG. 11A, and therefore detailed descriptions of these components will not be repeated.

[0107] 11A-11C, the area of ​​the top surface 112a of the isolation structure 112 is equal to the area of ​​the bottom surface 112b of the isolation structure 112. Alternatively, in other embodiments, the area of ​​the top surface 112a of the isolation structure 112 may be greater than or less than the area of ​​the bottom surface 112b of the isolation structure 112. Further alternatively, in some embodiments, the cross-sectional area of ​​the isolation structure 112 at the bottom surface 103c of the light-emitting layer 103 or at the bottom surface 108b of the bottom spacer 108 may be greater than the area of ​​the bottom surface 112b of the isolation structure 112.

[0108] Third modification of the eleventh embodiment Figure 11D is a cross-sectional view of a micro LED chip 11003 according to a third variant of the eleventh embodiment of the present disclosure. The micro LED chip 11003 shown in Figure 11D differs from the micro LED chip 11001 shown in Figure 11B in that the area of ​​the top surface 112a of the isolation structure 112 is larger than the area of ​​the bottom surface 112b of the isolation structure 112. Except for the isolation structure 112, the components of the micro LED chip 11003 shown in Figure 11D are the same as the components of the micro LED chip 11001 shown in Figure 11B, and therefore detailed descriptions of these components will not be repeated.

[0109] Twelfth embodiment 12A is a cross-sectional view of a micro LED chip 12000 according to a twelfth embodiment of the present disclosure. The micro LED chip 12000 shown in FIG. 12A differs from the micro LED chip 7000 shown in FIG. 7 in that the top surface 112a of the isolation structure 112 is above the top surface 107b of the top spacer 107 and between adjacent second type conductive layers 102, and the bottom surface 112b of the isolation structure 112 is below the light emitting layer 103. More specifically, in the embodiment shown in FIG. 12A, the bottom surface 112b of the isolation structure 112 is below the bottom surface 103c of the light emitting layer 103 and above the bottom surface 108b of the bottom spacer 108. Except for the isolation structure 112, the components of the micro LED chip 12000 shown in FIG. 12A are the same as the components of the micro LED chip 7000 shown in FIG. 7, and therefore detailed descriptions of these components will not be repeated.

[0110] First modification of the twelfth embodiment Figure 12B is a cross-sectional view of a micro LED chip 12001 according to a first variant of the twelfth embodiment of the present disclosure. The micro LED chip 12001 shown in Figure 12B differs from the micro LED chip 12000 shown in Figure 12A in that the bottom surface 112b of the isolation structure 112 is aligned with the bottom surface 108b of the bottom spacer 108. Except for the isolation structure 112, the components of the micro LED chip 12001 shown in Figure 12B are the same as the components of the micro LED chip 12000 shown in Figure 12A, and therefore detailed descriptions of these components will not be repeated.

[0111] Second modification of the twelfth embodiment Figure 12C is a cross-sectional view of a micro LED chip 12002 according to a second variant of the twelfth embodiment of the present disclosure. The micro LED chip 12002 shown in Figure 12C differs from the micro LED chip 12000 shown in Figure 12A in that the bottom surface 112b of the isolation structure 112 is below the bottom surface 108b of the bottom spacer 108 and is disposed on the isolation layer 109. Except for the isolation structure 112, the components of the micro LED chip 12002 shown in Figure 12C are the same as the components of the micro LED chip 12000 shown in Figure 12A, and therefore detailed descriptions of these components will not be repeated.

[0112] Third modification of the twelfth embodiment Figure 12D is a cross-sectional view of a micro LED chip 12003 according to a third variant of the twelfth embodiment of the present disclosure. The micro LED chip 12003 shown in Figure 12D differs from the micro LED chip 12002 shown in Figure 12C in that the area of ​​the top surface 112a of the isolation structure 112 is smaller than the area of ​​the bottom surface 112b of the isolation structure 112, and the cross-sectional area 112c of the isolation structure 112 at the bottom surface 103c of the light emitting layer 103 is larger than the area of ​​the bottom surface 112b of the isolation structure 112. Except for the isolation structure 112, the components of the micro LED chip 12003 shown in Figure 12D are the same as the components of the micro LED chip 12002 shown in Figure 12C, and therefore the detailed description of these components will not be repeated.

[0113] Thirteenth embodiment 13A is a cross-sectional view of a micro LED chip 13000 according to a thirteenth embodiment of the present disclosure. The micro LED chip 13000 may include a plurality of micro LEDs. At least one of the micro LEDs included in the micro LED chip 13000 may have any one of the micro LED structures 1000, 1001, ..., 3003 described above.

[0114] The micro LED chip 13000 shown in FIG. 13A differs from the micro LED chip 6000 shown in FIG. 6A in that the micro LED chip 13000 further includes a metal layer 113 formed on the light emitting layer 103 between adjacent micro LEDs 610 (1000) and 620 (1000). The metal layer 113 is formed on the top surface 103b of the light emitting layer 103 and does not contact either the first type conductive layer 101 or the second type conductive layer 102. More specifically, in the embodiment shown in FIG. 13A, a top spacer 107 is formed on the top of the light emitting layer 103, and a metal layer 113 is formed on the top surface 107b of the top spacer 107.

[0115] The lateral dimension d1 of the metal layer 113 is equal to or less than the distance d2 between the edge 103a of the light emitting layer 103 and the top edge 101a of the first type conductive layer 101, or the lateral dimension d1 of the metal layer 113 is equal to or less than the distance d3 between the edge 103a of the light emitting layer 103 and the bottom edge 102a of the second type conductive layer 102. The lateral dimension d1 of the metal layer 113 may be from about 2 nm to about 10 μm.

[0116] In some embodiments, the center point of the metal layer 113 may be aligned with the center point between adjacent micro LEDs 610 (1000) and 620 (1000). Alternatively, in some embodiments, the center point of the metal layer 113 is closer to one of the adjacent micro LEDs 610 (1000) and 620 (1000) than to the other of the micro LEDs 610 (1000) and 620 (1000).

[0117] Metal layer 113 may include a high work function metallic material having a work function that matches the work function of the material of light emitting layer 103. The high work function metallic material may include at least one of gold, platinum, palladium, beryllium, cobalt, nickel, or tungsten.

[0118] Modification of the thirteenth embodiment 13B is a cross-sectional view of a micro LED chip 13001 according to a variation of the thirteenth embodiment of the present disclosure. The micro LED chip 13001 shown in FIG. 13B differs from the micro LED chip 13000 shown in FIG. 13A in that the micro LED chip 13001 includes a plurality of metal layers 113 formed on the top surface 107b of the upper spacer 107 and between adjacent micro LEDs 610 (1000) and 620 (1000). The metal layers 113 are arranged in parallel along the top surface 103b of the light emitting layer 103.

[0119] 13B, there are three metal layers 113. In other embodiments, the number of metal layers 113 may be greater than three.

[0120] In the embodiment shown in Figures 13A and 13B, each of the micro LEDs 610 and 620 includes a micro LED structure 1000 as described in the first embodiment shown in Figure 1A. Alternatively, in other embodiments, each of the micro LEDs 610 and 620 may include any one of the micro LED structures 1001, 1002, and 1003 as described in the first, second, and third variants of the first embodiment shown in Figures 1B, 1C, and 1D, respectively.

[0121] Fourteenth embodiment Figure 14A is a cross-sectional view of a micro LED chip 14000 according to a fourteenth embodiment of the present disclosure. The embodiment shown in Figure 14A differs from the embodiment shown in Figure 13A in that the micro LED chip 14000 includes two micro LEDs 610 (2000) and 620 (2000), each of which includes a micro LED structure 2000 as described in the second embodiment shown in Figure 2A. Other components of the micro LED chip 14000 of the embodiment shown in Figure 14A are the same as those of the micro LED chip 13000 of the embodiment shown in Figure 13A, and therefore detailed descriptions of these components will not be repeated.

[0122] Modification of the fourteenth embodiment Figure 14B is a cross-sectional view of a micro LED chip 14001 according to a variation of the fourteenth embodiment of the present disclosure. The micro LED chip 14001 shown in Figure 14B differs from the micro LED chip 14000 shown in Figure 14A in that the micro LED chip 14001 includes a plurality of metal layers 113 formed on the top surface 107b of the top spacer 107 and between adjacent micro LEDs 610 (2000) and 620 (2000). Other components of the micro LED chip 14001 of the embodiment shown in Figure 14B are the same as those of the micro LED chip 13000 of the embodiment shown in Figure 13A, and therefore detailed descriptions of these components will not be repeated.

[0123] In the embodiment shown in Figures 14A and 14B, each of the micro LEDs 610 and 620 includes the micro LED structure 2000 described in the second embodiment shown in Figure 2A. Alternatively, in other embodiments, each of the micro LEDs 610 and 620 may include any one of the micro LED structures 2001, 2002, and 2003 described in the first, second, and third variants of the second embodiment shown in Figures 2B, 2C, and 2D, respectively.

[0124] Fifteenth embodiment Figure 15A is a cross-sectional view of a micro LED chip 15000 according to a fifteenth embodiment of the present disclosure. The embodiment shown in Figure 15A differs from the embodiment shown in Figure 13A in that the micro LED chip 15000 includes two micro LEDs 610 (3000) and 620 (3000), each of which includes a micro LED structure 3000 as described in the second embodiment shown in Figure 3A. Other components of the micro LED chip 15000 of the embodiment shown in Figure 15A are the same as those of the micro LED chip 13000 of the embodiment shown in Figure 13A, and therefore detailed descriptions of these components will not be repeated.

[0125] Modification of the fifteenth embodiment Figure 15B is a cross-sectional view of a micro LED chip 15001 according to a variation of the fifteenth embodiment of the present disclosure. The micro LED chip 15001 shown in Figure 15B differs from the micro LED chip 15000 shown in Figure 15A in that the micro LED chip 15001 includes a plurality of metal layers 113 formed on the top surface 107b of the top spacer 107 and between adjacent micro LEDs 610 (3000) and 620 (3000). The components of the micro LED chip 15001 of the embodiment shown in Figure 15B are the same as the components of the micro LED chip 13000 of the embodiment shown in Figure 13A, and therefore detailed descriptions of these components will not be repeated.

[0126] In the embodiment shown in Figures 15A and 15B, each of the micro LEDs 610 and 620 includes the micro LED structure 3000 described in the third embodiment shown in Figure 3A. Alternatively, in other embodiments, each of the micro LEDs 610 and 620 may include any one of the micro LED structures 3001, 3002, and 3003 described in the first, second, and third variants of the third embodiment shown in Figures 3B, 3C, and 3D, respectively.

[0127] Sixteenth embodiment 16A is a cross-sectional view of a micro LED chip 16000 according to a sixteenth embodiment of the present disclosure. The micro LED chip 16000 may include a plurality of micro LEDs. At least one of the micro LEDs included in the micro LED chip 16000 may have any one of the micro LED structures 4000, 4001, ..., 5003 described above.

[0128] In the embodiment shown in Figure 16A, the micro LED chip 16000 includes two micro LEDs 610 (4000) and 620 (4000). Each of the micro LEDs 610 (4000) and 620 (4000) includes a micro LED structure 4000 as described in the fourth embodiment shown in Figure 4A.

[0129] As shown in FIG. 16A, each of the micro LEDs 610 (4000) and 620 (4000) includes a first type of conductive layer 101, a second type of conductive layer 102 stacked on the first type of conductive layer 101, and a light-emitting layer 103 formed between the first type of conductive layer 101 and the second type of conductive layer 102. The outline of the first type of conductive layer 101 projected vertically onto the bottom surface 102b of the second type of conductive layer 102 is surrounded by the bottom edge 102a of the second type of conductive layer 102. The light-emitting layer 103 extends along a horizontal level away from the top edge 101a of the first type of conductive layer 101, and the edge 103a of the light-emitting layer 103 is aligned with the bottom edge 102a of the second type of conductive layer 102.

[0130] Each of the micro LEDs 610 (4000) and 620 (4000) further includes a top spacer 107 formed above the light emitting layer 103 and a bottom spacer formed below the light emitting layer 103. The edge 107a of the top spacer 107 and the edge 108a of the bottom spacer 108 are both aligned with the edge 103a of the light emitting layer 103, which is aligned with the bottom edge 102a of the second type conductive layer 102.

[0131] The micro LED chip 16000 further includes an upper isolation layer 114 surrounding the light emitting layer 103, and a microlens 111 formed on the second type conductive layer 102 and the upper surface 114a of the isolation layer 114.

[0132] Except for the edges 103a of the light emitting layer 103, the edges 107a of the top spacer 107, and the edges 108a of the bottom spacer 108 being aligned with the bottom edges 102a of the second type of conductive layer 102, the components of the micro LED chip 16000 shown in FIG. 16A are the same as the components of the micro LED chip 6005 shown in FIG. 6F, and therefore detailed descriptions of these components will not be repeated.

[0133] Modification of the sixteenth embodiment FIG. 16B is a cross-sectional view of a micro LED chip 16001 according to a variation of the sixteenth embodiment of the present disclosure. The embodiment shown in FIG. 16B differs from the embodiment shown in FIG. 16A in that the micro LED chip 16001 further includes a metal layer 113 formed on the top surface 114a of the separation layer 114 and between adjacent micro LEDs 610 (4000) and 620 (4000). In the embodiment shown in FIG. 16B, there is only one metal layer 113 between the micro LEDs 610 (4000) and 620 (4000). Alternatively, in other embodiments, there are multiple metal layers 113 between the micro LEDs 610 (4000) and 620 (4000), and the number of multiple metal layers 113 between the micro LEDs 610 (4000) and 620 (4000) may be three or more. Except for the metal layer 113, the components of the micro LED chip 16001 shown in FIG. 16B are the same as the components of the micro LED chip 16000 shown in FIG. 16A, and therefore detailed descriptions of these components will not be repeated.

[0134] In the embodiment shown in Figures 16A and 16B, each of the micro LEDs 610 and 620 includes the micro LED structure 4000 described in the fourth embodiment shown in Figure 4A. Alternatively, in other embodiments, each of the micro LEDs 610 and 620 may include any one of the micro LED structures 4001, 4002, and 4003 described in the first, second, and third variants of the fourth embodiment shown in Figures 4B, 4C, and 4D, respectively.

[0135] Seventeenth embodiment 17A is a cross-sectional view of a micro LED chip 17000 according to a seventeenth embodiment of the present disclosure. The micro LED chip 17000 includes two micro LEDs 610 (5000) and 620 (5000). Each of the micro LEDs 610 (5000) and 620 (5000) includes a micro LED structure 5000 as described in the fifth embodiment shown in FIG. 5A.

[0136] The micro LED chip 17000 differs from the micro LED chip 16000 in that the contour of the second type of conductive layer 102 projected vertically onto the top surface 101d of the first type of conductive layer 101 is surrounded by the top edge 101a of the first type of conductive layer 101. Furthermore, the edge 103a of the light emitting layer 103, the edge 107a of the top spacer 107, and the edge 108a of the bottom spacer 108 are aligned with the top edge 101a of the first type of conductive layer 101.

[0137] In addition, the micro LED chip 17000 further includes an upper isolation layer 114 surrounding the light emitting layer 103. The microlenses 111 are formed on the second type conductive layer 102 and the upper surface 114a of the isolation layer 114. Other components of the micro LED chip 17000 of the fourth embodiment shown in Figure 17A are the same as those of the micro LED chip 16000 of the second embodiment shown in Figure 16A, and therefore detailed descriptions of these components will not be repeated.

[0138] Modification of the seventeenth embodiment FIG. 17B is a cross-sectional view of a micro LED chip 17001 according to a variation of the seventeenth embodiment of the present disclosure. The embodiment shown in FIG. 17B differs from the embodiment shown in FIG. 17A in that the micro LED chip 17001 further includes a metal layer 113 formed on the top surface 114a of the separation layer 114 and between adjacent micro LEDs 610 (5000) and 620 (5000). In the embodiment shown in FIG. 17B, there is only one metal layer 113 between the micro LEDs 610 (5000) and 620 (5000). Alternatively, in other embodiments, there are multiple metal layers 113 between the micro LEDs 610 (5000) and 620 (5000), and the number of multiple metal layers 113 between the micro LEDs 610 (4000) and 620 (4000) may be three or more. Except for the metal layer 113, the components of the micro LED chip 17001 shown in FIG. 17B are the same as the components of the micro LED chip 17000 shown in FIG. 17A, and therefore detailed descriptions of these components will not be repeated.

[0139] In the embodiment shown in Figures 17A and 17B, each of the micro LEDs 610 and 620 includes a micro LED structure 5000 as described in the fifth embodiment shown in Figure 5 A. Alternatively, in other embodiments, each of the micro LEDs 610 and 620 may include any one of the micro LED structures 5001, 5002, and 5003 as described in the first, second, and third variants of the fifth embodiment shown in Figures 5B, 5C, and 5D, respectively.

[0140] Comparative Example Figure 18 is a cross-sectional view of a micro LED structure 1 according to a comparative example. The comparative micro LED structure 1 shown in Figure 18 differs from the first embodiment micro LED structure 1000 shown in Figure 1A in that the light emitting layer 103 does not extend along a horizontal level away from the top edge 101a of the first type of conductive layer 101 and the bottom edge 102a of the second type of conductive layer 102. Instead, in the comparative example, the edge 103a of the light emitting layer 103 is aligned with both the top edge 101a of the first type of conductive layer 101 and the bottom edge 102a of the second type of conductive layer 102.

[0141] As mentioned above, light emitting layer 103 can include multiple pairs of quantum well layers. The number of multiple quantum well (MQW) pairs in light emitting layer 103 is related to the exposed sidewall area of ​​light emitting layer 103, which is created, for example, by inductively coupled plasma etching. The more exposed sidewall area, the more MQW pairs there are and the greater the surface recombination carrier loss.

[0142] In the comparative example, the sidewalls of the light emitting layer 103 are aligned with the edges 101a and 102a of the first type conductive layer 101 and the second type conductive layer 102. As a result, large surface recombination carrier losses occur in the micro LED between the first type conductive layer 101 and the second type conductive layer 102, which may adversely affect the light emitting efficiency of the micro LED.

[0143] In contrast, in the first embodiment and other embodiments of the present disclosure, the light emitting layer 103 extends away from the top edge 101a of the first type conductive layer 101 and the bottom edge 102a of the second type conductive layer 102 such that the edge 103a of the light emitting layer 103 does not contact either the top edge 101a of the first type conductive layer 101 or the bottom edge 102a of the second type conductive layer 102. As a result, no surface recombination carrier loss can occur in the micro LED between the first type conductive layer 101 and the second type conductive layer 102. This improves the light emitting efficiency of the micro LED.

[0144] Although exemplary embodiments have been described herein, the scope of the disclosure encompasses any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and / or alterations as would be understood by one of ordinary skill in the art based on this disclosure. For example, features included in different embodiments shown in different figures can be combined. Any limitations in the claims should be interpreted broadly based on the language used in the claims, and not limited to the examples described in this specification or during prosecution of the application. The examples should be construed as non-exclusive. It is therefore intended that the specification and examples be considered as exemplary only, with a true scope and spirit being indicated by the full scope of the appended claims and their equivalents.

Claims

1. a first type of conductive layer; and a second type of conductive layer laminated on the first type of conductive layer; a light-emitting layer formed between the first type conductive layer and the second type conductive layer; the light emitting layer extends along a horizontal level away from a top edge of the first type of conductive layer and a bottom edge of the second type of conductive layer such that an edge of the light emitting layer does not contact either the top edge of the first type of conductive layer or the bottom edge of the second type of conductive layer; the bottom edge of the second type of conductive layer is aligned with the top edge of the first type of conductive layer.

2. an upper spacer formed on an upper surface of the light emitting layer; a bottom spacer formed on a bottom surface of the light emitting layer; an edge of the top spacer aligned with the edge of the light emitting layer; and an edge of the bottom spacer aligned with the edge of the light emitting layer; 10. The micro LED structure of claim 1 .

3. 3. The micro LED structure of claim 2, further comprising a microlens formed on a top surface of the second type conductive layer and the top spacer.

4. 3. The micro LED structure of claim 2, wherein a thickness of the top spacer is greater than a thickness of the light emitting layer and a thickness of the bottom spacer is greater than the thickness of the light emitting layer.

5. 10. The micro LED structure of claim 1, wherein a top area of ​​the first type of conductive layer is larger than a bottom area of ​​the first type of conductive layer and a top area of ​​the second type of conductive layer is smaller than a bottom area of ​​the second type of conductive layer.

6. 10. The micro LED structure of claim 1, wherein the light emitting layer comprises only one pair of quantum well layers or multiple pairs of quantum well layers.

7. 10. The micro LED structure of claim 1 further comprising a reflective structure surrounding the first type conductive layer.

8. the reflective structure is attached to a sidewall surface of the first type conductive layer; and 7. The micro LED structure of claim 6, further comprising a bottom connection structure formed below and electrically connected to the first type conductive layer.

9. 10. The micro LED structure of claim 8, further comprising a substrate underlying the first type conductive layer, the substrate being electrically connected to the bottom connection structure by a connection pad within the substrate.

10. 10. The micro LED structure of claim 9, wherein the substrate comprises an IC circuit.

11. 10. The micro LED structure of claim 9, wherein the reflective structures on the sidewalls of the first type conductive layer are inclined with respect to a surface of the substrate, the inclination angle of the reflective structures being between about 30° and about 75° with respect to the surface of the substrate.

12. 10. The micro LED structure of claim 8, wherein the bottom connection structure is made of a reflective and conductive material.

13. 10. The micro LED structure of claim 8, wherein the reflective structure on the sidewall of the first type conductive layer has a curved surface.

14. 9. The micro LED structure of claim 8, wherein the reflective structure on the sidewalls of the first type of conductive layer is made of an ODR (Omnidirectional Reflector) structure or a DBR (Distributed Bragg Reflector) structure.

15. 8. The micro LED structure of claim 7, wherein the reflective structure is attached to both a sidewall surface and a bottom surface of the first type conductive layer.

16. the reflective structure on the bottom surface of the first type conductive layer is conductive; and 16. The micro LED structure of claim 15, further comprising a bottom connection structure formed on the bottom of the reflective structure and electrically connected to the reflective structure.

17. 8. The micro LED structure of claim 7, wherein the reflective structure is configured to focus light onto the second type conductive layer.

18. a reflecting structure attached to the bottom surface of the first type conductive layer; 10. The micro LED structure of claim 1 further comprising:

19. the reflective structure is electrically conductive; and The micro LED structure further comprises a bottom connection structure formed on a bottom of the reflective structure and electrically connected to the reflective structure.

20. The micro LED structure of claim 18.

20. 10. The micro LED structure of claim 1, further comprising an isolation layer surrounding the first type conductive layer and underlying the light emitting layer, the isolation layer being made of a light absorbing material.

Images