LIGHT-EMITTING DEVICES WITH THROUGH-SUBSTRATE VIA CONNECTIONS
Multiple through-substrate vias (TSVs) are used to make electrical connections for an LED formed over a substrate. A first TSV extends through the substrate from a back surface of the substrate to the front surface of the substrate and includes a first TSV conductor that electrically connects to a first cladding layer of the LED. A second TSV extends through the substrate and an active layer of the LED from the back surface of the substrate to a second cladding layer or an ITO layer. The second TSV includes an isolation layer that electrically isolates a second TSV conductor from the first cladding layer and the active layer. Additionally dummy TSVs may be formed to conduct heat away from the LED optionally through a package substrate.
1 . A light-emitting device, comprising:
a first semiconductor layer;
a second semiconductor layer;
a light-emitting layer sandwiched by the first semiconductor layer and the second semiconductor layer
a first via penetrating the first semiconductor layer, the second semiconductor layer and the light-emitting layer, and electrically connected to the first semiconductor layer;
a first isolation layer penetrating the first semiconductor layer, the second semiconductor layer and the light-emitting layer; and
a second via electrically separated from the first semiconductor, the second semiconductor layer and the light-emitting layer by the first isolation layer.
2 . The light-emitting device of claim 1 , further comprising:
a third via electrically connected to the second semiconductor layer;
a second isolation layer connected to the second semiconductor layer; and
a fourth via electrically separated from the first semiconductor layer by the first isolation layer.
3 . The light-emitting device of claim 2 , wherein the second via and the fourth via have different lengths.
4 . The light-emitting device of claim 2 , wherein the second via and the fourth via reach to different depths from the first semiconductor layer.
5 . The light-emitting device of claim 1 , wherein the first via and the second via substantially reach to a same depth from the first semiconductor layer.
6 . A light-emitting device, comprising:
a first semiconductor layer;
a light-emitting layer formed on the first semiconductor layer;
a second semiconductor layer formed on the light-emitting layer;
a shorter via electrically separated from the first semiconductor layer, the second semiconductor layer and the light-emitting layer; and
a longer via penetrating the first semiconductor layer, the second semiconductor layer and the light-emitting layer without directly connected to the first semiconductor layer and the light-emitting layer.
7 . The light-emitting device of claim 6 , further comprising a shorter isolation layer surrounding the shorter via and exposing only one end portion of the shorter via.
8 . The light-emitting device of claim 6 , further comprising a longer isolation layer surrounding the longer via and exposing at least two end portions of the longer via.
9 . The light-emitting device of claim 6 , wherein the shorter via and the longer via are substantially coplanar with each other at one side of the light-emitting device.