Optoelectronic component with ESD protection
View Patent ↗The invention relates to an optoelectronic component ( 100 ) comprising a semiconductor layer sequence ( 1 ) having an active layer ( 10 ), wherein the active layer ( 10 ) is designed to produce or absorb electromagnetic radiation in intended operation. Furthermore, the component ( 100 ) comprises a first contact structure ( 11 ) and a second structure ( 12 ), by means of which the semiconductor layer sequence ( 1 ) can be electrically contacted in intended operation. In operation, a voltage is applied to the contact structures ( 11, 12 ), wherein an operation-related voltage difference ΔUbet between the contact structures ( 11, 12 ) arises. When the voltage difference is increased, a first arc-over occurs in or on the component ( 100 ) between the two contact structures ( 11, 12 ). A spark gap ( 3 ) between the contact structures ( 11, 12 ), which arises in the event of the first arc-over, passes predominantly through a surrounding medium in the form of gas or vacuum and/or through a potting. The first arc-over occurs at a voltage difference of 2·ΔUbet at the earliest.
1. An optoelectronic component, comprising:
a semiconductor layer sequence with an active layer, wherein the active layer is set up to generate or absorb electromagnetic radiation during normal operation,
a first contact structure and a second contact structure via which the semiconductor layer sequence is electrically contacted during normal operation, wherein
during operation, the contact structures are subjected to a voltage and an operational voltage difference ΔU bet between the contact structures occurs,
a first electrical flashover is formed in or on the component between the two contact structures when the voltage difference is increased,
a spark gap produced between the contact structures during the first flashover runs predominantly through a surrounding medium in the form of gas or vacuum and/or through a potting around the component,
the first flashover occurs at the earliest at a voltage difference of 2·ΔU bet , wherein
an ESD protection circuit of the optoelectronic component is realized by the two contact structures, and
the first electrical flashover occurs at the earliest at a voltage difference of 3 V and at the latest at a voltage difference of 80 V.
2. An optoelectronic component according to claim 1 , wherein
the contact structures adjoin at least in some regions directly to the surrounding medium and/or the potting,
the spark gap between the contact structures exclusively runs through the surrounding medium and/or the potting.
3. The optoelectronic component according to claim 1 , wherein
a passivation layer is at least partially arranged between the contact structures and the surrounding medium,
the spark gap between the contact structures passes through the passivation layer and runs to at least 90% through the surrounding medium and/or the potting.
4. Optoelectronic component according to claim 1 , wherein in the region of the forming spark gap the minimum distance between the two contact structures is at most 50 μm.
5. Optoelectronic component according to claim 1 , wherein the contact structures each have a tip or edge and the spark gap is formed between the tips or edges.
6. Optoelectronic component according to claim 1 , wherein
the contact structures are in direct contact with semiconductor layers of the semiconductor layer sequence,
the contact structures are each formed in one piece,
the contact structures comprise metal or consist thereof.
7. Optoelectronic component according to claim 1 , wherein the contact structures are contact elements for external electrical contacting, which are exposed in the unmounted state of the component on a side surface of the component.
8. Optoelectronic component according to claim 1 , wherein the contact structures are current distribution structures of the semiconductor layer sequence.
9. The optoelectronic component according to claim 1 , further comprising:—a radiation side for coupling or decoupling the electromagnetic radiation into or out of the component,
a rear side opposite of the radiation side,
at least one transverse side connecting the radiation side and the rear side,
a carrier carrying the semiconductor layer sequence between the semiconductor layer sequence and the radiation side or between the semiconductor layer sequence and the rear side, wherein
the semiconductor layer sequence comprises a first semiconductor layer facing the radiation side and a second semiconductor layer facing away from the radiation side, wherein the active layer is arranged between the first semiconductor layer and the second semiconductor layer,
the first contact structure is electrically conductively connected to the first semiconductor layer,
the second contact structure is electrically conductively connected to the second semiconductor layer,
the spark gap occurs in the region of the rear side or in the region of the radiation side or in the region of the transverse side.
10. The optoelectronic component according to claim 9 , wherein
the spark gap occurs in the region of the radiation side,
the semiconductor layer sequence is arranged between the carrier and the radiation side,
the first contact structure is arranged on a side of the first semiconductor layer facing away from the carrier,
the second contact structure is arranged on a side of the second semiconductor layer facing away from the carrier within a recess in the first semiconductor layer,
the second contact structure projects beyond the first semiconductor layer on the radiation side in the direction away from the carrier,
the shortest connection between the two contact structures does not cross any part of the semiconductor layer sequence,
the spark gap does not pass parts of the semiconductor layer sequence.
11. An optoelectronic component according to claim 9 , wherein
the carrier is formed between the rear side and the semiconductor layer sequence,
the contact structures form at least parts of vias through the carrier,
in the unmounted configuration of the component the contact structures are exposed as contact elements at the rear side.
12. An optoelectronic component according to claim 11 , wherein
in the region of the carrier the contact structures are additionally guided to the transverse side,
the spark gap occurs in the region of the transverse side.
13. An optoelectronic component according to claim 12 , wherein
an edge between the rear side and the transverse side is free of the contact structures,
the spark gap occurs spaced apart from the rear side.
14. An optoelectronic component according to claim 12 , wherein
the contact structures are guided to an edge between the transverse side and the rear side,
the spark gap occurs or can occur in the region of the edge.
15. Optoelectronic component according to claim 1 , wherein
the optoelectronic component is a semiconductor chip,
a lateral extent of the semiconductor layer sequence essentially corresponds to the lateral extent of the semiconductor chip and/or of the carrier.
16. Optoelectronic component according to claim 1 , wherein
the optoelectronic component is a light-emitting diode with an optoelectronic semiconductor chip mounted on a carrier,
the semiconductor chip comprises the semiconductor layer sequence,
the carrier has a lateral extent at least twice as large as the semiconductor layer sequence.
17. A method for operating an optoelectronic semiconductor chip comprising the steps:
A) providing an optoelectronic semiconductor chip having a first contact structure and a second contact structure, wherein the semiconductor chip further comprises a radiation side for coupling or decoupling the electromagnetic radiation into or out of the semiconductor chip, a rear side opposite of the radiation side, at least one transverse side connecting the radiation side and the rear side, and a carrier carrying a semiconductor layer sequence between the semiconductor layer sequence and the rear side;
B) electrically contacting the optoelectronic semiconductor chip via the first and second contact structures;
C) switching on and off of the optoelectronic semiconductor chip by controlled switching on and off of a current flow through the optoelectronic semiconductor chip, wherein
in the switched-on state of the optoelectronic semiconductor chip an intended voltage difference ΔU bet is applied between the two contact structures and the optoelectronic semiconductor chip emits electromagnetic radiation,
in the switched-on and/or switched-off state, voltage peaks occur at the semiconductor chip in which the voltage difference between the two contact structures increases to values greater than ΔU bet ,
during some voltage peaks, a first electrical flashover forms in or on the semiconductor chip between the two contact structures,
a spark gap produced between the contact structures during the first flashover runs predominantly through a surrounding medium in the form of gas or vacuum and/or through a potting around the semiconductor chip,
the first flashover occurs at the earliest at a voltage difference of 2·ΔU bet ,
the spark gap occurs in the region of the rear side or in the region of the radiation side or in the region of the transverse side, and
the first electrical flashover occurs at the earliest at a voltage difference of 3 V and at the latest at a voltage difference of 80 V.
18. An optoelectronic semiconductor chip, comprising:
a semiconductor layer sequence with an active layer, wherein the active layer is set up to generate or absorb electromagnetic radiation during normal operation,
a first contact structure and a second contact structure via which the semiconductor layer sequence is electrically contacted during normal operation,
a radiation side for coupling or decoupling the electromagnetic radiation into or out of the semiconductor chip,
a rear side opposite of the radiation side,
at least one transverse side connecting the radiation side and the rear side,
a carrier carrying the semiconductor layer sequence between the semiconductor layer sequence and the rear side, wherein
during operation, the contact structures are subjected to a voltage and an operational voltage difference ΔU bet between the contact structures occurs,
a first electrical flashover is formed in or on the semiconductor chip between the two contact structures when the voltage difference is increased,
a spark gap produced between the contact structures during the first flashover runs predominantly through a surrounding medium in the form of gas or vacuum and/or through a potting around the semiconductor chip,
the first flashover occurs at the earliest at a voltage difference of 2·ΔU bet ,
the semiconductor layer sequence comprises a first semiconductor layer facing the radiation side and a second semiconductor layer facing away from the radiation side, wherein the active layer is arranged between the first semiconductor layer and the second semiconductor layer,
the first contact structure is electrically conductively connected to the first semiconductor layer,
the second contact structure is electrically conductively connected to the second semiconductor layer,
the first contact structure is arranged on a side of the first semiconductor layer facing away from the carrier,
the second contact structure is arranged on a side of the second semiconductor layer facing away from the carrier within a recess in the first semiconductor layer,
the second contact structure projects beyond the first semiconductor layer on the radiation side in the direction away from the carrier,
the shortest connection between the two contact structures does not cross any part of the semiconductor layer sequence,
the spark gap occurs in the region of the rear side or in the region of the radiation side.