High-voltage solid-state transducers and associated systems and methods
High-voltage solid-state transducer (SST) devices and associated systems and methods are disclosed herein. An SST device in accordance with a particular embodiment of the present technology includes a carrier substrate, a first terminal, a second terminal and a plurality of SST dies connected in series between the first and second terminals. The individual SST dies can include a transducer structure having a p-n junction, a first contact and a second contact. The transducer structure forms a boundary between a first region and a second region with the carrier substrate being in the first region. The first and second terminals can be configured to receive an output voltage and each SST die can have a forward junction voltage less than the output voltage.
1. A solid-state transducer (SST) device comprising:
a conductive carrier substrate;
a first terminal;
a second terminal, wherein the first and second terminals are positioned to couple to a power supply having an output voltage, and wherein at least a portion of the conductive carrier substrate defines the second terminal;
a plurality of SST dies electrically connected in series between the first and second terminals, wherein the plurality of SST dies includes a first SST die adjacent to a second SST die, wherein individual SST dies have a forward junction voltage less than the output voltage, and wherein the individual SST dies comprise—
a transducer structure having a p-n junction, the transducer structure forming a boundary between a first region and a second region, with the conductive carrier substrate being in the first region;
a first contact in the first region and electrically connected to the p-n junction; and
a second contact electrically connected to the p-n junction, wherein the second contact extends along at least a portion of a backside of the first contact and includes a buried contact projecting through the first contact into the transducer structure beyond the p-n junction, and wherein the second contact is electrically isolated from the first contact by a dielectric material between the first contact and the second contact; and
an interconnect region between the first and second SST dies, wherein a portion of the second contact of first SST die extends beyond the backside of the first contact and beyond the transducer structure of the first SST die into the interconnect region, and wherein the portion of the second contact of the first SST die electrically couples to the first contact of the adjacent second SST die such that the first and second SST dies are electrically coupled together in series at the interconnect region,
wherein the transducer structure of the first SST die and the transducer structure of the second SST die define an opening at the interconnect region that exposes the portion of the second contact that extends beyond the backside of the of the first contact of the first SST die and a portion of the first contact of the second SST die that extends beyond the backside of the second SST die such that the second contact of the first SST die is coupled to the first contact of the second SST die in the opening.
2. The SST device of claim 1 wherein:
the transducer structure comprises a P-type gallium nitride (P-type GaN) facing toward the first region, an N-type gallium nitride (N-type GaN) facing toward the second region, and an indium gallium nitride (InGaN) between the P-type GaN and the N-type GaN;
the first contact is electrically coupled to the P-type GaN;
the second contact is electrically coupled to the N-type GaN, wherein the second contact extends through a plane containing the first contact to the N-type GaN; and
the first and second terminals are electrically accessible from the first region.
3. The SST device of claim 1 wherein:
the transducer structure includes a P-type GaN facing toward the first region, an N-type GaN facing toward the second region, and InGaN between the P-type GaN and the N-type GaN;
the first contact is electrically coupled to the P-type GaN;
the second contact is electrically coupled to the N-type GaN; and
the first terminal is in the first region of one of the SST dies.
4. The SST device of claim 1 wherein:
the first and second terminals are electrically accessible from a surface facing away from the conductive carrier substrate.
5. The SST device of claim 1 wherein the second contact is spaced vertically apart from the first contact.
6. The SST device of claim 1 wherein the SST device is configured to emit electromagnetic radiation in at least one of the ultraviolet spectrum, the visible spectrum, and the infrared spectrum.
7. The SST device of claim 1 wherein:
the first and second terminals are electrically accessible from the first region; and
the plurality of SST dies are serially coupled together such that current travels along a path that flows from the first terminal to the second terminal as follows: (a) through the transducer structure of the first SST die to the buried second contact of the first SST die, (b) through the buried second contact of the first SST die to the first contact of the second SST die, and (c) through the transducer structure of the second SST die to the buried second contact of the second SST die and then to the second terminal.
8. A solid-state transducer (SST) device, comprising:
a conductive carrier substrate;
a first terminal;
a second terminal, wherein the first and second terminals are positioned to couple to a power supply having an output voltage, and wherein at least a portion of the conductive carrier substrate defines the second terminal;
a plurality of SST dies electrically connected in series between the first and second terminals, wherein the plurality of SST dies includes a first SST die adjacent to a second SST die, wherein individual SST dies have a forward junction voltage less than the output voltage, and wherein the individual SST dies comprise—
a transducer structure having a p-n junction, the transducer structure forming a boundary between a first region and a second region, with the conductive carrier substrate being in the first region;
a first contact in the first region and electrically connected to the p-n junction; and
a second contact electrically connected to the p-n junction, wherein the second contact extends along at least a portion of a backside of the first contact and includes a buried contact projecting through the first contact into the transducer structure beyond the p-n junction, and wherein the second contact is electrically isolated from the first contact by a dielectric material between the first contact and the second contact;
an interconnect region between the first and second SST dies, wherein a portion of the second contact of first SST die extends beyond the backside of the first contact and beyond the transducer structure of the first SST die into the interconnect region, and wherein the portion of the second contact of the first SST die electrically couples to the first contact of the adjacent second SST die such that the first and second SST dies are electrically coupled together in series at the interconnect region; and
an isolating protrusion of dielectric material in the interconnect region between the second contacts of the adjacent first and second SST dies, wherein the isolating protrusion defines a lateral bound of the first SST die from a lateral bound of the adjacent second SST die.
9. The SST device of claim 8 wherein:
the transducer structure includes a P-type GaN facing toward the first region, an N-type GaN facing toward the second region, and InGaN between the P-type GaN and the N-type GaN;
the first contact is electrically coupled to the P-type GaN;
the second contact is electrically coupled to the N-type GaN and electrically isolated from the conductive carrier substrate;
the first terminal is electrically accessible from the first region; and
the second terminal is electrically coupled to the conductive carrier substrate.
10. The SST device of claim 8 wherein:
the first terminal is electrically accessible from a surface facing away from the conductive carrier substrate; and
the second terminal is electrically coupled to the conductive carrier substrate.
11. The SST device of claim 8 wherein the first terminal is in the second region and the second terminal is in the first region such that the first and second terminals are spaced vertically apart from each other.
12. A solid-state transducer (SST) system, comprising:
a conductive carrier substrate;
a plurality of SST dies on the conductive carrier substrate, wherein individual SST dies include a transducer structure having a p-n junction, a first contact and a second contact, the transducer structure forming a boundary between a first region and a second region, wherein the first contact is at a backside of the transducer structure in the first region, wherein the second contact extends along at least a portion of a backside of the first contact and includes a buried contact that extends through a plane containing the first contact and comprises—
a via having a sidewall extending from the first region, completely through the first contact, to beyond the p-n junction,
a dielectric material along the backside of the first contact and along the sidewall of the via, wherein the dielectric material does not cover a portion of the transducer structure beyond the p-n junction, and
a conductive material extending into the via on the dielectric material and onto the portion of the transducer structure not covered by the dielectric material, wherein the dielectric material is positioned between the conductive material and the p-n junction to electrically isolate the buried contact from the p-n junction; and
at least one interconnect region in the first region between two adjacent SST dies, wherein a portion of the second contact of one of the plurality of SST dies extends beyond the backside of the first contact and beyond the transducer structure into the interconnect region, and wherein the portion of the second contact electrically couples to the first contact of an adjacent SST die to electrically couple the adjacent SST dies together in series at the interconnect region,
wherein the transducer structures of the two adjacent SST dies define an opening at the interconnect region that exposes the portion of the second contact that extends beyond the backside of the first contact of on of the plurality of SST dies and a portion of the first contact of the adjacent SST die that extends beyond the backside such that the first and second contacts of the adjacent SST dies are coupled to together in the opening.
13. The SST system of claim 12 wherein:
the transducer structure of the individual SST dies comprise a P-type gallium nitride (P-type GaN) facing toward the first region, an N-type gallium nitride (N-type GaN) facing toward the second region, and an indium gallium nitride (InGaN) between the P-type GaN and the N-type GaN;
the first contact is electrically coupled to the P-type GaN; and
the second contact is electrically coupled to the N-type GaN.
14. The SST system of claim 12 wherein the first contact comprises a reflective material.
15. The SST system of claim 12 , further comprising:
a first terminal electrically coupled to the first contact of a first of the plurality of SST dies; and
a second terminal electrically coupled to the second contact of a second of the plurality of SST dies, wherein the first SST die is the first SST die coupled in series and the second SST die is the last SST die coupled in series, and wherein the first and second terminals are electrically accessible from the first region.
16. The SST system of claim 12 , further comprising:
a first terminal electrically coupled to the first contact of a first of the plurality of SST dies; and
a second terminal electrically coupled to the second contact of a second of the plurality of SST dies, wherein the first SST die is the first SST die coupled in series and the second SST die is the last SST die coupled in series, and wherein the second terminal is electrically coupled to a portion of the conductive carrier substrate.
17. The SST system of claim 1 , further comprising:
a first terminal defined at least in part by one of the first contacts;
a second terminal defined at least in part by one of the second contacts; and
a power supply electrically coupled to the first and second terminals, wherein the power supply has an output voltage and the plurality of SST dies have a combined forward junction voltage approximately the same as the output voltage.
18. The SST system of claim 12 wherein the transducer structure is configured to emit electromagnetic radiation in at least one of the ultraviolet spectrum, the visible spectrum, and the infrared spectrum.
19. A solid-state transducer (SST) device, comprising:
a conductive carrier substrate;
a first terminal;
a second terminal, wherein at least a portion of the conductive carrier substrate defines the second terminal;
a plurality of SST dies electrically connected in series between the first and second terminals, wherein the plurality of SST dies includes a first SST die and a second SST die adjacent to the first SST die, and wherein each SST die of the plurality of SST dies comprises—
a transducer structure having a p-n junction, the transducer structure forming a boundary between a first region and a second region, with the conductive carrier substrate being in the first region;
a first contact in the first region and electrically connected to the p-n junction; and
a second contact electrically connected to the p-n junction, wherein the second contact extends along at least a portion of a backside of the first contact and includes a buried contact projecting through the first contact into the transducer structure beyond the p-n junction, and wherein the second contact is electrically isolated from the first contact by a dielectric material between the first contact and the second contact;
an interconnect region having an opening between the transducer structures of the adjacent first and second SST dies, wherein the second contact of first SST die extends beyond the transducer structure of the first SST die into the opening, and wherein the second contact of the first SST die electrically couples to the first contact of the adjacent second SST die in the opening; and
an isolating protrusion of dielectric material between the second contacts of the adjacent first and second SST dies, wherein the isolating protrusion is in the interconnect region and defines a lateral bound of the first SST die from a lateral bound of the adjacent second SST die.