VERTICAL SOLID-STATE TRANSDUCERS HAVING BACKSIDE TERMINALS AND ASSOCIATED SYSTEMS AND METHODS

• US 20160049565A1
• Filed: 10/29/2015
• Published: 02/18/2016
• Est. Priority Date: 08/25/2011
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Odnoblyudov, Vladimir, Schubert, Martin F.
• Granted Patent: US 9,601,675 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 2933/0066 relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/382 the electrode extending partially in or entirely through the semiconductor body
• CPC Class Codes: H01L 33/387 with a plurality of electrode regions in direct contact with the semiconductor body and being electrically interconnected by another electrode layer
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/501 characterised by the materials, e.g. binder
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H01L 33/647 the elements conducting electric current to or from the semiconductor body

Abstract

Vertical solid-state transducers (“SSTs”) having backside contacts are disclosed herein. An SST in accordance with a particular embodiment can include a transducer structure having a first semiconductor material at a first side of the SST, a second semiconductor material at a second side of the SST opposite the first side, and an active region between the first and second semiconductor materials. The SST can further include first and second contacts electrically coupled to the first and second semiconductor materials, respectively. A portion of the first contact can be covered by a dielectric material, and a portion can remain exposed through the dielectric material. A conductive carrier substrate can be disposed on the dielectric material. An isolating via can extend through the conductive carrier substrate to the dielectric material and surround the exposed portion of the first contact to define first and second terminals electrically accessible from the first side.

Claims

1. A method of forming solid-state transducers (SSTs) having a first side and a second side, the method comprising:

forming a transducer structure having an active region positioned between a first semiconductor material and a second semiconductor material, wherein the first semiconductor material is at the first side of the SST and the second semiconductor material is at the second side of the SST;

forming a first contact on the first side of the SST;

forming a second contact on the first side of the SST, wherein the second contact includes a plurality of interconnected buried contact elements electrically coupled to the second semiconductor material;

forming a dielectric material on the first side of the SST leaving a portion of the first contact and a portion of the second contact exposed through the dielectric material;

disposing a conductive carrier substrate on the dielectric material, wherein the conductive carrier substrate is electrically coupled to the first and second contacts; and

electrically isolating the first contact from the second contact, wherein a portion of the conductive carrier substrate defines a first terminal electrically coupled to the first contact and a portion of the conductive carrier substrate defines a second terminal electrically coupled to the second contact, and wherein the first and second electrical terminals are both exposed at the first side of the SST.

2. The method of claim 1 wherein electrically isolating the first contact from the second contact comprises forming an isolating via around the portion of the first contact exposed through the dielectric material, wherein the isolating via extends through the carrier substrate to the dielectric material.

3. The method of claim 1, further comprising:

forming a plurality of separators that extend through the transducer structure to demarcate individual SSTs, wherein the separators project beyond the transducer structure toward the second side of the SST; and

forming discrete optical elements on the second side of the SST, wherein the separators form barriers between the discrete optical elements.

4. The method of claim 3 wherein forming the discrete optical elements comprises:

forming a first optical element on the second side of the SST, the first optical element having a first performance parameter;

forming a second optical element on the second side of the SST, the second optical element having a second performance parameter different from the first performance parameter, wherein the first and second optical elements are separated by an adjoining separator.

5. The method of claim 3 wherein forming the discrete optical elements comprises:

forming a first discrete optical element configured to emit a first color of radiation; and

forming a second discrete optical element configured to emit a second color of radiation different from the first color, wherein the first and second optical elements are separated by an adjoining separator.

6. The method of claim 1 wherein forming the transducer structure comprises forming a transducer structure configured to emit electromagnetic radiation in at least one of the ultraviolet spectrum, the visible spectrum, and the infrared spectrum.

7. A method of forming solid-state transducers (SSTs) having a first side and a second side facing away from the first side, the method comprising:

forming a transducer structure having an active region positioned between a first semiconductor material and a second semiconductor material, wherein the first semiconductor material is at the first side of the SSTs and the second semiconductor is at the second side;

forming a plurality of separators that extend through the transducer structure and project beyond the transducer structure toward the second side to form a plurality of protrusions, wherein the separators demarcate individual SSTs;

forming a first contact on the first side of the SSTs, wherein the first contact is electrically coupled to the first semiconductor material;

forming a second contact on the first side of the SSTs, the second contacts extending through the first semiconductor material to at least the second semiconductor material, wherein the second contact is electrically coupled to the second semiconductor material; and

disposing a conductive carrier substrate on the first side of the SSTs, wherein the first and second contacts are configured to be electrically accessible from the first side of the SSTs, and wherein the first contacts are electrically isolated from the second contacts.

8. The method of claim 7 wherein disposing the conductive carrier substrate comprises:

forming a dielectric material on the first and second contacts before forming the conductive carrier substrate, wherein a portion of the first contact and a portion of the second contact is exposed through the dielectric material;

forming a metal material on the dielectric material, wherein the metal material contacts the portions of the first and second contacts that are exposed through the dielectric material;

forming an isolating via in the metal material around at least one of the portions of the first and second contacts that are exposed through the dielectric material; and

plating the conductive carrier substrate on the metal material.

9. The method of claim 7 wherein forming the plurality of separators comprises:

forming a plurality of trenches from the first side of the SSTs, wherein the trenches have sidewalls that extend from at least the first semiconductor material beyond the second semiconductor material into an underlying growth substrate;

depositing at least one of a dielectric isolator, a barrier material, and a seed material into the trenches; and

removing the growth substrate from the second semiconductor material and from the sidewalls such that the separators form the plurality of protrusions extending beyond the second semiconductor material.

10. The method of claim 7, further comprising selectively depositing optical elements on the second side of the SSTs, wherein individual optical elements are separated by the protrusions, and wherein at least two adjacent optical elements have different performance parameters.

11. A solid-state transducer (SST) assembly comprising:

a plurality of SSTs having a first side and a second side opposite the first side, individual SSTs having a transducer structure, a first contact and a second contact, wherein the first and second contacts are configured to be electrically accessible from the first side;

a conductive carrier substrate on the first side of the SSTs, the conductive carrier substrate having a first terminal electrically coupled to the first contacts and a second terminal electrically coupled to the second contacts;

a plurality of separators demarcating the individual SSTs, wherein the separators project through the transducer structure toward the second side; and

a plurality of discrete optical elements on the second side, wherein the separators act as barriers between the discrete optical elements.

12. The SST assembly of claim 11 wherein each separator comprises:

a dielectric isolator extending along a sidewall adjacent to the SSTs; and

at least one metal material on the dielectric isolator.

13. The SST assembly of claim 11 wherein the plurality of discrete optical elements comprises at least one of converter elements and cover elements, and wherein the separators act as barriers between each converter element and between each cover element.

14. The SST assembly of claim 11 wherein the plurality of discrete optical elements comprise a first converter element configured to emit a first color of light and a second converter element configured to emit a second color of light different from the first color of light.

15. The SST assembly of claim 11 wherein:

the transducer structure comprises a first semiconductor material at a first side of the transducer structure, a second semiconductor material at a second side opposite the first side, and an active region between the first and second semiconductor materials, wherein the first and second sides of the transducer structure are proximate the corresponding first and second sides of the SST;

the second contact comprises—

a plurality of buried contact elements extending from the first side of the transducer structure into the second semiconductor material, wherein the buried contact elements have a contact material electrically coupled to the second semiconductor material and a dielectric material configured to electrically isolate the second contact material from the active region, the first semiconductor material, and the first contact; and

a plurality of conductive lines on the first side of the SST assembly between the buried contact elements, wherein the conductive lines are on an underlying dielectric layer that electrically isolates the conductive lines from the underlying first contact and the first semiconductor material, and wherein the conductive lines and the buried contact elements define the second contacts.

16. The SST assembly of claim 11, further comprising:

a dielectric material separating the first and second contacts from the conductive carrier substrate, wherein individual first and second contacts have an exposed portion not covered by the dielectric material; and

at least one isolating via extending through the conductive carrier substrate to the dielectric material, wherein the isolating via surrounds at least one of the exposed portions of the first and second contacts, and wherein the isolating via defines the first and second terminals.

17. The SST assembly of claim 11 wherein the SSTs are configured to emit electromagnetic radiation in at least one of the ultraviolet spectrum, the visible spectrum, and the infrared spectrum.

18. A method of forming solid-state transducers (SSTs) having a first side and a second side facing away from the first side, the method comprising:

forming a transducer structure having an active region between a first semiconductor material and a second semiconductor material, wherein the first semiconductor material is at the first side of the SST and the second semiconductor material is at the second side of the SST;

forming a first contact electrically coupled to the first semiconductor material and on the first side of the SST;

forming a second contact electrically coupled to the second semiconductor material and on the first side of the SST, wherein the second contact includes a plurality of buried contact elements;

disposing a conductive carrier substrate on the first side of the SST, and electrically coupling the first and second contacts to the conductive carrier substrate;

forming a first terminal from a first portion of the conductive carrier substrate, the first terminal being electrically coupled to the first contact;

forming a second terminal from a second portion of the conductive carrier substrate, the second terminal being electrically coupled to the second contact and electrically isolated from the first terminal; and

forming a plurality of separators that extend through the transducer structure and project beyond the transducer structure toward the second side to form a plurality of protrusions between individual SSTs.

19. The method of claim 18 wherein disposing the conductive carrier substrate comprises:

forming a dielectric material on the first and second contacts before forming the conductive carrier substrate, wherein a portion of the first contact and a portion of the second contact is exposed through the dielectric material;

forming a metal material on the dielectric material, wherein the metal material contacts the portions of the first and second contacts that are exposed through the dielectric material, wherein the metal material includes a via around at least one of the portions of the first and second contacts that are exposed through the dielectric material; and

plating the conductive carrier substrate on the metal material.