Wafer-level solid state transducer packaging transducers including separators and associated systems and methods

• US 8,952,395 B2
• Filed: 07/26/2011
• Issued: 02/10/2015
• Est. Priority Date: 07/26/2011
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Odnoblyudov, Vladimir
• Primary Examiner(s): Rizkallah, Kimberly
• Assistant Examiner(s): Belousov, Alexander
• Application Number:
  US13/190,971
• Publication Number:
  US 20130026499A1
• Time in Patent Office: 1,295 Days
• Field of Search: 438/40
• US Class Current: 257/88
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• 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 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

Wafer-level packaging of solid-state transducers (“SSTs”) is disclosed herein. A method in accordance with a particular embodiment includes forming a transducer structure having a first surface and a second surface opposite the first surface, and forming a plurality of separators that extend from at least the first surface of the transducer structure to beyond the second surface. The separators can demarcate lateral dimensions of individual SSTs. The method can further include forming a support substrate on the first surface of the transducer structure, and forming a plurality of discrete optical elements on the second surface of the transducer structure. The separators can form barriers between the discrete optical elements. The method can still further include dicing the SSTs along the separators. Associated SST devices and systems are also disclosed herein.

Claims

1. A method of forming solid-state transducers (SSTs), the method comprising:

forming a transducer structure on a growth substrate, the transducer structure having a first surface opposite a second surface, wherein the second surface is proximate to the growth substrate;

forming a plurality of trenches extending through the transducer structure and at least partially through the growth substrate;

depositing a dielectric isolator and a metallic material sequentially in the trenches to form separators in the trenches that demarcate individual SSTs;

forming a support substrate over the first surface of the transducer structure and the separators; and

removing the growth substrate from the second surface of the transducer structure without exposing the metallic material and such that at least a portion of the separators remains, the separators forming a plurality of protrusions that extend beyond the second surface of the transducer structure, wherein individual protrusions include a portion of the dielectric isolator, and wherein the portion of the dielectric isolator covers the metallic material and extends beyond the metallic material and the second surface of the transducer structure,

wherein removing the growth substrate includes—

planarizing the growth substrate to expose individual separators, and

etching the growth substrate to further expose the individual separators.

2. The method of claim 1 wherein forming the support substrate comprises plating a metal substrate on the metallic material, the metal substrate extending partially into the trenches.

3. The method of claim 2, further comprising:

forming first contacts on the first surface of the transducer structure before forming the support substrate;

forming second contacts on the second surface of the transducer structure after removing the growth substrate;

forming converter elements over the second surface of the transducer structure and the second contacts, wherein individual converter elements are separated by the protrusions; and

dicing along lines aligned with the protrusions to separate the individual SSTs.

4. The method of claim 1, further comprising forming converter elements over the first surface of the transducer structure, portions of the converter elements being separated by the protrusions.

5. The method of claim 1, further comprising:

measuring wavelengths of the individual SST; and

selecting a converter element for each SST according to the measured wavelength of each individual SST, wherein the SSTs with the selected converter elements are configured to generate a generally uniform color across the plurality of the SSTs.

6. The method of claim 1, further comprising forming cover elements over the first surface of the transducer structure, wherein the protrusions separate individual cover elements.

7. The method of claim 6 wherein forming the cover elements comprises positioning lenses over the individual SSTs.

8. The method of claim 1, further comprising:

forming converter elements over the second surface of the transducer structure, wherein individual converter elements are separated by the protrusions; and

forming cover elements over the converter elements, wherein individual cover elements are separated by the protrusions.

9. The method of claim 1, further comprising:

testing the individual SSTs before dicing the SSTs; and

dicing the SSTs along dicing lanes, wherein the dicing lanes are aligned with the protrusions.

10. The method of claim 1 wherein the SSTs are configured to emit electromagnetic radiation in at least one of the ultraviolet spectrum, the visible spectrum, and the infrared spectrum.

11. The method of claim 1, further comprising temporarily bonding a carrier substrate to the support substrate before removing the growth substrate.

12. The method of claim 1, further comprising:

measuring wavelengths of the individual SSTs; and

selecting a converter element for each SST based on the measured wavelength of the SST, wherein at least one of the selected converter elements differs from adjacent converter elements.

13. The method of claim 1 wherein removing the growth substrate from the second surface of the transducer structure further comprises removing the growth substrate from sidewalls of the separators to form the plurality of protrusions that extend beyond the second surface of the transducer structure.

14. The method of claim 1, further comprising at least partially filling a volume between the transducer structure and individual protrusions at opposite sides of the transducer structure with a converter material and/or cover material without spilling the converter material and/or cover material over onto an adjacent transducer structure, wherein the converter material and/or cover material covers at least a portion of the transducer structure and portions of the individual protrusions at opposite sides of the transducer structure.

15. A method of forming solid-state transducers (SSTs), the method comprising:

forming a transducer structure having a first surface and a second surface opposite the first surface;

forming a plurality of separators that extend through the transducer structure, wherein the separators extend from at least the first surface of the transducer structure and project beyond the second surface into an underlying growth substrate, wherein individual separators include a metallic material and a dielectric material between the metallic material and the underlying growth substrate, and wherein the separators demarcate individual SSTs;

planarizing the growth substrate to expose at least a portion of the dielectric material that extends beyond the second surface of the transducer structure;

after planarizing the growth substrate, etching the growth substrate to further expose the dielectric material;

forming a support substrate on the first surface of the transducer structure;

measuring a performance parameter of each SST;

forming discrete optical elements on the second surface of the transducer structure, wherein the separators form barriers between the discrete optical elements, and wherein each optical element is selected based on the measured performance parameter of the corresponding SST; and

dicing the SSTs along the separators.

16. The method of claim 15 wherein forming the discrete optical elements comprises forming discrete converter elements on the second surface of the transducer structure, wherein the separators form barriers between the discrete converter elements.

17. The method of claim 15 wherein forming the discrete optical elements comprises forming discrete cover elements on the second surface of the transducer structure, wherein the separators form barriers between the discrete cover elements.

18. The method of claim 15 wherein forming the plurality of separators comprises:

forming a plurality of trenches on the first surface of the transducer structure, wherein the trenches have sidewalls that extend from at least the first surface of the transducer structure beyond the second surface and into the underlying growth substrate; and

depositing the dielectric material and the metallic material sequentially into the trenches, wherein the metallic material includes at least one of a barrier material and a seed material,

wherein etching the growth substrate includes removing the growth substrate from the second surface of the transducer structure and from the sidewalls to form protrusions above the second surface of the transducer structure.

19. The method of claim 18 wherein forming the trenches further comprises plating a portion of the support substrate to the seed material.

20. The method of claim 15 wherein:

measuring the performance parameter of each SST comprises measuring the wavelength of each SST before forming the optical elements; and

the method further comprises selecting each optical element for each SST based on the measured wavelength of the corresponding SST.

21. The method of claim 15 wherein forming the support substrate comprises plating a metal substrate over the first surface of the transducer structure, wherein the metal substrate has a thickness between approximately 50 μ

m and approximately 300 μ

m.

22. The method of claim 15 wherein the SSTs are configured to emit electromagnetic radiation in at least one of the ultraviolet spectrum, the visible spectrum, and the infrared spectrum.

23. The method of claim 15 wherein forming discrete optical elements on the second surface of the transducer structure comprises selecting different optical elements for the individual SSTs based on differences in the measured performance parameters of the individual SSTs.

24. A method of forming solid-state transducers (SSTs), the method comprising:

forming a transducer structure on a growth substrate, the transducer structure having a first surface opposite a second surface, wherein the second surface is proximate to the growth substrate;

forming a plurality of trenches extending through the transducer structure and at least partially through the growth substrate;

depositing a dielectric isolator and a metallic material sequentially in the trenches to form separators in the trenches that demarcate individual SSTs;

forming a support substrate over the first surface of the transducer structure and the separators; and

removing the growth substrate from the second surface of the transducer structure without exposing the metallic material and such that at least a portion of the separators remains, the separators forming a plurality of protrusions that extend beyond the second surface of the transducer structure, wherein individual protrusions include a portion of the dielectric isolator, and wherein the portion of the dielectric isolator covers the metallic material and extends beyond the metallic material and the second surface of the transducer structure,

wherein removing the growth substrate includes—

planarizing the growth substrate to at least partially expose the portion of the dielectric isolator; and

etching the growth substrate to further expose the portion of the dielectric isolator.

25. A method of forming solid-state transducers (SSTs), the method comprising:

forming a transducer structure on a growth substrate, the transducer structure having a first surface opposite a second surface, wherein the second surface is proximate to the growth substrate;

forming a plurality of trenches extending through the transducer structure and at least partially through the growth substrate;

forming separators in the trenches that demarcate individual SSTs;

forming a support substrate over the first surface of the transducer structure and the separators;

planarizing the growth substrate to at least partially expose the separators; and

after planarizing the growth substrate, etching the growth substrate to further expose the separators such that individual separators extend beyond the second surface of the transducer structure.

26. The method of claim 25, wherein planarizing the growth substrate includes backgrinding the growth substrate.

27. The method of claim 25 wherein etching the growth substrate includes removing material of the growth substrate from the second surface of the transducer structure.

28. The method of claim 25 wherein etching the growth substrate includes removing material of the growth substrate from sidewalls of the separators.

29. The method of claim 25 wherein the separators each include a dielectric material and an underlying metallic material, wherein etching the growth substrate includes exposing the dielectric material of the separators.