Method of forming a permanent carrier and spacer wafer for wafer level optics and associated structure

1. A method of forming an imager structure, the method comprising:

etching trenches in a carrier substrate;

filling the trenches at least partially with a dissolvable material;

bonding an imager wafer to the carrier substrate, the imager wafer comprising imager arrays, each imager array being associated with and aligned within a respective trench and being spaced from the carrier substrate; and

removing the dissolvable material.

2. The method of claim 1 , further comprising:

removing portions of the carrier substrate within the trenches; and

affixing a lens element above the imager array to the remaining carrier substrate.

3. The method of claim 2 , wherein the carrier substrate is thinned to a thickness corresponding to a desired distance between the lens element and the imager array.

4. The method of claim 1 , wherein the carrier substrate has a thickness within the range of approximately 650 to approximately 850 microns.

5. The method of claim 1 , wherein the trenches have, a width within the range of approximately 50 to approximately 100 microns and have a depth within the range of approximately 400 to approximately 600 microns.

6. The method of claim 1 , wherein the step of filling the trenches at least partially with a dissolvable material further comprises removing air pockets within the dissolvable material.

7. The method of claim 1 , wherein the dissolvable material is a soluble adhesive.

8. The method of claim 7 , wherein the dissolvable material is a solvent-soluble adhesive.

9. The method of claim 7 , wherein the dissolvable material is a water-soluble adhesive.

10. A method of forming an imager structure, the method comprising:

etching trenches in a first wafer, the trenches forming perimeters around inner areas corresponding to imager arrays on an imager wafer;

placing a dissolvable material in the trenches;

applying a bonding material to outer areas of at least one of the first wafer and the imager wafer;

aligning the first wafer and the imager wafer, such that the imager arrays are aligned within the perimeters of the trenches;

bonding the first wafer and the imager wafer;

processing a backside of the imager wafer; and

removing the dissolvable material and portions of the first wafer within a periphery of the trenches.

11. The method of claim 10 , wherein the dissolvable material is a solvent-soluble adhesive.

12. The method of claim 10 , wherein the dissolvable material is a water-soluble adhesive.

13. The method of claim 10 , wherein the trenches are rectangular-shaped.

14. The method of claim 10 , wherein the trenches are circular-shaped.

15. The method of claim 10 , wherein the trenches have a depth less than a first thickness of the first wafer, and the method further comprises:

thinning the first wafer to a second thickness, the second thickness being less than or equal to the depth of the trenches; and

attaching respective lens structures to remaining portions of the first wafer at locations corresponding to the imager arrays.

16. A carrier wafer comprising:

a substrate having a thickness;

a plurality of trenches etched to form perimeters around a plurality of areas on the, substrate, the trenches corresponding to respective perimeters of imager arrays on an imager wafer, the trenches having a depth less than the thickness of the substrate; and

a dissolvable material within the trenches.

17. The carrier wafer of claim 16 , wherein the trenches have a width within the range of approximately 50 microns to approximately 100 microns.

18. The carrier wafer of claim 16 , wherein the trenches have a depth within the range of approximately 400 microns to approximately 600 microns.

19. The carrier wafer of claim 16 , wherein the trenches are at least partially filled with a solvent-soluble adhesive.

20. An intermediate structure for use in fabrication, the intermediate structure comprising:

a substrate having a thickness; and

at least one trench etched in the substrate corresponding to a location of a component on a separate structure, the at least one trench encircling a volume of the substrate.

21. The intermediate structure of claim 20 , the at least one trench having:

sidewalls that are substantially vertical; and

a depth less than the thickness of the substrate.

22. The intermediate structure of claim 20 , wherein the at least one trench corresponds to a location of an imager array on an imager wafer.

23. The intermediate structure of claim 22 , wherein the volume has a surface area corresponding to a surface area of the imager array.

24. The intermediate structure of claim 20 , wherein the at least one trench is rectangular-shaped.

25. An intermediate structure for use in imager module fabrication, the intermediate structure comprising:

a substrate having a thickness; and

at least one trench etched in the substrate, the at least one trench encircling a volume of the substrate, wherein the at least one trench is circular-shaped.