Controlled spalling of fine features

1. A method for fabricating a device, the method comprising:

patterning a substrate with a set of features comprising a portion of the device;

depositing a first photoresist layer on the substrate by a first deposition process;

depositing a second photoresist layer on the first photoresist layer by a second deposition process; and

inducing spalling of the features from the substrate, after depositing the second photoresist layer.

2. The method of claim 1 , further comprising:

patterning the first photoresist layer to create a series of trenches;

depositing a conformal seed layer of a stressor material on the first photoresist layer after patterning the first photoresist layer but prior to depositing the second photoresist layer, such that the first photoresist layer and the second photoresist layer are physically separated by the seed layer; and

patterning the second photoresist layer to maintain the series of trenches.

3. The method of claim 2 , wherein at least some of the trenches in the series of trenches are positioned directly over the set of features.

4. The method of claim 2 , wherein the seed layer comprises nickel.

5. The method of claim 2 , wherein the inducing comprises:

depositing a stressor layer directly on the second photoresist layer and within the series of trenches; and

processing the stressor layer until the spalling is induced in the substrate.

6. The method of claim 5 , wherein the processing comprises thermal processing.

7. The method of claim 5 , wherein the stressor layer and the seed layer are formed from a same material.

8. The method of claim 5 , wherein the stressor layer comprises nickel or tungsten.

9. The method of claim 5 , further comprising:

applying a first adhesive layer to the second photoresist layer and the stressor layer; and

pulling the first adhesive layer in a direction away from the substrate, after spalling is induced, so that portions of the substrate are detached and lifted away from a body of the substrate.

10. The method of claim 9 , wherein the first adhesive layer comprises ultraviolet release tape.

11. The method of claim 9 , further comprising:

applying a second adhesive layer to the portions of the substrate that are detached;

releasing the first adhesive layer; and

removing the first photoresist layer, the second photoresist layer, and the stressor layer, so that the portions of the substrate that are detached remain on the second adhesive layer.

12. The method of claim 11 , wherein the second adhesive layer comprises stretchable tape.

13. The method of claim 12 , wherein the releasing comprises:

irradiating the first adhesive layer.

14. The method of claim 1 , wherein the device comprises a resistor.

15. A method for fabricating a device, the method comprising:

patterning a substrate with a set of features comprising a portion of the device;

depositing a first photoresist layer on the substrate;

patterning the first photoresist layer to create a series of trenches;

depositing a conformal seed layer on the first photoresist layer and in the series of trenches;

depositing a second photoresist layer on the seed layer;

patterning the second photoresist layer to maintain the series of trenches;

depositing a stressor layer on the second photoresist layer and in the series of trenches;

applying a first adhesive layer to the stressor layer;

inducing spalling of the features from the substrate; and

pulling the first adhesive layer in a direction away from the substrate, after spalling is induced, so that portions of the substrate are detached and lifted away from a body of the substrate.

16. The method of claim 15 , wherein the stressor layer and the seed layer are formed from a same material.

17. The method of claim 16 , wherein the stressor layer and the seed layer are formed from nickel.

18. The method of claim 15 , further comprising:

applying a second adhesive layer to the portions of the substrate that are detached;

releasing the first adhesive layer; and

removing the first photoresist layer, the second photoresist layer, and the stressor layer, so that the portions of the substrate that are detached remain on the second adhesive layer.

19. The method of claim 18 , wherein the releasing comprises:

irradiating the first adhesive layer.

20. The method of claim 18 , wherein the second adhesive layer comprises stretchable tape.