Micro-transfer-printable flip-chip structures and methods
In certain embodiments, a method of making a semiconductor structure suitable for transfer printing (e.g., micro-transfer printing) includes providing a support substrate and disposing and processing one or more semiconductor layers on the support substrate to make a completed semiconductor device. A patterned release layer and, optionally, a capping layer are disposed on or over the completed semiconductor device and the patterned release layer or capping layer, if present, are bonded to a handle substrate with a bonding layer. The support substrate is removed to expose the completed semiconductor device and, in some embodiments, a portion of the patterned release layer. In some embodiments, an entry path is formed to expose a portion of the patterned release layer. In some embodiments, the release layer is etched and the completed semiconductor devices transfer printed (e.g., micro-transfer printed) from the handle substrate to a destination substrate.
1. A semiconductor structure suitable for transfer printing, comprising:
a handle substrate;
a cured bonding layer disposed in contact with the handle substrate;
a patterned release layer disposed in contact with the cured bonding layer; and
a completed semiconductor device disposed on or over the patterned release layer and attached to an anchor disposed on the handle substrate with at least one tether.
2. The semiconductor structure of claim 1 , wherein at least one of the completed semiconductor device and a portion of the patterned release layer is exposed.
3. The semiconductor structure of claim 1 , wherein a portion of the completed semiconductor device is a removal layer or the semiconductor structure comprises a removal layer in contact with the completed semiconductor device.
4. The semiconductor structure of claim 3 , comprising a support substrate in contact with the removal layer.
5. The semiconductor structure of claim 1 , comprising a support substrate in contact with the completed semiconductor device.
6. The semiconductor structure of claim 1 , wherein the completed semiconductor device comprises a semiconductor structure comprising at least two electrical contacts to the completed semiconductor device that are in different planes.
7. The semiconductor structure of claim 6 , wherein the completed semiconductor device comprises an electrically separate electrode electrically connected to each of the electrical contacts, wherein exposed portions of the electrodes are in a common plane.
8. The semiconductor structure of claim 7 , comprising a destination substrate having a non-planar surface that corresponds to a non-planar surface of the completed semiconductor structure.
9. The semiconductor structure of claim 1 , comprising one or more electrical contacts on a side of the completed semiconductor device adjacent to the patterned release layer or one or more electrical contacts on a side of the completed semiconductor device opposite the side of the completed semiconductor device adjacent to the patterned release layer.
10. The semiconductor structure of claim 9 , wherein (i) each electrical contact comprises a connection post or (ii) the semiconductor structure comprises an electrode electrically connected to each electrical contact and a connection post electrically connected to each electrode.
11. The semiconductor structure of claim 10 , wherein each connection post is tapered.
12. The semiconductor structure of claim 11 , wherein each connection post has a height to width aspect ratio of greater than 1:1.
13. The semiconductor structure of claim 1 , wherein the at least one tether is disposed between the completed semiconductor device and the handle substrate.
14. The semiconductor structure of claim 1 , comprising a plurality of completed semiconductor devices, wherein each of the plurality of completed semiconductor devices comprises an individual tether connected to a unique anchor.
15. The semiconductor structure of claim 1 , comprising a plurality of completed semiconductor devices, wherein at least two of the plurality of completed semiconductor devices are physically connected by respective tethers to a common anchor structure.
16. The semiconductor structure of claim 15 , wherein at least two of the plurality of completed semiconductor devices are connected to a common anchor structure that is a ridge of bonding layer material.
17. The semiconductor structure of claim 5 , wherein the support substrate is a growth substrate.
18. The semiconductor structure of claim 5 , wherein the support substrate comprises a semiconductor layer or a semiconductor seed layer.
19. The semiconductor structure of claim 1 , wherein the cured bonding layer comprises at least one of a cured resin, an epoxy, a metal layer, a metal alloy layer, a solder layer, and a layer of AuSn.
20. The semiconductor structure of claim 1 , wherein surfaces at opposing edges of the completed semiconductor device are in a common plane, wherein a first electrical contact is located at the bottom of a well, pit, or depression in the completed semiconductor device and is electrically connected to a first electrode, wherein a second electrical contact electrically separate from the first electrical contact is electrically connected to a second electrode, and wherein the first electrode has a greater height than the height of the second electrode so that exposed portions of the first and second electrodes are in a common plane.