Micro-transfer printing with selective component removal
An example of a method of micro-transfer printing comprises providing a micro-transfer printable component source wafer, providing a stamp comprising a body and spaced-apart posts, and providing a light source for controllably irradiating each of the posts with light through the body. Each of the posts is contacted to a component to adhere the component thereto. The stamp with the adhered components is removed from the component source wafer. The selected posts are irradiated through the body with the light to detach selected components adhered to selected posts from the selected posts, leaving non-selected components adhered to non-selected posts. In some embodiments, using the stamp, the selected components are adhered to a provided destination substrate. In some embodiments, the selected components are discarded. An example micro-transfer printing system comprises a stamp comprising a body and spaced-apart posts and a light source for selectively irradiating each of the posts with light.
1. A method of micro-transfer printing, comprising:
providing a component source wafer having micro-transfer printable components disposed on or in the component source wafer, wherein selected ones of the micro-transfer printable components are selected components and the micro-transfer printable components that are not selected are non-selected components;
providing a stamp comprising a body and spaced-apart posts protruding away from the body, the posts having a spatial distribution on the body matched to a spatial distribution of the micro-transfer printable components on or in the component source wafer;
providing a light source;
contacting each of the posts to a component of the micro-transfer printable components to adhere the component to the post, wherein posts contacting the selected components are selected posts and posts contacting the non-selected components are non-selected posts;
removing the stamp with the adhered components from the component source wafer; and
irradiating each of the selected posts through the body with light from the light source to detach the selected components adhered to the selected posts from the selected posts, leaving the non-selected components adhered to the non-selected posts,
wherein the body and the posts are substantially transparent to the light.
2. The method of claim 1 , wherein the component source wafer comprises a patterned sacrificial layer defining spaced-apart sacrificial portions and anchors, and the components are each disposed over a sacrificial portion and physically connected to an anchor by a tether, and wherein the steps of contacting the posts to the components and removing the stamp fractures the tethers.
3. The method of claim 1 , comprising:
providing a destination substrate; and
contacting the non-selected components to the destination substrate using the stamp to adhere the non-selected components to the destination substrate or to a layer on the destination substrate after detaching the selected components from the selected posts.
4. The method of claim 3 , wherein the step of providing a destination substrate comprises providing an adhesive layer on the destination substrate and the step of contacting the non-selected components to the destination substrate comprises directly contacting the non-selected components to the adhesive layer.
5. The method of claim 1 , wherein each of the components comprises an ablation layer and wherein the irradiating the selected posts vaporizes at least a portion of the ablation layer of the selected components.
6. The method of claim 1 , wherein the selected components are disposed in contact with a destination substrate or a layer disposed on the destination substrate during the irradiating.
7. The method of claim 1 , wherein the selected components are first selected components, the non-selected components are first non-selected components, and the method comprises:
providing a destination substrate;
transferring the first selected components to first component locations;
selecting second selected components from among the first non-selected components, wherein the non-selected posts to which the second selected components are adhered are second selected posts; and
transferring the second selected components to second component locations by irradiating the second selected posts through the body with the light to detach the second selected components adhered to the second selected posts from the second selected posts.
8. The method of claim 7 , wherein the components define an array, the first selected components are a first sparse subset of the array, and the second selected components are a second sparse subset of the array.
9. The method of claim 1 , comprising testing each of the components before contacting the posts to the components to determine faulty components and selecting components that are faulty so that each of the selected components is a faulty component.
10. The method of claim 1 , comprising testing each of the components before contacting the posts to the components to determine faulty components to select components that are not faulty so that each of the selected components is a non-faulty component.
11. The method of claim 1 , comprising providing a disposal area and moving the stamp to the disposal area before the irradiating of the selected posts so that the irradiating of the selected posts detaches the selected components from the selected posts and disposes the selected components in the disposal area.
12. The method of claim 1 , comprising providing a destination substrate and moving the stamp to the destination substrate before irradiating the selected posts so that the irradiating of the selected posts detaches the selected components from the selected posts and adheres the selected components to the destination substrate or to a layer on the destination substrate.
13. The method of claim 1 , wherein the selected components are disposed over, but not in contact with, the destination substrate or the layer on the destination substrate during the irradiating.
14. The method of claim 1 , wherein the irradiating of the selected posts comprises irradiating a single post at a time.
15. The method of claim 1 , wherein the irradiating of the selected posts comprises irradiating multiple posts at a time.
16. The method of claim 1 , wherein each of the posts has a distal end away from the body and the step of contacting each post to a component comprises contacting the distal end of the post to the component to adhere the component to the distal end of the post, and
wherein the irradiating of the selected posts with the light source irradiates the distal end of each selected post to detach the selected component adhered to the selected post from the distal end of the selected post.
17. The method of claim 1 , comprising providing a mapping of the selected components and the non-selected components.
18. The method of claim 1 , wherein the selected components have at least one characteristic different from a characteristic of the non-selected components.
19. The method of claim 1 , wherein the body and the posts are made from a same material.
20. The method of claim 19 , wherein the same material is polydimethylsiloxane (PDMS).