Vertical tethers for micro-transfer printing
A micro-transfer-printable component source structure includes a source wafer comprising an anchor portion, a sacrificial portion disposed on only a portion of the source wafer adjacent to the anchor portion, a component disposed directly and exclusively over the sacrificial portion, and a vertical tether physically connecting the component to the source wafer. The vertical tether extends from the component along a side of the sacrificial portion to the anchor portion and includes a vertical portion that extends in a direction at least partially orthogonal to a surface of the source wafer. The vertical portion can be between the component and the source wafer or adjacent to the component. Components with vertical tethers require less area on the source wafer and can be micro-transfer printed to a target substrate in closer alignment.
1 . A micro-transfer-printable component source structure, comprising:
a source wafer having a source-wafer thickness extending in a vertical direction to a source-wafer surface comprising an anchor portion;
a sacrificial portion of sacrificial material disposed on only a portion of the source-wafer surface adjacent to the anchor portion, the sacrificial portion having a sacrificial-portion side extending along a sacrificial-portion edge of the sacrificial portion at least partially in the vertical direction;
a component at least partially disposed on the sacrificial portion, the component having a component side extending along a component edge of the component at least partially in the vertical direction; and
a vertical tether physically connecting the component to the source-wafer surface, the vertical tether extending from the component along the sacrificial-portion side to the anchor portion and comprising a vertical portion that extends at least partially in the vertical direction such that the vertical portion is in contact with the sacrificial material along the sacrificial-portion side,
wherein the component is disposed directly and exclusively on the sacrificial portion or is disposed directly and exclusively on the sacrificial portion in combination with the vertical portion, and
wherein the vertical tether extends along and in contact with some but less than all of the component side.
2 . The micro-transfer-printable component source structure of claim 1 , wherein the component edge extends at an angle no less than 45 degrees from the source-wafer surface or wherein the component edge extends orthogonally from the source-wafer surface.
3 . The micro-transfer-printable component source structure of claim 1 , wherein the sacrificial-portion edge extends at an angle no less than 45 degrees from the source-wafer surface or wherein the sacrificial-portion edge extends orthogonally from the source-wafer surface.
4 . The micro-transfer-printable component source structure of claim 1 , wherein the sacrificial portion comprises a sacrificial portion material and the component comprises a component material that is differentially etchable from the sacrificial portion material.
5 . The micro-transfer-printable component source structure of claim 1 , wherein the vertical tether extends along and on at least a part of the source-wafer surface that is not the sacrificial portion.
6 . The micro-transfer-printable component source structure of claim 1 , wherein the sacrificial portion comprises a sacrificial portion material and the source wafer comprises a source wafer material that is differentially etchable from the sacrificial portion material.
7 . The micro-transfer-printable component source structure of claim 1 , wherein the component comprises a component material and the source wafer comprises a source wafer material that is the same as the component material.
8 . The micro-transfer-printable component source structure of claim 1 , wherein the vertical tether comprises an inorganic material, an organic material, or comprises layers comprising organic and inorganic materials.
9 . The micro-transfer-printable component source structure of claim 1 , wherein the vertical tether comprises silicon oxide, silicon nitride, an epoxy, polyimide, or a photoresist.
10 . The micro-transfer-printable component source structure of claim 1 , wherein the sacrificial portion is an etched sacrificial portion forming a gap between the component and the source wafer.
11 . The micro-transfer-printable component source structure of claim 1 , wherein a portion of the vertical tether that is not over the component extends in the vertical direction a greater distance than in a horizontal direction orthogonal to the vertical direction.
12 . The micro-transfer-printable component source structure of claim 1 , wherein the vertical tether is constructed to fracture along the sacrificial-portion side.
13 . A micro-transfer-printable component source structure, comprising:
a source wafer having a source-wafer thickness extending in a vertical direction and comprising an anchor portion;
a sacrificial portion disposed on only a portion of the source wafer adjacent to the anchor portion, the sacrificial portion having a sacrificial-portion side that extends at least partially in the vertical direction;
a component at least partially disposed on the sacrificial portion, the component having a component side extending along a component edge of the component at least partially in the vertical direction; and
a vertical tether physically connecting the component to the source wafer, the vertical tether extending from the component along the sacrificial-portion side of the sacrificial portion to the anchor portion and including a vertical portion that extends at least partially in the vertical direction such that the vertical portion is in contact with the sacrificial-portion side of the sacrificial portion,
wherein the component is disposed directly and exclusively on the sacrificial portion or is disposed directly and exclusively on the sacrificial portion in combination with the vertical portion, and
wherein the vertical tether extends along and in contact with some but less than all of the component side.
14 . A micro-transfer-printable component source structure, comprising:
a source wafer having a source-wafer thickness extending in a vertical direction to a source-wafer surface comprising an anchor portion;
a sacrificial portion comprising a sacrificial material disposed on only a portion of the source-wafer surface adjacent to the anchor portion, the sacrificial portion having a sacrificial-portion side extending along a sacrificial-portion edge of the sacrificial portion at least partially in the vertical direction;
a component at least partially disposed on the sacrificial portion, the component having a component side extending along a component edge of the component at least partially in the vertical direction; and
a vertical tether physically connecting the component to the source-wafer surface, the vertical tether extending from the component along the sacrificial-portion side to the anchor portion and comprising a vertical portion that extends at least partially in the vertical direction,
wherein the component is disposed directly and exclusively on the sacrificial portion or is disposed directly and exclusively on the sacrificial portion in combination with the vertical portion,
wherein the vertical tether has a first width on at least a first portion of the sacrificial-portion side that is narrower than a second width on at least a second portion of the sacrificial-portion side, wherein the first portion is different from the second portion.
15 . A micro-transfer-printable component source structure, comprising:
a source wafer having a source-wafer thickness extending in a vertical direction to a source-wafer surface comprising an anchor portion;
a sacrificial portion comprising a sacrificial material disposed on only a portion of the source-wafer surface adjacent to the anchor portion, the sacrificial portion having a sacrificial-portion side extending along a sacrificial-portion edge of the sacrificial portion at least partially in the vertical direction;
a component at least partially disposed on the sacrificial portion, the component having a component side extending along a component edge of the component at least partially in the vertical direction; and
a vertical tether physically connecting the component to the source-wafer surface, the vertical tether extending from the component along the sacrificial-portion side to the anchor portion and comprising a vertical portion that extends at least partially in the vertical direction,
wherein the component is disposed directly and exclusively on the sacrificial portion or is disposed directly and exclusively on the sacrificial portion in combination with the vertical portion,
wherein the vertical portion is directly between the component and the source wafer.
16 . A micro-transfer-printable component source structure, comprising:
a source wafer having a source-wafer thickness extending in a vertical direction and comprising an anchor portion;
a sacrificial portion disposed on only a portion of the source wafer adjacent to the anchor portion, the sacrificial portion having a sacrificial-portion side that extends at least partially in the vertical direction;
a component at least partially disposed on the sacrificial portion; and
a vertical tether physically connecting the component to the source wafer, the vertical tether extending from the component along the sacrificial-portion side of the sacrificial portion to the anchor portion and including a vertical portion that extends at least partially in the vertical direction,
wherein the component is disposed directly and exclusively on the sacrificial portion or is disposed directly and exclusively on the sacrificial portion in combination with the vertical portion, and
wherein the vertical portion is directly between the component and the source wafer.
17 . A micro-transfer-printable component source structure, comprising:
a source wafer having a source-wafer thickness extending in a vertical direction to a source-wafer surface comprising an anchor portion;
a sacrificial portion of sacrificial material disposed on only a portion of the source-wafer surface adjacent to the anchor portion, the sacrificial portion having a sacrificial-portion side extending along a sacrificial-portion edge of the sacrificial portion at least partially in the vertical direction;
a component at least partially disposed on the sacrificial portion, the component having a component side extending along a component edge of the component at least partially in the vertical direction; and
a vertical tether physically connecting the component to the source-wafer surface, the vertical tether extending from the component along the sacrificial-portion side to the anchor portion and comprising a vertical portion that extends at least partially in the vertical direction such that the vertical portion is in contact with the sacrificial material along the sacrificial-portion side,
wherein the component is disposed directly and exclusively on the sacrificial portion or is disposed directly and exclusively on the sacrificial portion in combination with the vertical portion, and
wherein the vertical tether has a sacrificial portion width on at least a portion of the sacrificial-portion side that is narrower than a component width on at least a portion of the component side.