Methods of making printable device wafers with sacrificial layers
Methods of forming integrated circuit devices include forming a sacrificial layer on a handling substrate and forming a semiconductor active layer on the sacrificial layer. The semiconductor active layer and the sacrificial layer may be selectively etched in sequence to define an semiconductor-on-insulator (SOI) substrate, which includes a first portion of the semiconductor active layer. A multi-layer electrical interconnect network may be formed on the SOI substrate. This multi-layer electrical interconnect network may be encapsulated by an inorganic capping layer that contacts an upper surface of the first portion of the semiconductor active layer. The capping layer and the first portion of the semiconductor active layer may be selectively etched to thereby expose the sacrificial layer. The sacrificial layer may be selectively removed from between the first portion of the semiconductor active layer and the handling substrate to thereby define a suspended integrated circuit chip encapsulated by the capping layer.
1. A method of making a wafer, comprising:
providing a substrate;
disposing a sacrificial layer of sacrificial material on the substrate;
patterning the sacrificial layer to form an array of spaced-apart sacrificial patterns;
disposing anchors between the spaced-apart sacrificial patterns that fill the space between the spaced-apart sacrificial patterns with an anchor material, wherein the sacrificial material is selectively etchable from the anchor material, wherein the anchors have a thickness that is greater than or equal to a thickness of the spaced-apart sacrificial patterns; and
forming a multi-layer interconnect network or a device on the substrate over each of the sacrificial patterns after the anchors are disposed.
2. The method of claim 1 , comprising selectively etching the sacrificial patterns.
3. The method of claim 1 , comprising disposing a tether over at least a portion of each spaced-apart sacrificial pattern and in contact with one of the anchors entirely after the anchors are disposed.
4. The method of claim 1 , comprising forming one or more devices, wherein each of the one or more devices is formed entirely over one of the spaced-apart sacrificial patterns.
5. The method of claim 4 , disposing an encapsulation layer over the one or more devices, at least a portion of one or more of the spaced-apart sacrificial patterns, and one or more of the anchors, and wherein the encapsulation layer forms a tether physically connecting each of the one or more devices to an anchor.
6. The method of claim 4 , wherein each of the one or more devices is an integrated circuit device.
7. The method of claim 4 , wherein each of the one or more devices is physically connected to at least one of the anchors by one or more respective tethers each laterally extending from a sidewall of the at least one of the anchors.
8. The method of claim 7 , wherein each of the one or more devices is attached to the one or more respective tethers over an attachment area having a height that is less than a height of the device.
9. The method of claim 4 , wherein each of the one or more devices is thicker than the spaced-apart sacrificial patterns.
10. The method of claim 4 , wherein each of the one or more devices is encapsulated by an inorganic capping layer and the capping layer comprises a metal or amorphous silicon.
11. The method of claim 4 , wherein one or more of the one or more devices has a roughened surface that is encapsulated by an inorganic capping layer.
12. The method of claim 4 , comprising forming a multi-layer electrical interconnect networks, the multi-layer electrical interconnect network disposed on a semiconductor active layer of a corresponding one or more of the devices, wherein one or more of the multi-layer electrical interconnect networks is encapsulated by an inorganic capping layer.
13. The method of claim 1 , wherein the anchors comprise polysilicon or an oxide.
14. The method of claim 1 , wherein the anchors are ring shaped.
15. The method of claim 1 , wherein the spaced-apart sacrificial patterns comprise at least one material selected from the group consisting of molybdenum, aluminum, copper, nickel, chromium, tungsten, titanium and alloys thereof.
16. The method of claim 1 , comprising removing the sacrificial layer to form recesses thereby exposing a sidewall of the anchors.
17. A method of making a wafer, comprising:
providing a substrate; and
disposing a sacrificial layer of sacrificial material on the substrate;
patterning the sacrificial layer to form an array of spaced-apart sacrificial patterns;
disposing anchors between the spaced-apart sacrificial patterns that fill the space between the spaced-apart sacrificial patterns with an anchor material, wherein the sacrificial material is selectively etchable from the anchor material, wherein the anchors have a thickness that is greater than or equal to a thickness of the spaced-apart sacrificial patterns;
removing the sacrificial layer to form recesses thereby exposing a sidewall of the anchors, wherein the anchors comprise polysilicon.