Techniques for bonding substrates using an intermediate layer
A method includes depositing a thin film on a first surface of a first substrate and moving a second surface of a second substrate into contact with the thin film such that the thin film is located between the first and second surfaces. The method further includes generating electromagnetic (EM) radiation of a first wavelength, the first wavelength selected such that the thin film absorbs EM radiation at the first wavelength. Additionally, the method includes directing the EM radiation through one of the first and second substrates and onto a region of the thin film until the first and second substrates are fused in the region.
1. A device comprising:
a first glass substrate;
a second glass substrate; and
an intermediate layer disposed between the first and second glass substrates, wherein the first and second glass substrates are fused together by the intermediate layer, and wherein the intermediate layer is configured to receive a first electromagnetic (EM) radiation through one of the first and second wafers and onto a region of the intermediate layer until the first and second glass substrates are fused in the region without causing the first and second glass substrates to melt or flow.
2. The device of claim 1 , wherein the bonding region, as viewed through the first and second glass substrates, is transparent to wavelengths of the first EM radiation in the visible spectrum.
3. The device of claim 1 , wherein the bonding region is stronger than the bulk of the first and second glass substrates.
4. The device of claim 1 , wherein the first and second glass substrates at least partially define an enclosed cavity, and wherein the bonding region circumscribes the enclosed cavity.
5. The device of claim 4 , wherein the bonding region hermetically seals the enclosed cavity from an environment external to the enclosed cavity.
6. The device of claim 4 , further comprising an electronic component housed within the enclosed cavity.
7. The device of claim 6 , wherein the electronic component includes at least one of an integrated circuit, a sensor, an energy storage device, and an antenna.
8. The device of claim 6 , wherein at least one of the first and second glass substrates includes a via that extends from the enclosed cavity to an environment external to the enclosed cavity, and wherein the electronic component is electrically coupled to the via.
9. The device of claim 1 , wherein the intermediate layer comprises an amorphous silicon thin film.
10. The device of claim 1 , wherein the intermediate layer comprises a metal thin film.
11. The device of claim 1 , wherein the first EM radiation is selected having a wavelength that is absorbable by the intermediate layer to cause melting of the intermediate layer.
12. The device of claim 1 , wherein the one of the first and second substrates is configured to be transparent to a wavelength of the first EM radiation.
13. The device of claim 1 , wherein the first and second substrates include at least one or more cavities.
14. The device of claim 13 , further comprising disposing electronic components within the at least one cavity.
15. The device of claim 13 , wherein the intermediate layer is deposited to circumscribe the at least one cavity, and the first and second substrates are arranged to be fused in the regions circumscribing the at least one cavity.
16. The device of claim 1 , wherein the intermediate layer is configured having a thickness of less than 100 nanometers.
17. The device of claim 1 , wherein a region of the intermediate layer is tinted in the visible spectrum prior to directing EM radiation onto the region, and wherein the region is transparent and colorless in the visible spectrum after the first and second substrates are fused in the region.