Method and structure for creating cavities with extreme aspect ratios
Embodiments relate to structures, systems and methods for more efficiently and effectively etching sacrificial and other layers in substrates and other structures. In embodiments, a substrate in which a sacrificial layer is to be removed to, e.g., form a cavity comprises an etch dispersion system comprising a trench, channel or other structure in which etch gas or another suitable gas, fluid or substance can flow to penetrate the substrate and remove the sacrificial layer. The trench, channel or other structure can be implemented along with openings or other apertures formed in the substrate, such as proximate one or more edges of the substrate, to even more quickly disperse etch gas or some other substance within the substrate.
1. An etch dispersion system formed in a substrate and comprising:
at least one dispersion aperture formed in the substrate and configured to provide access to a sacrificial layer of the substrate by an etch material; and
at least one dispersion channel formed in the substrate proximate the sacrificial layer and configured to facilitate dispersion of the etch material within the substrate,
wherein the at least one dispersion aperture and the at least one dispersion channel are formed prior to application of the etch material, and
wherein the at least one dispersion aperture and the at least one dispersion channel are separated by the sacrificial layer.
2. The system of claim 1 , wherein etch material gains access to the at least one dispersion channel by removing a portion of the sacrificial layer between the at least one dispersion aperture and the at least one dispersion channel.
3. The system of claim 1 , wherein the at least one dispersion aperture comprises a plurality of apertures formed proximate a perimeter of the substrate.
4. The system of claim 3 , wherein the at least one dispersion aperture comprises at least one aperture formed in an interior portion of the substrate.
5. The system of claim 1 , wherein the at least one dispersion channel comprises a plurality of channels.
6. The system of claim 5 , wherein at least two of the plurality of channels are coupled with one another.
7. The system of claim 5 , wherein at least two of the plurality of channels are formed in different layers of the substrate.
8. The system of claim 5 , wherein at least two of the plurality of channels are formed at different depths of the substrate.
9. The system of claim 1 , wherein a width of the at least one channel is less than about 300 nanometers.