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. A method of removing a sacrificial layer in a substrate, comprising:
applying an etch material to the substrate, wherein the substrate comprises at least one pre-existing aperture and at least one pre-existing channel;
penetrating the substrate with the etch material via the at least one pre-existing aperture formed in the substrate;
removing a portion of the sacrificial layer by the etch material to reach the at least one pre-existing channel formed in the substrate with the etch material;
dispersing the etch material via the at least one pre-existing channel formed in the substrate; and
removing a remaining portion of the sacrificial layer by the etch material via the at least one pre-existing channel and the at least one pre-existing aperture.
2. The method of claim 1 , further comprising:
forming the at least one pre-existing channel in a layer of the substrate proximate the sacrificial layer; and
forming the at least one pre-existing aperture in the substrate.
3. The method of claim 2 , wherein forming the at least one pre-existing channel comprises forming a plurality of channels.
4. The method of claim 2 , further comprising depositing at least one layer over the at least one pre-existing channel.
5. The method of claim 4 , wherein forming the at least one pre-existing aperture comprises forming the at least one pre-existing aperture in the at least one layer over the at least one pre-existing channel.
6. A method of removing a sacrificial layer in a substrate, comprising:
applying an etch material to the substrate, wherein the substrate comprises at least one pre-existing aperture formed in a surface of the substrate and at least one pre-existing channel formed within the substrate;
penetrating the substrate with the etch material via the at least one pre-existing aperture and the at least one pre-existing channel; and
removing the sacrificial layer by the etch material via the at least one pre-existing channel and the at least one pre-existing aperture.
7. The method of claim 6 , further comprising forming the at least one pre-existing aperture and the at least one pre-existing channel in the substrate.
8. The method of claim 7 , wherein forming the at least one pre-existing channel further comprises forming a first channel of the at least one pre-existing channel with a width less than about 300 nanometers.
9. The method of claim 6 , wherein the penetrating further comprises reaching the at least one pre-existing channel with the etch material via the at least one pre-existing aperture.