Etching technique for creation of thermally-isolated microstructures

摘要

There is described a method for creating a thermally-isolated microstructure on a slab of mono-crystalline silicon which uses a hybrid dry-then-wet etch technique that when controlled, can produce microstructures without any silicon adhering underneath, microstructures having small masses of silicon adhering underneath, and microstructures that are still attached to the slab of mono-crystalline silicon via a waisted silicon body. When creating the microstructures with a waisted silicon body, the thermal isolation of the microstructure can be designed by controlling the depth of the etching and the size of the waist.

主权项

1. A method for designing at least one thermally-isolated microstructure in a semiconductor chip, the method comprising;
(a) determining a size of said at least one microstructure by selecting a length and a width of a top layer and a dimension for a waist of the at least one microstructure, and determining a configuration of said at least one microstructure by selecting a design for a base of said microstructure having a plurality of regions and selected from one of a waisted structure, a silicon island, and a platform with no silicon beneath at least one of the plurality of regions; (b) selecting parameters of dry-etch depth (Ddry) to create vertical silicon walls and wet-etch depth (Dwet) to create inverted sidewalls in a cavity for said at least one microstructure to obtain the size and configuration selected in step (a); and (c) generating a layout specifying parameters for a patterned dielectric film on a slab of mono-crystalline silicon using the size, configuration, dry-etch depth and wet-etch selected in steps (a) and (b).