Method for etching deep, high-aspect ratio features into glass, fused silica, and quartz materials

摘要

A method or process is disclosed for etching deep, high-aspect ratio features into silicon dioxide material layers and substrates, including glass, fused silica, quartz, or similar materials, using a plasma etch technology. The method has application in the fabrication and manufacturing of MEMS, microelectronic, micro-mechanical, photonic and nanotechnology devices in which silicon dioxide material layers or substrates are used and must be patterned and etched. Devices that benefit from the method described in this invention include the fabrication of MEMS gyroscopes, resonators, oscillators, microbalances, accelerometers, for example. The etch method or process allows etch depths ranging from below 10 microns to over 1 millimeter and aspect ratios from less than 1 to 1 to over 10 to 1 with etched feature sidewalls having vertical or near vertical angles. Additionally, the disclosed method provides requirements of the etched substrates to reduce or eliminate undesired effects of an etch.

主权项

1. A method of making deep, high-aspect ratio features into a layer formed from a first material comprised of silicon dioxide, the method comprising:
selecting a substrate formed from a second material of a predetermined thickness; fabricating the first material layer of a predetermined thickness on top of the second material substrate; fabricating a layer formed from a third material of a predetermined thickness on the surface of the first material layer, the third material layer functioning as hard etch mask layer and having a pre-determined inverse pattern of features to be etched into the first material layer, the third material layer being comprised of a ceramic, semiconductor or metal material; and performing, without the presence of a hydrogen containing process gas, a deep, high-aspect ratio Inductively-Coupled Plasma (ICP) etch into the exposed regions of the first material layer to a predetermined depth of at least 2 microns using an ICP etch system configured with an electromagnetic neutral loop comprised of at least three (3) magnetic coils to provide a uniform etch of the first material layer across the substrate surface, wherein the material type and predetermined thickness of the third material layer hard etch mask allow the third material layer to persist until the predetermined etch depth into the first material layer is obtained.