Vapor phase etching MEMS devices
AssigneeSemitool, Inc.
InventorEric J. Bergman
Life of this patent
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Abstract
An etch release for a MEMS device on a substrate includes etching the substrate with an etchant vapor and a wetting vapor. A thermal bake of the MEMS device, after the etch release may be used to volatilize residues. A supercritical fluid may also be used to remove residual contaminants. The combination of the etchant vapor, such as HF, and the wetting vapor, such as an alcohol vapor, improves the uniformity of the etch undercut on the substrate.
Claims15
A method of manufacturing a MEMS device on a substrate, comprising the steps of:
- placing the substrate into a process chamber;
- generating an HF etchant vapor from an HF etchant liquid that includes water;
- providing the HF etchant vapor and water vapor into the process chamber;
- providing a wetting vapor into the process chamber, with the chamber substantially at or above ambient pressure;
- etching the substrate until etch release of the MEMS device occurs;
- and
- purging the vapors from the chamber.
A method of processing a MEMS device on a substrate, the device having a component requiring detachment from the substrate, comprising the steps of:
- placing the substrate into a process chamber;
- forming HF vapor from a liquid that includes HF and water;
- introducing HF vapor and an alcohol vapor into the process chamber to etch a surface of the substrate, with water vapor also introduced into the process chamber with the HF vapor;
- spraying the device with rinse water to remove contaminants from the device;
- discontinuing the spraying step before the component on the device detaches from the substrate;
- reintroducing HF vapor and an alcohol vapor into the process chamber to further etch the surface of the substrate at least until the component on the device detaches from the substrate;
- and
- purging the HF vapor and alcohol vapors from the chamber.
A method of manufacturing a MEMS device on a substrate, comprising the steps of:
- placing the substrate into a process chamber;
- flowing a carrier gas over a liquid including HF and water, to form an etchant vapor including HF vapor and water vapor;
- providing the HF etchant vapor and water vapor into the process chamber;
- providing an alcohol vapor into the process chamber;
- maintaining the process chamber substantially at or above ambient pressure;
- etching the substrate until etch release of the MEMS device occurs;
- and
- purging the vapors from the chamber.
Dependencies are inferred from the claim text.