Method of fabricating microstructures and devices made therefrom

A method of fabricating a micromachined device, comprising:

• forming a CMOS circuitry layer stack on a SCS substrate, the CMOS circuitry layer stack having a plurality of metal etch-resistant layers;
• directionally etching a first portion of the CMOS circuitry layer stack selectively masked by a first metal etch-resistant layer;
• directionally etching a first portion of the SCS substrate selectively masked by the first metal etch-resistant layer;
• isotropically etching a second portion of the SCS substrate for a controlled period of time to remove substrate material from under a first composite CMOS thin film microstructure;
• removing a portion of the first metal etch-resistant layer;
• directionally etching a second portion of the CMOS circuitry layer stack selectively masked by a second metal etch-resistant layer;
• and
• directionally etching a third portion of the SCS substrate selectively masked by the second metal etch-resistant layer to define a second microstructure, the second microstructure comprising a composite CMOS thin film layer stack portion and a SCS substrate layer portion.

A method of fabricating a micromachined device, comprising:

• forming a composite thin film layer stack on a substrate, the circuitry layer including a plurality of etch-resistant layers;
• backside etching the substrate;
• removing a first portion of the composite thin film layer stack selectively masked by a first etch-resistant layer;
• directionally etching a portion of the substrate selectively masked by a second etch-resistant layer to define a microstructure, the microstructure comprising a composite thin film layer stack portion and a substrate layer portion;
• and
• removing the composite thin film layer stack portion from the microstructure.

A MEMS device, comprising:

• a first microstructure including a first composite thin film microstructure portion and a first underlying substrate portion;
• a second microstructure having a bare substrate portion, wherein the bare substrate portion is electrically isolated from the first underlying substrate portion of the first microstructure by an opening;
• and
• a third microstructure disposed in the opening, the third microstructure having a composite thin film microstructure portion and no underlying substrate portion.