Non-planar surface structures and process for microelectromechanical systems

A method of making a microelectromechanical system (MEMS) device, comprising:

• providing a substrate;
• depositing a sacrificial material over at least a portion of the substrate, the sacrificial material being removable by a first etchant;
• forming a permeable layer over the sacrificial material using a non-lithographic method, wherein the permeable layer comprises a masking material more resistant to removal by the first etchant than the sacrificial material;
• removing a portion of the sacrificial material by flowing the first etchant through the permeable layer, thereby forming a non-planar surface on the remaining sacrificial material;
• and
• forming an electrically conductive layer over at least a portion of the non-planar surface.

A method of making an interferometric modulator, comprising:

• providing a substrate;
• depositing a first electrically conductive layer over at least a portion of the substrate;
• depositing a sacrificial material over at least a portion of the first electrically conductive layer, the sacrificial material being removable by an etchant;
• forming a permeable layer over the sacrificial material using a non-lithographic method, wherein the permeable layer comprises a masking material;
• removing a portion of the sacrificial material by flowing the etchant through the permeable layer, thereby forming a non-planar surface on the sacrificial material;
• and
• forming a second electrically conductive layer over at least a portion of the non-planar surface.