Process for forming MEMS

A process of forming a micromechanical electrical structure comprising:

• depositing a first seed layer on a substrate;
• depositing a first photoresist layer on the first seed layer;
• exposing the first photoresist layer to a first pattern of radiation to render the first photoresist layer dissolvable in a first pattern;
• removing the dissolvable photoresist of the first photoresist layer;
• removing a portion of the first seed layer in the area where the first photoresist layer has been removed;
• removing the remainder of the first photoresist layer;
• depositing a second seed layer on the substrate and first seed layer;
• depositing a second photoresist layer on the exposed surfaces of the first seed layer and the exposed surface of the second seed layer;
• exposing the second photoresist layer to a second pattern of radiation to render the second photoresist layer dissolvable in a second pattern;
• removing the dissolvable photoresist of the second photoresist layer;
• etching away a portion of the second seed layer in the area where the second photoresist layer has been dissolved;
• electroplating a layer of primary metal across the plating base in the area where the second photoresist layer has been removed;
• removing the remainder of the second photoresist layer;
• applying a third photoresist layer across the second seed layer and the layer of primary metal;
• exposing the third photoresist layer to a third pattern of radiation to render the third photoresist layer dissolvable in a third pattern, the third pattern being formed such that an area surrounding the primary metal is dissolved, wherein the area is less than the entirety of the substrate;
• electroplating an amount of secondary metal in the area where the third photoresist layer has been removed;
• machining the exposed surface of the secondary metal down to a substantially flat surface corresponding to a desired height of the layer of primary metal;
• removing the remainder of the photoresist of the third photoresist layer;
• etching away the remainder of the secondary metal;
• and
• etching away the second seed layer.

A process for forming a micromechanical structure comprising:

• providing a plating base on a surface of a substrate;
• forming a first photoresist layer on the plating base;
• exposing the first photoresist layer to a first pattern of radiation to render the first photoresist layer dissolvable in a first pattern;
• removing the dissolvable photoresist of the first photoresist layer;
• electroplating a layer of primary metal onto the plating base in the area where the first photoresist layer has been removed;
• removing the remainder of the first photoresist layer;
• forming a second photoresist layer over the plating base and the layer of primary metal;
• exposing the second photoresist layer to a second pattern of radiation to render the second photoresist layer dissolvable in a second pattern, the second pattern being formed such that an area surrounding the primary metal is dissolved, wherein the area is less than the entirety of the substrate;
• removing the dissolvable photoresist of the second photoresist layer;
• electroplating an amount of secondary metal in the area where the second photoresist layer has been removed;
• forming a layer of polymer over substantially the entire length of the substrate;
• machining the polymer, the secondary metal, and the primary metal down to a substantially flat surface corresponding to a desired height of the layer of primary metal;
• removing the remainder of the photoresist of the second photoresist layer;
• and
• etching away the remainder of the secondary metal.