Thin film precursor stack for MEMS manufacturing

A precursor film stack for use in the production of MEMS devices, the precursor film stack comprising:

• a carrier substrate;
• a first layer formed on the carrier substrate, the first layer comprising a plurality of sublayers, wherein at least one of the sublayers comprises a conductive material;
• a second layer of an insulator material formed on the first layer;
• and
• a third layer of a sacrificial material formed on the second layer.

A precursor film stack for use in the production of MEMS devices, the precursor film stack comprising:

• a carrier substrate;
• a first layer formed on the carrier substrate;
• a second layer comrpising an insulator material formed on the first layer;
• and
• a third layer comprising a sacrificial material formed on the second layer, wherein the third layer comprises at least two sublayers, each sublayer alternating with the other, wherein each sublayer is etched by the same release etchant, but has a different etch chemistry from the other, wherein the sublayers define etch stops for each other.

A method of making a precursor film stack for use in the production of MEMS devices, the method comprising:

• providing a substrate;
• forming an optical compensation layer over the substrate, the optical compensation layer comprising a material of a finite extinction coefficient;
• forming a first layer on the optical compensation layer;
• forming a second layer of an insulator material over the first layer;
• and
• forming a third layer of a sacrificial material on te second layer.