Multicomponent sacrificial structure

A method of fabricating a microelectromechanical systems device, the method comprising:

• forming over a first structural layer a sacrificial structure comprising a first portion proximal to the first structural layer and a second portion distal to the first structural layer, wherein
• the sacrificial structure is selectively etchable in the presence of the first structural layer and the second structural layer, and
• one of the first portion and the second portion is selectively etchable in the presence of the other of the first portion and the second portion;
• forming a second structural layer over the sacrificial structure;
• and
• forming a plurality of etchant access openings extending through the second structural layer.

A method of manufacturing a microelectromechanical systems device comprising:

• forming a sacrificial layer over a first layer;
• forming a second layer over the sacrificial layer;
• selectively etching the sacrificial layer from between the first layer and the second layer to form at least one pillar extending between the first layer and the second layer;
• and
• mechanically decoupling the sacrificial layer from at least one of the first layer and the second layer before etching away the at least one pillar.

An apparatus comprising a microelectromechanical systems device, wherein the micromechanical systems device comprises:

• a first sacrificial layer contacting a first structural layer;
• a second sacrificial layer formed over the first sacrificial layer;
• and
• a second structural layer contacting the second sacrificial layer, wherein
• the first sacrificial layer and the second sacrificial layer are selectively etchable in the presence of the first structural layer and the second structural layer using a preselected etchant, and
• one of the first sacrificial layer and second sacrificial layer is etched by the preselected etchant at faster rate than the other.

An apparatus comprising a microelectromechanical systems device, wherein the micromechanical systems device comprises:

• a dielectric layer formed over a first conductive layer;
• a sacrificial structure formed over the dielectric layer;
• and
• a second conductive layer formed over the sacrificial structure, wherein
• the sacrificial structure is selectively etchable in the presence of the dielectric layer and the second conductive layer using a preselected etchant, and
• the sacrificial structure comprises a faster etching portion and a slower etching portion with respect to the preselected etchant.

An apparatus comprising a microelectromechanical systems device, wherein the micromechanical systems device comprises:

• a compositionally non-uniform sacrificial structure formed over a first structural layer;
• and
• a second structural layer formed over the sacrificial structure, wherein
• the second structural layer comprises a plurality of etchant access openings extending through the second structural layer,
• the sacrificial structure is selectively etchable in the presence of the first structural layer and the second structural layer, and
• a preselected etchant etches the sacrificial structure non-uniformly.

An apparatus comprising a microelectromechanical systems device, wherein the micromechanical systems device comprises:

• a first structural means for supporting the microelectromechanical systems device;
• a sacrificial means for forming a cavity in the microelectromechanical systems device;
• and
• a second structural means for actuating the microelectromechanical systems device, wherein
• the second structural means comprises a plurality of etchant access means for contacting the sacrificial means with an etchant means, and
• the sacrificial means comprises a faster etching portion and a slower etching portion.

A method of manufacturing a microelectromechanical systems device comprising:

• forming a sacrificial structure over a first layer;
• forming a second layer over the sacrificial structure;
• and
• selectively etching away the sacrificial structure substantially completely from between the first layer and the second layer using a preselected etchant,
• wherein the sacrificial structure comprises a faster etching portion and a slower etching portion with respect to the preselected etchant.

An apparatus comprising a microelectromechanical systems device, wherein the micromechanical systems device comprises:

• a sacrificial structure formed over a first structural layer;
• and
• a second structural layer formed over the sacrificial structure, wherein
• the sacrificial structure comprises a first portion and a second portion,
• one of the first portion and the second portion has a faster intrinsic etching rate using a preselected etchant,
• the sacrificial structure is selectively etchable in the presence of the first structural layer and the second structural layer using the preselected etchant, and
• an aspect ratio of a width or length to thickness of the sacrificial structure is at least about 50:1.