Isolated protrusion/recession features in microelectromechanical systems
AssigneeTexas Instruments Incorporated
InventorsPatrick Ian Oden, James Carl Baker, Sandra Zheng, William C. McDonald
Life of this patent
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Abstract
In described examples, a microelectromechanical system (MEMS) includes a first element and a second element. The first element is mounted on a substrate and has a first contact surface. The second element is mounted on the substrate and has a second contact surface that protrudes from the second element to form an acute contact surface. The first element and/or the second element is/are operable to move in: a first direction, such that the first contact surface comes in contact with the second contact surface; and a second direction, such that the second contact surface separates from the first contact surface.
Claims13
A method for making a microelectromechanical system (MEMS) device, the method comprising:
- forming a photoresist layer on a spring tip layer, the spring tip layer over a substrate, the spring tip layer having a first wedge shaped protrusion having a first edge;
- sculpting the photoresist layer to form a shaped depression feature using gray-scale lithography with a photomask including both partial and complete concentric opaque circles;
- depositing a mirror layer over the photoresist layer, such that a second edge shaped protrusion is formed in a side of the mirror layer facing the spring tip layer, the second edge shaped protrusion of the mirror layer corresponding to the shaped depression feature in the photoresist layer;
- patterning the mirror layer to form a mirror having the second edge shaped protrusion, wherein the mirror is deformable and the mirror is coupled to the substrate;
- and
- removing the photoresist layer, wherein the second edge shaped protrusion has a second edge, the second edge configured to contact the first edge.
A method for fabricating a microelectromechanical system (MEMS) device, the method comprising:
- forming a sacrificial layer on a spring tip, the spring tip over a substrate, wherein the spring tip has a first wedge shaped protrusion having a first edge;
- performing gray-scale lithography with a photomask including both partial and complete concentric opaque circles on the sacrificial layer to form a depression in the sacrificial layer;
- depositing a deformable layer on the sacrificial layer and in the depression, wherein the deformable layer has a curved portion corresponding to the depression and the deformable layer is coupled to the substrate, wherein the curved portion of the deformable layer forms a second edge shaped protrusion having a second edge on a side of the deformable layer facing the spring tip, the second edge shaped protrusion corresponding to the depression in the sacrificial layer;
- and
- removing the sacrificial layer, wherein the second edge is configured to contact the first edge.
A method for fabricating a microelectromechanical system (MEMS) device, the method comprising:
- performing gray-scale lithography with a photomask including both partial and complete concentric opaque circles on a sacrificial layer over a spring tip, to form depression features in the sacrificial layer, wherein the spring tip has a contact surface;
- depositing a deformable layer on the sacrificial layer and in the depression features, wherein the deformable layer has protrusions corresponding to the depression features;
- etching the deformable layer to form a mirror having the protrusions on a side of the mirror facing the spring tip;
- and
- removing the sacrificial layer, wherein a protrusion of the protrusions has a radius of curvature of less than 10 microns.
Dependencies are inferred from the claim text.