MEMS DEVICES WITH MULTI-COMPONENT SACRIFICIAL LAYERS

• US 20110205615A1
• Filed: 04/29/2011
• Published: 08/25/2011
• Est. Priority Date: 03/02/2006
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Kogut, Lior, Tung, Ming-Hau
• Granted Patent: US 8,300,299 B2
• Time in Patent Office: Days
• US Class Current: 359/290
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81B 3/001 Structures having a reduced contact area, e.g. with bumps or with a textured surface
• CPC Class Codes: B81B 3/0072 For controlling internal stress or strain in moving or flexible elements, e.g. stress compensating layers
• CPC Class Codes: B81C 1/00801 Avoid alteration of functional structures by etching, e.g. using a passivation layer or an etch stop layer B81C1/00595, B81C1/00468 take precedence
• CPC Class Codes: B81C 2201/0109 Sacrificial layers not provided for in B81C2201/0107 - B81C2201/0108
• CPC Class Codes: B81C 2201/017 Methods for controlling internal stress of deposited layers not provided for in B81C2201/0164 - B81C2201/0169
• CPC Class Codes: B81C 2201/112 Depositing an anti-stiction or passivation coating, e.g. on the elastic or moving parts
• CPC Class Codes: B81C 2201/115 Roughening a surface
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer
• CPC Class Codes: Y10T 428/31678 Of metal
• CPC Class Codes: Y10T 428/31935 Ester, halide or nitrile of addition polymer

Abstract

Methods of forming a protective coating on one or more surfaces of a microelectromechanical device are disclosed comprising the steps of forming a composite layer of a sacrificial material and a protective material, and selectively etching the sacrificial material to form a protective coating. The protective coatings of the invention preferably improve one or more aspects of the performance of the microelectromechanical devices in which they are incorporated. Also disclosed are microelectromechanical devices formed by methods of the invention, and visual display devices incorporating such devices.

Claims

13-1. The method of claim 1, wherein the second material is selected from the group consisting of:

Si₃N₄, Al₂O₃, SiO₂, Cr, W, and Au.

22. A method of manufacturing an electromechanical device, the method comprising:

forming a composite layer on a surface of an electromechanical device, the composite layer comprising a mixture of a sacrificial material and a second material; and

selectively removing the sacrificial material, relative to the second material, from the composite layer, thereby forming a coating on one or more surfaces of the electromechanical device, the coating comprising the second material,

wherein forming the composite layer comprises sputtering a composite target, the composite target comprising the sacrificial material and the second material.

23. A method of manufacturing an electromechanical device, the method comprising:

forming a composite layer on a surface of an electromechanical device, the composite layer comprising a mixture of a sacrificial material and a second material; and

selectively removing the sacrificial material, relative to the second material, from the composite layer, thereby forming a coating on one or more surfaces of the electromechanical device, the coating comprising the second material,

wherein the coating is configured to dissipate an electrical charge between two or more components of the electromechanical device.