MEMS DEVICE WITH IMPROVED VIA SUPPORT PLANARIZATION

摘要

A microelectromechanical (MEMS) device has a movable member supported above a substrate on a via support. The member and via support are fabricated integrally from first and second member forming layers. A first member forming layer forms a lower part of the member and supporting structure for the via support. First and second fill layers are deposited and patterned to form a plug that fills an inner cavity opening in the via structure. The plug is planarized to a planar part of the first member forming layer, and a second member forming layer is deposited over the first member forming layer and the planarized plug to form an upper part of the member. In an example micromirror device, metal layers define a movable mirror member supported on a via support which has a cavity filled by BARC layers. The BARC layers are planarized to a planar portion of a first metal layer and a second metal layer is formed over the first metal layer planar portion and planarized BARC layer plug.

主权项

1. A method of making a MEMS device, comprising:
forming a via opening within a sacrificial support layer formed over a substrate; depositing a first member forming layer over the sacrificial support layer, including as a liner within and partially filling the via opening; depositing a first fill layer over the first member forming layer, including over the first member forming layer within and further partially filling the via opening; depositing a second fill layer over the first fill layer including within the via opening, the second fill layer filling the via opening to a level above a top surface of the first member forming layer; depositing a masking material over the second fill layer, and patterning the masking material to form a mask covering the filled via opening and extending for a given lateral distance beyond a top of the via opening; patterning the first and second fill layers using the mask to form a raised protrusion with a given step height and lateral width at the top of the via opening; removing the mask following the patterning of the first and second fill layers; depositing a third fill layer over the patterned first and second fill layers to fill an indentation in the raised protrusion; removing the raised protrusion to planarize a top surface of the filled via opening with the top surface of the first member forming layer; and depositing a second member forming layer over the first member forming layer and over the planarized top surface of the filled via opening.