Patent Number: 6,396,368

Title: CMOS-compatible MEM switches and method of making

Abstract: A microelectromechanical (MEM) switch is fabricated inexpensively by usingprocessing steps which are standard for fabricating multiple metal layerintegrated circuits, such as CMOS. The exact steps may be adjusted to becompatible with the process of a particular foundry, resulting in a devicewhich is both low cost and readily integrable with other circuits. Theprocessing steps include making contacts for the MEM switch from metalplugs which are ordinarily used as vias to connect metal layers which areseparated by a dielectric layer. Such contact vias are formed on eitherside of a sacrificial metallization area, and then the interconnectmetallization is removed from between the contact vias, leaving themseparated. Dielectric surrounding the contacts is etched back so that theyprotrude toward each other. Thus, when the contacts are moved toward eachother by actuating the MEM switch, they connect firmly withoutobstruction. Tungsten is typically used to form vias in CMOS processes,and it makes an excellent contact material, but other via metals may alsobe employed as contacts. Interconnect metallization may be employed forother structural and interconnect needs of the MEM switch, and ispreferably standard for the foundry and process used. Various metals anddielectric materials may be used to create the switches, but in apreferred embodiment the interconnect metal layers are aluminum and thedielectric material is SiO.sub.2, materials which are fully compatiblewith standard four-layer CMOS fabrication processes.

Inventors: Chow; Lap-Wai (South Pasadena, CA), Hsu; Tsung-Yuan (Westlake Village, CA), Hyman; Daniel J. (Cleveland, OH), Loo; Robert Y. (Agoura Hills, CA), Ouyang; Paul (San Jose, CA), Schaffner; James H. (Chatsworth, CA), Schmitz; Adele (Newbury Park, CA), Schwartz; Robert N. (Costa Mesa, CA)

Assignee:

International Classification: H01H 59/00 (20060101); H01H 1/00 (20060101); H01H 1/58 (20060101); H01P 001/10 (); H01H 057/00 (); H03K 017/975 ()

Expiration Date: 05/28/2014