Date of Award

Spring 1993

Document Type

Thesis

Degree Name

Master of Science in Electrical Engineering - (M.S.)

Department

Electrical and Computer Engineering

First Advisor

William N. Carr

Second Advisor

Durgamadhab Misra

Third Advisor

N. M. Ravindra

Fourth Advisor

Michael J. Grieco

Abstract

Tantalum silicide was studied as an alternative microelectromechanical material by fabricating a rotary micromotor utilizing a proven design. This material was used for the rotor, stators, and bearing over a silicon substrate. It has the attraction of potentially reducing the friction which is a major problem with polysilicon-to-polysilicon bearings.

The necessity of high aspect ratio features required that a plasma or reactive ion etch with a high degree of anisotropy be developed to etch tantalum silicide films in excess of 1.5μm. A sulfur hexafluoride/Freon 115 plasma provided the necessary process control during the etches. The stress present in annealed tantalum silicide films made it necessary to limit the maximum processing temperature to 300°C. These low temperature tantalum silicide films have thus far proved to be inadequate as a microelectromechanical material for the micromotor due to their inability to withstand the hydrofluoric acid release etch.

Share

COinS