Hostname: page-component-848d4c4894-8kt4b Total loading time: 0 Render date: 2024-06-26T06:23:27.706Z Has data issue: false hasContentIssue false

Dependence Of Silicon Fracture Strength And Surface Morphology On Deep Reactive Ion Etching Parameters

Published online by Cambridge University Press:  10 February 2011

Kuo-Shen Chen
Affiliation:
Massachusetts Institute of Technology, Cambridge, MA 02139
Arturo A. Ayon
Affiliation:
Massachusetts Institute of Technology, Cambridge, MA 02139
Kevin A. Lohner
Affiliation:
Massachusetts Institute of Technology, Cambridge, MA 02139
Mark A. Kepets
Affiliation:
Massachusetts Institute of Technology, Cambridge, MA 02139
Terran K. Melconian
Affiliation:
Massachusetts Institute of Technology, Cambridge, MA 02139
S. Mark Spearing
Affiliation:
Massachusetts Institute of Technology, Cambridge, MA 02139
Get access

Abstract

The development of a high power-density micro-gas turbine engine is currently underway at MIT. The initial goal is to produce the components by deep reactive ion etching (DRIE) single crystal silicon. The capability of the silicon structures to withstand the very high stress levels within the engine limits the performance of the device. This capability is determined by the material strength and by the achievable fillet radii at the root of turbine blades and other etched features rotating at high speeds. These factors are strongly dependent on the DRIE parameters. Etching conditions that yield large fillet radii and good surface quality are desirable from a mechanical standpoint. In order to identify optimal DRIE conditions, a mechanical testing program has been implemented. The designed experiment involves a matrix of 55 silicon wafers with radiused hub flexure specimens etched under different DRIE conditions. The resulting fracture strengths were determined through mechanical testing, while SEM analysis was used to characterize the corresponding fillet radii. The test results will provide the basis for process optimization of micro-turbomachinery fabrication and play an important role in the overall engine redesign.

Type
Research Article
Copyright
Copyright © Materials Research Society 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1]. Epstein, A. H, et al, “Micro-Heat Engines, Gas Turbines, and Rocket Engines - the MIT Microengine Project,” 28th AIAA Fluid Dynamics and 4th AIAA Shear Flow Control Conference, June 1997.Google Scholar
[2]. Chen, K-S, Ayon, A., and Spearing, S. M. [1997]: “Tailoring and Testing the Fracture Strength of Silicon at the Mesoscale,” To be published in Journal of American Ceramic Society.Google Scholar
[3]. Chen, K-S, Ayon, A., and Spearing, S. M. [1998]: “Silicon Strength Testing for Mesoscale Structural Applications,” Symposium N3.8, MRS Spring Meeting, April 13–17, San Francisco, CA.Google Scholar
[4]. Chen, K-S, Ph.D.Thesis, Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 1998.Google Scholar
[5]. Ayon, A. A., Bayt, R., Braff, R., Lin, C., Sawin, H. H., and Schmidt, M. A., Technical Digest, Solid- State Sensor and Actuator Workshop, Hilton Head, SC, June 8–11, 1998, pp. 4144.Google Scholar
[6]. Ayon, A.A., Chen, K-S, Lohner, K.A., Sawin, H.H., Schmidt, M.A., and Spearing, S.M. [1998]: “Dependence of Silicon Surface Morphology on Time Multiplexed Deep Etching Conditions,” To be appeared, MRS Fall Meeting, Boston, MA, Nov. 1998.Google Scholar
[7]. Weibull, W [1939]: Ing. Vetenskaps Akad. Handl., No. 151, pp. 45, 1939.Google Scholar
[8]. Nemeth, N. N., Manderscheid, J. M., and Gyekenyesi, J. P., NASA TP-2916, 1990.Google Scholar