Fracture strength and fatigue of polysilicon determined by a novel thermal actuator [MEMS]

Author

Kapels, Hergen ; Aigner, Robert ; Binder, Josef

Author_Institution

Infineon Technol., Munich, Germany

Volume

47

Issue

7

fYear

2000

fDate

7/1/2000 12:00:00 AM

Firstpage

1522

Lastpage

1528

Abstract

A novel thermal actuator for the determination of polysilicon fracture strength and investigation of its fatigue is presented. The actuator consists of two narrow beams, which expand due to electrical heating, and a cold plate to which a short fracture beam is attached. Because of its small dimensions, the actuator can be used for on-wafer testing. This method is suitable for tensile and compressive material. Using different types of fracture beams fracture strengths were compared for uniaxial tension and bending test. Using Weibull statistics, the fracture strength for polysilicon has been found to be (2.9±0.5) GPa in tensile tests and (3.4±0.5) GPa in bending tests. In fatigue investigations, we observe that fracture strength decreases slowly with time to 2.2 GPa after 10⁶ cycles

Keywords

Weibull distribution; bending; elemental semiconductors; fatigue testing; fracture toughness testing; microactuators; silicon; 2.4 to 3.4 GPa; 2.9 to 3.9 GPa; Si; Weibull statistics; bending test; cold plate; compressive material; electrical heating; fatigue; fracture strength; on-wafer testing; polysilicon; short fracture beam; tensile material; thermal actuator; uniaxial tension; Actuators; Cold plates; Fatigue; Mechanical factors; Micromechanical devices; Microstructure; Process control; Resistance heating; Tensile stress; Testing;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/16.848302

Filename

848302