Test Structure for Residual Stress of Thin Film Silicon Material on Insulating Substrate

Abstract

The invention provides a structure and method for testing the residual stress of a thin film silicon material on an insulating substrate. The testing structure comprises two structures, wherein the first structure is formed by a polycrystalline silicon cantilever beam, a thin film silicon double-end clamped beam and a base plate made from thin film silicon; the second structure is formed by a polycrystalline silicon cantilever beam and a base plate made from thin film silicon; the unit which actually measures the residual stress of thin film silicon is the thin film silicon double-end clamped beam; the difference of the two structures only lies in whether the structures comprise the thin film silicon double-end clamped beam; other corresponding unit structures in the two structures and the geometric dimensions are identical; the electrostatic force is applied to bend down the polycrystalline silicon cantilever beam and then press down the thin film silicon double-end clamped beam and the base plate to come into contact with the substrate; the force needed to individually drive the thin film silicon double-end clamped beam to achieve the testing deflection is extracted through testing of the two testing structures; the residual stress of the thin film silicon material on the insulating substrate can be computed according to the force, the testing deflection, the Young modulus and the geometric dimensions. The testing structure, the measuring method and a parameter extraction method are extremely simple.

Description

technical field [0001] The invention provides a test structure for the residual stress of thin film silicon material on an insulating substrate. The invention belongs to the technical field of microelectromechanical system (MEMS) material parameter testing. Background technique [0002] The performance of microelectromechanical devices is closely related to material parameters. Due to the influence of processing, some material parameters will change. These uncertain factors caused by processing technology will make device design and performance prediction uncertain and unstable. Case. The purpose of material parameter testing is to be able to measure the material parameters of MEMS devices manufactured by a specific process in real time, monitor the stability of the process, and feed back the parameters to the designer so that the design can be corrected. Therefore, testing without leaving the processing environment and using general-purpose equipment has become a necessar...

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Problems solved by technology

[0002] The performance of microelectromechanical devices is closely related to material parameters. Due to the influence of processing, some material parameters will change. These uncertain factors caused by processing technology will make device design and performance prediction uncertain and unstable. Case

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