On-line test structure for polycrystalline silicon Poisson ratio

Abstract

The invention discloses an on-line test structure for polycrystalline silicon Poisson ratio. The on-line test structure comprises an insulating substrate, an asymmetric polycrystalline cross beam, a first polycrystalline lower pole plate and a second polycrystalline lower pole plate, wherein the asymmetric polycrystalline cross beam is deflected in an electrostatic driving mode, so Poisson ratio parameters of a polycrystalline material are obtained according to a geometrical relationship and a material mechanics principle. The test structure rotates under the action of electrostatic force which is generated through excitation voltage, a maximum torsion angle becomes known quantity through structural design, and the Poisson ratio of the polycrystalline material is computed according to a measurement value of the excitation voltage when the test structure reaches the maximum torsion angle and unknown structure geometric parameters and physical parameters. Therefore, requirements for test equipment are low, a test method is simple, and the test process and test parameter values are stable. During synchronization of the polycrystalline silicon preparation process and the manufacturing process of a subsequent micro electro mechanical system (MEMS), special processing requirements are eliminated, and requirements for on-line test are completely met.

Description

technical field [0001] The invention belongs to the technical field of on-line testing of micro-electromechanical system material parameters, in particular to the technical field of on-line testing of the Poisson's ratio of polysilicon. Background technique [0002] The performance of microelectromechanical devices is closely related to the physical parameters of materials, and the physical parameters of materials for manufacturing microelectromechanical devices are related to the manufacturing process. The purpose of online testing is to be able to measure the physical parameters of MEMS materials manufactured by specific processes in real time. [0003] Polysilicon is an important and basic material for fabricating microelectromechanical device structures, and it is usually produced by chemical vapor deposition (CVD). Poisson's ratio is an important physical parameter of polysilicon material. The Poisson's ratio of polysilicon can be tested offline by special instruments...

AI Technical Summary

Problems solved by technology

These measurement methods require corresponding special optical equipment, which do not meet the requirements of on-line measurement of the process line

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