1210 SiN薄膜の引張・曲げ強度特性に及ぼす微小欠陥の影響(S05-3 ナノ・マイクロ材料の強度・信頼性(3)ナノ・マイクロ材料の強度物性評価,21世紀地球環境革命の機械工学:人・マイクロナノ・エネルギー・環境)

抄録

The mechanical properties of SiN thin film microelements, fabricated by sputtering and CVD processes, were evaluated using specially designed testing systems for the mechanical properties of thin tensile and bending microelements. The tensile testing system consists of a tensile testing machine actuated by a PZT driven positioning stage, a micro manipulation system, and a non-contact strain measurement system with a help of a double-filed-of-view microscope. For bending tests, the testing system used is based upon a Nano Indenter with a specially designed indenter and an ultra-precise positioning stage. In order to investigate the size effects on the mechanical properties, the thickness of the sample used were 1μm and 3μm, and the specimen width was varied from 5μm to 50μm. The Young's modulus of the SiN thin film was independent of sample width and thickness: the Young's modulus was not influenced by specimen size and loading mode. However, Young's modulus of the film fabricated by sputtering was higher than that by CVD. The tensile strength and bending strength increased with a decrease in thickness, and the strength of the film fabricated by CVD was higher than that by sputtering. The fracture initiation sites were closely examined by a high-resolution field-emission type scanning electron microscope, and the strength of the thin film was revealed to be determined by stress intensity factor of the micro defect in a thin microelement.