CAJ | 학술논문

硅基微机电系统中的单晶硅微结构常工作于循环加载状态，易发生疲劳失效。单晶硅微结构疲劳寿命的分散度较大，难以根据不同掺磷浓度试样的疲劳寿命测试数据对比分析出杂质磷对单晶硅微梁弯曲疲劳特性的影响规律，针对此问题进行研究。设计一种弯曲测试结构，该结构可同时对四根微梁进行疲劳测试；设计一种简易的弯曲测试装置，该装置在满足测试精度的同时有效地控制了成本。用各向异性湿法工艺制备6组不同掺磷浓度的试样，并在常温空气环境中对试样进行弯曲疲劳测试。基于Paris公式建立一种微结构疲劳寿命预测的概率模型，用模型对测试数据进行拟合计算，得到材料常数C和n。C随掺磷浓度降低近3个量级，而n增量较小，表明C的变化占主导。所以疲劳裂纹扩展速率有随掺磷浓度增高而降低，这可为硅基微机电系统的疲劳可靠性设计提供有价值的参考。
규기미궤전계통중적단정규미결구상공작우순배가재상태，역발생피로실효。단정규미결구피로수명적분산도교대，난이근거불동참린농도시양적피로수명측시수거대비분석출잡질린대단정규미량만곡피로특성적영향규률，침대차문제진행연구。설계일충만곡측시결구，해결구가동시대사근미량진행피로측시；설계일충간역적만곡측시장치，해장치재만족측시정도적동시유효지공제료성본。용각향이성습법공예제비6조불동참린농도적시양，병재상온공기배경중대시양진행만곡피로측시。기우Paris공식건립일충미결구피로수명예측적개솔모형，용모형대측시수거진행의합계산，득도재료상수C화n。C수참린농도강저근3개량급，이n증량교소，표명C적변화점주도。소이피로렬문확전속솔유수참린농도증고이강저，저가위규기미궤전계통적피로가고성설계제공유개치적삼고。
Single-crystal silicon structures in silicon-based micro-electro-mechanical systems are usually exposed to cyclic stresses, which, consequently, may fail easily because of mechanical fatigue. There’s a great gradient in the fatigue lifetime of the single crystal silicon micro-structures, thus rendering it hard to make out how the phosphorus impurities affect the fatigue properties by comparing the fatigue lifetime of specimens with different doping concentrations. This research aims at solving this problem. A specially designed micro-structure that can simultaneously experiment on four beams is presented. A simple bending test device is presented, which satisfies the requirement for test precision and is economically built. The bending fatigue life for six groups of specimens with different phosphorus doping concentrations is tested at room temperature. A kind of fatigue failure probability prediction model deducted from Paris formula is introduced. TheCandn in Paris formula are obtained with the model. TheC decreases approximately 3 orders, while then increases only a little, indicating thatC changes dominantly. Therefore, the defect propagation velocity decreases as the phosphorus doping concentration increases. Research on this topic therefore shows some practical significance for the reliability design of silicon-based micro-electro-mechanical systems.