Precise strain evaluation for high-performance bipolar transistor

用于局部应变评估的测试样品的几何尺寸小至5×5μm^2。我们建立了这种样品的光致发光测量系统。我们制作了独立的Si膜结构（Si-On-Nothing结构），然后沉积SiN膜。我们使用PL系统评估了这些样品中的菌株。其结果是，200 nm厚的SiN膜在200 nm厚的Si膜中产生约1%的压缩应变，沿着方向的应变<100>比沿着方向的应变大得多<110>。提出了一种根据PL信号峰位和强度随Si膜厚变化的关系来判断应变均匀与否的方法。

The geometry of test sample for local strain evaluation was as small as 5×5μm^2. We established photoluminescence measurement system for such a sample. We fabricated freestanding Si membranes structure (Si-On-Nothing structure), followed by deposition of SiN film. We evaluated strains in these samples using the PL system. As results, a compressive strain of approximately 1% was induced in the 200-nm-thick Si film by 200-nm-thick SiN film ; the strain along <100> direction was much larger than that along <110> direction. Also, we proposed a method for judging uniform or ununiform strain from dependence of PL signal peak position and its intensity on Si film thickness.