Cho Sang-Joon, Ahn Byung-Woon, Kim Joonhui, Lee Jung-Min, Hua Yueming, Yoo Young K, Park Sang-il
Park Systems Corporation, KANC 4F, Suwon, South Korea.
Rev Sci Instrum. 2011 Feb;82(2):023707. doi: 10.1063/1.3553199.
Sidewall surface roughness is an important parameter in electronic device manufacture. At present, no high resolution technique exists to quantitatively characterize this property for undercut structures created by semiconductor processing techniques. We developed a three-dimensional atomic force microscope (3D-AFM) to measure the surface roughness of undercut sidewalls with nanometer precision. Decoupled from the positional scanner, the 3D-AFM probe had a variable tilt up to 40° off the normal. Nonorthogonal scans resolved the sidewall surface roughness, base width, and acute critical angle for undercut structures, including a metal overhang and the transmission line of a photonic device. Compatible with standard cantilevers, the 3D-AFM demonstrates great potential for characterizing the sidewalls of soft materials such as photoresist.
侧壁表面粗糙度是电子器件制造中的一个重要参数。目前，不存在高分辨率技术来定量表征由半导体加工技术形成的底切结构的这一特性。我们开发了一种三维原子力显微镜（3D-AFM），以纳米精度测量底切侧壁的表面粗糙度。3D-AFM探头与位置扫描仪解耦，具有高达40°的可变倾斜角度（相对于法线）。非正交扫描解析了底切结构的侧壁表面粗糙度、底部宽度和锐角临界角，包括金属悬垂和光子器件的传输线。3D-AFM与标准悬臂兼容，在表征诸如光刻胶等软材料的侧壁方面显示出巨大潜力。
