摘要
纳米尺度线宽的测量广泛应用于半导体制造、数据存储、微机电系统等领域。随着制造技术的进步,线宽的极限尺寸也变得越来越小,目前已经缩小至100 nm左右。在这一尺度范围内,由于样本制造技术的限制和测量仪器的影响,目前很难得到准确的测量结果。为了获得样本的真实几何尺寸信息,剔除测量方法和仪器本身对测量结果的影响,建立了一个基于AFM测量技术的线宽计量模型和相应算法。该模型将被测样本的截面轮廓用20个关键点分成5个部分共19段,用基于最小二乘的直线来拟合实际轮廓。应用该模型和算法可以分别得到单刻线轮廓拟合前后的顶部线宽b_T、b_(TF),中部线宽b_M、b_(MF),底部线宽b_B、b_(BF),左右边墙角A_L、A_R,以及高度h_。使用NanoScope Ⅲa型AFM对一个单晶硅(Si)线宽样本进行了测量,测量结果表明该模型和算法可以满足纳米尺度线宽计量的基本要求。
Nano-scale linewidth measurements are widely performed in semiconductor manufacturing, data storage industry and micro-mechanical engineering. With the development of manufacturing technology in recent years, the sizes of linewidths are steadily shrinking and have been in the range of hundreds of nanometers. As a result, it is difficult to achieve accurate measurement results for nano-scale linewidth, because of the limitation of manufacturing technology and the influence of measuring instrument. In order to reduce the method divergences caused by different measurement methods and instruments for an accurate determination of nano-scale linewidth parameters, a metrological model and algorithm for linewidth measurements are established based on AFM measurements. The linewidth profile is divided into 5 parts with 19 sections and 20 key points and 6 accessorial
points. Each section is fitted by a least squares straight line. According to the algorithm, bT and bTF, bM and bMF, bB and bBF represent the widths at the top, the middle and the bottom of the linewidth profile before and after the least squares fitting, respectively. AL and AR represent the left and right side-wall angles, and the h represents the step height of the linewidth profile. A NIST nano-scale linewidth standard developed at NIST's Electronics and Electrical Engineering Laboratory (EEEL) was measured using a commercial AFM with ultrasharp tips. The measured linewidth profiles are used for analyses using our model, algorithm and software. The results show that the model developed addresses the need of nano-scale linewidth metrology.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2004年第4期50-57,共8页
Journal of Mechanical Engineering
基金
中国留学生基金委员会
美国国家标准与技术研究院(NIST)资助项目
