Imaging high-aspect-ratio contact holes

2020-03-15 12:22:27

potential contact Imaging surface holes

责任者: Sullivan, N.;Byoung-Ho Lee;Yeong-Uk Ko 单位: Soluris Inc., Concord, MA, USA 来源出处: Semiconductor International(Semicond. Int. (USA)),2005/10/,28(11):62-6 摘要: Clear images of the bottom surfaces of contact holes are necessary when designing ICs. This article explores how a CD-SEM was specifically developed to obtain clear images of the bottom of contact holes with 30:1 aspect ratios. We have developed a technique to extract imaging signals from deep contact holes with aspect ratios up to 30:1. The technique depends on maximizing the positive charge and potential on the surface of the sample surrounding the contact hole. This local charge accumulates as a result of interactions with the beam, and constitutes an additional element in the electron optical system. The strength of the surface potential is determined by the imposed field, with strong fields supporting stronger potentials. The surface potential works in concert with the imposed electric field to extract SEs from deep holes. The Yosemite SP-1000 CD-SEM, which incorporates a unique electron optical system designed to impose strong retarding fields that reduce beam landing energy, is also ideally suited to maximize signal extraction when imaging HAR contact holes 关键词: integrated circuit measurement;nanocontacts;scanning electron microscopy;signal processing;soft lithography;surface conductivity;surface potential;contact hole imaging;bottom surface imaging;IC design;CD-SEM;imaging signal;positive charge maximization;beam interaction;electron optical system;surface potential strength;Yosemite SP-1000;signal extraction;HAR contact hole