Tomohiro Funakoshi

Advanced Method for Monitoring Copper Interconnect Process

Stabilizing the copper interconnect process is the key to improving yield and reliability. A stable process for forming adequate grains in a copper film is important, but there is no proper method for monitoring the grains in that film. We introduce the micro-haze method, an advanced method for monitoring grain size using scattering light. We experimentally verified the effectiveness of the method and concluded that the method enables the monitoring the grains in a copper film.

On-demand inspection recipe to detect defects of interest using Mahalanobis distance

An on-demand inspection recipe-setup method to detect defects of interest (DOI) was proposed. The method applies Maharanobis distance to recognize DOI-like defects without its own recipe. Moreover, actual application was evaluated and the method effectiveness was confirmed from viewpoints of on-demand processing time and DOI detection. The proposed method enables inspection tool managers to rapidly select an appropriate recipe which detects the most DOI from several initial recipes. The future research work will focus on several examinations for threshold decision based on reviewing all detected defects experimentally.

Detection and review of crystal originated surface and sub surface defects on bare silicon

The continuous dimensional reduction for micro-and nano electronics is driving the technology for yield relevant defect detection. Defects originating in the crystal are always present in silicon wafers. Due to miniaturization, the size of these defects becomes comparable to the feature sizes of future technology generations. Therefore, they are identified as a future yield limiting mechanism. This paper shows that crystal originated sub surface defects impact the performance of dark Held Scanning Surface Inspection Systems with respect to defect counts, defect classification, defect sizing, and capture rate.

Advanced monitoring method for copper interconnect process

Stabilizing copper interconnect process is the key for yield and reliability improvement. Forming adequate grains in a copper film is so important to have the stable process, but there is no proper method of monitoring grains in a copper film. We introduce an advanced method of monitoring grain size using scattering light that we call the micro-haze method. We verified the effectiveness of the method by the experimental design and concluded that the method makes it possible to monitor grains in a copper film.