Satomi Inoue

Real-Time Transfer Control Method for Linear Tools

This paper describes a real-time transfer control method to produce a high throughput for linear tools of semiconductor manufacturing equipment. We developed a transfer control method for various process times with two steps during operation of the equipment. The first step uses a local search to find a transfer sequence producing a high throughput in advance for various process times, and the second step switches between transfer sequences during the operation of the equipment by referring to a decision tree made from the results of the first step. The method calculates the transfer sequence in a time period from recognizing the process time to the start of transferring the wafer and improves the throughput of linear tools in more than 60% of the tested process time combinations. In the most improved case, the throughput improved by 53%.

Correlational Study Between SiN Etch Rate and Plasma Impedance in Electron Cyclotron Resonance Plasma Etcher for Advanced Process Control

The correlation between the change in the etching rate of SiN and the change in the monitored plasma impedance was investigated to estimate the capability of critical dimension (CD) prediction with a plasma impedance monitor (PIM). The results obtained with the PIM were compared with those of optical emission spectroscopy (OES), which was performed using the emission intensity ratio of C2/H, and showed that the SiN etching rate is strongly correlated with several values obtained with the PIM. We conclude that the PIM has the potential to predict CDs with the same accuracy as that of OES.