Yuan-Hung Chiu

Plasma induced substrate damage in high dose implant resist strip process

In this communication we report our work on the ashing of post high dosage implant photoresist removal. Attention is focused on plasma damage to the silicon substrate, in addition to hard skin removal capabilities. An inductively coupled plasma (ICP) source is chosen for this study due to its capability of separate control of source and bias power, although our results are directly applicable to conventional plasma ashing facilities. Electrical data for both NMOS and PMOS devices are compared and correlated with the physical substrate damage, and suggestions for a residue-free process with minimum substrate damage are given.

Application of spectroscopic ellipsometry-based scatterometry for ultrathin spacer structure

The scatterometry technology has been developed widely in the poly gate and resist patterning application for critical dimension (CD) process control. The advantages of this technology are good precision, short cycle time and multiple information outputs. To extend this application even further on spectroscopic ellipsometry (SE) based scatterometry, the spacer structure application becomes one promising goal. In this work, we use SE based scatterometry to demonstrate a two-dimensional profile of ultra thin spacer with post-etched structure as well as CD measurement of the spacer. A brief theory and measurement results taken by dense and isolate structure will be discussed in this paper. The cross-section of TEM and the spectra fitting by scatterometry are also collected at the same location and compared. It shows a high correlation between the two. Finally, an example of minispacer fault detection methodology and repeatability test on scatterometry is also presented to show the capability for volume production.