Michael D. Steigerwalt

Defect Reduction by Nitrogen Purge of Wafer Carriers

Nitrogen purge of wafer carriers is driving defect density reduction at critical process steps. We discuss several examples of defect creation related to the environment of the semiconductor wafer and how nitrogen purge of carriers improves defect density. We have applied nitrogen purge at the gate formation, SiGe epitaxy and silicide formation process steps and we report experimental split data from in line inspection and the result at electrical test. From the impact of the nitrogen purge we can draw conclusions about the nature of defect formation. The impact on volume manufacturing is demonstrated.

Ellipsometry for cSiGe Metrology

In this paper we report the effectiveness of optical ellipsometry in measuring thickness and Germanium % of channel SiGe on SOI substrate used in advanced node high performance semiconductor devices.

First time right deposition of embedded SiGe in new products

Embedded SiGe, used to boost pFET performance, is grown by selective epitaxy on silicon. Pattern density effects cause the deposited thickness to be different across different product chips under otherwise identical conditions. Since device control depends critically on thickness, we apply a pattern-density based predictive growth rate, which is used as input for the existing advanced process control method. We demonstrate that the deposited layer thickness is in acceptable range for device performance across a product chip.