Modeling of ion-bombardment damage on Si surfaces for in-line analysis

• Published in: Thin solid films Vol. 518; no. 13; pp. 3481 - 3486
• Main Authors: Matsuda, Asahiko, Nakakubo, Yoshinori, Takao, Yoshinori, Eriguchi, Koji, Ono, Kouichi
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 30.04.2010; Elsevier
• Subjects: Condensed matter: structure, mechanical and thermal properties; Ellipsometry; Exact sciences and technology; Ion bombardment; Physical radiation effects, radiation damage; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma applications; Plasma processing; Silicon; Structure and morphology; thickness; Structure of solids and liquids; crystallography; Surface defects; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Silicon; Plasma processing; Surface defects; Ion bombardment; Ellipsometry; Radiation effects; RBS; Optical models; Molecular dynamics method; Plasma assisted processing; Theoretical study; Etching; Interface roughness; Interfaces; Transmission electron microscopy; Surface defect; Silicon oxides; Wafers; Modelling; Damage
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2009.11.044

Structures and mechanism of ion-bombardment damage on silicon wafers exposed to plasma were investigated comprehensively. By using molecular dynamics simulations high-resolution transmission electron microscopy, and composition analysis by high-resolution Rutherford backscattering spectroscopy, features such as gradual transition from the SiO 2 surface to the Si substrate and interface roughness were addressed. On the basis of these findings, the optical model that addresses the characteristics of plasma-damaged Si surfaces is given for ellipsometric analysis. The proposed model includes an interface layer modeled as a mixture of SiO 2 and Si phases. A part of the interface layer could not be removed by wet-etching, signifying the distinct features of the interface layer that are difficult to remove. The proposed model is anticipated to be practical for in-line monitoring of plasma-induced damage.