Study of silicon strain in shallow trench isolation

Abstract

Raman spectroscopy has been used as a primary tool to measure silicon strain on shallow trench isolation (STI) test structures. Different STI dielectric gap fill materials have been evaluated as well as the effect of tensile and compressive STI liners on silicon strain. It has been shown that both intrinsic stress of thin film dielectric material and STI structure type affect strain in silicon. Ways of generating high stress in silicon are discussed including the effect of the STI chemical vapor deposition liner material on Si strain. Strain simulation data are found to be in reasonably good agreement with the active area silicon. Advantages and limitations of Raman based strain metrology in the semiconductor industry are delineated. The findings have been confirmed electrically on metal-oxide-semiconductor field effect transistor devices with tensile and compressive strains in the STI region. An improvement in p-type field-effect transistor performance has been demonstrated for silicon on insulator devices with tensile dielectric in STI. © 2010 American Vacuum Society.