FRG/GOALI: Degradation Mechanisms, Micromechanics, and Microstructural Engineering of Thin Film Electrodes for High Permittivity Dielectrics

Stanford University, Stanford CA

Investigators

Abstract

This FRG/GOALI project is a collaborative effort between researchers at Stanford U., Lehigh U., and Applied Materials, Santa Clara, CA. The project addresses microstructural stability, micromechanics, and electrical properties of materials used in the fabrication of on-chip capacitors incorporating dielectrics such as BaxSr1-xTiO3 (BST) and PbZrxTi1-xO3 (PZT). The aim is to improve understanding of thin film micromechanics, on-chip capacitor electrical performance, and how both electrical and mechanical properties may be modified through thin film microstructural control. Emphasis is on development of a mechanistic understanding of stress relaxation, surface roughening, and film debonding processes occurring during processing of thin film electrodes and diffusion barriers for high-K capacitor applications. Degradation of interfacial contact resistivity and dielectric reliability using patterned capacitor test structures will also be studied. Thermal stress relaxation of electrodes, which affects both adhesion and roughness, will be modified by alloying electrode layers and producing two phase microstructures through internal oxidation. It is anticipated that the research will lead to new strategies for improving the reliability and processing stability of on-chip capacitors that use perovskite-structure high permittivity dielectrics. Research will be performed by a multi-disciplinary, multi-investigator team at Stanford University and Lehigh University. Students and faculty will collaborate with materials researchers and process-integration specialists at Applied Materials, Inc. Joint research activities with AMAT will include sharing of research resources and samples, joint planning of experiments and regular meetings to review progress, visits by students to Applied Materials' laboratories, and mentorship of students by AMAT personnel. %%% The project addresses basic research issues in a topical area of materials science with high technological relevance. The basic knowledge and understanding gained from the research is expected to contribute to improving electronic materials performance in current and future device and circuit applications. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. The multidisciplinary (materials science, electrical engineering) and industrially-connected nature of this FRG/GOALI program offers unique educational opportunities for students to experience a teamwork-oriented research environment from both academic and industrial perspectives. The project is co-funded by the Electronic Materials(EM) and Metals(MET) programs in DMR, the Mechanics And Structures of Materials program in ENG/CMS, and the ENG GOALI office. ***