Finite Element Models for Extracting Mechanical Properties of ILD Stack from Indentation Tests

  • Authors:
    Chun-Pei Chen (Purdue), Ganesh Subbarayan (Purdue), Tao Song (Purdue)
    Publication ID:
    P090365
    Publication Type:
    Deliverable Report
    Received Date:
    20-Feb-2017
    Last Edit Date:
    9-May-2017
    Research:
    2652.001 (Purdue University)

Research Report Highlight

An inverse finite element analysis technique has been used to estimate the yield strength of a metal film buried under an ILD stack. This indentation technique greatly simplifies sample generation since it does not require a free standing film.

Abstract

The fabrication process-induced variation in the yield strength of metal films in microelectronic devices critically impacts the reliability of inter-layer dielectric (ILD) stacks. However, estimation of the yield strength of buried films in multilayer stacks remains a significant challenge. The indentation technique, whose advantage is that it does not require a free-standing film, has been widely used to characterize thin films, but traditional analysis mostly focus on characterizing the top layer of the stack. In this report, we describe an optimization-based inverse finite element analysis (IFEA) technique to estimate the yield strength of a buried metal film in the ILD stack. The technique is demonstrated by estimating the yield strength of the buried aluminum film in a TEOS-Al-Si3N4-Si stack.

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