Real-time wafer curvature stress measurements to understand deposition and post-deposition stresses in thin films
- Date: Jul 5, 2023
- Time: 01:30 PM - 02:30 PM (Local Time Germany)
- Speaker: Prof. Piyush Jagtap
- Assistant Professor at the Indian Institute of Technology (IIT), Hyderabad
- Location: Max-Planck-Institut für Eisenforschung GmbH
- Room: Large Conference Room No. 203
- Host: on invitation of Dr. Rajaprakash Ramachandramoorthy and Prof. Gerhard Dehm
Thin films are ubiquitous in most advanced engineering
applications. The intrinsic stresses developed during the film deposition and
post-deposition treatments (induced by various factors such as interfacial
reactions, thermal cycling, absorption of gases, etc.) can limit the lifetime
of the component in which they are used. For this reason, understanding the origin
of growth stresses in thin films on a deeper level is desired. In this talk, I
will first discuss in-situ stress measurements during film deposition to
understand the atomistic processes that generate the stresses. The kinetic
models based on the atomistic processes will be discussed to model the stress
evolution during growth and growth interruptions [1]. After developing a basic
understanding of the origin of stresses, I will briefly discuss a few
stress-related reliability issues that arise due to stresses originating from
post-deposition treatments. In particular, I will talk about whisker growth in
Sn films driven by compressive stress in the Sn films [2,3] and (ii) stress
generation and relaxation kinetics during amorphous to crystalline phase transition
in GeTe thin films [4]. Throughout my talk, I will highlight the importance of
real-time stress measurement in thin films using the wafer curvature technique
to understand various stress-related issues in thin films.
References:
[1] P Jagtap, E Chason, A unified kinetic model for stress relaxation and recovery during and after growth interruptions in polycrystalline thin films, Acta Materialia, 2020
[2] P Jagtap, N Jain, E Chason, Whisker growth under a controlled driving force: Pressure induced whisker nucleation and growth, Scripta Materialia, 2020
[3] N Jain, X Wang, P Jagtap, A Bower, E Chason, Analysis of pressure-induced whisker nucleation and growth in thin Sn films, Journal of Electronic Materials, 2021
[4] P Jagtap, C Guichet, R Tholapi, P Noe, C Mocuta, O Thomas, Understanding crystallization in undoped and nitrogen doped GeTe thin films using substrate curvature measurements, Materialia, 2023