TY - JOUR

T1 - Film thickness dependent microstructural changes of thick copper metallizations upon thermal fatigue

AU - Bigl, Stephan

AU - Trost, Claus Othmar Wolfgang

AU - Wurster, Stefan

AU - Cordill, Megan J.

AU - Kiener, Daniel

PY - 2017/6/1

Y1 - 2017/6/1

N2 - With increasing performance requirements in power electronics, the necessity has emerged to investigate the thermo-mechanical behavior of thick Cu metallizations (≥5 μm). Cu films on rigid substrates in the range of 5-20 μm were thermally cycled between 170 and 400 °C by a fast laser device. Compared to the initial microstructures, a texture transition toward the {100} out-of-plane orientation with increasing film thickness was observed during thermo-mechanical cycling, along with an abnormal grain growth in the {100}-oriented grains and a gradual development of substructures in a crystallographic arrangement. Compared to the well-studied thin Cu film counterparts (≤5 μm), the surface damage showed a 1/h f dependency. Transition from an orientation independent (h f = 5 μm) to an orientation specific thermo-mechanical fatigue damage (h f = 10, 20 μm) was observed following a higher damager tolerance in {100} oriented grains.

AB - With increasing performance requirements in power electronics, the necessity has emerged to investigate the thermo-mechanical behavior of thick Cu metallizations (≥5 μm). Cu films on rigid substrates in the range of 5-20 μm were thermally cycled between 170 and 400 °C by a fast laser device. Compared to the initial microstructures, a texture transition toward the {100} out-of-plane orientation with increasing film thickness was observed during thermo-mechanical cycling, along with an abnormal grain growth in the {100}-oriented grains and a gradual development of substructures in a crystallographic arrangement. Compared to the well-studied thin Cu film counterparts (≤5 μm), the surface damage showed a 1/h f dependency. Transition from an orientation independent (h f = 5 μm) to an orientation specific thermo-mechanical fatigue damage (h f = 10, 20 μm) was observed following a higher damager tolerance in {100} oriented grains.

KW - fatigue

KW - texture

KW - thermal stresses

UR - http://www.scopus.com/inward/record.url?scp=85020723130&partnerID=8YFLogxK

U2 - 10.1557/jmr.2017.199

DO - 10.1557/jmr.2017.199

M3 - Article

AN - SCOPUS:85020723130

VL - 32.2017

SP - 2022

EP - 2034

JO - Journal of materials research (JMR)

JF - Journal of materials research (JMR)

SN - 0884-2914

IS - 11

ER -