X-ray diffraction imaging of fully packaged n–p–n transistors under accelerated ageing conditions

DOI: 10.1107/S1600576722007142

Authors: Brian K. Tanner (Durham University; Dublin City University) , Andreas Danilewsky (Albert-Ludwigs-Universität) , Patrick J. Mcnally (Dublin City University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Applied Crystallography , VOL 55

State: Published (Approved)
Published: October 2022
Diamond Proposal Number(s): 23563

Abstract: X-ray diffraction imaging was used to monitor the local strains that developed around individual n–p–n bipolar transistors within fully encapsulated packages under conditions of extremely high forward bias to simulate accelerated ageing. Die warpage associated with the packaging was observed to relax systematically as the polymer became viscous due to the temperature rise associated with the dissipation of heat in the transistor. The direct image size and intensity from the individual transistors were interpreted in terms of a model in which local thermal expansion is treated as a cylindrical inclusion of distorted material, contrast arising principally from lattice tilt. The extension of the thermal strain image along the emitter with increasing power dissipation was ascribed to the effect of current crowding in the emitter region. Weaker large-area contrast associated with the base–collector region was interpreted as arising from the smaller change in effective misorientation at the high X-ray energy of thermal lattice dilation in the base region.

Journal Keywords: X-ray diffraction imaging; current crowding; thermal dilation; silicon devices.

Diamond Keywords: Semiconductors

Subject Areas: Materials, Physics


Instruments: B16-Test Beamline

Added On: 01/09/2022 10:07

Documents:
Journal of Applied Crystallography - 2022 - Tanner - X%E2%80%90ray diffraction imaging of fully packaged n p n transistors under.pdf

Discipline Tags:

Physics Electronics Materials Science

Technical Tags:

Diffraction