Abstract:

Since the early days of the semiconductor industry, defect control has been key to the successful development of devices and circuits. This requires a thorough understanding of their formation and the impact on the electrical material parameters. This has led to the invention of powerful structural, chemical and electrical characterization tools, with the device itself perhaps as the most sensitive probe. This evolution was paralleled by the development of ab initio calculation methods, based on Density Functional Theory and more recently, also TCAD tools allow more and more refined modelling of the impact of defects on the electrical characteristics of devices.

In this presentation, some state-of-the art analysis techniques will be highlighted, including Deep Level Transient Spectroscopy (DLTS), Generation-Recombination (GR) noise and RTN spectroscopy and p-n diode lifetime analysis. These methods will be applied to several case studies. As will be shown, threading extended defects impact the recombination lifetime of lowly-doped n-type In0.47Ga0.53As starting from a density of a few 10⁷ cm-2. Likewise, it will be demonstrated that the GR noise observed in GaN-on-Si most likely originates from threading dislocations. It is concluded that when hetero-epitaxial layers can be grown with a sufficiently low defect density, their impact will be rather on the variability of the electrical parameters rather than on the effective values. In addition, the position of the defect with respect to strategic nodes like a p-n junction or depletion region largely determines its electrical impact.

Prof. Eddy Simoen has received the Electronics and Photonics Division Award 2022 of the ElectroChemical Society (ECS) at the 241st ECS meeting (May 29th-June 2nd, 2022 in Vancouver, BC, Canada).