Fachbereich 11 - Physik
Institut für Materialphysik
Diffusion and Defects in Elementary and Compound Semiconductors

Atomic mechanisms of mass transport in elemental and compound semiconductors

The controlled incorporation of point defects in elemental and compound semiconductors is one of the main tasks in the production of electronic devices. Homogeneous doping is generally achieved by adding a controlled amount of the dopant element to the melt or to the gas phase of epitaxial layer deposition systems. However, the fabrication of electronic devices like diodes, transistors, or complex integrated circuits requires spatially inhomogeneous dopant distributions. Such distributions are formed by deposition of the dopants on or implantation beneath the surface followed by a high temperature diffusion step. In order to tune electronic devices to the desired functionality the diffusion induced dopant distribution must be predictable and as accurate as possible. This requires a detailed knowledge of the atomic mechanisms of dopant diffusion, the properties of native point defects such as vacancies, self-interstitials, and antisite defects, and the interactions among the different point defects. Results from self- and foreign-atom diffusion experiments in elemental and compound semiconductors are summarised which were conducted in our research group. The experiments were performed deliberately to characterise the atomic mechanisms of mass transport and to gain a better understanding about the properties of native point defects in semiconductors. Moreover future experiments are suggested which will help to understand dopant- and self-diffusion in more detail. This information is highly desirable for predictive modelling of diffusion processes at high doping levels both in elemental and compound semiconductors.

Beteiligter Wissenschaftler:

HDoz. Dr. H. Bracht

Veröffentlichungen:

H. Bracht: Atomic mechanisms of mass transport in elemental and compound semiconductors, Habilitationsschrift im Fach Physik, Universität Münster (2001)