Manipulating Impurities and Defects During Semiconductor Epitaxy with Light

While controlling impurity and defect incorporation is a primary concern during semiconductor epitaxy, only a few process variables are typically available to regulate incorporation mechanisms. In the case of vapor phase epitaxy, they include substrate temperature and atomic or molecular flux. Access to additional control parameters may therefore prove useful for manipulating impurity and defect populations. This talk will focus on the use of light as an independent and tunable energy source that can be applied to modify growth processes. Observed changes in semiconductor materials grown under illumination have largely been linked to modification of adatom desorption rates and defect formation enthalpies in the presence of photogenerated carriers. Specific examples will be discussed along with opportunities for using photo-assisted techniques to control impurities and defects.