Improved frequency response in a SiGe npn device through improved dopant activation

Abstract

We study the impact of improved dopant activation in a BiCMOS SiGe technology, using laser annealing to improve activation, and a low temperature contact module to avoid de-activation. We present the results of simple DC test structure measurements and high frequency bipolar transistor measurements. Improved activation significantly reduces sheet resistance, particularly for polysilicon layers. Likewise, reductions in the bipolar device resistance parasitics cause an improvement in maximum power gain frequency (f MAX). © The Electrochemical Society.