Martin Giles

Large enhancement of boron solubility in silicon due to biaxial stress

One of the important challenges to the semiconductor industry today is to enhance the solid solubility of several dopants, boron in particular, in silicon. We calculate the equilibrium solid solubility of boron in Si from first principles and examine the effect of biaxial stress. We find an unexpectedly large enhancement, on the order of 150%, for only 1% strain primarily due to the charge of the substitutional boron impurity in Si. We point out that this effect is an intrinsic property of Si and is expected to be important for other dopants as well.

Physical Modeling of Layout-Dependent Transistor Performance

Design for Manufacturability (DFM) is a phrase that often accompanies discussion of layout optimization for lithography process effects, particularly Optical Proximity Correction (OPC). In an environment where process technology and circuit design are developed together, many other process-layout co-optimization strategies can be investigated. In this paper we discuss physical modeling to enable co-optimization strategies from a device performance point of view by examining layout-induced variation in front-end manufacturing processes used to engineer transistor strain and dopant diffusion/activation.