A physics-based compact model of band-to-band tunneling (BtBT) current in p-n junctions is presented in this paper. The model features a smooth transition to zero forward-bias tunneling current, a full physical temperature scaling, and an innovative parametrization. We present an accurate experimental verification of the physical temperature scaling rules for BtBT on carefully selected state-of-the-art industrial transistors. We explicitly demonstrate, by simulations of statistics, that our choice of model parameters yields improved parameter determinability. Furthermore, we explicitly demonstrate on the measured data that this improved parameter determinability is essential for good geometrical scalability of the parameter values.