Polycrystalline devices in bipolar IC-technology

Low pressure CVD polysilicon films have been used for making resistors, lateral diodes and bipolar poly-mono transistors. Recombination via grain boundary states dominates the forward characteristics of the lateral diodes whereas Poole-Frenkel emission is probably responsible for the reverse characteristics. The normal and inverse characteristics of the transistors are largely influenced by parasitic lateral diodes Nevertheless βupand βdown-Values of 40 have been reached.