| 摘要 |
PROBLEM TO BE SOLVED: To prevent current amplification rate from fluctuating through the means of an emitter dimension and to prevent the occurrence of emitter width dependency, by making a crystal grain boundary exist between a metal silicide film/emitter polycrystalline Si film interface and emitter polycrystalline Si film/Si substrate interface in a silicide process. SOLUTION: Unoccupied lattices generated in a metallic silicide process diffuse in an n+-type polycrystalline Si film 12. Most of them are trapped in a crystal grain boundary which exists in an interface with an n+-type polycrystalline Si film 10, and they hardly enter into the film. Thus, tensile stress due to the supersaturation of the idle lattice becomes small in the n+-type polycrystalline Si film 10 in despite the emitter dimension, the diffusion rate of P in the substrate drops, and a phenomenon where diffusion depth becoming shallow hardly occurs. The unoccupied lattice is prevented from reaching the interface between the film 10 and the substrate. The unoccupied lattice is trapped there, and the reconnection speed of a carrier is prevented from increasing. Namely, the drop in the current amplification rate which is depended on the emitter dimension becomes hard to occur.
|
