METHOD OF FORMING BIPOLAR JUNCTION TRANSISTOR

摘要

A method for forming a bipolar junction transistor is provided to prevent a PSG(Phosphor Silicate Glass) layer from being formed on a collector and to omit a cleaning process on the PSG layer without the generation of problems due to the thermal diffusion of POCl3 by forming a deep N+ well using an ion implantation. A first ion implantation mask is formed on a substrate to form a deep N+ well(21) in the substrate. A first ion implantation is performed on the resultant structure. A first drive-in heat treatment is performed on the resultant structure. A second ion implantation mask for forming an N well is formed. A second ion implantation is performed on the resultant structure. A second drive-in heat treatment is performed. A field oxide layer is then formed on the resultant structure.