| 摘要 |
PURPOSE:To protect a element against damage caused by a parasitic bipolar transistor action by a method wherein a source region is formed through a Schottky junction of a low concentrated diffusion layer with a metallic layer. CONSTITUTION:A p-type impurity diffusion region 14, an N-type low concen trated impurity diffusion layer region 21, and a P<+>-type high concentrated im purity diffusion region 22 are formed through diffusion, and the diffusion layers 14 and 22 are formed through a gate electrode serving as a mask. In this case, surface concentrations of the diffusion layers 21 and 22 are set so as to be about 10<18>-10<17> cm<-3> and 10<19> cm<-3> respectively. A metallic layers 23 and 24 are formed on a gate electrode and the diffusion layer 21 and 22 through diffusion of platinum silicide serving as a lifetime killer of a diode D1 built in between a base drain, through which a high-speed freewheel diode is formed. Thereafter, a layer insulating film 18 is formed through a vapor growth and a source electrode 19 is formed after a contact hole is built. By these processes, a source region is structured as a Schottky junction of the diffusion region 21 with the metallic layer 23, wherefore an element is protected against damage caused by a parasitic bipolar transistor action. |
