Semiconductor device

Abstract

A bipolar transistor has metal silicide as a base lead-out electrode instead of conventional polysilicon, and the metal silicide film extends to an edge of an etching stopper layer, to reduce an emitter resistance and restrain an occurrence of an emitter plug effect. Such bipolar transistor can be utilized in a CMOS semiconductor device. In this case, (1) commonly using a process of providing an active base region, a base lead-out electrode and a collector lead-out electrode of the bipolar transistor and a process of providing gate electrodes a MOS field effect transistor, (2) commonly using a process of adding a p-type impurity into the active base region and the base lead-out electrode and a process of executing an ion-implantation for providing high-concentration impurity diffused layers of pMOS transistors, (3) commonly using a process of providing an etching stopper layer and a process of providing side wall insulating films of gate electrodes, and (4) commonly using a silicidation process of the base lead-out electrode and the collector lead-out electrode and a silicidation process of electrodes of MOS transistors. In other embodiment of the bipolar transistor, a single insulating film exist between the base layer and the emitter electrode in the peripheral of the emitter opening. By this construction, the etching stopper film is not necessary resulting in reducing the base resistance.