US 6,633,069 B2 · 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.

Claims21

Dependent claims

A semiconductor device comprising:

a collector region provided on an active area of a surface of a semiconductor substrate, said active area being defined by an element isolation film;
a base layer provided on the collector region, said base layer extending on said element isolation film, an upper surface of said base layer being flat;
an insulating film formed on a predetermined portion on the base layer, said insulating film having an opening portion formed so as to reach the upper surface of said base layer;
an emitter layer formed on a surface of said base layer in the opening portion;
a metal suicide layer formed on an upper surface of the base layer and at least above the element isolation film;
and
a base contact formed on said element isolation film.

4 more elements

A semiconductor device comprising:

a bipolar transistor disposed on a first conductivity type epitaxial layer provided on a first region on a semiconductor substrate, and
a CMOS type field effect transistor including a first MIS transistor disposed on a surface area of a second conductivity type first well region provided on a second region on said semiconductor substrate, and a second MIS transistor disposed on a surface area of a first conductivity type second well region provided on a third region on said semiconductor substrate,
wherein said bipolar transistor includes:
a collector layer of the first conductivity type provided on an active area of said epitaxial layer, said active area being defined by a first insulating film;
a base layer of the second conductivity type provided on the collector layer, said base layer extending on said first insulation film, an upper surface of said base layer being flat;
a second insulating film having an opening to reach a predetermined region in said base layer, said second insulating film serving as an etching stopper layer provided on said base layer so that at least a part of peripheral edge of said base layer on said collector layer is exposed;
an emitter layer of a first conductivity type provided on a surface of said base layer in the opening;
and
a metal silicide layer formed on an upper surface of the base layer and at least above an element isolation film, an end of said metal silicide layer facing said opening and an end of said second insulating film at the opposite side of the opening being in a self-aligned state;
and
wherein said second MIS transistor includes a source and a drain which are composed of the same impurity and with substantially the same diffusion concentration as those of a part of said base region of said bipolar transistor.

8 more elements

Dependencies are inferred from the claim text.

Semiconductor device

Life of this patent

Semiconductor device

Life of this patent

Abstract

Claims21