Semiconductor device and method of manufacturing the same

Claim 1

A semiconductor device, comprising: a semiconductor substrate; a bipolar transistor, a first field effect transistor, and a second field effect transistor, formed on said semiconductor substrate separately from each other; wherein: the bipolar transistor is separated from the first field effect transistor by a first homogeneous field oxide region and the first field effect transistor is separated from the second field effect transistor by a second homogeneous field oxide region; the first homogeneous field oxide region has an upper surface with a recess formed by etching, with no corresponding recess in the second homogeneous field oxide region; and the thickness of the second homogeneous field oxide region is greater than the thickness of the recessed portion of the first homogeneous field oxide region; said bipolar transistor comprising: an external base electrode provided on said semiconductor substrate and having a first sidewall and a second sidewall; a first sidewall spacer provided on the first sidewall of said external base electrode; a second sidewall spacer provided on the second sidewall of said external base electrode; an emitter electrode adjacent to said external base electrode with said first sidewall spacer therebetween; each of said field effect transistors comprising: a gate electrode provided on said semiconductor substrate; and a third sidewall spacer provided on a sidewall of said gate electrode; wherein said emitter electrode and said external base electrode partially overlap each other; the thickness of said gate electrode of each of said field effect transistors is greater than the thickness of said emitter electrode of said bipolar transistor, and said second sidewall spacer has a width different from the width of said third sidewall spacer.