NPN transistor with P/N closed loop in contact with collector electrode

摘要

A semiconductor device capable of suppressing the influence of a parasitic pnp transistor caused when an npn transistor operates in saturation range in such a way that a p-type impurity region is formed in the outer layer of an n-type collector region and electrically short-circuited with the n-type collector region isolated by a p-type isolation diffusion layer in the npn bi-polar transistor.