Patent ID: 7622790

Claim:
A transistor assembly having a transistor, comprising: a plurality of transistor regions including a first set and a second set, each transistor region comprising a vertical transistor structure comprising a collector semiconductor region, a base semiconductor region and an emitter semiconductor region; emitter contacting regions arranged above the transistor regions; base contacting regions connected to the base semiconductor regions via a polycrystalline semiconductor layer; and wherein the polycrystalline semiconductor layer is structured such that base contacting regions of the first set of transistor regions which are not part of the transistor are electrically isolated from base contacting regions of the second set of transistor regions which are part of the transistor, wherein the polycrystalline semiconductor layer is further structured such that the base semiconductor regions of the second set of transistor regions are not connected to one another via the polycrystalline layer in an electrically conducting way.