Patent ID: 8772861

Claim:
A field effect trench transistor comprising: a multiplicity of trenches formed from a silicon surface of a semiconductor, said trenches running in parallel to one another and in a longitudinal direction parallel to the silicon surface of the semiconductor, including a plurality of stripe-shaped active trenches and at least two inactive trenches, which are adjacent to each other and a multiplicity of transistor cells arranged as an array of transistor cells and having gate electrodes lying in the active trenches; wherein the at least two inactive trenches lie in the array of the transistor cells between the active trenches and includes no gate electrodes but a plurality of polysilicon protective diodes which are integrated in the at least two inactive trenches, isolated by an oxide layer, connected in form of a series connection with one another in the longitudinal direction of the at least two inactive trenches, and are contact-connected at one end of the series connection of the plurality of polysilicon protective diodes to a gate metallization and at the opposite end of the series connection of the plurality of polysilicon protective diodes to a source metallization of the field effect trench transistor.