Gate structure for a transistor and method for fabricating a transistor with the gate structure

摘要

A gate structure of a transistor is fabricated with an additional barrier formed on a metal layer of the gate structure before the deposition of a silicon oxide layer. Applying this barrier layer on the metal layer before the deposition of the silicon oxide layer prevents an oxidation of the metal during the deposition of the silicon oxide layer. A lowering of the conductivity of the metal layer or a loss of metal through sublimating metal oxide is thereby prevented. As a result, in particular the performance of the gate structure or of the transistor is improved further. In addition, disturbing coupling effects in the circuit are significantly reduced by the use of the silicon oxide cap.