Patent ID: 6864129
Filing Date: 2005-03-08
Classification: H01L

Abstract:
1. A method for fabricating a double gate MOSFET, which comprises the steps in the following sequence: producing gates aligned accurately with one another by; providing a substrate structure having a silicon substrate layer, a first insulation layer disposed on the silicon substrate layer, a first separation layer disposed on the first insulation layer, and a semiconductor layer disposed on the first separation layer; patterning the semiconductor layer resulting in a semiconductor layer structure provided as a channel of the double gate MOSFET; depositing a second separation layer on the semiconductor layer structure and the first separation layer; completely embedding the semiconductor layer structure in the first and second separation layers by patterning the first and second separation layers; depositing a second insulation layer on a structure formed of the first and second separation layer; vertically etching two depressions disposed along one direction, the two depressions dimensioned such that the semiconductor layer structure is situated completely between them, during the etching of the two depressions, the second insulation layer, the first and second separation layers and, in each case on both sides, an edge section of the semiconductor layer structure being etched through completely in each case; filling the depressions with an electrically conductive material; forming a contact hole in the second insulation layer; removing a region of the separation layers extending from the contact hole to the semiconductor layer structure and in which region the semiconductor layer structure is embedded in the separation layers by etching the region of the separation layers through the contact hole; applying third insulation layers on inner walls of the region of removed separation layers and on surfaces of the semiconductor layer structure; and introducing a further electrically conductive material into the region of the removed separation layers.