Method of fabricating next-to-minimum-size transistor gate using mask-edge gate definition technique

摘要

A method of fabricating minimum size and next-to-minimum size electrically conductive members using a litho-less process is disclosed. A substrate is provided, and a layer of gate dielectric material is formed on the substrate. A layer of electrically conductive material is formed over the gate dielectric material. A first mask is used to form a hard mask. A layer of first spacer material is deposited over the existing structures, and the layer of first spacer material is etched back to form spacers adjacent to the hard mask. The width of the first spacers determines the minimum size gate length. A layer of second spacer material is deposited over the existing structures, including the hard mask and first spacers. The layer of second spacer material is etched back to form a second set of spacers adjacent to the first spacers. The width of the first and second spacers together determine the next-to-minimum size gate length. A second mask is used to protect the portion of the second spacers which are to be used to define next-to-minimum size gates, and the unprotected second spacers and the hard mask are removed. The exposed electrically conductive material is removed. The remaining spacers are then removed, leaving minimum size and next-to-minimum size gates.