Semiconductor structures and manufacturing methods

Abstract

A method for forming source/drain contacts to source/drain regions of an array of transistors. The method includes providing a semiconductor body with a gate oxide layer over the surface of the semiconductor body. The gate oxide layer extends over active areas in the semiconductor body. Gate stacks are provided on the gate oxide layer in columns across the rows of active areas. A dielectric material is deposited over the surface of the provided semiconductor body. Vias are etched through the dielectric material over source/drain regions in portions of the active area between the columns of gate stacks. First portion of sidewalls of such vias are formed over portions of adjacent columns of the gate stacks and second portions of the sidewalls of such vias are formed between adjacent columns of the gate stacks. The vias expose portions of the gate oxide layer over the source/drain regions. Source/drain contacts are formed in the vias, such formation comprising: forming spacers on the sidewalls of the regions of dielectric material; exposing the exposed portions of the gate oxide to an etch to remove such exposed portions of the gate oxide layer, such etch etching the gate oxide at a substantially higher etch rate that to the spacers; and forming conductive materials on the spacers and in contact with the source/drain regions.