BUTTED CONTACT SHAPE TO IMPROVE SRAM LEAKAGE CURRENT

摘要

The present disclosure relates to an SRAM memory cell. The SRAM memory cell has a semiconductor substrate with an active area and a gate region positioned above the active area. A butted contact extends from a position above the active area to a position above the gate region. The butted contact contains a plurality of distinct regions having different widths (i.e., the smaller dimensions of the butted contact), such that a region spanning the active area and gate region has width less than the regions in contact with the active area or gate region. By making the width of the region spanning the active area and gate region smaller than the regions in contact with the active area or gate, the etch rate is reduced at a junction of the gate region with the active area, thereby preventing etch back of the gate material and leakage current.

主权项

1. A method of forming a butted contact, comprising:
forming a dielectric material over a substrate; etching the dielectric material to form an opening having a first outer region, a second outer region, and a central region arranged between the first outer region and the second outer region; depositing metal within the opening in the dielectric material to form a butted contact; and wherein the dielectric material is etched using an etching process that etches the first outer region at a first etch rate, that etches the central region at a second etch rate less than the first etch rate, and that etches the second outer region at a third etch rate greater than the second etch rate.