Spacer for semiconductor structure contact

Abstract

An embodiment is a semiconductor structure. The semiconductor structure comprises an epitaxial region, a gate structure, a contact spacer, and an etch stop layer. The epitaxial region is in a substrate. A top surface of the epitaxial region is elevated from a top surface of the substrate, and the epitaxial region has a facet between the top surface of the substrate and the top surface of the epitaxial region. The gate structure is on the substrate. The contact spacer is laterally between the facet of the epitaxial region and the gate structure. The etch stop layer is over and adjoins each of the contact spacer and the top surface of the epitaxial region. A ratio of an etch selectivity of the contact spacer to an etch selectivity of the etch stop layer is equal to or less than 3:1.

Description

technical field [0001] The present invention relates generally to the field of semiconductors, and more particularly to spacers for contacting semiconductor structures Background technique [0002] Due to the development of integrated circuits (ICs), the semiconductor industry is constantly seeking to improve the performance or size of ICs. Many improvements have focused on smaller feature sizes to enable increased IC speed. As feature sizes decrease, the density of devices (eg, transistors, diodes, resistors, capacitors, etc.) on an IC increases. As density increases, the distance between devices typically decreases, which allows for less resistance and capacitance between devices. Therefore, the resistance-capacitance (RC) time constant can be reduced. [0003] Other improvements focus on using different materials to achieve beneficial effects. Epitaxial growth of different materials on the substrate is used to beneficial effect. For example, the growth of different m...

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Problems solved by technology

Therefore, the contact cannot touch the facet causing an open contact

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