US 6,306,701 B1 · Self-aligned contact process

Abstract

A self-aligned contact process. A substrate is provided. A gate including a polysilicon layer and a metal silicide layer is formed on the substrate. A cap layer is formed on the gate to protect the gate. A first spacer is formed on the sidewall of the gate. A first ion implantation is performed using the gate and the first spacer as a first mask to form lightly doped regions in the substrate. A conformal liner layer is formed on the cap layer, the first spacer and the substrate. An insulating layer is formed on the conformal liner layer. A part of the insulating layer and a part of the liner layer are removed until exposing the cap layer. A part of the liner layer remaining on the first spacer and a part of the insulating layer remaining on the remaining liner layer are used as a second spacer. A second ion implantation is performed to form source/drain regions with lightly doped drain (LDD) structures in the substrate beside the second spacer. An inter-layer dielectric layer is formed over the substrate and then is etched to form a contact opening therein that exposes a part of the source/drain regions.

Claims9

Dependent claims

A self-aligned contact process for formation of a contact opening on a semiconductor substrate comprising:

at least providing the semiconductor substrate with a gate structure thereon, wherein a cap layer is formed on the gate structure;
forming a first insulating layer on the substrate;
removing a part of the first insulating layer to form a first spacer on a sidewall of the gate structure and the cap layer;
performing a first ion implantation to form lightly doped regions in the substrate using the gate structure and the first spacer as a mask;
forming a liner layer on the substrate, the cap layer and the first spacer;
forming a second insulating layer on the liner layer;
removing a part of the second insulating layer and a part of the liner layer until exposing the cap layer to form a second spacer and leave another part of the liner layer on the first spacer;
performing a second ion implantation to form source/drain regions in the substrate;
forming a metal salicide layer on the source/drain regions;
forming an inter-layer dielectric layer on the cap layer, the second spacer and the metal salicide layer;
and
removing a part of the inter-dielectric layer to form a contact opening exposing a part of the source/drain regions.

9 more elements

Dependencies are inferred from the claim text.

Self-aligned contact process

Life of this patent

Self-aligned contact process

Life of this patent

Abstract

Claims9