US 5,854,103 A · Manufacturing method of self-aligned silicide load for static random access memory

Abstract

A self-aligned suicide SRAM load structure and its manufacturing method comprising the steps of providing a semiconductor substrate; then forming a first insulating layer over the substrate and etching an opening. Thereafter, a polysilicon layer is formed over the first insulating layer and the opening, and then a second insulating layer is formed over the polysilicon layer. Next, a photoresist layer for creating a connector pattern is formed over the second insulating layer using microlithographic processes. The second insulating layer is then etched to expose portions of the polysilicon layer. Subsequently, a metallic layer is deposited over the exposed polysilicon layer and the second insulating layer. Then, the metallic layer reacts with the polysilicon layer through heating until the two layers are completely converted into a metal silicide layer. The metal silicide layer functions as connectors, and the unreacted polysilicon layer beneath the second insulating layer functions as a polysilicon load.

Claims15

Dependent claims

A method for forming a self-aligned silicide static random access memory load, comprising the steps of:

Providing a semiconductor substrate having a device layer already formed thereon;
Forming a first insulating layer over the device layer;
Etching away portions of the first insulating layer to form an opening exposing portions of the device layer;
Forming a polysilicon layer over the first insulating layer and the opening;
Forming a second insulating layer over the polysilicon layer;
Forming a patterned photoresist layer over the second insulating layer using microlithographic processes;
Patterning a connector using the patterned photoresist layer;
Anisotropically etching away portions of the second insulating layer to expose portions of the polysilicon layer;
Removing the photoresist layer;
Performing an ion implantation process to dope impurities into the exposed polysilicon layer;
Forming a metallic layer over the exposed portions of the polysilicon layer and the second insulating layer;
Forming a metal silicide layer by heating to make the metallic layer react with the polysilicon layer below;
and
Removing any residual metallic layer and the second insulating layer.

11 more elements

Dependencies are inferred from the claim text.

Manufacturing method of self-aligned silicide load for static random access memory

Life of this patent

Manufacturing method of self-aligned silicide load for static random access memory

Life of this patent

Abstract

Claims15