US 6,586,321 B2 · Method for forming metal silicide layer

Abstract

A method of forming a metal silicide layer with low resistance, with minimal consumption of silicon, includes depositing a first metal layer over a silicon-containing region, depositing a second metal layer over the first metal layer, forming an antioxidation layer over the second metal layer, and performing a first heat treatment on the structure to form a metal silicide preliminary layer from the silicon-containing region and the first metal layer and to form an alloy layer including a first metal and a second metal from the second metal layer and the first metal layer. The antioxidation layer and then the alloy layer and a portion of the remaining first metal layer are removed. A second heat treatment on the metal silicide preliminary layer at a higher temperature than the first heat treatment is performed, to change the metal silicide preliminary layer into a metal silicide layer.

Drawings

Drawings are temporarily unavailable. Open the PDF at USPTO

Drawings

Claims27

Dependent claims

A method for forming a metal silicide layer, comprising:

performing a first heat treatment on a laminate of a silicon-containing region, a first metal layer on the silicon-containing region, and a second metal layer on the first metal layer, while said laminate is prevented from being oxidized, thereby forming a first metal silicide preliminary layer in a boundary region between the silicon-containing region and the first metal layer;
and
performing a second heat treatment at a higher temperature than in said first heat treatment on the first metal suicide preliminary layer, thereby changing the first metal suicide preliminary layer into a first metal suicide, thicknesses of the first metal layer and the second metal layer being selected so that all of the second metal layer finishes reaction simultaneously with or before all of the first metal layer on the silicon-containing region finishes reaction when said first heat treatment is performed,
said first heat treatment is performed until all of the first metal layer on the silicon-containing region finishes reaction.

1 more element

A method for simultaneously forming metal silicide layers of different thickness over different silicon-containing regions, comprising:

forming a titanium layer by depositing titanium over a first silicon-containing region and a second silicon-containing region;
forming a cobalt layer by depositing cobalt over said titanium layer;
removing a part of said cobalt layer located over said second silicon-containing region;
forming an antioxidation layer over a remaining portion of said cobalt layer and over said titanium layer exposed from said cobalt layer;
performing a first heat treatment on a structure comprising said first and second silicon-containing regions, said titanium layer, said cobalt layer, and said antioxidation layer, thereby forming a titanium silicide first preliminary layer from a region on a titanium layer side of said first silicon-containing region and a region on a first silicon-containing region side of said titanium layer, forming a titanium suicide second preliminary layer that is thicker than said titanium silicide first preliminary layer from a region on a titanium layer side of said second silicon-containing region and a region on a second silicon-containing region side of said titanium layer, and forming an ahoy layer including titanium and cobalt from a region on a cobalt layer side of said titanium layer and said remaining portion of said cobalt layer;
removing said antioxidation layer, and then removing said ahoy layer and a remaining portion of said titanium layer that remains on regions other than said first and second silicon-containing regions;
and
performing a second heat treatment on said titanium suicide first preliminary layer and said titanium suicide second preliminary layer at a higher temperature than in said first heat treatment so as to change said titanium suicide first preliminary layer and said titanium suicide second preliminary layer into a titanium suicide first layer and a titanium suicide second layer,
said titanium layer having a thickness greater than a thickness of said cobalt layer,
thicknesses of said titanium layer and said cobalt layer being selected so that all of said cobalt layer finishes reaction simultaneously with or before all of said titanium layer on said first silicon-containing region finishes reaction when said first heat treatment is performed, and
said first heat treatment is performed until all of said titanium layer on said first silicon-containing region finishes reaction.

8 more elements

A method for forming a metal suicide layer over a silicon-containing region, comprising:

forming a titanium layer by depositing titanium over a region containing said silicon-containing region;
forming a cobalt layer by depositing cobalt over said titanium layer;
forming an antioxidation layer over said cobalt layer;
performing a first heat treatment on the structure comprising said silicon-containing region, said titanium layer, said cobalt layer, and said antioxidation layer, thereby forming a titanium silicide preliminary layer from a region on a titanium layer side of said silicon-containing region and a region on a silicon-containing region side of said titanium layer, and forming an alloy layer including titanium and cobalt from said cobalt layer and a region on a cobalt layer side of said titanium layer;
removing said antioxidation layer, and then removing said alloy layer and a remaining portion of said titanium layer that remains on regions other than the region containing said silicon-containing region;
and
performing a second heat treatment on said titanium silicide preliminary layer at a higher temperature than in said first heat treatment so as to change said titanium silicide preliminary layer into a titanium silicide layer,
said titanium layer having a thickness greater than a thickness of said cobalt layer,
thicknesses of said titanium layer and said cobalt layer being selected so that all of said cobalt layer finishes reaction simultaneously with or before all of said titanium layer on said silicon-containing region finishes reaction when said first heat treatment is performed, and
said first heat treatment is performed until all of said titanium layer on said silicon-containing region finishes reaction.

7 more elements

Dependencies are inferred from the claim text.

Description7,382 words

Summary2,934 words

#1. Field of the Invention

#The present invention relates to a method for forming a metal silicide layer, and more particularly to a method for forming a cobalt silicide layer or a titanium silicide layer.

#2. Description of Related Art

Brief description of the drawings7 figures

#The foregoing and other objects, features and advantages of the present invention will be better understood from the following description taken in connection with the accompanying drawings, in which:

#FIGS. 1(A) to 1(C) are process diagrams illustrating an embodiment of the present invention;

#FIGS. 2(A) and 2(B) are process diagrams illustrating an embodiment of the present invention, and are a continuation of FIG. 1;

Detailed description4,321 words

#Embodiments of the present invention will now be described with reference to the figures. These figures are merely schematic illustrations of the shape, size, and arrangement relationships of the various components, and are intended to facilitate an understanding of the present invention, and therefore do not limit the present invention to the illustrated examples. In the figures, some of the hatching indicating cross sectional surfaces has been eliminated to make the figures easier to understand.

#FIGS. 1A-1C and 2A-2B are simplified process diagrams illustrating an embodiment of the present invention. These figures are cross sections of the structure during formation.

#The structure used in this embodiment has a silicon-containing region 12 formed as an island within an insulation region 10 such as an isolation region provided to a substrate (in this embodiment, the insulation region is encompassed by the term “substrate”).

Facts

Application

09/490,277Filed 24 Jan 2000

Priority

JP 11-18315229 Jun 1999

Published

US 2002/0111018 A115 Aug 2002

Granted

1 Jul 2003

Term ended

24 Jan 2020

Estimated · how

20 years from earliest known nonprovisional domestic filing. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination. Patent term adjustment is unavailable; no adjustment was added.

Classification5 codes

H10D 30/0212
Of FETs having insulated gates [IGFET]: using self-aligned silicidation
H10D 64/0112
To Group IV semiconductors: using conductive layers comprising silicides
Y10S 438/976
Semiconductor device manufacturing: process: temporary protective layer
H10D
Inorganic electric semiconductor devices

Method for forming metal silicide layer

Life of this patent

Method for forming metal silicide layer

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims27

Description7,382 words

Drawings

Description7,382 words

Classification5 codes

Life of this patent