EP0075085A2
Expired / Lapsed
EP
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Method of fabricating a conductive metal silicide structure
Assignee: International Business Machines Corp
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Filing: 1982-07-13
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Granted: —
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Expires: 2002-07-13
Abstract
Abstract A method of fabricating a silicide structure includes depositing a metal, e.g., molybdenum or tungsten, directly onto a thin insulating layer (12) of silicon dioxide and/or silicon nitride formed on a semiconductor substrate (10), co-depositing the metal and silicon onto the metal layer (20) and then depositing silicon (24) onto the co-deposited metal-silicon layer (22). This structure is annealed at a temperature sufficient to form a metal silicide between the thin insulating layer (12) and the layer of silicon (24). The silicon layer (24) serves as a source of silicon for the metal layer (20) which is consumed during the annealing step to form, along with the co-deposited metal-silicon layer (22), a relatively thick metal silicide layer directly on the thin silicon dioxide layer (12). A sufficiently thick silicon layer (24) is initially provided on the codeposited metal-silicon layer (22) so that a portion of the initial silicon layer remains after the annealing step has been completed. This excess silicon may be oxidized to form a passivating layer on top of the thick metal silicide layer.
Inventors
- 👤 Henry John Geipel, Jr.
- 👤 Larry Alan Nesbit
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 03:07
CPC Classifications
H; H10; H10P; H10P76/00; H10P76/20; H10P76/202; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01318; H10D64/0132; H10D64/01326; H10P95/00; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/056; H10W20/058; H10W20/064; H10W20/066; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/948; Y10S438/951
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
72 words
A method of making a conductive metal silicide structure, characterized by depositing a layer of metal (20) on an inert insulator (12), depositing a layer of metal silicide (22) on said metal, depositing a layer of silicon (24) on said silicide layer (22), and annealing said structure (20, 22, 24) so as to convert at least a portion of said silicon layer (24) and said metal layer (20) into metal silicide (22').
Claim 2
Independent Claim
72 words
A method of making a conductive metal silicide structure, characterized by depositing a layer of metal (20) on an inert insulator (12), depositing a layer of metal silicide (22) on said metal, depositing a layer of silicon (24) on said silicide layer (22), and annealing said structure (20, 22, 24) so as to convert at least a portion of said silicon layer (24) and said metal layer (20) into metal silicide (22').
Claim 3
Independent Claim
45 words
A method according to Claim I, characterized in that only a portion of said silicon layer (24) is converted into metal silicide (22') and that the remaining portion of said silicon layer is oxidized to form a passivating layer on said metal silicide layer (22').
Claim 4
Dependent Claim
42 words
A method according to Claim 1, characterized by including the step of etching at least some of the remaining portion of said silicon layer (24) and oxidizing the remaining structure to form a passivating layer on said metal silicide layer (22') .
Claim 5
Dependent Claim
32 words
Method according to claims 1 to 3, characterized in that said metal silicide layer (22) is deposited by co-evaporating said metal and silicon and said structure is annealed in an inert atmosphere.
Claim 6
Dependent Claim
18 words
Method according to claim 4, characterized in that said layers are formed by using electron beam evaporation techniques.
Claim 7
Dependent Claim
29 words
Method according to claim 4, characterized in that said layers are formed by first depositing metal (20), then co-depositing said metal and silicon (22) and finally depositing silicon (24).
Claim 8
Dependent Claim
19 words
Method according to claim 6, characterized in that said layers are deposited at a temperature between 100°C and 250°C.
Claim 9
Dependent Claim
38 words
Method according to claims 1 to 7, characterized in that said layers are annealed at a temperature between 750°C and 1200°C for a period of time between 30 minutes and 60 minutes in an argon or nitrogen atmosphere.
Claim 10
Dependent Claim
60 words
Method according to claims 1 to 8, characterized in that said inert insulator (12) has a thickness between 30 and 50 nanometers, said metal layer (20) has a thickness between 30 and 60 nanometers, said metal silicide layer (22) has a thickness between 125 and 225 nanometers and said silicon layer (24) has a thickness between 100 and 300 nanometers.
Claim 11
Dependent Claim
34 words
Method according to claims 1 to 9, characterized in that said metal (20) is a refractory metal and said inert insulator (12) includes a layer of silicon nitride deposited onto a semiconductor substrate 10.
Claim 12
Dependent Claim
147 words
Method according to claims 1 to 10, characterized the following steps: growing a layer of insulation (12) on a silicon substrate (10), depositing a metal selected from the group consisting of molybdenum, tungsten, tantalum, titanium, cobalt and rhodium directly onto the surface (18) of said insulation layer (12) to form the metal layer (20), co-depositing said metal and silicon onto the surface of said metal layer (20) to form a composite metal-silicon layer (22), depositing silicon onto said composite metal-silicon layer to form a silicon layer (24), and annealing said layers in an inert atmosphere at a temperature sufficient to convert said composite metal-silicon layer (22), said metal layer (20) and at least a portion of said silicon layer (24) into a silicide layer (22') forming a first interface with said insulation layer (12) and a second interface with the remaining portion of said silicon layer (24').
Claim 13
Dependent Claim
207 words
Method according to claims 1 to 10, characterized by the following steps: growing a layer of insulation (12) on the surface of a semiconductor substrate (10), depositing a layer of photoresist (14) onto said insulation layer (12), forming an opening (16) in said photoresist layer (14) to expose the surface (18) of said insulation layer (12), depositing a metal from the group consisting of molybdenum, tungsten, tantalum, cobalt, titanium and rhodium through said opening (16) to form the metal layer (20) directly in contact with said insulation layer (12), co-depositing said metal and silicon through said opening to form a composite metal-silicon layer (20) directly in contact with said metal layer (20), depositing silicon through said opening (18) to form a silicon layer (24) in contact with said composite metal-silicon layer (22), removing the remaining portion of said photoresist layer (14) from the surface of said insulation layer (12), and annealing said metal (20), composite metal-silicon (22) and silicon layers (24) at a temperature sufficient to convert said metal and composite metal-silicon layers and a portion of said silicon layer into a silicide layer (22') forming a first interface with said insulation layer (12) and a second interface with the remaining portion of said silicon layer (24').
References Cited (Backward Citations)
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