EP0244995A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Low resistance metal contact for silicon devices
Assignee: Advanced Micro Devices Inc
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Filing: 1987-04-24
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Granted: —
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Expires: 2007-04-24
Abstract
Abstract A three layer metal contact (40) including aluminum is provided for silicon-based semiconductor devices to minimize the effects of formation of silicon precipitates in the aluminum layer and low contact junction leakage. The metal contact comprises a first layer (42) of a refractory metal silicide formed on a silicon surface, an intermediate layer (44) of aluminum formed on the refractory metal silicide and a top layer (46) of a refractory metal silicide formed on the layer of aluminum. Where contact is made to polysilicon layers forming high resistance load resistors, the metal contact of the invention prevents reduction in resistance resulting from the interdiffusion of silicon and aluminum.
Inventors
- 👤 Robin W. Cheung
- 👤 Bernard W.K. Ho
- 👤 Hsiang-Wen Chen
- 👤 Hugo W.K. Chan
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 01:33
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/425; Y; Y10; Y10S; Y10S148/00; Y10S148/019
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
31 words
A metal contact system for silicon-based semiconductor devices comprising a first layer of a refractory metal silicide, an intermediate layer of aluminum and a top layer of a refractory metal silicide.
Claim 2
Dependent Claim
31 words
A metal contact system for silicon-based semiconductor devices comprising a first layer of a refractory metal silicide, an intermediate layer of aluminum and a top layer of a refractory metal silicide.
Claim 3
Dependent Claim
27 words
The metal contact system of Claim 1 wherein said refractory metal silicide includes a refractory metal selected from the group consisting of molybdenum, tungsten, titanium and tantalum.
Claim 4
Dependent Claim
13 words
The metal contact system of Claim 2 wherein said refractory metal comprises molybdenum.
Claim 5
Dependent Claim
21 words
The metal contact system of Claim 1 wherein said refractory metal silicide ranges in thickness from about 500 to 2,000 Å.
Claim 6
Dependent Claim
21 words
The metal contact system of Claim 4 wherein said thickness of said refractory metal silicide is about 1,000 to 1,100 Å.
Claim 7
Dependent Claim
57 words
A process for forming an improved metal contact to a silicon-based semiconductor device formed in a silicon substrate comprising forming a first layer of a refractory metal silicide on said substrate, forming a second layer of aluminum on said refractory metal silicide and forming a top layer of a refractory metal silicide on said layer of aluminum.
Claim 8
Dependent Claim
57 words
A process for forming an improved metal contact to a silicon-based semiconductor device formed in a silicon substrate comprising forming a first layer of a refractory metal silicide on said substrate, forming a second layer of aluminum on said refractory metal silicide and forming a top layer of a refractory metal silicide on said layer of aluminum.
Claim 9
Dependent Claim
25 words
The process of Claim 6 wherein said refractory metal silicide includes a refractory metal selected from the group consisting of molybdenum, tungsten, titanium and tantalum.
Claim 10
Dependent Claim
11 words
The process of Claim 7 wherein said refractory metal comprises molybdenum.
Claim 11
Dependent Claim
19 words
The process of Claim 6 wherein said refractory metal silicide ranges in thickness from about 500 to 2,000 Å.
Claim 12
Dependent Claim
19 words
The process of Claim 9 wherein said thickness of said refractory metal silicide is about 1,000 to 1,100 Å.
Claim 13
Dependent Claim
22 words
The process of Claim 6 wherein said refractory metal silicides and said aluminum are deposited on said substrate at an elevated temperature.
Claim 14
Dependent Claim
32 words
The process of Claim 11 wherein said refractory metal silicides and said aluminum are deposited by sputtering appropriate materials on a substrate maintained at a temperature ranging from about 100° to 300°C.
Claim 15
Dependent Claim
30 words
The process of Claim 11 wherein said contact is subsequently sintered in an oxygen-free atmosphere at a temperature less than about 450°C for a time less than about 2 hours.
Claim 16
Independent Claim
49 words
A method of minimizing the effects of silicon precipitation in aluminum contacts to silicon-based devices formed on silicon substrates which comprises providing a three-layer metallization contact comprising a first layer of a refractory metal silicide, a second layer of aluminum and a third layer of a refractory metal silicide.
Claim 17
Independent Claim
49 words
A method of minimizing the effects of silicon precipitation in aluminum contacts to silicon-based devices formed on silicon substrates which comprises providing a three-layer metallization contact comprising a first layer of a refractory metal silicide, a second layer of aluminum and a third layer of a refractory metal silicide.
Claim 18
Dependent Claim
25 words
The method of Claim 14 wherein said refractory metal silicide includes a refractory metal selected from the group consisting of molybdenum, tungsten, titanium and tantalum.
Claim 19
Dependent Claim
11 words
The process of Claim 15 wherein said refractory metal comprises molybdenum.
Claim 20
Dependent Claim
63 words
In combination, a polysilicon load resistor having an undoped or slightly doped region, said polysilicon load resistor in cooperative association with at least one silicon-based semiconductor device and provided with a metal contact to said region, said metal contact com prising a first layer of a refractory metal silicide, an intermediate layer of aluminum and a top layer of a refractory metal silicide.
Claim 21
Dependent Claim
63 words
In combination, a polysilicon load resistor having an undoped or slightly doped region, said polysilicon load resistor in cooperative association with at least one silicon-based semiconductor device and provided with a metal contact to said region, said metal contact com prising a first layer of a refractory metal silicide, an intermediate layer of aluminum and a top layer of a refractory metal silicide.
Claim 22
Dependent Claim
25 words
The combination of Claim 17 wherein said refractory metal silicide includes a refractory metal selected from the group consisting of molybdenum, tungsten, titanium and tantalum.
Claim 23
Dependent Claim
11 words
The combination of Claim 18 wherein said refractory metal comprises molybdenum.
Claim 24
Dependent Claim
69 words
A static random access memory cell having a gate, source and drain regions and a polysilicon load resistor operatively associated with one of said regions, said polysilicon load resistor having an undoped or slightly doped region and provided with a metal contact thereto, said metal contact comprising a first layer of a refractory metal silicide, an intermediate layer of aluminum and a top layer of a refractory metal silicide.
Claim 25
Dependent Claim
69 words
A static random access memory cell having a gate, source and drain regions and a polysilicon load resistor operatively associated with one of said regions, said polysilicon load resistor having an undoped or slightly doped region and provided with a metal contact thereto, said metal contact comprising a first layer of a refractory metal silicide, an intermediate layer of aluminum and a top layer of a refractory metal silicide.
Claim 26
Dependent Claim
26 words
The memory cell of Claim 20 wherein said refractory metal silicide includes a refractory metal selected from the group consisting of molybdenum, tungsten, titanium and tantalum.
Claim 27
Dependent Claim
12 words
The memory cell of Claim 21 wherein said refractory metal comprises molybdenum.
References Cited (Backward Citations)
No citation records indexed.
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