Patent US4619038A successfully refreshed from Google Patents.
US4619038A
Expired / Lapsed
US
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Selective titanium silicide formation
Assignee: NXP USA Inc
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Filing: 1985-08-15
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Granted: 1986-10-28
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Expires: 2005-08-15
Abstract
Abstract A process for selective formation of a titanium silicide, TiSi2, layer at high temperatures and low pressures via chemical vapor deposition during semiconductor device manufacturing. At 700 DEG to 1000 DEG C. and 0.5 to 1.5 torr, TiSi2 deposits only on exposed silicon or polysilicon surfaces and not at all on neighboring silicon dioxide. The process provides an excellent means of providing low resistivity interconnects without a mask step or subsequent annealing and removal of unreacted titanium.
Inventors
- 👤 Faivel S. Pintchovski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:25
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/20; H10D64/23; H10D64/251; H10D64/258; H10D64/259; H10D64/01; H10D64/011; H10D64/0111; H10D64/0112; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01306; H10D64/01308; H10D64/01312; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10W20/066; H10P; H10P14/00; H10P14/40; H10P14/42; H10P14/43; Y; Y10; Y10S; Y10S148/00; Y10S148/147
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
74 words
A process for selectively forming titanium silicide on silicon and polysilicon surfaces via low pressure chemical vapor deposition (LPCVD) comprising introducing a titanium halide gas and a stoichiometric excess of hydrogen with respect to said titanium halide gas into a reaction zone having silicon and/or polysilicon surfaces wherein the reaction temperature ranges from 700° to 1000° C. and the reaction pressure ranges from 0.5 to 1.5 torr, in the absence of a silicon-bearing gas.
Claim 2
Dependent Claim
74 words
A process for selectively forming titanium silicide on silicon and polysilicon surfaces via low pressure chemical vapor deposition (LPCVD) comprising introducing a titanium halide gas and a stoichiometric excess of hydrogen with respect to said titanium halide gas into a reaction zone having silicon and/or polysilicon surfaces wherein the reaction temperature ranges from 700° to 1000° C. and the reaction pressure ranges from 0.5 to 1.5 torr, in the absence of a silicon-bearing gas.
Claim 3
Dependent Claim
16 words
The process of claim 1 in which the reaction temperature ranges from 750° to 850° C.
Claim 4
Dependent Claim
16 words
The process of claim 1 in which the titanium halide gas is a titanium tetrahalide gas.
Claim 5
Dependent Claim
14 words
The process of claim 3 in which the titanium tetrahalide gas is titanium tetrachloride.
Claim 6
Dependent Claim
16 words
The process of claim 1 in the absence of subsequent anneal and unreacted titanium etch steps.
Claim 7
Dependent Claim
24 words
The process of claim 1 in which the titanium halide is present in the gaseous reaction mixture in a concentration of at least 1:50.
Claim 8
Dependent Claim
27 words
The process of claim 1 in which nitrogen may be present and the ratios of flow rates of titanium halide:nitrogen:hydrogen range from 5:0:500 sccm to 20:1000:2000 sccm.
Claim 9
Dependent Claim
147 words
A process for producing a semiconductor device comprising a low resistivity layer of titanium silicide selectively overlying a region of silicon comprising the steps of providing a single crystal silicon substrate, forming regions of a polycrystalline silicon material, forming regions of a silicon oxide material in the neighborhood of the polycrystalline silicon material and forming a titanium silicide layer selectively on the single crystal and polycrystalline silicon material, the improvement comprising reacting a gaseous titanium halide with the single crystal and polycrystalline silicon material at a temperature in the range of 700° to 1000° C. and a pressure in the range of 0.5 to 1.5 torr in the presence of a stoichiometric excess of hydrogen with respect to said titanium halide gas and in the absence of a silicon-bearing gas to form the titanium silicide layer, in the absence of subsequent anneal and unreacted titanium etch steps.
Claim 10
Dependent Claim
147 words
A process for producing a semiconductor device comprising a low resistivity layer of titanium silicide selectively overlying a region of silicon comprising the steps of providing a single crystal silicon substrate, forming regions of a polycrystalline silicon material, forming regions of a silicon oxide material in the neighborhood of the polycrystalline silicon material and forming a titanium silicide layer selectively on the single crystal and polycrystalline silicon material, the improvement comprising reacting a gaseous titanium halide with the single crystal and polycrystalline silicon material at a temperature in the range of 700° to 1000° C. and a pressure in the range of 0.5 to 1.5 torr in the presence of a stoichiometric excess of hydrogen with respect to said titanium halide gas and in the absence of a silicon-bearing gas to form the titanium silicide layer, in the absence of subsequent anneal and unreacted titanium etch steps.
Claim 11
Dependent Claim
25 words
The process of claim 8 in which nitrogen may be present and the ratio of flow rates of titanium halide:nitrogen:hydrogen ranges from 5:0:500 to 20:1000:2000.
Claim 12
Dependent Claim
16 words
The process of claim 8 in which the reaction temperature ranges from 750° to 850° C.
Claim 13
Dependent Claim
16 words
The process of claim 8 in which the titanium halide gas is a titanium tetrahalide gas.
Claim 14
Dependent Claim
14 words
The process of claim 11 in which the titanium tetrahalide gas is titanium tetrachloride.
Claim 15
Dependent Claim
24 words
The process of claim 8 in which the titanium halide is present in the gaseous reaction mixture in a concentration of at least 1:50.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-10-27 | 1990-04-28 | 1990-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-27 | 1994-04-28 | 1994-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-27 | 1998-04-28 | 1998-10-28 | $7700.00 | Window Closed / Lapsed |