Salicide method for producing a semiconductor device using silicon/amorphous silicon/metal structure
First Claim
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1. A method for forming semiconductor device comprising:
- providing a substrate;
forming a gate dielectric layer over said substrate;
forming a gate layer over said gate dielectric layer;
forming a cap layer over said gate layer;
creating a lightly doped source/drain region in the substrate, and not under the gate dielectric layer;
forming spacers on the sidewalls of said gate dielectric layer, and said gate layer, and said cap layer to form an intermediate structure;
forming a deep source/drain region in said substrate and under said lightly doped source/drain region;
annealing to activate the dopants;
removing the cap layer;
depositing a silicon film over said intermediate structure;
depositing a metal layer over said silicon film;
forming a silicide layer from the silicon film and the metal layer by using laser irradiation;
subjecting the silicon body to a heat treatment to convert the silicide regions into low-resistivity silicides;
depositing an interlevel dielectric layer over said silicide layer;
chemical-mechanical polish (CMP) said interlevel dielectric layer, said spacers and said silicide to break the continuity of the silicide film to create a source/drain silicide film and a gate silicide film.
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Abstract
The present invention provides an improved semiconductor device of a Silicon/Amorphous Silicon/Metal Structure (SASM) and a method of making an improved semiconductor device by a salicide process by using an anneal to form a thick silicide film on shallow source/drain regions and a chemical-mechanical polish (CMP) step is then performed to remove the silicide over the top of the spacers at the gate, thus breaking the continuity of the silicide film extending from the gate to the source drain region.
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Citations
26 Claims
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1. A method for forming semiconductor device comprising:
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providing a substrate;
forming a gate dielectric layer over said substrate;
forming a gate layer over said gate dielectric layer;
forming a cap layer over said gate layer;
creating a lightly doped source/drain region in the substrate, and not under the gate dielectric layer;
forming spacers on the sidewalls of said gate dielectric layer, and said gate layer, and said cap layer to form an intermediate structure;
forming a deep source/drain region in said substrate and under said lightly doped source/drain region;
annealing to activate the dopants;
removing the cap layer;
depositing a silicon film over said intermediate structure;
depositing a metal layer over said silicon film;
forming a silicide layer from the silicon film and the metal layer by using laser irradiation;
subjecting the silicon body to a heat treatment to convert the silicide regions into low-resistivity silicides;
depositing an interlevel dielectric layer over said silicide layer;
chemical-mechanical polish (CMP) said interlevel dielectric layer, said spacers and said silicide to break the continuity of the silicide film to create a source/drain silicide film and a gate silicide film. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
a. titanium, b. cobalt, c. or nickel.
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15. The method of claim 1, wherein the laser irradiation is from a pulsed excimer laser source.
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16. The method of claim 1, wherein the laser irradiation is done at about 157 nm to 308 nm.
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17. The method of claim 16, wherein the laser irradiation is done at 248 nm.
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18. The method of claim 1, wherein the silicide layer is one of the following:
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a. titanium silicide, b. cobalt silicide, c. or nickel silicid.
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19. The method of claim 1, wherein the interlevel dielectric layer is an oxide.
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20. The method of claim 1, wherein the silicide layer is formed from a Silicon/Amorphous Silicon/Metal structure.
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21. The method of claim 1, wherein the metal layer is deposited using physical vapor deposition.
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22. The method of claim 1, wherein the heat treatment can either be a RTA step or subsequent laser irradiation.
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23. The method claim of claim 22 wherein the RTA step is in the temperature range from 250 to 900 degrees Centigrade, and has a duration in the range of 5 seconds to 1 hour.
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24. The method claim of claim 22 wherein the heat treatment for using laser irradiation has a fluence is in the range of 0.05 to 0.5 J/cm squared, with the number of pulses applied ranging from 1 to 100″
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25. A method for forming semiconductor device comprising:
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providing a substrate;
forming a gate dielectric layer over said substrate;
forming a gate layer over said gate dielectric layer;
forming a cap layer over said gate layer;
forming spacers on the sidewalls of said gate dielectric layer, and said gate layer and said cap layer to form an intermediate structure;
creating a lightly doped source/drain region in the substrate, and not under the gate dielectric layer; and
said cap layer to form an intermediate structure;
forming a deep source/drain region in said substrate and under said lightly doped source/drain region;
removing the cap layer;
depositing a silicon film over said intermediate structure;
depositing a metal layer over said silicon film;
forming a silicide layer from the silicon film and the metal layer by using rapid thermal annealing;
depositing an inter level dielectric layer over said silicide layer;
chemical-mechanical polish (CMP)said inter level dielectric layer, said spacers and said silicide to break the continuity of the silicide film to create a source/drain silicide film and a gate silicide film. - View Dependent Claims (26)
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Specification