Schottky junction si nanowire field-effect bio-sensor/molecule detector
A Schottky junction silicon nanowire field-effect biosensor/molecule detector with a nanowire thickness of 10 nanometer or less and an aligned source/drain workfunction for increased sensitivity. The nanowire channel is coated with a surface treatment to which a molecule of interest absorbs, which modulates the conductivity of the channel between the Schottky junctions sufficiently to qualitatively and quantitatively measure the presence and amount of the molecule.
1. A method of manufacturing a Schottky junction field-effect sensor, comprising:
thinning a semiconductor layer of a semiconductor substrate with an embedded dielectric layer;
forming a channel region, a first electrode region, and a second electrode region within the semiconductor layer and abutting the embedded dielectric layer;
depositing a silicon nitride layer on the entire width of the channel region;
patterning the silicon nitride layer;
converting the first electrode region and the second electrode region into a metal silicide, thereby forming a first electrode and a second electrode;
implanting an impurity by blanket implantation, wherein the impurity is selected from the group consisting of boron, arsenic, indium, phosphorous, and aluminum;
diffusing the impurity to an interface between the channel region and the metal silicide by Thermal Rapid Annealing to form an interface layer comprising the impurity in an amount of about 1·10 18 atoms cm −3 to about 1·10 23 atoms cm −3 within the channel region between the metal silicide and the channel region covered by the silicon nitride;
removing the silicon nitride layer; and
providing a surface treatment of the channel region.
2. The method according to claim 1 , wherein the metal of the metal silicide is selected from the group consisting of nickel, platinum, nickel platinum, cobalt, titanium, and tungsten.
3. The method according to claim 2 , wherein the metal is nickel.
4. The method of claim 1 , wherein the annealing is performed at a temperature of from about 400° C. to about 650° C.
5. The method of claim 1 , wherein the embedded dielectric layer is silicon dioxide.
6. The method of claim 1 , wherein the removing the silicon nitride layer comprises exposing the silicon nitride layer to a phosphoric acid solution.
7. The method according to claim 6 , wherein the phosphoric acid solution is at a temperature of about at least 150° C.
8. The method according to claim 4 , wherein the annealing is a performed for about 5 seconds to about 5 minutes.
9. The method according to claim 2 , wherein the metal of the metal silicide is nickel.
10. The method according to claim 1 , wherein the silicon nitride layer is formed using chemical vapor deposition.
11. The method according to claim 10 , wherein the chemical vapor deposition is plasma-enhanced chemical vapor deposition.
12. The method according to claim 1 , wherein the channel region is a nanowire with a thickness of 10 nanometers or less.
13. The method according to claim 1 , wherein the channel region is a single crystalline material.
14. The method according to claim 13 , wherein the single crystalline material is single crystalline silicone.
15. The method according to claim 1 , wherein the channel region is germanium or gallium-arsenide.