1. A method of growing a tungsten nucleation layer over a structure on a substrate in an atomic layer deposition (ALD) process comprising:
contacting the substrate with a vapor phase tungsten compound such that no more than one molecular layer of the tungsten compound adsorbs on the substrate; and
contacting the adsorbed tungsten compound on the substrate with a vapor phase boron compound such that no more than one atomic layer of elemental tungsten is formed on the substrate.
2. The method of claim 1, wherein the ALD process is repeated to form a tungsten film of a desired thickness.
3. The method of claim 2, wherein the ALD process is repeated until a tungsten film with a thickness of from one atomic layer to 1000 nm is formed.
4. The method of claim 1, wherein the boron compound reduces the adsorbed tungsten compound into elemental tungsten.
5. The method of claim 1, wherein the tungsten compound and boron compound are fed into the reaction chamber with the aid of an inert carrier gas.
6. The method of claim 1, further comprising feeding an inert gas pulse to the reaction chamber after each pulse of tungsten compound and boron compound.
7. The method of claim 6, further comprising adding a mild reducing agent to the inert gas pulse.
8. The method of claim 7, wherein the inert gas pulse comprises 0.5% to 1% of the mild reducing agent by volume.
9. The method of claim 8, wherein the mild reducing agent is hydrogen.
10. The method of claim 1, wherein the boron compound contains no carbon atoms.
11. The method of claim 10, wherein the boron compound is selected from the group consisting of boranes of formula BnHn+x, wherein n is an integer from 1 to 10 and x is an even integer.
12. The method of claim 11, wherein the boron compound is selected from the group consisting of nido-boranes of formula BnHn+4, arachno-boranes of the formula BnHn+6, hypho-boranes of the formula BnHn+8 and conjuncto-boranes BnHm, wherein n is an integer from 1 to 10 and m is an integer from 1 to 10 that is different from n.
13. The method of claim 12, wherein the boron compound is diborane.
14. The method of claim 1, wherein the boron source compound is selected from the group consisting of boron halides and complexes thereof.
15. The method of claim 14, wherein the boron compound is selected from the group consisting of B2F4, B2Cl4 and B2Br4.
16. The method of claim 1, wherein the tungsten compound is selected from the group consisting of halide compounds, carbonyl compounds and cyclopentadienyl compounds.
17. The method of claim 16, wherein the tungsten compound is selected from the group consisting of WF6, WCl6, WCl4, WBr5, W(CO)6, tricarbonyl(mesitylene)tungsten, bis(cyclopentadienyl)tungsten dihydride, bi(cyclopentadienyl)tungsten dichloride, and bis(cyclopentadienyl)ditungsten hexacarbonyl.
18. The method of claim 17, wherein the tungsten compound is tungsten hexafluoride (WF6).
19. The method of claim 1, wherein the reaction space is maintained at a constant temperature during the ALD process.
20. The method of claim 19, wherein the temperature is between about 250\xb0 C. and about 500\xb0 C.
21. The method of claim 1, wherein the reaction space is maintained at a constant pressure during the ALD process.
22. The method of claim 21, wherein the pressure is between about 0.01 mbar and about 20 mbar.
23. The method of claim 1, wherein the structure is a dual damascene structure.
24. The method of claim 1, wherein the structure is a trench.
25. The method of claim 1, wherein the structure is a via.
26. A method of producing an interconnect an integrated circuit by an atomic layer deposition (ALD) process, comprising adsorbing less than a monolayer of a tungsten compound on a substrate and exposing the adsorbed tungsten compound on the substrate to a boron compound, thereby reducing the boron compound to elemental tungsten.
27. The method of claim 26, wherein the boron compound does not comprise a carbon atom.
28. A method of growing a thin film on a substrate in a reaction space, the method comprising:
contacting the substrate with a first vapor phase reactant comprising WF6 such that less than a monolayer of WF6 adsorbs on the substrate surface;
removing any unreacted portion of the first vapor phase reactant and any gaseous reaction byproduct from the reaction space;
introducing a second vapor-phase reactant comprising boron into the reaction space; and
removing any unreacted portion of the second vapor phase reactant and any gaseous reaction byproduct from the reaction space.
29. The method of claim 28, wherein the second vapor phase reactant comprises a boron compound that does not comprise a carbon atom.
30. The method of claim 29, wherein the boron compound is diborane.
31. The method of claim 28, wherein the second vapor phase reactant comprises a boron compound that comprises at least one carbon atom.
32. The method of claim 28, additionally comprising:
introducing a third vapor phase reactant comprising a metal other than tungsten;
removing any unreacted portion of the third vapor phase reactant and any gaseous reaction byproducts from the reaction space; and
reducing the third vapor phase reactant to elemental metal.
33. The method of claim 32, wherein the third vapor phase reactant comprises titanium.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A traffic sensor for monitoring a roadway, the traffic sensor comprising:
a radar system including a plurality of beams and configured to transmit signals into a roadway and to receive reflections of signals off of objects in the roadway using the plurality of beams;
a target identifying module configured to:
divide received reflections of signals into a plurality of range bins;
compute a position of at least one target in the roadway based on at least one received reflection and at least one corresponding range bin;
and
create a track file for the at least one target in the roadway.
2. The traffic sensor recited in claim 1, wherein the track file includes target position data for the at least one target in the roadway, and the target position data is selected from a group consisting of: a last known position for the at least one target and a predicted future position for the at least one target.
3. The traffic sensor recited in claim 1, wherein the target identifying module further comprises a track file maintenance module configured to maintain the track file for the at least one target in the roadway.
4. The traffic sensor recited in claim 3, wherein the track file maintenance module is configured to update the track file for the at least one target in the roadway when a new position has been computed for the at least one target and the new position is determined to correspond to either the last known position or the predicted future position of the at least one target.
5. The traffic sensor recited in claim 3, wherein the track file maintenance module is further configured to:
create a new track file for a second target when a new position of a target has been computed and the new position does not correspond to the last known position or the predicted future position of a previously detected target.
6. The traffic sensor recited in claim 3, wherein the track file maintenance module is configured to access all existing track files and to update at least one of the existing track files or create a new track file depending on the correspondence or lack of correspondence of a new position to the position data included in the existing track files.
7. The traffic sensor recited in claim 1, wherein the radar system further comprises:
transmit antennas for transmitting signals into the roadway using the plurality of beams, the signals being frequency modulated continuous wave radio frequency signals; and
receive antennas for receiving the reflections of the signals.
8. The traffic sensor recited in claim 1, wherein the target identifying module is further configured to:
detect a multi-beam image, the multi-beam image representing the at least one target within the roadway, the multi-beam image spanning one or more beams of the plurality of beams, the multi-beam image also spanning a plurality of range bins;
identify an energy peak within the multi-beam image, by determining, for a specified range bin in at least one of the plurality of beams, that the magnitude of the radio frequency energy in the specified range bin is above a specified threshold; and
that the magnitude of the radio frequency energy in the specified range bin is greater than the magnitude of the radio frequency energy in any adjacent range bins.
9. The traffic sensor recited in claim 1, further comprising:
one or more computer storage media having computer-executable instructions stored thereon, such instructions comprising the target identifying module; and
one or more processors electronically coupled to system memory and the one or more computer storage media, the one or more processors being configured to execute the computer-executable instructions.
10. The traffic sensor recited in claim 1, wherein the range bins are arranged in a grid.
11. The traffic sensor recited in claim 9, wherein the one or more computer storage media having computer-executable instructions stored thereon further comprises instructions comprising a track file maintenance module.
12. A traffic control system comprising:
a traffic sensor for monitoring a roadway, the traffic sensor comprising:
a radar system including a plurality of beams configured to transmit a signal into the roadway and to receive reflections of the signal off of objects in the roadway using the plurality of beams; and
a computer system coupled to the radar system and configured to:
detect one or more targets using the received reflections of the signal off of objects in the roadway;
access a target list for the roadway, the target list including currently computed positions for the one or more targets in the roadway, the currently computed positions being derived from a grid of range bins dividing returns from the plurality of beams;
maintain a track file for each target in the roadway, each track file including target data for a target that is within the roadway, the target data including target position data for the target, the target position data including at least one of: a last known position for the target and a predicted future position for the target.
13. The traffic control system recited in claim 12, wherein the computer system is further configured to:
access the track file for an existing target, the track file having target position data that may correspond to one of the currently computed positions;
determine if the one of the currently computed positions is a position of the existing target by comparing the one of the currently computed positions to the target position data in the accessed track file;
update the accessed track file for the existing target when the one of the currently computed positions is determined to correspond to the position of the existing target; and
create a new track file for a new target when the one of the currently computed positions is determined not to correspond to the position of the existing target.