Non-destructive in-situ elemental profiling
View Patent ↗A non-destructive in-situ elemental profiling of a layer in a set of layers method and system are disclosed. In one embodiment, a first emission of a plurality of photoelectrons is caused from the layer to be elementally profiled. An elemental profile of the layer is determined based on the emission. In another embodiment, a second emission of a plurality of photoelectrons is also received from the layer, and an elemental profile is determined by comparison of the resulting signals. A process that is altering the layer can then be controlled “on-the-fly” to obtain a desired material composition. Since the method can be employed in-situ and is non-destructive, it reduces turn around time and lowers wafer consumption. The invention also records the composition of all processed wafers, hence, removing the conventional statistical sampling problem.
1. A method of elemental profiling a layer in a set of layers undergoing a process, the method comprising:
irradiating the layer with a plurality of photons;
receiving an emission of a plurality of photoelectrons from the layer;
determining an elemental profile of the layer based on the emission; and
controlling the process in-situ based on the elemental profile, including adjusting at least one of: a gas flow rate, a chamber temperature, an annealing temperature, or a pressure.
2. The method of claim 1 , wherein the emission has a signal unique to a material of the layer undergoing thickness alteration and another emission of a plurality of photoelectrons from the layer has a signal unique to a material of an underlying layer.
3. The method of claim 2 , wherein the detecting step farther comprises comparing the signals.
4. The method of claim 1 , wherein the material of the layer includes one of an element and a compound and the set of layers comprises one of a semiconductor, a dielectric, and a conductor.
5. The method of claim 1 , wherein a material of the layer undergoing thickness alteration and a material of an underlying layer differ only in stoichiometry.
6. A method of elemental profiling a layer undergoing a process, the method comprising:
receiving an emission of a plurality of photoelectrons from the layer;
determining an elemental profile of the layer based on the emission; and
controlling the process in-situ based on the elemental profile, including adjusting at least one of: a gas flow rate, a chamber temperature, an annealing temperature, or a pressure.
7. The method of claim 6 , further comprising the step of causing the emission of the plurality of photoelectrons.
8. The method of claim 7 , wherein the causing step includes irradiating the layer with a plurality of photons.
9. The method of claim 6 , wherein the process includes one of depositing a material on the layer and removing a material from the layer.
10. The method of claim 6 , wherein the layer includes at least one of a semiconductor, a dielectric, and a conductor.
11. The method of claim 6 , wherein the emission has a signal unique to a material of the layer.
12. The method of claim 11 , wherein the material includes one of an element and a compound.
13. The method of claim 11 , wherein the material of the layer and a set of layers thereabout differ only in stoichiometry.
14. A system for elemental profiling a thickness of a layer in a set of layers undergoing a process, the system comprising:
a process chamber containing the layer in the set of layers undergoing the process in situ;
a causation device for causing an emission of a plurality of photoelectrons from the layer in the set of layers;
an alteration device for altering the process in situ; and
at least two detection devices for determining the elemental profile of the layer based on one of a receipt of the emission and an absence of the emission.
15. The system of claim 14 , further comprising a control device for controlling the alteration device altering the process based on the elemental profile.
16. The system of claim 15 , wherein the control device adjusts at least one of: a gas flow rate, a chamber temperature, an annealing temperature or a pressure.
17. The system of claim 14 , wherein the causation device includes an x-ray photoelectron spectrometer.
18. The system of claim 14 , wherein each detection device includes a time of flight photoelectron detector.