A FABRICATION PROCESS DEVIATION DETERMINATION METHOD, CALIBRATION METHOD, INSPECTION TOOL, FABRICATION SYSTEM AND A SAMPLE

摘要

Considering the above, it is an object of the invention to provide an inspection tool and corresponding method allowing an improved determination of fabrication process deviations According to an embodiment of the invention, there is provided a method for determining deviations in a fabrication process, comprising the following steps:a.providing a sample with a layer having a periodic structure fabricated using the fabrication process and intended to cause a corresponding part of the layer to be fully reflective for light having a wavelength in a wavelength range and having an angle of incidence in an angle range:b.illuminating the sample with light having a wavelength in the wavelength range and an angle of incidence in the angle range;c.detecting light reflected and/or scattered from the layer of the sample; and d.determining deviations in the fabrication process from the detected light. According to another embodiment of the invention, there is provided a method for calibrating a fabrication process, comprising the following steps:a.carrying out a method according to the invention to determine deviations in a fabrication process; and b.generating a correction signal for adjusting a fabrication process parameter based on the determined deviations in the fabrication process. According to a further embodiment of the invention, there is provided an inspection tool comprising:1.a sample holder for holding a sample;2.an illumination system for illuminating a sample in the sample holder 3.a detection system for detecting light reflected or scattered from a sample in the sample holder: and 4.a processing unit configured to determine deviations in a fabrication process used to fabricate a sample with a layer having a periodic structure intended to cause a corresponding part of the layer to be fully reflective for light having a wavelength in a wavelength range and having an angle of incidence in an angle range from an output of the detection system,wherein the illumination system is configured to emit light having a wavelength in the wavelength range and having an angle of incidence in the angle range.According to yet another embodiment of the invention, there is provided a fabrication system comprising a lithographic apparatus for carrying out at least a part of a fabrication process, and an inspection tool according to the invention.According to another embodiment of the invention, there is provided a sample with a layer having a periodic structure intended to cause a corresponding part of the layer to be fully reflective for light having a wavelength in a wavelength range and having an angle of incidence in an angle range, wherein the sample is suitable to be used in a method according to the invention or an inspection tool according to the invention.According to a further embodiment of the invention, there is provided a method for determining deviations in a fabrication process, comprising the following steps:a. providing a sample with a layer having a periodic structure fabricated using the fabrication process and intended to cause a corresponding part of the layer to be fully reflective for light having a wavelength in a wavelength range and having an angle of incidence in an angle range;b. illuminating the sample with light having a wavelength in the wavelength range and an angle of incidence in the angle range;c. detecting light transmitted through the sample; and d. determining deviations in the fabrication process from the detected light.According to yet another embodiment of the invention, there is provided a method for calibrating a fabrication process, comprising the following steps:a. providing a sample with a layer having a periodic structure fabricated using the fabrication process and intended to cause a corresponding part of the layer to be fully reflective for light having a wavelength in a wavelength range and having an angle of incidence in an angle range;b. illuminating the sample with light having a wavelength in the wavelength range and an angle of incidence in the angle range;c. detecting light transmitted through the sample;d. determining deviations in the fabrication process from the detected light; and e. generating a correction signal for adjusting a fabrication process parameter based on the determined deviations in the fabrication process.According to another embodiment of the invention, there is provided an inspection tool comprising:1.a sample holder for holding a sample;2.an illumination system for illuminating a sample in the sample holder;3.a detection system for detecting light transmitted through a sample in the sample holder; and 4.a processing unit configured to determine deviations in a fabrication process used to fabricate a sample with a layer having a periodic structure intended to cause a corresponding part of the layer to be fully reflective for light having a wavelength in a wavelength range and having an angle of incidence in an angle range from an output of the de