Abstract:
Methods and systems are described herein for producing high radiance illumination light for use in semiconductor metrology based on a confined, sustained plasma. One or more plasma confining circuits introduce an electric field, a magnetic field, or a combination thereof to spatially confine a sustained plasma. The confinement of the sustained plasma decreases the size of the induced plasma resulting in increased radiance. In addition, plasma confinement may be utilized to shape the plasma to improve light collection and imaging onto the specimen. The induced fields may be static or dynamic. In some embodiments, additional energy is coupled into the confined, sustained plasma to further increase radiance. In some embodiments, the pump energy source employed to sustained the plasma is modulated in combination with the plasma confining circuit to reduce plasma emission noise.
Abstract:
The disclosure is directed to systems for providing illumination to a measurement head for optical metrology. In some embodiments of the disclosure, illumination beams from a plurality of illumination sources are combined to deliver illumination at one or more selected wavelengths to the measurement head. In some embodiments of the disclosure, intensity and/or spatial coherence of illumination delivered to the measurement head is controlled. In some embodiments of the disclosure, illumination at one or more selected wavelengths is delivered from a broadband illumination source configured for providing illumination at a continuous range of wavelengths.
Abstract:
The present invention may include a modulatable illumination source configured to illuminate a surface of a sample disposed on a sample stage, a detector configured to detect illumination emanating from a surface of the sample, illumination optics configured to direct illumination from the modulatable illumination source to the surface of the sample, collection optics configured to direct illumination from the surface of the sample to the detector, and a modulation control system communicatively coupled to the modulatable illumination source, wherein the modulation control system is configured to modulate a drive current of the modulatable illumination source at a selected modulation frequency suitable for generating illumination having a selected coherence feature length. In addition, the present invention includes the time-sequential interleaving of outputs of multiple light sources to generate periodic pulses trains for use in multi-wavelength time-sequential optical metrology.
Abstract:
The present invention may include a modulatable illumination source configured to illuminate a surface of a sample disposed on a sample stage, a detector configured to detect illumination emanating from a surface of the sample, illumination optics configured to direct illumination from the modulatable illumination source to the surface of the sample, collection optics configured to direct illumination from the surface of the sample to the detector, and a modulation control system communicatively coupled to the modulatable illumination source, wherein the modulation control system is configured to modulate a drive current of the modulatable illumination source at a selected modulation frequency suitable for generating illumination having a selected coherence feature length. In addition, the present invention includes the time-sequential interleaving of outputs of multiple light sources to generate periodic pulses trains for use in multi-wavelength time-sequential optical metrology.
Abstract:
Methods and systems for performing co-located measurements of semiconductor structures with two or more measurement subsystems are presented herein. To achieve a sufficiently small measurement box size, the metrology system monitors and corrects the alignment of the measurement spot of each metrology subsystem with a metrology target to achieve maximum co-location of the measurement spots of each metrology subsystem with the metrology target. In another aspect, measurements are performed simultaneously by two or more metrology subsystems at high throughput at the same wafer location. Furthermore, the metrology system effectively decouples simultaneously acquired measurement signals associated with each measurement subsystem. This maximizes signal information associated with simultaneous measurements of the same metrology by two or more metrology subsystems.
Abstract:
The disclosure is directed to systems for providing illumination to a measurement head for optical metrology. In some embodiments of the disclosure, illumination beams from a plurality of illumination sources are combined to deliver illumination at one or more selected wavelengths to the measurement head. In some embodiments of the disclosure, intensity and/or spatial coherence of illumination delivered to the measurement head is controlled. In some embodiments of the disclosure, illumination at one or more selected wavelengths is delivered from a broadband illumination source configured for providing illumination at a continuous range of wavelengths.
Abstract:
Methods and systems for performing co-located measurements of semiconductor structures with two or more measurement subsystems are presented herein. To achieve a sufficiently small measurement box size, the metrology system monitors and corrects the alignment of the measurement spot of each metrology subsystem with a metrology target to achieve maximum co-location of the measurement spots of each metrology subsystem with the metrology target. In another aspect, measurements are performed simultaneously by two or more metrology subsystems at high throughput at the same wafer location. Furthermore, the metrology system effectively decouples simultaneously acquired measurement signals associated with each measurement subsystem. This maximizes signal information associated with simultaneous measurements of the same metrology by two or more metrology subsystems.
Abstract:
Methods and systems are described herein for producing high radiance illumination light for use in semiconductor metrology based on a confined, sustained plasma. One or more plasma confining circuits introduce an electric field, a magnetic field, or a combination thereof to spatially confine a sustained plasma. The confinement of the sustained plasma decreases the size of the induced plasma resulting in increased radiance. In addition, plasma confinement may be utilized to shape the plasma to improve light collection and imaging onto the specimen. The induced fields may be static or dynamic. In some embodiments, additional energy is coupled into the confined, sustained plasma to further increase radiance. In some embodiments, the pump energy source employed to sustained the plasma is modulated in combination with the plasma confining circuit to reduce plasma emission noise.
Abstract:
Various metrology systems and methods for high aspect ratio and large lateral dimension structures are provided. One method includes directing light to one or more structures formed on a wafer. The light includes ultraviolet light, visible light, and infrared light. The one or more structures include at least one high aspect ratio structure or at least one large lateral dimension structure. The method also includes generating output responsive to light from the one or more structures due to the light directed to the one or more structures. In addition, the method includes determining one or more characteristics of the one or more structures using the output.