Abstract:
Methods and systems for x-ray based semiconductor metrology utilizing a clean, hard X-ray illumination source are described herein. More specifically, a laser produced plasma light source generates high brightness, hard x-ray illumination having energy in a range of 25,000 to 30,000 electron volts. To achieve high brightness, a highly focused, very short duration laser beam is focused onto a dense Xenon target in a liquid or solid state. The interaction of the focused laser pulse with the high density Xenon target ignites a plasma. Radiation from the plasma is collected by collection optics and is directed to a specimen under measurement. The resulting plasma emission is relatively clean because of the use of a non-metallic target material. The plasma chamber is filled with Xenon gas to further protect optical elements from contamination. In some embodiments, evaporated Xenon from the plasma chamber is recycled back to the Xenon target generator.
Abstract:
X-ray imaging and classification of volume defects within a three-dimensional structure includes identifying one or more volume defects within a three-dimensional structure of a sample and acquiring, with a transmission-mode x-ray diffraction imaging tool, one or more coherent diffraction images of the one or more identified volume defects. The process includes classifying the one or more volume defects within a volume of the three-dimensional structure based on the one or more coherent diffraction images, and training an additional optical or electron-based inspection tool based on the one or more classified defects.
Abstract:
The present disclosure is directed to plasma-based light sources. Systems and methods are described for protecting components of the light source from plasma generated debris which can include target material gas, atomic vapor, high energy ions, neutrals, micro-particles, and contaminants. Particular embodiments include arrangements for reducing the adverse effects of plasma generated ions and neutrals on light source components while simultaneously reducing in-band light attenuation due to target material gas and vapor.
Abstract:
The present disclosure is directed to a system for protecting a reflective optic and/or any other surface in a plasma-based illumination system from debris by actively flowing gas against the debris flow direction. According to various embodiments, a vacuum chamber is configured to contain a target material, wherein a laser or discharge produced plasma is generated in response to an excitation of the target material. One or more outlets within the chamber are configured to receive gas flowing from a fluidically coupled gas source and further configured to actively flow the gas towards a source of debris and away from the reflective optic or any other protected surface at a controlled flow rate.
Abstract:
Spectral Purity Filters, or SPFs, are disclosed. Such SPFs are designed to block out the 1030 nm drive laser and other undesired out of band light in a EUV mask inspection system. Different phase grating configurations for near normal incidence and grazing incidence are provided in the present disclosure and are configured specifically for EUV mask inspection.
Abstract:
A system for generating broadband radiation is disclosed. The system includes a target material source configured to deliver one or more of a liquid or solid state target material to a plasma-forming region of a chamber. The system further includes a pump source configured to generate pump radiation to excite the target material in the plasma forming region of the chamber to generate broadband radiation. The system is further configured to transmit at least a portion of the broadband radiation generated in the plasma-forming region of the chamber out of the chamber through a windowless aperture.
Abstract:
Methods and systems for performing measurements of semiconductor structures based on high-brightness, polychromatic, reflective small angle x-ray scatterometry (RSAXS) metrology are presented herein. RSAXS measurements are performed over a range of wavelengths, angles of incidence, and azimuth angles with small illumination beam spot size, simultaneously or sequentially. In some embodiments, RSAXS measurements are performed with x-ray radiation in the soft x-ray (SXR) region at grazing angles of incidence in the range of 5-20 degrees. In some embodiments, the x-ray illumination source size is 10 micrometers or less, and focusing optics project the source area onto a wafer with a demagnification factor of 0.2 or less, enabling an incident x-ray illumination spot size of less than two micrometers. In another aspect, active focusing optics project programmed ranges of illumination wavelengths, angles of incidence, and azimuth angles, or any combination thereof, onto a metrology area, either simultaneously or sequentially.
Abstract:
The present disclosure is directed to laser produced plasma light sources having a target material, such as Xenon, that is coated on the outer surface of a cylindrically-symmetric element (e.g., drum). Embodiments include a pre-pulsing arrangement which can be optimized to reduce irradiation damage to the drum and a pulse trimming unit which can be employed to reduce irradiation damage to the drum. In addition, an embodiment is disclosed wherein the surface of a cylindrically-symmetric element is formed with a plurality of grooves having a groove depth greater than 1 mm and a focusing unit focusing a laser beam and establishing an irradiation site to produce plasma from the target material, with the irradiation site distanced from a groove surface portion to protect the surface portion from irradiation damage.
Abstract:
The present disclosure is directed to laser produced plasma light sources having a target material, such as Xenon, that is coated on the outer surface of a drum. Embodiments include bearing systems for rotating the drum that have structures for reducing leakage of contaminant material and/or bearing gas into the LPP chamber. Injection systems are disclosed for coating and replenishing target material on the drum. Wiper systems are disclosed for preparing the target material surface on the drum, e.g. smoothing the target material surface. Systems for cooling and maintaining the temperature of the drum and a housing overlying the drum are also disclosed.
Abstract:
The present disclosure is directed to a device having a nozzle for dispensing a liquid target material; one or more intermediary chamber(s), each intermediary chamber positioned to receive target material and formed with an exit aperture to output target material for downstream irradiation in a laser produced plasma (LPP) chamber. In some disclosed embodiments, control systems are included for controlling one or more of gas temperature, gas pressure and gas composition in one, some or all of a device's intermediary chamber(s). In one embodiment, an intermediary chamber having an adjustable length is disclosed.