Multicolor X-Ray XPS for Non-Destructive Depth Concentration Profiling

The patent segments the X-ray measurement into multiple discrete energy levels (e.g., Al Kα, Mg Kα, Si Kα X-rays with different energies). By using X-rays of different energies, the system can probe different depths within the semiconductor structure, with lower energy X-rays providing surface-sensitive information and higher energy X-rays providing deeper penetration information. This segmentation of measurement energies enables depth-resolved concentration profiling without requiring physical sectioning of the sample.

The patent adds the energy dimension to the traditional XPS measurement by simultaneously utilizing multiple X-ray energy sources. This transforms the measurement from a two-dimensional (intensity vs. binding energy) spectrum into a three-dimensional analysis space (intensity vs. binding energy vs. X-ray energy), where each X-ray energy provides information about a specific depth range. This dimensional expansion allows extraction of vertical concentration profiles from a single measurement.

The patent merges multiple X-ray sources (e.g., Al, Mg, Si anodes producing different X-ray energies) into a single integrated measurement system. The electron beam simultaneously excites multiple anode materials, generating multiple X-ray energy lines that illuminate the sample concurrently. The detector captures photoelectrons from all energy levels simultaneously, allowing depth-resolved concentration information to be obtained in a single measurement cycle rather than through sequential measurements.

The patent enables continuous acquisition of depth-resolved concentration data by maintaining simultaneous excitation from multiple X-ray energy sources throughout the measurement process. The system continuously collects photoelectron signals from all X-ray energy levels without interruption or sequential switching, maximizing the utilization of measurement time and eliminating idle periods between energy changes.

The patent replaces the mechanical sputtering process of SIMS (which physically removes material layers through ion bombardment) with a non-destructive electromagnetic interaction approach. Instead of using high-energy ion beams to physically erode the sample surface layer by layer, the system uses multiple energies of X-rays to probe different depths through photoelectric excitation. The photoelectron emission process does not remove material, allowing repeated measurements on the same sample without degradation.

The patent changes the measurement parameter from physical removal rate (in SIMS) to X-ray energy level. By varying the X-ray energy parameter rather than the physical etching rate, the system achieves depth profiling through selective excitation of electrons at different depths. Lower energy X-rays probe shallower regions while higher energy X-rays penetrate deeper, providing depth information without material removal.