HR-SPSmap brings advanced surface photovoltage measurements closer to semiconductor production. By combining contactless material characterization with fast, automated mapping, the system helps research and production teams identify yield-critical variations from the initial wafer to the processed device.
Assessing the electronic quality of semiconductor materials traditionally requires specialist knowledge and extensive laboratory analysis. This can make it difficult to use measurement results as a direct basis for decisions within routine production workflows.
Freiberg Instruments developed the HR-SPSmap to bridge this gap. The compact benchtop system is designed for both research and offline production monitoring, providing detailed information about surfaces, thin layers and semiconductor structures without contacting or damaging the sample.
Revealing defects and charge dynamics
The HR-SPSmap measures the time-resolved surface photovoltage response generated when a material is excited by light. The resulting signal provides insights into charge separation processes, carrier dynamics and electronic transitions associated with defects.
Different excitation wavelengths allow specific regions of a material or layer structure to be investigated. Depending on the configuration, up to four laser sources can be integrated into the optical head, covering wavelengths from 337 to 1,550 nm.
This flexibility enables the system to characterize a wide range of photoactive materials, including silicon, silicon carbide, germanium, gallium arsenide, gallium oxide, indium phosphide and diamond. Samples can be examined throughout different production stages – from as-grown materials and epitaxial layers to processed wafers and completed devices.
From detailed analysis to clear production decisions
High sensitivity and a time resolution ranging from 10 nanoseconds to 100 milliseconds allow the HR-SPSmap to detect fast and slow electronic processes. With a spatial resolution of up to 0.1 mm, it can reveal local variations across wafers and other samples.
A 150 mm wafer can be mapped in under five minutes at a spatial resolution of 1 mm. This enables manufacturers to identify variations within individual wafers, across batches or between different process stages without significantly slowing down established workflows.
Depending on the application, results can range from detailed measurement maps and primary datasets to clearly defined quality criteria. This allows the system to support both advanced scientific evaluation and straightforward production decisions.
Automated sample recognition, predefined measurement recipes and parameter setup simplify recurring measurements. Custom calculations and mapping configurations provide additional flexibility for specialized research tasks and material-specific quality-control processes.
Flexible metrology for emerging semiconductor materials
The transition to wide- and ultra-wide-bandgap semiconductors is creating new requirements for material characterization. Defects and charge-transfer processes that cannot be identified through conventional inspection methods may still influence device performance, process stability and final yield.
The HR-SPSmap provides a contactless method for investigating these properties in materials used for power electronics, optoelectronics, photovoltaics and photocatalytic applications. Its modular design allows the measurement configuration to be adapted to different samples, excitation conditions and research objectives.
By transferring sensitive surface photovoltage analysis from specialized laboratories into repeatable measurement workflows, the HR-SPSmap gives researchers and production teams earlier access to relevant material data. The result is a stronger foundation for process optimization, quality control and the development of next-generation semiconductor technologies.