LaserSense-SC SiF4 Detector

Block Engineering’s LaserSense-SC is a gas analyzer for demanding applications in the semiconductor industry that require both high-speed and high-sensitivity analysis.

The LaserSense-SC is unique in that it uses mid-infrared (MIR) laser technology. This enables multi-gas analysis with sensitivities at the parts-per-billion level (depending on the gas) and with measurement times of less than 1 second. The standard configuration for LaserSense-SC is designed for in-line process monitoring and control. The system can be customized based on user requirements.

Historically, mid-infrared spectroscopy has required Fourier-Transform Infrared (FTIR) spectrometers which use heated filaments as the source of light. To enable dramatically enhanced performance, Block Engineering has pioneered the development of widely tunable MIR lasers based on quantum cascade laser (QCL) technology. The LaserSense-SC provides the user with the ability to accurately measure PFC gases and process specific by-products with a response time that is faster and more robust than traditional FTIR systems.

 The LaserSense-SC has many advantages over FTIR-based systems. Since laser beams remain collimated over long distances, very long-path gas cells can be used. The lower detection limit (LDL) improves with increasing length of the gas cell, allowing LDLs that are greater than ten times better than with an FTIR.

Furthermore, gas cells designed for use with the LaserSense-SC can be made to have much smaller volume. This is important in applications where fast measurements are required and where the refresh-rate of the gas cell can be a limiting factor.

The table below gives examples of several gases along with their LDL when using gas cell having a path length of 6 to 60 meters. Since gas cells with path lengths of greater than 100 meters are available, the LDL can be further reduced below the values given in the table below.