Atomic absorption monitor for deposition process control of aluminum at 394 nm using frequency‐doubled diode laser Available to Purchase

A monitor for Al vapor density based on atomic absorption (AA) using a frequency‐doubled external‐cavity‐diode‐laser source at 394 nm has been demonstrated in both evaporation and sputtering processes. Closed loop operation was achieved for electron‐beam evaporated aluminum in a vacuum chamber using the AA signal for feedback. A series of runs in a dc sputtering chamber at the deposition rate of 900 Å/min illustrates the system reproducibility and the possibility of controlling the sputtering process and measuring the spatial distribution of the sputtered atoms with the AA monitor. Coherent light in the blue‐UV region (380–430 nm) using quasi‐phase‐matched lithium niobate waveguides was demonstrated with efficiencies of 25–150%/W, a range of wavelengths that covers many technologically important elements in physical vapor deposition processes.