Pulsed laser induced atomic layer etching of silicon

We demonstrate the laser mediated atomic layer etching (ALEt) of silicon. Using a nanosecond pulsed 266 nm laser focused loosely over and in a parallel configuration to the surface of the silicon, we dissociate Cl-2 gas to induce chlorination. Then, we use pulsed picosecond irradiation to remove the chlorinated layer. Subsequently, we perform continuous wave (CW) laser annealing to eliminate amorphization caused by the picosecond laser etching. Based on atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), we observed strong evidence of chlorination and digital etching at 0.85 nm etching per cycle with good uniformity.

Automated summary

We have demonstrated laser mediated atomic layer etching (ALEt) of silicon. Chlorination was induced by dissociating Cl-2 gas using a loosely focused nanosecond pulsed 266 nm laser in parallel to the silicon surface. The chlorinated layer was then removed using pulsed picosecond irradiation, followed by continuous wave (CW) laser annealing to eliminate amorphization. Strong evidence of chlorination and uniform digital etching at 0.85 nm etching per cycle was observed based on atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS).