Optimization of InP Thermal Processing & Oxidation Enabled through Protective Ultrathin ALD Films Coating

The stability and controlled oxidation of III–V semiconductors like Indium phosphide (InP) are critical for enabling next-generation optoelectronic and electronic devices. While oxide formation is necessary for passivation and integration in certain architectures, uncontrolled surface degradation during high-temperature processing poses a major limitation. To address this, our study investigates surface protection strategies that simultaneously mitigate thermal degradation and promote uniform oxide formation in InP.

Experiments were conducted in a cleanroom environment using ultrathin plasma-enhanced atomic layer deposition (PEALD) coatings, thermal annealing and oxidation in a III–V semiconductor furnace, and two oxidation pathways: dry oxidation and oxygen-enhanced wet thermal oxidation (OEWTO). This comparative framework allowed systematic evaluation of degradation resistance and oxidation control. Structural characterization of processed wafers was performed using optical microscopy, electron microscopy, and atomic force microscopy (AFM) to assess material integrity and oxide uniformity.

The results demonstrate that ALD coatings effectively preserve wafer stability up to 600 °C for three hours without evidence of degradation. Moreover, the OEWTO process produced a uniform, stable oxide layer across the surface, validating its reproducibility and extending prior demonstrations of the method. Together, these findings illustrate how protective coatings and optimized oxidation routes can be leveraged to both maintain structural integrity and enable tunable surface engineering while supporting scalable processing of InP for reliable optoelectronic and photonic device integration.