Growth Lab: Heat vs Plasma as the Chemistry Engine

Same precursor gas, same target film — two ways to switch the chemistry on. Watch what each one demands of the substrate.

Schematic teaching model. The central contrast is real — thermal CVD needs the substrate hot enough to drive precursor decomposition, while in PECVD energetic electrons create reactive radicals in the gas so films grow on substrates held hundreds of degrees cooler — but the threshold temperature, rates, thickness scale, and molecule graphics are illustrative, not calibrated to any one precursor system, and the growth readout is relative, not a measured thickness. Substrate temperature still matters in PECVD — it tunes hydrogen content, stress, and density even when the plasma pays the activation bill. Real films also care about ion bombardment, pressure, and gas ratios.