Experimental results on a new technique for making a thin silicon epitaxial layer on an insulating substrate are presented. The technique utilizes the anisotropy of the etch rate of silicon in the aqueous potassium hydroxide-isopropyl alcohol system. The silicon film can be either n‐ or p‐type with a thickness in the low micron range (under 3 /µm). The thickness variation can be controlled to ±0.5µm across a 2 in. diameter wafer.