Figure 9. Surface profile of etched wafer for (a) 4 hrs 45 mins and (b) 3 hrs 15 mins of TMAH etching

From

Etching Techniques for Thinning Silicon Wafer for Ultra Thin High Efficiency Interdigitated Back Contact Solar Cells

Iduabo John Afa, Gema López, Pablo Rafael Ortega Villasclaras

Journal of Optoelectronics Engineering. 2015, 3(1), 7-14 doi:10.12691/joe-3-1-2