“…The processes involved in the laser-assisted etching of n-type Si in fluoride solutions are illustrated in Figure . Assuming equivalence between electrochemical and laser-assisted etching, several aspects of Figure are unassailable: (1) a hole captured at the surface initiates etching, (2) defects enhance the initiation of etching, , (3) H 2 is a product, (4) electron injection into the Si occurs, − (5) the Si is predominantly H-terminated before, during, and after electrochemical etching − (6) Si
is a byproduct, (7) in the presence of K + , Rb + , and Cs + , hexafluorosilicate deposition can occur, , (8) the counter reaction occurs in a spatially separated region of the crystal, and (9) both HF and H
can react with the Si atom to be etched . Several aspects are probable but remain to be proved unequivocally: (1) a H + desorbs after hole capture at the surface, (2) a F - attacks the empty site, ,, and (3) the primary etch product reacts with HF to form Si
.…”