Thickness dependence of H radical treatment of Si thin films deposited by plasma-enhanced chemical vapor deposition using SiF4/SiH4/H-2 gases

Thickness dependence of H radical treatment of silicon thin films deposited using SiH4/H-2 and SiF4/SiH4/H-2 plasmas has been investigated. In both cases, H radicals have caused etching and crystallization. In the case of films less than 60 Angstrom thick, almost pure etching occurred. In the case of films more than 600 Angstrom thick, a crystallized layer under a roughened layer remained after etching. These results indicate that crystallization effect occurs in deeper layers than those in which etching occurs.