In early 1955, Carl Frosch from Bell Labs developed wet oxidation of silicon, and in the next two years, Frosch, Moll, Fuller and Holonyak did further research on it.[34][35] Later in 1958, Frosch and Lincoln Derick proposed that silicon oxide layers could protect silicon surfaces during diffusion processes, and could be used for diffusion masking.[36][37] This accidental discovery revealed the second fundamental advantage of silicon over germanium: contrary to germanium oxides, "wet" silica is a physically strong and chemically inert electrical insulator.