Chemical Control of Surfaces: From Fundamental Understanding to Practical Application
In the early days of the microelectronics industry, it became clear that even trace contaminants could have detrimental impact on the electronic properties of fabricated devices. This realization led to the development of the so-called RCA clean for silicon surfaces , which uses sequential baths in basic and acidic hydrogen peroxide solutions, now known as SCA-1 and SCA-2, to oxidize organic materials, remove particulates, and bind metallic impurities. The detailed characterization of this process as well as its simplicity and economic viability soon led to its widespread industrial adoption. Although the RCA clean includes an optional etch in dilute HF between the two cleaning solutions to remove the native oxide layer, the overall process results in an extremely clean but electronically defective oxide-terminated and thus extremely hydrophilic silicon surface, which we now know is quite rough on an atomic scale .
Paul Mertens, Marc Meuris and Marc Heyns
M. A. Hines, "Chemical Control of Surfaces: From Fundamental Understanding to Practical Application", Solid State Phenomena, Vol. 195, pp. 65-70, 2013