The evolution of surface roughening during etching of , , Si, , and in was studied. It was observed that surface roughness depended on self-bias voltage and pressure; lower surface roughness was obtained at higher bias voltage and lower pressure during etching of , , and Si in whose boiling temperature of by-products is low, whereas the lower surface roughness was obtained at lower bias voltage and higher pressure during etching of and in whose boiling temperature of by-products is high. It was understood that the contrasting trends from the experimental results originate from the different volatility of the etch by-products which were generated during etching in . It was also observed that, when bias voltage and pressure varied, surface roughness was inversely proportional to etch rate during etching of , , and Si, while surface roughness was proportional to etch rate of and in . In addition, it was found that surface roughness increased as a function of etching time and the effect of etching time on surface roughness was more conspicuous during etching of and .