Surface morphological evolution of crystalline Si during chemical dry etching using F radicals and NO gas

In this study, changes in the surface morphology of single crystalline Si during chemical dry etching using F radicals and direct-injected nitric oxide (NO) gas were investigated. When NO gas was injected into a chamber supplied with F radicals from NF3 input gas generated from a remote plasma source, the single crystalline Si surface was textured and roughened during the chemical dry etching. It was found that the roughened morphology varied as a function of the NO gas flow rate, the total gas flow rate of NF3 and NO gases, and the etching time. The roughened morphology that developed during the fast chemical dry etching of silicon led to a reduction in the reflectance of visible light.

► Single crystalline Si surface was effectively textured and roughened during the chemical dry etching using F radicals and direct-injected nitric oxide (NO) gas.
► The roughened morphology of the textured surface varied as a function of the NO gas flow rate, the total gas flow rate of NF3 and NO gases, and the etching time.
► The roughened morphology of silicon led to the reduced reflectance as low as 6.07% at a wavelength of 750 nm.