Formation of silicon nanocrystal films at low temperature during capacitive radio frequency discharge transition to the high-current mode

•Silicon nanocrystals were synthesized at high-current mode.•Current and voltage characteristics of the discharge were measured.•The plasma characteristics at high-current mode were analyzed deeply.

In this paper, silicon nanocrystal (Si-nc) films were synthesized via capacitive radio frequency (rf) discharge plasma with silane diluted in helium and hydrogen. The plasma conditions were chosen to simultaneously deposit both Si-ncs and amorphous silicon matrix. The structure and photoluminescence of Si-nc films have been studied. By changing the power delivered to the reactor, the transition from amorphous to crystalline growth in the gas phase can be systematically varied. This transition has been confirmed by detecting the change of current and voltage characteristics of the discharge. The results are interpreted in terms of rf discharge transition to the high-current mode. At high-current mode, plasma density will have a sharp rise by hot electron injection. The high plasma density and hot electrons will increase coupling parameter and cause the transition from amorphous particles to crystal particles.