The Suppression Effect of 830nm Laser Irradiation on Porous Silicon Formation
In the study, we used 5×5 cm2, boron-doped, 1 to10 Ωcm, (100) Si specimens and the laser with wavelength of 830nm at maximum power of 5.0mW with beam size of 1.0mm. The laser institutional platform was added the polarizer to control the power of the laser beam.
The power of laser was adjusted to1.0mW, 2.0mW, 3.0mW, 4.0mW, and 5.0mW in air at room temperature. In Fig. a and b, the pictures show the suppression of formation of porous silicon by the 830nm laser at 3.0mW after electrochemical etching in HF solution with current of 100mA for 10 minutes. The thickness of porous silicon varies of the outer region of laser-irradiated area could be observed by Field Emission Scanning Electron Microscope (FE-SEM). A straight-line slope of a porous silicon layer between the laser irradiation and non-laser irradiation that confirms the size of Gaussian beam with the suppression phenomenon of porous silicon. We called the propagating out profie of a Gaussian beam in the laser irradiation is the transition zone of porous silicon formation (TZPS).