Structural Characterization on Different Type of Silicon Wafer on the Formation of Porous Silicon Structure

Abstract

A set of n-type and p-type porous silicon (PS) layers were fabricated by photoelectrochemical etching using direct current (DC) and pulse current (PC) techniques. The study aims to compare the effect of different wafer type on the formation of the PS structure. The samples were etched in a solution of HF:C2H6O with a composition ratio of 1:4. All the samples were etched at a current density of J = 10 mA/cm2 for 30 minutes. During the PC etching process, the current was supplied through a pulse generator with 14 ms cycle time (T) which the on time (Ton) set to 10 ms and pause time (Toff) set to 4 ms respectively. The samples were then being characterized in terms of surface morphology by using FESEM, EDX, AFM and XRD. The FESEM results indicates that the p-type porous silicon structure produces more uniform structure as compared to the n-type porous silicon structure. On the other hand, XRD results shows that the intensity of p-type porous silicon exhibited higher intensity as compared to n-type porous silicon for both etching techniques applied for fabricating the porous structure.