Investigation on the Effect of Delay Time during Pulse Chemical Etching of Porous Silicon Formation

N.H.A. Wahaba, A.F.A. Rahima, A. Mahmoodb, R. Radzalia, Y. Yusofc aFaculty of Electrical Engineering, Universiti Teknologi MARA Cawangan Pulau Pinang, 13500, Permatang Pauh, Penang, Malaysia bDepartment of Applied Science, Universiti Teknologi MARA Cawangan Pulau Pinang, 13500, Permatang Pauh, Penang, Malaysia cSchool of Physics, Universiti Sains Malaysia, Pulau Pinang, Malaysia

Full Text PDF

A set of porous silicon (PS) layers was produced by the pulse current (PC) etching technique using a solution of HF:C2H6O in a composition ratio of 1:4 with delay time varying from 0 to 4 minutes. The set was compared with the one porous silicon sample that was etched by using the conventional direct current (DC) etching technique using the same ratio of solution. 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. An additional parameter called delay time (Td) had been introduced during the etching process. Our results showed that the uniformity of pores produced was better with the application of the delay time. FESEM indicated that the variation of Td affects the pore formation and pore size while EDX showed the composition of materials in PS. The HR-XRD analysis was also performed in order to investigate the structural characterization of produced PS.

DOI:10.12693/APhysPolA.135.873 topics: porous silicon, FESEM, EDX, XRD