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Porous silicon (PS) has been fabricated by Photo-electrochemical etching. Porous silicon was anodized on n-type Si in light using a current density of 20 mA/cm 2 for 10 min. The porous structure formation was confirmed using XRD and AFM studies. The root mean square (RMS) roughness of the Porous silicon layer is found to be around 47.5 nm and the ten point height was 317 nm. The average of pores diameter was 419.98nm, and the grain growth is columnar with a (211) preferred orientation. The grain size of the PS was estimated from the Scherer's formula and found to be 73 nm. All the properties of the porous silicon layer, such as porosity and the thickness depend on the anodization parameters. The porosity (P) was approximately 77 %. The thickness of the layer formed during an anodization in constant current was 3.54nm in gravimetric method, while its value was 1.77nm by using the theoretical relation.

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This paper reports the influence of the etching time on structural characteristics of porous silicon manufactured by electrochemical etching (ECE) anodization p-type silicon wafers. Micro and nano-structural features of the samples are mainly investigated by XRD and AFM techniques. The morphological properties of PS layer such as nano-crystalline size, the structure aspect of PS layer and lattice constant have been investigated. Nanocrystals size (grain size) computing from XRD data (145 to 85) nm is resulting the increasing etching time.AFM investigations reveal increase in (RMS) roughness, Sz.(Ten Point height) and average diameter of the porous structure with increase in etching time.

In this paper, the structural properties of porous silicon layer PSL were reported. Photo-assisted (laser) electrochemical etching PECE technique used to fabrication PSL from n-type wafer silicon as a function of etching time. Optical microscopy OM image is confirmed that the surface topography of porous silicon layer formation was a mud-like structure. The porosity and thickness have been determined gravimetrically are varied from 61% to 82% and 7.2 µm to 9.4µm respectively. The XRD patterns show that one diffraction peak for all PSL through anodization duration and it is assigned to the (400) plane and data confirmed the porous silicon PS was nanocrystalline.