Porous semiconductor materials have presented a special interest since the invention of the ELTRAN« process leading to the transfer of epitaxial thin films. Because of the high qualities of the transferred layer, this process allowed the development of the first SOI substrates. However, the ELTRAN« process or similar methods are limited to the transfer of silicon homoepitaxial or pseudomorphic layers. Therefore, alternative processes including porous materials have been recently developed. In this study, we focused on a process suggested by Joshi et al. using porous semiconductor materials and direct wafer bonding in conjunction with hydrogen exfoliation process. The main steps consist in the direct bonding of an implanted wafer to a porous silicon wafer. Then, through an annealing treatment, there is exfoliation of the implanted substrate leading to the layer transfer on the Si handle wafer. Thus, various semiconductor materials can be transferred and used as a thin layer. The porous substrate can be chosen depending on the application, recycled and substrates with different orientations can be integrated. One of the key steps is the direct wafer bonding. Direct wafer bonding refers to a process by which two wafers are put into contact and held together at room temperature by adhesive forces, without any additional materials. The conditions to obtain a successful bonding are contaminant-free surfaces and smooth enough to allow an intimate contact. Therefore, before bonding the porous layer is generally coated with another material to produce defect-free and high strength bonding interface. Because of its properties and the possibility to be deposited at low temperature, silicon nitride (SiN) is often used as a “bondable” layer. This work presents an investigation of the SiN deposition on porous Si in preparation for wafer bonding. For that, porous silicon has been made by electrochemical etching and coated with different thicknesses of SiN layers. The SiN has been deposited by plasma enhanced chemical vapor deposition with a deposition rate of 120 ┼/min. AFM measurements were performed on both porous Si and flat Si samples covered with the SiN corresponding to the same deposition times. In the case of porous Si, for short deposition times, the roughness increases and becomes compatible with wafer bonding again after 100 seconds of deposition. This is in agreement with SEM observations showing deposition mechanism of SiN through small, sub-micron size areas first, explaining an increase of surface roughness, and then the formation of a homogeneous and uniform layer. These analyses were complemented by EDX and TEM observations which brought more details about SiN deposition mechanisms. In contrast to SiN deposition on flat Si, a minimum thickness or deposition time is required to form a stoechiometric and uniform SiN layer on porous Si compatible with direct wafer bonding.