NOVELTY - The apparatus has an n-batch stack series array of monocrystalline semiconductor wafers (1-n) i.e. crystalline silicon wafers, arranged between an anode and a cathode in a tunnel. Each of the wafers is held in place by a wafer clamp securing a surface edge of the wafers and sealing fluid filled compartment formed between the wafers. The anode and the cathode face a backside wall of an electrolyte-filled chamber and away from the wafers. A set of vent holes in the chamber allows evolved byproduct gas i.e. hydrogen gas, to escape during anodization of the wafers.    USE - Apparatus for producing a uniform/multi layer porous electrolytic bath semiconductor on an n-batch stack series array of a thin-film substrate e.g. monocrystalline semiconductor wafer such as crystalline silicon wafer (claimed), in a solar photovoltaic unit. Can also be used for a microelectromechanical system (MEMS) and an optoelectronic system.    ADVANTAGE - The chamber is separated from a process chamber by a conducting membrane to prevent transfer of chemical ions and molecules, thus allowing use of different electrolyte chemicals in the chambers without interfering with each other. The membrane can be self- standing or be sandwiched by perforated non-conducting plates to provide mechanical stability. The apparatus allows additional vents and ports to allow the process chamber to be filled completely to required level and to maintain same level throughout manufacturing process. The apparatus is designed such that top of a vent port is placed outside liquid, so that an electrically connecting path outside an inner bath can be avoided, thus enabling low cost, high-throughput fabrication of the thin film substrate to be used for solar cell manufacturing by a preferably reusable template, while reducing tool footprint and enabling downstream rinsing and drying.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for forming a porous semiconductor on a set of monocrystalline semiconductor wafers.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of an electrolyte-filled chamber design with fluid fill and vent ports.    Monocrystalline semiconductor wafers (1-n)    Fluid fill and vent ports (208)