NOVELTY - Solar cell formation process comprises: positioning a substrate on a substrate receiving surface; determining the actual position of the patterned doped region on the substrate; receiving electromagnetic radiation at a first wavelength; aligning features in a screen printing mask; and depositing a layer of material through the features.    USE - The method is useful for the solar cell formation (claimed).    ADVANTAGE - The method reduces the manufacturing costs required to form the solar cells.    DETAILED DESCRIPTION - Solar cell formation process comprises: positioning a substrate on a substrate receiving surface, where the substrate has a first surface and a patterned doped region formed; determining the actual position of the patterned doped region on the substrate, where determining the actual position comprises; emitting electromagnetic radiation towards the first surface; receiving electromagnetic radiation at a first wavelength from a region of the first surface; aligning one or more features in a screen printing mask to the patterned doped region using information received from the determined actual position of the patterned doped region on the substrate; and depositing a layer of material through the one or more features and onto at least a portion of patterned doped region after aligning the one or more features to the patterned doped region. An INDEPENDENT CLAIM is an apparatus for processing a substrate comprising: a substrate supporting surface; an electromagnetic radiation source that is positioned to emit electromagnetic radiation towards the substrate supporting surface; a detector assembly that is positioned to receive at least a portion of the emitted electromagnetic radiation that is directed towards a surface of a substrate that is disposed on the substrate supporting surface, where the received electromagnetic radiation is provided at a wavelength that is preferentially transmitted through or reflected by a patterned heavily doped region formed on a surface of the substrate or preferentially transmitted through or reflected by regions of the substrate that do not comprise the patterned heavily doped region; a deposition chamber having a screen printing mask and at least one actuator which is configured to position the screen printing mask; and a controller configured to receive a signal from the detector assembly regarding the position of a patterned heavily doped region formed on a surface of a substrate that is disposed on the substrate supporting surface, and adjust the position of the screen printing mask relative to the patterned heavily doped region based on the information received from the detector assembly.