NOVELTY - The removal method involves diffusing impurities from the substrate using a phosphorus gettering process. The phosphorus gettering process involves impregnating at least one surface of the semiconductor wafer with a phosphorus material and optionally with other gettering agents to form impurity clusters associated with the gettering centers. A portion including the impregnated phosphorus material and the impurity clusters is removed from the surface of the semiconductor wafer to yield a semiconductor wafer including a substrate having generally reduced impurity content.    USE - Method for removing impurities from low-grade crystalline semiconductor wafers (claimed), such as refined metallurgical-grade crystalline silicon substrate used for providing semiconductor solar cells.    ADVANTAGE - Allows the formation of solar cells in greater quantities and in a greater number of fabrication facilities. Provides the ability to reduce the amount of impurities present in a semiconductor wafer such as a silicon wafer in a process occurring prior to the standard solar cell fabrication. Enables processes for inexpensively making wafer treatments needed for highly efficient mass scale solar cell production. Enables use of saw damage that may be inherently present after slicing a silicon ingot into wafers. The inherent saw damage that occurs in slicing a semiconductor wafer benefits attracting impurities in favorable thermodynamic process conditions. Supports gettering impurities during a favorable thermodynamic treatment by adding one or more contaminated layers with controlled levels of foreign atoms at the wafer surface. The foreign atoms may include metals (e.g., iron, nickel and copper) and non-metals (e.g., phosphorus, oxygen). Removes a highly contaminated layer at the surface of the wafer using etching prior to the solar cell fabrication, thereby, reduces the concentration of electrically active species within grains, while concentrating metallic impurities at grain boundaries in multicrystalline silicon. Generates denuded zones in silicon wafers by applying treatments that reduce the concentration of non-surface electrically active species.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a semiconductor wafer.    DESCRIPTION OF DRAWING(S) - The drawing shows the flowchart of forming a semiconductor solar cell.    Resulting silicon (36)    Silicon ingot formation (38)    Formation of wafers (40)    Wafer treatment (42)    Solar cell process (44)