According to a process for manufacturing an integrated power device, projections and depressions are formed in a semiconductor body that extend in a first direction and are arranged alternated in succession in a second direction, transversely to the first direction. Further provided are a first conduction region and a second conduction region. The first conduction region and the second conduction region define a current flow direction parallel to the first direction, along the projections and the depressions. To form the projections and the depressions, portions of the semiconductor body that extend in the first direction and correspond to the depressions, are selectively oxidized.