A two-step hole etching method including: providing a semiconductor wafer which has a plurality of solar cell stacks and performing a first and a second processing step. In the first processing step, a first resist layer is applied to a top surface of the semiconductor wafer, at least a first opening is produced in the first resist layer and, via a first etching process, a hole which extends beyond a p/n junction of the Ge sub-cell into the semiconductor wafer is produced in the area of the first opening. In the second process step a second resist layer is applied to the top surface of the semiconductor wafer, a second opening greater than the first opening and surrounding the hole is produced in the second resist layer, and, the hole is widened in an area which extends to the Ge sub-cell serving as an etch stop layer.