A nonvolatile semiconductor memory device includes transistor-based memory cells. Each memory cell has a first and a second source/drain region, a channel region separating the first and the second source/drain region, a storage layer and a control gate. The control gates of the memory cells are connected to word lines. The first and second source/drain regions are connected to bit lines respectively. Each memory cell may be programmed by injecting first charge carriers of a first polarity and may be erased by injecting second charge carriers having the opposite polarity into the storage layer respectively. By applying a high stress voltage between bit line and word line, weak insulator structures may break through such that they become detectable as short-circuits by a low voltage leakage test. By applying the stress voltage contemporaneously on both sides of the memory cells, an early overerase/overprogram, resulting from hot carrier injection, is avoided.