With Si substrate, the silicon-oxide-nitride-oxide-silicon-type nonvolatile memory formed on a Ge layer with thermal SiO2 as the tunnel dielectric is explored in this work. The promising performance of the Ge-based memory is evidenced by the large hysteresis memory window, the high operation speed of 4.2 V flatband voltage shift by erasing at -16 V for 1 ms, the negligible memory window degradation up to 10(5) operation cycles, and a good retention characteristic with 15% charge loss after a 10 year operation. The asymmetry in programming and erasing speed is observed, and the mechanism, along with the approaches to alleviate this phenomenon, is also discussed. Most importantly, the Ge-based memory device can be implemented by the process fully compatible with existent ultralarge-scale integration technology, paving the way to enable high performance nonvolatile memory for the next-generation electronic system. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3242292]