Reliable hybrid bonded apparatuses are provided. An example process cleans nanoparticles from at least the smooth oxide top layer of a surface to be hybrid bonded after the surface has already been activated for the hybrid bonding. Conventionally, such an operation is discouraged. However, the example cleaning processes described herein increase the electrical reliability of microelectronic devices. Extraneous metal nanoparticles can enable undesirable current and signal leakage from finely spaced traces, especially at higher voltages with ultra-fine trace pitches. In the example process, the extraneous nanoparticles may be both physically removed and/or dissolved without detriment to the activated bonding surface.