Simple metal-Hf0.8Si0.2Ox-silicon capacitors have been fabricated. It is observed that the capacitor after high-temperature rapid thermal annealing treatment exhibits a significant charge storage phenomenon, with large hysteresis windows of 3.93 V in a ±8 V gate sweeping voltage range, faster operating speed and good data retention characteristics. The occurrence of charge memory should be attributed to the high-temperature treatment, which gives rise to the HfO2 crystallization and elemental composition redistribution in the Hf0.8Si0.2Ox film, forming a typical metal-oxide-high-κ-oxide-silicon memory structure. Therefore, the high-temperature treatment that induced the internal structure transformation is an appealing approach, and provides a guide for future charge-trap memory design.