Bonded unified semiconductor chips and fabrication and operation methods thereof

A method for forming a unified semiconductor chip, comprising:

• forming a first semiconductor structure comprising one or more processors, an array of embedded dynamic random-access memory (DRAM) cells, and a first bonding layer comprising a plurality of first bonding contacts;
• forming a second semiconductor structure comprising an array of NAND memory cells and a second bonding layer comprising a plurality of second bonding contacts;
• and
• bonding the first semiconductor structure and the second semiconductor structure in a face-to-face manner, such that the first bonding contacts are in contact with the second bonding contacts at a bonding interface.

A method for operating a unified semiconductor chip comprising one or more processors, an array of embedded dynamic random-access memory (DRAM) cells, and an array of NAND memory cells in a same bonded chip, the method comprising:

• transferring data from the one or more processors to the array of embedded DRAM cells;
• buffering the data in the array of embedded DRAM cells;
• and
• storing the data in the array of NAND memory cells from the array of embedded DRAM cells.