Semiconductor chip stack structure and method are provided. A first chip has a first metal bump formed on a first electrode pad. The first chip is attached to and electrically connected to a substrate. The electrical connection is made by a bump reverse bonding method in which one end of a bonding wire is ball-bonded to the substrate and the other end is stitch-bonded to the metal bump. The second chip is stacked on the first chip. The bonding wire is substantially parallel with a top surface of the first chip. Accordingly, the chip stack structure and method minimize a space between the first chip and the second chip, thereby reducing the total height of semiconductor chip stack.