Chip on chip semiconductor device

A semiconductor device comprising:

• a first semiconductor chip;
• and
• a second semiconductor chip which is connected to the surface side of said first semiconductor chip via electrode terminals provided on each of said first semiconductor chip and said second semiconductor chip,
• wherein one electrode terminal is formed on said first semiconductor chip in a portion corresponding to any of electrode terminals of said second semiconductor chip,
• wherein said one electrode terminal and an electrode pad for connection to an external lead provided on the outside of said first semiconductor chip are connected to each other via an interconnection formed on the surface of a passivation film, and
• wherein an electric signal can be transmitted directly to said second semiconductor chip via said electrode pad of said first semiconductor chip.

A semiconductor device comprising:

• a semiconductor substrate in which a circuit element is formed;
• an electrode pad for wire bonding provided either on the surface of the semiconductor substrate via an insulating film or in contact with the semiconductor substrate;
• and
• a wire to be bonded to said electrode pad so as to be connected to an external lead,
• wherein an Au layer and an Sn layer or an Au—Sn layer are provided on the surface of said electrode pad, and said wire and said electrode pad are connected to each other via an Au—Sn alloy layer.

A semiconductor device comprising;

• a first semiconductor chip having a first bump;
• a second semiconductor chip having a second bump having a top surface area smaller than that of said first bump, and
• an Au—Sn alloy layer for bonding said second bump onto said first bump,
• wherein a step by which at least a part of the peripheral portion of said first bump becomes lower than a center portion is formed, and
• wherein a fillet of said Au—Sn alloy layer is formed so as to extend from a top surface on the center portion side of said first bump to the periphery of said second bump.