At least one polymer material may be employed to facilitate bonding between the semiconductor dies. Plasma treatment, formation of a blended polymer, or formation of polymer hairs may be employed to enhance bonding. Alternatively, air gaps can be formed by subsequently removing the polymer material to reduce capacitive coupling between adjacent bonding pads.

In a semiconductor device according to an embodiment, a first connection wiring layer and a second connection wiring layer are bonded such that a first surface and a second surface face each other and a first electrode and a second electrode are in contact with each other, wherein the first electrode includes a first barrier metal film provided in a first trench and containing Ti, and a first conductive film provided in the first trench via the first barrier metal film and containing polycrystalline Cu, the second electrode includes a second barrier metal film provided in a second trench and containing Ti, and a second conductive film provided in the second trench via the second barrier metal film and containing polycrystalline Cu, and Ti and O are present on a bonding surface between the first electrode and the second electrode.

In a wafer to wafer bonding method, a first wafer is vacuum suctions on a first surface of a lower stage and a second wafer is vacuum suctioned on a second surface of an upper stage. Pressure is applied to a middle portion of the first wafer by a lower push rod and pressure is applied to a middle portion of the second wafer by an upper push rod. Bonding of the first and second wafers propagates radially outwards. A bonding propagation position of the first and second wafers is detected. A ratio of protruding lengths of the lower push rod and the upper push rod is changed according to the bonding propagation position.

A method of making a secure integrated-circuit system comprises providing a first integrated circuit in a first die having a first die size and providing a second integrated circuit in a second die. The second die size is smaller than the first die size. The second die is transfer printed onto the first die and connected to the first integrated circuit, forming a compound die. The compound die is packaged. The second integrated circuit is operable to monitor the operation of the first integrated circuit and provides a monitor signal responsive to the operation of the first integrated circuit. The first integrated circuit can be constructed in an insecure facility and the second integrated circuit can be constructed in a secure facility.

A method of making a secure integrated-circuit system comprises providing a first integrated circuit in a first die having a first die size and providing a second integrated circuit in a second die. The second die size is smaller than the first die size. The second die is transfer printed onto the first die and connected to the first integrated circuit, forming a compound die. The compound die is packaged. The second integrated circuit is operable to monitor the operation of the first integrated circuit and provides a monitor signal responsive to the operation of the first integrated circuit. The first integrated circuit can be constructed in an insecure facility and the second integrated circuit can be constructed in a secure facility.

A multi-chip package may include a plurality of semiconductor chips and a printed circuit board (PCB). Each of the semiconductor chips may have an upper surface, a bottom surface, and a plurality of side surfaces. Circuit terminals may be arranged on the upper surface. A plurality of side bonding pads may be arranged on one or more selected side surface among the side surfaces. The semiconductor chips may be mounted on the PCB. The PCB may be configured to surround the selected side surface on which the side bonding pads may be arranged.

A multi-chip package may include a plurality of semiconductor chips and a printed circuit board (PCB). Each of the semiconductor chips may have an upper surface, a bottom surface, and a plurality of side surfaces. Circuit terminals may be arranged on the upper surface. A plurality of side bonding pads may be arranged on one or more selected side surface among the side surfaces. The semiconductor chips may be mounted on the PCB. The PCB may be configured to surround the selected side surface on which the side bonding pads may be arranged.

A method of making a secure integrated-circuit system comprises providing a first integrated circuit in a first die having a first die size and providing a second integrated circuit in a second die. The second die size is smaller than the first die size. The second die is transfer printed onto the first die and connected to the first integrated circuit, forming a compound die. The compound die is packaged. The second integrated circuit is operable to monitor the operation of the first integrated circuit and provides a monitor signal responsive to the operation of the first integrated circuit. The first integrated circuit can be constructed in an insecure facility and the second integrated circuit can be constructed in a secure facility.

A method of making a secure integrated-circuit system comprises providing a first integrated circuit in a first die having a first die size and providing a second integrated circuit in a second die. The second die size is smaller than the first die size. The second die is transfer printed onto the first die and connected to the first integrated circuit, forming a compound die. The compound die is packaged. The second integrated circuit is operable to monitor the operation of the first integrated circuit and provides a monitor signal responsive to the operation of the first integrated circuit. The first integrated circuit can be constructed in an insecure facility and the second integrated circuit can be constructed in a secure facility.

A method of liquid assisted micro cold binding is provided. The method includes: forming a conductive pad on the substrate in which the conductive pad consists essentially of indium; forming a liquid layer on the conductive pad; placing a micro device having an electrode facing the conductive pad over the conductive pad such that the micro device is in contact with the liquid layer and is gripped by a capillary force produced by the liquid layer between the micro device and the conductive pad in which the electrode consists essentially of indium; and evaporating the liquid layer such that the electrode is bound to the conductive pad and is in electrical contact with the conductive pad.