Wafer-level packaging structure is provided. First chips are bonded to the device wafer. A first encapsulation layer is formed on the device wafer, covering the first chips. The first chip includes: a chip front surface with a formed first pad, facing the device wafer; and a chip back surface opposite to the chip front surface. A first opening is formed in the first encapsulation layer to expose at least one first chip having an exposed chip back surface for receiving a loading signal. A metal layer structure is formed covering the at least one first chip, a bottom and sidewalls of the first opening, and the first encapsulation layer, followed by an alloying treatment on the chip back surface and the metal layer structure to form a back metal layer on the chip back surface.

A semiconductor device includes a first electrode and a second electrode. The first electrode is connected to a collector layer and a first portion on the collector layer side of a cathode layer. The second electrode is connected to a second portion of the cathode layer excluding the first portion. A work function of the first electrode is larger than a work function of the second electrode, and one of the first electrode and the second electrode and the semiconductor substrate sandwich another of the first electrode and the second electrode in a thickness direction of the semiconductor substrate.

A semiconductor structure includes a gate stack surrounding a semiconductor channel; a first semiconductor source/drain; a first metallic contact that touches the first source/drain; a second semiconductor source/drain; and a second metallic contact that touches the second source/drain. A conductive path length from the channel to the first metallic contact through the first source/drain is smaller than a conductive path length from the channel through the second source/drain to the second metallic contact. The second source/drain includes a bypass layer that touches the second metallic contact, and the bypass layer includes a metastable alloy of two or more elements of semiconductors and dopants.

The invention relates to a method for producing ohmic contacts, of type including a metal, a semiconductor and tin, including: a) forming a first layer (6), of an alloy of the semiconductor and of tin; b) then, on the first layer, forming a second layer (8), of said metal; c) laser annealing the first layer and the second layer at an energy density between 0.1 and 2 J/cm.sup.2.

There is provided a method of patterning platinum on a substrate. A platinum layer is deposited on the substrate, and a patterned photoresist layer is formed over the platinum layer leaving partly exposed regions of the platinum layer. An aluminum layer is deposited over the partly exposed regions of the platinum layer. An alloy is formed of aluminum with platinum from the partly exposed regions. The platinum aluminum alloy is etched away leaving a remaining portion of the platinum layer to form a patterned platinum layer on the substrate. In an embodiment, a thin hard mask layer is deposited on the platinum layer on the semiconductor substrate before the patterned photoresist layer is formed.

There is provided a method of patterning platinum on a substrate. A platinum layer is deposited on the substrate, and a patterned photoresist layer is formed over the platinum layer leaving partly exposed regions of the platinum layer. An aluminum layer is deposited over the partly exposed regions of the platinum layer. An alloy is formed of aluminum with platinum from the partly exposed regions. The platinum aluminum alloy is etched away leaving a remaining portion of the platinum layer to form a patterned platinum layer on the substrate. In an embodiment, a thin hard mask layer is deposited on the platinum layer on the semiconductor substrate before the patterned photoresist layer is formed.

There is provided a method of patterning platinum on a substrate. A platinum layer is deposited on the substrate, and a patterned photoresist layer is formed over the platinum layer leaving partly exposed regions of the platinum layer. An aluminum layer is deposited over the partly exposed regions of the platinum layer. An alloy is formed of aluminum with platinum from the partly exposed regions. The platinum aluminum alloy is etched away leaving a remaining portion of the platinum layer to form a patterned platinum layer on the substrate. In an embodiment, a thin hard mask layer is deposited on the platinum layer on the semiconductor substrate before the patterned photoresist layer is formed.

There is provided a method of patterning platinum on a substrate. A platinum layer is deposited on the substrate, and a patterned photoresist layer is formed over the platinum layer leaving partly exposed regions of the platinum layer. An aluminum layer is deposited over the partly exposed regions of the platinum layer. An alloy is formed of aluminum with platinum from the partly exposed regions. The platinum aluminum alloy is etched away leaving a remaining portion of the platinum layer to form a patterned platinum layer on the substrate. In an embodiment, a thin hard mask layer is deposited on the platinum layer on the semiconductor substrate before the patterned photoresist layer is formed.

Wafer-level packaging structure is provided. First chips are bonded to the device wafer. A first encapsulation layer is formed on the device wafer, covering the first chips. The first chip includes: a chip front surface with a formed first pad, facing the device wafer; and a chip back surface opposite to the chip front surface. A first opening is formed in the first encapsulation layer to expose at least one first chip having an exposed chip back surface for receiving a loading signal. A metal layer structure is formed covering the at least one first chip, a bottom and sidewalls of the first opening, and the first encapsulation layer, followed by an alloying treatment on the chip back surface and the metal layer structure to form a back metal layer on the chip back surface.

Wafer-level packaging method and package structure are provided. In an exemplary method, first chips are bonded to the device wafer. A first encapsulation layer is formed on the device wafer, covering the first chips. The first chip includes: a chip front surface with a formed first pad, facing the device wafer; and a chip back surface opposite to the chip front surface. A first opening is formed in the first encapsulation layer to expose at least one first chip having an exposed chip back surface for receiving a loading signal. A metal layer structure is formed covering the at least one first chip, a bottom and sidewalls of the first opening, and the first encapsulation layer, followed by an alloying treatment on the chip back surface and the metal layer structure to form a back metal layer on the chip back surface.