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 of an embodiment includes: a semiconductor substrate; a first insulating layer provided on or above the semiconductor substrate; an aluminum layer provided on the first insulating layer; a second insulating layer provided on the first insulating layer, the second insulating layer covering a first region of a surface of the aluminum layer; and an aluminum oxide film provided on a second region other than the first region of the surface of the aluminum layer, the aluminum oxide film including -alumina as a main component, and a film thickness of the aluminum oxide film being equal to or larger than 0.5 nm and equal to or smaller than 3 nm.

A semiconductor substrate has a bond pad. The bond pad includes a layer of an aluminum alloy having a chemical composition including at least 0.3% by weight of at least one of Zn, Mg, Sc, Zr, Ti, Ag and/or Mn, with the balance being at least Al and incidental impurities.

Semiconductor dies including ultra-thin wafer backmetal systems, microelectronic devices containing such semiconductor dies, and associated fabrication methods are disclosed. In one embodiment, a method for processing a device wafer includes obtaining a device wafer having a wafer frontside and a wafer backside opposite the wafer frontside. A wafer-level gold-based ohmic bond layer, which has a first average grain size and which is predominately composed of gold, by weight, is sputter deposited onto the wafer backside. An electroplating process is utilized to deposit a wafer-level silicon ingress-resistant plated layer over the wafer-level Au-based ohmic bond layer, while imparting the plated layer with a second average grain size exceeding the first average grain size. The device wafer is singulated to separate the device wafer into a plurality of semiconductor die each having a die frontside, an Au-based ohmic bond layer, and a silicon ingress-resistant plated layer.

Semiconductor dies including ultra-thin wafer backmetal systems, microelectronic devices containing such semiconductor dies, and associated fabrication methods are disclosed. In one embodiment, a method for processing a device wafer includes obtaining a device wafer having a wafer frontside and a wafer backside opposite the wafer frontside. A wafer-level gold-based ohmic bond layer, which has a first average grain size and which is predominately composed of gold, by weight, is sputter deposited onto the wafer backside. An electroplating process is utilized to deposit a wafer-level silicon ingress-resistant plated layer over the wafer-level Au-based ohmic bond layer, while imparting the plated layer with a second average grain size exceeding the first average grain size. The device wafer is singulated to separate the device wafer into a plurality of semiconductor die each having a die frontside, an Au-based ohmic bond layer, and a silicon ingress-resistant plated layer.

In a described example, a method includes: forming a metal layer on a backside surface of a semiconductor wafer, the semiconductor wafer having semiconductor dies spaced apart by scribe lanes on an active surface of the semiconductor wafer opposite the backside surface; forming a layer with a modulus greater than about 4000 MPa up to about 8000 MPa over the metal layer; mounting the backside of the semiconductor wafer on a first side of a dicing tape having an adhesive; cutting through the semiconductor wafer, the metal layer, and the layer with a modulus greater than about 4000 MPa up to about 8000 MPa along scribe lanes; separating the semiconductor dies from the semiconductor wafer and from one another by stretching the dicing tape, expanding the cuts in the semiconductor wafer along the scribe lanes between the semiconductor dies; and removing the separated semiconductor dies from the dicing tape.

In a described example, a method includes: forming a metal layer on a backside surface of a semiconductor wafer, the semiconductor wafer having semiconductor dies spaced apart by scribe lanes on an active surface of the semiconductor wafer opposite the backside surface; forming a layer with a modulus greater than about 4000 MPa up to about 8000 MPa over the metal layer; mounting the backside of the semiconductor wafer on a first side of a dicing tape having an adhesive; cutting through the semiconductor wafer, the metal layer, and the layer with a modulus greater than about 4000 MPa up to about 8000 MPa along scribe lanes; separating the semiconductor dies from the semiconductor wafer and from one another by stretching the dicing tape, expanding the cuts in the semiconductor wafer along the scribe lanes between the semiconductor dies; and removing the separated semiconductor dies from the dicing tape.

A semiconductor Schottky rectifier built in an epitaxial semiconductor layer over a substrate has an anode structure and a cathode structure extending from the surface of the epitaxial layer. The cathode contact structure has a trench structure near the epi-layer and a vertical sidewall surface covered with a gate oxide layer. The cathode structure further comprises a polysilicon element adjacent to the gate oxide layer.

Described examples provide microelectronic devices and fabrication methods, including fabricating a contact structure by forming a titanium or titanium tungsten barrier layer on a conductive feature, forming a tin seed layer on the barrier layer, forming a copper structure on the seed layer above the conductive feature of the wafer or die, heating the seed layer and the copper structure to form a bronze material between the barrier layer and the copper structure, removing the seed layer using an etching process that selectively removes an exposed portion of the seed layer, and removing an exposed portion of the barrier layer.

Semiconductor dies including ultra-thin wafer backmetal systems, microelectronic devices containing such semiconductor dies, and associated fabrication methods are disclosed. In one embodiment, a method for processing a device wafer includes obtaining a device wafer having a wafer frontside and a wafer backside opposite the wafer frontside. A wafer-level gold-based ohmic bond layer, which has a first average grain size and which is predominately composed of gold, by weight, is sputter deposited onto the wafer backside. An electroplating process is utilized to deposit a wafer-level silicon ingress-resistant plated layer over the wafer-level Au-based ohmic bond layer, while imparting the plated layer with a second average grain size exceeding the first average grain size. The device wafer is singulated to separate the device wafer into a plurality of semiconductor die each having a die frontside, an Au-based ohmic bond layer, and a silicon ingress-resistant plated layer.