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.

An electrode structure with an alloy interface is provided. In one aspect, a method of forming a contact structure includes: patterning a via in a first dielectric layer; depositing a barrier layer onto the first dielectric layer, lining the via; depositing and polishing a first metal layer (Element A) into the via to form a contact in the via; depositing a second metal layer (Element B) onto the contact in the via; annealing the first and second metal layers under conditions sufficient to form an alloy AB; depositing a third metal layer onto the second metal layer; patterning the second and third metal layers into a pedestal stack over the contact to form an electrode over the contact, wherein the alloy AB is present at an interface of the electrode and the contact; and depositing a second dielectric that surrounds the pedestal stack. A contact structure is also provided.

A GaN-based compound semiconductor device includes a GaN-based epitaxial structure and an annealed metal layered structure that is formed on the GaN-based epitaxial structure. The annealed metal layered structure includes a metallic barrier layer, a conductive unit, and a protective unit which is formed on a lateral surface of the conductive unit. The metallic barrier layer and the conductive unit are sequentially disposed on the GaN-based epitaxial structure in such order. An ohmic contact is formed between the GaN-based epitaxial structure and the annealed metal layered structure. The protective unit includes a metal oxide material having one of NiAlO, AuAlO, and a combination thereof.

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.

A method for integrating fin field effect transistors (FinFETs) and resistors on a common substrate is provided. By employing a digital alloy as a channel material for each FinFET and as a resistor body for each resistor, FinFETs with improved charge carrier mobility, and resistors with good temperature coefficient of resistance are obtained.

A multilayer structure with excellent crystallinity and a semiconductor device of the multilayer structure with good mobility are provided. A multilayer structure includes: a corundum structured crystal substrate; and a crystalline film containing a corundum structured crystalline oxide as a major component, the film formed directly on the substrate or with another layer therebetween, wherein the crystal substrate has an off angle from 0.2° to 12.0°, and the crystalline oxide contains one or more metals selected from indium, aluminum, and gallium.

A method for forming a semiconductor device comprises forming an insulation trench structure comprising insulation material extending into the semiconductor substrate from a surface of the semiconductor substrate. The insulation trench structure laterally surrounds a portion of the semiconductor substrate. The method further comprises modifying the laterally surrounded portion of the semiconductor substrate to form a vertical electrically conductive structure comprising an alloy material. The alloy material is an alloy of the semiconductor substrate material and at least one metal.

A method for forming a semiconductor device comprises forming an insulation trench structure comprising insulation material extending into the semiconductor substrate from a surface of the semiconductor substrate. The insulation trench structure laterally surrounds a portion of the semiconductor substrate. The method further comprises modifying the laterally surrounded portion of the semiconductor substrate to form a vertical electrically conductive structure comprising an alloy material. The alloy material is an alloy of the semiconductor substrate material and at least one metal.

A method for fabricating a semiconductor device includes: forming a silicon nitride film having a refractive index equal to or larger than 2.2 on a nitride semiconductor layer; and introducing at least one of elements that are oxygen, nitrogen, fluorine, phosphorus, sulfur and selenium into the silicon nitride film, the silicon nitride film including the at least one of elements remaining on the nitride semiconductor layer. The at least one of elements is introduced by a process of exposing the silicon nitride film to plasma including the at least one of elements, a process of ion-implanting the at least one of elements into the silicon nitride film, or a process of thermally diffusing the at least one of elements into the silicon nitride film. The silicon nitride film is formed in contact with a surface of the nitride semiconductor layer.