A semiconductor structure with an air gap includes a dielectric stack having a first dielectric layer on a substrate, a second dielectric layer on the first dielectric layer, and a third dielectric layer on the second dielectric layer. A first conductive layer and a second conductive layer are disposed in the dielectric stack. The first conductive layer and the second conductive layer are coplanar. A cross-like-shaped air gap is disposed in the dielectric stack between the first and second conductive layers. An oxide layer is disposed on a sidewall of the second dielectric layer within the cross-like-shaped air gap.

A method for manufacturing an air bridge, an air bridge, and an electronic device are disclosed. The method for manufacturing an air bridge includes: applying a first photoresist layer to a substrate; applying a second photoresist layer to the first photoresist layer; exposing, developing, and fixing the second photoresist layer, to form a patterned structure; etching away the first photoresist layer in a specified area through the patterned structure, to form a structure for blocking a deposition material from diffusing to a periphery on the substrate, the specified area including a projection area formed on the first photoresist layer by a top opening of the patterned structure; and depositing a bridge support structure on a surface of the substrate exposed after the first photoresist layer in the specified area is etched away, and forming an air bridge based on the bridge support structure.

The present disclosure describes a method for reducing RC delay in radio frequency operated devices or devices that would benefit from an RC delay reduction. The method includes forming, on a substrate, a transistor structure having source/drain regions and a gate structure; depositing a first dielectric layer on the substrate to embed the transistor structure; forming, within the first dielectric layer, source/drain contacts on the source/drain regions of the transistor structure; depositing a second dielectric layer on the first dielectric layer; forming metal lines in the second dielectric layer; forming an opening in the second dielectric layer between the metal lines to expose the first dielectric layer; etching, through the opening, the second dielectric layer between the metal lines and the first dielectric layer between the source/drain contacts; and depositing a third dielectric layer to form an air-gap in the first and second dielectric layers and over the transistor structure.

A semiconductor device includes a semiconductor die, an N-doped region, an N-contact metal, a PN junction mesa, a P-contact metal, a first passivation layer, an anode feed metal, and a cathode feed metal. The semiconductor die may include a plurality of semiconductor layers disposed on an insulating substrate. The N-doped region may define an active area of the device. The N-contact metal may be disposed on a first portion of the N-doped region. The PN junction mesa may be disposed on a second portion of the N-doped region. The PN junction mesa may comprise a hyperabrupt N-doping layer disposed on the first portion of the N-doped region and a P-doped layer disposed on the hyperabrupt N-doping layer. The P-contact metal may be disposed on the P-doped layer of the PN junction mesa. The first passivation layer may cover the semiconductor layers of the semiconductor device and have openings for the N-contact metal and the P-contact metal. The anode feed metal may connect the P-contact metal to a first bond pad. The anode feed metal generally forms an arch from the P-contact metal to the first bond pad and the arch defines a space between the anode feed metal and the first passivation layer covering the semiconductor layers and a the of the PN junction mesa.

Interconnects that facilitate reduced capacitance and/or resistance and corresponding techniques for forming the interconnects are disclosed herein. An exemplary interconnect is disposed in an insulating layer. The interconnect has a metal contact, a contact isolation layer surrounding sidewalls of the metal contact, and an air gap disposed between the contact isolation layer and the insulating layer. An air gap seal for the air gap has a first portion disposed over a top surface of the contact isolation layer, but not disposed on a top surface of the insulating layer, and a second portion disposed between the contact isolation layer and the insulating layer, such that the second portion surrounds a top portion of sidewalls of the metal contact. The air gap seal may include amorphous silicon and/or silicon oxide. The contact isolation layer may include silicon nitride. The insulating layer may include silicon oxide.

A photodetector includes: a semiconductor substrate; a mesa portion formed on a major surface of the semiconductor substrate to extend along an optical waveguide direction; a first contact layer; a second contact layer; a first electrode; and an air bridge wiring electrically connected to the first contact layer and the first electrode. When viewed in a direction perpendicular to the major surface of the semiconductor substrate, a length of the mesa portion in the optical waveguide direction is longer than a length of the mesa portion in a direction perpendicular to the optical waveguide direction. The air bridge wiring is led out from the first contact layer to one side in the direction perpendicular to the optical waveguide direction, and is bridged between the first contact layer and the first electrode.

A device is disclosed. The device includes a gate conductor, a first source-drain region and a second source-drain region. The device includes a first air gap space between the first source-drain region and a first side of the gate conductor and a second air gap space between the second source-drain region and a second side of the gate conductor. A hard mask layer that includes holes is under the gate conductor, the first source-drain region, the second source-drain region and the air gap spaces. A planar dielectric layer is under the hard mask.

Techniques are described for forming a sealed cavity within a semiconductor wafer, where a conductor wafer includes a structure, such as a T-gate electrode or passive component, formed over a substrate. The sealed-cavity structure may be embedded into the wafer without interfering with any subsequent processes. That is, once the cavity is closed, any subsequent backend processes may continue as usual.

Various embodiments are disclosed for improved and structurally optimized transistors, such as RF power amplifier transistors. A transistor may include a drain metal portion raised from a surface of a substrate, a drain metal having a notched region, a gate manifold body with angled gate tabs extending from the gate manifold, and/or a source-connected shielding. The transistor may include a high-electron-mobility transistor (HEMT), a gallium nitride (GaN)-on-silicon transistor, a GaN-on-silicon-carbide transistor, or other type of transistor.

A method for manufacturing a semiconductor device includes a process of providing two source electrodes on a substrate, a process of providing a gate electrode on one surface of the substrate between the two source electrodes, a process of providing an insulating film on the gate electrode, the substrate, and side surfaces of the two source electrodes, a process of providing an airbridge foundation resist on the insulating film, providing an airbridge on the two source electrodes and the airbridge foundation resist, and a process of removing the airbridge foundation resist, in which surfaces of the two source electrodes at sides opposite to the substrate and a front surface of the airbridge foundation resist provided in the subsequent process are substantially coplanar.