In a method for manufacturing a semiconductor device, a dummy gate layer and a hard mask layer are sequentially formed on a substrate. A first doped portion is formed in the dummy gate layer, and has an etching selectivity with respect to the other portion of the dummy gate layer. Etching masks are formed on portions of the hard mask layer. The hard mask layer and the dummy gate layer are etched to pattern the first doped portion and the other portion of the dummy gate layer into first dummy gates and second dummy gates. The first dummy gates and the second dummy gates have different widths. A dielectric layer is formed to peripherally enclose each of the first dummy gates and each of the second dummy gates. The first dummy gates and the second dummy gates are replaced with first metal gates and second metal gates.

A semiconductor device may include a first active pattern, a second active pattern spaced apart at a first distance from the first active pattern, a third active pattern spaced apart at a second distance from the second active pattern, a first device isolation layer between the first and second active patterns, a second device isolation layer between the second and third active patterns, a first channel structure overlapping the first active pattern, a second channel structure overlapping the second active pattern, a third channel structure overlapping the third active pattern, and a separation dielectric layer between the first and second channel structures. The separation dielectric layer may overlap the first device isolation layer. A level of a top surface of the first device isolation layer may be higher than a level of a top surface of the second device isolation layer.

The present disclosure describes a structure including a fin field effect transistor (finFET) and a nano-sheet transistor on a substrate and a method of forming the structure. The method can include forming first and second vertical structures over a substrate, where each of the first and the second vertical structures can include a buffer region and a first channel layer formed over the buffer region. The method can further include disposing a masking layer over the first channel layer of the first and second vertical structures, removing a portion of the first vertical structure to form a first recess, forming a second channel layer in the first recess, forming a second recess in the second channel layer, and disposing an insulating layer in the second recess.

Devices and methods for layout-dependent voltage handling improvement in switch stacks. In some embodiments, a switching device can include a first terminal and a second terminal, a radio-frequency signal path implemented between the first terminal and the second terminal, and a plurality of switching elements connected in series to form a stack between the second terminal and ground. The stack can have an orientation relative to the radio-frequency signal path, and the switching elements can have a non-uniform distribution of a first parameter based in part on the orientation of the stack.

Gate-all-around integrated circuit structures having asymmetric source and drain contact structures, and methods of fabricating gate-all-around integrated circuit structures having asymmetric source and drain contact structures, are described. For example, an integrated circuit structure includes a vertical arrangement of nanowires above a fin. A gate stack is over the vertical arrangement of nanowires. A first epitaxial source or drain structure is at a first end of the vertical arrangement of nanowires. A second epitaxial source or drain structure is at a second end of the vertical arrangement of nanowires. A first conductive contact structure is coupled to the first epitaxial source or drain structure. A second conductive contact structure is coupled to the second epitaxial source or drain structure. The second conductive contact structure is deeper along the fin than the first conductive contact structure.

An integrated circuit (IC) structure includes a first transistor and a second transistor. The first transistor includes a first active region and a first gate disposed on the first active region, in which the first gate has a first effective gate length along a first direction parallel to a lengthwise direction of the first active region. The second transistor includes a second active region and a second gate disposed on the second active region, and includes a plurality of gate structures arranged along the first direction and separated from each other, in which the second gate has a second effective gate length along the first direction, the second effective gate length is n times the first effective gate length, and n is a positive integer greater than 1.

Methods related to radio-frequency (RF) switching devices having improved voltage handling capability. In some embodiments, a method for fabricating an RF switching device can include: providing a semiconductor substrate; forming a plurality of field-effect transistors (FETs) on the semiconductor substrate such that the FETs have a non-uniform distribution of a parameter; and connecting the FETs to form a stack, such that the non-uniform distribution results in the stack having a first voltage handling capacity that is greater than a second voltage handling capacity corresponding to a similar stack having a substantially uniform distribution of the parameter.

A semiconductor structure includes a substrate, an isolation structure disposed in the substrate, and a hybrid structure disposed over the isolation structure. The hybrid structure is substantially conformal with respect to a profile of the isolation structure. The hybrid structure includes an oxide component, a nitride component surrounding the oxide component, and a first polysilicon component alongside the nitride component. The nitride component includes a first upper surface closed to the first polysilicon component, and a second upper surface distal to the first polysilicon component. The second upper surface is lower than the first upper surface.

A wireless front-end can include a plurality of circuits, including a power amplifier (PA), a low noise amplifier (LNA), and an RF switch. In order to decrease the size and improve the performance of the front-end, the various circuits of the front end can include N-polar III-N transistors that are all formed from the same epitaxial material structure and monolithically integrated onto a single chip. Due to the different performance requirements of the various transistors in the different circuits, parameters such as gate length, gate-to-channel separation, and surface-to-channel separation in the access regions of the devices can be varied to meet the desired performance requirements.

A semiconductor device structure includes a substrate and a metal gate stack over the substrate. The metal gate stack has a gate dielectric layer and a work function layer over the gate dielectric layer, and the gate dielectric layer has a curved sidewall and a vertical sidewall. The semiconductor device structure also includes a protection element over the metal gate stack, and the protection element extends conformally along the curved sidewall and the vertical sidewall to reach a topmost surface of the work function layer. The semiconductor device structure further includes a spacer structure over a sidewall of the metal gate stack. A topmost surface of the gate dielectric layer is lower than a topmost surface of the spacer structure, and the topmost surface of the gate dielectric layer is closer to the topmost surface of the spacer structure than the topmost surface of the work function layer.