Abstract:
Device structures for a field-effect transistor and methods of forming a device structure for a field-effect transistor. A trench isolation region is formed in a substrate, and surrounds a semiconductor body. An undercut cavity region is also formed in the substrate. The undercut cavity region extends laterally beneath the semiconductor body and defines a body pedestal as a section of the substrate that is arranged in vertical alignment with the semiconductor body.
Abstract:
Structures that include contact trenches and isolation trenches, as well as methods for forming structures including contact trenches and isolation trenches. A contact trench is formed that extends through a device layer of a silicon-on-insulator (SOI) substrate to a buried oxide layer of the SOI substrate. An isolation trench is formed that extends through the device layer to the buried oxide layer. An electrical insulator is deposited that fills the contact trench and the first isolation trench. The electrical insulator is removed from the contact trench. After the electrical insulator is removed from the contact trench, an electrical conductor is formed in the contact trench. The electrical contact may be coupled with a doped region in a handle wafer of the SOI substrate.
Abstract:
Various embodiments include structures for field effect transistors (FETs). In various embodiments, a structure for a FET includes: a deep n-type well; a shallow n-type well within the deep n-type well; and a shallow trench isolation (STI) region within the shallow n-type well, the STI region including: a first section having a first depth within the shallow n-type well as measured from an upper surface of the shallow n-type well, and a second section contacting and overlying the first section, the second section having a second depth within the shallow n-type well as measured from the upper surface of the shallow n-type well.
Abstract:
Disclosed are methods that employ a mask with openings arranged in a pattern of elongated trenches and holes of varying widths to achieve a linearly graded conductivity level. These methods can be used to form a lateral double-diffused metal oxide semiconductor field effect transistor (LDMOSFET) with a drain drift region having an appropriate type conductivity at a level that increases essentially linearly from the body region to the drain region. Furthermore, these methods also provide for improve manufacturability in that multiple instances of this same pattern can be used during a single dopant implant process to implant a first dopant with a first type (e.g., N-type) conductivity into the drain drift regions of both first and second type LDMOSFETs (e.g., N and P-type LDMOSFETs, respectively). In this case, the drain drift region of a second type LDMOSFET can subsequently be uniformly counter-doped. Also disclosed are the resulting semiconductor structures.
Abstract:
Disclosed are methods that employ a mask with openings arranged in a pattern of elongated trenches and holes of varying widths to achieve a linearly graded conductivity level. These methods can be used to form a lateral double-diffused metal oxide semiconductor field effect transistor (LDMOSFET) with a drain drift region having an appropriate type conductivity at a level that increases essentially linearly from the body region to the drain region. Furthermore, these methods also provide for improve manufacturability in that multiple instances of this same pattern can be used during a single dopant implant process to implant a first dopant with a first type (e.g., N-type) conductivity into the drain drift regions of both first and second type LDMOSFETs (e.g., N and P-type LDMOSFETs, respectively). In this case, the drain drift region of a second type LDMOSFET can subsequently be uniformly counter-doped. Also disclosed are the resulting semiconductor structures.