A method for fabricating a semiconductor device may include receiving a gated substrate comprising a substrate with a channel layer and a gate structure formed thereon, over-etching the channel layer to expose an extension region below the gate structure, epitaxially growing a halo layer on the exposed extension region using a first in-situ dopant and epitaxially growing a source or drain on the halo layer using a second in-situ dopant, wherein the first in-situ dopant and the second in-situ dopant are of opposite doping polarity. Using an opposite doping polarity may provide an energy band barrier for the semiconductor device and reduce leakage current. A corresponding apparatus is also disclosed herein.

A structure includes a substrate and a tunnel field effect transistor (TFET). The TFET includes a source region disposed in the substrate having an overlying source contact, the source region containing first semiconductor material having a first doping type; a drain region disposed in the substrate having an overlying drain contact, the drain region containing second semiconductor material having a second, opposite doping type; and a gate structure that overlies a channel region between the source and the drain. The source region and the drain region are asymmetric with respect to one another such that one contains a larger volume of semiconductor material than the other one. A method is disclosed to fabricate a plurality of the TFETs using a plurality of spaced apart mandrels having spacers. A pair of the mandrels and the associated spacers is processed to form four adjacent TFETs without requiring intervening lithographic processes.

A structure includes a substrate and a tunnel field effect transistor (TFET). The TFET includes a source region disposed in the substrate having an overlying source contact, the source region containing first semiconductor material having a first doping type; a drain region disposed in the substrate having an overlying drain contact, the drain region containing second semiconductor material having a second, opposite doping type; and a gate structure that overlies a channel region between the source and the drain. The source region and the drain region are asymmetric with respect to one another such that one contains a larger volume of semiconductor material than the other one. A method is disclosed to fabricate a plurality of the TFETs using a plurality of spaced apart mandrels having spacers. A pair of the mandrels and the associated spacers is processed to form four adjacent TFETs without requiring intervening lithographic processes.

Integrated circuits including tunnel transistors and methods for fabricating such integrated circuits are provided. An exemplary method for fabricating an integrated device includes forming a lower source/drain region in and/or over a semiconductor substrate. The method forms a channel region overlying the lower source/drain region. The method also forms an upper source/drain region overlying the channel region. The method includes forming a gate structure beside the channel region.

Various embodiments of the present disclosure are directed towards an integrated chip including a first semiconductor layer overlying a substrate. A first barrier layer is disposed on the first semiconductor layer. A second semiconductor layer overlies and directly contacts the first barrier layer. A second barrier layer directly contacts the first barrier layer. A third semiconductor layer overlies the second barrier layer. A fourth semiconductor layer overlies the third semiconductor layer. Outer sidewalls of the third semiconductor layer, outer sidewalls of the fourth semiconductor layer, and outer sidewalls of the second barrier layer are respectively aligned.

A fin field effect transistor device structure includes a fin structure formed over a substrate. The structure also includes a liner layer and an isolation structure surrounding the fin structure. The structure also includes a gate dielectric layer formed over the fin structure and the isolation structure. The structure also includes a gate structure formed over the gate dielectric layer. The structure also includes source/drain epitaxial structures formed on opposite sides of the gate structure. The fin structure includes a protruding portion laterally extending over the liner layer.

An integrated circuit can include a plurality of first transistors formed in a substrate and having gate lengths of less than one micron and at least one tipless transistor formed in the substrate and having a source-drain path coupled between a circuit node and a first power supply voltage. In addition or alternatively, an integrated circuit can include minimum feature size transistors; a signal driving circuit comprising a first transistor of a first conductivity type having a source-drain path coupled between a first power supply node and an output node, and a second transistor of a second conductivity type having a source-drain path coupled between a second power supply node and the output node, and a gate coupled to a gate of the first transistor, wherein the first or second transistor is a tipless transistor.

Some embodiments relate to an integrated circuit (IC) including one or more finFET devices. A finFET includes a fin of semiconductor material extending upwards from a semiconductor substrate. First and second source/drain regions, which have a first doping type, are spaced apart laterally from one another in the fin. A channel region is disposed in the fin and physically separates the first and second source/drain regions from one another. The channel region has a second doping type opposite the first doping type. A conductive gate electrode straddles the fin about the channel region and is separated from the channel region by a gate dielectric. A shallow doped region, which has the first doping type, is disposed near a surface of the fin around upper and sidewall fin regions. The shallow doped region extends continuously under the gate electrode between outer edges of the gate electrode.

In one example implementation, the present disclosure provides a modular approach to reducing flicker noise in metal-oxide semiconductor field-effect transistors (MOSFETs) in a device. First, a circuit designer may select one or more surface channel MOSFETs in a device. Then, the one or more surface channel MOSFETs are converted to one or more buried channel MOSFETs to reduce flicker noise. One or more masks may be applied to the channel(s) of the one or more surface channel MOSFETs. The technique maybe used at the input(s) of operational amplifiers, and more particularly, rail-to-rail operational amplifiers, as well as other analog and digital circuits such a mixers, ring oscillators, current mirrors, etc.

Semiconductor memory devices and methods of forming the semiconductor devices may be provided. The semiconductor memory devices may include a channel portion of an active pillar that may be formed of a semiconductor material having a charge mobility greater than a charge mobility of silicon. The semiconductor devices may also include a non-channel portion of the active pillar including a semiconductor material having a high silicon content.