A method for forming a high electron mobility transistor is disclosed. A substrate is provided. A channel layer is formed on the substrate. An electron supply layer is formed on the channel layer. A dielectric passivation layer is formed on the electron supply layer. A gate recess is formed into the dielectric passivation layer and the electron supply layer. A surface modification layer is conformally deposited on an interior surface of the gate recess. The surface modification layer is first subjected to the nitride treatment and is then subjected to the oxidation treatment. A P-type GaN layer is formed in the gate recess and on the surface modification layer.

A gate electrode includes a main portion formed of a gate electrode material, and a gate electrode barrier layer disposed between the main portion and a barrier layer and formed of a conductive material that prevents the gate electrode material from diffusing into the barrier layer. A surface of the main portion in a region above a first insulating layer faces a periphery without a layer of the conductive material being formed.

Embodiments provide an integrated capacitor disposed directly over and aligned to a vertical gate all around memory cell transistor. In some embodiments, an air gap may be provided between adjacent word lines to provide a low k dielectric effect between word lines. In some embodiments, a bottom bitline structure may be split across multiple layers. In some embodiments, a second tier of vertical cells may be positioned over a first tier of vertical cells.

Embodiments of the present application disclose a semiconductor structure, a formation method thereof and a memory. The semiconductor structure includes: a substrate; a channel located in the substrate, the channel being configured to form a gate structure; and a convex portion arranged on an inner wall of the channel. The embodiments of the present application can increase a channel length and solve a short-channel effect.

A device and a method of making the device comprising, a semiconductor substrate layer and an epitaxial layer formed on the semiconductor substrate. One or more trenches are formed in the epitaxial layer, each trench having a pair of opposing sidewalls, wherein a distance between the opposing sidewalls is greater near a bottom of the trench than near a top of the trench, wherein the bottom of the trench is closer to the semiconductor substrate layer than the top.

A semiconductor device including a device isolation layer defining an active region; a first trench in the device isolation layer; a second trench in the active region; a main gate electrode structure filling a portion of the first trench and including a first barrier conductive layer and a main gate electrode; a pass gate electrode structure filling a portion of the second trench and including a second barrier conductive layer and a pass gate electrode; a support structure filling another portion of the second trench above the pass gate electrode; a first capping pattern filling another portion of the first trench above the main gate electrode; and a second gate insulating layer extending along a bottom and sidewall of the second trench, wherein the second barrier conductive layer is between the second gate insulating layer and the pass gate electrode and extends along a bottom and sidewall thereof.

A power semiconductor device includes a semiconductor layer, a ladder-shaped trench recessed a specific depth from a surface of the semiconductor layer into the semiconductor layer and including a pair of lines having a first depth and a plurality of connectors connected between the pair of lines and having a second depth shallower than the first depth, a well region defined in the semiconductor layer between the pair of lines and between the plurality of connectors of the trench, a floating region defined in the semiconductor layer outside the pair of lines of the trench, a gate insulating layer disposed on an inner wall of the trench, and a gate electrode layer disposed on the gate insulating layer to fill the trench and including a first portion in which the pair of lines is filled and a second portion in which the plurality of connectors is filled. A depth of the second portion of the gate electrode layer is shallower than a depth of the first portion of the gate electrode layer.

A transistor, integrated semiconductor device and methods of making are provided. The transistor includes a dielectric layer having a plurality of dielectric protrusions, a channel layer conformally covering the protrusions of the dielectric layer to form a plurality of trenches between two adjacent dielectric protrusion, a gate layer disposed on the channel layer. The gate layer 106 has a plurality of gate protrusions fitted into the trenches. The transistor also includes active regions aside the gate layer. The active regions are electrically connected to the channel layer.

A main semiconductor device element has first and second p.sup.+-type high-concentration regions that mitigate electric field applied to bottoms of trenches. The first p.sup.+-type high-concentration regions are provided separate from p-type base regions, face the bottoms of the trenches in a depth direction, and extend in a linear shape in a first direction that is a same direction in which the trenches extend. Between adjacent trenches of the trenches, the second p.sup.+-type high-concentration regions are provided scattered in the first direction, separate from the first p.sup.+-type high-concentration regions and the trenches and in contact with the p-type base regions. Between the second p.sup.+-type high-concentration regions adjacent to one another in the first direction, n-type current spreading regions or n.sup.+-type high-concentration regions having an impurity concentration higher than that of the n-type current spreading regions are provided in contact with the second p.sup.+-type high-concentration regions.

An example includes a semiconductor structure including a semiconductor layer, front-side logic devices arranged in a front-side of the semiconductor layer, four epitaxial layers on a back-side of the semiconductor layer, where the four epitaxial layers include a first epitaxial layer of a first conductivity type, a second epitaxial layer of a second conductivity type, a third epitaxial layer of the second conductivity type, and a fourth epitaxial layer of the first conductivity type, a plurality of back-side contacts exposed at a back-side surface of the fourth epitaxial layer, where the plurality of back-side contacts include a set of first terminal contacts extending into and contacting the fourth epitaxial layer, a set of second terminal contacts extending into and contacting the second epitaxial layer, a set of first gate contacts extending into the third epitaxial layer, and a set of second gate contacts extending into the first epitaxial layer.