Stacked FET devices having wrap-around contacts to optimize contact resistance and techniques for formation thereof are provided. In one aspect, a stacked FET device includes: a bottom-level FET(s) on a substrate; lower contact vias present in an ILD disposed over the bottom-level FET(s); a top-level FET(s) present over the lower contact vias; and top-level FET source/drain contacts that wrap-around source/drain regions of the top-level FET(s), wherein the lower contact vias connect the top-level FET source/drain contacts to source/drain regions of the bottom-level FET(s). When not vertically aligned, a local interconnect can be used to connect a given one of the lower contact vias to a given one of the top-level FET source/drain contacts. A method of forming a stacked FET device is also provided.

A crystalline channel layer of a semiconductor material is formed in a backend process over a crystalline dielectric seed layer. A crystalline magnesium oxide MgO is formed over an amorphous inter-layer dielectric layer. The crystalline MgO provides physical link to the formation of a crystalline semiconductor layer thereover.

A semiconductor device includes first to tenth transistors and first to fourth capacitors. Gates of the first and the fourth transistors are electrically connected to each other. First terminals of the first, second, fifth, and eighth transistors are electrically connected to a first terminal of the fourth capacitor. A second terminal of the fifth transistor is electrically connected to a gate of the sixth transistor and a first terminal of the second capacitor. A second terminal of the eighth transistor is electrically connected to a gate of the ninth transistor and a first terminal of the third capacitor. Gates of the second, seventh, and tenth transistors are electrically connected to first terminals of the third and fourth transistors and a first terminal of the first capacitor. First terminals of the sixth and seventh transistors are electrically connected to a second terminal of the second capacitor.

A method for forming a memory device includes: forming a first layer stack and a second layer stack successively over a substrate, wherein each of the first and the second layer stacks comprises a dielectric layer, a channel layer, and a source/drain layer formed successively over the substrate; forming openings that extends through the first layer stack and the second layer stack, where the openings includes first openings within boundaries of the first and the second layer stacks, and a second opening extending from a sidewall of the second layer stack toward the first openings; forming inner spacers by replacing portions of the source/drain layer exposed by the openings with a dielectric material; lining sidewalls of the openings with a ferroelectric material; and forming first gate electrodes in the first openings and a dummy gate electrode in the second opening by filling the openings with an electrically conductive material.

Transistors with metal oxide channel material that is in-situ doped for desired charge carrier concentrations. The metal oxide channel material may be deposited by atomic layering of multiple constituent metals with an oxidation of each layer. Such an ALD process may be performed by cyclically depositing a precursor of one of the metals upon a substrate during a deposition phase, and oxidizing the absorbed precursor during an oxidation phase. For a quinary metal oxide, each of three metal precursors may be introduced and oxidized during the ALD process, and charge carrier concentrations may be modulated by further introducing a fourth metal precursor during the ALD process in a manner that disperses this dopant metal within the film at a significantly lower chemical concentration than the other metals.

Provided is a semiconductor device. The semiconductor device includes a semiconductor substrate including monocrystalline silicon or polycrystalline silicon, a first insulating layer on the semiconductor substrate, the first insulating layer including a local region in which a portion of an upper surface of the first insulating layer is recessed, a channel layer provided in the local region of the first insulating layer, a silicide provided on one side surface of the channel layer, a control gate provided on the channel layer, a gate insulating film provided between the channel layer and the control gate, and a polarity control gate arranged so as to overlap an interface between the channel layer and the silicide, wherein the polarity control gate is spaced apart from the control gate, and the channel layer includes monocrystalline silicon.

A semiconductor device with low parasitic capacitance is provided. The semiconductor device includes a first oxide insulator, an oxide semiconductor, a second oxide insulator, a gate insulating layer, a gate electrode layer, source and drain electrode layers and an insulating layer. The oxide semiconductor includes first to fifth regions. The first region overlaps with the source electrode layer. The second region overlaps with the drain electrode layer. The third region overlaps with the gate electrode layer. The fourth region is between the first region and the third region. The fifth region is between the second region and the third region. The fourth region and the fifth region each contain an element N (N is hydrogen, nitrogen, helium, neon, argon, krypton, or xenon). A top surface of the insulating layer is positioned at a lower level than top surfaces of the source and drain electrode layers.

A method includes etching a hybrid substrate to form a recess extending into the hybrid substrate. The hybrid substrate includes a first semiconductor layer having a first surface orientation, a dielectric layer over the first semiconductor layer, and a second semiconductor layer having a second surface orientation different from the first surface orientation. After the etching, a top surface of the first semiconductor layer is exposed to the recess. A spacer is formed on a sidewall of the recess. The spacer contacts a sidewall of the dielectric layer and a sidewall of the second semiconductor layer. An epitaxy is performed to grow an epitaxy semiconductor region from the first semiconductor layer. The spacer is removed.

A minute transistor is provided. A transistor with low parasitic capacitance is provided. A transistor having high frequency characteristics is provided. A semiconductor device including the transistor is provided. A semiconductor device includes a first opening, a second opening, and a third opening which are formed by performing first etching and second etching. By the first etching, the first insulator is etched for forming the first opening, the second opening, and the third opening. By the second etching, the first metal oxide, the second insulator, the third insulator, the fourth insulator, the second metal oxide, and the fifth insulator are etched for forming the first opening; the first metal oxide, the second insulator, and the third insulator are etched for forming the second opening; and the first metal oxide is etched for forming the third opening.

An imaging device which has a stacked-layer structure and can be manufactured easily is provided. The imaging device includes a signal processing circuit, a memory device, and an image sensor. The imaging device has a stacked-layer structure in which the memory device is provided above the signal processing circuit, and the image sensor is provided above the memory device. The signal processing circuit includes a transistor formed on a first semiconductor substrate, the memory device includes a transistor including a metal oxide in a channel formation region, and the image sensor includes a transistor formed on a second semiconductor substrate.