A nitride semiconductor device includes an electron transit layer (103) that is formed of a nitride semiconductor, an electron supply layer (104) that is formed on the electron transit layer (103), that is formed of a nitride semiconductor whose composition is different from the electron transit layer (103) and that has a recess (109) which reaches the electron transit layer (103) from a surface, a thermal oxide film (111) that is formed on the surface of the electron transit layer (103) exposed within the recess (109), a gate insulating film (110) that is embedded within the recess (109) so as to be in contact with the thermal oxide film (111), a gate electrode (108) that is formed on the gate insulating film (110) and that is opposite to the electron transit layer (103) across the thermal oxide film (111) and the gate insulating film (110), and a source electrode (106) and a drain electrode (107) that are provided on the electron supply layer (104) at an interval such that the gate electrode (108) intervenes therebetween.

A substrate in which a high-dielectric-constant gate insulator is formed on a silicon substrate with an interface layer film sandwiched in between is housed in a chamber. The method of the invention including: (a) housing the substrate in a chamber; (b) supplying ammonia to the chamber to foam an ammonia atmosphere; and (c) applying flash light to a surface of the substrate housed in the chamber to heat the high dielectric constant film, wherein the flash light applied in said step (c) has a spectral distribution that has a peak in a wavelength range of 200 to 300 nm.

A method of fabricating the gate structure in a semiconductor device includes forming a gate dielectric layer over a semiconductor substrate. A capping layer is formed over the gate dielectric layer. The capping layer is treated with a first hydrogen plasma to form a first-treated capping layer. A gate electrode is formed over the first-treated capping layer. The method may further includes treating the first-treated capping layer with a nitrogen plasma.

A memory device includes: a semiconductor column extending vertically on a substrate and including a source region of a first conductivity type, an intrinsic region, and a drain region of a second conductivity type; a first gate electrode disposed adjacent to the drain region to cover the intrinsic region; a second gate electrode spaced apart from the first gate electrode and disposed adjacent to the source region to cover the intrinsic region; a first gate insulating layer disposed between the first gate electrode and the intrinsic region; and a second gate insulating layer disposed between the second gate electrode and the intrinsic region.

Semiconductor devices may include a substrate, gate electrodes on the substrate, and source/drain regions at both sides of each of the gate electrodes. Each of the gate electrodes may include a gate insulating pattern on the substrate, a lower work-function electrode pattern that is on the gate insulating pattern and has a recessed upper surface, and an upper work-function electrode pattern that conformally extends on the recessed upper surface of the lower work function electrode pattern. Topmost surfaces of the lower work-function electrode patterns may be disposed at an equal level, and the upper work-function electrode patterns may have different thicknesses from each other.

The present invention provides a thin-film transistor in which transistor characteristics such as drain current and threshold voltage are improved, and a method of manufacturing the same. The present invention provides a thin-film transistor provided with a source electrode (108), a drain electrode (109), a semiconductor layer (105), a gate electrode (103), and an insulating layer (104); wherein the semiconductor layer (105) contains a composite metal oxide obtained by adding to a first metal oxide an oxide having an oxygen dissociation energy that is at least 200 kJ/mol greater than the oxygen dissociation energy of the first metal oxide, whereby the amount of oxygen vacancy is controlled; and the insulating layer (104) is provided with an SiO.sub.2 layer, a high-permittivity first layer, and a high-permittivity second layer, whereby the dipoles generated at the boundary between the SiO.sub.2 layer and the high-permittivity layers are used to control the threshold voltage.

A method of fabricating advanced node field effect transistors using a replacement metal gate process. The method includes dopant a high-k dielectric directly or indirectly by using layers composed of multi-layer thin film stacks, or in other embodiments, by a single blocking layer. By taking advantage of unexpected etch selectivity of the multi-layer stack or the controlled etch process of a single layer stack, etch damage to the high-k may be avoided and work function metal thicknesses can be tightly controlled which in turn allows field effect transistors with low Tinv (inverse of gate capacitance) mismatch.

According to one embodiment, an inter-electrode insulating film interposed between a floating gate electrode and a control gate electrode includes a lower layer insulating film disposed on a side closer to the floating gate electrode, an upper layer insulating film disposed on a side closer to the control gate electrode, and an intermediate insulating film interposed between the lower layer insulating film and the upper layer insulating film, wherein the intermediate insulating film contains a first element, and the lower layer insulating film contains the first element and a second element, such that a ratio of the first element relative to the second element is larger on a side closer to the intermediate insulating film than on a side closer to the floating gate electrode.

A non-volatile semiconductor storage device has a plurality of memory strings to each of which a plurality of electrically rewritable memory cells are connected in series. Each of the memory strings includes first semiconductor layers each having a pair of columnar portions extending in a vertical direction with respect to a substrate and a coupling portion formed to couple the lower ends of the pair of columnar portions; a charge storage layer formed to surround the side surfaces of the columnar portions; and first conductive layers formed to surround the side surfaces of the columnar portions and the charge storage layer. The first conductive layers function as gate electrodes of the memory cells.

A semiconductor device includes an interfacial layer on a substrate and agate structure on the interfacial layer. Preferably, the gate structure includes a patterned high-k dielectric layer, the patterned high-k dielectric layer comprises a metal oxide layer, and a horizontal direction width of the patterned high-k dielectric layer and a horizontal direction width of the interfacial layer are different. The semiconductor device also includes a first spacer adjacent to the gate structure and on part of the interfacial layer and contacting a top surface of the interfacial layer and a second spacer on the sidewalls of the first spacer and the interfacial layer. Preferably, a planar bottom surface of the second spacer is lower than a planar bottom surface of the first spacer and extending along a same direction as the planar bottom surface of the first spacer.