A semiconductor device according to the present invention includes a semiconductor layer, a gate trench defined in the semiconductor layer, a first insulating film arranged on the inner surface of the gate trench, a gate electrode arranged in the gate trench via the first insulating film, and a source layer, a body layer, and a drain layer arranged laterally to the gate trench, in which the first insulating film includes, at least at the bottom of the gate trench, a first portion and a second portion with a film elaborateness lower than that of the first portion from the inner surface of the gate trench in the film thickness direction.

The present disclosure provides semiconductor devices and fabrication methods thereof. A work function layer is formed on the semiconductor substrate. A buffer layer is formed on the work function layer. The work function layer is doped through the buffer layer with impurity ions. The buffer layer obstructs a flow of the impurity ions to control a concentration of the impurity ions in different regions of the work function layer to regulate a work function of the work function layer in the different regions.

An integrated circuit includes a semiconductor substrate, a gate dielectric over the substrate, a metal gate structure over the semiconductor substrate and the gate dielectric, a dielectric film on the metal gate structure, the dielectric film comprising oxynitride combined with metal from the metal gate, and an interlayer dielectric (ILD) on either side of the metal gate structure.

A method for removing a native oxide film from a semiconductor substrate includes repetitively depositing layers of germanium on the native oxide and heating the substrate causing the layer of germanium to form germanium oxide, desorbing a portion of the native oxide film. The process is repeated until the oxide film is removed. A subsequent layer of strontium titanate can be deposited on the semiconductor substrate, over either residual germanium or a deposited germanium layer. The germanium can be converted to silicon germanium oxide by exposing the strontium titanate to oxygen.

A method for fabricating a semiconductor device includes forming a deposition-type interface layer over a substrate, converting the deposition-type interface layer into an oxidation-type interface layer, forming a high-k layer over the oxidation-type interface layer, forming a dipole interface on an interface between the high-k layer and the oxidation-type interface layer, forming a conductive layer over the high-k layer, and patterning the conductive layer, the high-k layer, the dipole interface, and the oxidation-type interface layer to form a gate stack over the substrate.

The present invention provides a TFT substrate manufacturing method and a TFT substrate manufactured with the method. The TFT substrate manufacturing method of the present invention uses a photoresist pattern to serve as a shielding mask to allow a metal layer to be directly oxidized, through the anodic oxidation technology, into a gate insulation layer or a passivation layer, and at the same time, forming electrode patterns of gate or source/drain. The entire operation can be conducted in room temperature and is applicable to a flexible substrate that is not resistant to high temperatures without the involvement of expensive high temperature facility, such as chemical vapor deposition, so as to greatly reduce the operation cost of manufacturing a flexible display device. The TFT substrate manufactured with the present invention shows excellent electrical characteristics and is suitable for a flexible display device.

A semiconductor device includes first and second semiconductor fins, a first gate structure, and a second gate structure. The first and second semiconductor fins respectively includes a first channel region and a second channel region, which the first and second gate structures are respectively on. The first gate structure includes a first silicon oxide layer on the first channel region, a first high-k dielectric layer on the first silicon oxide layer, and a first metal gate on the first high-k dielectric layer. The second gate structure includes a second silicon oxide layer on the second channel region, a second high-k dielectric layer on the second silicon oxide layer, and a second metal gate on the second high-k dielectric layer. The first silicon oxide layer has a Si.sup.4+ ion concentration greater than a Si.sup.4+ ion concentration of a bottom portion of the second silicon oxide layer.

A method for forming an oxide layer includes forming an interfacial layer on a substrate, forming an amorphous silicon layer on the interfacial layer, performing a direct oxidation process to selectively oxidize the formed amorphous silicon layer, and performing a thermal oxidation process to oxidize the formed amorphous silicon layer.

A transistor comprises a substrate, a pair of spacers on the substrate, a gate dielectric layer on the substrate and between the pair of spacers, a gate electrode layer on the gate dielectric layer and between the pair of spacers, an insulating cap layer on the gate electrode layer and between the pair of spacers, and a pair of diffusion regions adjacent to the pair of spacers. The insulating cap layer forms an etch stop structure that is self aligned to the gate and prevents the contact etch from exposing the gate electrode, thereby preventing a short between the gate and contact. The insulator-cap layer enables self-aligned contacts, allowing initial patterning of wider contacts that are more robust to patterning limitations.

A semiconductor device includes first and second semiconductor fins, a first gate structure, and a second gate structure. The first and second semiconductor fins respectively includes a first channel region and a second channel region, which the first and second gate structures are respectively on. The first gate structure includes a first silicon oxide layer on the first channel region, a first high-k dielectric layer on the first silicon oxide layer, and a first metal gate on the first high-k dielectric layer. The second gate structure includes a second silicon oxide layer on the second channel region, a second high-k dielectric layer on the second silicon oxide layer, and a second metal gate on the second high-k dielectric layer. The first silicon oxide layer has a Si.sup.4+ ion concentration greater than a Si.sup.4+ ion concentration of a bottom portion of the second silicon oxide layer.