Methods for manufacturing a semiconductor structure are provided. The semiconductor structure includes a substrate a substrate and channel layers vertically stacked over the substrate. The semiconductor structure also includes a dielectric fin structure formed adjacent to the channel layers and a gate structure abutting the channel layers and the dielectric fin structure. The semiconductor structure also includes a source/drain structure attached to the channel layers and a contact formed over the source/drain structure. The semiconductor structure also includes a Si layer covering a portion of a top surface of the source/drain structure. In addition, the Si layer is sandwiched between the dielectric fin structure and the contact.

To provide a novel method for manufacturing a semiconductor device. To provide a method for manufacturing a highly reliable semiconductor device at relatively low temperature. The method includes a first step of forming a first oxide semiconductor film in a deposition chamber and a second step of forming a second oxide semiconductor film over the first oxide semiconductor film in the deposition chamber. Water vapor partial pressure in an atmosphere in the deposition chamber is lower than water vapor partial pressure in atmospheric air. The first oxide semiconductor film and the second oxide semiconductor film are formed such that the first oxide semiconductor film and the second oxide semiconductor film each have crystallinity. The second oxide semiconductor film is formed such that the crystallinity of the second oxide semiconductor film is higher than the crystallinity of the first oxide semiconductor film.

An object is to provide a display device which operates stably with use of a transistor having stable electric characteristics. In manufacture of a display device using transistors in which an oxide semiconductor layer is used for a channel formation region, a gate electrode is further provided over at least a transistor which is applied to a driver circuit. In manufacture of a transistor in which an oxide semiconductor layer is used for a channel formation region, the oxide semiconductor layer is subjected to heat treatment so as to be dehydrated or dehydrogenated; thus, impurities such as moisture existing in an interface between the oxide semiconductor layer and the gate insulating layer provided below and in contact with the oxide semiconductor layer and an interface between the oxide semiconductor layer and a protective insulating layer provided on and in contact with the oxide semiconductor layer can be reduced.

A method for manufacturing a novel semiconductor device is provided. The method includes a first step of forming a first oxide semiconductor film over a substrate, a second step of heating the first oxide semiconductor film, and a third step of forming a second oxide semiconductor film over the first oxide semiconductor film. The first to third steps are performed in an atmosphere in which water vapor partial pressure is lower than water vapor partial pressure in atmospheric air, and the first step, the second step, and the third step are successively performed in this order.

To provide a crystalline oxide semiconductor film, an ion is made to collide with a target including a crystalline In—Ga—Zn oxide, thereby separating a flat-plate-like In—Ga—Zn oxide in which a first layer including a gallium atom, a zinc atom, and an oxygen atom, a second layer including an indium atom and an oxygen atom, and a third layer including a gallium atom, a zinc atom, and an oxygen atom are stacked in this order; and the flat-plate-like In—Ga—Zn oxide is irregularly deposited over a substrate while the crystallinity is maintained.

Systems and methods for forming semiconductor layers, including oxide-based layers, are disclosed in which a material deposition system has a rotation mechanism that rotates a substrate around a center axis of the substrate. The system includes a heater configured to heat the substrate and a positioning mechanism that allows dynamic adjusting of an orthogonal distance, a lateral distance, and a tilt angle of an exit aperture of a material source relative to the substrate. In some embodiments, the dynamic adjusting is based on a desired layer uniformity for a desired layer growth rate. In some embodiments, the orthogonal distance, the lateral distance, or the tilt angle depends on a predetermined material ejection spatial distribution of the material source.

To provide a crystalline oxide semiconductor film. By collision of ions with a target including a crystalline In—Ga—Zn oxide, a flat-plate-like In—Ga—Zn oxide is separated. In the flat-plate-like In—Ga—Zn oxide, a first layer including a gallium atom, a zinc atom, and an oxygen atom, a second layer including a zinc atom and an oxygen atom, a third layer including an indium atom and an oxygen atom, and a fourth layer including a gallium atom, a zinc atom, and an oxygen atom are stacked in this order. After the flat-plate-like In—Ga—Zn oxide is deposited over a substrate while maintaining the crystallinity, the second layer is gasified and exhausted.

The present invention provides an etching liquid which has a suitable etching rate for etching of an oxide containing zinc and tin and is suppressed in change of the etching rate due to dissolution of the oxide, while being free from the generation of a precipitate. The corrosiveness of this etching liquid to wiring materials is low enough to be ignored, and this etching liquid has excellent linearity of a pattern shape. The present invention uses an etching liquid which contains (A) one or more substances selected from the group consisting of sulfuric acid, nitric acid, hydrochloric acid, methanesulfonic acid, perchloric acid and salts of these acids, and (B) oxalic acid or a salt thereof and water, and which has a pH of from −1 to 1.

A method for evaluating a semiconductor film of a semiconductor device which is configured to include an insulating film, the semiconductor film, and a conductive film and to have a region where the semiconductor film and the conductive film overlap with each other with the insulating film provided therebetween, includes a step of performing plasma treatment after formation of the insulating film, and a step of calculating a peak value of resistivity of a microwave in the semiconductor film by a microwave photoconductive decay method after the plasma treatment, so that the hydrogen concentration in the semiconductor film is estimated.

Semiconductor structures and methods for forming those semiconductor structures are disclosed. For example, a semiconductor structure with a p-type superlattice region, an i-type superlattice region, and an n-type superlattice region is disclosed. The semiconductor structure can have a polar crystal structure with a growth axis that is substantially parallel to a spontaneous polarization axis of the polar crystal structure. In some cases, there are no abrupt changes in polarisation at interfaces between each region. At least one of the p-type superlattice region, the i-type superlattice region and the n-type superlattice region can comprise a plurality of unit cells exhibiting a monotonic change in composition from a wider band gap (WBG) material to a narrower band gap (NBG) material or from a NBG material to a WBG material along the growth axis to induce p-type or n-type conductivity.