Provided is a thin film transistor (TFT) that includes a first electrode on a substrate separated from a second electrode, an oxide semiconductor pattern on the second electrode including a channel region, a third electrode on the oxide semiconductor pattern, a first insulating layer on the substrate including the third electrode including first contact holes exposing a part of the first electrode, a part of the second electrode, and a part of the third electrode, a gate electrode on the first insulating layer and corresponding to a part of the oxide semiconductor pattern, a second insulating layer on the substrate including the gate electrode including a second contact hole corresponding to the first contact hole that exposes a part of the second electrode, and a pixel electrode on the second insulating layer electrically connected to the second electrode through the first contact hole and the second contact hole.

A semiconductor substrate includes a base portion, an auxiliary layer and a surface layer. The auxiliary layer is formed on the base portion. The surface layer is formed on the auxiliary layer. The surface layer is in contact with a first main surface of the semiconductor substrate. The auxiliary layer has a different electrochemical dissolution efficiency than the base portion and the surface layer. At least a portion of the auxiliary layer and at least a portion of the surface layer are converted into a porous structure. Subsequently, an epitaxial layer is formed on the first main surface.

A semiconductor substrate includes a base portion, an auxiliary layer and a surface layer. The auxiliary layer is formed on the base portion. The surface layer is formed on the auxiliary layer. The surface layer is in contact with a first main surface of the semiconductor substrate. The auxiliary layer has a different electrochemical dissolution efficiency than the base portion and the surface layer. At least a portion of the auxiliary layer and at least a portion of the surface layer are converted into a porous structure. Subsequently, an epitaxial layer is formed on the first main surface.

A method for fabricating a metal oxide thin film transistor comprises selecting a substrate and fabricating a gate electrode thereon; growing a layer of dielectric or high permittivity dielectric on the substrate to serve as a gate dielectric layer; growing a first metal layer on the gate dielectric layer and a second metal layer on the first metal layer; fabricating a channel region at a middle position of the first metal layer and a passivation region at a middle position of the second metal layer; anodizing the metals of the passivation region and the channel region at atmospheric pressure and room temperature; fabricating a source and a drain; forming an active region comprising the source, the drain, and the channel region; depositing a silicon nitride layer on the active region; fabricating two electrode contact holes; depositing a metal aluminum film; and fabricating two metal contact electrodes by photolithography and etching.

A method for fabricating a metal oxide thin film transistor comprises selecting a substrate and fabricating a gate electrode thereon; growing a layer of dielectric or high permittivity dielectric on the substrate to serve as a gate dielectric layer; growing a first metal layer on the gate dielectric layer and a second metal layer on the first metal layer; fabricating a channel region at a middle position of the first metal layer and a passivation region at a middle position of the second metal layer; anodizing the metals of the passivation region and the channel region at atmospheric pressure and room temperature; fabricating a source and a drain; forming an active region comprising the source, the drain, and the channel region; depositing a silicon nitride layer on the active region; fabricating two electrode contact holes; depositing a metal aluminum film; and fabricating two metal contact electrodes by photolithography and etching.

A method includes, for example, providing an intermediate semiconductor structure comprising a metallic layer, a patternable layer disposed over the metallic layer, and a hard mask disposed over the patternable layer, the intermediate semiconductor structure comprising a plurality of vias extending through the hard mask onto the metallic layer, depositing a sacrificial barrier layer over the intermediate semiconductor structure and in the plurality of vias, removing a portion of the sacrificial barrier layer between the plurality of vias while maintaining a portion of the sacrificial barrier layer in the plurality of vias, forming a trench in the patternable layer between the removed portion of the sacrificial barrier layer and the plurality of vias, and removing the remaining portions of the sacrificial barrier layer from the plurality of vias.

The present disclosure provides manufacturing techniques in which the layout pattern of a RAM cell may be obtained on the basis of a single lithography step, followed by a sequence of two deposition processes, thereby resulting in a self-aligned mechanism for providing the most critical lateral dimensions for active regions. In this manner, the smallest pitch of approximately 80 nm and even less may be accomplished with superior device uniformity, while at the same time reducing overall manufacturing complexity.

The present disclosure provides manufacturing techniques in which the layout pattern of a RAM cell may be obtained on the basis of a single lithography step, followed by a sequence of two deposition processes, thereby resulting in a self-aligned mechanism for providing the most critical lateral dimensions for active regions. In this manner, the smallest pitch of approximately 80 nm and even less may be accomplished with superior device uniformity, while at the same time reducing overall manufacturing complexity.

A semiconductor device includes a first oxide insulating layer over a first insulating layer, an oxide semiconductor layer over the first oxide insulating layer, a source electrode layer and a drain electrode layer over the oxide semiconductor layer, a second insulating layer over the source electrode layer and the drain electrode layer, a second oxide insulating layer over the oxide semiconductor layer, a gate insulating layer over the second oxide insulating layer, a gate electrode layer over the gate insulating layer, and a third insulating layer over the second insulating layer, the second oxide insulating layer, the gate insulating layer, and the gate electrode layer. A side surface portion of the second insulating layer is in contact with the second oxide insulating layer. The gate electrode layer includes a first region and a second region. The first region has a width larger than that of the second region.

A semiconductor device includes a first oxide insulating layer over a first insulating layer, an oxide semiconductor layer over the first oxide insulating layer, a source electrode layer and a drain electrode layer over the oxide semiconductor layer, a second insulating layer over the source electrode layer and the drain electrode layer, a second oxide insulating layer over the oxide semiconductor layer, a gate insulating layer over the second oxide insulating layer, a gate electrode layer over the gate insulating layer, and a third insulating layer over the second insulating layer, the second oxide insulating layer, the gate insulating layer, and the gate electrode layer. A side surface portion of the second insulating layer is in contact with the second oxide insulating layer. The gate electrode layer includes a first region and a second region. The first region has a width larger than that of the second region.