Abstract: A thin film transistor in which an effect of photo current is small and an On/Off ratio is high is provided. In a bottom-gate bottom-contact (coplanar) thin film transistor, a channel formation region overlaps with a gate electrode, a first impurity semiconductor layer is provided between the channel formation region and a second impurity semiconductor layer which is in contact with a wiring layer. A semiconductor layer which serves as the channel formation region and the first impurity semiconductor layer preferably overlap with each other in a region where they overlap with the gate electrode. The first impurity semiconductor layer and the second impurity semiconductor layer preferably overlap with each other in a region where they do not overlap with the gate electrode.

Abstract: An object is to provide a method for manufacturing a thin film transistor and a display device with reduced number of masks, in which adverse effects of optical current are suppressed. A manufacturing method comprises forming a stack including, from bottom to top, a light-blocking film, a base film, a first conductive film, a first insulating film, a semiconductor film, an impurity semiconductor film, and a second conductive film; performing first etching on the whole thickness of the stack using a first resist mask formed over it; forming a gate electrode layer by side etching the first conductive film in a second etching; forming a second resist mask over the stack; and performing third etching down to the semiconductor film, and partially etching it, using the second resist mask to form a source and drain electrode layer, a source and drain region, and a semiconductor layer.

Abstract: To provide a method for manufacturing a thin film transistor and a display device using a small number of masks, a thin film transistor is manufactured in such a manner that a first conductive film, an insulating film, a semiconductor film, an impurity semiconductor film, and a second conductive film are stacked; then, a resist mask is formed thereover; first etching is performed to form a thin-film stack body; second etching in which the first conductive film is side-etched is performed by dry-etching to form a gate electrode layer; and a source electrode, a drain electrode, and the like are formed. Before the dry etching, it is preferred that at least a side surface of the etched semiconductor film be oxidized.

Abstract: A method for manufacturing a thin film transistor and a display device using a small number of masks is provided. A conductive film is formed, a thin-film stack body having a pattern is formed over the conductive film, an opening portion is formed in the thin-film stack body so as to reach the conductive film, a gate electrode layer is formed by processing the conductive film using side-etching, and an insulating layer, a semiconductor layer, and a source and drain electrode layer are formed over the gate electrode layer, whereby a thin film transistor is manufactured. By provision of the opening portion, controllability of etching is improved.

Abstract: A light-blocking layer is formed using a first resist mask, and a base film is formed over the light-blocking layer. A first conductive film, a first insulating film, a semiconductor film, an impurity semiconductor film, and a second conductive film are sequentially formed over the base film, and first etching is performed on the second conductive film, the impurity semiconductor film, the semiconductor film, and the first insulating film using a second resist mask over the second conductive film. Then, second etching in which side-etching is performed is performed on part of the first conductive film to form a gate electrode layer, and source and drain electrode layers, source and drain region layers, and a semiconductor layer are formed using a third resist mask. The first resist mask and the second resist mask are formed using the same photomask. Thus, a thin film transistor is manufactured.

Abstract: A first conductive film, a first insulating film, a semiconductor film, an impurity semiconductor film, a second conductive film, and a first resist mask are formed; first etching is performed to expose at least a surface of the first conductive film; second etching accompanied by side etching is performed on part of the first conductive film to form a gate electrode layer; a second resist mask is formed; third etching is performed to form a source and drain electrode layers, a source and drain regions, and a semiconductor layer; a second insulating film is formed; an opening portion is formed in the second insulating film to partially expose the source or drain electrode layer; a pixel electrode is selectively formed in the opening portion and over the second insulating film; and a supporting portion formed using the gate electrode layer is formed in a region overlapping with the opening portion.

Abstract: The present invention improves mechanical strength of a micro-electro-mechanical device (MEMS) having a movable portion to improve reliability. In a micro-electro-mechanical device (MEMS) having a movable portion, a portion which has been a hollow portion in the case of a conventional structure is filled with a filler material. As the filler material, a block copolymer that is highly flexible is used, for example. By filling the hollow portion, mechanical strength improves. Besides, warpage of an upper portion of a structure body in the manufacture process is prevented, whereby yield improves. A micro-electro-mechanical device thus manufactured is highly reliable.

Abstract: To provide a semiconductor device in which a channel formation region can be thinned without adversely affecting a source region and a drain region through a simple process and a method for manufacturing the semiconductor device. In the method for manufacturing a semiconductor device, a semiconductor film, having a thickness smaller than a height of a projection of a substrate, is formed over a surface of the substrate having the projections; the semiconductor film is etched to have an island shape with a resist used as a mask; the resist is etched to expose a portion of the semiconductor film which covers a top surface of the projection; and the exposed portion of the semiconductor film is etched to be thin, while the adjacent portions of the semiconductor film on both sides of the projection remain covered with the resist.

Abstract: The present invention is an article management system using a central management device with an interrogator and an alarm portion. Because the central management device and a central response device worn by a user of the system are provided separately, loss of the central management device can be prevented. The central response device is worn by a user. The central response device communicates with the central management device wirelessly and includes a detector that detects when the communication distance reaches or exceeds a given value and an alarm portion that notifies the user of this. The central management device communicates wirelessly with one or more articles in which a response device is installed.