A solid state imaging device according to the invention includes: a semiconductor layer of a first conductivity type; a gate insulation film that is located on the semiconductor layer; a gate electrode that is located on the gate insulation film; a first impurity region of a second conductivity type that is located at least in a region outside the gate electrode on a first end portion side; a second impurity region of the second conductivity type that is located in a region extending across a second end portion that is opposite to the first end portion of the gate electrode; and a third impurity region of the first conductivity type that is located on top of the second impurity region at a position outside the gate electrode on the second end portion side, and is in contact with the second impurity region.

A tunneling field effect transistor for light detection, including a p-type region connected to a source terminal, a n-type region connected to a drain terminal, an intrinsic region located between the p-type region and the n-type region to form a P-I junction or an N-I junction with the n-type region or the p-type region, respectively, a first insulating layer and a first gate electrode, the first gate electrode covering a portion of the intrinsic region on one side, and a second insulating layer and a second gate electrode, the second insulating layer and the second gate electrode covering an entire other side of the intrinsic region opposite to the one side, wherein an area of the intrinsic region that is not covered by the first gate electrode forms a non-gated intrinsic area configured for light absorption.

When a semiconductor device including a transistor in which a gate electrode layer, a gate insulating film, and an oxide semiconductor film are stacked and a source and drain electrode layers are provided in contact with the oxide semiconductor film is manufactured, after the formation of the gate electrode layer or the source and drain electrode layers by an etching step, a step of removing a residue remaining by the etching step and existing on a surface of the gate electrode layer or a surface of the oxide semiconductor film and in the vicinity of the surface is performed. The surface density of the residue on the surface of the oxide semiconductor film or the gate electrode layer can be 110.sup.13 atoms/cm.sup.2 or lower.

A photo detection substrate, including: a base substrate; and a plurality of detection pixel units on the base substrate, where each detection pixel unit includes a signal reading circuit and a photoelectric conversion structure; the signal reading circuit includes at least one transistor each including a gate and an active layer pattern, the active layer pattern includes a channel region and a source/drain doped region; at least one transistor in the signal reading circuit is a superposed transistor on a side of the photoelectric conversion structure away from the base substrate, an orthographic projection of the active layer pattern of the superposed transistor on the base substrate overlaps an orthographic projection of the photoelectric conversion structure in the same detection pixel unit on the base substrate, and a material of the gate of the superposed transistor includes a transparent conductive material.

A novel input/output device that is highly convenient or reliable, or a novel data processor and a novel semiconductor device are provided. The inventors have devised a structure in which a display portion and an input portion are included; the display portion includes a first display element, a first conductive film electrically connected to the first display element, a second conductive film including a region overlapping with the first conductive film, an insulating film including a region between the second conductive film and the first conductive film, a pixel circuit electrically connected to the second conductive film, and a second display element electrically connected to the pixel circuit; the insulating film includes an opening; and the second conductive film is electrically connected to the first conductive film through the opening. The input portion has a function of sensing an object that approaches a region overlapping with the display portion.

A semiconductor device in which parasitic capacitance is reduced is provided. A first oxide insulating layer and a first oxide semiconductor layer are sequentially formed over a first insulating layer. A first conductive layer is formed over the first oxide semiconductor layer and etched to form a second conductive layer. The first oxide insulating layer and the first oxide semiconductor layer are etched with the second conductive layer as a mask to form a second oxide insulating layer and a second oxide semiconductor layer. A planarized insulating layer is formed over the first insulating layer and the second conductive layer. A second insulating layer, a source electrode layer, and a drain electrode layer are formed by etching the planarized insulating layer and the second conductive layer. A third oxide insulating layer, a gate insulating layer, and a gate electrode layer are formed over the second oxide semiconductor layer.

In a photoelectric changing unit, a photoelectric conversion unit converts light into electric charge, and an electric charge accumulation unit accumulates the electric charge in a polygonal area whose plurality of sides are adjacent to the photoelectric conversion unit on a light receiving surface. A voltage generation unit accumulates the electric charge and generates a voltage according to an amount of the accumulated electric charge. A first transfer unit transfers the electric charge from the photoelectric conversion unit to the electric charge accumulation unit when an instruction on a transfer to the electric charge accumulation unit is issued. A second transfer unit transfers the electric charge from the electric charge accumulation unit to the voltage generation unit when an instruction on a transfer to the voltage generation unit is issued.

An imaging device which does not include a color filter and does not need arithmetic processing using an external processing circuit is provided. A first circuit includes a first photoelectric conversion element, a first transistor, and a second transistor; a second circuit includes a second photoelectric conversion element, a third transistor, and a fourth transistor; a third circuit includes a fifth transistor, a sixth transistor, a seventh transistor, and a second capacitor; the spectroscopic element is provided over the first photoelectric conversion element or the second photoelectric conversion element; and the first circuit and the second circuit is connected to the third circuit through a first capacitor.

Provided is a complementary metal-oxide-semiconductor (CMOS) image sensor. The CMOS image sensor can include a substrate having a first device isolation layer defining and dividing a first active region and a second active region, a photodiode disposed in the substrate and can be configured to vertically overlap the first device isolation layer, a transfer gate electrode can be disposed in the first active region and can be configured to vertically overlap the photodiode, and a floating diffusion region can be in the first active region. The transfer gate electrode can be buried in the substrate.

Methods of forming semiconductor devices are disclosed. In some embodiments, a first trench and a second trench are formed in a substrate, and dopants of a first conductivity type are implanted along sidewalls and a bottom of the first trench and the second trench. The first and second trenches are filled with an insulating material, and a gate dielectric and a gate electrode over the substrate, the gate dielectric and the gate electrode extending over the first trench and the second trench. Source/drain regions are formed in the substrate on opposing sides of the gate dielectric and the gate electrode.