A thin film transistor includes an active layer, first and second electrodes, and a third doped pattern. The active layer has a channel region, and a first electrode region and a second electrode region, the first electrode region has a first ion doping concentration, and the second electrode region has a second ion doping concentration. The first electrode and the second electrode are disposed on a side of the active layer in the thickness direction. The first electrode is coupled to the first electrode region, and the second electrode is coupled to the second electrode region. The third doped pattern is disposed between the first electrode and the first electrode region, and in direct contact with the first electrode and the first electrode region. The third doped pattern has a third ion doping concentration, and the third ion doping concentration is different from the first ion doping concentration.

A thin film transistor includes a substrate and an active layer having a channel region. The active layer includes a first active pattern and at least one second active pattern. The first active pattern includes a bottom surface, a top surface and at least one side surface. The at least one side surface connects the bottom and top surfaces, and is in contact with the at least one second active pattern. A length direction of each side surface is approximately perpendicular to a length direction of the channel region. A material of at least the top surface of the first active pattern includes a first polysilicon material, and a material of the second active pattern includes a second polysilicon material; and in the length direction of the channel region, an average grain size of the first polysilicon material is greater than an average grain size of the second polysilicon material.

A highly reliable memory device is provided. In a method for manufacturing a memory device that includes a first insulator, a first conductor including a first opening over the first insulator, a second insulator including a second opening over the first conductor, a second conductor including a third opening over the second insulator, a third insulator over the second conductor, and a semiconductor provided in the first opening to the third opening, the first insulator is formed, the first conductor is formed over the first insulator, the second insulator is formed over the first conductor, a fourth insulator is formed over the second insulator, the third insulator is formed over the fourth insulator, the third opening is formed in the fourth insulator, the second opening is formed in the second insulator, the first opening is formed in the first conductor, the semiconductor is formed in the first opening to the third opening, the fourth insulator is removed, and the second conductor is formed between the second insulator and the third insulator.

A novel semiconductor device is provided. A structure body extending in a first direction, a first conductor extending in a second direction, and a second conductor extending in the second direction are provided. In a first intersection portion where the structure body and the first conductor intersect with each other, a first insulator, a first semiconductor, a second insulator, a second semiconductor, a third insulator, a fourth insulator, and a fifth insulator are provided concentrically around a third conductor. In a second intersection portion where the structure body and the second conductor intersect with each other, the first insulator, the first semiconductor, the second insulator, a fourth conductor, the second semiconductor, and the third insulator are provided concentrically around the third conductor.

An upper surface of a plug (PL1) is formed so as to be higher than an upper surface of an interlayer insulating film (PIL) by forming the interlayer insulating film (PIL) on a semiconductor substrate (1S), completing a CMP method for forming the plug (PL1) inside the interlayer insulating film (PIL), and then, making the upper surface of the interlayer insulating film (PIL) to recede. In this manner, reliability of connection between the plug (PL1) and a wiring (W1) in a vertical direction can be ensured. Also, the wiring (W1) can be formed so as not to be embedded inside the interlayer insulating film (PIL), or a formed amount by the embedding can be reduced.

A memory device with a small number of wirings using a NAND flash memory having a three-dimensional structure with a large number of stacked memory cell layers is provided. A decoder is formed using an OS transistor. An OS transistor can be formed by a method such as a thin film method, whereby the decoder can be provided to be stacked above the NAND flash memory having a three-dimensional structure. This can reduce the number of wirings provided substantially perpendicular to the memory cell layers.

Provided is a semiconductor element including: a multilayer structure including: a conductive substrate; and an oxide semiconductor film arranged directly on the conductive substrate or over the conductive substrate via a different layer, the oxide semiconductor film including an oxide, as a major component, containing gallium, the conductive substrate having a larger area than the oxide semiconductor film.

A semiconductor device includes an insulating substrate, a first semiconductor region configured of polysilicon formed on the insulating substrate, an insulating film laminated on the first semiconductor region, a contact hole formed in the insulating film and reaching the first semiconductor region, a second semiconductor region configured of an oxide semiconductor formed on the insulating film, a contact electrode configured of a conductive material and electrically connected to the first semiconductor region, where the conductive material is embedded in the contact hole. The insulating film contains a metallic element at an interface with the contact hole, where the metallic element forms the oxide semiconductor.

An upper surface of a plug (PL1) is formed so as to be higher than an upper surface of an interlayer insulating film (PIL) by forming the interlayer insulating film (PIL) on a semiconductor substrate (1S), completing a CMP method for forming the plug (PL1) inside the interlayer insulating film (PIL), and then, making the upper surface of the interlayer insulating film (PIL) to recede. In this manner, reliability of connection between the plug (PL1) and a wiring (W1) in a vertical direction can be ensured. Also, the wiring (W1) can be formed so as not to be embedded inside the interlayer insulating film (PIL), or a formed amount by the embedding can be reduced.

A semiconductor device with a novel structure is provided. A plurality of memory circuits, a switching circuit, and an arithmetic circuit are included. Each of the plurality of memory circuits has a function of retaining weight data and a function of outputting the weight data to a first wiring. The switching circuit has a function of switching a conduction state between any one of the plurality of first wirings and a second wiring. The arithmetic circuit has a function of performing arithmetic processing using input data and the weight data supplied to the second wiring. The memory circuits are provided in a first layer. The switching circuit and the arithmetic circuit are provided in a second layer. The first layer is provided in a layer different from the second layer.