A semiconductor device having favorable electrical characteristics is provided. The semiconductor device includes a conductor, a first insulator in contact with a side surface of the conductor, a second insulator in contact with a top surface of the conductor and a top surface of the first insulator, and an oxide over the second insulator. The oxide includes a region that overlaps with the conductor with the second insulator interposed therebetween. The maximum height of a roughness curve (Rz) of the top surface of the conductor is 6.0 nm or smaller. The region includes crystals, and c-axes of the crystals are aligned in the normal direction of the top surface of the conductor.

A semiconductor device with a small variation in characteristics is provided. In a manufacturing method of a semiconductor device including a capacitor with reduced leak current, a first conductor is formed; a second insulator is formed over the first conductor; a third insulator is formed over the second insulator; a second conductor is formed over the third insulator; a fourth insulator is deposited over the second conductor and the third insulator; by heat treatment, hydrogen contained in the third insulator diffuses into or is absorbed by the second insulator; the first conductor is one electrode of the capacitor; the second conductor is the other electrode of the capacitor; and each of the second insulator and the third insulator is a dielectric of the capacitor.

A non-volatile memory cell includes a first well of a first conductivity type and a second well of a second conductivity type in a body adjacent to each other; a first conduction region, a second conduction region and a third conduction region in the first well, the first, second and third conduction regions being of the second conductivity type; a control gate region, of the first or second conductivity type, in the second well; a selection gate over the first well forming, together with the first and second conduction regions, a selection transistor; and a floating gate region. The floating gate region has a programming portion overlying the first well and a capacitive portion overlying the second well. The floating gate region forms, together with the second and third conduction regions, a storage transistor and, together with the control gate region, a capacitive element.

A non-volatile memory cell includes a first well of a first conductivity type and a second well of a second conductivity type in a body adjacent to each other; a first conduction region, a second conduction region and a third conduction region in the first well, the first, second and third conduction regions being of the second conductivity type; a control gate region, of the first or second conductivity type, in the second well; a selection gate over the first well forming, together with the first and second conduction regions, a selection transistor; and a floating gate region. The floating gate region has a programming portion overlying the first well and a capacitive portion overlying the second well. The floating gate region forms, together with the second and third conduction regions, a storage transistor and, together with the control gate region, a capacitive element.

A multi-time programming non-volatile memory includes a select transistor, a floating gate transistor, a switch transistor, a capacitor and an erase gate element. The select transistor is connected with a select line and a source line. The floating gate transistor includes a floating gate. The floating gate transistor is connected with the select transistor. The switch transistor is connected with a word line, the floating gate transistor and a bit line. A first terminal of the capacitor is connected with the floating gate. A second terminal of the capacitor is connected with a control line. The erase gate element includes the floating gate, a gate oxide layer and a p-type region. The erase gate element is connected with an erase line. The floating gate of the erase gate element at least includes an n-type floating gate part.

A method for modifying an insulating film is provided. The method includes a first step of preparing an insulating film containing hydrogen, and a second step of performing microwave treatment on the insulating film to release the hydrogen in the insulating film as water molecules, so that a hydrogen concentration in the insulating film is reduced. Note that the microwave treatment is preferably performed using an oxygen gas and an argon gas at a temperature range of higher than or equal to 200° C. and lower than or equal to 300° C., and the proportion of the flow rate of the oxygen gas to the total of the flow rate of the oxygen gas and the flow rate of the argon gas is preferably greater than 0 % and less than or equal to 50 %.

A transistor which is resistant to a short-channel effect is provided. The transistor includes a first conductor in a ring shape, an oxide semiconductor including a region extending through an inside of a ring of the first conductor, a first insulator between the first conductor and the oxide semiconductor, a second insulator between the first conductor and the first insulator, and a charge trap layer inside the ring of the first conductor. The charge trap layer is inside the second insulator and configured to be in a floating state.

A transistor which is resistant to a short-channel effect is provided. The transistor includes a first conductor in a ring shape, an oxide semiconductor including a region extending through an inside of a ring of the first conductor, a first insulator between the first conductor and the oxide semiconductor, a second insulator between the first conductor and the first insulator, and a charge trap layer inside the ring of the first conductor. The charge trap layer is inside the second insulator and configured to be in a floating state.

A semiconductor device with a novel structure is provided. A first memory circuit portion includes a first memory circuit for retaining a plurality of pieces of first weight data. A second memory circuit portion includes a second memory circuit for retaining a plurality of pieces of second weight data. A first arithmetic circuit portion includes a first arithmetic circuit, a first switching circuit, and a third switching circuit. A second arithmetic circuit portion includes a second arithmetic circuit, a second switching circuit, and a fourth switching circuit. The first switching circuit has a function of supplying any one of the plurality of pieces of the first weight data to a first wiring. The second switching circuit has a function of supplying any one of the plurality of pieces of the second weight data to a second wiring. The third switching circuit has a function of supplying to the first arithmetic circuit the first weight data supplied to the first wiring or the second weight data supplied to the second wiring. The fourth switching circuit has a function of supplying to the second arithmetic circuit the first weight data supplied to the first wiring or the second weight data supplied to the second wiring.

A novel semiconductor device is provided. The semiconductor device includes an oxide semiconductor as a first semiconductor, silicon as a second semiconductor, and a plurality of memory cells lined up in a first direction; and a memory cell includes a writing transistor and a reading transistor. The first semiconductor and the second semiconductor extend in the first direction, part of the first semiconductor functions as a channel formation region of the writing transistor, and part of the second semiconductor functions as a channel formation region of the reading transistor. The second semiconductor includes a region in contact with a first layer containing a first metal element.