33results about How to "High on-state current" patented technology

The reliability of a transistor including an oxide semiconductor can be improved by suppressing a change in electrical characteristics. A transistor included in a semiconductor device includes a first oxide semiconductor film over a first insulating film, a gate insulating film over the first oxide semiconductor film, a second oxide semiconductor film over the gate insulating film, and a second insulating film over the first oxide semiconductor film and the second oxide semiconductor film. The first oxide semiconductor film includes a channel region in contact with the gate insulating film, a source region in contact with the second insulating film, and a drain region in contact with the second insulating film. The second oxide semiconductor film has a higher carrier density than the first oxide semiconductor film.

The reliability of a transistor including an oxide semiconductor is improved. The transistor in a semiconductor device includes a first oxide semiconductor film over a first insulating film, a gate insulating film over the first oxide semiconductor film, a second oxide semiconductor film over the gate insulating film, and a second insulating film over the first oxide semiconductor film and the second oxide semiconductor film. The first oxide semiconductor film includes a channel region overlapping with the second oxide semiconductor film, a source region and a drain region each in contact with the second insulating film. The channel region includes a first layer and a second layer in contact with a top surface of the first layer and covering a side surface of the first layer in the channel width direction. The second oxide semiconductor film has a higher carrier density than the first oxide semiconductor film.

In a transistor including an oxide semiconductor, a change in electrical characteristics is suppressed and reliability is improved. The transistor includes an oxide semiconductor film over a first insulating film; a second insulating film over the oxide semiconductor film; a metal oxide film over the second insulating film; a gate electrode over the metal oxide film; and a third insulating film over the oxide semiconductor film and the gate electrode. The oxide semiconductor film includes a channel region overlapping with the gate electrode, a source region in contact with the third insulating film, and a drain region in contact with the third insulating film. The source region and the drain region contain one or more of hydrogen, boron, carbon, nitrogen, fluorine, phosphorus, sulfur, chlorine, titanium, and a rare gas.

A semiconductor device includes a first oxide semiconductor film, a second oxide semiconductor film over the first oxide semiconductor film, a source electrode in contact with the second oxide semiconductor film, a drain electrode in contact with the second oxide semiconductor film, a metal oxide film over the second oxide semiconductor film, the source electrode, and the drain electrode, a gate insulating film over the metal oxide film, and a gate electrode over the gate insulating film. The metal oxide film contains M (M represents Ti, Ga, Y, Zr, La, Ce, Nd, or Hf) and Zn. The metal oxide film includes a portion where x / (x+y) is greater than 0.67 and less than or equal to 0.99 when a target has an atomic ratio of M:Zn=x:y.

Provided is a transistor with stable electrical characteristics. Provided is a semiconductor device including an oxide semiconductor over a substrate, a first conductor in contact with a top surface of the oxide semiconductor, a second conductor in contact with the top surface of the oxide semiconductor, a first insulator over the first and second conductors and in contact with the top surface of the oxide semiconductor, a second insulator over the first insulator, a third conductor over the second insulator, and a third insulator over the third conductor. The third conductor overlaps with the first conductor with the first and second insulators positioned therebetween, and overlaps with the second conductor with the first and second insulators positioned therebetween. The first insulator contains oxygen. The second insulator transmits less oxygen than the first insulator. The third insulator transmits less oxygen than the first insulator.

A transistor with stable electrical characteristics is provided. Provided is a method for manufacturing a semiconductor device that includes, over a substrate, an oxide semiconductor, a first conductor, a first insulator, a second insulator, and a third insulator. The oxide semiconductor is over the first insulator. The second insulator is over the oxide semiconductor. The third insulator is over the second insulator. The first conductor is over the third insulator. The oxide semiconductor has a first region and a second region. To form the first region, ion implantation into the oxide semiconductor is performed using the first conductor as a mask, and then hydrogen is added to the oxide semiconductor using the first conductor as a mask.

A method for manufacturing a semiconductor device has a first step including a step of forming an oxide semiconductor film, a second step including a step of forming a gate insulating film over the oxide semiconductor film and a step of forming a gate electrode over the gate insulating film, a third step including a step of forming a nitride insulating film over the oxide semiconductor film and the gate electrode, a fourth step including a step of forming an oxide insulating film over the nitride insulating film, a fifth step including a step of forming an opening in the nitride insulating film and the oxide insulating film, and a sixth step including a step of forming source and drain electrodes over the oxide insulating film so as to cover the opening. In the third step, the nitride insulating film is formed through at least two steps: plasma treatment and deposition treatment. The two steps are each performed at a temperature higher than or equal to 150° C. and lower than 300° C.

The reliability of a transistor including an oxide semiconductor can be improved by suppressing a change in electrical characteristics. A transistor included in a semiconductor device includes a first oxide semiconductor film over a first insulating film, a gate insulating film over the first oxide semiconductor film, a second oxide semiconductor film over the gate insulating film, and a second insulating film over the first oxide semiconductor film and the second oxide semiconductor film. The first oxide semiconductor film includes a channel region in contact with the gate insulating film, a source region in contact with the second insulating film, and a drain region in contact with the second insulating film. The second oxide semiconductor film has a higher carrier density than the first oxide semiconductor film.

A semiconductor device includes a first oxide semiconductor film, a second oxide semiconductor film over the first oxide semiconductor film, a source electrode in contact with the second oxide semiconductor film, a drain electrode in contact with the second oxide semiconductor film, a metal oxide film over the second oxide semiconductor film, the source electrode, and the drain electrode, a gate insulating film over the metal oxide film, and a gate electrode over the gate insulating film. The metal oxide film contains M (M represents Ti, Ga, Y, Zr, La, Ce, Nd, or Hf) and Zn. The metal oxide film includes a portion where x / (x+y) is greater than 0.67 and less than or equal to 0.99 when a target has an atomic ratio of M:Zn=x:y.

A transistor with stable electrical characteristics. A semiconductor device that includes an oxide semiconductor, a first conductor, a first insulator, a second insulator, a third insulator, and a fourth insulator. The oxide semiconductor is positioned over the first insulator. The second insulator is positioned over the oxide semiconductor. The third insulator is positioned over the second insulator. The first conductor is positioned over the third insulator. The fourth insulator is positioned over the first conductor. The fourth insulator includes a region in contact with a top surface of the second insulator. The oxide semiconductor includes a region overlapping with the first conductor with the second insulator and the third insulator positioned therebetween. When seen from above, a periphery of the first insulator and a periphery of the second insulator are located outside a periphery of the oxide semiconductor.

A chopper comparator with a novel structure is provided. The comparator includes an inverter, a capacitor, a first switch, a second switch, and a third switch. An input terminal and an output terminal of the inverter are electrically connected to each other through the first switch. The input terminal of the inverter is electrically connected to one of a pair of electrodes of the capacitor. A reference potential is applied to the other of the pair of electrodes of the capacitor through the second switch. A signal potential input is applied to the other of the pair of electrodes of the capacitor through the third switch. A potential output from the output terminal of the inverter is an output signal. A transistor whose channel is formed in an oxide semiconductor layer is used as the first switch.

In a transistor including an oxide semiconductor, a change in electrical characteristics is suppressed and reliability is improved. The transistor includes an oxide semiconductor film over a first insulating film; a second insulating film over the oxide semiconductor film; a gate electrode over the second insulating film; a metal oxide film in contact with a side surface of the second insulating film; and a third insulating film over the oxide semiconductor film, the gate electrode, and the metal oxide film. The oxide semiconductor film includes a channel region overlapping with the gate electrode, a source region in contact with the third insulating film, and a drain region in contact with the third insulating film. The source region and the drain region contain one or more of hydrogen, boron, carbon, nitrogen, fluorine, phosphorus, sulfur, chlorine, titanium, and a rare gas.

A miniaturized transistor with reduced parasitic capacitance and highly stable electrical characteristics is provided. High performance and high reliability of a semiconductor device including the transistor is achieved. A first conductor is formed over a substrate, a first insulator is formed over the first conductor, a layer that retains fixed charges is formed over the first insulator, a second insulator is formed over the layer that retains fixed charges, and a transistor is formed over the second insulator. Threshold voltage Vth is controlled by appropriate adjustment of the thicknesses of the first insulator, the second insulator, and the layer that retains fixed charges.

A semiconductor device includes first electrodes disposed upon a substrate, wherein each first electrode comprises a metal containing material, switching devices disposed overlying the first electrodes, wherein each switching device comprises a first switching material, a second switching material, and an active metal, wherein the first switching material is disposed overlying and contacting the first electrodes, wherein the second switching material is disposed overlying and contacting the first switching material, wherein the active metal is disposed overlying and contacting the second switching material, wherein the first switching material is characterized by a first switching voltage, wherein the second switching material is characterized by a second switching voltage greater than the first switching voltage; and second electrodes disposed above the switching devices, comprising the metal material, and wherein each of the second electrodes is electrically coupled to the active metal material of the switching devices.

A silicon / germanium (SiGe) heterojunction Tunnel Field Effect Transistor (TFET) and a preparation method thereof are provided, in which a source region of a device is manufactured on a silicon germanium (SiGe) or Ge region, and a drain region of the device is manufactured in a Si region, thereby obtaining a high ON-state current while ensuring a low OFF-state current. Local Ge oxidization and concentration technique is used to implement a Silicon Germanium On Insulator (SGOI) or Germanium On Insulator (GOI) with a high Ge content in some area. In the SGOI or GOI with a high Ge content, the Ge content is controllable from 50% to 100%. In addition, the film thickness is controllable from 5 nm to 20 nm, facilitating the implementation of the device process. During the oxidization and concentration process of the SiGe or Ge and Si, a SiGe heterojunction structure with a gradient Ge content is formed between the SiGe or Ge and Si, thereby eliminating defects. The preparation method according to the present invention has a simple process, which is compatible with the CMOS process and is applicable to mass industrial production.

A semiconductor device includes an oxide semiconductor film, a source electrode, a drain electrode, a gate insulating film, a gate electrode, and an insulating film. The source electrode includes a region in contact with the oxide semiconductor film. The drain electrode includes a region in contact with the oxide semiconductor film. The gate insulating film is provided between the oxide semiconductor film and the gate electrode. The insulating film is provided over the gate electrode and over the gate insulating film. The insulating film includes a first portion and a second portion. The first portion includes a step portion. The second portion includes a non-step portion. The first portion includes a portion with a first thickness. The second portion includes a portion with a second thickness. The second thickness is larger than or equal to 1.0 time and smaller than or equal to 2.0 times the first thickness.

A self-aligned transistor including an oxide semiconductor film, which has excellent and stable electrical characteristics, is provided. A semiconductor device is provided with a transistor that includes an oxide semiconductor film, a gate electrode overlapping with part of the oxide semiconductor film, and a gate insulating film between the oxide semiconductor film and the gate electrode. The oxide semiconductor film includes a first region and second regions between which the first region is positioned. The second regions include an impurity element. A side of the gate insulating film has a depressed region. Part of the gate electrode overlaps with parts of the second regions in the oxide semiconductor film.

A method for manufacturing a semiconductor device has a first step including a step of forming an oxide semiconductor film, a second step including a step of forming a gate insulating film over the oxide semiconductor film and a step of forming a gate electrode over the gate insulating film, a third step including a step of forming a nitride insulating film over the oxide semiconductor film and the gate electrode, a fourth step including a step of forming an oxide insulating film over the nitride insulating film, a fifth step including a step of forming an opening in the nitride insulating film and the oxide insulating film, and a sixth step including a step of forming source and drain electrodes over the oxide insulating film so as to cover the opening. In the third step, the nitride insulating film is formed through at least two steps: plasma treatment and deposition treatment. The two steps are each performed at a temperature higher than or equal to 150° C. and lower than 300° C.

A change in electrical characteristics of a semiconductor device including an oxide semiconductor is prevented, and the reliability of the semiconductor device is improved. An oxide semiconductor is formed over a substrate; an insulator is formed over the oxide semiconductor; a metal oxide is formed over the insulator; a conductor is formed over the metal oxide; a portion of the oxide semiconductor is exposed by removing the conductor, the metal oxide, and the insulator over the oxide semiconductor; plasma treatment is performed on a surface of the exposed portion of the oxide semiconductor; and a nitride insulator is formed over the exposed portion of the oxide semiconductor and over the conductor. The plasma treatment is performed in a mixed atmosphere of an argon gas and a nitrogen gas.