US20130187150A1 - Semiconductor device - Google Patents

Semiconductor device Download PDF

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US20130187150A1
US20130187150A1 US13/735,424 US201313735424A US2013187150A1 US 20130187150 A1 US20130187150 A1 US 20130187150A1 US 201313735424 A US201313735424 A US 201313735424A US 2013187150 A1 US2013187150 A1 US 2013187150A1
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film
transistor
oxide semiconductor
insulating film
layer
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Shunpei Yamazaki
Daisuke Matsubayashi
Yutaka Okazaki
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Semiconductor Energy Laboratory Co Ltd
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Semiconductor Energy Laboratory Co Ltd
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Assigned to SEMICONDUCTOR ENERGY LABORATORY CO., LTD. reassignment SEMICONDUCTOR ENERGY LABORATORY CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: OKAZAKI, YUTAKA, MATSUBAYASHI, DAISUKE, YAMAZAKI, SHUNPEI
Publication of US20130187150A1 publication Critical patent/US20130187150A1/en
Priority to US16/821,433 priority Critical patent/US20200220028A1/en
Priority to US17/826,265 priority patent/US20220293798A1/en
Abandoned legal-status Critical Current

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    • H01L29/78696—
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
    • H10D86/00—Integrated devices formed in or on insulating or conducting substrates, e.g. formed in silicon-on-insulator [SOI] substrates or on stainless steel or glass substrates
    • H10D86/40—Integrated devices formed in or on insulating or conducting substrates, e.g. formed in silicon-on-insulator [SOI] substrates or on stainless steel or glass substrates characterised by multiple TFTs
    • H10D86/60—Integrated devices formed in or on insulating or conducting substrates, e.g. formed in silicon-on-insulator [SOI] substrates or on stainless steel or glass substrates characterised by multiple TFTs wherein the TFTs are in active matrices
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
    • H10D86/00—Integrated devices formed in or on insulating or conducting substrates, e.g. formed in silicon-on-insulator [SOI] substrates or on stainless steel or glass substrates
    • H10D86/40—Integrated devices formed in or on insulating or conducting substrates, e.g. formed in silicon-on-insulator [SOI] substrates or on stainless steel or glass substrates characterised by multiple TFTs
    • H10D86/481—Integrated devices formed in or on insulating or conducting substrates, e.g. formed in silicon-on-insulator [SOI] substrates or on stainless steel or glass substrates characterised by multiple TFTs integrated with passive devices, e.g. auxiliary capacitors
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
    • H10D30/00—Field-effect transistors [FET]
    • H10D30/60—Insulated-gate field-effect transistors [IGFET]
    • H10D30/67—Thin-film transistors [TFT]
    • H10D30/6729—Thin-film transistors [TFT] characterised by the electrodes
    • H10D30/6737—Thin-film transistors [TFT] characterised by the electrodes characterised by the electrode materials
    • H10D30/6739—Conductor-insulator-semiconductor electrodes
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
    • H10D30/00—Field-effect transistors [FET]
    • H10D30/60—Insulated-gate field-effect transistors [IGFET]
    • H10D30/67—Thin-film transistors [TFT]
    • H10D30/674—Thin-film transistors [TFT] characterised by the active materials
    • H10D30/6755—Oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
    • H10D30/00—Field-effect transistors [FET]
    • H10D30/60—Insulated-gate field-effect transistors [IGFET]
    • H10D30/67—Thin-film transistors [TFT]
    • H10D30/6757—Thin-film transistors [TFT] characterised by the structure of the channel, e.g. transverse or longitudinal shape or doping profile
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
    • H10D62/00—Semiconductor bodies, or regions thereof, of devices having potential barriers
    • H10D62/40—Crystalline structures
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
    • H10D86/00—Integrated devices formed in or on insulating or conducting substrates, e.g. formed in silicon-on-insulator [SOI] substrates or on stainless steel or glass substrates
    • H10D86/40—Integrated devices formed in or on insulating or conducting substrates, e.g. formed in silicon-on-insulator [SOI] substrates or on stainless steel or glass substrates characterised by multiple TFTs
    • H10D86/421—Integrated devices formed in or on insulating or conducting substrates, e.g. formed in silicon-on-insulator [SOI] substrates or on stainless steel or glass substrates characterised by multiple TFTs having a particular composition, shape or crystalline structure of the active layer
    • H10D86/423—Integrated devices formed in or on insulating or conducting substrates, e.g. formed in silicon-on-insulator [SOI] substrates or on stainless steel or glass substrates characterised by multiple TFTs having a particular composition, shape or crystalline structure of the active layer comprising semiconductor materials not belonging to the Group IV, e.g. InGaZnO
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
    • H10D86/00—Integrated devices formed in or on insulating or conducting substrates, e.g. formed in silicon-on-insulator [SOI] substrates or on stainless steel or glass substrates
    • H10D86/40—Integrated devices formed in or on insulating or conducting substrates, e.g. formed in silicon-on-insulator [SOI] substrates or on stainless steel or glass substrates characterised by multiple TFTs
    • H10D86/441—Interconnections, e.g. scanning lines
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
    • H10D86/00—Integrated devices formed in or on insulating or conducting substrates, e.g. formed in silicon-on-insulator [SOI] substrates or on stainless steel or glass substrates
    • H10D86/40—Integrated devices formed in or on insulating or conducting substrates, e.g. formed in silicon-on-insulator [SOI] substrates or on stainless steel or glass substrates characterised by multiple TFTs
    • H10D86/471—Integrated devices formed in or on insulating or conducting substrates, e.g. formed in silicon-on-insulator [SOI] substrates or on stainless steel or glass substrates characterised by multiple TFTs having different architectures, e.g. having both top-gate and bottom-gate TFTs

Definitions

  • the present invention relates to a semiconductor device and a method of manufacturing the semiconductor device.
  • a semiconductor device refers to any device that can function by utilizing semiconductor characteristics, and an electro-optical device, a semiconductor circuit, an electronic device, and the like are all included in the category of semiconductor devices.
  • the integration degree of a semiconductor device including silicon has been increased with miniaturization obeying the scaling law of a transistor or the like, and thus a reduction in power consumption and an improvement in performance have been achieved.
  • Patent Document 2 various methods for reducing a short-channel effect due to miniaturization of a transistor have been examined.
  • a main object of conventional art is to reduce an influence of a short-channel effect that is a major factor of degradation of electrical characteristics of a transistor accompanying miniaturization, and a transistor in which a short-channel effect is not substantially caused has not been proposed.
  • An object of one embodiment of the present invention is to provide a transistor in which a short-channel effect is not substantially caused and which has switching characteristics even in the case where the channel length is short.
  • Another object is to provide a highly integrated semiconductor device including the transistor.
  • the transistor includes an oxide semiconductor film, in which the channel length is greater than or equal to 5 nm and less than 60 nm and the channel width is greater than or equal to 5 nm and less than 200 nm.
  • the channel width is made 0.5 to 10 times as large as the channel length.
  • the oxide semiconductor film preferably contains at least In.
  • the oxide semiconductor film preferably contains at least In, Ga, and Zn.
  • the present inventors have found that a short-channel effect which is caused in a transistor including silicon is not substantially caused in a transistor including an oxide semiconductor film in some cases. This is significantly remarkable. Accordingly, it can be said that a rule for miniaturization which is utterly different from a rule for miniaturization of a transistor obeying the conventional scaling law needs to be established.
  • DIBL drain induced barrier lowering
  • DIBL caused in a transistor including silicon is not easily caused in a transistor including the oxide semiconductor film.
  • FIG. 21A is a schematic view of a band structure in the case of a long channel
  • FIG. 21B is a schematic view of a band structure in the case of a short channel.
  • V g the gate voltage
  • the band is curved in the vicinity of a p-n junction interface even when the drain voltage (V d ) is zero (shown with a solid line).
  • V d drain voltage
  • the reason for this is that carriers are exchanged between n + regions and a p region so that the Fermi level of the n + regions and that of the p region are equal to each other, which results in formation of depletion layers having donor ions and acceptor ions and generation of an electric field.
  • V d when V d is applied, the band in the n + region on the drain side is lowered by eV d and the depletion layer is extended from the drain side (shown with a dotted line). At this time, in the case of the long channel, V d does not affect the source side. On the other hand, in the case of the short channel, the depletion layer from the drain side is extended to the source side due to V d , whereby a reduction in the potential of the p region is caused (i.e., bank is made to recede). As a result, current easily flows and the threshold voltage shifts in the negative direction.
  • the width of a depletion layer extended from a drain side that is, the curve width of a band is increased due to V d .
  • the curve width of a band in the vicinity of a junction portion between a channel and a source and a drain (p-n junction interface) of each of a transistor including silicon and a transistor including an oxide semiconductor film will be analytically derived.
  • FIG. 22 shows a band structure on a source side of a transistor including n-type silicon.
  • L s Si the curve width of a band on the source side in a p region of the transistor including n-type silicon is obtained.
  • L s Si is equal to the width of a depletion layer having acceptor ions.
  • ⁇ (y) represents the potential of a region at a distance of y from a p-n junction interface, and the origin of ⁇ (y) is the intrinsic level E ipL Si in the p region.
  • e represents elementary charge.
  • the curve width of the band reflects a spatial variance of ⁇ (y).
  • Formula (1) corresponds to the Poisson equation.
  • ⁇ Si represents a dielectric constant
  • ⁇ represents a charge density.
  • ⁇ may be determined only in consideration of the acceptor ions having negative charge, and Formula (2) is obtained.
  • N A Si represents acceptor density
  • Formula (7) shows that, in the transistor including silicon, L d Si is increased due to V d , that is, the depletion layer is extended from the drain side due to V d .
  • the above is a description on DIBL in the transistor including silicon.
  • FIG. 23 shows a band structure between a source and a drain in a transistor including an oxide semiconductor film.
  • the curve width L s OS of a band on a source side and the curve width L d OS of the band on a drain side in an oxide semiconductor region in the transistor including the oxide semiconductor film are obtained.
  • the metal and the oxide semiconductor form an ohmic contact.
  • ⁇ (y) represents the potential of a region at a distance of y from a metal-oxide semiconductor junction interface on the source side.
  • ⁇ (y) The origin of ⁇ (y) is the intrinsic level E iL OS in the oxide semiconductor region.
  • the curve width of the band in the oxide semiconductor region is thought to be derived from the electron density n OS (y) (electrons corresponds to majority carriers), so that the charge density ⁇ is represented by Formula (8).
  • n 0 OS represents the electron density in a bulk region of the oxide semiconductor, and is represented by Formula (9) using an intrinsic carrier density n i OS .
  • n 0 OS n i OS ⁇ Exp [ - ⁇ F OS kT ] ( 9 )
  • ⁇ (y) is obtained using the Poisson equation in Formula (10).
  • L s OS 2 ⁇ ⁇ OS ⁇ kT ⁇ 2 ⁇ n 0 OS ⁇ ArcCos ⁇ ⁇ Exp [ - E g OS / 2 + ⁇ F OS 2 ⁇ kT ] ⁇ ( 14 )
  • L d OS at the time of application of V d is obtained by substituting e ⁇ F OS +eV d for e ⁇ F OS in Formula (13). Also in this case, E g OS /2+e ⁇ F OS +eV d >>2kT is satisfied, so that Formula (16) is obtained.
  • L d OS does not depend on V d . Therefore, it can be said that DIBL is not caused in the transistor including the oxide semiconductor film.
  • a punch-through phenomenon in a transistor including silicon is caused when a depletion layer due to an electric field of a gate is not extended to a deep area of a channel region in some cases. This is because the density of minority carriers in silicon is as high as about 1 ⁇ 10 11 /cm 3 . That is, by accumulation of the minority carriers, the electric field of the gate does not enter a deep area; thus, the transistor cannot be completely off, which results in an increase in off-state current.
  • the density of minority carriers in an oxide semiconductor film can be as low as about 1 ⁇ 10 ⁇ 9 /cm 3 . That is, in a transistor including an oxide semiconductor film, accumulation of minority carriers hardly occurs, and an electric field of a gate enters a deep area; thus, the transistor can be easily completely off, and thus off-state current can be made small. In this manner, in a transistor including an oxide semiconductor film, a depletion layer is significantly extended due to an electric field of a gate.
  • a short-channel effect which is generally known to be caused in a transistor including silicon, is not substantially caused in a transistor including an oxide semiconductor film.
  • a transistor including an oxide semiconductor film can easily have switching characteristics even in the case where the channel length is short.
  • the channel width is generally decreased when the channel length is decreased.
  • the threshold voltage shifts in the negative direction when the channel width is decreased as well as the channel length. This fact also has become clear thanks to the diligent research by the present inventors.
  • a transistor When electrons are generated in an oxide semiconductor film, a transistor is likely to have so-called normally-on electrical characteristics, that is, the transistor is likely to be on even at a gate voltage of 0 V. Therefore, oxygen vacancies in the oxide semiconductor film are preferably reduced.
  • oxygen supplied from the outside of the oxide semiconductor film may be utilized.
  • oxidation treatment such as ion doping treatment, ion implantation treatment, or plasma treatment or the like may be performed.
  • a layer containing excess oxygen may be provided so that oxygen is supplied therefrom to the oxide semiconductor film.
  • the proportion of oxygen vacancies in the oxide semiconductor film is larger than that of oxygen supplied from the outside in the case where the transistor including the oxide semiconductor film is miniaturized.
  • One reason for this is that the ratio of the surface area to the volume of the oxide semiconductor film is increased with miniaturization. Also in view of this, it can be said that it is important to make the channel width large in the case where the channel length is short.
  • the channel width is extremely large, miniaturization of the transistor, which is the original object, cannot be achieved. Therefore, the ratio of the channel width to the channel length is determined realistically. From such a reason, there is a possibility that intent to make the channel length small without particular limitation is not practical because the channel width cannot be made larger than a predetermined value.
  • the transistor it is important to efficiently utilize oxygen supplied from the outside of the oxide semiconductor film.
  • a layer having low oxygen permeability is provided over the transistor including the oxide semiconductor film, whereby outward diffusion of oxygen is suppressed and thus oxygen can be efficiently utilized. Therefore, even when the channel length is short and the channel width is a predetermined value or smaller, the transistor can have switching characteristics.
  • a parasitic channel is formed on a side surface of the oxide semiconductor film when the transistor including the oxide semiconductor film is miniaturized. This fact also has become clear thanks to the diligent research by the present inventors.
  • the threshold voltage for forming the parasitic channel is generally lower than that for forming the original channel of the transistor. Therefore, when the influence of the parasitic channel becomes large, it seems as if the threshold voltage of the transistor shifts in the negative direction. This is because carriers are easily generated on the side surface of the oxide semiconductor film. For that reason, it is important that the side surface of the oxide semiconductor film be supplied with a larger amount of oxygen than the other surfaces of the oxide semiconductor film.
  • a layer having low oxygen permeability may be provided on the side surface of the oxide semiconductor film so that oxygen vacancies are not easily generated. Further, a layer containing excess oxygen and the layer having low oxygen permeability may be stacked together to be provided on the side surface of the oxide semiconductor film. At this time, the layer containing excess oxygen is preferably provided in contact with the side surface of the oxide semiconductor film.
  • the transistor including the oxide semiconductor film in which the density of minority carriers is extremely low and a source of carriers such as oxygen vacancies or hydrogen is reduced has extremely small off-state current.
  • the transistor including the oxide semiconductor film can be used in combination with a conventional transistor including silicon or the like.
  • a transistor including silicon and a transistor including a compound semiconductor are likely to have improved on-state characteristics. Therefore, the transistor including silicon or the transistor including a compound semiconductor may be used as a transistor for which on-state characteristics are required, and the transistor including the oxide semiconductor film may be used as a transistor for which small off-state current is required.
  • the oxide semiconductor film can be formed by a thin film formation method such as a sputtering method, and thus is not limited so much in combination with another semiconductor material; this is one feature of the oxide semiconductor film.
  • the transistor including silicon can have excellent electrical characteristics when dangling bonds on a silicon surface are terminated with hydrogen. Therefore, a hydrogen-containing layer serving as a source of hydrogen for the transistor including silicon is preferably provided. However, as described above, hydrogen serves as a source of carriers for the transistor including the oxide semiconductor film, and is a factor of degrading the electrical characteristics of the transistor including the oxide semiconductor film.
  • the hydrogen-containing layer is preferably provided closer to the transistor including silicon, and a layer having low hydrogen permeability is preferably provided closer to the transistor including the oxide semiconductor film.
  • a highly integrated semiconductor device including the transistor can be provided.
  • FIGS. 1A to 1C are a top view and cross-sectional views illustrating an example of a semiconductor device according to one embodiment of the present invention.
  • FIGS. 2A to 2C are a top view and cross-sectional views illustrating an example of a semiconductor device according to one embodiment of the present invention.
  • FIGS. 3A to 3C are a top view and cross-sectional views illustrating an example of a semiconductor device according to one embodiment of the present invention.
  • FIGS. 4A to 4C are a top view and cross-sectional views illustrating an example of a semiconductor device according to one embodiment of the present invention.
  • FIGS. 5A to 5C are cross-sectional views illustrating an example of a method of manufacturing the semiconductor device according to one embodiment of the present invention.
  • FIGS. 6A to 6C are cross-sectional views illustrating the example of the method of manufacturing the semiconductor device according to one embodiment of the present invention.
  • FIGS. 7A to 7C are a top view and cross-sectional views illustrating an example of a semiconductor device according to one embodiment of the present invention.
  • FIGS. 8A to 8D are cross-sectional views illustrating an example of a method of manufacturing the semiconductor device according to one embodiment of the present invention.
  • FIGS. 9A to 9C are a top view and cross-sectional views illustrating an example of a semiconductor device according to one embodiment of the present invention.
  • FIGS. 10A to 10C are cross-sectional views illustrating an example of a method of manufacturing the semiconductor device according to one embodiment of the present invention.
  • FIGS. 11A to 11C are cross-sectional views illustrating the example of the method of manufacturing the semiconductor device according to one embodiment of the present invention.
  • FIGS. 12A to 12C are cross-sectional views illustrating the example of the method of manufacturing the semiconductor device according to one embodiment of the present invention.
  • FIGS. 13A to 13C are a top view and cross-sectional views illustrating an example of a semiconductor device according to one embodiment of the present invention.
  • FIGS. 14A to 14C are cross-sectional views illustrating an example of a method of manufacturing the semiconductor device according to one embodiment of the present invention.
  • FIGS. 15A to 15C are a top view and cross-sectional views illustrating an example of a semiconductor device according to one embodiment of the present invention.
  • FIGS. 16A to 16C are cross-sectional views illustrating an example of a method of manufacturing the semiconductor device according to one embodiment of the present invention.
  • FIGS. 17A to 17C are a circuit diagram and a cross-sectional view illustrating an example of a semiconductor memory device according to one embodiment of the present invention, and a graph showing electrical characteristics thereof.
  • FIGS. 18A to 18C are a circuit diagram and a cross-sectional view illustrating an example of a semiconductor memory device according to one embodiment of the present invention, and a graph showing electrical characteristics thereof.
  • FIGS. 19A to 19C are a block diagram illustrating a specific example of a CPU according to one embodiment of the present invention, and circuit diagrams each illustrating part of the CPU.
  • FIGS. 20A to 20D are perspective views each illustrating an example of an electronic device according to one embodiment of the present invention.
  • FIGS. 21A and 21B are each a band diagram between a source and a drain of a transistor including n-type silicon.
  • FIG. 22 is a band diagram on a source side of a transistor including n-type silicon.
  • FIG. 23 is a band diagram between a source and a drain of a transistor including an oxide semiconductor film.
  • a drain when one of a source and a drain of a transistor is called a drain, the other is called a source in this specification. That is, they are not distinguished depending on the potential level. Therefore, in this specification, a portion called a source can be alternatively referred to as a drain.
  • a voltage refers to a potential difference between a certain potential and a reference potential (e.g., a ground potential (GND) or a source potential) in many cases. Accordingly, a voltage can also be called a potential.
  • a reference potential e.g., a ground potential (GND) or a source potential
  • a channel length refers to a distance between a source and a drain of a transistor. The shorter the channel length is, the lower the on-state resistance becomes; thus, a transistor having a short channel length is capable of high-speed operation.
  • a channel width refers to the length of opposite sides of a source and a drain of a transistor. The larger the channel width is, the lower the on-state resistance becomes; thus, a transistor having a large channel width is capable of high-speed operation.
  • FIG. 1A is a top view of a transistor according to one embodiment of the present invention.
  • FIG. 1B is a cross-sectional view taken along dashed-dotted line A 1 -A 2 in FIG. 1A .
  • FIG. 1C is a cross-sectional view taken along dashed-dotted line A 3 -A 4 in FIG. 1A . Note that a base insulating film 102 and the like are not illustrated in FIG. 1A for simplicity.
  • the channel length (L) and the channel width (W) of the transistor are shown.
  • the channel region of the transistor corresponds to a region of an oxide semiconductor film 106 overlapping with a gate electrode 104 . At least part of two side surfaces of the oxide semiconductor film 106 overlap with the gate electrode 104 .
  • the channel length is greater than or equal to 5 nm and less than 60 nm
  • the channel width is greater than or equal to 5 nm and less than 200 nm.
  • the ratio of the channel width to the channel length is 0.5:1 to 10:1.
  • FIG. 1B illustrates a cross-sectional structure of the transistor including the base insulating film 102 provided over a substrate 100 ; the oxide semiconductor film 106 provided over the base insulating film 102 ; a gate insulating film 112 provided over the oxide semiconductor film 106 ; and the gate electrode 104 provided over the gate insulating film 112 so as to overlap with the oxide semiconductor film 106 .
  • an interlayer insulating film 118 which is provided over the oxide semiconductor film 106 and the gate electrode 104 and has openings reaching the oxide semiconductor film 106 , and wirings 136 provided in contact with the oxide semiconductor film 106 through the openings in the interlayer insulating film 118 are illustrated.
  • an In—M—Zn—O-based material for example, an In—M—Zn—O-based material may be used.
  • a metal element M is an element whose bond energy with oxygen is higher than that of In and that of Zn.
  • the metal element M is an element which has a function of suppressing desorption of oxygen from the In—M—Zn—O-based material. Owing to the effect of the metal element m, generation of oxygen vacancies in the oxide semiconductor film is suppressed to some extent. It is thus possible to reduce variation in the electrical characteristics of the transistor which is caused by oxygen vacancies, so that a highly reliable transistor can be obtained.
  • the metal element M may be Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Ga, Y, Zr, Nb, Mo, Sn, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, or W, and is preferably Al, Ti, Ga, Y, Zr, Ce, or Hf.
  • the metal element m one or more elements may be selected from the above elements.
  • Si or Ge may be used instead of the metal element M.
  • the hydrogen concentration in the oxide semiconductor film 106 is 2 ⁇ 10 20 atoms/cm 3 or lower, preferably 5 ⁇ 10 19 atoms/cm 3 or lower, more preferably 1 ⁇ 10 19 atoms/cm 3 or lower. This is because hydrogen in the oxide semiconductor film 106 generates unintentional carriers in some cases. The generated carriers are a factor of changing electrical characteristics of the transistor.
  • the oxide semiconductor film 106 is in a single crystal state, a polycrystalline (also referred to as polycrystal) state, an amorphous state, or the like.
  • the oxide semiconductor film 106 is preferably a c-axis aligned crystalline oxide semiconductor (CAAC-OS) film.
  • the CAAC-OS film is not completely single crystal nor completely amorphous.
  • the CAAC-OS film is an oxide semiconductor film with a crystal-amorphous mixed phase structure where crystal parts are included in an amorphous phase. Note that in most cases, the crystal part fits inside a cube whose one side is less than 100 nm. From an observation image obtained with a transmission electron microscope (TEM), a boundary between an amorphous part and a crystal part in the CAAC-OS film is not clear. Further, with the TEM, a grain boundary in the CAAC-OS film is not found. Thus, in the CAAC-OS film, a reduction in carrier mobility, due to the grain boundary, is suppressed.
  • TEM transmission electron microscope
  • a c-axis is aligned in a direction perpendicular to a surface where the CAAC-OS film is formed or a top surface of the CAAC-OS film, triangular or hexagonal atomic arrangement which is seen from the direction perpendicular to the a-b plane is formed, and metal atoms are arranged in a layered manner or metal atoms and oxygen atoms are arranged in a layered manner when seen from the direction perpendicular to the c-axis.
  • the directions of the a-axis and the b-axis of one crystal part may be different from those of another crystal part.
  • a simple term “perpendicular” includes a range from 85° to 95°.
  • the CAAC-OS film distribution of crystal parts is not necessarily uniform.
  • the proportion of crystal parts on the top surface of the oxide semiconductor film is sometimes higher than that on the surface where the oxide semiconductor film is formed.
  • the crystal part in a region to which the impurity is added becomes amorphous in some cases.
  • the directions of the c-axes may be different from each other depending on the shape of the CAAC-OS film (the cross-sectional shape of the surface where the CAAC-OS film is formed or the cross-sectional shape of the top surface of the CAAC-OS film).
  • the direction of c-axis of the crystal part is the direction parallel to a normal vector of the surface where the CAAC-OS film is formed just after the formation of the CAAC-OS film or a normal vector of the top surface of the CAAC-OS film just after the formation of the CAAC-OS film.
  • the crystal part is formed by film formation or by performing treatment for crystallization such as heat treatment after film formation.
  • the transistor With the use of the CAAC-OS film in a transistor, a change in electric characteristics of the transistor due to irradiation with visible light or ultraviolet light is small. Thus, the transistor has high reliability.
  • the oxide semiconductor film 106 includes a region 106 a and regions 106 b .
  • the region 106 a functions as a channel region
  • the regions 106 b function as a source region and a drain region. Therefore, in some cases, the regions 106 b should be called not a semiconductor but a conductor. For that reason, even when the expression “oxide semiconductor film 106 ” is used for simplicity, this means only the region 106 a and does not include the regions 106 b in some cases.
  • the regions 106 b have lower resistance than the region 106 a .
  • the regions 106 b contain an impurity having a function of reducing the resistance of the oxide semiconductor film.
  • the impurity having a function of reducing the resistance of the oxide semiconductor film include helium, boron, nitrogen, fluorine, neon, aluminum, phosphorus, argon, arsenic, krypton, indium, tin, antimony, and xenon.
  • the band gap is approximately 2.8 eV to 3.2 eV
  • the density of minority carriers is as extremely low as approximately 10 ⁇ 9 /cm 3
  • majority carriers flow only from the source of the transistor.
  • the oxide semiconductor film 106 has a wider band gap than silicon by approximately 1 eV to 2 eV. For that reason, in the transistor including the oxide semiconductor film 106 , impact ionization is unlikely to occur and avalanche breakdown is unlikely to occur. That is, it can be said that, in the transistor including the oxide semiconductor film 106 , hot-carrier degradation is unlikely to occur.
  • the impurity concentration is low and oxygen vacancies are not easily generated. Therefore, in the transistor including the oxide semiconductor film 106 , the region 106 a can be completely depleted by an electric field of the gate electrode 104 even in the case where the thickness of the oxide semiconductor film 106 is large (for example, greater than or equal to 15 nm and less than 100 nm). For that reason, in the transistor including the oxide semiconductor film 106 , a shift of the threshold voltage in the negative direction due to a puch-through phenomenon is not caused and, when the channel length is, for example, 3 ⁇ m, the off-state current can be lower than 10 ⁇ 21 A or lower than 10 ⁇ 24 A per micrometer of channel width at room temperature.
  • the oxide semiconductor film with few oxygen vacancies does not have a signal due to oxygen vacancies, which can be evaluated by electron spin resonance (ESR). Specifically, the spin density attributed to oxygen vacancies of the oxide semiconductor film is lower than 5 ⁇ 10 16 spins/cm 3 . When the oxide semiconductor film has oxygen vacancies, a signal having symmetry is found at a g value of around 1.93 in ESR.
  • the base insulating film 102 be sufficiently flat.
  • the base insulating film 102 has an average surface roughness (R a ) of 1 nm or less, preferably 0.3 nm or less, further preferably 0.1 nm or less.
  • R a is less than or equal to the above value, the oxide semiconductor film 106 can have high crystallinity. Further, when the degree of roughness at the interface between the base insulating film 102 and the oxide semiconductor film 106 is small, the influence of interface scattering can be reduced.
  • R a is obtained by expanding arithmetic mean surface roughness, which is defined by JIS B 0601: 2001 (ISO4287: 1997), into three dimensions so as to be applied to a curved surface.
  • R a can be expressed as “an average value of the absolute values of deviations from a reference surface to a specific surface” and is defined by Formula (17).
  • Ra 1 S 0 ⁇ ⁇ y ⁇ ⁇ 1 y ⁇ ⁇ 2 ⁇ ⁇ x ⁇ ⁇ 1 x ⁇ ⁇ 2 ⁇ ⁇ f ⁇ ( x , y ) - Z 0 ⁇ ⁇ ⁇ x ⁇ ⁇ y ( 17 )
  • the specific surface is a surface which is a target of roughness measurement, and is a quadrilateral region which is specified by four points represented by the coordinates (x 1 , y 1 , f(x 1 , y 1 )), (x 1 , y 2 , f(x 1 , y 2 )), (x 2 , y 1 , f(x 2 , y 1 )), and (x 2 , y 2 , f(x 2 , y 2 )).
  • S 0 represents the area of a rectangle which is obtained by projecting the specific surface on the xy plane
  • Z 0 represents the height of the reference surface (the average height of the specific surface).
  • R a can be measured using an atomic force microscope (AFM).
  • the base insulating film 102 is preferably an insulating film containing excess oxygen.
  • An insulating film containing excess oxygen refers to an insulating film in which the amount of released oxygen which is converted into oxygen atoms is greater than or equal to 1 ⁇ 10 18 atoms/cm 3 , greater than or equal to 1 ⁇ 10 19 atoms/cm 3 , or greater than or equal to 1 ⁇ 10 20 atoms/cm 3 in thermal desorption spectroscopy (TDS).
  • TDS thermal desorption spectroscopy
  • the total amount of released gas in TDS is proportional to the integral value of the ion intensity of the released gas. Then, this integral value is compared with the reference value of a standard sample, whereby the total amount of the released gas can be calculated.
  • the number of released oxygen molecules (N O2 ) from an insulating film can be calculated according to Formula (18) using the TDS results of a silicon wafer containing hydrogen at a predetermined density, which is the standard sample, and the TDS results of the insulating film.
  • all gasses having a mass number of 32 which are obtained by the TDS are assumed to originate from an oxygen molecule.
  • CH 3 OH can be given as a gas having a mass number of 32, but is not taken into consideration on the assumption that CH 3 OH is unlikely to be present.
  • an oxygen molecule including an oxygen atom having a mass number of 17 or 18, which is an isotope of an oxygen atom is also not taken into consideration because the proportion of such a molecule in the natural world is minimal.
  • N O ⁇ ⁇ 2 N H ⁇ ⁇ 2 S H ⁇ ⁇ 2 ⁇ S O ⁇ ⁇ 2 ⁇ ⁇ ( 18 )
  • N H2 is the value obtained by conversion of the number of hydrogen molecules desorbed from the standard sample into density.
  • S H2 is the integral value of ion intensity when the standard sample is analyzed by TDS.
  • the reference value of the standard sample is expressed by N H2 /S H2 .
  • S O2 is the integral value of ion intensity when the insulating film is analyzed by TDS, and ⁇ is a coefficient affecting the ion intensity in the TDS.
  • the amount of released oxygen from the insulating film was measured with a thermal desorption spectroscopy apparatus produced by ESCO Ltd., EMD-WA1000S/W using a silicon wafer containing hydrogen atoms at 1 ⁇ 10 16 atoms/cm 3 as the standard sample.
  • oxygen is partly detected as an oxygen atom.
  • the ratio between oxygen molecules and oxygen atoms can be calculated from the ionization rate of oxygen molecules. Note that, since the above ⁇ is determined considering the ionization rate of oxygen molecules, the number of released oxygen atoms can be estimated through the evaluation of the number of the released oxygen molecules.
  • N O2 is the number of released oxygen molecules.
  • the number of released oxygen atoms is twice the number of released oxygen molecules.
  • the insulating film containing excess oxygen may contain a peroxide radical.
  • the spin density attributed to a peroxide radical of the insulating film is 5 ⁇ 10 17 spins/cm 3 or higher. Note that the insulating film containing a peroxide radical has a signal having asymmetry at a g value of around 2.01 in ESR.
  • the insulating film containing excess oxygen may be formed using oxygen-excess silicon oxygen (SiO x (X>2)).
  • oxygen-excess silicon oxide SiO x (X>2)
  • the number of oxygen atoms per unit volume is more than twice the number of silicon atoms per unit volume.
  • the number of silicon atoms and the number of oxygen atoms per unit volume are measured by Rutherford backscattering spectrometry.
  • the base insulating film 102 may be formed of a single layer or a stacked layer using one or more of the following materials: aluminum oxide, aluminum nitride, magnesium oxide, silicon oxide, silicon oxynitride, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, and tantalum oxide.
  • silicon nitride oxide or silicon nitride may be stacked.
  • the amount of oxygen is larger than that of nitrogen in silicon oxynitride, and the amount of nitrogen is larger than that of oxygen in silicon nitride oxide.
  • the gate insulating film 112 is preferably an insulating film containing excess oxygen.
  • the gate insulating film 112 may be formed of a single layer or a stacked layer using one or more of the following materials: aluminum oxide, magnesium oxide, silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, and tantalum oxide.
  • Excess oxygen contained in at least one of the base insulating film 102 and the gate insulating film 112 means that the oxygen content is in excess of that in the stoichiometric composition. Therefore, “excess oxygen” is released when energy such as heat is applied to the film. Since “excess oxygen” means that the oxygen content is in excess of that in the stoichiometric composition, the film quality is not impaired even when “excess oxygen” is released from the film.
  • the oxygen vacancies in the oxide semiconductor film 106 can be reduced by oxygen supplied from at least one of the base insulating film 102 and the gate insulating film 112 . That is, when the oxygen vacancies in the oxide semiconductor film 106 are reduced, a shift of the threshold voltage of the transistor in the negative direction can be prevented.
  • at least one of the base insulating film and the gate insulating film may be an insulating film containing excess oxygen.
  • At least one of the base insulating film 102 and the gate insulating film 112 might be lost through the heat treatment in some cases.
  • at least one of the base insulating film 102 and the gate insulating film 112 preferably contains excess oxygen even after the heat treatment is performed.
  • the substrate 100 there is no particular limitation on the substrate 100 as long as it has heat resistance enough to withstand at least heat treatment performed later.
  • a glass substrate, a ceramic substrate, a quartz substrate, or a sapphire substrate may be used as the substrate 100 .
  • a single crystal semiconductor substrate or a polycrystalline semiconductor substrate made of silicon, silicon carbide, or the like, a compound semiconductor substrate made of silicon germanium or the like, a silicon-on-insulator (SOI) substrate, or the like may be used.
  • SOI silicon-on-insulator
  • any of these substrates provided with a semiconductor element may be used as the substrate 100 .
  • a large glass substrate such as the fifth generation (1000 mm ⁇ 1200 mm or 1300 mm ⁇ 1500 mm); the sixth generation (1500 mm ⁇ 1800 mm); the seventh generation (1870 mm ⁇ 2200 mm); the eighth generation (2200 mm ⁇ 2500 mm); the ninth generation (2400 mm ⁇ 2800 mm); or the tenth generation (2880 mm ⁇ 3130 mm) as the substrate 100
  • microfabrication is difficult in some cases due to the shrinkage of the substrate 100 , which is caused by heat treatment or the like in a manufacturing process of the semiconductor device. Therefore, in the case where the above-described large glass substrate is used as the substrate 100 , a substrate which is unlikely to shrink through the heat treatment is preferably used.
  • a large-sized glass substrate which has a shrinkage of 10 ppm or less, preferably 5 ppm or less, more preferably 3 ppm or less after heat treatment at 400° C., preferably at 450° C., more preferably 500° C. for one hour may be used as the substrate 100 .
  • a flexible substrate may be used as the substrate 100 .
  • a method for forming a transistor over a flexible substrate there is a method in which, after a transistor is formed over a non-flexible substrate, the transistor is separated from the non-flexible substrate and transferred to the substrate 100 which is a flexible substrate. In that case, a separation layer is preferably provided between the non-flexible substrate and the transistor.
  • the gate electrode 104 may be formed of a single layer or a stacked layer of a simple substance selected from Al, Ti, Cr, Co, Ni, Cu, Y, Zr, Mo, Ag, Ta, and W; a nitride containing one or more kinds of the above substances; an oxide containing one or more kinds of the above substances; or an alloy containing one or more kinds of the above substances.
  • the interlayer insulating film 118 may be formed of a single layer or a stacked layer using one or more materials containing any of aluminum oxide, aluminum nitride, magnesium oxide, silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, and tantalum oxide.
  • the interlayer insulating film 118 have low relative permittivity and a sufficient thickness.
  • a silicon oxide film having a relative permittivity of approximately 3.8 and a thickness greater than or equal to 200 nm and less than or equal to 1000 nm may be provided.
  • a top surface of the interlayer insulating film 118 has a little fixed charge because of the influence of atmospheric components and the like, which might cause the shift of the threshold voltage of the transistor. Therefore, it is preferable that the interlayer insulating film 118 have relative permittivity and a thickness such that the influence of the charge at the top surface is sufficiently reduced.
  • a resin film of a polyimide resin, an acrylic resin, an epoxy resin, a silicone resin, or the like may be formed over the interlayer insulating film 118 in order to reduce the influence of the charge at the top surface of the interlayer insulating film 118 .
  • the wirings 136 may be formed of a single layer or a stacked layer of a simple substance selected from Al, Ti, Cr, Co, Ni, Cu, Y, Zr, Mo, Ag, Ta, and W; a nitride containing one or more kinds of the above substances; an oxide containing one or more kinds of the above substances; or an alloy containing one or more kinds of the above substances.
  • a transistor having a structure different from that of the transistor illustrated in FIGS. 1A to 1C will be described with reference to FIGS. 2A to 2C .
  • FIG. 2A is a top view of a transistor according to one embodiment of the present invention.
  • FIG. 2B is a cross-sectional view taken along dashed-dotted line B 1 -B 2 in FIG. 2A .
  • FIG. 2C is a cross-sectional view taken along dashed-dotted line B 3 -B 4 in FIG. 2A . Note that the base insulating film 102 and the like are not illustrated in FIG. 2A for simplicity.
  • the channel length (L) and the channel width (W) of the transistor are shown. Note that the channel region of the transistor corresponds to a region of the oxide semiconductor film 106 overlapping with the gate electrode 104 . At least part of two side surfaces of the oxide semiconductor film 106 overlap with the gate electrode 104 .
  • the channel length is greater than or equal to 5 nm and less than 60 nm
  • the channel width is greater than or equal to 5 nm and less than 200 nm.
  • the ratio of the channel width to the channel length is 0.5:1 to 10:1.
  • FIG. 2B illustrates a cross-sectional structure of the transistor including the base insulating film 102 provided over the substrate 100 ; the oxide semiconductor film 106 provided over the base insulating film 102 ; the gate insulating film 112 provided over the oxide semiconductor film 106 ; the gate electrode 104 provided over the gate insulating film 112 so as to overlap with the oxide semiconductor film 106 ; and a barrier film 108 which is provided over the base insulating film 102 , the oxide semiconductor film 106 , and the gate electrode 104 and has openings reaching the oxide semiconductor film 106 .
  • the interlayer insulating film 118 which is provided over the oxide semiconductor film 106 and the gate electrode 104 and has openings reaching the oxide semiconductor film 106 , and the wirings 136 provided in contact with the oxide semiconductor film 106 through the openings in the interlayer insulating film 118 are illustrated.
  • the transistor in FIGS. 2A to 2C is different from the transistor in FIGS. 1A to 1C only in the presence of the barrier film 108 which is provided over the base insulating film 102 , the oxide semiconductor film 106 , and the gate electrode 104 and has the openings reaching the oxide semiconductor film 106 . Therefore, for structures of the other components, the description with reference to FIGS. 1A to 1C can be referred to.
  • the barrier film 108 is an insulating film having low oxygen permeability. Specifically, the barrier film 108 is an insulating film through which oxygen does not pass even when heat treatment is performed at 350° C. for one hour.
  • the barrier film 108 may be formed of a single layer or a stacked layer using one or more of the following materials: aluminum oxide, aluminum nitride, magnesium oxide, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, and tantalum oxide.
  • aluminum oxide film is preferably used.
  • FIGS. 1A to 1C and FIGS. 2A to 2C A transistor having a structure different from those of the transistors illustrated in FIGS. 1A to 1C and FIGS. 2A to 2C will be described with reference to FIGS. 3A to 3C .
  • FIG. 3A is a top view of a transistor according to one embodiment of the present invention.
  • FIG. 3B is a cross-sectional view taken along dashed-dotted line C 1 -C 2 in FIG. 3A .
  • FIG. 3C is a cross-sectional view taken along dashed-dotted line C 3 -C 4 in FIG. 3A . Note that the base insulating film 102 and the like are not illustrated in FIG. 3A for simplicity.
  • the channel length (L) and the channel width (W) of the transistor are shown. Note that the channel region of the transistor corresponds to a region of the oxide semiconductor film 106 overlapping with the gate electrode 104 . At least part of two side surfaces of the oxide semiconductor film 106 overlap with the gate electrode 104 .
  • the channel length is greater than or equal to 5 nm and less than 60 nm
  • the channel width is greater than or equal to 5 nm and less than 200 nm.
  • the ratio of the channel width to the channel length is 0.5:1 to 10:1.
  • FIG. 3B illustrates a cross-sectional structure of the transistor including the base insulating film 102 provided over the substrate 100 ; the oxide semiconductor film 106 provided over the base insulating film 102 ; a gate insulating film 132 which is provided over the oxide semiconductor film 106 and includes a first layer 132 a and a second layer 132 b ; and the gate electrode 104 provided over the gate insulating film 132 so as to overlap with the oxide semiconductor film 106 .
  • the first layer 132 a is closer to the oxide semiconductor film 106 than the second layer 132 b.
  • the interlayer insulating film 118 which is provided over the oxide semiconductor film 106 and the gate electrode 104 and has openings reaching the oxide semiconductor film 106 , and the wirings 136 provided in contact with the oxide semiconductor film 106 through the openings in the interlayer insulating film 118 are illustrated.
  • the transistor in FIGS. 3A to 3C is different from the transistor in FIGS. 1A to 1C only in that the gate insulating film 132 including the first layer 132 a and the second layer 132 b is provided instead of the gate insulating film 112 . Therefore, for structures of the other components, the description with reference to FIGS. 1A to 1C can be referred to.
  • the first layer 132 a is formed using an insulating film containing excess oxygen.
  • the first layer 132 a may be formed of a single layer or a stacked layer using one or more of the following materials: aluminum oxide, aluminum nitride, magnesium oxide, silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, and tantalum oxide.
  • the second layer 132 b is formed using an insulating film having low oxygen permeability. Specifically, an insulating film through which oxygen does not pass even when heat treatment is performed at 350° C. for one hour is used.
  • the second layer 132 b may be formed of a single layer or a stacked layer using one or more of the following materials: aluminum oxide, aluminum nitride, magnesium oxide, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, and tantalum oxide.
  • aluminum oxide film is preferably used.
  • the first layer 132 a is provided in contact with parts of the side surfaces of the oxide semiconductor film 106 overlapping with the gate electrode 104 . Therefore, oxygen can be supplied from the first layer 132 a to the side surfaces of the oxide semiconductor film 106 overlapping with the gate electrode 104 . Since the second layer 132 b is provided so as to cover the first layer 132 a , oxygen can be efficiently supplied from the first layer 132 a.
  • a parasitic channel is formed on the side surfaces of the oxide semiconductor film depending on the properties of the side surfaces of the oxide semiconductor film.
  • the threshold voltage for forming the parasitic channel is generally lower than that for forming the original channel of the transistor. Therefore, when the influence of the parasitic channel becomes large, it seems as if the threshold voltage of the transistor shifts in the negative direction. This is because carriers are easily generated on the side surfaces of the oxide semiconductor film. For that reason, it is important that the side surfaces of the oxide semiconductor film be supplied with a larger amount of oxygen than the other surfaces of the oxide semiconductor film.
  • FIGS. 3A to 3C The influence of the parasitic channel becomes noticeable in a short-channel transistor in some cases; thus, the structure illustrated in FIGS. 3A to 3C is effective for a miniaturized transistor.
  • the parasitic channel is unlikely to be formed on the side surfaces of the oxide semiconductor film 106 overlapping with the gate electrode 104 . That is, a shift of the threshold voltage of the transistor in the negative direction can be further suppressed in comparison with the transistor in FIGS. 1A to 1C .
  • FIGS. 1A to 1C A transistor having a structure different from those of the transistors illustrated in FIGS. 1A to 1C , FIGS. 2A to 2C , and FIGS. 3A to 3C will be described with reference to FIGS. 4A to 4C .
  • FIG. 4A is a top view of a transistor according to one embodiment of the present invention.
  • FIG. 4B is a cross-sectional view taken along dashed-dotted line D 1 -D 2 in FIG. 4A .
  • FIG. 4C is a cross-sectional view taken along dashed-dotted line D 3 -D 4 in FIG. 4A . Note that the base insulating film 102 and the like are not illustrated in FIG. 4A for simplicity.
  • the channel length (L) and the channel width (W) of the transistor are shown. Note that the channel region of the transistor corresponds to a region of the oxide semiconductor film 106 overlapping with the gate electrode 104 . At least part of two side surfaces of the oxide semiconductor film 106 overlap with the gate electrode 104 .
  • the channel length is greater than or equal to 5 nm and less than 60 nm
  • the channel width is greater than or equal to 5 nm and less than 200 nm.
  • the ratio of the channel width to the channel length is 0.5:1 to 10:1.
  • FIG. 4B illustrates a cross-sectional structure of the transistor including the base insulating film 102 provided over the substrate 100 ; the oxide semiconductor film 106 provided over the base insulating film 102 ; the gate insulating film 132 which is provided over the oxide semiconductor film 106 and includes the first layer 132 a and the second layer 132 b ; the gate electrode 104 provided over the gate insulating film 132 so as to overlap with the oxide semiconductor film 106 ; and the bather film 108 which is provided over the base insulating film 102 , the oxide semiconductor film 106 , and the gate electrode 104 and has openings reaching the oxide semiconductor film 106 .
  • the first layer 132 a is closer to the oxide semiconductor film 106 than the second layer 132 b.
  • the interlayer insulating film 118 which is provided over the oxide semiconductor film 106 and the gate electrode 104 and has openings reaching the oxide semiconductor film 106 , and the wirings 136 provided in contact with the oxide semiconductor film 106 through the openings in the interlayer insulating film 118 are illustrated.
  • the transistor in FIGS. 4A to 4C is the same as the transistor in FIGS. 2A to 2C in the presence of the barrier film 108 which is provided over the base insulating film 102 , the oxide semiconductor film 106 , and the gate electrode 104 and has the openings reaching the oxide semiconductor film 106 . Further, the transistor in FIGS. 4A to 4C is the same as the transistor in FIGS. 3A to 3C in that the gate insulating film 132 including the first layer 132 a and the second layer 132 b is provided instead of the gate insulating film 112 . Therefore, for the structure of the transistor in FIGS. 4A to 4C , the description with reference to FIGS. 1A to 1C , FIGS. 2A to 2C , and FIGS. 3A to 3C can be referred to.
  • the first layer 132 a is provided in contact with parts of the side surfaces of the oxide semiconductor film 106 overlapping with the gate electrode 104 . Therefore, oxygen can be supplied from the first layer 132 a to the side surfaces of the oxide semiconductor film 106 overlapping with the gate electrode 104 . Since the second layer 132 b is provided so as to cover the first layer 132 a , oxygen can be efficiently supplied from the first layer 132 a.
  • the parasitic channel is unlikely to be formed on the side surfaces of the oxide semiconductor film 106 overlapping with the gate electrode 104 . That is, a shift of the threshold voltage of the transistor in the negative direction can be suppressed.
  • a transistor including an oxide semiconductor film with a large channel width (greater than or equal to 5 nm and less than 200 nm) is proposed as a transistor in which a short-channel effect is not substantially caused even when the channel length is short (greater than or equal to 5 nm and less than 60 nm).
  • a transistor including an oxide semiconductor film having a constant ratio of a channel width to a channel length is proposed.
  • FIGS. 4A to 4C A method of manufacturing the transistor in FIGS. 4A to 4C will be described below with reference to FIGS. 5A to 5C and FIGS. 6A to 6C . Note that the method of manufacturing the transistor in FIGS. 4A to 4C may be employed as appropriate for methods of manufacturing the transistors in FIGS. 1A to 1C , FIGS. 2A to 2C , and FIGS. 3A to 3C . Here, only cross-sectional views corresponding to FIG. 4B are illustrated for simplicity.
  • the substrate 100 is prepared.
  • the base insulating film 102 is formed over the substrate 100 (see FIG. 5A ).
  • the base insulating film 102 may be formed using any of the above materials for the base insulating film 102 by a sputtering method, a chemical vapor deposition (CVD) method, a molecular beam epitaxy (MBE) method, an atomic layer deposition (ALD) method, or a pulsed laser deposition (PLD) method.
  • CVD chemical vapor deposition
  • MBE molecular beam epitaxy
  • ALD atomic layer deposition
  • PLD pulsed laser deposition
  • the base insulating film 102 may be subjected to dehydration or dehydrogenation treatment.
  • heat treatment can be performed as the dehydration or dehydrogenation treatment.
  • the heat treatment may be performed at a temperature higher than or equal to 250° C. and lower than or equal to 650° C., preferably higher than or equal to 300° C. and lower than or equal to 500° C.
  • the heat treatment is performed in an inert gas atmosphere, an atmosphere containing an oxidizing gas at 10 ppm or more, preferably 1% or more, more preferably 10% or more, or under reduced pressure.
  • the heat treatment may be performed in such a manner that heat treatment is performed in an inert gas atmosphere, and then another heat treatment is performed in an atmosphere containing an oxidizing gas at 10 ppm or more, preferably 1% or more, more preferably 10% or more in order to compensate desorbed oxygen.
  • an oxidizing gas at 10 ppm or more, preferably 1% or more, more preferably 10% or more in order to compensate desorbed oxygen.
  • plasma treatment, UV treatment, or chemical treatment may be performed as the dehydration or dehydrogenation treatment.
  • oxygen may be added to the base insulating film 102 from the upper surface side of the base insulating film 102 .
  • the addition of oxygen may be performed by an ion implantation method or an ion doping method. In that case, the acceleration voltage is made higher than or equal to 5 kV and lower than or equal to 100 kV.
  • the amount of added oxygen is made greater than or equal to 1 ⁇ 10 14 ions/cm 2 and less than or equal to 1 ⁇ 10 16 ions/cm 2 . Note that oxygen may be further added to the base insulating film 102 from the upper surface side of the base insulating film 102 under a different condition.
  • the addition of oxygen may be performed by application of a bias voltage to the substrate side in plasma containing oxygen.
  • the bias voltage is made higher than or equal to 10 V and lower than 1 kV.
  • the application time of the bias voltage is made longer than or equal to 10 s and shorter than or equal to 1000 s, preferably longer than or equal to 10 s and shorter than or equal to 200 s, more preferably longer than or equal to 10 s and shorter than or equal to 60 s.
  • the base insulating film 102 can be an insulating film containing excess oxygen.
  • the formation method of the insulating film containing excess oxygen is not limited to the above.
  • the insulating film containing excess oxygen can be formed also by a sputtering method under an atmosphere containing a high proportion of oxygen with the substrate temperature higher than or equal to room temperature (approximately 25° C.) and lower than or equal to 150° C.
  • the proportion of an oxidizing gas such as oxygen in a deposition gas may be set to 20% or higher, preferably 50% or higher, more preferably 80% or higher.
  • the formation methods of the insulating film containing excess oxygen may be combined as appropriate.
  • the base insulating film 102 containing excess oxygen may be formed in the above manner. Note that this embodiment is not limited to the case where the base insulating film 102 contains excess oxygen.
  • the base insulating film 102 may be subjected to planarization treatment.
  • planarization treatment chemical mechanical polishing (CMP) or a dry etching method may be used.
  • the base insulating film 102 is provided so as to have an average surface roughness (R a ) of 1 nm or less, preferably 0.3 nm or less, more preferably 0.1 nm or less.
  • the oxide semiconductor film may be formed using any of the above materials for the oxide semiconductor film 106 by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method.
  • the oxide semiconductor film is preferably formed by a sputtering method.
  • a deposition gas which includes an oxidizing gas such as oxygen at 5% or more, preferably 10% or more, further preferably 20% or more, still further preferably 50% or more is used.
  • an oxidizing gas such as oxygen at 5% or more, preferably 10% or more, further preferably 20% or more, still further preferably 50% or more is used.
  • the deposition gas a gas in which the concentration of impurities such as hydrogen is low is used.
  • first heat treatment may be performed.
  • the first heat treatment may be performed at a temperature higher than or equal to 250° C. and lower than or equal to 650° C., preferably higher than or equal to 300° C. and lower than or equal to 500° C.
  • the first heat treatment is performed in an inert gas atmosphere, an atmosphere containing an oxidizing gas at 10 ppm or more, preferably 1% or more, further preferably 10% or more, or under reduced pressure.
  • the first heat treatment may be performed in such a manner that heat treatment is performed in an inert gas atmosphere, and then another heat treatment is performed in an atmosphere containing an oxidizing gas at 10 ppm or more, preferably 1% or more, further preferably 10% or more in order to compensate desorbed oxygen.
  • an oxidizing gas at 10 ppm or more, preferably 1% or more, further preferably 10% or more in order to compensate desorbed oxygen.
  • the oxide semiconductor film is processed to form an island-shaped oxide semiconductor film 107 (see FIG. 5B ).
  • the first layer 133 a may be formed using any of the above materials for the first layer 132 a by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method.
  • the first layer 133 a may be subjected to dehydration or dehydrogenation treatment.
  • heat treatment can be performed as the dehydration or dehydrogenation treatment.
  • the heat treatment may be performed at a temperature higher than or equal to 250° C. and lower than or equal to 650° C., preferably higher than or equal to 300° C. and lower than or equal to 500° C.
  • the heat treatment is performed in an inert gas atmosphere, an atmosphere containing an oxidizing gas at 10 ppm or more, preferably 1% or more, more preferably 10% or more, or under reduced pressure.
  • the heat treatment may be performed in such a manner that heat treatment is performed in an inert gas atmosphere, and then another heat treatment is performed in an atmosphere containing an oxidizing gas at 10 ppm or more, preferably 1% or more, more preferably 10% or more in order to compensate desorbed oxygen.
  • an oxidizing gas at 10 ppm or more, preferably 1% or more, more preferably 10% or more in order to compensate desorbed oxygen.
  • plasma treatment, UV treatment, or chemical treatment may be performed as the dehydration or dehydrogenation treatment.
  • oxygen may be added to the first layer 133 a from the upper surface side of the first layer 133 a .
  • the addition of oxygen may be performed by an ion implantation method or an ion doping method. In that case, the acceleration voltage is made higher than or equal to 5 kV and lower than or equal to 100 kV.
  • the amount of added oxygen is made greater than or equal to 1 ⁇ 10 14 ions/cm 2 and less than or equal to 1 ⁇ 10 16 ions/cm 2 . Note that oxygen may be further added to the first layer 133 a from the upper surface side of the first layer 133 a under a different condition.
  • the addition of oxygen may be performed by application of a bias voltage to the substrate side in plasma containing oxygen.
  • the bias voltage is made higher than or equal to 10 V and lower than 1 kV.
  • the application time of the bias voltage is made longer than or equal to 10 s and shorter than or equal to 1000 s, preferably longer than or equal to 10 s and shorter than or equal to 200 s, more preferably longer than or equal to 10 s and shorter than or equal to 60 s.
  • the first layer 133 a can be an insulating film containing excess oxygen.
  • the formation method of the insulating film containing excess oxygen is not limited to the above.
  • the insulating film containing excess oxygen can be formed also by a sputtering method under an atmosphere containing a high proportion of oxygen with the substrate temperature higher than or equal to room temperature and lower than or equal to 150° C.
  • the proportion of oxygen may be set to 20% or higher, preferably 50% or higher, more preferably 80% or higher.
  • the formation methods of the insulating film containing excess oxygen may be combined as appropriate.
  • the first layer 133 a containing excess oxygen may be formed in the above manner. Note that this embodiment is not limited to the case where the first layer 133 a contains excess oxygen.
  • the second layer 133 b may be formed using any of the above materials for the second layer 132 b by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method.
  • the conductive film 105 may be formed using any of the above materials for the gate electrode 104 by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method.
  • the conductive film 105 is processed to form the gate electrode 104 .
  • the second layer 133 b and the first layer 133 a are processed with the use of the gate electrode 104 as a mask or with the use of a mask used for the processing for forming the gate electrode 104 , whereby the gate insulating film 132 including the second layer 132 b and the first layer 132 a is formed (see FIG. 6A ).
  • an impurity is added to the oxide semiconductor film 107 with the gate electrode 104 used as a mask.
  • the impurity one or more of helium, boron, nitrogen, fluorine, neon, aluminum, phosphorus, argon, arsenic, krypton, indium, tin, antimony, and xenon may be added.
  • the impurity may be added by an ion implantation method or an ion doping method.
  • the acceleration voltage is made higher than or equal to 5 kV and lower than or equal to 100 kV.
  • the amount of the added impurity is made greater than or equal to 1 ⁇ 10 14 ions/cm 2 and less than or equal to 1 ⁇ 10 16 ions/cm 2 . After that, heat treatment may be performed.
  • the resistance of part of the oxide semiconductor film 107 is reduced.
  • regions whose resistance is reduced become the regions 106 b
  • a region whose resistance is not reduced becomes the region 106 a ; the regions 106 b and the region 106 a are collectively referred to as the oxide semiconductor film 106 .
  • the impurity may be added to the oxide semiconductor film 107 through the second layer 133 b and the first layer 133 a after the gate electrode 104 is formed.
  • the impurity may be added to the oxide semiconductor film 107 through the second layer 133 b and the first layer 133 a after the gate electrode 104 is formed.
  • the barrier film 108 is formed (see FIG. 6B ).
  • the barrier film 108 may be formed using any of the above materials for the barrier film 108 by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method.
  • second heat treatment is performed.
  • oxygen can be released from the base insulating film 102 and/or the gate insulating film 132 . Released oxygen is supplied to the oxide semiconductor film 106 , whereby oxygen vacancies can be reduced. Further, an influence of a parasitic channel can be reduced.
  • the second heat treatment may be performed under a condition similar to that of the first heat treatment.
  • the timing of the second heat treatment is not necessarily performed.
  • the transistor in FIGS. 4A to 4C can be manufactured.
  • the oxide semiconductor film 106 has few oxygen vacancies and an influence of a parasitic channel is small; thus, the transistor can have switching characteristics even when miniaturized.
  • the interlayer insulating film 118 is formed over the barrier film 108 .
  • the interlayer insulating film 118 may be formed using any of the above materials for the interlayer insulating film 118 by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method.
  • the openings are provided in the interlayer insulating film 118 and the barrier film 108 , so that the oxide semiconductor film 106 is exposed.
  • the conductive film to be the wirings 136 may be formed using any of the above materials for the wirings 136 by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method.
  • the conductive film to be the wirings 136 is processed to form the wirings 136 (see FIG. 6C ).
  • a transistor that can have switching characteristics even when miniaturized can be provided. Further, a highly integrated semiconductor device including the transistor can be provided.
  • This embodiment can be implemented in appropriate combination with any of the other embodiments.
  • FIG. 7A is a top view of a transistor according to one embodiment of the present invention.
  • FIG. 7B is a cross-sectional view taken along dashed-dotted line E 1 -E 2 in FIG. 7A .
  • FIG. 7C is a cross-sectional view taken along dashed-dotted line E 3 -E 4 in FIG. 7A . Note that a base insulating film 202 and the like are not illustrated in FIG. 7A for simplicity.
  • the channel length (L) and the channel width (W) of the transistor are shown.
  • the channel region of the transistor corresponds to a region of an oxide semiconductor film 206 overlapping with a gate electrode 204 . At least two side surfaces of the oxide semiconductor film 206 overlap with the gate electrode 204 .
  • the channel length is greater than or equal to 5 nm and less than 60 nm
  • the channel width is greater than or equal to 5 nm and less than 200 nm.
  • the ratio of the channel width to the channel length is 0.5:1 to 10:1.
  • FIG. 7B illustrates a cross-sectional structure of the transistor including the base insulating film 202 provided over a substrate 200 ; the oxide semiconductor film 206 provided over the base insulating film 202 ; a pair of electrodes 216 provided on the same layer as the oxide semiconductor film 206 ; a gate insulating film 212 provided over the oxide semiconductor film 206 ; and the gate electrode 204 provided over the gate insulating film 212 so as to overlap with the oxide semiconductor film 206 .
  • an interlayer insulating film 218 which is provided over the oxide semiconductor film 206 , the pair of electrodes 216 , and the gate electrode 204 and has openings reaching the pair of electrodes 216 , and wirings 236 provided in contact with the pair of electrodes 216 through the openings in the interlayer insulating film 218 are illustrated.
  • the substrate 200 may be formed using a material similar to that for the substrate 100 .
  • the base insulating film 202 may be formed using a material similar to that for the base insulating film 102 .
  • the gate electrode 204 may be formed using a material similar to that for the gate electrode 104 .
  • the gate insulating film 212 may be formed using a material similar to that for the gate insulating film 112 . Note that the gate insulating film 212 may have a layer structure similar to that of the gate insulating film 132 .
  • the oxide semiconductor film 206 may be formed using a material similar to that for the oxide semiconductor film 106 .
  • the interlayer insulating film 218 may be formed using a material similar to that for the interlayer insulating film 118 .
  • the wirings 236 may be formed using a material similar to that for the wirings 136 .
  • the pair of electrodes 216 may be formed of a single layer or a stacked layer of a simple substance selected from Al, Ti, Cr, Co, Ni, Cu, Y, Zr, Mo, Ag, Ta, and W; a nitride containing one or more kinds of the above substances; an oxide containing one or more kinds of the above substances; or an alloy containing one or more kinds of the above substances.
  • a barrier film may be formed over the base insulating film 202 , the pair of electrodes 216 , the oxide semiconductor film 206 , and the gate electrode 204 .
  • the barrier film may be formed using a material similar to that for the barrier film 108 , which enables the barrier film to have a function similar to that of the barrier film 108 .
  • the transistor in FIGS. 7A to 7C is different from the transistors in FIGS. 1A to 1C , FIGS. 2A to 2C , FIGS. 3A to 3C , and FIGS. 4A to 4C in the shape of the oxide semiconductor film 206 and in the presence of the pair of electrodes 216 . Therefore, for structures of the other components, the description with reference to FIGS. 1A to 1C , FIGS. 2A to 2C , FIGS. 3A to 3C , and FIGS. 4A to 4C can be referred to.
  • the transistor in FIGS. 7A to 7C has a structure in which the pair of electrodes 216 is provided instead of the regions 106 b of the oxide semiconductor film 106 in the transistor in FIGS. 1A to 1C . Therefore, the resistance between a source and a drain can be made lower than that in any of the transistors described in Embodiment 1. Accordingly, such a transistor can have excellent on-state characteristics even when miniaturized.
  • FIGS. 7A to 7C A method of manufacturing the transistor in FIGS. 7A to 7C will be described below with reference to FIGS. 8A to 8D .
  • FIGS. 8A to 8D A method of manufacturing the transistor in FIGS. 7A to 7C will be described below with reference to FIGS. 8A to 8D .
  • FIG. 7B Only cross-sectional views corresponding to FIG. 7B are illustrated for simplicity.
  • the substrate 200 is prepared.
  • the base insulating film 202 is formed over the substrate 200 .
  • the base insulating film 202 may be formed using a material and a method similar to those for the base insulating film 102 .
  • a conductive film to be the pair of electrodes 216 is formed.
  • the conductive film to be the pair of electrodes 216 may be formed using any of the above materials for the pair of electrodes 216 by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method.
  • the conductive film to be the pair of electrodes 216 is processed to form a conductive film 217 having an opening through which the base insulating film 202 is exposed.
  • the oxide semiconductor film 207 is formed (see FIG. 8A ).
  • the oxide semiconductor film 207 may be formed using any of the above materials and methods for the oxide semiconductor film 106 .
  • first heat treatment may be performed.
  • the first heat treatment described in Embodiment 1 is referred to.
  • planarization treatment is performed on the oxide semiconductor film 207 and the conductive film 217 .
  • CMP treatment or the like may be used as the planarization treatment.
  • the oxide semiconductor film is provided only in the opening in the conductive film 217 .
  • the conductive film 217 and the oxide semiconductor film provided only in the opening in the conductive film 217 are processed into an island shape, so that the oxide semiconductor film 206 and the pair of electrodes 216 are formed (see FIG. 8B ).
  • the gate insulating film 212 and the gate electrode 204 over the gate insulating film 212 are formed (see FIG. 8C ).
  • the gate insulating film 212 may be formed using a material and a method similar to those for the gate insulating film 112 or the gate insulating film 132 .
  • the gate electrode 204 may be formed using a material and a method similar to those for the gate electrode 104 .
  • the barrier film may be formed using a material and a method similar to those for the barrier film 108 .
  • the transistor in FIGS. 7A to 7C can be manufactured.
  • the oxide semiconductor film 206 has few oxygen vacancies and an influence of a parasitic channel is small; thus, the transistor can have switching characteristics even when miniaturized. Further, since the pair of electrodes 216 is provided, the transistor can have excellent on-state characteristics even when miniaturized.
  • the interlayer insulating film 218 is formed.
  • the interlayer insulating film 218 may be formed using a material and a method similar to those for the interlayer insulating film 118 .
  • the openings are provided in the interlayer insulating film 218 , so that the pair of electrodes 216 is exposed.
  • the wirings 236 are formed.
  • the wirings 236 may be formed using a material and a method similar to those for the wirings 136 (see FIG. 8D ).
  • a transistor that can have switching characteristics and excellent on-state characteristics even when miniaturized can be provided. Further, a highly integrated semiconductor device including the transistor can be provided.
  • This embodiment can be implemented in appropriate combination with any of the other embodiments.
  • FIG. 9A is a top view of a transistor according to one embodiment of the present invention.
  • FIG. 9B is a cross-sectional view taken along dashed-dotted line F 1 -F 2 in FIG. 9A .
  • FIG. 9C is a cross-sectional view taken along dashed-dotted line F 3 -F 4 in FIG. 9A . Note that a base insulating film 302 and the like are not illustrated in FIG. 9A for simplicity.
  • the channel length (L) and the channel width (W) of the transistor are shown.
  • the channel region of the transistor corresponds to a region of an oxide semiconductor film 306 overlapping with a gate electrode 304 . At least two side surfaces of the oxide semiconductor film 306 overlap with the gate electrode 304 .
  • the channel length is greater than or equal to 5 nm and less than 60 nm
  • the channel width is greater than or equal to 5 nm and less than 200 nm.
  • the ratio of the channel width to the channel length is 0.5:1 to 10:1.
  • FIG. 9B is a cross-sectional view of the transistor including the base insulating film 302 provided over a substrate 300 ; the oxide semiconductor film 306 which is provided over the base insulating film 302 and includes a first region 306 a and second regions 306 b ; a gate insulating film 312 provided over the oxide semiconductor film 306 ; the gate electrode 304 provided over the gate insulating film 312 so as to overlap with the oxide semiconductor film 306 ; an insulating film 320 provided over the gate electrode 304 ; sidewall insulating films 310 provided in contact with side surfaces of the gate electrode 304 and the insulating film 320 ; a pair of electrodes 316 provided over the oxide semiconductor film 306 and in contact with the sidewall insulating films 310 and the second regions 306 b of the oxide semiconductor film 306 ; and an interlayer insulating film 318 which is provided over the pair of electrodes 316 and whose top surface is level with that of the insulating film 320 .
  • FIG. 9B an interlayer insulating film 328 provided over the interlayer insulating film 318 and the insulating film 320 , and wirings 336 provided in contact with the pair of electrodes 316 through openings which are provided in the interlayer insulating film 318 and the interlayer insulating film 328 so as to reach the pair of electrodes 316 are illustrated.
  • the shape of the gate electrode 304 is similar to that of the insulating film 320 when seen from above.
  • the shape of the gate insulating film 312 is similar to that of the gate electrode 304 and the sidewall insulating films 310 when seen from above.
  • the first region 306 a of the oxide semiconductor film 306 serves as the channel region of the transistor.
  • the second regions 306 b of the oxide semiconductor film 306 serve as a source region and a drain region of the transistor.
  • the pair of electrodes 316 is provided close to the gate electrode 304 with the sidewall insulating films 310 interposed therebetween. Therefore, the resistance between the source and the drain can be low. Accordingly, the transistor can have excellent on-state characteristics.
  • the substrate 300 may be formed using a material similar to that for the substrate 100 .
  • the base insulating film 302 may be formed using a material similar to that for the base insulating film 102 .
  • the gate electrode 304 may be formed using a material similar to that for the gate electrode 104 .
  • the gate insulating film 312 may be formed using a material similar to that for the gate insulating film 112 . Note that the gate insulating film 312 may have a layer structure similar to that of the gate insulating film 132 .
  • the oxide semiconductor film 306 may be formed using a material similar to that for the oxide semiconductor film 106 .
  • the sidewall insulating films 310 may be formed using one or more of the following materials: aluminum oxide, aluminum nitride, magnesium oxide, silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, and tantalum oxide.
  • the insulating film 320 may be formed using one or more of the following materials: aluminum oxide, aluminum nitride, magnesium oxide, silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, and tantalum oxide.
  • the pair of electrodes 316 may be formed using a material similar to that for the pair of electrodes 216 .
  • the interlayer insulating film 318 may be formed using a material similar to that for the interlayer insulating film 218 .
  • the interlayer insulating film 328 may be formed using a material similar to that for the interlayer insulating film 218 .
  • the wirings 336 may be formed using a material similar to that for the wirings 136 .
  • a barrier film may be formed over the base insulating film 302 , the pair of electrodes 316 , the oxide semiconductor film 306 , the insulating film 320 , and the gate electrode 304 .
  • the barrier film may be formed using a material similar to that for the barrier film 108 , which enables the barrier film to have a function similar to that of the barrier film 108 .
  • FIGS. 9A to 9C A method of manufacturing the transistor in FIGS. 9A to 9C will be described below with reference to FIGS. 10A to 10C , FIGS. 11A to 11C , and FIGS. 12A to 12C .
  • FIGS. 9B Only cross-sectional views corresponding to FIG. 9B are illustrated for simplicity.
  • the substrate 300 is prepared.
  • the base insulating film 302 is formed.
  • the base insulating film 302 may be formed using a material and a method similar to those for the base insulating film 102 .
  • the oxide semiconductor film 307 may be formed using a material and a method similar to those for the oxide semiconductor film 107 .
  • the gate insulating film 313 may be formed using a material and a method similar to those for the gate insulating film 112 or the gate insulating film 132 .
  • the conductive film 305 may be formed using any of the above materials for the gate electrode 304 by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method.
  • the insulating film 321 may be formed using any of the above materials for the insulating film 320 by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method.
  • the insulating film 321 and the conductive film 305 are processed, whereby an insulating film 322 and the gate electrode 304 are formed (see FIG. 10B ).
  • the shape of the insulating film 322 is similar to that of the gate electrode 304 when seen from above.
  • an impurity is added to the oxide semiconductor film 307 with the insulating film 322 and the gate electrode 304 used as masks.
  • the impurity one or more of helium, boron, nitrogen, fluorine, neon, aluminum, phosphorus, argon, arsenic, krypton, indium, tin, antimony, and xenon may be added.
  • the impurity may be added by an ion implantation method or an ion doping method.
  • an ion implantation method is used.
  • the acceleration voltage is made higher than or equal to 5 kV and lower than or equal to 100 kV.
  • the amount of the added impurity is made greater than or equal to 1 ⁇ 10 14 ions/cm 2 and less than or equal to 1 ⁇ 10 16 ions/cm 2 . After that, heat treatment may be performed.
  • the oxide semiconductor film 306 including the first region 306 a and the second regions 306 b is formed (see FIG. 10C ).
  • an insulating film to be the sidewall insulating films 310 is formed.
  • the insulating film to be the sidewall insulating films 310 may be formed using any of the above materials for the sidewall insulating films 310 by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method. Then, highly anisotropic etching treatment is performed on the insulating film to be the sidewall insulating films 310 , whereby the sidewall insulating films 310 can be formed in contact with side surfaces of the insulating film 322 and the gate electrode 304 .
  • Processing of the gate insulating film 313 with the sidewall insulating films 310 and the gate electrode 304 used as masks is performed at the same time as the formation of the sidewall insulating films 310 , whereby the gate insulating film 312 is formed (see FIG. 11A ).
  • the conductive film 317 may be formed using any of the above materials for the pair of electrodes 316 by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method.
  • second heat treatment is performed.
  • oxygen can be released from the base insulating film 302 and/or the gate insulating film 312 . Released oxygen is supplied to the oxide semiconductor film 306 , whereby oxygen vacancies can be reduced.
  • the second heat treatment may be performed under a condition similar to that of the second heat treatment described in Embodiment 1.
  • the second heat treatment is not necessarily performed just after the formation of the conductive film 317 ; there is no particular limitation on the timing of the second heat treatment as long as it is after the formation of the conductive film 317 .
  • the interlayer insulating film 319 may be formed using any of the above materials for the interlayer insulating film 318 by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method.
  • planarization treatment (such as CMP treatment or dry etching treatment) is performed from the upper surface side of the interlayer insulating film 319 , whereby the pair of electrodes 316 , the interlayer insulating film 318 , the sidewall insulating films 310 , and the insulating film 320 are formed (see FIG. 12A ).
  • the planarization treatment By performing the planarization treatment from the upper surface side of the interlayer insulating film 319 , only a region of the conductive film 317 overlapping with the insulating film 322 (and the gate electrode 304 ) can be removed. At that time, the insulating film 322 is also subjected to the planarization treatment to be the insulating film 320 with a smaller thickness.
  • the pair of electrodes 316 can be provided close to the gate electrode 304 with the sidewall insulating films 310 interposed therebetween.
  • the transistor in FIGS. 9A to 9C can be manufactured.
  • the oxide semiconductor film 306 has few oxygen vacancies and an influence of a parasitic channel is small; thus, the transistor can have switching characteristics even when miniaturized. Further, since the pair of electrodes 316 is provided, the transistor can have excellent on-state characteristics even when miniaturized.
  • the interlayer insulating film 328 is formed (see FIG. 12B ).
  • the interlayer insulating film 328 may be formed using any of the above materials for the interlayer insulating film 328 by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method.
  • the interlayer insulating film 328 and the interlayer insulating film 318 are processed, so that the openings through which the pair of electrodes 316 is exposed are formed.
  • the wirings 336 are formed (see FIG. 12C ).
  • the wirings 336 may be formed using a material and a method similar to those for the wirings 136 .
  • a transistor that can have switching characteristics and excellent on-state characteristics even when miniaturized can be provided. Further, a highly integrated semiconductor device including the transistor can be provided.
  • This embodiment can be implemented in appropriate combination with any of the other embodiments.
  • FIG. 13A is a top view of a transistor according to one embodiment of the present invention.
  • FIG. 13B is a cross-sectional view taken along dashed-dotted line G 1 -G 2 in FIG. 13A .
  • FIG. 13C is a cross-sectional view taken along dashed-dotted line G 3 -G 4 in FIG. 13A . Note that a base insulating film 402 and the like are not illustrated in FIG. 13A for simplicity.
  • the channel length (L) and the channel width (W) of the transistor are shown.
  • the channel region of the transistor corresponds to a region of an oxide semiconductor film 406 overlapping with a gate electrode 404 . At least two side surfaces of the oxide semiconductor film 406 overlap with the gate electrode 404 .
  • the channel length is greater than or equal to 5 nm and less than 60 nm
  • the channel width is greater than or equal to 5 nm and less than 200 nm.
  • the ratio of the channel width to the channel length is 0.5:1 to 10:1.
  • FIG. 13B illustrates a cross-sectional structure of the transistor including the base insulating film 402 provided over a substrate 400 ; the oxide semiconductor film 406 which is provided over the base insulating film 402 and whose thickness is 1 to 5 times as large as the channel width; a gate insulating film 412 provided over the oxide semiconductor film 406 ; and the gate electrode 404 provided over the gate insulating film 412 so as to overlap with the oxide semiconductor film 406 .
  • an interlayer insulating film 418 which is provided over the oxide semiconductor film 406 and the gate electrode 404 and has openings reaching the oxide semiconductor film 406 , and wirings 436 provided in contact with the oxide semiconductor film 406 through the openings in the interlayer insulating film 418 are illustrated.
  • the transistor in FIGS. 13A to 13C is a so-called fin transistor.
  • the fin transistor can have a large conduction path of carriers because of its thick channel region, and can have excellent on-state characteristics even in the case where the channel width is small.
  • a depletion layer due to an electric field of a gate is not completely extended because of its thick channel region; thus, there is a problem in that it is difficult to completely turn off the transistor.
  • a depletion layer due to an electric field of a gate can be sufficiently extended even when a channel region is thick; thus, the transistor can be turned off.
  • the substrate 400 may be formed using a material similar to that for the substrate 100 .
  • the base insulating film 402 may be formed using a material similar to that for the base insulating film 102 .
  • the gate electrode 404 may be formed using a material similar to that for the gate electrode 104 .
  • the gate insulating film 412 may be formed using a material similar to that for the gate insulating film 112 . Note that the gate insulating film 412 may have a layer structure similar to that of the gate insulating film 132 .
  • the oxide semiconductor film 406 may be formed using a material similar to that for the oxide semiconductor film 106 .
  • the thickness of the oxide semiconductor film 406 is greater than or equal to 100 nm and less than 2 ⁇ m.
  • the interlayer insulating film 418 may be formed using a material similar to that for the interlayer insulating film 118 .
  • the wirings 436 may be formed using a material similar to that for the wirings 136 .
  • a barrier film may be formed over the base insulating film 402 , the oxide semiconductor film 406 , and the gate electrode 404 .
  • the barrier film may be formed using a material similar to that for the barrier film 108 , which enables the barrier film to have a function similar to that of the barrier film 108 .
  • FIGS. 13A to 13C A method of manufacturing the transistor in FIGS. 13A to 13C will be described below with reference to FIGS. 14A to 14C .
  • FIGS. 14A to 14C Only cross-sectional views corresponding to FIG. 13B are illustrated for simplicity.
  • the substrate 400 is prepared.
  • the base insulating film 402 is formed over the substrate 400 .
  • the base insulating film 402 may be formed using a material and a method similar to those for the base insulating film 102 .
  • the oxide semiconductor film 407 is formed (see FIG. 14A ).
  • the oxide semiconductor film 407 may be formed using a material and a method similar to those for the oxide semiconductor film 107 .
  • the gate insulating film 412 and the gate electrode 404 over the gate insulating film 412 are formed (see FIG. 14B ).
  • the gate insulating film 412 may be formed using a material and a method similar to those for the gate insulating film 112 or the gate insulating film 132 .
  • the gate electrode 404 may be formed using a material and a method similar to those for the gate electrode 104 .
  • an impurity is added to the oxide semiconductor film 407 with the gate electrode 404 used as a mask.
  • the impurity one or more of helium, boron, nitrogen, fluorine, neon, aluminum, phosphorus, argon, arsenic, krypton, indium, tin, antimony, and xenon may be added.
  • the impurity may be added by an ion implantation method or an ion doping method.
  • an ion implantation method is used.
  • the acceleration voltage is made higher than or equal to 5 kV and lower than or equal to 100 kV.
  • the amount of the added impurity is made greater than or equal to 1 ⁇ 10 14 ions/cm 2 and less than or equal to 1 ⁇ 10 16 ions/cm 2 . After that, heat treatment may be performed.
  • the barrier film may be formed using a material and a method similar to those for the barrier film 108 .
  • the transistor in FIGS. 13A to 13C can be manufactured.
  • the oxide semiconductor film 406 has few oxygen vacancies and an influence of a parasitic channel is small; thus, the transistor can have switching characteristics even when miniaturized. Further, since the thickness of the oxide semiconductor film 406 is 1 to 5 times as large as the channel width, the transistor can have excellent on-state characteristics even when miniaturized.
  • the interlayer insulating film 418 is formed.
  • the interlayer insulating film 418 may be formed using a material and a method similar to those for the interlayer insulating film 118 .
  • the openings are provided in the interlayer insulating film 418 , so that the oxide semiconductor film 406 is exposed.
  • the wirings 436 are formed.
  • the wirings 436 may be formed using a material and a method similar to those for the wirings 136 (see FIG. 14C ).
  • a transistor that can have switching characteristics and excellent on-state characteristics even when miniaturized can be provided. Further, a highly integrated semiconductor device including the transistor can be provided.
  • This embodiment can be implemented in appropriate combination with any of the other embodiments.
  • FIG. 15A is a top view of a transistor according to one embodiment of the present invention.
  • FIG. 15B is a cross-sectional view taken along dashed-dotted line H 1 -H 2 in FIG. 15A .
  • FIG. 15C is a cross-sectional view taken along dashed-dotted line H 3 -H 4 in FIG. 15A . Note that a base insulating film 502 and the like are not illustrated in FIG. 15A for simplicity.
  • the channel length (L) and the channel width (W) of the transistor are shown.
  • the channel region of the transistor corresponds to a region of the oxide semiconductor film 506 which is located between a pair of electrodes 516 when seen from above. At least two side surfaces of the oxide semiconductor film 506 overlap with the gate electrode 504 .
  • the channel length is greater than or equal to 5 nm and less than 60 nm
  • the channel width is greater than or equal to 5 nm and less than 200 nm.
  • the ratio of the channel width to the channel length is 0.5:1 to 10:1.
  • FIG. 15B is a cross-sectional view of the transistor including the base insulating film 502 provided over a substrate 500 ; the gate electrode 504 provided over the base insulating film 502 ; a gate insulating film 512 provided over the gate electrode 504 ; the oxide semiconductor film 506 provided so as to overlap with the gate electrode 504 with the gate insulating film 512 therebetween; the pair of electrodes 516 provided over the oxide semiconductor film 506 ; and an interlayer insulating film 518 provided over the pair of electrodes 516 .
  • the substrate 500 may be formed using a material similar to that for the substrate 100 .
  • the base insulating film 502 is provided in order that an impurity due to the substrate 500 is prevented from affecting the oxide semiconductor film 506 . Note that in the case where the substrate 500 does not include an impurity, the base insulating film 502 is not necessarily provided. Further, in the case where an impurity can be prevented from being diffused by the gate insulating film 512 , the base insulating film 502 is not necessarily provided.
  • the base insulating film 502 may be formed of a single layer or a stacked layer using one or more of the following materials: aluminum oxide, aluminum nitride, magnesium oxide, silicon oxide, silicon oxynitride, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, and tantalum oxide.
  • silicon nitride oxide or silicon nitride may be stacked.
  • the gate electrode 504 may be formed using a material similar to that for the gate electrode 104 .
  • the gate insulating film 512 may be formed using a material similar to that for the gate insulating film 112 or the gate insulating film 132 .
  • the oxide semiconductor film 506 may be formed using a material similar to that for the oxide semiconductor film 106 .
  • the pair of electrodes 516 may be formed using a material similar to that for the pair of electrodes 216 .
  • the interlayer insulating film 518 may be formed of a single layer or a stacked layer using one or more of the following materials: aluminum oxide, aluminum nitride, magnesium oxide, silicon oxide, silicon oxynitride, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, and tantalum oxide.
  • silicon nitride oxide or silicon nitride may be stacked.
  • the interlayer insulating film 518 have low relative permittivity and a sufficient thickness.
  • a silicon oxide film having a relative permittivity of approximately 3.8 and a thickness greater than or equal to 200 nm and less than or equal to 1000 nm may be provided.
  • a top surface of the interlayer insulating film 518 has a little fixed charge because of the influence of atmospheric components and the like, which might cause the shift of the threshold voltage of the transistor. Therefore, it is preferable that the interlayer insulating film 518 have relative permittivity and a thickness such that the influence of the charge at the top surface is sufficiently reduced.
  • a resin film of a polyimide resin, an acrylic resin, an epoxy resin, a silicone resin, or the like may be formed over the interlayer insulating film 518 in order to reduce the influence of the charge at the top surface of the interlayer insulating film 518 .
  • FIGS. 15A to 15C A method of manufacturing the transistor in FIGS. 15A to 15C will be described below with reference to FIGS. 16A to 16C .
  • FIGS. 16A to 16C A method of manufacturing the transistor in FIGS. 15A to 15C will be described below with reference to FIGS. 16A to 16C .
  • FIG. 15B Only cross-sectional views corresponding to FIG. 15B are illustrated for simplicity.
  • the substrate 500 is prepared.
  • the base insulating film 502 is formed over the substrate 500 .
  • the base insulating film 502 may be formed using any of the above materials for the base insulating film 502 by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method.
  • the gate electrode 504 is formed.
  • the gate electrode 504 may be formed using a material and a method similar to those for the gate electrode 104 .
  • the gate insulating film 512 is formed (see FIG. 16A ).
  • the gate insulating film 512 may be formed using a material and a method similar to those for the gate insulating film 112 or the gate insulating film 132 .
  • the oxide semiconductor film 506 is formed (see FIG. 16B ).
  • the oxide semiconductor film 506 may be formed using a material and a method similar to those for the oxide semiconductor film 107 .
  • a conductive film to be the pair of electrodes 516 is formed.
  • the conductive film to be the pair of electrodes 516 may be formed using any of the above materials for the pair of electrodes 516 by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method.
  • the conductive film to be the pair of electrodes 516 is processed to form the pair of electrodes 516 .
  • an electron beam drawing equipment also referred to as electron beam (EB) lithography system
  • An EB lithography system enables extremely minute processing, and thus is suitable for manufacturing a miniaturized transistor.
  • the interlayer insulating film 518 is formed (see FIG. 16C ).
  • the interlayer insulating film 518 may be formed using any of the above materials for the interlayer insulating film 518 by a sputtering method, a CVD method, an MBE method, an ALD method, or a PLD method.
  • the transistor in FIGS. 15A to 15C can be manufactured.
  • the oxide semiconductor film 506 has few oxygen vacancies and an influence of a parasitic channel is small; thus, the transistor can have switching characteristics even when miniaturized. Further, since the pair of electrodes 516 is provided, the transistor can have excellent on-state characteristics even when miniaturized.
  • a transistor that can have switching characteristics and excellent on-state characteristics even when miniaturized can be provided. Further, a highly integrated semiconductor device including the transistor can be provided.
  • This embodiment can be implemented in appropriate combination with any of the other embodiments.
  • Typical examples of a volatile semiconductor memory device include a dynamic random access memory (DRAM) which stores data by selecting a transistor included in a memory element and accumulating an electric charge in a capacitor, and a static random access memory (SRAM) which holds stored data using a circuit such as a flip-flop.
  • DRAM dynamic random access memory
  • SRAM static random access memory
  • Typical examples of a nonvolatile semiconductor memory device include a flash memory which has a floating gate between a gate and a channel region of a transistor and stores data by holding an electric charge in the floating gate.
  • any of the transistors described in Embodiments 1 to 5 can be applied to some of transistors included in the above-described semiconductor memory device.
  • a memory cell includes a bit line BL, a word line WL, a sense amplifier SAmp, a transistor Tr, and a capacitor C (see FIG. 17A ).
  • the voltage held in the capacitor C is gradually decreased with time as shown in FIG. 17B owing to the off-state current of the transistor Tr.
  • a voltage originally charged from V 0 to V 1 is decreased with time to VA that is a limit for reading out data 1 .
  • This period is called a holding period T_ 1 .
  • refresh operation needs to be performed within the holding period T_ 1 .
  • the holding period T_ 1 can be increased because the off-state current of the transistor is extremely small. That is, frequency of the refresh operation can be reduced; thus, power consumption can be reduced.
  • a memory cell is formed using the transistor Tr having an off-state current of 1 ⁇ 10 ⁇ 21 A to 1 ⁇ 10 ⁇ 25 A, data can be held for several days to several decades without supply of electric power.
  • the area of the memory cell can be made smaller because the transistor is miniaturized. Accordingly, the integration degree of the semiconductor memory device can be increased.
  • FIG. 17C illustrates an example of a cross-sectional structure of the memory cell. Note that in FIG. 17C , the transistor in FIGS. 4A to 4C is used as the transistor Tr. Therefore, for components of the transistor Tr which are not described below, the description in Embodiment 1 or the like can be referred to.
  • the capacitor C over the base insulating film 102 includes an electrode 116 which is in contact with the region 106 b of the transistor Tr; an insulating layer which is formed from the same layer and the same material as the gate insulating film 132 ; and an electrode (capacitor electrode) which is formed from the same layer and the same material as the gate electrode 104 .
  • the electrode 116 is embedded in the base insulating film 102 in FIG. 17C ; however, the shape of the electrode 116 is not limited thereto.
  • the electrode 116 may have any shape as long as the electrode 116 is provided over the base insulating film 102 and in contact with the region 106 b of the transistor Tr.
  • the electrode 116 may be formed of a single layer or a stacked layer of a simple substance selected from Al, Ti, Cr, Co, Ni, Cu, Y, Zr, Mo, Ag, Ta, and W; a nitride containing one or more kinds of the above substances; an oxide containing one or more kinds of the above substances; or an alloy containing one or more kinds of the above substances.
  • the word line WL is electrically connected to the gate electrode 104 .
  • the bit line BL is electrically connected to the wiring 136 .
  • the transistor Tr and the capacitor C include the electrodes formed from the same layer and the same material and the insulating films formed from the same layer and the same material; thus, the number of manufacturing steps can be reduced and the productivity can be improved.
  • the transistor Tr and the capacitor C do not necessarily include the electrodes formed from the same layer and the same material and the insulating films formed from the same layer and the same material.
  • the area of the memory cell may be made smaller by providing the transistor Tr and the capacitor C so as to overlap with each other.
  • a semiconductor memory device with high degree of integration and low power consumption can be provided.
  • FIGS. 17A to 17C a memory cell in a semiconductor device including any of the transistors in Embodiments 1 to 5, which is a different example from FIGS. 17A to 17C , will be described with reference to FIGS. 18A to 18C .
  • FIG. 18A is a circuit diagram of a memory cell.
  • the memory cell includes a transistor Tr_ 1 , a word line WL_ 1 electrically connected to a gate of the transistor Tr_ 1 , a source line SL_ 1 electrically connected to a source of the transistor Tr_ 1 , a transistor Tr_ 2 , a source line SL_ 2 electrically connected to a source of the transistor Tr_ 2 , a drain line DL_ 2 electrically connected to a drain of the transistor Tr_ 2 , a capacitor C, a capacitor line CL electrically connected to one terminal of the capacitor C, and a node N electrically connected to the other terminal of the capacitor C, a drain of the transistor Tr_ 1 , and a gate of the transistor Tr_ 2 .
  • the semiconductor memory device described in this embodiment utilizes variation in the apparent threshold voltage of the transistor Tr_ 2 , which depends on the potential of the node N.
  • FIG. 18B shows a relation between a voltage V CL of the capacitor line CL and a drain current I d — 2 flowing through the transistor Tr_ 2 .
  • the potential of the node N can be controlled through the transistor Tr_ 1 .
  • the potential of the source line SL_ 1 is set to VDD.
  • the potential of the word line WL_ 1 when the potential of the word line WL_ 1 is set to be higher than or equal to a potential obtained by adding VDD to the threshold voltage Vth of the transistor Tr_ 1 , the potential of the node N can be HIGH. Further, when the potential of the word line WL_ 1 is set to be lower than or equal to the threshold voltage Vth of the transistor Tr_ 1 , the potential of the node N can be LOW.
  • the off-state current of the transistor can be significantly reduced; therefore, unintentional leakage of an electric charge accumulated in the node N by flowing between the source and the drain of the transistor Tr_ 1 can be suppressed. As a result, data can be held for a long time. Since high voltage is not needed in data writing, power consumption can be made small and operation speed can be high as compared to a flash memory or the like.
  • the area of the memory cell can be made smaller because the transistor is miniaturized. Accordingly, the integration degree of the semiconductor memory device can be increased.
  • FIG. 18C illustrates an example of a cross-sectional structure of the memory cell. Note that in FIG. 18C , the transistor in FIGS. 4A to 4C is used as the transistor Tr_ 1 . Therefore, for components of the transistor Tr_ 1 which are not described below, the description in Embodiment 1 or the like can be referred to.
  • transistor Tr_ 2 the case where a transistor including silicon is used as the transistor Tr_ 2 will be described. Note that any of the transistors described in Embodiments 1 to 5 may be used as the transistor Tr_ 2 .
  • the transistor including silicon has an advantage that on-state characteristics can be easily improved in comparison with the transistors described in Embodiments 1 to 5. Therefore, it can be said that the transistor including silicon is suitable for not the transistor Tr_ 1 for which small off-state current is required but the transistor Tr_ 2 for which excellent on-state characteristics are required.
  • the transistor Tr_ 2 includes a base insulating film 152 provided over a substrate 150 ; a silicon film 156 which is provided over the base insulating film 152 and includes a region 156 a and regions 156 b ; a gate insulating film 162 provided over the silicon film 156 ; a gate electrode 154 which is provided over the gate insulating film 162 so as to overlap with the silicon film 156 ; and a sidewall insulating films 160 in contact with sidewalls of the gate insulating film 162 and the gate electrode 154 .
  • an interlayer insulating film 158 is provided over the transistor Tr_ 2 , and a hydrogen-containing layer 168 is provided over the interlayer insulating film 158 .
  • the substrate 150 may be formed using a material similar to that for the substrate 100 .
  • the base insulating film 152 may be formed using a material similar to that for the base insulating film 102 .
  • a silicon film such as a single crystal silicon film or a polycrystalline silicon film may be used as the silicon film 156 .
  • the region 156 a functions as a channel region.
  • the regions 156 b function as a source region and a drain region.
  • the silicon film is used for the channel region and the source and drain regions in this embodiment; however, in the case where the substrate 150 is a semiconductor substrate such as a silicon wafer, the channel region and the source and drain regions may be provided in the semiconductor substrate.
  • the gate insulating film 162 may be formed using a material similar to that for the gate insulating film 112 .
  • the gate electrode 154 may be formed using a material similar to that for the gate electrode 104 .
  • the sidewall insulating films 160 may be formed using a material similar to that for the sidewall insulating films 310 .
  • the interlayer insulating film 158 may be formed using a material similar to that for the interlayer insulating film 118 . Note that a resin film of a polyimide resin, an acrylic resin, an epoxy resin, a silicone resin, or the like may be formed over the interlayer insulating film 158 .
  • the hydrogen-containing layer 168 is formed using an insulating film in which the hydrogen concentration measured by secondary ion mass spectrometry (SIMS) is 1 ⁇ 10 21 atoms/cm 3 or higher.
  • SIMS secondary ion mass spectrometry
  • the hydrogen-containing layer 168 may be formed using, for example, a silicon nitride oxide film or a silicon nitride film.
  • the transistor Tr_ 2 is a transistor including silicon, the electric characteristics of the transistor Tr_ 2 can be improved by terminating dangling bonds on a surface of the silicon film 156 with hydrogen. For that reason, hydrogen is preferably supplied from the hydrogen-containing layer 168 . Note that this embodiment is not limited to the structure where the hydrogen-containing layer 168 is provided. For example, hydrogen may be supplied to the transistor Tr_ 2 without using the hydrogen-containing layer 168 .
  • a layer having low hydrogen permeability may be provided between the hydrogen-containing layer 168 and the base insulating film 102 .
  • the transistor Tr_ 1 is a transistor including an oxide semiconductor film. Since hydrogen serves as a source of carriers in the oxide semiconductor film, hydrogen is preferably prevented from entering the oxide semiconductor film as much as possible. For that reason, in the case where the hydrogen-containing layer 168 is provided, diffusion of hydrogen to the transistor Tr_ 1 is preferably prevented by the layer having low hydrogen permeability.
  • the layer having low hydrogen permeability is formed using, for example, an insulating film through which hydrogen does not pass even when heat treatment is performed at 350° C. for one hour.
  • the capacitor C over the base insulating film 102 includes an electrode 166 which is in contact with the region 106 b of the transistor Tr_ 1 ; an insulating layer which is formed from the same layer and the same material as the gate insulating film 132 ; and an electrode (capacitor electrode) which is formed from the same layer and the same material as the gate electrode 104 .
  • the electrode 166 is in contact with the gate electrode 154 of the transistor Tr_ 2 through an opening provided in the base insulating film 102 , the hydrogen-containing layer 168 , and the interlayer insulating film 158 .
  • the electrode 166 is embedded in the base insulating film 102 in FIG. 18C ; however, the shape of the electrode 166 is not limited thereto.
  • the electrode 166 may have any shape as long as the electrode 166 is provided over the base insulating film 102 and in contact with the region 106 b of the transistor Tr_ 1 and the gate electrode 154 of the transistor Tr_ 2 .
  • the electrode 166 may be formed of a single layer or a stacked layer of a simple substance selected from Al, Ti, Cr, Co, Ni, Cu, Y, Zr, Mo, Ag, Ta, and W; a nitride containing one or more kinds of the above substances; an oxide containing one or more kinds of the above substances; or an alloy containing one or more kinds of the above substances.
  • the word line WL_ 1 is electrically connected to the gate electrode 104 .
  • the source line SL_ 1 is electrically connected to the wiring 136 .
  • the capacitor line CL is electrically connected to the capacitor electrode.
  • the transistor Tr_ 1 and the capacitor C include the electrodes formed from the same layer and the same material and the insulating films formed from the same layer and the same material; thus, the number of manufacturing steps can be reduced and the productivity can be improved.
  • the transistor Tr_ 1 and the capacitor C do not necessarily include the electrodes formed from the same layer and the same material and the insulating films formed from the same layer and the same material.
  • the area of the memory cell may be made smaller by providing the transistor Tr_ 1 and the capacitor C so as to overlap with each other.
  • a semiconductor memory device with high degree of integration and low power consumption can be provided.
  • This embodiment can be implemented in appropriate combination with any of the other embodiments.
  • a central processing unit can be formed using any of the transistors described in Embodiments 1 to 5 or the semiconductor memory device described in Embodiment 6 for at least part of the CPU.
  • FIG. 19A is a block diagram illustrating a specific structure of the CPU.
  • the CPU illustrated in FIG. 19A includes an arithmetic logic unit (ALU) 1191 , an ALU controller 1192 , an instruction decoder 1193 , an interrupt controller 1194 , a timing controller 1195 , a register 1196 , a register controller 1197 , a bus interface (Bus I/F) 1198 , a rewritable ROM 1199 , and a ROM interface (ROM I/F) 1189 over a substrate 1190 .
  • a semiconductor substrate, an SOI substrate, a glass substrate, or the like is used as the substrate 1190 .
  • the ROM 1199 and the ROM interface 1189 may be provided over a separate chip.
  • the CPU shown in FIG. 19A is just an example in which the configuration has been simplified, and an actual CPU may have various configurations depending on the application.
  • An instruction that is input to the CPU through the bus interface 1198 is input to the instruction decoder 1193 and decoded therein, and then, input to the ALU controller 1192 , the interrupt controller 1194 , the register controller 1197 , and the timing controller 1195 .
  • the ALU controller 1192 , the interrupt controller 1194 , the register controller 1197 , and the timing controller 1195 conduct various controls in accordance with the decoded instruction. Specifically, the ALU controller 1192 generates signals for controlling the operation of the ALU 1191 . While the CPU is executing a program, the interrupt controller 1194 determines an interrupt request from an external input/output device or a peripheral circuit on the basis of its priority or a mask state, and processes the request. The register controller 1197 generates an address of the register 1196 , and reads/writes data from/to the register 1196 in accordance with the state of the CPU.
  • the timing controller 1195 generates signals for controlling operation timings of the ALU 1191 , the ALU controller 1192 , the instruction decoder 1193 , the interrupt controller 1194 , and the register controller 1197 .
  • the timing controller 1195 includes an internal clock generator for generating an internal clock signal CLK 2 based on a reference clock signal CLK 1 , and supplies the clock signal CLK 2 to the above circuits.
  • a memory element is provided in the register 1196 .
  • the memory element in the register 1196 for example, the semiconductor memory device described in Embodiment 6 can be used.
  • the register controller 1197 selects operation of retaining data in the register 1196 in accordance with an instruction from the ALU 1191 . That is, the register controller 1197 selects whether data is retained by a flip-flop or a capacitor in the memory element included in the register 1196 . When data is retained by the flip-flop, a power supply voltage is supplied to the memory element in the register 1196 . When data is retained by the capacitor, the data in the capacitor is rewritten, and supply of the power supply voltage to the memory element in the register 1196 can be stopped.
  • FIGS. 19B and 19C each illustrate an example of a structure including any of the transistors described in Embodiments 1 to 5 as a switching element for controlling supply of a power supply potential to a memory element.
  • the memory device illustrated in FIG. 19B includes a switching element 1141 and a memory element group 1143 including a plurality of memory elements 1142 .
  • the semiconductor memory device described in Embodiment 6 can be used as each of the memory elements 1142 .
  • Each of the memory elements 1142 included in the memory element group 1143 is supplied with the high-level power supply potential VDD through the switching element 1141 . Further, each of the memory elements 1142 included in the memory element group 1143 is supplied with a potential of a signal IN and a potential of the low-level power supply potential VSS.
  • a transistor with an extremely small off-state current is used as the switching element 1141 , and the switching of the transistor is controlled by a signal SigA supplied to a gate thereof.
  • FIG. 19B illustrates the structure in which the switching element 1141 includes only one transistor; however, without limitation thereon, the switching element 1141 may include a plurality of transistors.
  • the switching element 1141 includes a plurality of transistors which serves as switching elements, the plurality of transistors may be connected to each other in parallel, in series, or in combination of parallel connection and series connection.
  • FIG. 19C an example of a memory device in which each of the memory elements 1142 included in the memory element group 1143 is supplied with the low-level power supply potential VSS through the switching element 1141 is illustrated.
  • the supply of the low-level power supply potential VSS to each of the memory elements 1142 included in the memory element group 1143 can be controlled by the switching element 1141 .
  • the transistor and the semiconductor memory device can also be applied to an LSI such as a digital signal processor (DSP), a custom LSI, or a field programmable gate array (FPGA).
  • DSP digital signal processor
  • FPGA field programmable gate array
  • This embodiment can be implemented in appropriate combination with any of the other embodiments.
  • FIG. 20A illustrates a portable information terminal.
  • the portable information terminal illustrated in FIG. 20A includes a housing 9300 , a button 9301 , a microphone 9302 , a display portion 9303 , a speaker 9304 , and a camera 9305 , and has a function as a mobile phone.
  • One embodiment of the present invention can be applied to an arithmetic unit, a wireless circuit, or a memory circuit in a main body.
  • FIG. 20B illustrates a display, which includes a housing 9310 and a display portion 9311 .
  • One embodiment of the present invention can be applied to an arithmetic unit, a wireless circuit, or a memory circuit in a main body.
  • FIG. 20C illustrates a digital still camera.
  • the digital still camera illustrated in FIG. 20C includes a housing 9320 , a button 9321 , a microphone 9322 , and a display portion 9323 .
  • One embodiment of the present invention can be applied to an arithmetic unit, a wireless circuit, or a memory circuit in a main body.
  • FIG. 20D illustrates a double-foldable portable information terminal.
  • the double-foldable portable information terminal illustrated in FIG. 20D includes a housing 9630 , a display portion 9631 a , a display portion 9631 b , a hinge 9633 , and an operation switch 9638 .
  • One embodiment of the present invention can be applied to an arithmetic unit, a wireless circuit, or a memory circuit in a main body.
  • Part or the whole of the display portion 9631 a and/or the display portion 9631 b can function as a touch panel. By touching an operation key displayed on the touch panel, a user can input data, for example.
  • the performance of an electronic device can be improved and the power consumption of the electronic device can be reduced.
  • This embodiment can be implemented in appropriate combination with any of the other embodiments.

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Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8969867B2 (en) 2012-01-18 2015-03-03 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
US20150084046A1 (en) * 2013-09-23 2015-03-26 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
US9012913B2 (en) 2012-01-10 2015-04-21 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing semiconductor device
US9029863B2 (en) 2012-04-20 2015-05-12 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing the same
US20150162452A1 (en) * 2013-12-06 2015-06-11 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
US9105658B2 (en) 2013-01-30 2015-08-11 Semiconductor Energy Laboratory Co., Ltd. Method for processing oxide semiconductor layer
US20160054362A1 (en) * 2014-08-25 2016-02-25 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for measuring current of semiconductor device
US9318484B2 (en) 2013-02-20 2016-04-19 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
JP2016167591A (ja) * 2015-03-03 2016-09-15 株式会社半導体エネルギー研究所 半導体装置およびその作製方法、ならびに電子機器
US9704704B2 (en) 2014-10-28 2017-07-11 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and display device including the same
US9722091B2 (en) 2014-09-12 2017-08-01 Semiconductor Energy Laboratory Co., Ltd. Method for manufacturing semiconductor device
US9768314B2 (en) 2013-01-21 2017-09-19 Semiconductor Energy Laboratory Co., Ltd. Method for manufacturing semiconductor device
US9905435B2 (en) 2014-09-12 2018-02-27 Semiconductor Energy Laboratory Co., Ltd. Manufacturing method of semiconductor device comprising oxide semiconductor film
US10020322B2 (en) 2015-12-29 2018-07-10 Semiconductor Energy Laboratory Co., Ltd. Transistor and semiconductor device
US10236287B2 (en) 2013-09-23 2019-03-19 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device including semiconductor electrically surrounded by electric field of conductive film
US10304961B2 (en) 2014-01-28 2019-05-28 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
JP2019091935A (ja) * 2013-12-27 2019-06-13 株式会社半導体エネルギー研究所 半導体装置
US10361290B2 (en) 2014-03-14 2019-07-23 Semiconductor Energy Laboratory Co., Ltd. Method for manufacturing semiconductor device comprising adding oxygen to buffer film and insulating film
US10680116B2 (en) 2014-02-05 2020-06-09 Semiconductor Energy Laboratory Co., Ltd. Manufacturing method of semiconductor device including oxide semiconductor
US10784284B2 (en) 2015-11-13 2020-09-22 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing the same
US10872982B2 (en) 2012-02-28 2020-12-22 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing the same
US11133402B2 (en) 2014-08-22 2021-09-28 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device, method for manufacturing semiconductor device, and electronic appliance having semiconductor device
US11133337B2 (en) 2017-10-26 2021-09-28 Japan Display Inc. Display device and method for manufacturing same
EP3896736A1 (en) * 2020-04-17 2021-10-20 Samsung Display Co., Ltd. Display device and method for manufacturing the same
CN114512497A (zh) * 2020-11-11 2022-05-17 武汉天马微电子有限公司 薄膜晶体管电路及薄膜晶体管电路的制造方法
US20230066509A1 (en) * 2021-08-27 2023-03-02 United Microelectronics Corp. Semiconductor device and method for fabricating the same
US20240021150A1 (en) * 2017-12-25 2024-01-18 Semiconductor Energy Laboratory Co., Ltd. Display and electronic device including the display
US12062723B2 (en) 2018-09-07 2024-08-13 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing semiconductor device
US12249652B2 (en) 2020-11-11 2025-03-11 Wuhan Tianma Micro-Electronics Co., Ltd. Oxide semiconductor thin-film transistor and method of manufacturing oxide semiconductor thin-film transistor
US12349460B2 (en) 2013-11-29 2025-07-01 Semiconductor Energy Laboratory Co., Ltd. Manufacturing method of semiconductor device
US12364126B2 (en) 2020-11-10 2025-07-15 Lg Display Co., Ltd. Display device

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9590109B2 (en) * 2013-08-30 2017-03-07 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing the same
BR112016001909B1 (pt) 2013-09-02 2022-03-08 Philip Morris Products S.A. Método e aparelho para fabricação de material para rede frisada variável
JP6345544B2 (ja) * 2013-09-05 2018-06-20 株式会社半導体エネルギー研究所 半導体装置の作製方法
DE102014220672A1 (de) * 2013-10-22 2015-05-07 Semiconductor Energy Laboratory Co., Ltd. Halbleitervorrichtung
TWI642186B (zh) * 2013-12-18 2018-11-21 日商半導體能源研究所股份有限公司 半導體裝置
US9461179B2 (en) * 2014-07-11 2016-10-04 Semiconductor Energy Laboratory Co., Ltd. Thin film transistor device (TFT) comprising stacked oxide semiconductor layers and having a surrounded channel structure
KR102316103B1 (ko) * 2014-12-02 2021-10-26 엘지디스플레이 주식회사 수소 공급 박막을 구비한 산화물 반도체를 포함하는 박막 트랜지스터 기판
CN114695562A (zh) * 2015-05-22 2022-07-01 株式会社半导体能源研究所 半导体装置以及包括该半导体装置的显示装置
US11024725B2 (en) * 2015-07-24 2021-06-01 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device including metal oxide film
JP6925819B2 (ja) * 2017-02-17 2021-08-25 株式会社半導体エネルギー研究所 半導体装置の作製方法
JP2019125789A (ja) * 2019-01-23 2019-07-25 株式会社半導体エネルギー研究所 半導体装置
KR20220096469A (ko) * 2020-12-31 2022-07-07 엘지디스플레이 주식회사 중첩된 화소 구동부들을 포함하는 표시장치

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060199305A1 (en) * 2005-02-13 2006-09-07 Neng-Kuo Chen Method for fabricating ultra-high tensile-stressed film and strained-silicon transistors thereof
US20100301340A1 (en) * 2009-06-01 2010-12-02 Ishiang Shih Thin film transistors and arrays
US20110127523A1 (en) * 2009-11-28 2011-06-02 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and manufacturing method thereof
US20110133191A1 (en) * 2009-12-04 2011-06-09 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and manufacturing method thereof
US20110147738A1 (en) * 2009-12-18 2011-06-23 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing the same
US20110182110A1 (en) * 2010-01-22 2011-07-28 Semiconductor Energy Laboratory Co., Ltd. Semiconductor memory device and driving method thereof
US20110215326A1 (en) * 2010-03-08 2011-09-08 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing semiconductor device

Family Cites Families (51)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04134832A (ja) 1990-09-27 1992-05-08 Toshiba Corp 電界効果トランジスタ
JPH0990416A (ja) * 1995-09-26 1997-04-04 Toshiba Corp 液晶表示装置の製造方法およびそれに用いられる薄膜トランジスタの製造方法
JP2895963B2 (ja) * 1996-01-29 1999-05-31 株式会社大貴 動物用排泄物処理材及びその製造方法
JPH09318975A (ja) * 1996-05-30 1997-12-12 Nec Corp 薄膜電界効果型トランジスタ素子アレイおよびその製造 方法
JP2000216387A (ja) * 1999-01-21 2000-08-04 Sony Corp 半導体装置およびその製造方法
JP4372939B2 (ja) 1999-02-12 2009-11-25 株式会社半導体エネルギー研究所 半導体装置の作製方法
JP2002033331A (ja) * 2000-05-12 2002-01-31 Semiconductor Energy Lab Co Ltd 半導体装置及びその作製方法
JP2002050764A (ja) * 2000-08-02 2002-02-15 Matsushita Electric Ind Co Ltd 薄膜トランジスタ、アレイ基板、液晶表示装置、有機ｅｌ表示装置およびその製造方法
JP2002329869A (ja) * 2001-04-27 2002-11-15 Matsushita Electric Ind Co Ltd 半導体装置の製造方法
TW586144B (en) * 2002-11-15 2004-05-01 Toppoly Optoelectronics Corp Method of forming a liquid crystal display
US7112458B2 (en) * 2003-10-02 2006-09-26 Tpo Displays Corp. Method of forming a liquid crystal display
JP2005116977A (ja) * 2003-10-10 2005-04-28 Sharp Corp 薄膜トランジスタおよびその製造方法
JP2005268724A (ja) * 2004-03-22 2005-09-29 Sony Corp 電子素子およびその製造方法
JP4405458B2 (ja) 2005-10-31 2010-01-27 株式会社東芝 半導体装置
JP5015470B2 (ja) * 2006-02-15 2012-08-29 財団法人高知県産業振興センター 薄膜トランジスタ及びその製法
US20070215945A1 (en) * 2006-03-20 2007-09-20 Canon Kabushiki Kaisha Light control device and display
WO2007142167A1 (en) 2006-06-02 2007-12-13 Kochi Industrial Promotion Center Semiconductor device including an oxide semiconductor thin film layer of zinc oxide and manufacturing method thereof
JP4404881B2 (ja) * 2006-08-09 2010-01-27 日本電気株式会社 薄膜トランジスタアレイ、その製造方法及び液晶表示装置
JP4609797B2 (ja) * 2006-08-09 2011-01-12 Ｎｅｃ液晶テクノロジー株式会社 薄膜デバイス及びその製造方法
JP2008187084A (ja) * 2007-01-31 2008-08-14 Oki Electric Ind Co Ltd 半導体装置の製造方法
JP2008216940A (ja) * 2007-03-08 2008-09-18 Seiko Epson Corp 電気光学装置の製造方法
US8232598B2 (en) * 2007-09-20 2012-07-31 Semiconductor Energy Laboratory Co., Ltd. Display device and method for manufacturing the same
US7972898B2 (en) * 2007-09-26 2011-07-05 Eastman Kodak Company Process for making doped zinc oxide
JP5430846B2 (ja) * 2007-12-03 2014-03-05 株式会社半導体エネルギー研究所 半導体装置の作製方法
JP2009170794A (ja) * 2008-01-18 2009-07-30 Advanced Lcd Technologies Development Center Co Ltd 薄膜半導体装置の製造方法
JP5414203B2 (ja) * 2008-05-23 2014-02-12 株式会社半導体エネルギー研究所 半導体装置の作製方法
JP5552753B2 (ja) * 2008-10-08 2014-07-16 ソニー株式会社 薄膜トランジスタおよび表示装置
KR101547326B1 (ko) * 2008-12-04 2015-08-26 삼성전자주식회사 트랜지스터 및 그 제조방법
US8441007B2 (en) * 2008-12-25 2013-05-14 Semiconductor Energy Laboratory Co., Ltd. Display device and manufacturing method thereof
JP2010263064A (ja) * 2009-05-07 2010-11-18 Videocon Global Ltd 薄膜トランジスタ、液晶表示装置及びこれらの製造方法
JP2011071476A (ja) * 2009-08-25 2011-04-07 Canon Inc 薄膜トランジスタ、薄膜トランジスタを用いた表示装置及び薄膜トランジスタの製造方法
CN116343705B (zh) * 2009-10-16 2025-08-26 株式会社半导体能源研究所 显示设备
JP5397175B2 (ja) * 2009-11-13 2014-01-22 セイコーエプソン株式会社 半導体装置用基板及びその製造方法、半導体装置並びに電子機器
KR101813460B1 (ko) * 2009-12-18 2017-12-29 가부시키가이샤 한도오따이 에네루기 켄큐쇼 반도체 장치
WO2011086847A1 (en) * 2010-01-15 2011-07-21 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
KR101810261B1 (ko) * 2010-02-10 2017-12-18 가부시키가이샤 한도오따이 에네루기 켄큐쇼 전계 효과 트랜지스터
WO2011102217A1 (en) * 2010-02-19 2011-08-25 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing the same
WO2011108475A1 (en) * 2010-03-04 2011-09-09 Semiconductor Energy Laboratory Co., Ltd. Semiconductor memory device and semiconductor device
WO2011114905A1 (en) * 2010-03-19 2011-09-22 Semiconductor Energy Laboratory Co., Ltd. Semiconductor memory device
KR102001820B1 (ko) * 2010-03-19 2019-07-19 가부시키가이샤 한도오따이 에네루기 켄큐쇼 반도체 장치 및 반도체 장치 구동 방법
JP5708910B2 (ja) * 2010-03-30 2015-04-30 ソニー株式会社 薄膜トランジスタおよびその製造方法、並びに表示装置
KR102292523B1 (ko) * 2010-04-02 2021-08-20 가부시키가이샤 한도오따이 에네루기 켄큐쇼 반도체 장치
WO2011129233A1 (en) * 2010-04-16 2011-10-20 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
KR101689378B1 (ko) * 2010-04-23 2016-12-26 가부시키가이샤 한도오따이 에네루기 켄큐쇼 반도체 장치의 제작 방법
WO2011135999A1 (en) * 2010-04-27 2011-11-03 Semiconductor Energy Laboratory Co., Ltd. Semiconductor memory device
TWI511236B (zh) * 2010-05-14 2015-12-01 Semiconductor Energy Lab 半導體裝置
WO2011142371A1 (en) * 2010-05-14 2011-11-17 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
WO2011145634A1 (en) * 2010-05-21 2011-11-24 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
WO2011152233A1 (en) * 2010-06-04 2011-12-08 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
TWI543166B (zh) * 2010-09-13 2016-07-21 半導體能源研究所股份有限公司 半導體裝置
JP5352599B2 (ja) * 2011-01-17 2013-11-27 株式会社半導体エネルギー研究所 半導体装置

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060199305A1 (en) * 2005-02-13 2006-09-07 Neng-Kuo Chen Method for fabricating ultra-high tensile-stressed film and strained-silicon transistors thereof
US20100301340A1 (en) * 2009-06-01 2010-12-02 Ishiang Shih Thin film transistors and arrays
US20110127523A1 (en) * 2009-11-28 2011-06-02 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and manufacturing method thereof
US20110133191A1 (en) * 2009-12-04 2011-06-09 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and manufacturing method thereof
US20110147738A1 (en) * 2009-12-18 2011-06-23 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing the same
US20110182110A1 (en) * 2010-01-22 2011-07-28 Semiconductor Energy Laboratory Co., Ltd. Semiconductor memory device and driving method thereof
US20110215326A1 (en) * 2010-03-08 2011-09-08 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing semiconductor device

Cited By (59)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9012913B2 (en) 2012-01-10 2015-04-21 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing semiconductor device
US8969867B2 (en) 2012-01-18 2015-03-03 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
US10483402B2 (en) 2012-01-18 2019-11-19 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
US9614100B2 (en) 2012-01-18 2017-04-04 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
US10872982B2 (en) 2012-02-28 2020-12-22 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing the same
US9570593B2 (en) 2012-04-20 2017-02-14 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing the same
US9029863B2 (en) 2012-04-20 2015-05-12 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing the same
US10964821B2 (en) 2013-01-21 2021-03-30 Semiconductor Energy Laboratory Co., Ltd. Method for manufacturing semiconductor device
US11380802B2 (en) 2013-01-21 2022-07-05 Semiconductor Energy Laboratory Co., Ltd. Method for manufacturing semiconductor device
US9768314B2 (en) 2013-01-21 2017-09-19 Semiconductor Energy Laboratory Co., Ltd. Method for manufacturing semiconductor device
US11888071B2 (en) 2013-01-21 2024-01-30 Semiconductor Energy Laboratory Co., Ltd. Method for manufacturing semiconductor device
US10050153B2 (en) 2013-01-21 2018-08-14 Semiconductor Energy Laboratory Co., Ltd. Method for manufacturing semiconductor device
US9306077B2 (en) 2013-01-30 2016-04-05 Semiconductor Energy Laboratory Co., Ltd. Method for processing oxide semiconductor layer
US9105658B2 (en) 2013-01-30 2015-08-11 Semiconductor Energy Laboratory Co., Ltd. Method for processing oxide semiconductor layer
US9318484B2 (en) 2013-02-20 2016-04-19 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
US10068906B2 (en) 2013-02-20 2018-09-04 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device including oxide semiconductor transistors with low power consumption
US20150084046A1 (en) * 2013-09-23 2015-03-26 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
US10236287B2 (en) 2013-09-23 2019-03-19 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device including semiconductor electrically surrounded by electric field of conductive film
US10217736B2 (en) * 2013-09-23 2019-02-26 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device including transistor and capacitor
US12349460B2 (en) 2013-11-29 2025-07-01 Semiconductor Energy Laboratory Co., Ltd. Manufacturing method of semiconductor device
US9923097B2 (en) * 2013-12-06 2018-03-20 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
US20150162452A1 (en) * 2013-12-06 2015-06-11 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
JP2019091935A (ja) * 2013-12-27 2019-06-13 株式会社半導体エネルギー研究所 半導体装置
US10304961B2 (en) 2014-01-28 2019-05-28 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
US10680116B2 (en) 2014-02-05 2020-06-09 Semiconductor Energy Laboratory Co., Ltd. Manufacturing method of semiconductor device including oxide semiconductor
US11942555B2 (en) 2014-02-05 2024-03-26 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and manufacturing method thereof
US11011648B2 (en) 2014-02-05 2021-05-18 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and manufacturing method thereof
US12283634B2 (en) 2014-02-05 2025-04-22 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and manufacturing method thereof
US11640996B2 (en) 2014-02-05 2023-05-02 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and manufacturing method thereof
US10361290B2 (en) 2014-03-14 2019-07-23 Semiconductor Energy Laboratory Co., Ltd. Method for manufacturing semiconductor device comprising adding oxygen to buffer film and insulating film
US11876126B2 (en) 2014-03-14 2024-01-16 Semiconductor Energy Laboratory Co., Ltd. Method for manufacturing semiconductor device
US11094804B2 (en) 2014-03-14 2021-08-17 Semiconductor Energy Laboratory Co., Ltd. Method for manufacturing semiconductor device
US11133402B2 (en) 2014-08-22 2021-09-28 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device, method for manufacturing semiconductor device, and electronic appliance having semiconductor device
US11600705B2 (en) 2014-08-25 2023-03-07 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for measuring current of semiconductor device
US20160054362A1 (en) * 2014-08-25 2016-02-25 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for measuring current of semiconductor device
US10559667B2 (en) * 2014-08-25 2020-02-11 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for measuring current of semiconductor device
US9722091B2 (en) 2014-09-12 2017-08-01 Semiconductor Energy Laboratory Co., Ltd. Method for manufacturing semiconductor device
US9905435B2 (en) 2014-09-12 2018-02-27 Semiconductor Energy Laboratory Co., Ltd. Manufacturing method of semiconductor device comprising oxide semiconductor film
US10438815B2 (en) 2014-09-12 2019-10-08 Semiconductor Energy Laboratory Co., Ltd. Manufacturing method of semiconductor device comprising oxide semiconductor film
US11862454B2 (en) 2014-10-28 2024-01-02 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and display device including the same
US9704704B2 (en) 2014-10-28 2017-07-11 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and display device including the same
US10529864B2 (en) 2014-10-28 2020-01-07 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and display device including the same
US11158745B2 (en) 2014-10-28 2021-10-26 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and display device including the same
JP2016167591A (ja) * 2015-03-03 2016-09-15 株式会社半導体エネルギー研究所 半導体装置およびその作製方法、ならびに電子機器
US10784284B2 (en) 2015-11-13 2020-09-22 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing the same
US11271013B2 (en) 2015-11-13 2022-03-08 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device including a plug
US10020322B2 (en) 2015-12-29 2018-07-10 Semiconductor Energy Laboratory Co., Ltd. Transistor and semiconductor device
US11133337B2 (en) 2017-10-26 2021-09-28 Japan Display Inc. Display device and method for manufacturing same
US12347364B2 (en) * 2017-12-25 2025-07-01 Semiconductor Energy Laboratory Co., Ltd. Display and electronic device including the display
US20240021150A1 (en) * 2017-12-25 2024-01-18 Semiconductor Energy Laboratory Co., Ltd. Display and electronic device including the display
US12062723B2 (en) 2018-09-07 2024-08-13 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and method for manufacturing semiconductor device
EP3896736A1 (en) * 2020-04-17 2021-10-20 Samsung Display Co., Ltd. Display device and method for manufacturing the same
US11469283B2 (en) 2020-04-17 2022-10-11 Samsung Display Co., Ltd. Display device and method for manufacturing the same
US12364126B2 (en) 2020-11-10 2025-07-15 Lg Display Co., Ltd. Display device
US12224353B2 (en) 2020-11-11 2025-02-11 Wuhan Tianma Micro-Electronics Co., Ltd. Thin-film transistor circuit and method of manufacturing thin-film transistor circuit
US12249652B2 (en) 2020-11-11 2025-03-11 Wuhan Tianma Micro-Electronics Co., Ltd. Oxide semiconductor thin-film transistor and method of manufacturing oxide semiconductor thin-film transistor
CN114512497A (zh) * 2020-11-11 2022-05-17 武汉天马微电子有限公司 薄膜晶体管电路及薄膜晶体管电路的制造方法
US12041784B2 (en) * 2021-08-27 2024-07-16 United Microelectronics Corp. Semiconductor device and method for fabricating the same
US20230066509A1 (en) * 2021-08-27 2023-03-02 United Microelectronics Corp. Semiconductor device and method for fabricating the same

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