Abstract: A write-once memory can be written only once to each memory cell; therefore, a defective bit cannot be detected by an actual inspection of writing. Accordingly, as described above, the measures, in which a redundant circuit is provided and the defective bit is modified before shipping, cannot be taken; thus, it is difficult to provide a memory with few defects. It is an object of the present invention to provide a write-once memory where the probability of a defect is reduced considerably. A nonvolatile memory that can be written only once includes a redundant memory cell, a first circuit which allocates an address to the redundant memory cell, a second circuit which outputs a determination signal that expresses whether writing is performed normally or not, and a third circuit, to which the determination signal is inputted, which controls the first circuit and the second circuit.

Abstract: By doping an organic compound functioning as an electron donor (hereinafter referred to as donor molecules) into an organic compound layer contacting a cathode, donor levels can be formed between respective LUMO (lowest unoccupied molecular orbital) levels between the cathode and the organic compound layer, and therefore electrons can be injected from the cathode, and transmission of the injected electrons can be performed with good efficiency. Further, there are no problems such as excessive energy loss, deterioration of the organic compound layer itself, and the like accompanying electron movement, and therefore an increase in the electron injecting characteristics and a decrease in the driver voltage can both be achieved without depending on the work function of the cathode material.

Abstract: The present invention provides a radio field intensity measurement device having a display portion with improved visibility, in the case of measuring a weak radiowave from a long distance. In the radio field intensity measurement device, a battery is provided as a power source for power supply and the battery is charged by a received radiowave. When a potential of a signal obtained from the received radiowave is higher than an output potential of the battery, the power is stored in the battery. On the other hand, when the potential of the signal obtained from the received radiowave is lower than the output potential of the battery, power produced by the battery is used as power to drive the radio field intensity measurement device. As an element to display the radio field intensity, a thermochromic element or an electrochromic element is used.

Abstract: A material suitable for a semiconductor included in a transistor, a diode, or the like is provided. The material is an oxide material including In, M1, M2 and Zn, in which M1 is an element in the group 13 of the periodic table, a typical example thereof is Ga, and M2 is an element whose content is less than the content of M1. Examples of M2 are Ti, Zr, Hf, Ge, Sn, and the like. To contain M2 leads to suppression of generation of oxygen vacancies in the oxide material. A transistor which includes as few oxygen vacancies as possible can be achieved, whereby reliability of a semiconductor device can be increased.

Abstract: To suppress a decrease in on-state current in a semiconductor device including an oxide semiconductor. A semiconductor device includes an insulating film containing silicon, an oxide semiconductor film over the insulating film, a gate insulating film containing silicon over the oxide semiconductor film, a gate electrode which is over the gate insulating film and overlaps with at least the oxide semiconductor film, and a source electrode and a drain electrode which are electrically connected to the oxide semiconductor film. In the semiconductor device, the oxide semiconductor film which overlaps with at least the gate electrode includes a region in which a concentration of silicon distributed from an interface with the insulating film is lower than or equal to 1.1 at.%. In addition, a concentration of silicon contained in a remaining portion of the oxide semiconductor film except the region is lower than the concentration of silicon contained in the region.

Abstract: Defective display by a liquid crystal display device is reduced. In a liquid crystal composition which contains a liquid crystal material exhibiting a blue phase and has a transmission spectrum with a single peak in a temperature range where the liquid crystal material exhibits a blue phase, it is found that the blue phase of the liquid crystal material can be stabilized in a wide temperature range by polymer stabilization treatment. Thus, the liquid crystal composition allows the polymer stabilization treatment to be achieved in a wider temperature range. This makes it possible to reduce defective orientation in a composite of polymer and liquid crystal formed by subjecting the liquid crystal composition to the treatment. As a result, it is possible to reduce defective display by a liquid crystal display device which includes the composite of polymer and liquid crystal.

Abstract: An object is to manufacture a semiconductor device including an oxide semiconductor at low cost with high productivity in such a manner that a photolithography process is simplified by reducing the number of light-exposure masks. In a method for manufacturing a semiconductor device including a channel-etched inverted-stagger thin film transistor, an oxide semiconductor film and a conductive film are etched using a mask layer formed with the use of a multi-tone mask which is a light-exposure mask through which light is transmitted so as to have a plurality of intensities. The etching step is performed by wet etching in which an etching solution is used.

Abstract: A highly reliable semiconductor device and a method for manufacturing the semiconductor device are provided. In a semiconductor device including a bottom-gate transistor in which an insulating layer functioning as a channel protective film is provided over an oxide semiconductor film, elements contained in an etching gas can be prevented from remaining as impurities on a surface of the oxide semiconductor film by performing impurity-removing process after formation of an insulating layer provided over and in contact with the oxide semiconductor film and/or formation of source and drain electrode layers. The impurity concentration in the surface of the oxide semiconductor film is lower than or equal to 5×1018 atoms/cm3, preferably lower than or equal to 1×1018 atoms/cm3.

Abstract: Hydrogen concentration and oxygen vacancies in an oxide semiconductor film are reduced. Reliability of a semiconductor device which includes a transistor using an oxide semiconductor film is improved. One embodiment of the present invention is a semiconductor device which includes a base insulating film; an oxide semiconductor film formed over the base insulating film; a gate insulating film formed over the oxide semiconductor film; and a gate electrode overlapping with the oxide semiconductor film with the gate insulating film provided therebetween. The base insulating film shows a signal at a g value of 2.01 by electron spin resonance. The oxide semiconductor film does not show a signal at a g value of 1.93 by electron spin resonance.

Abstract: Provided are a method of heating a composition which is applicable to a substrate provided with a material having low heat resistance and a method of forming a glass pattern which leads to reduction of cracks. A composition formed over a substrate is irradiated with a laser beam to bake the paste through local heating. Scan with the laser beam is, performed so that there can be no difference in the laser beam irradiation period between the middle portion and the perimeter portion of the composition. Specifically, irradiation with the laser beam is performed so that the width of the beam spot overlapping with the composition in the scanning direction is substantially uniform.

Abstract: In a conventional DRAM, data read errors are more likely to occur along with miniaturization of DRAM. A small change in the potential of a first bit line is inverted by a first inverter constituted by an n-channel transistor and a p-channel transistor, and is output to a second bit line through a first selection transistor, which is a first switch. Since the potential of the second bit line is the inverse of the potential of the first bit line, the potential difference between the first bit line and the second bit line is increased. The increased potential difference is amplified by a known sense amplifier, a flip-flop circuit composed of the first inverter and a second inverter (constituted by an n-channel transistor and a p-channel transistor), or the like.

Abstract: A semiconductor memory device in which capacitance of a capacitor is lower and integration degree is higher. A plurality of memory blocks is connected to one bit line BL_m. A memory block MB_n_m includes a sub bit line SBL_n_m, a write switch, and a plurality of memory cells. A sub bit line SBL_n+1_m adjacent to the sub bit line SBL_n_m is connected to an amplifier circuit AMP_n/n+1_m including two inverters and two selection switches. A circuit configuration of the amplifier circuit can be changed with the selection switches. The amplifier circuit is connected to the bit line BL_m through a read switch. Because of a sufficiently low capacitance of the sub bit line SBL_n_m, potential change due to electric charges of the capacitor in each memory cell can be amplified by the amplifier circuit AMP_n/n+1_m without an error, and the amplified data can be output to the bit line BL_m.

Abstract: A current drive circuit which can improve a rate for signal writing and a driving rate of an element even when a signal current is small, and a display device using the current drive circuit are provided. The current drive circuit for supplying a signal current to a node of a driven circuit through a signal line includes a precharge function for supplying a precharge voltage to the node through the signal line and the precharge function includes a supply function for supplying the precharge voltage to the node and the signal line prior to supplying the signal current.

Abstract: An object is to provide a semiconductor device with a novel structure in which stored data can be retained even when power is not supplied, and does not have a limitation on the number of times of writing operations. A semiconductor device includes a source-bit line, a first signal line, a second signal line, a word line, and a memory cell connected between the source-bit lines. The memory cell includes a first transistor, a second transistor, and a capacitor. The second transistor is formed including an oxide semiconductor material. A gate electrode of the first transistor, one of a source and drain electrodes, and one of electrodes of the capacitor are electrically connected to one another. The source-bit line and a source electrode of the first transistor are electrically connected to each other. Another source-bit line adjacent to the above source-bit line and a drain electrode of the first transistor are electrically connected to each other.

Abstract: When a semiconductor device including a transistor in which a gate electrode layer, a gate insulating film, and an oxide semiconductor film are stacked and a source and drain electrode layers are provided in contact with the oxide semiconductor film is manufactured, after the formation of the gate electrode layer or the source and drain electrode layers by an etching step, a step of removing a residue remaining by the etching step and existing on a surface of the gate electrode layer or a surface of the oxide semiconductor film and in the vicinity of the surface is performed. The surface density of the residue on the surface of the oxide semiconductor film or the gate electrode layer can be 1×1013 atoms/cm2 or lower.

Abstract: Objects are to provide a semiconductor device for high power application in which a novel semiconductor material having high productivity is used and to provide a semiconductor device having a novel structure in which a novel semiconductor material is used. The present invention is a vertical transistor and a vertical diode each of which has a stacked body of an oxide semiconductor in which a first oxide semiconductor film having crystallinity and a second oxide semiconductor film having crystallinity are stacked. An impurity serving as an electron donor (donor) which is contained in the stacked body of an oxide semiconductor is removed in a step of crystal growth; therefore, the stacked body of an oxide semiconductor is highly purified and is an intrinsic semiconductor or a substantially intrinsic semiconductor whose carrier density is low. The stacked body of an oxide semiconductor has a wider band gap than a silicon semiconductor.

Abstract: To provide a highly reliable semiconductor device which includes a transistor including an oxide semiconductor, in a semiconductor device including a staggered transistor having a bottom-gate structure provided over a glass substrate, a gate insulating film in which a first gate insulating film and a second gate insulating film, whose compositions are different from each other, are stacked in this order is provided over a gate electrode layer. Alternatively, in a staggered transistor having a bottom-gate structure, a protective insulating film is provided between a glass substrate and a gate electrode layer. A metal element contained in the glass substrate has a concentration lower than or equal to 5×1018 atoms/cm3 (preferably, lower than or equal to 1×1018 atoms/cm3) at the interface between the first gate insulating film and the second gate insulating film or the interface between the gate electrode layer and a gate insulating film.

Abstract: When writing a signal current from a current source to a current source circuit, noise occurs in some cases in a wiring through which a current flows, which may cause a potential of the wiring to be outside the normal range. As the potential does not turn back within the normal range easily at this time, writing to the current source circuit is delayed. According to the invention, when the potential becomes outside the normal range due to noise occurring in a wiring through which a current flows when writing a signal current from a current source to a current source circuit, a current is supplied from other than the current source, thereby the potential of the wiring can turn back within the normal range rapidly.

Abstract: A load, a transistor which controls a current value supplied to the load, a capacitor, a power supply line, and first to third switches are provided. After a threshold voltage of the transistor is held by the capacitor, a potential in accordance with a video signal is inputted and a voltage that is the sum of the threshold voltage and the potential is held. Accordingly, variation in current value caused by variation in threshold voltage of the transistor can be suppressed. Therefore, a desired current can be supplied to a load such as a light emitting element. In addition, a display device with a high duty ratio can be provided by changing a potential of the power supply line.

Abstract: In a conventional display device comprising a sub-display, the display device is increased in thickness and in the number of components as the number of displays is increased. In the present invention, a dual emission display device is used so that either surface of a display is used as a main display or a sub-display. Accordingly, the display device can be reduced in thickness and in the number of components. Further, mechanical reliability can be enhanced when the invention is applied to a tablet PC, a video camera and the like.