摘要:
In a semiconductor crystal growth apparatus, a growth vessel enclosing a substrate is evacuated to an ultrahigh vacuum, and gas molecules containing a component element of a semiconductor which should grow on the substrate is introduced according to a predetermined time sequence into the growth vessel from an external gas source. Infrared radiation from an infrared radiation emitting lamp associated with the growth vessel and controlled by a temperature control unit is directed toward and onto the substrate whose temperature is to be maintained at a predetermined setting. Crystal growth of one molecular layer after another can be achieved by the apparatus with dimensional accuracy of the thickness of a single molecular layer.
摘要:
A substrate is heated in a crystal growth vessel evacuated to a ultrahigh vacuum, and gases containing component elements of a crystal to be grown on the substrate are introduced into the vessel under predetermined conditions to cause successive epitaxial growth of single molecular layers, the number of growth cycles being automatically controlled. A mass analyzer is disposed opposite to the substrate in the vessel so that the progress of crystal growth can be incessantly traced and evaluated for each of the molecular layers. An etchant gas introduction nozzle extends into the vessel to make etching treatment of the surface of the substrate in the evacuated vessel prior to the crystal growth.
摘要:
The thickness of a thin film of an element semiconductor may be determined by counting the number of cycles of gaseous component introductions within a crystal growth vessel. Each cycle permits at most one monolayer of growth since the pressure in the vessel during gaseous component introduction is maintained under a saturation condition. The temperature to which a substrate in the vessel is heated is that for which epitaxial growth results.
摘要:
A GaAs monocrystal film was grown by use of a process which comprises introducing a gaseous compound containing a component element desired to be grown into a vacuum tank, and submitting the compound to reaction on a base to thereby grow a semiconductor crystal each one molecular layer.Triethylgallium (TEG) and arsine (AsH.sub.3) are used as the gaseous compound. One gas is introduced into the vaccum tank and then discharged after the passage of a predetermined time, and the other gas is introduced thereinto and then discharged after the passage of a predetermined time whereby a crystal for one molecular layer grows.By use of TEG as a gallium source, reaction progresses even when a temperature of the base is below 300.degree. C., and a GaAs monocrystal film which is extremely less in lattice failure and impurities was obtained.
摘要:
A cycle of alternately or cyclically introducing external gases containing molecules of component elements of a compound semiconductor to be formed on a substrate is repeated while appropriately controlling the pressure, substrate temperature and gas introduction rate in a crystal growth vessel, so that a monocrystal which is dimensionally as precise as a single monolayer can grow on the substrate by making use of chemical reactions on the heated substrate surface. Doped molecular layer epitaxy of a compound semiconductor comprising individual steps of introducing and evacuating a first source gas, introducing and evacuating a second source gas, and introducing and evacuating an impurity gas which contains an impurity element. The doped impurity concentration varies almost linearly with the pressure during doping in a wide range.
摘要:
In a semiconductor crystal growth apparatus, a substrate is heated in a growth vessel evacuated to a ultrahigh vacuum, and gas containing component elements of a semiconductor which should grow on the substrate are introduced into the growth vessel from external gas sources. Radiation having a specific wavelength is directed from an external irradiation source toward and onto the substrate.
摘要:
A substrate is heated in a crystal growth vessel evacuated to a ultrahigh vacuum, and gases containing component elements of a crystal to be grown on the substrate are introduced into the vessel under predetermined conditions to cause successive epitaxial growth of single molecular layers, the number of growth cycles being automatically controlled. A mass analyzer is disposed opposite to the substrate in the vessel so that the progress of crystal growth can be incessantly traced and evaluated for each of the molecular layers. An etchant gas introduction nozzle extends into the vessel to make etching treatment of the surface of the substrate in the evacuated vessel prior to the crystal growth.
摘要:
Between a source electrode (25) of a main device (24) and a current sensing electrode (22) of a current detection device (21), a resistor for detecting current is connected. Dielectric withstand voltage of gate insulator (36) is larger than a product of the resistor and maximal current flowing through the current detection device (21) with reverse bias. A diffusion length of a p-body region (32) of the main device (24) is shorter than that of a p-body (31) of the current detection device (21). A curvature radius at an end portion of the p-body region (32) of the main device (24) is smaller than that of the p-body (31) of the current detection device (21). As a result, at the inverse bias, electric field at the end portion of the p-body region (32) of the main device (24) becomes stronger than that of the p-body region (31) of the current detection device (21). Consequently, avalanche breakdown tends to occur earlier in the main device 24 than the current detection device (21).
摘要:
An engine air intake system for an engine-powered working machine includes a lever cover which covers at least a base portion of an operation control lever mounted on an operation handle for operation by a human operator to control operation of at least one of the working machine and an engine of the working machine, a lower cover disposed inside the lever cover so as to define jointly with the lever cover a hollow space, an air intake portion having an air inlet opening and disposed in the lever cover such that at least the air inlet opening is disposed within the hollow space, and a fresh air guide hose interconnecting the air intake portion and the interior of an air-cleaner case.
摘要:
Disclosed is an engine fuel supply apparatus which can be made smaller in size and in which the amount of fuel in an air-fuel mixture can be increased with a fast response in correspondence with the operation of a throttle valve when the engine is accelerated rapidly. The fuel supply apparatus is provided with a fuel booster pump. A portion of an air-fuel mixture is introduced into a negative-pressure chamber of the fuel booster pump via a negative-pressure chamber channel, and the fuel booster pump is actuated. The actuation forces air in a pump chamber to flow into a pressure chamber, and fuel in a fuel storage chamber is temporarily supplied to a carburetor.