90 results about "Acceptor impurity" patented technology

A thin film transistor (1) wherein a gate electrode (3) is formed on an insulative substrate (2), a gate insulating layer (4) is formed on the gate electrode (3), a semiconductor layer (5) is formed on the gate insulating layer (4), a source electrode (6) and a drain electrode (7) are formed on the semiconductor layer (5), and a protective layer (8) covering them are formed. The semiconductor layer (5) is isolated from the atmosphere. The semiconductor layer (5) (active layer) is formed of a ZnO polycrystalline semiconductor doped with, for example, a group V element. Since the surface state of the ZnO semiconductor is reduced thanks to the protective layer (8) and inward expansion of the depletion layer is prevented, the ZnO semiconductor is of an n-type showing its intrinsic resistance value and contains excessive free electrons. The added element acts as acceptor impurities in the ZnO semiconductor, decreasing the excessive electrons. Thus the gate voltage to eliminate the excessive free electrons lowers, thereby making the threshold voltage around 0 V. A semiconductor device using a zinc oxide for an active layer and having a protective layer for isolating the active layer from the atmosphere can be actually used.

An n-cap layer is formed on a top surface of p-type clad layers, the p-type clad layer is a top layer of a stacked structure having a pn-junction for emitting carriers into light-emitting region of a GaN based light-emitting device, thus increasing the activation ratio of acceptor impurities in the p-type clad layers. The n-cap layer is used also as a current blocking layer, thereby constructing a current-blocked structure. The n-cap layer should preferably be made of InuAlvGa1-u-vN (0<u, v<1) deposited as thick as 1.0 micron or more. The present invention will easily provide a high luminous efficiency GaN based semiconductor light-emitting device without using any complicated processes such as electron-beam irradiation or thermal annealing.

Disclosed is a semi-insulating silicon carbide mono-crystal, which comprises intrinsic point defects, deep level dopants, background shallow donors, and acceptor impurities; wherein the concentration sum of the deep level dopants and the intrinsic point defects is larger than the difference between the shallow donors and the acceptor impurities, and the concentration of the intrinsic point defects is smaller than that of the deep level dopants. Resistivity of the semi-insulating silicon carbide mono-crystal is larger than 1x105 omega.cm at the room temperature, and electric properties and crystal quality meet the producing requirements of corresponding microwave devices. According to the mono-crystal, shallow level impurities are compensated through the combined action of the deep level dopants and the intrinsic point defects to obtain high-quality semi-insulating mono-crystals; resistivity is not obviously decreased and maintains over 1x105 omega.cm after annealing the mono-crystals at a temperature of 1800 DEG C.

The present invention relates to a semiconductor device including a thin film transistor comprising a microcrystalline semiconductor which forms a channel formation region and includes an acceptor impurity element, and to a manufacturing method thereof. A gate electrode, a gate insulating film formed over the gate electrode, a first semiconductor layer which is formed over the gate insulating film and is formed of a microcrystalline semiconductor, a second semiconductor layer which is formed over the first semiconductor layer and includes an amorphous semiconductor, and a source region and a drain region which are formed over the second semiconductor layer are provided in the thin film transistor. A channel is formed in the first semiconductor layer when the thin film transistor is placed in an on state.

The present invention relates to the production of electrochemical capacitors with a DEL. The proposed electrodes with DEL are based on non-metal conducting materials, including porous carbon materials, and are capable of providing for high specific energy, capacity and power parameters of electrochemical capacitors. P-type conductivity and high concentration of holes in electrode materials may be provided by thermal, ionic or electrochemical doping by acceptor impurities; irradiating by high-energy fast particles or quantums; or chemical, electrochemical and/or thermal treatment. The present invention allows for an increase in specific energy, capacity and power parameters, as well as a reduction in the cost of various electrochemical capacitors with DEL. The proposed electrodes with DEL can be used as positive and/or negative electrodes of symmetric and asymmetric electrochemical capacitors with aqueous and non-aqueous electrolytes.

An emission layer (5) for a light source device is formed to have a multi-layer structure, doped with an acceptor and a donor impurity. The multi-layer structure may include a quantum well (QW) structure or a multi quantum well (MQW) structure (50). With such a structure, a peak wavelength of the light source can be controlled, because the distances between atoms of the acceptor and the donor impurities are widened. Several arrangements can be made by, e.g., altering the thickness of each composite layer of the multi-layer structure, altering their composition ratio, forming undoped layer 5 between the impurity doped layers, and so forth. Further, luminous intensity of ultra violet color can be improved, because doping the donor impurity and the acceptor impurity realizes a donor-acceptor emission mechanism and abundant carriers. Several arrangements can be made by, e.g., optimizing the materials of the composite layers, optimizing their composition ratios, optimizing their lattice constants, and so forth to further enhance the luminous intensity of the light source.

The invention discloses a growth method of a gallium-nitride-based epitaxial wafer. In the epitaxial wafer, triethyl gallium used as a metal organic source of gallium and di (cyclopentadienyl) magnesium used as an acceptor impurity growth p-type cavity injection layer are adopted between a multiple quantum well layer and a p-type AlGaN layer; and according to the growth structure, the bulk resistance of the p-type layer is reduced, the effective concentration of the injected cavity is improved, the effective compound of the cavity and an electron in an active region is enlarged, and the luminous efficiency of a light-emitting diode (LED) is improved. According to a standard chip process, a chip which has a size of 300*200 mu m<2> and uses Indium tin oxide (ITO) as a transparent electrode is manufactured, the forward voltage of the chip can be reduced by 0.15V, and the light transmission efficiency is improved by above 17%.

The invention provides a prediction method for the performance of a rare-earth-doped modified titanium-based stannic oxide electrode. The modified performance is predicted by calculating changes of stannic oxide crystal structure parameters before and after rare earth doping on the basis of a density functional theory of the first principles; the crystal geometric structures of SnO2 doped with La with the different concentrations are optimized by taking lanthanum as a doping agent, the lattice constant, the energy band structure, the state density and the formation energy of crystal cells of SnO2 with the different lanthanum doping quantities are calculated, and it shows that doped SnO2 has the higher electric conductivity and the good electro-catalytic property, energy band degeneration is intensified and the acceptor impurity energy level moves towards the direction away from the valence band maximum along with increasing of the doping concentration, the formation energy is lowest when the doping concentration is 1.39%, the electronic structure of SnO2 is most stable at the moment, and experiments verify that when the actual adding amount is 1.5%, the catalytic performance is best. According to the method, the performance of different systems of oxide electrodes doped with other rare earth or elements can be effectively predicted and analyzed according to the difference of doping elements and the different doped electrode systems.

A method for producing a semiconductor device includes the steps of forming first and second pillar-shaped semiconductors on a substrate at the same time so as to have the same height; forming a first semiconductor layer by doping a bottom region of the first pillar-shaped semiconductor with a donor or acceptor impurity to connect the first semiconductor layer to the second pillar-shaped semiconductor; forming a circuit element including an upper semiconductor region formed by doping an upper region of the first pillar-shaped semiconductor with a donor or acceptor impurity; forming a first conductor layer in the second pillar-shaped semiconductor; forming first and second contact holes that are respectively connected to the first and second pillar-shaped semiconductors; and forming a wiring metal layer that is connected to the upper semiconductor region and the first conductor layer through the first and second contact holes, respectively.

The present invention provides an epitaxial substrate for field effect transistor. In the epitaxial substrate for field effect transistor, a nitride-based Group III-V semiconductor epitaxial crystal containing Ga is interposed between the ground layer and the operating layer, and the nitride-based Group III-V semiconductor epitaxial crystal comprises the following (i), (ii) and (iii). (i) a first buffer layer containing Ga or Al and containing a high resistivity crystal layer having added thereto compensation impurity element present in the same period as Ga in the periodic table and having small atomic number; (ii) a second buffer layer containing Ga or Al, laminated on the operating layer side of the first buffer layer; and (iii) a high purity epitaxial crystal layer containing acceptor impurities in a slight amount such that non-addition or depletion state can be maintained, provided between the high resistivity layer and the operating layer.

The invention relates to a GaN-based semiconductor laser and a manufacturing method thereof, belonging to the field of semiconductor lasers. The device has the structure that a quantum cascade radiation layer is introduced between an n-type optical confinement layer and an n-type waveguide layer of the laser. By applying infrared radiation generated by the quantum cascade radiation layer when the laser works, the ionization of magnesium acceptor impurities in a p-type GaN waveguide layer, a p-type AlGaN optical confinement layer and a p-type GaN covering layer is realized, the carrier concentration of each p-type layer is increased, and the working voltage of the laser is reduced. The average Al component of the quantum cascade radiation layer is close to that of an n-type AlGaN optical confinement layer, thus the optical confinement factor of the laser has no obvious change. Although the voltage drop of the n-type layers can be increased when the laser works, the laser can still work at a lower voltage because the voltage drop of the p-type layers is greatly reduced. By applying the structure of the laser, the series resistance of the laser can be reduced to further reduce the working voltage of the laser and prolong the service life of the laser.

A photoelectric conversion device includes at least one p-type semiconductor layer made of amorphous like hydrogenated carbon film or diamond like carbon (DLC) film doped with acceptor impurities such as boron (B). In a solar cell having a photoelectric conversion region, hydrogenated carbon is used as substances forming a p-type semiconductor layer, making it possible to provide a solar cell with high photoelectric conversion efficiency.

The present invention proposes variations of the laser separation method allowing separating homoepitaxial films from the substrates made from the same crystalline material as the epitaxial film. This new method of laser separation is based on using the selective doping of the substrate and epitaxial film with fine donor and acceptor impurities. In selective doping,, concentration of free carries in the epitaxial film and substrate may essentially differ and this can lead to strong difference between the light absorption factors in the infrared region near the residual beams region where free carriers and phonon-plasmon interaction of the optical phonons with free carriers make an essential contribution to infrared absorption of the optical phonons. With the appropriate selection of the doping levels and frequency of infrared laser radiation it is possible to achieve that laser radiation is absorbed in general in the region of strong doping near the interface substrate- homoepitaxial film. When scanning the interface substrate- homoepitaxial film with the focused laser beam of sufficient power, thermal decomposition of the semiconductor crystal takes place with subsequent separation of the homoepitaxial film. The advantage of the proposed variations of the method for laser separation of epitaxial films in comparison with the known ones is in that it allows to separate homoepitaxial films from the substrates, i.e., homoepitaxial films having the same width of the forbidden gap as the initial semiconductor substrate has. The proposed variations of the method can be used for separation of the epitaxial films. Besides, the proposed method allows using the high-effective and inexpensive infrared gas silicon dioxide CO2 or silicon oxide CO lasers for separation of the epitaxial films.

A doping method comprising the steps of; obtaining a proportion X of ions of a compound including a donor or an acceptor impurity in total ions from mass spectrum by using a first source gas of a first concentration; analyzing a peak concentration Y of the compound in a first processing object which is doped by using a second source gas of a second concentration equal to or lower than the first concentration, referring to a dose amount of total ions as Do and setting an acceleration voltage at a value, obtaining a dose amount D₁ of total ions from a expression, Y=(D₁/D₀)(aX+b), and doping a second processing object with the donor or the acceptor impurity by a ion doping apparatus using a third source gas, wherein a dose amount of total ions is set at D₁, and an acceleration voltage is set at the value.

Complementary high-voltage bipolar transistors formed in standard bulk silicon integrated circuits are disclosed. In one disclosed embodiment, collector regions are formed in an epitaxial silicon layer. Base regions and emitters are disposed over the collector region. An n-type region is formed under collector region by implanting donor impurities into a p-substrate for the PNP transistor and implanting acceptor impurities into the p-substrate for the NPN transistor prior to depositing the collector epitaxial regions. Later in the process flow these n-type and p-type regions are connected to the top of the die by a deep n+ and p+ wells respectively. The n-type well is then coupled to VCC while the p-type well is coupled to GND, providing laterally depleted portions of the PNP and NPN collector regions and hence, increasing their BVs.

A method for producing a semiconductor device includes a step of forming a conductor layer and a first semiconductor layer containing a donor impurity or an acceptor impurity on a first semiconductor substrate; a step of forming a second insulating layer so as to cover the first semiconductor layer; a step of thinning the first semiconductor substrate to a predetermined thickness; a step of forming, from the first semiconductor substrate, a pillar-shaped semiconductor having a pillar-shaped structure on the first semiconductor layer; a step of forming a first semiconductor region in the pillar-shaped semiconductor by diffusing the impurity from the first semiconductor layer; and a step of forming a pixel of a solid-state imaging device with the pillar-shaped semiconductor into which the impurity has been diffused.

An opening extending through a gate insulating layer and a gate conductor layer is formed in the circumferential portion of a Si pillar at an intermediate height of the Si pillar. A laminated structure including two sets each including a Ni film, a poly-Si layer containing donor or acceptor impurity atoms, and a SiO₂ layer is formed so as to surround the opening. A heat treatment is carried out to form silicide from the poly-Si layers and this silicide formation causes the resultant NiSi layers to protrude and come into contact with the side surface of the Si pillar. The donor or acceptor impurity atoms diffuse from the NiSi layers into the Si pillar to thereby form an N⁺ region and a P⁺ region serving as a source or a drain of SGTs.

The invention relates to a silicon infrared optical detector structure and a manufacturing method therefor. A super-heavy doped silicon single crystal material with weight compensation is taken as an infrared photoelectric conversion material; a super-heavy donor doped silicon single crystal material with weight acceptor compensation or a super-heavy acceptor doped silicon single crystal material with weight donor compensation is singly adopted for absorbing infrared light to generate electron-hole pairs; or the super-heavy donor doped silicon single crystal material with weight acceptor compensation and the super-heavy acceptor doped silicon single crystal material with weight donor compensation are adopted concurrently to form a PN junction for absorbing infrared light to generate the electron-hole pairs. According to the silicon infrared optical detector structure, the donor impurity and the acceptor impurity are heavily doped in the silicon single crystal material concurrently, so that a donor impurity energy band and an acceptor impurity energy band are formed in a forbidden band at the same time; meanwhile, an energy band tail connected with a conduction band and an energy band tail connected with a valence band are formed as well, so that the energy levels of the impurities participate in the infrared photon absorption and electron and hole jumps; and therefore, the photoelectric conversion efficiency of the silicon material at the near infrared communication waveband is improved.

The invention is suitable for the technical field of semiconductors, and provides a preparation method of an enhanced high-electron-mobility transistor. The method comprises the steps that a buffer layer, a channel layer and a barrier layer are grown on a substrate in turn, wherein the material of the buffer layer, the channel layer and the barrier layer is the III-nitride, and the intensity of polarization of the material of the barrier layer is greater than that of the material of the channel layer; a p-type doped III-nitride p-type layer is grown on the upper surface of the gate electrode region of the barrier layer; the doping element in the p-type layer is activated in the atmosphere of the nitrogen oxide; a gate electrode is formed on the upper surface of the p-type layer; and a source electrode is formed on the upper surface of the source electrode region of the barrier layer, and a drain electrode is formed on the upper surface of the drain electrode region of the barrier layer. The ionization rate of the acceptor impurities can be enhanced and thus the carrier concentration of the p-type layer can be enhanced.