摘要:
A multiple quantum well light emitting compositional semiconductor device ch as a laser diode or a light emitting diode has an active region comprising an alternating sequence of layers of well layer material and of barrier layer material. The thickness of the barrier layer and of the adjacent well layers is chosen such that for one type of charge carrier a relatively high probability exists for such charge carriers to be present in the barrier region whereas the other type of charge carriers are localized in the potential wells. In this way it is possible to reduce the probability of non-radiative Auger recombination processes occurring thus reducing the threshold current and increasing the quantum efficiency of the device. This is particularly important since material systems with a small bandgap which lase at long wavelengths suitable for optical fibre transmission normally suffer performance penalties due to non-radiative Auger recombination and these penalties can be substantially reduced by tailoring the layer thicknesses to achieve the described probability distributions.
摘要:
A semiconductor device consisting of epitaxial material is provided with at least one monoatomic layer of doping atoms, i.e. with a layer which is just one atom thick. A preferred device is a bipolar transistor in which case the Dirac-delta doped p-type layer 38 is directly between n-type collector and emitter layers (32, 33). The bipolar transistor described herein has an extremely low base width and is capable of operating at high frequencies.
摘要:
An electron-wave coupled semiconductor device, in particular a semiconductor switching device, comprises a first layer of semiconducting material having a first bandgap, and a second layer of material formed on said first semiconducting layer and having a second bandgap greater than the first said bandgap. First and second electron waveguides are formed alongside but spaced apart from each other in the first semiconductor layer adjacent the boundary between this layer and said second layer. A gate region extends over said second layer transverse to and over said electron waveguides. First contact means provides input connections to said first and second electron waveguides on one side of said gate region and further contact means provides separate output connections from said first and second electron waveguides on the opposite side of the gate region from said first contact means. The dimension of the electron waveguides under said gate region, both along and transverse to said electron waveguides, and also the dimension between said electron waveguides are smaller than the elastic mean free path for electrons at the operating temperature of the device. A signal applied to the gate region can be used to switch a signal applied to said input contact means selectively to a selected one of the output connections.
摘要:
A new method for GaAs substrate preparation which significantly reduces theormation of oval defects during MBE growth of selectively doped n-Al.sub.x Ga.sub.1-x As/GaAs heterostructures. The method simply requires treatment in H.sub.2 SO.sub.4 after mechano-chemical polishing in NaOCl solution and generation of a protective surface oxide during in soldering. Routinely a density of oval defects of less than 200 cm.sup.-2 is achieved for 2-.mu.m thick heterostructures. The efficiency of the new preparation procedure is demonstrated by 2DEG mobilities in excess of 10.sup.6 cm.sup.2 /Vs at 6K obtained with a spacer width as narrow as 18 nm.
摘要翻译:一种用于GaAs衬底制备的新方法,其在选择性掺杂的n-Al x Ga 1-x As / GaAs异质结构的MBE生长期间显着减少椭圆形缺陷的形成。 该方法只需要在NaOCl溶液中机械化学抛光后在H2SO4中进行处理,并在焊接过程中产生保护性表面氧化物。 实际上,对于2μm厚的异质结构,实现小于200cm-2的椭圆形缺陷的密度。 新的制备方法的效率通过在6K处超过106cm 2 / Vs的2DEG迁移率证明,其间隔宽度窄至18nm。
摘要:
A semiconductor device consisting of epitaxial material is provided with at least one monoatomic layer of doping atoms, i.e. with a layer which is just one atom thick. A particularly preferred device is injection laser in which case the Dirac-delta doped layers 45 and 46 are within intrinsic layer 43. The injection laser is constructed with a hetero structure.
摘要:
A semiconductor device consisting of epitaxial material is provided with at least one monoatomic layer of doping atoms, i.e. with a layer which is just one atom thick. A particularly preferred device is a field effect transistor in which case the Dirac-delta doped layer 13 extends between the source and drain zones (18, 19) respectively. The field effect transistor can be constructed either with a homogeneous structure or with a hetero structure or with a superlattice structure. The field effect transistors described herein have a high transconductance and are capable of operating at high current densities.
摘要:
A method for operating a magnetic logic device (10) is described wherein at least one output variable O=F (IA, IB) is formed from input variables (IA, IB) by at least one logic operation with an operator function F of the magnetic logic device (10), whereby the logic device (10) is set at a starting state for executing the operator function F with a certain operator control signal (SET) before the operation, whereby the operator control signal is selected from a group of control signals with which various non-volatile starting states can be set in a controlled manner, each state being characteristic of a different logic function. Furthermore, a magnetic logic device (10) equipped for implementation of this method is also described.
摘要翻译:描述了一种用于操作磁逻辑器件(10)的方法,其中至少一个输出变量O = F(I A,I B B)由输入变量(I 通过具有磁逻辑器件(10)的操作器功能F的至少一个逻辑运算,由此将逻辑器件(10)设置在一个或多个逻辑器件(10) 用于在操作之前用一定的操作员控制信号(SET)执行操作功能F的起动状态,从而从可以以受控的方式设置各种非易失性起动状态的一组控制信号中选择操作员控制信号, 每个状态是不同逻辑功能的特征。 此外,还描述了配备用于实现该方法的磁逻辑装置(10)。
摘要:
A unipolar electronic component is proposed with a quasi one dimensional carrier channel which has all the characteristics of an FET. This component can be very simply produced, has "self-alignment" and linear gates with a low capacity in place of planar gates. In this way a very high operating frequency of the component is possible. The structure comprises an initially homogenous 2D-layer with a high carrier mobility which is formed by epitaxy of for example GaAs. The implantation of focussed ions (for example Ga.sup.+ with 100 keV) locally destroys the conductivity of the electron layer. The irradiated regions remain insulating at low temperature or room temperature even after illuminating the cristal with bandgap radiation. The writing in of the insulating layer is carried out along two paths on the chip so that the 2D-carrier layer is subdivided into three regions insulated from one another. The source and drain are only connected by a narrow channel 44 the width of which is continuously tunable by a gate potential which is simultaneously applied to the two gate regions relative to the source, so that a pronounced change of the carrier concentration and thus of the channel resistance arises. The specification also describes integrated circuits made using the same methods.
摘要:
An optically bistable semiconductor device which has a doped or undoped gallium arsenide substrate and a series of alternating n-type and p-type Dirac-delta doped monoatomic layers formed on the substrate. Each Dirac-delta doped monoatomic layer is separated from the next adjacent Dirac-delta doped monoatomic layer by a layer of pure, undoped intrinsic semiconductor material such as gallium arsenide.
摘要:
A unipolar electronic component is proposed with a quasi one dimensional carrier channel which has all the characteristics of an FET. This component can be very simply produced, has "self-alignment" and linear gates with a low capacity in place of planar gates. In this way a very high operating frequency of the component is possible. The structure comprises an initially homogenous 2D-layer with a high carrier mobility which is formed by epitaxy of for example GaAs. The implantation of focussed ions (for example Ga.sup.+ with 100 keV) locally destroys the conductivity of the electron layer. The irradiated regions remain insulating at low temperature or room temperature even after illuminating the cristal with bandgap radiation. The writing in of the insulating layer is carried out along two paths on the chip so that the 2D-carrier layer is subdivided into three regions insulated from one another. The source and drain are only connected by a narrow channel 44 the width of which is continuously tunable by a gate potential which is simultaneously applied to the two gate regions relative to the source, so that a pronounced change of the carrier concentration and thus of the channel resistance arises. The specification also describes integrated circuits made using the same methods.