摘要:
A method of growing an AlGaN semiconductor layer structure by Molecular Beam Epitaxy comprises supplying ammonia, gallium and aluminum to a growth chamber thereby to grow a first (Al,Ga)N layer by MBE over a substrate disposed in the growth chamber. The first (Al,Ga)N layer has a non-zero aluminum mole fraction. Ammonia is supplied at a beam equivalent pressure of at least 1 10−4 mbar, gallium is supplied at a beam equivalent pressure of at least 1 10−8 mbar and aluminum is supplied at a beam equivalent pressure of at least 1 10−8 mbar during the growth step. Once the first (Al,Ga)N layer has been grown, varying the supply rate of gallium and/or aluminum enables a second (Al,Ga)N layer, having a different aluminum mole fraction from the first (Al,Ga)N layer to be grown by MBE over the first (Al,Ga)N layer. This process may be repeated to grown an (Al,Ga)N multilayer structure.
摘要:
A method of MBE growth of a semiconductor layer structure comprises growing a first (Al,Ga)N layer (step 13) over a substrate at the first substrate temperature (T1) using ammonia as the nitrogen precursor. The substrate is then cooled (step 14) to a second-substrate temperature (T2) which is lower than the first substrate temperature. An (In,Ga)N quantum well structure is then grown (step 15) over the first (Al,Ga)N layer by MBE using ammonia as the nitrogen precursor. The supply of ammonia to the substrate is maintained continuously during the first growth step, the cooling step, and the second growth step. After completion of the growth of the (In,Ga)N quantum well structure, the substrate may be heated to a third temperature (T3) which is greater than the second substrate temperature (T2). A second (Al,Ga)N layer is then grown over the (In,Ga)N quantum well structure (step 17).
摘要:
A method of growing a p-type nitride semiconductor material having magnesium as a p-type dopant by molecular beam epitaxy (MBE), comprises supplying ammonia gas, gallium and magnesium to an MBE growth chamber containing a substrate so as to grow a p-type nitride semiconductor material over the substrate. Magnesium is supplied to the growth chamber at a beam equivalent pressure of at least 1 10-9 mbar, and preferably in the range from 1 10-9 mbar to 1 10-7 mbar during the growth process. This provides p-type GaN that has a high concentration of free charge carriers and eliminates the need to activate the magnesium dopant atoms by annealing or irradiating the material.
摘要:
The invention provides a method of growing an (In, Ga)N multiplayer structure by molecular beam epitaxy. Each GaN or InGaN layer in the multilayer structure is grown at a substrate temperature of at least 650° C., and this provides improved material quality. Ammonia gas is used as the source of nitrogen for the growth process. Ammonia and gallium are supplied to the growth chamber at substantially constant rates, and the supply rate of indium to the growth chamber is varied to select the desired composition for the layer being grown. This allows the structure to be grown at a substantially constant growth rate. The substrate temperature is preferably kept constant during the growth process, to avoid the need to interrupt the growth process to vary the substrate temperature between the growth of one layer and the growth of another layer.
摘要:
This invention relates to a method of growing a nitride semiconductor layer by molecular beam epitaxy comprising the steps of: a) heating a GaN substrate (S) disposed in a growth chamber (10) to a substrate temperature of at least 850° C.; and b) growing a nitride semiconductor layer on the GaN substrate by molecular beam epitaxy at a substrate temperature of at least 850° C., ammonia gas being supplied to the growth chamber (10) during the growth of the nitride semiconductor layer; wherein the method comprises the further step of commencing the supply ammonia gas to the growth chamber during step (a), before the substrate temperature has reached 800° C.
摘要:
A method of growing a nitride semiconductor layer, such as a GaN layer, by molecular beam epitaxy comprises the step of growing a GaAlN nucleation layer on a substrate by molecular beam epitaxy. The nucleation layer is annealed, and a nitride semiconductor layer is then grown over the nucleation layer by molecular beam epitaxy. The nitride semiconductor layer is grown at a V/III molar ratio of 100 or greater, and this enables a high substrate temperature to be used so that a good quality semiconductor layer is obtained. Ammonia gas is supplied during the growth process, to provide the nitrogen required for the MBE growth process.
摘要:
A method of manufacturing a nitride semiconductor device comprises the steps of: growing an InxGa1-xN (0≦x≦1) layer, and growing an aluminium-containing nitride semiconductor layer over the InxGa1-xN layer at a growth temperature of at least 500° C. so as to form an electron gas region at an interface between the InxGa1-xN layer and the nitride semiconductor layer. The nitride semiconductor layer is then annealed at a temperature of at least 800° C. The method of the invention can provide an electron gas having a sheet carrier density of 6×1013cm−2 or greater. An electron gas with such a high sheet carrier concentration can be obtained with an aluminium-containing nitride semiconductor layer having a relatively low aluminium concentration, such as an aluminium mole fraction of 0.3 or below, and without the need to dope the aluminium-containing nitride semiconductor layer or the InxGa1-xN layer.
摘要翻译:一种制造氮化物半导体器件的方法包括以下步骤:生长In 1 x 1 Ga 1-x N(0 <= x <= 1)层,并生长 含铝氮化物半导体层,在至少500℃的生长温度下在In 1 x 1 Ga 1-x N层上形成电子气区域 在In 1 x 1 Ga 1-x N层和氮化物半导体层之间的界面。 然后将氮化物半导体层在至少800℃的温度下退火。本发明的方法可以提供具有6×10 13 cm -2的薄片载体密度的电子气体, SUP>或更大。 具有如此高的片状载流子浓度的电子气体可以用具有相对较低的铝浓度的铝含量的氮化物半导体层,例如0.3或更低的铝摩尔分数,并且不需要掺杂含铝氮化物 半导体层或In 1 x 1 Ga 1-x N层。
摘要:
A method of manufacturing a nitride semiconductor structure includes disposing a semiconductor substrate in a molecular beam epitaxy reactor; growing a wetting layer comprising AlxInyGa(1−(x+y))As(0≦x+y≦1) or AlxInyGa(1−(x+y))P(0≦x+y≦1) on the substrate; in-situ annealing the wetting layer; growing a first AlGaInN layer on the wetting layer using plasma activated nitrogen as the source of nitrogen with an additional flux of phosphorous or arsenic; and growing a second AlGaInN layer on the first AlGaInN layer using ammonia as a source of nitrogen.
摘要翻译:制造氮化物半导体结构的方法包括将半导体衬底设置在分子束外延反应器中; 在衬底上生长包含Al x In y Ga(1-(x + y))As(0&amp; nE; x + y&nlE; 1)或Al x In y Ga(1-(x + y))P(0和nlE; x + y和nlE; 1) 原位退火润湿层; 使用等离子体活化氮作为氮源,再加入磷或砷的助熔剂,在润湿层上生长第一AlGaInN层; 以及使用氨作为氮源在所述第一AlGaInN层上生长第二AlGaInN层。
摘要:
The present application provides nitride semiconductor nanoparticles, for example nanocrystals, made from a new composition of matter in the form of a novel compound semiconductor family of the type group II-III-N, for example ZnGaN, ZnInN, ZnInGaN, ZnAlN, ZnAlGaN, ZnAlInN and ZnAlGaInN. This type of compound semiconductor nanocrystal is not previously known in the prior art. The invention also discloses II-N semiconductor nanocrystals, for example ZnN nanocrystals, which are a subgroup of the group II-III-N semiconductor nanocrystals. The composition and size of the new and novel II-III-N compound semiconductor nanocrystals can be controlled in order to tailor their band-gap and light emission properties. Efficient light emission in the ultraviolet-visible-infrared wavelength range is demonstrated. The products of this invention are useful as constituents of optoelectronic devices such as solar cells, light emitting diodes, laser diodes and as a light emitting phosphor material for LEDs and emissive EL displays.
摘要:
The present application provides nitride semiconductor nanoparticles, for example nanocrystals, made from a new composition of matter in the form of a novel compound semiconductor family of the type group II-III-N, for example ZnGaN, ZnInN, ZnInGaN, ZnAlN, ZnAlGaN, ZnAlInN and ZnAlGaInN. This type of compound semiconductor nanocrystal is not previously known in the prior art. The invention also discloses II-N semiconductor nanocrystals, for example ZnN nanocrystals, which are a subgroup of the group II-III-N semiconductor nanocrystals.The composition and size of the new and novel II-III-N compound semiconductor nanocrystals can be controlled in order to tailor their band-gap and light emission properties. Efficient light emission in the ultraviolet-visible-infrared wavelength range is demonstrated.The products of this invention are useful as constituents of optoelectronic devices such as solar cells, light emitting diodes, laser diodes and as a light emitting phosphor material for LEDs and emissive EL displays.