摘要:
Disclosed is a fabricating method of a GaAs substrate having a V-shaped groove in a higher density, that is a double density, the method comprising the steps of forming a Si.sub.3 N.sub.4 layer on a main surface of the GaAs substrate; patterning the Si.sub.3 N.sub.4 layer using a photo-lithography to form a patterned Si.sub.3 N.sub.4 layer having a minimum width; wet-etching the GaAs substrate using the patterned Si.sub.3 N.sub.4 layer as a mask, so as to form (111) and (100) surfaces of the GaAs substrate beneath the patterned Si.sub.3 N.sub.4 ; selectively growing a GaAs film on the GaAs substrate etched thus using the patterned Si.sub.3 N.sub.4 layer as a mask so as to form the GaAs film with two (111) facets only on a (100) surface of the GaAs substrate; and removing the Si.sub.3 N.sub.4 layer. The V-shaped grooves can be formed on a GaAs substrate utilizing a difference of growth rate caused by surface orientation of the substrate, and therefore the grooves can be formed in double density.
摘要翻译:本发明公开了一种GaAs衬底的制造方法,该GaAs衬底具有较高密度的V形沟槽,即双重密度,该方法包括以下步骤:在GaAs衬底的主表面上形成Si 3 N 4层; 使用光刻法构图Si 3 N 4层以形成具有最小宽度的图案化的Si 3 N 4层; 使用图案化的Si 3 N 4层作为掩模对GaAs衬底进行湿法蚀刻,以在图案化的Si 3 N 4之下形成GaAs衬底的(111)和(100)表面; 在GaAs衬底上选择性地生长GaAs膜,使用图案化的Si 3 N 4层作为掩模进行蚀刻,以便仅在GaAs衬底的(100)表面上形成具有两个(111)面的GaAs膜; 并去除Si3N4层。 可以使用由衬底的表面取向引起的生长速度差,在GaAs衬底上形成V形槽,因此可以以双重密度形成沟槽。
摘要:
A crystal growth method for a compound semiconductor is capable of forming a plurality of quantum wells (formed of a barrier layer having a large energy band gap and an active layer having a small energy band gap) on the compound semiconductor substrate. After etching a V-shaped groove having a (111) surface with a predetermined angle .theta.1 with respect to the (100) surface on the GaAs semiconductor substrate, the substrate is further etched by a hydrochloric solution and a solution of H.sub.2 SO.sub.4 :H.sub.2 O.sub.2 :H.sub.2 O=20:1 to cause the V-shaped groove walls to become a non-(111) surface having a lower predetermined slope angle .theta.2. The quantum wells then grown in the bottom of the V-shaped groove will be effectively disconnected from simultaneous growths on the side walls of the groove thus giving rise to closely controlled multi-dimensional quantum well structures.
摘要翻译:化合物半导体的晶体生长方法能够在化合物半导体基板上形成多个量子阱(由具有大能带隙的势垒层和具有小能带隙的有源层形成)。 在GaAs半导体衬底上蚀刻具有相对于(100)表面的具有预定角度θ(111)的(111)表面的V形槽之后,用盐酸溶液和H 2 SO 4 :H 2 O 2: H 2 O = 20:1使V形槽壁成为具有较低预定倾斜角度θ2的非(111)表面。然后在V形槽的底部生长的量子阱将被有效地从 在槽的侧壁上同时生长,从而产生紧密控制的多维量子阱结构。
摘要:
An epitaxial growth method for a compound semiconductor thin film, capable of forming a p-n junction with an atomic-scale ultra-micro structure is disclosed. The method involves loading the compound semiconductor substrate in a reaction chamber, injecting Group V and III metal organic source gases not processed by a thermal pre-decomposition process into the reaction chamber, and growing a p- or n-type compound semiconductor on the compound semiconductor substrate while adjusting the growth temperature of the p- or n-type compound semiconductor.
摘要:
A surface adsorption apparatus for dissociating H.sub.2 molecules into atomic hydrogen in a vacuum vessel and adsorbing the atomic hydrogen on a sample surface is disclosed. A vacuum tube is mounted in the vacuum vessel. A nozzle is connected to the vacuum tube having a plurality of bent portions. A heating member receives electrical power from a power supply source and heats the nozzle to a predetermined temperature. A heat shielding member is located in a path of the atomic hydrogen between one end of the nozzle and the sample surface for shielding the sample surface from heat radiating from the nozzle. The H.sub.2 molecules collide with inner wall surfaces of the bent portions to be readily dissociate into the atomic hydrogen. The atomic dissociated hydrogen propagates toward the sample surface and is adsorbed on the sample surface. Since the nozzle comprises bent portions, H.sub.2 molecules frequently collide with inner wall surfaces of the nozzle to readily dissociate into atomic hydrogen. The H.sub.2 collision efficiency is significantly improved by increased surface collisions with the bent portions. Because the bent portions of the nozzle are heated by the heating member, the construction of the apparatus is simplified.
摘要:
A linear motion apparatus for moving an object in a vacuum chamber comprising an antenna or a telescoping shaft such as a fishing rod to effectively utilize space, and to avoid the need of a rear projection thereby achieving stability. The linear motion apparatus includes: a body having a space portion penetrated horizontally; a rotary handle which penetrates at a right angle to the space portion of the body thereby controlling a linear motion; locking portion which is mounted in the space portion of the body, is inserted into a shaft of the rotary handle, and used to lock the motion; a guide rod which is formed as a multistage rod, whose one end is inserted and fixed into a predetermined position of the space portion of the body; linear motion force providing portion whose one end is fixed to the rotary plate and the other end is fixed to a nose portion of the guide rod, thereby providing a linear motion force to the guide rod; and a bellows seal which surrounds a circumference of the guide rod, is shrunken or expanded according to a linear motion of the guide rod. As a result, this apparatus performs a linear motion control by a contraction and expansion under ultra high vacuum.
摘要:
A vertical modulator with a dual mode distributed Bragg reflection (DBR), includes a pair of integrated elements using different wavelengths to provide functions of logical operation, data switching and wavelength conversion. The optical device includes a first optical structure operating at a first wavelength (.lambda..sub.1) and a second optical structure operating at a second wavelength (.lambda..sub.2). The first and second optical structures are formed over a semiconductor substrate. The first optical structure, which operates at the first wavelength (.lambda..sub.1), transmits its data to the second optical structure so that data corresponding to the second wavelength (.lambda..sub.2) can be output. Since the wavelength of input light is different from the wavelength of output light, the optical device serves as a modulator which performs a logic operation and switching function while carrying out wavelength conversion.
摘要:
A fiber-optic address detector comprises fiber-optic delay lines on one surface of which a metal thin film is evaporated, the fiber-optic delay lines being connected in a melting state to fiber-optic couplers, wherein inputting address photonic signals are tapped by the inputting fiber-optic couplers, reflected by the metal thin films at the end portion of the fiber-optic delay line and then re-combined by the inputting fiber-optic coupler, whereby it can reduce the number of the fiber-optic coupler used in the conventional fiber-optic address detector to one half as well as obtain the same address detection effect.
摘要:
Disclosed is an ultrafast optical switching device having two types of multiple quantum well structures to be connected with each other, the device comprising a semi-insulating substrate; and a first and a second multiple quantum well structure formed sequentially on the substrate and united with each other to produce a double-junction multiple quantum well structure. Each of the multiple quantum well structures has nonlinear optical effects and two life time constants present while switching off in the device. One of the life time constants corresponds to a short life time constant to be determined dependent on electrons in the double-junction multiple quantum well structure and the other of the life time constants corresponds to a long life time constant to be determined dependent on holes and lattices therein. The multiple quantum well structures are formed in such a manner that short life time constants thereof may be in-phase with each other and long life time constants thereof may be out-of-phase to each other. The multiple quantum well structures are formed differently from each other in composition.
摘要:
Disclosed is a nonbiased bistable optical device and a method for fabricating the device, which has a semi-insulating GaAs substrate; a lower mirror having a plurality of reflecting layers which are repeatedly formed on said substrate at least more than twelve times, each of said reflecting layers having a first reflecting film having a first refractive index on said substrate and a second reflecting film a second refractive index different from the first refractive index; a first contact layer formed on the lower mirror; a first buffer layer formed on the first contact layer; a multiple quantum well(MQW) having a plurality of shallow layers which are repeatedly formed, each of said shallow layers having a barrier and a shallow quantum well; a second buffer layer grown on said MQW; and a second contact layer formed on said second buffer layer. The device has an excellent bistablity even without an external applied voltage.
摘要:
An all-optical signal processing apparatus of a non-linear fiber loop mirror type comprises a very high-speed all-optical switch that can be used as a reverse multiplexed switch in a high-speed time division optical communication. The apparatus includes a non-linear loop mirror for switching signal light by adjusting light using the non-linear effect of an optical fiber and the characteristics of a sagnac interferometer as the fundamental configuration. The all-optical switch is constructed so that another adjustment light having an appropriate time delay with respect to an existing adjusting light is additionally introduced in order to compensate for the limitation on the switching bandwidth imposed by the walk-off between adjusting and signal lights in a conventional non-linear optical fiber loop mirror. This compensates for the cross-talk of the noise signals due to DC components generated in the conventional apparatus. A switching window of a desirable size is obtained by properly adjusting the time delay between two adjusting lights and resolving the bandwidth limitation of the switch due to the walk-off of the adjusting and signal lights according to the timing jitter of signal light.