Abstract: A technique for achieving a substantially planar structure incorporating embedded vapor phase epitaxial growth involves the use of a window-frame shaped mask 40 of epitaxial growth resistant material to define a well in which embedded growth is to occur, and subsequently to ease mask registration problems in the location of a mask 60 employed while selectively removing unwanted material epitaxially grown on regions surrounding the well. Complementary format structures may also be formed in which epitaxial growth is provided up the sides of a mesa to substantially the same height as material grown on top of the mesa itself.

Abstract: A semiconductor light emitting device includes a vertical aperture produced at a main surface of a semi-insulating or insulating substrate, a transverse aperture provided in the substrate communicating with the vertical aperture, a conducting semiconductor layer buried in the vertical aperture and the transverse aperture, a groove produced by etching the substrate from the surface thereof until reaching the conducting semiconductor layer at a portion of the transverse aperture, and a light emitting element produced in the groove, and the light emitting region of the element being buried in the groove and connected with the buried conducting semiconductor layer. Accordingly, no pn junction exists at the periphery of the light emitting region, and a semiconductor light emitting element of quite low parasitic capacitance is obtained at high yield. A planar structure in which two electrodes are produced at the same plane is obtained, resulting in ease of integration and enhancement in the integration density.

Abstract: A method of providing sublayer contacts in vertical walled trenches is proposed. In accordance with the present invention, the phosphorus doped amorphous silicon is deposited at temperatures less than 570.degree. C. The conversion into the extremely large crystal low resistivity polysilicon is accomplished by a low temperature anneal at 400.degree. C. to 500.degree. C. for several hours and a short rapid thermal anneal (RTA) treatment at a high temperature approximately 850.degree. C. for twenty seconds. These two conversion heat treatments are done at sufficiently low thermal budget to prevent any significant dopant movement within a shallow junction transistor. After anneal, the excess low resistivity silicon is planarized away by known techniques such as chemical/mechanical polishing.

Abstract: A trench structure (10) using germanium silicate. The trench structure (10) has a substrate material (12) and a hard mask material (14) that overlies the substrate material (12). An opening is formed in the hard mask material and the opening is used to form a trench (16) in the substrate material (12). The trench (16) has a sidewall portion and a bottom portion. A barrier (18 and 20) is formed overlying the bottom portion of the trench (16) and adjacent to the sidewall portion of the trench (16). A planar germanium silicate region (22) is formed overlying the barrier (18 and 20).

Abstract: For manufacturing an electrically conductive tip composed of a doped semiconductor material, a mask layer is produced on a substrate composed of the semiconductor material. This mask layer contains a material at least at its surface and directly on the substrate whereon the semiconductor material does not grow in a selective epitaxy. An opening wherein the surface of the substrate lies exposed is produced in the mask layer. The electrically conductive tip is produced by a selective epitaxy on the exposed surface of the substrate such that the layer growth in the direction parallel to the surface of the substrate is lower than in the direction perpendicular to the surface of the substrate.

Abstract: A planar interconnect using selective, electroless deposition of a metal such as copper into interconnect channels is disclosed. A first dielectric layer is deposited on the surface of a substrate, such as an integrated circuit wafer. Thereafter, a second dielectric layer is formed on the first dielectric layer. Then a photoresist layer is spun on the top surface of the second dielectric layer. Channels are formed in the dielectric layers by patterning and etching the composite dielectric layers. Silicon atoms are implanted in the bottom of the interconnect channels and then the metal layer is selectively, electrolessly deposited to fill the channels in the first dielectric film, thus forming a level of interconnect. This process is repeated to form subsequent levels of interconnect.

Abstract: A method of forming isolation trenches and mesa areas in a semiconductor substrate and of forming FETs in the mesa areas is disclosed. The method includes providing a first oxide layer, a first undoped polysilicon layer, and an etch stop layer on a silicon substrate. Isolation trenches and mesa areas are then defined by etching the substrate. A second oxide layer is provided to fill the isolation trenches, and is subsequently etched to remove second layer oxide above the mesa areas, thus exposing the first polysilicon layer. The method further comprises providing a second, conductively doped polysilicon layer over the exposed first polysilicon layer, wherein the first polysilicon layer is autodoped by the second polysilicon layer in a subsequent step. The first and second layers of polysilicon are patterned and etched to define FET gates in the mesa areas, with the first oxide layer beneath the first polysilicon layer being utilized as gate oxide.

Abstract: A method of planarizing the surface of a silicon wafer of the type employing trench isolation is disclosed where the trenches and active areas of wafer surface may be of varying widths. The trenches and active areas are covered with a conformal coating of silicon oxide, and, according to one embodiment, this coating is subjected to an etch to leave sidewall spacers of oxide at the sidewalls of the trenches, then a second conformal coating of oxide is applied. A first layer of photoresist is applied to the face and patterned to leave photoresist only in the wider trenches. According to another embodiment the remaining photoresist of the first layer is reflowed by a heat treatment to account for any misalignment or the like. A second layer of photoresist is applied, then etched back to the conformal coating on the active areas, leaving some resist in narrow trenches.

Abstract: Distributed Bragg Reflectors of high efficacy based on alternating layers of large difference in refractive index are fabricated by epitaxial growth followed by etchant removal and back-filling to produce a structure in which alternation is between layers of retained epitaxially grown material and layers of back-filled material. Such reflectors may serve simply as mirrors or may be incorporated in a variety of devices including lasers, LEDs, detectors, optical switches in which the DBRs serve e.g. for cavitation.

Abstract: A bipolar type of semiconductor integrated circuit device is provided with U-shaped grooves which are formed by cutting a main surface of a semiconductor body to form isolation regions between bipolar transistors. A silicon oxide film can be formed in the U-shaped grooves by thermal oxidation simultaneously with the formation of a silicon oxide film used to form isolation regions between each collector contact region and base region. No separate step is needed for forming the silicon oxide film between the collector contact region and the base region. The thickness of the silicon oxide film can be controlled, and has a sufficient thickness even at its two edges, i.e., at its boundaries with the U-shaped grooves, so that the bipolar transistors exhibit good electrical characteristics. Namely, the collector resistance thereof does not increase, and the breakdown voltage at the pn junction between the collector region and the base region does not decrease.

Abstract: One embodiment of the present invention provides an EPROM array having floating gate field effect transistors formed on the sidewalls of trenches formed in a semiconducting substrate. Simultaneous with the fabrication of these trench wall transistors, column lines are formed between the trenches to the top surface and in the bottom of the trenches which extend from one end to the other of the memory array.

Abstract: A method of producing patterned epitaxial silicon films and devices fabricated thereby is described. The method forms a first layer of a refractory material on a substrate and pattern delineates the first layer. Silicon is then deposited at a temperature within the range between 400 degrees C. and 700 degrees C. and the polycrystalline material that forms is removed.

Abstract: A method of manufacturing semiconductor devices by forming a U-shaped insulated gate on a substrate, etching the substrate to expose a sidewall of the U-shaped insulated gate, covering the exposed part with a masking material, forming the sidewall of the masking material only adjoining to the exposed U-shaped insulated gate, etching the substrate vertically to form a groove, forming a semiconductor region on the groove and burying a metal into the groove.

Abstract: The present invention is a self-aligned, vertical bipolar transistor structure and a method of manufacturing such a structure. Reducing lateral dimensions with optical lithography is difficult and not much is gained without concurrently reducing alignment tolerances. For bipolar transistors the alignment tolerance is particularly important since it determines the parasitic capacitances and resistances and thus directly affects speed. In this application a new fully self-aligned transistor structure is presented that self-aligns the shallow trench, extrinsic base contact, and the emitter polysilicon to the intrinsic device area. The structure has no critical alignments. To insure extrinsic-intrinsic base linkup the intrinsic base is put in early in the process, conserved during the stack etch, and patterned underneath the sidewall during the silicon mesa etch.

Abstract: A wafer fabrication process uses peripheral etching to form grooves in a wafer substrate around the periphery of windows opened for dopant diffusion and alignment mark formation, and forms Si.sub.3 N.sub.4 tapers in the grooves. Although ultimately removed, the grooves create a pattern with nearly vertical sidewalls in the substrate which, when transferred to an epitaxial layer, forms wafer alignment marks with sharp edges. The process can be used to form wafer alignment marks having arbitrary patterns and can be adopted to improve the reliability of automatic alignment without the need to make new masks.

Abstract: A vertical transistor device is characterized by active regions vertically separated by a narrower control region. The control region is defined by conducting layer extensions which extend into a groove within which semiconductor material is regrown during device fabrication. The device is further characterized by regions of isolating material, located horizontally adjacent to the active regions, said isolating material serving to reduce parasitic capacitance and improve thermal distribution within the device, thereby improving frequency and power performance.

Abstract: A method of etching and regrowing III-V compounds in a sharply defined vertical feature. Molecular beam epitaxy is used to grow a laterally undefined vertical-cavity, surface-emitting diode laser structure from semiconducting III-V materials. The structure includes interference mirrors defining the end of a Fabry-Perot cavity and a quantum-well layer in the middle of the cavity. A tungsten mask is then defined over the areas of the intended two-dimensional array of lasers. A chemically assisted ion beam etches through to the bottom of the laser structure to from an array of high aspect-ratio pillars. A thermal chlorine gas etch removes a portion of the sidewalls of the pillars without attacking the tungsten, thereby removing ion-beam damage at the sides of the vertical-cavities and creating a lip of the tungsten mask overhanging the pillar sidewall. Organo-metallic chemical vapor deposition is used to regrow III-V material around the pillars. This growth process can quickly planarize the pillars.

Abstract: A method is described for selectively masking sidewall regions of a concave surface formed in a semiconductor body, the method comprising the steps of: forming a conformal layer of masking material on a sidewall of the concave structure; emplacing in the concave structure, a selectively removable material that partially fills the concave structure, an upper surface of the material determining the edge of a region of the concave structure to be masked; removing a portion of the conformal layer above the upper surface of the selectively removable material; and removing the selectively removable material to leave a region of remaining conformal material as a mask.

Abstract: A method for forming semiconductor device isolation regions including steps of forming a first insulating film on a semiconductor substrate, removing the first insulating film in a portion to become a device isolation region with use of a resist pattern formed in a one-time lithography step as a mask so as to form an opening which reaches the semiconductor substrate, removing the resist pattern to deposit a second insulating film on the first insulating film and the inside of the opening and then etching the entire surface in order to make the second insulating film remain on only the periphery of the bottom of the opening and to expose the surface of the semiconductor substrate in a central portion of the bottom of the opening, forming an oxide film on the surface of the semiconductor substrate exposed in the central portion of the bottom of the opening with use of the first insulating film and the second insulating film on the periphery of the bottom of the opening as a mask by a selective oxidation method,

Abstract: A process for fabricating ultra-high density (e.g., 64Mbit) contactless EPROMs and/or flash EPROMs in a silicon substrate is described. Spaced-apart island members are formed of poly 2/ dielectric/poly 1 layers over gate oxide regions. Each island member is associated with one of the cells within the array, and is separated from each other by trenches extending down to either the field oxide or substrate regions. Elongated, parallel, spaced-apart source/drain regions are formed on adjacent sides of the channel regions by ion implantation. The trenches are then filled with an insulating material and a plurality of wordlines patterned across the array. Each wordline makes electrical contact to the control gate members associated with the single row of cells within the array.

Abstract: A planarization method utilizing three resist layers is disclosed. In a substrate where the surface geometry contains trenches or steps of constant height separated by varying distances, after a CVD oxidation layer is formed, a first resist layer (plugs) is formed in wide trenches. A second resist layer is formed on the substrate to provide a gross global planarization of the substrate, which is etched back until all of the resist is removed from the active areas. A third resist layer is then formed on the substrate to provide a near planar surface. All of the resist and CVD oxide is removed from the active areas.

Abstract: This is a method of fabricating a high-performance semiconductor device. The method comprises: forming a first insulating structure, preferably a layer of silicon nitride (e.g. region 24 in FIG. 2) on a layer of thermally grown oxide (e.g. region 22), on a substrate (e.g. region 20), preferably silicon; patterning and anisotropically etching the first insulating structure to expose a portion of the substrate and sidewalls of the first insulating structure; forming a second insulating structure, preferably a layer of oxide (e.g. region 28 in FIG. 3) on a layer of nitride (the bottom second insulating layer is preferably an etch-stop layer with respect to the removal of the top second insulating layer) (e.g. region 26 in FIG. 3), on the patterned first insulating structure, along the sidewalls of the first insulating structure, and on the exposed semiconductor substrate; anisotropically removing portions of the second insulating structure leaving a sidewall region of the second insulating structure (e.g.

Abstract: A method for forming an array of single crystalline seed crystals separated by an insulator and suitable for use in the formation of infrared detector elements is disclosed. The seed crystals are formed from a single crystalline substrate having first and second planar surfaces. An array of grooves is formed in the first planar surface of the single crystalline substrate such that a plurality of protrusions are formed upon the first planar surface of the single crystalline substrate. The grooves are then filled with an insulator. A portion of the second planar surface of the substrate is then removed to expose the insulator disposed within the grooves to form an array of single crystalline seed crystals. The single crystalline seed crystals are separated by the insulator. The single crystalline seed crystals and the insulator are exposed upon both the first and second surfaces of the array.

Abstract: The disclosure relates to the article and a method of forming a field oxide which extends over an isolation trench and the adjacent substrate wherein a portion of the trench insulating sidewall at the top region thereof is removed and replaced by polysilicon. The exposed silicon on the substrate and adjacent polysilicon are than oxidized to form the field oxide which is continuous, disposed above and contacts the remaining sidewall insulator in the trench.

Abstract: A microwave monolithic integrated circuit comprising a GaAs substrate having upper and lower opposed surfaces, an active region and at least one passive region produced on the upper surface of the substrate, and a heat sink produced on the lower surface of the substrate, wherein the substrate thickness beneath the active region is smaller than the substrate thickness beneath at least one passive region, thereby disposing the heat sink near the active region to improve heat dissipation therefrom. The active region and the passive regions are separated by intermediate areas and the substrate thickness beneath the intermediate areas is smaller than the substrate thickness beneath the active region such that the heat sink at least partially surrounds the substrate beneath the active region.

Abstract: A process for forming electrodes for semiconductor devices having a semiconductor substrate and an electrically conductive portion covered and protected by an electrically insulating coating. The process includes the steps of forming an electrically conductive film on the electrically insulating coating, forming an electrode to be connected to an external circuit on the electrically conductive film at a position overlying the electrically conductive portion by exposing portions of the electrically insulating coating and the first electrically conductive film to a converged ion beam, electrically connecting the electrode to the exposed portions of the electrically conductive film, and removing the portions of the electrically conductive film not covered by the electrode. As a result, the likelihood of breakdown of the internal circuit of the semiconductor device connected to the electrically conductive portion while the electrode is being formed is greatly reduced.

Abstract: A process for forming a feature on a substrate without etching into the surface of the substrate and causing recessed regions. A first layer of material is deposited to overlie the substrate and is formed of a different material to the substrate. The first layer is patterned, using conventional photolithography, to form windows in the first layer of material which expose a substrate surface. The etch selectively etches the first layer of material without substantially etching into the substrate material. A second layer of material, which is the same material as the substrate, is deposited to overlie the first layer of material and makes physical contact with the substrate through the windows patterned in the first layer. The second layer is blanket etched so that isolated regions are formed in regions defined by the windows patterned in the first layer.

Abstract: A novel process is provided for fabricating transistors (14), contacts (46s, 40g, 46d) and interconnections (46c) in a novel self-aligned configuration. The process of the invention permits higher packing densities, and allows feature distances to approach 0.5 .mu.m and lower. In a preferred embodiment, the configuration is also planarized.A unique combination of masks in conjunction with a multi-layer structure (28) formed on the surface of a semiconductor wafer (16), the multi-layer structure including a buried etch-stop layer therein (28b), defines the source (18), gate (22), and drain (20) elements and their geometry relative to each other and to interconnects. Polysilicon plug (40, 46) contacts through slots in the multi-structure layer permit vertical contact to be made to the various elements. Silicidation (56) of the polysilicon plugs reduces series resistance in the vertical direction and permits strapping of N.sup.+ and P.sup.+ polysilicon plugs.

Abstract: A source diffusion region and a drain diffusion region are formed under an insulation film which is thicker than a gate insulation film and which isolates the adjacent channel regions from each other. The adjacent source and drain diffusion regions are isolated from each other by a trench which extends from the central portion of the thick insulation film to the interior of a semiconductor substrate. The trench is formed in a self-alignment manner with reference to the end portions of the adjacent floating gate electrodes, and the depth of this trench is determined so that the adjacent source and drain diffusion regions can be spaced sufficiently apart from each other. Since the trench reliably prevents punch-through and current leakage to the adjacent element, it is possible to remarkably reduce the cell size. Moreover, the peripheral circuits are not complicated since the functions of the source and drain regions are fixed.

Abstract: In a method for the fabrication of a layer of a monocrystalline semiconducting layer on a layer of insulating material, an epitaxial growth is achieved in a cavity closed by layers of dielectric material, using a seed of monocrystalline semiconducting material of a substrate. The growth takes place first of all, vertically, perpendicularly to the seed, and then horizontally in the plane of the cavity. This method thus enables a three-dimensional integration of semiconductor components.

Abstract: The specification discloses an isolation trench (36) formed in a semiconductor body. A stress relief layer (38) of oxide is formed on the interior walls of the trench (36), the layer (38) being sufficiently thin to prevent stressing of the lower corners of the trench (36). A masking layer (40) of nitride is formed over the layer (38). An isolation body (42) of oxide or polysilicon then refills the remainder of the trench and a cap oxide (43) and layer (44) of field oxide is formed over the semiconductor body and the filled trench.

Abstract: Proposed is a method of fabricating semiconductor devices involving vapor etching of channels and/or growth of layers in a substrate. The etch or growth rate is controlled by opening up additional regions in the mask which are separated from the opening used to define the active region. The etching or growth in the additional exposed regions of the substrate consumes a certain amount of reactant and controllably reduces the amount available for etching or growth in the active region.

Abstract: A novel process is provided for fabricating contacts (46s, 40g, 46d) in a novel, completely self-aligned, planarized configuration for transistors (14), with self-aligned interconnections (46c). The process of the invention permits higher packing densities, and allows feature distances to approach 0.5 .mu.m and lower.A unique combination of masks in conjunction with a multi-layer structure (28) formed on the surface of a semiconductor wafer (16), the multi-layer structure including a buried etch-stop layer therein (28b), defines the source (18), gate (22), and drain (20) elements and their geometry relative to each other and to interconnects. Polysilicon plug (40, 46) contacts through slots in the multi-structure layer permit vertical contact to be made to the various elements. Silicidation (56) of the polysilicon plugs reduces series resistance in the vertical direction and permits strapping of N.sup.+ and P.sup.+ polysilicon plugs.

Abstract: A method of fabricating a lateral transistor is provided, including the steps of: providing a body of semiconductor material including a device region of a first conductivity type; patterning the surface of the device region to define a first transistor region; filling the patterned portion of the device region surrounding the first transistor region with an insulating material to a height generally equal to the surface of with first transistor region; removing portions of the insulating material so as to define a pair of trenches generally bonding opposite sides of the first transistor region; filling the pair of trenches with doped conductive material of opposite conductivity type to the first transistor region; and annealing the semiconductor body whereby to form second and third transistor regions of opposite conductivity type to the first transistor region in the opposing sides of the first transistor region.

Abstract: A process for forming electrodes for semiconductor devices having a semiconductor substrate and an electrically conductive portion covered and protected by an electrically insulating coating. The process includes the steps of forming an electrically conductive film on the electrically insulating coating, forming an electrode to be connected to an external circuit on the electrically conductive film at a position overlying the electrically conductive portion by exposing portions of the electrically insulating coating and the first electrically conductive film to a converged ion beam, electrically connectig the electrode to the exposed portions of the electrically conductive film, and removing the portions of the electrically conductive film not covered by the electrode. As a result, the likelihood of breakdown of the internal circuit of the semiconductor device connected to the electrically conductive portion while the electrode is being formed is greatly reduced.

Abstract: Submicron structure fabrication is accomplished by providing vapor chemical erosion of a compound crystal by suppressing the more volatile elements so that the less volatile element is provided with an anti-agglomeration and erosion rate limiting capability which can be followed by subsequent regrowth in the same environment. The erosion is sensitive to crystallographic orientation.

Abstract: Disclosed is a process for making a DMOS, including lining a groove with a dielectric material to form an inner groove having sidewalls extending through the bottom of the first groove, and lining the inner groove with a dielectric material to obtain increased thickness of the gate dielectric on the sidewalls of the inner groove.

Abstract: A process for making an inverted silicon-on-insulator semiconductor device having a pedestal structure. After the processing of polysilicon layers, dielectric layers, an epitaxial region and a nitride layer, a second substrate is bonded to the nitride layer and the first substrate is removed. This allows for an epitaxial region which is isolated from the substrate.

Abstract: To completely isolate an island of silicon, a trench is cut into an epitaxial layer to provide access to a differently doped buried layer. While suspending the portion of the epitaxial layer surrounded by the trench by means of an oxide bridge, the underlying region of the buried layer is etched away to form a cavity under the active area. This cavity, as well as the surrounding trench, is then filled with a suitable insulating material to isolate the active island from the substrate.

Abstract: A method has been developed for altering the resistivity of selected regions (tubs) in a dielectrically isolated (DI) wafer. Subsequent to the formation of the conventional tub structure, the wafer is patterned and etched to expose selected tubs. These tubs are then etched and selectively implanted and an epitaxial layer of a new resistivity value is grown in the empty tube regions. The resistivity of the epitaxial material may be chosen to alter the conductivity of the selected tub regions.

Abstract: An active layer is formed on an n-type InP buffer layer of a substrate. A pair of strip-shaped grooves are formed into the active layer to divide it into a contract portion and side portions. A p-type Inp cladding layer is deposited on the entire surface of the active layer and grooves. The cladding layer is selectively etched to form a mesa portion including the central active portion and expose the buffer layer. An insulating film is coated on the mesa portion and buffer layer, so that a semiconductor light-emitting device is manufactured.

Abstract: A method of manufacturing a semiconductor device includes the steps of (a) forming a first conductive pattern on a semiconductor substrate, (b) forming a first interlayer insulating film, covering the first conductive pattern, (c) forming a second conductive pattern, composed of a refractory metal, on the first interlayer insulating film, (d) forming a contact hole reaching the first conductive pattern through the second conductive pattern and the first interlayer insulating film at a predetermined position, (e) performing an annealing step before or after formation of the contact hole in step (d), and (f) covering in the contact hole with a metal film, after annealing step (e), to connect the second conductive pattern to the first conductive pattern. In this method, annealing step--for example, gettering--is performed before the wiring layer of the refractory metal is placed in contact with the semiconductor layer.

Abstract: A process for forming electrodes for semiconductor devices having a semiconductor substrate and an electrically conductive portion covered and protected by an electrically insulating coating. The process including the steps of forming an electrically conductive film on the electrically insulating coating, forming an electrode to be connected to an external circuit on the electrically conductive film at a position overlying the electrically conductive portion by exposing portions of the electrically insulating coating and the first electrically conductive film to a converged ion beam, electrically connecting the electrode to the exposed portions of the electrically conductive film, and removing the portions of the electrically conductive film not covered by the electrode. As a result, the likelihood of breakdown of the internal circuit of the semiconductor device connected to the electrically conductive portion while the electrode is being formed in greatly reduced.

Abstract: A novel process and structure is taught which provides discrete semiconductor islands located in a semiconductor substrate, the islands being electrically isolated from each other. Certain of these islands, in addition to being electrically isolated from other islands, are also electrically isolated from the substrate. Yet other ones of these islands are electrically isolated from other islands, but are electrically connected to the substrate. In accordance with the teachings of this invention, a substrate is used and a layer of electrical insulation is formed over only a portion of the surface of the substrate. Grooves are then formed to serve as vertical isolation regions. The grooves are filled with a non-conductive material, or covered with a layer of insulation on their sides and bottom, and filled with any convenient material, such as polycrystalline silicon. A second semiconductor substrate is then bonded to the first, and serves as the ultimate substrate of the finished device.

Abstract: A multiple recess isolation technology avoids stress induced defects while providing a substantially planar surface. A silicon substrate (10) is patterned and etched, creating active moat regions (18) and recesses (20a-b and 21a-b). The recesses are filled with oxide by growing a field oxide (40) in wide recessed regions (21) using a LOCOS process, while depositing a planarization field oxide (44) in narrow recessed regions (20). After etching the structure to obtain a planar surface, standard procedures are used to fabricate the active devices. The process uses a single photolithographic masking step and results in only a very small loss of the width electrically active regions.

Abstract: A novel MOS field effect transistor which operates at high speed and with low power consumption has impurity doped source and drain regions deposited at 850.degree. C. or less by molecular layer epitaxial growth method. The molecular layer epitaxial growth is concurrently carried out with the control of impurity doping concentration so that the layers epitaxially deposited has a lightly doped region and a heavily doped region. Since the thickness of the growth layer can be controlled with a degree of accuracy on the order of an atom layer and thermal diffusions can remarkably be reduced by the low deposition temperature, an overlap of a gate over each of the source and drain regions can be reduced to 500 .ANG. or less.

Abstract: A method of manufacturing a trench filled with an insulation material in a semiconductor substrate which includes the steps of forming a trench in the substrate, subjecting the substrate to an RF bias sputtering to form an oxide layer on the substrate, form a slope at an upper corner of the trench and produce a roundness at a lower corner of the trench, and filling the trench with the insulation material.

Abstract: A direct moat wafer processing for maximizing the functional continuity of a field oxide layer employs a processing sequence through which respective differently sized apertures are successively formed in the oxide layer. A first of these apertures prescribes the size of the polysilicon gate, while a second aperture is formed around the completed gate structure and prescribes the geometry of source/drain regions to be introduced into exposed surface areas of the substrate on either side of the gate. The sidewalls of the first and subsequently formed, second aperture are effectively perpendicular to the substrate surface, thereby maintaining the functional continuity of the field oxide layer across the entirety thereof. Thereafter, a separate gate interconnect layer is selectively formed atop the field oxide layer to provide a conductive path to the gate.

Abstract: A method for generating a strip laser in a buried hetero-structure composed of layers, wherein a raised strip is etched out of the layer structure and the strip is laterally etched with an erosion melt. The lateral edges of the laser active layer are protected by leaving them covered with a portion of the layer dissolved out by the erosion melt. The deposits thus remaining are used to initiate the generation of an epitaxial layer which extends laterally from the laser-active layer.

Abstract: A technique for etching tub structures and vias on the backside of a wafer comprised of gallium arsenide and for providing a planar surface on said backside of the gallium arsenide wafer is described. The tubs are formed by providing a layer of resist over the backside of the gallium arsenide substrate, and this layer is patterned to provide selected areas covering regions where tub structures and vias will be provided. In the selectively exposed regions, palladium and gold are sequentially deposited. The resist pattern is then stripped, and a second resist layer pattern is deposited masking portions of the continuous conductive layer and areas where vias are to be provided. The tub structures are then provided by suitably etching the tub to undercut portions of the resist and the palladium layer. A second continuous conductive coating is then provided in the tub structure to provide a plating layer for subsequent plating of a gold film over the palladium.