Abstract: A fiducial for aligning an integrated circuit die. In one embodiment, the fiducial is configured to be exposed by laser chemical etching through a silicon substrate through the back side of a C4 packaged integrated circuit die. The presently described fiducial includes floating diffusion regions disposed in the substrate. An oxide layer free of metal contacts is disposed over the diffusion regions within the fiducial region of the integrated circuit. A metal pattern layer is disposed beneath the oxide layer to provide alignment information. The metal pattern layer is configured to be visible through the oxide layer after the silicon substrate has been removed from the fiducial region. A light block is disposed between the metal pattern layer and an underlying epoxy underfill layer to minimize the risk of an excessive amount of light from being exposed to the underlying epoxy layer, which minimizes the risk of the epoxy layer from damaging the integrated circuit from excessive light exposure.

Abstract: Novel triangular alignment marks and a novel algorithm are used to provide improved global alignment of the substrate on a substrate stage in an align-and expose tool. The method provides an improved metrology for aligning to a recessed alignment mark in the substrate having a material layer, such as insulating, polysilicon, and conducting layers that are inadvertently made asymmetric by processing such as chemical/mechanically polishing. The method also employs an algorithm that detects the recessed edges of the triangle and mathematically generates three lines representing the edges of the triangle. The algorithm then generates a family of lines moving inward from the edges of the triangular alignment marks and parallel to the edges until the lines converge to a common point which determines the alignment center for the triangular alignment marks.

Abstract: A method for aliging a shallow trench isolation is provided. An aligning mark which is deeper than a prior technique is formed in a provided substrate. A trench is formed and an aligning trench is formed in the position over the aligning mark. A thick oxide layer is deposited on the semiconiductol substrate, in the trench and in the aligning trench. After a portion of the thick oxide layer removed, another portion of the thick oxide layer is removed by etching back. A gate oxide layer is formed on a substrate comprising the trench and the aligning trench. A polysilicon layer with the step-height profile in the position over the aligning mark is formed on the gate oxide layer.

Abstract: There are disclosed a bipolar alignment mark structure for semiconductor device and a process for forming the same. The bipolar alignment mark structure comprises: a semiconductor substrate having a scribe region for defining a integrated circuit region; a plurality of negatively polar alignment marks having a form of trench which are aligned on the scribe region regularly distant from one another; and a plurality of positively polar alignment marks having a form of column which are aligned in such a way that they alternate with the negatively polar alignment marks. A step generated in the structure is more enlarged, which allows easy and accurate measurement of alignment mark. Based on this ease, the structure gives convenience to the fabrication process for a semiconductor device, along with high yield. In addition, the accuracy in measuring alignment mark can bring about an effect that the semiconductor device is improved in reliability.

Abstract: Disclosed herein is a composite SOI substrate which allows, by use of a conventional visible light aligner, high-precision alignment of insulator film patterns buried in an SOI substrate and patterns which are to be formed on the SOI layer located above it. The composite SOI substrate is fabricated by forming alignment oxide film patterns I a on the periphery of a main surface of a first silicon substrate 10 which also has buried oxide film patterns formed thereon; preparing a second silicon substrate having preferably V-shaped notch sections 9 on its periphery to expose the alignment patterns provided on the first silicon substrate; bonding the second silicon substrate to the main surface side of the first silicon substrate 10 while exposing the alignment oxide film patterns 1a; and then thinning the second silicon substrate to form an SOI layer 20a.

Abstract: A mask, which does not require additional reticles, and a method of using the mask for recovering alignment marks in a wafer after an inter-level dielectric layer has been planarized and a second layer of metal has been deposited on the planarized inter-level dielectric layer are described. An alignment mark protection pattern and a clearout window pattern are sub-divided so they can be formed from a first and a second mask element. These mask elements can be formed in the peripheral region of the reticle used to pattern the device region of the wafer. The mask elements are used to expose the alignment mark protection pattern in a first layer of photoresist and the clearout window pattern in a second layer of photoresist.

Abstract: To form NPN and PNP transistors on the same base for example to obtain a complementary bipolar transistor it has been necessary to make an epitaxial layer a thick film, and this has resulted in deterioration of the characteristics of the NPN transistor. Also, because a step of forming an alignment mark has been necessary this has increased the number of manufacturing steps needed to make a complementary bipolar transistor. This invention provides a semiconductor device manufacturing method which solves this problem as follows: After a first opening 13 (alignment mark 16) and a second opening 14 are formed in an insulating film 12 formed on a semiconductor base 11 and a doping mask 15 is then formed on the semiconductor base 11, a third opening 17 is formed thereon with the alignment mark 16 as a reference.

Abstract: A method of fabricating high step alignment marks on a twin-well integrated circuit. An alignment mark photoresist pattern is formed overlaying the nitride layer using lithography technique. The nitride layer is partially etched to form a nitride alignment pattern using the alignment mark photoresist pattern as a mask. After the formation of N-well and P-well regions using lithography technique, the N-doped and P-doped impurities are subject to a thermally drive in process to activate and form N-well and P-well regions, respectively. At the same time, the pad oxide layer overlaying the N-well and P-well regions and the region not covered by the nitride alignment pattern is converted to a thermal oxide layer. The thermal oxide layer can be removed to reveal a recessed portion on the surface of the P-type silicon substrate, whereby the thickness of the nitride layer plus the depth of the recessed portion causes high step alignment marks to be formed.

Abstract: A structure of a readable alignment mark and method of manufacturing the readable alignment mark in an alignment mark area on a semiconductor substrate. A semiconductor substrate 10 comprising a product area 12 and an alignment mark area 30 is provided. The alignment mark area 30 has an outer area 40 and an inner area 50. The outer area surrounds 40 the inner area 50. A plurality of alignment mark trenches 24 is formed in the substrate 10 within the inner area 50. A pad oxide layer 20 and a silicon nitride layer 44 are formed sequentially in at least the alignment mark area 12. An isolation trench 43 is formed in the substrate 10 in at least the outer area 40. An insulating layer 46 is formed at least over the alignment mark area 30. The insulating layer 46 is chemical-mechanical polished thereby removing a first thickness of the insulating layer from the inner alignment mark area 50 and leaving a residual insulating layer 46A in the alignment mark trenches 48.

Abstract: Each die containing a resistive element which is to be trimmed has associated therewith a plurality of alignment targets. A cut mask having a trim pattern and an alignment key formed thereon is employed in a masking and etching step to trim the resistive element to a desired resistance. The number of links cut in the resistive element, and thus the final resistance thereof, depends on the particular positioning of the cut mask with respect to the die as determined by which of the alignment targets is aligned with the alignment key. For instance, aligning the alignment key with a first alignment target would result in cutting one link in the resistive element so as to achieve a first resistance value, while re-aligning the cut mask such that the alignment key aligns with another of the alignment targets would result in cutting two links in the resistive element so as to achieve a second resistance value.

Abstract: A method for forming a patterned non-transparent layer over a substrate. There is first provided a substrate which has an alignment mark formed thereupon. There is then formed over the substrate including the alignment mark a blanket non-transparent layer. The blanket non-transparent layer only partially replicates the alignment mark to yield upon the blanket non-transparent layer a partially replicated alignment mark at a location substantially corresponding with the location of the alignment mark formed upon the substrate. There is then removed through a first photolithographic and etch method a first portion of the blanket non-transparent layer to completely expose the alignment mark while simultaneously forming a partially patterned non-transparent layer. The first photolithographic and etch method employs the partially replicated alignment mark to register a first photolithographic mask with respect to the substrate.

Abstract: A target for determining bias or overlay error in a substrate formed by a lithographic process uses a pair of straight vernier arrays of parallel elements, a staggered vernier array of parallel elements, and optionally at least one image shortening array on the substrate. The ends of the elements form the array edges. The vernier arrays are overlaid such that: i) the elements of the straight and staggered arrays are substantially parallel; ii) one of the edges of the staggered array intersects with one of the edges of one the straight arrays; and iii) the other of the edges of the staggered array intersects with one of the edges of the other of the straight arrays.

Abstract: A semiconductor processing method of forming integrated circuitry on a semiconductor wafer includes, a) forming at least two discrete wafer alignment patterns on the wafer, the two discrete alignment patterns having respective series of elevation steps provided therein; and b) while fabricating integrated circuitry elsewhere on the wafer, processing a first portion of at least one of the alignment patterns differently from a second portion of the one alignment pattern to render the first portion to be different from the second portion in the one alignment pattern. Such preferably superimposes a secondary step, most preferably of the same degree, over only a portion of the elevation steps in at least one of the wafer alignment patterns.

Abstract: Alignment marks used in different processes are arranged on scribing lines. The scribing lines are used for cutting off individual semiconductor devices formed on a wafer, and the alignment marks have widths which are larger than widths of the scribing lines. The width of areas corresponding to positions where alignment marks are formed are larger so as to accommodate the alignment marks within the areas. A part of the area of a used alignment mark is covered with a new film so that the area is permitted to have a scribing line having a desired width every time a used alignment is generated. A new alignment mark is arranged within other areas where an alignment mark is not formed. In such an arrangement of the alignment marks, the center line of the scribing line is made clear, and the area where the semiconductor devices are formed can be made large.

Abstract: A method and apparatus for providing a mask (200) on a multi-site wafer (100) is accomplished by first creating a first mask key (204) which contains information, such as alignment cues and test structures. A copy of the first mask key is modified to produce a second mask key (201). When the two mask keys are transferred to adjacent sites on the wafer, they physically overlap, preventing double-exposure of the information in the first mask key.

Abstract: A gate electrode, a semiconductor thin film, a channel protecting film and a photoresist are accumulated on the overall surface of a transparent substrate on which a gate electrode and a gate line are formed. Ultraviolet rays are irradiated through the substrate so that the photoresist and the channel protecting film are self-aligned with respect to the gate electrode and the gate line. A mask is formed on the channel protecting film so as to extend in a direction perpendicular to the channel protecting film. The channel protecting film and the semiconductor thin film are etched using the mask. As a result, the semiconductor thin film and the channel protecting film are patterned without positional deviation so as to have the same width W. Therefore, it is possible to reduce the thin film transistor forming region and the number of steps of the manufacturing process.

Abstract: The present invention provides a method of manufacturing an optical component, having the steps of forming a first position aligning pattern on a surface of a substrate, forming a second position aligning recess-projection pattern conforming with the first position aligning pattern and a third position aligning recess-projection pattern having a predetermined positional relationship with the second position aligning recess-projection pattern, and applying a predetermined processing with the third position aligning recess-projection pattern used as a reference under a predetermined positional relationship with the first position aligning pattern.

Abstract: A thin-film field-effect transistor is fabricated by forming an electrically insulative island between the source and the drain. A cap is formed on the island with a brim that overhangs the island. A layer of source-drain metal, which will subsequently constitute the source and drain contacts, is then deposited upon the source, the drain, and the cap, but the overhang creates an exposed region which can be attacked by an etchant. When the etchant is applied, it etches away the cap, thereby lifting off the source-drain metal which coated the cap, leaving the fully formed source and drain contacts separated by the island.

Abstract: The use of separate masks to pattern the same layer of material formed over a semiconductor substrate serves to reduce or avoid lithographic rounding effects. A layer of material formed over a semiconductor substrate may be patterned in accordance with separate masks. A first mask may have a feature which is substantially perpendicular to a feature of a separate second mask. Where the layer is patterned to form transistor gates, the minimum amount each transistor gate should extend over the edge of its active region under the endcap rule may be reduced. In this regard, a line pattern mask and a gap mask are used to avoid lithographic rounding effects in forming the transistor gates. Semiconductor devices may thus be fabricated with higher packing densities as transistors may be placed closer to one another.

Abstract: A method comprising the steps of forming an insulating film on a semiconductor substrate in which a certain infrastructure is built, forming a series of conductive wirings on the insulating film, forming a blanket interlayer insulating film over the resulting structure, forming first photoresist film patterns on the interlayer insulating film, the side walls of said patterns each being located above the conductive wirings, forming sacrificial film spacers at the side walls of the first photoresist film patterns, forming second photoresist film patterns on the interlayer insulating film between the sacrificial film spacers, and forming contact holes to expose areas of the conductive wirings by sequentially removing the sacrificial spacers and the thus exposed areas of the interlayer insulating film, which results in an improvement in the operating reliability of semiconductor devices and the production yield as well as the high integration of devices.

Abstract: A method for forming an alignment mark during semiconductor device manufacturing. A first alignment mark having a first step height is formed in a semiconductor substrate. An interlayer dielectric is formed over the alignment mark and planarized to a first thickness. During contact/via etch an opening is formed through the first dielectric layer away from the first alignment mark. The opening is then filled with a material until the material in the bottom of the opening has a thickness less than thickness of the planarized dielectric layer.

Abstract: Alignment marks used in different processes are arranged on scribing lines. The scribing lines are used for cutting off individual semiconductor devices formed on a wafer, and the alignment marks have widths which are larger than widths of the scribing lines. The width of areas corresponding to position where alignment marks are formed area enlarged so as to accommodate the alignment marks within the areas. A part of the area a used alignment mark is covered with a new film so that the area is permitted to have a scribing line having a desired width every time a used alignment is generated. A new alignment mark is arranged within other areas where an alignment mark is not formed. In such an arrangement of the alignment marks, the center line of the scribing line is made clear and the area where the semiconductor devices are formed can be made large.

Abstract: An alignment method for a semiconductor device having a conductive thin film on a conductive substrate surface across an insulation film, comprises steps of:a) forming in the insulation film, at least two apertures exposing the substrate surface therein;b) selectively depositing a conductive material in the apertures thereby forming a stepped portion in at least one of said apertures; andc) forming the conductive thin film at least on said insulation film. The alignment is conducted utilizing the stepped portion.

Abstract: A trench structure is produced in a substrate wafer in a two-step trench process. A trench mask is produced in a first etching step and the trench structure is realized in the substrate wafer in a second etching step. An auxiliary lithography structure is produced in the substrate wafer in the trench process. A protective structure that protects the substrate wafer in the region of the auxiliary lithography structure against an etching attack in the second etching step is formed in the region of the auxiliary lithography structure in the manufacture of the trench mask.

Abstract: A semiconductor device includes a base layer, a chip region formed on the base layer, a peripheral region which surrounds the chip region on the base layer, and a patterned stacked structure formed on the base layer in both the chip region and the peripheral region. The patterned stacked structure includes a lower layer which is formed on the base layer, an intermediate layer which is formed on the lower layer and an upper layer formed on the intermediate layer. The upper layer and the intermediate layer are aligned to one side surface of the lower layer in at least a part of the chip region. The intermediate layer and the upper layer cover one side surface of the lower layer in at least a part of the peripheral region.

Abstract: The object of the present invention is to prevent the electrical short between the adjacent metal wires by forming metal wires alternately between insulation films and to improve the process margin in the lithography process and the etching process.The present invention alternately forms a plurality of metal wires between the insulation films by manufacturing the photomask for metal wires in two separate pieces to correspond to the photomask for general metal wires for forming a plurality of metal wires which are densely constituted, and by utilizing the two photomasks.

Abstract: The present invention is directed to a method for fabricating a dual beam semiconductor laser, wherein the laser includes first and second semiconductor laser dies respectively affixed to one another while separated by intervening alignment structures. The alignment structures provide accurate placement of the dual laser beams with respect to one another while also assuring thermal isolation of the laser diodes. The fabrication method employs photolithographic techniques to accurately position the alignment structures across an entire semiconductor wafer, thereby assuring accuracy in alignment of the assembled dual beam lasers. As a result, the need for multiple-step alignment operations commonly employed in the production of multiple diode laser devices is eliminated.

Abstract: The invention is a method of preventing active metal circuit corrosion on a semiconductor device. Non-corrosive multi-layers of metals are applied over the entire surface of a semiconductor, and then the multi-layers are etched to separate the portions on device contacts from the portions on the non-contact areas of the semiconductor device.

Abstract: Techniques for identifying and determining the orientation, magnitude, and direction of slip plane dislocations transecting semiconductor dies are described, whereby a four point alignment pattern is examined for "squareness" and size integrity. Lack of squareness or significant change in apparent size of various aspects of the alignment pattern indicate slip-plane dislocations. The magnitude, orientation and direction of the dislocations are determined geometrically from measurement of the alignment pattern. Various other aspects of the invention are directed to optimal alignment of a photolithographic mask to a die which has experienced a slip-plane dislocation, and to discrimination between slip-plane dislocation and die-site rotation.

Abstract: A semiconductor device is manufactured with precisely formed base and emitter regions. This is accomplished by arranging a plurality of insulator layer portions to form a plurality of windows. A dopant is then applied to the semiconductor device between the windows in order to accurately position emitter regions relative to base regions. In this manner a base of controlled dimensions can be formed. Thus the parasitic resistance of the base can be reduced and the figure of merit (emitter periphery/base area) can be increased.

Abstract: A composite target used in alignment of layers on a wafer uses alignment marks placed in a target area. First alignment marks are composed of material from a first layer placed on the wafer. As subsequent layers are placed on the wafer, alignment marks composed of material from the subsequent layers are placed within the target area. For example, alignment marks composed of material from a second layer are each placed adjacent to one of the alignment marks composed of material from the first layer. Alignment marks composed of material from a third layer are each placed adjacent to one of the alignment marks composed of material from the second layer. Alignment marks composed of material from a fourth layer are each placed adjacent to the alignment marks composed of material from the third layer. And so on. The alignment marks are, for example, each rectangular in shape.

Abstract: A method of manufacturing mask alignment marks on an active surface of a semiconductor substrate (12) is disclosed, in which first, at least one layer (13) of a material resistant to oxidation is formed on the active surface, after which by a local etching of this layer, zones (15') for isolation by a field oxide, are defined simultaneously with the alignment marks (17'). There are formed, after the local etching of the layer (13) of anti-oxidation material while using the remaining parts of the anti-oxidation layer as a mask, depressions (26) at the substrate surface of a given depth at least at locations containing the alignment marks, which locations are designated as alignment windows (18) and the surface of the substrate is then exposed within the windows, and finally a thermal oxidation step is effected to obtain the field oxide (19'), during which the alignment marks (18) are simultaneously covered by oxide (24).

Abstract: A method for manufacturing a semiconductor device which allows to form a semiconductor device on an insulating amorphous material or an insulating crystallized glass in high precision alignment is provided.The present invention is characterized in that alignment markers of masks are formed along a direction in which a degree of expansion-contraction of a substrate is smaller when the semiconductor device is fabricated by laminating thin films having patterns on the substrate.

Abstract: A new method of metallization of an integrated circuit is described. Semiconductor device structures are fabricated in and on a semiconductor substrate. At least one contact opening to the semiconductor substrate and at least one lithography alignment cross mark opening structure are formed. A barrier layer is preferably sputtered within the contact openings and over the semiconductor device structures. A cold aluminum seed layer is sputtered over all surfaces of the contact openings. Next, a hot aluminum flow layer is provided to obtain the desired step coverage of the contact openings. A second cold aluminum layer is then sputtered onto the hot aluminum layer to define the edges of the wide lithography alignment marks while maintaining good contact opening coverage.

Abstract: A method of manufacturing a semiconductor device whereby an spacer is formed from a second layer in a fully self-registering manner after a layer portion of a first layer has been formed. For this purpose, the second layer and a masking layer are provided in that order, which masking layer has a greater thickness next to the layer portion than above it. The portion of the second layer situated above the layer portion and the spacer to be formed is then exposed in that the masking layer is etched back over at least substantially its entire surface. A portion of the masking layer then remains next to the layer portion, which masking layer portion is sufficiently thick for adequately protecting the subjacent portion of the second layer against the treatment which is subsequently carried out and by which the etching resistance of at least the top layer of the exposed portion of the second layer is increased.

Abstract: An embodiment of the present invention is a process for semiconductor device having a silicon substrate. The process comprises positioning at least one field implant mask and field implanting a silicon substrate around a bipolar active region in a substrate such that boron atoms are blocked out of an active region, and only the field region surrounding said active area is implanted, said implanting such that a predetermined layout area of a semiconductor device does not need to be increased to compensate for a BV.sub.bso problem.

Abstract: A method for forming a mask pattern for contact hole in a highly integrated semiconductor device is disclosed. The method according to the invention utilizes a SOG film in order to form an accurate and compact mask pattern for the formation of a contact hole within the highly limited area at a predetermined semiconductor layer where a sizable step difference exists. The method according to the invention is also applicable for manufacturing a multi-layered highly integrated semiconductor device.

Abstract: A method for fabricating a sub-micron geometry semiconductor device using a chromeless mask. An optical exposure system (22) directs light through a chromeless mask (21). The chromeless mask (21) uses destructive interference of light to pattern a light sensitive material (32) on a semiconductor wafer (28). Phase differences in light passing thru chromeless mask (21) creates dark regions which form a non-exposed area of light sensitive material (37). The exposed light sensitive material is removed. The non-exposed area of light sensitive material (37) which remains, protects the gate material underneath it, as all other gate material is removed from the wafer. The non-exposed area of light sensitive material (37) is removed leaving a sub-micron gate (39). A drain and source is then formed to complete the device.

Abstract: A process for fabricating a CMOS integrated circuit having both P-channel and N-channel areas in the substrate. The process forms a single self-aligned mask to define the positions of both of the channel areas on the substrate. The process includes: depositing a maskable material on the substrate; photopatterning and etching the maskable material to expose a pattern of areas on the substrate; tailoring the pattern of areas as P-channel or N-channel; depositing a second material over the maskable material and over the tailored areas of the substrate; chemically mechanically polishing (CMP) the second material to an endpoint of the maskable material; selectively etching the maskable material to expose a second pattern of areas on the substrate aligned with the first pattern of areas; and then tailoring the second pattern of areas as P-channel or N-channel.

Abstract: A method of manufacturing a semiconductor device having a semiconductor substrate of a first conductivity type, an N-type diffusion layer formed in the substrate, and a P-type diffusion layer formed in the substrate. Two contact holes are formed in separate steps, thus exposing the N-type diffusion layer and the P-type diffusion layer, respectively. Hence, when one of the diffusion layers is again doped with an impurity, or again heat-treated, the other diffusion layer is already protected by inter-layer insulation film. Therefore, the impurity cannot diffuse into the contact formed in the contact hole made in the other diffusion layer. As a result of this, SAC technique can be successfully achieved, without deteriorating the characteristic of the contact.

Abstract: A wafer alignment mark consists of patterns, such as a chevron and two stripes, formed in the surface of a semiconductor wafer. Each pattern is defined by a pair of parallel grooves, separation between all pairs of grooves being the same. Each groove provides one sharp edge which can be reliably detected by an automatic alignment system.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.

Abstract: This invention relates to a bipolar transistor which incorporates, in a raised base regime, an emitter, collector pedestal and intrinsic and extrinsic bases all of which are self-aligned. The invention also relates to a process for fabricating such devices which obtains the self-alignment of the above mentioned elements using a single lithographic and masking step. The structure of the transistor, in addition to having the self-algined elements, incorporates a composite dielectric isolation layer which not only permits the carrying out of a number of functions during device fabrication but also provides for desired electrical characteristics during device operation. The composite isolation layer consists of an oxide layer adjacent the semiconductor surface; a nitride layer on the oxide layer and an oxide layer on the nitride layer in the final structure of the device.

Abstract: A generally T-shaped gate is formed by electron beam irradiation of a multilevel resist structure on a substrate. The resist structure has an upper layer which is more sensitive to the electron beam than a lower layer thereof. A generally T-shaped opening is formed in the resist structure by etching of the irradiated areas. An electrically conductive metal is deposited to fill the opening and thereby form a T-shaped gate on the substrate. After the resist layer structure and metal deposited thereon is removed, a masking layer is formed on the substrate around the gate, having an opening therethrough which is aligned with and wider than the cross section of the gate, and defining first and second lateral spacings between opposite extremities of the cross section and adjacent edges of the opening. Deposition of an electrically conductive metal forms source and drain metallizations on the substrate on areas underlying the first and lateral spacings respectively.

Abstract: A semiconductor device with an identification pattern is manufactured by forming a field oxide layer on its substrate, implanting impurity ions on this layer through a patterned mask and exposing the layer to an etching liquid after the mask is removed. A pattern is formed on the device due to a difference in the rate of etching between ion-implanted and masked parts.

Abstract: A method is disclosed for forming a shorting contact for shorting P-type and N-type conductivity regions in a semiconductor together. In one embodiment of this method, the P-type region is substantially a square and is surrounded by the N-type region. A substantially square contact opening is made to expose the P-type region and a portion of the N-type region. Sides of the contact opening are formed to be at substantially 45 degree angles with respect to sides of the substantially square P-type region. In this manner, the alignment tolerance for forming the contact opening is less critical than if the sides of the contact opening were parallel to the sides of the P-type region. The contact opening is then filled with a conductive material to electrically short the P-type region to the N-type region. The conductivity types in this example may be reversed.

Abstract: A shadow-masking process for manufacturing low dark current photodetectors with low noise characteristics is disclosed. The process includes shadow-masking a semiconductor wafer by positioning a patterned shadow-mask on a surface of the wafer. The shadow-mask is patterned with, for example, circular openings or stripe openings. Layers, such as metallization layers to form metallic contacts or anti-reflection layers are deposited onto the wafer through the patterned openings in the shadow-masks. This shadow-masking process may be used in the production of any semiconductor device requiring patterned layers.

Abstract: A semiconductor substrate is provided with alignment marks for recognizing and deciding positions of registration of a wafer and a mask in a photolithographic step that is included in a process of manufacturing a semiconductor device. The alignment marks, X alignment marks and Y alignment marks in a preferred embodiment are arranged only on straight lines which are parallel to corresponding X and Y axes of a Cartesian Coordinate system for registration of the substrate the alignment marks which extend to avoid obstructions, such as steps defined along dicing lines that prevent flow of resist to be coated onto the semiconductor substrate.

Abstract: A method is provided to improve the alignment process in fabricating an integrated circuit with buried layers. The buried layers are implanted in a substrate and driven in, but without the usual step at their perimeter. A target pattern is etched into the substrate surface by means of plasma-assisted etching. An isotropic epitaxial layer is then grown at reduced pressure over the substrate surface so that the target is replicated on the epitaxial layer surface. The target as replicated is thus suitable for optical alignment, either manually or by automatic alignment equipment.

Abstract: A process is disclosed for producing a high density split gate nonvolatile memory cell which includes a floating gate and a control gate that is formed above the floating gate. The drain region is self-aligned to the floating gate and the source region is self-aligned to the control gate. Fully self-aligned implantation is made possible by the process and structure using self-aligned etch. Programming of the memory cell uses standard EPROM programming, and erasing is accomplished by Fowler-Nordheim tunneling or photoemission. The memory cell can be made with a reduced cell size and read current uniformity is obtained.

Abstract: A method of making semiconductive developments, especially MESFETs, which applies a template to a surface of the substrate previously formed with circuit elements in alignment with these elements and so bonds the template to the substrate that the template can be utilized as a holder for the substrate. The rear surface is then coated with a resist and a second template aligned externally with the first utilizing markings exterior to the substrate to form the structure on the rear surface which can include throughholes for a metal deposit extending through the preferably GaAs substrate.