Abstract: Disclosed is a process for forming resist patterns on selected substrates and includes the steps of forming an ion absorption mask on the surface of a thin supporting membrane and thereafter aligning the mask with a substrate having a layer of resist thereon. Next, the ion absorption mask is exposed to a beam of ions which pass through certain areas of the absorption mask and into the resist layer to thereby expose selected regions in the resist layer (i.e., to increase or decrease the solubility of the resist to a chosen developer). In a specific embodiment of the invention, the ion absorption mask is formed by initially anodizing an aluminum substrate to form a thin coating of aluminum oxide thereon, and thereafter depositing a gold mask on one surface of the aluminum oxide coating.

Abstract: The specification describes new high frequency ion implanted semiconductor devices, novel microwave integrated circuits employing same, and a planar fabrication process for both wherein initially an ion implantation and PN junction passivation mask is formed on one surface of a semiconductor substrate. Next a heavily doped buried region is ion implanted through an opening in the mask and into the substrate to a preselected controlled depth. Thereafter, one or more additional ion implants are made through the mask opening to complete the active device regions and a PN junction therebetween, all of which are bounded by an annular, higher resistivity unimplanted region of the semiconductor substrate.

Abstract: The specification describes a process wherein short wavelength or "hard" x-rays (less than about 4 Angstroms) are used to align a semiconductor processing mask with a semiconductor wafer without the requirement for thinning the wafer to permit the x-rays to pass through. These short wavelength x-rays may be obtained from either the continuum x-rays which accompany the "soft" (longer wavelength) characteristic x-rays used for resist exposure, or from a specialized source of hard x-rays. Alternatively, alignment marks may be provided on the surface of the wafer to project alignment-indicative fluorescent x-rays onto an x-ray detector without passing through the underlying semiconductor wafer. A null condition in the intensity of the "hard" x-rays, or the fluorescent x-rays in the alternative embodiment of the invention, which are received at an x-ray detector is indicative of an alignment between a reference mark on the mask and either a reference mark or an opening on the wafer.

Abstract: Disclosed are new high frequency ion implanted passivated semiconductor devices and a planar fabrication process therefor wherein initially an ion implantation and PN junction passivation mask is formed on one surface of a semiconductor crystal. Thereafter, one or more conductivity type determining ion species are implanted through an opening in the mask and into the semiconductor crystal to form active device regions including a PN junction, all of which are bounded by an annular, higher resistivity unimplanted region of the semiconductor crystal. The PN junction thus formed terminates beneath the implantation and passivation mask, and the semiconductor crystal is then annealed to remove ion implantation damage and to electrically activate the ion implanted regions, while simultaneously controlling the lateral movement of the PN junction beneath the passivation mask.

Abstract: Disclosed is a process for fabricating small geometry electronic devices, including a variety of integrated optical devices. The process includes the steps of holographically exposing a resist masking layer to a plurality of optical interference patterns in order to develop a masking pattern on the surface of a semiconductive body. Thereafter, regions of the body exposed by openings in the masking pattern are ion beam machined to thereby establish very small dimension undulations in these regions. These closely spaced undulations have a variety of uses in optical devices as will be described. The present invention is not limited to the geometry control of semiconductive structures, and may also be used in the geometry control of metallization patterns which have a variety of applications, or the geometry control of any ion beam sensitive material.

Abstract: A substantially two-dimensional integrated phase shifter and radiator module wherein a plurality of phase shifting elements are deposited in microstrip configuration on one side of a common substrate, and at least one radiating element is constructed from ground plane metallization on the other side of the substrate. Electrical coupling between the output of the phase shifter and the radiator is accomplished by means of a pin interconnect which extends vertically through the substrate. The phase shifting elements are serially connected and positioned in predetermined patterns on the substrate so as to maximize circuit density, without any adverse electrical interaction with the radiator. Additionally, the serially connected phase shifting elements are each connected to individually receive a separate DC control voltage in order that varying degrees of phase shift may be introduced into microwave signals which are coaxially fed into the input terminal of the phase shifting circuitry.

Abstract: Electrically isolated active device regions are fabricated in GaAs semi-insulating wafers by the implantation therein of sulphur ions. The implanted wafers are then coated with a passivating oxide and annealed at an elevated temperature of 800.degree. C or greater in order to achieve carrier mobilities in excess of 3000 cm.sup.2 /volt second.

Abstract: Disclosed is an infrared radiation (IR) sensor and imaging tube employing same wherein the sensor includes a pyroelectric substrate having a conductive layer of infrared radiation absorbing material on one surface thereof. An electron-emissive metallic grid is disposed on the opposite surface of the pyroelectric substrate and is configured to expose predefined discrete areas of the pyroelectric substrate at which radiation-dependent voltages are developed. These voltages permit the metallic grid to emit electrons in quantity proportional to the infrared radiation received by the radiation absorbing material and the pyroelectric substrate. This IR sensor may advantageously be incorporated in a thermal imaging tube which includes means for flooding the grid surface of the pyroelectric substrate with photons and means for accelerating electrons emitted therefrom to a suitable target, such as a charge coupled device (CCD), a phosphor, a silicon intensified target (SIT), or other suitable electron collector.

Abstract: Disclosed is an active radial-to-coaxial transmission line wherein an annular configured semiconductor device, such as an IMPATT diode, is embedded in a chosen dielectric material which is in turn positioned between two conductive members forming a radial transmission line. Advantageously, the lower conductive member of the transmission line also serves as a heat sink for the diode, and the upper conductive member of the radial transmission line may be formed as a highly conductive coating which makes good ohmic contact to the diode, thereby minimizing power losses at this contact. The radial transmission line transforms the relatively low impedance of the diode to a substantially higher value at the outer periphery thereof where contact to a coaxial transmission line may be achieved with good impedance matching, thereby maximizing power transfer between the radial and coaxial transmission lines.

Abstract: Disclosed is a process for fabricating chromium-doped semi-insulating epitaxial layers of gallium arsenide which includes contacting a gallium arsenide substrate with a chromium-doped saturated solution of gallium arsenide in gallium and maintaining the solution at a relatively low liquid phase epitaxial (LPE) deposition temperature on the order of about 750.degree.-850.degree. C.

Abstract: The specification describes new high frequency ion implanted semiconductor devices, novel microwave integrated circuits employing same, and a planar fabrication process for both wherein initially an ion implantation and PN junction passivation mask is formed on one surface of a semiconductor substrate. Next, a heavily doped buried region is ion implanted through an opening in the mask and into the substrate to a preselected controlled depth. Thereafter, one or more additional ion implants are made through the mask opening to complete the active device regions and a PN junction therebetween, all of which are bounded by an annular, higher resistivity unimplanted region of the semiconductor substrate.

Abstract: A process for forming a monolithic gallium arsenide structure having a plurality of electrically insulated gallium arsenide regions.

Abstract: The specification describes a liquid phase epitaxial (LPE) crystal growth process wherein semi-insulating epitaxial layers of gallium arsenide (GaAs) are formed on selected substrates by dipping the substrates into a saturated solution of GaAs in gallium. Prior to exposing the substrates to the above solution, the substrates are shielded by a nonreactive container of a material possessing a high thermal conductivity which, when immersed in the solution, serves to establish a thermal equilibrium between the substrate and the solution. This insures good nucleation in and crystal growth of the high quality semiconductor layers grown, and these layers may be grown to minimum thicknesses on the order of 0.2 micrometers or less with excellent control.

Abstract: Disclosed is a radiation sensitive detector element or array and process for fabricating same wherein conductive patterns are formed on both sides of a selected radiation sensitive material. These patterns have aligned openings or discontinuities therein which define the radiation sensitive elements of the array. One of the metallization patterns is bonded via a suitable epoxy material to an insulating substrate material, and the other metallization pattern merges into electrical contact with the one metallization pattern at an electrical contact pad remote from the radiation sensitive material. Therefore, wires may be bonded to the contact pad without exerting pressure on the radiation sensitivematerial, and a good strong series electrical connection is made to the exposed radiation sensitive material by the one or lower metallization pattern.

Abstract: Disclosed is an ion implantation process control system wherein the ion dosage in semiconductor wafers is continuously controlled. This control is achieved by controllably and incrementally integrating the ion beam current to provide a control signal, and then utilizing this control signal to provide controlled relative movement between the ion beam and the surface area upon which it fails.

Abstract: Disclosed is a novel ruler apparatus useful for the rapid and precise marking of a plurality of parallel horizontal lines on a classroom blackboard or the like. This ruler, or line tool to which it is sometimes referred, includes, among other elements, an adjustable staff member which is slidably mounted in a vertical support frame; and this vertical support frame is in turn securily affixed to one end of a horizontal slide member. This horizontal slide member and the vertical staff member are further secured, one to another, by means of a handle which is affixed at one end to the top of the staff member and affixed at its other end to the other end of the slide member. The staff member includes a plurality of precisely spaced passages therein adapted to receive a marking member, such as a felt-tip pen.

Abstract: Disclosed is a dielectric image guide integrated circuit including first and second sections of image guide of preselected cross-sectional areas joined by an image guide transition section of variable cross-sectional area and all mounted on the surface of an image or ground plane. The image guide transition section has a cavity therein for receiving microwave/millimeter wave energy from the first section of the image guide, and this energy is coupled into a diode mounted within the cavity where it is either detected or frequency converted by the diode. Advantageously, the diode may be mounted on a metal cover which is positioned atop the cavity in the waveguide transition section, and it receives its operating bias from a bias pin connection extending through an opening in the ground plane and including a wisker contact to the diode.

Abstract: Disclosed is a process for fabricating chromium-doped semi-insulating epitaxial layers of gallium arsenide which includes contacting a gallium arsenide substrate with a chromium-doped saturated solution of gallium arsenide in gallium and maintaining the solution at a relatively low liquid phase epitaxial (LPE) deposition temperature on the order of about 750.degree. C-850.degree. C.

Abstract: An active millimeter wave integrated circuit including a thin non-metallic waveguiding layer mounted on an image plane and having an opening therein which exposes a given area of the image plane. An active solid state device, such as a millimeter wave diode, is mounted on the exposed area of the image plane, and millimeter wave energy is coupled to and from the device into the waveguiding layer by way of both a metallic ribbon (or wire) bonded to the active device and a connecting metallization pattern atop the waveguiding layer. This metallization pattern may assume various geometries corresponding to functional components such as low-pass filters, resonators, stepped or tapered metallized transitions, and the like, and also provides the desired impedance matching and efficient energy coupling between the active device and the waveguiding layer.

Abstract: AC-DC voltage regulation is achieved utilizing, among other components, a series pass control element which is serially connected to a detector and filter output stage and between circuit input terminals and an output load. A rectified input voltage is applied to the series pass control element which controls the required amount of current flowing into a load every 1/2 cycle of the input signal. This current is, in turn, detected and filtered to provide the regulated DC output voltage. A voltage sensor is connected to the output of the series pass control element and in parallel with the detector and filter stage; this sensor breaks down at a predetermined level of series pass voltage to, in turn, generate a feedback control voltage. This control voltage is fed back to a current controlled switch which is connected in shunt with the series pass control element.