Abstract: Articles for irradiation are introduced from atmospheric pressure through a vacuum lock to a high vacuum environment for processing. The maintenance of low operating pressures while water vapor is released from the surfaces of the lock and the article is principally achieved by a separate pumping device operating in the high vacuum enclosure, which device preferably takes the form of a large cryo-panel. The cryo-panel can be electrically isolated from ground to provide a charge collection surface within a Faraday cage for ion implantation processing of the article.

Abstract: A charged particle beam exposure system for selectively irradiating the surface of a workpiece to be patterned. The beam has a cross-section at the surface of the workpiece comprising a projected line on variable length, of controlled width and one of two orthogonal orientations. An image of an L-shaped aperture is focussed on a shaping aperture with two adjacent orthogonal edges and is deflected relative to the shaping aperture to provide an intermediate line of desired length, width and orientation. The intermediate line is defined by the portion of the image of the L-shaped aperture which is superimposed on the shaping aperture. An image of the intermediate line is projected onto the workpiece to form the projected line which is scanned over the surface of the workpiece. Radial beam spreading is reduced and pattern line resolution is improved in the disclosed system.

Abstract: An apparatus for the enhanced neutralization of a positively charged particle beam has a source of primary electrons which are directed at a dummy target positioned adjacent the ion beam. The secondary electrons have a low energy and are susceptible to being entrapped within the volume of the positively charged beam. The ion beam attracts these low energy electrons until effective beam neutralization is achieved. The ions in the beam are individually neutralized when the beam strikes the target.

Abstract: For enhanced heat conductive transfer from a semiconductor wafer during ion implantation, the wafer is clamped to a platen having a contour f(r,.theta.) computed to establish uniform contact pressure over said wafer for a number, n, of discrete clamping locii distributed along the periphery of the wafer. The available area of the wafer is thus maximized.

Abstract: Apparatus and method are provided for effecting gas-assisted, solid-to-solid thermal transfer with a semiconductor wafer. A semiconductor wafer is loaded at its periphery onto a shaped platen. Sufficient contact pressure from the loading is produced between the wafer and the platen so that significant gas pressure may be accommodated against the back side of the wafer without having the wafer bow outwardly or break. Gas under pressure is introduced into the microscopic void region between the platen and the wafer. The gas fills the microscopic voids between the platen and semiconductor wafer. The gas pressure approaches that of the preloading contact pressure without any appreciable increase in the wafer-to-platen spacing. Since the gas pressure is significantly increased without any increase in the wafer-to-platen gap, the thermal resistance is reduced and solid-to-solid thermal transfer with gas assistance produces optimum results.

Abstract: Plasma etch durability of polymeric resists used in electron beam lithography is improved by vapor phase impregnation with an aromatic compound after development of an image. The aromatic compound should possess a polarity similar to the polymeric resist and should be relatively volatile to facilitate vapor phase diffusion.

Abstract: A system for the automated transfer of semiconductor wafers between a cassette and a wafer processing chamber. Included in the system are a cassette conveyor assembly, a wafer transfer assembly and a wafer handling assembly associated with the entrance to the processing chamber. Wafers of any standard size can be accommodated by the system. The cassette conveyor assembly includes a cassette holder which retains and precisely positions two standard plastic cassettes. The cassette holder is positioned by a ball reverser driven by a motor and a mechanical stepper. The wafer transfer assembly includes an elevator blade which vertically raises and lowers wafers to and from the wafer handling assembly. The elevator blade is actuated by a crank driven by a motor and a mechanical stepper. The crank provides a high rate of wafer transfer and a low risk of wafer damage.

Abstract: In an ion implantation system, wafer heating is reduced without significantly reducing wafer throughput. An ion beam is time shared between two or more target positions in the system. The ion beam repeatedly is deflected to each target position for a time interval which is small in comparison with the thermal time constant of the wafer as mounted in the system. During each time interval, the beam is scanned in a two-dimensional pattern over the surface area of the wafer. An integral number of scan patterns is completed during each time interval so as to insure uniform dosage of the wafer. It is preferred that the time interval be less than five percent of the thermal time constant of the wafer when mounted in the ion implantation system.

Abstract: A pattern data handling system for an electron beam exposure system wherein figure data conversion is performed simultaneously with irradiation of a workpiece, thereby providing high speed operation. Figure data, containing figure descriptions for a stripe area, is subdivided into blocks of segment figure data and is stored in a pattern data memory. Multiple pattern generators, each including a bit map memory, simultaneously convert blocks of segment figure data to bit maps and store the bit maps in their respective bit map memories. The bit maps are transferred out of the bit map memories and through a shift register one at a time to provide continuous beam blanking data. The system is particularly useful for electron beam exposure of reticles which are characterized by little or no repetition of features and by relatively large features.

Abstract: A processor apparatus is provided in which a blackbody radiator having a constant planar energy flux characteristic is placed in opposition to semiconductor material. The blackbody source produces a constant planar energy flux to uniformly heat the material. The source is heated to a sufficiently high temperature for a sufficient time to anneal or activate a semiconductor wafer or to epitaxially regrow a thin epitaxial film. The processor is operated by accomplishing the steps of presenting a blackbody radiator in opposition to semiconductor material to be thermally treated, radiatively heating the material to a sufficiently high temperature for a sufficient time to accomplish the desired process result, and cooling and removing the material. In the interval between presentation of successive samples of the material to the source, the source may be shuttered or idled to reduce energy consumption.

Abstract: A hybrid moving stage and scanning electron beam lithography system employs a circuit to make an approximate correction to the electron optical beam steering element. Correction is accomplished for observed, repetitive distortions. The position of the beam is thereby corrected for various modes of raster scan distortion. Field curvature distortion is corrected by a circuit which employs a term proportional to the square of the value of the scan direction coordinate. Keystone error is corrected by a circuit which employs a term proportional to the value of the coordinate orthogonal to the scan direction.

Abstract: Method of and apparatus for scanning a charged particle beam over a semiconductor wafer in a prescribed pattern. A triangular waveform, including alternating positive and negative ramp portions of constant slope and controllable time durations, is applied to a horizontal deflection system and produces horizontal scanning of the beam. The time durations of the ramp portions determine the length of the horizontal scan lines and are controlled according to a predetermined sequence so as to provide the prescribed pattern. The triangular waveform is provided by an integrator which receives a square wave from a frequency source of controllable frequency. The predetermined sequence is stored in a read only memory which controls the frequency of the frequency source. At the completion of each ramp portion, a voltage applied to a vertical deflection system is incremented so as to step the beam vertically up or down.

Abstract: A processor apparatus is provided in which a blackbody radiator having a constant planar energy flux characteristic is placed in opposition to semiconductor material. The blackbody source produces a constant planar energy flux to uniformly heat the material. The source is heated to a sufficiently high temperature for a sufficient time to anneal or activate a semiconductor wafer or to epitaxially regrow a thin epitaxial film. The processor is operated by accomplishing the steps of presenting a blackbody radiator in opposition to semiconductor material to be thermally treated, radiatively heating the material to a sufficiently high temperature for a sufficient time to accomplish the desired process result, and cooling and removing the material. In the interval between presentation of successive samples of the material to the source, the source may be shuttered or idled to reduce energy consumption.

Abstract: A processor apparatus is provided in which a blackbody radiator having a constant planar energy flux characteristic is placed in opposition to semiconductor material. The blackbody source produces a constant planar energy flux to uniformly heat the material. The source is heated to a sufficiently high temperature for a sufficient time to anneal or activate a semiconductor wafer or to epitaxially regrow a thin epitaxial film. The processor is operated by accomplishing the steps of presenting a blackbody radiator in opposition to semiconductor material to be thermally treated, radiatively heating the material to a sufficiently high temperature for a sufficient time to accomplish the desired process result, and cooling and removing the material. In the interval between presentation of successive samples of the material to the source, the source may be shuttered or idled to reduce energy consumption.

Abstract: An electron bombardment ion source of the Freeman type incorporates an electrode having multiple segments which are electrically connected in parallel to provide increased surface area for constant cross section.

Abstract: An ion beam implanter includes a high energy accelerator having N electrodes equally spaced along the path of an ion beam, where N is an integer greater than 2. A resistor voltage divider has N terminals respectively connected to the N electrodes. Resistances of the divider between adjacent ones of the electrodes have the same value. A variable DC voltage source applies a high positive voltage to terminal N of the divider, while the first terminal of the divider is grounded. Terminal N is connected to an electrode that is upstream of the electrode connected to the first terminal. A shorting bar is dimensioned and positioned to selectively engage terminals N, (N-1 . . . 1. Drive means stepwise moves the shorting bar so an end portion of the bar sequentially engages terminals N, (N-1) . . . 1 in order. The remainder of the bar engages terminals N, (N-1) . . . (a+1) while the bar end portion engages terminal a, where a is selectively every integer from 1 to N.

Abstract: A weatherproof cover assembly includes a housing and a pivotally attached cover in a configuration in which no gasket is required between the cover and the housing. The housing includes a base having an aperture therethrough, an outer wall and an inner wall. The cover includes a flange which is located between the inner and outer walls when the cover is closed. The cover, the inner and outer walls, and the flange together inhibit entry of liquids into the assembly. A hinge construction for pivotal attachment of the cover to the housing includes a cylindrical opening in the cover and a pivot insert attached to the housing. A cylindrical torsion spring, having end loops on a diameter thereof, is retained in the hinge by slotted posts in the cylindrical opening and on the pivot insert. The cover pivots about sleeve portions of the pivot insert.

Abstract: A vacuum-tight assembly, such as a discharge tube for a sodium vapor arc lamp, includes a high density polycrystalline ceramic body, such as alumina or yttria, having a cavity and at least one closure member and a sealing material for sealing the cavity from the atmosphere. The closure member is formed from a molybdenum alloy containing titanium, vanadium, chromium or mixtures thereof. The closure member and the sealing material have thermal coefficients of expansion closely matched to the thermal coefficient of expansion of the ceramic body over a wide temperature range. In a preferred embodiment, an alumina discharge tube is sealed by a closure member formed from a molybdenum alloy containing 50 atom percent titanium.

Abstract: A high frequency amplifier utilizes series-connected transistors to achieve high voltage class C operation. High frequency input power is coupled to the gate of a first FET which is normally biased off. The source of a second FET is coupled to the drain of the first FET. The drain of the second FET, which forms the output of the amplifier, is coupled through a radio frequency choke to a supply voltage. The gate of the second FET is dc biased at about one half of the supply voltage. A capacitor coupled between the gate of the second FET and ground controls the level of high frequency power applied to the second FET. The amplifier can be operated at a dc voltage which is approximately equal to one half the sum of the individual breakdown voltages of the serially connected FET's.