Abstract: In a charged-particle-beam lithographic system, charge accumulation on the workpiece during alignment or writing can cause significant pattern placement errors. A film (16) formed directly under the resist layer (56) to be patterned is utilized as a charge-conducting medium during lithography. The pattern delineated in the resist layer (56) is transferred into the film (16) and subsequently into an underlying layer (20). The film (16) is highly compatible with standard lithographic and etching processes used to fabricate LSI and VLSI circuits.

Abstract: A fabrication process for making palladium-plated target anodes for X-ray lithographic systems is characterized by a unique sequence of surface preparation, plating and annealing steps. Anodes made by the process have been operated reliably at high-power levels for extended periods of time.

Abstract: Contaminants that accumulate on test probes utilized to contact aluminum pads on integrated circuit chips cause the probe resistance to become unacceptably high. As disclosed herein, the contaminants (predominantly a mixture of aluminum and aluminum oxide) are substantially removed by immersing the probes in boiling water. Adding small quantities of phosphoric and/or hydrofluoric acids to the water further improves the cleaning action.

Abstract: By utilizing a fluorine-containing gaseous compound in a plasma etching process, isotropic etching of monocrystalline silicon (48) and doped or undoped polycrystalline silicon (54) is achieved. The etching processes, which are applicable, for example, to pattern delineation in the processing of semiconductor wafers, are substantially free of any proximity effects and are characterized by a high etching rate at relatively low power levels, high selectivity (with respect to, for example, silicon dioxide) and excellent uniformity. By mixing other gases (for example, chlorine) with the fluorine-containing gas, the amount of undercutting achieved during the etching process can be selectively controlled.

Abstract: A lens design for submicron photolithography images a mask (21) onto a semiconductor wafer (23) using light in the far ultraviolet. Illustratively, the lens design is a modified Dyson imaging system comprising a thick plano-convex lens (31), a beam splitter, adjacent to the planar surface of the plano-convex lens comprising two right angle prisms (34, 35) separated by a dielectric interface (36), and an aspherical mirror (32) located on the convex side of the lens. Stress-induced birefringence is used to rotate the plane of polarization of the object radiation.

Abstract: An apparatus for high-throughput sputter etching or reactive sputter etching of wafers comprises a multi-faceted wafer holder centrally disposed within a cylindrical chamber. A source of r-f power is capacitively coupled to the holder and the cylindrical chamber is grounded. By establishing a suitable plasma within the chamber, simultaneous anisotropic etching of, for example, twenty-four 6-inch wafers can be achieved in an apparatus that is approximately the same size as a conventional parallel-plate reactor that has a capacity of only three 6-inch wafers.

Abstract: In a high-throughput electron beam exposure system, an electron spot is rapidly scanned across a mask plate that includes an aperture whose opening dimension parallel to one axis varies as a function of position along another axis. The extent of each scan across the aperture purposely exceeds the opening dimension of the aperture at any specified scanning position. In this way, the relatively inaccurate end or on-off portions of each scan line are in effect mechanically blanked by the apertured plate. High-speed uniform scanning of an electron spot along a precisely defined line segment on a surface to be irradiated is thereby realized. Such a system is characterized by high-speed exposure of the surface with excellent edge definition of specified features.

Abstract: A high-throughput apparatus for sputter etching or reactive sputter etching of wafers comprises a large-area electrode centrally disposed within a relatively small-area cylindrical electrode. Wafers to be etched are mounted on the inside surface of the cylindrical electrode. A source of a-c power is capacitively coupled to the cylindrical electrode and the center electrode is grounded. By establishing a suitable plasma within the apparatus, simultaneous anisotropic etching of multiple wafers can be achieved.

Abstract: A high-power X-ray source comprises a stationary hollow metallic cone. X-rays are emitted from a portion of the surface of the inside of the cone in response to bombardment of the surface portion by electrons. By means of a unique diverter, a substantially uniform and turbulent flow of water characterized by nucleate boiling is established in the immediate vicinity of the outside surface of the cone to achieve highly efficient cooling thereof. As a result, reliable operation of an X-ray source at high power densities is realized.

Abstract: A mask substrate for use in an x-ray lithographic system comprises a boron nitride member (32, FIG. 2) coated with a polyimide layer (20) whose thickness is approximately the same as that of the boron nitride member. The substrate is mechanically strong and both optically and x-ray transparent. Mask patterns formed on the substrate are characterized by low distortion and a low defect density.

Abstract: In an integrated circuit fabrication sequence, a relatively thick sacrificial layer (18) is deposited on a nonplanar surface of a device wafer in which high-resolution features are to be defined. The thick layer is characterized by a conforming lower surface and an essentially planar top surface and by the capability of being patterned in a high-resolution way. An intermediate masking layer (22) and then a thin resist layer (20) are deposited on the top surface of the sacrificial layer, the thickness of the resist layer being insufficient by itself to provide adequate step coverage if the resist layer were applied directly on the nonplanar surface. A high-resolution pattern defined in the resist layer is transferred into the intermediate masking layer. Subsequently, a dry processing technique is utilized to replicate the pattern in the sacrificial layer. A high-resolution pattern with near-vertical sidewalls is thereby produced in the sacrificial layer.

Abstract: In a two-level overlapping polysilicon device even the slightest amount of undercutting of an oxide layer (12) which underlies a first polysilicon layer (14) can lead to unacceptably low breakdown voltages in the device. In accordance with the invention, the first polysilicon and oxide layers of an LSI MOS wafer are defined as usual. But then the standard fabrication process is modified to etch the first polysilicon layer back beyond the edge of the oxide undercut. Subsequently, the structure is reoxidized and a second polysilicon layer (22) deposited and patterned. The modified process is characterized by the absence of any oxide thinning between the first and second polysilicon layers or between the second polysilicon layer and the substrate (10) of the device. As a result, voltage breakdown problems in the individual chips of the wafer are thereby greatly reduced and the yield of the wafer significantly increased.

Abstract: Even ultra-thin films deposited on the surface of a high-power X-ray target anode (14) during water cooling thereof form thermal barriers that significantly limit the lifetime of the anode. The deposition of such films on the anode is minimized by utilizing several techniques. These include the use of low-corrosion metals such as high-chrome stainless steel in the cooling system, preferential etching of the water-carrying metallic members to provide chrome-rich surfaces, and complexing the metallic hydroxides that are produced in the cooling medium to hold them in a highly soluble state even in the immediate vicinity of the hot anode. These techniques, coupled with submicron filtering and systematic cleaning and maintenance of the cooling system, are important contributors to achieving highly reliable long-lifetime operation of a high-power X-ray source.

Abstract: A moisture sensing unit (30, FIG. 1 or 58, FIG. 4) is included within a hermetically sealed package. A localized external portion of the package in close proximity to the unit is cooled while the temperature and the alternating-current capacitance and/or conductance characteristic of the unit are measured. The measured characteristic exhibits a sharp increase at the temperature corresponding to the dew point of the atmosphere within the package. In turn, the dew point temperature is a direct indicator of the moisture content of the package.

Abstract: An apparatus and method for holding a thin workpiece such as a semiconductor wafer for operations which require the workpiece to have a high degree of planarity such as photolithographic printing includes positioning the workpiece onto a planar holding face comprising the points of a multiplicity of regularly spaced-apart substantially parallel pins with a thin rim encompassing all pins to contain a vacuum in the region adjacent to the workpiece. The small abutting area of each pinpoint abutment reduces the probability of dirt particles collecting on the holding face and provides a high thrust pressure to dislodge dirt particles interposed between the abutment and the workpiece. A small amount of lateral motion is imparted to the workpiece when it first contacts the holding face to brush off any dirt particles on the abutments.

Abstract: A number of known circuit configurations require high-ratio-accuracy capacitors. Maintaining such ratios during the various processing steps involved in fabricating the configurations in integrated-circuit form has been found to be difficult. In accordance with this invention, ratio capacitors are made in integrated-circuit form utilizing a unique geometry. In one specific embodiment, a so-called H-section geometry that is largely insensitive to processing variations is utilized to form the capacitors. In this way, high-yield low-parasitic precisely matched pairs of ratio capacitors are achieved.

Abstract: A method and an apparatus for continuously patterning a photosensitive tape or foil wherein a master pattern and the tape or foil are synchronously coupled. An optical system comprising a plano-convex lens, a concave spherical mirror, and a pair of right-angle prisms is optically-coupled between the master pattern and the tape or foil for projecting an image of the pattern onto the tape. The optical system is such that the movement of the image is in the same direction as the movement of the tape. The apparatus is such that patterning can take place through projecting an image on one or on both sides of the tape. Alternatively, projecting an image on one side of the tape and contact printing of a pattern on the other side of the tape is also made possible by the apparatus.

Abstract: X-ray lithographic systems as heretofore constructed include a low-attenuation chamber for propagating x-rays from a source toward a mask member that is positioned in close proximity to a resist-coated wafer. Both the mask and the wafer are included in the chamber which typically is either filled with helium or evacuated to a pressure less than about 10.sup.-2 Torr. In accordance with this invention, an x-ray lithographic system is constructed to enable establishment in the wafer-to-mask region of a controlled atmosphere that is separate and distinct from that maintained in the low-attenuation chamber. In this way, an improved lithographic system with advantageous throughput and other characteristics is realized.

Abstract: A light-spot-emitting stylus (21) is utilized by an operator to write graphical information on the surface of a simple multilayer planar transducer device (10) that includes a photoconductive layer (16) sandwiched between a transparent conductive layer (14) and a resistive layer (18) that includes spaced-apart electrodes (23 through 32 . . . ). In response to the writing spot, the transducer device generates electrical output signals indicative of successive coordinate positions of the spot on the transducer surface. In turn, these signals are transmitted to a remote location where the originally written graphical information is reconstructed. Moreover, by positioning the transducer on the face of a display unit (51), the information being written on the transducer can be viewed by the operator during the writing process.

Abstract: A compact image projection apparatus comprises a concave spherical mirror, a plano-convex lens, a quarter wave plate and two prisms one of which is a roof prism. The apparatus is such that object and image have the same orientation and are positioned in two parallel planes. The apparatus is located, for example, between a mask and a semiconductor wafer in a scanning projection printing system.