摘要:

A fast magnetic deflection system and beam blanking unit have been incorporated into the electron optical column of a commercial SEM for application to electron lithography. The achieved response-time of the deflection system is about 1 μsec. Double deflection coils are located outside of a glass tube enclosing the electron beam. A thin silver film deposited on the inside surface of the tube serves to conduct charge to ground but does not significantly impede high-frequency deflection fields. A ferrite magnetic shield is placed between the deflection coils and the surrounding iron pole-piece of the objective lens. The function of the shield is to minimize the undesirable eddy currents induced in the iron by the deflection field. The response time of the beam blanking unit is about 10 nsec. The unit employs a pair of electrostatic plates which blank the beam by deflecting the latter against an aperture-stop. The center of deflection of the plates coincides with the crossover point produced by the first condenser lens. Under this condition the beam can be deflected and blanked without affecting the position of the writing spot. The spot position is also insensitive to unequal charging of the contaminated plates by stray electrons. The writing spot position drift, caused by electron charging of other surfaces in the column, has also been minimized by properly restricting the beam width in the column and centering the beam on the final aperture.

ISSN:0022-5355    

DOI:10.1116/1.1318533

出版商:American Vacuum Society    

年代:1973

数据来源: AIP

摘要:

The properties of an intense annular relativistic electron beam generated by a ring cathode and conical anode have been studied in detail. The beam is injected into a channel between concentric cones (containing a neutral gas for space charge and current neutralization) where it is transported and focused. Half of the return current is then fed back through the cathode to prevent radial pinching of the primary current sheet. On the Sandia Reba accelerator which generated a beam of about 120 kA at 1 MeV an area compression of 10 was achieved with 50% efficiency. The compressability of the beam was found to depend primarily on the azimuthal temperature of the beam as it emerged from the diode and on the diode plasma closure rate.

ISSN:0022-5355    

DOI:10.1116/1.1318534

出版商:American Vacuum Society    

年代:1973

数据来源: AIP

摘要:

Some recent developments show that a neutral-particle accelerator (e.g., a molecular accelerator) can be an important tool not only to the chemical investigator but may also have potential use in an entirely new field namely solid-state device fabrication. Experimental evidence of alternate gradient focusing of neutral particles has already been reported by one of the authors elsewhere. This paper now presents a theoretical analysis and considers the possibilities of extending the work for construction of a neutral-particle accelerator. An ammonia molecular-beam is considered as an example. A particular advantage in this case is that the transported molecular beam can be analyzed in a conventional superheterodyne set up.

ISSN:0022-5355    

DOI:10.1116/1.1318535

出版商:American Vacuum Society    

年代:1973

数据来源: AIP

摘要:

The electrode configuration in electron-beam preionized electrical discharge pumped molecular gas lasers can be arranged such that the drift field of the pump accelerates the fast electrons which are concurrently scattered. In designing lasers with output pulses beyond the kJ energy level, one uses the drift field to extend the range and to enhance the energy deposition of the fast electron beam. Although scattering and energy loss of electrons penetrating into matter without an external field is well known, electrical fields of the order ofkV cm−1at atmospheric pressures substantially affect both the range and the energy deposition of the primaries. We report numerical results in range and differential and integral energy deposition enhancement for 100 keV to 2 MeV electron beams in external fields up to10−16 V cm2electric field to number density (ε/N) ratio, forZeff=6gas mixtures obtained byMonte Carlocalculations of transport of fast electrons in thick absorbers modified to include the effects of an external electrical field applied across the scatterer. Detailed results are given in the form of graphs directly usable by the designer.

ISSN:0022-5355    

DOI:10.1116/1.1318452

出版商:American Vacuum Society    

年代:1973

数据来源: AIP

摘要:

Fabrication and inspection of two-dimensional lattice structures in thin polymer films have been carried out using a computer-controlled scanning electron microscope (CCSEM). Periods of 0.2 μ are quite regular, finer resolutions show some irregularities possibly due to film instabilities. Using the CCSEM permits great flexibility, and using thin films eliminates the problem of backscattered electrons from the substrate, which severely limits the resolution of periodic structures fabricated on a solid substrate. These structures should be useful in integrated optics, and may be used as x-ray lithography or evaporation masks.

ISSN:0022-5355    

DOI:10.1116/1.1318453

出版商:American Vacuum Society    

年代:1973

数据来源: AIP

摘要:

A computer-controlled electron beam microfabrication system has been used to fabricate complex, high-frequency acoustic surface wave devices. System hardware and software, fabrication process, and results are described.

ISSN:0022-5355    

DOI:10.1116/1.1318454

出版商:American Vacuum Society    

年代:1973

数据来源: AIP

摘要:

The design and construction of a low-cost but high-performance digitally driven scanning electron microscope (SEM) system is described. The low cost of the system is achieved by designing the digital drive mechanism around a programmable desk calculator with expanded cassette or disk memory. Precision of beam placement and deflection, uniformity of beam current, and reproducibility of beam location; are achieved by combining the best elements of previously developed analog and digital beam-drive systems. A hybrid analog/digital technique is used to generate lines. Endpoint data for lines are specified digitally and a continuous line is generated between the endpoints at a constant writing speed. This technique results in the generation of lines free of steps, glitches, and transients, can be used for generation of rotated or skewed vectors, and is not limited to rectangular geometry. In order to facilitate high-speed operation, not limited by the relatively low-output cycle time of most small programmable calculators, and to conserve the limited memory capabilities of these machines, a dedicated hardware logic system is used to generate all endpoint data needed to fill in rectangular areas. Upon command, a special subprogram can be called to generate circles or other desired geometries. The system can be scaled in time and hence made compatible with mostx–yplotters to allow checking of the exposure program. The interface to the HP9820 and the hardware logic system described can be applied easily to other calculators with similar capabilities. Since its capabilities can be achieved at relatively low cost, this system could be of great use in smaller research establishments in programs involving SEM diagnostics and scanning electron-beam exposure of resists for microfabrication, particularly in the semiconductor device field.

ISSN:0022-5355    

DOI:10.1116/1.1318455

出版商:American Vacuum Society    

年代:1973

数据来源: AIP

摘要:

An electron-beam mask-generation system designed to demonstrate fast turn around and high resolution capability is described. The system has been developed using an Advanced Metals Research 900 SEM and a Nuclear Data 812 computer. Patterns are generated utilizing a matrix of4096×4096randomly addressable data points. Complex and/or large patterns can be generated by mechanical repositioning of the substrate and scanning of adjacent fields. A complete stepped and repeated master plate is produced in several hours as compared with several days using conventional systems. The time saving has been primarily achieved by combining the artwork generation, reduction, and step and repeat operations into a single operation. Compatibiltiy with conventional computer aided design and graphics software has been maintained by translating ordinary artwork generation data into information acceptable by the electron-beam system. Extensive software allows virtually all geometries to be generated by the system.

ISSN:0022-5355    

DOI:10.1116/1.1318456

出版商:American Vacuum Society    

年代:1973

数据来源: AIP

摘要:

An over-all system approach has been undertaken to make electron-beam microfabrication practical in a production environment at throughput rates which make it economically attractive to semiconductor manufacturers. An electron-beam system designed for fabrication of IC masks at final size in one step is described. Novel features include an ultrahigh-speed 16-bit digital deflection system, high-vacuum compatible x–y table and a field-emission source. System features described are single operator performance, multiple methods to input mask designs, high-speed deflection system, and (intelligent) beam logic interface and CAD system. The system is capable of producing 1.0-μ lines with ± 0.2-μ precision over a0.25×0.25-in.scan field with coverage of3×3-in.masks using step and repeat techniques. The system also includes an automated load-lock, cryopumped vacuum system and a high-speed 16-bit minicomputer. System parameters such as throughout time, writing speed, and factors affecting these parameters will be discussed.

ISSN:0022-5355    

DOI:10.1116/1.1318457

出版商:American Vacuum Society    

年代:1973

数据来源: AIP

摘要:

The combined use of the digitally controlled single electron beam pattern generator to make micron-scale LSI patterns and the 1:1 electron image projection system to replicate these patterns on device substrates represents a practical means for realizing high-density integrated circuits in large volume production. After six years of research and development at Westinghouse, most of the obstacles to successful use of these methods have been removed. Among the problems solved are uniform exposure of points, lines, and areas in a device pattern, fabrication of high-resolution electromasks for the electron image projector, and registration of successive device patterns in both electron beams systems, used in combination. In the most recent work, a 1024-bit random access memory was used as a test vehicle. Eight mask levels were involved, including a buried diffusion. In both machines, alignment of a new pattern with a preexisting pattern on the substrate was obtained through electron beam probing of fiducial mark areas. An automatic alignment system developed for the electron image projection system made possible alignment within a few seconds and subsequent controlled exposure. Including alignment errors originating in the electron beam mask generator, over-all pattern registrations were within ±1.5μ.

ISSN:0022-5355    

DOI:10.1116/1.1318458

出版商:American Vacuum Society    

年代:1973

数据来源: AIP