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A process-compatible electron beam direct write system
World Abstracts on Microelectronics and Reliability
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each being correlated to specific mechanisms within the writing strategy of the system. An error budget was formulated which would meet the development goals. Each observed error was placed in a hierarchy of ascending order, concluding with a total overlay error. These results were compared with the error budget. Based on these comparisons, a set of tasks was formulated. Completion of the tasks resulted in a system with 0.12 ~tm overlay accuracy 99.7 ~ of the time.
systems development activity that led to the EL series of lithography tools was begun in 1968. The latest in the series, the EL-3, is the highest throughput e-beam lithography system in operation today, and is being used for fabrication of logic and memory devices as well as mask making. This paper describes key design aspects of the EL series that have resulted in the outstanding system performance, and reviews the status of their applications today.
Characterization of ion implanted silicon--applications for IC process control. MATTHEW MARKERT and MICHAEL I. CURRENT. Solid St. Technol. 101 (November 1983). Process characterization tools for ion implantation are reviewed, with an emphasis on resistivity measurements. Examples of process control applications include dose accuracy, dose uniformity, heating, and charging effects during implantation and a double-implant method for low dose monitoring. The use of lateral doping contour maps is a particularly important aspect of many of these applications. A review of relative dose accuracy surveys of implanters shows dose variations of 3 to 5 ~ at a dose of 10 ~4 ions : cm 2, increasing to over I0~o at 1016 ions : cm 2.
High throughput variable shaped electron beam lithography. B. P. PIWCZYK and A. E. WILLIAMS.Solid St. Technol. 145 (September 1983). Because of its favourable combination of characteristics such as submicrometer resolution, maskless operation, interlayer registration accuracy and throughput, the variable shaped beam (VSB) architecture is the basis for several current electron lithography development programs. The flexibility in scanning and stage motion strategies for such systems requires consideration of a large~ set of factors than those relevant for pure raster systems in projecting throughput. Among the most significant of these factors are pattern personality, stage operating mode, and pattern data transfer speed as well as exposure system/resistcharacteristics.
Reactive-ion etching eases restrictions on materials and feature sizes. DAVIDN. K. WANGand DAN MAYDAN.Electronics 157 (3 November 1983). With chemical and ion etching, the technique creates the anisotropic profile needed for VLSI.
Ion implantation and rapid annealing of 125mm wafers. MICHAELCURRENTand ABRAHAMYEE.Solid St. Technol. 197 (October 1983). The desire for increased productivity of IC production areas continues to drive the introduction of larger area wafers. Comparisons are given for the impact of wafer size on ion implantation equipment design, throughput, dose uniformity and control of wafer temperature during implant. Single-wafer annealers, using incoherent light power sources, provide several unique advantages over furnace annealing for processing large diameter wafers. Comparisons are given of wafer flatness and sheet resistance uniformity for implanted 100 and 125 mm wafers.
Some present and future applications of laser processing-an overview. EDWARD J. SWENSON. Solid St. Technol. 156 (November 1983). Present and future developments in laser processing as a production technique to modify semiconductor devices, improve yields and decrease development times is described. Early and current applications include wafer-level trimming of thin-film resistors, the disconnecting of failed rows or columns on MOS memories and the enabling of redundant elements. Future laser processes under investigation include pattern generation for microelectronic circuits, selective annealing and laser heating of semiconductor material. A process-compatible electron beam direct write system. W. R. LIVESAY,J. S. GREENEICH, J. E. WOLFE and R. J. FELKER. Solid St. Technol. 137 (September 1983). A high current gaussian E-beam system is described which exhibits excellent throughput and pattern dimensional control in the resolution ranges where direct writing is economically feasible. The Wafer-writerT M system is an ultrahigh current density gaussian beam system capable of exposing popular photoresists at very high rates in the 0.5-2 ~tm feature size range. In addition, good pattern linewidth control can be achieved due to the sharp beam edge gradients produced in the resists. High accuracy alignment and overlay are achieved due to improved signal-to-noise ratio obtained with a bright electron beam source. Low temperature processed MOSFET's using laser recrystallized polycrystalline silicon films. HAN-SHENG LEE. Solid-St Electron. 26 (11), 1123 (1983). An n-channel MOS transistor was fabricated on a laser recrystallized polycrystalline silicor, film at temperatures below 630°C. The gate oxide was sputter deposited at 200°C. Lasers were used for substrate recrystallization, implantation damage annealing and dopant drive-in. An electron field effect mobility higher than 100cm2/V.sec was observed on the finished transistors. With 10 V applied to the gate of the transistors for 2 hr, less than a 20 mV shift in threshold voltage was observed. EL systems: high throughput electron beam lithography tools. R. D. MOORE. Solid St. Technol. 127 (September 1983). Electron beam lithography systems (the EL Series) have been pivotal fabrication tools in product development and product manufacturing at IBM for over 10 years. The
An AES, SAM and RHEED study of InP (110) subjected to ion bombardment and annealing treatments. D. C. PEACOCK. Vacuum 33 (10-12), 601 (1983). It has been found that preferential sputtering of P from InP(110) is pronounced at low Ar ion energies (500eV) but that for higher ion energies (ca 3keV) no departure from the stoichiometric surface composition is observed. Annealing of the disordered surface produced by bombardment causes agglomeration of In atoms into microdroplets accompanied by a reordering of the remaining surface regions which, after the loss of In to the droplets, have a near stoichiometric composition. Reordering involves the formation of randomly oriented crystallites which at higher temperatures align with the underlying InP crystal structure to form flat ordered surface regions. These regions give rise to LEED and RHEED patterns essentially similar to those from the (110) cleavage surface despite the non-stoichiometric large-area composition. Molecular beam epitaxy for research and production. PETERH. SINGER.Semiconductor Int. 71 (October 1983). The versatility and control exhibited by molecular beam epitaxy has made it ideal for thin film research and more recently, for several production applications. Quality assurance with laser light and microprocessors on moving workpieces. W. R. WEBERR. Feinwerktechnik Messtechnik 91 (8), 377 (1983). In German. In order to meet the growing demands put to production and quality control, a contact-free operating measuring device has been developed on the bases of the laser scanner. The device design and diverse application in the metal processing production are described. Improving the reverse recovery of power MOSFET integral diodes by electron irradiation. B. JAYANTBALIGAand JOHNP. WALDEN. Solid-St. Electron. 26 (12), 1133 (1983). This paper demonstrates that controlled electron irradiation of silicon
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each being correlated to specific mechanisms within the writing strategy of the system. An error budget was formulated which would meet the development goals. Each observed error was placed in a hierarchy of ascending order, concluding with a total overlay error. These results were compared with the error budget. Based on these comparisons, a set of tasks was formulated. Completion of the tasks resulted in a system with 0.12 ~tm overlay accuracy 99.7 ~ of the time.
systems development activity that led to the EL series of lithography tools was begun in 1968. The latest in the series, the EL-3, is the highest throughput e-beam lithography system in operation today, and is being used for fabrication of logic and memory devices as well as mask making. This paper describes key design aspects of the EL series that have resulted in the outstanding system performance, and reviews the status of their applications today.
Characterization of ion implanted silicon--applications for IC process control. MATTHEW MARKERT and MICHAEL I. CURRENT. Solid St. Technol. 101 (November 1983). Process characterization tools for ion implantation are reviewed, with an emphasis on resistivity measurements. Examples of process control applications include dose accuracy, dose uniformity, heating, and charging effects during implantation and a double-implant method for low dose monitoring. The use of lateral doping contour maps is a particularly important aspect of many of these applications. A review of relative dose accuracy surveys of implanters shows dose variations of 3 to 5 ~ at a dose of 10 ~4 ions : cm 2, increasing to over I0~o at 1016 ions : cm 2.
High throughput variable shaped electron beam lithography. B. P. PIWCZYK and A. E. WILLIAMS.Solid St. Technol. 145 (September 1983). Because of its favourable combination of characteristics such as submicrometer resolution, maskless operation, interlayer registration accuracy and throughput, the variable shaped beam (VSB) architecture is the basis for several current electron lithography development programs. The flexibility in scanning and stage motion strategies for such systems requires consideration of a large~ set of factors than those relevant for pure raster systems in projecting throughput. Among the most significant of these factors are pattern personality, stage operating mode, and pattern data transfer speed as well as exposure system/resistcharacteristics.
Reactive-ion etching eases restrictions on materials and feature sizes. DAVIDN. K. WANGand DAN MAYDAN.Electronics 157 (3 November 1983). With chemical and ion etching, the technique creates the anisotropic profile needed for VLSI.
Ion implantation and rapid annealing of 125mm wafers. MICHAELCURRENTand ABRAHAMYEE.Solid St. Technol. 197 (October 1983). The desire for increased productivity of IC production areas continues to drive the introduction of larger area wafers. Comparisons are given for the impact of wafer size on ion implantation equipment design, throughput, dose uniformity and control of wafer temperature during implant. Single-wafer annealers, using incoherent light power sources, provide several unique advantages over furnace annealing for processing large diameter wafers. Comparisons are given of wafer flatness and sheet resistance uniformity for implanted 100 and 125 mm wafers.
Some present and future applications of laser processing-an overview. EDWARD J. SWENSON. Solid St. Technol. 156 (November 1983). Present and future developments in laser processing as a production technique to modify semiconductor devices, improve yields and decrease development times is described. Early and current applications include wafer-level trimming of thin-film resistors, the disconnecting of failed rows or columns on MOS memories and the enabling of redundant elements. Future laser processes under investigation include pattern generation for microelectronic circuits, selective annealing and laser heating of semiconductor material. A process-compatible electron beam direct write system. W. R. LIVESAY,J. S. GREENEICH, J. E. WOLFE and R. J. FELKER. Solid St. Technol. 137 (September 1983). A high current gaussian E-beam system is described which exhibits excellent throughput and pattern dimensional control in the resolution ranges where direct writing is economically feasible. The Wafer-writerT M system is an ultrahigh current density gaussian beam system capable of exposing popular photoresists at very high rates in the 0.5-2 ~tm feature size range. In addition, good pattern linewidth control can be achieved due to the sharp beam edge gradients produced in the resists. High accuracy alignment and overlay are achieved due to improved signal-to-noise ratio obtained with a bright electron beam source. Low temperature processed MOSFET's using laser recrystallized polycrystalline silicon films. HAN-SHENG LEE. Solid-St Electron. 26 (11), 1123 (1983). An n-channel MOS transistor was fabricated on a laser recrystallized polycrystalline silicor, film at temperatures below 630°C. The gate oxide was sputter deposited at 200°C. Lasers were used for substrate recrystallization, implantation damage annealing and dopant drive-in. An electron field effect mobility higher than 100cm2/V.sec was observed on the finished transistors. With 10 V applied to the gate of the transistors for 2 hr, less than a 20 mV shift in threshold voltage was observed. EL systems: high throughput electron beam lithography tools. R. D. MOORE. Solid St. Technol. 127 (September 1983). Electron beam lithography systems (the EL Series) have been pivotal fabrication tools in product development and product manufacturing at IBM for over 10 years. The
An AES, SAM and RHEED study of InP (110) subjected to ion bombardment and annealing treatments. D. C. PEACOCK. Vacuum 33 (10-12), 601 (1983). It has been found that preferential sputtering of P from InP(110) is pronounced at low Ar ion energies (500eV) but that for higher ion energies (ca 3keV) no departure from the stoichiometric surface composition is observed. Annealing of the disordered surface produced by bombardment causes agglomeration of In atoms into microdroplets accompanied by a reordering of the remaining surface regions which, after the loss of In to the droplets, have a near stoichiometric composition. Reordering involves the formation of randomly oriented crystallites which at higher temperatures align with the underlying InP crystal structure to form flat ordered surface regions. These regions give rise to LEED and RHEED patterns essentially similar to those from the (110) cleavage surface despite the non-stoichiometric large-area composition. Molecular beam epitaxy for research and production. PETERH. SINGER.Semiconductor Int. 71 (October 1983). The versatility and control exhibited by molecular beam epitaxy has made it ideal for thin film research and more recently, for several production applications. Quality assurance with laser light and microprocessors on moving workpieces. W. R. WEBERR. Feinwerktechnik Messtechnik 91 (8), 377 (1983). In German. In order to meet the growing demands put to production and quality control, a contact-free operating measuring device has been developed on the bases of the laser scanner. The device design and diverse application in the metal processing production are described. Improving the reverse recovery of power MOSFET integral diodes by electron irradiation. B. JAYANTBALIGAand JOHNP. WALDEN. Solid-St. Electron. 26 (12), 1133 (1983). This paper demonstrates that controlled electron irradiation of silicon