2,721 research outputs found
Models of MOS and SOS devices
Quarterly report describes progress in three programs: dc sputtering machine for aluminum and aluminum alloys; two dimensional computer modeling of MOS transistors; and development of computer techniques for calculating redistribution diffusion of dopants in silicon on sapphire films
Electron lithography STAR design guidelines. Part 1: The STAR user design manual
The STAR system developed by NASA enables any user with a logic diagram to design a semicustom digital MOS integrated circuit. The system is comprised of a library of standard logic cells and computer programs to place, route, and display designs implemented with cells from the library. Library cells of the CMOS metal gate and CMOS silicon gate technologies were simulated using SPICE, and the results are shown and compared
Post heat treatment effects on double layer metal structures for VLSI applications
The realization of high yield double layer metal systems using wet chemistry processes and the ability to extend yields beyond that attainable with wet chemistry by means of post sintering processes at temperatures below 500 C for potential applications in very large scale integration structures were studied. Yields in excess of 98% and average total contact resistance of less than 150 ohms and 200 ohms were realized for a series of 560 vias of 0.5 X 0.5 mils and 0.2 X 0.2 mils in size, respectively
Trends and techniques for space base electronics
A system was developed for depositing aluminum and aluminum alloys by the D.C. sputtering technique. This system which was designed for a high level of cleanliness and ion monitoring the deposition parameters during film preparation is ready for studying the deposition and annealing parameters upon double level metal preparation. The finite element method was studied for use in the computer modeling of two dimensional MOS transistor structures. An algorithm was developed for implementing a computer study which is based upon the finite difference method. The program was modified and used to calculate redistribution data for boron and phosphorous which had been predeposited by ion implantation with range and straggle conditions typical of those used at MSFC. Data were generated for 111 oriented SOS films with redistribution in N2, dry O2 and steam ambients. Data are given showing both two dimensional effects and the evolution of the junction depth, sheet resistance and integrated dose with redistribution time
‘My Usual Despicable Hold on Life’: The View from Sylvia Townsend Warner’s Diaries (The Sylvia Townsend Warner Society Lecture 2021)
A study of trends and techniques for space base electronics
The use of dry processing and alternate dielectrics for processing wafers is reported. A two dimensional modeling program was written for the simulation of short channel MOSFETs with nonuniform substrate doping. A key simplifying assumption used is that the majority carriers can be represented by a sheet charge at the silicon dioxide-silicon interface. In solving current continuity equation, the program does not converge. However, solving the two dimensional Poisson equation for the potential distribution was achieved. The status of other 2D MOSFET simulation programs are summarized
Trends and Techniques for Space Base Electronics
Simulations of various phosphorus and boron diffusions in SOS were completed and a sputtering system, furnaces, and photolithography related equipment were set up. Double layer metal experiments initially utilized wet chemistry techniques. By incorporating ultrasonic etching of the vias, premetal cleaning a modified buffered HF, phosphorus doped vapox, and extended sintering, yields of 98% were obtained using the standard test pattern. A two dimensional modeling program was written for simulating short channel MOSFETs with nonuniform substrate doping. A key simplifying assumption used is that the majority carriers can be represented by a sheet charge at the silicon dioxide silicon interface. Although the program is incomplete, the two dimensional Poisson equation for the potential distribution was achieved. The status of other Z-D MOSFET simulation programs is summarized
Posthuman? Animal Corpses, Aeroplanes and Very High Frequencies in the Work of Valentine Ackland and Sylvia Townsend Warner
The aim of this article is to establish the critical significance and value of work which was the product of the unique creative partnership developed
by Valentine Ackland and Sylvia Townsend Warner during the 1930s. During that period, I argue, they imagined more variously and more incisively together, through mutual awareness and acceptance, than they would in all likelihood have done had they never met and fallen in love. An understanding of the sharp differences in temperament, outlook and reputation which precluded full-scale collaboration freed each of them, in turn,to pursue contrasting aspects of concerns held in common. So adventurous was that pursuit, at times, that it merits comparison with recent investigationsof the idea of the ‘posthuman’. Since Warner was by far the moreprolific author, I have tried to balance my account of her partnership with Ackland by drawing extensively not only on published fiction and poetry, but also on diaries and letters, and on a variety of other kinds of material from the archive
- …