Lawrence Alan Goodman

Topography of obliquely evaporated silicon oxide films and its effect on liquid-crystal orientation

The topography of silicon oxide films deposited at an angle of incidence of either 60° or 83° has been investigated using transmission electron microscopy. Columnar-growth structure arrayed in rowlike order has been detected for films deposited at both angles of incidence. The columns lie in the plane of incidence in both cases. The column angle of inclination from the normal to the substrate is 35° for the 60° deposition and it is 50° for the 83° deposition. The rows are, on the average, perpendicular to the plane of incidence. The ratio of the column width to the column periodicity is 0.70 for the 60° evaporation and is about 0.20-0.25 for films deposited at an angle of incidence of 83°. It is asserted that the topography of films deposited at the two angles is the primary factor determining the directional orientation of liquid crystals on obliquely deposited silicon oxide.

Enhanced CMOS for analog-digital power IC applications

Elementary process additions to 2-3-µm polygate CMOS provide enhanced high-voltage MOSFETs and broadband complimentary bipolars. This allows monolithic integration of a modern logic family and quality analog function with high-voltage high-current buffers and drivers. The technology is suitable for data conversion, telecommunication, analog switch, and industrial IC applications where low-voltage digital and analog control circuitry must be interfaced to high-voltage high-current outputs.

The effect of surface orientation on the operation of multiplexed twisted-nematic devices

The voltage and angular dependence of the electro-optic transfer characteristic of a twisted-nematic display are strongly affected by the average orientation (tilt bias) of the liquid-crystal molecules at the solid surfaces enclosing the fluid. A cell made with low tilt bias of the liquid-crystal molecules has a much sharper threshold in its electro-optic transfer curve and much better viewability when operated in a multiplexed mode than a display with a high tilt bias of the liquid-crystal molecules. As an example, a four-digit multiplexed twisted-nematic display of low tilt bias is viewable over a solid angle of about II/2 sr; whereas a high tilt-bias twisted-nematic device operating under the same multiplexing conditions is only viewable over a solid angle of about 0.50 sr.