Abstract:
The optical projection of information stored in a relief image such as a pattern of surface deformation of a light reflecting medium is accomplished by a projector which images on a screen the foci of either of the two sets of mirrors produced by the curved surfaces of the deformations. The hollows or concave mirrors provided by the bottoms of the deformations have their foci in front of the recording and when imaged on a screen by the projection optics provide a bright line image on a light background. The convex mirrors at the edges of the deformations have their foci (virtual) located to the rear of the recording and when imaged on the screen by the projection optics provide a dark outline of the deformations on a light background. In the embodiment illustrated, the projector is a reader and is provided with a back projection screen at the same end of the reader as the recording to be projected and the projection path includes suitable mirrors for reversing the direction of the projected light.
Abstract:
HIGH STABLITY, SELF-REGISTERED FIELD EFFECT TRANSISTORS ARE FORMED BY ETCHING THE METAL GATE ELECTRODE SIMULTANEOUSLY WITH EXPOSURE OF SURFACE ADJACENT AREAS OF A SEMICONDUCTIVE WAFER, GROWING AN ACTIVATOR CONTAINING GLASS ATOP ONLY THE EXPOSED AREAS OF THE WAFER BY PASSING A GASEOUS STREAM CONTAINING A MILD OXIDIZING AGENT AND AN ACTIVATOR IMPURITY ACROSS THE ETCHED FACE OF THE WAFER HEATED TO A TEMPERATURE BETWEEN 700*C. AND 1000*C., AND SUBSEQUENTLY BAKING THE SEMICONDUCTIVE WAFER IN A REDUCING ATMOSPHERE AT TEMPERATURES IN EXCESS OF 1000*C. TO FORM THE SOURCE AND DRAIN REGIONS OF THE SEMICONDUCTIVE WAFER. IN A PARTICULARLY PREFERRED EMBODIMENT, A GASEOUS STREAM CONTAINING 5-10% HYDROGEN AND 90-95% HELIUM OR ARGON IS BUBBLED THROUGH WATER AND ETHYL BORATE SOLUTIONS AT ROOM TEMPERATURE WHEREUPON THE STREAM IS PASSED OVER AN ETCHED WAFER TO FORM A SILICO-BORATE GLASS ATOP THE EXPOSED SILICON SURFACE. THE SEMICONDUCTIV WAFER THEN IS BAKED FOR APPROXIMATELY 4 HOURS AT 1000*C. IN A NITROGEN ATMOSPHERE CONTAINING 5-10% BY VOLUME HYDROGEN TO DRIVE THE ACTIVATOR IMPURITIES INTO THE WAFER. A TECHNIQUE FOR FORMING COMPLEMENTARY PAIRS OF HIGH STABILITY SELF-REGISTERED FIELD EFFECT TRANSISTORS ON A SINGLE SUBSTRATE ALSO IS DISCLOSED.
Abstract:
Voltage losses, and consequent reduced transconductance, can be overcome in metal-oxide-semiconductor (MOS) circuits by the use of a voltage variable coupling capacitor comprising a drain and a gate electrode. Since the capacitor is voltage variable, selective coupling is obtainable. In a dynamic memory cell, a voltage variable capacitor connected to the storage node selectively couples enabling to the storage node to increase the transconductance of the read transistor. Selective coupling is also used in apparatus ancillary to the memory cell to enhance the ''''refresh'''' operation. A flip-flop type of memory is also disclosed in which an enhanced output signal is obtained by selective coupling.
Abstract:
A storage medium is described wherein coded information is destructively written by selectively inducing breakdown in a threshold biased capacitor having an electron sensitive variable conductivity layer positioned therein. In one specific embodiment, a hexachlorobutadiene dielectric layer and a juxtaposed lead oxide semiconductive layer are sandwiched between a tin oxide electrode and an electron transparent aluminum electrode. After threshold biasing the structure in a direction opposing conductivity in the lead oxide layer, a 10 kv. electron beam is selectively penetrated into the layer of lead oxide to induce conductivity therein thereby shifting the biasing voltage division in the storage medium to effect a localized dielectric breakdown in the hexachlorobutadiene. The dielectric breakdown in the hexachlorobutadiene selectively ruptures both the dielectric layer and the aluminum electrode thereover producing 10- 50 mil diameter apertures at points of electron beam irradiation. Information is readout by reverse biasing the storage medium and selectively scanning the medium with an electron beam. In a preferred embodiment, a semiconductive wafer is substituted for the tin oxide electrode to permit readout of the recorded information unimpeded by capacitive coupling between the electrodes.
Abstract:
An improved method of bonding metal to a ceramic is described in which the metal is shaped, surface treated, and curved prior to heating the metal to form a eutectic bond between the metal and the ceramic. The surface treatment comprises heating the metal in a reactive atmosphere, e.g., in an oxidizing atmosphere to produce an oxide layer. The surface treatment is carried out at a temperature lower than the metal-metal oxide eutectic temperature.