Varian Associates

About: Varian Associates is a based out in . It is known for research contribution in the topics: Beam (structure) & Wafer. The organization has 2160 authors who have published 2591 publications receiving 46002 citations.

Diamond bonded electronic circuit

Abstract: Diamonds are good thermal conductors and also good insulators. They are thus exceptionally useful as heat-removing supports for small microwave circuit elements which must be electrically insulated from their ultimate heat sink. Bonding diamonds to metallic parts has been done using active metals such as titanium and zirconium in conjunction with or as ingredients in solder alloys, which then are able to wet the diamond surface and bond to it. The invention comprises a method of diffusion bonding to diamonds without a molten solder. This solves the problem of contaminating the open diamond surfaces with braze materials which produce electrical leakage. Also the bonded area is precisely limited so that the electrical properties of the circuit are not disturbed. A tiny slow-wave circuit for a traveling-wave tube has been supported by a linear array of diamonds bonded to it and to the surrounding heat-sink barrel of the tube.

Collective free-electron laser studies

Abstract: We present the results of a series of collective free-electron laser (FEL) experiments. Under the conditions of a resonant pump, a wide-band emission spectrum (50-350 GHz) is observed. However, in nonresonant conditions, very little radiation is detected from the laser. Occurrence of the emission for a resonant pump is explained using a very simple model. The wide-band nature of the emitted radiation is not completely understood.

Semiconductor processor incorporating blackbody radiation source with constant planar energy flux

Abstract: A processor apparatus is provided in which a blackbody radiator having a constant planar energy flux characteristic is placed in opposition to semiconductor material. The blackbody source produces a constant planar energy flux to uniformly heat the material. The source is heated to a sufficiently high temperature for a sufficient time to anneal or activate a semiconductor wafer or to epitaxially regrow a thin epitaxial film. The processor is operated by accomplishing the steps of presenting a blackbody radiator in opposition to semiconductor material to be thermally treated, radiatively heating the material to a sufficiently high temperature for a sufficient time to accomplish the desired process result, and cooling and removing the material. In the interval between presentation of successive samples of the material to the source, the source may be shuttered or idled to reduce energy consumption.

Method and apparatus for improved ion dose accuracy

Abstract: The implant chamber pressure during ion implantation is controlled within a specified intermediate pressure range higher than the baseline pressure. Implanted dose errors resulting from neutralizing collisions of the beam with residual gas molecules are held constant and can be compensated. The pressure is maintained within the specified intermediate pressure range by a control system including a controllable vacuum valve associated with a vacuum pump, a chamber pressure sensor and a valve controller responsive to the pressure sensor. The valve controller opens and closes the valve to maintain the chamber pressure within the specified range after introduction of a wafer.