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.

Microwave applicator employing flat multimode cavity for treating webs

Abstract: A microwave applicator is disclosed. The applicator includes a flat multimode cavity having openings on opposite sides thereof for passing therethrough a web of material to be treated with microwave energy. The cavity is both designed and fed so as to be excited at its operating frequency only in those TEl, m,n and TMl, m,n classes of modes such that the value of l is limited to 1 and m or n or both have a value greater than zero (preferably both m and n have a range of values which includes 10) and such that the E-vector of the microwave energy lies generally in the plane of the treatment zone and has maximum intensity in the treatment zone. The flat multimode cavity resonator is fabricated in two half sections an upper half and a lower half which are joined together at their edges. A mode-damping means is provided for attenuating a certain undesired class of modes that could otherwise be supported within the cavity. Air ducts are provided at opposite ends of the resonator for directing air either parallel or antiparallel to the direction of movement of the web to be treated.

Valve incorporating wafer handling arm

Abstract: A valve for a wafer processing machine is formed with a wedge-shaped sliding gate. A folded wafer handling arm is stored within the wedge and pumped to keep the arm clean while the valve is closed.

Zero reference and offset compensation circuit

Abstract: A zero reference and offset compensation circuit for an operational amplifier operating in the inverting mode in order to correct for both current and voltage offset errors. The zero reference and offset compensation circuit includes comparators for comparing the zero condition output of the operational amplifier with representations of lower and upper boundary signal levels, a pair of digital-to-analog converters having their respective analog outputs connected through appropriate scaling networks to the inverting input terminal and to the non-inverting input terminal of the operational amplifier, a microprocessor connected to the output of the comparators for providing an input to the associated digital-to-analog convertor so it produces an incremented digital signal whenever the comparators indicate the zero condition signal output exceeds either boundary signal level, the incremented digital signal being incremented in a direction to drive the associated digital-to-analog converter in a direction to bring said zero condition signal within the boundary which has been exceeded. The microprocessor has a current range selection capability so that the digital-to-analog converter connected to the inverting terminal is incremented for nanoampere range signal currents and the digital-to-analog converter associated with the non-inverting terminal is incremented for signal currents in the microampere range and above.

Sputtering apparatus with a magnet array having a geometry for a specified target erosion profile

Abstract: A rotatable magnet configuration for use in a magnetron sputtering system for obtaining a desired sputter target erosion profile and for obtaining a sputtered film on a substrate having a desired film characteristic, such as uniformity of thickness, and a method of designing such a magnet configuration are disclosed. The disclosed design and method compensate for the discrepancy between the actual position of the magnet and the 'effective' position of the magnet as measured by a static erosion profile obtained holding the magnet stationary. The method shown describes how to adjust the actual shape of the magnet to obtain a desired effective shape that will produce a predetermined erosion profile in the sputter target. In addition, the disclosure describes how to determine an optimal erosion profile to produce a sputtered film having a desired characteristic.