Hewlett-packard Company

Donald R Bradbury

Armand P Neukermans

Theodore I Kamins

Frederic N Schwettmann

Kuo L Chiang

Richard C Ruby

James H Boyden

Clifford I Drowley

Gary William Ray

Lawrence R Hanlon

Garrett A Garrettson

Timothy R Groves

Chi-Wing Tsao

Yogesh Desai

An acoustical resonator and a method for making the same. A resonator according to the present invention includes a layer of piezoelectric material sandwiched between first and second electrodes. The first electrode includes a conducting sheet having a RMS variation in height of less than 2 .mu.m. The resonator bridges a cavity in a substrate on which the resonator is constructed. The resonator is constructed by creating a cavity in the substrate and filling the same with a sacrificial material that can be rapidly removed from the cavity after the deposition of the various layers making up the resonator. The surface of the filled cavity is polished to provide a RMS variation in height of less than 0.5 .mu.m. The first electrode is deposited on the polished surface to a thickness that assures that the RMS variation in height of the metallic layer is less than 2 .mu.m. The piezoelectric layer is deposited on the first electrode and the second electrode is then deposited on the piezoelectric layer. The sacrificial material is then removed from the cavity by opening vias into the cavity and removing the material through the vias. The preferred sacrificial material is phophor-silica-glass.

SBAR structures and method of fabrication of SBAR.FBAR film processing

A method of forming a plug for electrical connection between two metallic layers on an integrated circuit substrate includes retaining an antinucleation resist layer atop an insulator layer through which the plug is to be formed. After a contact hole is etched through the insulator layer, the antinucleation resist layer is baked. Cleaning of an area exposed by said contact hole in order to minimize contact resistance occurs during a two step process of argon sputter etching and oxygen plasma descumming the exposed area. Because the argon sputter etch and the oxygen plasma descum uncover an annular region about the contact hole, a concentration of phosphorous within the insulator layer and a low temperature selective deposition are used to reduce the occurrence of unwanted nucleation. After selective deposition, the antinucleation resist layer is stripped and an upper metallic layer is formed.

Method for reducing selectivity loss in selective tungsten deposition

A layered structure for use in an X-ray membrane (pellicle) mask or a vacuum window is provided in which an intermediate amorphous layer such as silicon dioxide is grown on a silicon substrate which provides a stress relief medium and surface properties which enhance and improve subsequent process layers by breaking the epitaxial nature of these later deposited layers. Upon subsequent deposition of an inorganic overcoat, such as SiC, on the intermediate amorphous layer, the overcoat produces a nearly defect-free layer with a substantially reduced stress of suitable quality for X-ray lithography mask fabrication. Furthermore, additional alternating layers of a silicon carbide film and an intermediate inorganic layer, such as silicon nitride, can be deposited to obtain an even smoother silicon carbide surface and stronger structure.

Silicon carbide film for X-ray masks and vacuum windows

A method for growing Silicon On Insulator (SOI) films using only conventional very large scale integration (VLSI) techniques is provided. By sequentially varying the flow of HCL gas during the vertical-growth, lateral-overgrowth, coalescence, and planarization stages of the epitaxial deposition process allows the formation of high-quality SOI films on wider oxide stripes suitable for general transistor applications.

CVD lateral epitaxial growth of silicon over insulators

A method for trench isolation of a silicon island for device fabrication using only conventional very large scale integration (VLSI) techniques is provided. The combination of the sidewall isolation achieved with the trench isolation and the underlying oxide film create a totally dielectrically isolated structure without the possibility of latch-up between adjacent devices.

Trench isolated transistors in semiconductor films

A new type of thermal ink jet print head is provided which is driven by an electron beam. The print head is constructed of an electron permeable thin film (electron window) which in one embodiment, has on one of its surfaces a plurality of electron absorbing (heater) pads that are in thermal contact with an ink reservoir. As electrons from a CRT traverse the thin film and are absorbed by a pad, they introduce an extremely large and rapid temperature increase in the pad. As a result, a sufficient amount of thermal energy is absorbed by the ink to cause a vapor explosion within the ink, thereby ejecting ink droplets from a nearby orifice in the ink reservoir. In another embodiment, the electrons traverse the window and are absorbed in the ink rather than in pads, and in another embodiment the electrons are absorbed directly in the window itself.

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Palo Alto, CA, United States of America

Donald R Bradbury